摘要
为研究聚偏二氟乙烯(PVDF)含量对铝基固体推进剂燃烧性能的影响。通过溶剂-非溶剂法制备了包覆量为2%~14%的Al@PVDF复合粉体。结合热重-差热分析、定容燃烧及同步点火等测试方法,对比分析了复合铝粉的热反应性和相应固体推进剂的能量及燃烧性能。结果表明,PVDF包覆结构能显著提高铝粉的热反应性,PVDF包覆量为6%时,铝粉的热增重和放热焓达最大值78.96%和16.14 k J·g^(-1)。随PVDF含量的增加,固体推进剂的释能量呈先增后减,再增再减的变化趋势,包覆量为10%时,固体推进剂最大放热量为6026 J·g^(-1)、增压值为4.45 MPa;铝氧反应的点火延迟由53 ms降低至12 ms;燃速压力指数由0.43降至0.36再降至0.26的三阶段演变。冷凝燃烧产物(CCPs)阐明了PVDF含量对燃烧性能的阶段性作用机制:低包覆量(2%~4%)时,热解产物抑制铝熔融团聚;中包覆量(6%~8%)时,能加速颗粒破碎点火,还会诱发二次团聚;高包覆量(10%~14%)时,过量热解产物会促进团聚体在气相区的二次破碎。
To elucidate the effect of polyvinylidene fluoride(PVDF)content on the combustion performances of aluminum-based solid propellants,Al@PVDF composite powders with coating contents ranging from 2%to 14%were prepared via the solvent and non-solvent method.The thermal reactivity of Al@PVDF composite powders and the energy release and combustion perfor-mances of the corresponding solid propellants were analyzed using thermogravimetric-differential scanning calorimetry,constant volume combustion tests,and simultaneous ignition experiments.Results indicate that the PVDF coating significantly enhances the thermal reactivity of aluminum.At the 6%PVDF coating content,the aluminum powder achieves the maximum thermal weight gain and exothermic enthalpy value of 78.96%and 16.14 kJ·g^(-1),respectively.As the PVDF content increases,the energy release of solid propellants exhibits a trend of initial increase,following by a decrease,subsequent re-increase,and final de-cline,and reaching the maximum heat release of 6026 J·g^(-1) and pressurization of 4.45 MPa at 10%coating content.The ignition delay time of aluminum-oxygen reaction decreases from 53 ms to 12 ms.The pressure exponent of burning rate underwent a three-stage evolution,declining from 0.43 to 0.36,and further to 0.26.Analysis of condensed combustion products(CCPs)re-veals a stage-dependent mechanism of PVDF content on combustion performances:the low coating content(2%-4%)inhibits molten aluminum agglomeration via pyrolysis products;the medium content(6%-8%)accelerates particle fragmentation and ig-nition but induces secondary agglomeration;the high content(10%-14%)generates excessive pyrolysis products that promote secondary fragmentation of agglomerates in gas-phase region.
作者
陈文聪
邓皓源
石情文
张子怡
孙一
罗国强
沈强
CHEN Wen-cong;DENG Hao-yuan;SHI Qing-wen;ZHANG Zi-yi;SUN Yi;LUO Guo-qiang;SHEN Qiang(State Key Lab of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China;Hubei Longzhong Laboratory,Wuhan University of Technology(Xiangyang Demonstration Zone),Xiangyang 441000,Hubei,China)
出处
《含能材料》
北大核心
2025年第6期589-600,共12页
Chinese Journal of Energetic Materials
基金
国家自然科学基金(52104363)
教育部联合基金(8091B03052305)
广东省重点研发计划(2020B010181001)。
关键词
铝基固体推进剂
铝粉
PVDF含量
包覆
燃烧性能
团聚
作用机理
aluminum based solid propellants
aluminum fuel
PVDF content
coating
combustion performances
agglomeration
pro-motion mechanism
