Corrosion inhibition and adsorption studies of some barbiturates on mild steel/acid interface

Abstract

Four new corrosion inhibitors namely 5-(3-phenylallylidene) pyrimidine-2,4,6-trione (PPT), 5-(2-hydroxybenzylidene) pyrimidine-2,4,6-trione (HPT), 5-benzlidenepyrimidine-2,4,6-trione (BPT) and 5-(4-nitrobenzylidene) pyrimidine-2,4,6-trione (NPT) were synthesized and their inhibiting effect on corrosion of mild steel in 1M HCl was investigated using electrochemical impedance spectroscopy (EIS), Tafel polarization and weight loss measurements. The adsorption of the inhibitors obeyed Langmuir isotherm. Both thermodynamic and activation parameters were calculated and discussed. Polarization curves indicate that the inhibitors are of mixed type. © 2012 by ESG.