Synthesis and characterization of new precursors to nearly stoichiometric SiC ceramics. Part II. A homopolymer route

An original route to SiC ceramics possessing low free carbon(∼3.8 at%) and oxygen (∼1 at%) contents is reported. It consists of the polycondensation of 2,4-dichloro-2,4-disilapentane, prepared by Grignard reaction of dichloromethane on methyldichlorosilane. The undesired remaining chlorine was eliminated via a subsequent reduction using lithium aluminum hydride. The synthesis of the ceramic precursor was achieved by thermolysis under argon at atmospheric pressure, with the evolution of hydrogen and methane. The pyrolysis of the precursor provided SiC ceramics in an excellent yield (≈79%).