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  • 1995-1999  (14,996)
  • 1985-1989  (16,437)
  • 1970-1974  (10,782)
  • Polymer and Materials Science  (42,214)
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Year
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  • 201
    Electronic Resource
    Electronic Resource
    Polymerization by oxidative coupling: Discovery and commercialization of PPO® and Noryl® resins (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 505-517 
    Details
    ISSN: 0887-624X
    Keywords: oxidative coupling ; polymerization ; PPO® ; Noryl® ; discovery ; commercialization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The discovery of oxidative polymerization and the commercial development of PPO® and Noryl® resins is described. The scope of the oxidative polymerization reaction is discussed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 505-517, 1998
    Additional Material: 8 Ill.
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  • 202
    Electronic Resource
    Electronic Resource
    Preparation and characterization of thermoresponsive isopropylacrylamide-hydroxyethylmethacrylate copolymer gels (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 527-541 
    Details
    ISSN: 0887-624X
    Keywords: isopropylacrylamide ; hydroxyethylmethacrylate ; thermoresponsive gel ; stimuli-responsive polymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A random copolymer of N-isopropylacrylamide and 2-hydroxyethylmeth-acrylate, poly(NIPAM-co-HEMA), having thermoresponsive character was prepared bya redox copolymerization method. Poly(ethylene glycol), PEG 4000 was included in the copolymerization recipe to increase the thermoresponsivity of copolymeric structure. Poly(NIPAM-co-HEMA) copolymer gels having more elastic character and higher mechanical strength relative to poly(NIPAM) gel could be achieved by the proposed copolymerization procedure. The equilibrium and dynamic response against the temperature were investigated for the gel matrices produced by changing the initial NIPAM/HEMA mol ratio and PEG 4000 concentration in the copolymerization mixture. The effective diffusion coefficient of water within the gel matrix was estimated for either swollen or shrunken states by applying an unsteady-state diffusion model on the dynamic swelling and shrinking behaviors of gel matrix prepared in the cylindrical form. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 527-541, 1998
    Additional Material: 11 Ill.
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  • 203
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of interpenetrating polymer networks for nonlinear optics (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 553-561 
    Details
    ISSN: 0887-624X
    Keywords: interpenetrating networks ; nonlinear optics ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two-component simultaneous interpenetrating networks (IPN) of thepoly(4′-[[2-(methylacryloxy)ethyl]ethylamino]-4-nitroazobenzene-co-methyl meth-acrylate) (PDR1MA-co-MMA)/poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) system, the PDR1MA/PPO system and 4′-[[2-(acetoxy)ethyl]ethylamino]-4-nitroazo benzene (ACDR1) doped MMA/PPO system were synthesized and characterized. As studied by differential scanning calorimetry (DSC) the full IPNs of the PDR1MA-co-MMA/PPO system and the PDR1MA/PPO system showed a single Tg varying with the PPO composition. A single-phase morphology of the full IPNs was also indicated by scanning electron microscopy (SEM). Transparent films were cast onto clean microscopic glass slides and poled at 190°C for 1 h. The UV-VIS absorption spectra of the three IPN systems before and after curing and corona poling showed a shift in the maximum absorption due to the induced alignment of the nonlinear optical chromophores in the IPN systems. The absorption intensity of the full IPNs remained same after heating at 120°C for 72 h, indicating that the electric field-induced alignment is stable in the full IPN materials. Preliminary second harmonic generation (SHG) data on these IPNs are presented. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 553-561, 1998
    Additional Material: 4 Ill.
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  • 204
    Electronic Resource
    Electronic Resource
    Radical polymerization of ortho-(1,3-dioxolan-2-yl)phenyl ethyl fumarate involving intramolecular hydrogen abstraction and ring opening of cyclic acetal (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 563-572 
    Details
    ISSN: 0887-624X
    Keywords: radical polymerization ; ortho-(1,3-dioxolan-2-yl)phenyl ethyl fumarate ; hydrogen abstraction ; cyclic acetal ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of o-(1,3-dioxolan-2-yl)phenyl ethyl fumarate (DOPEF) initiated with dimethyl 2,2′-azobisiso-butyrate (MAIB) was studied kinetically in benzene. The polymerization rate (Rp) at 60°C was given by Rp = k [MAIB]0.76 [DOPEF]0.71. The overall activation energy of polymerization was calculated to be 98.3 kJ/mol. The number-average molecular weight of resulting poly(DOPEF) was in the range of 1000-3100. 1H- and 13C-NMR spectra of resulting polymers revealed that the radical polymerization of DOPEF proceeds in a complicated manner involving vinyl addition, intramolecular hydrogen abstraction, and further ring opening of the cyclic acetal at higher temperatures. From the copolymerization of DOPEF (M1) and styrene (St) (M2) at 60°C, the monomer reactivity ratios were obtained to be r1 = 0.02 and r2 = 0.20, the values of which are similar to those of the copolymerization of ethyl o-formylphenyl fumarate and St. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 563-572, 1998
    Additional Material: 12 Ill.
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  • 205
    Electronic Resource
    Electronic Resource
    Polymerization of ethylene using high-activity Ziegler-type catalysts: Active center determination (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 573-585 
    Details
    ISSN: 0887-624X
    Keywords: polymerization ; Ziegler-Natta ; catalysis ; active centers ; ethylene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The concentration of active centers of a high-activity magnesium chloride-supported Ziegler-Natta catalyst has been determined using three different methods. The initial active center concentration has been determined by quenching the reaction slurry with MeOT. To determine the concentration of the propagation species along the course of the polymerization the radio-tagging agent, 14CO, and the tagging agent, CS2, were used. CS2, was also investigated as a tagging agent of the growing chains, in a metallocene catalyst system. The results obtained were compared to obtain some insight about the reliability of each method and the kind of information each method can provide. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 573-585, 1998
    Additional Material: 10 Ill.
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  • 206
    Electronic Resource
    Electronic Resource
    Synthesis, hydrophilicity, and oxygen permeability of poly[(trimethylsilyl)propyne]-gr-poly(N,N-dimethylacrylamide) (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 603-610 
    Details
    ISSN: 0887-624X
    Keywords: poly[(trimethylsilyl)propyne] ; poly(N,N-dimethylacrylamide) ; graft copolymer ; oxygen permeability ; hydrophilicity ; water contact angle ; contact lens ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N,N-dimethylacrylamide (DMAA) was graft copolymerized on poly[(trimethylsilyl)propyne] (PTMSP) by single electron reduction of PTMSP with potassium naphthalenide (K-Naph), followed by anion polymerization of DMAA from the carbanion formed in the reduction. A hard and practically non-water-swelling PTMSP-gr-poly(DMAA) was obtained under the conditions using controlled amount of K-Naph and DMAA. The graft copolymer was characterized with regard to structure, number-averaged molecular weight, and the amount of grafting poly(DMAA) determined by the relative absorbance of the IR absorption band assigned to the C=O and SiC—H functionalities (AC=O/ASiC—H). The oxygen permeability and water contact angle (θ) of the graft copolymer were evaluated while varying the amount of grafting poly(DMAA). The graft copolymer proved to be highly oxygen permeable (165 Barrers) and hydrophilic (θ = 27°). Its transparency was also elucidated with UV-vis spectra. This graft copolymer was proposed as a promising candidate for use as a hard contact lens material. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 603-610, 1998
    Additional Material: 9 Ill.
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  • 207
    Electronic Resource
    Electronic Resource
    Polymers from multifunctional isocyanates 14. Alternating copolymers from isocyanato alkenes: Copolymerization of 2-propenyl isocyanate with trimethylsilyl methacrylate as electron acceptor monomer (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 611-616 
    Details
    ISSN: 0887-624X
    Keywords: alternating copolymerization ; free radical ; isopropenylisocyanate ; trimethylsilyl methacrylate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of 2-propenyl isocyanate (1) with trimethylsilyl methacrylate (2) has been investigated. 1 is an electron donor monomer with little tendency to undergo homopolymerization, while 2 is an electron acceptor monomer, capable of free radical homopolymerization. Polymerization to low conversion in benzene gave copolymers with preferential incorporation of 2 and a tendency towards alternating copolymers with increasing amounts of 1 in the feed (1 : 1.13 with a 9 : 1 feed ratio of monomers 1 : 2). The glass transition temperatures of the amorphous polymers are in the range from 100-70°C, with a Tg of poly(trimethylsilyl methacrylate) being 135°C. Desilylation occurs in the presence of water, causing an exothermal reaction above the glass transition temperature probably with formation of amides, a reaction that can be used for crosslinking. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 611-616, 1998
    Additional Material: 4 Ill.
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  • 208
    Electronic Resource
    Electronic Resource
    In situ FTIR investigation of MMA plasmas, plasma-polymerized films, and reaction mechanisms (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 587-602 
    Details
    ISSN: 0887-624X
    Keywords: plasma polymerization ; methyl methacrylate ; in situ FTIR/ATR diagnostic ; in situ FTIR plasma diagnostic ; analysis of variance ; regression analysis ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methyl methacrylate (MMA) plasmas and plasma-polymerized methyl methacrylate (PPMMA) films were studied in situ with FTIR and FTIR/ATR (attenuated total reflection) in an r.f. capacitively coupled glow discharge. A statistically designed experiment was conducted by varying the r.f. power, process pressure, and MMA flow rate. MMA plasma fragments were identified from the gas-phase FTIR measurements. They include the intermediate species such as dimethylketene, formaldehyde, allene, and propene; small hydrocarbons such as acetylene, methane, and ethylene; and oxygenates such as carbon dioxide, carbon monoxide, and methanol. Statistical analysis techniques (correlation analysis, analysis of variance and regression analysis) were used on both gas and film data. Gas-phase reaction mechanisms are proposed, and the relationship between the gas and film data is investigated to understand the film deposition chemistry. The deposition rate is positively correlated to the relative concentrations of MMA fragments which are identified as the major film precursors in the deposition process. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 587-602, 1998
    Additional Material: 11 Ill.
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  • 209
    Electronic Resource
    Electronic Resource
    ABC triblock polymethacrylates: Group transfer polymerization synthesis of the ABC, ACB, and BAC topological isomers and solution characterization (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 617-631 
    Details
    ISSN: 0887-624X
    Keywords: group transfer polymerization ; methyl methacrylate ; (dimethylamino)-ethyl methacrylate ; tetrahydropyranyl methacrylate ; methacrylic acid ; ABC triblock copolymers ; polymethacrylates ; polyampholytes ; block sequence ; water-soluble copolymers ; micelles ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ABC triblock copolymers of methyl methacrylate (MMA), (dimethylamino)-ethyl methacrylate (DMAEMA), and tetrahydropyranyl methacrylate (THPMA) consisting of 12 units of each type of monomer were synthesized by group transfer polymerization (GTP). These were the three topological isomers with differentblock sequences: DMAEMA12-THPMA12-MMA12, DMAEMA12-MMA12-THPMA12, and THPMA12-DMAEMA12-MMA12. The molecular weights and molecular weight distributions of the copolymers were determined by gel permeation chromatography (GPC) in tetrahydrofuran, and their number-average degrees of polymerization and copolymer compositions were calculated by proton nuclear magnetic resonance spectroscopy (1H-NMR). These molecular weights and degrees of polymerization corresponded closely to the values expected from the monomer/initiator ratios. The polydispersities were low as expected for GTP, and ranged from 1.09 to 1.25. The three triblocks were chemically modified by converting the THPMA units to methacrylic acid (MAA) units either by thermolysis or acid hydrolysis. The resulting ABC triblock poly-ampholytes were characterized by 1H-NMR spectroscopy and hydrogen ion titration. Aqueous GPC studies in 1.0M NaCl at pH 8.5 showed that the triblock copolymers form micelles whose size depends on their block sequence. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 617-631, 1998
    Additional Material: 11 Ill.
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  • 210
    Electronic Resource
    Electronic Resource
    Polymerization of styrene with nickel complex/methylaluminoxane catalytic systems (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2119-2126 
    Details
    ISSN: 0887-624X
    Keywords: stereospecific polymerization ; isotactic polystyrene ; nickel catalysts ; methylaluminoxane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of styrene using catalytic systems based on nickel derivatives and methylaluminoxane (MAO) was studied. Among tested catalysts, nickel bis(acetylacetonate) and nickel dichloride show the maximum activity. Bis(phosphine)nickel dichlorides exhibit lower activity, depending on the nature of the phosphine ligand. Polymer yields decrease by lowering the catalyst concentration, by increasing the reaction temperature, or by carrying out the polymerization in a polar donor solvent. Weight average molecular weight of most of the prepared polystyrenes ranges from 9000 to 25,000, with polydispersity indexes of 1.6-3.8. However, polystyrene prepared in dioxane solvent exhibits a small fraction of very high molecular weight (about 140,000). From NMR analysis, the products seem generally to be constituted of two polymers with different steric microstructure: atactic polystyrene and partially isotactic polystyrene (ca. 75-85% meso diads). Catalytic site specificity is correlated with the type of nickel ligand, while the effect of reaction temperature is less defined. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2119-2126, 1998
    Additional Material: 1 Ill.
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  • 211
    Electronic Resource
    Electronic Resource
    Gel formation in cationic polymerization of divinyl ethers. I. 1,4-Bis(2-vinyloxyethoxy)benzene (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 675-683 
    Details
    ISSN: 0887-624X
    Keywords: cationic polymerization ; vinyl ether ; divinyl ether ; crosslinking ; gelation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of 1,4-bis(2-vinyloxyethoxy)benzene (CH2=C—O—CH2—CH2—O—C6H4—O—CH2CH2—O—C=CH2; 1) was investigated in CH2Cl2 at 0°C with the use of a variety of cationic initiators. SnCl4, SnBr4, AlEtCl2, and BF3OEt2 (strong Lewis acids) and CF3SO3H (a strong protonic acid) yielded crosslinked insoluble polymers immediately after the polymerizations were initiated. The binary initiating systems such as HCl/ZnCl2 and (C6H5O)2P(O)OH/ZnCl2 also produced insoluble poly(1)s. At the low initial concentration of ZnCl2, however, the (C6H5O)2P(O)OH/ZnCl2 system gave the soluble polymers quantitatively, and gelation occurred only when the reaction mixture was stored for a long time after complete consumption of the monomer. The content of the unreacted pendant vinyl ether groups of the soluble polymers decreased with monomer conversion, and almost all the pendant vinyl ether groups were consumed in the soluble polymer obtained at 100% monomer conversion; this may be ascribed to frequent occurrence of intramolecular crosslinking. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 675-683, 1998
    Additional Material: 10 Ill.
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  • 212
    Electronic Resource
    Electronic Resource
    Peroxide induced crosslinking and degradation of polyvinyl chloride (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 851-860 
    Details
    ISSN: 0887-624X
    Keywords: polyvinyl chloride ; peroxide modification ; crosslinking ; degradation ; electron spin resonance ; kinetics ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Peroxide induced crosslinking and degradation of polyvinyl chloride (PVC) were experimentally investigated using an on-line electron spin resonance (ESR) spectroscopy technique. The reaction variables included temperature, peroxide type and concentration. A single line ESR spectrum was observed with its peak-to-peak width decreasing during the reaction. The mechanism involved in the reaction was elucidated based on the radical information. The radical concentration versus reaction time profile exhibited two distinct regions: the chemically initiated reaction continued by the thermal initiation. The addition of peroxide induced and significantly enhanced the thermal initiated crosslinking and degradation. The radical concentration data coupled with the extent of dehydrochlorination gave an estimate of the rate constant of polyene propagation. A significant decrease of the rate constant was observed during the reaction. The gel content and swelling ratio were also measured to provide additional information to the reaction process. The initial gelation rate increased with the increase of temperature and/or peroxide concentration. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 851-860, 1998
    Additional Material: 12 Ill.
