熔融酯交换合成聚碳酸酯预聚体的动力学

Kinetics of synthesizing polycarbonate prepolymer via melt transesterification

研究了双酚A与碳酸二苯酯以氢氧化四丁基铵为催化剂的酯交换反应动力学。根据官能团模型推导出以苯酚浓度表示的积分型速率方程,得到了不同温度下的预聚合反应平衡常数,正、逆反应速率常数,活化能和反应热。酯交换反应的反应级数为二级,反应为放热反应,反应热为-17.45 kJ/mol,反应活化能为77.170 kJ/mol。探讨了不同反应温度、催化剂用量对反应速率的影响。实验数据与官能团模型符合良好,可以为后期的实验设计提供一定的理论指导。

The authors studied transesterification reaction kinetics of bisphenol A and diphenyl carbonate with tetrabutyl ammonium hydroxide as catalyst. The integral rate equation expressed in phenol molar concentration was deduced according to the functional group model. The prepolymerization reaction equilibrium constant at different temperatures, the positive and the reverse reaction rate constant, the activation energy and the reaction heat were acquired. The transesterification belonged to the second order reaction. The reaction was exothermic one with the reaction heat of -17.45 kJ/mol and the activation energy of 77.170 kJ/mol. The effects of reaction temperature and catalyst amount on the reaction rate were investigated. The experimental data accord well with the functional group model, which can provide the later experimental design with a certain theoretical guidance.