COMPATIBILIZATION EFFECTS IN THE THERMAL-DEGRADATION OF BLENDS CONTAINING SAN AND EPDM POLYMERS

Thermal degradation of blends containing SAN and EPDM was investigated and compared with that of graft EPDM-g-SAN copolymer molecules. Chara cterization of decomposition products and of degradation residues was carried out in order to reveal the differences in the degradation proc esses. With plain mixtures of SAN and EPDM, degradation behaviour is p ractically additive whereas in the case of EPDM-g-SAN lower volatile p roducts and larger chain scissions are produced. The results can be ex plained by considering that the degradation process is influenced by t he dispersion of the blend components. In phase segregated systems ver y few interactions take place between the different types of polymers, whereas in the graft copolymer molecular dispersion favours reactive interactions between the structurally different components. (C) 1998 E lsevier Science Ltd. All rights reserved.