A non crosslinked, covalently crosslinked and/or ionically crosslinked polymer, having repeating units of the general formula (1)

KR(1)

In which K is a bond, oxygen, sulfur,

##STR00001##

the radical R is a divalent radical of an aromatic or heteroaromatic compound.

A non crosslinked, covalently crosslinked and/or ionically crosslinked polymer, having repeating units of the general formula (1)

KR(1)

In which K is a bond, oxygen, sulfur,

##STR00001##

the radical R is a divalent radical of an aromatic or heteroaromatic compound.

The invention relates to the coating of anion exchange membranes (AEM) with catalytically active substances. The CCM thus obtained are used in electrochemical cells, especially for alkaline water electrolysis. It was an object of the invention to specify a process for producing a CCM by direct coating which maintains the necessary planarity of the AEM and ideally avoids the use of lost films and eschews CMR substances. Swelling shall also be minimized. The process shall also be performable with fluorine-free ionomers. The invention is based on the finding that the addition of certain organic substances has the result that the AEM swells only to a small extent, if at all (antiswelling agent). It has surprisingly been found that substances suitable as antiswelling agents are identifiable by their solubility behaviour, more particularly by their Hansen parameters.

The invention relates to a graft polyarylether (PAE) copolymer (P1), a process for preparing the graft PAE copolymer (P1) from a side-chain allyl/vinylene-functionalized PAE copolymer (P0) via free radical reaction with vinyl pyrrolidone, and the use of the graft PAE copolymer (P1) in the preparation of an article, such as a membrane or a part thereof. The graft PAE copolymer (P1) comprises at least two types of recurring units, one of which having side-chain grafted poly(vinylpyrrolidone). The invention also relates to an amorphous side-chain allyl/vinylene-functionalized polyaryletherketone copolymer (P0).