An aqueous composition includes water and a cationic polymeric resin having at least one reactive aldehyde group and formed from the reaction of glyoxal and a polymer. The polymer comprises at least one acrylamide repeating unit and at least one cationic repeating unit wherein a number of reactive aldehyde equivalents divided by a number of equivalents of residual glyoxal based on the total weight of the polymer is greater than about 1.2, wherein prior to reaction the polymer has greater than about 50 mole % acrylamide repeat units and from about 2 to about 30 mole % cationic repeating units, wherein greater than about 5 mole % of the acrylamide repeating units are converted to reactive aldehyde groups in the cationic polymer resin; and wherein the composition exhibits a viscosity gain of less than about 200%.

A polyvinyl alcohol-based crosslinked copolymer may include an unsaturated monocarboxylic acid-based structural unit, wherein an amount of carboxylate-forming structural units in the crosslinked copolymer is 1% by mole or more and 35% by mole or less with respect to all structural units constituting the crosslinked copolymer, and a solubility of the crosslinked copolymer in water is 90% or less.

A polyvinyl alcohol-based crosslinked copolymer may include an unsaturated monocarboxylic acid-based structural unit, wherein an amount of carboxylate-forming structural units in the crosslinked copolymer is 1% by mole or more and 35% by mole or less with respect to all structural units constituting the crosslinked copolymer, and a solubility of the crosslinked copolymer in water is 90% or less.

A thermoplastic elastomer for profile control and water shutoff is prepared from the following raw materials in parts by weight: 8-10 parts of a component A, 1-3 parts of a strong acid, 1-3 parts of a hydrophobic modifier and 100-105 parts of water. The component A is one of polyethylene glycol, polyvinylether, polyvinyl alcohol, copolymer of acrylamide and acrylonitrile. The strong acid is one of concentrated hydrochloric acid and concentrated sulfuric acid. The hydrophobic modifier is any one of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, β-propiolactone, γ-butyrolactone, δ-valerolactone, methyltriacetylsilane, methyltrimethylsilane, butyl acrylate and ethylene glycol dimethacrylate. The thermoplastic elastomer for profile control and water shutoff provided by the disclosure has the advantages of one-step preparation and molding, strong deformation capability, temperature resistance, salt tolerance, strong stability and the like, and is suitable for large-scale production and application.

Provided is a hydrogel-forming composition capable of forming a sterilized hydrogel having a high mechanical strength. Also provided are a hydrogel using the hydrogel-forming composition, and a method for producing the hydrogel-forming composition. The hydrogel-forming composition contains a vinyl alcohol polymer having an ethylenically unsaturated group and having a polymerization degree of 450 or more, in which the ethylenically unsaturated group introduction ratio is 0.01 to 10 mol % in all the structural units constituting the vinyl alcohol polymer, and in which no microorganisms detectable by the sterility test method (direct method) specified in the general test methods of the Japanese Pharmacopoeia are present.

Provided is a hydrogel-forming composition capable of forming a sterilized hydrogel having a high mechanical strength. Also provided are a hydrogel using the hydrogel-forming composition, and a method for producing the hydrogel-forming composition. The hydrogel-forming composition contains a vinyl alcohol polymer having an ethylenically unsaturated group and having a polymerization degree of 450 or more, in which the ethylenically unsaturated group introduction ratio is 0.01 to 10 mol % in all the structural units constituting the vinyl alcohol polymer, and in which no microorganisms detectable by the sterility test method (direct method) specified in the general test methods of the Japanese Pharmacopoeia are present.

An object of the present invention is to provide a modified vinyl alcohol polymer having a sulfonic acid or a salt thereof, the polymer having notably improved water solubility as compared with a pre-modified vinyl alcohol polymer. A modified vinyl alcohol polymer (A) has in a side chain thereof a sulfonic acid group or a salt thereof, and in the modified vinyl alcohol polymer (A), a degree of modification with the sulfonic acid group or the salt thereof is 0.01 mol % or more and 10 mol % or less, and a block character of residual vinyl ester units is 0.55 or more and 1 or less.

An object of the present invention is to provide a modified vinyl alcohol polymer having a sulfonic acid or a salt thereof, the polymer having notably improved water solubility as compared with a pre-modified vinyl alcohol polymer. A modified vinyl alcohol polymer (A) has in a side chain thereof a sulfonic acid group or a salt thereof, and in the modified vinyl alcohol polymer (A), a degree of modification with the sulfonic acid group or the salt thereof is 0.01 mol % or more and 10 mol % or less, and a block character of residual vinyl ester units is 0.55 or more and 1 or less.

Disclosed herein are water-soluble polymers comprising hydrolyzable cross-linked monomer units, and methods for recovering hydrocarbon fluids from a subterranean formation using the water-soluble polymers.

Disclosed herein are water-soluble polymers comprising hydrolyzable cross-linked monomer units, and methods for recovering hydrocarbon fluids from a subterranean formation using the water-soluble polymers.