Study On The Preparation And Anticorrosion Of Modified Epoxy Coatings

In recent years, along with the deepening of reform and opening up, people have been aware of the importance about the ocean gradually. The development and utilization of marine resources is becoming more and more common. Q235 carbon steel is commonly used in marine environment due to its good mechanical properties and plastic properties. So Q235 carbon steel plays a very important role in the development and utilization of marine environment.Seawater is an electrolyte solution with good electric capability which contains a wealth of resources and electrical conductivity. The metals in seawater were destroyed through chemistry and electrochemistry corrosion reactions. The application of protective polymer coatings is one of the most widespread methods used nowadays for corrosion protection of different metallic structures in marine environments. As one of the most common and cost-effective methods, the polymer coating could improve the corrosion resistance and the durability of the metal structure.The effect of glass fibers and organic corrosion inhibitors on the corrosion resistance of coating is rarely studied. Polymer composite coatings with fibers and thiourea were applied to Q235 carbon steel for corrosion inhibition. SEM method was used to characterize the distribution in the coating. The electrochemical impedance spectroscopy and wire beam electrode were employed to determine the different stages of the modified coatings. EDS technique was used to characterize the distribution of the defects in 120 days. The results showed that the glass fibers could not only improve the protective performance of the coating, but also sever as a carrier of the corrosion inhibitor to increase its long-term protective performance. Compared with the blank coating, glass fibers and corrosion inhibitor could improve the membrane resistance of the coating and decrease the membrane capacitance of the coating obviously. The glass fiber and corrosion inhibitor could inhibit the diffusion of the corrosion medium in the coating effectively, slow down the release rate of the coating, and prolong the service life of the coating.On the other hand, to improve the heterogeneous dispersion of nano materials in epoxy resin, sodium dodecyl benzene sulfonate was used to modify the surface of nano-Mo S2. The modified MoS2 was added to epoxy resin to study the anticorrosion of the epoxy resin. Fourier transform infrared spectroscopy and X-ray diffraction were used to investigate the modification property of nano-Mo S2. The electrochemical impedance spectroscopy was employed to determine the different stages of the modified coatings. The hydrophobic properties and neutral salt spray of the modified coatings were tested and analyzed simply. Results indicated that sodium dodecyl benzene sulfonate was modified on the surface of nano-Mo S2. The modified epoxy coating with nano-Mo S2 had high impermeability and coating resistance. The hydrophobic properties and neutral salt spray tests verified that the nano-MoS2 modified coating on the surface of Q235 steel has more excellent effects.