Borate-catalyzed thermolysis of polymethylsilane

Polymethylsilane (PMS) with a general formula [-(CH3SiH)(1-y)-(CH3Si)(y)-](n), has been synthesized by Wurtz type polycondensation of methyldichlorosilane. Copolycondensation with dimethylchlorosilane was realized in an attempt to control the viscosity of the PMS. Thermal reactions at 230 degrees C with small amounts (1 wt %) of boron derivatives such as B[OSi-(CH3)(3)](3) serve to cross-link this Si-H-containing organosilicon polymer. As a result, when the products of these reactions are pyrolyzed at 1000 degrees C under argon, the ceramic residue yields are increased considerably over those obtained with the original polymers.