Combustion Studies of 4-Nitramino-1,2,4-Triazole (4-NRTZ) and Its Salts: High Impulse Nitrogenous Fuels for Propellant Composite Materials

The nitrogenous salts of 4-nitramino-1,2,4-triazole (4-NRTZ, 2), namely ammonium-4-nitramino-1,2,4-triazolate (Amm-4-NRTZ, 3), hydrazinium-4-nitramino-1,2,4-triazolate (Hy-4-NRTZ, 4) and hydroxylammonium-4-nitramino-1,2,4-triazolate (HyAm-4-NRTZ, 5) were synthesized, characterized by spectroscopic (FTIR, FT-Raman, NMR) methods and their structures were confirmed by single-crystal X-ray diffraction technique. The salts (3-5) prepared in good yields showed good thermal stabilities and positive heat of formation. Ordered packing in lattice proved the better insensitivity of 3 & 5 towards IS, FS and ESD. Compounds 2 & 5 were further studied for its pressure generating capability inside a constant volume combustion chamber. Pressure-time (P-t) traces as well as dp/dt analysis revealed compound 5 has good gas generating capability. Theoretical predictions on the ballistic parameters in comparison with known compounds substantiate the potential of 5 as a strong candidate in propellant/gas generating composite materials.