Corrosion Resistance of Nano Al₂O₃ Doped Phenolic Resin/Epoxy Composite Coatings

Using phenolic resin (PF) modified epoxy resin (EP) as the matrix and doping silane-modified nano-Al₂O₃ into it, the nano Al₂O₃-PF/EP composite coating was prepared. The composite coatings were characterized by testing techniques such as infrared spectroscopy (FTIR), contact angle measurement and electrochemical impedance spectroscopy (EIS). The results showed that the silane modified nano-Al₂O₃ and PF reacted with EP, the permeability and crosslinking density of the coating cured by PF were improved. The corrosion resistance of nano Al₂O₃-PF/EP composite coating was better than that of EP coating and PF/EP coating, and the composite coating doped with nano-Al₂O₃ mass fraction of 3% had the best corrosion resistance. The dispersion and stability between nano-Al₂O₃ modified by silane and PF/EP were increased, and the coating becomed denser, which hindered the diffusion of corrosive medium, thus the corrosion resistance of composite coating was improved.