Preparation of Soluble Polyphenylsilsesquioxanes

Abstract

Soluble polyphenylsilsesquioxane was obtained almost quantitatively from the reactions of tripotassiumphenylsilanetriolate aqueous solution with (1)acetic anhydride and (2) chloroform, and from (3) hydrolysis of phenyltrichloresilane with aqueous amine solution according to the following schemes:
(1) PhSi(OK)3 + 312 (MeCO)20. 1/n (PhSiOi.s)n + 3 MeCOOK
(2) PhSi(OK)3+3/4 CHC13-1/n(PhSiOi.s)n+9/4 KC1+3/4 HCOOK
(3) PhSiC13 +3/2 H20+3/2 diamine.1/n(PhSiOi.s).+2/3 diamine-2 HCI
All the reactions were so undertaken as to proce6d through interfaces of binary liquid layers at refluxing temperature by use of MIBK layer as a medium. Intrinsic viscosity of the initial prepolymer ranging from 0.06 to O.13 increased gradually by heating the solution with O.1% KOH.
Analogous reactions which involve co-hydrolysis of phenyltrichlorosilane and equimolar amount of each diphenyldichlorosilane and of methylphenyldichlorosilane were found to give cotresponding soluble polysiloxanes with cyclotetrasiloxane segment in the structural repeating unit.
Co-hydrolysis of a mixture of phenyltrichlorosilane-vinyltrichlorosilane (1:1) also gave asoluble and infusible polymer.