Abstract: A solid propellant restrictor for preventing erosive burning in solid prolant grain critical areas is described. The restrictor is a mixture of hydroxyl-terminated polybutadiene with 1% by weight of dissolved 2,2'-methylene-bis(4-methyl-6-tert-butyl) phenol, dioctyl adipate, triethanolamine, ferric acetylacetonate, carbon black, aluminum oxide, silicon oxide, and toluene diisocyanate, curing at room temperature and illustrates superior hardening, adhesive, and application properties.

Abstract: In a method wherein propellant ingredients including a hydroxy terminated nder, an isocyanate curative therefor and transition metal compounds or traces thereof are mixed, worked into a suitable container and allowed to cure, gossypol is used to prolong the potlife of the propellant mix. Gossypol is dissolved in a portion of the hydroxy terminated binder material and the solution is utilized as a portion of the total binder. Final formulations containing from 0.02 to 0.1 weight percent gossypol are preferred although more gossypol may be used.

Abstract: Solid rocket propellants which utilize hydroxy terminated polybutadiene as he binder and a reactive burn-rate catalyst selected from 4, 4-diferrocenyl-1-pentanol and 3, 3-diferrocenylbutyl isocyanate are disclosed. The burn-rate catalysts are chemically bound to the binder to prevent migration.

Abstract: A double base propellant grain inhibitor is comprised of a hydroxyl-termied polybutadiene polymer having from 2 to about 3 hydroxyl groups per average molecule and an approximate molecular weight of 2800 to 3600, an inert filler, a cross-linking agent, a thickening agent, an antioxidant, a curative, and a catalyst. When properly applied to the surface of a propellant grain, the inhibitor bond does not weaken with age and the inhibitor produces planar, no-cone grain burning having a constant chamber pressure during the burning of the propellant grain. A 1,4-butylene oxide-type polyether barrier layer consisting of a poly-1,4-butylene oxide diisocyanate with an approximate molecular weight of 850 to 1000, a diol curative, a triol cross-linker, and antioxidant and a cure catalyst can be added between the propellant grain and inhibitor to reduce propellant plasticizer migration.