Dynamic processes and charge carriers transport in polyvinyl acetate–polyaniline composites

Abstract

This work studies the effect of composite formation between polyvinyl acetate (PVAc) and conductive polyaniline (PAni) on its conductivity mechanism. To achieve this goal, different concentrations of PAni in mini-emulsion of PVAc are prepared. The dynamic relaxation and electric conductivity are evaluated using broadband dielectric spectroscopy technique. The relaxation rate of the local reorientations (β-process) of ester group follows an Arrhenius relation with activation energy 39 kJ/mole. The coupling of the segmental dynamic (α-process) and terminal fluctuation (β′-process) occurs just above the calorimetric glass transition temperatures, Tg, of pure PVAc. This is reasonable since α-process that originated from a structural rearrangement became very slow below Tg which takes the polymer toward its equilibrium state. There is also decoupling of the charge carriers transport, and the segmental motion, the concept concluded in this manuscript, sounds reasonable if one thinks about the ion motion at T < Tg. This conclusion is straightforwardly deduced from the experimental data, as explained in more detail. The study also confirms that PAni electrical conductivity mechanism is conserved.