五羟乙基二乙烯三胺在0.5 mol/L H_(2)SO_(4)溶液中对2024铝的缓蚀性能

Corrosion Inhibition Effect of N,N,N,N,N′-Pentakis(2-Hydroxyethyl)-1,4,7-Triazaheptane on 2024 Aluminum in 0.5 mol/L H 2 SO_(4) Solution

为抑制2024铝在硫酸酸洗液中的腐蚀,以二乙烯三胺与2-溴乙醇为主要原料合成了五羟乙基二乙烯三胺(PHT),采用静态失重法、极化曲线法和电化学阻抗谱研究了PHT在0.5 mol/L H_(2)SO_(4)溶液中对2024铝的缓蚀性能,通过扫描电子显微镜进行了腐蚀形貌分析,并通过腐蚀反应动力学和吸附模型探讨了其缓蚀机理。结果表明:25℃下PHT的缓蚀效率随其浓度的增加而增大,当PHT的浓度为700 mg/L时,其缓蚀效率可达90.85%以上,具有显著的缓蚀性能。PHT的添加显著增大了腐蚀反应的表观活化能,有效抑制了腐蚀反应的进行,是一种以抑制阳极过程为主的混合型缓蚀剂。25℃下PHT在2024铝表面的吸附是物理吸附和化学吸附的混合吸附,且吸附遵循Langmuir吸附等温模型。

For restraining the corrosion of 2024 aluminum in the pickling solution of H_(2)SO_(4),the compound of N,N,N,N,N′-Pentakis(2-hydroxyethyl)-1,4,7-triazaheptane(PHT)was synthesized by using diethylenetriamine and 2-bromoethanol as the main raw materials.The corrosion inhibition performance of PHT for 2024 aluminum in 0.5 mol/L H_(2)SO_(4)solution was tested by static mass loss method,polarization curve,electrochemical impedance spectroscopy(EIS).The corrosion morphology was analyzed by scanning electron microscope.The corrosion inhibition mechanism of PHT on 2024 aluminum was also discussed by the investigation of corrosion reaction dynamics and adsorption model.Results showed that the inhibition efficiency of PHT increased with the increasing of PHT concentration at 25℃,and the inhibition efficiency could exceed 90.85%when the concentration of PHT was up to 700 mg/L,presenting a remarkable inhibition effect.Besides,the apparent activation energy of the corrosion reaction was significantly increased by the addition of PHT,which indicated that the process of corrosion reaction was effectively inhibited,and it was a mix-type inhibitor that had great restraint action on anodic process.The adsorption of PHT on surface of 2024 aluminum was the mixed adsorption involved physical adsorption and chemical adsorption at 25℃,and the adsorption conformed to the Langmuir isothermal adsorption model.