Use of boron and nitrogen-based polymers as precursors for boronnitride-based ceramics thus obtained.

摘要

Polymers based on boron and nitrogen, which are precursors of boron nitride, are obtained by the addition of at least one trihaloborane to a molar excess of at least one silazane compound containing at least one IDENTICAL Si-NH-Si IDENTICAL group. The trihaloborane may be run into the reactor at the same time as the silazane compound or onto a silazane base stock. The reaction may be carried out at room temperature. The invention relates to the use of the polymers obtained for obtaining boron nitride-based ceramics by pyrolysis of these polymers at a temperature of between 1000 DEG C and 2000 DEG C.