Smart composites containing modified cellulosic nanomaterials

Patent metadata

Field	Value
Publication number	US-9475919-B2
Application number	US-201514675145-A
Country	US
Kind code	B2
Filing date	Mar 31, 2015
Priority date	Mar 11, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

In accordance with some embodiments of the present invention, a composite material is prepared by blending a bio-derived filler into a polymer, wherein the filler includes a diene-modified cellulosic nanomaterial (e.g., cellulose nanocrystals (CNCs) and/or cellulose nanofibrils (CNFs) functionalized to contain a diene) and a dienophile-modified cellulosic nanomaterial (e.g., CNCs and/or CNFs functionalized to contain a dienophile). The modulus of the composite material is reversibly controllable by adjusting a degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial. This degree of crosslinking is thermally reversible. On one hand, the degree of crosslinking may be increased via a Diels-Alder (DA) cycloaddition reaction at a first temperature, thereby increasing the modulus of the composite material. On the other hand, the degree of crosslinking may be decreased via a retro-DA reaction at a second temperature higher than the first temperature, thereby decreasing the modulus of the composite material.

First claim

What is claimed is:

1. A method of making composite material, comprising:
providing a polymer;
blending a bio-derived filler into the polymer, wherein the filler comprises a diene-modified cellulosic nanomaterial and a dienophile-modified cellulosic nanomaterial.

2. The method as recited in claim 1 , wherein at least some of the diene-modified cellulosic nanomaterial and at least some of the dienophile-modified cellulosic nanomaterial are crosslinked to each other in a crosslinked network, further comprising:
reversibly controlling a modulus of the composite material by adjusting a degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial by at least one of:
increasing the degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial via a Diels-Alder (DA) cycloaddition reaction at a first temperature; and
decreasing the degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial via a retro-DA reaction at a second temperature higher than the first temperature.

3. The method as recited in claim 1 , wherein the diene-modified cellulosic nanomaterial comprises at least one of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) functionalized to contain a diene.

4. The method as recited in claim 3 , wherein the dienophile-modified cellulosic nanomaterial comprises at least one of CNCs and CNFs functionalized to contain a dienophile.

5. The method as recited in claim 4 , wherein at least some of the diene-modified cellulosic nanomaterial and at least some of the dienophile-modified cellulosic nanomaterial are crosslinked to each other in a crosslinked network, further comprising:
reversibly controlling a modulus of the composite material by adjusting a degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial by at least one of:
increasing the degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial via a Diels-Alder (DA) cycloaddition reaction at a first temperature; and
decreasing the degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial via a retro-DA reaction at a second temperature higher than the first temperature.

6. The method as recited in claim 1 , wherein the diene-modified cellulosic nanomaterial comprises cellulose nanocrystals (CNCs) functionalized to contain a diene, and wherein the dienophile-modified cellulosic nanomaterial comprises CNCs functionalized to contain a dienophile.

7. The method as recited in claim 1 , wherein the polymer selected from a group consisting of polylactic acid (PLA), polyhydroxyalkanoates (PHA), polybutylene succinate (PBS), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and combinations thereof.

8. A method making composite material, comprising:
providing a polymer;
blending a bio-derived filler into the polymer, wherein the filler comprises diene-modified cellulosic nanocrystals (CNCs) and dienophile-modified CNCs, wherein the diene-modified CNCs comprise CNCs functionalized to contain a diene, wherein the dienophile-modified CNCs comprise CNCs functionalized to contain a dienophile, wherein at least some of the diene-modified CNCs and at least some of the dienophile-modified CNCs are crosslinked to each other in a crosslinked network, and wherein the composite material has a modulus that is reversibly controllable by adjusting a degree of crosslinking between the diene-modified CNCs and the dienophile-modified CNCs.

9. The method as recited in claim 8 , wherein the diene-modified CNCs are represented by the following formula:

10. The method as recited in claim 9 , wherein the dienophile-modified CNCs are represented by the following formula:

11. A method making composite material, comprising:
providing a polymer;
blending a bio-derived filler into the polymer, wherein the filler comprises a diene-modified cellulosic nanomaterial and a dienophile-modified cellulosic nanomaterial, wherein the diene-modified cellulosic nanomaterial comprises at least one of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) functionalized to contain a diene, wherein the dienophile-modified cellulosic nanomaterial comprises at least one of CNCs and CNFs functionalized to contain a dienophile, wherein at least some of the diene-modified cellulosic nanomaterial and at least some of the dienophile-modified cellulosic nanomaterial are crosslinked to each other in a crosslinked network, and wherein the composite material has a modulus that is reversibly controllable by adjusting a degree of crosslinking between the diene-modified cellulosic nanomaterial and the dienophile-modified cellulosic nanomaterial.

12. The method as recited in claim 1 , wherein the dienophile-modified cellulosic nanomaterial comprises at least one of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) functionalized to contain a dienophile.

13. The method as recited in claim 8 , wherein the dienophile-modified CNCs are represented by the following formula:

Assignees

• IBM

Inventors

• Boday Dylan J
• Kuczynski Joseph
• Meyer Iii Robert E

Classifications

• C08B15/00

  Preparation of other cellulose derivatives or modified cellulose {, e.g. complexes} · CPC title

• C08L55/02

  ABS [Acrylonitrile-Butadiene-Styrene] polymers · CPC title

• C08L1/08

  Cellulose derivatives · CPC title

• C08L67/04 Primary

  Polyesters derived from hydroxycarboxylic acids, e.g. lactones (C08L67/06 takes precedence) · CPC title

• C08L2205/16

  Fibres; Fibrils · CPC title