Enhanced electrical conductivity of polypyrrole prepared by chemical oxidative polymerization: effect of the preparation technique and polymer additive

The electrical conductivity of chemically prepared polypyrrole in aqueous s olution was found to be strongly dependent on the preparation technique and polymer additive. Owing to the hygroscopic nature of polypyrrole, it is es sential to remove residual water. Accordingly, the conductivity can be enha nced by about two orders of magnitude when using a preparation technique th at includes a washing treatment with organic solvents and drying under vacu um at elevated temperatures to attain maximum removal of water. Thus. the e lectrical conductivity of polypyrrole is affected not only by reported fact ors such as the ratio of oxidant to pyrrole, reaction temperature, and reac tion time, but also by the preparation technique. Additionally, a significa nt enhancement of the conductivity up to 90 S cm(-1) by using of poly(ethyl ene glycol) as an additive during the polymerization could be achieved. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.