Morphology and physico-electrochemical properties of poly(aniline-co-pyrrole)

Copolymers of aniline (An) and pyrrole (Py), poly(aniline-co-pyrrole), have been prepared by a conventional chemical oxidative polymerization from monomer Mixtures of various compositions, with ammonium persulfate (APS) as the oxidant and hydrochloric acid as the dopant, and the morphologies and physico-electrochemical properties of the poly(aniline-co-pyrrole) have been investigated. Poly(aniline-co-pyrrole) prepared with more polyaniline (PANI) or polypyrrole (PPy) component have similar morphologies, structures, thermal and electrochemical performances, and the relative dosage (molar ratio) of An and Py monomers during the polymerization is crucial to the properties of the resulting poly(aniline-co-pyrrole). More monomer applied in the polymerization of An and Py mixtures would result in products with similar properties to the individual homopolymer of that monomer, while poly(aniline-co-pyrrole) prepared from equimolar An and Py monomer displays unique properties. The conductivity is a non-linear function of chemical composition, and this chemical heterogeneity might lead to the broad DSC curves and various morphologies of the poly(aniline-co-pyrrole) copolymers. (C) 2008 Elsevier B.V. All rights reserved.