Dissolution and processing of cellulose using ionic liquids
AssigneeUniversity of Alabama
InventorsRichard Patrick Swatloski, Robin Don Rogers, John David Holbrey
Life of this patent
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Abstract
Cellulose is dissolved in an ionic liquid without derivatization, and is regenerated in a range of structural forms without requiring the use of harmful or volatile organic solvents. Cellulose solubility and the solution properties can be controlled by the selection of the ionic liquid constituents, with small cations and halide or pseudohalide anions favoring solution.
Claims58
A method for dissolving cellulose that comprises admixing cellulose with a molten ionic liquid that is molten at a temperature of about −10 to about 100° C. and in the substantial absence of water or a nitrogen-containing base to form an admixture, wherein said ionic liquid is comprised of cations and anions, and agitating the a mixture until dissolution is complete.
A method for dissolving cellulose that comprises the steps of:
- (a) admixing cellulose with an ionic liquid in the substantial absence of water or nitrogen-containing base to form an admixture, wherein said ionic liquid is molten at a temperature of about −10 to about 100° C. and is comprised of cations and anions, wherein the cations correspond in structure to a formula selected from the group consisting of
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5, R6, R7, R8 and R9 (R3-R9), when present, are independently a hydrido, a C1-C6 alkyl, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group, and the anions of the ionic liquid are halogen, pseudohalogen, or C1-C6 carboxylate;
- (b) irradiating said admixture with microwave radiation to assist in dissolution;
- and
- (c) agitating the admixture until dissolution is complete.
A method for dissolving cellulose that comprises the steps of:
- (a) admixing cellulose with an ionic liquid comprised of cations and anions in the substantial absence of water to form an admixture, wherein said ionic liquid is molten at a temperature of about −44° C. to about 120° C. wherein said cations contain a single five-membered ring that is free of fusion to other ring structures and said anions are halogen, pseudohalogen, or C1-C6 carboxylate;
- (b) irradiating said admixture with microwave radiation to assist in dissolution;
- and
- (c) agitating the admixture until dissolution is complete.
A method for dissolving cellulose that comprises the steps of:
- (a) admixing cellulose with an ionic liquid comprised of cations and anions in the substantial absence of water to form an admixture, wherein said ionic liquid is molten at a temperature of about −44° C. to about 120° C., wherein the cations are 1,3-di-C1-C6-alkyl imidazolium ions corresponding in structure to Formula A
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5 (R3-R5) are independently a hydrido, a C1-C6 alkyl group, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group and the anions of the ionic liquid are a halogen or pseudohalogen;
- (b) irradiating said admixture with microwave radiation to assist in dissolution;
- and
- (c) agitating the admixture until dissolution is complete.
A method for dissolving cellulose that comprises the steps of:
- (a) admixing cellulose with an ionic liquid comprised of cations and anions in the substantial absence of water to form an admixture, wherein said ionic liquid is molten at a temperature of about −44° C. to about 120° C., and wherein the cations are 1,3-di-C1-C6-alkyl imidazolium ions corresponding in structure to Formula B
- wherein R1 is a C1-C6 alkyl group and the anions of the ionic liquid are a halogen or pseudohalogen;
- (b) irradiating said admixture with microwave radiation to assist in dissolution;
- and
- (c) agitating the admixture until dissolution is complete.
A solution comprised of cellulose in a molten ionic liquid solvent that is substantially free of water or a nitrogen-containing base, wherein said ionic liquid is comprised of cations and anions and is molten at a temperature of about −44° C. to about 120° C., and wherein said cations contain a single five-membered ring that is free of fusion to other ring structures and said anions are halogen, pseudohalogen, or C1-C6 carboxylate.
A solution comprise of about 5 to about 35 weight percent cellulose in an ionic liquid solvent that is molten at a temperature of about −10 about 100° C. and is substantially free of water or nitrogen-containing base, wherein said ionic liquid is comprised of cations and anions in which the cations correspond in structure to a formula selected from the group consisting of
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5, R6, R7, R8 and R9 (R3-R9), when present, are independently a hydrido, a C1-C6 alkyl, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group, and the anions of the ionic liquid are halogen, pseudohalogen, or C1-C6 carboxylate.
A solution comprised of about 10 to about 25 weight percent cellulose in an ionic liquid solvent that is molten a temperature of about −10 to about 100° C. and is substantially free of water, wherein said ionic liquid is comprised of cations and anions in which the cations are 1,3-di-C1-C6 alkyl imidazolium ions corresponding in structure to Formula A
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5 (R3 R5) are independently a hydrido, a C1-C6 alkyl group, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group and the anions of the ionic liquid are a halogen or pseudohalogen.
A method for regenerating cellulose that comprises admixing a solution of cellulose in a molten ionic liquid solvent that is substantially free of water or nitrogen-containing base, wherein said ionic liquid is comprised of cations and anions and said molten ionic liquid is either (i) molten at a temperature of about −10° C. to about 100° C. or (ii) is molten at a temperature of about −44° C. to about 120° C. and wherein said cations contain a single five-membered ring that is free of fusion to other ring structures, with a liquid non-solvent for said cellulose that is miscible with said ionic liquid, said admixing causing the cellulose and ionic liquid to form solid and liquid phases, respectively.
A method for regenerating cellulose that comprises the steps of:
- (a) admixing a solution of cellulose in a molten ionic liquid solvent that is molten at a temperature of less than about 150° C. and is substantially free of water or a nitrogen-containing base, wherein said ionic liquid is comprised of cations and anions, with a liquid non-solvent for said cellulose that is miscible with said ionic liquid, said admixing causing the cellulose and ionic liquid to form solid and liquid phases, respectively, wherein the cations correspond in structure to a formula selected from the group consisting of
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5, R6 R7, R8 and R9 (R3-R9), when present, are independently a hydrido, a C1-C6 alkyl, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group, and the anions of the ionic liquid are halogen, pseudohalogen, or C1-C6 carboxylate and the anions of said ionic liquid are halogen or pseudohalogen;
- and
- (b) collecting the formed cellulose phase.
A method for regenerating cellulose that comprises the steps of:
- (a) admixing a solution of cellulose in a molten ionic liquid solvent that is molten at a temperature of about −44° to about 120° C. and is substantially free of water, herein said ionic liquid is comprised of cations and anions, with a liquid non-solvent for said cellulose that is miscible with said ionic liquid and is also miscible with water, said admixing causing the cellulose and ionic liquid to form solid a d liquid phases, respectively, wherein the cations correspond in structure to a formula selected from the group consisting of
- wherein R1 and R2 are independently a C1-C6 alkyl group or a C1-C6 alkoxyalkyl group, and R3, R4, R5 (R3-R5) are independently a hydrido, a C1-C6 alkyl group, a C1-C6 alkoxyalkyl group or a C1-C6 alkoxy group and the anions of the ionic liquid are a halogen or pseudohalogen;
- and
- (b) collecting the formed cellulose phase.
Dependencies are inferred from the claim text.