Dow Silicones Corporation

Ronen Weingarten

Dimitris Katsoulis

Gary Michael Wieber

David Lawrence Witker

Juan Mauricio Venegas

A process for preparing polysiloxanes is a two-part polycondensation of alkoxy silanes and/or alkoxy siloxanes the process comprising the following steps: (a) hydrolysis of the alkoxy silanes and/or alkoxy siloxanes to hydroxyl-functional silanes and/or hydroxyl-functional siloxanes; and (b) condensation of the hydroxyl-functional silanes and/or hydroxyl-functional siloxanes to form polysiloxane polycondensation product; where the process is characterized by having both gel-type heterogeneous acid catalysts and gel-type heterogeneous base catalysts present concurrently during both the hydrolysis and condensation steps.

Polycondensation preparation of polysiloxanes using concurrent acid/base catalysts

A method of preparing an organosilicon compound via selective silylation of ethylene is disclosed. The method comrises prises reacting via silylation (A) a hydridochlorosilane compound and (B) ethylene in the presence of (C) a catalyst, thereby preparing the organosilicon compound. The silylation may be selectively conducted as a dehydrogenative coupling to prepare the organosilicon ompound as a vinylchlorosilane compound, or as a hydrosilylation to prepare the organosilicon compound as an ethylchlorosilane compound. The catalyst (C) comprises a Ru(0) complex, and may be recycled for use in subsequent silylation reactions without purification. The organosilicon compound prepared according to the method is also disclosed.

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Midland, MI, United States of America

Ronen Weingarten