OA02.02. Phytochemical constituents and antioxidative property of Musa acuminata flower as green corrosion inhibitor of mild steel in acid media

PURPOSE: Corrosion is a major problem that must be confronted for safety, environmental and economic reasons. Organic compounds used as corrosion inhibitors are expensive, toxic and non biodegradable. The present investigation deals with the aim of finding eco friendly and cost effective natural inhibitor. The adsorption characteristic of phytochemical of Musa acuminata ‘nendran’ flower [MAN (F)] was studied to assess the mechanism of corrosion inhibition. METHOD: The inhibitive effect MAN (F) extracts in 1 N HCl, 1 N H2SO4 and 1 N H3PO4 on mild steel was evaluated using conventional weight loss, electrochemical potentiodynamic polarization, AC impedance techniques and SEM analysis. RESULT: The inhibitor efficiency of MAN (F) extracts increases with an increase in concentration but decreased with temperature. The potentiodynamic polarization curves reveal that MAN (F) acts as a mixed type inhibitor and adsorption of extract follows Temkin adsorption. Surface studies SEM confirmed the efficiency of the flower extract as corrosion inhibitor. The flower extract was an excellent corrosion inhibitor for mild steel showing a maximum efficiency of 97.16%, 95.01% and 70.03 % in 1N HCl, H2SO4 and H3PO4 respectively at 5 hours in 2 % v/v extract. CONCLUSION: In traditional medicine of India and the ancient Persia this Golden fruit called the ‘fruit of wise’ is regarded as nature's secret of perpetual youth. Musa acuminata ‘nendran’ (AAB) is good source of vitamins, potassium, magnesium, phosphorus, calcium and iron. All parts of the banana plant have medicinal applications. The flowers are used in treatment of bronchitis, constipation, ulcers, diabetic, reduce painful and excess menstrual bleeding and enhance milk supply in lactating mothers. The phytochemical components of Musa acuminata flower like tannins, flavonoids, saponin, alkaloid and phenols are found to be responsible for inhibiting corrosion. The natural flavonoids present in the flower extract exhibit antioxidative activity that stop oxidation and hence corrosion.