| Marine corrosion often brings economic losses,environmental pollution and other issues,and even endangers the safety of staff.Therefore,the development of marine corrosion protection technology is imperative.At present,epoxy resin has been widely used in the field of organic coatings because of its excellent corrosion resistance,chemical resistance,adhesion and other characteristics.However,there are also some defects.Micropores and cracks generated by the curing of epoxy resin coating will form a"channel"to accelerate the penetration of electrolyte solution and shorten the corrosion cycle of the coating.Therefore,the neat epoxy coating cannot meet the needs of today’s corrosion protection technology.The basalt powder/epoxy resin composite coatings（BP/EP）with different BP content were prepared on the surface of metal substrate by adding basalt powder（BP）as filler into epoxy resin coating.The hardness,impact resistance and other physical properties of the coating were characterized.The results show that the addition of BP can improve the hardness of the coating,reduce the impact resistance and water absorption of the coating,and the BP/EP coating shows good adhesion to the substrate surface.At the same time,the corrosion resistance of each coating was tested by electrochemical impedance spectroscopy（EIS）for15d（3.5%Na Cl）,and the corrosion mechanism of the coating was analyzed.The results showed that the appropriate addition of BP could block the corrosive medium,and the coating with 10%BP showed better barrier ability to the corrosive medium.At the 15d of immersion,the low frequency impedance modulus(|Z|0.01Hz)of BP-10/EP was 8.28×107Ω·cm2,the self-corrosion current was 5.628×10-10A·cm-2,and the corrosion rate was significantly lower than that of pure epoxy coating.In this thesis,the weak interface performance between BP and EP was improved.3-aminopropyltrimethoxysilane（APTMS）was used as coupling agent to modify the surface of BP,and the modified basalt powder（MBP）was obtained.The interface performance between MBP and EP was characterized by SEM.The results showed that the interface strength between MBP surface and epoxy resin was significantly higher than that of BP.However,when the content of MBP was too high（20%-30%）,MBP was locally aggregated due to the presence of coupling agent on the powder surface,and the interface strength between the two was reduced.Through the performance test of modified basalt powder/epoxy coating（MBP/EP）,it is found that the addition of MBP can improve the hardness and impact resistance of the coating,and the impact resistance of MBP/EP coating is 25%-33.3%higher than that of BP/EP.The coating with 10%MBP showed better corrosion resistance.The low frequency impedance modulus(|Z|0.01Hz)of MBP-10/EP was 2.43×108Ω·cm2 and the self-corrosion current was 2.992×10-10A·cm-2 after 15d of immersion.The corrosion resistance of MBP-10/EP was significantly better than that of BP-10/EP coating.At the same time,the corrosion resistance maintenance time of MBP-20/EP and MBP-30/EP coatings in the middle of immersion was significantly longer than that of BP-20/EP and BP-30/EP,which proved that the modified BP can further improve the corrosion resistance of the coating to a certain extent.In addition,when the MBP particle size is too small（0-10μm）or too large（40-50μm）,the protective performance of the coating decreases rapidly during immersion,and when the particle size is 10-20μm,the corrosion resistance of the coating can be effectively improved.This study preliminarily proves that the appropriate addition of BP can effectively improve the corrosion resistance of the coating,and can improve the coating performance through the improvement of the interface interaction between BP and EP.The results of this study can provide a theoretical basis for the application of basalt powder fillers in marine anticorrosive coatings in the future,and preliminarily verify the feasibility of the application of basalt filler in anticorrosive coatings. |
PDF Full Text Request