磺化炭催化苯甲酸二甘醇酯化反应制备二甘醇二苯甲酸酯

Esterification of Diethylene Glyc ol Benzoate to Diethylene Glycol Dibenzoate Catalyzed by Sulfonated Carbon

从精对苯二甲酸(PTA)氧化残渣回收苯甲酸(BA)制备环保增塑剂二甘醇二苯甲酸酯(DEDB),用于替代邻苯二甲酸酯类增塑剂的研究具有重要意义。本工作通过磺化将—SO3H基团负载到活性炭(AC)表面,成功制备了磺化炭(SAC)催化剂。并以BA和二甘醇(DEG)为原料,SAC为催化剂,考察了催化剂浓度、反应温度、酸醇物质的量比[n(BA):n(DEG)]、带水剂甲苯用量对直接酯化合成DEDB的影响。结果表明:原料n(BA):n(DEG)为2.2、催化剂与原料BA的质量比为2%、带水剂甲苯与原料BA的质量比为14%、反应温度为210℃为最佳反应工艺条件,此条件下BA的转化率为90.1%,DEDB的收率为82.6%。

Study on recovery of benzoic acid(BA)from the oxidation residue of pure terephthalic acid(PTA)to prepare the environmentally friendly plasticizer diethylene glycol dibenzoate(DEDB),which is used as a substitute for phthalate plasticizers,is of great importance.In this paper,the sulfonated activated carbon(SAC)catalyst was successfully prepared by loading—SO3H groups onto the surface of activated carbon(AC)through sulfonation.And the effects of catalyst concentration,reaction temperature,acid-alcohol molar ratio and the water-carrying agent toluene dosage on the direct esterification synthesis of DEDB were investigated using BA and diethylene glycol(DEG)as raw materials and SAC as catalyst.The optimal reaction conditions were as followed:the acid-alcohol molar ratio of BA to DEG was 2.2,the mass ratio of catalyst to BA was 2%,the mass ratio of water-carrying agent toluene to BA was 14%and the reaction temperature was 210℃.The conversion of BA was 90.1%and the yield of DEDB was 82.6%under the optimal reaction conditions.