A crosslinked copolymer is provided, which includes a copolymer crosslinked by a crosslinking agent. The copolymer is copolymerized of (a) styrene-based monomer, (b) monomer having conjugated double bonds or acrylate ester monomer, and (c) ammonium-containing heterocyclic monomer. The crosslinking agent is (d) ##STR00001##
or the product of the reaction between ##STR00002##
and (e) ##STR00003##
or a combination thereof. Z is ##STR00004##
wherein each R.sup.1 is independently H or C.sub.1-4 alkyl group, each R.sup.2 is independently H or C.sub.1-4 alkyl group, R.sup.3 is single bond, —O—, —S—, —CH.sub.2—, or —NH—. n is a positive integer. x is 1 to 12, y is 1 to 5, and z is 1 to 5.

A method for manufacturing a crosslinked polyolefin separator and the crosslinked polyolefin separator obtained therefrom are provided. The method includes non-grafted polyolefin having a weight average molecular weight of 300,000 or more and silane-grafted polyolefin having a weight average molecular weight of 300,000 or more. The method minimizes gel formation, a side reaction occurring in an extruder during the manufacture of the separator, and provides the separator having a uniform surface.

A cation-exchange membrane using a polyolefin-based substrate with reduced swelling of an ion-exchange resin and a low electrical resistance is provided. The cation-exchange membrane of the present invention includes a substrate made of polyolefin-based woven fabric, and a sulfonic acid group-containing cation-exchange resin. A portion of the cation-exchange membrane other than the substrate has 23 mass % or more to 35 mass % or less of polyvinyl chloride.

Provided are a curable composition including a compound expressed by General Formula (1) below; a polymerization initiator; and a chain transfer agent, and a cured polymer product. ##STR00001##
In General Formula (1), m represents an integer of 1 to 4, and n represents an integer of 1 to 4. Here, a sum of m and n is not greater than 5. M.sup.A represents a hydrogen ion, an inorganic ion, or an organic ion. Here, an inorganic ion and an organic ion may be bivalent or higher ions. Each of R.sup.1 and R.sup.2 independently represents a hydrogen atom or an alkyl group.

An ion exchange membrane obtained by using an ionic monomer having at least two or more polymerizable functional groups, in which a hydrophobicity index H obtained by an expression below from a monomer for forming an ion exchange resin and a material fixed to the resin in the ion exchange membrane is 1.6 or greater, and a manufacturing method therefor. Hydrophobicity index H=Σ{(log P of each component)×(molar ratio of each material in resin)}.

Highly energy efficient electrodialysis membranes having low operating costs and a novel process for their manufacture are described herein. The membranes are useful in the desalination of water and purification of waste water. They are effective in desalination of seawater due to their low electrical resistance and high permselectivity. These membranes are made by a novel process which results in membranes significantly thinner than prior art commercial electrodialysis membranes. The membranes are produced by polymerizing one or more monofunctional ionogenic monomers with at least one multifunctional monomer in the pores of a porous substrate.

An ion exchange membrane having a structure that an ion exchange resin is filled in spaces of a porous base film, the porous base film has a structure that at least two porous olefin resin layers are laminated with a bonding strength of 100 gf/cm or more to less than 700 gf/cm and a Gurley air permeance of 500 sec/100 ml or less in terms of a 100 μm thick film. In this ion exchange membrane, base film has high air permeability though it has a multi-layer structure that a plurality of porous resin films are bonded together, and therefore a rise in electric resistance caused by the lamination of the base sheets is effectively suppressed.

A cation-exchange membrane including: layer (I) containing repeating units (A) each represented by formula (1) and repeating units (S) each containing a sulfonic acid-type ion-exchange group, wherein the mass proportion of repeating units (A) based on the total mass proportion of repeating units (A) and repeating units (S) being 100% by mass is 53% by mass or more and 70% by mass or less; and layer (II) containing a fluorine-containing polymer containing a carboxylic acid-type ion-exchange group and disposed on layer (I), wherein the water content of layer (I) is 26% or more and 35% or less:

CF.sub.2—CF.sub.2  (1)

Described are ion-exchange membranes that include a porous polymeric membrane and imidazole ion-exchange groups at surfaces of the membrane; ion-exchange membranes and filters that contain the ion-exchange membranes; and methods of using the ion-exchange membranes and filters for separating charged biological molecule from a liquid.

Ion exchange membranes for use in electrochemical energy conversion and storage applications include copolymers having a backbone produced from an olefin, such as ethylene, and a cyclic olefin, such as norbornene. Haloalkyl side chains with terminal halide groups are connected to the polymer backbone via Friedel-Crafts alkylation. The halide groups are then replaced with ionic groups via substitution. The ion exchange membrane material can then be cast or impregnated into a reinforcing mesh to form cation exchange membrane or anion exchange membranes. Rigidity of the ion exchange membranes can be controlled by varying the ratio of olefin to cyclic olefin in the polymer backbone.