STUDIES ON IMPACT MODIFICATION OF POLYSTYRENE (PS) BY ETHYLENE PROPYLENE DIENE (EPDM) RUBBER AND ITS GRAFT-COPOLYMERS .1. PS EPDM AND PS EPDM-G-STYRENE BLENDS

Ethylene–propylene–diene (EPDM) rubber is an excellent rubber for outdoor use. High impact polystyrene (PS) containing EPDM rubber may show improved weathering resistance. PS is incompatible with EPDM; hence bulk polymerization technique is adopted for the synthesis of graft products which show limited compatibility with PS. Two initiators were chosen at two different working temperatures to produce high grafting efficiency and grafting percentage. In the present system, it is shown that the graft copolymer and polystyrene compositions show higher improved impact strength behavior than that of the products based upon simple dispersion of EPDM in polystyrene. Copyright © 1990 John Wiley & Sons, Inc.