Since corrosion with its direct and indirect negative effects is a global issue, coatings are commonly used as a structural corrosion protection strategy. The reinforcement effects of Poly (aniline-co-pyrrole) (PACP) nanospheres on corrosion resistance of solvent-based epoxy coatings are investigated in this study. The corrosion behavior of mild steel substrates coated with epoxy containing different weight percents (0.25, 0.5, 0.75, and 1.0 wt%) of PACP nanospheres is investigated using electrochemical impedance spectroscopy (EIS) in a 3.5 wt% NaCl solution, while the fracture cross-section is studied by field emission scanning electron microscopy (FESEM). The incorporation of the PACP nanospheres in the polymer coatings considerably improves the protective performance of the epoxy coatings. The results of the EIS test shows that the highest corrosion resistance is for the EP-PACP- 0.75 wt% sample. In the first day of immersion, |Z|100kHz is equal to 5.2 × 1012 Ω.cm2, which is much more than the pure epoxy sample (105 Ω.cm2). After two months of immersion, the resistance reduction for the optimum sample is negligible and the amount of water uptake into the coating is the lowest. These findings demonstrate that the epoxy/PACP nanocomposite is superior when compared to the pure epoxy coating.
