Copolymers and elastomers with alternating dioxysilphenylene and silane units

Copolymers with alternating dioxysilphenylene and diorganosilane units were investigated as a source of high‐temperature elastomers for the aerospace industry. A copolymer with dimethylsilane units alternating with dioxysilphenylene had a glass transition temperature of −63°C and exceptional thermal stability; a polymer with diphenylsilane units alternating with dioxysilphenylene had a glass transition temperature of 0°C and slightly higher thermal stability. Both were cured to elastomers at room temperature with ethyl silicate in combination with dibutyltin diacetate. Both had tensile strengths (ultimate) above 4000 psi even without reinforcing fillers. Reinforced elastomers of the dimethyl copolymer had tensile strengths (ultimate) up to 16,000 psi.