Preparation of silicon carbide foams using polymeric precursor solutions

A simple method was developed to produce silicon carbide foams using polysi lane polymeric precursors. Polyurethane foams were immersed in polysilane p recursor solutions to prepare pre-foams. Subsequently, these were heated in nitrogen at different temperatures in the range of 900 degrees C to 1300 d egrees C. The silicon carbide foams produced in this manner showed well-def ined open-cell structures and the struts in the foams were free of voids. T he shrinkage which accompanies pyrolysis of the pre-foams was reduced by in creasing the concentration of the polymeric precursor in the solutions. (C) 2000 Kluwer Academic Publishers.