Abstract: To solve the problem of oxidation and discoloration of copper surface during metal-forming process, the corrosion inhibition behaviors of methyl benzentriazole derivatives(MBD), 2,5-bis(n-octyldithiazole) thiadiazole(EDD) and 2,5-bis(dodecyldithiazole) thiadiazole (BDDT) as corrosion inhibitor in vacuum, oil, water and emulsions were studied by density functional theory (DFT), electrochemistry and surface characterization methods. The results show that the adsorption of MBD on Cu surface is dominated by physical adsorption, while the adsorption of EDD and BDDT on Cu surface is dominated by chemical adsorption. The inhibition efficiency of the three corrosion inhibitors on the copper surface is in the order of MBD(76.39%) <EDD(83.95%) <BDDT(89.01%). BDDT has the best inhibition effect on inhibiting the corrosion of copper immersed in emulsion.

Key words: DFT, emulsion, corrosion inhibitor, copper corrosion