Regulation of Catalysts on Tightly Packaged Solid Propellant Energetic Particles: High Combustion Performance with Low Temperature Sensitivity

Although the effectiveness of combustion catalysts promoting the combustion performance of solid propellant (SP) was identified in many research studies, its regulation on the temperature sensitivity coefficient of burning rate (δ_<i>p</i>) has been rarely explored, where SP with low δ_<i>p</i> is a big challenge with little progress. Herein, several ammonium perchlorate (AP)-enriched (>70 wt %) pomegranate-structured SP energetic particles (SPPs), AP/nitrocellulose (NC)/Al (SPP), SPP/CoWO₄-rGO (SPP-Co), SPP/Bi₂WO₆-rGO (SPP-Bi), and SPP/CuCo₂O₄/GO (SPP-Cu), were prepared by the electrospray granulation method, tightly packaging AP with high-efficiency catalysts to promote its reactivity and reduce temperature sensitivity. The pressurization rates of SPPs in a constant volume combustion chamber at 50, 0, and -40 °C were obtained to determine δ_<i>p</i>. The burning rates of SPP-Co, SPP-Bi, and SPP-Cu loose strips are 0.319, 0.312, and 0.356 m/s, which are increased by 11.1%, 8.7%, and 24.0% compared to that of SPP (0.287 m/s), respectively. The peak pressures and pressurization rates of SPP-Co, SPP-Bi, and SPP-Cu at 0 °C are increased by 18.8%, 10.1%, and 9.1% and 62.3%, 67.1%, and 64.1% compared with SPP, respectively, indicating that these catalysts significantly accelerate the combustion process. Compared with SPP, the δ_<i>p</i> of SPP-Co, SPP-Bi, and SPP-Cu decreased by 26.6%, 60.6%, and 24.7% at 0-50 °C and 19.5%, 61.6%, and 27.6% at -40-0 °C, respectively. It suggests that the Bi₂WO₆-rGO catalyst reduces the δ_<i>p</i> by 61% at -40-50 °C, exhibiting the optimal δ_<i>p</i> regulation performance. This research introduces a novel approach to lower the δ_<i>p</i> from the chemical by tightly packaging temperature-sensitive AP with high-efficiency catalysts.