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  • 1990-1994  (21,194)
  • 1960-1964  (6,215)
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  • Polymer and Materials Science  (27,409)
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  • 101
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 435-444 
    ISSN: 0887-624X
    Keywords: poly(amide-imide)s ; direct polycondensation ; 2,3-bis (4-aminophenoxy) naphthalene ; 2,3-bis (4-trimellitimidophenoxy) naphthalene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The new polymer-forming diimide-diacid, 2,3-bis(4-trimellitimidophenoxy) naphthalene (I), was readily obtained by the condensation reaction of 2,3-bis (4-aminophenoxy) naphthalene with trimellitic anhydride. A series of novel aromatic poly (amide-imide)s were prepared by the direct polycondensation of diimide-diacid I with various aromatic diamines using triphenyl phosphite in N-methyl-2-pyrrolidone (NMP)/pyridine solution containing dissolved calcium chloride. The resultant polymers have inherent viscosities in the range of 0.65-1.02 dL/g at 30°C in N, N-dimethylacetamide. These polymers were readily soluble in various organic solvents and could be cast into transparent, tough, and flexible films. Their casting films showed tensile strength at break up to 86 MPa, elongation to break of 5-9%, and initial moduli up to 2.35 GPa. The wide-angle X-ray diffraction revealed that those polymers containing p-phenylene or p-oxyphenylene group are partially crystalline, and the other polymers are evidenced as amorphous patterns. These polymers show a glass transition in the range of 213-290°C in their differential scanning calorimetry (DSC) traces. The thermal stability of the polymers was evaluated by thermogravimetry analysis, which showed the 10% weight-loss temperatures in the range of 508-565°C in nitrogen and 480-529°C in air atmosphere. © 1994 John Wiley & Sons, Inc.
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  • 102
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 33-38 
    ISSN: 0887-624X
    Keywords: electrical conductivity ; poly (vinyl chloride) ; photo-dehydrochlorination ; composite film ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polypyrrole (PPy) was deposited electrochemically on a platinum plate from a nitric acid solution of pyrrole. The PVC/PPy composite film was finally obtained by casting poly(vinyl chloride) (PVC) onto the PPy electrode from a tetrahydrofuran solution of PVC. The prepared composite film was irradiated at 90°C with a low-pressure mercury lamp in the stream of hydrogen gas saturated with steam, and the PVC film was dehydrochlorinated, leading to the formation of conjugated polyene. The electrical conductivity (σ) of the PVC film in the irradiated composite film was reveled: σ=2.51 × 10-5S cm-1. By iodine doping, σ was further enhanced up to 5.04 X 10-3 S cm-1. The tensile strength of the irradiated composite film became larger than that of the original PVC film; i.e., the stress at break was: 461 (composite film); 401 kg cm-2 (PVC). These results were brought about by the doping of radical species to the conjugated polyene. The anion, NO-3, doped during the electrodeposition of PPy was photodecomposed to generate radical NO2 and this species was doped to the polyene, resulting in the formation of electrically conductive PVC and mechanically improved composite film. © 1994 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
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  • 103
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1001-1008 
    ISSN: 0887-624X
    Keywords: conductive rubber ; polypyrrole/EPDM blend ; chemical preparation ; electrical conductivity ; mechanical properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This work describes the preparation of polypyrrole and EPDM rubber blends, PPy/EPDM, by the sorption of pyrrole (vapor phase) in an EPDM matrix containing CuCl2. We investigated the effect of the oxidant particle-size on the sorption and polymerization equilibrium, electrical conductivity, and mechanical properties of the blends. Independently of the CuCl2 concentration and polymerization time, the polypyrrole weight fraction in the blend, Xppy, increases when the oxidant particle-size in changed from 150-250 μm to smaller than 106 μm. For blends containing 50 phr of CuCl2, obtained following 72 h of exposure to pyrrole, an increase in the Young's Modulus (from 2.2 ± 0.2 to 3.9 ± 0.6 MPa) and an increase in the electrical conductivity (from 10-9 to 10-7 S cm-1) was observed when the oxidant particle-size was decreased. Infrared spectroscopy, thermogravimetric analysis, scanning differential calorimetry, and scanning electron microscopy were used in sample characterization. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
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  • 104
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1043-1048 
    ISSN: 0887-624X
    Keywords: polyalkylviologen - polyanion complex ; electron-transfer catalysis (ETC) ; diphenyl bromomethane (Ph2CHBr) ; debromination ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several polyelectrolyte complexes were prepared by the reaction of polyalkylviologens [polyethylviologen (PEV2+), polypropylviologen (PPrV2+), and polybutylviologen (PBV2+)] with polyanions [sodium alginic (ALG), sodium polyacrylate (PAA), or sodium polystyrenesulfonate (PSS)]. These complexes were used as electron-transfer catalysts (ETC) on the debromination of diphenyl bromomethane (Ph2CHBr) under heterophase condition [reductant: Na2S2O4, in H2O (liquid)-polyelectrolyte complex(S) - Ph2CHBr in CH2Cl2]. The work showed that these complexes could induce the debromination of Ph2CHBr to afford tetraphenyl ethane, and different polyanions in the complexes also affected the mediating abilities. © 1994 John Wiley & Sons, Inc.
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  • 105
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1071-1076 
    ISSN: 0887-624X
    Keywords: functional aromatic polyethers ; fluorescent polymers ; aromatic nucleophillic substitution polymerization ; thermal behavior ; electron spin resonance ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The poly(arylene ether)s were prepared by the nucleophillic aromatic substitution polymerization of phenolphthalin and its derivatives with activated aromatic difluorides. The polymers had glass transition temperatures ranging from 210 to 240°C. Though the monomers have no fluorescence, the resulting polymers fluoresced a light green color in solid and solution states. The maximum excitation and emission wavelengths are 420 nm and 470 nm, respectively. In the polymer solutions, the fluorescence intensity decreased gradually, but the intensity was recovered by heating the polymer at 220°C for a few minutes. The fluorescent polymer had a stable radical. A model compound having the same repeating unit of the polymer was also prepared. The fluorescence properties of this model were almost the same as those of the polymers. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
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  • 106
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    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1113-1120 
    ISSN: 0887-624X
    Keywords: phenylacetylene ; stereoregular polymerization ; Rh complex catalyst ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Phenylacetylene and its homologues bearing methoxy or chloro groups in the para position of the phenyl ring were stereoregularly polymerized by Rh complex catalysts, e.g., [Rh (norbornadiene) Cl]2, in the presence of various solvents. The 1H-NMR and UV study of the Rh complex showed that the activity of the Rh catalysts greatly depends upon not only the ligand in the Rh catalyst but also on the solvent used, e.g., polyphenylacetylene with a highly cis-transoidal content was quantitatively obtained when norbornadiene was coordinated as the ligand, and triethylamine (TEA) was used as solvent, whereas tetrahydrofuran (THF) and benzene reduced the cis content. It was also found that the Rh catalyst as a dimer complex dissociates into the monomeric species not only when TEA was used but also when alcohol, benzene, and THF were used. The resulting monomeric species was considered as the important propagation species in this polymerization. The sharp line width observed in the 1H-NMR spectrum of polyphenylacetylene and its homologues which were prepared in ethanol or TEA was interpreted by the narrow chemical shift distribution arising from the high cis content. © 1994 John Wiley & Sons, Inc.
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  • 107
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    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1137-1147 
    ISSN: 0887-624X
    Keywords: Ziegler-Natta catalysts ; propylene polymerization ; catalysts characterization ; supported catalysts ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this article we present the results of the preparation and characterization of two Ziegler-Natta precatalysts: MgCl2/Ethyl benzoate (EB)/TiCl4 and MgCl2/2,2,6,6 tetramethylpiperidine (TMPiP)/TiCl4 by means of FTIR, X-ray diffraction, SEM, BET surface area measurements, and other techniques applied at different steps of their preparation procedures.The precatalysts were prepared by impregnating with TiCl4 a given amount of MgCl2, which was previously ball-milled with the electron donor chosen.Prior to impregnation, the ball-milled material presented different surface compounds depending on the electron donor used: [(MgCl2)2] · 2EB, MgCl2 · EB, or a salt of the amine. The solid milled with EB is more homogeneous than the one milled with the TMPiP.Titanium is better retained in the solid milled with EB. This precatalyst has better morphological properties and larger BET surface area. By means of FTIR, we found evidences that an adequate surface structure for the formation of stereospecific sites in MgCl2/TMPiP/TiCl4 was formed. © 1994 John Wiley & Sons, Inc.
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  • 108
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    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1189-1193 
    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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  • 109
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    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1213-1223 
    ISSN: 0887-624X
    Keywords: chitosan ; semi-IPN hydrogel ; swelling kinetics ; pH-sensitivity ; controlled release ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aqueous swelling kinetics of a series of crosslinked chitosan (cr-CS) with glutaraldehyde (GA) interpenetrating polyether hydrogels have been studied as functions of pH, the N-deacetylation degree of chitosan, the amount of crosslinking agent, the electrolyte composition in solution, temperature, and gel composition. Based on these results, the swelling mechanism of the hydrogels was discussed. The release profiles of chlorhexidini acetas from the semi-IPN were also investigated. © 1994 John Wiley & Sons, Inc.
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  • 110
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    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 333-342 
    ISSN: 0887-624X
    Keywords: liquid crystalline polymer ; thermotropic homopolyester ; nematic ; X-ray diffraction ; synthesis ; characterization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of fully aromatic, thermotropic homopolyesters, derived from 3,4′-benzophenone dicarboxylic acid and various aromatic diols, was prepared by the melt polycondensation method and examined for thermotropic behavior by a variety of experimental techniques. The aromatic diols used in the study were hydroquinone, 2,6-, 1,4-, 1,5-, 2,3-, and 2,7-naphthalenediol isomers. All of the homopolyesters of 3,4′-benzophenone dicarboxylic acid with aromatic diols (except that with 2,7-naphthalenediol) formed a nematic LC phase in the melt. They had the glass transition temperatures (Tg) in the range of 133-164°C, the melting transitions (Tm) in the range 305-360°C and the high thermal stabilities (Td) in the range of 410-483°C. The 2,6-naphthalenediol based homopolymer had the highest Tm (360°C) and the 2,3-naphthalenediol based homopolymer had the lowest Tm (305°C) among all of the homopolymers of naphthalenediol isomers. © 1994 John Wiley & Sons, Inc.
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  • 111
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 363-368 
    ISSN: 0887-624X
    Keywords: 2-vinylpyridine ; t-butyl methacrylate ; anionic polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of well defined and monodisperse (Mw/Mn ≤ 1.2) narrow molecular weight distribution poly (2-vinylpyridine)-poly (t-butyl methacrylate) (P2VP-PTBMA) AB block copolymers is carried out by initiation of 2-vinylpyridine polymerization by 1,1-diphenylhexyllithium in THF at-78°C, followed by addition of TBMA and termination at -78°C using MeOH. The formation of the BAB block copolymer is carried out in a similar fashion except that 1,4-dilithio-1,1,4,4-tetraphenylbutane is used as initiator. The corresponding synthesis of P2VP-PMMA block copolymers is carried in a similar manner, except that 1-2 equivalents of TBMA is used to end-functionalize the living P2VP before the addition of MMA. Without the addition of TBMA, trimodal molecular weight distributions in P2VP-b-PMMA are obtained. All the block copolymers are characterized by Size Exclusion Chromatography (SEC), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry (DSC). © 1994 John Wiley & Sons, Inc.
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  • 112
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 397-400 
    ISSN: 0887-624X
    Keywords: molecular composites ; rigid polymers ; sulfonated poly(p-phenylene terephthalamide) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 113
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 445-449 
    ISSN: 0887-624X
    Keywords: radical polymerization ; surface-active monomer ; quaternary salt ; dimethylaminoethyl methacrylate ; stereochemistry ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of monomer micellization on the polymerization was studied from the standpoint of stereochemistry in the polymerization. Quaternary salts (CnBr) of dimethylaminoethyl methacrylate with n-alkyl bromide having N (=4, 8 and 12) carbon atoms were polymerized with radical initiators in isotropic and anisotropic media and the resulting polymers were converted to poly (methyl methacrylate) (PMMA) to determine their tacticity. Tacticities of poly (C12Br)s were little affected by initiators and solvents used for their preparations. There was little dependence of the tacticities on alkyl chain length (N) for poly (CnBr)s prepared in water and dimethylformamide (DMF). Most of polymers produced here conformed to Bernoullian propagation statistics and a definite difference was not found in the tacticities between the polymers prepared in isotropic and anisotropic media. From the results obtained here it was deduced that the micellar aggregation has little influence upon the stereochemistry in the polymerization of the quaternary monomers. © 1994 John Wiley & Sons, Inc.
