An Improved Synthesis of Borazine with Aluminum Chloride as Catalyst

Abstract

Borazine is an excellent precursor for boron nitride. However the existing synthetic methods for the preparation of borazine have drawbacks such as relatively high reaction temperatures, side reactions, long reaction times, and low yields. An improved synthesis procedure was disclosed, which involved the use of aluminum chloride as a catalyst in the reaction of sodium borohydride with ammonium sulfate. The aluminum chloride catalyst brought the reaction temperature down from 120–140 °C to 45 °C. Improved yields of borazine were obtained in comparison to the reaction without a catalyst. In addition, the reaction process was investigated in detail by 11B NMR spectroscopy and Fourier transform infrared spectroscopy (FTIR). It was found that aluminum borohydride formed in very small quantity when aluminum chloride was introduced, which plays an important role in the reaction.

Boron nitride coatings by chemical vapor deposition from borazine

“…Borazine was synthesized and purified according to our previous work [13], which was used as precursor for boron nitride by CVD. The depositions were carried out in a hot-wall reactor as illustrated in Fig.…”

“…Borazine, which is isoelectronic and isostructural with benzene, is a potential precursor for BN [12]. Its structure consists of six-membered planar ring with alternating boron and nitrogen atoms and has the correct B/N stoichiometry [13]. There have been a lot of investigations on BNmonolayer, which is a two-dimensional material, prepared from borazine in the last decade.…”

Fabrication and properties of borazine derived boron nitride matrix wave-transparent composites reinforced by 2.5 dimensional fabric of Si–N–O fibers

“…In the present investigation, to better evaluate the application potential of the Si-N-O f /BN composites, and then purified according to our previous work [25]. The precursor was obtained as a 5 transparent, low viscosity (2.45 mPaÂs at 20 ºC) and volatile liquid with a low density of 0.86 gÂcm -3 .…”

High-temperature properties and associated structure evolution of continuous SiNO fiber-reinforced BN composites for wave transparency

“…The absorption peak at around 1460 cm À1 can be assigned to B-N stretching in a cyclic B-N ring in the matrix. The main bands at 1390 cm À1 and 800 cm À1 are typical absorptions of hexagonal boron nitride in the matrix [31,32], with the latter corresponding to a B-N-B bending vibration [33]. For the heat-treated specimen, an intensity increase of the peak at around 1390 cm À1 and a wave number shift from 800 to 650 cm À1 may be attributed to more regular hexagonal boron nitride rings being formed at elevated temperature.…”