The present invention relates to a process for preparing aqueous
formulations (A) comprising at least one polyaromatic compound bearing
acid groups, in particular a sulfonated polyaromatic compound, and also
aqueous formulations (A) which have been prepared by the process of the
invention. Furthermore, the present invention relates to a process for
preparing dried formulations (B) by removing the water from the aqueous
formulations (A) and also the dried formulations (B) themselves. The
present invention further provides a formulation (C) comprising the dried
formulation (B) of the invention and water or the formulation A of the
invention and a water-comprising formulation (D) comprising the aqueous
formulation (A) or the formulation (C) of the invention and additionally
at least 2% by weight of an organic solvent. Furthermore, the present
invention relates to dry formulations (E) which are obtained by removing
water and solvent from the water-comprising formulations (D) of the
invention. The present invention further provides for the use of the
water-comprising formulations (D) of the invention and of the dry
formulations (E) obtained from these for producing a polymer electrolyte
membrane and also the polymer electrolyte membrane itself and a
membrane-electrode assembly (MEA) and also a fuel cell comprising the
polymer electrolyte membrane of the invention.