Electrically conducting-adhesive coating on polyamide fabrics

Solvent-based preliminary treatments were carried out on polyamide fabrics to be coated with a thin layer of electrically conducting doped polypyrrole, with the aim of improving the adhesion of the conducting layer to the fibre substrate. Polyamide fabrics were treated with dilute formic acid, pure tetrachloroethylene and ethanol/water at different temperatures and times. After the treatments, the fabrics were coated with polypyrrole by in situ chemical oxidative polymerisation. The adhesion of the PPy layer was evaluated by means of surface resistivity measurements, SEM investigation and ATR FT-IR analysis after Martindale abrasion tests. The adhesion of PPy layer on the fibre surface was strongly improved by the solvent treatments, in particular with ethanol and tetrachloroethylene. The surface resistivity of the ethanol-treated fabrics did not change after more than 200 abrasion cycles and the PPy layer linked to the fibre surface was observed by SEM and ATR FT-IR also after 4000 abrasion cycles.