Durability and performance of polystyrene- b -poly(vinylbenzyl trimethylammonium) diblock copolymer and equivalent blend anion exchange membranes
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden Colorado 80401
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden Colorado 80401
- X-Ray Science Division, Argonne National Laboratory, Argonne Illinois 60439
Anion exchange membranes (AEM) are solid polymer electrolytes that facilitate ion transport in fuel cells. In this study, a polystyrene-b-poly(vinylbenzyl trimethylammonium) diblock copolymer was evaluated as potential AEM and compared with the equivalent homopolymer blend. The diblock had a 92% conversion of reactive sites with an IEC of 1.72 ± 0.05 mmol g-1, while the blend had a 43% conversion for an IEC of 0.80 ± 0.03 mmol g-1. At 50°C and 95% relative humidity, the chloride conductivity of the diblock was higher, 24–33 mS cm-1, compared with the blend, 1–6 mS cm-1. The diblock displayed phase separation on the length scale of 100 nm, while the blend displayed microphase separation (~10 μm). Mechanical characterization of films from 40 to 90 microns thick found that elasticity and elongation decreased with the addition of cations to the films. At humidified conditions, water acted as a plasticizer to increase film elasticity and elongation. While the polystyrene-based diblock displayed sufficient ionic conductivity, the films' mechanical properties require improvement, i.e., greater elasticity and strength, before use in fuel cells. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41596.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); U.S. Army Research Laboratory - U.S. Army Research Office (ARO)
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1239585
- Journal Information:
- Journal of Applied Polymer Science, Vol. 132, Issue 10; ISSN 0021-8995
- Publisher:
- Wiley
- Country of Publication:
- United States
- Language:
- English
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