STRUCTURE-PROPERTY RELATIONSHIPS IN ELASTOMER-MODIFIED TERPOLYMER SYSTEMS

A number of terpolymers, incorporating as the elastomer phase polybutadiene, polyisoprene, poly‐2,3‐dimethylbutadiene, poly(butadiene‐co‐styrene), and poly(butadiene‐co‐2‐methyl‐5‐vinypyridine), were studied. Matrices were composed of poly(styrene‐co‐acrylonitrile) (SAN), poly(α‐methylstyrene‐co‐acrylonitrile), and poly(styrene‐co‐acenaphthylene). At constant elastomer content and elastomer molecular weight in systems employing a SAN matrix, Izod impact resistance was found to vary inversely with rising elastomer‐glass transition temperature. In systems of various matrix composition, using a polybutadiene elastomer, heat deflection temperatures were found to very directly and impact resistance inversely with rising matrix‐glass transition temperature. In acrylonitrile–butadiene–styrene (ABS), systems of constant matrix composition and elastomer content, varying the elastomer molecular weight from 0.6 to 2.6 × 105 resulted in increasing the Izod impact resistance from 0.67 to 12.8 ft‐lb/in. of notch. Copyright © 1969 John Wiley & Sons, Inc.