INVESTIGATION INTO VAPOR-PHASE FORMATION OF POLYPYRROLE

Vapour-phase chemical polymerization of pyrrole was investigated in wh ich a cotton thread coated with FeCl3 oxidant was exposed to pyrrole v apour and the electrical resistance of this conductive polypyrrole sup ported on cotton thread was measured using a specially designed four-p oint probe. The relationships of the resistance of the polypyrrole sup ported on cotton thread with various experimental parameters such as c oncentrations of the oxidant and monomer, polymerization time, solvent effect and temperature were studied. It was found that the vapour-pha se polymerization was a fast reaction. The resistance decreased with a n increasing concentration of FeCl3 and polymerization temperature. Th e presence of some solvents such as water, hexane and toluene in the v apour phase did not affect the polymerization process. However, some s olvents such as methanol and acetone were found to be unsuitable for t his process.