Preparation of Spherical HMX/DMF Solvates, Spherical HMX Particles, and HMX@NTO Composites: A Way to Reduce the Sensitivity of HMX.

To reduce the sensitivity of HMX (HMX = high-melting explosive-cyclotetramethylenetetranitramine), spherical HMX/DMF (DMF = dimethylformamide) solvates, spherical HMX particles, and HMX@NTO (NTO = 1,2,4-triazol-5-one) composites are prepared by crystallization. The structure and performance of spherical HMX crystals, HMX particles, and HMX@NTO composites are characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, accelerating rate calorimetry, and mechanical sensitivity test. The results show that the space group of the spherical HMX/DMF solvate is R̅3c with the lattice parameters of a = 15.9159(4) Å, b = 15.9159(4) Å, and c = 30.5136(8) Å. The non-isothermal stability and adiabatic thermal stability of HMX/DMF solvates are similar to those of HMX particles. The non-isothermal stability of HMX@NTO composites is lower than that of NTO and HMX particles, while the adiabatic thermal stability of HMX@NTO composites is higher than that of NTO but lower than that of HMX particles. The mechanical sensitivities of spherical HMX/DMF cocrystals, spherical HMX particles, and HMX@NTO composites are lower than that of raw HMX. This study can provide some guidance for desensitizing HMX and other energetic materials.