Composite solid propellant contains immobilised burning modifier - comprising a ferrocene deriv. immobilised by hydroxyl gps. reacting with PU binder during curing, useful as rocket or gas generator fuel..

Abstract
Composite solid propellant contains a crystalline inorganic oxidant, a binder with a liq. poly-OH-substd. prepolymer, crosslinking agent(s), polymer-specific plasticiser, antioxidant and adhesion promoter, a ferrocene deriv. coupled to the binder as burning modifier and opt. a metallic fuel and/or energy-rich nitramine. The ferrocene deriv. is a ferrocenyl methyl ether or ferrocenyl-carboxylate ester with free OH gps. of formula (I): Z = the ether gp. CH2-OX or the ester gp. C(O)-O-X; X = an oligoalkylene glycol or diol gp.; R = satd. hydrocarbyl or H. Also claimed is a method of producing the propellant. USE - Solid fuel of this type is esp. useful as rocket or gas generator fuel. ADVANTAGE - The ferrocene deriv., which has low viscosity and can be prepd. easily, is immobilised by chemical bonding of its OH gps. to the polymer during cure.