Preparation of electrically conducting plastic film by CVD of pyrrole

Abstract

The optimum condition of preparation of conducting plastic film by CVD of pyrrole was studied. The conducting plastic film was carried out by varying concentration of ferric chloride solution and pyrrole monomer, reaction temperature, reaction time, iodine doping time, and iodine doping temperature. The electrical conductivity of prepared conducting plastic film was measured by van der Pauw method. The occurrence of polypyrrole was confirmed by Elemental Analyzer. The effect of ferric chloride concentration on electrical conductivity of prepared conducting plastic film was determined by UV-visible spectroscopy. The effect of pyrrole monomer concentration, reaction temperature, reaction time, iodine doping temperature and iodine doping time on electrical conductivity of prepared conducting plastic film was studied by infrared spectroscopy (FT-IR), and optical microscopy. The optimum conditions of preparation of conducting plastic films were 25% FeCl3, 25% pyrrole in distilled water, at -15°c and 20 hours for polymerization, and electrical conductivity was measured as 1.16x10-1 S/cm at nearby for each PVC/PPY, PP/PPY, and LDPE/PPY film. When performed to iodine doping at -15°c about 60 minutes in reduced pressure the electrical conductivity was as high as 26.45 S/cm. The applications of conducting plastic films in high temperature condition were studied. The mechanical and thermal properties were investigated by Universal testing material machine, Thermogravimetric Analyzer (TGA), and Differential Scanning Calorimetry (DSC), respectively. The effect of parameters on mechanical and thermal properties of prepared conducting plastic films were also studied. It was found that PCV/PPY at low temperature has well electrical conductivity, and mechanical properties, but at high temperature (~70°c and above) PP/PPY or LDPE/PPY has good mechanical and thermal properties that suitable for applications. From DSC thermogram of prepared conducting plastic film, it clearly exhibited Tg and Tm similar to original plastic film. The tensile strength of exposed iodine vapor of PP/PPY film decreased more with increasing iodine doping time than those of PP/PPY and LDPE/PPY films.