The pressure-dependent glass-transition temperatures (Tgs) of poly(methyl methacrylate) (PMMA)/poly(styrene-co-acrylonitrile) (SAN) blends were determined by pressure–volume–temperature (PVT) dilatometry via an isobaric cooling procedure. The Gordon–Taylor and Fox equations were used to evaluate the relationships between the Tgs and compositions of the PMMA/SAN system at different pressures. The relationships were well fitted by the Gordon–Taylor equation, and the experimental data for Tg positively deviated from the values calculated with the Fox equation. Also, the influence of the cooling rate (during the PVT measurements) on Tg was examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 959–962, 2003.

Paper address: http://onlinelibrary.wiley.com/doi/10.1002/app.12692/abstract;jsessionid=D8E6A601572FBB671B89D1D0FCA02364.f04t02