Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Acrolein-acrylic acid copolymers: A solid-state 13C-NMR study of free aldehyde groupsN.C.L. Communication No. 4967. (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1077-1081 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080290716
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Random thermotropic elastomers. I. Effects of substitution and hard/soft segment lengths on propertiesNCL Communication no. 5848. (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2999-3007 
    Details
    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.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321601
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Hydrophobic effects in the copolymerization of methacrylic acid with acrylamideNCL Communication number 3944. (1987)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 25 (1987), S. 73-77 
    Details
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1987.140250204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Poly(phenylene sulfide): Synthesis from 1,4-dibromobenzene and sodium sulfideNCL communication no. 3980. (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2581-2588 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new route to synthesize poly(p-phenylene sulfide) by nucleophilic substitution of 1,4-dibromobenzene with sodium sulfide in N-methylpyrrolidone is described. Kinetic evaluation shows the reaction to be of second order with two distinctive rate constant regimes. The first rate constant is higher and is operative until 50% conversion, whereas in the second regime (between 50 and 92% conversion) the rate is slower. The kinetics of this route is compared under identical conditions with the conventional synthesis based on 1,4-dichloro benzene and sodium sulfide.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080260927
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Block copolymers of telechelic poly(phenylene sulfide) and semiaromatic thermotropic liquid crystalline polyester segments (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2707-2713 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We report the synthesis and characterization of copolymers comprising poly(phenyl sulfide) (PPS) blocks and semiaromatic thermotropic liquid crystalline polymer (TLCP) blocks. The copolymers, synthesized by melt-transesterification of dicarboxy-terminated poly(phenylene sulfide) with poly(ethylene terephthalate-co-oxybenzoate) (PET/OB), were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized light optical microscopy (PLOM). The crystallizability and liquid crystalline properties of the copolymers are greatly influenced by the extent of interchange reactions, the mole percent of oxybenzoate with respect to the PET, the PPS : PET/OB weight ratio, and the reaction time. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2707-2713, 1998
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 6
    Electronic Resource
    Electronic Resource
    Effect of microenvironment of oxirane groups on the immobilization of penicillin G acylase (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 45 (1992), S. 279-284 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Macroporous beaded terpolymers containing oxirane groups were synthesized for immobilization of penicillin G acylase. The effect of incorporation of various monomers such as hydroxyethyl methacrylate and methyl methacrylate, and the effect of crosslinking agents such as ethylene glycol dimethacrylate and divinyl benzene on binding and expression of penicillin G acylase were studied. The terpolymers were modified to varying extents by treating with polyethyleneimine. The influence of the microenvironment around the oxirane group on the binding and expression of penicillin G acylase was investigated.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1992.070450209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Thermolysis of orthonovolaks. II. Phenol-formaldehyde and α-naphthol-formaldehyde resinsNCL Communication No. 5265. (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 50 (1993), S. 685-692 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A series of α-naphthol-formaldehyde orthonovolak resins were synthesized by altering the mol ratios of α-naphthol and formaldehyde involved in the condensation reaction. Oxalic acid was used as the catalyst. The softening temperatures and thermal degradation behavior of these resins are presented. Thermal degradation kinetics of these resins were investigated by applying nonisothermal integral methods of Coats-Redfern and Horowitz-Metzger. The dynamic thermogravimetric experiments were conducted in air to obtain differential ther-mogravimetric (DTG) plots. The ratio of the partial integrated area at temperature T to the total area was used to estimate the fractional degradation in the analysis. Degradation proceeded in two stages. The second stage was the predominant one. The thermal degradation profile and activation energies in this stage are discussed in relation to orthonovolaks of similar composition based on phenol-formaldehyde. © 1993 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1993.070500414
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Poly(phenylene sulfide): Polymerization kinetics and characterization (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 32 (1986), S. 4479-4490 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The polycondensation kinetics of aromatic nucleophilic substitution on 1,4-dichlorobenzene by sodium sulfide has been investigated at 195°C in N-methyl pyrrolidone. The reaction follows second-order kinetics. The rate is bimodal with an initial slow rate till 50% conversion followed by a faster rate between 50 and 97% conversion. The specific reaction rates have been evaluated as 3.97 × 10-3 L m-1 s-1 and 1.02 × 10-2 L m-1 s-1 for the initial and later part (50-97%) of the reaction. The development of the degree of polymerization with reaction time was followed by end-group analysis and intrinsic viscosity measurements of polymer samples collected at different conversions. The reaction differs from conventional polycondensation reactions in two aspects. Polymer formation occurs at low conversions, and a significant amount of uncreacted monomer is present even at very high conversions. Unlike other precipitation polymerization reactions, the polymer chain continues to grow even after precipitation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070320416
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Nematic and cholesteric thermotropic polyesters with azoxybenzene mesogenic units and flexible spacers in the main chain (1982)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 20 (1982), S. 877-892 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Properties of linear polyesters based on azoxybenzene and 2,2′-methylazoxybenzene moieties with linear, flexible spacers based on mixtures of dodecanedioic acid (DDA) and methyladipic acid (MAA), chiral or racemic, of various compositions (system MAA/DDA-8 and MAA/DDA-9, respectively) have been described. Substitution of methyl groups in the 2,2′ or 3,3′ positions of the mesogenic core leads to soluble and relatively low-melting-point polyesters. The viscosity law for (MAA/DDA-9) polyesters in 1,1,2,2 tetrachloroethane gives an exponent 0.76, indicating well-sol-vated, coiled chain conformations in dilute solution. Calorimetric data show an increase in isotropization entropy ΔSNI with increasing average length of the spacer. This suggests a nonrandom conformation of the spacer in the nematic melt with a degree of order superior to that of low-molecular-weight analogs. X-ray data obtained with an oriented nematic glass quenched from the nematic melt of DDA-9 subjected to a magnetic field of 10-12 T also support the extended-chain model in the nematic phase of DDA-9. Oriented fibers can be produced by subjecting nematic melts of polyesters 8 and 9 either to magnetic fields of high intensity or to shear fields. The x-ray data obtained from these fibers also support the extended-chain model. Cholesteric systems do not orient in the magnetic field of 10-12 T. The study of mesophases of systems 8 and 9 indicates a dramatic influence of the position of the ester group on the stability of the mesophase in the azoxybenzene polyesters. The results are interpreted in terms of geometric factors influencing the colinearity of the mesogenic core and of the extended spacer.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1982.180200510
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Collapsed conformation of poly(methacrylic acid) chain containing nonionic hydrophilic units (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2183-2190 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of methacrylic acid (MAA) and a nonionic hydrophilic monomer N-vinylpyrrolidone (NVP) were synthesized by polymerization in aqueous solution in the absence of metal ions. The NVP content of the copolymers ranged from 2 to 36 mole % with sequences of MAA interrupted at random by a single unit of NVP at all compositions. The pH-induced conformational transition of these copolymers was followed by potentiometric titration and viscosity studies and the results were compared with those of pure poly(methacrylic acid) (PMAA). The negative free energy of transition from the un-ionized compact from to expanded structure showed a gradual decrease with increasing NVP content, and the collapsed conformation observable for PMAA at low degrees of ionization (0 〈 α 〈 0.3) disappeared at NVP contents greater than 15 mole%. These findings are supported by viscosity data. The results suggest that long-range methyl-methyl hydrophobic contacts still possible in higher NVP content copolymers are not sufficient to bring about the collapse of the molecule and a minimum average sequence length of about 20 MAA units is required to compact the molecule. Hydrophilic “shielding” of MAA chains by NVP segments could also partly destabilize the collapsed structure.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160908
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...