Study On The Thiourea And Benzotriazole Mannich Alkali Corrosion Inhibition For Copper In Alkali Medium

In this thesis, the copper corrosion inhibitors in alkaline medium were researched and developed. For the purpose of preventing underground oil pipeline corrosion in the northwest.Five mannich bases had been synthesized, including thiourea mannich mannich (OPPT and OBT), bis-benzotriazole mannich (BBTAP and BBTAM), imidazole-benzotriazole(IMBTA). Their structures were characterized by IR spectrum. The inhibition actions of five mannich bases, BTA and IM on copper in aqueous NaHCO3 ( mass fraction 5%) solution were investigated by means of mass loss and electrochemical techniques including polarization curve and electrochemical impedance spectroscopy (EIS). The corrosion kinetics , thermodynamic functions and the effect of temperature on inhibition efficiency were also calculated by datas of weight loss. Their adsorption actions on the surface of copper and inhibition mechanism were discussed simple. The results showed that the five Mannich bases for copper were good inhibition corrosion.It was a kind of highly efficient inhibitor in alkaline medium. BTA molety and IM molety had good synerglstic effect. Both OBT and OPPT were mix-type inhibitors and mainly inhibits the cathode dissolution reaction. BBTAP, BBTAM, IMBTA, BTA and IM are mix-type inhibitors and mainly inhibits the dissolution anodic reaction. In the studied temperature range, the adsorption processes were exothermic reaction and belonged to physical and chemical mix absorption, the adsorption behaviors followed Langmuir isotherm.