High-ceramic-yield precursor to SiC-based ceramic: A hyperbranched polytitaniumcarbosilane bearing self-catalyzing units

摘要

A novel hyperbranched polytitaniumcarbosilane (HPTiCS) was synthesized by a monomer route. The obtained HPTiCS contains dicyclopentadienyl titanium units, which exhibits excellent self-catalytic activation of the dehydrocoupling reaction during its cross-linking process. As a result, the 1200 degrees C ceramic yield of the pyrolyzed HPTiCS is 32 wt% higher than that of titanium-free hyperbranched hydridopolycarbosilane (HPCS). Compared with titanium-free HPCS-derived SiC, the resulting HPTiCS-derived SiC-based ceramic exhibits a significantly enhanced resistance toward the growth of the in situ formed beta-SiC crystals as the matrix phase after being annealed at 1600 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.