Method for forming new preceramic polymers for SiC and Si.sub.3 N. sub.4 /SiC systems

摘要

A method of forming preceramic polymers using a organopolysilane of the formula (RSiH).sub.x (RSi).sub.y !.sub.n, where R is a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbons atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group and n is an integer greater than 1, and reacting it with alkali metal amides or silylamides in catalytic quantities is disclosed. Preferably, the alkali metal amide is a polymeric alkali metal silylamide of the formula (R.sup.1 SiHNH).sub.a (R. sup.1 SiN).sub.b (R.sup.1 SiHNM).sub.c !.sub.m where a+b+c=1; R.sup.1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and n and m are integers greater than 1. Novel preceramic polymers formed by this method are also disclosed.