Crosslinked dextran and crosslinked dextran-poly alpha-1,3-glucan graft copolymers
Compositions are disclosed herein comprising one or more crosslinked dextrans or crosslinked dextran-poly alpha-1,3-glucan graft copolymers. Further disclosed are processes for preparing such crosslinked materials, as well as their use in absorption applications.
1. A composition comprising a crosslinked graft copolymer,
wherein the graft copolymer portion of the crosslinked graft copolymer comprises:
(i) a backbone comprising dextran, and
(ii) poly alpha-1,3-glucan side chains comprising at least 50% alpha-1,3-glucosidic linkages;
wherein one or more crosslinks of the crosslinked graft copolymer are covalent.
2. The composition of claim 1 , wherein one or more crosslinks of the crosslinked graft copolymer comprise phosphorus.
3. The composition of claim 2 , wherein one or more crosslinks of the crosslinked graft copolymer comprise a phosphodiester bond.
4. The composition of claim 1 , wherein the graft copolymer portion of the crosslinked graft copolymer comprises at least 50 wt % dextran.
5. The composition of claim 1 , wherein the dextran has a weight-average molecular weight (Mw) of at least 100000 Daltons.
6. The composition of claim 1 , wherein the poly alpha-1,3-glucan side chains comprise at least 95% alpha-1,3-glucosidic linkages.
7. The composition of claim 1 , wherein the molecular weight of one or more individual poly alpha-1,3-glucan side chains is at least 100000 Daltons.
8. The composition of claim 1 , wherein the crosslinked graft copolymer has a centrifugal retention capacity (CRC) of at least 6 gram aqueous fluid per gram crosslinked graft copolymer.
9. The composition of claim 1 , wherein the composition is a personal care product, household care product, medical product, or industrial product.
10. A method of producing a crosslinked graft copolymer, said method comprising:
contacting at least a solvent, a crosslinking agent, and a graft copolymer,
wherein the graft copolymer comprises:
(i) a backbone comprising dextran, and
(ii) poly alpha-1,3-glucan side chains comprising at least 50% alpha-1,3-glucosidic linkages,
whereby a crosslinked graft copolymer is produced having one or more crosslinks that are covalent.
11. The method of claim 10 , wherein the solvent is aqueous.
12. The composition of claim 5 , wherein the dextran has an Mw of at least 10 million Daltons.
13. The composition of claim 12 , wherein the dextran has an Mw of at least 50 million Daltons.
14. The composition of claim 13 , wherein the dextran has an Mw of at least 100 million Daltons.
15. The composition of claim 1 , wherein the dextran comprises at least 85% alpha-1,6-glucosidic linkages.
16. The composition of claim 1 , wherein the poly alpha-1,3-glucan side chains comprise at least 85% alpha-1,3-glucosidic linkages.
17. The composition of claim 1 , wherein the composition is a product selected from the group consisting of baby diapers, potty training pants, incontinence products, feminine hygiene products, wound healing dressings, and sanitary towels.
18. The composition of claim 1 , wherein the composition is a product selected from the group consisting of (i) telecommunication cable wrapping, (ii) food pad, (iii) fire-fighting device, (iv) product for cleanup of acidic or basic aqueous solutions spills, and (v) agricultural or forestry product for retaining water in soil and/or to release water to plant roots.
19. The method of claim 10 , further comprising isolating the crosslinked graft copolymer.