High performance UV curable polyurethane dispersions by incorporating multifunctional extender

UV curable polyurethane dispersions (UV-PUDs) were synthesized and characterized in terms of prepolymer chain length, content of crosslinking agent (1,3-dihydroxy-2-propanone) and type of polyol. With decreasing prepolymer chain length and increasing crosslinking agent content, high hardness, modulus and low elongation at break were obtained. Among three types of polyol (PPG, PTMG, and PTAd) PTAd-based UV-PUD showed the highest tensile strength. All the UV-PUDs were tack free before UV-curing and showed improved solvent and hydrolysis resistant.