论文部分内容阅读
[目的]探寻合成顺丁烯二酸二乙酯的高效、环境友好型催化剂,并对顺丁烯二酸二乙酯合成工艺进行优化。[方法]使用Ti(SO4)2/SiO2为催化剂,顺丁烯二酸酐和无水乙醇为原料合成顺丁烯二酸二乙酯。探讨酐醇物质的量之比、催化剂用量、反应时间、带水剂等因素对反应酯化率的影响,并对催化剂的重复使用情况进行考察。[结果]合成顺丁烯二酸二乙酯的最佳反应条件为酐醇物质的量之比为1∶3;催化剂用量为顺丁烯二酸酐量的31%;带水剂环己烷用量为15 mL;加热回流2 h;此时,酯化率可达96.41%;并且催化剂Ti(SO4)2/SiO2重复使用4次后,酯化率仍可达到74.54%,产品经GC-MS分析知顺丁烯二酸二乙酯的纯度达90.10%。[结论]Ti(SO4)2/SiO2是合成顺丁烯二酸二乙酯的高效、环境友好型催化剂;该合成工艺操作简便、反应条件温和、收率高、产品纯度高。
[Objective] The research aimed to explore an efficient and environmentally friendly catalyst for the synthesis of diethyl maleate and to optimize the synthesis of maleic acid diethyl ester. [Method] The diethyl maleate was synthesized by using Ti (SO4) 2 / SiO2 as catalyst, maleic anhydride and anhydrous ethanol as raw materials. The effects of the ratio of the amount of the anhydride to the amount of the catalyst, the amount of the catalyst, the reaction time, the amount of the water-carrying agent and other factors on the esterification reaction were investigated. The repeated use of the catalyst was also investigated. [Result] The optimal reaction conditions for the synthesis of diethyl maleate were as follows: the ratio of the amount of anhydride to alcohol was 1: 3; the amount of catalyst was 31% of maleic anhydride; the amount of cyclohexane (15 mL) and heated to reflux for 2 h. At this time, the esterification rate reached 96.41%. After repeated use of Ti (SO 4) 2 / SiO 2 for 4 times, the esterification rate still reached 74.54%. The product was analyzed by GC-MS Diethyl maleate purity of 90.10%. [Conclusion] Ti (SO4) 2 / SiO2 is an efficient and environmentally friendly catalyst for the synthesis of diethyl maleate. The synthesis process is simple and convenient, the reaction conditions are mild, the yield is high and the product purity is high.