Synthesis and evaluation of hexamethylenetetramine quaternary ammonium salt as corrosion inhibitor

摘要

A novel corrosion inhibitor, hexamethylenetetramine quaternary ammonium salt, is synthesized using hexamethylenetetramine (HMTA) and bromohexane as main reactants. The inhibitive action of HQAS on QT800-2 steel in hydrochloric acid medium is evaluated by weight-loss method, electrochemical method, and quantum chemical calculation. The obtained results show that the efficiency of 0.5 wt% HQAS inhibitor in 30 wt.% HCl solution at 363 K is 92.95% and HQAS can form an excellent synergistic effect with some additives. Polarization curves reveal that HQAS behaves as a mixed-type inhibitor with dominant anodic inhibition. Furthermore, the theoretical calculation verifies the relationship between the HQAS molecular structure and corrosion inhibition properties.