UV-curable waterborne polyurethane-acrylate: preparation, characterization and properties

The waterborne polyurethane-acrylate (PUA) oligomer was firstly prepared based on isophorone diisocyanate (IPDI), polyether polyol (NJ-210), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA) via in situ and anionic self-emulsifying method. The UV-curable polyurethane-acrylate (UV-PUA) was obtained with oligomer, monomers (BA and TPGDA) and photoinitiator Darocur 1173. FT-IR, DSC and TGA were employed to investigate the structures and thermal properties of the UV-PUA films. The effects of BA/TPGDA (R) value, the content of Darocur 1173 and the UV curing time on the performances were investigated. Some mechanical performances, solvent resistance and the gel content of UV-PUA films were measured. When the ratio of BA/TPGDA was 5/5, the UV-PUA film had the best solvent (water, alkali and ethanol) resistances. Besides, with the ratio of the BA/TPGDA increasing, the surface drying time increased. When the content of Darocur 1173 was 4%, the gel content achieved the maximum while the surface drying time achieved the minimum. The obtained UV-curable polyurethane-acrylates are promising as oligomers for UV-curable coatings, plastics, inks and adhesives.

. The waterborne UV-PUA emulsion was prepared using UV-PUA oligomer, the Darocur 1173 and the monomers composed of BA and TPGDA. The curing time was very short at room temperature. The obtained UV-PUA films have good hardness, solvent resistance and mechanical properties. It is hopeful that the UV-PUA dispersions can be applied to commercial use in different regions.Figure optionsDownload as PowerPoint slideHighlights
► Preparation of UV-PUA oligomer.
► Preparation of UV-PUA film.
► The effect of the ratio of BA/TPGDA on the properties of UV-PUA films.
► The effect of the content of Darocur 1173 on the properties of UV-PUA films.
► The effect of curing time on the properties of UV-PUA films.