engleski

Investigation of Corrosion Inhibitor Performance on Rotating Disc Electrode

The influence of two corrosion inhibitors on the dissolution of copper in hydrochloric acid was studied on the rotating disc electrode by means of electrochemical polarization methods. Both investigated inhibitors are azole compounds: benzotriazole and 1-phenyl-4-methylimidazole. The aim of this study was to determine in which way the temperature and the flow of electrolyte, influence performance of these inhibitors. The copper corrosion rate in inhibited and uninhibited solutions was determined by Tafel extrapolation method and polarization resistance measurements in temperature range 25°C-55°C and electrode rotating speed range 300-2000 rpm. It was established that both inhibitors significantly reduce copper corrosion at low temperatures and low rotating speeds. An increase in temperature and rotating speed significantly reduces the inhibiting efficiency of 1-phenyl-4-methylimidazole while the benzotriazole efficiency is only slightly reduced. The anodic polarization of copper up to the limiting current region has shown that the limiting current density is only slightly reduced in the presence of 1-phenyl-4-methylimidazole. Its efficiency in this region is not greatly influenced by the electrode rotation speed, while the inhibitor efficiency decreases with an increase in temperature. On the contrary, in the presence of benzotriazole, limiting current densities have been about 30 times lower when compared to pure acid solution at all investigated temperatures and rotating speeds. The difference in behaviour of investigated inhibitors may be attributed to the difference in adsorption mechanism.

copper corrosion inhibitors; benzotriazole; imidazole; flow conditions

nije evidentirano