Poly(1-vinylimidazole) formation on copper surfaces via surface-initiated graft polymerization for corrosion protection

Abstract

To improve the corrosion resistance of copper, poly(1-vinylimidazole) (P(VIDz)) coatings were tethered on copper via surface-initiated free radical graft polymerization of 1-vinylimidazole. An epoxide-containing trimethoxysilane was first coupled to the hydroxyl-enriched substrates for the introduction of polymerization initiator, 4,4′-azobis-(4-cyanpentanoic acid) (ACP). P(VIDz) brushes were subsequently grafted from the polymerization initiator-immobilized surfaces. The electrochemical behavior and anti-corrosion properties of the functionalized copper coupons in 0.5 M HCl solution were investigated by the measurement of open-circuit potential (OCP) temporal variation, Tafel polarization curves, and electrochemical impedance spectroscopy (EIS). As physical barriers to active species with the chelation of nitrogen and/or the π-conjugation of the ring to copper ions, the P(VIDz) coatings exhibited a high corrosion inhibition efficiency. The stability and integrity of the grafted polymers on copper substrates was evaluated by scanning electron microscopy (SEM) and cyclic voltammetry (CV). © 2010 Elsevier Ltd. All rights reserved.