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  • 114
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1351-1360 
    ISSN: 0887-624X
    Keywords: 1,3-bis(3-hydroxypropylsulfonyl)propane ; 1,4-bis(3-hydroxysulfonyl)butane ; polyesters ; poly(ester-sulfone) ; liquid crystalline ; glass transition ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aliphatic and aromatic-aliphatic poly(ester-sulfone)s were synthesized by the transesterifications of diphenyl adipate and diphenyl phthalates (ortho, meta, para) with two sulfonecontaining diols, 1,3-bis (3-hydroxypropylsulfonyl) propane (Diol-333) and 1,4-bis(3-hydroxypropylsulfonyl) butane (Diol-343). Based on DSC and WAXD studies, the aliphatic homopoly(ester-sulfone)s are semicrystalline at room temperature and liquid crystalline at elevated temperature, while their copolymers with alkanediols are liquid crystalline. The liquid crystalline phase formation in aliphatic poly(ester-sulfone)s is attributed to the strong dipole-dipole interactions between sulfone groups. The aromatic-aliphatic poly(estersulfone)s from diphenyl phthalate (ortho) and isophthalate (meta) are amorphous. They are soluble in trifluoroacetic acid and m-cresol at room temperature, and DMF, DMAC, and DMSO at elevated temperature. The aromatic-aliphatic poly(ester-sulfone)s from diphenyl terephthalate are semicrystalline and are soluble only in trifluoroacetic acid. For a given diol, the glass transition temperatures of aromatic-aliphatic poly(ester-sulfone)s increase from phthalate to isophthalate to terephthalate. This is because the flexibility of the benzene ring in the polymer backbone decreases from ortho to meta to para substitution. As a comparison, polyesters without sulfone groups were synthesized from two alkanediols, 1,9-nonanediol and 1,10-decanediol, and the diphenyl esters. The poly(ester-sulfone)s have glass transition temperatures 60-80°C higher than the corresponding polyesters without sulfone groups, due to the strong dipolar interactions between sulfone groups. © 1994 John Wiley & Sons, Inc.
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  • 115
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 389-392 
    ISSN: 0887-624X
    Keywords: fluorinated poly (ether sulfone) ; semicrystalline polymer ; aromatic nucleophilic substitution ; trimethylsilyl ether ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 116
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1431-1435 
    ISSN: 0887-624X
    Keywords: polystyrene ; latex ; sodium styrenesulfonate ; crosslinked ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Latexes of 100 nm diameter were synthesized by emulsifier-free copolymerization of styrene, sodium styrenesulfonate, and 1-5 wt% divinylbenzene using persulfate initiator at 91°C. A shot growth method was used to incorporate a high density of sulfonate groups. Coefficients of variation of particle size were 0.04-0.08 without resort to seed growth polymerization. Redox initiation at 40-50°C produced larger, more polydisperse, and less colloidally stable crosslinked latexes. © 1994 John Wiley & Sons, Inc.
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  • 117
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1459-1469 
    ISSN: 0887-624X
    Keywords: methyl methacrylate ; redox polymerization ; kinetics ; mechanism ; additives ; copper saccharinate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetics of methyl methacrylate polymerization initiated by a redox system [cumene hydroperoxide (CHP)/copper saccharinate] were studied in bulk at 20°C in the presence of accelerators such as N,N-dimethyl-p-toluidine (DMPT) and o-benzoic sulphimide (saccharin). Assuming a steady-state concentration of propagating radicals, the polymerization rate depends on the square root of the initiation rate and the kinetic orders with respect to each compound in the initiation step may be deduced. Initiation is first-order in CHP, copper saccharinate, and saccharin and second-order in DMPT. A reaction scheme consistent with these orders is proposed. The main features are the following: (1) CHP reduces rapidly Cu(II) to Cu(I); (2) a small fraction of Cu(I) is complexed with DMPT; (3) the complexed ions (Cu+, DMPT2) are strong reductants with respect to CHP whereas uncomplexed Cu+ are almost inactive; (4) the decomposition of CHP is strongly catalyzed by saccharin (protonated CHP is 13000 times more reactive than free CHP). Thus both accelerators are necessary to get high polymerization rates. © 1994 John Wiley & Sons, Inc.
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  • 118
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1507-1521 
    ISSN: 0887-624X
    Keywords: crosslinkable ; poly(arylene ether) ; triazene ; gel content ; dielectric constant ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Self-crosslinkable poly(arylene ether)s 6, and 8, containing pendent triazene groups were prepared by nucleophilic substitution reaction of poly(arylene ether)s 5, and 7, respectively, with 1-[4-(4-hydroxyphenoxy)phenylene]triazenes, 4, in the presence of potassium carbonate in N,N-dimethylacetamide. A series of triazenes 4 containing various substituents have been synthesized. Self-crosslinkable polymer 6e containing phenyl-substituted triazene pendants can be crosslinked at 215°C, which is about 40°C lower than the glass transition temperature of the virgin base polymer 5. The degree of crosslinking can be tailored by varying the concentration of the pendent phenylenetriazene groups in the polymer. After curing, the flexible polymer films (ca. 10 μm thick) exhibit high gel contents, increased glass transition temperatures, improved resistance to organic solvents, and little change in dielectric constant and thermal stability. These self-crosslinkable poly(arylene ether)s are potential candidates for electronic applications. © 1994 John Wiley & Sons, Inc.
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  • 119
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1531-1537 
    ISSN: 0887-624X
    Keywords: 1,3-bis(3 hydroxy propyl sulfonyl)propane ; 1,4-bis(3-hydroxypropyl sulfonyl)butane ; 1,3-propane dithiol ; 1,4-butane dithiol ; poly(urethane) ; poly sulfone ; methylene diphenyl diisocyanate (MDI) ; toluene diisocyanate (TDI) ; hexamethylene diisocyanate (HMDI) ; melt temperature ; glass transition temperature ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Eight poly(urethane-sulfone)s were synthesized from two sulfone-containing diols, 1,3-bis(3-hydroxypropylsulfonyl)propane (Diol-333) and 1,4-bis(3-hydroxypropylsulfonyl)butane (Diol-343), and three diisocyanates, 1,6-hexamethylene diisocyanate (HMDI), 4,4′-diphenylmethane diisocyanate (MDI), and tolylene diisocyanate (TDI, 2,4- 80%; 2,6-20%). As a comparison, eight polyurethanes were also synthesized from two alkanediols, 1,9-nonanediol and 1,10-decanediol, and three diisocyanates. Diol-333 and Diol-343 were prepared by the addition of 1,3-propanedithiol or 1,4-butanedithiol to allyl alcohol and subsequent oxidation of the resulting sulfide-containing diols. The homopoly(urethanesulfone)s from HMDI and MDI are semicrystalline, and are soluble in m-cresol and hot DMF, DMAC, and DMSO. The copoly(urethane-sulfone)s from a 1/1 molar ratio mixture of Diol-333 and Diol-343 with HMDI or MDI have lower crystallinity and better solubility than the corresponding homopoly(urethane-sulfone)s. The poly(urethane-sulfone)s from TDI are amorphous, and are readily soluble in m-cresol, DMF, DMAC, and DMSO at room temperature. Differential scanning calorimetry data showed that poly(urethane-sulfone)s have higher glass transition temperatures and melting points than the corresponding polyurethanes without sulfone groups. The rise in glass transition temperature is 20-25°C while the rise in melting temperature is 46-71°C. © 1994 John Wiley & Sons, Inc.
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  • 120
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 753-765 
    ISSN: 0887-624X
    Keywords: pyrazole blocked isocyanate ; pyrazole masked isocyanate ; blocking group ; blocking agent ; synthesis ; deblocking reaction ; reactivity ; gelation time ; latency ; stability ; adhesion ; primer ; polymer ; bis (pyrazole) ; EPIC-systems ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrazoles were found as a novel class of blocking groups for isocyanates. Adhesive mixtures of pyrazole blocked isocyanates and amine terminated prepolymers like Jeffamines® (Texaco Chem. Co.) combine excellent reactivities (gelation times within minutes at 100-120°C), good latencies (more than 170 days at 40°C), and good adhesion properties on many substrates. The reactivity of pyrazole blocked isocyanates toward nucleophiles increases with the number of electron donor substituents on the pyrazole nucleus and, thus, can be fine tuned by the appropriate substitution pattern. This behavior contrasts sharply with that of phenolic blocked isocyanates, where reactivities with the same nucleophiles decrease with more and stronger electron donor substituents on the phenol nucleus. Therefore, different deblocking reaction mechanisms were proposed for pyrazole vs. phenol blocked isocyanates. The excellent latency of pyrazole blocked isocyanate/Jeffamine® mixtures is due to the insolubility of the two components at ambient temperature and the slow endothermic dissolution process at higher temperature. The good adhesion of formulations with pyrazole blocked isocyanates as reactive components on most plastic and metal substrates is ascribed to the primer action of the released blocking group. © 1994 John Wiley & Sons, Inc.
