Synthesis Of EPDM-g-SAN By Graft Copolymerization By Dispersion Polymerization

The fracture toughness of brittle or notch-sensitive polymers by the incorporation of a rubber phase is an effective toughening method of polymers. Butadiene-based rubber-toughened styrene-acrylonitrile(SAN) copolymer has been well known as ABS(acrylonitrile-butadiene-styrene), which is one of the most commonly used engineering plastics. However, ABS and related blends will suffer yellow discoloration and visibly drop in mechanical properties in outdoor use. To overcome the problems, the substitution of ethylene-propylene-diene terpolymer(EPDM) for butadiene-based rubber has been widely investigated. The superior resistance of the EPDM component to heat, oxidation, ozone, and UV radiation endows high rubber styrene-EPDM-acrylonitrile graft copolymer (AES) with good weatherability.Graft copolymerization of acrylonitrile(AN) and styrene onto ethylene-propylene-diene terpolymer(EPDM) was carried out using N-hexane as solvent. The effect of reaction time, reaction temperature, initiator concentration, monomer ration was examined. The result showed that the reaction variables, such as reaction temperature, initiator concentration, rubber content, and reaction time, significantly affect the monomer conversion, grafting ration, and grafting efficiency of copolymerization. It was also found that there are orbicular particles in reaction outcome as shown by transmission electron microscopy.