Preparation, characterization and properties of UV-curable waterborne polyurethane acrylate/SiO2 coating

The UV-curable waterborne polyurethane acrylate (UV-WPUA) oligomer was first prepared based on isophorone diisocyanate (IPDI), polyether polyol (NJ-220), dimethylol propionic acid (DMPA), and hydroxyethyl methyl acrylate (HEMA) via an in situ method. With the different content tetraethoxysilane (TEOS) and 3-glycidyloxypropyltrimethoxysilane (GLYMO) as coupling agents, a series of waterborne UV-WPUA/SiO2 oligomers were prepared by the sol-gel process. The physical and mechanical properties of the UV-WPUA and UV-WPUA/SiO2 hybrid coating materials were measured. The UV-WPUA and WPUA/SiO2 hybrid materials were characterized using FTIR spectra, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD) measuring apparatuses to determine their structures, thermal properties, surface morphologies, etc. The results showed the SiO2 particles of the hybrid materials had wide dispersion, forming a good interfacial bonding layer on surfaces. The tensile strength, water resistance, and thermal properties of the hybrid materials were better than those of the UV-WPUA. The resulting UV-WPUA/SiO2 hybrids are promising for a number of applications, e.g., for high-performance water-based UV-curable coatings.