Study on the preparation and anticorrosive performance of silica/modified kaolin/epoxy resin composite coating

Abstract

A silica/aminated kaolin (SiO2@AK) composite was prepared by modifying kaolin and loading silica, using intercalation complex method and sol–gel method. Quantitative composites were dispersed in epoxy resin to obtain a silica/aminated kaolin/epoxy resin composite coating (SiO2@AK/EP) on stainless steel. The results showed that the thickness of the dry coating was approximately 110 ± 10 μm, and the surface was flat without evident agglomeration. As the SiO2@AK composite was introduced, the water contact angle increased from 40° to 88°, the average surface roughness of the prepared composite coating was reduced from 10.3 nm to 3.19 nm, and the corrosion current decreased by nearly three orders of magnitude. After the coating was soaked in 3.5 wt% NaCl solution for 30 days, the impedance modulus of the composite coating remained above 2.511 × 109 Ω cm2, reflecting that the introduction of the composite could effectively improve the anticorrosion property of the epoxy resin.