Dissolution of oxidized cellulose and particle preparation by solvent and non-solvent precipitation
View Patent ↗A process for dissolving modified cellulose includes contacting modified cellulose solution with at least one non-solvent to form a plurality of modified cellulose particles.
1. A process comprising:
contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose;
adjusting the swelled oxidized cellulose to a first temperature;
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form the oxidized cellulose solution;
adjusting the oxidized cellulose solution to a second temperature that is lower than the first temperature; and
contacting the oxidized cellulose solution with at least one non-solvent to form a plurality of oxidized cellulose particles.
2. The process according to claim 1 , wherein the at least one non-solvent is selected from the group consisting of alkanes, oils, glycerins, glycols, and combinations thereof.
3. The process according to claim 1 , further comprising shearing the oxidized cellulose solution to form the plurality of oxidized cellulose particles.
4. The process according to claim 1 , wherein the first temperature is from about 115° C. to about 145° C. and the second temperature is from about 90° C. to about 120° C.
5. 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.
6. 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.
7. The process according to claim 1 , wherein the plurality of oxidized cellulose particles include oxidized cellulose having a degree of oxidation from about 80% to about 120% of a degree of oxidation of the predissolved oxidized cellulose.
8. The process according to claim 1 , wherein the plurality of oxidized cellulose particles include oxidized cellulose having a molecular weight from about 80% to about 120% of the molecular weight of the predissolved oxidized cellulose.
9. A process comprising:
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;
adjusting the swelled oxidized cellulose to a first temperature;
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form an oxidized cellulose solution;
adjusting the oxidized cellulose solution to a second temperature that is lower than the first temperature; and
contacting the oxidized cellulose solution with at least one non-solvent to form a plurality of oxidized cellulose particles having a degree of oxidation from about 80% to about 120% of the degree of oxidation of the predissolved oxidized cellulose.
10. The process according to claim 9 , wherein the first temperature is from about 115° C. to about 145° C. and the second temperature is from about 90° C. to about 120° C.
11. The process according to claim 9 , further comprising shearing the oxidized cellulose solution to form the plurality of oxidized cellulose particles.
12. The process according to claim 9 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
13. The process according to claim 9 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
14. The process according to claim 9 , wherein the at least one non-solvent is selected from the group consisting of alkanes, oils, glycerins, glycols, and combinations thereof.
15. A process comprising:
contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled oxidized cellulose;
adjusting the swelled oxidized cellulose to a first temperature;
contacting the swelled oxidized cellulose with a salt under the inert atmosphere to form the oxidized cellulose solution;
adjusting the oxidized cellulose solution to a second temperature that is lower than the first temperature; and
contacting the oxidized cellulose solution with at least one non-solvent to form a plurality of oxidized cellulose particles having a molecular weight from about 80% to about 100% of the molecular weight of the predissolved oxidized cellulose.
16. The process according to claim 15 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
17. The process according to claim 15 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
18. The process according to claim 15 , wherein the first temperature is from about 115° C. to about 145° C. and the second temperature is from about 90° C. to about 120° C.
19. The process according to claim 15 , further comprising shearing the oxidized cellulose solution to form the plurality of oxidized cellulose particles.
20. The process according to claim 15 , wherein the at least one non-solvent is selected from the group consisting of alkanes, oils, glycerins, glycols, and combinations thereof.