冲击作用下CL-20含能共晶的反应分子动力学模拟

共晶技术是降低六硝基六氮杂异伍兹烷(CL-20)感度的有效方法之一，研究冲击作用下CL-20共晶的化学反应，有助于理解CL-20共晶的冲击反应机制，对炸药安全评价分析具有重要意义。本研究采用ReaxFF-lg反应力场的分子动力学方法，同时结合非平衡加载方法，对CL-20/2,5-二硝基甲苯(DNT)、CL-20/1,3-二硝基苯(DNB)和CL-20/1-甲基-3,5-二硝基-1,2,4-三唑(MDNT)三种共晶在2～5 km·s^-1冲击速度下的冲击压缩过程进行了分子动力学模拟，获得了含能共晶在冲击作用后的热力学演化特征、初始化学反应路径和产物信息，并与CL-20的情况进行了对比分析。研究发现：CL-20/DNT、CL-20/DNB和CL-20/MDNT 3种共晶都有一定程度的降低冲击感度作用，3种共晶的冲击感度顺序依次为CL-20/MDNT>CL-20/DNB>CL-20/DNT。3种共晶的分解反应均是从CL-20分解开始，且CL-20的分解速度比DNT、DNB和MDNT快。在2 km·s^-1冲击速度下，CL-20共晶首先发生聚...

Reaction Molecular Dynamics Simulations of CL-20 Energetic Co-crystal under Shock

Co-crystal technology is one of the effective methods to reduce the sensitivity of CL-20. Studying the chemical reaction of CL-20 co-crystal under shock is helpful to understand the shock reaction mechanism of CL-20 co-crystal， which is of great significance to the safety evaluation and analysis of explosives. In this study， the molecular dynamics method of ReaxFF-lg reaction force field and the non-equilibrium loading method were used to simulate the shock compression process of CL-20/DNT， CL-20/DNB and CL-20/MDNT co-crystals at 2-5 km·s^-1 shock velocity. The thermodynamic evolution characteristics， initial chemical reaction path and product information of energetic co-crystals after shock are obtained and compared with those of CL-20. It’s discovered that the three co-crystals of CL-20/DNT， CL-20/DNB and CL-20/MDNT have a certain degree of shock sensitivity reduction， and the order of shock sensitivity of the three co-crystals is CL-20/MDNT>CL-20/DNB>CL-20/DNT. The decomposition reaction of the three co-crystals all starts from the decomposition of CL-20， and the decomposition rate of CL-20 is faster than that of DNT， DNB and MDNT. At the shock velocity of 2 km·s^-1， the polymerization reaction of CL-20 co-crystal occurs first. The polymerization reaction between CL-20 and co-crystal ligand molecules is earlier than that between CL-20 molecules， and the reaction frequency is much higher than that between CL-20 molecules. At the shock velocity of 3 km·s^-1， the N─N and C─N bonds of CL-20 are first broken， and the cage structure is destroyed. At the same time， NO₂ is generated. NO₂ generated by the initial bond breaking of CL-20 further combines with the eutectic ligand molecules DNT， DNB and MDNT to reduce the concentration of the intermediate products of CL-20 reaction， so as to achieve the desensitization effect. At the shock velocity of 4 or 5 km·s^-1， the ring skeleton structure in CL-20 is directly destroyed， the C-N bond is broken， generating small molecular fragments， including N_2， NO₂， H₂， CO₂， H₂O and other products.