Surface-Accelerated Decomposition of 未-HMX

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• 作者：Onise Sharia ; Roman Tsyshevsky ; Maija M. Kuklja
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2013
• 出版时间：March 7, 2013
• 年：2013
• 卷：4
• 期：5
• 页码：730-734
• 全文大小：265K
• 年卷期：v.4,no.5(March 7, 2013)
• ISSN：1948-7185

文摘

Despite extensive efforts to study the explosive decomposition of HMX, a cyclic nitramine widely used as a solid fuel, explosive, and propellant, an understanding of the physicochemical processes, governing the sensitivity of condensed HMX to detonation initiation is not yet achieved. Experimental and theoretical explorations of the initiation of chemistry are equally challenging because of many complex parallel processes, including the 尾鈥撐?phase transition and the decomposition from both phases. Among four known polymorphs, HMX is produced in the most stable 尾-phase, which transforms into the most reactive 未-phase under heat or pressure. In this study, the homolytic NO₂ loss and HONO elimination precursor reactions of the gas-phase, ideal crystal, and the (100) surface of 未-HMX are explored by first principles modeling. Our calculations revealed that the high sensitivity of 未-HMX is attributed to interactions of surfaces and molecular dipole moments. While both decomposition reactions coexist, the exothermic HONO-isomer formation catalyzes the N-NO₂ homolysis, leading to fast violent explosions.

Keywords:

cyclic nitramines; molecular materials; transition state; activation barrier and decomposition kinetics; surface鈭抦olecule interactions; explosive reactions