Dissolution of oxidized cellulose
A process for dissolving modified cellulose is disclosed. The process includes contacting modified cellulose with a solvent in a mixture to form swelled modified cellulose and then contacting the mixture with a salt to dissolve the swelled modified cellulose.
1. A process comprising:
forming a mixture by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose;
adjusting the mixture to a first temperature;
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution; and
adjusting the oxidized cellulose solution to a second temperature lower than the first temperature.
2. The process according to claim 1 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
3. The process according to claim 1 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
4. The process according to claim 1 , wherein the oxidized cellulose solution includes dissolved oxidized cellulose having a degree of oxidation from about 80% to about 120% of a degree of oxidation of the oxidized cellulose prior to dissolution.
5. The process according to claim 1 , wherein oxidized cellulose solution includes dissolved oxidized cellulose having a molecular weight from about 80% to about 120% of a molecular weight of the oxidized cellulose prior to dissolution.
6. A process comprising:
forming a mixture by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose, the oxidized cellulose having a degree of oxidation of from about 0.2 to about 1.0;
heating the mixture; and
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution, wherein the dissolved oxidized cellulose has a degree of oxidation from about 80% to about 120% of the degree of oxidation of the oxidized cellulose prior to dissolution.
7. The process according to claim 6 , wherein heating the mixture includes adjusting the mixture to a first temperature and the process further comprises subsequently adjusting the mixture to a second temperature lower than the first temperature.
8. The process according to claim 6 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
9. The process according to claim 6 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
10. The process according to claim 6 , wherein the salt is present in an amount of from about 0.1% by weight to about 3% by weight of the oxidized cellulose.
11. A process comprising:
forming a mixture by contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose;
heating the mixture; and
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution under the inert atmosphere, wherein the dissolved oxidized cellulose has a molecular weight from about 80% to about 100% of the molecular weight of the oxidized cellulose prior to dissolution.
12. The process according to claim 11 , wherein heating the mixture includes adjusting the mixture to a first temperature and the process further comprises subsequently adjusting the mixture to a second temperature lower than the first temperature.
13. The process according to claim 11 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
14. The process according to claim 11 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
15. The process according to claim 11 , wherein the salt is present in an amount of from about 0.1% by weight to about 3% by weight of the oxidized cellulose.