Influence of polymerization time on the properties of polypyrrole-poly[bis(phenoxyphosphazene)] composites electrogenerated at constant current density

The influence of different polymerization times on the characteristics of films of polypyrrole, PPy, and of composites of polypyrrole-poly[bis(phenoxyphosphazene)], PBPP-PPy, both with p-toluenesulfonic acid (HTSO) as supporting electrolyte and acetonitrile as solvent, has been studied. Films and composites were grown for 10-60 min under galvanostatic control at a current density of 4.2 mA cm(-2). The electrooxidation of the PPy in the films and the composites was controlled by diffusion. With increasing electropolymerization time the specific charge storage capacity of both the films and the composites decreased. PBPP increased the conductivity for all polymerization times, but had almost negligible effect on polimerization efficiency. The specific charge storage capacity and the conductivity increased with PBPP thickness. In contrast, the polymerization efficiency decreased for the thicker composite. The presence of PBPP increased PPy/TSO adhesion to the electrode surface but did not decrease its stability. The influence of the polymerization time on the morphology of films and composites was also studied. (c) 2005 Elsevier Ltd. All rights reserved.