Electrodeposition and characterization of polypyrrole films on T304 stainless steel

Abstract

This work presents a study on the electrochemical deposition of polypyrrole (PPy) on T304 stainless steel and the effects that glow discharge plasma (GDP) in aqueous solution had when doping with polypyrrole (PPy). Deposition and doping were carried out at atmospheric pressure with times of 10, 30, and 60 min. The results showed that GDP doping changed the morphology and increased the presence of C=C, C=O, and C=N double bonds, associated with an increase in the level of crosslinking of deposited films, the disappearance of NH functional group, and the appearance of N–O bonds. It is observed that the treatment time with GDP played an important role in the modification of the deposited film, as well as the increase in conductivity from 0.075 to 0.32 S/cm. The corrosion performance of the films deposited on the stainless steel surfaces under immersion of sulfuric acid at 0.1 M are presented. The results obtained revealed that the coating at 60 min provided a notable improvement against corrosion due to the more compact morphology.

Graphical abstract

This work presents a study on the electrochemical deposition of Polypyrrole on T304 stainless steel doped with iodine (PPy/I) with glow discharge plasma (GDP). Coating was carried out at atmospheric pressure with PPy deposition and doping times of 10, 30, and 60 min. The results showed that GDP doping changed the morphology of coating. Conductivity of the samples ranges from 0.075 to 0.32 S/cm. Functional groups assigned to the N–H bonds usually in 3500 cm⁻¹ undergo a reduction, this suggests a high level of crosslinking by synthesis in aqueous medium. The 900, 1039, and 1539 cm⁻¹ bands refer to the structure of the pyrrole ring and the 614 cm⁻¹ band shows the addition of iodine to the polymer chain. The coating on the stainless steel carried out at 60 min showed better anticorrosive properties.