Use of a theoretical prediction method and quantum chemical calculations for the design, synthesis and experimental evaluation of three green corrosion inhibitors for mild steel

Abstract

Three phenylmethanimine derivatives (Schiff bases) were designed after a theoretical prediction of their corrosion inhibition efficiencies and a corroboration through the use of quantum chemical calculations. The molecules were then prepared using a classical condensation reaction between aldehydes and amines but taking in account the tenets of green chemistry. Their application as corrosion inhibitors for ASTM A36 steel in 1 mol L−1 hydrochloric acid media was explored by means of a weight loss analysis, electrochemical tests and a surface morphology analysis to physically evaluate the metallic sacrifice surfaces used. The results of the electrochemical tests revealed that the three compounds have a good anti-corrosion capacity and act as mixed-type corrosion inhibitors. In addition, cross-checking the data from weight loss analysis and electrochemical tests confirm Langmuir monolayer formation theory. The corrosion inhibition efficiencies found range between 83.5 and 95.6%.