XPS studies of environmental stability of polypyrrole-poly(vinyl alcohol) composites

In this paper, we report a study on the aging effects of polypyrrole-poly(vinyl alcohol) composites. A decrease of the conductivity is observed when samples are stored in ambient atmosphere, whereas they are stable in inert environment. A careful analysis of the studied samples has been performed by using both scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is known that oxidation processes occur, breaking the conjugation of the polymeric unsaturated chains and this is the main cause for the non-stability of the composites in ambient conditions. Consequently, several oxygen-containing groups are formed in the polymer backbone, as deduced from the analysis of the C, O, N and Cl binding energies.