Evaluation of anti-corrosion performance of epoxy ester coating in the presence of a new generation of hybrid pigments based on Echium amoenum extract and zinc acetate

The impact of hybrid organic/inorganic pigments based on the herbal extract of Echium amoenum and zinc acetate on the corrosion protection performance of epoxy ester coating was investigated in this paper. The electrochemical impedance spectroscopy (EIS) measurement showed that the presence of hybrid pigment can expressively prevent the corrosion of steel in saline solution. The results of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), visible ultraviolet (UV-Vis) spectroscopy and static contact angle proved the formation of chelates and protective complexes in the pigment structure. The inhibition efficiency of 89.3% shows the same point. The low-frequency impedance value of epoxy coating increased in the absence and presence of the hybrid pigment from 344 MΩ cm2 to 6056MΩ cm2. This parameter was calculated after 45 days for the blank coating and the one containing pigment 4.2 MΩ cm2 and 200 MΩ cm2, respectively, which indicates the role of pigment in increasing the barrier performance of the coating. Increasing the overall resistance values equivalent to 16343 Ω.cm2 in the epoxy coating containing pigments with synthetic scratches shows the active inhibitory role of hybrid pigments.