| As the most extensively applied metal material on a global scale,it will suffer severe corrosion during service,shortening the service life of the material.Organic coatings were widely used in metal anti-corrosion because of their low cost and ability to isolate corrosive media.However,pure epoxy resin(EP)coatings had high brittleness,unsatisfactory mechanical behaviors and some micro holes in the curing stage,which conducted a sharp shortening of the service life of the coatings.Adding some functional fillers in the resin matrix is an effective way to enhance the performance of epoxy coating.Firstly,the hydrophilic SiC was transformed into superhydrophobic SiC(F-SiC)by superhydrophobic modifier,and the strengthening action of F-SiC on the performance of EP coatings was explored.Then,through the grafting of silane,the functional material BN@F-SiC with hydrophobicity,super wear resistance and corrosion resistance was prepared by attaching F-SiC nanoparticles to BN surface according to the characteristics of functional groups of coupling agent.Finally,a super wear-resistant and hydrophobic anti-corrosion coating containing 1 wt%composite was obtained by blending the composite into EP.The main research items and results of this paper are as follows:(1)Preparation and characterization of superhydrophobic SiC.Fluorinated SiC(f-sic)was prepared by chemical grafting of perfluorooctyltriethoxysilane(FAS)on the surface of SiC.Then,various detection techniques were used to detect the F-SiC.The WCA test found that the angle before SiC modification was only 31.9°which indicated that it was hydrophilic material.After modification,the static water contact angle was more than 150°(rolling angle was 4.2°),which became superhydrophobic material.The Si-O-Si bond produced by chemical grafting was found by FTIR and XPS,which indicated the success of chemical grafting.Then the conditions of the highest grafting efficiency were explored,and the results obtained were that the best grafting effect was when the reaction solution was weakly acidic,the temperature was controlled at 70°C,and the amount of FAS added was twice that of SiC.(2)Preparation and performance study of F-SiC/EP coatings with different contents.First,the F-SiC/EP coatings with different F-SiC contents were prepared,then the properties of the coatings were fully discussed.From the performance test results of the coating,F-SiC powder can enhance the performance of the EP coating.The specific performance was as follows:the WCA of the coating contained 5 wt%F-SiC increased by nearly 70°to 150°;the average friction coefficient of the coating decreased from 0.7211 to 0.1991(3 wt%);the polarization test showed that the coating with 3 wt%ratio had the best performance,and the corrosion current of the coating was only1.837×10-10 A/cm2 was 103 times less than that of EP coating.From the EIS test,the impedance mode value of 3 wt%composite coating in low frequency region reached1.386×109?·cm2,which showed excellent protective effect.Similarly,the same results were obtained in the salt spray experiment.(3)The influence of BN@F-SiC composite material on the properties of the coating.First,the bonding state between h-BN and SiC was tested by chemical structure test,and then through routine tests on the coating,the properties of the coating was tested.Results from the test,the BN@F-SiC(2:1)composite had the most significant improvement on the whole coating.The wear resistance of the BN@F-SiC(2:1)/EP coating was 89%higher than that of the EP coating.After 400 h of immersion,the|Z|0.01Hz of the BN@F-SiC(2:1)/EP coating was still higher than 108?·cm2,which showed good shielding performance.Due to the filling of BN@F-SiC(2:1)material,the BN@F-SiC(2:1)/EP coating showed only slight corrosion marks in the 480h salt spray corrosion test.The improvement in BN@F-SiC/EP coating performance was attributed to the superhydrophobic modified F-SiC,which can provide good hydrophobicity to the coating and slow down the corrosion of the substrate,and the shielding labyrinth formed by SiC and BN,which prevented the corrosives from reaching the substrate smoothly and played a synergistic protective effect. |
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