Aliphatic polycarbonate quench method

• US 9,868,816 B2
• Filed: 03/10/2015
• Issued: 01/16/2018
• Est. Priority Date: 09/17/2008
• Status: Active Grant

• Current Assignee: Saudi Aramco Technologies Company
• Original Assignee: Saudi Aramco Technologies Company
• Inventors: Allen, Scott D., Conuel, Jeffrey R., Decker, David E., Cherian, Anna E.
• Primary Examiner(s): Fang, Shane
• Application Number:
  US14/643,057
• Publication Number:
  US 20150361215A1
• Time in Patent Office: 1,043 Days
• Field of Search: 558277, 558260, 568905, 528395, 528405
• CPC Class Codes: C08G 64/0208 saturated
• CPC Class Codes: C08G 64/34 and cyclic ethers
• CPC Class Codes: C08G 64/406 Purifying; Drying

Abstract

The present disclosure is directed to, in part, an aliphatic polycarbonate polymerization reaction initiated by combining an epoxide with carbon dioxide in the presence of a catalytic transition metal-ligand complex to form a reaction mixture, and further quenching that polymerization reaction by contacting the reaction mixture with an acid containing a non-nucleophilic anion produces a crude polymer solution with improved stability and processability.

Claims

1. A method comprising:

initiating an aliphatic polycarbonate polymerization reaction by combining an epoxide with carbon dioxide in the presence of a catalytic transition metal-ligand complex to form a reaction mixture comprising a polycarbonate chain, wherein the catalytic transition metal-ligand complex comprises at least one ligand that is a polymerization initiator and at least one ligand that is not a polymerization initiator; and

quenching the polymerization reaction by contacting the reaction mixture with an acid containing an anion that is not a polymerization initiator.

2. The method of claim 1, wherein the ligand that is a polymerization initiator is a nucleophilic ligand.

3. The method of claim 2, wherein the nucleophilic ligand is selected from the group consisting of —

OR^x, —

O(C═

O)R^x, —

NC, —

CN, halo, —

Br, —

I, —

Cl, and —

N₃, wherein each R^x is, independently, selected from hydrogen, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl and optionally substituted heteroaryl.

4. The method of claim 3, wherein R^x is selected from the group consisting of optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl, and optionally substituted heteroaryl.

5. The method of claim 1, wherein the ligand that is not a polymerization initiator is a salen ligand.

6. The method of claim 5, wherein the salen ligand is selected from the group consisting of:

7. The method of claim 6, wherein the catalytic transition metal complex is selected from the group consisting of:

8. The method of claim 7, wherein the catalytic transition metal complex is selected from the group consisting of:

9. The method of claim 8, wherein the catalytic transition metal complex is selected from the group consisting of:

10. The method of claim 1, wherein the anion is non-nucleophilic.

11. The method of claim 1, wherein the acid is a sulfonic acid.

12. The method of claim 11, wherein the sulfonic acid has the formula R¹SO₃H where R¹ is a radical selected from the group consisting of:

optionally substituted aliphatic, optionally substituted aryl, and optionally substituted heterocyclic.

13. The method of claim 12, wherein R¹ is selected from the group consisting of optionally substituted C₁ to C₂₀ alkyl, C₁ to C₂₀ alkenyl, and optionally substituted phenyl.

14. The method of claim 12, wherein the sulfonic acid is selected from the group consisting of ρ

-toluene sulfonic acid, methane sulfonic acid, ethane sulfonic acid, 1-propane sulfonic acid, trifluoromethyl sulfonic acid, 4-nitrophenyl sulfonic acid, sulfoacetic acid, cumenesulphonic acid, xylene sulfonic acid, 3-amino-l-propanesulfonic acid, 2-(methylamino)ethanesulfonic acid, 2-aminoethanesulfonic acid, 2-sulfanylethanesulfonic acid, 3-hydroxy-1-propanesulfonic acid, benzenesulfonic acid, 3-Pyridinesulfonic acid, 2-pyridinesulfonic acid, 4-piperidinesulfonic acid, 2-aminobenzenesulfonic acid, 1-methylpyridinium 3-sulfonate, 1-methyl-2-pyridiniumsulfonate, 4-hydroxybenzenesulfonic acid, cyclohexane sulfonic acid, 4-ethylbenzenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, 4-methylmetanilic acid, 4-amino-3-methylbenzenesulfonic acid, 1-Naphthalenesulfonic acid, 2-amino-5-methylbenzenesulfonic acid, and perfluorooctane sulfonic acid.