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  • 121
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1627-1637 
    ISSN: 0887-624X
    Keywords: degradable hydrogels ; crosslinking of polymeric precursors ; colon-specific polymer ; pH-dependent swelling ; azoaromatic crosslinks ; N,N-dimethylacrylamide copolymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel pH-sensitive hydrogels containing azoaromatic crosslinks were synthesized by the crosslinking of polymeric precursors. First, a reactive polymeric precursor was synthesized by copolymerization of N,N-dimethylacrylamide, N-tert-butylacrylamide, acrylic acid, and N-methacryloylglycylglycine p-nitrophenyl ester. The hydrogel was prepared in the second step by the reaction of the polymeric precursor with N,N′-(ω-aminocaproyl)-4,4′-diaminoazobenzene. The hydrogels were characterized by the network structure, (that is, content of crosslinks, unreacted pendent groups, and cycles), the equilibrium swelling ratio as a function of pH, modulus of elasticity in compression, and the degradability in vitro. The results obtained indicated that the hydrogel network structure strongly depends on the reaction conditions such as polymer concentration, and the ratio of the reactive groups during the crosslinking reaction. The swelling and mechanical properties of hydrogels can be controlled by the modification of polymer backbone structure and/or the crosslinking density. The rates of hydrogel degradation depended on their degree of swelling. The higher the degree of swelling, the higher the degradability. The properties of the hydrogels suggest that they have a potential as carriers for colon-specific drug delivery. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1665-1672 
    ISSN: 0887-624X
    Keywords: polyurethane ; bismaleimide ; crosslinking reaction ; mechanical property ; thermal property ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of novel bismaleimides (BMIs) were prepared from maleic anhydride and polyurethane prepolymers based on MDI (4,4′-diphenylmethane diisocyanate) and polyether and polyester diols with various chain lengths. All the BMIs were characterized by IR, 1H-NMR, and elemental analysis. DSC studies indicated that the thermal polymerization of the BMIs could be carried out in the temperature range of 102-245°C, and that curing behavior was significantly affected by the molecular weight of the BMIs. The crosslinked BMI elastomers showed good mechanical properties and much better thermal stability than that of the traditional polyurethane elastomers. The glass transition temperatures, mechanical, and dynamic mechanical properties were dependent on the types of polyols used and the resultant crosslink densities due to various chain lengths of the BMIs. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1703-1710 
    ISSN: 0887-624X
    Keywords: cationic polymerization ; 10-methylphenothiazine ; cation radical ; electron transfer ; initiation mechanism ; vinyl ethers ; electrochemical oxidation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A small quantity of 10-methylphenothiazine cation radical (MPT.+), electrochemically prepared and stocked in acetonitrile solution, initiated cationic polymerizations of n-butyl, t-butyl, and 2-methoxyethyl vinyl ethers and p-methoxystyrene, while no initiation occurred for phenyl vinyl ether, styrene, methyl methacrylate, and phenyl glycidyl ether. 1H-NMR studies of oligomers and low molecular weight compounds isolated from the reaction mixture for the polymerization of t-butyl vinyl ether in the presence of a small amount of D2O indicated that electron transfer from the monomer to MPT.+ was involved in the initiation step. 1H- and 13C-NMR and MO calculation implied that monomers with higher electron densities on the vinyl groups and with lower ionization potentials were more susceptible to the initiation of MPT.+. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1711-1717 
    ISSN: 0887-624X
    Keywords: durable catalyst ; thiazolium salt ; aqueous system ; acyloin condensation ; enzyme model ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We characterized three low-molecular-weight thiazolium salt analogues: N-methyl-5-(2′-benzyloxyethyl)-4-methylthiazolium iodide (MBMTI), N-methyl-4-phenylthiazolium iodide (MPTI), and N-methylbenzothiazolium iodide (MBTI). MBMTI, having high-electron density on the thiezolium ring, was found to be a durable thiazolium salt in buffer solution. Then, the polymer-supported thiazolium salt catalyst having MBMTI structure as a catalytic site for acyloin condensation was prepared by the polymerization of the corresponding thiazole monomer and the following quaternization. The polymer catalyst had excellent catalytic activity even in buffer solution, while the corresponding low molecular weight catalyst did not show any activity in aqueous system. Furthermore, the durable polymer catalyst could be reused under the aqueous condition. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1719-1728 
    ISSN: 0887-624X
    Keywords: living cationic polymerization ; isobutyl vinyl ether ; cyclic ether additives ; cyclic formal additives ; acyclic ether additives with oxyethylene units ; EtAlCl2 ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The living cationic polymerization of isobutyl vinyl ether (IBVE) was investigated in the presence of various cyclic and acyclic ethers with 1-(isobutoxy)ethyl acetate [CH3CH(OiBu)OCOCH3, 1]/EtAlCl2 initiating system in hexane at 0°C. In particular, the effect of the basicity and steric hindrance of the ethers on the living nature and the polymerization rate was studied. The polymerization in the presence of a wide variety of cyclic ethers [tetrahydrofuran (THF), tetrahydropyran (THP), oxepane, 1,4-dioxane] and cyclic formals (1,3-dioxolane, 1,3-dioxane) gave living polymers with a very narrow molecular weight distribution (MWD) (M̄ω/M̄n ≤ 1.1). On the other hand, propylene oxide and oxetane additives resulted in no polymerization, whereas 1,3,5-trioxane gave the nonliving polymer with a broader MWD. The polymerization rates were dependent on the number of oxygen and ring sizes, which were related to the basicity and the steric hindrance. The order of the apparent polymerization rates in the presence of cyclic ether and formal additives was as follows: nonadditive ∼ 1,3,5-trioxane ≫ 1,3-dioxane 〉 1,3-dioxolane ≫ 1,4-dioxane ≫ THP 〉 oxepane ≫ THF ≫ oxetane, propylene oxide ≫ 0. The polymerization in the presence of the cyclic formals was much faster than that of the cyclic ethers: for example, the apparent propagation rate constant k in the presence of 1,3-dioxolane was 103 times larger than that in the presence of THF. Another series of experiments showed that acyclic ethers with oxyethylene units were effective as additives for the living polymerization with 1/EtAlCl2 initiating system in hexane at 0°C. The polymers obtained in the presence of ethylene glycol diethyl ether and diethylene glycol diethyle ether had very narrow molecular weight distribution (M̄ω/M̄n ≤ 1.1), and the M̄n was directly proportional to the monomer conversion. The polymerization behavior was quite different in the polymerization rates and the MWD of the obtained polymers from that in the presence of diethyl ether. These results suggested the polydentate-type interaction or the alternate interaction of two or three ether oxygens in oxyethylene units with the propagating carbocation, to permit the living polymerization of IBVE. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1049-1056 
    ISSN: 0887-624X
    Keywords: tetraacetoxysilane ; boron tri-n-butoxide ; sol-gel method ; condensation ; SiO2 - B2O3 gel fibers ; borosilicates ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Formation of SiO2-B2O3 gel fibers and oxides was investigated by the sol-gel method using tetraacetoxysilane (TAS) and boron tri-n-butoxide (BTB). Low molecular weight borosiloxanes (BS) were formed by the reaction of TAS with BTB in THF. Partial alkoxylation and hydrolysis of BS followed by further condensation of the resulting polymer (PBS) solutions led to the formation of highly polymerized polyborosiloxanes (HPBS) with good spinnability. Gel fibers were obtained by dry spinning of HPBS. The compositions of PBS and gels were not consistent with that in feed. Heat treatment of the gels, however, provided SiO2-B2O3 oxides with compositions almost compatible with those of the gels. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1077-1085 
    ISSN: 0887-624X
    Keywords: liquid crystal polymer ; polymethacrylate ; tolane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and characterization of nine polymethacrylates containing 4-alkoxy-4′-trifluoromethyltolane, 4-alkoxy-4′-cyanotolane, and 4-alkoxy-4′-nitrotolane side groups were described in this study. The phase behavior of the prepared monomers and polymers was characterized by differential scanning calorimetry, optical polarizing microscopy, and x-ray diffraction. All of the obtained monomers exhibit no mesophase, while most of the synthesized polymers reveal enantiotropic mesomorphism. The polymethacrylate containing 4-propanyloxy-4′-nitrotolane side groups was the only one which shows no mesomorphic behavior. Both the spacer length and the nature of terminal groups have profound influence on the phase transition temperatures and thermal stability of the mesophase. The polymers with longer spacers tend to form a more ordered mesophase with a wider temperature range. Among three polymers with the same spacer length, the polymer with a trifluoromethyl terminal end group is inclined to form a more ordered mesophase than the other two polymers. No side chain crystallization occurred for all obtained polymers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1131-1135 
    ISSN: 0887-624X
    Keywords: poly(propylene oxide) ; allyl, propenyl ; isomerization ; 1H NMR ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The isomerization of allyl ether to propenyl ether end group in anionically-polymerized poly (propylene oxide) was monitored by 1H NMR spectroscopy. It was confirmed that the reaction followed a simple second-order rate law: -d[allyl]dt = k2[allyl] [O-]. Values of k2 determined over the 90-130°C temperature range, indicated an activation energy of 116 kJ mol-1. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 949-960 
    ISSN: 0887-624X
    Keywords: dimethyltitanocene ; biodegradable polymers ; poly(glycolic acid) ; surface degradation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The purpose of this research was to selectively alter the rate of surface degradation of linear aliphatic polyesters without adversely affecting their bulk properties by way of functional group transformation, where the surface ester linkages would be converted to vinyl ether functionalities with dimethyltitanocene. It has been observed that dimethyl titanocene causes surface degradation of poly (glycolic acid) without adversely affecting its bulk properties, such as Mv, bursting strength, and thermal properties The vinvl ether resulting from the conversion of the PGA ester groups was unstable under ambient conditions, and further reacted by polymer chain scissioning, as was observed from measurements of molecular weight. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1893-1898 
    ISSN: 0887-624X
    Keywords: excimer laser ; organosilicon compounds ; additive-free polymers ; high chemical and spectral purity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Excimer lasers (ArF, λ = 193 nm, and KrF, λ = 248 nm) were used to generate polymers free of additives such as catalysts, initiators, or sensitizers. The layers obtained are of potential interest for medical applications and future molecular electronics. Dimethylpolysiloxanes and dimethylsiloxane copolymers that contain phenyl-, n-hexyl- or 3.3.3-trifluoropropyl groups or silicon-bound hydrogen atoms were crosslinked in the liquid phase, whereby layer thicknesses in the range from 1-300 μm were obtained. Disiloxanes and alkoxysilanes were deposited from the gas phase (LCVD, laser chemical vapor deposition) resulting in layer thicknesses below 1 μm. In almost all cases, organic layers with a smooth surface, transparency, and good adhesion were obtained on silicon as well as quartz substrates. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1909-1914 
    ISSN: 0887-624X
    Keywords: phase transfer catalyst ; free-radical polymerization ; kinetics of polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of phase-transfer catalyzed free-radical polymerization of acrylonitrile (AN) was carried out with water-soluble initiator peroxomonosulphate (PMS) with phase-transfer catalysts (tetrabutylammonium chloride and benzyltributylammonium chloride (TBAC and BTBAC) in tolune/water two-phase systems in the temperature range of 45-55°C at fixed pH (4) and ionic strength. The rates of polymerization (Rp) were evaluated at various values of [PMS], [PTC], and [AN]. It has been observed that the rates of polymerization increase with an increase of [AN], [PMS], and [PTC]. A kinetic scheme has been proposed to account for the experimental observations. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1939-1947 
    ISSN: 0887-624X
    Keywords: polytetrahydrofuran ; acetylhexachloro-antimonate ; chain transfer ; THF ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the presence of acetic anhydride, the catalyst containing protons makes the polymerization complex.1,2 Thus, whether the living center, during the polymerization process of THF, transfers to the acetic anhydride is a difficult problem to answer. In this article, CH3COSbCl6 is used as the catalyst to avoid the interference of the protons. It is found that acetic anhydride is an effective chain transfer agent, by the experiment at different temperatures for two systems in the presence or absence of acetic anhydride, and by the comparison of kinetic behavior. In the system without acetic anhydride at the temperature of 7, 15, and 22°C, the propagation rate constants of THF, kp are 7.90, 14.23, and 23.35 10-3L/Mol.S, respectively. In the presence of acetic anhydride, kp are 1.51, 2.85, and 4.98 10-3L/Mol.S; and ktr are 2.04, 3.59, and 6.49 10-4L/Mol.S, respectively. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1739-1746 
    ISSN: 0887-624X
    Keywords: macromerinitiator (macroinimer) ; crosslinked block copolymer ; macroinitiator ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several new macroinitiators and macromerinitiators (macroinimers) were synthesized and evaluated for the bulk polymerization of sytrene at 60°C. Macroinitiators were prepared from the reaction of 4,4′-dicyano-4,4′ azovaleryl chloride (1) with poly(ethylene glycol) (PEG) with a Mω of 400 and with either benzoyl chloride, acetyl chloride, phenyl isocyanate, or poly(ethylene glycol) oleyl ether. Macromer initiators were also prepared from the reaction of 1 with PEG having Mω values of 200, 400, 600, 1000, or 1500 and with 4-vinylbenzyl chloride. The bulk polymerization of styrene by macroinimers gave crosslinked styrene-PEG block copolymers, while the polymerization by macroinitiators gave soluble copolymers. The molecular weights of the styrene-PEG block copolymers obtained with macroinitiators having either oleyl, benzoyl, or phenyl urethane end groups were 22000-29000 g/mol. DSC measurements showed that the crosslinked block copolymers had crystalline PEG units with melting transitions ranging from 11-37°C. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1305-1315 
    ISSN: 0887-624X
    Keywords: polyethylenenaphthalate ; bis(hydroxyethyl)naphthalate ; molecular weight ; polycondensation kinetics ; intrinsic viscosity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bis(hydroxyethyl) naphthalate (BHEN) was polymerized to polyethylenenaphthalate (PEN) in the presence of various metallic catalysts. The influence of the nature and concentration of these catalysts on the rate of polymerization has been investigated. The order of decreasing catalytic influence of various metal ions on the polymerization of BHEN was found to be: Ti 〉 Sb 〉 Zn 〉 Co 〉 Pb 〉 Ni(Mg). The effect of the reaction temperature has also been studied. The optimal concentration of these catalyst and reaction temperature were found to be 30 × 10-5 (mol/mol BHEN) and 285-293°C, respectively. Because of its insolubility in ordinary solvent, the molecular weight of PEN was measured using the light scattering method. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1807-1815 
    ISSN: 0887-624X
    Keywords: poly(phenylenesulfide) ; thermal degradation ; direct pyrolysis-mass spectrometry ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal degradation Processes which occur in poly(phenylenesulfide) (PPS) have been studied by direct pyrolysis-mass spectrometry (DPMS). The structure of the compounds evolved in the overall temperature range of PPS decomposition (400-700°C) suggests the occurrence of several thermal decomposition steps. At the onset of the thermal degradation (430-450°C) this polymer decomposes with the formation of cyclic oligomers, generated by a simple cylization mechanism either initiated at the - SH end groups or by the exchange between the inner sulfur atoms along the polymer chain. At higher temperature (〉 500°C) another decomposition reaction takes over with the formation of aromatic linear thiols. The formation of thiodibenzofuran units by a subsequent dehydrogenation reaction occurs in the temperature range of 550-650°C; in fact, pyrolysis products with a quasi-ladder structure have also been detected. Ultimately, above 600°C, extrusion of sulfur from the pyrolysis residue occurs with the maximum evolution at the end of decomposition (about 700°C). It appears, therefore, that the residue obtained at high temperature tends to have a crosslinked graphite-like structure from which the bonded sulfur is extruded. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1885-1891 
    ISSN: 0887-624X
    Keywords: copolycarbonate ; bisphenol A ; tetrabromobisphenol A ; end group ; analysis ; properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The types and concentrations of end groups present in bisphenol A-tetrabromobisphenol A copolycarbonates (BA-TBBA coPCs) have major effects on the copolymer solution washability and thermal stability. Six types of coPC end groups are possible: two by monophenol capping of each comonomer, two phenolics (BA-OH and TBBA-OH), and two carbamates (one from each comonomer). BA-TBBA coPCs were prepared by typical solution and interfacial methods and their phenolic and carbamate end group concentrations were correlated with their solution washability and thermal discoloration. Both phenolic and carbamate end groups proved deleterious to these two copolymer properties. An improved interfacial process that employs 4-N,N-dimethylaminopyridine as the coupling catalyst provides coPCs having low concentrations of phenolic and carbamate end groups and that, therefore, wash without emulsification and are thermally stable. © 1994 John Wiley & Sons, Inc.
