Preparation and thermal properties study of HMX/RDX composites

HMX/RDX composites were prepared using the solvent-antisolvent alternating method. The morphology and structure of the composites were characterized by optical microscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (PXRD). The composite exhibited a morphology with HMX as the core and RDX as the coating layer. The HMX existed in the β-phase, and molecular interactions were observed between the two components (a blue shift of 2.06 cm^{− 1} in the NO₂ symmetric stretching vibration peak of HMX and a red shift of 2.06 cm^{− 1} in the C-H stretching vibration peak of RDX). Thermal analysis revealed synergistic effects in the thermal decomposition process (lower decomposition peak temperature for HMX and higher for RDX), with an apparent activation energy (149.41 kJ/mol) in the first decomposition stage lower than that of the physical mixture and pure RDX component. Concurrently, both the critical thermal detonation temperature (227.74 ℃) and self-accelerating decomposition temperature (213.78 ℃) exceed those of the physical mixture and pure RDX component, thereby demonstrating superior thermal safety. This composite material strikes a balance between energy release efficiency and safety, offering significant application value for weapon systems that pursue higher performance and lower vulnerability. It also provides a novel approach and technical pathway for high-energy explosive formulation design.