POLYBLENDS BASED ON VINYL CHLORIDE-PROPYLENE COPOLYMER

Blends of vinyl chloride/propylene copolymer (VCM–P) with aromatic polycarbonate (PC) and with ABS terpolymer were studied. Particular emphasis was on characteristics of deflection temperature under load (DTUL), simply referred to as heat deflection temperature (HDT). In a binary system which contained PC and VCM–P, the HDT–composition plot exhibited an S‐shaped curve, suggesting incompatibility. In contrast, a straight‐line correlation, indicating compatibility, was found for VCM–P/ABS blends. These observations are consistent with dynamic measurements by viscoelastometer (Vibron Model DDV‐II). Compatibility of the VCM–P/PC system was improved through incorporation of ABS copolymer, as indicated by the broadening of tan δ peak. Electron photomicrographs revealed that, in a 50% VCM–P binary blend, polycarbonate existed in a string‐like morphology which differed from the compatible ABS system where the ABS copolymer was dispersed in a form of discrete particles. Copyright © 1979 John Wiley & Sons, Inc.