| Epoxy resins are widely used in rail transit protective coatings due to their excellent adhesion,heat resistance and chemical resistance.However,epoxy resins have inherent defects,which adversely affect their wear resistance and anti-corrosion properties,limiting their application in harsh working conditions.In recent years,studies have shown that the use of polyacrylate to modify epoxy resin to form an interpenetrating polymer network（IPN）can increase the density of the polymer;core-shell materials can make the core material and shell layer materials play a synergistic role to enhance the wear resistance and corrosion resistance of the matrix.In this thesis,epoxy resin/polyacrylate IPN emulsion was prepared by seed emulsion polymerization,and was used as a matrix for research.In order to enhance the wear resistance and anti-corrosion performance of IPN matrix,silicon nitride@molybdenum disulfide（Si3N4@Mo S2）core-shell materials were prepared based on passive protection.The synergistic effect of Si3N4 and Mo S2 was used to enhance the wear resistance of IPN matrix,and the special petal structure of Mo S2 was used to enhance the anti-corrosion performance of composite coatings.Based on the active protection design,the 1,10-phenanthroline@titanium dioxide（Phen@Ti O2）core-shell material was prepared.The corrosion inhibitor Phen was encapsulated in mesoporous Ti O2 and coated with polyelectrolyte layer.Then the Phen@Ti O2 core-shell material with p H stimulation response was obtained.On the basis of enhancing the wear resistance and corrosion resistance of IPN matrix,Phen@Ti O2 core-shell material makes the composite coating have self-repairing,self-diagnostic and UV-resistant properties.The core-shell material reinforced composite coating with excellent wear resistance and anti-corrosion properties can be obtained through the design of core-shell materials,which provides a research direction for the development and preparation of high-performance wear-resistant and anti-corrosion coatings.In this thesis,the morphology,structure and composition of the core-shell materials were characterized in detail.And the mechanical properties,tribological properties,anti-corrosion properties,tribo-corrosion resistance,self-repair properties and UV resistance of the composite coatings were tested.At the same time,the wear resistance and anti-corrosion mechanism of composite coatings reinforced by core-shell materials of different designs are systematically explained.The main conclusions are as follows:（1）The prepared Si3N4@MoS2 core-shell materials are uniformly dispersed in the IPN matrix and have good interfacial interaction with the matrix.After the formation of Si3N4@Mo S2core-shell materials,there is a synergistic effect between hard-phase Si3N4 nanoparticles and soft-phase Mo S2 nanosheets,which significantly enhance the anti-friction and anti-wear properties of IPN matrix.At the same time,Si3N4@MoS2 core-shell materials can play a passive protective role,increasing the tortuosity of the diffusion path of corrosion media,thus enhancing the anti-corrosion performance of IPN matrix.In addition,the tribo-corrosion resistance of IPN matrix was significantly enhanced with the addition of 1.5 wt%Si3N4@Mo S2 core-shell material.（2）The prepared Phen@TiO2 core-shell materials have good dispersion in IPN matrix.During the friction process,the formation of tribofilms and the load-bearing effect of Phen@Ti O2 core-shell materials enhance the wear resistance of IPN matrix.The barrier effect of Phen@Ti O2 core-shell material enhance the anti-corrosion performance of IPN matrix.When the protective coating is damaged,the Phen@TiO2 core-shell material plays an active protective role and releases Phen molecules.Phen molecules can form an orange-red passivation film on the substrate surface and inhibit the corrosion reaction,so that the composite coating has self-repairing properties and the function of self-diagnosis.In addition,the Ti O2 nano-containers with UV shielding properties endow the composite coatings with UV resistance. |
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