MDI与PPG预聚反应动力学

Prepolymer Reaction Kinetics of MDI and PPG

二苯基甲烷二异氰酸酯与聚醚多元醇反应是合成二苯基甲烷二异氰酸酯(MDI)型预聚体的重要反应。文中采用ReactTM4000在线红外分析系统,以聚丙二醇(PPG)主链中亚甲基伸缩振动峰作为内标,监测不同异构体组成的MDI单体与PPG聚醚反应过程中异氰酸酯官能团的红外吸收峰变化,系统研究了MDI与PPG的预聚反应动力学过程,得到MDI中4位异氰酸酯与2位异氰酸酯反应速率常数分别为k=2.833×104exp(-47862/RT)(L/mol.min),k=6.725×109exp(-88078/RT)(L/mol.min)。

The reaction kinetics between diphenyl-methane-diisocyanate（MDI） and polypropylene glycol（PPG） was investigated by IR online monitor system,IR ReactTM 4000.The IR absorption peak development of isocyanate and urethane in the reaction process of MDI monomer with different isomers and PPG polyether were studied.The reaction kinetics of the isocyanate in the different space position of MDI molecular structure with the hydroxy group of PPG polyether was analysised systematically by these IR spectrum figure and the reaction kinetics constants of 4-NCO and 2-NCO in MDI monomer k4=2.833×104 exp（-47862/RT）（L/mol·min）,k2=6.725×10^9 exp（-88078/RT）（L/mol·min）were obtained.