冲击作用下CL-20含能共晶的反应分子动力学模拟OACSTPCD

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 sig-nificance 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 re-duction,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 N2,NO2,H2,CO2,H2O and other products.