The Effect of PETA/PETTA Composite System on the Performance of UV Curable Waterborne Polyurethane Acrylate

UV curable waterborne polyurethane acrylate based on pentaerythritol triacrylate (PETA)/pentaerythritol tetraacrylate (PETTA) composite system was prepared by using polycaprolactone glycol (PCL), isophorone diisocyanate (IPDI), -cyclodextrin (-CD) and 2,2-dimethylol butanoic acid (DMBA) as the main materials. Besides, PETA was used as capping agent and PETTA was used as reactive diluent. By varying the additive amount of PETA and PETTA, a series of emulsions and films were obtained. The molecular structure was characterized by infrared spectra and a series of performance tests such as particle size, contact angle, tensile properties, UV curing performance, differential scanning calorimetry and thermogravimetric analysis were conducted. The result showed that more compact network structure was formed by introducing PETTA with higher reactivity into the polyurethane molecule under UV irradiation and many performances were improved as a whole. However, there existed phase separation to a certain extent. Especially when the content of PETTA was higher than 83.33%, the effect of compatibility became more prominent. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41262.