Thermal and dc Conductivity Behavior of Fly Ash Filled Polyaniline Composites

In this paper temperature dependence of dc conductivity (σdc) of emeraldine base form of polyaniline (PANI) and fly ash filled PANI are presented. Samples were prepared by in situ polymerization of aniline using ammonium persulphate as an oxidant and hydrochloric acid as dopant. Fly ash filled PANI composites were prepared by adding 3 gms of fly ash. Thermal characteristics of samples were measured using differential scanning calorimetry. The dc conductivity (σdc) of fly ash filled PANI was found to be on the order of 1.63 × 10−11 s/cm at room temperature, which was lower than that of pure PANI. The activation energies calculated from σdc for PANI and the PANI 3 fly ash system were 1.35 and 1.16 eV, respectively. It was found that addition of fly ash to PANI drastically decreased the enthalpy from 2259.2 to 196.6 mJ. the endothermic peak due to the glass transition temperature shifted from 99.8 to 94.6°C. This was attributed to the change in the morphology of the composites on adding fly ash, as observed in the scanning electron micrographs.