Waterborne Polyurethanes for Coating Applications

Several waterborne polyurethane dispersions were synthesized by using different polyols such as polyethylene glycols, alkyd resin and castor oil, the aliphatic and aromatic di-isocynates, dimethylol proponic acid as ionic center and dibutyl tin dilurate as catalyst. By varying the mole ratios of polyols, di-isocynates and dimethylol proponic acid different waterborne polyurethane dispersions were synthesized. The synthesized Polyurethane dispersions were characterized by IR spectroscopy, particle size analysis and various physical properties like, color, appearance, viscosity and self-life. The film formation of the synthesized polyurethane dispersions and their characterization were carry out. The dispersions were casted into films and were characterized by physical properties such as drying time, surface dry, Tack-free dry, hard dry and chemical resistances (alkali and acid resistance).mechanical study (Tensile strength). Thermogravimetric (TGA) and Dynamic Mechanical Analysis (DMA) of polyurethane dispersion films are carried out.