Pyrrole chemical polymerization on textiles: kinetics and operating conditions

The chemical polymerization of pyrrole was studied with the aim of defining the best operating condi- tions for obtaining conductive fabrics of synthetic fibers. Am- monium persulfate was chosen as the oxidant, and various dopants were tested. Among these, naphtalene-2,6-disul- fonic acid disodium salt enabled the lowest surface resistivity to be reached. Hence, several kinetic runs were performed to explain the influence of some operating conditions as oxidant concentration and temperature. A pseudo-first-order kinetic equation was derived, and the reaction rates were found to be practically unaffected by the presence of the textile sub- strate. Pyrrole polymerization was faster than adsorption of the monomer, suggesting the hypothesis of fast polymeriza- tion outside the fibers followed by adsorption onto the fiber surface. The surface coating of polypyrrole was evidenced by microscopic observation of the fiber cross sections.