Synthesis of polycarbonate-poly(methyl methacrylate) copolymer via sonochemical polymerization of methyl methacrylate in polycarbonate solution

Methyl methacrylate (MMA) was polymerized in the presence of polycarbonate (PC) by ultrasonic irradiation-initiated polymerization. The resulting products consisted of mixtures of homopolymers of poly(methyl methacrylate) (PMMA), PC and PC-PMMA copolymer because of the homopolymerization of MMA itself and copolymerization with macroradicals of PC. Formation of the PC-PMMA copolymer was confirmed by FTIR analysis of the reaction products after a proper extraction of free PMMA from the mixture. In order to verify the effectiveness of the PC-PMMA copolymer as a compatibilizer for PC/styrene-coacrylonitrile (SAN) blend, 5 phr of PC-PMMA was added during melt mixing of PC/ SAN in a batch mixer. It was found from the investigation of morphology and rheological properties that interphase of SAN and PC was fortified by numerous ligaments of PC-PMMA copolymer, which resulted in increase of melt viscosity and storage modulus of the blend.