Lactose-derived hydrogels and methods of producing the same

Patent metadata

Field	Value
Publication number	US-10800893-B2
Application number	US-201816185406-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Nov 9, 2018
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

Lactose-derived hydrogels include at least lactose and methacrylic anhydride. A method of preparing lactose-derived hydrogels includes copolymerizing lactose methacrylate, methacrylic acid, and sodium methacrylate using light-induced photopolymerization. Polymerization proceeds in the absence of a photoinitiator. No volatile organic compounds or waste are produced by the method. The lactose may be provided by a milk permeate waste stream from the dairy or food processing industry.

First claim

What is claimed is:

1. A method of producing a lactose-derived hydrogel, the method comprising:
distributing lactose in water to produce a lactose solution;
adjusting the pH of the lactose solution;
adding methacrylic anhydride to the lactose solution to produce a reaction mixture;
adjusting the pH of the reaction mixture;
neutralizing the reaction mixture;
filtering the reaction mixture to produce a hydrogel precursor mixture; and
exposing the hydrogel precursor mixture to light to produce a lactose-derived hydrogel.

2. The method of claim 1 , wherein the lactose is from one or more of purified lactose, milk permeate, whey, whey permeate, de-lactosed permeate, de-proteinized whey, dairy-derived polysaccharides, buttermilk, skim milk, mammalian milk, whole milk powder, non-fat dry milk, and butter milk powder.

3. The method of claim 1 , wherein the lactose is from a waste product of a dairy or food processing operation.

4. The method of claim 3 , wherein the waste product is milk permeate.

5. The method of claim 1 , wherein the molar ratio of lactose to methacrylic anhydride is from about 1.0:0.5 to about 1.0:2.0.

6. The method of claim 1 , wherein the pH of the reaction mixture is adjusted to at most about 10 with aqueous sodium hydroxide.

7. The method of claim 1 , wherein the reaction mixture comprises lactose methacrylate, sodium methacrylate, and methacrylic acid.

8. The method of claim 7 , wherein the light induces copolymerization of monomers of two or more of lactose methacrylate, sodium methacrylate, and methacrylic acid.

9. The method of claim 1 , wherein the reaction mixture is neutralized to a pH of about 7 with hydrochloric acid.

10. The method of claim 1 , wherein the filtering is by gravity filtration, vacuum filtration, or centrifugation.

11. The method of claim 1 , wherein the hydrogel is undried, the undried hydrogel is lyophilized to produce a dried hydrogel, and the dried hydrogel is rewetted to increase the equilibrium water content compared to the equilibrium water content of the undried hydrogel.

12. A method of utilizing a lactose-containing waste product, the method comprising:
obtaining the waste product;
heating the waste product in water to produce a lactose solution;
adding methacrylic anhydride to the lactose solution to produce a reaction mixture;
adjusting the pH of the reaction mixture;
neutralizing the reaction mixture;
filtering the reaction mixture to produce a hydrogel precursor mixture; and
exposing the hydrogel precursor mixture to light to produce a lactose-derived hydrogel.

13. The method of claim 12 , wherein the waste product is from a dairy or food processing operation.

14. The method of claim 12 , wherein the waste product is selected from one or more of milk permeate, whey, whey permeate, de-lactosed permeate, de-proteinized whey, dairy-derived polysaccharides, buttermilk, skim milk, mammalian milk, whole milk powder, non-fat dry milk, and butter milk powder.

15. The method of claim 14 , wherein the waste product is milk permeate.

16. The method of claim 12 , wherein the molar ratio of lactose to methacrylic anhydride is from about 1.0:0.5 to about 1.0:2.0.

17. The method of claim 12 , wherein the pH of the reaction mixture is adjusted to at most about 10 with aqueous sodium hydroxide.

18. The method of claim 12 , wherein the reaction mixture comprises lactose methacrylate, sodium methacrylate, and methacrylic acid.

19. The method of claim 18 , wherein the light induces copolymerization of monomers of two or more of lactose methacrylate, sodium methacrylate, and methacrylic acid.

20. The method of claim 12 , wherein the filtering is by gravity filtration, vacuum filtration, or centrifugation.

Assignees

• Winfield Solutions Llc
• Univ Minnesota

Inventors

• Patel Hasmukh
• Hillmyer Marc Andrew
• Ribeiro Da Fonseca Larissa
• Dirlam Philip Thomas

Classifications

• C08F220/20 Primary

  of polyhydric alcohols or phenols {, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate} · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C08J2333/14

  of esters containing halogen, nitrogen, sulfur, or oxygen atoms in addition to the carboxy oxygen · CPC title

• C08K5/1545

  Six-membered rings · CPC title

• C08J3/075 Primary

  Macromolecular gels · CPC title