Corrosive inhibition behavior of well-dispersible aniline/p-phenylenediamine copolymers

Well-dispersible aniline/p-phenylenediamine copolymer [P(ANI-co-p-PDA)-F] was synthesized by chemical oxidative polymerization in the presence of nonylphenol ethoxylate (TX-8) with the hydrophilic lipophilic balance (HLB) value of 10-11. The FTIR and H-1 NMR spectra proved that there was TX-8 composition in P(ANI-co-p-PDA)-F copolymer. And the P(ANI-co-p-PDA)-F had the smaller particle diameter and better dispersion stability in toluene than that of P(ANI-co-p-PDA) copolymer without TX-8. The anti-corrosion performance of carbon steel samples coated by P(ANI-co-p-PDA)-F/epoxy composite coatings in 5 wt% NaCl and 0.1 M HCl aqueous solution were evaluated by the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the P(ANI-co-p-PDA)-F/epoxy coatings on carbon steel possessed good corrosion resistance, and composite coating containing 7 wt% P(ANI-co-p-PDA)-F exhibited best anti-corrosive performance. (c) 2012 Elsevier B.V. All rights reserved.