Electrochemical Corrosion Behavior of Three PU-based Low Infrared Emissivity Coatings Modified by EP

Electrochemical impedance spectroscopy(EIS) technique was used to investigate the electrochemical corrosion behavior of three low infrared emissivity coatings with polyurethane(PU) modified by epoxy(EP) as adhesive agent,Cu powders,Cu powders modified by silane couple agent,and Cu powders modified by acrylic acid as fillers in simulated sea water(3.5% NaCl).And the corrosion resistance of the three coating systems was compared.The results showed that at the initial stage of immersion,the coating with Cu powders as filler showed relatively good corrosion resistance,but its failure rate was speeded up as immersion time inceeased,throughout the immersion process it showed the worst corrosion resistance.According to coating resistance (Rcoat) and characteristic frequency of coating (fb),the corrosion resistance of the coating filled by acrylic acid modified Cu powders was the best.