Wang Fuping, Chen Lang, Geng Deshen, Wu Junying, Lu Jianying, Wang Chen
State Key Laboratory of Explosion Science and Technology , Beijing Institute of Technology , Beijing 100081 , China.
J Phys Chem A. 2018 Apr 26;122(16):3971-3979. doi: 10.1021/acs.jpca.8b01256. Epub 2018 Apr 11.
Hexanitrohexaazaisowurtzitane (CL-20) has a high detonation velocity and pressure, but its sensitivity is also high, which somewhat limits its applications. Therefore, it is important to understand the mechanism and characteristics of thermal decomposition of CL-20. In this study, a ε-CL-20 supercell was constructed and ReaxFF-lg reactive molecular dynamics simulations were performed to investigate thermal decomposition of ε-CL-20 at various temperatures (2000, 2500, 2750, 3000, 3250, and 3500 K). The mechanism of thermal decomposition of CL-20 was analyzed from the aspects of potential energy evolution, the primary reactions, and the intermediate and final product species. The effect of temperature on thermal decomposition of CL-20 is also discussed. The initial reaction path of thermal decomposition of CL-20 is N-NO cleavage to form NO, followed by C-N cleavage, leading to the destruction of the cage structure. A small number of clusters appear in the early reactions and disappear at the end of the reactions. The initial reaction path of CL-20 decomposition is the same at different temperatures. However, as the temperature increases, the decomposition rate of CL-20 increases and the cage structure is destroyed earlier. The temperature greatly affects the rate constants of HO and N, but it has little effect on the rate constants of CO and H.
六硝基六氮杂异伍兹烷（CL-20）具有高爆速和高爆压，但其感度也较高，这在一定程度上限制了其应用。因此，了解CL-20的热分解机理和特性具有重要意义。在本研究中，构建了一个ε-CL-20超胞，并进行了ReaxFF-lg反应分子动力学模拟，以研究ε-CL-20在不同温度（2000、2500、2750、3000、3250和3500 K）下的热分解。从势能演化、初级反应以及中间产物和最终产物种类等方面分析了CL-20的热分解机理。还讨论了温度对CL-20热分解的影响。CL-20热分解的初始反应路径是N-NO键断裂形成NO，随后是C-N键断裂，导致笼状结构破坏。在早期反应中出现少量团簇，在反应末期消失。CL-20在不同温度下的初始分解反应路径相同。然而，随着温度升高，CL-20的分解速率增加，笼状结构更早被破坏。温度对HO和N的速率常数影响很大，但对CO和H的速率常数影响较小。
