Method for making fiber having biodegradable superabsorbent particles attached thereto

1. A method for making fibers having particles attached thereto, comprising:

(a) blending a carboxyalkyl cellulose and a starch in water to provide an aqueous gel;

(b) treating the aqueous gel with a first crosslinking agent to provide a crosslinked gel;

(c) drying the crosslinked gel to provide a solid;

(d) comminuting the solid to provide a plurality of particles;

(e) combining at least a portion of the plurality of particles with a aqueous dispersion comprising cellulose fibers and a first water-miscible solvent and, optionally, a second crosslinking agent, to provide a mixture comprising swollen particles and cellulose fibers; and

(f) adding a second water-miscible solvent to the mixture to provide fibers having particles attached thereto.

2. The method of claim 1 further comprising adding the second crosslinking agent only after adding the second water-miscible solvent.

3. The method of claim 1 , further comprising drying the fibers having particles attached thereto to provide partially-dried fibers having particles attached thereto.

4. The method of claim 3 , further comprising fiberizing the partially-dried fibers to provide partially-dried fiberized fibers having particles attached thereto.

5. The method of claim 4 , further comprising drying the partially-dried fiberized fibers to provide dried, fiberized fibers having particles attached thereto.

6. The method of claim 1 , wherein the carboxyalkyl cellulose has a degree of carboxyl group substitution of from about 0.3 to about 2.5.

7. The method of claim 1 , wherein the carboxyalkyl cellulose is carboxymethyl cellulose.

8. The method of claim 1 , wherein the starch is selected from the group consisting of corn, wheat, maize, rice, sorghum, potato, cassava, barley, buckwheat, millet, oat, arrowroot, beans, peas, rye, tapioca, sago, and amaranth starches.

9. The method of claim 1 , wherein the aqueous gel comprises from about 60 to about 99 percent by weight carboxyalkyl cellulose based on the total weight of particles.

10. The method of claim 1 , wherein the aqueous gel comprises from about 1 to about 20 percent by weight starch based on the total weight of particles.

11. The method of claim 1 , wherein the first crosslinking agent is selected from the group consisting of aluminum (III) compounds, titanium (IV) compounds, bismuth (III) compounds, boron (III) compounds, and zirconium (IV) compounds.

12. The method of claim 1 , wherein the first crosslinking agent is present in an amount from about 0.1 to about 20 percent by weight based on the total weight of particles.

13. The method of claim 1 , wherein the second crosslinking agent is selected from the group consisting of aluminum (III) compounds, titanium (IV) compounds, bismuth (III) compounds, boron (III) compounds, and zirconium (IV) compounds.

14. The method of claim 1 , wherein the second crosslinking agent is present in an amount up to about 20 percent by weight based on the total weight of composite fibers.

15. The method of claim 1 , wherein the first water-miscible solvent is an alcohol.

16. The method of claim 1 , wherein the first water-miscible solvent is selected from the group consisting of methanol, ethanol, isopropanol, and mixtures thereof.

17. The method of claim 1 , wherein the second water-miscible solvent is an alcohol.

18. The method of claim 1 , wherein the second water-miscible solvent is selected from the group consisting of methanol, ethanol, isopropanol, and mixtures thereof.