2-己基咪唑作为铜的盐酸酸洗缓蚀剂作用机理的研究

通过失重法研究了2-己基咪唑 (2-HeIM )在5%盐酸中对铜的酸洗缓蚀性能。探讨了温度和 2-HeIM浓度对缓蚀效果的影响，从中得出了 2-HeIM在铜表面的吸附等温式，计算了吸附热及 2-HeIM的加入对铜在盐酸中腐蚀反应活化能的影响，进而探讨了 2-HeIM对铜的缓蚀作用机理。结果表明，30℃下，在 5%盐酸中，当 2-HeIM的浓度在 6mmol/L以下缓蚀率随 2-HeIM浓度的增加而增加 ,当浓度达到 6mmol/L时 ,缓蚀率趋于定值。在 2mmol/L到 6mmol/L浓度范围内吸附在铜表面的 2-HeIM分子间的作用力整体表现为引力；2-HeIM在铜表面的吸附是吸热反应；2-HeIM的加入降低了铜的腐蚀反应活化能。

Corrosion inhibition mechanism of 2-HeIM as inhibitor of copper for hydrochloric acid pickling

The corrosion inhibition property of 2-mercapto-1-methy-imidazole (2-HeIM) for copper in 5% HCl was studied using the weight-loss method. The influences of the temperature and concentration of 2-HeIM on the corrosion inhibition efficiency were determined, from which the adsorption isotherm was obtained. The adsorption heat and the influence of the adding of 2-HeIM on the activation energy of the corrosion reaction were calculated. The corrosion inhibition mechanism of 2-HeIM for copper was put forward. The results indicated that the corrosion inhibition efficiency of 2-HeIM for copper increased with increase in the concentration of 2-HeIM when its concentration was lower than 6mmol/L and became constant approximately when its concentration was higher than 6mmol/L.The acting force between the adsorbed 2-HeIM molecules displayed an attractive one on the whole when its concentration was in the range from 2 mmol/L to 6 mmol/L.The adsorption of 2-HeIM on the surface of copper was a heat-adsorbing reaction,and the adding of 2-HeIM reduced the activation energy of the corrosion reaction of copper.