锌粉表面改性对水性富锌防腐涂层性能的影响

为了改善片状锌粉在实际应用中抗沉降性、分散性和耐腐蚀性差的缺点,采用溶胶-凝胶法对片状锌粉进行了表面改性,并利用改性锌粉制备了水性富锌防腐涂层.利用X射线衍射仪、物理性能检测设备和扫描电子显微镜分析了锌粉改性效果及其对富锌防腐涂层性能的影响.结果表明:经过硅烷偶联剂BTSPA掺杂硝酸镱改性后,锌粉分散性提高了53.3%;改性涂层的表干时间缩短了20%,实干时间缩短了8.3%,物理性能得到了提升;涂层表面裂痕减少,孔隙率降低为0.14%;经NaCl溶液浸泡120 h后,涂层表面几乎未发生腐蚀;自腐蚀电位正移15.1%,自腐蚀电流密度降低一个数量级,线性极化电阻增大一个数量级.硅烷偶联剂BTSPA掺杂稀土硝酸镱改性锌粉优于其他改性方法.

Effect of surface modified zinc powders on performance of waterborne zinc rich anti corrosion coatings

In order to improve the poor subsidence resistance, dispersion and corrosion resistance of flake zinc powder in practical application, the surface modification of flake zinc powder was performed with a sol-gel method, and the waterborne zinc-rich anti-corrosion coatings were prepared with the modified zinc powder. The modification effect of zinc powder and its influence on the performance of zinc-rich anti-corrosion coatings were investigated with X ray diffractometer(XRD), physical property testing equipment and scanning electron microscope(SEM), respectively. The results show that after the modification by silane coupling agent BTSPA and ytterbium nitrate, the dispersion of zinc powder is improved by 53.3%. The surface drying time and full drying time of modified coating reduce by 20% and 8.3%, respectively. In addition, the physical properties of modified coating are improved. The cracks on the surface of the coating reduce, and the porosity decreases to 0.14%. After immersion in NaCl solution for 120 h, almost no sign of corrosion is found on the surface of coating. The self-corrosion potential is positively moved by 15.1%, the self-corrosion current reduces by an order of magnitude, and the linear polarization resistance increases by an order of magnitude. The method that the zinc powder is modified by silane coupling agent BTSPA and ytterbium nitrate is prior to other modification methods.