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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 8 (1970), S. 1169-1175 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly-4,4′-oxydiphenylenesulfonyl and poly-4,4′-methylenediphenylenesulfonyl were synthesized by an electrophilic substitution polymerization of the arylene monosulfonyl chloride monomers. The glass-transition temperatures Tg of these polymers were determined by calorimetric and dynamic mechanical measurements, and the number-average molecular weights were determined by vapor-pressure osmometry. Both polymers were found to have the same Tg at equivalent molecular weight; the limiting value at high molecular weight is 238°C. Both polymers have two dynamic mechanical relaxation peaks at temperatures far below Tg. One is in the neighborhood of 0°C, and the other is at -110°C. Plausible origins for these relaxations, and the absence of any near 0°C in poly(4,4′-isopropylidenediphenylene-co-4,4′-sulfonyldiphenylene dioxide), are discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 11 (1973), S. 275-287 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: As model polymers for isolated short-chain branches in low-density polyethylene, a series of ethylene-1-olefin copolymers was examined by use of 13C NMR at 25.2 MHz. An array of 13C resonances was observed that could be associated independently with methyl through amyl branches. The 13C chemical shifts became insensitive to branch length with hexyl and longer branches. Assignments of the various carbon resonances associated with branching were accomplished by using off-resonance decoupling techniques and the behavior of alkane chemical shifts previously observed by other investigators. The ratio of certain backbone and branch resonances could be used to establish the short-chain branch distribution in a low-density polyethylene.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 11 (1973), S. 737-758 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dielectric dispersions of reconstituted collagens and gelatin were measured from 0.1 to 10 kHz and -160 to +160°C. At 0.1 kHz there is a γ transition at -80°C which is attributed to the H2O-coupled local modes. The process has an activation energy of 7.5 kcal. A devitrification process is observed at 10-20°C. Both of these processes have their counterparts in the dynamic mechanical measurements. The tan δ values are up to 3 times as great for the dynamic mechanical dispersions. There is an additional hightemperature dielectric loss transition which does not correspond to any seen with the mechanical experiments. A probable mechanism for this absorption is the Maxwell-Wagner-Sillars effect.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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