Improving the corrosion protection ability of epoxy coating using CaAl LDH intercalated with 2-mercaptobenzothiazole as a pigment on steel substrate

Abstract

Using epoxy resin coating is an alternative candidate for the corrosion protection of metals especially steel, which is utilized in numerous applications. Herein, the CaAl LDH intercalated with 2-mercaptobenzothiazole (MBT) was prepared and incorporated with epoxy resin as pigment at different concentrations to enhance the corrosion protection ability of coating on Q235 steel. The electrochemical measurements confirmed the significant enhancement in corrosion protection of the steel substrate when the usage of CaAl-MBT LDH is 2%. The enhancement in the corrosion resistance is mainly due to the barrier against the corrosive medium and also the entrapment of Cl− ions by LDH, accompanied by the release of MBT ions from the LDH layer that could react with Fe2+ and construct a chelate network over the steel surface, which finally impeded the infusion of electrolyte. Moreover, this coating shows self-healing and good adhesion (5.83 MPa) to the substrate.