INHIBITION OF MILD STEEL CORROSION IN 1N HCL AND 1N H2SO4 BY LEAVES EXTRACT OF GOSSYPIUM HERBACEUM

Abstract

Inhibitory effect of ethanol extract of Gossypium herbaceum leaves on the corrosion of mild steel in 1N HCl and 1N H2SO4 has been investigated by burden Loss Method, FTIR, SEM, Potentiodynamic and Polarization measurements. The
experiment by Weight Loss Method has shown that the ethanol extract of Gossypium herbaceum inhibits mild steel
corrosion and the inhibition efficiency of the extract increases with increase in concentration and temperature. FTIR
spectra were used to examine the protective layer formed on the metal surface. The Electrochemical Impedance
Spectroscopy result have revealed that variation in the impedance parameters, charge transfer resistance and double layer
capacitance, with the deviation in extract concentration are due to the adsorption of active molecules resulting in the
construction of a protective layer on the mild steel surface. The SEM method has provided the confirmatory evidence of
the safeguard of mild steel by the green inhibitor. The consequences of the study have shown that the leaf extract of
Gossypium herbaceum exhibits fine corrosion inhibition efficiency for mild steel in both acid media.
Keywords: Gossypium herbaceum, Green inhibitors, Impedance, Polarization, SEM.