Regulation\nof Catalysts on Tightly Packaged Solid\nPropellant Energetic Particles: High Combustion Performance with Low\nTemperature Sensitivity

Although the effectiveness of combustion catalysts promoting\nthe\ncombustion performance of solid propellant (SP) was identified in\nmany research studies, its regulation on the temperature sensitivity\ncoefficient of burning rate (δ<sub><i>p</i></sub>)\nhas been rarely explored, where SP with low δ<sub><i>p</i></sub> is a big challenge with little progress. Herein, several ammonium\nperchlorate (AP)-enriched (>70 wt %) pomegranate-structured SP\nenergetic\nparticles (SPPs), AP/nitrocellulose (NC)/Al (SPP), SPP/CoWO<sub>4</sub>-rGO (SPP-Co), SPP/Bi<sub>2</sub>WO<sub>6</sub>-rGO (SPP-Bi), and\nSPP/CuCo<sub>2</sub>O<sub>4</sub>/GO (SPP-Cu), were prepared by the\nelectrospray granulation method, tightly packaging AP with high-efficiency\ncatalysts to promote its reactivity and reduce temperature sensitivity.\nThe pressurization rates of SPPs in a constant volume combustion chamber\nat 50, 0, and −40 °C were obtained to determine δ<sub><i>p</i></sub>. The burning rates of SPP-Co, SPP-Bi, and\nSPP-Cu loose strips are 0.319, 0.312, and 0.356 m/s, which are increased\nby 11.1%, 8.7%, and 24.0% compared to that of SPP (0.287 m/s), respectively.\nThe peak pressures and pressurization rates of SPP-Co, SPP-Bi, and\nSPP-Cu at 0 °C are increased by 18.8%, 10.1%, and 9.1% and 62.3%,\n67.1%, and 64.1% compared with SPP, respectively, indicating that\nthese catalysts significantly accelerate the combustion process. Compared\nwith SPP, the δ<sub><i>p</i></sub> of SPP-Co, SPP-Bi,\nand SPP-Cu decreased by 26.6%, 60.6%, and 24.7% at 0–50 °C\nand 19.5%, 61.6%, and 27.6% at −40–0 °C, respectively.\nIt suggests that the Bi<sub>2</sub>WO<sub>6</sub>-rGO catalyst reduces\nthe δ<sub><i>p</i></sub> by 61% at −40–50\n°C, exhibiting the optimal δ<sub><i>p</i></sub> regulation performance. This research introduces a novel approach\nto lower the δ<sub><i>p</i></sub> from the chemical\nby tightly packaging temperature-sensitive AP with high-efficiency\ncatalysts.