COMPATIBILIZING EFFECT OF A STYRENE METHYL-METHACRYLATE BLOCK COPOLYMER ON THE PHASE-BEHAVIOR OF POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE) AND POLY(STYRENE-CO-ACRYLONITRILE) BLENDS

The effect of poly(styrene-b-methyl methacrylate) block copolymer on the phase behavior of an immiscible polymer pair, poly(2,6-dimethyl-1,4-phenylene oxide) (MPPO) and poly(styrene-co-acrylonitrile) (SAN), was examined in terms of phase structure and thermal properties. The block copolymer was prepared by sequential anionic polymerization of styrene and methyl methylacrylate and blended with two polymers by precipitation. Scanning electron micrographs show that the blends exhibit a more regular and finer dispersion as the block copolymer is added. Thermal analysis with the aid of physical aging reveals that the block copolymer is located at the interface.