Synthesis and anticorrosion properties of polydiphenylamine blended vinyl coatings

Inherently conducting polymers such as polyaniline and polypyrrole containing organic coatings have been found to offer corrosion protection of steel in acid and neutral media. In this study, the use of polydiphenylamine in vinyl coating for corrosion protection of steel in 3% NaCl solution is reported. The polydiphenylamine was prepared by chemical oxidative method of diphenylamine by ammonium persulfate in hydrochloric acid medium. The synthesized polydiphenylamine (PDPA) was blended with vinyl resin at 0–5% concentrations and the corrosion protection performance of the coating on steel was evaluated by EIS for a period of 80 days. It has been found that the coating containing 3% PDPA is able to protect steel more effectively.