Polysaccharide-polyamine copolymers for removal of phosphate

Patent metadata

Field	Value
Publication number	US-12186336-B2
Application number	US-202017077950-A
Country	US
Kind code	B2
Filing date	Oct 22, 2020
Priority date	Mar 20, 2015
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

Covalently cross-linked copolymers are described herein. More specifically, polysaccharide-polyamine copolymeric matrices or structures and cationic copolymeric matrices are described herein. The polysaccharide-polyamine copolymers, when protonated, can form cationic copolymeric matrices having exceptionally high densities of cationic sites. In one form, the covalently cross-linked copolymers provide a three-dimensional structure, especially when hydrated.

First claim

What is claimed is:

1. A method to effect removal of phosphate from an aqueous phosphate solution, the method comprising applying a protonated particulate polysaccharide- polyamine copolymeric material having a three-dimensional structure, the particulate polysaccharide-polyamine polymeric material comprising:
selectively oxidized polysaccharides having a 2,3 di-aldehyde moiety; and
amino polymers which provide a cationic amino functionality, the amino polymers covalently cross linking the selectively oxidized polysaccharides to provide a particulate polysaccharide-polyamine copolymer and copolymeric material having an amino functionality which when protonate will provide the cationic copolymeric material with a nitrogen content of at least 12.3 wt. %, the cationic particulate polysaccharide-polyamine copolymer and cationic copolymeric material being water insoluble,
wherein the selectively oxidized polysaccharides have β-1,6-glycosidic bonds.

2. The method to effect removal of phosphate as recited in claim 1 , wherein the selectively oxidized polysaccharides are selected from the group consisting of consisting of selectively oxidized starch, selectively oxidized dextran, selectively oxidized glycogen and mixtures thereof, the polysaccharide having been oxidized in an amount effective to provide the 2,3 di-aldehyde moiety which is reactive with the amino polymers.

3. The method to effect removal of phosphate of claim 1 , wherein the amino polymers have a nitrogen content of at least 24.5 wt. %, based on the weight of the amino polymers, and a molecular weight in the range of from about 15,000 to about 900,000.

4. The method to effect removal of phosphate of claim 1 , wherein the amino polymers which provide a cationic amino functionality are selected from the group consisting of polyethylenimine, poly (allylamine) and polypropylenimine tetramine and mixtures thereof.

5. The method to effect removal of phosphate of claim 1 , wherein the selectively oxidized polysaccharides further have β-1,4-glycosidic bonds.

6. The method to effect removal of phosphate of claim 1 , wherein the particulate polysaccharide-polyamine copolymer and copolymeric material has particulates having sizes in the range of from about 100 μm to about 10 mm and pore sizes of less than about 50 μm.

Assignees

• Univ Howard

Inventors

• Mitchell James W
• Yang Dazhi

Classifications

• C08L5/08

  Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof · CPC title

• C08L5/02

  Dextran; Derivatives thereof · CPC title

• C08L3/20

  Oxidised amylose; Oxidised amylopectin · CPC title

• C08L1/08

  Cellulose derivatives · CPC title

• C08G73/0206

  Polyalkylene(poly)amines · CPC title