Absorbent articles and methods of making

1. An absorbent article comprising:

a first substrate; and

a layer of copolymer irreversibly bonded onto the first substrate to form a core, wherein the core comprises acidic functional groups,

wherein the copolymer is derived from:

a first monomer selected from a (meth)acrylic acid or salt thereof;

a second monomer, wherein the second monomer is hydrophilic; and

greater than 1 wt % of a third monomer based on the total weight of monomers used, wherein the third monomer is a hydrophilic crosslinking monomer,

wherein at least 50% of the acidic functional groups in the core are neutralized with salt forming cations.

2. The absorbent article of claim 1 , wherein the second monomer is selected from at least one of 2-hydroxyethylmethacrylate, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, N,N-dimethylacrylamide, and acrylamide.

3. The absorbent article of claim 1 , wherein the copolymer comprises at least 1% of the second monomer.

4. The absorbent article of claim 1 , wherein the third monomer is selected from at least one of methylenebisacrylamide and polyethyleneglycoldiacrylate.

5. The absorbent article of claim 1 , further comprising a second layer, wherein the second layer is a liquid pervious layer.

6. The absorbent article of claim 5 further comprising a third layer, wherein the third layer is a liquid impervious layer and the core sandwiched between the second layer and the third layer.

7. The absorbent article of claim 5 , wherein the second layer is selected from polyester, polyolefin, rayon, cotton, and combinations thereof.

8. The absorbent article of claim 1 , wherein the first substrate is selected from at least one of a thermoplastic and a fabric.

9. The absorbent article of claim 1 , wherein the absorbent article is selected from a diaper, a feminine hygiene pad, an animal hygiene pad, a wound care article, and a chemical absorbent pad.

10. The absorbent article of claim 1 , wherein the first substrate is selected from at least one of a polypropylene, polyethylene, Nylon X, cotton, and cellulose.

11. The absorbent article of claim 1 , wherein the copolymer comprises no more than 30% by weight of a second monomer versus the total weight of monomer.

12. The absorbent article of claim 1 , wherein the copolymer comprises at least 3 and no more than 10% by weight of the third monomer.

13. The absorbent article of claim 1 , wherein the copolymer comprises at least 5% and no more than 20% by weight of the second monomer versus the total weight of monomer.

14. The absorbent article of claim 1 , wherein the copolymer comprises 40 to 97% by weight of the first monomer versus the total weight of monomer.

15. The absorbent article of claim 1 , wherein the copolymer comprises a fourth monomer, wherein the fourth monomer is not hydrophilic.

16. The absorbent article of claim 1 , wherein the second monomer comprises a hydroxyl group-, containing monomer.

17. A method of making an absorbent article comprising:

(a) contacting a polymerizable solution to a first substrate, wherein the polymerizable solution comprises (i) a first monomer selected from a (meth)acrylic acid or salt thereof; (ii) a second monomer, wherein the second monomer is hydrophilic; and (iii) greater than 1 wt % of a third monomer based on the total weight of monomers used, wherein the third monomer is a hydrophilic crosslinking monomer; and

(b) polymerizing the polymerizable solution to irreversibly bond a copolymer onto the first substrate forming a core, wherein the core comprises acidic functional groups, and

wherein at least 50% of the acidic functional groups in the core are neutralized with salt forming cations.

18. The method of claim 17 , wherein the polymerizable solution further comprises a Type II photoinitiator.

19. The method of claim 17 , further comprising washing the core.

20. The method of claim 17 , where the absorbent article is a roll good.