The Effect of Different Percentages of Functionalized Graphite Nano-Platelets on Corrosion Resistance Performance of Zinc Rich Epoxy Coatings

In this research, the effect of functionalized graphite nano-platelets (FGNP) on improvement of corrosion protection of zinc rich epoxy coating in different percentages of FGNP and zinc powder were investigated. TEM and SEM analysis, salt spray, electrochemical impedance spectroscopy, Pull- off adhesion and cathodic delamination tests were used for evaluation of the coatings. The results showed that FGNP is able to enhance the cathodic protection duration of ZRP from ۱۴ days up to ۴۲ days. Also, due to its lamellar structure, and regular arrangements in nano-coating, FGNP is able to increase the second stage of ZRP corrosion protection (barrier protection). The adhesion test results showed FGNP has a significant effect on adhesion strength enhancement and by limiting OH- contents under layer the nano-coating enhances the cathodic delamination resistance. So the service life of the nano- coating is increased. The best results were obtained for zinc rich coating contains ۷۵% of zinc dust with ۰.۷۵% wt of FGNP.