A Mohammad Rabea - Amirkabir University of Technology, Department of Polymer Eng. and Color Tech
M Mohseni - Amirkabir University of Technology, Department of Polymer Eng. and Color Tech
S.M Mirabedini - Iran Polymer & Petrochemical Institute, Color & Surface Coatings Dept

In this study, surface properties of a polyurethane clear coating were modified using a silicone containing polyacrylate additive. Surface free energy and mechanical properties of prepared coating samples were evaluated by contact angle measurement and dynamic mechanical thermal analysis (DMTA). The results showed that surface free energy of the samples decreased with replacement of the polyol with additive up to 10 mole percent and after that a constant trend was observed. The plausible explanation for the reduction in surface energy was attributed to the decrease in the polar component of the surface energy, the effect of which was shown on improvement of the cleanability of the surface. DMTA analysis revealed a homogenous matrix with no significant changes in glass transition temperatures. Furthermore, it was observed that the elastic modulus tended to increase as the concentration of the surface modifying additive increased.

Anti-Graffiti, Cleanability, Stainability, Polyurethane, Silicone Additive, Surface free energy