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  • 213
    Electronic Resource
    Electronic Resource
    BF3·OEt2-initiated polymerization of 2-methylene-1,3-dioxepanes (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 873-881 
    Details
    ISSN: 0887-624X
    Keywords: 2-methylene-1,3-dioxepane ; 4,7-dimethyl-2-methylene-1,3-dioxepane ; cyclic ketene acetal ; cationic polymerization ; ring-opening polymerization ; ring-retained polymerization ; copolymerization ; boron trifluoride etherate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: BF3·OEt2-initiated polymerizations of 2-methylene-1,3-dioxepane gave polymers composed of both ring-retained and ring-opened structures. The ring-opening content increased with an increase in polymerization temperature. Poly(4,7-dimethyl-2-methylene-1,3-dioxepane) propagated slower during BF3·OEt2-initiated polymerization and had a lower ring-opened content than poly(2-methylene-1,3-dioxepane). The type of acid initiator used also affected the amount of ring opening observed. Stronger acids gave less ring opening. Attempted BF3·OEt2-initiated copolymerizations of these seven-membered ring cyclic ketene acetals with isobutyl vinyl ether at room temperature resulted in formation of the two homopolymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 873-881, 1998
    Additional Material: 3 Ill.
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  • 214
    Electronic Resource
    Electronic Resource
    Synthesis and properties of polyamidines (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 929-938 
    Details
    ISSN: 0887-624X
    Keywords: polyamidines ; chain conformation ; hydrogen bonds ; prototropic tautomerism ; thermal stability ; hydrolytic stability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymers with amidine groups —NH—CR=N— in the main chain were prepared by acid catalysed melt polycondensation of 4,4′-diaminodiphenyl methane (DAPM) with various orthoesters. The resulting polyamidines were characterized by 1H-, 13C- and 15N-NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetry (TGA) and wide angle x-ray scattering (WAXS) measurements. The properties of the polyamidines are strongly determined by the substituent R on the amidine group. Some peculiarities of the polyformamidine (R=H) could be attributed to the conformation of the amidine group. Glass transition temperatures varied from 106 to 161°C depending on the substituent R. All polyamidines possessed good thermal stability up to 370°C and, with exception of the polyformamidine, good solubility in common solvents. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 929-938, 1998
    Additional Material: 4 Ill.
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  • 215
    Electronic Resource
    Electronic Resource
    Synthesis of a novel highly conjugated conducting polymer (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 949-953 
    Details
    ISSN: 0887-624X
    Keywords: conjugated polyacetylene ; acetylene derivative ; poly(HPB) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The new conjugated polyacetylene derivative dehydrated poly(4-hydroxy-4-phenyl-1-butyne) [dehydrated poly(HPB)] was synthesized from poly(4-hydroxy-4-phenyl-1-butyne) [poly(HPB)], which was obtained by the polymerization of 4-hydroxy-4-phenyl-1-butyne. The resulting dehydrated poly(HPB) was soluble in common organic solvents. The dehydrated poly(HPB) was found to have extended conjugated polyene structure. The dehydrated poly(HPB) was thermally stable up to 300°C. The electrical conductivity of I2-doped dehydrated poly(HPB) was 10-2 S cm-1. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 949-953, 1998
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  • 216
    Electronic Resource
    Electronic Resource
    Effect of substituents on the curing of liquid crystalline epoxy resin (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 911-917 
    Details
    ISSN: 0887-624X
    Keywords: liquid crystalline epoxy resin ; substitution ; curing ; network ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of an aromatic ester based liquid crystalline epoxy resin (LCE) with a substituent in the mesogenic central group is described. Chlorine and methyl groups were introduced as substituents. The curing behaviors of three epoxy resins were investigated using diaminodiphenyl ester as the curing agent. The curing rate and heat of curing of LCE were measured with dynamic and isothermal DSC. The chlorine substituent accelerated the curing of LCE, while the methyl substituent decelerated the curing of LCE. The heat of curing of substituted LCE was diminished compared to LCE with no substituent. Glass transition temperature and elastic modulus of LCE decreased with increasing the size of the substituent. Three liquid crystalline epoxy resins based on aromatic ester mesogenic groups formed a liquid crystalline phase after curing, and the liquid crystalline phase was stable up to the decomposition temperature. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 911-917, 1998
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  • 217
    Electronic Resource
    Electronic Resource
    New poly(amide-imide) syntheses. XXI. Synthesis and properties of aromatic poly(amide-imide)s based on 2,6-bis(4-trimellitimidophenoxy)naphthalene and aromatic diamines (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 919-927 
    Details
    ISSN: 0887-624X
    Keywords: poly(amide-imide)s ; direct polycondensation ; 2,6-bis(4-aminophenoxy)naphthalene ; 2,6-bis(4-trimellitimidophenoxy)naphthalene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel polymer-forming diimide-diacid, 2,6-bis(4-trimellitimidophenoxy)naphthalene, was prepared by the condensation reaction of 2,6-bis(4-aminophenoxy)naphthalene with trimellitic anhydride (TMA). A series of novel aromatic poly(amide-imide)s containing 2,6-bis(phenoxy)naphthalene units were prepared by the direct polycondensation of the diimide-diacid with various aromatic diamines using triphenyl phosphite (TPP) in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved calcium chloride. Thirteen of the obtained polymers had inherent viscosities above 1.01 dL/g and up to 2.30 dL/g. Most of polymers were soluble in polar solvents such as DMAc and could be cast from their DMAc solutions into transparent, flexible, and tough films. These films had tensile strengths of 79-117 MPa, elongation-at-break of 7-61%, and initial moduli of 2.2-3.0 GPa. The wide-angle X-ray diffraction revealed that some polymers are partially crystalline. The glass transition temperatures of some polymers could be determined with the help of differential scanning calorimetry (DSC) traces, which were recorded in the range 232-300°C. All the poly(amide-imide)s exhibited no appreciable decomposition below 450°C, and their 10% weight loss temperatures were recorded in the range 511-577°C in nitrogen and 497-601°C in air. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 919-927, 1998
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  • 218
    Electronic Resource
    Electronic Resource
    Preparation and properties of processable polyimides having bulky pendent ether groups (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 971-978 
    Details
    ISSN: 0887-624X
    Keywords: processable polyimide ; bulky pendent ether groups ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of aromatic diamines containing pendent methoxy, phenoxy, and biphenoxy moieties were synthesized. By the reaction of diamines with 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), several kinds of polyimides having bulky pendent ether groups were synthesized. Thermal properties and processability such as melt processability and solubility in organic solvents of obtained polyimides were investigated by focusing on the chemical structures of their repeating structure units. It was found that the thermal stability and melt processability of the polyimides did not strongly depend on the existence of bulky pendent phenoxy and biphenoxy moieties. Their solubility in organic solvents, however, was improved by introducing the bulky pendent ether groups such as methoxy, phenoxy, and biphenoxy moieties into their repeating structure units. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 971-978, 1998
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    A new direct preparation of electroconductive polyimide/carbon black composite via polycondensation of nylon-salt-type monomer/carbon black mixture (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1031-1034 
    Details
    ISSN: 0887-624X
    Keywords: electroconductive polymer ; polyimide-carbon black composite ; direct polycondensation ; salt monomer method ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract.
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    Deposition conditions influence the postdeposition oxidation of methyl methacrylate plasma polymer films (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 985-1000 
    Details
    ISSN: 0887-624X
    Keywords: plasma polymers ; methyl methacrylate ; oxidation ; long-term stability ; XPS ; FTIR ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma polymer films were deposited from methyl methacrylate (MMA) vapor under various plasma conditions and XPS and FTIR used to study the changes to the compositions of the films as they were stored in air for longer than 1 year. The plasma power input per monomer mass unit (W/FM) markedly affected the composition of the freshly deposited MMA plasma polymers. A low value of W/FM led to a high degree of retention of the original monomer structure, whereas a high value of W/FM resulted in substantial monomer fragmentation and the formation of a partially unsaturated material considerably different to conventional PMMA. As the MMA plasma coatings were stored in ambient air after fabrication, all showed spontaneous oxidative changes to their composition, but the extents and reaction products differed substantially. Deposition at low W/FM led to moderate oxidative changes, whereas high power led to a pronounced increase in the oxygen content over time and resulted in a wide range of carbon-oxygen functionalities in the aged material. As the initial compositions/plasma deposition conditions thus influenced the oxidative postdeposition reactions, MMA plasma polymers deposited under different conditions not only varied in their initial composition but then became even more diverse as they aged. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 985-1000, 1998
    Additional Material: 11 Ill.
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    Molecular weight distribution of crosslinked polymers produced in emulsion (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1127-1156 
    Details
    ISSN: 0887-624X
    Keywords: emulsion polymerization ; crosslinking and long-chain branching ; molecular weight distribution ; compartmentalization ; gel formation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A kinetic model for evaluating the chain length distribution of a branched polymer produced in emulsion was developed. Chain branching occurring through any intermolecular mechanism is considered, namely, crosslinking, chain transfer to polymer and propagation to terminal double bond. The model accounts for active chain compartmentalization and, when coupled to a model able to describe the evolution of the polymerization system, allows evaluation of the cumulative properties of the produced polymer both in the pregel and postgel phases. The numerical difficulties related to the description of a rather wide polymer chain population and of gel formation are overcome by using the ‘numerical fractionation’ technique. A parametric analysis of both instantaneous and cumulative properties is reported and discussed, with special attention to the role of radical compartmentalization in determining the molecular weight properties of a polymer produced in emulsion. Significant differences with the molecular weights computed using models developed for homogeneous (non compartmentalized) systems have been found. A comparison with the predictions of Flory's statistical theory is also reported in terms of gel point and gel weight fraction. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1127-1156, 1998
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    Controlling molecular weight distributions of polyethylene by combining soluble metallocene/MAO catalysts (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 831-840 
    Details
    ISSN: 0887-624X
    Keywords: molecular weight distribution ; polyethylene ; soluble metallocene/MAO catalysts ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A critical look at the possibility of controlling the molecular weight distribution (MWD) of polyolefins by combining metallocene/methylalumoxane (MAO) catalysts is offered. Catalysts investigated were bis(cyclopentadienyl)zirconium dichloride (Cp2ZrCl2), its titanium and hafnium analogues (Cp2TiCl2 and Cp2HfCl2), as well as rac-ethylenebis(indenyl)zirconium dichloride (Et(Ind)2ZrCl2). As observed by other researchers, the MWD of polyethylene can be manipulated by combining soluble catalysts, which on their own produce polymer with narrow MWD but with different average molecular weights. Combined in slurry polymerization reactors, the catalysts in consideration produce ethylene homopolymer just as they would independently. Unimodal or bimodal MWDs can be obtained. This effect can be mimicked by blending polymers produced by the individual catalysts. We demonstrate how a variability in catalyst activity translates into a variability in MWD when mixing soluble catalysts in polymerization. Such a variability in MWD must be considered when setting goals for MWD control. We introduce a more quantitative approach to controlling the MWD using this method. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 831-840, 1998
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    Sulfonation of a poly(phenylquinoxaline) film (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1197-1199 
    Details
    ISSN: 0887-624X
    Keywords: sulfonation ; proton exchange membrane ; poly(phenylquinoxaline) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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    Thermosensitive lactitol-based polyether polyol (LPEP) hydrogels (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 979-984 
    Details
    ISSN: 0887-624X
    Keywords: lactitol ; hydrogel ; polyether polyol ; PEO and PPO linkage ; swelling degree ; thermosensitivity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of new thermosensitive polymer hydrogels were prepared by reacting acylated poly(ethylene glycol) bis(carboxymethyl) ether (PEGBCOCl) with lactitol-based polyether polyols (LPEP). The polyether polyols were generated from propoxylation of lactitol and have molecular weights ranging from 1337 to 4055 g/mol. The hydrogels absorb water up to 1000% of their dry weight and expel free water at temperatures at and above 30°C. The wide ranging swelling behavior and excellent thermosensitivity depend closely on the degree of crosslinking and the propylene oxide lengths in the polyols. Differential scanning calorimetry of the hydrogels showed two endotherms associated with the phase transitions of PO and EO segments in the hydrogel structures. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 979-984, 1998
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    Kinetic and microstructure studies of poly(ethylene-co-p-methylstyrene) copolymers prepared by metallocene catalysts with constrained ligand geometry (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1017-1029 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper discusses the poly(ethylene-co-p-methylstyrene) copolymers prepared by metallocene catalysts, such as Et(Ind)2ZrCl2 and [C5Me4(SiMe2NtBu)]-TiCl2, with constrained ligand geometry. The copolymerization reaction was examined by comonomer reactivity (reactivity ratio and comonomer conversion versus time), copolymer microstructure (DSC and 13C-NMR analyses) and the comparisons between p-methylstyrene and other styrene-derivatives (styrene, o-methylstyrene and m-methylstyrene). The combined experimental results clearly show that p-methylstyrene performs distinctively better than styrene and its derivatives, due to the cationic coordination mechanism and spatially opened catalytic site in metallocene catalysts with constrained ligand geometry. A broad composition range of random poly(ethylene-co-p-methylstyrene)copolymers were prepared with narrow molecular weight and composition distributions. With the increase of p-methylstyrene concentration, poly(ethylene-co-p-ethylstyrene)copolymer shows systematical decrease of melting point and crystallinity and increase of glass transition temperature. At above 10 mol % of p-methylstyrene, the crystallinity of copolymer almost completely disappears. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1017-1029, 1998
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    Acid-catalyzed deprotection mechanism of tert-butyloxycarbonyloxy polymers in chemically amplified resists (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1035-1042 
    Details
    ISSN: 0887-624X
