Kinetics of water–isocyanate reaction in N,N-dimethylformamide  

作　　者：Zhirong Chen Weitao Yang Hong Yin Shenfeng Yuan 

机构地区：[1]College of Chemical and Biologlical Engineering, Zhejiang University, Hangzhou 310027, China

出　　处：《Chinese Journal of Chemical Engineering》2017年第10期1435-1441,共7页中国化学工程学报（英文版）

基　　金：Supported by the Key Science and Technology Innovation Team of Zhejiang Province(2011R50007)

摘　　要：The uncatalyzed reaction of p-tolyl isocyanate(p-TI)with water in N,N-dimethylformamide(DMF)was investigated by high performance liquid chromatography(HPLC).The reactions were carried out at different temperatures from 293 K to 323 K,using various molar ratios of water to p-TI.DMF,as a special amide,was proved to be an efficient catalyst for water–isocyanate reaction.Under the reaction conditions in this study,substituted urea was the only final product observed.An appreciable amount of intermediate p-toluidine was detected.Concentrations of the isocyanate group as well as the amine and urea were determined as a function of time.New kinetic equations were deduced for each of the substance on the basis of a multistep mechanism,instead of a simple second order reaction as usual.Kinetic constants were calculated using the software MATLAB.Furthermore,the effects of temperature and concentrations of reactants on the reaction rate and amine content were discussed.The activation energy of each step was also determined.The uncatalyzed reaction of p-tolyl isocyanate（p-TI）with water in N,N-dimethylformamide（DMF）was investigated by high performance liquid chromatography（HPLC）.The reactions were carried out at different temperatures from 293 K to 323 K,using various molar ratios of water to p-TI.DMF,as a special amide,was proved to be an efficient catalyst for water–isocyanate reaction.Under the reaction conditions in this study,substituted urea was the only final product observed.An appreciable amount of intermediate p-toluidine was detected.Concentrations of the isocyanate group as well as the amine and urea were determined as a function of time.New kinetic equations were deduced for each of the substance on the basis of a multistep mechanism,instead of a simple second order reaction as usual.Kinetic constants were calculated using the software MATLAB.Furthermore,the effects of temperature and concentrations of reactants on the reaction rate and amine content were discussed.The activation energy of each step was also determined.

关 键 词：Kinetics Isocyanate Polyurethane Catalysis HPLC Kinetic modeling 

分 类 号：O643.1[理学—物理化学]