A study on the electrical conductivity decay of polypyrrole coated wool textiles

Loose wool fibres were coated with electrically conducting doped polypyrrole (PPy) by in situ chemical oxidative synthesis from an aqueous solution of pyrrole. PPy coated wool fibres were spun and knitted using conventional industrial machinery. Electrical and thermal properties of the fabrics were studied using simulated ageing tests, with the aim of evaluating the performances decay during the processing stages and the final use of the products. Fastness tests were performed according to established international standards. The coating evenness and degradation were investigated by Light Microscopy (LM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) Microanalysis and Infrared Spectroscopy (FT-IR). The results show that fabrics made of PPy coated wool fibres have an acceptable conductivity decay with respect to most of the stress that textile products are usually subjected to; low fastness was found only to washing, probably due to alkali dedoping of conducting PPy coating, although an excellent resistance to organic solvents allows conventional dry cleaning treatments.