硫酸镓改性离子交换树脂催化合成异丁酸异丁酯

Synthesis of isobutyl isobutyrate catalyzed by modified strong acid cation Ion exchange resin by gallium sulfate

首次采用硫酸镓与阳离子交换树脂作用制备的改性离子交换树脂为酯化催化剂催化合成了食用香料异丁酸异丁酯。考察了催化剂用量、醇酸物质的量比、反应时间、带水剂种类及催化剂重复使用性等因素对产品收率的影响。结果表明,该催化剂具有催化活性高,易分离回收,后处理方便,不需加带水剂,重复使用性好等优势,能够克服浓硫酸为均相酯化催化剂存在的严重腐蚀设备、后处理工艺复杂、废液排放量多、环境污染严重等缺点。硫酸镓改性离子交换树脂是合成异丁酸异丁酯的优良催化剂,可基本实现目标产物的环境友好合成。最佳反应条件为:异丁酸0.2mol,醇酸物质的量比1.6,催化剂1.25g,反应时间60min,收率可达93.9%。该催化剂经简单烘干再生处理就有良好的重复使用性,第7次使用收率仍可达83.6%。

A cation ion exchange resin which was modified by a new strong acid catalyst and gallium sulfate was used as the new catalyst in the reaction of isobutyric acid and isobutyl alcohol reacted to form isobutyl isobutyrate.Factors affected the yield including the amount of catalyst,reaction time,molar ratio of alcohol to acid,different carrying water agents and times for repeated uses were discussed.The new catalyst had many advantages such as insoluble in reaction system,high activity and easy recycling.It was also non-corrosive and non-polluted to the environment.It solved the problems generated by concentrated sulfuric acid in the esterification reaction.Experimental results showed that isobutyric acid 0.2mol,molar ratio of alcohol to acid 1.6,the catalyst 1.25g,reaction time 60min,the yield was 93.9%.It also has a good reusability.After the resin was used for seven times,the yield still reached to 83.6%.It was an efficient,economic and environmental friendly catalyst.