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  • 137
    ISSN: 0887-624X
    Keywords: 1,4-bis(2,2-dicyanovinyl)benzene ; thermally stable polymers ; thermosetting resins ; conductive polymers ; electrical resistivity ; cyano-substituted polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New thermosetting resins were prepared from the reaction of 1,4-bis(2,2-dicyanovinyl)benzene with aromatic diamines in varying molar ratios. The thermal stability of these resins was correlated with their composition and the curing conditions. They were stable in N2 up to 370-448°C and afforded anaerobic char yields of 73-84% at 800°C after curing at 300°C for 20-60 h. The temperature dependence of the electrical resistivity of all resins pyrolyzed at 700°C for 15 h was studied in the temperature range from -173-327°C (100-600 K). The results showed that at room temperature the unpyrolyzed polymers have insulating properties, whereas a dramatic decrease in the electrical resistivity is observed following pyrolysis. The temperature dependence of the electrical resistivity suggests that all of the materials studied have semiconducting properties. The observed electrical conductivity is thermally activated with activation energies ranging from 0.03-0.06 eV. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1949-1956 
    ISSN: 0887-624X
    Keywords: polysilanes ; polysilylenes ; copolysilane ; alkoxy-substituted polysilane ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of γ;-methoxypropylmethyldichlorosilane, and its subsequent polymerization and copolymerization with di;-n;-hexyldichlorosilane through the reductive coupling with sodium has been accomplished. The resulting polymers contain methyl ether side groups that allow further synthetic transformations on the polysilane backbone. For poly (γ;-methoxypropylmethylsilylene) these groups impart solubility characteristics different than typical alkyl and aryl substituted polysilanes. These new polymers and copolymers have been characterized by GPC and 1H-, 13C-, and 29Si-NMR. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1983-1989 
    ISSN: 0887-624X
    Keywords: polyurethane cationomer ; PTAd ; IPDI ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyurethane (PU) cationomers were synthesized from polytetramethylene adipate glycol (PTAd), isophorone diisocyanate (IPDI), and N-methyl diethanolamine (MDEA) according to a prepolymer mixing process. Basic structure-property behavior of the emulsion (obtained by adding water to the ionomer solution) and emulsion cast film was studied with regard to the molecular weight (Mn) of PTAd, MDEA content, degree of neutralization, and extender functionality. Particle size decreased asymptotically with increasing Mn of PTAd due to the increased chain flexibility, and with the degree of neutralization due to the increased hydrophilicity of the PU. Emulsion viscosity generally showed the opposite tendency with particle size dependence. The major transition temperature, corresponding to the glass transition (Tg) of phase mixed PU or hard segment-rich phase of the PU monotonically increased with MDEA content, degree of neutralization, and with increasing extender functionality. However, with increasing Mn of PTAd, Tg first decreased (Mn = 1000) and then increased (Mn = 1500, 2000), due respectively to the increased hard fraction of phase mixed PU, and soft segment crystallization. Tensile strength increased and elongation at break decreased with MDEA content, degree of neutralization, and extender functionality. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2011-2021 
    ISSN: 0887-624X
    Keywords: polyisobutylene ; living carbocationic polymerization ; proton NMR analysis ; hydroxyl-ended, chlorine-ended, olefin-ended, phenyl-ended polyisobutylenes ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1H-NMR spectra of various telechelic (i.e., ∼ CH2C(CH3)2Cl, ∼ CH2C(CH3)=CH2, ∼ CH=C(CH3)2, and ∼ CH2CH(CH3)CH2OH capped) polyisobutylenes (PIB) have been analyzed. The products were prepared by living carbocationic polymerization followed by end-group functionalization. Shielding and deshielding effects strongly influence the 1H-NMR spectra of these products. Inductive effects (chlorine-ended PIBs), magnetically anisotropic end-groups (olefin groups and phenyl rings), allylic coupling (olefin end-groups), chirality (hydroxyl end-groups), and the interaction of these effects on the 1H-NMR spectra are discussed. Numerous heretofore unidentified resonances have been assigned and better insight into the detailed structure of end-functionalized PIBs has been obtained. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2049-2056 
    ISSN: 0887-624X
    Keywords: metallocenes ; olefin polymerizations ; Ziegler-Natta catalysts ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Propylene was polymerized with rac-ethylene-bis (1-η5-indenyl)dichlorozirconium/methylaluminoxane in solvents of different polarity. The poly (propylene) formed was separated by solvent extraction; 13C-NMR and DSC measurements were made on the polymer fractions. The poly(propylene) in each solvent fraction has its characteristic molecular weight steric pentad distributions, melting transition temperature, and enthalpy for fusion irrespective of the polymerization medium. The results suggest that the medium dielectric constant does not affect the polymerization rate or the intrinsic stereoselectivity, propagation and chain transfer rates a given catalytic species but can alter the occurrence of steric insertion errors through shifting of distributions of the propagating species producing poly(propylenes) of different stereoregularities. © 1994 John Wiley & Sons, Inc.
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  • 142
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2085-2091 
    ISSN: 0887-624X
    Keywords: radical polymerization ; 1,1-disubstituted ethylene itaconamate ; itaconamide ; thermal property ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two kinds of itaconamic esters, α-substituted acrylate derivatives (IAE-I) and α-substituted acrylamide derivatives (IAE-II), as well as itaconamides (IAm) were prepared and polymerized with a radical initiator. It has been revealed that N,N-disubstituted IAE-I as an acrylate is more reactive in polymerization than N,N-disubstituted IAE-II as an acrylamide and that N,N′-dialkyl substituted IAm homopolymerizes but N,N,N′,N′;-tetraalkyl substituted one does not. In radical copolymerization with styrene, IAE-I showed a higher polymerization reactivity than IAE-II. The effects of the N-substituents on the polymerization reactivity were discussed on the basis of conformation of the monomers. The polymers obtained were also characterized. © 1994 John Wiley & Sons, Inc.
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  • 143
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2127-2134 
    ISSN: 0887-624X
    Keywords: Ziegler-Natta catalyst ; polymer support ; ethylene ; polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymer-supported Ziegler-Natta catalysts based on various polymer carriers were synthesized by different methods, including (1) loading TiCl4 directly onto the polymer supports; (2) loading TiCl4 onto the polymer supports modified by magnesium chloride (MgCl2); (3) loading TiCl4 onto the polymer supports modified by Grignard reagent (RMgCl); and (4) loading TiCl4 onto the polymer supports modified by magnesium alkyls (MgR2). The activity and kinetic features of the catalysts for ethylene polymerization were examined. Among the combinations tested, the best was found to be TiCl4/n-Bu2Mg.Et3Al/poly(ethylene-co-acrylic acid) (92:8), which produced a catalyst of very high activity for ethylene polymerization. © 1994 John Wiley & Sons, Inc.
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  • 144
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2155-2159 
    ISSN: 0887-624X
    Keywords: block copolymer ; tetrahydrofuran ; oxetanc ; ring opening ; cationic polymerization ; energetic ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel energetic thermoplastic elastomers (TPEs) based on tetrahydrofuran (THF) and 3,3-bis (azidomethyl) oxetane (BAMO) were prepared in this present study by cationic living polymerization. A bifunctional catalyst, triflic anhydride [(CF3SO2)2)O] was selected to be an initiator for the polymerization THF and BAMO. The resulting polymers were characterized by IR, NMR, and DSC, which demonstrated that triblock copolymers with A-B-A type were formed. The polymers were indicated from thermogravimetric analysis (TGA) to have decomposed at approximately 243°C. The decomposition enthalpies were determined by DSC. These enthalpies were varied with the poly-BAMO contents of the copolymers. The synthesized polymers exhibited relatively good mechanical properties and thermoplastic characteristics at room temperature. © 1994 John Wiley & Sons, Inc.
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  • 145
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2187-2192 
    ISSN: 0887-624X
    Keywords: polyurethane ; poly (oxazoline) ; fluoropolymer ; biomaterial ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have prepared an amphiphilic oxazoline block copolymer of hydrophilic poly(2-methyl-2-oxazoline) and hydrophobic poly[2-(2-perfluorooctyl)ethyl-2-oxazoline] chains. By controlling the length and composition of polymer chains, we found that this fluorinated block copolymer can be readily dissolved in water. Furthermore, we can achieve a stable surface coating of the fluorinated block copolymer by dissolving the copolymer in water, then coating the aqueous copolymer solution onto surfaces of nonwater-soluble polymers. This is a simple and useful method of modifying the surface character of polymer substrates. We have found that the polyether urethane (PEU) coated by block copolymer has a different surface chemistry and biological reactivity than the uncoated PEU. From XPS analysis, we found the fluorinated copolymer was coated on PEU (atomic % of F: 31.3 on coated PEU, 0.3 on uncoated). The two surfaces have different affinities for biological molecules. Specifically, the fibrinogen adsorption on the fluorinated copolymer-coated PEU was 62 ± 39 ng/cm2, compared to a value of 156 ± 99 ng/cm2 for uncoated PEU. In an ex vivo evaluation of platelet adhesion, the surface of coated PEU attached a few white cells while uncoated PEU was covered with activated platelets. © 1994 John Wiley & Sons, Inc.
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  • 146
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1557-1568 
    ISSN: 0887-624X
    Keywords: free-radical polymerization ; mechanism and kinetics ; nontraditional initiators ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the basis of a rather general scheme of elementary reactions of radical polymerization conducted in the presence of iniferters, kinetic equations have been derived describing this process over the whole range of monomer conversion. Proceeding from thorough analysis of these equations, different regimes of polymerization have been found that differ in values of order with respect to the iniferter and monomer of the initial rate of polymerization. Conditions for kinetic parameters have been formulated whose fulfillment predetermines that radical polymerization occurs according to the iniferter mechanism. © 1994 John Wiley & Sons. Inc.
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  • 147
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1601-1607 
    ISSN: 0887-624X
    Keywords: poly(4-hydroxybenzoate) ; whiskers ; crystal growth ; nylon-6 composites ; mechanical properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Whiskers of poly(4-hydroxybenzoate) [poly(4-HBA)] were prepared by polycondensation of free 4-hydroxybenzoic acid with acetic anhydride and pyridine in a high boiling inert solvent. The purity of the monomer is decisive for the success of the synthesis. For a less pure 4-hydroxybenzoic acid, the preparation of acetylated oligomers with acetylchloride, followed by polycondensation of the isolated oligomers is a suitable alternative. Whiskers, with a solid-solid phase transition at 364°C were obtained, which is the highest temperature reported for this transition so far. Two batches of composites were prepared from nylon-6 using polyester whiskers with an alkaline or an acidic surface treatment. A third batch was prepared using poly(ester-amide) whiskers. The mechanical properties of these composites indicate that the surface treatment does not play any role, and that the poly(esteramide)s are inferior to the polyester whiskers, because they are not single crystals. © 1994 John Wiley & Sons, Inc.
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  • 148
    ISSN: 0887-624X
    Keywords: polyorganosiloxane ; pyridine-Cu(II) complex ; catalysis ; hydroquinone oxidation ; copolymerization ; hydrophobicity ; flexibility ; equilibrium dialysis ; ESR spectroscopy ; cyclic voltammetry ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The oxidation of hydroquinone catalyzed by pyridine-Cu(II) complexes attached to polyorganosiloxane was investigated in the mixed solvent of methanol/water (vol. ratio 2/1). The catalytic oxidation followed Michaelis-Menten-like kinetics. The large k2 term related to a turnover number indicated that the present polymeric catalysts have a remarkable effect on the activation process. The methylene number between the side-chain acid amido and pyridyl groups of the polymeric ligand was shown to be closely related to the appearance of hydrophobic effects in both the substrate-binding and the activation processes as deduced from the Michaelis constant and the thermodynamic and activation parameters. The binding parameters for 4-methoxyphenol with pyridyl-functionalized polyorganosiloxanes supported that the flexible backbone is also effective in the oxidation of hydroquinone. The Cu(II) complexes with pyridyl-functionalized polyorganosiloxane would have the structures distorted from square planar formation, which would promote the reduction of Cu(II) to Cu(I), as concluded from ESR spectroscopy and electrochemical measurement. © 1994 John Wiley & Sons, Inc.
