Studying different solvent systems on extraction performance of pomegranate peel extract as a green corrosion inhibitor for carbon steel in 15% HCl medium

Document Type : Original Article

Authors

1 Namjoo St. Department of Applied Chemistry, Faculty of Chemistry, University of Guilan, Rasht, Iran

2 Department of Applied Chemistry, Faculty of Chemistry, University of Guilan, P.O. Box: 41635-1914, Rasht, Iran

Abstract

Corrosion inhibition properties of pomegranate peel extract (PPE) extracted with water, water/ethanol and water/acetonitrile were investigated as a green corrosion inhibitor for carbon steel in 15% HCl medium. The results of the total phenolic content (TPC) test showed the highest amount of TPC in the extracted PPE with water-acetonitrile (1:2 V/V) compared to water and water-ethanol (1:2 V/V). The characterization of PPE was performed by TPC test, FT-IR, scanning electron microscope/X-ray diffraction spectrometer (SEM/EDX). The corrosion protection efficiency was studied by weight loss, electrochemical impedance spectroscopy (EIS), polarization, absorption isotherm, attenuated total reflectance (ATR) and X-Ray diffraction (XRD) analysis. The concentrations of 0.5 g/L, 1 g/L, 1.5 g/L, and 2 g/L of the inhibitor were investigated that the best result was obtained at concentration of 2 g/L. The polarization results showed that the resulting inhibitor acted as a mixed type inhibitor with a dominant cathodic effect. According to the EIS test, after 24 hours, the inhibitor efficiency at the optimal concentration was equal to 95%. The results of SEM- EDX showed the formation of a protective film on the metal surface. Also, the XRD showed no corrosion products on the metal surface in the presence of the inhibitor.

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