Preparation of poly(<i>o</i>-toluidine)/polyacrylonitrile composite fibres using CrO₃

Abstract

Poly(<i style="">o</i>-toluidine) (POT) and polyacrylonitrile (PAN) fibres have been used to prepare conducting composite fibres by <i style="">in situ</i> chemical polymerization using CrO₃ as oxidant. The POT content and surface resistivity of POT/PAN composite fibres have been systematically evaluated as a function of the polymerization temperature and time, types of oxidant and dopant, and concentrations of monomer, oxidant and dopant. At the polymerization carried out at 30 °C for 4 h by 0.125 M <i style="">o</i>-toluidine, 0.08 M CrO₃ and 1.2 M HCl, the composite fibres having the highest POT content (about 2.3 %) and the lowest surface resistivity (about 0.12 Mohm/cm²) are obtained. Surface resistivity measurements together with FTIR, TGA and SEM techniques have been used for the characterization of composite fibres prepared. Furthermore, the mechanical properties of composite such as tensile strength and elongation-at-break are also measured. SEM images show that the surface of fibre is coated by POT with a flaky shape and there are accumulation of large and small POT particles at some regions.