Advanced anticorrosive coatings prepared from electroactive polyimide–TiO2 hybrid nanocomposite materials

In this study, we present the first preparation and corrosion protection studies of a series of electroactive polyimide–TiO2 (EPTs) hybrid nanocomposite materials containing conjugated segments of electroactive amino-capped aniline trimer (ATs) and TiO2 nanoparticles of ∼10 nm in diameter. Redox behavior of as-prepared EPTs hybrid materials was identified by electrochemical cyclic voltammetry (CV) studies. Higher concentration of TiO2 component in as-prepare corresponding EPTs was found to reveal better corrosion protection effect on cold-rolled steel (CRS) electrode based on sequential electrochemical corrosion measurements in 5 wt.% NaCl electrolyte. Enhancement of corrosion protection of EPTs coatings on CRS electrode could be interpreted by following three possible reasons: (1) Electroactive polyimide (EPI) could act as a physical barrier coating. (2) The redox catalytic capabilities of ATs units existed in EPTs may induce the formation of passive metal oxide layers on CRS electrode. (3) The well-dispersed TiO2 nanoparticles in EPTs matrix could act as effective hinder to enhance the oxygen barrier property of EPTs.