硅烷改性纳米TiO2-Zn-Al/水性环氧涂层的防腐性能

为实现纳米TiO₂颗粒的均匀分散，首先对纳米TiO₂进行硅烷改性，再通过溶液共混法制备出不同纳米TiO₂添加量的硅烷改性纳米TiO₂-Zn-Al/水性环氧复合涂层。研究了纳米TiO₂与Zn-Al片层粉在涂层中的综合作用。利用XRD和FTIR分析涂层的物相组成和组织结构，SEM和EDS表征涂层表面的微观形貌和元素组成，采用极化曲线和电化学阻抗谱（EIS）研究涂层的耐腐蚀性能。EDS和FTIR表明，经改性的纳米TiO₂均匀分散于涂层中，纳米TiO₂与环氧树脂的枝联作用使涂层更加致密。EIS结果显示，由于Zn-Al片层粉与纳米TiO₂的枝联和填充作用，使添加纳米TiO₂的硅烷改性纳米TiO₂-Zn-Al/水性环氧涂层腐蚀行为较未添加纳米TiO₂时有所减缓。当纳米TiO₂添加量增加到4wt%时，硅烷改性纳米TiO₂-Zn-Al/水性环氧涂层的腐蚀电流密度为9.86×10^-6 A/cm²，比未添加纳米TiO₂的涂层高一个量级。

Anticorrosion performance of silane modified nano TiO2-Zn-Al/waterborne epoxy coatings

In order to achieve homo-disperse of nano TiO₂, nano TiO₂ was treated by the silane coupling agent and the Zn-Al/waterborne epoxy composited coatings containing silane modified nano TiO₂ were prepared by incorporating different mass fraction of TiO₂ nanoparticles in the epoxy resin and Zn-Al powders via solution blended process. The combination action of the nano TiO₂ and Zn-Al flake powder in the coating was explored. The XRD and FTIR were used to analyze the phase composition and structure of the coating. The micro morphology and elementary composition of the coating surface were representated by the SEM and EDS. The corrosion resistance of coatings was investigated by polarization curves and electrochemical impedance spectroscopy(EIS) tests. EDS and FTIR results suggest that the modified nano TiO₂ is symmetrical dispersion in the coating, the crosslinking reaction of nano TiO₂ and epoxy resin makes the coating more pyknoticly. The EIS tests show that due to the filling effects of Zn-Al flake powder and nano TiO₂, the corrosion behavior of the silane modified nano TiO₂-Zn-Al/waterborne epoxy coatings is more slower than that of nano TiO₂, when the content of nano TiO₂ increases to 4wt%, the corrosion current density of the silane modified nano TiO₂-Zn-Al/waterborne epoxy coatings is 9.86×10^-6 A/cm², the corrosion current density is higher one rank than none nano TiO₂.