Analyses of the Gravimetric and Electrochemical Effects of C₁₆H₁₃N₃O₃ on Mild Steel Corrosion in 0.5 M H₂SO₄

This study analyzed the gravimetric and electrochemical effects of C₁₆H₁₃N₃O₃ (methyl-5-benzoyl-2-benzimidazole carbamate: Mebendazole) on mild steel corrosion in 0.5 M H₂SO₄, for gaining insights on correlation and significance of differences between the two corrosion-monitoring techniques. For the gravimetric method, weight loss of mild steel specimens immersed in different C₁₆H₁₃N₃O₃ concentrations mixed in the 0.5 M H₂SO₄ were obtained for corrosion rates and inhibition efficiencies estimations. For the electrochemical approach, mild steel samples were subjected to potentiodynamic polarization experiments in the different C₁₆H₁₃N₃O₃ concentrations in 0.5 M H₂SO₄ that were employed for the gravimetric technique for obtaining instrumental readout of corrosion rate. Results showed that the corrosion rate from the electrochemical experiments exhibited excellent linear correlation (R = 99.91; Nash-Sutcliffe Efficiency = 99.83) with the dataset obtained from the gravimetric corrosion assessments. Both the gravimetric and electrochemical monitoring of mild steel corrosion gave inhibition efficiencies, η > 90%, by the different C₁₆H₁₃N₃O₃ concentrations for the study. Also, homeoscedastic and heteroscedastic student's t-test statistics indicated that the differences between the corrosion inhibition efficiencies from the electrochemical and gravimetric techniques were not significant, p-value = 0.9729, but significant for their corrosion rates: 1.52 × 10^–6 > p-value > 8.15 × 10^–9.