Preparation and performance of UV-curable waterborne polyurethane prepared using dipentaerythritol hexaacrylate/dipropylene glycol diacrylate monomers

Abstract In this study, a series of UV-curable waterborne polyurethane (UV-WPU) emulsions with different contents of dipentaerythritol hexaacrylate (DPHA)/dipropylene glycol diacrylate (DPGDA) were prepared using isophorone diisocyanate, and poly(tetramethylene glycol) as the main materials. Besides, DPHA/DPGDA with a mass ratio of 1:1 was used as the reactive diluent and UV curing agent, and pentaerythritol triacrylate was used as the capping agent. The UV-WPU films were obtained by using photo-initiator 184 and an ultraviolet curing machine. The molecular structure was characterized by infrared spectroscopy, and several properties such as particle size, contact angle, tensile properties were measured, thermogravimetric analysis was conducted. Results revealed that a more compact network structure is formed by the introduction of DPHA/DPGDA, with a higher reactivity, into the polyurethane molecule under UV irradiation; tensile strength increases to 21.03 MPa; and several performance parameters improve, with a DPHA/DPGDA content of 40 wt%. However, some phase separation was observed, at a DPHA/DPGDA content of greater than 40 wt%. Graphical Abstract