Chemical Characterization of Si‐Al‐C‐O Precursor and Its Pyrolysis

Abstract

Polycarbosilane was modified by reaction with an aluminum alkoxide to get a precursor for Si‐Al‐C‐O ceramics. The precursor was essentially characterized by magic‐angle spinning nuclear magnetic resonance ( 29 Si, 27 Al, and 13 C) and appeared as a dispersion of Al(OH) 3 ‐based particles in a polycarbosilane chain matrix. After the material was heat‐treated under argon at 1500°C, X‐ray diffraction showed that it crystallized mainly as SiC 2H. The presence of this rather unusual polytype for polycarbosilane‐derived ceramics seemed to be related to the presence of aluminum atoms.