Inhibited propellant powders - with cellulose binder and inhibitor coating of polyol-isocyanate compsn.

摘要

Inhibited propellant powder has a cellulose binder and is coated with an inhibitor comprising a reaction prod. of a polyfunctional isocyanate (I) and a polyol (II). The inhibitor retards the rate of burning of the powder, and remains thermally and structurally intact during the ballistic cycle. Pref. (I) and (II) are dissolved in an inert solvent, the soln. applied to the surface of the powder and cross linking between (I), residual OH gps. in the cellulosic binder and (II) carried out with a urethane-forming catalyst such as dibutyltin dilaurate. Pref. (I) is a polyalkylene glycol such as polyethylene glycol or polypropylene glycol. (II) is e.g. an aromatic polyisocyanate such as polymethylene polyphenylisocyanate. The binder may be e.g. nitrocellulose.