Abstract: A composite article includes a substrate having a surface, a cation-sensitive layer including a cation-sensitive material disposed on the surface of the substrate, and a silicone layer disposed between the substrate and the cation-sensitive layer. Cations are present on the surface of the substrate in an amount of at least 0.1 atomic weight percent based on the total atomic weight of the atoms on the surface of the substrate. The silicone layer includes a cured silicone composition for preventing cations from migrating from the substrate to the cation-sensitive layer. The inclusion of the silicone layer between the cation-sensitive layer and the substrate enables the use of materials for the substrate that have not been useable in the past due to the presence of excessive amounts of cations in the materials.

Abstract: A resinous organosilicon preceramic polymer is melt spun into filaments which are rapidly cured, continuously gathered into a thread, and pyrolyzed in a continuous process to form ceramic fibers which may be either solid or hollow. The preferred preceramic polymer is hydridopolysilazane and the preferred curing agents are Cl.sub.2, HCl, HBr, thionyl chloride and trichlorosilane, followed by treatment with an atmosphere containing water vapor.

Abstract: The present invention describes a novel method for crosslinking polysilazane polymers having Si--H or N--H bonds. The method comprises mixing the polysilazane with a silazane crosslinker having at least 2 boron functional groups which can react with the Si--H or N--H bonds of the polysilazane and then facilitating crosslinking.

Abstract: The present invention describes a novel method for crosslinking polysilazane polymers having Si--H or N--H bonds. The method comprises mixing the polysilazane with a silazane crosslinker having at least 2 boron functional groups which can react with the Si--H or N--H bonds of the polysilazane and then facilitating crosslinking.

Abstract: A solution of resinous organosilicon polymer dissolved in an inert solvent is moved downstream as a film through a heated, film-forming zone having an inert atmosphere and a temperature above the polymer's melting point. The solvent is vaporized from the film and withdrawn from the film-forming zone. Molten resinous organosilicon polymer in the solvent-depleted film is withdrawn from the zone. The molten polymer is then directly melt spun into filaments which are gathered into a fiber. Various processing parameters are controlled.