The relation between molecular weights and electrical properties was investigated for electrochemically prepared poly(3-hexylthiophene) (PHT). The PHT films with weight-average molecular weight (Mw) in the range 12 500-58 000 were prepared by controlling the polymerization conditions. For Mw < 25 000, the electrical conductivities (tz) of as-polymerized PHT films increased rapidly from 10 -1 to 101 S cm-1 with increasing Mw. For Mw > 25 000, the increase in a with Mw was minor. The visible absorption maximum (Tr-Tr* absorption band) of the neutral PHT films shifted to the red side as Mw increased. The shift was more prominent in the samples with low Mw ( < 25 000). Wide-angle X-ray analyses of the films showed that the increase in Mw resulted in an increase in regularity of supermolecular structure in the as-polymerized PHT films, which enhanced the development of a ~z-conjugated system in the sample.
Посилання на статтю:
Effects of molecular weight on the electrical properties of electrochemically synthesized poly ( 3- hexylthiophene ) / Satoshi Osawa*, Masayoshi Ito*% Satoshi Iwase, Hirofumi Yajima,Ryuichi Endo and Koji Tanaka // Polymer. – 1992. – Vol 33. – P. 914-919.