| Solvent-based epoxy resin coating have the advantages of good electrical insulation and thermal stability,as well as strong adhesion and low cost,and have attracted widespread attention.However,due to the corrosive medium entering the interior of the epoxy coating through the surface defects of the epoxy coating,cracks occur on the surface of the epoxy coating,which seriously limits the long-term application of epoxy coatings in the marine humid environment.In this paper,modified kaolin（Kaolin）was added to epoxy resin to improve its anticorrosion performance,and silane coupling agent（APTES）,tetraethyl orthosilicate（TEOS）and 8-hydroxyquinoline（8-HQ）as modifiers.The composition and structure of the composites were characterized by Fourier transform infrared spectroscopy（FTIR）and X-ray diffraction（XRD）,the morphology of the composites and pore size changes before and after modification were studied by scanning electron microscopy（SEM）and N2 adsorption-desorption analyzer（BET）.The effects of composite materials on the hydrophobicity,surface roughness and corrosion resistance of epoxy coatings were explored by contact angle,atomic mechanical microscopy（AFM）and alternating current impedance（EIS）.The main research contents were as follows:（1）Kaolin was modified by the intercalation method,and the high-performance composite aminated kaolin（APTES@Kaolin）was prepared by optimizing the process conditions.The structural composition,dispersibility and degree of agglomeration of the composites,as well as the hydrophobicity,surface roughness and anticorrosion properties of the composite coatings were studied.The results showed that compared with the epoxy coating（hydrophobic angle was 40°,the average surface roughness Ra was 10.3 nm,the hardness grade was 3B,and the adhesion was grade 1）,the roughness Ra of the composite coating was reduced to 5.64 nm,hardness grade was 6H,adhesion grade was 0.When the mass ratio of APTES to Kaolin was 1:1,the reaction time was5 h and the reaction temperature was 70℃,the maximum hydrophobic angle of the composite coating was 67°.After soaking for 30 days,the epoxy coating failed obviously,while the impedance modulus|Z|0.01Hz of the composite coating was still no less than 8.99×108Ω·cm2.（2）TEOS was added to the APTES@Kaolin prepared in（1）,and the TEOS hydrolysis reaction was carried out in an alkaline environment by the sol-gel method,the composite material Si O2@AK was prepared by optimizing the process conditions.The structural composition and pore size change of Si O2@AK,the hydrophobicity,surface roughness and anti-corrosion properties of the composite coating were also investigated.The results showed that compared with APTES@Kaolin,the average pore size of Si O2@AK was reduced to 24.63 nm,and the surface defects were reduced.When the mass ratio of APTES@Kaolin and Si O2 was 1:1,the reaction time was 5 h,p H was 12,and the reaction temperature was 80℃,the maximum hydrophobic angle of the composite coating was 88°.The roughness Ra was 3.19 nm,the hardness and adhesion level remain unchanged.After soaking for 30 days,the impedance modulus|Z|0.01Hz of the composite coating was still not less than 2.511×109Ω·cm2.（3）The small-molecule corrosion inhibitor 8-HQ was added to Si O2@AK,and the composite material 8-HQ@Si O2@AK was prepared by the inorganic particle modification method for hydrothermal reaction in acidic environment.The structural composition and loading of 8-HQ@Si O2@AK,as well as the hydrophobic properties,surface roughness and anti-corrosion properties of the composite coating 8-HQ@Si O2@AK/EP were explored.The results showed that 8-HQ was successfully loaded into the Si O2@AK material,the maximum hydrophobic angle of the composite coating was 88°,the roughness Ra was 3.09 nm,and the hardness and adhesion grade did not change.Under the conditions of p H was 3,reaction temperature was 60℃and reaction time was 7 h,the loading of 8-HQ was the largest.After soaking for 30 days,the impedance modulus|Z|0.01Hzof the composite coating was 3.662×109Ω·cm2,which greatly improved the anticorrosion performance of the epoxy coating. |
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