Investigation of the Inhibitive Properties of Mangifera indica (Mango) and Annona Muricata (Soursop) Blend Leaves Extract on Carbon Steel in 0.5M H2SO4

The inhibition efficiency of mango (Mangnifera indica) and Soursop (Anonna muricata) blend leaves extract as inhibitor of carbon steel in 0.5M H2SO4 acidic solution is presented. The corrosion inhibition study was carried out using, gravimetric method. Gas Chromatography (GC) and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyze the Mangifera indica and Annona muricata blend leaves extract. Scanning Electron Microscopy (SEM) was employed to investigate the surface morphology of steel coupons before and after exposure to the corrosive environment. Analyses of the results revealed that adsorption of the Mangifera indica and Annona muricata blend leaves extract on the surface of the carbon steel was spontaneous and occurred according to the mechanism of physical adsorption. The inhibition efficiency was dependent on concentration of the extract and time. Mangifera indica and Annona muricata blend leaves extract exhibited the highest inhibition efficiency (about 93.68%) observed at 48 hours of 1.0 g/ml of extract concentration. At increased concentration of extract, the corrosion rate of carbon steel samples gradually decreased as the days progressed. The least corrosion rate of 2.99 mm/yr was obtained at 1.0g/ml extract concentration. The result showed that Mangifera indica and Annona muricata blend leaves extract is a good inhibitor for the corrosion of carbon steel in H2SO4 media. It has a high significant effect on the reduction of the corrosion of carbon steel at room temperature as a result of the formation of films on the substrate thereby displacing water molecules from the metal surface when compared with the control experiment.