Aquilaria malaccensis as a green corrosion inhibitor for mild steel in HCl solution

Abstract

The methanolic extract from the leaf of Aquilaria malaccensis was confirmed to inhibit the corrosion of mild steel in 1 mol dm-3 HCl based on gravimetric and electrochemical methods, and the leaf extract was found to inhibit corrosion by as much as 94.49 % at the concentration of 1500 ppm. The leaf extract acted as a mixed-type, but predominantly cathodic inhibitor for the potentiodynamic polarization measurement. The adsorption of the leaf extract on the surface of mild steel was by a mixed-type, but predominantly physisorption process, fitting the best into the Langmuir adsorption isotherm model. The surface morphology analysis revealed a less damaged surface when the leaf extract was added.