Chemical reactions during the thermal processing of borazene polymers

Journal Article · Tue May 01 00:00:00 EDT 1990 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1990.tb05213.x· OSTI ID:6066186

Rye, R R ^[1]; Borek, T T; Lindquist, D A; Paine, R T ^[2]

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1. Sandia National Labs., Albuquerque, NM (USA)
2. New Mexico Univ., Albuquerque, NM (USA). Dept. of Chemistry

A class of borazene polymers was developed which consists of a two-dimensional array of six-membered borazene rings with the borons of adjacent borazene rings separated by -NH- groups. Pyrolysis of these polymers above {approx}1000{degrees}C leads to crystalline graphite-like boron nitride (h-BN). The thermal chemistry of thin films of one polymer deposited on KOH-etched aluminum was examined by thermal decomposition mass spectroscopy (TDMS) and thermal gravimetric analysis (TGA) and the gas evolution chemistry was found to be essentially complete at temperatures less than 400{degrees}C. All products desorb with the same temperature profile and the major desorbing species are NH{sub 3} and N{sub 2}, consistent with a loss of excess nitrogen and hydrogen in the polymer, and HCI from decomposition of byproducts of the synthesis step. Since the formation of ordered crystalline h-BN films requires heating to temperatures of the order of 1000{degrees}C, whereas the gas evolution chemistry is complete by roughly 400{degrees}C, it is concluded that gas evolution chemical processes are not rate limiting in BN ceramic production.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6066186
• Journal Information: Journal of the American Ceramic Society; (USA), Journal Name: Journal of the American Ceramic Society; (USA) Vol. 73:5; ISSN 0002-7820; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360601 -- Other Materials-- Preparation & Manufacture
360602* -- Other Materials-- Structure & Phase Studies
656003 -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALI METAL COMPOUNDS
ALUMINIUM
BORON COMPOUNDS
BORON NITRIDES
CARBON
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTAL MINERALS
ELEMENTS
ETCHING
FILMS
GRAPHITE
GRAVIMETRIC ANALYSIS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROXIDES
MASS SPECTRA
METALS
MINERALS
NITRIDES
NITROGEN
NITROGEN COMPOUNDS
NONMETALS
OXYGEN COMPOUNDS
PNICTIDES
POLYMERS
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
PYROLYSIS
QUANTITATIVE CHEMICAL ANALYSIS
SPECTRA
SURFACE FINISHING
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
THERMOCHEMICAL PROCESSES
THIN FILMS