Chemical Combination of 4-(4-Hydroxybut-2-ynyl) Pyridine and 3-Methylbenzenamine to Construct an Effective Inhibitor: Theoretical and Practical Investigation

Abstract

A new inhibitor, N-m-benzylamine-4-(4-hydroxybut-2-ynyl) pyridinium bromide (designated as BAP) was designed and synthesized. Quantum chemical calculation and molecular dynamics (MD) simulations manifested that BAP, a compound by covalent combination of 4-(4-hydroxybut-2-ynyl) pyridine (HYP) and 3-methyl benzenamine (MBA), functioned better than did the two moieties (HYP and MBA) for X70 steel corrosion inhibition. The corrosion inhibition investigation revealed that the experiment outcome was in good consistency with the theoretical calculation. The inhibition efficiency of BAP was 95.72% for X70 steel in 5 M HCl at 90 0C. BAP adsorbed on X70 steel surface, obeyed Langmuir isotherm, retarded both the metal dissolution and the hydrogen evolution, and enhanced greatly the acid corrosion resistance of X70 steel. Comparative test demonstrated that the inhibition efficiency of BAP was about 10 times of that for MAB and 8 times of that for HYP albeit the concentration of BAP was tenth of that of HYP and MBA. The experimental investigation backs up the theoretical calculation and manifests intramolecular synergism of the structure moieties being beneficial to design of high effective inhibitors.