AlH3/HTPB和Al/HTPB体系热反应过程的分子动力学研究OA

To investigate the thermal reaction process over the high temperature range in the composite propellants and con-struction of the interaction mechanisum between aluminum hydride(AlH3)particles with hydroxyl-terminated polybutadiene(HTPB),a model of AlH3 particles coated with HTPB was constructed,the thermal reaction process of this system were inves-tigated by using the reactive force field(ReaxFF)method under constant temperature baths of 500K,1 000K,and 2000K,respectively with an NVT ensemble.The simulated results were compared with those of model of aluminum(Al)particles coa-ted by HTPB under the same conditions.The result shows that at low temperatures(500K and 1 000 K),hydrogen evolution from AlH3 particles is limited by the oxide layer and form gas cavities in the oxide layer.At high temperatures(2000K),oxy-gen in the oxide layer combines with hydrogen in the gas cavities to produce water,facilitating the oxidation process.In addi-tion,it was also revealed that the diffusion process of Al,oxygen atoms in AlH3 differs from that of pure Al.For pure Al,the oxygen atoms diffuse from the oxide layer into the core Al,while for AlH3,Al atoms diffuse outward and adsorb onto the oxide layer,where they bond with oxygen atoms to form aluminum oxide.Al atoms originally in the oxide layer diffuse toward the exterior of the particles,bonding with carbon atoms from HTPB,aggregating into Al-carbon compound micro-clusters.The re-sults indicate that comparing to the pure Al,the dehydrogenation of AlH3 have significant impact on the interaction between the fuel and HTPB in the composite propellants and solid fuels.