Inhibition effect of Hibiscus rosa sinensis Leaves Extract on Corrosion Rate of Mild Steel in HCl Medium

Abstract

There is a growing trend to utilize plant extracts compounds as corrosion inhibitor. Corrosion Inhibition of Mild Steel in 2M Hydrochloric acid (HCl) by leaves extract of Hibiscus rosa sinensis has been studied at 35 ^oC using weight loss measurement and spectrophotometric technique. Results confirmed that the leaves extract of Hibiscus rosa sinensis inhibited the acid induced corrosion of Mild Steel (MS). The inhibition efficiency increases with increases in concentration of the extract. The investigation showed optimal inhibition efficiency of about 87.23% at 1.08%v/v concentration of inhibitor. Spectrophotometric technique was used to evaluate the inhibition efficiency based on ferrous ion concentration. As concentration of inhibitor increase, decreases in concentration of ferrous ion that indicate increase in inhibition efficiency of inhibitor. Inhibitive effect was afforded by adsorption of the extracts’ components which was approximated by Freundlich, Langmuir and Temkin adsorption isotherm. Characterization of   Hibiscus rosa sinensis leaves extract was carried out using GC-MS technique.