核桃青皮及其复配物在二氯乙酸溶液中对钢的缓蚀协同效应  

Synergistic Inhibition Effect of Juglans regia Green Husk and Its Composite on Steel in Dichloroacetic Acid Solution

作　　者：王丽姿 黄苗 李向红 Wang Lizi;Huang Miao;Li Xianghong(College of Chemical Engineering/Key Laboratory ofNational Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China,Southwest Forestry University,Kunming Yunnan 650233,China)

机构地区：[1]西南林业大学化学工程学院,西南地区林业生物质资源高效利用国家林业和草原局重点实验室,云南昆明650233

出　　处：《西南林业大学学报（自然科学）》2021年第1期100-109,共10页Journal of Southwest Forestry University：Natural Sciences

基　　金：国家自然科学基金(51761036)资助;云南省农业基础研究联合专项重点项目[2017FG001(-004)]资助;云南省中青年学术和技术带头人培养项目(2015HB049)资助;云南省万人计划“青年拔尖人才”专项(51900109)资助。

摘　　要：以核桃青皮为原料提取制备出核桃青皮缓蚀剂,通过失重法、动电位极化曲线、电化学阻抗谱和扫描电子显微镜研究了核桃青皮缓蚀剂和聚乙二醇辛基苯基醚对冷轧钢在二氯乙酸的缓蚀协同效应,分析了缓蚀剂复配浓度、温度、浸泡时间、二氯乙酸浓度对核桃青皮缓蚀剂缓蚀协同性能的影响情况。结果表明:核桃青皮缓蚀剂具有中等程度缓蚀效果,200 mg/L核桃青皮缓蚀剂的缓蚀率为65%;而聚乙二醇辛基苯基醚的缓蚀效果较差,最大缓蚀率仅为40%;将核桃青皮缓蚀剂和聚乙二醇辛基苯基醚混合复配后在酸溶液有较好的缓蚀性能,最大缓蚀率超过93%,产生了明显的缓蚀协同效应。缓蚀协同效应系数随核桃青皮缓蚀剂浓度、浸泡时间、酸浓度的增加而总体增大,但随温度升高而总体下降,核桃青皮缓蚀剂、聚乙二醇辛基苯基醚及核桃青皮缓蚀剂/聚乙二醇辛基苯基醚均在钢/二氯乙酸界面上服从Langmuir吸附等温式;核桃青皮缓蚀剂/聚乙二醇辛基苯基醚复配后吸附平衡常数增大,标准吸附Gibbs自由能为-28.2 kJ/mol。聚乙二醇辛基苯基醚对钢在二氯乙酸的缓蚀主要是抑制了钢的阴极反应,但核桃青皮缓蚀剂、核桃青皮缓蚀剂/聚乙二醇辛基苯基醚则同时抑制了阴极和阳极反应,两者皆为混合抑制型缓蚀剂,且复配后抑制程度进一步增强。Nyquist图谱主要呈弥散容抗弧特征,核桃青皮缓蚀剂与聚乙二醇辛基苯基醚复配后电荷转移电阻显著增大。扫描电子显微镜证实了核桃青皮缓蚀剂/聚乙二醇辛基苯基醚复配缓蚀剂明显减缓了二氯乙酸对钢表面的腐蚀。Juglans regia green husk inhibitor was prepared from forestry and agricultural residue of walnut green husk by using the extraction solvent of ethanol water solution. The synergistic inhibition effect of walnut green husk inhibitor and nonionic surfactant of polyethylene glycol mono-(p) octyl phenyl ether(OP) on the corrosion of cold rolled steel(CRS) in dichloroacetic acid(Cl2 HCCOOH) solution was studied by weight loss and potentiodynamic polarization curves, electrochemical impedance spectra and scanning electron microscope methods. Effects of composite inhibitors concentrations, temperature, immersion time and dichloroacetic acid concentration on synergistic inhibition performance were discussed in detail. The results show that J. regia green husk inhibitor exhibits moderate inhibition with the maximum inhibition efficiency(ηw) of 200 mg/L is 65%, and OP acts as a poor inhibitor with the maximum inhibition efficiency(ηw) of only 40%. However, incorporation of J. regia green husk inhibitor with OP can obtain better inhibitive performance, and the maximum inhibition efficiency(ηw)is higher than 93%. There is a strong synergistic inhibition effect for J. regia green husk inhibitor and OP. The synergistic performance increases with the increase of J. regia green husk inhibitor concentration, immersion time and acid concentration in general, while decreases with an increase of temperature in general. The adsorption of J.regia green husk inhibitor, OP or J. regia green husk inhibitor/OP on steel/Cl2 HCCOOH interface follows Langmuir adsorption isotherm, and the adsorption equilibrium constant increases for the composite inhibitors. The standard adsorption Gibbs free energy value for J. regia green husk inhibitor/OP is-28.2 kJ/mol. Either J. regia green husk inhibitor or OP is a cathodic inhibitor, while the mixture of walnut green husk inhibitor/OP acts as a mixed-type inhibitor that more efficiently retards both cathodic and anodic reactions. Nyquist spectrum exhibits a depressed capacitive loop, and the presen

关 键 词：核桃青皮 缓蚀剂 协同效应 钢 二氯乙酸 

分 类 号：TG172[金属学及工艺—金属表面处理]