西洋菜提取液在酸性介质中的缓蚀性能  

Corrosion Inhibition Performance of Watercress Extract in Acid Medium

作　　者：刘燕[1] 许宁斌 梁诗铭 唐春保[1] LIU Yan;XU Ning-bin;LIANG Shi-ming;TANG Chun-bao(School of Chemistry and Environment, Jiaying University, Meizhou 514015 , China)

机构地区：[1]嘉应学院化学与环境学院

出　　处：《材料保护》2019年第4期33-37,共5页Materials Protection

基　　金：嘉应学院大学生创新创业训练计划项目(201710582052);嘉应学院省级重点建设学科“化学工程与技术”经费资助

摘　　要：植物缓蚀剂因具有来源广、成本低和可生物降解等优点而受到广泛关注。为促进绿色植物型缓蚀剂的研究应用,以西洋菜为原料,采用酸液浸泡提取制得了天然缓蚀剂。利用失重法、极化曲线、电化学阻抗谱研究了其在3%盐酸溶液中对铁片的缓蚀性能,并对缓蚀分子的吸附和腐蚀动力学过程进行探讨;对西洋菜粉末进行红外光谱分析,推断其可能的缓蚀机理。结果表明:西洋菜提取液对酸性介质中铁片的腐蚀反应有明显抑制作用,缓蚀剂的最佳工艺条件为浸泡时间96h,温度20-30℃,浓度1250mg/L;西洋菜提取液属于混合型缓蚀剂,缓蚀效率随浓度增加而增加,随温度的上升而减小,其缓蚀分子的吸附符合Langmuir等温方程式;西洋菜里含有不饱和有机化合物的极性基团(竣基、龛基、疑基等),可作为酸性缓蚀剂。Owing to wide resource, low cost and biodegradable property, the plant corrosion inhibitors have attracted extensive attentions. In order to assist the application of green plant corrosion inhibitors, the plant corrosion inhibitor was extracted by using acid soaking watercress as raw material, and the performances of the corrosion inhibitor on steel in 3% HC1 solution were investigated by weight-loss method, polarization curves and electrochemical impedance spectrum, respectively. The adsorption of corrosion inhibitor and the corrosion kinetics processes were discussed. Moreover, the inhibitor functional groups were determined by infrared spectrum, and the mechanical corrosion of steel was discussed. Results showed that the extract from watercress possessed an effective inhibiting effect on the corrosion reaction of steel in acid medium, and the optimal conditions of corrosion inhibitor were 96 hours of soaking time, 20-30℃ of temperature and extract content of 1250mg/L. The watercress extract belonged to mixed-type inhibitor, and the inhibition performance was enhanced with the increase of concentration, but weakened with the rise of experiment temperature. Besides, the adsorption of watercress extract molecules followed Langmuir adsorption isotherm. The polar groups (carboxyl, hydroxyl, carbonyl, etc.) of unsaturated organic compounds in watercress could be employed as acidic corrosion inhibitor.

关 键 词：植物缓蚀剂 西洋菜 缓蚀性能 酸性介质 

分 类 号：TG174.42[金属学及工艺—金属表面处理]