Modification of SiC precursors with an amine-borane complex

Abstract

Two methods for preparing precursors of Si/C/B-based thermostructural materials have been developed. The first consists of a thermal treatment of a mixture of polydimethylsilane (PDMS), (Me2Si)n, and triethylamine–borane adduct, Et3N : BH3 at atmospheric pressure. The second involves two steps: (i) transformation of PDMS into a polymer displaying Si–CH2–Si and Si–Si linkages in its backbone, and (ii) heating this product at atmospheric pressure, in the presence of Et3N: BH3. The ceramic material obtained from the second approach contains 2.2 at% boron and 1.5 at% oxygen.