Chemical and Electrochemical Syntheses of Conducting Polymers

Abstract

Polymers can be prepared using chemical and/or electrochemical methods of polymerization. However, most redox polymers have been synthesized by chemical polymerization. Electrochemically active groups are either built into the polymer structure inside the chain or included as a pendant group (prefunctionalized polymers), incorporated into the polymer phase during the polymerization, or fixed into the polymer network in an additional step performed after the coating procedure (post-coating functionalization). Several other alternative synthetic approaches exist; in fact, virtually the whole arsenal of synthetic polymer chemistry techniques has been exploited. The electrochemical polymerization of cheap, simple aromatic and heterocyclic compounds is of the utmost interest from an applications perspective. The reaction utilized is usually an oxidative polymerization, although reductive polymerization is also possible. Electrochemical polymerization is preferable, especially if the polymeric product is intended for use as a polymer film electrode, thin layer sensor, in microtechnology, etc., because potential control is a prerequisite for the production of good-quality material and the formation of the polymer film at the required spot to serve as an anode during synthesis. A chemical route is recommended if large amounts of polymer are needed. The polymers are obtained in an oxidized, highly conductive state containing counterions incorporated from the solution used in the preparation procedure. The mechanism and the kinetics of the electropolymerization are also discussed in this chapter.

Keywords: Chemical polymerization – Electrochemical polymerization – Post-functionalization – Mechanism and kinetics of polymerization