Method for producing anionic water-soluble polymer on the basis of bioacrylamide and acrylic acid

1. A process for the production of anionic water-soluble polymer obtained by the polymerization of acrylic acid and bioacrylamide, said process comprising the steps of:

preparing a diluted solution of acrylic acid by mixing acrylic acid and water wherein the mass ratio between acrylic acid and water is between 95:5 and 70:30;

preparing a diluted solution of acrylamide obtained by biocatalysed reaction called bioacrylamide and water, wherein the mass ratio between bioacrylamide and water is between 60:40 and 10:90;

mixing said diluted solution of acrylic acid with said diluted solution of bioacrylamide;

neutralizing partially or totally the acid function of acrylic acid; and

polymerizing the resulting mixture.

2. The process according to claim 1 wherein the mass ratio between acrylic acid and water is between 93:7 and 80:20.

3. The process according to claim 1 wherein the mass ratio between bioacryamide and water in the diluted solution of bioacrylamide, before this solution is mixed with the diluted solution of acrylic acid, is between 60:40 and 20:80.

4. The process according to claim 1 wherein during said neutralizing at least 40% of acrylic acid functions are neutralized.

5. The process according to claim 1 wherein acrylic acid functions are fully neutralized.

6. The process according to claim 1 wherein the water is distilled or purified water.

7. The process according to claim 1 wherein the molar ratio of acrylic acid in the monomer mixture before polymerization is between 5 mol % and 95 mol %, based on the total moles of monomers in the monomer mixture before polymerization.

8. The process according to claim 1 wherein the molar ratio of acrylamide obtained by the biocatalysed reaction in the monomer mixture before polymerization is between 5 mol % and 95 mol %, based on the total moles of monomers in the monomer mixture before polymerization.

9. The process according to claim 1 wherein said polymerizing the resulting mixture comprises gel polymerization.

10. The process according to claim 1 wherein the polymer comprises units from other monomers in addition to the bioacrylamide obtained by the biocatalysed reaction and acrylic acid, said monomers being selected from the following list:

non ionic monomers: methacrylamide, N,N-dimethylacrylamide, N-vinylpyrrolidone, N-vinylformamide, the methacrylates of polyethylene glycol, diacetoneacrylamide, N-isopropylacrylamide, 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate,

- anionic monomers: 2-acrylamido- 2 -methylpropane sulfonic acid (ATBS), methacrylic acid, itaconic acid, maleic acid, non-salified, partially or completely salified,

- cationic monomers: diallyldimethylammonium chloride (DADMAC), dialkylaminoethyl acrylate (DAMEA) and dialkylaminoethyl methacrylate (DAMEMA), acrylamido dialkylaminopropyl, methacrylamido dialkylaminopropyl, and their acidified or quaternized salts.

11. The process according to claim 1 wherein the mass ratio between acrylic acid and water is between 92:8 and 85:15.

12. The process according to claim 1 wherein the mass ratio between bioacryamide and water in the diluted solution of bioacrylamide, before this solution is mixed with the diluted solution of acrylic acid, is between 60:40 and 30:70.

13. The process according to claim 1 wherein the mass ratio between bioacryamide and water in the diluted solution of bioacrylamide, before this solution is mixed with the diluted solution of acrylic acid, is between 55:45 and 45:55.

14. The process according to claim 11 wherein the mass ratio between bioacryamide and water in the diluted solution of bioacrylamide, before this solution is mixed with the diluted solution of acrylic acid, is between 60:40 and 30:70.

15. The process according to claim 1 wherein the molar ratio of acrylic acid in the monomer mixture before polymerization is between 20 mol % and 50 mol %, based on the total moles of monomers in the monomer mixture before polymerization.

16. The process according to claim 14 wherein the molar ratio of acrylic acid in the monomer mixture before polymerization is between 20 mol % and 50 mol %, based on the total moles of monomers in the monomer mixture before polymerization.

17. The process according to claim 1 wherein the molar ratio of acrylamide obtained by the biocatalysed reaction in the monomer mixture before polymerization is between 50 mol % and 80 mol %, based on the total moles of monomers in the monomer mixture before polymerization.

18. The process according to claim 16 wherein the molar ratio of acrylamide obtained by the biocatalysed reaction in the monomer mixture before polymerization is between 50 mol % and 80 mol %, based on the total moles of monomers in the monomer mixture before polymerization.

19. The process according to claim 18 wherein the polymer comprises units from other monomers in addition to the bioacrylamide obtained by the biocatalysed reaction and acrylic acid, said monomers being selected from the following list:

- non ionic monomers: methacrylamide, N,N-dimethylacrylamide, N-vinylpyrrolidone, N-vinylformamide, the methacrylates of polyethylene glycol, diacetoneacrylamide, N-isopropylacrylamide, 2 -hydroxyethyl acrylate, 2 , 3 -dihydroxypropyl acrylate, 2 -hydroxyethyl methacrylate, 2 , 3 -dihydroxypropyl methacrylate,

- anionic monomers: 2 -acrylamido- 2 -methylpropane sulfonic acid (ATBS), methacrylic acid, itaconic acid, maleic acid, non-salified, partially or completely salified,

- cationic monomers: diallyldimethylammonium chloride (DADMAC), dialkylaminoethyl acrylate (DAMEA) and dialkylaminoethyl methacrylate (DAMEMA), acrylamido dialkylaminopropyl, methacrylamido dialkylaminopropyl, and their acidified or quaternized salts.