Abstract: Commercially available solid rubber modified acrylic multipolymers and polycarbonate polymer are tumble blended and melted and extruded through an extruder. Resulting alloys comprise an unsaturated rubber such as polybutadiene grafted with methylmethacrylate and styrene; a multipolymer comprising methylmethacrylate and styrene, and acrylonitrile, ethylacrylate, or methylacrylate; and polycarbonate. The ratio of rubber to graft monomers ranges from about 1:1 to about 6:1 and is preferably about 3:1. Graft monomers comprise from about 60 to about 85 parts methylmethacrylate, about 15 to about 30 parts styrene, and up to about 15 parts methylacrylate, ethylacrylate, or acrylonitrile. The multipolymer comprises from about 60 to about 80 parts of methylmethacrylate, about 15 to about 30 parts of styrene, and up to 15 parts of methylacrylate, ethylacrylate, or acrylonitrile. The ratio of graft rubber to multipolymer ranges from about 5:95 to about 25:75.

Abstract: Modified rubber compositions comprise, by weight, about 15-60% of a highly saturated aliphatic rubber, such as ethylene-propylene-diene rubber, about 25-80% of preferably non-nitrogenous acrylate monomer units; and less than about 5% multi-functional monomer units. The compositions exist as amorphous heterogeneously dispersed phases. The first phase comprises the copolymer rubber, to which polymers of at least 10%, preferably 20%, and more preferably 30% of the other monomer units are grafted. The second phase comprises the other monomers polymerized as homo and copolymers, not grafted to the rubber.The modified rubber composition, preferably non-nitrogenous polyacrylate polymer, and another polymer are mixed together to form a polymer blend having higher impact strength and other important properties.