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 P2(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 degrees C with a decomposition temperature of 253 degrees 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.