不同晶型 CL-20 冲击分解机理的分子动力学模拟.

唐 梅; 曾淑琼; 刘桂林; 牛振威

To deeply understand the impact initiation, impact ignition, detonation process, and detonation product states of energetic materials under extreme conditions, the decomposition reaction processes of α-, β-, γ-and ε-CL-20 crystals under shock loading were studied using self-consistent charge density functional-based tight-binding (SCC-DFTB) in combination with multiscale shock technique. The influence of water molecules on the decomposition of α-CL-20 was also studied because α-CL-20 generally exists in the form of hydrate. The results show that γ-CL-20 has the largest compression ratio among these four CL-20 crystals at the same shock velocity. When the shock velocity is 8 km/s, γ-CL-20 completely decomposes, while the other three crystals do not completely decompose until the shock velocity reaches 9km/s. Moreover, the addition of water molecules can significantly increase the activity of CL-20 molecules, and accelerate the decomposition of solid phase α-CL-20. In addition, the initial decomposition path of CL-20 under shock loading is not significantly affected by the crystal forms, but is mainly affected by the shock velocity. When the shock velocity is lower than 8km/s, the decomposition reaction is triggered by the dissociation of N—NO2 bond. However, when the shock velocity is higher than 9 km/s, the N—NO2 bond is inhibited by high pressure. The H in the C—H bond may preferentially form a five-membered ring with the adjacent NO2, and further produces NO and OH.

CHEMICAL decomposition; MOLECULAR dynamics; QUANTUM theory; VELOCITY; CRYSTALS

Chinese Journal of Explosives & Propellants, 2024, Vol 47, Issue 11, p1000

1007-7812

Academic Journal

10.14077/j.issn.1007-7812.202312012