A process for forming a low smoke, low erosion rocket motor insulation comprising mixing organic fiber selected from the group polyaramid and polybenzimidazole; an inorganic powder filler; a vulcanizable hydrocarbon elastomer and a non-fluorinated phosphazene polymer of the formula ##STR1## where Q and Q' are the same or different and are substituted or unsubstituted alkoxy or aryloxy and Q" is a group having olefinic unsaturation.
The addition polymerization resin systems phthalonitrile, diethynyldiphenyl methane, phenolic triazine, and polyphosphazene are disclosed as the matrix constituent in fiber-reinforced ablative nozzle components. Various types of fibers such as carbon fibers, preferably rayon and polyacrylonitrile (PAN) based, graphite fibers, glass fibers, ceramic fibers, and silica fibers may be used in the nozzle composite materials. Fillers, such as carbon black, ground silica, ground petroleum coke, and microballoons, may also be included in the ablative nozzle components. The fiber-reinforced ablative nozzle components include from about 20% to about 40% resin, by weight, from about 45% to about 60% fiber, by weight, and when present, from about 3% to about 15% filler, by weight.
Incorporation of phosphate and phosphonate units into the side groups of aryloxyphosphazenes, at both the polymer and cyclic trimer levels, is disclosed. Phosphorylated cyclic trimers are utilized as flame-retardant additives to polystyrene.
Insulation for a rocket motor is provided, as is a method for insulating a rocket motor. The insulation includes a cured elastomer and vapor-grown carbon fibers dispersed in the cured elastomer. The cured elastomer is preferably formed from a precursor composition comprising an EPDM terpolymer. Generally, the vapor-grown carbon fibers have an internal graphitized tube surrounded by a sheath of vapor-deposited amorphous carbon.
A fused metal matrix abrasive body and method of preparing a fused metal matrix abrasive body is provided. The fused metal matrix abrasive body comprises a plurality of metal coated abrasive particles and a fused metal matrix comprising a bond metal and an effective amount of an oxygen scavenger metal. The metal coated abrasive particles are distributed in the fused metal matrix which bonds the abrasive particles together. The oxygen scavenger metal functions as a scavenger (i.e., "getter) for oxygen thereby protecting the adhesion promoting metal coating on the abrasive particle from the oxidation.
Insulation for a rocket motor is provided, as is a method for insulating a rocket motor. The insulation includes a cured elastomer and vapor-grown carbon fibers dispersed in the cured elastomer. The cured elastomer is preferably formed from a precursor composition comprising an EPDM terpolymer. Generally, the vapor-grown carbon fibers have an internal graphitized tube surrounded by a sheath of vapor-deposited amorphous carbon.
