An investigation on the effect of acid dyes as dopants on the electrical conductivity and heat generation of polypyrrole coated polyester fabric

Abstract

This study investigates the effect of three different acid dyes as dopants on the electrical properties and heat generation of polypyrrole-coated polyester fabric. The polyester fabric was weight reduced by 11 %. Sodium dodecyl sulfate (SDS) was chosen as a reference dopant. Polypyrrole was synthesized on polyester fabric through in-situ chemical polymerization in an oxidation bath containing ferric chloride as oxidant. SEM micrographs showed that the undoped polypyrrole layer is considerably denser with much smaller pores in comparison to the doped ones. It was also revealed that the undoped and SDS doped samples showed the lowest and highest add-on, respectively. Weight reduction of polyester fabric led to a lower electrical resistance irrespective of employing a dopant or not. All the doped polypyrrole-coated weight-reduced polyester fabrics showed a lower resistance than the undoped sample. SDS doped sample enjoyed the lowest electrical resistance, followed by acid red1, acid red 18 and indigo carmine. The SDS doped polypyrrole-coated fabric also showed the highest add-on followed by acid red 1, acid red 18 and indigo carmine. The rise of temperature versus time for the coated samples is exponential, reaching a plateau after about 3 min. Moreover, higher voltages led to higher temperatures. Acid red 1 doped polypyrrole reached the highest temperature (96 °C) at 12 V. In spite of higher electrical resistance, the fabric coated with acid dye doped polypyrrole showed a higher capacity for heat generation than the fabric coated with SDS doped polypyrrole.