    Keywords: acid-catalyzed deprotection mechanism ; chemically amplified resist ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mechanism of acid-catalyzed deprotection of poly(4-tert-butyloxycarbonyloxy-styrene), PBOCST, in chemically amplified resists has been elucidated in terms of elementary processes by means of semiempirical molecular orbital calculations. It is concluded that the overall deprotection of tert-butyloxycarbonyl (t-BOC) group proceeds stepwise; i.e., (a) the first products are an acid carbonate and a tert-butyl cation; (b) a phenolic compound is the secondary and final product from the acid carbonate, which is realized by assistance with a counter anion accompanied by acid; (c) the counter anion also assists acid regeneration from the tert-butyl cation to produce isobutylene. The yield rate of the phenol is proportional to the product of concentrations of the polymer, the catalytic acid, and the counter anion. The activation energy (21 kcal/mol) calculated for the rate-determining step (a) is in good agreement with an experiment. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1035-1042, 1998
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    Synthesis and properties of new polyamides derived from 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene and aromatic dicarboxylic acids (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1069-1074 
    Details
    ISSN: 0887-624X
    Keywords: 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene (BADTB) ; polyamides ; direct polycondensation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The diamine 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene, containing symmetric, bulky di-tert-butyl substituents and a flexible ether unit, was synthesized and used to prepare a series of polyamides by the direct polycondensation with various aromatic dicarboxylic acids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. All the polymers were obtained in quantitative yields with inherent viscosities of 0.32-1.27 dL g-1. Most of these polyamides, except IIa, IId, and IIe, showed an amorphous nature and dissolved in polar solvents and less polar solvents. Polyamides derived from 4,4′-sulfonyldibenzoic acid, 4,4′-(hexafluoro-isopropylidene)dibenzoic acid, and 5-nitroisophthalic acid were even soluble in a common organic solvent such as THF. Most polyamide films could be obtained by casting from their N,N-dimethylacetamide (DMAc) solutions. The polyamide films had a tensile strength range of 49-78 MPa, an elongation range at break of 3-5%, and a tensile modulus range of 1.57-2.01 GPa. These polyamides had glass transition temperatures ranging between 253 and 276°C, and 10% mass loss temperatures were recorded in the range 402-466°C in nitrogen atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1069-1074, 1998
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    Stereochemical and compositional assignment of acrylonitrile/methyl methacrylate copolymers by DEPT and inverse HECTOR NMR spectroscopy (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1081-1092 
    Details
    ISSN: 0887-624X
    Keywords: NMR ; microstructure ; acrylonitrile/methyl methacrylate copolymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The acrylonitrile/methyl methacrylate copolymers of different monomer concentration were prepared by photo polymerization using uranyl ion as initiator. The carbon 13 and proton spectra of these copolymers are overlapping and complex. The complete spectral assignment of the 13C- and 1H-NMR spectra were done with the help of Distortionless Enhancement by Polarization Transfer (DEPT) and two dimensional 13C-1H Heteronuclear Single Quantum Correlation (HSQC) experiments. The methylene, methine and the methyl carbon resonances show both stereochemical (triad level) and compositional (dyad, triad, tetrad, pentad and hexad level) sensitivity. 2D Double Quantum Filtered Correlated Spectroscopy (DQFCOSY) experiment was used to ascertain the various geminal couplings between the methylene protons. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1081-1092, 1998
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    Self-propagating frontal copolymerization (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1117-1126 
    Details
    ISSN: 0887-624X
    Keywords: frontal copolymerization ; propagation velocity ; polymer chain ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The application of self-propagating frontal polymerization (FP) to synthesize copolymers has been investigated. Frontal copolymerizations of methyl methacrylate and methacrylic acid (MMA-MAA), acrylic acid and methacrylic acid (AA-MAA), and styrene and methacrylic acid (STY-MAA) with benzoyl peroxide (BPO) as initiator have been performed. The measured front velocities have been compared with the results of a suitably developed model. This is based on the pseudokinetic approach, accounts for the depropagation reaction, and is fully predictive; i.e., it does not include any adjustable parameter (although one had to be used for the specific experimental setup used in this work). An explicit, simplified solution of the model has been obtained using the constant pattern approximation. The microstructures of copolymers produced in bulk and by FP have been analyzed by differential scanning calorimetry. Their comparison indicates that self-propagating frontal copolymerization provides a substantial improvement in the uniformity of the chain composition distribution. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1117-1126, 1998
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    Vinyl monomers bearing chromophore moieties and their polymers. V. Synthesis and fluorescence behavior of a vinyloxy monomer bearing electron-accepting chromophore moiety, N-(2-(vinyloxy)ethyl)-1,8-naphthalimide, and its polymer (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1111-1116 
    Details
    ISSN: 0887-624X
    Keywords: N-(2-(vinyloxy)ethyl)-1,8-naphthalimide ; fluorescence structural self-quenching effect ; C60 ; electron donor ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A vinyloxy monomer bearing electron-accepting chromophore, N-(2-(vinyloxy)ethyl)-1,8-naphthalimide (VOENI), was synthesized by reaction of potassium 1,8-naphthalimide with 2-chloroethyl vinyl ether. VOENI can be homopolymerized by cationic initiation and copolymerized with maleic anhydride (MAn) under radical initiation. The fluorescence behaviors of VOENI and its polymers were investigated. It has been found that the fluorescence intensity of the VOENI monomer is much lower than that of its polymers at the same chromophore concentration. This means that a “structural self-quenching effect” (SSQE) has been also observed in the vinyloxy monomer consisting of an electron-accepting chromophore, which has opposite electronic structure in comparison with acrylates bearing electron-donating chromophores as we have reported previously. The SSQE is attributed to the charge-transfer interaction between the electron-accepting chromophore and the electron-donating double bond in the same molecule. The fluorescence quenching of 1,8-naphthalic anhydride and P(VOENI-co-MAn) by ethyl vinyl ether (EVE), dihydrofuran, triethylamine (TEA), etc. evidences that the electron-rich vinyloxy group does act as an important role in the SSQE of VOENI. C60 can also quench the fluorescence of the polymers, and an upward deviation from the linearity of the Stern-Volmer plot was observed showing that C60 acted as a powerful electron donor to quench the fluorescence of the copolymer. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1111-1116, 1998
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    Novel one-pot syntheses of sulfur-containing polymers from a bifunctional five-membered cyclic dithiocarbonate (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1189-1195 
    Details
    ISSN: 0887-624X
    Keywords: one-pot syntheses ; sulfur-containing polymers ; dithiol ; bifunctional five-membered cyclic dithiocarbonates ; diisocyanates ; acid dichlorides ; dibromoalkane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel one-pot syntheses of sulfur-containing polymers from a bifunctional five-membered cyclic dithiocarbonate (1a) were carried out. Polythiourethanes were obtained by the polyaddition of 4,4′-methylenebis(phenyl isocyanate), tolylene 2,6-diisocyanate, and hexamethylene diisocyanate with a dithiol (2a) obtained by the reaction of 1a and benzylamine under mild conditions. Polythioesters were also obtained by the polycondensation of terephthaloyl and succinyl chlorides with 2a. Further, polythioether was obtained by the polycondensation of α,α′-dibromo-p-xylene with 2a. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1189-1195, 1998
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    Poly(arylene ether)s, poly(arylene thioether)s, and poly(arylene sulfone)s derived from a dihydroxy(imidoarylene) monomer (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1201-1208 
    Details
    ISSN: 0887-624X
    Keywords: poly(arylene ether) ; poly(arylene thioether) ; poly(arylene sulfone) ; polyimide ; pendent group ; one-pot polymerization ; thiocarbamate ; thermal stability ; high-performance polymer ; oxidation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel poly(arylene ether)s, poly(arylene thioether)s, and poly(arylene sulfone)s were synthesized from the dihydroxy(imidoarylene) monomer 1. The syntheses of poly(arylene ether)s were carried out in DMAc in the presence of anhydrous K2CO3 by a nucleophilic substitution reaction between the bisphenol and activated difluoro compounds. Poly(arylene thioether)s were synthesized according to the recently discovered one-pot polymerization reaction between a bis(N,N′-dimethyl-S-carbamate) and activated difluoro compounds in the presence of a mixture of Cs2CO3 and CaCO3. The bis(N,N′-dimethyl-S-carbamate) 3 was synthesized by the thermal rearrangement reaction of bis(N,N′-dimethylthiocarbamate) 2, which was synthesized from 1 by a phase-transfer catalyzed reaction. The poly(arylene thioether)s were further oxidized to form poly(arylene sulfone)s, which would be very difficult, if not impossible, to synthesize by other methods. All of the polymers described have extremely high Tgs and thermal stability as determined from DSC and TGA analysis. Poly(arylene sulfone)s have the highest Tgs and they are in the range of 298-361°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1201-1208, 1998
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    Synthesis and characterization of aromatic poly(ether ketone)s containing cyclotriphosphazene units (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1227-1232 
    Details
    ISSN: 0887-624X
    Keywords: cyclotriphosphazene ; aromatic poly(ether ketone) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(4-oxybenzoic acid) tetrakis(phenoxy) cyclotriphosphazene (IUPAC name: 4-[4-(carboxyphenoxy)-2,4,6,6-tetraphenoxy-1,3,5,2λ5,4λ5,6λ5-triazatriphosphinin-2-yl]oxy-benzoic acid) was synthesized and direct polycondensed with diphenylether or 1,4-diphenoxybenzene in Eaton's reagent at the temperature range of 80-120°C for 3 hours to give aromatic poly(ether ketone)s. Polycondensations at 120°C gave polymer of high molecular weight. Incorporation of cyclotriphosphazene groups in the aromatic poly(ether ketone) backbone greatly enhanced the solubility of these polymers in common organic polar solvents. Thermal stabilities by TGA for two polymer samples of polymer series ranged from 390 to 354°C in nitrogen at 10% weight loss and glass transition temperatures (Tg) ranged from 81.4 to 89.6°C by DSC. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1227-1232, 1998
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    Preparation and thermotropic liquid crystalline properties of semirigid copolyurethanes composed of biphenyl units and partially fluorinated aliphatic chains (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1243-1249 
    Details
    ISSN: 0887-624X
    Keywords: semirigid copolyurethanes ; biphenyl unit ; fluorine-containing diols ; alkylene diphenyl dicarbamates ; melt polycondensation ; nematic phase ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New semirigid thermotropic liquid crystalline (LC) copolyurethanes 4 and 5 made up of biphenyl units and partially fluorinated aliphatic chains in the backbones were synthesized by melt polycondensation of a mixture of a dioxydihexanol of biphenyl 1 and two fluorine-containing diols 2a,b taken in definite feed mole ratios with alkylene diphenyl dicarbamates 3a-i having various lengths of aliphatic chains. The assigned structures of copolyurethanes 4 and 5 were identified by FTIR, 1H- and 13C-NMR spectra, and elemental analyses. The thermal and mesogenic properties were evaluated by differential scanning calorimetry (DSC), thermal mechanical analyses (TMA), polarizing microscopy, and temperature-changeable X-ray analyses, whose measurements indicated that the copolymers 4 and 5 form thermotropic nematic phases and have glass transition steps around room temperature. It is suggested that the incorporation of partially fluorinated aliphatic chains into the backbones has no drastic effect on the LC formation in the semirigid copolyurethanes 4 and 5. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1243-1249, 1998
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    Synthesis and characterization of a family of biodegradable poly(ester amide)s derived from glycine (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1271-1282 
    Details
    ISSN: 0887-624X
    Keywords: glycine ; synthesis ; biodegradation ; poly(ester amide)s ; thermal analysis ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of aliphatic poly(ester amide)s derived from 1,6-hexanediol, glycine, and diacids with a variable number of methylenes (from 2 to 8) have been synthesized and characterized. Infrared spectroscopy shows that the studied polymers present a unique kind of hydrogen bond that is established between their amide groups. Thermal properties as melting, glass transition, and decomposition temperatures are reported. The data indicate that all the polymers are highly crystalline. Thus, different kinds of spherulites (positive and/or negative) were obtained depending on the preparation conditions and on the polymer samples. Moreover, all the polymers crystallized from dilute diol solutions as ribbonlike crystals where a regular folding habit and a single hydrogen bond direction could be deduced. A test of enzymatic hydrolysis was employed to assess the potential biodegradability of these polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1271-1282, 1998
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    Synthesis and characteristics of polydepsipeptide with pendant thiol groups (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1283-1290 
    Details
    ISSN: 0887-624X
    Keywords: biodegradability ; oligo[(glycolic acid)-alt-(L-cysteine)] ; poly[(lactic acid)-depsipeptide] ; ring-opening polymerization ; pendant thiol group ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To obtain water-soluble oligodepsipeptide with pendant thiol groups, the alternating co-oligomer [oligo(Glc-alt-Cys)], consisting of glycolic acid (Glc) and L-cysteine (Cys) residues as α-hydroxy acid and α-amino acid residues, respectively, was prepared by means of ring-opening homo-oligomerization of cyclo[Glc-Cys(MBzl)] and subsequent deprotection of methoxybenzyl groups. Moreover, to modify the properties of poly(lactic acid) [poly(LA)] and to introduce pendant thiol groups to poly(LA), the terpolymer of LA, Glc, and Cys {poly[LA-(Glc-Cys)]} was synthesized through ring-opening and copolymerization of L-lactide with the protected cyclodepsipeptide, cyclo[Glc-Cys(MBzl)] and subsequent deprotection of methoxybenzyl groups. By changing the mol fraction of (Glc-Cys) unit, the solubility, thermal transition, degradation behavior of the modified poly(LA), and the water contact angle of its film could be varied. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1283-1290, 1998
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    Synthesis of poly(1,4-dioxan-2-one-co-trimethylene carbonate) for application in drug delivery systems (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1301-1307 
    Details
    ISSN: 0887-624X
    Keywords: 1,4-dioxan-2-one ; trimethylene carbonate ; stannous octoate ; drug delivery system ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(1,4-dioxan-2-one-co-trimethylene carbonate), P(DON-co-TMC), copolymers with different compositions were synthesized by copolymerizations of 1,4-dioxan-2-one (DON) and trimethylene carbonate (TMC) at 120°C in the presence of Sn(Oct)2. Their structures and compositions were determined with FT-IR and 1H-NMR spectroscopies. The intrinsic viscosities of copolymers increased with the increase of the TMC fraction in feed. The DSC results of copolymers showed that the glass transition temperatures (Tgs) of copolymers are lower than those of homopolymers. Most copolymers are amorphous except for one with a high DON composition. The hydrophilicity of the copolymers is in proportion with the DON molar fraction in the copolymers. It was found that the Levonorgestrel (LNG) release rate is dependent of the composition and flexibility of polymer chains. The fastest one is the copolymer with nearly a equivalent fraction of DON to TMC. Among copolymers with other compositions, a higher DON fraction would be favorable to the release of LNG. All measurements demonstrate an almost constant release rate in the period of 1 month. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1301-1307, 1998
