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.