Effect of Temperature on the Corrosion Inhibition of 4ethyl-1-(4-oxo-4-phenylbutanoyl)thiosemicarbazide on Mild Steel in HCl Solution

Abstract

The temperature effect of 4-ethyl-1-(4-oxo-4-phenylbutanoyl)thiosemicarbazide (EOPT) on the mild steel corrosion in 1 M HCl solution was studied by gravimetric techniques at temperatures varying from 303 to 333 K. The investigated inhibitor concentrations were started from 100 ppm and ended with 500 ppm. The inhibition efficiency increased with the increase of the concentration of the inhibitor and reached 96.1% with the concentration of 500 ppm at 303 K and decreased to 66.3% at 333 K. Moreover, the inhibition efficiencies decreased with the temperature increase for both acids. Using the Langmuir adsorption isotherm for the adsorption of this inhibitor on the mild steel surface was determined. EOPT was found to be an efficient corrosion inhibitor due to its structural molecules, which contain sulfur, nitrogen, and oxygen, hetero atoms an addition to the aromatic ring.