A NEW APPROACH TO SILICON CARBIDE FIBERS AND CERAMICS IS PROPOSED.

A NEW APPROACH TO SILICON CARBIDE FIBERS AND CERAMICS IS PROPOSED. A NOVEL CHEMICAL SYNTHESIS PRODUCES AN IDEAL SI-C POLYMER BACKBONE WITH ALTERNATIVE ATOMS OF SILICON AND CARBON, E.G., CH(3)SIH(2) [CH(2)SIH(2)](N)CH(2)CH(3). THE SYNTHESIS INVOLVES THE REDUCTIVE COUPLING OF X XCH(2)SIH(2)CL (X=BR,CL) WITH A REACTIVE METAL, SUCH AS MAGNESIUM, SODIUM AND LITHIUM IN AN ORGANIC SOLVENT. METHYL CHLORIDE IN CALCULATED AMOUNTS AS END-BLOCKER IS USED TO CONTROL THE MOLECULAR WEIGHT TO PRODUCE THE DESIRABLE PHYSICAL PROPERTIES, SUCH AS FOR FILM AND FIBER FORMING OR FOR MOLDING INTO A STURDY OBJECT. SUBSEQUENT PYROLYSIS OF THIS SI-C POLYMER PRECURSOR IS EXPECTED TO GIVE HIGH YIELD OF THE SILICON CARBIDE CERAMIC MATERIAL.