Tuning the electrical properties of polyaniline by copolymerization with o-bromoaniline

Abstract

Polyaniline, poly(o-bromoaniline) and poly(aniline-co-o-bromoaniline)s have been prepared by chemical oxidative polymerization methods. A series of poly(aniline-co-o-bromoaniline) derivatives has been prepared by the chemical oxidative copolymerization of aniline with different mole ratio of o-bromoaniline by varying the feed ratios of the monomers with the introduction of o-bromoaniline units along the polymer backbone. The morphology of each poly(aniline-co-o-bromoaniline) derivative is observed as a porous network of aggregated nanoparticles with each nanoparticle having smaller nanoflake structures. Room temperature electrical conductivity studies reveal that polyaniline has a conductivity value of the order of 10-3S/cm. However, the corresponding poly(aniline-co-o-bromoaniline), with 10% o-bromoaniline content, shows a fivefold increase of the electrical conductivity relative to the polyaniline homopolymer. The different polymer derivatives were characterized by 1H NMR spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) methods, AC conductivity and dielectric permittivity measurements.