TX-100与MBI复配体系对Q235钢的缓蚀性能

Corrosion Inhibition Performance of TX-100 and MBI Mixed System for Q235 Steel

目的通过分析曲拉通(TX-100)与2-巯基苯并咪唑(MBI)复配体系在酸性介质中对Q235钢的缓蚀情况,获得缓蚀效果最佳条件,如两者的配比、浓度等,分析其缓蚀效果和机理。方法采用静态失重法对缓蚀剂的缓蚀性能进行了初步判定,用极化曲线法和交流阻抗法进一步研究缓蚀机理和效率,通过SEM和XPS对不同情况下的碳钢进行表面形貌观察和表面成分分析,采用综合分析法研究混合缓蚀剂对碳钢表面的缓蚀机理。结果保持混合缓蚀剂总浓度2×10^(-4) mol/L,TX-100和MBI以不同摩尔比混合时,随着TX-100摩尔分数α(TX-100)的增加,缓蚀效率增大。当α(TX-100)=50%时,缓蚀效果达到90%,继续增大α(TX-100),缓蚀效率减小。当TX-100和MBI等摩尔混合时,随着总浓度的增大,缓蚀效率增大。当达到2×10^(-4) mol/L时,再增大缓蚀剂的总浓度,缓蚀效率没有明显增大,且达到90%以上。分析表明,两种缓蚀剂TX-100和MBI之间存在分子间相互作用,使其在Q235钢表面形成致密牢固的保护层,且混合物属于控制阴极反应为主的混合型抑制剂。结论经过优选TX-100和MBI混合缓蚀剂的配比和浓度,降低了MBI的用量和缓蚀剂的应用成本,同时为金属防腐奠定了理论基础。

The work aims to obtain the optimum conditions for inhibition efficiency,like proportion,concentration,etc.through the corrosion inhibition analysisof Q235 steel by TritonX-100(TX-100)and 2-mercaptobenzimidazole(MBI)mixed system in acid solution and analyze the corrosion inhibition efficiency and mechanism.The performance of corrosion inhibitor was preliminarily determined by weight loss method.The corrosion inhibition efficiency and mechanism were investigated furtherby polarization measurements and electrochemical impedance spectroscopy.The morphology and the chemical composition of metal surface in different conditions were observed by SEM and XPS.Corrosion inhibition mechanism of mixed corrosion inhibitor on carbon steel surface was studied by comprehensive analysis method.When the total concentration of the mixed corrosion inhibitor was kept at 2×10^-4 mol/L and TX-100 and MBI were mixed by different molar ratios,the inhibition efficiency(η)increased with the increasing ofα(TX-100).The value ofηreached the largest 90%atα(TX-100)=50%and then decreased with the increasing ofα(TX-100).When TX-100 and MBI were mixed with equal molar,ηincreased with the increasing of inhibitor concentration.The value ofηdid not increase distinctly with the increasing of inhibitor concentration that had reached 2×10^-4 mol/L sinceηreached 90%.Molecular interaction existing between TX-100 and MBI led to the tight protective layer at the surface of Q235 steel.TX-100 and MBI were mixed inhibitors that controled the cathodic reaction mainly.Through optimized selection of the proportion and concentration of TX-100 and MBI,the dosage and cost of MBI are reduced and theoretical foundation is established for metal corrosion.