磺酸功能化咪唑类离子液体催化丁二酸与丁二醇预聚酯化的过程研究

采用咪唑、1,3-丙磺酸内酯、1,2-二溴乙烷、1,4-二溴丁烷和聚乙二醇-200等为原材料合成了四种功能性磺酸类咪唑离子液体,考察了这四种离子液体催化剂酯化合成丁二酸丁二醇酯的性能,研究了催化剂用量、醇酸摩尔比、反应时间等因素对酯化反应的影响,并与钛酸正丁酯及钛酸异丙酯催化剂进行对比,得出其较佳工艺条件为:使用双-(3-丙烷磺酸-1-亚丁基咪唑)磺酸功能化离子液体为催化剂,用量为丁二酸摩尔质量的0.40%,醇酸比为1.3:1,反应温度160℃,反应时间为2 h,酯化率最高达到94.2%.

The Studies of the Process in Esterification of Succinate with Butanediol over Sulfonic Functionalized Imidazolium Ionic Liquids Catalysts

Using imidazole,1,3-propane sultone,1,2-ethyl bromide,1,4-butane bromide and PEG-200 as raw materials,a series of sulfonic acid functional imidazole ionic liquids were synthesized,and the catalytic performances of the synthesized ionic liquids were investigated respectively by the esterification of butylene glycol with succinic acid over these ionic liquid catalysts.The effects of the reaction conditions,such as the amount of catalyst used,reaction time and molar ratio of alcohol to acid,on the esterification were investigated,and the catalytic esterification effects of the ionic liquids were compared with those of the catalysts tetrabutyl titanate and titanium isopropoxide.It was found that the optimal esterification conditions are as follows: use bis-(3-propane-1-butylene imidazole) sulfonic acid functional ionic liquid as catalyst and its used amount is about 0.40% molar weight of the succinate acid,the molar ratio of alcohol to acid is 1.3:1,reaction temperature is 160℃ and the reaction time is 2 h.Under above conditions,the esterification ratio can reach 94.2%.