应用响应面法优化丁酸环己酯的制备

选取反应时间、酸醇物质的量比、催化剂用量和带水剂用量4个因素进行中心组合设计,运用响应面法对酸性离子液体催化制备丁酸环己酯的工艺参数进行了优化。试验结果表明,离子液体1-甲基-3-(丙基-3-磺酸基)咪唑硫酸氢盐([HSO3-pmim]HSO4)具有最好的催化活性,以该催化剂合成丁酸环己酯的最佳反应条件为:反应时间2.6 h,n(丁酸):n(环己醇)=1∶1.7,离子液体剂量4.8%,带水剂用量9.8mL,在该条件下,丁酸环己酯的酯化率为97.2%,与模型预测值基本相符。离子液体[HSO3-pmim]HSO4重复使用5次后,催化活性基本未降低。

Optimization of process variables in the synthesis of cyclohexyl butyrateby response surface methodology

Response surface methodology(RSM) was applied to optimize the synthesis of cyclohexyl butyrate in acidic ionic liquid.The effects of various reaction conditions,including reaction time,alcohol/acid mole ratio,amount of water carrying agent and amount of ionic liquid were investigated.A Box-Behnken experimental Design(BBD) was employed to search for the optimal yield of cyclohexyl butyrate.Factors influencing the synthesis were discussed. HSO4 ionic liquid showed the best catalytic activity on the esterification of cyclohexanol with butyric acid.The optimum conditions were as follows: n(butyric acid) : n(cyclohexanol) =1∶ 1.7,ionic liquid 4.8% of acid,reaction time 2.6 h and the amount of water carrying agent 9.8 mL.Under the optimized conditions,the conversion rate of butyrate acid reached 97.2%,in basic agreement with values predicted by the mathematical model. HSO4 ionic liquid could be reused five times without noticeable drop in activity.