Synthesis and characterization of monomer and its polymer as a precursor to boron nitride fiber

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, (Me2N)B(NHMe)(2), was prepared by firstly reaction of borontrichloride (1mol) with dimethylamine (1mol), and then reaction with excess methylamine (2.5mol) at low temperature (-80 degrees C). Heating this monomer under nitrogen protection up to 170 degrees C 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 H-1 NMR, B-11 NMR, C-13 NMR, and FTIR, DSC, TGA. Results show that the precursor could be spun into fibers.