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  • 149
    ISSN: 0887-624X
    Keywords: polymer electrolyte ; latex ; battery ; styrene-butadiene ; acrylonitrile-butadiene ; dual-phase ; emulsion polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ion-free latices of styrene-butadiene rubber (SBR) and nitrile-butadiene rubber (NBR) were synthesized by emulsion polymerization with use of poly (vinyl pyrrolidone) (PVP) stabilizer. The goal was to prepare ion-free latex films, possessing dual-phase latex particle morphology, and swell the films with liquid electrolyte to yield dual-phase polymer electrolytes (DPE). SBR/PVP latex was prepared readily, but NBR/PVP latex was sensitive to coagulation. Differential scanning calorimetric (DSC) and scanning electron microscopic (SEM) analyses of latex films provided morphological evidence concerning particle structure and phase separation. Blends of NBR/PVP and PB/PVP latices (PB = polybutadiene) were also investigated, but particle structure was not present in the blended latex film, even though particle structure was present in the individual NBR/PVP and PB/PVP latex films. After extensive swelling of SBR/PVP latex films, PVP was extracted from the films, and ionic conductivities greater than 10-3 S/cm were achieved. © 1994-John Wiley & Sons, Inc.
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  • 150
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1903-1908 
    ISSN: 0887-624X
    Keywords: polyimides ; pendant hydroxyl ; hydrophilic ; amine hydrochloride ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High Tg polyimides containing pendant phenolic hydroxyl groups were synthesized in high molecular weight via one-step solution polymerization of the dihydrochloride salt of 4,6-diaminoresorcinol with various commercially available dianhydrides. Polymerization proceeds via initial dissociation of diaminoresorcinol dihydrochloride to hydrogen chloride gas and diaminoresorcinol, followed by rapid dissolution of diaminoresorcinol and polymerization with the dianhydride monomer to afford soluble, fully-cyclized polyimide. The resulting poly(hydroxy-imide)s, which contain two phenolic hydroxyl groups per repeat unit, were soluble in amide solvents and dilute aqueous bases, displayed reasonably high glass transition temperatures and a high degree of water uptake. © 1994 John Wiley & Sons, Inc.
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  • 151
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1931-1938 
    ISSN: 0887-624X
    Keywords: FEP ; styrene ; radiation grafting ; synthesis ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gamma radiation-induced grafting of styrene into FEP films was investigated by the pre-irradiation method. The degree of grafting was found to be strongly dependent on the synthesis conditions, such as radiation dose, monomer concentration, crosslinker, temperature, and film thickness. The order of dependence of the rate of grafting on pre-irradiation dose and monomer concentration was found to be 0.64 and 1.90, respectively. The activation energy for the grafting in the temperature range of 50-80°C was determined to be 27.9 kJ/mol. A negative first order dependence of grafting on film thickness was observed. The results suggest that the initial grafting takes place at the film surface and proceeds to the middle by progressive diffusion of monomer through the polystyrene grafted layers. © 1994 John Wiley & Sons, Inc.
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  • 152
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1969-1975 
    ISSN: 0887-624X
    Keywords: high-performance aromatic polyethers ; aromatic nucleophilic substitution polymerization ; aromatic polyether ketone containing imide ; thermal behavior ; high-temperature polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly(arylene ether ketone)s containing imide units were prepared by the aromatic nucleophilic displacement reaction of the potassium salts of bisphenols with bis(4-fluorobenzoyl)phthalimides in N-methyl-2-pyrrolidone at elevated temperature. The polymers having inherent viscosities of 0.34-0.77 dL/g were obtained in 2 h. The polymers exhibited glass transition temperatures ranging from 216 to 268°C and decomposition temperatures (5% weight loss under air atmosphere) ranging from 450-570°C mainly depending on the bisphenols used in the polymer synthesis. The isothermal TGA measurements (400°C under air or nitrogen atmosphere) revealed that the 4,4'-biphenol- and hydroquinone-based poly(arylene ether ketone imide)s belong to a superior class of heat resistant polymers. The mechanical properties of these polymers are also described. © 1994 John Wiley & Sons, Inc.
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  • 153
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1991-1995 
    ISSN: 0887-624X
    Keywords: allenyl ethers ; oligo(oxyethylene)s ; crosslinking ; nonionic hydrogel ; cationic catalyst ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cationic crosslinking reactions of poly(allenyl ether)s having oligo(oxyethylene) moieties prepared by the radical polymerization of the corresponding allenyl ethers were carried out under some varied reaction conditions. For instance, a crosslinked polymer was obtained in 82% yield by the treatment of poly(ethylene glycol methyl allenyl ether) (1a) with 1.2 mol% of BF3·OEt2 (2) under high concentration in dichloromethane (46 wt %). The gels obtained showed good swelling properties in water, alcohols, and polar organic solvents such as dichloromethane. In particular, the degrees of swelling of these gels in aqueous sodium chloride (1M) were quite similar to those in ion-free water, indicating that these gels served as nonionic hydrogels. © 1994 John Wiley & Sons, Inc.
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  • 154
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2437-2441 
    ISSN: 0887-624X
    Keywords: metathesis ; graphite-like crystal ; pyrolysis ; conductivity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Poly-(2,4-hexadiyn-1,6-diol) (PHDO), prepared by NbCl5/(n-Bu)4Sn catalyzed metathesis of HDO, was pyrolyzed at various temperatures and electrical and structural properties of resulting polymers were investigated by FT-IR, Laser Raman, CP/MAS 13C-NMR and X-ray diffraction methods. The polymer obtained by pyrolysis of PHDO at 800°C showed a conductivity of about 10 S/cm at room temperature. The structure of the polymer seems to be a graphite-like crystal consisting of condensed aromatic layers. © 1994 John Wiley & Sons, Inc.
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  • 155
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2479-2486 
    ISSN: 0887-624X
    Keywords: surface treatment ; silent discharge ; plasma ; polyethylene ; polypropylene ; polyisobutylene ; polystyrene ; polyisoprene ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dielectric barrier air discharge treatment of polyethylene, polypropylene, polyisobutylene, polystyrene, and polyisoprene substrates has been characterized by x-ray photoelectron spectroscopy (XPS). The relative reactivities of these polymers towards silent discharge oxidation are rationalized in terms of ozone molecules interacting with an excited surface. © 1994 John Wiley & Sons, Inc.
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  • 156
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2493-2500 
    ISSN: 0887-624X
    Keywords: aromatic polyketone ; palladium catalysis ; diacetal ; cross-coupling condensation ; zinc reagent ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dibromobenzophenone diacetals (BrC6H4)2C(OR)2 undergo cross-coupling reactions with (Bu3SnC6H4)2O in the presence of palladium catalysts to give poly (diacetal ether)s whose molecular weights reflect the solubility changes of the growing polymer chains as a function of the diacetal precursors, R = Me 〈 1/2 CH2CH2 〈 1/2 CH2CHMe and are significantly higher than those of polymers derived from dibromobenzophenone. New di-zinc reagents based on diacetal derivatives were synthesized and used as organometallic coupling reagents with a range of dibromoarenes, resulting in a series of previously inaccessible poly (biphenylene ketone)s and poly (biphenylene ketone sulfone)s. While poly (biphenylene ether ketone)s are insoluble, poly (biphenylene ketone)s readily dissolve in concentrated sulfuric acid. The effects of reaction parameters on the molecular weight of poly (biphenylene ketone) were determined. © 1994 John Wiley & Sons, Inc.
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  • 157
    ISSN: 0887-624X
    Keywords: living polymerization ; cationic polymerization ; styrene ; end-functionalized polymer ; macromonomer ; organosilicon compounds ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The end-functionalization of living polymers with bases (methanol, benzylamine, diethyl sodiomalonate, and sodium methoxide) and organosilicon compounds [X — Si(CH3)3;X —: CH2=C(CH3)COO—, CH3COO—, CH2=CHCH2—, C6H5—] was investigated in the living cationic polymerization of styrene initiated with the 1-phenylethyl chloride/SnCl4/nBu4NCl system in CH2Cl2 at -15°C. The four bases and C6H5SiMe3, independent of their structures, were apparently incapable of reacting with the living end and invariably led to polystyrenes with the ω-end chlorine [∼ ∼ ∼ CH2CH(Ph)Cl] originated from the initiating system. The number-average end-functionality (F̄n) of the chloride, determined by 1H-NMR, was close to unity (F̄n 〉 0.9). The presence of chlorine in the polymer was also confirmed by elemental analysis. In contrast, the quenching by the trimethylsilyl compounds with X = methacryloxy, acetoxy, and allyl gave ω-end-functionalized polystyrenes with the corresponding terminal groups (X) for which the F̄n values were close to unity (F̄n 〉 0.9). The effects of the structure of silyl compounds on end-capping are also discussed. © 1994 John Wiley & Sons, Inc.
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  • 158
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2073-2083 
    ISSN: 0887-624X
    Keywords: radical polymerization ; anionic polymerization ; polyimide ; thermal stability ; itaconic derivatives ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N-alkyl-substituted itaconimides (RII) and N-(alkyl-substituted phenyl)itaconimides (RPhII) with various alkyl substituents were prepared and polymerized in the presence of a radical or anionic initiator to give high molecular weight polymers in high yields. The effects of the alkyl substituents on the polymerization reactivities were investigated. It has been revealed that RII and RPhII have the highest polymerization reactivity compared with other itaconic and citraconic derivatives including dialkyl itaconates and citraconimides. The structure and some properties of poly(RII) and poly(RPhII) were examined. These polymers were found to have excellent thermal stability, better than poly (dialkyl itaconate)s. © 1994 John Wiley & Sons, Inc.
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  • 159
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2193-2198 
    ISSN: 0887-624X
    Keywords: ESR ; polypropylene ; radical ; morphology ; diffusion ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To gain some knowledge on the influence of a substrate morphology upon radiochemical grafting efficiency, the formation and the evolution of irradiation induced peroxy-radicals were measured by ESR in two polypropylene (PP) films of different origins. The creation rate of peroxy-radicals was found to be almost proportional to the irradiation dose in the film presenting the best crystallinity, the bi-oriented PP, while it saturates in the unoriented one. The recombination kinetics of the radicals appeared to be controlled by their diffusion in the matrix and the corresponding diffusion coefficients are dependent on the matrix itself and on its evolution under irradiation. It is suggested that the crystalline order of the matrix is the parameter governing the mobility and thus the lifetime of the radicals. © 1994 John Wiley & Sons, Inc.
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  • 160
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2257-2265 
    ISSN: 0887-624X
    Keywords: helix in amylopectin-iodine complex ; I4 unit in amylopectin-iodine complex ; spectra of amylopectin-iodine complex ; amylopectin-iodine chromophore composition ; amylopectin fine structures and complex formation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A partial hydrolysis of amylose followed by the addition of iodine provides a spectrum almost identical to that of the amylopectin-iodine (API) complex suggesting the involvement of smaller “amylose-like” units in the API complex. Our theoretical studies on different polyiodine and polyiodide species suggest that a nearly linear I4 unit stabilized within the cavity of a small “amylose-like” helix is responsible for the characteristic API spectrum. Since there are 2.75 anhydroglucose residues (AGU) for every iodine atom in the amylose-iodine (AI) complex and a structural similarity exists between the API and the AI (amylose-iodine) complexes, we identify (C6H10O5)11I4 to be the chromophore in the API complex. © 1994 John Wiley & Sons, Inc.
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  • 161
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2283-2290 
    ISSN: 0887-624X
    Keywords: epoxide ; bicyclic amide acetal ; 2-oxazoline ; ring-opening polymerization ; zwitterion polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various bicyclic amide acetals were synthesized from the cycloaddition reactions of 2-substituted-2-oxazolines with styrene oxide. Ring-opening polymerization of the bicyclic amide acetals occurred upon heating in the presence of methyl tosylate. Characterization of the bicyclic amide acetals and their polymers was accomplished by NMR and elemental analysis. Vapor pressure osmometry showed the highest polymer molecular weight was only 2,400. The mechanisms for cycloaddition and polymerization are discussed. © 1994 John Wiley & Sons, Inc.
