Aluminum hydride (AlH₃) is a promising replacement for aluminum in hybrid and solid propellants, where hydroxyl-terminated polybutadiene (HTPB) is normally used as a binder. In this study, a reactive molecular dynamics simulation method is employed to investigate the fundamental oxidation mechanisms of AlH₃/HTPB solid fuel using a core-shell nanoparticle configuration. The overall oxidation is found to proceed in three distinctive stages: (I) preheating, (II) acceleration and (III) oxidation. Furthermore, oxidation mechanisms of AlH₃ and HTPB are separately studied to understand their different roles during the overall oxidation process. With respect to the oxidation of the AlH₃ nanoparticle, the reaction is delayed compared with the oxidation of pure AlH₃, due to the initial coverage of the nanoparticle surface by HTPB molecules. Additionally, decomposition of HTPB/HTPB intermediates is observed to occur on the nanoparticle surface and some of the decomposed products are integrated with the nanoparticle. In the meantime, the AlH₃ nanoparticle facilitates the HTPB initiation by dehydroxylation or dehydrogenation. Moreover, the primary decomposition pathway of HTPB/HTPB intermediates is the continuous scission of carbon chain to form a large amount of C₄ species, which are finally oxidized at a later stage of the reaction producing CO, CO₂ and H₂O. The new atomistic insights obtained from the present research could potentially benefit the design of AlH₃/HTPB-based solid propellants.

氢化铝（AlH ₃）是混合和固体推进剂中铝的有希望的替代品，其中通常将羟基封端的聚丁二烯（HTPB）用作粘合剂。在这项研究中，反应性分子动力学模拟方法被用来研究AlH ₃ / HTPB固体燃料使用核壳纳米粒子配置的基本氧化机理。发现总氧化在三个不同的阶段进行：（I）预热，（II）加速和（III）氧化。此外，分别研究了AlH ₃和HTPB的氧化机理，以了解它们在整个氧化过程中的不同作用。关于AlH ₃的氧化与纯AlH ₃的氧化相比，由于HTPB分子最初覆盖了纳米颗粒表面，反应被延迟了。另外，观察到HTPB / HTPB中间体的分解发生在纳米颗粒表面上，并且一些分解产物与纳米颗粒结合在一起。同时，AlH ₃纳米颗粒通过脱羟基或脱氢促进HTPB的引发。此外，HTPB / HTPB中间体的主要分解途径是碳链的连续断裂，形成大量的C ₄物种，这些C ₄物种最终在反应的后期被氧化，生成CO，CO ₂和H _2。O.从本研究中获得的新原子学见解可能会有益于AlH ₃ / HTPB基固体推进剂的设计。