Inhibition of Mild Steel and Aluminium Corrosion in 1M H₂SO₄ by Leaves Extract of African Breadfruit

摘要

Inhibitory effects of African breadfruit leaves extract (BLE) on the corrosion of mild steel and aluminium in 1M sulphuric acid (H₂SO₄) solution was studied at 30℃ and 60℃. Kinetic, thermodynamic and adsorption parameters for the inhibition process were determined from the adsorption data. Corrosion rates were found to increase as temperature increased, but decreased in the presence of the extract compared to the blank. Inhibition efficiency increased with increase in inhibitor concentration reaching 70.55% for mild steel and 78.56% for Al at 30°C in the presence of 5g/L of BLE. The results obtained also show that the plant extract inhibited the corrosion process by physical adsorption mechanism and the process followed Freundlich adsorption isotherm model better than Langmuir and Temkin models. Kinetic analysis showed that the equilibrium constants were higher for mild steel (1.136) than aluminium (0.985), at 30℃. The implications of these results were discussed for the plant extract.