Halogenated polycarbosilane, their preparation, preceramic polycarbosilane derivative preparation, and ceramic article preparation

摘要

PURPOSE: To obtain a polycarbosilane that can be converted into a ceramic material by pyrolysis at a high temp. by treating a polycarbosilane with a specified halogenating agent. ;CONSTITUTION: A polycarbosilane (a) having ≥0.1 wt.% Si-H groups is treated with a halogenating agent (b) to obtain the object polycarbosilane essentially comprising units expressed by formula II (R is a 1-4C alkyl) and units expressed by formula III and having 0.1 to 80 wt.% X as a halogen. The halogenating agent (b) is a mixture of (i) one kind selected from Cl, Br, PCl₅, PBr₅, SbCl₅, N-chlorosuccinimide, N-bromosuccinimide, SOCl₂, formula I ((e) is 0 or 1; (f) is 3 or 4 satisfying e+f=4; X is Cl or Br) and (ii) a radical initiator. The obtd. polycarbosilane is formed into a desired shape and heated at a temp. of ≥800°C in an inert atmosphere or in vacuum to obtain a silicon carbide-contg ceramic article.;COPYRIGHT: (C)1989,JPO