Dissolution of oxidized cellulose and particle preparation by cross-linking with multivalent cations
View Patent ↗A process for dissolving modified cellulose includes contacting modified cellulose solution with at least one multivalent cation 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 from about 115° C. to 145° C.;
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 from about 90° C. to about 120° C.; and
contacting the oxidized cellulose solution with at least one multivalent cation selected from cations of calcium, barium, zinc, magnesium, chromium, platinum, or iron to form a plurality of oxidized cellulose particles.
2. The process according to claim 1 , further comprising shearing the oxidized cellulose solution to form the plurality of oxidized cellulose particles.
3. 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.
4. 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.
5. 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.
6. 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.
7. A process comprising:
contacting an oxidized cellulose with a solvent under an inert atmosphere to form a swelled 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 from about 120° C. to about 140° C.;
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 from about 100° C. to about 110° C.; and
contacting the oxidized cellulose solution with at least one multivalent cation selected from cations of calcium, barium, zinc, magnesium, chromium, platinum, or iron 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.
8. The process according to claim 7 , further comprising shearing the oxidized solution to form the plurality of oxidized cellulose particles.
9. The process according to claim 7 , wherein the solvent is selected from the group consisting of N,N-Dimethylacetamide, N-methyl-2-pyrrolidinone, and combinations thereof.
10. The process according to claim 7 , wherein the salt is selected from the group consisting of lithium halides, sodium halides, potassium halides, and combinations thereof.
11. 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 from about 120° C. to about 140° C.;
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 from about 100° C. to about 110° C.; and
contacting the oxidized cellulose solution with at least one multivalent cation selected from cations of calcium, barium, zinc, magnesium, chromium, platinum, or iron 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.
12. 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.
13. 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.
14. The process according to claim 11 , further comprising shearing the oxidized cellulose solution to form the plurality of oxidized cellulose particles.