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  • 162
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2327-2332 
    ISSN: 0887-624X
    Keywords: surface grafting of polymers ; ultrafine silica ; titanium oxide ; photografting ; azo groups ; vinyl polymer ; dispersibility ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photografting of polymers onto ultrafine inorganic particles, such as silica and titanium oxide, initiated by azo groups introduced onto these surfaces was investigated. The introduction of azo groups onto the particles was achieved by the reaction of 4,4′-azobis(4-cyanopentanoic acid) with surface isocyanate groups, which were introduced by the treatment with tolylene 2,4-diisocyanate. It was found that the photopolymerization of vinyl monomers, such as methyl methacrylate (MMA), styrene, and N-vinylcarbazole, is initiated by ultrafine particles having azo groups. The corresponding polymers were effectively grafted onto these surfaces through the propagation of the polymer from the surface radicals formed by the photodecomposition of the azo groups: e.g., the percentage of grafting of PMMA and polystyrene onto silica was reached to 112 and 176%, respectively. The percentage of grafting onto silica in the graft polymerization initiated by photodecomposition of surface azo groups was much larger than that initiated by thermal decomposition. Polymer-grafted ultrafine particles thus obtained gave a stable colloidal dispersion in good solvents for the grafted chain. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2377-2385 
    ISSN: 0887-624X
    Keywords: thermosetting imides ; 1,4-phenylenebis(phenylmaleic anhydride) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dianhydride monomer 1,4-phenylenebis(phenylmaleic anhydride) was polymerized with various aromatic diamines in a one-step solution polymerization to afford high molecular weight, soluble polyimides containing backbone phenylmaleimide structures. The polymides were soluble in amide solvents, chlorinated hydrocarbons, and tetrahydrofuran at 25°C at a concentration of 15% (w/v), displayed molecular weight distributions (Mw/Mn) of 2.0-2.2 as determined by absolute GPC and showed Tg values of 240°C and above as measured by differential scanning calorimetry. In addition, polyimide thermosets were prepared from these materials by thermal cure at 350-360°C. The crosslinked polyimides displayed Tgs 20-25°C higher than their soluble precursors, and chloroform extraction indicated gel fractions ranging from 74-100% after cure. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2403-2411 
    ISSN: 0887-624X
    Keywords: poly (styrylpyridine) polyamide and polyimides ; heat-resistant polymers ; bismaleimide ; bisnadimide ; 2,2′-(1,4-phenylenedivinylene) bisaminoquinoline ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nitration of quinaldine by fuming nitric and sulfuric acid afforded nitroquinaldine. It was condensed with a half molar amount of 1,4-benzenedicarbaldehyde in the presence of acetic anhydride to yield 2,2′-(1,4-phenylenedivinylene) bisnitroquinoline. The latter was catalytically hydrogenated to the corresponding diamine, PBAQ. The new polyamide and polymides bearing styrylpyridine segments were prepared utilizing PBAQ as starting material. In addition, a model diamide and diimide were synthesized and characterized IR and 1H-NMR spectroscopy. Inherent viscosities of polymers ranged from 0.31 to 0.60 dl/g. Certain polymer precursors such as a bismaleimide and bisnadimide were synthesized from the reactions of PBAQ with maleic and nadic anhydride, respectively. Their curing behavior was investigated by DTA. Curing of polyamide, polyimides, and polymer precursors at 240°C for 15 h yielded crosslinked polymers. They were stable up to 329-310°C in N2 or air and afforded a char yield of 67-62% in N2 at 800°C. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2443-2455 
    ISSN: 0887-624X
    Keywords: polycaprolactone ; polylactide ; ring-opening polymerization ; biocompatible ; co-aminopolyester ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Since bromides are well-known precursors of primary amines, diethylaluminum 12 bromo-1-dodecyl oxide has been prepared and used as an initiator for the ring-opening polymerization of ∊-caprolactone and L-lactide. Uner strictly controlled conditions, the end-functionalization of the polyesters in quantitative and the bromo end-group is easily converted into an azide group whatever the polymeric backbone. The subsequent reduction of the azide into the expected primary amine has been investigated by catalytic transfer hydrogenation (CTH) in DMF and by hydrolysis in the presence of triphenylphosphine in THF, respectively.The hydrolysis reaction (PΦ3/H2O) is perturbed by a coupling reaction, which involves a protonate secondary amine and leads to a twofold increase in the polyester molecular weight. The CTH method gives rise to the expected ω-NH2 poly (∊-caprolactone), in contrast to polylactide which seems to be unstable toward the nascent amine end group. Whatever the polarity of the medium (DMF or THF), aminolysis of polylactides is observed to occur and leads to the formation of an internal amide. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2487-2492 
    ISSN: 0887-624X
    Keywords: PMMA ; radiolysis ; temperature effect ; degradation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Effect of irradiation temperature on the main-chain scission of poly (methyl methacrylate) (PMMA) caused by γ-irradiation was studied by means of gel permeation chromatography and ESR spectroscopy. Although no temperature dependency was observed on the scission efficiency for purified PMMA, the efficiency for crude or monomer-doped purified PMMA was decreased by decreasing the temperature below ca. 200 K. Above 200 K the efficiency was constant and did not depend on the purity of PMMA. ESR study of the irradiated PMMA revealed that the suppression of the scission below 200 K is induced by the addition of methyl methacrylate monomer to primary radical species, which otherwise cause the main-chain scission by warming the polymer above 200 K. The primary radical generated above 200 K immediately converts to the scission-type — CH2 — Ċ(CH3) COOCH3 radical through the β-scission of the polymer main chain, so that the efficiency of the scission does not depend on both the impurity and the irradiation temperature. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2517-2522 
    ISSN: 0887-624X
    Keywords: radical crosslinking ; poly (vinylcyclopropanone acetal)s ; 1,4-butanediol ; dimethanonaphthalene-2,3-dimethanol ; 1,5-ring-opening ; density ; Tg ; thermal analysis ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and radical crosslinking reaction of poly (vinylcyclopropanone acetal)s (4), volume change on the crosslinking, and thermal analysis of 4 and the crosslinked polymers were carried out. 4was prepared by the reaction of 1,1-dichloro-2-vinylcyclopropane with sodium dialkoxides. Radical crosslinking of 4a was carried out in the presence of AIBN, BPO, or DTBP at 60, 80, or 120°C, respectively. 4a afforded no dichloromethane-insoluble part in the crosslinking in chlorobenzene but afforded in 37% yield in bulk at 120°C. On the other hand, 4b afforded dichloromethane-insoluble part in 33% yield in the crosslinking in chlorobenzene at 120°C. Volume shrinkage of 4a and 4b on crosslinking at 120°C was 4.11 and 3.55%, respectively. Glass transition temperatures of the crosslinked polymers obtained from 4a and 4b were 28 and 163°C, respectively, which were 32 ∼ 49°C higher than those before crosslinking. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2523-2530 
    ISSN: 0887-624X
    Keywords: substituted polyacetylene ; poly (diphenylacetylene) ; metathesis polymerization ; tantalum catalyst ; solubility ; thermal stability ; gas permeability ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-(p-t-Butylphenyl)-2-phenylacetylene and 1-(p-n-butylphenyl)-2-phenylacetylene were polymerized in catalytic systems based on TaCl5 to give new polymers in high yields. These monomers were more reactive than diphenylacetylene (DPA) in copolymerization. Unlike poly (DPA), the present polymers were soluble in toluene, CHCl3, etc. owing to the high configurational entropy induced by the para-substituents. Their relative weight-average molecular weights determined by GPC were in the range of 6 × 105-36 × 105, and films could be obtained by solution casting. These polymers were fairly thermally stable, as seen from their high onset temperatures (320-380°C) of weight loss in TGA in air. The oxygen permeability coefficient of the polymer with t-Bu group was 1100 barrers, the highest among those of all the hydrocarbon polymers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2551-2558 
    ISSN: 0887-624X
    Keywords: latex ; polymer electrolyte ; dual-phase ; acrylonitrile-butadiene rubber (NBR) ; styrene-butadiene rubber (SBR) ; TEM ; EELS ; EDX ; percolation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dual-phase polymer electrolytes (DPE) that have high ionic conductivity (〉 10-3 S/cm) and good mechanical strength were prepared by mixing NBR and SBR latices and casting films. The latex films absorbed large quantities of lithium salt solution (e.g., 1M lithium perchlorate in γ-butyrolactone) to obtain DPE films but did not dissolve with swelling. The NBR phase is polar and was impregnated selectively with the polar lithium salt solution, whereas the SBR phase is nonpolar and formed a mechanically-supportive matrix. Transmission electron microscopic (TEM), electron energy loss spectral (EELS), and energy-dispersive x-ray (EDX) analyses showed microscopically the dual-phase structure. Evidence for swelling by lithium salt solution was found only in the NBR phase and not in the SBR phase by EDX microanalysis. Ionic conductivity as a function of NBR content or swelling degree showed clearly that a percolation threshold for ionic conductivity exists. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2603-2603 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2625-2628 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Crosslinked poly (methyl methacrylate) and poly (carbonate-urethane) as well as full interpenetrating network on their base (IPN) were characterized by precise heat capacity measurements in the temperature interval 1.2-150 K. As judged by the positive sign of the excess Gibbs free energy in the whole temperature interval above 30 K, the apparently single-phase state of IPN is thermodynamically unstable; however, its kinetic stability is ensured by permanent chamical crosslinks prohibiting the incipient phase separation. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2663-2675 
    ISSN: 0887-624X
    Keywords: polyimides ; polyimide synthesis ; transimidization route ; imide siloxane copolymers ; perfectly alternating segmented imide siloxane copolymer ; thermal properties ; mechanical properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New strategies for the synthesis of perfectly alternating segmented polyimide-polydimethyl siloxane copolymers were developed by utilizing a transimidization method. Imide oligomers endcapped with 2-aminopyrimidine were reacted with aminopropyl terminated (dimethyl siloxane) oligomers to afford perfectly alternating segmented imide siloxane copolymers. The polymerization was conducted in solvents such as chlorobenzene and chlorofrom. High molecular weight, fully imidized perfectly alternating segmented imide siloxane copolymers were obtained within 2 h at temperatures of 60-110°C. The mechanism of the reaction was further elucidated via model compounds and NMR characterization. The block copolymers exhibited two Tgs due to the microphase separation of the polyimide and polysiloxane phases. The Tg of the polyimide phase was a function of the length of the polyimide block. However, partial phase mixing was also evident from the DSC results on the imide siloxane copolymers prepared with low molecular weight polyimide segments. Thermooxidative stability and tensile properties of the perfectly alternating segmented imide siloxane copolymers were found to be principally dependent on the amount of poly (dimethyl siloxane) incorporated in the copolymer and did not correlate with the poly (dimethyl siloxane) or polyimide block lengths. The stress-strain behavior of both solvent cast films or molded films is also reported. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2709-2713 
    ISSN: 0887-624X
    Keywords: bis(triphenylphosphine) bis(2-propinyl-l-ol) palladium catalyst ; propargyl alcohol ; polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Homogeneous polymerization of propargyl alcohol (OHP) with Pd (C=CCH2OH)2(PPh3)2 [Pd=C] catalyst in CHCl3-CH3OH mixed solvent system has been investigated. [Pd=C] was found to be a novel effective catalyst for the OHP polymerization. Some features, kinetic behavior, and effect of solvent for the OHP polymerization are described and discussed. The overall polymerization activation energy was found to be 75.6kJ/mol and the rate equation can be expressed as Rp = kp[OHP] [Pd=C]0.7, where kp = 3.14 × 10-4 L0.7/ mol0.7 S (60°C). Polypropargyl alcohol (POHP) obtained is a brown powder with a number-average molecular weight (M̄n) of 103-2 × 103, and soluble in MeOH, DMF, and DMSO. Conducting properties of the resulting POHP were investigated. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2745-2754 
    ISSN: 0887-624X
