Methods for the preparation of fibrous superabsorbent composite containing cellulose

1. A method for making a fibrous composite, comprising:

(a) blending a carboxyalkyl cellulose and a galactomannan polymer or a glucomannan polymer in water to provide an aqueous solution;

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

(c) drying the 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 an aqueous suspension comprising cellulose wood pulp fibers treated with a galactomannan polymer or a glucomannan polymer, and optionally a second crosslinking agent, to provide a mixture; and

(f) mixing the mixture with a water-miscible solvent to provide a fibrous composite.

2. The method of claim 1 further comprising drying the fibrous composite to provide partially-dried fibrous composite.

3. The method of claim 2 further comprising fiberizing the partially-dried fibrous composite to provide partially-dried fiberized fibrous composite.

4. The method of claim 3 further comprising drying the partially-dried fiberized fibrous composite to provide dried fiberized fibrous composite.

5. 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.

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

7. The method of claim 1 , wherein the galactomannan polymer is selected from the group consisting of guar gum, locust bean gum, and tara gum.

8. The method of claim 1 , wherein the glucomannan polymer is konjac gum.

9. The method of claim 1 , wherein the aqueous solution 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 solution comprises from about 1 to about 20 percent by weight galactomannan polymer or glucomannan polymer 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 cellulose wood pulp fibers treated with a galactomannan polymer or glucomannan polymer comprises cellulose wood pulp fibers treated with from about 1 to about 20 percent by weight galactomannan polymer or glucomannan polymer based on the weight of cellulose wood pulp fibers.

14. 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.

15. 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.

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

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

18. The method of claim 1 , wherein the volume of water-miscible solvent to water is from about 1:1 to about 1:5.