THERMAL AND ELECTRICAL-PROPERTIES OF POLY(3-ALKYLTHIOPHENE)S PREPARED BY THE OXIDATIVE POLYMERIZATION

Thermal and electrical properties of poly(3-hexylthiophene)(P3HT), which was prepared by the oxidative polymerization in the range from -30 to 40 degrees C, have been investigated. Differential scanning calorimetry (DSC) showed that the P3HT had a relatively high melting point (170 to 190 degrees C). The P3HT polymerized at a lower temperature gave a sharper endothermic peak in DSC profile, suggesting that crystallinity of the P3HT increased with a decrease in the polymerization temperature. DC conductivity was measured for cast films of the P3HT as a function of temperature (-160 to 200 degrees C). The conductivity increased remarkably with an increase in temperature over the range below room temperature, leveled off at 10(-4) to 10(-7) [S/cm] between room temperature and some 100 degrees C, and reached a peak at around the melting point.