Properties of polypyrrole-coated textiles

Activities of this work were focused on the development and the evaluation of antibacterial and/or EMI shielding properties of fabrics produced by polypyrrole-based finishing processes. PPy was applied to textile materials by chemical oxidative in situ polymerisation from aqueous solutions of pyrrole. The textile materials were selected among those manufactured by the industrial partners. Process conditions (monomer, oxidant and dopant concentrations, oxidant/monomer molar ratio, liquor ratio, weight uptake, kind of dopant) were studied to improve antibacterial properties. Antibacterial activity against Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae of treated textile materials was evaluated following international standard test method ASTM E 2149. The antibacterial efficiency was assessed after fastness tests simulating stresses to which the textiles are subjected during processing, maintenance and final use. Fastness was evaluated following international standard test methods, namely laundering (with anionic and non-ionic detergents), dry-washing and fastness to acid and alkaline perspiration. The second goal of the project was the development of electro-conductive coating for EMI shielding. High-conducting (doped) PPy coatings were applied to textiles keeping the track of the findings related to the development of antibacterial PPy-based finishing. Before laundering, fabrics treated with PPy showed 100% of bacterial reduction, while untreated cotton fabric had practically no antimicrobial activity. After dry-cleaning, PPy fabrics showed high bacterial reductions (99%). Antimicrobial properties resulted depleted after non-ionic and anionic launderings. For the production of EMI shielding textiles it was found that 4 g/l of pyrrole concentration is enough for obtaining significant attenuation of microwaves. Electrical conductivity of uncoated silver-containing fabrics was measured to be 3400 ?/sq.