Synthesis, Characterization, and Theoretical Calculations of a Novel Organic Corrosion Inhibitor for Mild Steel

Q235 is a carbon structural steel sheet that is widely used in the construction and engineering sectors due to its cost-effectiveness and durability. Here, a novel organic corrosion inhibitor for a Q235 sheet based on furan-thiadiazole (5-amino-2-furyl-1, 3, 4-thiadiazole, AFTZ) has been designed, successfully synthesized, and characterized in this work. Results of experimental data and theoretical calculations indicated that AFTZ has an excellent corrosion inhibition property for a Q235 sheet in 1.0 mol/L H₂SO₄. The highest efficiency of corrosion inhibitor tested by a weight loss experiment can reach 91.17% and an electrochemical experiment was up to 95.85% when AFTZ increased to 2 mg/mL in H₂SO₄ solution. The morphological characteristics of Q235 sheets with or without corrosion inhibitor showed that the target inhibitor has good corrosion inhibition performance. Quantum computation using the density functional theory method of Gaussian09 software and Fourier-transform infrared data attribute the excellent corrosion inhibition to the film-forming nature of AFTZ.