Preparation and Characterization of Waterborne Polyurethane with Unique Nanoparticles by Controlling Water

A facile method, focusing on emulsification, chain extension and dispersion process in preparing waterborne polyurethane, was developed to prepare emulsion with rod-like nanoparticles. The facile method involves a water addition procedure by in situ generated water to react with polyurethane prepolymer instead of the external water addition process. As a comparison, waterborne polyurethane was synthesized through the external water addition process. According to the characterization methods including FTIR, 1H-NMR, TEM and water swelling experiments, it is suggested there are two kinds of hydrogen bonds interactions in hard/soft domain of the novel polyurethane, and the phase separation of hard/soft domains increases significantly. The morphology of the two polyurethanes was quite different (nanorods and spherical particles, respectively), presenting a different surface property. In addition, the water swelling of the novel polyurethane indicates that it holds significant potential application as degradable material.