15. The method of claim 14, wherein the sulfonic acid is p-toluene sulfonic acid.

16. The method of claim 1, wherein the acid is a sulfamic acid derivative.

17. The method of claim 16, wherein the sulfamic acid derivative has the formula R¹R²N—

SO₃H, where R¹ and R² are radicals independently selected from the group consisting of;

—

H;

optionally substituted alkyl;

optionally substituted aryl; and

optionally substituted heterocyclic and R¹ and R² may optionally be taken together with intervening atoms to form an optionally substituted ring.

18. The method of claim 1, wherein the acid is a phosphoric acid derivative having at least one acidic hydrogen atom.

19. The method of claim 18, wherein the phosphoric acid derivative is selected from the group consisting of phosphoric acid, pyrophosphoric acid, triphosphoric acid, an alkyl derivative of phosphoric acid, pyrophosphoric acid, or triphosphoric acid, an aryl derivative of phosphoric acid, pyrophosphoric acid, or triphosphoric acid, and a mixture of any two or more thereof.

20. The method of claim 18, wherein the phosphoric acid derivative has the formula:

21. The method of claim 1, wherein the transition metal is a Group 6 transition metal.

22. The method of claim 21, wherein the transition metal is chromium or molybdenum.

23. The method of claim 1, wherein the transition metal is a Group 7 transition metal.

24. The method of claim 23, wherein the transition metal is manganese.

25. The method of claim 1, wherein the transition metal is a Group 9 transition metal.

26. The method of claim 25, wherein the transition metal is cobalt.

27. The method of claim 1, wherein the transition metal is a Group 12 transition metal.

28. The method of claim 1, wherein less than 10 equivalents of the acid are added to the reaction mixture relative to the amount of catalytic transition metal-ligand complex present in the reaction mixture.

29. The method of claim 1, wherein between 0.1 and 10 equivalents of the acid are added to the reaction mixture relative to the amount of catalytic transition metal-ligand complex present in the reaction mixture.

30. The method of claim 1, wherein between about 0.1 and about 2 equivalents of the acid are added to the reaction mixture relative to the amount of catalytic transition metal-ligand complex present in the reaction mixture.

31. The method of claim 1, wherein between 1 and 2 equivalents of the acid are added to the reaction mixture relative to the amount of catalytic transition metal-ligand complex present in the reaction mixture.

32. The method of claim 1, wherein about 1 equivalent of the acid is added to the reaction mixture relative to the amount of catalytic transition metal-ligand complex present in the reaction mixture.

33. The method of claim 1, wherein the epoxide is selected from the group consisting of ethylene oxide, monosubstituted alkyl epoxides, 1,2 disubstituted alkyl epoxides, 1,1-disubstituted epoxides, and polycyclic epoxides.

34. The method of claim 1, wherein the epoxide is selected from the group consisting of ethylene oxide, propylene oxide, epichlorohydrin, glycidyl ethers, glycidyl esters, 1,2-butylene oxide, 2,3-butylene oxide, cyclopentene oxide, cyclohexene oxide, cyclooctene oxide, norbornene oxide, a glycidyl ether, and limonene oxide.

35. The method of claim 1, wherein the epoxide is propylene oxide.

36. The method of claim 1, wherein the polymerization reaction is performed in a reactor, the method further comprising:

depressurizing the reactor containing the reaction mixture;

removing excess carbon dioxide from the reactor; and

diluting the reaction mixture by adding a solvent prior to the quenching step.

37. The method of claim 1, wherein the epoxide is ethylene oxide.