The Effect of the Presence of Glass Flake and Cerium Nitrate Particles on the Anti-corrosion Properties of Phenolic Epoxy

In order to strengthen the epoxy phenolic coating, glass flakes and cerium nitrate have been used. For this purpose, 6 samples with different combinations of cerium nitrate and glass flake were prepared and applied on ST37 steel. The self-healing properties of the samples at the scratch site were investigated by field emission scanning electron microscope (FESEM), elemental map analysis (MAP), and energy dispersive spectroscopy (EDS). According to the results, 58.52% of the complexes formed in the scratch area are composed of cerium nitrate (in sample EP2CN1.5G-04). In order to measure the anti-corrosion performance, electrochemical impedance spectroscopy (EIS), polarization and salt spray tests were performed. The obtained results showed a significant improvement in the protective performance of coatings containing glass flake and cerium nitrate compared to the pure epoxy. The results indicated that the presence of glass flakes and the combination of its protective mechanism with the self-healing properties of cerium nitrate increased Rct (charge transfer resistance) in sample 04 compared to sample 01 by 11.2 and 4.8 times, respectively, after 18 days of immersion. This sample also had the highest RP and the lowest icorr compared to other under-studed samples. These results prove the release of cerium nitrate in addition to the barrier properties of glass flakes. According to the results, it was observed that the EP2CN1.5G04 sample had better anti-corrosion performance than other samples.