Toward real applications of conductive polymers

The chemical polymerization of pyrrole in the presence of textile substrates results in the formation of electrically conducting, polypyrrole coated fabrics. Applications of these materials include microwave attenuation, static charge dissipation, and EMI shielding. The degradation kinetics of the electrical conductivity of these materials has been investigated and found to proceed by multiple rate laws. In the initial stages of conductivity loss, a diffusion controlled mechanism predominates, where oxygen diffusion into the polypyrrole film is rate limiting. At longer times, the degradation follows a simple first-order decay. The dopant anion employed during polymerization has a profound influence on the stability of the resulting film, and SEM analysis indicate that film morphology plays an important role in this effect. In the absence of oxygen, conductivity loss is significantly slower and displays a strong dependence on chloride content.