Efficiency of Alstonia schoalris Leaves on Mild Steel in Acid Medium as Pickling Inhibitor

Abstract

This work aims to find the inhibition efficiency of Alstonia schoalris leaves on mild steel in 1N HCl medium. Corrosion monitoring was done using weight loss method, potentiodynamic polarization studies like Tafel and impedance studies and the results shows that the inhibitor acts well on mild steel in acidic medium. Polarization studies show that the inhibitor behaves like a mixed type. The inhibitor was characterized using FTIR which showed the presence of hetero atoms in the inhibitor molecule that get adsorbed on metal surface and provided better efficiency and that was proven by different adsorption isotherm. Zeta potential showed the stability of particle in the medium. Surface analysis of specimen was studied using FESEM, EDX and contact angle measurements. The analysis showed that the surface exposed to inhibitor is less corroded and contact angle measurement showed hydrophilic nature of the surface. Here, the inhibition is attributed to the electrostatic interaction of active sites on metal and inhibitor.