| abstract |
a crosslinked polymer comprising reagents of a first repeating unit, a second repeating unit, a first crosslinking agent, and a second crosslinking agent that reacts to form the crosslinked polymer, wherein the first repeating unit is a monomer which contains 50% to 99% by weight sulfonic acid present in the reactants, wherein the second repeating unit is selected from the group consisting of an n-vinyl amide-containing monomer, a double-bonded terminal monomer and any combination thereof , and is present from 1% to 50% by weight of the reactants, wherein the first crosslinking agent comprises at least two olefinic bonds, wherein the second crosslinking agent comprises at least two olefinic bonds, and wherein the first and second crosslinking agents together are present in the range of from about 0.01% to about 25% by weight of the reactants. |