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  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 2941-2949 
    ISSN: 0887-624X
    Keywords: Polyvinylchloride ; vinylchloride-vinylthiocresol copolymer ; vinylchloride-vinylthionaphthol copolymer ; vinylchloride-vinylthiobenzene copolymer ; glass transition temperature ; NMR spectroscopy ; polymer-solvent interaction ; polymer association ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinylchloride-vinylthiocresol and vinylchloride-vinylthionaphthol copolymers of various compositions were prepared by the substitution reaction of PVC with sodium thiocresol and sodium thionaphthol, respectively, in different solvents and at different temperatures. The variation of the glass transition temperature of these copolymers with chemical com-position does not follow the Flory-Fox equation, but is found to depend on the solvent and the temperature at which the copolymer is obtained. The comonomer sequence distribution and stereosequence content of the above copolymers, and those of vinylchloride-vinyl-thiobenzene copolymer, were determined by 1H- and 13C-NMR spectroscopy. The depen-dence of comonomer distribution and stereoregularity content with chemical composition for the three series of copolymers, prepared in different solvents and temperatures, are similar. The Tg deviations for the three series of copolymers were attributed to the con-tribution of physical characteristics of the PVC structure, originating from polymer-solvent interactions. © 1995 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 17 (1996), S. 15-23 
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 2-Mercaptobenzyl alcohol and 4-mercaptobenzyl alcohol were synthesized in good yields starting form thiosalicylic acid and p-toluenesulfonic acid, respectively. Poly(vinyl chloride) (PVC) reacts selectively with the thiol group of these bifunctional compounds leading to modified PVC with free hydroxy groups. In a second step the polymer chains can be partially crosslinked by reaction with hexamethylene diisocyanate. According to the degree of PVC modification, the network density of the resulting elastomers is freely adjustable.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 6 (1995), S. 285-290 
    ISSN: 1042-7147
    Keywords: polymer films ; thermomechanical properties ; emulsion polymerization ; functional and crosslinkable monomers ; rubber elasticity ; 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
    Notes: Batch emulsion polymerization was used in order to obtain latexes from a mixture of butyl acrylate (ca. 90% mole), and a hydrophobic crosslinkable functional monomer called N-isobutoxymethyl acrylamide (ca. 10% mole). Films were then cast from these latexes, and their thermomechanical properties were studied before and after a heat treatment intended to provoke crosslinking of the functional groups. The differential thermal analysis and the dynamic mechanical analysis of the film samples proved that the functional monomer copolymerized with butyl acrylate; the dynamic mechanical analysis revealed also that crosslinking took place after the heat treatment. Different kinds of high strain experiments (among which there were stress relaxation tests) were carried out in a tensile testing machine Important differences were thus shown to appear between the “as-dried” and “annealed” samples. In the case of stress relaxation experiments, simple mechanical models were used in order to fit the experimental data, both during the stretching experiment and the stress relaxation following it. The analysis of the high-strain experiments and their simulation led to the conclusion that the films contained high molecular weight polymers having a broad molecular weight distribution, and that their crosslinking enhanced the entropic elastic behavior, even though a viscoelastic, large relaxation time contribution was kept; the hypothesis of its coming from a trapped-entanglement effect was proposed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 6 (1995), S. 296-300 
    ISSN: 1042-7147
    Keywords: polymer films ; thermomechanical properties ; emulsion polymerization ; coalescence ; scanning electron microscopy ; small angle neutron scattering ; 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
    Notes: A two-stage emulsion polymerization procedure was used in order to obtain core-shell polymer particles having a core of polystyrene (PS), covered by a shell of either pure poly(butyl acrylate) (PBA) or a methacrylic acid-functionalized PBA. Films were then cast from these latexes, and their properties were studied without further treatments (“as-dried” films), as well as after a 3 hr heat treatment intended to provoke the coalescence of PS domains (“annealed” films). “As-dried” and “annealed” film samples were studied by dynamic mechanical analysis (DMA), scanning electron microscopy (SEM) and small angle neutron scattering (SANS). DMA and SEM results, as described in previous works, showed that for unfunctionalized films, the percolated PS domains coalesced under the annealing treatment, while for the functionalized films, they did not. On the other hand, SANS results presented here showed that even in the case of functionalized films, the presence of coalescence could be detected. It was concluded that while DMA and SEM reveal large-scale modifications provoked by the heat treatment, SANS is capable of detecting very smallscale changes which do not have a direct effect on the bulk physical properties of the samples.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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