Constructing PANI@CF hybrids enhanced epoxy coatings with integrated functionalities of interfacial enhancement, erosion wear resistance and anti-corrosion

Factors such as sediment erosion and diffusion of corrosive ions in the splash zone result in a serious decrease in the protective performance of organic coatings. Carbon fiber (CF) reinforced polymer coatings have attracted much attention due to the impressive high mechanical strength and reliable chemical stability, but their protection period for steel structures is usually limited by the surface inertness and poor interfacial compatibility of the original CF. Herein, we created a composite coating with excellent erosion and wear resistance and corrosion resistance through simple self-polymerization of polyaniline on carbon fibers. The PANI layer not only helped to improve the interfacial compatibility between fibers/resin, but also exerted its corrosion inhibition effect. The interfacial shear strength (IFSS) value of the modified PANI4@CF monofilament and resin (60.63 MPa) was 46.73 % larger than that of the unmodified CF monofilament. In the simulated splash zone, PANI4@CF5/EP composite coating showed the best erosion resistance and corrosion resistance, and the mass loss and volume loss after erosion test were reduced by 53.39 % and 50.10 %, respectively, compared with pure epoxy coating. The local electrochemical impedance spectroscopy (LEIS) value of PANI4@CF5/EP coating with artificial defect was one order of magnitude higher than the epoxy coating after 48 h immersion. Finally, the environmental conditions of the splash zone were simulated to evaluate the anti-corrosion performance and erosion resistance of the CF reinforced composite coatings, and the protective mechanism was discussed in depth, which has great significance to the development of protective coatings for the splash zone under extreme marine environments.