BORON-NITRIDE PRECERAMIC POLYMER STUDIES

Reactions of 8-trichloro-N-trimethylsilylborazine with hexamethyl-disilazane were investigated with the objective to prepare the trimethylsilylamino-substituted borazines. The type and proportion of products formed was found to be dependent on the nature and presence of solvent as well as relative ratios of the reagents. Aminolysis of the borazines gave the corresponding amino derivatives. For fiber forming preceramic polymers the ratio of B-triamino-N-trimethylsilylborazine to B-diamino(trimethylsilylamino)-N-trimethylsilylborazine of approximately 2:8 appeared most promising. To obtain fiber forming preceramic polymer from mixtures containing B-bis(trimethyLsilylamino)amino-N-trimethylsilylborazine required the presence of ammonia during the pyrolysis process.