USE OF BORON-BASED POLYMERS AND NITROGEN AS PRECURSORS OF CERAMICS BASED ON BORON NITRIDE AND CERAMIC PRODUCTS THUS OBTAINED

摘要

According to the invention, the boron nitride boron and nitrogen precursor polymers are obtained by adding at least one trihaloborane to a molar excess of at least one silazane compound having at least one Cong Si group. The trihaloborane can be poured into the reactor at the same time as the silazane or silazane standing compound. The reaction can be carried out at room temperature. The invention relates to the use of the polymers obtained to obtain boron nitride-based ceramic by pyrolysis of these polymers at a temperature of between 1000 and 200.degree. and 2,000 degrees C / P