Investigation of Anticorrosion and Mechanical Properties of Azole Functionalized Graphene Oxide Encapsulated Epoxy Coatings on Mild Steel

Abstract

Improvement of the corrosion protection properties of epoxy coatings on mild steel has been carried out by incorporating the imidazole modified graphene oxide (GO). Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the graphene oxide and functionalized graphene oxide (fGO). The protective performance of the functionalized GO with epoxy-fGO composite coating against corrosion was studied by electrochemical techniques and pull off adhesion test. The electrochemical impedance spectroscopic measurements showed high film resistance, charge transfer resistance with low capacitance for the epoxy-fGO coatings compared to neat epoxy coatings. SECM analysis showed less current distribution (0.5–2.3 I/nA) for fGO-grafted composite coatings compared to neat epoxy coatings (2–10 I/nA). The surface morphological analysis of epoxy-fGO composite coatings was done by field emission scanning electron microscopy with energy-dispersive X-ray analysis and X-ray diffraction (FE-SEM/EDX). Mechanical properties of the coatings were also found to be improved in the presence of modified GO nanoparticles in adhesive measurement. Thus, the epoxy-fGO coatings can enhance the adhesion strength and corrosion protection performance on mild steel.