Synthesis And Properties Of Temperature-Controlled Imidazolium Ionic Liquid

With the rapid development of the printing and dyeing industry,dyeing technology is also constantly improving,and the traditional polyester fiber dyeing technology has various drawbacks and problems in the practical application process,making it difficult to be widely used in industrial production.In order to solve the problems of traditional polyester fiber dyeing and realize the green printing and dyeing of polyester fiber,a temperature-controlled imidazolium ionic liquid was designed and synthesized by starting from the molecular structure of polyester fiber and disperse dye.In this paper,the main research content was divided into two parts,one was the design of ionic liquid precursor and ionic liquid,and the other was the synthesis of ionic liquid.In the design of ionic liquids,the imidazolium ionic liquid precursors based on nitrogen heterocycles were selected.In the preparation of ionic liquids,the synthesis of ionic liquid precursors was mainly involved,including the synthesis of 2-heptyl imidazole,and The oxypropylation reaction of 2-heptyl imidazole,and the effects of reaction temperature,reaction time and molar ratio of raw materials on the reaction were investigated.Finally,the ionic liquid precursor reacted with carbon dioxide to form an ionic liquid,which was soluble in ionic liquid.The PH value was tested and the following conclusions were obtained.(1)Using 2-glyoxal,ammonia water and octanal as raw materials,2-heptyl imidazole was prepared by dehydration condensation reaction,and the effects of reaction temperature,reaction time and material molar ratio on the conversion rate of raw materials were investigated,and The effect of tertiary amine values was produced in the system.The results of single factor experiments showed that the molar ratio of raw material glyoxal,octanal and ammonia was 1:1:2.2,the reaction temperature was 85?,the reaction time was 4 hours,and the conversion of raw materials reached the maximum.At this time,the raw material aldehyde was The conversion rate was 81%,the tertiary amine value was 4.475mmol/g,and2-heptylimidazole was successfully synthesized by high performance liquid chromatography,elemental analysis,infrared,nuclear magnetic and other characterization methods.(2)The 2-heptidazole and propylene oxide synthesized in the above step were used as raw materials,and tetramethylammonium hydroxide was used as a catalyst to synthesize anionic liquid precursor by a cyclopropane ring-opening addition reaction,and the reaction temperature and reaction time were investigated.The molar ratio of the material and the amount of catalyst added to the yield of the ionic liquid precursor and the molecular weight of the ionic liquid precursor.Through the single factor experiment,the experimental results show that the molar ratio of the raw material 2-heptyl imidazole and propylene oxide is 1:6,the reaction temperature was 55?,the reaction time was 12 hours,and the catalyst dosage was 0.5%(mass percentage).At the time,the yield of the ionic liquid precursor reached a maximum of 74%,and the average molecular weight of the polymer reached 340.The molecular structure was further characterized by infrared and nuclear magnetic,which proved to be consistent with the expected results.(3)mixing the synthesized ionic liquid precursor with water.When the volume ratio of the current body to water was 1:5,the two were completely dissolved.When the ratio of the two was 1:2,The [ionic liquid precursor + water ] system was poorly soluble,and the system was turbid milky white.After the carbon dioxide was introduced,the milky white disappears,the whole system becomes homogeneous,and the pH was measured to be neutral.