Phase separated methylated polybenzimidazole (O-PBI) based anion exchange membranes

Wiebke Germer, Janine Leppin, Carolina Nunes Kirchner, Hyeongrae Cho, Hyoung Juhn Kim, Dirk Henkensmeier, Kwan Young Lee, Mateusz Brela, Artur Michalak, Alexander Dyck

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9 Citations (Scopus)

Abstract

Methylated polybenzimidazole (O-PBI) based anion exchange membranes with a degree of methylation of ca. 78% were prepared in the iodide, chloride, carbonate, bicarbonate, and hydroxide form. Swelling in water showed a high anisotropy for chloride and carbonate exchanged membranes and a strong plasticizing effect of water was confirmed by DMA. Carbonate and bicarbonate exchanged membranes revealed an ionomer peak around 0.25 Å<sup>-</sup><sup>1</sup> in SAXS measurements suggesting a phase separated morphology. Theoretical DFT calculations were used to characterize geometries and electronic structure of polymer models and interactions with different anions, and to rationalize the water uptake/swelling behavior. Anion exchange membranes are prepared from methylated polybenzimidazole and are exchanged with various anions. Thermal and mechanical properties are evaluated. Unlike other anions, carbonate and bicarbonate exchanged membranes reveal an ionomer peak in SAXS measurements suggesting a phase separated morphology. Water uptake and swelling behavior are rationalized by theoretical DFT calculations.

Original languageEnglish
Pages (from-to)497-509
Number of pages13
JournalMacromolecular Materials and Engineering
Volume300
Issue number5
DOIs
Publication statusPublished - 2015 May 1

Keywords

  • Anion exchange membranes
  • Computer modeling
  • Ion exchange
  • Mechanical properties
  • Thermal properties

ASJC Scopus subject areas

  • Organic Chemistry
  • Materials Chemistry
  • Polymers and Plastics
  • Chemical Engineering(all)

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  • Cite this

    Germer, W., Leppin, J., Kirchner, C. N., Cho, H., Kim, H. J., Henkensmeier, D., Lee, K. Y., Brela, M., Michalak, A., & Dyck, A. (2015). Phase separated methylated polybenzimidazole (O-PBI) based anion exchange membranes. Macromolecular Materials and Engineering, 300(5), 497-509. https://doi.org/10.1002/mame.201400345