十二烷基苯磺酸/环己烷/水微乳体系中合成香料己酸乙酯

Synthesis of Ethyl Caproate in DBSA/Cyclohexane/Water Microemulsion System

在十二烷基苯磺酸(DBSA)/环己烷/水微乳体系中进行香料己酸乙酯的催化合成反应,考察微乳体系的含水量w0、反应温度、物料配比、溶剂效应等因素对己酸乙酯收率的影响。研究发现,在w0=3,反应时间4 h,反应温度313 K,反应物酸醇物质的量比1∶2,cDBSA=0.25 mol/L条件下,己酸乙酯具有较好收率为96.0%。DBSA一方面作为Br覬nsted酸催化酯化反应,另一方面,DBSA作为表面活性剂,与环己烷和水形成稳定微乳体系,增大反应接触面积,吸收酯化反应产生的水,从而提高酯化反应转化率。

Esterification reaction of hexanoic acid and ethanol in the dodecylbenzenesulfonie acid （DBSA）/ cyclohex-ane/water reverse microemulsion system had been investigated. The effect of several parameters, such as w0（[H2O]/[surfac-tant]） value, reaction temperature, molar ratio of reactants and various solvent on the esterification was studied. The re-sults showed that the optimal reaction conditions for the esterification were as follows： w0=3, t=4 h, T=313 K, molar ra-tio of reactants was 1：2 and CDBSA=0.25 mol/L, the yield of ethyl caproate reached 96.0%. On the one hand, DBSA as a BrФnsted acid can catalyze esterification. At the same time, microemulsion system was formed with the surfactant DBSA, cyclohexane and water, which improved the reaction contact area, absorbed the water produced by the esterification and incresed the conversion rate.