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    Chain end analysis of bisphenol A polysulfone and its relation to molecular weight (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1309-1316 
    Details
    ISSN: 0887-624X
    Keywords: polysulfone ; step polymerization ; end-capping ; end group titration ; multiple end groups ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of amine-terminated polysulfone by step polymerization of the monomers bisphenol A and dichlorodiphenyl sulfone in the presence of end-capping reagent 4-aminophenol was investigated. A persistent problem with end-capping strategy as applied to step polymerization is the presence of end groups other than those introduced by the end-capping reagent. These unintended end groups, which can persist in the polymer product even when 100% of the end-capping reagent has reacted, are associated with a proportionate decrease in polymer chain length. This situation renders quantitative analysis of a single type of end group invalid as a method for molecular weight determination. The presence of unintended end groups does not appear to correlate with a particular set of reaction conditions; unintended end groups were found to occur in polymerizations conducted under strong base conditions (NaOH), under weak base conditions (K2CO3), and with a wide range of monomer feed ratios. A scheme for unambiguous quantification of chain ends and molecular weight for end-capped polysulfone is described. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1309-1316, 1998
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    Successful synthesis of a 1: 1 salt monomer derived from bis(4-aminophenyl) ether and pyromellitic acid for direct polycondensation to an aromatic polyimide (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1341-1344 
    Details
    ISSN: 0887-624X
    Keywords: aromatic polyimide ; direct polycondensation ; salt monomer method ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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    Effect of tacticity on conformation of p-tert-butylphenol acetaldehyde resins as studied by molecular simulation (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1355-1361 
    Details
    ISSN: 0887-624X
    Keywords: p-tert-butylphenol acetaldehyde resin ; tacticity ; molecular simulation ; structural stability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: p-tert-Butylphenol acetaldehyde resins can have isotactic, syndiotactic, and atactic sequences. Structural characteristics of the p-tert-butylphenol acetaldehyde resin with different tacticities were studied using molecular mechanics and molecular dynamics. Trimer-decamer isotactic and syndiotactic resins and 12 stereoisomers of a hexamer were calculated. In the p-tert-butylphenol acetaldehyde resin, the hydroxyl groups cluster in the center of the molecule through intramolecular hydrogen bonding and the tert-butyl groups are extended out. It has been found that the energy-minimized structures of the isotactic resin are more stable than those of the syndiotactic resin by 7-17 kcal/mol. From the results of molecular dynamics at 303, 373, 474, and 573 K for 300 ps, the isotactic resin was also found to be more stable than the syndiotactic resin. For atactic resins, the closer to isotactic their structures are, the more stable they are. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1355-1361, 1998
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    Macrocycles IV. Macrocyclic polylactones as bifunctional monomers for polycondensations (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1373-1378 
    Details
    ISSN: 0887-624X
    Keywords: macrocyclic polymerization ; polycondensation ; 2-stanna-1,3-dioxacycloalkanes ; poly(ε-caprolactone) ; poly(δ-valerolactone) ; poly(β-D,L-butyrolactone) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tin containing macrocyclic polylactones were prepared by di-n-butyl-2-stanna-1,3-dioxepane-initiated polymerizations of ε-caprolactone in bulk. The average ring size was varied from 10 to 100 monomer units via the monomer/initiator (M/I) ratio. Addition of terephthaloyl or sebacoyl chloride to the in situ prepared macrocycles yielded polycondensates under elimination of di-n-butyl tin dichloride. The molecular weights increased with the reaction temperature (e.g., 80-140°C) and with the size of the macrocycles. Number-average molecular weights (Mns) up to 90,000 and polydispersities between 1.65 and 2.0 were obtained. Further polycondensations were conducted with isophthaloyl chloride, 4,4′-biphenyldicarbonylchloride and 4,4′-phenylenebisacryloylchloride. Several polycondensations were performed with macrocyclic poly (δ-valerolactone) and poly (β-D,L-butyrolactone). In those cases the increase of the molecular weight was lower. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1373-1378, 1998
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    Synthesis and properties of poly(ether imide)s derived from 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride and aromatic diamines (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1657-1665 
    Details
    ISSN: 0887-624X
    Keywords: 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride ; poly(ether imide)s ; thermal behavior ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new naphthalene unit-containing bis(ether anhydride), 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride, was synthesized in three steps starting from the nucleophilic nitrodisplacement reaction of 2,6-dihydroxynaphthalene and 4-nitrophthalonitrile in N,N-dimethylformamide (DMF) solution in the presence of potassium carbonate, followed by alkaline hydrolysis of the intermediate bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). High-molar-mass aromatic poly(ether imide)s were prepared using a conventional two-step polymerization process from the bis(ether anhydride) and various aromatic diamines. The intermediate poly(ether amic acid)s had inherent viscosities of 0.65-2.03 dL/g. The films of poly(ether imide)s derived from two rigid diamines, i.e. p-phenylenediamine and benzidine, crystallized during the thermal imidization process. The other poly(ether imide)s belonged to amorphous materials and could be fabricated into transparent, flexible, and tough films. These aromatic poly(ether imide) films had yield strengths of 104-131 MPa, tensile strengths of 102-153 MPa, elongation to break of 8-87%, and initial moduli of 1.6-3.2 GPa. The glass transition temperatures (Tg's) of poly(ether imide)s were recorded in the range of 220-277°C depending on the nature of the diamine moiety. All polymers were stable up to 500°C, with 10% weight loss being recorded above 550°C in both air and nitrogen atmospheres. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1657-1665, 1998
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    A simple method for the anionic polymerization of α-carbonyl acids in water (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1683-1683 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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    Synthesis and binding properties of a noncovalent molecularly imprinted testosterone-specific polymer (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1725-1732 
    Details
    ISSN: 0887-624X
    Keywords: crosslinked polymer ; template polymerization ; noncovalent molecular imprinting ; testosterone ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this study, molecular imprinting was used to develop a method based on noncovalent interactions for synthesis of a testosterone-specific polymer. The effect of the different template-monomer ratios, the particle sizes of polymers, and chromatographic mobile phases on steroid-polymer interactions are discussed. The polymer obtained was found to interact specifically with testosterone, while other steroids under study were eluted close to the void volume in the HPLC experiments. Batch rebinding studies in acetonitrile were undertaken to quantitatively evaluate the affinity of the polymer for testosterone. During this experiment, the testosterone concentration was measured in two ways: spectrophotometrically and by HPLC on a column with testosterone-specific imprinted polymer synthesized by us. Both methods resulted in similar values of association constants and the number of binding sites. However, the second method has obvious advantages when the analyzed solution contains a mixture of optically dense compounds. The results obtained focus on the two-point binding nature of the imprinted polymer-testosterone interaction and the significant role of hydrogen bonds between the OH group of testosterone and carboxy group of methacrylic acid residues inside specific recognition sites of the imprinted polymer. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1725-1732, 1998
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    Comparison of activities of homogeneous Ti-based catalysts in the presence of methylaluminoxane (MAO) for synthesis of syndiotactic polystyrene by UV/visible spectroscopic study (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1733-1741 
    Details
    ISSN: 0887-624X
    Keywords: homogeneous Ti-based catalyst ; methylaluminoxane ; catalytic activity ; UV/visible spectroscopy ; syndiotactic polystyrene ; polymorphic structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The catalytic activities in syndiospecific polymerization of styrene in hydrocarbon using homogeneous Ti-based catalysts in the presence of methylaluminoxane (MAO) were investigated through UV/visible spectroscopic analysis. A strong UV absorption band of CpTiCl3, itself, incipiently appeared at λmax = 400 nm in toluene, followed by a bathochromic shift with its remarkable decrease by the addition of MAO. The absorption band intensity at λmax = 400 nm arising from delocalization of π-electrons on the cyclopentadienyl ring decreased by methylation in the presence of MAO with regard to the mechanism for production of an active center (“cation-like”), for example, the change of the ionic nature. The intensity decrease at λmax = 400 nm was suppressed over 2000 of the [Al]/[Ti] ratio. In the case of Ti(OC4H9)4 having a σ-ligand, new and broad UV absorption bands were developed at λmax = 340 nm and 410 nm in the presence of MAO in contrast with the CpTiCl3/MAO system. Comparison between the relative absorption intensities at λmax = 340 nm and 410 nm led to the determination of a maximum catalytic activity of Ti(OC4H9)4 in the presence of MAO related to the polymerization yield. The maximum polymerization yield was observed with regard to the relative maximum value of the absorption intensity at λmax = 410 nm with the [Al]/[Ti] ratio (500). From observation for polymorphism of the final products via differential scanning calorimetric analysis (DSC), the thermally unstable β-form seemed to be produced by the CpTiCl3/MAO system independent of the MAO concentration, the Ti(OC4H9)4/MAO system produced a thermally stable α-form in the low MAO concentration (up to 100 of the [Al]/[Ti] ratio), and a mixture of α- and/or β-forms over 200 of the [Al]/[Ti] ratio under our experimental conditions. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1733-1741, 1998
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    Synthesis of isotactic polystyrene with a rare-earth catalyst (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1773-1778 
    Details
    ISSN: 0887-624X
    Keywords: rare-earth coordination catalyst ; styrene ; isotactic polystyrene ; neodymium ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of styrene with the neodymium phosphonate Nd(P507)/H2O/Al(i-Bu)3 catalytic system has been examined. The polymer obtained was separated into a soluble and an insoluble fraction by 2-butanone extraction. 13C-NMR spectra indicate that the insoluble fraction is isotactic polystyrene and the soluble one is syndiotactic-rich atactic polystyrene. The polymerization features are described and discussed. The optimum conditions for the polymerization are as follows: [Nd] = (3.5-5.0) × 10-2 mol/L; [styrene] = 5 mol/L; [Al]/[Nd] = 6-8 mol/mol; [H2O]/[Al] = 0.05-0.08 mol/mol; polymerization temperature around 70°C. The percent yield of isotactic polystyrene (IY) is markedly affected by catalyst aging temperature. With increase of the aging temperature from 40 to 70°C, IY increases from 9% to 48%. Using AlEt3 and Al(i-Bu)2H instead of Al(i-Bu)3 decreases the yield of isotactic polystyrene. Different neodymium compounds give the following activity order: Nd(P507)3 〉 Nd(P204)3 〉 Nd(OPri)3 〉 NdCl3 + C2H5OH 〉 Nd(naph)3. With Nd(naph)3 as catalyst, only atactic polystyrene is obtained. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1773-1778, 1998
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    Copolymerization of carbon monoxide and norbornene derivatives with ester groups by palladium catalyst (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1785-1790 
    Details
    ISSN: 0887-624X
    Keywords: carbon monoxide ; norbornene ester ; glass transition temperature ; palladium catalyst ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this article we will discuss the synthesis of the new copolymers of norbornene derivatives with an ester group and carbon monoxide, using Pd(CH3CN)4(BF4)2 as a catalyst and 2,2′-bipyridine as a ligand in nitromethane/methanol at 60°C. Elementary analysis, infrared spectra, and NMR spectra indicated that copolymers contain ketone, ester, and bicyclic structures. Methanol functions as the coinitiator and chain transfer agent in copolymerization. A decrease in the molar ratio of [CH3OH]/[Pd] caused an increase in molecular weight and a decrease in yield of the copolymer. The number-average molecular weight of copolymers (Mn) ranged from 3800 to 5300, and the glass transition temperature (Tg) ranged from -32 to 117°C. Thermal analysis revealed that both T10%d and Tmaxd exceeded 180 and 230°C, respectively. Linear long-chain substituents such as n-C11H23C(O)—O—CH2— drastically reduced Tg to a value of -32°C. In general, copolymers having a longer linear side-chain substituents of ester on norbornene have a more desirable solubility. Moreover, X-ray diffraction demonstrated that the degree of crystallinity decreases with an increasing length of side chain substituents. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1785-1790, 1998
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    Synthesis and reactions of a poly(methacrylate) from an optically active amino alcohol (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1981-1986 
    Details
    ISSN: 0887-624X
    Keywords: synthesis ; radical polymerization ; (L)-phenylalaninol ; methacrylate ; cleavage ; optically active polymeric amine ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and radical polymerization of a novel optically active methacrylate, (S)-2-tert-butoxycarbonylamino-3-phenylpropyl methacrylate (MA-F-BOC), were examined. MA-F-BOC was synthesized from methacrylic acid and N-protected (L)-phenylalaninol. Radical polymerization of MA-F-BOC quantitatively afforded the corresponding polymethacrylate with a relatively high molecular weight. Radical copolymerizations of MA-F-BOC were carried out with styrene and acrylamide to afford the copolymers. Radical polymerization of MA-F-BOC in the presence of n-butanethiol afforded the oligomers, whose degrees of polymerizations were 3.3-8.0. The BOC group was completely cloven with HBr to afford the corresponding optically active polymeric amine quantitatively. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 1981-1986, 1998
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    Morphology and grafting of oxazoline-functional polymer particles with various carboxylic acids (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1821-1827 
    Details
    ISSN: 0887-624X
    Keywords: morphology ; grafting ; oxazoline-functionalized polymer particles ; carbolic acids ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxazoline-functionalized, crosslinked PMMA-particles, prepared by free radical nonaqueous dispersion polymerization, were grafted with n-decanoic acid and carboxylic acid-terminated polystyrene. Oxazoline groups, separated by an alkylspacer from the PMMA backbone, showed enhanced mobility with respect to the backbone, as evaluated by solid-state NMR spectroscopy using a dipolar filter. As a function of molecular mass of the carboxylic acid, the oxazoline conversion varied from 70 mol % for n-decanoic acid to 1% for monocarboxylate-terminated polystyrene CT-PS with Mn: 15,900 g/mol. Morphological studies, performed by TEM, showed that reaction with acid terminated polystyrene results exclusively in interfacial grafting at the particle surface. At low grafting levels a raspberry-like morphology was obtained, whereas grafting levels exceeding 14 wt % CT-PS resulted in core-shell morphology. Core-shell morphology was also verified by static light scattering using toluene solvent, which is isorefractive to the PMMA core. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1821-1827, 1998
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    Editorial (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. VII 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract.
