Korean Membrane Journal

The Membrane Society of Korea (한국막학회)
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Synthesis and Characterization of Polybenzimidazoles Containing Perfluorocyclobutane Groups for High-temperature Fuel Cell Applications

  • Chang, Bong-Jun (Environment & Energy Research Center, Sustainable Chemical Technology, Korea Research Institute of Chemical Technology) ;
  • Kim, Dong-Jin (Environment & Energy Research Center, Sustainable Chemical Technology, Korea Research Institute of Chemical Technology) ;
  • Kim, Jeong-Hoon (Environment & Energy Research Center, Sustainable Chemical Technology, Korea Research Institute of Chemical Technology) ;
  • Lee, Soo-Bok (Biorefinery Research Center, Sustainable Chemical Technologies, Korea Research Institute of Chemical Technology) ;
  • Joo, Hyeok-Jong (Department of Polymer Science and Engineering, Chungnam National University)
  • Published : 2007.12.31
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Abstract

This paper describes the preparation and characterization of two kinds of fluorinated polybenzimidazole (PBI)s which can be potentially used for phosphoric acid-doped, high-temperature polymer electrolyte membrane fuel cells. Two kinds of perfluorocyclobutane (PFCB)-containing monomers were prepared via following synthetic steps; after fluoroalkylation of methyl 3-(hydroxy) benzoate and methyl 4-(hydroxy) benzoate with 1,2-dibromotetrafluoroethane and subsequent Zn-mediated dehalogenation, these compounds were cyclodimerized at $200^{\circ}C$ affording the ester-terminated monomers containing PFCB ether groups. The synthesized intermediates and monomers were characterized using FT-IR, $^1H-NMR,\;^{19}F-NMR$, and mass spectroscopy. The fluorinated PBIs were then successfully prepared through the solution polycondensation of the monomers and 3,3'-diaminobenzidine in polyphosphoric acid. Compared with traditional PBI, the glass transition temperatures of the fluorinated PBIs were obtained at $262^{\circ}C\;and\;269^{\circ}C$ which are lower than that of PBI and their initial degradation temperatures were still high over $400^{\circ}C$ under nitrogen. The fluorinated PBIs showed higher d-spacing values and improved solubility in several organic solvents as well as phosphoric acid, which confirmed they could be good candidates for the high temperature fuel cell membranes.

