SUPERABSORBENT CROSSLINKED AMPHOLYTIC ION PAIR COPOLYMERS

摘要

The present invention provides crosslinked ampolyticcopolymers that are highly absorbent to aqueous electrolyte solutions.The polymers of the present invention comprise copolymers formed by thecopolymerization of an effective amount of each of the followingcomponents to produce a polymer which is highly absorbent to aqueouselectrolyte solutions:(a) an ampholytic ion pair monomer comprising(i) the ammonium cation3-methacrylamidopropyldimethylammonium and(ii) a sulfonate anion selected from the group consistingof 2-acrylamido-2-methylpropane sulfonate, 2-methacryloyloxyethanesulfonate, vinyl sulfonate, styrene sulfonate and combinations of two ormore thereof;(b) at least one comonomer selected from the group consistingof acrylamide, methacrylamide, acrylonitrile, acrylic acid, methacrylicacid, alkali salts of acrylic acid, alkali salts of methacrylic acid,3-methacrylamidopropyldimethylamine, 2-acrylamido-2-methylpropanesulfonic acid, alkali salts of 2-acrylamido-2-methylpropane sulfonicacid, 2-methacryloyloxyethane sulfonic acid, alkali salts of2-methacryloyloxyethane sulfonic acid, N-vinyl-2-pyrrolidone andcombinations of two or more thereof; and(c) at least one crosslinking agent which has at least twopolymerizable olefinic functionalities wherein the olefinicfunctionalities are suitable for crosslinking.The invention also provides a method of using the polymers ofthe present invention for absorbing aqueous electrolyte solutionscomprising the step of contacting the polymers of the present inventionwith the aqueous electrolyte solution.