Protective coatings on iron by anodic oxidation of phenols in oxalic acid medium

The feasibility of anodic electropolymerization of phenol(s) in oxalic acid solutions at different electrodes (Pt, graphite, Fe) was demonstrated by voltammetric experiments. By scanning the potential of an Fe electrode towards positive potentials. passivation by Fe oxalate. further partial oxidation of the surface layer, and eventual deposition of a polyoxyphenylene coating are observed. The thin (1-2 m) coatings, which were shown to consist of an inner Fe oxalate and an outer polymer layer by IR spectroscopy, are promising as an Fe pretreatment.