Abstract: This invention provides a composition comprising a blend of EPDM, styrene-butadiene rubber and styrene-butadiene resins that has improved modulus in the vulcanizates by the incorporation into the composition of about 1 to 20 parts per 100 of a tackifying resin, the tackifying resin being one of those normally utilized to improve the tack of the rubber.

Abstract: The green strength of synthetic elastomers is improved by mixing a synthetic elastomer such as synthetic cis-1,4-polyisoprene or polybutadiene with from about 0.25 to about 2.0 parts by weight of a dihydrazide compound per 100 parts of the elastomer. Upon mixing at temperatures ranging from about 125.degree. F to about 300.degree. F, the dihydrazide will crosslink the synthetic elastomers and impart thereto improved green strength. This synthetic elastomer may then be blended with either natural or synthetic cis-1,4-polyisoprene in accordance with common practice in the rubber industry when the end product is a tire.

Abstract: The green strength of synthetic elastomers is improved by mixing a synthetic elastomer such as synthetic cis-1,4-polyisoprene or polybutadiene with from about 0.25 to about 2.0 parts by weight of a dihydrazide compound per 100 parts of the elastomer. Upon mixing at temperatures ranging from about 125.degree. F to about 300.degree. F, the dihydrazide will crosslink the synthetic elastomers and impart thereto improved green strength. This synthetic elastomer may then be blended with either natural or synthetic cis-1,4-polyisoprene in accordance with common practice in the rubber industry when the end product is a tire.

Abstract: A paintable rubber composition of SBR rubber and EPDM rubber, containing, as a stiffening agent, a high styrene resin of butadiene and styrene. This rubber composition can be used in molded and extruded products such as sight shields, automotive facia, fender liners and automotive door panels.