Abstract:A series of sulfonic acid / carboxylic acid type high solid content of waterborne polyurethane (ZW1~ZW4) was synthesized with dimethylol propionic acid (DMPA), A95 (amino sulfonate content 50%) as two hydrophilic chain expanding agent. The structures of the products were characterized by FTIR and X-ray diffractometer, the results showed that the reaction was carried out in accordance with the expected route. With the increase of the amount of sulfonic acid group, the emulsion solid content increased, particle size decreased and the distribution became wider. The Zeta potential was from -44.5 mV to -62.7 mV, but the stability of the acid was decreased. The results of film performance showed that, with the increase of the amount of sulfonic acid group, the elongation at break increased to 2800 % from 2100 %, the tensile strength decreased to 14 Mpa from 28 Mpa, and the crystallinity increased. In addition, heat resistance and water resistance decreased.