基于癸二酸二异辛酯的环保型复合缓蚀剂对钢筋的缓蚀效应

应用缓蚀剂控制混凝土中钢筋的腐蚀具有高效、廉价和易操作等优点，越来越受腐蚀研究者的关注。近年来，对环保型缓蚀剂的需求日益增加。因此，本工作发展了由癸二酸二异辛酯、D-葡萄糖酸钠和硫酸锌组成的环保型复合缓蚀剂并应用电化学测试技术和表面分析方法研究其对钢筋的缓蚀作用。结果表明，Q235钢筋在pH为11.00，含0.5 mol∙L^-1 NaCl的模拟污染的混凝土孔隙液中处于活化状态并发生局部腐蚀。含有59 mmol∙L^-1癸二酸二异辛酯，0.5 mmol∙L^-1 D-葡萄糖酸钠和1.5 mmol∙L^-1硫酸锌组成的复合缓蚀剂对钢筋具有良好的协同缓蚀效应，在模拟污染混凝土孔隙液中和水泥砂浆试样中对钢筋的缓蚀效率分别达到96.8%和90.0%。该复合缓蚀剂是一种混合型缓蚀剂，对钢筋腐蚀的阴极反应和阳极反应均有抑制作用。

Effect of an Environmentally Friendly Diisooctyl Sebacate-based Mixed Corrosion Inhibitor on Reinforcing Steel

Corrosion protection of reinforcing steel in concrete is an urgent task in modern society. Use of corrosion inhibitors in concrete is an effective, simple, and economical method for protecting reinforcing steel from corrosion. Mixed corrosion inhibitors usually perform better than a single inhibitor in actual reinforced concrete systems because of their synergistic inhibition effects. In recent years, environmentally friendly corrosion inhibitors have attracted increasing attention from corrosion researchers. Diisooctyl sebacate and sodium D-gluconate are environmentally friendly organic corrosion inhibitors, and ZnSO₄ is an inorganic cathodic inhibitor, they may form an innovative, nontoxic, and pollution-free mixed corrosion inhibitor to control reinforcing steel corrosion. Additionally, diisooctyl sebacate and sodium D-gluconate serve as absorption-type inhibitors, and ZnSO₄ acts as a precipitation-type inhibitor. We hypothesized that their combination might show a good synergistic corrosion inhibition effect on reinforcing steel. In this study, we developed a diisooctyl sebacate-based mixed corrosion inhibitor that includes D-gluconate and ZnSO₄ and investigated its synergistic inhibition effects on reinforcing steel (Q235 steel) corrosion in a simulated polluted concrete pore solution. The reinforcing steel corrosion behavior and the properties of the mixed corrosion inhibitor were studied by polarization curve measurements, electrochemical impedance spectroscopy tests, and surface analysis methods (scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy). The results indicated that the reinforcing steel in the simulated polluted concrete pore solution (pH 11.00, 0.5 mol·L^-1 NaCl) was in an active dissolving state and that localized corrosion took place. The mixed corrosion inhibitor, consisting of diisooctyl sebacate (59 mmol·L^-1), sodium D-gluconate (0.5 mmol·L^-1), and ZnSO₄ (1.5 mmol·L^-1), had an obvious and powerful inhibition effect. Its inhibition efficiency reached 96.8% and 90.0% in the simulated polluted concrete pore solution and the cement mortar, respectively. The mixture of diisooctyl sebacate with sodium D-gluconate and ZnSO₄ acted as a mixed-type inhibitor and effectively controlled both anodic and cathodic reactions of the steel corrosion.