INVESTIGATION INTO VAPOR FORMATION OF POLYANILINE

The vapour phase chemical polymerization of aniline was investigated i n which a cotton thread coated with ammonium persulphate [(NH4)(2)S2O8 ] was exposed to aniline vapour and the electrical resistance of this polyaniline supported on cotton thread was measured using a four-point probe. The effects of various experimental conditions, such as the co ncentrations of the oxidant and monomer, the polymerization time, the solvent, and the temperature, on the vapour phase polymerization proce ss were studied. The resistance decreased with increasing concentratio n of (NH4)(2)S2O8 and polymerization temperature. This vapour phase po lymerization can also be carried out in the presence of solvents such as water, n-hexane, toluene, and methylene chloride. However, some sol vents, such as methanol and acetone, were found to be unsuitable for t his process.