Hybrid HMX multi-level assembled under the constraint of 2D materials with efficiently reduced sensitivity and optimized thermal stability

The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive attention. However, screening suitable coating agents to enhance the interfacial effect to obtain high-energy and low-sensitivity explosives has long been a major challenge. In this work, HMX-PEI/rGO/g-C3N4 (HPrGC) composites were innovatively prepared by a multi-level coating strategy of two-dimensional graphite rGO and g-C3N4. The g-C3N4 used for desensitization has a rich π-conjugated system and shows outstanding ability in reducing friction sensitivity. The hierarchical structure of HPrGC formed by electrostatic self-assembly and π-π stacking can effectively dissipate energy accumulation under heat and mechanical stimulation through structural evolution, thus exhibiting a prominent synergistic desensitization effect on HMX. The results show that rGO/g-C3N4 coating has no effect on the crystal structure and chemical structure of HMX. More importantly, the perfect combination of g-C3N4 and rGO endows HPrGC with enhanced thermal stability and ideal mechanical sensitivity (IS: 21 J, FS: 206 N). Obviously, the new fabrication of HPrGC enriches the variety of desensitizer materials and helps to deepen the understanding of the interaction between explosives and coatings.