| 摘要 |
<p>A method of forming preceramic polymers using a polycarbosilane having repeat units of the formula ¢RSi(H)-(CH2)q! (where R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, q is an integer 1 or greater), by reacting it with alkali metal silylamides in a weight ratio of polycarbosilane:silylamide of 10:1. or less is disclosed. Preferably, the alkali metal silylamide is a polymeric alkali metal silylamide of the formula ¢(R1SiHNH)a(R1SiN)b(R1SiHNM)c!m where a + b + c = 1; R1 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)alkylor 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.</p> |
