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离子液体的制备及其性质研究
Study on Preparation and Physical-Thermodynamic Properties of Ionic Liquids
【作者】 于春影;
【导师】 李春喜;
【作者基本信息】 北京化工大学 , 化学工程, 2005, 硕士
【摘要】 离子液体是指在室温附近很大的温度范围内均为液体的离子化合物。由于其具有液体温度区间大、溶解范围广、蒸气压极低、热稳定性好等特性而有望成为过程工业的一种重要绿色溶剂。离子液体最早应用在电镀和电化学领域。近年来,离子液体作为溶剂和催化剂在有机合成方面的研究十分活跃,另外,也有大量应用于分离过程的研究报道。虽然离子液体被看作是水和超临界流体之后的第二代最有前景的绿色溶剂,但离子液体的工业化应用尚受到其成本的限制,例如,Aldrich公司离子液体产品的价格均高于黄金,因此,降低离子液体的生产成本,开发新型离子液体是其获得工业化应用的基础。 本论文主要包括以下三个部分:对咪唑类离子液体的合成路线进行优化;探索新型咪唑类离子液体的合成路线;对合成出新的咪唑类离子液体的物理性质进行测定,并探讨其规律性。 离子液体主要由无机阴离子和含氮或含磷有机杂环阳离子构成。典型的阳离子包括1-烷基-3-甲基咪唑[RR’im]+,烷基吡啶[Rpy]+,季胺,季磷等。典型的无机阴离子为[AlxXy]n-(X为卤素),[BF4]-,[PF6]-,[CH3COO]-,[CF3SO3]-等等。上述离子液体的合成一般需要两步。阳离子部分的合成基本上都采用N-取代咪唑,吡啶,叔胺,或叔磷与卤代烃反应首先制备出相应的季胺卤化物[Rmim]X、[RPy]X、[R4N]X、[R4P]X等。然后将这些季胺卤化物与含目标阴离子的盐通过复分解反应,制备出含目标阴阳离子的离子液体。因此,优化[Rmim]X的工艺路线,简化
【Abstract】 Room-temperature ionic liquids (ILs) are organic salts composed of cations and anions, which are usually in the liquid at room temperature. Ionic liquid has aroused increasing interests in both industry and academia for its unique chemical and physical properties, for example, its good solubility for a wide spectrum of compounds, non-detectable vapor pressure, wide liquid temperature range, good thermal and electric conductivity and good thermal stability. Ionic liquid was initially utilized in electroplating and electrolysis due to its wide electronic windows, however its application has been expanded greatly, e.g. used as a green solvent, as a catalyst for some reactions, and as a solvent in a separation process. Although it is widely recognized as a promising next generation green solvent after water and supercritical fluid, there is a long way to go to be commercialized in industry before its production cost can be reduced to be comparable with common organic solvents. Therefore, it is imperative to reduce the production cost of ionic liquid by exploring new type of ionic liquids or renovating the present production routes.The thesis is composed of three sections. Firstly, optimization of synthesisprocess for ionic liquids with 1-alkyl-3-methylimidazolium [Rmim]+ cations. Secondly, exploitation of new ionic liquids composed of [Rmim]+. Thirdly, measurement of physical and thermodynamic properties for the new ionic liquids prepared.The majority of ionic liquids are composed of complex inorganic anions and nitrogen- or phosphorus-containing organic cations with different kind and length of substitutes. Typical cations include 1-alkyl-3-alkylimidazolium [RR’im]+, N-alkylpyridinium [Rpy]+, quaternary amine [R4N]+, quaternary phosphor [R4P]+ etc., and the typical inorganic anions are [AlxXy]n-(X are halogen), [BF4]-, [PF6]-, [CH3COO]-, [CF3SO3]- and so on. The synthesis of above mentioned ionic liquids generally need two steps. Firstly, objective cations are formed in a halide form e.g. [Rmim]X, [RPy]X, [R4N]X, and [R4P]X by reacting tertiary amines or tertiary phosphorus with alkyl halide. Then the target ionic liquids are prepared via metathetical reaction between a quaternary amine halide and a salt containing the objective anion. Therefore, it is of great significance for the industrial application of ionic liquid to optimize [Rmim]X technical process, simplify reaction conditions, facilitate separation and purification process. We have optimized the preparation process for a series of 1-alkyl-3-methylimidazolium halide, and products were made with mild conditions and simple experiment equipment. This research helps the industrial production and application of ionic liquid.Traditional ionic liquids are produced with extremely high cost. And some ionic liquids with BF4 and PF6 anions are apt to be decomposed to some corrosive materials such as HF in the present of water. Some ionic liquids with
- 【网络出版投稿人】 北京化工大学 【网络出版年期】2005年 07期
- 【分类号】TQ413
- 【被引频次】22
- 【下载频次】2824