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Polybenzimidazoles/Phosphoric Acid Solid Polymer Electrolytes: Mechanical and Electrical Properties

Published online by Cambridge University Press:  10 February 2011

M. Litt ,
R. Ameri ,
Y. Wang ,
R. Savinell  and
J. Wainwright
M. Litt
Affiliation:
Macromolecular Science Dept. and Chemical Engineering Dept., Case Western Reserve University, Cleveland, OH 44106-7202, [email protected]
R. Ameri
Affiliation:
Macromolecular Science Dept. and Chemical Engineering Dept., Case Western Reserve University, Cleveland, OH 44106-7202
Y. Wang
Affiliation:
Macromolecular Science Dept. and Chemical Engineering Dept., Case Western Reserve University, Cleveland, OH 44106-7202
R. Savinell
Affiliation:
Chemical Engineering Dept., Case Western Reserve University, Cleveland, OH 44106-7202
J. Wainwright
Affiliation:
Chemical Engineering Dept., Case Western Reserve University, Cleveland, OH 44106-7202
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Abstract

Poly (2,2'-(m-phenylene) 5,5'-bibenzimidazole), PBI and poly (2,5-benzimidazole), ABPBI, were cast into films and doped with phosphoric acid. Their mechanical properties were studied as a function of inherent viscosity and phosphoric acid content. The commercial PBI with an I. V. of 0.8 to 0.9 had relatively low elongation at break. It was fractionated; the higher the inherent viscosity the higher the modulus and elongation. At low phosphoric acid doping the modulus rose because a crystalline phase developed, and then dropped as more phosphoric acid was added. A second doping method produced films with high crystallinity and higher conductivity (0.02-.03 vs. 0.06-.08 S/cm) but poorer elongation than those made by doping a cast film in phosphoric acid. In order to get higher molecular weight films that could have better mechanical properties, we decided to polymerize 3,4-diaminobenzoic acid to ABPBI, an AB polymer for which I. V.'s of∼16 have been reported. After learning how to purify and polymerize the monomer, I. V.'s of 6–8 were easily obtained. Conductivities of the doped ABPBI films were as high as those of the best PBI films. With their high viscosities, the ABPBI films were much tougher and had better elongation than the doped PBI films.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 548: Symposia EE – Solid State Ionics V , 1998 , 313
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. Aharoni, S. M. and Litt, M. H., J. Polym. Sci., A–1, 12, p. 639, (1974)Google Scholar
2. Hoel, D. and Grunwald, E., J. Physical Chemistry, 81 p. 2135 (1977)Google Scholar
3. Moaddel, H., Ph.D. Thesis, Case Western Reserve University, 1996 Google Scholar
4. Ameri, R., Ph.D. Thesis, Case Western Reserve University, 1997 Google Scholar
5. Wang, Y., M. S. Thesis, Case Western Reserve University, 1997 Google Scholar
6. Wainwright, J. S., Wang, J.-T., Weng, D., Savinell, R. F. and Litt, M., J. Electrochem. Soc., 142(7), p. L121 (1995).Google Scholar
7. Wang, J.-T., Savinell, R. F., Wainright, J., Litt, M. and Yu, H., Electrochimica Acta, 41(2), p. 193 (1996).Google Scholar
8. Wang, J.-T., Wainright, J. S., Savinell, R. F. and Litt, M., J. Appl. Electrochem., 26, p. 751 (1996).Google Scholar
9. Proton Conducting Polymers Used as Membranes, Savinell, Robert F. and Litt, Morton H., U.S. Patent 5,525,436, June 11, 1996.Google Scholar
10. Product literature from Hoechst-Celanese and the references therein.Google Scholar
11. Private communication, Kurz, David, Case Western Reserve UniversityGoogle Scholar
12. Proton Conducting Polymers by Direct Acid Casting, Savinell, Robert F. and Litt, Morton H., U. S. Patent 5,716,727, February 10 1998 Google Scholar
13. Wereta, Anthony Jr., and Gehatia, Matatiahu T., Poly. Eng. Sci. 18 (3), p. 204, (1978)Google Scholar
14. Delano, Chadwick B., Doyle, R. Randolph and Milligan, Robert J., High Strength, Thermally Stable Polymeric Fibers, AFML-TR-74-22, Feb. 1974 Google Scholar