片状锌粉改性对水性硅酸钾富锌防腐蚀涂料性能的影响

Surface Modification of Flake Zinc Powders and Their Effect on the Performances of Waterborne Potassium Silicate Zinc-Rich Anti-Corrosion Coating

为了提高片状锌粉在水性涂料应用中的分散性和耐腐蚀性能,以硅烷和硝酸镧共同改性片状锌粉,并以其制备水性硅酸钾富锌防腐蚀涂料。通过X射线能谱仪(EDS)、扫描电镜(SEM)、电化学工作站研究了锌粉改性前后表面成分、耐腐蚀性的变化及其对富锌涂料性能的影响。结果表明:经硅烷与硝酸镧共同改性后,在锌粉表面检测到Si与La元素,沉降30 min后沉降体积仅为0.6 m L/g,在质量分数5.0%的Na Cl溶液浸泡4 d后锌粉仅有小部分腐蚀,改性锌粉所制涂料涂层表干时间缩短20%,在3.5%Na Cl溶液中浸泡14 d后涂层仍处于服役中期,防腐蚀性能提高。

Silane and lanthanum nitrate were used to modify flake zinc powders,and then the modified zinc powders were used to prepare waterborne potassium silicate zinc-rich anti-corrosion coatings. X-ray energy spectro-meter( EDS),scanning electron microscope( SEM) and electrochemical workstation were used to investigate the surface composition and corrosion resistance of zinc powder before and after modification as well as their effects on the performances of zinc-rich coatings,respectively. Results showed that under the modification of the silane and lanthanum nitrate,Si and La elements were detected on the surface of modified zinc powders. After settling for 30 min,the settling volume was only 0. 6 mL/g,and only a small part of zinc powders was corroded in 5. 0% NaC l solution for 4 d. Besides,the surface drying time of coating made by modified zinc particles was reduced by 20%,and the coating was still in the medium serving stage after immersion for 14 d in 3. 5% NaC l solution,which proved that the corrosion resistance was improved.