Get access

Synthesis and properties of fluorine- and siloxane-containing polybenzimidazoles for high temperature proton exchange membrane fuel cells

Authors

  • Steve Lien-Chung Hsu,

    Corresponding author
    • Department of Materials Science and Engineering, Research Center for Energy Technology and Strategy, National Cheng-Kung University, Tainan City, Tainan, Taiwan ROC
    Search for more papers by this author
  • Yung-Chung Lin,

    1. Department of Materials Science and Engineering, Research Center for Energy Technology and Strategy, National Cheng-Kung University, Tainan City, Tainan, Taiwan ROC
    Search for more papers by this author
  • Tsung-Yu Tasi,

    1. Department of Materials Science and Engineering, Research Center for Energy Technology and Strategy, National Cheng-Kung University, Tainan City, Tainan, Taiwan ROC
    Search for more papers by this author
  • Li-Cheng Jheng,

    1. Department of Materials Science and Engineering, Research Center for Energy Technology and Strategy, National Cheng-Kung University, Tainan City, Tainan, Taiwan ROC
    2. Nano-Materials Center, ITRI-S, Industrial Technology Research Institute, Tainan, Taiwan ROC
    Search for more papers by this author
  • Cheng-Hsun Shen

    1. Department of Materials Science and Engineering, Research Center for Energy Technology and Strategy, National Cheng-Kung University, Tainan City, Tainan, Taiwan ROC
    Search for more papers by this author

Correspondence to: S.L.-C. Hsu (E-mail: lchsu@mail.ncku.edu.tw)

ABSTRACT

In this study, new fluorine–siloxane-containing polybenzimidazole (PBI) copolymers were synthesized by copolymerization of 3,3′-diaminobenzidine, 2,2-bis(4-carboxyphenyl)-hexafluoropropane (HFA), and 1,3 bis(carboxypropyl)tetramethyldisiloxane (BTMDS) with different molar ratios. PBI copolymer membranes were prepared by solution-casting and then doped with phosphoric acid. The structures of PBI copolymers were characterized by FTIR and X-ray diffraction. The solubility of the PBI copolymers was significantly increased by the introduction of the bulky HFA group and the flexible BTMDS group into the polymer backbone. The PBI copolymers still maintained good thermal stability and mechanical properties. Because of the introduction of the flexible and hydrophobic siloxane group in the polymer backbone, the methanol permeability was reduced and the proton conductivity under anhydrous condition at high temperatures was increased compared to the PBI without the siloxane group. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4107–4112, 2013

Ancillary