针对低表面处理基材上环氧涂层附着力低且耐蚀性差的问题,利用双-(3-三乙氧基硅丙基)硅烷配制了6种不同浓度的硅烷偶联剂溶液,分别对St2级打磨钢板表面进行预处理并配套环氧涂料,通过FT-IR、XPS对反应过程进行分析,同时对涂层体系界面附着力和电化学性能进行测试。试验结果表明:双-(3-三乙氧基硅丙基)硅烷水解生成的硅羟基与钢板表面活性羟基反应形成Si—O—Fe键是涂层附着力和耐蚀性提升的关键;7.5%的硅烷浓度可实现最佳的预处理效果,涂层附着力较未处理涂层提升1.5倍,达到18.2 MPa;同时海水浸泡1000 h的涂层体系具有更正的开路电位及10^(11)Ω·cm^(2)的电化学阻抗值,表现为单一的容抗弧特征,具备优异的腐蚀介质屏蔽效果。

In order to solve the problem of low adhesion and poor corrosion resistance of epoxy coating on the surface of low surface treated substrate,a bis(3-(triethoxysilyl)propyl)amine coupling agent solution with 6 different concentrations was used to pretreat the surface of St2 polished steel plate and equipped with epoxy coating.The reaction process was analyzed by FT-IR and XPS,while the interfacial adhesion and electrochemical properties of the coating system were tested.The experimental results revealed that the formation of Si—O—Fe bonds,which occur through the reaction between silanol groups generated by the hydrolysis of bis-(3-triethoxysilylpropyl)silane and the active hydroxyl groups on the steel plate surface,is crucial for enhancing coating adhesion and corrosion resistance.Notably,a silane concentration of 7.5%achieved optimal pretreatment outcomes,with the coating adhesion improving 1.5 times to 18.2 MPa compared to the untreated coating.Additionally,the coating system immersed in seawater for 1000 hours exhibited a more positive open-circuit potential and an electrochemical impedance value of 10^(11)Ω·cm^(2),demonstrating a single capacitive arc feature and superior corrosion medium barrier properties.