Mild steel corrosion inhibition by synthesized 7-(Ethylthiobenzimidazolyl) Theophylline

N’Guessan Yao Silvère Diki,Kadjo François Kassi,Albert Trokourey,Nagnonta Hippolyte Coulibaly

doi:10.5599/jese.952

Abstract

The corrosion inhibition of mild steel by 7-(ethylthiobenzimidazolyl) theophylline (7-ETBT) in 1 M HCl medium was investigated through weight loss and Tafel polarization techniques within a temperature range of 298 to 318 K. The inhibition efficiency depends on the concentration of 7-ETBT and reaction system temperature. The maximum inhibition efficiency values of 90.73 and 87.06 %, respectively, were estimated using both weight loss and Tafel polarization techniques at 298 K. The results suggest spontaneous and predominant physical adsorption of 7-ETBT on the metal surface which obeys Langmuir isotherm model. Furthermore, Tafel polarization method revealed that 7-ETBT is a mixed-type inhibitor. Potentiodynamic polarization results are in accordance with weight loss data to a good extent.

Highlights

Corrosion of metallic materials in acidic solution is of huge concern and its inhibition has been deeply investigated [1,2]
The aim of the present paper is to evaluate the behavior of the studied inhibitor against mild steel corrosion in 1M HCl, by analyzing both thermodynamic data and potentiodynamic polarization parameters
The data obtained from weight loss measurements for the corrosion rates of mild steel samples in 1M HCl solutions with and without 7-(ethylthiobenzimidazolyl) theophylline (7-ETBT) at different temperatures are presented in Figures 1 and 2

Summary

Introduction

Corrosion of metallic materials in acidic solution is of huge concern and its inhibition has been deeply investigated [1,2]. Hydrochloric acid is widely used in various technological processes in industry including pickling baths, extraction and processing of oil and gas and in other chemical and petrochemical industries [3,4]. Corrosion of mild steel is important and expensive problem in the industries and represents a significant portion of losses as a result of lost production, inefficient operation, and high maintenance cost. It has been found that one of the best methods for protecting metals against corrosion involves the use of inhibitors which are mostly organic compounds.

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Conclusion