Corrosion Inhibition of Mild Steel in Acidic Environments using Polyphenol-Rich Extract from Senegalia Senegal (L.) Britton Stem Bark

Abstract

Corrosion presents a significant challenge to various industries, compromising the integrity and longevity of materials like mild steel. This study explores the efficacy of a polyphenol-rich fraction extracted from the stem bark of Senegalia senegal (PRFSS) as a green corrosion inhibitor for mild steel in acidic environments. The PRFSS extract, containing tannins, phenols, and anthocyanins, was assessed for its corrosion inhibition capabilities through various experimental methods, including gravimetric weight loss, phytochemical screening, and potentiodynamic polarization measurements. Results indicated that increasing concentrations of PRFSS notably reduced the corrosion rate of mild steel and enhanced surface coverage, suggesting effective protective layer formation. Thermodynamic analyses confirmed that the adsorption process of PRFSS onto mild steel is exothermic and spontaneous, with the adsorption behavior fitting Langmuir, Freundlich, and El-Awady isotherm models. FT-IR spectrum analysis further validated the successful adsorption of PRFSS on the mild steel surface, while TGA highlighted the extract’s thermal stability. SEM images corroborated the protective role of PRFSS, showing a smoother and less corroded surface compared to untreated steel. The study demonstrates that PRFSS is a promising, environmentally benign alternative to conventional chemical inhibitors, offering significant corrosion protection for mild steel. These findings open avenues for its application in industries. Future research should investigate the long-term stability and performance of this green inhibitor under diverse operational conditions