Polybenzimidazolium hydroxides are of potential interest for the use in alkaline anion exchange membrane fuel cells (AAEMFC). Introduction of an ether group in para-position of the 2-phenyl substituent improves the mesomeric stabilization of imidazolium cations, and O-PBI seems to be more stable than meta-PBI under alkaline conditions. NMR, IR and XPS analysis show a structural change when the iodide form is exchanged into the hydroxide form. Surprisingly, this structural change is subject to a pH sensitive equilibrium and the pure imidazolium form is retained immediately when the pH is lowered. The molecular structure at high pH is either the 2-carbinol or the amine-amide. Further hydrolysis necessitates excess hydroxide.
|Number of pages
|Polymer Degradation and Stability
|Published - 2012 Mar
Bibliographical noteFunding Information:
The authors would like to thank GOI and “E-Bank” program of Korea Institute of Science and technology. Also, this work was supported by a Grant ( M2009010025 ) from the fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy (MKE), Republic of Korea .
- 2-Phenyl-imidazolium hydroxide
- Anion exchange membrane
- Polymer electrolyte
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Polymers and Plastics
- Materials Chemistry