The Synthesis Of The Ionic Liquid [Emim]CH₃COO And Physical Property Measurement

With the science and technology improving and the human’s awareness ofenvironmental protection growing, it is an inevitable trend that chemical industry andchemical research develop towards the direction of clean, low consumption and highefficiency. Most of the chemical reactions in solvents, the large amount and the strongvolatility of organic solvent is one of the main reasons to cause chemical pollution.Room temperature ionic liquids for its unique physical and chemical properties get theattention of chemical workers in the countries all over the world, that is considered tobe "a new generation of green solvents" after the supercritical CO2, and relatedresearch is very active.Current research in ionic liquids, cations mainly are the imidazolium cations,andanions mainly are halogen anions and other inorganic acid ions (such as BF4-). Asresearch continuing to progress, some novel anion of ionic liquids are synthesized.[Emim]CH3COO is one of them.In this paper, the ionic liquid [Emim]CH3COO is the object to study. At first,using the equilibrium method, the solubility of the four substances of CH3COONaand NaBr, CH3COOK and KBr in the solvent acetone and ethanol are measured atdifferent temperatures, then the temperature-solubility curves are made by using thesolubility difference of CH3COONa and NaBr, CH3COOK and KBr in the samesolvent (ethanol, acetone). After analyzing temperature-solubility curves it isobtained that with acetone as solvent and CH3COONa as raw material the reactiontemperature should be controled at about35C, and this laid the foundation forstudies of following researches.The second, the ionic liquid [Emim]CH3COO is prepared by using two stepmethod and one step method. The first step of two step method is that ethyl bromideis dropped in the N-methyl imidazole by using constant pressure funnel, the droppingspeed should be controled, and ionic liquid intermediates [Emim]Br is prepared.Then[Emim]CH3COO is prepared through a variety of methods of ion exchange. One stepmethod is that N-methyl imidazole and other raw materials under certain conditions are directly mixed reaction to prepare ionic liquids [Emim] CH3COO. Water contentof ionic liquids [Emim] CH3COO is determined after drying. Emim] CH3COO isdetected by using infrared and thermal gravity.In addition, at25C to55C, the data of the density, viscosity and refractiveindex, surface tension and conductivity of ionic liquids [Emim]CH3COO are alsedetermined. The corresponding moore conductivity is calculatied. Fit the functionrelations of the density, viscosity and refractive index, surface tension, conductivityand moore conductivity of ionic liquids [Emim]CH3COO to temperature. Discusse thechange of physical properties to temperature.This article lays the foundation for subsequent researches of ionic liquid[Emim]CH3COO.