Biological interface engineering of HMX/KC-CTS/NTO core-shell composites: Ternary synergistic optimization of mechanical sensitivity, thermal stability and energy release efficiency

A novel 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) based energetic composite material was synthesized. With ultrafine NTO as the shell, the sensitivity of HMX was reduced and the thermal stability was enhanced while ensuring the detonation performance. In addition, biomass κ-carrageenan (KC) and chitosan (CTS) were used as coatings to synergistically improve the interfacial interaction of energetic materials and promote the energy release efficiency of HMX. Specifically, HMX/KC-CTS/NTO composites increase the β-δ phase transition temperature of HMX by 13.3 °C. The overall combustion rate of HMX/KC-CTS/NTO increased by 23.3 %, the maximum flame combustion rate increased by 62.7 %, and the combustion area increased by 228.9 %. Compared with HMX (IS = 6J, FS = 100 N), the impact sensitivity of HMX/KC-CTS/NTO (IS = 15 J, FS = 260 N) is significantly reduced due to the perfect and dense ultrafine-NTO coating on the surface of HMX particles. Finally, the formation mechanism of HMX/KC-CTS/NTO composites was revealed by DFT calculation.