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    Living polymers. Their discovery, characterization, and properties (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. IX 
    Details
    ISSN: 0887-624X
    Keywords: living polymerization ; discovery ; significance ; revised definition ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The story of the discovery of living polymers is presented. Living polymers are polymers that retain their ability to propagate and grow to a desired size while their degree of termination or chain transfer is still negligible. Theoretical and mechanistic considerations are discussed. The living polymerization technique provides access to uniform polymers (Poisson molecular weight distribution) of controllable size, block copolymers, functional polymers, and star and comb-shaped polymers. The quantitative aspects of electron transfer are fully discussed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: ix-xv, 1998
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    Controlling surfaces and interfaces with functional polymers: Preparation and functionalization of dendritic-linear block copolymers via metal catalyzed “living” free radical polymerization (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1-10 
    Details
    ISSN: 0887-624X
    Keywords: living free-radical polymerization ; dendrimer ; polystyrene ; block copolymer ; chemical modification ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation and chemical modification of dendritic-linear block copolymers with surface functionalized dendritic components are presented. Isophthalate ester-functionalized dendrons featuring benzylic halide groups at their focal points have been used for the metal catalyzed “living” radical polymerization of styrene. The molecular weight of the dendritic-linear block copolymers determined by MALDI-TOF and Size Exclusion Chromatography was found to be accurately controlled up to molecular weights of ca. 30,000 a.m.u., with polydispersities less than 1.2. Subsequent functional group modifications of the peripheral ethyl ester groups of the dendritic block have been successfully carried out leading to carboxylic acids, butyl amides, benzyl alcohols, benzyl halides, and also accelerated generation growth via transesterification with a first generation dendritic alcohol. Several of these new dendritic-linear block copolymers exhibit interesting aggregation characteristics as evidenced by 1H-NMR spectroscopic studies. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1-10, 1998
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    Polymerization of N,N′-methylenebis(acrylamide) using potassium peroxydiphosphate-thiocarboxylic acid redox systems: A comparison (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 11-20 
    Details
    ISSN: 0887-624X
    Keywords: polymerization ; divinyl monomer ; redox ; thiocarboxylic acid ; mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of aqueous polymerization of the symmetrical nonconjugated divinyl monomer N,N′-methylenebis(acrylamide) (MBA), was studied at 35°C and at constant ionic strength under nitrogen atmosphere involving potassium peroxydiphosphate (PDP) as oxidant with three different activators thiolactic acid (TLA), thiomalic acid (TMA), and thioglycollic acid (TGA). The rate of polymerization, RP, and rate of disappearance of peroxydiphosphate, -RPDP have been followed while polymerization was initiated separately by the PDP-TLA/PDP-TMA/PDP-TGA redox systems. RP for the above three systems showed first-order dependences on both [monomer] and [activator] and zero-order dependence on [PDP]. First-order dependence on [PDP] and zero-order dependences on [monomer] and [activators] were observed with respect to -RPDP in the above three systems. A reaction mechanism which involves complex formation between PDP and thiocarboxylic acid, propagation through intramolecular-intermolecular reactions, degradative chain transfer reaction of the growing radical with PDP, and linear termination by the interaction of the chain radical with primary radical was proposed. The kinetic parameters for the three polymerization systems were calculated and compared. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 11-20, 1998
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    High-pressure synthesis and properties of aliphatic-aromatic polyimides via nylon-salt-type monomers derived from aliphatic diamines and benzophenonetetracarboxylic acid (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 39-47 
    Details
    ISSN: 0887-624X
    Keywords: aliphatic polyimides ; polycondensation ; salt monomers ; crystallinity ; thermal behavior ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aliphatic polyimides (P-XBTA) having inherent viscosities of 0.4-1.4 dL/g were readily synthesized by the high-pressure polycondensation of the salt monomers, composed of aliphatic diamines having various methylene chain lengths (X = 4-12) and 3,3′,4,4′-benzophenonetetracarboxylic acid (BTA), under 200-250 MPa at 200-320°C. The salt monomers with odd-numbered methylene units were found to be more susceptible to crosslinking than those containing even-numbered methylene chains. The polyimides having even-numbered methylene units were highly crystalline, whereas those with odd-numbered methylene chains were crosslinked and therefore amorphous with only one exception, i.e., P-11BTA. The thermal behavior of these polymers was also studied. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 39-47, 1998
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    Preparation and properties of anion exchange membranes having pyridinium or pyridinium derivatives as anion exchange groups (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 49-58 
    Details
    ISSN: 0887-624X
    Keywords: anion exchange membrane ; electrodialysis ; permselectivity between two anions ; pyridinium groups ; hydrophilicity of anion exchange membrane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Anion exchange membranes with pyridinum groups and various pyridinium derivative groups were prepared from a copolymer membrane composed of chloromethylstyrene and divinylbenzene, and pyridine and pyridine derivatives. The anion exchange membranes obtained showed excellent electrochemical properties in electrodialysis. The transport numbers of sulfate ions, bromide ions, nitrate ions, and fluoride ions relative to chloride ions were evaluated in connection with the species of a substituent and the position of the substituent in the pyridinium groups. In general, when a hydrophilic substituent (methanol groups) existed at the 2-position of the pyridinium groups, nitrate ions and bromide ions, which are less hydrated, permeated through the membranes with difficulty, and sulfate ions permeated selectively through the membranes. On the other hand, when hydrophobic groups, for example, ethyl groups, existed at the 2-position of the pyridinium groups, bromide ions and nitrate ionspermeated selectively through the membranes and fluoride ions had difficulty permeating through the membranes. The carbon number of the alkyl chain of 4-alkyl pyridinium groups also affected permeation of nitrate ions and bromide ions due to the change in hydrophilicity of the membranes. Though the hydration of the anions and the species of the substituent at the 2-position of the pyridinium groups were related to selective permeation of the anion through the membranes, permeation of sulfate ions was not as sensitive to the hydrophilicity of the membranes. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 49-58, 1998
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    Preparation of plasma-grafted polymer membranes and their morphology and pervaporation properties toward benzene/cyclohexane mixtures (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2247-2259 
    Details
    ISSN: 0887-624X
    Keywords: pervaporation ; plasma graft polymerization ; membrane ; glycidyl methacrylate ; morphology ; porous polyethylene ; benzene/cyclohexane separation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Composite membranes were prepared by plasma-induced graft polymerization of vinyl monomers onto porous substrates of high density polyethylene, and the relationship between the polymerization conditions and morphological structure and pervaporation performance toward benzene/cyclohexane mixtures was investigated in detail. The morphological structures of the plasma-grafted membranes depended on the monomer reactivity, plasma treatment manner, and graft polymerization conditions. Pervaporation properties were closely related to the graft monomers and the morphological structures. The poly(glycidyl methacrylate)-grafted membranes prepared by homogeneous both sides plasma treatment and under mild polymerization conditions showed the highest pervaporation performance with a permeation flux of 0.3 kg/(m2 h) and separation factor of 22 at 60 wt % benzene and 70°C. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2247-2259, 1998
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    Polymerization of olefins with a novel dinuclear ansa-zirconocene catalyst having a biphenyl bridge (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2269-2274 
    Details
    ISSN: 0887-624X
    Keywords: dinuclear ansa-zirconocene catalyst ; diastereomers ; biphenyl and phenyl ligands ; polymerization of ethene and propene ; copolymerization of ethene and 1-octene ; thermal stability of active species ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Both the rac- and meso-dinuclear ansa-zirconocene catalysts (μ-C12H8{[SiPh(Ind)2]ZrCl2}2) were prepared by a coupling reaction between 2 equiv of diindenylphenylchlorosilane (rac- and meso-isomers) and 1 equiv of p-dilithiobiphenyl in diethyl ether at -80°C, followed by a successive reaction with ZrCl4 · 2THF in THF at -78°C. Polymerizations of ethene and propene were conducted in a 1 dm3 high-pressure glass reactor equipped with a mechanical stirrer at 60, 80, 100, 120, and 150°C using methylalumoxane (MAO) as cocatalyst and toluene or decahydronaphthalene as the solvent. Copolymerization of ethene and 1-octene was also checked in brief. For ethene polymerization, the meso-catalyst was found to be more active, which displayed an extremely high activity to give linear polyethene with a high molecular weight and a narrow molar mass distribution (MMD). The apparent activity increased monotonously with rising polymerization temperature from 60°C up to 150°C, indicating that the active species are stable even at a high temperature. On the other hand, both the rac- and meso-catalysts showed very poor activities for propene polymerization. However, copolymerization of ethene and 1-octene proceeded at a high speed. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2269-2274, 1998
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    Synthesis and properties of stereoregular poly(ester amides) derived from carbohydrates (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 67-77 
    Details
    ISSN: 0887-624X
    Keywords: stereoregular poly(ester amides) ; carbohydrate-based polymers ; polycondensation reactions ; chiral polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two poly(ester amides) containing three methoxy groups stereoregularly attached to the main chain have been prepared by using naturally occurring L-arabinose and D-xylose as the starting materials. The polymers were prepared by the active ester polycondensation method and characterized by elemental analysis, IR, and 1H- and 13C-NMR spectroscopies. Both viscosimetry and GPC were used to estimate the molecular weights. The polymers are hydrophilic, one of them being water soluble, and exhibited moderate optical activity. Thermal and X-ray diffraction studies revealed that they are slightly crystalline and stable up to 250°C under nitrogen. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 67-77, 1998
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    Properties and morphology of poly(L-lactide). II. Hydrolysis in alkaline solution (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 59-66 
    Details
    ISSN: 0887-624X
    Keywords: poly(lactide) ; hydrolysis ; degradation ; erosion ; alkaline solution ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hydrolysis of poly(L-lactide) (PLLA) films in 0.01N NaOH at 37°C was investigated by gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, and polarizing optical microscopy. The change in molecular weight distribution and surface morphology of PLLA films during hydrolysis revealed that PLLA film hydrolysis in dilute alkaline solution proceeded mainly via the surface erosion mechanism. An insignificant dependence of the rate of weight loss per unit surface area on the PLLA film thickness also supported this conclusion. Etching of the outside of PLLA spherulites resulted in preferred hydrolysis of PLLA chains in the amorphous region. The disorientation of lamella and inhomogeneous erosion in the spherulites implied that hydrolysis of PLLA chains occurred predominantly in the amorphous region between the crystalline regions in the spherulites. The rate of weight loss per unit surface area decreased linearly with the increase in the initial crystallinity of PLLA film, while the radius of spherulites had practically no significant effect on the hydrolysis of PLLA film. The specific low molecular weight of PLLA chains produced by hydrolysis increased with the rise in annealing temperature of the PLLA film, suggesting that the PLLA chains released were the component of one fold in the crystalline region. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 59-66, 1998
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    Synthesis and properties of p-nitrophenylacetylene-phenylacetylene copolymers (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 93-102 
    Details
    ISSN: 0887-624X
    Keywords: p-nitrophenylacetylene ; phenylacetylene ; copolymers ; structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of phenylacetylene (PA) and p-nitrophenylacetylene (pNPA) with various monomers ratios were prepared and characterized. The solubility of copolymers is dependent on the number of PA units in the chain. They show a good degree of stereoregularity and the MWs are in the 103-105 a.m.u. range, depending on the monomers and catalyst molar ratios. The soluble samples exhibit film-forming properties and the film-surface morphology may be varied by using different solvents. The copolymers give good electrical response to relative humidity variations. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 93-102, 1998
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    Epoxidation of bacterial polyesters with unsaturated side chains. III. Crosslinking of epoxidized polymers (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2389-2396 
    Details
    ISSN: 0887-624X
    Keywords: bacterial polyesters ; epoxidation of polyesters ; polyhydroxyalkanoates ; crosslinking polyesters ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The vinyl groups in the pendant substituents of a series of poly(3-hydroxyoctanoate-co-3-hydroxy-10-undecenoate)s, PHOUs, were completely converted into epoxide groups with m-chloroperbenzoic acid to produce a series of copolymers, poly(3-hydroxyoctanoate-co-3-hydroxy-10,11-epoxyundecenoate)s, PHOEs containing 5, 9, 14, and 22 mol % of epoxide repeating units. The epoxidized polymers were crosslinked by reactions with succinic anhydride, using 2-ethyl-4-methylimidazole as an initiator, at 90°C during a period of 0.5-4 h. Mild conditions were used for the crosslinking reactions to prevent degradation or rearrangement reactions, and the extent of crosslinking was evaluated from the sol-gel content. Both Tg and gel content increased after crosslinking, depending upon the amount of epoxide group in the initial PHOE sample. Kinetic parameters for the crosslinking reaction were determined by use of the Kissinger and the Ozawa methods. The activation energy (15.6-16.0 kcal/mol) for the crosslinking reaction was the same for each sample, and the frequency factors were of the same order of magnitude, regardless of epoxide group content in the PHOE. The values obtained from the Ozawa method were slightly higher than those obtained from the Kissinger method. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2389-2396, 1998
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    Synthesis and characterization by MALDI-TOF MS of polycyclic siloxanes derived from p-substituted novolac resins by MALDI-TOF MS (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2429-2437 
    Details
    ISSN: 0887-624X
    Keywords: phenol-formaldehyde resin ; polycyclic dimethylsiloxanes ; polycyclic diphenylsiloxanes ; ring-opening polymerization ; matrix assisted laser desorption ionization time of flight mass spectrometry ; MALDI-TOF ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel polycyclic siloxane resins were prepared from phenol-formaldehyde novolac type resins by reacting them with dialkyl or diaryl dichlorosilanes under anhydrous and high dilution conditions. The formation of polycyclic species was confirmed by the detection of absolute masses by MALDI-TOF mass spectrometry. 1H- and 29Si-NMR confirmed the substitutions of phenolic hydroxy groups by siloxane bonds. Curing studies were conducted on the polycyclic siloxane resins as well as on the polycyclic siloxane resins incorporated into two types of polysiloxane gums. A trace amount of potassium hydroxide was used as a catalyst for the crosslinking of these systems. The blend of polysiloxane with 30 wt % polycyclic siloxane was found to be stable at the curing temperature. Differential scanning calorimetry and thermogravimetric analysis techniques were used to study the thermal profiles of these systems. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2429-2437, 1998
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    Formation of conjugated polyene and polyyne structure by KrF excimer laser-induced dehydrochlorination on polyvinylidenechloride film (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2483-2487 
    Details
    ISSN: 0887-624X
    Keywords: KrF excimer laser ; dehydrochlorination ; poly(vinylidenechloride&) ; film ; polyene and polyyne structures ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The surface dehydrochlorination of poly(vinyldenchloride) film was performed to produce a conjugated polyyne and polyene structures by photo-irradiation with a KrF excimer laser at 248 nm in a vacuum chamber. The reaction was confirmed by detection of HCl with a mass spectrometer and by measurement of chlorine content on the film with X-ray photoelectron spectroscopy. UV-visible absorption spectroscopy for the laser-treated film showed the formation of new broad absorption bands in the visible and near IR region, indicating that sequential dehydrochlorination induced the formation of conjugated carbon multiple bonds in the polymer chain. Its conjugation number is estimated to be 30 for a triple bond and 10-25 for a double bond from the peak positions on the Raman spectrum of the film. ESR spectra of laser-irradiated PVDC powder also showed long-lived radicals having a narrow band width (ΔHpp = 0.15 mT), suggesting that the radicals were delocalized on the conjugated bonds. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2483-2487, 1998
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    Spectroscopic investigations of polyacrylonitrile thermal degradation (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2503-2512 
