abstract |
A crosslinked polymer comprising reactants of a first repeating unit, a second repeating unit, a first crosslinker, and a second crosslinker that react to form the crosslinked polymer, wherein the first repeating unit is a sulfonic acid-containing monomer present from 50% to 99% by weight of the reactants, wherein the second repeating unit is selected from the group consisting of an N-vinyl amide-containing monomer, a terminal double bond-containing monomer, and any combination thereof, and is present from 1% to 50% by weight of the reactants, wherein the first crosslinker comprises at least two olefinic bonds, wherein the second crosslinker comprises at least two olefinic bonds, and wherein the first and second crosslinkers combined are present in the range of about 0.01% to about 25% by weight of the reactants. |