Physical aging in poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) blends. Part I. Enthalpy relaxation

T. Ho, J. Mijovic, T. K. Kwei

Research output: Contribution to journalConference article


In this study, a series of blends of poly(methyl methacrylate) (PMMA) and poly(styrene-co-acrylonitrile) (SAN) were prepared, aged and their enthalpy relaxation evaluated. The overall objective was to monitor and analyze physical aging and enthalpy, volume and stress relaxation measurements. The following general findings were observed; 1. the higher the aging temperature, the faster the relaxation process; 2. under similar aging conditions, SAN-rich blends relax more slowly than PMMA-rich blends at Tg-20°C and Tg-35°C; 3. relaxation rate is insensitive to composition at Tg-50°C; 4. the effect of blending on relaxation is related to the aging temperature in a complex manner; and 5. the maximum possible error in the normalized deviation in enthalpy is ±4%, with the actual error being much smaller.

Original languageEnglish (US)
Pages (from-to)693-695
Number of pages3
JournalAnnual Technical Conference - Society of Plastics Engineers
StatePublished - Dec 1 1989
EventANTEC 89 - 47th Annual Technical Conference of SPE - New York, NY, USA
Duration: May 1 1989May 4 1989


ASJC Scopus subject areas

  • Engineering(all)

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