Propellent compositions

A propellent composition suitable for gas generators and cartridge-actuated devices comprises an oxidizing material dispersed in a silicone rubber or resin which is prepared by curing a polysiloxane comprising a proportion of acyclic alkenyl groups bonded to silicon atoms of the polysiloxane chain. The polysiloxane may contain 0.1-25% by weight of alkenyl, e.g. vinyl, groups and may also contain methyl, ethyl, or propyl groups in the chain. Suitable oxidizers are alkali metal and ammonium perchlorates and nitrates. Curing is effected at 150 DEG C, or below in the presence of a catalyst, for example benzoyl peroxide, di-tertiary butyl peroxide, a platinum metal, or a platinum metal complex as described in Specification 1,027,051. In examples (1) a mixture of polysiloxane gum containing methylvinyl siloxane units, fume silica, dimethylpinacoxysilane, potassium perchlorate, and 2,4-dichlorobenzoyl peroxide is extruded, cut, and heated at 120 DEG C.; (2) a mixture of polysiloxane fluid containing methylvinyl siloxane units, potassium perchlorate, cyclohexene platinous chloride solution, and trimethylsilyl end-stopped methylhydrogenpolysiloxane as a cross-linking agent is cast in a mould and heated at 100 DEG C.ALSO:A propellent composition suitable for gas generators and cartridge-actuated devices comprises an oxidizing material dispersed in a silicone rubber or resin which is prepared by curing a polysiloxane comprising a proportion of acyclic alkenyl groups bonded to silicon atoms of the polysiloxane chain. The polysiloxane may contain 0.1-25% by weight of alkenyl, e.g. vinyl, groups and may also contain methyl, ethyl, or propyl groups in the chain. Suitable oxidizers are alkali metal and ammonium perchlorates and nitrates. Curing is effected at 150 DEG C. or below in the presence of a catalyst, for example benzoyl peroxide, di-tertiary butyl peroxide, a platinum metal, or a platinum metal complex as described in Specification 1,027,051. In examples (1) a mixture of polysiloxane gum containing methylvinyl siloxane units, fume silica, dimethylpinacoxysilane, potassium perchlorate, and 2,4-dichlorobenzoyl peroxide is extruded, cut, and heated at 120 DEG C.; (2) a mixture of polysiloxane fluid containing methylvinyl siloxane units, potassium perchlorate, cyclohexene platinous chloride solution, and trimethylsilyl end-stopped methylhydrogenpolysiloxane as a cross-linking agent is cast in a mould and heated at 100 DEG C.