Synthesis of EPDM-graft-methyl methacrylate and styrene and its toughening effect on MS resin

EPDM-graft-methyl methacrylate and styrene (EPDM-g-MS), a toughen agent for MS resin, was synthesized by solution graft copolymerization of methyl methacrylate (MMA) and styrene (St) onto ethylene-proplene-diene terpolymer (EPDM) in toluene/n-heptane cosolvent using benzoyl peroxide (BPO) as an initiator. The effects of reaction conditions on the graft copolymerization were discussed. EPDM-g-MS/MS resin blends, a novel high impact engineering plastic, was prepared by melt blending EPDM-g-MS and MS resin. The toughening effect of EPDM-g-MS on MS resin was investigated. The results showed that the optimized reaction conditions were EPDM/MMA-St ratio of 50/50, MMA/St ratio of 75/25, initiator dosage of 1%, reactant concentration of 20%, toluene/n-heptane ratio of 75/25, at 80 °C for 20h, and EPDM-g-MS with the higher EPDM content (56.8%) and grafting ratio (52.8%) was obtained under the optimized reaction conditions. SEM analysis showed that EPDM-g-MS had good compatibility with MS resin. EPDM-g-MS had excellent toughening effect on MS resin and could be used for toughen agent of MS resin.