Bis(5-nitroimino-1,2,4-triazole-3-yl) methane-based energetic salts: Synthesis, crystal structure, thermal behavior and catalytic activity

Abstract

Four energetic ionic salts of bis(5-nitroimino-1,2,4-triazole-3-yl) methane (BNTM) potassium (KBNTM), ammonium (A2BNTM), hydroxylamine ((HA)2BNTM), 1,3-diaminoguanidine ((DAG)2BNTM) have been synthesized and characterized by Elemental analysis(EA), Fourier infrared(FI) and Nuclearmagnetic resonance(NMR). Fortunately, the single crystals available for determination of KBNTM was acquired by slow evaporation of solvent method and its structure was discussed. The thermal behaviors of them were explored by Differential Scanning Calorimetry(DSC) and Thermogravimetry/ Derivative Thermogravimetry (TG/DTG) technique, and the result displayed that all of them had good thermal stability. The most possible mechanism function of main exothermic decomposition process were obtained (No.35 for KBNTM, No.6 for A2BNTM, No.24 for (HA)2BNTM, No.14 for (DAG)2BNTM). In addition, (HA)2BNTM has the best thermal safety, followed by KBNTM and A2BNTM according to the calculated value of self-accelerating decomposition temperature (TSADT) and critical temperature of thermal explosion (Tb). Moreover, the catalytic effects of four ionic salts on Cyclotrimethylenetrinitramine(RDX) and Octogen(HMX) were investigated respectively. The consequent showed that (HA)2BNTM accelerated the thermal decomposition of RDX and HMX, and reduced the decomposition temperature and apparent activation energy of RDX and HMX by 6.94 °C, 17.37 kJ·mol−1 and 4.17 °C, 2.77 kJ·mol−1, respectively. Surely, the thermal decomposition mechanism function of (HA)2BNTM/RDX was different from that of RDX (No.5, f(α)=6(1-α)2/3 [1-(1-α)1/3]1/2). In summary, (HA)2BNTM can be regarded as a potential energetic combustion catalyst with insensitive to physical impact (IS=16 J).