Corrosion Inhibitive and Adsorption Behaviour of Methanolic Extracts of Adansonia digitata (Baobab) Fruit Pulp and Seeds for Mild Steel in 1.0 M H2SO4

Abstract : Adansonia digitata (Baobab) pulp and seeds extracts have been tested for corrosion inhibition of mild steel in 1.0 M H2SO4 solution at room temperature. The inhibition efficiency and corrosion rate were studied using gravimetric, polarization and electrochemical impedance spectroscopy (EIS) methods. The surface morphology of MS was studied with scanning electron microscope (SEM). The Results revealed that Adansonia digitata seeds extract (ADSE) was found to be better corrosion inhibitor for mild steel in H2SO4 than Adansonia digitata pulp extracts (ADPE). Inhibition efficiency was found to be 57.65% and 68.70% for ADPE and ADSE respectively. Polarization studies revealed that both ADPE and ADSE act as mixed-type inhibitor. Adsorption isotherm was found using experimental data obtained in weight loss measurements. The absorption of both extracts on the mild steel surface was found to follow Langmuir adsorption isotherm. The surface analysis using scanning electron microscopy (SEM) confirmed both ADPE and ADSE played a significant protective effect on mild steel in1.0 M H2SO4 solution. ADPE and ADSE could serve as effective green inhibitors for mild steel corrosion in 1.0 M H2SO4 solution due to the adsorption of phytoconstituents of extracts.