On solvent-free preparation process of waterborne polyurethane

This paper introduced the preparation of waterborne polyurethane(WPU) by prepolymer method and discussed the synthesis stability and experimental operation feasibility of solvent-free preparation process of WPU.The effects of raw material selection,material mixture ratio,feding method of DMPA,reaction temperature,etc.were investigated.The synthesis process of WPU obtained from the experiments are as follows:the initial temperature during prepolymerization of TDI and polyol is 60℃ ,the hydrophilic groups are added in the later period during prepolymerization,the reation temperature is 75-80℃,dibutyltin dilaurate,diethylene triamie and triethylamine are used as the catalyst,chain extender and neutralizer,respectively.