Reaction Mechanism of Embedding Oxidizing Small Molecules in Energetic Materials to Improve the Energy by Reactive Molecular Dynamics Simulations

Novel host-guest/multicomponent energetic materials can be obtained by embedding hydrogen- or nitrogen-containing oxidizing small molecules between the molecules of high-energy explosives, which can improve their explosive energy. To better understand the mechanism of oxidizing small molecules in the reaction and improve the energy, ReaxFF-lg reactive molecular dynamics simulations were performed to investigate the thermal decomposition reaction at different temperatures of the CL-20/H2O2 solvate formed by embedding H2O2 in the cavity of CL-20. We propose an analytical method to investigate the mechanism of H2O2 in the CL-20 reaction by tracing the interactions between the H and O atoms of H2O2 and the C, H, N, and O atoms of CL-20. During thermal decomposition of CL-20/H2O2 CL-20 and H2O2 first separately decompose, and then, the decomposition products react. The H atoms, O atoms, and hydroxyl (HO) groups generated by H2O2 decomposition connect with the O atoms of nitro groups, leading to N-O bond cleavage. The O atoms generated by H2O2 decomposition connect with C atoms, leading to C-N bond cleavage, which catalyzes 'destruction of the CL-20 cage structure and increases the CL-20 decomposition rate. Eventually, the H and O atoms of H2O2 mainly bond to the O and C atoms of CL-20, respectively, which causes generation of greater amounts of H2O and CO2 and increases the heat released. These mechanisms increase the detonation velocity and pressure of explosives. The proposed analytical method can be used to investigate the reaction mechanisms of other host-guest/multicomponent energetic materials.