Novel cationic UV-curable cathodic electrophoretic coatings with pendant amine salt

N-Methyldiethanolamine (MDEA) bearing main chain tertiary amine and 7, 12-dioxa-3, 16-diaza-3, 16-diethyl-5, 14-octadecanediol (DDDOD) bearing pendant tertiary amine were used as the hydrophilic monomers, respectively to prepare polyurethane dispersions. Hydrophilcity of the two hydrophilic monomers was compared by the dispersibilities of the polyurethanes and mean diameters of the dispersions. The results showed that DDDOD had a better hydrophilcity than MDEA, revealing that hydrophilic monomer with pendant tertiary amine had a superior hydrophilic ability than that with backbone tertiary amine. Polyurethane was prepared by the reaction between DDDOD, poly-caprolaclone glycol (PCL) and isophorone diisocyanate (IPDI). UV-curable monomers were added into the polyurethane and dispersed together. The properties of the dispersions and films were studied. The conversion of carbon-carbon double bonds after UV-curing was analyzed. © All Right Reserved.