回流脱水体系中固体酸催化合成调香剂乳酸乙酯的研究  

Study on synthesis of flavouring ethyl lactate by solid acid in reflux dehydration system

作　　者：陈志胜[1] 郭海福[1] 闫鹏[1] 林瑞芝 

机构地区：[1]肇庆学院化学化工学院,肇庆526061

出　　处：《中国食品添加剂》2014年第9期107-113,共7页China Food Additives

基　　金：广东省自然科学基金(S2012040007383);广东省教育厅科技创新项目(2013KJCX0193);肇庆市科技计划项目(2011C001;2012G030);肇庆市科技创新计划项目(2011G28)

摘　　要：以NH4Fe(SO4)2·12H2O、Na2SiO3、NH4NO3和Ce(SO4)2·5H2O为原料,采用共沉淀法制备了固体酸SO2-4/CeO2-Fe2O3-SiO2催化剂,并对催化剂进行了FTIR和TG-DTA表征,以回流脱水合成乳酸乙酯反应为探针反应,得酯化反应的最佳反应条件:催化剂用量为乳酸质量的3.4%(0.25 g),醇酸物质的量的比为2.5∶1.0(乳酸6 mL),反应时间3 h,带水剂环己烷用量为乙醇体积的62.5%(7.5 mL),脱水剂无水硫酸镁用量为2.9 g,该反应条件下酯化率平均达96.0%,催化剂重复使用五次后,反应酯化率依然可达91.6%。产品经FTIR、GC-MS分析确认,并由GC-MS分析知其纯度为94.59%。The solid acid SO/ CeO2 -Fe2O3 -SiO2 was prepared from NH4Fe （SO4 ）2 . 12H2O, Na2SiO3, NH4 NO3 and Ce （SO4 ）2 . 5H2O in co -precipitation system, And its physic -chemical properties were characterized by FYIR and TG - DTA. Synthesis conditions of ethyl lactate by SO42 -/Fe2 O3 - CeO2 - SiO2 in reflux dehydration system were studied. The optimal reaction conditions on synthesis of ethyl lactate were ： the dosage of catalyst 3.4% of lactic acid （0. 25 g）, the mole ratio of alcohol to acid 2. 5 ： 1.0 （lactic acid 6 mL）, reaction time 3 h, the amount of cy- clohexane as water carrier 62. 5% （7. 5 mL） , the amount of dehydrant MgSO4 2. 9 g, In this condition, the esterifi- cation rate was up to 96.0% , the esterification rate reached 91.6% when the catalyst was reused for fifth times. The product is confirmed to be ethyl lactate by PTIR and GC - MS. The purity was up to 94. 59% by GCMS.

关 键 词：固体超强酸 回流脱水 酯化 乳酸乙酯 

分 类 号：TQ655[化学工程—精细化工]