聚偏氟乙烯包覆与表面纯化协同增强硼粉的点火燃烧性能OA

To address the problem where the compact oxide layer on the surface of boron powder significantly inhibits its igni-tion and combustion processes,resulting in low energy release efficiency and prolonged ignition delay time,the boron powder was purified,and polyvinylidene fluoride(PVDF)was used as a fluorine-containing coating material to prepare Bw@PVDF core-shell composite particles with different coating ratios by the solvent-nonsolvent method.The structure of the samples was characterized by SEM,TEM/EDS and XPS,and their thermal behavior,ignition performance and combustion properties were systematically investigated using TG-DSC,laser ignition and calorimetry.The results showed that PVDF can stably coat on boron particles surface and formed a core-shell structure,and the optimal coating quality was obtained at a PVDF mass fraction of 6％.PVDF coating decreased the initial oxidation temperature of boron by 10℃ and significantly enhanced heat release inten-sity,while the ignition delay time of Bw@6％PVDF was reduced by 39％compared with raw boron,and the combustion effi-ciency increased from 25.20％to 32.35％.Fluorine species generated from PVDF were found to react with lattice impurities on boron surface,producing a"chemical breakage"effect,and surface purification removed oxidized boron that hindered pri-mary ignition and combustion;the synergistic effect of purification and PVDF coating effectively enhanced the ignition and com-bustion performance of boron powder.