Poly(methylsilane) and poly(vinylsilane) were synthesized using a titanocene
catalyst, and their pyrolytic conversion to ceramics was followed using a
combination of thermal analysis and infrared spectroscopy. The two polymers
have distinctly different backbone structures, as determined by
29Si NMR; methylsilane polymerizes to a polysilane, while
vinylsilane polymers have a predominately polycarbosilane backbone, with
some polysilane structure as well. The pyrolysis path and char yield were
dependent primarily on backbone structure, with little influence of polymer
molecular weight. The majority of the weight loss on conversion occurs below
650 °C, although bond rearrangement continues to 1400 °C. Poly(vinylsilane)
produced a C-rich Si-C ceramic in which the carbon was dispersed on a
sufficiently fine level to show resistance to oxidation on heating in air to
1400 °C.