Final rept. 1 Jul 82-30 Jul 85,
ULTRASYSTEMS INC IRVINE CA
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The objective was to develop processible preceramic polymers amenable to transformation into pure boron nitride for potential applications as fibers and coatings. A series of alkyl, aryl, and trimethylsilyl-substituted borazines was synthesized and subjected to pyrolysis to determine the type of substituent leading to an optimum preceramic polymer. The feasibility of the process was established. From trimethylsilyl-substituted precursors, following stepwise pyrolysis, fibers were drawn and cured in an ammonia atmosphere giving pure boron nitride. Mechanisms responsible for borazine condensations were elucidated processes involved in precursor synthesis were investigated.
- Ceramics, Refractories and Glass