Abstract: Rubber compositions comprising a blend of a major amount of polybutadiene having 1,2-addition in the range of about 25 to about 65 percent and a minor amount of polybutadiene having trans-1,4-addition of at least about 70 percent. Also vulcanized cellular rubber compositions in which the rubber comprises a blend of a major amount of polybutadiene having 1,2-addition in the range of about 25 to about 65 percent and a minor amount of polybutadiene having trans-1,4-addition of at least about 70 percent.

Abstract: A rubbery composition of matter comprises a blend of three components, A, B and C, wherein component A comprises a rubbery homopolymers of 1,3-butadiene in an amount in the range of from about 10 to about 60 parts by weight based on weight of the blend, the homopolymer characterized by having at least 35 percent of the polymer in the cis configuration; component B comprises a rubbery 1,3-butadiene-styrene copolymer in an amount in the range of from about 15 to about 65 parts by weight based on weight of the blend; and component C comprises a medium vinyl homopolymer of 1,3-butadiene in an amount in the range of from about 25 to about 75 parts by weight based on weight of the blend, the homopolymer characterized by having at least 30 but not more than 50 percent of the polymer in the vinyl configuration.