酯交换法合成对苯二甲酸二环己酯

Synthesis of dicyclohexyl terephthalate by transesterification

研究了以无水碳酸钾、自制的钛酸酯等化合物为催化剂,对苯二甲酸二甲酯和环己醇为原料,进行酯交换反应制取对苯二甲酸二环己酯,考察了催化剂用量、反应温度、反应时间、反应物摩尔配比等因素的影响。适宜的操作条件为:环己醇与对苯二甲酸二甲酯的摩尔配比为3∶1、反应温度160～190℃、反应时间7h、催化剂用量为1.0%。此时,对苯二甲酸二甲酯转化率达93%以上,对苯二甲酸二环己酯的收率达92%以上。

A transesterification process for synthesis of dicyclohexyl terephthalate from dimethyl terephthalate and cyclohexanol is studied with potassium carbonate,titanate and other catalysts.The influences of the amount of catalyst,reaction temperature,reaction time and ratio of reactants are investigated.The optimal conditions are obtained as follows:3∶1 of the molar ratio of cyclohexanol/(dimethyl terephthalate,160-190℃ of the reaction temperature,7 hours of the reaction time and the self-titanate catalyst amount of 1.0%.Under above conditions the conversion rate of dimethyl terephthalate can be over 93% with dicyclohexyl terephthalate yield higher than 92%.