Preparation, characterization of UV-Curable Waterborne Polyurethane-Acrylate and the application in metal iron surface protection

Hydroxyethyl methyl acrylate (HEMA) capped waterborne polyurethane-acrylate (WPUA) oligomer was firstly prepared from isophorone diisocyanate (IPDI), polyether polyol (NJ-220), dimethylolbutanoic acid (DMBA), HEMA via in-situ and anionic self-emulsifying method. Ultraviolet (UV) curable WPUA coating was obtained from HEMA-capped oligomer, butyl acrylate (BA) and multifunctional acrylates (TPGDA) as reactive diluents, and Darocur 1173 as photoinitiator. The physical properties of WPUA oligomers, such as particle size, apparent viscosity, and surface tension were investigated. Some mechanical properties of UV-WPUA films, such as contact angles, thermal properties, and solvent (water, HCl, NaOH, NaCl, and ethanol) resistance of UV-WPUA coating films were measured. The surface morphologies were measured by scanning electron microscope and atomic force microscope. The surface free energy of the UV-cured film was calculated from contact angle measurements using the Lewis acid-base three liquids method. The specific UV-WPUA coating was selected to protect the iron materials that observed the effect of the protection. The results indicate that the prepared UV-WPUA coating has excellent protective behavior to metal iron materials and may offer some contributions to protect iron cultural relics. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3142-3152, 2013