Mild Steel Deterioration Inhibition in 1.0M and 5.0M Tetraoxosulphate (VI) Acid using Leaf Extract of Pterocarpus santaliniodes

The prevention of deterioration of mild steel in 1.0M and 5.0M H_2SO_4 solution by leaf extracts of Pterocarpus santaliniodes was investigated in this study using gravimetric and gasometric methods. Data obtained from the study revealed that leaf extracts had a maximum inhibition efficiency of 88.70% and 96% for weight loss and gasometric analysis, respectively for 1.0M H_2SO_4, and an inhibition efficiency of 71.76% and 79.66% for weight loss and gasometric analysis respectively for 5.0M H_2SO_4. It was observed that the gasometric method gave the optimum protection. The average activation energy was 73.71KJ/mol in 1.0M H_2SO_4, and 74.41KJ/mol in 5.0M H_2SO_4. The adsorption of the phytochemicals on the surface of the mild steel were further assessed by the Langmuir and Freundlich isotherms. The extract was found to be good inhibitor for mild steel corrosion in the H_2SO_4 solutions. The amount of material loss decreased in the in the presence of the extract when compared to the blank acid solution.