Synthesis and Characterization of Monomer and its Polymer as a Precursor to Boron Nitride Fiber

摘要

Boron Nitride is a kind of advanced ceramics, which are deemed to be excellent candidates for high-temperature structural applications. It was reported that B (NHMe)<,3> and its polymer had been prepared, [1] however, the polymer is poor for processing due to its network structural. In this article, a new monomer, (Me<,2>N) B (NHMe)<,2>, was prepared by firstly reaction of borontrichloride (lmol) with dimethylamine (lmol), and then reaction with excess methylamine (2.5mol) at low temperature (-80℃). Heating this monomer under nitrogen protection up to 170℃ through a four-step procedure, resulted in its conversion to a yellow solid polymer, which was expected be linear or less network structure. The monomer and polymer were characterized by <'1>H NMR, <'11>B NMR, <'13>C NMR, and FTIR, DSC, TGA. Results show that the precursor could be spun into fibers.