    Details
    ISSN: 0887-624X
    Keywords: PAN ; FT-IR ; 13C CP-MAS ; Py-GC-MS ; cyclization ; thermal degradation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: PAN undergoes chemical decomposition in stages on thermal treatment. In the literature, several mechanisms were proposed for the degradation process. However, the decomposition pathway and the structural rearrangement of solid residue in relation to the loss of volatile products are not fully understood. The degradation process has therefore received further attention in this work by employing a combination of FT-IR, high-resolution solid-state 13C-NMR, pyrolysis GC-MS, and microelemental analysis. These investigations have established that PAN decomposes to gaseous and volatile products over a range of temperatures (150-590°C) with concurrent stabilization of the structure of residual matter occurring on a parallel course. While linear polymerization of nitrile group is the principal reaction in the decomposition process, cyclization followed by extended conjugation is the notable exothermic process. No evidence has been obtained for the formation of oxygen-containing chromophores either as intermediates or as part of the chemical structure of the residue. Temperature sensitivity of oligomer formation has been established through pyrolysis-GC-MS studies. The overall decomposition profile of PAN has thus been established. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2503-2512, 1998
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    Near-monodisperse, n-alkyl, end-functionalized poly(methyl vinyl ether)s: Synthesis by living cationic polymerization and solution characterization (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2547-2554 
    Details
    ISSN: 0887-624X
    Keywords: living cationic polymerization ; poly(methyl vinyl ether) ; acetals ; end-functionalized polymers ; diblock copolymers ; water-soluble polymers ; amphiphiles ; nonionic polymeric surfactants ; cloud points ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Water-soluble amphiphilic diblock copolymers were synthesized by the living cationic polymerization of methyl vinyl ether (hydrophilic block) and its subsequent termination with n-alcohols of chain lengths varying from one to eight, and three n-alkyl carboxylic acids with 10, 12, and 18 carbon atoms. Additionally, water and ethylene glycol were tested as terminating agents. The extent of the functionalization was determined using 1H NMR spectroscopy. The cloud points of 1% w/w aqueous solutions of the polymers as determined by turbidimetry decreased from 32 to 21°C as the number of carbon atoms of the terminating agent increased. Aqueous GPC revealed micellization of the stearic acid-terminated block copolymer, while the other block copolymers existed mainly as unimers. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2547-2554, 1998
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    Polymers with electron-deficient olefin moieties by oxidation of precursors containing “push-pull” olefin (β-alkylmercaptoenoate) moieties in the main chain (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2589-2592 
    Details
    ISSN: 0887-624X
    Keywords: polymer reaction ; oxidation ; push-pull olefin ; electron-deficient olefin ; vinyl sulfone ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxidation of a polymer (1) having β-alkylmercaptoenoate moieties in the main chain by m-chloroperbenzoic acid (MCPBA) is described. Oxidation of 1 proceeded selectively to give polymers having vinyl sulfoxide or vinyl sulfone moieties in the main chain by using an appropriate amount of MCPBA. In the case of 1.1 equiv of MCPBA (relative to the sulfur atom), a polymer (4) having vinyl sulfoxide moieties selectively in the main chain was obtained in quantitative yield without side reactions. Likewise, a polymer (5) having vinyl sulfone moieties was obtained in quantitative yield by using 2.6 equiv of MCPBA. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2589-2592, 1998
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    Graft copolymers having hydrophobic backbone and hydrophilic branches. XVIII. Poly(styrene) nanospheres with novel thermosensitive poly(N-vinylisobutyramide)s on their surfaces (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2581-2587 
    Details
    ISSN: 0887-624X
    Keywords: poly(N-vinylisobutyramide) ; free radical polymerization ; macromonomer ; nanosphere ; thermosensitive property ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(styrene) nanospheres having poly(N-vinylisobutyramide)s (PNVIBA)s, which are structurally the same composition as well-known thermosensitive poly(N-isopropylacrylamide)s (PNIPAAm)s and show the thermosensitive property as well, on their surfaces were synthesized by the free radical polymerization of hydrophilic PNVIBA macromonomers and hydrophobic styrene with AIBN as a radical initiator in ethanol as a polar solvent and were characterized in regard to their thermosensitive properties. Both the NVIBA oligomers and PNVIBA macromonomers that we synthesized showed a lower critical solution temperature (LCST) at around 40°C, as was predicted by our previous research. The nanospheres were spherical in form and have a narrow size distribution. Their sizes could be controlled by varying the molecular weight of the macromonomers and the amount of it in feed. The size in the nanosphere became small above the LCST of the corresponding macromonomer, possibly due to thermosensitive shrinking of the PNVIBA on the nanosphere surface, while transmittance of its dispersion did not change at all at studied temperature range. The nanospheres having the PNVIBA on their surfaces, which response sharply to atmospheres such as dispersion temperature, can be significant and useful materials in technological and medical fields. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2581-2587, 1998
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    Poly[(S)-(+)-2-methylbutyl]pentylsiloxane (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 169-177 
    Details
    ISSN: 0887-624X
    Keywords: polysiloxane ; hexagonal columnar mesophase ; optically active polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly[(S)-(+)-2-methylbutyl]pentylsiloxane has been synthesized by anionic ring opening polymerization of the corresponding strained cyclic trisiloxane \documentclass{article}\pagestyle{empty}\begin{document}$ (D^{\rm{MeBu, Pe}}_{3}) $\end{document} with cryptated lithium (Li+/[211]) as counterion. The polymer did not show the low and high temperature crystalline phases, that are generally found for poly(di-n-alkylsiloxane)s. Instead, the material formed a hexagonal columnar mesophase until it melted around 400°C. MAS and solution 13C- and 29Si-NMR, polarizing microscopy and WAXS indicated an unexpectedly regular chain structure. It was tentatively concluded that the steric interaction of the (S)-(+)-2-methylbutyl side chains introduces sufficient regularity of the tacticity and that the chains tend to adopt a defect helix conformation. On the other hand, DSC showed the presence of a glass transition at -113°C, indicating a high flexibility of the backbone. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 169-177, 1998
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    Novel study on the liquid crystalline behavior of poly(methacrylate)s with biphenyl side groups (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2669-2679 
    Details
    ISSN: 0887-624X
    Keywords: poly(methacrylate)s ; biphenyl ; liquid crystals ; X-ray diffraction ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report the synthesis and characterization of a series of liquid crystalline polymers substituted with the 4′-methoxybiphenyl-4-yloxy group. The spacer length is varied from 4-8 methylene units. The materials are characterized by polarized light microscopy, differential scanning calorimetry, and X-ray analysis. All homologues show highly ordered phases. Additionally, the butylene polymer shows a broad nematic mesophase. For the first time, the narrow nematic phase of the hexylene homologue could be confirmed experimentally. X-ray analysis of the polymers made exact assignments of the low temperature phases possible, thus giving access to the analysis of the arrangement of the mesogenes within the layers. The pentylene homologue shows a distinct deviation from the behavior of the other polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2669-2679, 1998
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    Synthesis of carbosilane block copolymers by means of a living anionic polymerization of 1,1-diethylsilacyclobutane (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2699-2706 
    Details
    ISSN: 0887-624X
    Keywords: poly(1,1-diethylsilabutane) ; block copolymer ; polystyrene ; poly(4-hydroxystyrene) ; poly(methyl methacrylate) ; poly(2-hydroxyethyl methacrylate) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Block polymerization of 1,1-diethylsilacyclobutane with styrene derivatives and methacrylate derivatives was investigated. Sequential addition of styrene to a living poly(1,1-diethylsilabutane), which was prepared from phenyllithium and 1,1-diethylsilacyclobutane in THF-hexane at -48°C, gave poly(1,1-diethylsilabutane)-b-polystyrene. Similarly, addition of 4-(tert-butyldimethylsiloxy)styrene to the living poly(1,1-diethylsilabutane) provided poly(1,1-diethylsilabutane)-b-poly(4-(tert-butyldimethylsiloxy)styrene). Poly(1,1-diethylsilabutane)-b-poly(methyl methacrylate) was obtained by treatment of living poly(1,1-diethylsilabutane) with 1,1-diphenylethylene followed by an addition of methyl methacrylate. Poly(1,1-diethylsilabutane)-b-poly(2-(tert-butyldimethylsiloxy)ethyl methacrylate) was also synthesized by adding 2-(tert-butyldimethylsiloxy)ethyl methacrylate to the living poly(1,1-diethylsilabutane) which was end-capped with 1,1-diphenylethylene in the presence of lithium chloride. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2699-2706, 1998
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    Ring-opening polymerization of cyclic carbonates by alcohol-acid catalyst (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2463-2471 
    Details
    ISSN: 0887-624X
    Keywords: ring-opening reaction ; ring-opening polymerization ; alcohol ; cyclic carbonate ; activated monomer mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ring-opening reactions of 1,3-dioxepan-2-one (1) and 1,3-dioxan-2-one (2) with several alcohols were examined. The reactions proceeded without trifluoroacetic acid (TFA) in low conversions, while they proceeded smoothly with TFA to afford the ring-opened adducts and oligomers. Ring-opening polymerizations of 1 and 2 were also carried out by alcohol-acid catalysts to afford the corresponding polycarbonates (Mn = 2500-6800). The molecular weights increased with increase of the conversions of 1 and 2. The observed polymerization rates of 1 and 2 were determined as 24.4 × 10-6 and 0.8 × 10-6 s-1, respectively. Mechanistic aspects were studied by NMR spectroscopy. The methylene protons α and β to the carbonate moieties shifted to lower fields in 0.06-0.11 ppm in the 1H-NMR spectra by the addition of TFA. Downfield shifts of the carbonyl carbon signals of 1 and 2 were observed in 3.94-4.15 ppm in the 13C-NMR spectra. These results strongly suggest that the cyclic carbonates are activated by TFA. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2463-2471, 1998
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    Physical properties and structure of a poly(styrene-co-butadiene) rubber/poly(acrylonitrile-co-butadiene) rubber latex mixture film (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2493-2501 
    Details
    ISSN: 0887-624X
    Keywords: latex ; poly(styrene-co-butadiene&) ; rubber (SBR) ; poly(acrylonitrile-co-butadiene&) ; rubber (NBR) ; modulus ; phase continuity ; tensile strength ; elongation at breakpoint ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The physical properties and the structure of a poly(styrene-co-butadiene) rubber (SBR) and poly(acrylonitrile-co-butadiene) rubber (NBR) latex mixture film are studied in relation to the composition of SBR/NBR for optimization as the precursor of a polymer electrolyte. The composition of SBR50/NBR50 is most suitable in terms of mechanical strength and ionic conductivity. The relationship between the mechanical strength and the structure is analyzed using a simple equivalent mechanical model modified from the Takayanagi model. Our model gives better agreement with experimental results and extends the range of validity of the model to the cocontinuous phase type morphologies. It is possible to estimate the mechanical strength from the continuity of the mechanical supporting phase, calculated from the mechanical model. The tensile properties are found to be strongly affected by the fragile component. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2493-2501, 1998
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    Synthesis and characterization of polymaleimides containing 4-cyanobiphenyl-based side groups for nonlinear optical applications (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2531-2546 
    Details
    ISSN: 0887-624X
    Keywords: side-chain liquid-crystal polymers ; thermal behavior ; phase transitions ; glass transition temperature ; functionalized polymaleimides ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new homologous series of SCLCPs containing the 4-cyanobiphenyl mesogenic group attached to the polymaleimide backbone through paraffinic spacers of two to eight methylene units have been prepared. All the polymers exhibit liquid crystalline behavior; specifically SAd- (or SC-) like and nematic phases are observed. The glass transition temperature decreases from 150 to 43°C on increasing spacer length. The isotropization temperatures exhibit an odd-even effect on varying the length and parity of the spacer, in which the odd members exhibit the higher values. This is attributed to the change in the average shape of the side chain as the parity of spacer is varied. The isotropization temperatures (〉300-120°C) and the mesophase thermal stabilities (190-60°C) are high. Comparison is made with polymers containing the same mesogenic group attached to backbones of decreasing rigidity. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2531-2546, 1998
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    Synthesis and characterization of polysilabutane having oligo(oxyethylene)phenyl groups on the silicon atom (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 225-231 
    Details
    ISSN: 0887-624X
    Keywords: silacyclobutane ; polysilabutane ; oligooxyethylene ; polycarbosilane ; anionic polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new class of polar polysilabutanes with mono- or tri-(oxyethylene)phenyl groups on the silicon atom have been synthesized by anionic polymerization of silacyclobutanes having ω-(t-butyldimethylsilyl-protected) mono- or tri-(oxyethylene)phenyl groups and subsequent deprotection of the silyl groups. The monomers were synthesized by treatment of 1,1-dichlorosilacyclobutane with ω-(t-butyldimethylsilyl-protected) mono- or tri-(oxyethylene)phenyl Grignard reagents. Anionic polymerization of silacyclobutane was performed with butyllithium initiator in THF. t-Butyldimethylsilyl-protecting groups at polymer pendant groups were hydrolyzed with tetrabutyl ammonium fluoride in water-containing THF. The obtained polysilabutanes were soluble in a polar organic solvent such as methanol, and their mass distributions were analysed by matrix-assisted laser-desorption-ionization mass spectrometry (MALDI TOF MS). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 225-231, 1998
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    Model block-graft copolymer via anionic living polymerization: Preparation and characterization of polystyrene-block-[poly(p-hydroxystyrene)-graft-poly(ethylene oxide)]-block-polystyrene (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 3021-3034 
    Details
    ISSN: 0887-624X
    Keywords: block-graft copolymer ; grafting from process ; macromolecular initiator ; anionic polymerization ; poly(p-hydroxystyrene) ; poly(styrene) ; poly(ethylene oxide) ; poly(p-tert-butoxystyrene) ; molecular characterization ; microphase-separated structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A model graft copolymer in which position of graft points was set to the center of a backbone molecule was prepared via anionic living polymerization. Polystyrene-block-poly(p-tert-butoxystyrene)-block-polystyrene (PSt-b-PBSt-b-PSt) was prepared by three-stage sequential addition. The tert-butyl group was removed from PBSt by hydrogen bromide to yield PSt-b-PHSt-b-PSt, having a poly(p-hydroxystyrene) (PHSt) block. The hydroxyl group of PHSt was reacted with dimeric potassium dianions of 1, 1-diphenylethylene (DPE-K) or cumyl potassium (cumyl K) to yield the corresponding macromolecular initiators of PSt-b-PHSt-K+-b-PSt containing the potassium alkoxide ion of PHSt. The newly formed alkoxide groups and remaining initiators of DPE-K or cumyl K are capable of initiating the additionally introduced ethylene oxide (EO). Thus, two block-graft copolymers of polystyrene-block-[poly(p-hydroxystyrene)-graft-poly(ethylene oxide)]-block-polystyrene (PSt-b-(PHSt-g-PEO)-b-PSt) were prepared by a “grafting from” process (backbone initiation). A PSt-b-PHSt-b-PSt backbone (Mn = 1.75 × 105 by osmometry and Mw/Mn = 1.08 by GPC), and two PSt-b-(PHSt-g-PEO)-b-PSt block-graft copolymers (Mn = 2.45 × 105 by osmometry and Mw/Mn 〈 1.10 by GPC) had narrow molecular weight distributions. A relationship between nonquantitative metallation and spacing of the graft points on a backbone molecule was discussed in detail. Two benzene-cast films formed clear microphase-separated structures of lamellar structure. The dependence of composition on the morphology of the block-graft copolymers was found to differ from that of common block copolymers. A degree of crystallinity of PEO segment and lamellar thickness of PEO phase serving as graft molecule were also found to differ from those of homo PEO and/or PEO segment in common block copolymer. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3021-3034, 1998
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    Effect of TPA addition at the initial feed on DEG formation in the preparation of PET and the kinetics of ethylene glycol with protons in the etherification reaction (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 3081-3087 
    Details
    ISSN: 0887-624X
    Keywords: TPA ; mol ratio ; DEG ; kinetics ; protons ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This research focused on studies of the effect of terephthalic acid (TPA) addition at the initial feed on diethylene glycol formation (DEG) in the process of polyethylene terephthalate (PET) preparation. Experimental results show that, when the mol ratio of ethylene glycol (EG) with TPA ranges from 1.0 to 1.3, the greater the amount of TPA added at the initial feed, the more DEG formed, and the greater the suppression of the rate of esterification and polymerization. In addition, the kinetics of EG with protons in the etherification reaction was considered in the study. It is found that, during the etherification reaction, the reactivity of hydroxyl end groups with ether bonds is higher than that of hydroxyl end groups on their own, and the activation energy of EG with protons is much lower than that of pure EG on its own. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3081-3087, 1998
