Study On The Inhibition Of Pyrazole And Its Synergistic Effect

The literatures of copper corrosion inhibitors were reviewed. The inhibitors(pyrazole(Pz),benzotriazole(BTA),2-mercaptbenzothiazole(MBT)) effect on the corrosion behavior of copper in 0.5mol/L H2SO4 solution ,0.05mol/L NaHCO3 and 1.00mol/L K2CO3+0.80mol/L KHCO3 solutions were studied and evaluated by cyclic voltammetry curves measurement ,XPS surface analysis technique and rotating disk electrode , and the synergistic effects among them. The influence of chloride,NaClO on pyrazole also were investigated. It was found that :The anodic dissolution of copper in 0.5mol/L H2SO4 solution contained pyrazole is determined (or controlled) by both the electrochemical step and diffusion step .The pyrazole adsorption on copper in 0.05mol/L NaHCO3 solution obeys the Frumkin adsorption isotherm, the anodic dissolution of copper is determined by the electrochemical.The out layer of the protective film formed by pyrazole on the surface of copper comprised Cu(II),O,N and C. The protective film probably formed by Pz- Cu(II) and the inner CuO film.3,The chlorine ion accelerates the corrosion of copper in 0.05mol/L NaHCO3 solution. But the hypochlorite passives the copper and inhibits the corrosion.4,The BTA and MBT adsorption on copper in 0.05mol/L NaHCO3 solution also obeys the Frumkin adsorption isotherm, the anodic dissolution of copper is determined by both the electrochemical step and diffusion step .5,There was a synergistic effect between pyazole and BTA, their adsorption on copper in 0.05mol/L NaHCO3 solution obeys certain adsorption isotherm. There was a synergistic effect between pyazole and MBT, their adsorption on copper in 0.05mol/L NaHCO3 solution obeys Frumkin adsorption isotherm.The out layer of the protective film formed by pyazole and BTA on surface of copper comprised Cu(II),Cu(I),O,N and C. The protective film probably formed by the compound of Cu-BTA-Pz. The out layer of the protective film formed by pyazole and MBT on surface of copper comprised Cu(I),S,O,N and C. The protective film probably formed by the compound of Cu-MBT-Pz.