Copolymerized superabsorbent polymers
Described herein are novel super absorbent materials. The super absorbent materials are copolymerized with strong or super strong ionizable monomers and bulky counter ions or select metal salts. The copolymer-based super absorbent materials have significantly improved absorbance properties. The compositions and methods described herein are useful in a variety of absorbent products.
1 . A superabsorbent polymer comprising:
a polymer backbone comprising:
a strong or super strong ionizable backbone monomer comprising:
an anion of a strong organic acid; and
a super ionizable counter ion;
a neutralized backbone monomer; and
an un-neutralized backbone monomer; and
optionally a crosslinker;
wherein the polymer backbone lacks structured ordering of the strong or super strong ionizable backbone monomer, the neutralized backbone monomer, and the un-neutralized backbone monomer.
2 . The superabsorbent polymer of claim 1 , wherein the strong or super strong ionizable backbone monomer is present in an amount in the range of from about 0.01 to about 5 mol % of the superabsorbent polymer, the neutralized backbone monomer is present in an amount in the range of from about 50 to about 99 mol % of the superabsorbent polymer, and the un-neutralized backbone monomer is present in an amount in the range of from about 0 to about 40 mol % of the superabsorbent polymer.
3 . The superabsorbent polymer of claim 1 , wherein the strong or super strong ionizable backbone monomer is present in an amount less than about 15 wt % of the combined amounts of the neutralized backbone monomer and the un-neutralized backbone monomer.
4 . The superabsorbent polymer of claim 1 , wherein the superabsorbent polymer is in a form selected from the group consisting of a particle, a gel, a fiber, a bead, a liquid, a solid, a paste, or combinations thereof.
5 . The superabsorbent polymer of claim 1 , wherein the superabsorbent polymer is in the form of a particle with a diameter in the range of about 100 μm to about 1000 μm.
6 . The superabsorbent polymer of claim 1 , wherein the superabsorbent polymer does not comprise a crosslinker.
7 . The superabsorbent polymer of claim 1 , wherein the neutralized backbone monomer and the un-neutralized backbone monomer are each individually selected from the group consisting of acrylic acids, methacrylic acids, vinyl sulfonic acids, vinyl phosphoric acids, partially hydrolyzed maleic anhydrides, and combinations thereof.
8 . The superabsorbent polymer of claim 1 , wherein the super ionizable counter ion is selected from the group consisting of ammonium, tetramethylammonium, tetraethylammonium, tetrabutylammonium, and combinations thereof.
9 . The superabsorbent polymer of claim 1 , wherein the super ionizable counter ion has a major dimension greater than about 0.25 nm.
10 . The superabsorbent polymer of claim 1 , wherein the anion of a strong organic acid is selected from the group consisting of sulfonic acids, sulfuric acids, phosphonic acids, nitric acids, and combinations thereof.