摘要
目的解决Q235钢的腐蚀问题,研究开发一种智能防腐涂层。方法以乙烯基三乙氧基硅烷、丙烯酸和丙烯酸羟丙酯为单体,采用自由基聚合法制备一种装载缓蚀剂苯并三氮唑(BTA)的pH敏感性有机-无机杂化凝胶BTA@PHVA/PEI,通过扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)、热重/差热分析(TGA/DSC)和紫外可见光谱(UV-vis)分别对BTA@PHVA/PEI的形态、结构、热稳定性及pH敏感性进行表征。通过将BTA@PHVA/PEI粉末分散到醇酸树脂漆中,在Q235钢样品表面制备一种智能防腐涂层。先后通过电化学阻抗谱(EIS)、Tafel极化曲线对智能涂层在NaCl腐蚀介质中的自修复性能进行研究,通过盐雾加速腐蚀试验对智能涂层的防腐性能进行评价,并探讨智能涂层的自修复机理。结果BTA@PHVA/PEI释放BTA的速率随环境pH值的升高而增大,在pH值为2.0、7.0和11.0的溶液中,BTA的32 h累积释放率分别为68.78%、74.51%和91.02%。BTA@PHVA/PEI在智能涂层中的最佳掺杂量为10%。结论基于BTA@PHVA/PEI的智能防腐涂层对Q235钢具有显著的自修复防腐性能,且在其他金属材料上也具有潜在应用价值。其机理为涂层中掺杂的BTA@PHVA/PEI可响应因腐蚀而导致的pH值变化,释放出BTA分子并被吸附到Q235钢表面成膜,从而抑制腐蚀的进一步发展。
The work aims to study a smart anti-corrosion coating to solve the corrosion problem of Q235 steel.Firstly,the pH-sensitive organic-inorganic hybrid hydrogel of BTA@PHVA/PEI preloaded with the inhibitor benzotriazole was prepared through free radical polymerization method with triethoxyvinylsilane,acrylic acid and hydroxypropyl acrylate as the monomers.The morphology,structure,thermostability and pH-sensitivity of BTA@PHVA/PEI were characterized by scanning electron microscopy,Fourier transform infrared spectroscopy,thermogravimetric/differential scanning calorimetry analysis and ultraviolet-visible spectroscopy,respectively.Afterwards,a smart anti-corrosion coating was fabricated on Q235 steel by the dispersion of BTA@PHVA/PEI into alkyd resin.The self-healing performance of the smart coating in the corrosion medium of NaCl was investigated via electrochemical impedance spectroscopy and Tafel polarization curve in sequence.The anti-corrosion performance of the smart coating was evaluated by the salt spray tests.Meanwhile,the self-healing mechanism of the smart coating was also discussed.The releasing rate of BTA from BTA@PHVA/PEI rose with the increase of the external environment pH values.The cumulative releasing rate of benzotriazole for 32 h immersion in the solution with the pH values of 2.0,7.0 and 11.0 was 68.78 wt%,74.51 wt%and 91.02 wt%,respectively.The optimal content of BTA@PHVA/PEI doped into the smart coating was 10 wt%.The self-healing and anti-corrosion performance of the smart coating based on BTA@PHVA/PEI for Q235 steel are remarkable,which can be also used for corrosion protection of other metallic materials.The self-healing mechanism of the smart coating is that BTA@PHVA/PEI doped into the coating can release benzotriazole molecules response to the corrosion-induced changes of pH values.The released benzotriazole molecules can form an adsorptive film on the steel for preventing the corrosion development.
作者
文家新
刘云霞
张欣
周永福
刘克建
WEN Jia-xin;LIU Yun-xia;ZHANG Xin;ZHOU Yong-fu;LIU Ke-jian(Chongqing Industry Polytechnic College,Chongqing 401120,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2020年第11期277-287,共11页
Surface Technology
基金
重庆市自然科学基金面上项目(cstc2020jcyj-msxmX3461)。
关键词
PH敏感性
杂化凝胶
智能涂层
腐蚀防护
Q235钢
电化学阻抗谱
pH-sensitivity
hybrid hydrogel
smart coating
corrosion protection
Q235 steel
electrochemical impedance spectroscopy
