CHARACTERIZATION OF POLYANILINE FILMS ELECTRODEPOSITED ON MILD-STEEL IN AQUEOUS P-TOLUENESULFONIC ACID-SOLUTION

Aqueous p-toluenesulfonic acid solution is used to electrosynthesize a polyaniline (PANi) film on mild steel. Polarization of the substrate in this medium leads to passivation of the surface mainly via the form ation of an iron oxide layer, When aniline is added to the solution, e lectropolymerization is not hindered and a dark green deposit is obtai ned in high yield (80%). Spectrochemical techniques (IR, XPS and UV) a nd mass determination (SEC and MALDI) indicate that it has the same pr operties as reported for PANi. Evaluation of the anticorrosion perform ances of the film shows that the corrosion current is divided nearly b y ten, suggesting that this polymer coating could be used for corrosio n protection. (C) 1998 Elsevier Science S.A. All rights reserved.