Synthesis of boron nitride ceramics from poly(borazinylamine) precursors

Abstract

Atoms in 3), Table VII (Atomic Coordinates and Isotropic Thermal Parameters for Hydrogen Atoms in 3), Table VIII (Bond Lengths and Bond Angles in 3), and spectral/analytical data for compounds 1, 2, 4, 5, and 6 (23 pages); structure factor amplitude tables for 2 and 3(18 pages). Ordering information is given on any current masthead page.

Anisotropic Hexagonal Boron Nitride Nanomaterials: Synthesis and Applications

“…Narula et al prepared porous BN from poly(2, 4, 6-borazinylamine) with surface areas ranging from 30-50 m 2 /g for powders produced at 900 ºC [113]. BN aerogels formed by critical point drying of poly(2,4,6-borazinylamine) gels and heated to 1000 ºC exhibit low density, are highly porous, and have surface areas of ~400 m 2 /g [69].…”

Synthesis of poly(borazinylamine)

“…The reaction mixture was aerated with BCl 3 quantitatively and slowly. Next, (Me 3 Si) 2 NH was dripped into the flask for 2 h. After that, the reactants were kept at a low temperature for one more hour. The solvent and unreacted reactant were then removed by filter or vacuum distillation at room temperature, and poly (borazinylamine) was obtained in powder or resin form.…”

“…1,2 Soluble and/or fusible preceramic polymers offer several unique benefits in the manufacture of complex, multifunctional materials. Polymeric precursors that convert to shape articles without complex processing would alleviate many processing problems and would be of great value.…”

“…3 However, it was also pointed out that poly(borazinylamine) was insoluble, infusible, and essentially impossible to process probably as a result of significant crosslinking chemistry, even at relatively low temperature. 4 In the present study, BCl 3 , NH 4 Cl and (Me 3 Si) 2 NH were used as raw materials to synthesize poly(borazinylamine). The effect of solvent, reaction temperature, and ratio of raw material on synthesis yield, solubility, molecule structure, and ceramic yield of poly(borazinylamine) was investigated in detail.…”

Pyrolytic Organic-to-Inorganic Conversion of Precursors into AlN-A Review

“…95 Paine and Narula prepared polyborazinylamine gels obtained by a reaction between hexamethyldisilazane and Btrichloroborazine. 98,99 Crystalline graphite-like BN h-BN was obtained by pyrolysis of polyborazinylamine gels at 1200c C. The formation of coatings and fibers was also achieved using these gels. Sneddon and co-workers investigated the preparation of B-vinylborazine via transition metalcatalyzed addition between borazine and acetylene and its polymerization by thermal treatment 100,101 and free-radical initiation with AIBN 102 .…”