hide
Free keywords:
-
Abstract:
The synthesis of novel soluble copolyarylenes, their
functionalization with sulfonic and carboxylic acid groups, and
the determination of fuel cell relevant parameters (swelling
behavior, methanol permeation, and ionic conductivity) are
described. The Ni(O)-catalyzed homocoupling reaction of aryl
chlorides was employed for the polymerizations. Carboxylic acid
groups were incorporated by copolymerization of methyl 2,5-
dichlorobenzoate and subsequent hydrolysis. The composition was
varied from 53 to 100 mol % carboxylic acid groups. Sulfonic
acid groups were introduced by sulfonation with chlorosulfonic
acid. Flexible and transparent membranes with sulfonic and/or
carboxylic acid groups were prepared that exhibited higher
proton conductivities (values in the range of sigma = 0.11-0.23
S/cm) compared to those of Nafion and sulfonated PEEK as a
result of higher ion exchange capacity and water content.
Incorporation of carboxylic acid groups led to a reduced water
uptake but lower conductivities.
