Adhesive hydrogel and method for electrolytic protection of concrete structure

An adhesive hydrogel which comprises a polymer matrix, water, and a polyhydric alcohol,

• the polymer matrix containing a copolymer of a monofunctional monomer with a single polymerizable C—C double bond and a polyfunctional monomer with two or more polymerizable C—C double bonds,
• the monofunctional monomer containing a nonionic (meth)acrylamide-based monomer, and
• the polyfunctional monomer having a composition formula:
• ClHmOn,
• where O is an oxygen atom in an ether bond, 1 is an integer greater than or equal to 4, m is an integer greater than or equal to 6, and n is an integer greater than or equal to 0,
• wherein the polyfunctional monomer is at least one compound selected from aromatic divinyl compounds,
• wherein the adhesive hydrogel comprises, as the polyhydric alcohol, only at least one compound selected from the group consisting of ethylene glycol, propylene glycol, butanediol, glycerin, pentaerythritol, sorbitol, polyethylene glycol, and polypropylene glycol, and
• wherein the monofunctional monomer comprises, as the nonionic (meth)acrylamide-based monomer, only at least one compound selected from the group consisting of (meth)acrylamide, N,N-dimethyl(meth)acrylamide, and dimethylaminopropyl(meth)acrylamide.