Abstract: This invention relates to the use of particular urethane or urethane/sulfur cured acrylonitrile-butadiene elastomers in systems wherein a vulcanizate component with resistance to oxidized (sour) hydrocarbon fuel is desired, that is in systems wherein a vulcanizate functions in contact with hydrocarbon fuel having oxidation products therein. The vulcanizate composition consists essentially of the reaction produces of (i) 100 parts by weight of an acrylonitrile-butadiene copolymer and (ii) a curative comprising 1-10 parts by weight of a urethane curing agent, wherein the urethane curing agent is the reaction product of a nitrosophenol and a diisocyanate. The curative may additionally comprise sulfur.

Abstract: A soft, heat and fatigue resistant vulcanizate adapted for transmitting load between moving mechanical parts comprising (a) 100 parts by weight of crosslinked elastomer consisting essentially of (i) natural or synthetic polyisoprene rubber, and (ii) elastomeric polybutadiene made from monomers consisting essentially of butadiene at a weight ratio of (i) to (ii) of about 1:10 to 10:1, (b) about 10-75 parts by weight of substantially internally saturated, substantially linear polymer that (i) is made from monomers consisting essentially of isobutylene, (ii) is a strain crystallizable, elastic solid at 20.degree. C. and (iii) has a viscosity average molecular weight (Flory) above about 1.

Abstract: A thick, highly filled, shaped elastomeric body comprising a thermally conductive elastomer suitable for high temperature, e.g. 240.degree.-260.degree. C., mechanical applications. The elastomer composition comprises organopolysiloxane, particulates, and a viscosity modifier. The organopolysiloxane crosslinks between the vinyl or allyl functionality of an organopolysiloxane polymer and the silyl hydride functionality of an organopolysiloxane oligomer. The particulates comprise silica as well as a thermally conductive boron refractory powder, preferably boron nitride. The addition of a viscosity modifier comprising silicone oil is essential to the inclusion of the high levels of particulates.