Fabrication of bi-functionalized nanocomposite coating for simultaneous improved thermal stability and corrosion protection performance based on polyaniline-reduced graphene oxide/organo-modified montmorillonite

In this study, a bi-functionalization strategy for epoxy-based coatings was performed with the aim of simultaneously improving thermal stability and corrosion protection performance. For this purpose, organo-modified montmorillonite (OMMT) with hexadecyltriphenylphosphonium (HDTPP) and polyaniline-reduced graphene oxide (PANI-rGO) were synthesized and characterized by FTIR, XRD, SEM, AFM, and TGA analyses. Then, epoxy-based nanocomposite coatings loaded with different amounts of OMMT or/and PANI-rGO in four groups (EP, EP/OMMT, EP/PANI-rGO, and EP/OMMT/PANI-rGO) were prepared. The synergistic effects of OMMT and PANI-rGO, individually and simultaneously, on corrosion protection performance of various formulation of epoxy-based nanocomposite coatings was assessed by electrochemical impedance spectroscopy (EIS). From the given results, the epoxy coating containing 5 phr of OMMT and 0.5 phr of PANI-rGO can be introduced as the optimal sample of bi-functionalized nanocomposite coating, which remarkably improved the barrier performance of the epoxy coating.