Influence of the 2,2-Dimethylol Propionic Acid Content on the Structure-properties of Waterborne Polyurethane

摘要

Series waterborne polyurethane (WPU) dispersions with different 2,2-dimethylol propionic acid (DMPA) content were synthesized by the prepolymer method. Different configurations in the waterborne polyurethanes were obtained by varying the DMPA content. The structure-properties of the WPU dispersions were characterized by Fourier transformed infrared spectroscopy, Thermogravimetric analysis, differential scanning calorimetry, Zetasizer nano etc. The results indicated that the amount of urethane and urea groups (hard segment) increased in the structure of WPU chains with the increasing content of DMPA. In the meantime, the degree of micro-phase separation increased. On the other hand, as the content of DMPA increased, the particle size, the thermal stability and T-peel strength decreased. Moreover, the increased content of DMPA resulted in higher tensile strength and hardness, but lower elongation at break.