Synthesis and Characterization of Electroactive Fluorinated Poly (amic acid) Bearing Oligoaniline Pendants

A novel electroactive fluorinated poly (amic acid) (EFPAA) was firstly synthesized in a single step from 4,4’-(Hexafluoroisopropylidene) diphthalic anhydride (HFDA) and electroactive diamine monomer (EDA). The structure of EFPAA was confirmed by Fourier-transform infrared spectra (FTIR), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The electroactivity of EFPAA was evaluated by performing electrochemical cyclic voltammetry in 0.5 M H₂SO₄ confirming a surface-controlled process. EFPAA/ITO electrode displayed good electrochromic behavior with high contrast value, moderate switching times, acceptable coloration efficiency. Moreover, anticorrosion performance of the EFPAA coatings on the stainless steel (SS) in 3.5 wt% NaCl solution was investigated by tafel plot analysis and electrochemical impedance spectroscopy. A comprehensive and detailed study of corrosive protection of EFPAA will provide an insightful tool for developing electrochromic displays and anticorrosive paint.