6/6/2023 0 Comments Aluminum reactivityThis strategy may improve the reactivity of the Al particles, however, it will decrease the energy content of the system due to the inert nature of modified materials.Īs an energetic binder, glycidyl azide polymer (GAP) has a high density of 1.3 g cm −3, good thermal stability, a positive enthalpy of formation of 117.2 kcal mol −1, and a high burning rate 16, 17, 18. To address this issue, one prevailing strategy is to modify the Al surface with polymer layer to reduce the content of the oxide shell 13, 14, 15. The thick oxide shell can significantly retard mass and heat transfer to the Al core, which leads to low reaction efficiency 9, 10, 11, 12. However, these excellent properties have not been fully exploited because of the inherent oxide shell, especially in the case of Al nanoparticles 5, 6, 7, 8. This study suggests after coating by GAP, the aluminum particles possess enhanced reaction performance, which shows potential application value in the fields of aluminized explosives and other energetic fields.Īluminum (Al) powders can effectively enhance the energy content and regulate the reaction performance of energetic materials, owing to its high chemical activity and energy density 1, 2, 3, 4. Furthermore, the LASEM experiment suggested the shock wave velocity of the GAP coated aluminum particles was larger than that of non-coated aluminum particles, and the largest velocity difference for them could be 0.6 km s −1. In addition, the P– t test showed the peak pressure and pressurization rate of GAP coated aluminum particles were separately 1.4 times and 1.9 times as large as those of non-coated aluminum particles. And due to the synergistic effect between aluminum and GAP, the decomposition products of GAP were prone to be oxycarbide species rather than carbonitride species. In return, aluminum particles reduced the activation energy of the second stage decomposition of the GAP by 276 kJ mol −1. Besides, the oxidation activation energy of aluminum particles was also reduced by ~ 15 kJ mol −1. It was found that GAP shifted the oxidation onset of aluminum particles to a lower temperature by ~ 10 ☌. Besides, the comparison on the energy content was also conducted based on P– t tests and a laser-induced air shock from energetic materials (LASEM) technique. The coated aluminum particles were compared to non-coated powder by the corresponding reactivity parameters obtained from simultaneous differential scanning calorimetry, thermal gravimetric analysis, coupled with mass spectral and infrared spectral analyses. We found that the aluminum particles were coated with a GAP layer of thickness around 8.5 nm. To address this issue, we investigate creating aluminum particles with a glycidyl azide polymer (GAP) coating to improve their reactivity while retaining their energy content. One of the major impediments to their use is that Al 2O 3 shell significantly decreases overall performance. Aluminum particles are of significant interest in enhancing the energy release performance of explosives.
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