Thermal and electrical properties of poly(3-alkylthiophene)S prepared by the oxidative polymerization

Summary form only given. Thermal and electrical properties of poly(3-hexylthiophene) (P3HT), which was prepared by the oxydative polymerization in the range from -30 to 40/spl deg/C, have been investigated. Differential scanning calorimetry (DSC) showed that the P3HT had a relatively high melting point (170 to 190/spl deg/C ). The P3HT polymerized at a lower temperature gave a sharper endothermic peak in DSC proffle, 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/spl deg/C). The conductivity increased remarkably with an increase in temperature over the range below room temperature, leveled off at 10/sup ´8/ to 10/sup -7/ S/cm between room temperature and some 100/spl deg/C, and reached a peak at around the melting point. Other poly(3-alkylthiopherie)s with different length of alkyl side chains have been examined to correlate the thermal properties with the electrical properties.