Oxidized cellulose-based material, method for obtaining same and use thereof as compress

1. A method of obtaining a solid material based on a polymer comprising cellobiose units, wherein:

at least some of the cellobiose units have at least one carboxylic acid function attached to the C 6 carbon, the other C 6 carbons having a primary alcohol function attached thereto; and

at least some of the cellobiose units have at least one of the two rings open between the C 2 and C 3 carbons, the other C 2 and C 3 carbons forming a ring and having an alcohol function attached thereto, said method comprising the following steps:

a first step of placing in contact a solid material based on polymer containing cellobiose units and an oxidizing mixture comprising a hypohalite, a halite, and an oxoammonium salt or a precursor of said salt, wherein the first step is carried out at neutral or acidic pH, and wherein the solid material comprises an assembly of yarns or fibers that form a unitary entity that is insoluble in water at said pH; and

then

a second step of placing in contact the material comprising the assembly of yarns or fibers that form a unitary entity thus processed and a solution of periodic acid or of a salt thereof,

wherein the solid material so obtained has a degree of oxidation which corresponds to the conversion of alcohol and/or aldehyde functions in the cellobiose units into carboxylic acid functions, of greater than 10% calculated by the mass of said carboxylic acid functions contained in 100 g of the solid material.

2. The method according to claim 1 , wherein said method comprises a third step of placing in contact the material having been submitted to the first two steps and a halite solution.

3. The method according to claim 2 , wherein the halite solution comprises from 0.0025 to 0.012 mole of halite per gram of polymer.

4. The method according to claim 2 , wherein the third step is carried out at a pH in the range from 5 to 7.

5. The method according to claim 2 , wherein the third step is carried out at a temperature greater than 15° C.

6. The method according to claim 2 , wherein the third step is carried out for a duration in the range from 0.25 to 2 hours.

7. The method according to claim 1 , wherein the oxidizing mixture comprises from 0.0003 to 0.0006 mole of oxoammonium salt or a precursor of said salt, per gram of polymer.

8. The method according to claim 1 , wherein the oxidizing mixture comprises from 0.0006 to 0.0049 mole of hypohalite per gram of polymer.

9. The method according to claim 1 , wherein the oxidizing mixture comprises from 0.006 to 0.025 mole of halite per gram of polymer.

10. The method according to claim 1 , wherein the first step is carried out at a pH in the range from 5 to 7.

11. The method according to claim 1 , wherein the first step is carried out at a temperature greater than 40° C.

12. The method according to claim 1 , wherein the first step is carried out for a duration in the range from 1 to 6 hours.

13. The method according to claim 1 , wherein the solution of periodic acid or of a salt thereof comprises from 0.003 to 0.012 mole of periodic acid, or of a salt thereof, per gram of polymer.

14. The method according to claim 1 , wherein the second step is carried out at a pH in the range from 2 to 5.

15. The method according to claim 1 , wherein the second step is carried out at a temperature in the range from 5 to 60° C.

16. The method according to claim 1 , wherein the second step is carried out for a duration in the range from 1 to 6 hours.

17. The method according to claim 1 , wherein the first step is stopped by addition of an excess quantity of primary alcohol.

18. The method according to claim 1 , said method optionally comprising a third step of placing in contact the material having been submitted to the first two steps and a halite solution, wherein between the first two steps and/or after the second step and/or after the third step, the material is incubated in a protonation medium.

19. The method according to claim 18 , wherein after the material is incubated in the protonation medium, the material is submitted to washing and optionally drying.

20. The method according to claim 1 , wherein the oxidizing mixture comprises:

from 0.0003 to 0.0006 mole of TEMPO per gram of polymer;

from 0.0006 to 0.0049 mole of sodium hypochlorite per gram of polymer; and

from 0.006 to 0.025 mole of sodium chlorite per gram of polymer.

21. The method according to claim 1 , wherein the first step generates no aldehyde functions at the C 6 carbon of the cellobiose units.