MDI与TDI封端聚酯预聚物和扩链剂间反应速率的研究

The Study on the Chain Extension Reaction of MDI and TDITerminated Polyester Prepolymers with Extenders

用ＦＴＩＲ法系统地研究了不同硬段结构对聚酯型聚氨酯扩链反应动力学的影响，结果显示：不同类型的二异氰酸酯ＭＤＩ和ＴＤＩ形成的ＮＣＯ封端的聚酯预聚体与二元胺（ＭＯＣＡ）和三元醇（ＴＭＰ）的扩链反应均为二级反应，由ＭＤＩ形成的ＮＣＯ封端的聚酯预聚体与胺或醇的扩链反应速度比ＴＤＩ类的要快，ＭＯＣＡ扩链比ＴＭＰ扩链反应活化能低。从基团反应活性对不同体系扩链反应速度的差别进行了讨论．

The effects of the hard segment structure on the chain extension reaction kinetics of MDI or TDI terminated PEPA-prepolymer with diamine(MOCA) and polyol(TMP) have been studied by FTIR method systematically. The reaction rate constants and activation en ergy for these systems have been measured. The chain extension reactions in these systems are found to be reactions of second order. The chain extension reaction of NCO terminated PEPA-MDI-prepolymer with MOCA or TMP is faster than that of PEPA-TDI-prepolymer with the same extenders. The activation energy of the chain extension reaction of NCO ter minated PEPA-prepolymer with MOCA is much lower than that with TMP.Such chain ex tension reaetion difference has been discussed.