Effects of nano silica on the Anticorrosive properties of epoxy coatings

In this study a series of epoxy/silica nanocomposites were prepared by using nano silica particles which had different surface modifications. The morphology of the nanocomposite coatings was characterized by scanning electron microscopy SEM. The effects of the hydrophilic and hydrophobic feature of the nano particles on the Tg and anticorrosive properties of nanocomposite coatings were evaluated by DSC and EIS instruments. It was observed that the presence of the hydrophobic nano silica particles affected the curing and cross linking density of the organic coatings and consequently reduction in corrosion resistance of nanocomposite coatings. On the other hand hydrophilic nano composites coatings showed better corrosion resistance even after 60 day immersion in NaCl3.5 solution in comparison to pure epoxy coating