Evaluation of Corrosion Performance of Waterbased Polyurethane Coating with Fe2O3 Nanoparticles

Nanocomposite coatings were formed by addition of nano-Fe2O3 to specially developed polyurethane coatings by in situ polymerization method were applied on mild steel substratein various concentrations of nanoparticles. In order to improve dispersion of iron oxide nanoparticles in polymer matrix and better chemical interactions between nanoparticles and polymer coating, the nanoparticles were surface modified with the Tetraethyloorthosilicate (TEOS) silane. Ensuring from Interaction of nano-particles with silane and suitability of surface modification was demonstrated using FTIR test. The effects of iron oxide nanoparticles addition on the electrochemical behavior and corrosion performance of coatings were studied using electrochemical impedance spectroscopy (EIS) and polarization tests in 3.5% NaCl solution. The uniformity of coatings and dispersion of Fe2O3 nanoparticles in the polymer coatings were investigated FESEM. The results demonstrated that addition of modified iron oxide nanoparticles surprisingly reduced the corrosion rate of the nanocomposite coatings with respect to neat coating. Besides, coatings with high concentrations of nano-Fe2O3 particles (0.6 wt. % Fe2O3) showed better corrosion performance. This was as a result of properties of iron oxide nanoparticles interdiction against corrosive agents, as well as better adhesion of the coating to the substrate.