Dow Corning Corporation

Gary E Le Grow

Timothy N Biggs

Vicky Sue Cobb

Duane R Bujalski

Jonathan Lipowitz

Beth I Gutek

Ann Walstrom Norris

Thomas F Lim

Donald E Mc Vannel

Linear or straight-chain trimethylsiloxy endcapped methylhydrogen polysiloxanes are made by contacting hexamethyldisiloxane with a highly pure methylhydrogen cyclic siloxane, in the presence of anhydrous trifluoromethane sulfonic acid catalyst at room temperature. Trimethylsiloxy endcapped alkylmethyl siloxanes are made by reacting the linear or straight-chain trimethylsiloxy endcapped methylhydrogen polysiloxanes with an alpha-olefin, in the presence of a platinum catalyst. Alkylmethyl cyclic siloxanes containing zero parts per million residual .tbd.SiH, are made by reacting anhydrous alpha-olefins and a highly pure methylhydrogen cyclic siloxane, in the presence of dried platinum supported on carbon catalyst.

Methods of making polysiloxanes

Linear or straight-chain trimethylsiloxy endcapped methylhydrogen polysiloxanes are made by contacting hexamethyldisiloxane with a highly pure methylhydrogen cyclic siloxane, in the presence of anhydrous trifluoromethane sulfonic acid catalyst at room temperature. Trimethylsiloxy endcapped alkylmethyl siloxanes are made by reacting the linear or straight-chain trimethylsiloxy endcapped methylhydrogen polysiloxanes with an alpha-olefin, in the presence of a platinum catalyst. Alkylmethyl cyclic siloxanes containing zero parts per million residual .ident.SiH, are made by reacting anhydrous alpha-olefins and a highly pure methylhydrogen cyclic siloxane, in the presence of dried platinum supported on carbon catalyst.

Describes alkylhydrido siloxanes RSi(OSiMe.sub.2 H).sub.3. Me is methyl and R is a C.sub.6 to C.sub.18 straight or branched-chain alkyl group.

Alkylhydrido siloxane fluids

New alkylpolyether siloxanes are prepared by reacting an unsaturated ether with alkylhydrido siloxanes such as (i) comonomers RSi(OSiMe.sub.2 H).sub.3, (ii) oligomers (HMe.sub.2 SiO).sub.2 --Si(R)--O--Si(R)--(OSiMe.sub.2 H).sub.2, and (iii) higher molecular weight siloxane species RSi[(OSiMe.sub.2).sub.x OSiMe.sub.2 H].sub.3 and [HMe.sub.2 SiO(Me.sub.2 SiO).sub.x ].sub.2 Si(R)O(R)Si[(OSiMe.sub.2).sub.x OSiMe.sub.2 H].sub.2. R is a C.sub.2 to C.sub.18 straight-chain or branched-chain alkyl substituent.

Alkylpolyether siloxanes

A method is described to prepare preceramic polysilanes which contain at least one weight percent vinyl. To ensure the survival of the vinyl groups in the polysilane the reaction and process conditions must be carefully controlled. The vinyl-containing polysilanes can be formed into fibers, cured either thermally or by UV irradiation, and then pyrolyzed to form ceramic fibers. Thermal curing and pyrolysis can be combined into a single process step.

Growing community of inventors

Midland, MI, United States of America

Gary E Le Grow