A New Challenge of Polymer Thermoelectric Materials as Ecomaterials
Typical conductive polymers of poly(3-alkylthiophenes) were synthesized by oxidative polymerization. Polythiophene with no side chain was also electrolyticaly polymerized. Alkyl side chains were CnH2n+1 with n=4, 6, 8, 12. The regioregularity with the HT linkage was larger than 99% based on NMR analysis. We have evaluated the effect of side chain size on the thermoelectric properties of Seebeck coefficient and electrical conductivity. The results were as follows: 1) Seebeck coefficient decreased with an increasing electrical conductivity. 2) High Seebeck coefficient >1mV/K was observed at low electrical conductivity <10-2S/cm. 3) Small side chains, especially no side chain caused higher thermoelectric properties of polythiophene series.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
Y. Shinohara et al., "A New Challenge of Polymer Thermoelectric Materials as Ecomaterials", Materials Science Forum, Vols. 539-543, pp. 2329-2332, 2007