Enhancement of Electrical Conductivity of Polypyrrole and Its Derivative

In this work, the effect of polymer structures on electrical properties of polypyrrole and a 3-derivatized polypyrrole was investigated. Polypyrrole and the 3-derivatized polypyrrole weresynthesized and investigated for their electrical conductivity in the atmosphere of nitrogen. A 3-derivatized monomer, which was achieved in 49 % yield from N-tosylpyrrole and 3-bromopropionylchloride and used aluminium trichloride as a catalyst. The 3-derivartized pyrrole was then undergoneoxidative polymerization to form the 3- derivatized polypyrrole. The chemical structure of eachpolymer was characterized by 1H-NMR and FT-IR techniques. The electrical conductivities of theundoped polypyrrole and the 3- derivatized polypyrrole were 0.0266 and 0.0141 S cm-1, respectively.In this work, lithium fluoride (LiF), lithium perchlorate (LiClO4) and p-dodecylbenzenesulfonic acid(DBSA) were used as dopants and the molar ratio of pyrrole unit to each dopant was 1:1. Theelectrical conductivities of polypyrrole and the 3-derivatized polypyrrole which were doped with LiFwere found to have electrical conductivities of 45,600 and 1900 S cm-1, respectively. The lithiumfluoride doped polymers showed the highest electrical conductivity of all the doped polymers due toits smallest size of F- anion (1.33 ) which could be transported easily through the polymer matrix tostabilize the positive charges occurred on polymer chains.