Studying Performance And Anti-corrosion Mechanism On Coatings Of Coal-based Polyaniline

Coal Base Polyaniline (CPANi) was polymerized by inducing aniline monomer into template of coal to get interlinked network and intercalate compound, which utilized macromolecular structure, chemical state and accumulating state, carboxyl group and pheonol hydroxyl group of natural coal. The CPANi is similar to polyaniline in conductivity, stability and endurance. The investigation aspect of this paper is whether CPANi can be used in anti-corrosion coating, which has more important signification in academic and practical for new approach to make use of coal in function material.Three types expoxy resin used in anti-corrosion coating widely were chosen to be essential stuff because expoxy resin has more excellent adhesion and waterproof, and were confected solution with solvent. Then the relevant harder was chosen. The testing methods including uniformity, tension, dry and wet adhesion, blister and corrosion degree of coating after accelerating immersion by ASTM D610-85 and D714-87 were used to test coating relevant performance. Through these test results, the proportion of CPANi, expoxy resin and harder was selected, which is CPANi:epoxy Model XK-3:harder=20～30:100:6 with excellent anti-corrosion performance.Then the electrochemical testing including open circuit potential, line polarization resistance and Tafel polarization, and XRD, SEM were used to investigate anti-corrosion performance and mechanism of CPANi anti-corrosion coating. The content of study include: the relevant anti-corrosion performance with different proportion of CPANi in coating; maintaining the proportion of expoxy and harder, the anti-corrosion performance with different filling such as Zn, red lead and CPANi; the similarities and differences anti-corrosion performance of CPANi coating with polyamicester anti-corrosion coating, expoxy rich zine primer and sliver powder coating;The result of investigation indicate CPANi anti-corrosion coating has excellent anti-corrosion performance. CPANi in coating can provide good shield performance for coating during immersion so that the coating can maintenance good adhesion with fundus. The CPANi anti-corrosion coating can provide carbon steel with anodic protection, because the OCP of carbon steel can be increased 500mV. The corrosion rate of carbon steel can be decreased three magnitude comparing with blank coating. At last, basing on the testing results, the anti-corrosion model of CPANi coating was built, which was used to explain shield, inhibition and positive protection performance of CPANi coating.Therefore, CPANi anti-corrosion coating is worth developing and has applicable foreground.