Acid base polymer membrane for use as fuel cells membrane for e.g. hydrogen or direct methanol fuel cells, comprises at least one polymeric acid or polymer base with specified proton conductivity

摘要

An acid-base polymer blend membrane comprises (a) at least one polymeric acid with SO3H, PO3H2, COOH, or B(OH)2 groups and (b) at least one polymeric base (I) with a specific proton conductivity of at least 10-5 Scm. Independent claims are included for the following: (i) the preparation of a polymer blend membrane by mixing at least one polymeric acid with SO3X, PO3X, COOX, or B(OX)2 groups, where X = H or a mono-, di-, tri-, or quadrivalent metal cation and at lest one polymeric base (I) of specific proton conductivity of at least 10-5 Scm in a dipolar-aprotic solvent, especially N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, or sulfolanes to give a polymer solution; and (ii) thin films drawn from the polymer solution onto a base, especially a glass, metal plate, fabric, fleece, or a porous polymer membrane, where the solvent is evaporated under normal pressure at 80-150 deg C or under vacuum, and the thin film is post-treated in the following steps, where optionally step (a) and/or step (b), and/or step (c) can be omitted: (a) in water at 50-100 deg C; (b) in 1-100% mineral acid, especially a hydrogen halide, sulfuric acid, phosphoric acid, at 50-100 deg C; (c) in 1-50% aqueous liquor, especially ammonia solution, amine solution, NaOH, KOH, Na carbonate solution, Ca or Ba hydroxide solution, and (d) in water at the region of 100 deg C.