Effect of the Mass Ratio of Iron Red Pigment to Epoxy Resin on Corrosion Resistance of Waterbone Epoxy Coatings Containing Nano-oxides

The corrosion resistance of waterborne epoxy coatings containing 3% nano-titanium dioxide particles was studied by electrochemical impedance spectroscopy, infrared spectroscopy, Machu test and polarization curve. The results show that the addition of iron red pigment to the waterborne epoxy coating containing nano-oxide could further improved the corrosion resistance of the coating, and when the pigment-to-base ratio was 1, the coating had the best corrosion resistance. After immersing in 3.5% NaCl solution for 8 000 h, the coating resistance still reached 10⁹ Ω·cm², which was about two orders of magnitude higher than that of the iron-free red coating. Adding iron red pigment to the water-based epoxy coating containing nano-oxide particles would not reduce the adhesion of the coating, and when the ratio of pigment to base was 1, the adhesion of the coating was improved.