Hydrophilic membrane

• US 6,039,872 A
• Filed: 04/10/1998
• Issued: 03/21/2000
• Est. Priority Date: 10/27/1997
• Status: Expired due to Term

• Current Assignee: Pall Corporation (Danaher Corporation)
• Original Assignee: Pall Corporation (Danaher Corporation)
• Inventors: Konstantin, Peter, Shertok, Joel, Wu, Xiaosong
• Primary Examiner(s): FORTUNA, ANA M
• Application Number:
  US09/058,631
• Time in Patent Office: 711 Days
• Field of Search: 210/500.35, 210/500.41, 210/500.38, 210/500.27, 264/41
• US Class Current: 210/500.35
• CPC Class Codes: B01D 2323/12 Specific ratios of components used
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 2323/40 in-situ membrane formation
• CPC Class Codes: B01D 2325/34 Molecular weight or degree of polymerisation
• CPC Class Codes: B01D 2325/36 Hydrophilic membranes
• CPC Class Codes: B01D 67/0006 by chemical reactions in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125
• CPC Class Codes: B01D 67/0011 Casting solutions therefor
• CPC Class Codes: B01D 69/141 Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
• CPC Class Codes: B01D 71/40 Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
• CPC Class Codes: B01D 71/68 Polysulfones; Polyethersulfones

Abstract

A hydrophilic porous membrane is provided which comprises a network of a non-crystalline hydrophobic polymer and a hydrophilic acrylate polymer. A method of preparing such a hydrophilic porous membrane also is provided, wherein a reaction solution of a non-crystalline hydrophobic polymer, a crosslinkable diacrylate, a polymerization initiator, and, optionally, a hydrophilic monoacrylate, is polymerized and/or crosslinked in situ and cast to provide a hydrophilic porous membrane.

Claims

1. A hydrophilic membrane having a pore rating from about 0.02 μ

m to about 10 μ

m, said membrane comprising a network of a non-crystalline hydrophobic polymer selected from the group consisting of polyethersulfone and polysulfone, and a hydrophilic acrylate polymer derived from a polyalkylene glycol diacrylate defined by two acrylate groups attached by ester linkages at opposite ends of a hydrophilic polyalkylene glycol chain having a molecular weight of at least about 200 and, optionally, a hydrophilic monoacrylate.

2. The hydrophillic membrane of claim 1, wherein said hydrophilic acrylate polymer is derived from said polyalkylene glycol diacrylate alone.

3. The hydrophilic membrane of claim 1, wherein said hydrophilic acrylate polymer is a hydrophilic acrylate copolymer derived from a polyalkylene glycol diacrylate, defined by two acrylate groups attached by ester linkages at opposite ends of a hydrophilic polyalkylene glycol chain having a molecular weight of at least about 200, and a hydrophilic monoacrylate.

4. The hydrophilic membrane of claim 3, wherein said hydrophilic monoacrylate is a compound of the formula:

##STR11## wherein R⁴ is H, CH₃, CH₂ CH₃, (CH₂)₂ CH₃, CH(CH₃)₂, C₁ -C₃ hydroxyalkyl, C₁ -C₃ arylalkyl, C₁ -C₃ fluoroalkyl, or aryl; and

R⁵ is (OCH₂ CHR³)_n OH or (OCH₂ CH₂ CH₂)_n OH, wherein R³ is H or CH₃ and n is an integer from 1 to 15.

5. The hydrophilic membrane of claim 4, wherein R⁴ is CH₃ and R⁵ is (OCH₂ CH₂)_n OH.

6. The hydrophilic membrane of claim 5, wherein n is 1.

7. The hydrophilic membrane of claim 5, wherein n is at least 5.

8. The hydrophilic membrane of claim 5, wherein n is at least 10.

9. The hydrophilic membrane of claim 4, wherein R³ is CH₃.

10. The hydrophilic membrane of claim 3, wherein said hydrophilic monoacrylate is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, 2-methoxyethyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, and combinations thereof.

11. The hydrophilic membrane of claim 3, wherein said hydrophilic monoacrylate is an acrylamidosulfonic acid.

12. The hydrophilic membrane of claim 3, wherein said hydrophilic monoacrylate is a (trialkylammonium)alkyl acrylate.

13. The hydrophilic membrane of claim 3, wherein said hydrophilic monoacrylate is a (dialkylamino)alkyl acrylate.

14. The hydrophilic membrane of claim 1, wherein said hydrophilic polyalkylene glycol diacrylate comprises a polyethylene glycol dimethacrylate of PEG 200 or greater.

