使用价格相对便宜的锡类化合物和高比表面积的高岭土,采用超声波沉淀及微波干燥方法制得性价比较高的固体超强酸催化剂SO42-/SnO2-高岭土,并应用于食用香精丙酸正丁酯的合成反应。考察了该酯化反应中酸醇物质量之比、催化剂用量、反应时间、带水剂种类及用量等因素对酯化率的影响、并对催化剂的重复使用情况进行了考察。得到最佳反应条件:醇酸摩尔比为2∶1,催化剂用量为反应物料总量的3%,反应温度114~116℃,正丁醇作带水剂,反应时间为4 h,此时酯化率达97.02%,高于多数文献值,催化剂重复使用第3次酯化率仍达到86.58%,经GCMS分析知产品纯度达96.68%。

The solid super acidic SO42-/ SnO2-kaolin was prepared by tin compounds and kaolin assisted by ultrasonic microwave drying method,it has a higher surface area and is used in the synthesis of food essence butyl propionate.The influence factors on conversion rate of n-butyl propionate were discussed,such as acid and butyl alcohol molar ratio,catalyst dosage,reaction time,type and amount of entrainer.The optimal reaction conditions on synthesis of butyl propionate were: the mole ratio of alcohol to acid is 2∶ 1,the dosage of catalyst 3% of the total reaction materials,reaction temperature 114 ~ 116 ℃,entrainer n-butyl alcohol,and reaction time 4 h.In this condition the esterification rate was up to 97.02%,much higher than the majority catalysis mentioned in the literature,the esterification rate still reached to 86.58% even when the catalyst was reused for third times,the purity of the product was 96.68% by GCMS.