Thermal Properties of specific Nonconjugated Conductive Polymers studied using Differential Scanning Calorimetry

Differential scanning calorimeter (DSC) has been used to measure the thermal properties of nonconjugated conductive polymers, poly($\beta $-pinene) and trans-1,4-polyisoprene before and after doping with iodine. The measurements have been made over the temperature range of -50 $^{\circ}$C to 110$^{\circ}$C. The heat capacity of poly($\beta $-pinene) has been observed to increase upon iodine doping. The T$_{g}$ of undoped poly($\beta $-pinene) and the T$_{m}$ of undoped trans-1,4-polyisoprene have been measured and were found to be 77 $^{\circ}$C and 60 $^{\circ}$C respectively. After doping the T$_{g}$ and T$_{m}$ transitions were not clearly observable. X-ray diffraction studies have shown the $\gamma $-phase crystal structure for trans-1,4-polyisoprene film in the undoped state. These results will be discussed considering the molecular and nano-structures of these materials before and after doping.