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The crystal of dimethylamine 5,5′-bistetrazole-1,1′-diolate, one possibly unknown intermediate in the production of the famous high energy insensitive explosive TKX-50, was easily prepared from the precursor of TKX-50 and solvent media and characterized by single-crystal X-ray analysis. In addition, the thermal behavior, and safety parameters of DMA-BTO were investigated, which will offer an important message for the production and application of TKX-50. Finally, the stabilization energy E(2), molecular electrostatic potential, HOMO–LUMO energy gaps and Mulliken charge distributions were calculated using Gaussian 09 at the B3LYP/6-311G(d,p) level.

Dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) is a promising candidate to replace traditional explosives, 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), used in insensitive munitions, which is currently being explored to achieve shock insensitive melt cast formulations. Safety and energetic properties of melt cast explosive formulations help in implementing applications in the future. In the present study, TKX-50 based melt cast formulations are prepared with 2,4,6-trinitrotoluene (TNT) as a dispersant. Furthermore, the safety assessment and energy performance are studied along with HMX based melt cast formulations for comparison. In order to gain insight into the coating mechanism, the interaction energies calculations were performed at the B3LYP/6-311G** level. The results revealed that stronger attractive forces exist in TKX-50–TKX-50 than in HMX–HMX pairs and similarly in TKX-50–TNT than in HMX–TNT, which have good agreement with the coating conditions. This comparative study reveals that the safe and energy performance of TKX-50 based formulations is superior to HMX based formulations.

N,N′-Dinitro-4,4′-azo-bis(1,2,4-triazolone) (DNZTO) is synthesized by the reaction of 4,4′-azo-bistriazolone (ZTO) with a mixture of nitric acid and acetic anhydride. The product was fully characterized by IR, NMR, matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry, and single-crystal X-ray analysis. The explosive performance including detonation pressures (P), velocities (D) of DNZTO, and heats of formation were predicted usinggaussian 09at B3LYP/6-311+G**.

Molecular dynamics has been carried out to simulate the well-known new explosive compound 5,5′-bistetrazole-1,1′-diolate (TKX-50) and TKX-50 based polymer bonded explosives (PBXs) with four kinds of polymer binders, such as, fluorine (F2311), fluorine resin (F2641), polyethylene glycol (PEG) and ethylene-vinyl acetate copolymer (EVA). The isotropic mechanical properties (tensile modulus, bulk modulus, shear modulus and Poisson’s ratio), moldability, and bonding energy are reported for first time for TKX-50 crystal and TKX-50 based PBXs. The mechanical properties of the explosive can be effectively raised by adding polymer binders in small amounts and the ability of different polymer binders improving the plasticity of TKX-50 in the increasing order PEG > EVA > F2641 = F2311. The moldability of TKX-50 based PBXs is better than that of pure TKX-50, and the increasing order is PEG > EVA > F2311 > F2641. The interaction between each of the crystalline surfaces and each of the polymers is different, the order of the abilities of different binders to combine TKX-50 crystal decreases as follows: F2311 > PEG ≈ F2641 > EVA. The calculated detonation performances for pure TKX-50 and TKX-50 based PBXs show that both of them are comparable with those of HMX. Ultimately, as for the four polymer binders, PEG is considered the best one for explosive TKX-50.

Thermogravimetric–differential thermal analysis (TG–DTA) and accelerating rate calorimetry (ARC) were performed to understand thermal characteristics and kinetics of energetic N,N′-dinitro-4,4′-azo-Bis(1,2,4-triazolone) (DNZTO). A single sharp and narrow exothermic decomposition occurred at 143.3, 150.3, 156.4, 157.4, 159.8 and 160.3 °C at different heating rates (0.5, 1, 2, 3, 4, and 5 °C min −1 ) suggesting that DNZTO composition was vulnerable to thermal hazard. The FTIR–TGA–MS results revealed that the decomposition product was made up of H 2 O, NO 2 , NO, CO 2 , CO, HCN, and N 2 O. ARC studies depicted onset temperature at 116.6 °C with temperature step of 5 °C and phi factor of 41.46, and a sharp rise in exothermic reaction at 127.69 °C within the time span of 49.04 min with the maximum heat release rate of 0.47 °C min −1 . The exothermic activity resulted in adiabatic pressure rise of the sample up to 300 kPa by the sample pyrolysis into gas. In addition, the kinetic parameters of DNZTO were estimated for the thermal process by TG–DTA and ARC.

4,4-azo-bis(1,2,4-triazol-5-one) (ZTO) and its solvent adducts have been reported, and the single crystal X-ray measurements indicated that the ZTO crystals appeared as a monoclinic system with space group P2(1)/c, while ZTO·2H2O and ZTO·2DMF displayed as monoclinic with space group P2(1)/n and triclinic with space group Pī, respectively. In addition, the thermal decomposition process of the three crystals was studied by thermogravimetric differential analysis (TG-DTA), and the result showed that only one exothermic peak was found in each case of ZTO, ZTO·2H2O, and ZTO·2DMF, and the peak temperature (T p) are observed at 292.36, 291.82, and 272.73 °C, respectively.

C6H5N11O6, monoclinic, P21/n (no. 14), a = 13.463(5) Å, b = 6.526(2) Å, c = 14.068(5) Å, β = 95.961(5)°, V = 1229.3(7) Å3, Z = 4, R gt (F) = 0.0417, wR ref (F 2 ) = 0.1067, T = 153 K.

C6H6N12O12 · 0.33 H2O, orthorhombic, Pbca (no. 61), a = 9.5152(7) Å, b = 13.2551(11) Å, c = 23.6736(18) Å, V = 2985.8(7) Å3, Z = 4, R gt(F) = 0.0727, wR ref(F 2) = 0.1268, T = 293(2) K.