A Novel Liquid Poly[(Alkylamino)Borazine] for Boron Nitride

Abstract

A novel liquid polymeric precursor for boron nitride (BN), which can be directly used as an impregnant for ceramic matrix composites, was synthesized by condensation of the substituent from 2,4,6-trichloroborazine and n-propylamine. The structure and composition of the precursor were characterized by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and chemical analysis. The preceramic polymer was composed of B₃N₃ hexagons linked mainly with =NCH₂– units and had a chemical formula of BC_2.4N_1.63H_8.6. Pyrolysis of the cured precursor to 1,200°C in NH₃ yielded turbostratic BN almost without carbon impurity. Moreover, the BN displayed good anti-oxidation property in air up to 950°C.

Keywords:

• Ceramics
• Polymer
• Properties
• Synthesis

ACKNOWLEDGMENTS

We are grateful for the financial support from the National 863 Program of China (No. 2006AA03A217) and the National Natural Science Foundation of China (No. 51203182). We thank Dr. Haitao Gou and Dr. Deyin Wang for discussions. We also appreciate the reviewer's comments.