Electrochemical evaluation of corrosion protection performance of epoxy/polyaniline-imidazole modified ZnO nanocomposite coating on mild steel

In this research, ZnO nanoparticles modified with imidazole in Oxylene solution and characterized with Fourier transform infrared FT-IR spectroscopy. Then, polyaniline-ZnO unmodified and imidazole modified nanocomposites were synthesized via in-situ emulsion polymerization method. The synthesized nanocomposites were characterized by FT-IR and scanning electron microscopy SEM. The anticorrosion behavior of the epoxy coating in the presence of unmodified ZnO, imidazole modified ZnO, polyaniline-ZnO unmodified and imidazole modified were studied in NaCl 3.5 wt solution at 65 ℃ for 100 h by electrochemical impedance spectroscopy EIS. The coating resistance Rcoat of epoxy coating containing unmodified ZnO, imidazole modified ZnO, polyaniline/ unmodified ZnO and polyaniline/ imidazole modified ZnO after 100 h immersion in saline electrolyte found to be 7.2×10^4 , 1.3×10^5 , 2.3×10^5 and 1.7×10^7 Ω cm², respectively. It can be seen that polyaniline/ imidazole modified ZnO nanocomposite exhibited higher corrosion resistance and provided better barrier properties against ingress of corrosive electrolyte.