Inhibitory effect of Acacia hamulosa methanolic extract on the corrosion of mild steel in 1 M hydrochloric acid

Abstract

The flora of Saudi Arabia comprises about 18 species of Acacia species including Acacia hamulosa Benth. The methanolic extract of the flowering tops of A. hamulosa was tested for its radical scavenging activity toward 2,2-diphenyl-1-pricylhydrazyl (DPPH) radical and the activity was compared with L-ascorbic acid, quercetin and Trolox as standards. The total phenolic content was determined using Folin-Ciocalteu method. In addition the methanolic extract has been evaluated as a corrosion inhibitor for steel in 1 M HCl solution by means of weight loss measurements, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS). Tafel polarization study revealed that extract of Acacia hamulosa acts as a cathodic type inhibitor. Inhibition was found to increase with increasing concentration of the extract of Acacia hamulosa. Values of inhibition efficiency calculated from weight loss, Tafel polarization curves, and EIS are in good agreement. The effect of temperature on the corrosion behaviour of mild steel in 1 M HCl with addition of extract was also studied and thermodynamic parameters were determined and discussed.

Experimental, Statistical Modelling and Molecular Dynamics Simulation Concept of Sapium ellipticum Leaf Extract as Corrosion Inhibitor for Carbon Steel in Acid Environment

“…5 Conventional inhibitors have been well documented; however, the quest for achieving clean and green environment suggest the use of plant derived inhibitor as a globally acceptable means of mitigating corrosion. [6][7] The extract molecules shield the metal from acid attack by forming a coating layer which acts as an impediment between corroding and metal surface. Thus there is need to explore the potentials in the Sapium ellicpticum (SE) leaf extract, considering that it is cost-effective, readily available and eco-friendly.…”