The Inhibition Effect of Breadfruit Leaf Extract on Mild Steel Corrosion

The inhibitive effect of breadfruit (Artocarpusaltilis) extract on the corrosion of mild steel in hydrochloric acid solution was investigated. Liquid from breadfruit leaves was extracted via solvent extraction method. Gravimetric and electrochemical techniques were used to test the effectiveness of the extract as corrosion inhibitor at 0.1- 0.5g/L of the extract in solution of 0.5M hydrochloric acid. Both methods showed that increase in the extract concentration in acidic environment, enhanced the inhibition efficiency of Artocarpusaltilis extract. Although increase in exposure time slightly affect the inhibition process, but addition of the extract reduces the corrosion rate of mild steel. From the gravimetric method, the corrosion rate of mild steel in the acid solution after 10 hours was 6.815mm/yr for control sample, but reduced to 1.862mm/yr after the addition of 0.5g/L concentration of breadfruit. Also, in polarization method, the corrosion rate obtained as 2.209mm/yr for control sample reduced to 0.283mm/yr for sample inhibited with 0.5g/L extract. Similarly, the inhibition efficiency of breadfruit leaves extract increased with increase in extract concentration for both measurement methods. The maximum inhibition efficiency of 82.15 was recorded for the gravimetric method, whereas, 87.19% was obtained from the polarization method, showing that inhibition efficiency is higher with the polarization method. Nevertheless, both techniques indicate that breadfruit leaves extract is a good inhibitor for mild steel in acidic medium, which acts as mixed-type inhibitor. Therefore, the utilisation of breadfruit leaves extract will help reduce failure of equipment and expenses incurred in production industries as a result of corrosion.