BLENDS OF POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE) WITH STYRENE COPOLYMERS

Binary blends of poly(2,6-dimethyl-1,4-phenylene oxide) (PPE) with var ious styrene copolymers were investigated. Poly(styrene-co-acrylonitri le) (SAN), poly(styrene-co-(methyl methacrylate)] (SMMA), poly[styrene -co-(acrylic acid)] (SAA) and poly[styrene-co-(maleic anhydride)] (SMA ) are only miscible with PPE when the amount of comonomer is rather sm all. From calculated binary interaction densities it can be concluded that the strong repulsion between PPE and comonomer limits miscibility . In blends of PPE with SAN, as well as with ABS, the interfacial tens ion between the blend components is significantly reduced upon additio n of polystyrene-block-poly-(methyl methacrylate) diblock copolymers ( PS-b-PMMA) and lock-poly(ethylene-co-butylene)-block-poly-(methyl meth acrylate) triblock copolymers (PS-b-PEB-b-PMMA). They show a profound influence on morphology, phase adhesion and mechanical blend propertie s.