METHOD OF PREPARING POLYCARBOSILANES

摘要

: Method of preparing polycarbosilanes There is disclosed a method of preparing polycarbosilanes having high molecular weight and also having the major structural unit of silicon-carbon linkage. The method comprises heating a polysilane at 50 - 600.degree.C. in atmosphere of an inert gas and distilling out a low molecular weight polycarbosilane fraction having the number mean molecular weight of 300 - 600, followed by polymerizing the fraction by heating it at 250 - 500.degree.C. in atmosphere of an inert gas. The polycarbosilane obtained by the method of the present invention are useful for the precursor of preparing silicon carbide fibres and shaped articles.