ABSTRACT
30Poly(aniline-co-A-phenylaniline) copolymers have been synthesized by the chemically oxidative copolymerization of aniline and A-phenylaniline in aqueous hydrochloric acid medium under nitrogen atmosphere at 0-4°C. The molar feed ratio of monomers is varied to prepare copolymers of different compositions. The copolymers are characterized by FTIR, UV-visible spectroscopy. The solubility and spectroscopic analysis suggest that the product is a copolymer of aniline and A-phenylaniline. The electrical conductivity of the compressed pellets was measured by two probe method. The electrical conductivity of copolymers is found to be less than polyaniline but processability has been improved significantly in solvents like 1-methyl-2-pyrrolidone, dimethyl sulphoxide, and dimethyl formamide. The decrease in room temperature conductivity of the copolymers with increase of the A-phenylaniline is due to the introduction of phenyl groups in to the copolymer which reduces the conjugation of the polymer chain and reduces the mobility of charge carrier along the main chain. From temperature dependence of electrical conductivity, charge localization length and hopping distance are calculated and the effect of substituent and dopant on crystallinity is discussed. The temperature dependence of dielectric data and conductivity suggests that copolymers are quasi ID-disordered state composed of 3D-metallic crystalline regions in ID-localized amorphous regions.
