EVALUATION OF THE PROTECTION PERFORMANCE OF Securidaca longipedunculata PLANT EXTRACTS ON STEEL CORROSION

Abstract

The efficiency of Securidaca longipedunculata (SL) leaves extracts against mild steel (MS) corrosion has been investigated in near neutral solution. The open circuit potential (OCP), potentiodynamic curves (Tafel plots), and electrochemical impedance spectroscopy (EIS) were used in the experiment. The results indicate that the corrosion protection capability of SL rises with increasing concentration, reaching a maximum of 91.9 % at 1.0 (w/v %). The surface analysis of the corroded surfaces was performed using visual examination, scanning electron microscopy (SEM), and energy disperse X-ray (EDX) spectroscopy in the absence and presence of the plant extract. Phytochemical screening, UV-visible spectroscopy, and FT-IR spectroscopy were used to examine and characterize the extract. Corrosion inhibition efficiency was measured as a function of the extraction solvent, the extracts concentration, and surface analysis. The Adejo-Ekwenchi, El-Awady, Flory-Hggins, Freundlich, Langmuir, and Temkin isotherms were used to conduct the adsorption studies. All the procedures used yielded consistent results, indicating that the ethanol extracts of SL have significant potential to act as an inhibitor of mild steel corrosion in near neutral solution.