Keywords

References

  1. H. Vogel and C. S. Marvel, 'Polybenzimidazoles, new thermally stable polymers', J. Polym. Sci., L, 511 (1961)
  2. Y. Iwakura, U. Uno, and Y. Imai, 'Polyphenylene-benzimidazoles', J. Polym. Sci. Part A, 2, 2605 (1964)
  3. H. K. Mark, N. M. Bikales, C. G. Overberger, and G. Menges, vol. 11, 'Encyclopedia of polymer science and engineering', Wiley-Interscience, pp. 572-601 (1988)
  4. T. S. Chung and Z. L. Xu, 'Asymmetric hollow fiber membranes prepared from miscible polybenzimidazole and polyetherimide blends', J. Membr. Sci., 147, 35 (1998)
  5. H. A. Pohl, 'Carriers and unpaired spins in some organic semiconductors', J. Polym. Sci. Part A, 2, 2787 (1964)
  6. J. S. Wainright, J. T. Wang, D. Weng, R. F. Savinell, and M. H. Litt, 'Acid-doped polybenzimidazoles: a new polymer electrolyte', J. Electrochem. Soc., 142, L121 (1995) https://doi.org/10.1149/1.2043853
  7. D. J. Jones and J. Roziere, 'Recent advances in the functionalisation of polybenzimidazole and polyetherketone for fuel cell applications', J. Membr. Sci., 185, 41 (2001) https://doi.org/10.1016/S0376-7388(00)00630-X
  8. T. Brock, D. C. Sherrington, and H. G. Tang, 'Synthesis and characterization of polybenzimidazoles carrying additional pyridine and imidazole groups in the main chain', Polymer, 32, 353 (1991)
  9. B. Gordon, R. J. Kumpf, and P. C. Painter, 'A thermally stable polybenzimidazole polybenzoxazole segmented block copolymer', J. Polym. Sci. Part A: Polym. Chem., 26, 1689 (1998)
  10. M. B. Gieselman and J. R. Reynolds, 'Water-soluble polybenzimidazole-based polyelectrolytes', Macromolecules, 25, 4832 (1992)
  11. M. B. Gieselman and J. R. Reynolds, 'Aramid and imidazole based polyelectrolytes: physical properties and ternary phase behavior with poly(benzobisthiazole) in methanesulfonic acid', Macromolecules, 26, 5633 (1993)
  12. K. Uno, K. Niume, Y. Iwata, F. Toda, and Y. Iwakura, 'Synthesis of polybenzimidazoles with sulfonic acid groups', J. Polym. Sci.: Polym. Chem. Ed., 15, 1309 (1997)
  13. H. Pu and G. Liu, 'Synthesis and solubility of poly(N-methylbenzimidazole) and poly(N-ethylbenzimidazole): control of degree of alkylation', Polym. Int., 54, 175 (2005)
  14. D. A. Babb, B. R. Ezzell, K. S. Clement, W. F. Richey, and A. P. Kennedy, 'Perfluorocyclobutane aromatic ether polymers', J. Polym. Sci. Part A: Polym. Chem., 31, 3465 (1993)
  15. A. P. Kennedy, D. A. Babb, J. N. Bremmer, and A. J. Pasztor Jr., 'Perfluorocyclobutane aromatic ether polymers. II. Thermal/ oxidative stability and decomposition of a thermoset polymer', J. Polym. Sci. Part A: Polym. Chem., 33, 1859 (1995)
  16. W. S. Choi and F. W. Harris, 'Synthesis and polymerization of trifluorovinylether-terminated imide oligomers. I', Polymer, 41, 6213 (2000)
  17. S. Wong, H. Ma, A. K. Y. Jen, R. Barto, and C. W. Frank, 'Highly fluorinated trifluorovinyl aryl ether monomers and perfluorocyclobutane aromatic ether polymers for optical waveguide applications', Macromolecules, 36, 8001 (2003)
  18. S. Wong, H. Ma, A. K. Y. Jen, R. Barto, and C. W. Frank, 'Perfluorocyclobutane-based polyester(arylene ether)s for applications in integrated optics', Macromolecules, 36, 8001 (2003)
  19. J. Ghim, D. S. Lee, B. G. Shin, D. Yak, D. K. Yi, M. J. Kim, H. S. Shim, J. J. Kim, and D. Y. Kim, 'Optical properties of perfluorocyclobutane aryl ether polymers for polymer photonic devices', Macromolecules, 37, 5724 (2004)
  20. D. W. Smith Jr., D. A. Babb, H. V. Shah, A. Hoeglund, R. Traiphol, D. Perahia, H. W. Boone, C. Langhoff, and M. Radler, 'Perfluorocyc1obutane (PFCB) polyaryl ethers: versatile coatings materials', J. Fluorine Chem., 104, 109 (2000) https://doi.org/10.1016/S0022-1139(00)00221-9
  21. J. F. Rabek, 'Experimental methods in polymer chemistry', Wiley-Interscience, New York (1980)
  22. S. C. Ligon Jr., M. Krawiec, A. Kitaygorodskiy, and D. W. Smith Jr., 'First separation and characterization of cis and trans 1,2-bisaryloxy perfluorocyclobutanes', J. Fluorine Chem., 123, 139 (2003) https://doi.org/10.1016/S0022-1139(03)00147-7
  23. D. A. Babb, K. S. Clement, W. F. Richey, and B. R. Ezzell, U.S. patent 5037917 (1991)
  24. D. K. Kim, B. J. Chang, C. K. Shin, J. H. Kim, S. B. Lee, and H. J. Joo, 'Preparation and characterization of fluorenyl polymer electrolyte membranes containing PFCB groups', Membrane Journal, 16(1), 16 (2006)