Study Of Electrochemical Behavior In The Water-based Epoxy Coating With Nano-size Cerium Oxide

Because of the particular nanometer effects of nanometer-materials, adding the nanometer-materials into environment-friendly water-based coatings can obtain excellent performances. Therefore, how to disperse the nanometer materials well , exert its nanometer domino effect ,suspend stability in water-based coatings are very important.First, the reunion issues of nano- CeO2 in the water-based medium has been solved, The dispersion and modification of nano-CeO2 ceria in waterborne epoxy coating has been approached and the best technology has been finalized in this article. Then the optimal dosage of all the dispersers which are sodium hexametahposphate, fatty alcohol polyoxyethylene and Sodium dodecyl has been determined through the settlement experiment..Secondly the best proportion of water-based epoxy latex and firming agent is conformed Nano-materials have joined the three components of water-based epoxy coating the new-prepared nanocomposite coatings have been tested by acid alkali and salt immersion experiment,low-temperatured and constant moist heated experiment and electrochemical experiments.Finally water-based coatings are made with nano-CeO2and the best proportion of water-based epoxy latex and firming agent. Various water-based nano-CeO2 epoxy paint modified with different dispersers are prepared through appropriate decentralization process when nano-CeO2 and one of the dispersers have been added to water-based epoxy paint and broken up.The experimental results present that in comprarison with the common water-based nano-CeO2 epoxy paint only with nano-CeO2, the nanocomposite coatings modified with disperser shows better corrosion resistance, however, the nanocomposite coating modified with sodium hexametahposphate shows the best corrosion resistance. The effective way to modify the water-based nano-CeO2 epoxy coating is adding proper quantity of sodium hexametahposphate with using of high-shear decentralized process. The EIS shows that the impedance is strong at the beginning of immersion, then appear double-capacitive reactance in the metaphase, and again became finished at last, which illustrates with the electrolyte solution immersing coatings, the formation of corrosion product films generating at the interface and then is destroyed and the coating is failure. The testing and research results show that the addition of nano-materials can make water-based epoxy coating greatly increasing in the corrosion resistance.