Mechanism of the improvement of the energy of host-guest explosives by incorporation of small guest molecules: HNO and HO promoted C-N bond cleavage of the ring of ICM-102.

Host-guest materials exhibit great potential applications as an insensitive high-energy-density explosive and low characteristic signal solid propellant. To investigate the mechanism of the improvement of the energy of host-guest explosives by guest molecules, ReaxFF-lg reactive molecular dynamics simulations were performed to calculate the thermal decomposition reactions of the host-guest explosives systems ICM-102/HNO, ICM-102/HO, and pure ICM-102 under different constant high temperatures and different heating rates. Incorporation of guest molecules significantly increased the energy level of the host-guest system. However, the initial reaction path of the ICM-102 molecule was not changed by the guest molecules. The guest molecules did not initially participate in the host molecule reaction. After a period of time, the HO and HNO guest molecules promoted cleavage of the C-N bond of the ICM-102 ring. Stronger oxidation and higher oxygen content resulted in the guest molecules more obviously accelerating destruction of the ICM-102 ring structure. The guest molecules accelerated the initial endothermic reaction of ICM-102, but they played a more important role in the intermediate exothermic reaction stage: incorporation of guest molecules (HNO and HO) greatly improved the heat release and exothermic reaction rate. Although the energies of the host-guest systems were clearly improved by incorporation of guest molecules, the guest molecules had little effect on the thermal stabilities of the systems.