POLYMERIC THERMORESISTANT BLENDS BASED ON POLY-SAN AND IMIDIZED PMMA - THERMAL AND ELECTRICAL CHARACTERIZATION

Blends of styrene/acrylonitrile copolymers (poly-SAN) with imidized PM MA exhibit increased thermoresistance in comparison with poly-SAN alon e. The miscibility of two modified poly (methyl methacrylate) (PMMA) w ith poly-SAN has been evaluated with the aid of different techniques: isothermal calorimetry, through which mixing enthalpy and the Flory-Hu ggins chi parameter can be determined; dielectrical spectroscopy and t hermally stimulated discharging currents (TSDC). The results obtained exhibit great consistency, thus supporting the usefulness of the appli ed methods for determining the mixing behavior of these polymer blends , which can be considered as model systems for thermoresistant ABS now adays widely used in the automotive industry. Furthermore, the applied methods allow one to obtain useful data for the electrical applicatio n of the investigated blends. (C) 1994 John Wiley & Sons, Inc.