双酚A与碳酸乙烯酯合成羟乙基化双酚A

Synthesis of bis(hydroxyethyl ether)of bisphenol A by reacting bisphenol A with ethylene carbonate

为了研究反应条件的影响以及反应机理,在120~180℃双酚A与碳酸乙烯酯以1∶2的摩尔比比例进行投料,改变反应温度,用碳酸钾、三辛胺和三苯基膦催化双酚A与碳酸乙烯酯反应合成羟乙基化双酚A,产物组成的分析方法为高效液相色谱.结果表明：双酚A转化率随反应温度升高迅速增大;碳酸钾催化时反应速率最高,三辛胺和三苯基膦催化时反应速率较低;不同反应条件下羟乙基化双酚A选择性随双酚A转化率的变化趋势基本一致,反应温度和催化剂种类对反应选择性的影响不显著,不同催化剂作用下的反应遵循相同的反应机理.对反应机理的初步探讨表明：双酚A与碱性催化剂作用形成的酚负离子进攻碳酸乙烯酯的亚甲基碳原子,发生取代反应,脱去CO2后形成羟乙基化合物,同时生成的酚负离子继续参与反应.

The reaction and mechanism of bis（hydroxyethyl ether）of bisphenol A（BHE-BPA）synthesis by bisphenol A（BPA）and ethylene carbonate（EC）were investigated.The reactions were carried out under the catalysis of potassium carbonate（K2CO3）,triphenylphophine（TPP）and trioctylamine（TOA）at fixed ratio of 1mole bisphenol A to 2mole ethylene carbonate when reaction temperature ranged from 120 ℃to 180 ℃.HPLC was utilized to follow the composition through the reaction progress.Results show that the conversion of BPA increases rapidly as the reaction temperature rises,and K2CO3catalyzes the reaction to get faster reaction rate than TPP or TOA.The relationships between the selectivity of BHE-BPA and the conversion of BPA under different reaction conditions are similar,and temperature and catalyst do not show significant effect on the reaction selectivity.The reactions catalyzed by different catalysts follow the same mechanism as follows：BPA reacts with base catalyst to produce BPA anion,which can act as a nucleophilic reagent to attack the methylene carbon atom on EC followed by substitution reaction,and BHE-BPA is synthesized after CO2has totally released,the BPA anion generated at the same time is supposed to show the same behavior of a nucleophilic reagent.