Investigation of multiphase polymeric systems of poly(vinyl chloride)/ethylene‐propylene‐diene‐gp‐(styrene‐ CO ‐acrylonitrile) blends

The graft copolymer, ethylene‐propylene‐diene rubber (EPDM)‐gp‐(styrene‐co‐acrylonitrile) has been synthesized by solution precipitation polymerization using benzoyl perixide as initiator. The graft copolymer has been characterized after separation through soxhlet extraction by IR, NMR, and elemental analysis techniques. The graft copolymer of EPDM is melt blended with PVC. The nature of compatibility of the graft copolymers with PVC has been studied by means of morphological analysis and by thermal analysis. The mechanical properties, Izod impact strength, tensile strength, and flexural modulus of the blends are extensively studied over the wide range of concentrations. The results of both compatibility and mechanical properties are compared with those of PVC/EPDM blends. The nature of compatibility obtained shows that PVC/EPDM blends are incompatible and the PVC/EPDM‐gp‐SAN system is semicompatible. Also, these results indicate that the PVC/EPDM‐gp‐SAN system has its highest impact strength at 14 wt% of EPDM/gp‐SAN graft copolymer. The fractured surface analysis of the impact fractured samples is also undertaken by an SEM technique. The results of the mechanical properties are discussed in view of existing theories of impact modification, along with the morphological feature of fractographs.