Preparation of Waterborne Polyurethane Paint

The waterborne polyurethane dispersion was synthesized by the reaction of polyester glycol with toluene diisocyanate(TDI) and dimethylolpropionic acid(DMPA),and the coatings can be made based on it. The factors influenced on the properties of waterborne polyurethane film were discussed. And the results showed that the waterborne polyurethane coatings have good mechanical properties. When the suitable ratio of —NCO/—OH was equal to 1 2, the synthetic method was proved feasible and its technical parameters such as the reaction temperature and reaction time were obtained with adding DMPA in dissolved state and with NMP.