Sulfonierte Polyethersulfone, Verfahren zu deren Herstellung sowie deren Verwendung

Die Erfindung betrifft ein Verfahren zur Sulfonierung von aromatischen Polyethersulfonen, wobei in Abhaengigkeit vom Substitutionsgrad stoechiometrische Mangen eines Sulfonierungsmittels eingesetzt werden. Durch Wahl eines geeigneten Loesungsmittelgemisches erfolgt die Sulfonierung in homogener Loesung. Ebenso betrifft die Erfindung sulfonierte Polyethersulfone, deren Substitutionsgrad in Abhaengigkeit von den Verfahrensparametern einstellbar ist. Verwendung finden die sulfonierten Polyethersulfone als Ausgangsmaterialien fuer die Herstellung von Kationenaustauschermembranen.

DE 10149034 A UPAB: 20030723 NOVELTY - A process for sulfonation of aromatic polyether sulfones consisting of repeating units containing SO2 groups, phenylene groups optionally substituted by 1-6C alkyl, 1-6C alkoxy or aryl groups involving the steps: (A) reaction of a polyether sulfone with a sulfonating agent in a halogenated hydrocarbon and a strongly polar organic solvent and (B) precipitation of the sulfonated compound with a polar precipitation agent is new. DETAILED DESCRIPTION - A process for sulfonation of aromatic polyether sulfones consisting of repeating units containing SO2 groups of formula (I) involving the steps: (A) reaction of a polyether sulfone with a sulfonating agent in a halogenated hydrocarbon and a strongly polar organic solvent and (B) precipitation of the sulfonated compound with a polar precipitation agent. -(Z-SO2-Ar-)- (I) Z = selected from groups of formula (II) to (IV) Ar = 1,4-phenylene, 1.3-phenylene, or 1,2-phenylene groups, optionally substituted by 1-6C alkyl, 1-6C alkoxy or aryl groups -O-Ar- (II) -O-Ar-O-Ar- (III) -O-Ar-Ar-O-Ar- (IV) An INDEPENDENT CLAIM is included for a sulfonated polyether sulfone from monomer units of formula (V): -(-O-Ar-Ar-O-Ar-SO2-Ar-)- (V) obtained as above, in which the degree of substitution is higher than 0.8 mmole sulfonic acid groups per gram of dry substance. USE - The sulfonated polyether sulfone is useful for preparation of coatings, shaped bodies, films, membranes, e.g. cation exchange membranes, or fibers (claimed). ADVANTAGE - The process avoids some drawbacks of previous processes, e.g. precipitation of large amounts of impurities in using a large excess of sulfonating agent, difficulty in product isolation and difficulty in scaling up to the industrial scale.