EFFECTS OF POLYMERIZATION TEMPERATURE AND OXIDANTS ON THE SYNTHESIS OF POLYPYRROLE POLYURETHANE CONDUCTIVE COMPOSITE FOAMS BY VAPOR-PHASE POLYMERIZATION

An electrically conductive composite foam of polypyrrole and polyurethane was prepared by vapor phase polymerization of pyrrole on polyurethane foam containing Fe(III) salts as the oxidizing agents. The rate of the polymerization and the conductivity of the composite foam were strongly dependent on the polymerization temperature. At lower temperatures, the amount of polypyrrole decreased, but the conductivity increased; by changing the reaction temperature from 30 to 0-degrees-C, die conductivity increased from 1 x 10(-3) to 9.8 x 10(-3) Scm-1. The conductivity was also strongly dependent on the nature of the oxidant. The conductivity of composite foams prepared with Fe(III) salts as oxidizing agents decreased in this order: perchlorate > chloride > sulfate, nitrate. The result can be related to the effect of doping by counter anions. Thermal and mechanical properties of the composite foam were investigated. The surface structures of composite foam observed by SEM were significantly different for the composites prepared by different oxidants.