冲击诱导CL-20/TNT含能共晶初始分解机制

Initial Decomposition Mechanism of Shock-Induced Energetic Co-Crystal CL-20/TNT

采用ReaxFF反应力场分子动力学方法,同时结合活塞加载模拟了0.8~4.0 km/s撞击速度下CL-20/TNT含能共晶的物理化学过程。冲击波入射至CL-20/TNT共晶中,随着冲击波强度的增加,初始反应路径主要分为3种:当u p=0.8 km/s,冲击压缩作用下CL-20聚合形成二聚体,无CL-20和TNT分解;当u p介于1.0~2.0 km/s,CL-20聚合和分解同时存在,并且聚合和分解的程度随着冲击波强度的增加而增加,但聚合过程占主导;当压缩区压力高于爆轰压力后,冲击引发CL-20/TNT共晶直接分解占主导作用,NO 2的数量明显增多并快速增加,而二聚体的数量逐渐减少。冲击引发CL-20/TNT共晶反应起爆的初始分解路径为CL-20中N-NO2键的断裂,另外,采用冲击雨贡纽关系计算得到CL-20/TNT共晶冲击起爆压力为11.15 GPa。CO2,N2,H2O为支撑能量释放的主要产物,并且,N2首先形成,H2O和CO2随后产生。

ReaxFF reactive force field molecular dynamics was used to simulate the initial chemical events of energetic co-crystal CL-20/TNT under the impact velocity of 0.8-4.0 km/s by using piston loading.When the shock waves propagated into CL-20/TNT,the initial reaction paths were mainly divided into three types with the increase of shock wave intensity:in the case of u p=0.8 km/s,CL-20 molecules were directly dimerized to form dimers,and no CL-20 molecule decomposition and no reaction in TNT.When the impact velocity is between 1.0 km/s and 2.0 km/s,CL-20 molecules dimerization and decomposition exist simultaneously,and the degree of dimerization and decomposition increases gradually,but dimerization process dominates.At impact velocity of 1.5 km/s,the TNT molecules begin to decompose.When the pressure of the compression zone is higher than the detonation pressure,the impact induced CL-20/TNT co-crystal direct decomposition is dominant,and the amount of NO 2 increases rapidly,while the number of dimers decreases gradually.The initial decomposition path of shock induced CL-20/TNT co-crystal reaction initiation is the N-NO 2 bond breaking in CL-20 molecule.In addition,the shock initiation pressure of CL-20/TNT co-crystal is 11.15 GPa.CO 2,N 2 and H 2O are the main final products,and N 2 is first formed,and H 2O and CO 2 are subsequently generated.