CJCU

Chem. J. Chinese Universities ›› 1999, Vol. 20 ›› Issue (6): 969.

• Articles • Previous Articles     Next Articles

Relationship Between Breakdown of Time-temperature Superposition Principle and Phase-separation for PMMA/α-MSAN Blends

ZHENG Qiang1, TAKAHASHI Masaoki2, MASUDA Toshiro3   

  1. 1. Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027;
    2. Department of Polymer Science and Engineering, Kyoto Institute of Technology, Kyoto 606, Japan;
    3. Division of Material Chemistry, Faculty of Engineering, Kyoto University, Kyoto 606, Japan
  • Received:1998-07-26 Online:1999-06-24 Published:1999-06-24

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Abstract: By examining superposition of viscoelastic functions of poly(methyl methacrylate)(PMMA)/poly(α-methylstyrene-co-acrylonitrile)(α-MSAN) blends, we found that breakdown of time-temperature superposition principle in the long time relaxation region(terminal region) is related to phaseseparation of this blends. Heterogeneity in the blends results in the relationship between dynamic storage modulus G′(or dynamic loss modulus G″) and frequency in the terminal region no longer obey the model of linear viscoelasticity. It is interesting that there exists temperature dependence of this breakdown. This breakdown temperature(Td) can be used as a criterion for phaseseparation of the blends and was considered superior to socalled critical temperature(Tb) obtained by plotting of lgG′vs. lgG″.

Key words: Poly(methyl methacrylate)/poly(α-methylstyrene-co-acrylonitrile) blends, Timet-emperature superposition, Dynamic viscoelastic functions, Phase-separation

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