Rubber leaf extract: A green inhibitor for mild steel corrosion in 1.0 M HCl medium, response surface analyzer and electrochemical approach

Abstract

Strong adsorption is a requisite surface property for long time protection of inhibitors. The present research investigates the potential of the anchoring sites and water expelling characteristics of rubber leave extract on mild steel for corrosion protection in HCl environment. Using rubber leave promises to be advantageous not only because of its abundance but also environmentally friendly. Based on this, atomic absorption spectroscopy (AAS), gasometric, weight loss, electrochemical and surface imaging techniques were employed to investigate the efficiency of the inhibitor extract. Three isotherm models were utilized to explain the adsorption characteristic of the inhibitor. The results showed comparatively high inhibition efficiencies from the techniques as follows; weight loss (96.98%), AAS (99.68%), electrochemical (96.52%) and gasometric (86.53%). The minor deviation in the case of the gasometric method was attributed to errors relating to unavoidable gas leakage. The overall protection efficiency can be linked to the material adhesion and high electrical resistance (48000 Ω) of rubber extract. The scanning electron microscopy (SEM) shows a surface morphology of the adsorbent molecules on the mild steel surface according to Langmuir and Temkin adsorption isotherms. • Inhibition of Fe corrosion was improved to 99.68% efficiency via conversion of N-H to N-Fe bond. • Adhesion and high electrical resistance (48000 Ω) of rubber extract are the major corrosion protection strength. • Film morphology and robust water expelling characteristics contribute to the protection ability. • The correlation of weight loss, AAS, gasometric, electrochemical and surface techniques is a strong confirmation of good performance.