The isothermal decomposition of a CL-20/HMX co-crystal explosive

The isothermal decomposition process of CL-20/HMX co-crystals was studied through an isothermal decomposition dynamics research method. The pressure versus time curves of the gas generated by the CL-20/HMX co-crystal thermal decomposition present a significant inflection point at the decomposition extent of 70%. Furthermore, the residue of the CL-20/HMX co-crystals was investigated by HPLC and FTIR spectroscopy to understand the decomposition process. The results manifest that the decomposition of the CL-20/HMX co-crystals before and after the inflection point conforms to different model equations with the activation energies of 149.3 kJ mol⁻¹ and 169.0 kJ mol⁻¹, respectively. The thermal decomposition of the CL-20/HMX co-crystals is a coupling process. Clearly, the decomposition rate of CL-20 is much higher than that of HMX before the inflection point; CL-20 is almost consumed when the inflection point is reached in the pressure–time curve of the CL-20/HMX co-crystal thermal decomposition and then, HMX accelerates the thermal decomposition of the CL-20/HMX co-crystals.