EFFECT OF STRUCTURE ON STRESS-RELAXATION OF POLYMER BLENDS IN GLASSY STATE

POLYMER

卷:32

Article

HO, T ; MIJOVIC, J ; LEE, C

关键词: PHYSICAL AGING;    STRESS RELAXATION;    POLYMER BLENDS;    MORPHOLOGY;    WILLIAMS-WATTS EQUATION;   

DOI  :  10.1016/0032-3861(91)90473-V

来源: Elsevier

【 摘 要 】

Short-term stress-relaxation measurements were performed on blends of poly(methyl methacrylate) with poly(styrene-co-acrylonitrile), of polystryene with poly(2,6-dimethyl-1,4-phenylene oxide) and poly(methyl methacrylate) with poly(vinylidene fluoride), at different temperatures below the glass transition region and a constant strain of 0.5%. Stress-relaxation moduli were analysed using the Williams-Watts equation. For amorphous blends, a universal value for the distribution parameter beta of 0.41 was found, and the relaxation time tau showed a power-law correlation with ageing temperature and ageing time. The time and temperature dependences of tau changed with blend composition in systems containing polymers with dissimilar chemical structures, while little variation was observed in systems consisting of molecules of similar structures. Stress relaxation proceeded much faster in semicrystalline systems than in amorphous systems.

【 授权许可】

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