Nitrogen-rich energetic salts of 5,5′-dinitramino-3,3′-methylene-1H-1,2,4-bistriazolate: powerful alliance towards good thermal stability and high performance

Abstract

Two new nitrogen-rich energetic salts based on 5,5′-dinitramino-3,3′-methylene-1H-1,2,4-bistriazolate (DNAMT), namely, (DAG)₂(DNAMT)·4H₂O (1) and (NH₃OH)(DNAMT) (2), were designed and synthesized, and they were characterized by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The thermal stability of the two salts were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The decomposition temperatures of 1 and 2 were determined to be 221.2 °C and 214 °C, respectively. The apparent activation energies (E_a) of the thermal decomposition processes of 1 and 2 were 189.2 and 218.9 kJ mol⁻¹, respectively. Compound 1 had appropriate impact sensitivity (11.5 J) and was friction-insensitive (>360 N). In contrast, compound 2 was an impact- and friction-sensitive explosive (IS: 3 J; FS: 56 N). The detonation properties of compounds 1 and 2 were calculated using EXPLO 5 (V6.04) based on their experimental densities and calculated heats of formation. The detonation properties of 1 (D: 7943 m s⁻¹ and P: 21.20 GPa) and 2 (D: 8339 m s⁻¹ and P: 26.75 GPa) dramatically exceeded those of TNT but were lower than those of RDX. Meanwhile, compounds 1 and 2 possessed higher nitrogen contents (53.83% and 50.82%, respectively). Both compounds displayed good thermal stability, high energetic properties and low sensitivities as high nitrogen content energetic materials.