    Keywords: radical polymerization ; copolymerization ; chain transfer ; α-(substituted methyl) acrylate ; α-(substituted methyl) styrene ; addition-fragmentation ; Co (III) complex ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dimerization of methyl methacrylate, ethyl methacrylate, methacrylonitrile, and α-methylstyrene to 2-substituted-1-allylic compounds [CH2=C(X)CH2C(CH3)2X] (X = COOR, C6H5, or CN), and methyl α-ethylacrylate to a 3-substituted-2-allylic compound [CH3CH=C(COOCH3)CH2C(CH3)(C2H5) COOCH3] was carried out by catalytic chain transfer using benzylbis (dimethylglyoximato) (pyridine) cobalt (III). These dimers were then used as addition-fragmentation chain transfer agents in the polymerizations of methyl methacrylate and styrene at 800C or above. Cross-dimers from methacrylic ester-α-methylstyrene and methacrylonitrile-α-methylstyrene mixtures were similarly prepared. Except for those from methyl α-ethylacrylate and methacrylonitrile, all the dimers participated in the addition-fragmentation and the copolymerization to different extents. The dimer of methyl α-ethylacrylate was actually inactive during the styrene and methyl methacrylate polymerizations. The methacrylonitrile dimer was primarily incorporated in the polymer chain through copolymerization. Among the dimer and the cross-dimers from α-methylstyrene with the other monomers, those bearing the α-methylstyrene moiety in the α-substituent [CH2=C(X)CH2C(CH3)2C6H5, X=COOCH3, COOC2H5, and CN] are noted as highly reactive chain transfer agents. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2789-2792 
    ISSN: 0887-624X
    Keywords: conjugated polymer ; carbazole ; electrochemical ; electrochromic ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2597-2601 
    ISSN: 0887-624X
    Keywords: silanol-containing polymers ; poly(4-vinylphenylmethylphenylsilanol) ; oxyfunctionalization of silane ; hydrogen bonding ; glass transition temperature ; FT-IR ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2619-2624 
    ISSN: 0887-624X
    Keywords: oligodihexanoylchitin ; selective acid hydrolysis ; block copolymer ; poly (propylene glycol) ; 4,4'-methylenedi (phenyl isocyanate) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of oligodihexanoylchitin (3) having hydroxy groups at the both ends was carried out by an acid hydrolysis of a parent dihexanoylchitin in a mixed solution of acetic acid and conc. hydrochloric acid (11 : 1 in volume) at a room temperature. After 13-21 h, the products were isolated and their molecular weights were calculated as 7400-1100 by GPC analyses. The structure of the product 3 was determined by 1H and 13C-NMR and IR spectra. The IR spectra of the products yielded for longer hydrolysis times than 30 h, however, indicated the occurrence of the dehexanoylation. The block copolymerization of 3 with poly (propylene glycol) (PPG) using 4,4'-methylenedi (phenyl isocyanate) (MDI) as a coupling reagent gave the block copolymer 6. The molecular weight of 6 as obrained by GPC was 52,000. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2653-2662 
    ISSN: 0887-624X
    Keywords: poly(amide-imide)s ; 9,9-bis (4-hydroxyphenyl) fluorene ; 9,9-bis[4-(4-aminophenoxy) phenyl] fluorene ; triphenyl phosphite ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A dicarboxylic acid (I) was prepared from the condensation of 9,9-bis[4-(4-aminophenoxy) phenyl] fluorene and trimellitic anhydride. A new family of poly(amide-imide)s having inherent viscosities of 0.75-1.04 dL/g was prepared by the triphenyl phosphite activated polycondensation from the diimide-diacid I with various aromatic diamines in a medium consisting of N-methyl-2-pyrrolidone (NMP), pyridine, and calcium chloride. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All the soluble poly(amide-imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 262-325°C and the 10% weight loss temperatures were above 525°C in air. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2699-2708 
    ISSN: 0887-624X
    Keywords: living polymerization ; cationic polymerization ; multifunctional coupling agent ; end-functionalized polymer ; multiarmed polymer ; silyl enol ether ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Telechelic (8) and end-functionalized four-arm star polymers (9) were synthesized through the coupling reactions of end-functionalized living poly(isobutyl vinyl ether) (5; DPn ∼ 10) with the bi-and tetrafunctional silyl enol ethers, H4-nC—[CH2OC6H4C(OSiMe3) = CH2]n (3: n = 2; 4: n = 4). The precursor polymers 5 were prepared by living cationic polymerization with functionalized initiators, CH3CH(Cl)OCH2CH2X(6), in conjunction with zinc chloride in methylene chloride at -15°C. The initiators 6 were obtained by the addition of hydrogen chloride gas to vinyl ethers bearing pendant functional groups X, including acetoxy [—OC(O)CH3], styryl (—OCH2C6H4-p-CH = CH2), and methacryloyl [—OC(O)C(CH3) = CH2]. The coupling reactions with 3 and 4 in methylene chloride at -15°C for 24 h afforded the end-functionalized multiarmed polymers (8 and 9) in high yield (〉91%), where those with styryl or methacryloyl groups are new multifunctional macromonomers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2739-2743 
    ISSN: 0887-624X
    Keywords: fullerenes ; carbazole ; Friedel-Crafts alkylation ; brornination ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Surface-substituted and homogeneous fullerenated polymers were produced by bromination followed by a Friedel-Crafts reaction. Control over bonding patterns was provided by the bromination, which enabled the production of photodegradation-resistant fullerenated polymers. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2765-2773 
    ISSN: 0887-624X
    Keywords: new photoresponsive polymer ; pendant NBD moiety ; photochemical reaction of NBD ; photosensitization ; catalytic reversion of QC ; stored thermal energy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New photoresponsive polymers 1-4 containing pendant norbornadiene (NBD) moieties with N,N-disubstituted amide groups were synthesized with 97, 98, 92, and 94% conversions by the substitution reaction of poly (p-chloromethyl) styrene] with potassium salts of 3piperidyloxo-2,5-NBD-2-carboxylic acid, 3-(NN-dipropylcarbamoyl) -2,5-NBD-2-carboxylic acid, 3-(N-methyl-N-phenylcarbamoyl)-2,5-NBD-2-carboxylic acid, and 3-(N,N-dipheylcarbmoyl)-2,5-NBD-2-carboxylic acid, respectively, using tetrabutylammonium bromide as a phase transfer catalyst for all. Polymers 1-4 with N,N-disubstituted amide groups on the NBD moieties were sensitized by adding appropriate photosensitizers such as Michler's ketone and 4- (N,N-dimethylamino) benzophenone in the film state, although the reactivities of the polymers without photosensitizer were lower than that of our previously reported polymer 5 containing pendant 3- (N-phenylcarbamoyl) -2,5-NBD-2-carboxylate moiety. It was also found that the photo-irradiated retaining polymers 1-4 containing the corresponding QC moieties can be stored about 80-86 kJ/mol of their thermal energy. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2997-2997 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [no Abstrat]
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2825-2839 
    ISSN: 0887-624X
    Keywords: polyimides ; polyethers ; polybenzoxazoles ; polyesters ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4-Hydroxy-5-nitrophthalimides were produced via nucleophilic aromatic substitution (NAS) of 4,5-dichloro phthalimide substituents by potassium nitrite. The use of a N-phenyl-phthalimide having a protected 4′-hydroxyl group allows concurrent deprotection and nitro reduction to amine to give the 4-hydroxy-5-amino-N-(4′-hydroxyphenyl) phthalimide. This key intermediate is the precursor to a poly (ether-imide-benzoxazole), and is the condensable monomer for a poly (ester-imide-benzoxazole). Benzoxazole monomer formation via condensation with p-fluorobenzoyl chloride afforded 2-(4′-fluorophenyl)-5,6,-N-[4′(-hydroxyphenyl) imide]-benzoxazole, which was polymerized under NAS conditions to produce a poly(ether-imide-benzoxazole) having an endothermic transition at 454°C with weight retention of 90% at 500°C in both air and nitrogen. Solution polycondensation of the 4-hydroxy-5-amino-N-(4′-hydroxyphenyl) phthalimide monomer with isophthaloyl chloride afforded a poly(ester-amide-imide) which was isolated and thermally cyclodehydrated in the solid state under vacuum to give a poly(ester-imide-benzoxazole) having 95% weight retention at 500°C in both air and nitrogen, with no detectable DSC transitions up to 500°C. © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2873-2881 
    ISSN: 0887-624X
    Keywords: poly(ethylene 2,6-naphthalate) ; bis (2-hydroxyethyl) naphthalate ; kinetic constant ; catalyzed formation ; stability constant (log β1) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The catalyzed transesterification between dimethyl 2,6-naphthalate and ethylene glycol and polycondensation of bis (2-hydroxyethyl) naphthalate have been investigated in the presence of various metal compounds as catalysts. The effect of the nature and concentration of these catalysts on both reactions has been studied. The observed overall rate of the transesterification was third order; first order with respect to dimethyl 2,6-naphthalate, ethylene glycol, and the catalyst including initial concentration of catalyst, respectively. The decreasing order in catalytic activity on the transesterification was the order of Pb(II) 〉 Zn(II) 〉 Mn(II) 〉 Co(II) 〉 Ti(IV) 〉 Sn(II) 〉 Mg(II) 〉 Ca(II) 〉 Na(I) 〉 Sb(III). And also, the decreasing order in catalytic activity on the polycondensation was found to be Ti(IV) 〉 mixtures of Ti(IV) and Sb(III) 〉 Sn(II) 〉 Sb(III) 〉 Co(II) 〉 Zn(II) 〉 Pb(II) 〉 Mn(II) 〉 Mg(II). © 1994 John Wiley & Sons, Inc.
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    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2911-2918 
    ISSN: 0887-624X
    Keywords: iniferter ; dithiocarbamate ; methyl acrylate ; photopolymerization ; star polymer ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of methyl acrylate (MA) with benzyl N, N-diethyldithiocarbamate (BDC) was carried out in bulk or in benzene under UV irradiation. The polymerization proceeded to give a high yield of polymer, however it was found that BDC did not function as an iniferter in the MA polymerization. Bimolecular termination leading to deactivation of the iniferter site was observed during the polymerization in preference to chain transfer and primary radical termination which reproduce the iniferter site. The deactivation was successfully prevented by combining BDC and tetraethylthiuram disulfide (TD) as a two-component iniferter. This two-component iniferter system was also applied to synthesis of a star polymer with 1,2,4,5-tetrakis (N,N-diethyldithocarbamylmethyl) benzene (DDC) as a tetrafunctional photoiniferter. © 1994 John Wiley & Sons, Inc.
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2937-2945 
    ISSN: 0887-624X
    Keywords: phase transfer ; α-hydroxymethylacrylates ; substituted acrylates ; methacrylates ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New ester derivatives of ethyl α-hydroxymethylacrylate were synthesized using acid chlorides (traditional solution reactions), sodium salts of acids (with phase transfer catalysis), and trifluoroacetic anhydride (trifluoroacetate). The interfacial process gave high yields of clean products under very mild conditions. Derivatives obtained include the formate, acetate, hexanoate, stearate, benzoate, trifluoroacetate, and adamantanoate. Bulk polymerizations with 2,2′-azobis (isobutyronitrile) gave high molecular weight polymers with intrinsic viscosities of over 2 dL/g and molecular weights of several million [based on size-exclusion chromatography (SEC) comparison to polystyrene standards]. These high molecular weights were the result of autoacceleration in the bulk as shown by monitoring molecular weight with respect to conversion. Solution polymerization in benzene gave more typical polymer, e.g., the acetate derivative showed an SEC molecular weight of 52,000. Glass transition temperatures for the n-alkyl esters decreased from the formate (77°C) to the hexanoate (15°C); the stearate showed a side-chain melting point of 40°C but no Tg. Glass transitions were observed for the trifluoroacetate, benzoate, and adamantanoate polymers at 69, 130, and 214°C, respectively. Solution 13C-NMR showed evidence of tacticity information for the formate and acetate derivatives with appaent preference for syndiotactic polymer formation similar to that of methyl methacrylate. FTIR and solid-state 13C-NMR analysis gave spectra with functional group peaks and chemical shift values expected based on composition. The stearate monomer and polymer gave solid-state 13C chemical shifts of 34 and 33 ppm, respectively, for the central CH2 units consistent with monoclinic and orthorhombic crystal packing. © 1994 John Wiley & Sons, Inc.
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  • 187
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2971-2978 
    ISSN: 0887-624X
    Keywords: free-radical copolymerization ; complex-participation ; penultimate effect ; 1:1 electron donor-acceptor complex ; copolymer composition ; copolymer sequence distribution ; Comppen model ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Comppen model for the mechanism of free-radical copolymerization has been developed to account for both penultimate effects and the participation of 1:1 electron donor-acceptor complexes during chain propagation. This was achieved by incorporating penultimate effects into the existing complex participation model of Cais, Farmer, Hill, and O'Donnell, using probability theory to derive new copolymer composition and sequence distribution equations that are solely functions of the reactivity ratios, the composition of the comonomer feed, and the equilibrium constant for 1:1 electron donor-acceptor complex formation. The model was applied to experimental data from styrene/maleic anhydride copolymers prepared in methyl ethyl ketone at 50°C over a wide range of comonomer feed compositions, using nonlinear least-squares curve fitting techniques to determine best estimates of the reactivity ratios. Copolymer compositions and sequence distributions for copolymers in this comonomer system were then predicted using the Comppen model and compared to those determined experimentally via 13C-NMR spectroscopy. © 1994 John Wiley & Sons, Inc.
