Abstract

Antifouling coatings are of great interest in many fields including the leather industry. Herein, the effects of zwitterionic groups on the preparation, structure, and performance of anti-biofouling zwitterionic polyurethanes have been investigated. The results show that the addition of excessive 1,3- propane sulfone (1,3-PS) contribute to the completion of the ionization reaction of the polyurethane in the preparation process. However, the residual 1,3-PS leads to the formation of micropores in the polyurethane films and this can be removed by the precipitation of the synthesized products in water. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) show the decreased Tg of polyurethanes with the increasing of zwitterionic groups, indicating the slightly enhanced microphase separation of the polyurethanes. The water vapour permeability (WVP) and water absorption rate (WAR) of polyurethane films increase with zwitterion groups, and thus the waterresistant property of the films needs to be improved for the purpose of leather coatings. In the emulsification of polyurethane, the presence of zwitterionic sulfobetaine causes the pHdec rease of the emulsions, and proper neutralization may adjust it in the further investigations.