A stack of ion exchange membranes suitable for water purification comprising a plurality of anion exchange membranes (AEMs) and a plurality of cation exchange membranes (CEMs), wherein the colour properties of the AEMs are visibly different to the colour properties of the CEMs. The invention also provides a process for making membrane stacks in which the likelihood of there being two consecutive membranes of like charge is reduced. Furthermore, it is easy to identify whether there are two consecutive membranes of like charge present in the stacks.

Bipolar membranes (BPMs) comprising a cation exchange layer (CEL) and an anion exchange layer (AEL) wherein the colour properties of the CEL are visibly different to the colour properties of the AEL. The CEL and the AEL are easily distinguishable so that a stack of membranes comprising the BPMs can be built fast and without mistakes in layer order.

Bipolar membranes (BPMs) comprising a cation exchange layer (CEL) and an anion exchange layer (AEL) wherein the colour properties of the CEL are visibly different to the colour properties of the AEL. The CEL and the AEL are easily distinguishable so that a stack of membranes comprising the BPMs can be built fast and without mistakes in layer order.

Provided are a polymer medicament for treating hyperkalemia, and a preparation method thereof. Specifically, a polymer is provided, and the polymer includes repeating units obtained by polymerizing a monomer and a crosslinking agent. A molar ratio of the monomer to the crosslinking reagent ranges from 1:0.02 to 1:0.20. The monomer includes an acidic group and a pKa-reducing group next to the acidic group. The acidic group is selected from the group consisting of sulfonic acid group (—SO.sub.3—), sulfuric acid group (—OSO.sub.3—), carboxylic group (—CO.sub.2—), phosphonic acid group (—OPO.sub.3.sup.2—), phosphate group (—OPO.sub.3.sup.2—), and sulfamic acid group (—NHSO.sub.3—). The pKa-reducing group is selected from the group consisting of nitro, cyano, carbonyl, trifluoromethyl, and halogen atoms. The crosslinking agent has three or four reaction sites. The polymer can be used to treat hyperkalemia.

Provided are a polymer medicament for treating hyperkalemia, and a preparation method thereof. Specifically, a polymer is provided, and the polymer includes repeating units obtained by polymerizing a monomer and a crosslinking agent. A molar ratio of the monomer to the crosslinking reagent ranges from 1:0.02 to 1:0.20. The monomer includes an acidic group and a pKa-reducing group next to the acidic group. The acidic group is selected from the group consisting of sulfonic acid group (—SO.sub.3—), sulfuric acid group (—OSO.sub.3—), carboxylic group (—CO.sub.2—), phosphonic acid group (—OPO.sub.3.sup.2—), phosphate group (—OPO.sub.3.sup.2—), and sulfamic acid group (—NHSO.sub.3—). The pKa-reducing group is selected from the group consisting of nitro, cyano, carbonyl, trifluoromethyl, and halogen atoms. The crosslinking agent has three or four reaction sites. The polymer can be used to treat hyperkalemia.

The invention relates to copolymers and molding compounds having reactively bonded sulfur and an overall low sulfur content. The copolymers and molding compounds of the invention are substantially colorless and odorless while sufficiently flame-retardant and can be used in the building industry and electrical industry.

The invention relates to copolymers and molding compounds having reactively bonded sulfur and an overall low sulfur content. The copolymers and molding compounds of the invention are substantially colorless and odorless while sufficiently flame-retardant and can be used in the building industry and electrical industry.

The invention relates to copolymers and molding compounds having reactively bonded sulfur and an overall low sulfur content. The copolymers and molding compounds of the invention are substantially colorless and odorless while sufficiently flame-retardant and can be used in the building industry and electrical industry.

The present invention relates to a method for preparing a macromolecular composition comprising indene-derivatives. The invention also relates to the macromolecular compositions per se, and to methods of using the macromolecular compositions. The macromolecular compositions are useful for undergoing subsequent reactions with small molecules.

The present invention relates to a method for preparing a macromolecular composition comprising indene-derivatives. The invention also relates to the macromolecular compositions per se, and to methods of using the macromolecular compositions. The macromolecular compositions are useful for undergoing subsequent reactions with small molecules.