AMINE-BORANES AS PRECURSORS FOR BORON CARBONITRIDE

Amine-Boranes have been investigated with respect to their ther.mal decomposition in the temperature range from rom temperature to 1050-degrees-C. The phase transformation of the pyrolytic residue derived from BH3 . C5H5N subsequently heat-treated at temperatures up to 2200-degrees-C was studied. The progress of the pyrolysis has been detected by thermal analysis (TGA) and mass spectroscopy. Chemical analysis and ESCA measurements show that the pyrolytic products are single-phase boron carbonitride (BxCyNz) which can be described as a boron and nitrogen containing pyrolytic carbon. This is also supported by means of analytical electron microscopy. Hot pressing of the pyridine-borane-derived BxCyNz at 1 800-degrees-C and a pressure of 190 MPa yields whiskerlike crystals whose d-values are in accordance with that of BN and/or graphite.