SUPERABSORBENT CROSSLINKED AMPHOLYTIC ION PAIR COPOLYMERS

摘要

The present invention provides crosslinked ampholytic copolymersthat are highly absorbent to aqueous electrolyte solutions. The polymers of thepresent invention comprise polymers formed by the copolymerization of aneffective amount of each of the following components to produce a polymer whichis highly absorbent to aqueous electrolyte solutions:(a) an ampholytic ion pair monomer comprising(i) the ammonium cation2-methacryloyloxyethyldimethylammonium and(ii) a sulfonate anion selected from the group consistingof 2-acrylamido-2-methylpropane sulfonate, 2-methacryloyloxyethane sulfonate,vinyl sulfonate, styrene sulfonate and any combination of two or more therof:(b) at least one comonomer selected from the group consistingof acrylamide, methacrylamide, acrylonitrile, acrylic acid, methacrylic acid, alkalisalts of acrylic acid, alkali salts of methacrylic acid, 2-methacryloyloxyethyldimethylamine, 2-acrylamido-2-methylpropane sulfonic acid,alkali salts of 2-acrylamido-2-methylpropane sulfonic acid, 2-methacryloyloxyethane sulfonic acid, alkali salts of 2-methacryloyloxyethanesulfonic acid, N-vinyl-2-pyrrolidone and any combination of two or more thereof;and(c) at least one crosslinking agent which has at least twopolymerizable olefinic functionalities wherein the olefinic functionalities are suitablefor crosslinking.The invention also provides a method of using the polymers ofthe present invention for absorbing an aqueous electrolyte solution comprising thestep of contacting the polymers of the present invention with the aqueouselectrolyte solution.