A systematic overview of melt cast explosives is given. The research on melt cast explosives over several decades can be divided into three broad areas: (i) aromatic compounds with CCH3, NCH3, OCH3 CNO2, NNO2 and ONO2 groups, (ii) improved synthesis of compounds, which are currently used in formulations or which have shown promise for such use and (iii) the preparation of melt cast formulations with various compositions. Exudation, high volume change from liquid to solid, super cooling, irreversible growth, fragility and unpredictable sensitivity are the disadvantages of existing melt cast formulations.

We have investigated the decomposition kinetics of imidazole, 2-nitroimidazole, and 4-nitroimidazole using TG-DTA technique under nitrogen atmosphere. Isoconversional methods were used for the evaluation of kinetic parameters from the kinetic data of different heating temperatures. The Friedman method provided comparably higher values of activation energy than the Flynn-Wall-Ozawa method. Imidazole, 2-nitroimidazole, and 4-nitroimidazole were decomposed by the multistep reaction mechanism evident from the nonlinear relationship of activation energy and the conversion rate. The NO2 elimination and nitro-nitrite isomerization are expected to be competitive reactions in the decomposition of 2-nitroimidazole and 4-nitroimidazole. The present study may be helpful in understanding how the position of NO2 group affects the decomposition kinetics of substituted imidazoles.

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Density functional theory (DFT) calculations at the B3LYP/aug-cc-pVDZ level were performed to explore the geometric and electronic structures, band gaps, thermodynamic properties, densities and performances of aminonitroimidazoles. The calculated performance properties, stabilities and sensitivities of the model compounds appear to be promising compared with those of the known explosives 2,4-dinitro-1H-imidazole (2,4-DNI), 1-methyl-2,4,5-trinitroimidazole (MTNI), hexahydro-1,3,5-trinitro-1,3,5-triazinane (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocane (HMX). The position of the NH(2) or the number of NO(2) groups on the diazole presumably determines the structure, heat of formation, stability, sensitivity, density and performance of the compound.

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Polynitropyrazoles such as 3,4‐dinitro‐1H‐pyrazole (9), 3,4,5‐trinitro‐1H‐pyrazole (10), 1‐methyl‐3,4‐dinitropyrazole (8) and 1‐methyl‐3,4,5‐trinitropyrazole (3) have been synthesized in good yields adopting iodination route for the first time.