Synthesis of one-component polyurethane emulsion and investigation of structure and its properties

Polyethylene glycol adipate (PEA),toluene diisocyanate (TDI),dimethylol propionic acid (DMPA) were used as main raw materials to synthesize polyurethane prepolymer whose molecular chain have hydrophilic group(-COOH). The polyester waterbome polyurethane emulsion was obtained through special hydration technique. The paper discussed the influence of temperature,the ratio of -NCO versus -OH groups,the content of hydrophilic group,hydration technique on the mechanical property,water-resistance and Tg of the polymer. It was found that the polyester waterborne polyurethane emulsion has excellent storage stability, and its film has good water-resistance and mechanical properties. The hydration process was conducted via addition of prepolymer into the water with high speed stirring after neutralization, the optimal ratio of NCO versus OH groups,and the content of carboxyl groups for the polymer are 1.2 and 1.6%, respectively.