Fabrication of UV-curable waterborne polyurethane coatings with self-cleaning, anti-graffiti performance, and corrosion resistance

A novel UV-curable anti-smudge coating based on waterborne polyurethane (WPU) was constructed by using polydimethylsiloxane (PDMS) as hydrophobic material and pentaerythritol triacrylate (PETA) as UV-curable cross-linking agent. At the same time, the effect of PDMS loading and the cross-linking density on the transparency, hydrophobicity, as well as graffiti resistance of the coating, were investigated. Due to the high cross-linking density, the obtained coating possessed desirable optical transparency. The synergistic effect of hydrophobic side chains and dense cross-linking imparts the coating favorable repellency to pollutant liquids such as water, coffee, muddy water, ink, hexadecane, ethanol, fingerprint liquid and others. The coating showed good anti-graffiti properties on a variety of substrates, including glass, tinplate, ceramics, wood, and paper sheet. In addition, aside from protecting the substrate against strong acid, alkali, and salt solutions, the coatings remained stain resistant despite being folded and curled. This study provides a new strategy for the design of WPU UV-curable anti-smudge coatings.