Benzotriazole loaded polypyrrole/cerium oxide synthesized composite blend within epoxy resin designed as superior coatings against mild steel oxidative corrosion in sodium chloride medium

Abstract

In the present research work, benzotriazole or BTA-loaded polypyrrole/CeO2 (PCeB) coatings with different weight fractions as 0.5 %, 1.0 %, and 1.5 % blended with epoxy resin (EPR) were prepared and used to inspect the self-healing and corrosion protection behavior of the composite polypyrrole/CeO2 or PCe prior and after the loading of BTA. The synthesized composites were characterized structurally by XRD and FTIR studies and morphologically by SEM analysis. The surface topology of the coatings over mild steel was analyzed through SEM and AFM studies, furthered with the wettability/water resistance of coated surfaces through contact angle measurements, wherein BTA as inhibitor release rate was studied by the ultra-violet spectroscopy to assess the release amount of BTA within 220–400 nm. The corrosion protection of coated samples was evaluated by the potentiodynamic polarization method and electrochemical impedance spectroscopy or EIS, immersing the steel samples in 3.5 % NaCl solutions. There is a positive shift in Ecorr values and the composite PCeB/EPR (1 %) showed a stupendous protection efficiency of 99.95 % after 3 h immersion obtained through the EIS studies. These findings indicate that Polypyrrole/CeO2@BTA could be a potential substitute for persistent anticorrosive coatings for mild steel against aggressive chloride ions.