Preparation of C/SiC ceramics using a preceramic polycarbosilane synthesized via hydrosilylation

International audienceThis paper deals with the preparation of C/SiC powders via the pyrolysis of a novel polycarbosilane, synthesized by hydrosilylation. The preceramic polymer structure was studied by 1H, 13C and 29Si NMR, and in situ dynamic IR analysis. A pyrolysis up to 1800 °C of this low molecular weight polymer led to β-SiC particles dispersed in a carbon matrix. The excess of free carbon was revealed by elemental analysis and High-Resolution TEM. The ceramization behavior was discussed thanks to TGA/DTA-MS, and XRD analyses. Thus, the crystallization was effective for pyrolysis temperatures above 1200 °C, and the ceramic yield reached a value of 62%. This present study highlights the potential of hydrosilylation to prepare C/SiC powders