Study of Bitter Leaves Extract as Inhibitive Agent in HCl Medium for the Treatment of Mild Steel through Pickling

Bitter leaves extract as inhibitive agent in HCl medium for the treatment of mild steel through pickling was studied. Thermometric, gravimetric and potentiodynamic polarization methods were employed in the corrosion inhibition study. The bitter leaves extract was analyzed using gas chromatography-ma...

Full description

Bibliographic Details
Main Author: Onukwuli,O. D. (author)
Other Authors: Omotioma,M. (author)
Format: article
Language:eng
Published: 2019
Subjects:
Online Access:http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042019000200004
Country:Portugal
Oai:oai:scielo:S0872-19042019000200004
Description
Summary:Bitter leaves extract as inhibitive agent in HCl medium for the treatment of mild steel through pickling was studied. Thermometric, gravimetric and potentiodynamic polarization methods were employed in the corrosion inhibition study. The bitter leaves extract was analyzed using gas chromatography-mass spectrometer. The analysis of the extract revealed the presence of C6H8O (96 g/mole: 2,4-Hexadienal); C7H12(96 g/mole: 3,4-Heptadiene; 1,3-Diethylallene) and C10H18O2 (170 g/mole: 2-Decenoic acid) as the predominant chemical constituents. The activation energy for the corrosion inhibition process ranged from 39.831 to 77.533 kJ/mol, while the heat of adsorption ranged from -16.093 to -30.224 kJ/mol. These values showed that exothermic and spontaneous adsorption of the extract on the mild steel followed the mechanism of physical adsorption. Maximum inhibition efficiency of 85.4% was obtained. The extract was highly efficient in the corrosion inhibition function. The plant-based inhibitor of bitter leaves extract is a suitable additive for pickling, cleaning and descaling operations.