Method for making boron nitride fibres from aminoborazines

摘要

The invention concerns a method for making boron nitride fibres by drawing a polymer precursor and treating with ceramics the polymer fibres obtained by drawing. The invention is characterized in that the precursor polymer is obtained by thermal polymerization of a borazine of formula (I) wherein: R1, R3, R4 and R5, identical or different, represent an alkyl, cycloalkyl or aryl group; and R2 represents a hydrogen atom or an alkyl, cycloalkyl or aryl group.