KHAYA SENEGALEASIS OIL AND AZADIRACHTA INDICA OIL (FATTY ACIDS) AS CORROSION INHIBITORS FOR MILD STEEL IN SULPHURIC ACID (H2SO4) SOLUTION
Abstract
Corrosion inhibitors namely Khaya Senegaleasis oil and Azadirachta indica oil fatty acids have been synthesized and their inhibitive performances towards the corrosion of mild steel in 0.5M sulphuric acid (H2S04) at room and elevated temperatures (30 to 80°C) have been investigated. Preliminary screening of the inhibition efficiency (E) was carried out using weight - loss measurements technique. The inhibition efficiencies of the vegetable based fatty acids increase with increase in concentration at all temperatures considered. The trend of inhibition efficiency with temperature suggests that inhibitor molecules are adsorbed physically on the corroding metal surface which was assumed to occur via the adsorption of the fatty acid molecules on the metal surface. These results were further corroborated by some thermodynamic (kinetic and activation) parameters such as heat of adsorption, free energy of adsorption and activation energy for corrosion and adsorption processes evaluated from experimental data at the temperature studied khaya senegaleasis oil and azadirachta indica oil-fatty acids were found to obey Lamgmuir and Temkin adsorption Isotherms in the concentration rate investigated.
