He Zheng-Hua, Huang Yao-Yao, Ji Guang-Fu, Chen Jun, Wu Qiang
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China.
National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.
Molecules. 2022 Apr 27;27(9):2787. doi: 10.3390/molecules27092787.
Plastic-bonded explosives (PBXs) consisting of explosive grains and a polymer binder are commonly synthesized to improve mechanical properties and reduce sensitivity, but their intrinsic chemical behaviors while subjected to stress are not sufficiently understood yet. Here, we construct three composites of β-HMX bonded with the HTPB binder to investigate the reaction characteristics under shock loading using the quantum-based molecular dynamics method. Six typical interactions between HMX and HTPB molecules are detected when the system is subjected to pressure. Although the initial electron structure is modified by the impurity states from HTPB, the metallization process for HMX does not significantly change. The shock decompositions of HMX/HTPB along the (100) and (010) surface are initiated by molecular ring dissociation and hydrogen transfer. The initial oxidations of C and H within HTPB possess advantages. As for the (001) surface, the dissociation is started with alkyl dehydrogenation oxidation, and a stronger hydrogen transfer from HTPB to HMX is detected during the following process. Furthermore, considerable fragment aggregation is observed, which mainly derives from the formation of new C-C and C-N bonds under high pressure. The effect of cluster evolution on the progression of the following reaction is further studied by analyzing the bonded structure and displacement rate.
由炸药颗粒和聚合物粘合剂组成的塑料粘结炸药（PBXs）通常是为了改善机械性能和降低敏感度而合成的，但其在受力时的内在化学行为尚未得到充分理解。在此，我们构建了三种由β-HMX与HTPB粘合剂粘结而成的复合材料，以使用基于量子的分子动力学方法研究冲击载荷下的反应特性。当系统受到压力时，检测到HMX与HTPB分子之间的六种典型相互作用。尽管初始电子结构因HTPB的杂质态而改变，但HMX的金属化过程并未显著变化。HMX/HTPB沿（100）和（010）表面的冲击分解由分子环解离和氢转移引发。HTPB中C和H的初始氧化具有优势。至于（001）表面，解离从烷基脱氢氧化开始，并且在随后的过程中检测到从HTPB到HMX更强的氢转移。此外，观察到相当多的碎片聚集，这主要源于高压下新的C-C和C-N键的形成。通过分析键合结构和位移速率，进一步研究了团簇演化对后续反应进程的影响。
