木薯淀粉-丙烯酰胺接枝共聚物对冷轧钢在NH_(4)Cl溶液中的缓蚀作用  

Corrosion inhibition effect of cassava starch-acrylamide graft copolymer on cold-rolled steel in NH_(4)Cl solution

作　　者：雷然 余丽蓉 张富 李向红 LEI Ran;YU Li-rong;ZHANG Fu;LI Xiang-hong(College of Chemical Engineering,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学化学工程学院,云南昆明650224

出　　处：《应用化工》2021年第7期1771-1775,1779,共6页Applied Chemical Industry

基　　金：国家自然科学基金项目(51561027);云南省大学生创新创业训练计划项目(201910677035);云南省万人计划“青年拔尖人才”专项(51900109)。

摘　　要：对木薯淀粉高分子聚合物进行接枝共聚改性得到木薯淀粉-丙烯酰胺接枝共聚物(CS-AAGC),采用失重法、电化学法和扫描电子显微镜(SEM)形貌分析研究了CS-AAGC作为缓蚀剂对冷轧钢在0.5 mol/L NH 4Cl溶液中的腐蚀抑制效果,并对缓蚀性能影响规律和缓蚀作用机理进行探究。结果表明,CS-AAGC作为缓蚀剂对冷轧钢在0.5 mol/L NH_(4)Cl溶液中的腐蚀抑制效果明显,随着CS-AAGC的浓度增大,η_(w)增大,当浓度为500 mg/L时,缓蚀率达到了90.2%,由极化曲线也得出了同样的结论;CS-AAGC在冷轧钢表面的吸附服从Langmuir吸附等温式,通过静电作用和共价键等物理和化学方式在冷轧钢表面形成吸附膜层;极化曲线表明CS-AAGC为混合抑制型缓蚀剂,能够有效控制阴极析氢腐蚀和阳极溶解过程;阻抗谱为单一压缩容抗弧,添加CS-AAGC后,电荷转移电阻增大,腐蚀反应速率降低,SEM微观形貌进一步证实了CS-AAGC能够显著减缓冷轧钢在0.5 mol/L NH_(4)Cl介质中的腐蚀。The copolymer(CS-AAGC)of cassava starch was prepared by grafting copolymerization of cassava starch.The effect of CS-AAGC as a corrosion inhibitor on CRS was studied by weight loss method,electrochemical method and scanning electron microscope(SEM).It is aimed to reveal how corrosion inhibitors inhibit metal from being corroded,and explore the mechanism of corrosion inhibition.The results show that CS-AAGC has a significant inhibitory effect on CRS in 0.5 mol/L NH_(4)Cl solution.As the concentration of CS-AAGC increases,η_(w) also increases,and reached 90.2% with the addition of 500 mg/L CS-AAGC,and the same conclusion can be drawn from the polarization curves.The adsorption of CS-AAGC on the surface of CRS obeys Langmuir adsorption isotherm.The adsorption film layer formed by the combined forces of physical electrostatic adsorption and chemical covalent bond adsorption.Polarization curves show that the CS-AAGC acts as a mixed inhibitor that suppresses both cathodic and anodic reactions simultaneously.Nyquist gram appears single diffuse capacitive resistance arc characteristic,and the charge transfer resistance increasing with the adding of CS-AAGC concentration.SEM morphology further confirmed that CS-AAGC can significantly slow down the corrosion of cold rolled steel in 0.5 mol/L NH_(4)Cl medium.

关 键 词：木薯淀粉接枝共聚物 冷轧钢 氯化铵 缓蚀 吸附 

分 类 号：TQ047.6[化学工程] TQ133.3