Electroactive polymer with oligoanilines in the main chain and azo chromophores in the side chain: synthesis, characterization and dielectric properties

Abstract

By an oxidative coupling polymerization approach, we have synthesized a novel electroactive polymer with good solubility containing alternating phenyl-capped aniline tetramer in the main chain and azo chromophores in the side chain. Dielectric properties of the as-synthesized polymer were investigated in detail and gratifying results have been observed. Firstly, a large enhancement in the dielectric constant was achieved utilizing the method of doping the conjugated oligoaniline segments with hydrochloric acid. Secondly, the adjustment of dielectric constant was implemented primarily by means of exposing the samples to UV and visible irradiation, mainly owing to the photoisomerization derived from azo chromophores in the side chain. The detailed characteristics of the as-synthesized polymer were systematically studied by Fourier-transform infrared (FTIR) spectra, nuclear magnetic resonance (¹H NMR) and gel permeation chromatography (GPC). UV-vis spectra were used to monitor the photoisomerization and doping process of the polymer. The thermal characteristics of the polyamide were evaluated by thermogravimetric analysis (TGA). Moreover, the electrochemical activity of the polymer was explored by cyclic voltammogram (CV) measurement, showing that the intrinsic electroactivity of the oligoaniline was maintained in the polymer.