Study of solvent-free sulfonated waterborne polyurethane as an advanced leather finishing material

A solvent-free waterborne polyurethane was synthesized via one-component crosslinking using N-[(2-amionoethyl)-amino] ethane sulphonated sodium as the post-chain extender. The effects of the N-[(2-amionoethyl)-amino] ethane sulphonated sodium and polyol content on the properties of waterborne polyurethane were investigated. The results indicate that at the optimum post-chain extender (6 mol%) and polyol (15.5 mol%) content, the waterborne polyurethane demonstrated best comprehensive properties. A clear advantage of the approach is that, in contrast with the traditional synthesis technique of waterborne polyurethane, the reaction process did not need any organic solvents to reduce the system viscosity. Also, a more natural optical appearance was obtained by the drying process of waterborne polyurethane itself. The as-developed waterborne polyurethane coating can be extensively used on the artificial leather and synthetic leather surfaces.