Nanostructured SiC/BN/C ceramics derived from mixtures of B3N3H6 and [HSi(Me)C≡C]n

Three borazine-modified polycarbosilanes were synthesized by reaction of poly[1,2-ethynediyl-(methylsilylene)], [HSi(Me)C≡C] , and borazine, B using different stoichiometries. The polymeric precursors were transformed into inorganic Si–B–C–N materials by solid state thermolysis at 1400 °C each in 88% yield. High temperature thermogravimetric analysis in an argon atmosphere showed no substantial decomposition reactions below 1800 °C. Crystallization behavior up to 2000 °C in a nitrogen atmosphere was studied by post-thermolysis heat treatment of as-obtained ceramics at various temperatures and subsequent examination of samples at room temperature using powder X-ray diffraction. Ceramics annealed at 1800 °C were additionally characterized by transmission electron microscopy.