Electric conductivity of poly(3-dodecylthiophene) and its dependence on the conformational changes of polymer chains

The influence of the heat-induced conformational changes in side alkyls and in the backbone of poly(3-dodecylthiophene) (PDDT) with a higher content of configurational head-to-head defects (39%) on electric conductivity was studied. It has been found that conformational changes affect the electric conductivity values of PDDT doped with FeCl3 which attain at 0.021 mol of Fe/mol dodecylthiophene more than 10(8) Sm-1 within the whole temperature range (from 78 up to 320 K). For the analysis of conformational changes the entropy temperature dependence was calculated from the experimental data on the specific heat capacity. In this paper dependences between the resistance and the conformational changes of PDDT were discussed.