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    Polymer grafting onto carbon black by use of TEMPO-terminated polystyrene with controlled molecular weight (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 3165-3172 
    Details
    ISSN: 0887-624X
    Keywords: carbon black ; surface grafting of polymer ; living radical polymerization ; TEMPO-terminated polystyrene ; radical trap ; dispersibility ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The grafting of polystyrene with controlled molecular weight and narrow molecular weight distribution onto the carbon black surface through the trapping of polymer radicals formed by the thermal dissociation of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-terminated polystyrene (PSt-TEMPO) by the carbon black surface was investigated. PSt-TEMPO was prepared by living radical polymerization of St with the benzoyl peroxide/TEMPO system. When PSt having no terminal TEMPO moiety was heated with carbon black, no grafting of PSt onto the surface was observed. On the contrary, by the heating of PSt-TEMPO with carbon black in m-xylene at 125°C, PSt with controlled molecular weight and narrow molecular weight distribution was grafted onto the surface: the percentage grafting of PSt (Mn = 3.2 × 103;Mw/Mn = 1.07) onto furnace black was determined to be 16.0%. On the basis of the above results, it is concluded that PSt radicals formed by the thermal dissociation of the C—ON bond between PSt and TEMPO are trapped by polycondensed aromatic rings of carbon black. The mole number of grafted PSt chains on the carbon black surface decreased with increasing molecular weight of PSt-TEMPO. PSt-grafted carbon black gave a stable colloidal dispersion in THF. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3165-3172, 1998
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    Syntheses and antitumor activities of medium molecular weight polymers containing 5-fluorouracil (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2985-2992 
    Details
    ISSN: 0887-624X
    Keywords: α-ethoxy-3,6-endo-methylene-1,2,3,6-tetrahydrophthaloyl-5-fluorouracil (EMTFU) ; 5-fluorouracil (5-FU) ; poly(EMTFU) ; poly(EMTFU-co-AA) ; poly(EMTFU-co-VAc) ; average molecular weights ; in vitro cytotoxicities ; in vivo antitumor activity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The new monomer α-ethoxy-3,6-endo-methylene-1,2,3,6-tetrahydrophthaloyl-5-fluorouracil (EMTFU) was synthesized from 5-fluorouracil (5-FU) and α-ethoxy-3,6-endo-methylene-1,2,3,6-tetrahydrophthaloyl chloride (EMTC). Poly(α-ethoxy-3,6-endomethylene-1,2,3,6-tetrahydrophthaloyl-5-fluorouracil) [poly(EMTFU)], poly(α-ethoxy-3,6-endo-methylene-1,2,3,6-tetrahydrophthaloyl-5-fluorouracil-co-acrylic acid) [poly(EMTFU-co-AA)], and poly(α-ethoxy-3,6-endomethylene-1,2,3,6-tetrahydrophthaloyl-5-fluorouracil-co-vinyl acetate) [poly(EMTFU-co-VAc)] were synthesized by photopolymerizations using 2,2-dimethoxy-2-phenylacetophenone (DMP) as the photoinitiator. The synthesized EMTFU and its polymers were identified by Fourier transfer infrared (FT-IR), 1H nuclear magnetic resonance (NMR), and 13C-NMR spectroscopies. The contents of EMTFU in poly(EMTFU-co-AA) and poly(EMTFU-co-VAc) determined by elemental analysis were 46 and 70 mol %, respectively. The number average molecular weights of the synthesized polymers determined by gel permeation chromatography (GPC) were in range of 17,200-20,900. The in vitro cytotoxicities of samples were evaluated with mouse mammary carcinoma (FM3A), mouse leukemia (P388), and human histiocytic lymphoma (U937) as cancer cell lines and AC2F as a normal cell line. The cytotoxicities of 5-FU and synthesized samples against cancer cell lines increased in following orders: 5-FU ≈ EMTFU 〉 poly(EMTFU-co-AA) 〉 poly(EMTFU) 〉 poly(EMTFU-co-VAc). The in vivo antitumor activities of the synthesized samples against mice bearing the sarcoma 180 tumor cell line were evaluated. The in vivo antitumor activities of EMTFU and its polymers were greater than those of 5-FU at a dosage of 80 mg/kg. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2985-2992, 1998
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    Preparation and thermal properties of thermoplastic poly(vinyl alcohol) complexes with boronic acids (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 3045-3050 
    Details
    ISSN: 0887-624X
    Keywords: poly(vinyl alcohol) ; n-butyl boronic acid ; phenyl boronic acid ; complex ; melting temperature ; spinnability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(vinyl alcohol) (PVA) was converted into melt flowable derivatives by complexation with a small amount of n-butyl boronic acid (BBA) and phenyl boronic acid (PBA) in dimethylsulfoxide (DMSO), and their thermal properties were examined from a viewpoint of the melt spinning of the complexes. It was found that (1) the melting temperature of the PVA-boronic acid complexes decreases and their degradation temperature increases with increasing the boronic acid content; (2) no gelation occurs for the PVA complexes with BBA and PBA in DMSO; (3) PBA gives a larger melting-temperature depression for PVA than BBA, but the spinnability of the complexes with BBA is much better than that with PBA; and (4) the melt-molded PVA complex fibers can be easily regenerated into PVA fibers with hot water. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3045-3050, 1998
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    Crosslinkable fluorinated poly(arylene ethers) bearing phenyl ethynyl moiety for low-loss polymer optical waveguide devices (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2881-2887 
    Details
    ISSN: 0887-624X
    Keywords: fluorinated poly(arylene ether) ; phenyl ethynyl ; polymer optical waveguide ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Crosslinkable fluorinated poly(arylene ethers) (FPAE-Fn-PEP) with high transparency and high thermal stability have been investigated for low-loss optical waveguide materials. FPAE-Fn-PEP bearing phenyl ethynyl moiety at the polymer chain end were synthesized by the reaction of 4,4′-(hexafluoro-isopropylidene)diphenol with an excess decafluorobiphenyl, followed by the reaction of 4-phenyl ethynyl phenol. The Mns and Mw/Mns of the polymers determined by GPC with polystyrene standard were in the range of 6200 to 19,400 and 1.4 to 2.04, respectively. The resulting polymers were thermally crosslinked at 320°C for 2 h. The cured polymers show good chemical resistance and high thermal stability up to 510°C under nitrogen. The refractive indices of their films were controlled between 1.495 and 1.530 at 1.55 μm by adjusting molecular weight. A single-mode channel waveguide made of FPAE-F20-PEP was fabricated by conventional photolithography and O2 reactive ion etching (RIE). The propagation loss of the channel waveguide was measured and found to be less than 0.2 dB/cm at 1.55 μm. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2881-2887, 1998
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    Synthesis of polymers with pendant hydroxyl groups by polyaddition of bis(oxetane)s with dithiols (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2873-2880 
    Details
    ISSN: 0887-624X
    Keywords: polyaddition ; bis(oxetane) ; aromatic dithiol ; catalyst ; quaternary onium salt ; crown ether complex ; new reactive polymer ; pendant primary hydroxyl group ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Addition reaction of (3-methyl-3-oxetanyl)methyl acetate (MOMA) with bis(4-mercaptophenyl) sulfide (BMPS) was examined in certain organic solvents. When the reaction of MOMA with BMPS was performed without any catalyst in hexamethylphosphoric triamide (HMPA) and N-methyl-2-pyrrolidone (NMP) at 130°C for 24 h, conversions of the corresponding adduct were 96 and 36%, respectively, which was confirmed by 1H-NMR spectra. On the other hand, when the reaction was carried out using tetraphenylphosphonium bromide (TPPB) as a catalyst under the same conditions, conversions of the adduct were 96 and 81% in HMPA and NMP, respectively. This result shows that although the addition reaction of oxetane compound with aromatic dithiol proceeds without any catalyst in HMPA, the reaction was strongly enhanced by adding TPPB in NMP. On the basis of the above results, polyadditions of bis((3-methyl-3-oxetanyl)methyl) terephthalate (BMOT) and bis((3-ethyl-3-oxetanyl)methyl) terephthalate with BMPS were performed using TPPB as the catalyst in NMP at 130°C for 24 h. As a result, the corresponding high molecular weight polymers 1 (Mn = 22,400) and 2 (Mn = 12,800) with pendant primary hydroxyl groups were obtained in 83 and 89% yields without any gel products, respectively. Furthermore, a low molecular weight oligomer was obtained from the polyaddition of BMOT with aliphatic dithiol, bis(mercaptomethyl)benzene, under the same reaction conditions. The catalytic activity on the polyaddition of BMOT with BMPS was also examined, and it was found that thermally stable TPPB and crown ether complexes at the reaction temperature (130°C) have higher catalytic activity than tetrabutylammonium bromide and tetrabutylphosphonium bromide to produce polymer 1 with high molecular weight. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2873-2880, 1998
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    Polyketomalonate by catalytic oxidation of glycerol over a CeBiPt catalyst. II (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2995-2995 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: No abstract.
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    Nanoparticles from vesicles polymerization. II. Evaluation of their encapsulation capacity (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 3035-3043 
    Details
    ISSN: 0887-624X
    Keywords: nanoencapsulation ; tyrosine ; dyes ; poly(isodecyl acrylate) ; nanoparticles ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of isodecyl acrylate (ISODAC) in vesicles of sodium di-2-ethylhexyl phosphate (SEHP) loaded with dyes or tyrosine was achieved. The study of the polymerization rate-conversion curve of the monomer confirmed that this polymerization was different from other polymerizations known, as it was proposed previously. Then the entrapment of hydrophilic molecules such as tyrosine or brilliant cresyl blue and lipophilic molecules such as sudan III into the nanoparticles was evaluated and confirmed by different methods. While tyrosine was not retained, brilliant cresyl blue and sudan III were entrapped inside nanoparticles. The size and the polarity of the molecules to be encapsulated, which are related to their diffusion coefficients and partition coefficients between water and the nanoparticle, seem to be the parameters responsible of the entrapment. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3035-3043, 1998
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    Analysis of microstructure of ethylene-1-hexene copolymer prepared over thermally pretreated MgCl2/THF/TiCl4bimetallic catalyst (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 291-300 
    Details
    ISSN: 0887-624X
    Keywords: olefin polymerization ; temperature rising elution fractionation ; ethylene-1-hexene copolymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermally pretreated catalysts were prepared by heating MgCl2/THF/TiCl4 (TT-0) at 80°C for 5 min (TT-1) and 60 min (TT-2), and at 108°C for 5 min (TT-3) and 60 min (TT-4). Ethylene-1-hexene copolymers were prepared with these catalysts. The TT-1 catalyst produced more blocky and higher 1-hexene content polymer than TT-0, 2, 3, and 4. Temperature rising elution fractionation (TREF) analysis was used to investigate the chemical composition distribution of the ethylene-1-hexene copolymer, exhibiting bimodal distribution for TT-0 and trimodal for TT-1, 2, 3, and 4. A portion of higher hexene content of the copolymer markedly increased when the copolymerization was performed with TT-1, indicating that copolymerization active sites were newly generated. Portion of homopolyethylene increased drastically when the copolymerization was performed with TT-4, indicating that ethylene homopolymerization active sites were increased. Gel permeation chromatography (GPC) also revealed that three kinds of active sites existed on the catalyst. 13C-NMR spectrum of each fraction after TREF analysis suggested that the isospecific active site could polymerize 1-hexene well, resulting in random and alternating copolymers. A scheme for generation of the active site and change of its nature during thermal treatment of bimetallic complex catalyst is proposed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 291-300, 1998
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    Synthesis of polyurethane from cashew nut shell liquid (CNSL), a renewable resource (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 391-400 
    Details
    ISSN: 0887-624X
    Keywords: cardanol ; polyurethane ; thermoplastic polyurethane ; differential scanning calorimetry ; dynamic mechanical thermal analyzer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel thermoplastic polyurethane was prepared from cardanol, a renewable resource and a waste of the cashew industry. Cardanol was recovered from cashew nut shell liquid (CNSL) by double vacuum distillation. It was characterized by CHN analysis and IR, 1H-NMR, and 13C-NMR spectroscopy techniques. Cardanol is a meta-substituted long chain phenol. The long aliphatic chain unit substituent was found to be a monoene. The monomer, 4-[(4-hydroxy-2-pentadecenylphenyl)diazenyl]phenol was prepared from cardanol. It was a dihydroxy compound as characterized by CHN analyzer, UV, and 1H-NMR spectroscopy. The polyurethane was synthesized from this dihydroxy compound by the treatment with 4,4′-diphenylmethane diisocyanate (MDI) in dimethylformamide (DMF) solvent at 80-90°C under nitrogen atmosphere. The polymer was characterized by 1H-NMR, FTIR, and UV spectroscopy. The elemental analysis was done for determining the percentage content of C, H, and N, and the intrinsic viscosity [η] of polymer showed 1.85 dL/gm. Thermogravimetric investigations (TGA) of the cardanol, the dihydroxy compound, and the polyurethane were performed to study their decomposition. The semicrystalline nature of the PU was confirmed by differential scanning calorimetry (DSC) and dynamic mechanical thermal analyzer (DMTA). The wide-angle X-ray diffraction (WAXS) study of PU shew a broad amorphous halo indicative of absence of crystallinity in the polymer, which has been explained as due to strong hydrogen bonding in the hard phase. PU may possibly be useful as a telecommunication and as a nonlinear optical material. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 391-400, 1998
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    Synthesis and characterization of liquid crystalline copolyester of 4-hydroxy-2,3,5,6-tetrafluorobenzoic acid with 6-hydroxy-2-naphthoic acid (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 413-419 
    Details
    ISSN: 0887-624X
    Keywords: liquid crystalline polymer ; polyarylates ; 4-hydroxy-2,3,5,6-tetrafluorobenzoic acid ; 6-hydroxy-2-naphthoic acid ; fine structure ; thermal property ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4-Hydroxy-2,3,5,6-tetrafluorobenzoic acid/6-hydroxy-2-naphthoic acid copolymers (FHBA/HNA copolymer) with different copolymer compositions were prepared and the influence of FHBA residue on the thermal properties and structures of the copolymers were investigated. Introduction of FHBA decreased the crystal/nematic phase transition temperatures(TCNs) of the FHBA/HNA copolymers. TCNs of the copolymers were in the temperature range between 200 and 250°C, depending on the copolymer composition. They are approximately 40°C lower than those of 4-hydroxybenzoic acid/HNA copolymers. FHBA/HNA copolymers exhibited low crystallinity, and annealing treatment hardly influenced the crystalline natures. FHBA residue possibly interferes with the recrystallization during annealing. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 413-419, 1998
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    Preparation and characterization of fluorine-containing aromatic condensation polymers. VI. Aromatic polybenzothiazoles from 4,4′-(hexafluoroisopropylidene)dibenzoic acid and tetrafluoroterephthalic acid and 2,5-diamino-1,4-benzenedithiol dihydrochloride (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 429-435 
    Details
    ISSN: 0887-624X
    Keywords: fluorine-containing polymers ; aromatic polybenzothiazoles ; 4,4′-(hexafluoroisopropylidene)dibenzoic acid ; tetrafluoroterephthalic acid ; 2,5-diamino-1,4-benzenedithiol ; direct polycondensation ; phosphorus pentoxide/methanesulfonic acid ; polyphosphoric acid ; high-temperature soluble polymers ; liquid crystalline polymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two fluorine-containing aromatic polybenzothiazoles were synthesized by direct polycondensation of 4,4′-(hexafluoroisopropylidene)dibenzoic acid and tetrafluoroterephthalic acid with 2,5-diamino-1,4-benzenedithiol dihydrochloride using phosphorus pentoxide/methanesulfonic acid or polyphosphoric acid as both condensing agent and solvent. The effect of introduction of fluorine atom on the synthesis and properties of these polymers was discussed in detail. The perfluoroisopropylidene unit-containing polybenzothiazole was amorphous, and showed good solubility in organic solvents, excellent mechanical properties, and high thermal stability. The perfluoro-p-phenylene unit-containing polybenzothiazole was crystalline, and exhibited lyotropic behavior in concentrated sulfuric acid. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 429-435, 1998
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  • 288
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    Application of solid-state NMR (13C and 29Si CP/MAS NMR) spectroscopy to the characterization of alkenyltrialkoxysilane and trialkoxysilyl-terminated polyisoprene grafting onto silica microparticles (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 437-453 
    Details
    ISSN: 0887-624X
    Keywords: functionalized silica ; functional polyisoprene ; grafting onto silica ; polyisoprene-grafted silica ; alkenyl-bonded silica ; 13C and 29Si CP/MAS NMR ; grafting characterization ; surface characterization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The solid-state Nuclear Magnetic Resonance (NMR) was used to characterize surfaces of silica gels chemically modified by alkenyltrialkoxysilanes and trialkoxysilyl terminated 1,4-polyisoprenes. The formation of covalent bonds created between alkoxy functional groups from alkenyltrialkoxysilane or trialkoxysilyl-terminated 1,4-polyisoprene and silanol groups on silica was clearly demonstrated by means of 13C and 29Si CP/MAS NMR spectroscopy. Quantitative data, including calculation of the grafting yields in relation with the initial silanol concentrations, were also obtained by using solid-state 29Si-NMR leading to a final well-defined characterization of the silica surfaces. A relatively good agreement was noticed between the grafting yields calculated from 29Si-NMR spectra and those determined from other analytical techniques such as Wijs titration or elementary analysis. The reactivity of the various silica silanols towards each coupling agent was clearly characterized and estimated, as were the proportions of the various grafted structures formed at the silica surface. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 437-453, 1998
    Additional Material: 6 Ill.