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  • 188
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2999-3007 
    ISSN: 0887-624X
    Keywords: segmented copoly(ether-ester)s ; hard segment ; soft segment ; random copolymers ; thermotropic liquid crystalline polymers ; mesophase ; thermotropic elastomers ; thermal properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of segmented copoly(ether-ester)s with (oxy-2-methyl-1,4-phenyleneoxycarbonyl-1,4-phenylene carbonyl)/(oxy-2-chloro-1,4-phenyleneoxycarbonyl-1,4-phenylene carbonyl) (methyl-/chloro-substituted) hard segments and poly(oxytetramethylene) soft segments, are reported. The methodology consisted of staged addition melt condensation of terephthaloyl chloride, poly(oxytetramethylene)glycol (POTMG; \[ \bar M_n \] = 250, 650, 1000, 2000) and methyl-/chloro-hydroquinone. Lengths of hard and soft segments were varied while the weight ratio of hard to soft segment was maintained constant. Copolymers were characterised for solubility behavior, and by infrared spectroscopy, x-ray diffraction, DSC, and polarizing microscopy. Thermal properties were found to be dependent on length of soft segment as well as on the type of substituent in the mesogenic core. In both methyl- as well as chloro-substituted copoly(ether-ester)s soft segment glass transition temperature (Tgs) was obtained between -40 and -50°C. All copoly(ether-ester)s are elastomeric at room temperature (25°C). These polymers exhibit thermotropic liquid crystalline behavior and were easily sheared and aligned in liquid crystalline state. © 1994 John Wiley & Sons, Inc.
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  • 189
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 3047-3059 
    ISSN: 0887-624X
    Keywords: MgCl2-supported catalyst ; polymer/catalyst morphology ; replication ; electron microscopy ; particle growth mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To elucidate the particle growth mechanism in propylene polymerization with high-yield MgCl2-supported Ziegler-Natta catalysts, observations have been carried out by electron microscopy on a series of samples having different degrees of polymer growth (from 0.1 to 1000 g/g of catalyst). Topics such as surface and bulk morphology, catalyst fragmentation, as well as distribution of the catalyst residues in the polymer have been investigated. The experimental data suggest that if the site distribution in the catalyst is uniform and the polymerization conditions are mild, the polymer growth starts uniformly throughout the catalyst particle, which then undergoes an even and progressive fragmentation into very fine units homeogeneously dispersed in the polymer matrix. The above results thus provide further experimental support to the particle growth mechanism outlined in the multigrain or polymeric flow models. © 1994 John Wiley & Sons, Inc.
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  • 190
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 3061-3067 
    ISSN: 0887-624X
    Keywords: Oligomers ; phenylethynyl termination ; thermally stable polymers ; polyimides ; high-performance polymers ; films ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two new phenylethynyl endcapping compounds, 3- and 4-amino-4′-phenylethynylbenzophenone, were synthesized and used to terminate imide oligomers from 3,4′-oxydianiline and 4,4′-oxydiphthalic anhydride at a calculated molecular weight of 9000 g/mol and from 3,4′-oxydianiline (0.85 mol), 1,3-bis (3-aminophenoxy) benzene (0.15 mol), and 3,3′,4,4′-biphenyltetracarboxylic dianhydride at a calculated molecular weight of 5000 g/mol. Glass transition temperatures for the cured oligomers were ∼ 249°C for the former and 272°C for the latter. Films cured at 350°C for 1 h were tough and flexible and provided high tensile properties. The uncured oligomers were readily compression molded to provide tough, solve nt-resistant moldings. © 1994 John Wiley & Sons, Inc.
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  • 191
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 3115-3122 
    ISSN: 0887-624X
    Keywords: copolycondensation ; biodegradable thermotropic liquid crystalline copolyester ; characterization ; microstructure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of novel thermotropic liquid crystalline copolyesters derived from aliphatic hydroxy acid (glycolic acid, GA) and aromatic hydroxy acid (p-hydroxybenzoic acid, PHBA) via a melt-copolycondensation process in the presence of various catalysts was explored. The following three possible routes were checked: PHBA and GA in different feed ratios with or without a catalyst; PHBA and GA in different feed ratios with or without a catalyst in the presence of acetic anhydride as a condensation agent; and different PHBA derivatives were used to examine the reactivity of aromatic hydroxy acid. The copolycondensability, chemical structure, liquid crystallinity, textures and morphology, phase transition behaviors and thermal stability, and solubility were investigated by FTIR, NMR, DSC, TGA, and polarized-light microscope. It has been found that only the 60-70 mol % PHBA-containing copolyesters could exhibit a nematic liquid crystallinity. The as-prepared polymers were brittle due to relatively lower molecular weights. © 1994 John Wiley & Sons, Inc.
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  • 192
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 3147-3151 
    ISSN: 0887-624X
    Keywords: polymerization of methyl methacrylate ; diphenylbutadiynes ; ESR spectra ; radical stabilization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The free radical polymerization of methyl methacrylate (MMA) in the presence of p,p′- disubstituted diphenylbutadiynes was studied. Both the rate and degree of polymerization are somewhat lowered by the presence of the diynes, but the propagating radicals were stabilized giving clear ESR signals of the interacted polyMMA radicals at the polymerization temperature of 70°C. The magnitude of the interaction depended on the electron density of the diynes; in the cases of diphenylbutadiyne and dimethoxycarbonyldiphenylbutadiyne, the intoraction was more enhanced showing ESR signals with smaller spectra widths and increasing the number of radicals with the polymerization time, while in the cases of electron donor-substituted diynes the interaction was weaker and the radical concentration remained constant during the polymerization. These systems are considered to be examples of the stabilization of transient radicals by the direct interaction of radicals with additives without formation or breaking of chemical bonds. No diacetylenic group was found in the polyMMA obtained. © 1994 John Wiley & Sons, Inc.
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  • 193
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 3197-3200 
    ISSN: 0887-624X
    Keywords: polyethylene ; γ-irradiation ; crosslinking ; NMR alkanes ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 194
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 257-263 
    ISSN: 0887-624X
    Keywords: IPNs ; PPO ; poly (butadiene) diol ; SEM ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The fracture surface topography of simultaneous interpenetrating polymer networks (SIN'S) of poly (2,6-dimethyl-1,4 phenylene oxide) (PPO)/poly (butadiene) diol was examined by scanning electron microscopy (SEM). The phase morphology of the IPNs is highly dependent on PPO/poly (butadiene) diol mass ratio. A single-phase morphology of the IPNs was achieved when the content of poly (butadiene) diol is below 40 wt % in the initial composition. The SEM observations are also wholly consistent with the glass transition temperature behavior obtained in the differential scanning calorimetric (DSC) measurements. © 1994 John Wiley & Sons, Inc.
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  • 195
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 47-56 
    ISSN: 0887-624X
    Keywords: acrylic esters ; fluorinated acrylates ; polyacrylates ; fluorinated polyacrylates ; fluorinated polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Five acrylic esters having different fluorine contents and distributions in their side-groups (i.e., CH2=CHC(O)OR, where R = —C(CH3)2C6F4H, —C(CH3)2C6F5, —C(CF3)2C6F5, —C(CF3)2C6H5, and —C(CH3)2C6H5) have been prepared from the reactions of the lithium salts of their corresponding alcohols with acryloyl chloride. These monomers are polymerized under identical conditions by the radical initiator AIBN and five polyacrylates were prepared having the structure of — [ —CH2CHC(O)OR—]n—. These addition polymers were compared and fully characterized by GPC, VPO, DSC, TGA, NMR, IR, and UV-visible spectroscopies, and they showed potential for practical applications. Significant differences in their thermal stabilities were found with respect to fluorine contents and distributions in these polyacrylates, and the highest stability arises from CF3 substitutions in the side-chains of the polymers. © 1994 John Wiley & Sons, Inc.
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  • 196
    ISSN: 0887-624X
    Keywords: aromatic polyformals ; 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane ; 2,2-bis(4-hydroxyphenyl)propane ; dichloromethane ; polycondensation ; copolycondensation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of fluorine-containing aromatic homopolyformal and copolyformals with a wide range of unit ratio were synthesized by the solution polycondensation of 2,2-bis (4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (Bisphenol AF) and/or 2,2-bis (4-hydroxyphenyl)propane (Bisphenol A) with dichloromethane, and the effect of the fluorine substitution on the preparation and properties of these polymers was investigated by comparing with those of Bisphenol-A-based homopolyformal without fluorine. Irrespective of the ratio of Bisphenol AF, high-molecular-weight, fluorine-containing polyformals with reduced viscosities of 1.4-5.3 dL/g were obtained in high yields by using dichloromethane as both comonomer and solvent, potassium hydroxide as a base, and N-methyl-2-pyrrolidone as a comedium at 75°C for 4 h. Their solubility increased markedly by the introduction of fluorine atom. Colorless, transparent, and tough films were cast from chloroform solution irrespective of fluorine content. These films had good mechanical properties comparable to that of Bisphenol-A-based homopolyformal. The contact angles by water were larger than 90°, regardless of their fluorine contents, at 25°C. The glass transition temperature and thermal stability increased monotonically with increasing fluorine content. © 1994 John Wiley & Sons, Inc.
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 121-130 
    ISSN: 0887-624X
    Keywords: plasma polymerization ; thin films ; fluorosiloxanes ; antiscratch coatings ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thin films have been deposited from radio-frequency glow discharges fed with vapors of a silicon- and fluorine-containing organic compound, namely 2,4,6-tris[(3,3,3-trifluoropropyl) (methyl)] cyclotrisiloxane, in mixture with argon. 2,4,6-tris[(3,3,3-trifluoropropyl)(methyl)]cyclotrisiloxaneA triode reactor has been utilized to deposit films by independently changing substrate temperature and bias-induced ion-bombardment. Laser interferometry, electron spectroscopy for chemical analysis and Fourier-transform infrared spectroscopy have been used to monitor film growth rate and composition. Results unambiguously show an activating effect of the ion-bombardment, which confirm the validity of the ion-assisted deposition model utilized for the plasma deposition of both teflon- and silicone-like films. In our experiments, low substrate temperature and bias conditions results in films with a “monomer-like” stoichiometry, while drastic conditions give origin to materials with a completely different composition and a markedly increased hardness. © 1994 John Wiley & Sons, Inc.
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  • 198
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 393-396 
    ISSN: 0887-624X
    Keywords: isoimide ; polyisoimide ; poly (amic acid) ; polyimide ; benzyloxyamine ; isomerization ; cyclization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 199
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 413-421 
    ISSN: 0887-624X
    Keywords: functional polyesters ; amino acid moiety ; organic/organic two-phase interfacial polycondensation ; complex catalytic action ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N, N-di (2-hydroxyethyl)-3-aminopropionic acid (M3) was synthesized and used for the preparation of a series of polyesters having amino acid moieties in the main chain and carboxyl groups as the side group. Polycondensation of M3, diols, bisphenol A, and isophthaloyl dichloride were performed in the presence of tertiary amine by solution and interfacial methods. Molecular weights of the polymers obtained by the solution method were not high, because oligomers produced at the early stage of reaction are ionized by H+ ions from the by-product, and become nonreactive triethylamine hydrochloride. Polymers with high M̄w (1-10 × 104) were obtained in a high yield by organic/organic two-phase interfacial polycondensation using DMAc and n-heptane as solvents. The combined nucleophilic and basic complex catalytic action of N, N, N′, N′-tetramethyl ethyiene diamine (TEMED) is suggested for the present organic phase/organic phase interfacial polycondensation. This method can be applied for the preparation of novel functional polyesters. © 1994 John Wiley & Sons, Inc.
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  • 200
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 15-31 
    ISSN: 0887-624X
    Keywords: poly(bisphenol-A-carbonate) ; nylon 6 ; blend ; melt mixing ; exchange reactions ; copolymer ; thermal degradation ; mess spectrometry ; NMR ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical reactions occurring in the melt mixing of nylon6/polycarbonate (Ny6/PC) at 240°C were investigated. The reaction of equimolar Ny6/PC blends can be reconciled within the overall scheme of an exchange reaction occurring with the attack of active amino terminals on the inner carbonate groups. We have performed the synthesis of low molecular weight amino-terminated nylon 6 and the effect of the active amino terminal groups on the exchange kinetics was investigated. The exchange reaction yields sizeable amounts of copolymer, in fact after 75 min of melt mixing the (initially equimolar) blend contains 30 mol of unreacted PC and 70 mol of Ny6/PC copolymer (all the Ny6 was therefore incorporated in the copolymer). Trifluoroacetylation of nylon 6 was used to produce CHCl3-soluble Ny6/PC copolymers, that could be analyzed by NMR. The NMR analysis yielded, beside the copolymer composition, evidence of the presence of urethane units interconnecting the Ny6 and PC blocks. The amount of urethane units increased with the reaction time, indicating a reduction of the block size as a function of the extent of exchange. Our study established the structure of the products formed, provided the materials balance of the process, and investigated some salient kinetic aspects. A thermal degradation study was also performed by thermogravimetry and direct pyrolysis mass spectrometry, to identify the products formed in the thermal treatment of the blends and to investigate the possible role of the inner amide groups in the intermolecular exchange reactions occurring between Ny6 and PC. Our results prove that these reactions occur above 300°C, and that only the cleavage of carbonate groups, by means of Ny6 amino end groups, is actually occurring at 240°C. © 1994 John Wiley & Sons, Inc.
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