Corrosion Inhibition Of Copper In TBAB Solution

The corrosion inhibition behavior of different inhibitors on copper in 17wt.% (0.534 mol/L) tetra-n-butylammonium bromide (TBAB) aerated aqueous solution was investigated by weight-loss tests, potentiodynamic polarization,electrochemical impedance spectroscopy and scanning electron microscopy/energy dispersive X-ray spectroscopy.(1) The corrosion inhibition behavior of benzotriazole (BTA) on copper in 17wt% tetra-n-butylammonium bromide (TBAB) aerated aqueous solution was investigated by four methods (weight-loss tests, potentiodynamic polarization,electrochemical impedance spectroscopy and scanning electron microscopy/energy dispersive X-ray spectroscopy).BTA acts as an effective mixed-type inhibitor against copper corrosion in 17 wt% TBAB aqueous solution, which inhibits both anodic and cathodic reactions.The inhibition efficiency is up to 90%。The IE of BTA increases with the increase of inhibitor concentration from 0.1 to 6 g/L. Adsorption of BTA in 17 wt% TBAB solution on the copper surface is found to obey the Langmuir adsorption isotherm.(2) The corrosion inhibition efficiencies of Na 3 PO4 against copper in 17 wt% TBAB aqueous solution were studied. Tafel polarization and impedance measurement show that Na 3 PO4 has inhibition in a certain extent. It is due to the adsorption of deposition on copper in short time. But the adhesion is weak. Weight-loss test and scanning electron microscopy/energy dispersive X-ray show that Na 3 PO4 is not a good inhibitor against copper instead it increases the corrosion. It is due to the reaction of Na 3 PO4 with copper and the deposition layer on copper is destroyed in long time. It speeds up the corrosion. Na3PO4 could not acts as an effective inhibitor against copper corrosion in 17 wt% TBAB aqueous solution separately.(3) The corrosion inhibition of BTA and Na 3 PO4 against copper in 17 wt% TBAB aqueous solution was studied and the best inhibition efficiency was determined by the three methods (weight-loss test, Tafel polarization and impedance measurement).The change of copper surface was observed by SEM/EDS. The results indict that the mixture of BTA and Na 3 PO4 is a good anodic inhibitor against copper corrosion in 17 wt% TBAB aqueous solution and the inhibition efficiency is up to 90%. The inhibition mechanism is attributed to the combination adsorption of BTA and Cu 3 (PO4 )2 on the copper which inhibits the corrosion of Br- and oxygen.(4) The corrosion of copper in 0.534 mol/L NaBr aqueous solution was studied by the three methods (weight-loss test, Tafel polarization and impedance measurement). The results indict that the corrosion of copper in NaBr solution is severe than in TBAB aqueous solution. It is attributed to the inhibition of (C4H9)4N+.(5) The corrosion inhibition of Na 3 PO4 against copper in NaBr aqueous solution was studied and the best inhibition efficiency was determined by the three methods (weight-loss test, Tafel polarization, and impedance measurement). The results indict that Na3PO4 is not a good inhibitor against copper in NaBr solution instead it increases the corrosion. It is attributed to the formation of Cu3 (PO4 )2 in the reaction of Na3PO4 and copper. It speeds up the corrosion of copper.