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  • 289
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    A study of the thermal cure of a phenylethynyl-terminated imide model compound and a phenylethynyl-terminated imide oligomer (PETI-5) (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 461-470 
    Details
    ISSN: 0887-624X
    Keywords: kinetics ; polyimides ; thermal cure ; infrared spectroscopy ; DSC ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetic mechanism of the thermal cure of a phenylethynyl-terminated imide model compound, 3,4′-bis[(4-phenylethynyl)phthalimido]diphenyl ether (PEPA-3,4′-ODA) and a phenylethynyl-terminated imide oligomer PETI-5 (MW 5000 g/mol) was studied. FTIR was used to follow the cure of the model compound, while thermal analyses (DSC) was used to follow the cure of the PETI-5 oligomer. The changes in IR absorbance of phenylethynyl triple bonds at 2214 cm-1 of PEPA-3,4′-ODA as a function of cure time were detected at 318, 336, 355, and 373°C, respectively. The changes in the glass transition temperature, Tg, of PETI-5 as a function of time were measured at 350, 360, 370, 380, and 390°C, respectively. The DiBenedetto equation was applied to define the relative extent of cure, x, of the PETI-5 oligomer by Tg. For the model compound, the reaction followed first order kinetics, yielding an activation energy of 40.7 kcal/mol as determined by infrared spectroscopy. For PETI-5, the reaction followed 1.5th order, yielding an activation energy of 33.8 kcal/mol for the whole cure reaction, as determined by Tg using the DiBenedetto method. However, the cure process of PETI-5 just below 90% by this method followed first-order kinetics yielding an activation energy of 37.2 kcal/mol. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 461-470, 1998
    Additional Material: 13 Ill.
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  • 290
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    Synthesis and properties of polyimides from thianthrene-2,3,7,8-tetracarboxylic dianhydride-5,5,10,10-tetraoxide (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 485-494 
    Details
    ISSN: 0887-624X
    Keywords: thianthrene-tetraoxide ; polyimide ; synthesis ; membrane ; CO2 gas separation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thianthrene - 2,3,7,8 - tetracarboxylic dianhydride - 5,5,10,10 - tetraoxide (TADATO), a dianhydride having two sulfonyls between two phenyl rings, was synthesized and polymerized with several diamines by a two-step method. Tough polyimide membranes were obtained with flexible diamines but not with rigid diamines. Most of TADATO-based polyimides are soluble in polar solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone. IR study confirmed that almost complete imidization of TADATO-based poly(amic acid) membranes could be achieved by thermal treatment at 100, 200, and 300°C for each 1 h. In a series of polyimides based on 4,4′-oxydianiline, the polyimide from TADATO showed higher gas permeability coefficient of CO2 and higher selectivities of CO2/N2 and CO2/CH4 than those of polyimides from pyromellitic dianhydride and 3,3′,4,4′-biphenyltetracarboxylic dianhydride, and was comparable to that from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 485-494, 1998
    Additional Material: 6 Ill.
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  • 291
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    Immobilization of α-chymotrypsin in thermally reversible isopropylacrylamide-hydroxyethylmethacrylate copolymer gel (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 543-552 
    Details
    ISSN: 0887-624X
    Keywords: isopropylacrylamide ; hydroxyethylmethacrylate ; chymotrypsin ; thermoresponsive gels ; enzyme immobilization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this study, α-chymotrypsin was immobilized via physical entrapment within thermally reversible poly(isopropylacrylamide-co-hydroxyethylmethacrylate), poly(NIPAM-co-HEMA) copolymer gels. The thermoresponsive gel matrices in cylindrical geometry were prepared in an aqueous buffer medium by a redox polymerization method. The kinetic behavior of enzyme-gel cylinders was investigated in a batch reactor. The results indicated that the overall reaction rate was controlled by the substrate diffusion through the gel matrix. Due to the thermoresponsive character of the carrier gel, the maximum activity was achieved at 30°C with the enzyme-gel system while the free enzyme exhibited maximum activity at 40°C. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 543-552, 1998
    Additional Material: 12 Ill.
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  • 292
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    A novel route to poly(2-hydroxyethyl methacrylate) and its amphiphilic block copolymers (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 1865-1872 
    Details
    ISSN: 0887-624X
    Keywords: anionic polymerization ; poly(2-hydroxyethyl methacrylate) ; amphiphilic block copolymer ; poly(methyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) ; poly(styrene)-b-poly(2-hydroxyethyl methacrylate) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The vinyl of the ester group of 2-vinyloxyethyl methacrylate was first selectively reacted with acetic acid to obtain 2-[1-(acetoxy)ethoxy]ethyl methacrylate (2). This protected monomer was subjected to anionic polymerization in tetrahydrofuran at -60°C in the presence of LiCl, using 1,1-diphenylhexyllithium as initiator. The molecular weight of the polymer could thus be controlled and a narrow molecular weight distribution obtained. The protecting group, 1-(acetoxy)ethyl, could be easily eliminated (by quenching the polymerization reaction with methanol and water) to generate poly(2-hydroxyethyl methacrylate) (poly(HEMA)). Block copolymers were also prepared by the sequential anionic polymerization of MMA and 2 or styrene and 2. They possess narrow molecular weight distributions, and controlled molecular weights and compositions. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1865-1872, 1998
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  • 293
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    Atactic polymerization of propylene catalyzed by mono(η5-cyclopentadienyl)titanium tribenzyloxide combined with methylaluminoxane (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2051-2057 
    Details
    ISSN: 0887-624X
    Keywords: propylene polymerization ; metallocene catalyst ; methylaluminoxane ; atactic polypropylene ; regioselectivity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Propylene has been polymerized with mono(η5-cyclopentadienyl)titanium tribenzyloxide activated with methylaluminoxane (MAO). It was found that the content of residual trimethylaluminium (TMA) in MAO has a determinative effect on the polymerization. An excess of TMA in the catalyst system reduces the Ti species to inactive lower valent states. The catalyst system gives medium molecular-weight atactic polypropylene (Mv = 2-7 × 104) with narrow molecular weight distribution (Mw/Mn = 1.4-1.8). The polymer has a stereoirregular structure described by Bernoullian statistics. Statistical analysis of the regiotriad distribution of the polypropylene chains indicates a regioblock microstructure. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2051-2057, 1998
    Additional Material: 4 Ill.
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  • 294
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    Kinetic model-based experimental design of the polymerization conditions in suspension copolymerization of styrene/divinylbenzene (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2081-2094 
    Details
    ISSN: 0887-624X
    Keywords: copolymerization ; crosslinking ; polystyrene-divinylbenzene ; experimental designs ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The use of a mechanistic model-based experimental design technique to determine the polymerization conditions and polymer properties in suspension copolymerization of styrene and divinylbenzene is reported. The technique consists of using a mathematical model to design the polymerization conditions of a copolymer with characteristics specified beforehand. The properties (conversion, gel content, molecular weight averages, and copolymer composition) of the copolymer synthesized using this approach agree very well with the calculated properties for the pregelation period, but accurate prediction of properties during the postgelation period is still uncertain. It is demonstrated that the use of mechanistic modeling for experimental design purposes can be more adequate (when the model is sound, yet simple to solve) than other design techniques (e.g., factorial designs). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2081-2094, 1998
    Additional Material: 9 Ill.
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    Synthesis of divinylbenzene-maleic anhydride microspheres using precipitation polymerization (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2223-2227 
    Details
    ISSN: 0887-624X
    Keywords: divinylbenzene ; maleic anhydride ; microspheres ; copolymer particles ; precipitation polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Narrow disperse micron-range divinylbenzene-maleic anhydride microspheres have been prepared in near quantitative yields using precipitation polymerization. A variety of solvents were investigated for use as the reaction medium with a 40:60 mixture of methyl ethyl ketone and heptane providing the best results. The effects of solvent composition on particle size and morphology and monomer loading effects were also investigated. Particle size decreased with increasing solvency (increasing MEK fraction) while increases in monomer loading caused larger particle sizes. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2223-2227, 1998
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  • 296
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    Polymerizations of butadiene, isoprene, and 2,3-dimethylbutadiene by Gd(OCOCCl3)3-(i-Bu)3Al-Et2AlCl and the cis polymerization mechanism for dienes (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2283-2290 
    Details
    ISSN: 0887-624X
    Keywords: Ziegler type catalyst ; Gd(OCOCCl3)3 catalyst ; polymerization of dienes ; cis-1,4 polymerization mechanism ; back-biting coordination ; MO calculation of σ-allylnickel complex ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Homopolymerizations of butadiene (BD), isoprene (IP), and 2,3-dimethylbutadiene (DMBD) were carried out by a Gd(OCOCCl3)3-based catalyst, to investigate the effects of the energy levels of the monomers or the sterical factor of the methyl substituents on the polymerizability and the cis-selectivity of the monomers. The order of the polymerizability at 50°C was as follows: BD (4.5 kg of polymer/(mol of Gd h)) ∼ IP (4.8) 〉 DMBD (0.6). On the other hand, the cis-selectivity of the polymers was as follows: BD (98%) 〉 IP (94%) 〉 DMBD (35%). These results suggest that the terminal BD and IP units are controlled by the cis configuration by the coordination between the penultimate cis-vinylene unit and the catalyst metal, whereas the penultimate DMBD unit unfavorably controls the terminal DMBD unit to the cis-1,4 configuration through the back-biting coordination with difficulty by two methyl substituents compared with the penultimate BD and IP units. The validity of the back-biting coordination was examined by MO calculation with σ-allylnickel complexes. According to the formation energy with respect to the BD-BD diad, the cis-cis form is somewhat preferable to the trans-cis form through the coordination of the penultimate BD unit by ΔE = 0.028 au (ca. 17.6 kcal/mol). © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2283-2290, 1998
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  • 297
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    Synthesis of ordered polymer by direct polycondensation. VIII. Ordered polymer from two nonsymmetric monomers (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2309-2314 
    Details
    ISSN: 0887-624X
    Keywords: direct polycondensation ; ordered polymer ; polyamide ; condensing agent ; steric effect ; nonsymmetric monomer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The ordered (-aacdbbdc-) polymer was prepared by the direct polycondensation of a pair of symmetric monomers (XabX), 4,4′-(oxydi-p-phenylene)dibutanoic acid (XaaX) and 2-methoxyisophthalic acid (XbbX), with a nonsymmetric monomer (YcdY), 4-aminobenzhydrazide, using the condensing agent diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (1). The polymerization was carried out by a one-pot procedure, that is, mixing the dicarboxylic acids, condensing agent 1 and triethylamine in NMP for 2 h at room temperature, followed by the addition of 4-aminobenzhydrazide. This polymerization proceeded smoothly, yielding the ordered polymer with an inherent viscosity of 0.34 dL g-1. The microstructure of the ordered polymer was confirmed by comparing the authentic ordered polymer in their 13C-NMR spectrum. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2309-2314, 1998
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  • 298
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    Polyesters containing sulfur. VI. Synthesis and characterization of polyesters from naphthalene-1,4- or naphthalene-1,5-bis(methylthioacetic acid) and aliphatic diols (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2359-2369 
    Details
    ISSN: 0887-624X
    Keywords: linear polyesters containing sulfur ; melt polycondensation ; kinetic parameter ; thermoplastic polyurethane elastomers ; melt polyaddition ; physicochemical and tensile properties ; thermal behavior ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two series of new linear polyesters containing sulfur in the main chain were obtained by melt polycondensation of naphthalene-1,4-bis(methylthioacetic acid) (N-1,4-BMTAA) or naphthalene-1,5-bis(methylthioacetic acid) (N-1,5-BMTAA) with some aliphatic diols using a 0.05 molar excess of diol. Softening temperatures ranging from 55 to 130°C, reduced viscosities in the range of 0.15-0.39 dL/g, and low-molecular weights were their characteristic. The structure and thermal properties of all polyesters were examined by using elemental analysis, FT-IR and 1H-NMR spectroscopy, X-ray diffraction analysis, differential thermal analysis (DTA), thermogravimetric analysis (TGA), and differential scanning calorymetry (DSC). The kinetics of polyester formation by uncatalyzed melt polycondensation was studied in a model system: N-1,4-BMTAA or N-1,5-BMTAA and 2,2′-oxydiethanol (ODE) at 150, 160, and 170°C. Reaction rate constants (k3) and activation parameters (ΔG
    Additional Material: 9 Ill.
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  • 299
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    Studies on metathetical and thermal polymerization of 5-norbornene 2,3-dicarboximide end-capped resins pt-II (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2427-2427 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 300
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    Synthesis and characterization of side-chain liquid-crystalline poly(ether ester)s having p-substituted biphenyl mesogenic side groups (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2439-2455 
    Details
    ISSN: 0887-624X
    Keywords: spiro-orthoester monomers ; poly(ether ester)s ; cationic ring-opening polymerization ; side-chain liquid-crystalline polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several novel mesogenic spiro-orthoester monomers such as 1,6,10-trioxaspiro[4,5]decanes 4, containing biphenyl mesogens at the C-8 positions of the five- and six-membered spirocyclic ring, through the alkylene spacers of different lengths were prepared by condensation reaction of the corresponding biphenyl mesogenic 1,3-propanediol 3 with 2,2-diethoxytetrahydrofuran, with 50-75% yields. Through cationic double ring-opening polymerization, carried out with boron trifluoride etherate as an initiator (5 mol % vs. monomer) in bulk at 150°C, spiro-orthoester monomers 4 afforded a novel class of side-chain thermotropic LC polymers with a poly(ether ester) as the main chain 8. The liquid-crystalline properties of the spiro-orthoester monomers and the resulting polymers were examined by differential scanning calorimetry and optical polarized microscopy. Biphase separation was observed in the side-chain liquid-crystalline poly(ether ester)s upon annealing in the broad isotropic region. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2439-2455, 1998
    Additional Material: 20 Ill.
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