Abstract: Preceramic compositions which have particular utility in providing protective ceramic coatings on normally oxidizable materials, such as carbon/carbon and other carbon-containing composites and other materials, are obtained by dispersing solid particles comprising aluminum nitride particles in an organic solvent solution of a polysilazane. Ceramic coatings derived from the dispersions may serve as intermediate strata in multilayer ceramic coatings over substrates, such as carbon/ carbon composites, to provide even greater protection to the substrates, even when exposed to humidity.

Abstract: Preceramic compositions which have particular utility in providing protective ceramic coatings on normally oxidizable materials, such as carbon/silicon carbide and other carbon-containing composites and other materials, are obtained by dispersing solid particles comprising aluminum nitride particles in an organic solvent solution of an organoborosilazane polymer obtainable by reacting about 0.25-20 parts by weight of a trialkoxy-, triaryloxy-, or tri(arylalkoxy)boroxine with one part by weight of a polysilazane in an organic solvent. Ceramic coatings derived from the dispersions may be overcoated with ceramics derived from other preceramic polysilazane compositions to provide even greater protection to the substrates.

Abstract: A magnetic recording media containing a normally liquid polyphosphazene lubricant, e.g. low molecular weight linear or cyclic poly-fluoroalkoxy phosphazene mixtures.

Abstract: A mixture of compounds of the formulas:[X--(PX.sub.2 .dbd.N).sub.n --PX.sub.3 ].sup.+ [R].sup.-andX--(PX.sub.2 .dbd.N).sub.n --POX.sub.2wherein X is a halogen atom, R is X or PX.sub.6 or both of them, and n is an integer, usually below about 15, is heated either with no other reactant or with a suitable phosphorus reactant such as PX.sub.5 ; PX.sub.3 +X.sub.2 ; P+X.sub.2 ; or a mixture of two or more such phosphorus reactants so that a halophosphazene having a --PX.sub.3.sup.+ end group is formed as one of the co-products of the reaction. This co-product is a substance having the general formula[X--(PX.sub.2 .dbd.N).sub.n --PX.sub.3 ].sup.+ [R].sup.-wherein X, R and n are as defined above. The other co-product is phosphoryl trihalide, POX.sub.3. In a second stage the resultant reaction product is heated with at least a stoichiometric amount (preferably, an excess) of a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.

Abstract: One or a mixture of compounds of the formula:X--(PX.sub.2 .dbd.N).sub.n --POX.sub.2wherein X is a halogen atom and n is an integer, usually below about 15 is heated with a suitable phosphorus reactant such as PX.sub.5 ; PX.sub.3 +X.sub.2 ; P+X.sub.2 ; or oligomer of the formula[X--(PX.sub.2 .dbd.N).sub.n --PX.sub.3 ].sup.+ [R].sup.-wherein X is a halogen atom, R is PX.sub.6 or X, and n is an integer usually below about 15; or a mixture of two or more such phosphorus reactants so that a halophosphazene having a --PX.sub.3.sup.+ end group is formed as one of the co-products of the reaction. This co-product is a substance having the general formula[X--(PX.sub.2 .dbd.N).sub.n --PX.sub.3 ].sup.+ [R].sup.-wherein X, R and n are as defined above. The other co-product is phosphoryl trihalide, POX.sub.3. In a second stage the resultant reaction product is heated with at least a stoichiometric amount (preferably, an excess) of a nitrogen source (e.g., NH.sub.3 ; NH.sub.4 Cl; etc.