Homoconjugated Acids as Low Cyclosiloxane-Producing Silanol Polycondensation Catalysts.

Polycondensation of α,ω-disilanols is a foundational technology for silicones producers. Commercially, this process is carried out with strong Brønsted acids and bases, which generates cyclosiloxane byproducts. Homoconjugated acids (a 2:1 complex of acid:base or a 1:1 complex of acid:salt), a seldom used class of silanol polycondensation catalysts, were evaluated for their ability to polymerize α,ω-disilanols while forming low levels of cyclosiloxane byproducts.