Patent ID: 7247675

Claim:
An elastomeric composition, comprising a mixture of: about 20-80% by weight of a high performance elastomer; about 20-80% by weight of a low performance elastomer; and about 1-10% by weight of a graft copolymer of the high and low performance elastomers; wherein the graft copolymer is selected from the group consisting of a) block copolymers in which a block of the high performance elastomer is chemically attached to a backbone molecule of the low performance elastomer, b) block copolymers in which a block of the low performance elastomer is chemically attached to a backbone molecule of the high performance elastomer, and c) combinations thereof; and the graft copolymer is formed during solid state shear pulverization of the high and low performance elastomers at a temperature below the melting or softening temperatures of both elastomers.