Nitramine propellants absent a pressure exponent shift in the burning rate curves are prepared by matching the burning rate of a selected nitramine or combination of nitramines within 10% of burning rate of a plasticized active binder so as to smooth out the break point appearance in the burning rate curve.
Addition of a specified alkanol amine and a polybutadiene having terminal maleic anhydride groups to a conventional nitramine composite propellant which contains a nitramine oxidizer in a high content improves the resulting uncured propellant slurry in fluidity and the cured propellants are excellent in mechanical and burning properties.
The object of the present invention is novel solid pyrotechnic compositions with a loaded and plasticized thermoplastic binder, which can be used notably as propellants with non-polluting combustion, as propellants with a high combustion rate or as compositions generating non-toxic gases for air-bags. The plasticizer for the binder comprises a polybutadiene having a number average molecular weight of between 1500 and 7500 and having, added to some of its ethylenic non-saturations, silylferrocene groups.
The propellant compositions of this invention are crosslinked with from at 0.1 to about 1.0 weight percent of nitrocellulose which improves the physical properties and the thermal stabilities of these propellants thereby permitting their storing and testing up to 165.degree. F. These propellants employ additional ingredients which include one or more binder ingredients selected from the group consisting of polyglycol adipate (PGA), polyethylene glycol (PEG), polycapralactone (PCL or PCP), and hydroxy-terminated polybutadiene (HTPB); plasticizer ingredients selected from the nitrate ester plasticizers consisting of nitroglycerin (NG), trimethylol ethane trinitrate (TMETN), triethylene glycol dinitrate (TEGDN), and butane trioltrinitrate (BTTN); oxidizer ingredient selected from the group consisting of cyclotetramethylenetetranitramine (HMX), cyclotrimethylenetrinitramine (RDX), triaminoguanidine nitrate (TAGN), and oxamide; thermal stabilizers selected from the group consisting of 2-nitrodiphenylamine, 4-nitrodiphenylamine, n-methyl-p-nitroaniline, and resorcinol; isocyanate curing agent; carbon black additive; and a modifying additive selected from ballistic additives and curing catalyst additives.
Gas generating propellants with flame temperatures below 1400.degree. K. (isobaric) based on duroplastic and/or thermoplastic binders containing up to 80% by weight of triaminoguanidine nitrate as the chief gas generating component which can be cast or pressed into shapes having good chemical stability and excellent mechanical properties useful in propulsion engines and energy yielding systems.
