Corrosion inhibition efficiency of nonionic Schiff base amphiphiles of p-aminobenzoic acid for aluminum in 4N HCL

A novel series of self-assembled nonionic Schiff base amphiphiles was synthesized and their chemical structures were confirmed using elemental analysis, FTIR spectroscopy and 1H NMR spectra. The surface activities of these amphiphiles were determined based on the data of surface and interfacial tension, critical micelle concentration, effectiveness, efficiency, maximum surface excess and minimum surface area. Thermodynamics of adsorption and micellization processes of these amphiphiles in their solutions were also calculated. The surface and thermodynamic data showed their higher tendency towards adsorption at the interfaces. The synthesized amphiphiles were evaluated as corrosion inhibitors for aluminum (3SR) at different doses (400–10 ppm) in acidic medium (4N HCl) using weight loss and hydrogen evolution techniques. The corrosion measurements showed that the synthesized nonionic Schiff bases could serve as effective corrosion inhibitors. The surface and corrosion inhibition activities were correlated to the chemical structures of the inhibitors.