ReaxFF molecular dynamics (ReaxFF MD) simulations in conjunction with TG-FTIR-MS (Thermogravimetric-Fourier transform infrared-Mass spectrometry) techniques were performed to illuminate the pyrolysis mechanism of 3,7-dinitro-1,3,5,7-tetraazabicyclo [3,3,1] nonan (DPT). The characteristics of DPT decomposition under different temperatures were explored by ReaxFF molecular dynamics. The simulation results show the evolution of primary intermedia products and final products of DPT decomposition varies with time. The complete dynamic process of DPT decomposition at the atomic level is revealed. The pyrolysis of DPT is primary triggered by N-NO₂ rupture, which is confirmed by the bond dissociation energy (BDE) calculation. Subsequently, the intermedia products undergo a series of complex interactions and H₂O, N₂, NH₃ and C network generate as final products. The volatile gas detected by ReaxFF molecular dynamics are all certified by the TG-FTIR-MS techniques, which demonstrating the reasonability of theoretical simulations. Thus, a full microscopic picture of the thermal decomposition of DPT is presented, which is a great help in the safe manufacture of octogen (HMX).

ReaxFF 分子动力学 (ReaxFF MD) 模拟与 TG-FTIR-MS（热重-傅里叶变换红外-质谱）技术相结合，以阐明 3,7-二硝基-1,3,5,7-四氮杂双环的热解机制[3,3,1] 壬烷 (DPT)。ReaxFF分子动力学研究了DPT在不同温度下的分解特性。模拟结果表明DPT分解的初级中间产物和最终产物的演变随时间变化。揭示了原子级DPT分解的完整动态过程。DPT 的热解主要由 N-NO ₂破裂触发，这通过键解离能 (BDE) 计算得到证实。随后，中间产品经历了一系列复杂的相互作用和H₂ O、N ₂、NH ₃和C 网络作为最终产品生成。ReaxFF分子动力学检测到的挥发性气体均经过TG-FTIR-MS技术验证，证明了理论模拟的合理性。因此，呈现了DPT热分解的全显微图像，这对安全生产八氢溴二苯醚（HMX）有很大帮助。