Chain-extended poly(bis-azidomethyloxetane), and combustible cartridge cases and ammunition comprising the same

Ammunition comprising:

• a combustible ammunition cartridge case configured with a chamber and comprising an energetic composition;
• propellant received within said chamber of said combustible ammunition cartridge case;
• and
• a projectile in operative relation with the combustible ammunition cartridge case to receive a propulsive force upon ignition of said combustible ammunition cartridge case and said propellant,
• said energetic composition comprising at least one energetic thermoplastic binder, said energetic thermoplastic binder comprising at least one member selected from the group consisting of a chain-extended poly(bis-azidomethyloxetane) homopolymer and a chain-extended copolymer or terpolymer, wherein:
• (a) said chain-extended poly(bis-azidomethyloxetane) homopolymer is derived from poly(bis-azidomethyloxetane) prepolymer blocks terminated with isocyanate-reactive groups and chain extended with at least one diisocyanate end-capping compound and at least one linking compound comprising two functional groups which are reactive with isocyanate moieties of said diisocyanate end-capping compound;
• and
• (b) said chain-extended copolymer or terpolymer is derived from poly(bis-azidomethyloxetane) prepolymer blocks and one or more additional co-polymerizable prepolymer blocks, said poly(bis-azidomethyloxetane) prepolymer blocks and said additional co-polymerizable prepolymer blocks being terminated with isocyanate-reactive groups and chain extended with each other with at least one diisocyanate end-capping compound and at least one linking compound comprising two functional groups which are reactive with isocyanate moieties of said diisocyanate end-capping compound.

A method for making a combustible ammunition cartridge case configured with a chamber for receiving a propellant and comprising at least one energetic thermoplastic binder, said method comprising preparing the combustible ammunition cartridge case by performing at least one step selected from the group consisting of:

• (a) providing poly(bis-azidomethyloxetane) prepolymer blocks terminated with isocyanate-reactive groups, end-capping the prepolymer blocks with at least one diisocyanate end-capping compound, and chain extending the end-capped prepolymer blocks with at least one linking compound comprising two functional groups which are reactive with isocyanate moieties of said diisocyanate end-capping compound to form a chain-extended poly(bis-azidomethyloxetane) homopolymer, and
• (b) providing poly(bis-azidomethyloxetane) prepolymer blocks and one or more additional co-polymerizable prepolymer blocks each terminated with isocyanate-reactive groups, end-capping the prepolymer blocks and the co-polymerizable prepolymer blocks with at least one diisocyanate end-capping compound, and chain extending the end-capped prepolymer blocks and the end-capped co-polymerizable prepolymer blocks with at least one linking compound comprising two functional groups which are reactive with isocyanate moieties of said diisocyanate end-capping compound to form a chain-extended copolymer or terpolymer.

A method for making ammunition comprising a combustible ammunition cartridge case configured with a chamber and comprising an energetic composition;

• propellant received within said chamber of the combustible ammunition cartridge case;
• and a projectile in operative relation with the combustible ammunition cartridge case to receive a propulsive force upon ignition of the combustible ammunition cartridge case and the propellant, the energetic composition comprising at least one energetic thermoplastic binder, said method comprising preparing the combustible ammunition cartridge case of the ammunition by performing at least one step selected from the group consisting of:
• (a) providing poly(bis-azidomethyloxetane) prepolymer blocks terminated with isocyanate-reactive groups, end-capping the prepolymer blocks with at least one diisocyanate end-capping compound, and chain extending the end-capped prepolymer blocks with at least one linking compound comprising two functional groups which are reactive with isocyanate moieties of said diisocyanate end-capping compound to form a chain-extended poly(bis-azidomethyloxetane) homopolymer, and
• (b) providing poly(bis-azidomethyloxetane) prepolymer blocks and one or more additional co-polymerizable prepolymer blocks each terminated with isocyanate-reactive groups, end-capping the prepolymer blocks and the co-polymerizable prepolymer blocks with at least one diisocyanate end-capping compound, and chain extending the end-capped prepolymer blocks and the end-capped co-polymerizable prepolymer blocks with at least one linking compound comprising two functional groups which are reactive with isocyanate moieties of said diisocyanate end-capping compound to form a chain-extended copolymer or terpolymer.