Precursors for boron nitride coatings
AssigneeUniversity of New Mexico
InventorsRobert T. Paine, Jr., Chaitanya K. Narula, Riley O. Schaeffer, David A. Lindquist, Theodore T. Borek, III
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Abstract
The disclosure is directed to compositions and methods for forming boron nitride coatings, using polymers derived from tri-substituted borazine and chloroborazine compounds. The polymeric compounds are mixed with ammonia, pyrolized at high temperatures to obtain a high temperature melt, and further converted to boron nitride coatings on various substrates. The polymeric compounds can be stored prior to pyrolysis.
Claims31
A process for the pyrolytic conversion of a polymeric precursor composition to boron nitride comprising the following steps:
- (a) obtaining a borazine compound having a general formula selected from the group consisting of tris-dialkylamino borazines (R.sub.2 NBNH).sub.3 ;
- tris-alkylsulfide borazines (RSBNH).sub.3 ;
- B-trichloroborazine (ClBNH).sub.3 ;
- and 1-B-dialkylamino,3,5-B dichloroborazine (R.sub.2 NB)(BCl).sub.2 (NH).sub.3 ;
- wherein R is an alkyl group and wherein boron atoms are not bonded to hydrogen atoms;
- (b) dissolving the borazine compound in a solvent in the presence of a cross-linking agent to from an insoluble, solid polymer wherein boron atoms are not bonded to hydrogen atoms and wherein there are no direct N(ring)-B(ring) bonds;
- (c) removing substantially all the solvent from the insoluble solid polymer;
- (d) applying the insoluble, solid polymer as a dry coating to an article;
- and
- (e) converting the polymer to boron nitride by pyrolysis.
Dependencies are inferred from the claim text.