Efficienza inibitrice di basi di schiff come inibitori di corrosione del bronzo

Abstract

As part of an M-ERA.NET project called B-IMPACT some polidentate Schiff bases were synthesized and tested as corrosion inhibitors of bronze. The tests consisted of exposures of bronze specimens to a concentrated artificial acid rain solution, containing or not containing the studied substances added under saturation conditions (< 10(3) M). Their inhibiting effect was evaluated during 20 day immersions by means of non-destructive electrochemical tests (Electrochemical Impedance Spectroscopy) and by finally recording the polarization curves. Observations by a scanning electron microscope coupled with Energy Dispersive X-ray Spectroscopy allowed comparing the morphology of corrosion attack in the absence and presence of inhibitors. The best inhibiting properties were achieved in the presence of 2-(salicylideneimino)thiophenol (SITP). The addition of phosphate ions to SITP induced the formation of a surface film particularly resistant against localized corrosion phenomena. Raman and XPS spectroscopy were applied in order to investigate the inhibition mechanism of sire without and with the presence of phosphate ions.