Get access

Temperature-rise fractionation of poly(3-alkyl thiophenes)

Authors

  • Scott W. Lefevre,

    1. Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180
    Search for more papers by this author
  • Heungyeal Choi,

    1. Department of Chemistry and Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang 790-784, Korea
    Search for more papers by this author
  • Taihyun Chang,

    1. Department of Chemistry and Division of Advanced Materials Science, Pohang University of Science and Technology, Pohang 790-784, Korea
    Search for more papers by this author
  • Chang Y. Ryu

    Corresponding author
    1. Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180
    • Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180
    Search for more papers by this author

Abstract

In this article, we have investigated a temperature-rise fractionation procedure for poly(3-hexyl thophene) (P3HT) and poly(3-octyl thophene) (P3OT) that provides well-defined molecular weight (MW) fractions with improved molecular weight distributions (MWD) when compared with Soxhlet extraction. This process involves dispersing the material over C18-boned silica stationary phase in a jacketed column and using incremental rises in column temperature (Tcol) to gradually improve solvent quality and selectively dissolve higher molecular weight samples with a narrow polydispersity (PDI). Fractionation of P3HT with ΔTcol = 5 °C in methylene chloride (MC) yielded 7 fractions ranging from Mp of 20 to 53 kg/mol with an average PDI of 1.80 compared with a mother sample of 3.10. Predominant recovery of P3HT was acquired for fractions with Tcol > 20 °C (30 wt %). Subsequent separation of P3OT in methylene chloride, with a reduced ΔTcol of 3 °C per fraction, due to increased solubility from the longer alkyl chain, generated 8 fractions with a weight range of Mn = 22 to 57 kg/mol with an mean PDI of 1.23 with the mother sample having PDI = 2.34, demonstrating the tunability of this method. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2547–2555, 2009

Ancillary