Influence of polymerization rate on conductivity and crystallinity of electropolymerized polypyrrole

We report studies on electronic conductivity and crystallinity in electropolymerized polypyrrole. Different growth rates during electropolymerization strongly influence and determine structural and electronic properties. Polymer films grown using low current density show higher electronic conductivity and increased crystallinity. The conductivity is also less temperature activated compared to that of the polymer grown at higher rate. X-ray diffractograms are compared to simulated diffraction data and the results are discussed in terms of increased order in the material. This may result from a different coupling route in the polymerization, induced by the lower current density.