Abstract:Two kinds of sulfonated polyaniline (PANI-SDS, PANI-LGS) were synthesized by chemical oxide method with sodium dodecyl sulfate (SDS) and sodium lignosulfonate (LGS) as dopant, followed by mixed with silicone resin (SiR) prepared by gel-gel method, and then coated on the surface of Q235 steel to prepare composite aniticorrosion coatings. The structures of sulfonated PANI were characterized by FTIR, and the basic properties of PANI-SDS and PANI-LGS were compared. The hydrophobicity, adhesion, mechanical properties and anticorrosion properties of SiR, PANI-SDS/SiR and PANI-LGS/SiR composite coatings were investigated, and the anticorrosion mechanism of the composite coating was described. The results showed that PANI-LGS/SiR composite coating had better hydrophobic property. The water contact angle of the coating was 113.0°, and the water absorption was only 7.58%. Electrochemical test results showed that the composite coating had better corrosion resistance to Q235 steel. The corrosion rate was 5.56×10-3 mm/a. The metal corrosion is protected by the effect of physical barrier and anodic protection of the composite coatings.