Solid-State Polymerization of 2,5-Dibromothiophene Derivatives and Properties of Corresponding Conducting Polymers
Conducting polymers poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedithiathiophene) (PEDTT) have been synthesized by solid-state polymerization of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) and 2,5-dibromo-3,4-ethylenedithiathiophene (DBEDTT) respectively in air and under vacuum. Both polymers were completely insoluble in common organic solvents and retained partial crystal structure of monomers as indicated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. Thermoelectric tests showed that PEDTT exhibited Seebeck coefficient about 120 µV K−1 at 170 K, which is higher than PEDOT, while the later exhibited higher electrical conductivity (0.1S cm-1 at 298 K) and better thermal stability indicated by the thermal analyses. These results showed that replacement of oxygen by sulfur in the monomer structure played an important role on the properties of polymers.
Zhong Cao, Xueqiang Cao, Lixian Sun, Yinghe He
S. A. Chen et al., "Solid-State Polymerization of 2,5-Dibromothiophene Derivatives and Properties of Corresponding Conducting Polymers", Advanced Materials Research, Vols. 239-242, pp. 924-929, 2011