Attenuation of Mild Steel-Acid Corrosion Using Exfoliated Graphite Oxide-Polymer Composite: Synthesis, Characterization, Electrochemical, and Response Surface Method Approach

Abstract

This work deals with the study of the anticorrosion behavior of a biopolymer, namely Guar Gum (GG) and its composite on mild steel (MS) in sulfamic acid (SA) solution using electrochemical techniques. GG was found to be a potential inhibitor relatively at its higher concentration and showed maximum inhibition efficiency (IE) of 74% at 3 g/L (3000 ppm). To improve its IE, exfoliated graphite oxide (xGO)/GG polymer composite was prepared, and its inhibition property was assessed in 1 M SA solution at different temperatures by weight loss method (WL). The chemical structure of xGO/GG polymer composite was examined by FT-IR, and the morphology was inspected by optical microscopy, scanning electron microscopy study, and energy dispersive spectroscopy technique. xGO/GG polymer composite emerged as an efficient corrosion inhibitor for MS as marked from the outcomes of the electrochemical investigations and showed improved IE of 93% at 0.6 g/L (600 ppm) when compared to GG. Experimental results found by WL measurements are used to evaluate the thermodynamic parameters at various temperatures. Further, a Box-Behnken composite design with three factors and three levels has been used to minimize the experimental conditions. The IE was enhanced with the increase in the inhibitor concentration as observed from the main effect plot. The maximum IE of 84.21% was projected by the response surface method (RSM) with temperature (A = 30 °C), inhibitor concentration (B = 600 ppm), and time (C = 1 h).