Investigation of Nano-ZnO on Properties of Coatings Based on Fluorinated Polyurethane Emulsion

Abstract

To develop environmentally friendly antifouling coatings, based on fluoro-modified polyurethane emulsion, eight coatings were prepared in which the content of nano-ZnO powder is respectively 0%, 0.2%,0.4%,0.6%,0.8%,1.0%,1.2% and 1.4 wt% in mass. Based on the measurement of mechanical and optical properties, surface roughness, morphological observation of coatings by Scanning Electron Microscopy (SEM), the influence of nano-ZnO was investigated on impact resistance, hardness, adhesive and flexibility, gloss, hydrophobicity, morphology and roughness of the coatings. The results showed that adding some nano-ZnO powder in paint did not affect the mechanical properties of the coatings, but it influenced obviously the surface topography and characteristics. The gloss reduces and the roughness increases with the content of nano-ZnO. The water contact angle is only 76.5° for the coating without nano-ZnO. The coating changed from hydrophilic to hydrophobic when nano-ZnO content increases up to 0.8 wt%, water contact angle excesses 90°, max water contact angle is up to 97.8° for coating with 1.4 wt % nano-ZnO powder.