Hergenrother William L: Block polymers of polysiloxanes and polybutadiene. The Firestone Tire & Rubber Company, December 23, 1975: US3928490 (24 worldwide citation)

Block polymers are produced by polymerizing butadiene and joining to polysiloxane to make a copolymer with alternating blocks of polybutadiene and polysiloxane. The products are useful for the manufacture of gaskets, hose, belts, and other products designed for high-temperature use.