# US 11,999,809 B2 · Graft copolymers of dextran and polyacrylamide and methods of making and using same

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- Number: US 11,999,809 B2
- Document ID: US11999809B2
- Status: Granted
- Kind: B2
- Application number: 17/837,946
- Filed: 2022-06-10
- Published: 2023-12-14
- Granted: 2024-06-04
- Earliest claimed: 2022-06-10
- Assignees: FermWorx, LLC
- Applicants: FermWorx, LLC
- Inventors: D. V. Satyanarayana Gupta; Michael Joseph Rubal; Derek Christopher Mouton
- Web page: https://patentgrep.com/patent/US11999809B2

## CPC

- C08F 251/00: Macromolecular compounds obtained by polymerising monomers on to polysaccharides or derivatives thereof
- C09K 8/68: containing organic compounds
- C09K 8/604: {Polymeric surfactants}
- C09K 8/80: Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open
- C09K 8/88: macromolecular compounds
- C09K 2208/28: Friction or drag reducing additives
- C09K 2208/32: Anticorrosion additives
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

Disclosed herein are new graft copolymers of dextran and polyacrylamide. The graft copolymers can include dextran, where the dextran is a backbone polymer including about 15 wt % to about 50 wt % of the graft copolymer; and polyacrylamide, where the polyacrylamide is a side chain polymer including about 50 wt % to about 85 wt % of the graft copolymer, based on the total weight of the graft copolymer, where the graft copolymer has a weight-average molecular weight from about 1,000,000 g/mol to about 1,500,000 g/mol. The graft copolymers of dextran and polyacrylamide can be used as friction reducers for well treatment fluids.

## Claims

### Claim 1

A graft copolymer composition comprising:
a graft copolymer, wherein the graft copolymer comprises:
dextran, wherein the dextran is a backbone polymer comprising about 10_wt % to about 50 wt % of the graft copolymer, based on the total weight of the graft copolymer; and
polyacrylamide, wherein the polyacrylamide is a side chain polymer comprising about 50 wt % to about 90 wt % of the graft copolymer, based on the total weight of the graft copolymer, wherein the graft copolymer has a weight-average molecular weight from about 1,000,000 g/mol to about 1,500,000 g/mol; and
water, wherein the graft copolymer composition has a weight percent of the graft copolymer from about 0.12 to about 0.36 and wherein the graft copolymer composition has viscosity from about 0.5 cP to about 10 cP at a temperature of about 48.9° C.

### Claim 2

A graft copolymer comprising:
dextran, wherein the dextran is a backbone polymer comprising about 70 wt % to about 82 wt % of the graft copolymer, based on the total weight of the graft copolymer; and
polyacrylamide, wherein the polyacrylamide is a side chain polymer comprising about 18 wt % to about 30 wt % of the graft copolymer, based on the total weight of the graft copolymer, wherein the graft copolymer has a weight-average molecular weight from about 1,000,000 g/mol to about 1,500,000 g/mol.

### Claim 3

A graft copolymer comprising:
dextran, wherein the dextran is a backbone polymer comprises about 15 wt % to about 25 wt % of the graft copolymer, based on the total weight of the graft copolymer; and
polyacrylamide, wherein the polyacrylamide is a side chain polymer comprises about 75 wt % to about 85 wt % of the graft copolymer, based on the total weight of the graft copolymer, wherein the graft copolymer has a weight-average molecular weight from about 1,000,000 g/mol to about 1,500,000 g/mol.