Determination of the Effect of Newbouldia Leavis Leaf Extract on the Corrosion of Mild Steel in Sulphuric Acid

The inhibitive properties of Newbouldia leavis leaf extract for the corrosion of mild steel was investigated using gravimetric technique in 1 mole of sulphuric acid. The leaves were gotten and dried after which they were ground to micron size. The extract of the leaves was obtained using ethanol reflux method and the weight of the leaves extracted deduced. The quantities for different concentrations (0.1g/L, 0.2g/L, 0.3g/L, 0.4g/L and 0.5g/L) of the extract were also deduced and applied into the acidic medium, and the mild steel coupons dipped into them over four hours intervals (4 to 20hrs). The weight loss values for each metal coupon were obtained and the inhibition efficiency calculated. The gravimetric technique used confirmed that Newbouldia leavis leaf extract is a good inhibitor of mild steel corrosion with increasing inhibition efficiency as concentration of the inhibitor increases. Inhibition efficiency values of 72% to 90% were obtained. From the results obtained for weight loss and corrosion rate, it was revealed that Newbouldia leavis leaf extract act as an efficient inhibitor showing weight loss (from 0.173g to 0.017g) and corrosion rate (from 43mm/yr. to 4.2 mm/yr.) decreasing with increase in concentration (from 0.0g/L to 0.5g/L) of the plant extract. Plant extracts are excellent substitute as corrosion inhibitors because of it availability, biodegradability, not expensive, less harmful to humans and environment. This research work has shown that Newbouldia leavis leaf extracts if applied in the right proportions will prolong the life of mild steel in service.