High Energy Explosive with Low Sensitivity: A New Energetic Cocrystal Based on CL-20 and 1,4-DNI

A new 1:1 cocrystal explosive composed of 2,4,6,8,10,12-hexanitrohexaazaiso-wurtzitane (CL-20) and 1,4-dinitroimidazole (1,4-DNI) was synthesized through cocrystallization by slow solvent evaporation. The cocrystal has a crystal density of 1.922 g/cm 3 at 296 K and belongs to the orthorhombic system with P 2 1 2 1 2 1 space group. The properties of the cocrystal including thermal stability, impact sensitivity, and detonation performances were studied. DSC test shows that the cocrystal has a melting point of 115 °C with a decomposition temperature of 253 °C, suggesting an excellent thermal stability. Furthermore, the cocrystal exhibits an impact energy with 50% ignition probability of 10 J, showing a substantial reduction in impact sensitivity compared to pure CL-20 and HMX. Besides, the predicted detonation velocity and detonation pressure of the cocrystal are 9242 m/s and 39.01 GPa, respectively, which are similar to those of HMX. Therefore, the CL-20/1,4-DNI cocrystal may be an attractive high energy explosive with low sensitivity and, thus, may act as a promising explosive candidate instead of HMX for low vulnerability formulations in the future.