论文中文题名: | 新型二氰胺类自燃离子液体的合成及性质研究 |
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学号: | 201205166 |
学生类型: | 硕士 |
学位年度: | 2015 |
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论文外文题名: | Synthesis and Characterization of New Dicyanamide-based Hypergolic Ionic Liquids |
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论文外文关键词: | Ionic liquids ; Hypergolic ; Tetramethylethylenediamine ; Amine borane ; Analog computation |
论文中文摘要: |
自燃推进剂作为一类化学点火的液体推进剂,可简化发动机设计及实现万次无故障点火,是火箭及太空飞行器的重要动力,已成为航空航天领域主要研究方向。近年来,自燃离子液体显示出了良好的热稳定性和燃烧性能,具有替代传统推进剂燃料(肼及其衍生物)的应用潜能,受到含能材料科技工作者的广泛关注。
本论文以四甲基乙二胺和三甲胺硼烷络合物为反应底物,设计合成了4种四甲基乙二胺类和10种双(R-基咪唑)硼烷类自燃离子液体。通过1H和13C NMR、IR和元素分析(或高分辨质谱)综合表征,确认了所得离子液体的结构;通过密度、粘度、热稳定性、点火性能测试及相关计算,系统表征了离子液体的结构-物性关系。
对于四种四甲基乙二胺类离子液体,计算模拟的振动光谱与实验相符,为离子液体结构确认提供了理论支撑。阳离子烷基侧链对离子液体性质有显著影响,呈现规律性。该类离子液体热稳定性好,分解温度均在200 ºC以上,生成焓在85.1~154.4 kJ•mol-1之间。其中,2-(二甲基胺)-N,N,N-三甲基乙二胺二氰胺的燃烧性能较好,点火延迟时间84 ms,比冲158 s。
对于十种双(R-基咪唑)硼烷类离子液体,阳离子的烃基侧链对离子液体性质也有规律性的影响。该类离子液体密度在1.04~1.27 g•cm-3之间,生成焓在12.4~484.9 kJ•mol-1之间,分解活化能在74.72~130.82 kJ•mol-1之间。其中,双(烯丙基咪唑)硼烷二氰胺的燃烧性能较好,点火延迟时间18 ms,比冲176.7 s。
设计合成的离子液体在一定程度上显示出良好的自燃燃料特性,是肼及其衍生物的潜在替代产品。2-(二甲基胺)-N,N,N-三甲基乙二胺二氰胺和双(烯丙基咪唑)硼烷二氰胺具有良好的综合性能,有望成为双组元自燃推进剂的绿色燃料。
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论文外文摘要: |
Hypergolic propellants as a kind of liquid propellants with chemical ignition have become important power source of rockets and space vehicles, which can simplify the design of engine and achieve the trouble-free ignition for thousands of times. With the unique properties, hypergolic propellants have become main topic in the aerospace field. Currently, hypergolic ionic liquids (ILs) with good thermal stability and combustion performance show application potential to replace traditional propellant fuels (hydrazine and its derivatives), and have attracted increasing attentions in energetic material field.
In this paper, four tetramethylethylenediamine-based (TMEAD-based) and ten bis(R-imiazolium)dihydroboronium-based hypergolic ILs were designed and synthesized from TMEAD and borane-trimethylamine complex as reaction substrates, respectively. The resulting ILs were characterized by 1H and 13C NMR, infrared spectroscopy, and elemental analysis (or high resolution mass spectrum). Their properties such as density, viscosity, thermal stability and ignition performance were studied by experimental or theoretical methods.
For the TMEAD-based hypergolic ILs, their calculated frequencies are in good agreement with the corresponding experimental values. The results indicate that the alkyl substitutes of cations have a major impact on the physicochemical properties of ILs. With thermal stability up to 200 °C, the resulting ILs have heats of formation from 85.1 to 154.4 kJ mol-1. Moreover, 2-(dimethylamino)-N,N,N-trimethylethanaminium dicyanamide exhibits good combustion performance with ignition delay time (84 ms) and specific impulse (158 s).
For the bis(R-imiazolium)dihydroboronium-based hypergolic ILs, their alkyl substitutes of cations have a big effect on the physicochemical properties also. Densities of ILs range from 1.04 to 1.27 g cm-3, heats of formation from 12.4 to 484.9 kJ mol-1, and decomposition activation energy from 74.72~130.82 kJ•mol-1. Among them, bis(1-allyl-1H-imidazole-3-yl)dihydroboronium dicyanamide shows best combustion performance including ignition delay time (18 ms) and specific impulse (176.7 s).
In short, the obtained ILs possess relatively good hypergolic performance to be the promising alternative products of hydrazine and its derivatives. Moreover, 2-(dimethylamino)-N,N,N-trimethylethanaminium and bis(1-allyl-1H-imidazole-3-yl) dihydroboronium dicyanamide exhibit excellent combined properties, and have potential as the green fuels of liquid bipropellants.
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中图分类号: | TQ 517.4 |
开放日期: | 2015-06-16 |