Epoxy composite coating corrosion protection properties reinforcement through the addition of hydroxyl-terminated hyperbranched polyamide non-covalently assembled graphene oxide platforms

Abstract This paper presents the role of GO particle functionalization by different contents of hydroxyl-terminated hyper-branched polyamide on the epoxy coating corrosion protection properties. Raman spectroscopy, UV–visible analysis, and field emission scanning electron microscopy (FE-SEM) methods were applied to study the HB/GO interactions and morphology at different ratios. Then, by electrochemical impedance spectroscopy (EIS) and accelerated corrosion test (salt spray) the Epoxy-GO and Epoxy-HB/GO = 0.25, 0.5, 1.0 and 2.5 systems corrosion protection properties were investigated. Results obtained from Raman spectroscopy, UV–Visible analysis, and FE-SEM measurement proved that the GO sheets were successfully modified by HB molecules. SEM results evidenced that the GO particle dispersion quality in the epoxy matrix was significantly improved after modification by HB. Pull-off results revealed significant improvement in the epoxy film adhesion to the steel surface in the presence of HB/GO. Results disclosed that the epoxy composite coating reinforced with HB/GO = 0.5 and 1.0 showed the largest impedance (>1010 ohm cm2) and lowest delamination values. Generally, the modified GO sheets significantly improved the epoxy coating corrosion protection properties due to the role of HB in improving the dispersion state (proved by SEM results) and interfacial interactions between the GO and epoxy matrix.