15. The hydrophilic membrane of claim 14, wherein said hydrophilic polyalkylene glycol diacrylate comprises a polyethylene glycol dimethacrylate of PEG 400 or greater.

16. The hydrophilic membrane of claim 15, wherein said hydrophilic polyalkylene glycol diacrylate comprises a polyethylene glycol dimethacrylate of PEG 600 or greater.

17. The hydrophilic membrane of claim 1, wherein said hydrophilic polyalkylene glycol diacrylate comprises a compound of the formula:

##STR12## wherein R¹ and R² are the same or different, and are each H, CH₃, CH₂ CH₃, (CH₂)₂ CH₃, or CH(CH₃)₂ ; and

A is a hydrophilic polyalkylene glycol chain of the formula (CH₂ CHR₃ O)_n or (CH₂ CH₂ CH₂ O)_n, wherein R₃ is H or CH₃, and n is at least 5.

18. The hydrophilic membrane of claim 17, wherein R¹ and R² are the same and are each H or CH₃, and A is (CH₂ CH₂ O)_n or (CH₂ CH(CH₃)O)_n.

19. The hydrophilic membrane of claim 1, wherein said hydrophilic polyalkylene glycol diacrylate is selected from the group consisting of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, and combinations thereof.

20. The hydrophilic membrane of claim 1, which wets in 10% aqueous sodium chloride after extraction with refluxing isopropanol for about 6 hours at about 100 kPa.

21. The hydrophilic membrane of claim 1, which wets in 10% aqueous sodium chloride after extraction with refluxing isopropanol for about 48 hours at about 100 kPa.

22. A filtration device comprising a housing and the hydrophilic membrane of claim 1.

23. A method of treating a fluid comprising contacting a fluid with the hydrophilic membrane of claim 1.

24. A method of preparing the hydrophilic membrane of claim 1 comprising:

(a) providing a reaction solution comprising a solvent, a non-crystalline hydrophobic polymer selected from the group consisting of polysulfone and polyethersulfone, a hydrophilic polyalkylene glycol diacrylate defined by two acrylate groups attached by ester linkages at opposite ends of a hydrophilic polyalkylene glycol chain having a molecular weight of at least about 200, a pore-forming agent, a thermal polymerization initiator, and, optionally, a hydrophilic monoacrylate,

(b) heating said reaction solution to a temperature sufficient to allow said hydrophilic polyalkylene glycol diacrylate and, if present, said hydrophilic monoacrylate to undergo polymerization and/or crosslinking in situ to provide a casting solution, and

(c) casting said casting solution to provide said hydrophilic membrane.

25. The method of claim 24, wherein said hydrophilic monoacrylate is not present.

26. The method of claim 24, wherein said hydrophilic monoacrylate is present.

27. The method of claim 26, wherein said hydrophilic monoacrylate is a a compound of the formula:

##STR13## wherein R⁴ is H, CH₃, CH₂ CH₃, (CH₂)₂ CH₃, CH(CH₃)₂, C₁ -C₃ hydroxyalkyl, C₁ -C₃ arylalkyl, C₁ -C₃ fluoroalkyl, or aryl; and

R⁵ is (OCH₂ CHR³)_n OH or (OCH₂ CH₂ CH₂)_n OH, wherein R³ is H or CH₃ and n is an integer from 1 to 15.

28. The method of claim 27, wherein R⁴ is CH₃ and R⁵ is (OCH₂ CH₂)_n OH.

29. The method of claim 28, wherein n is 1.

30. The method of claim 28, wherein n is at least 5.

31. The method of claim 27, wherein R³ is CH₃.

32. The method of claim 26, wherein said hydrophilic monoacrylate is selected from the group consisting of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, polypropylene glycol monoacrylate, polypropylene glycol monomethacrylate, 2-methoxyethyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, and combinations thereof.

33. The method of claim 24, wherein said hydrophilic polyalkylene glycol diacrylate comprises a polyethylene glycol dimethacrylate of PEG 200 or greater.

34. The method of claim 33, wherein said hydrophilic polyalkylene glycol diacrylate comprises a polyethylene glycol dimethacrylate of PEG 400 or greater.

35. The method of claim 34, wherein said hydrophilic polyalkylene glycol diacrylate comprises a polyethylene glycol dimethacrylate of PEG 600 or greater.

36. The method of claim 24, wherein said hydrophilic polyalkylene glycol diacrylate comprises a compound of the formula:

##STR14## wherein R¹ and R² are the same or different, and are each H, CH₃, CH₂ CH₃, (CH₂)₂ CH₃, or CH(CH₃)₂ ; and

A is a hydrophilic polyalkylene glycol chain of the formula (CH₂ CHR³ O)_n or (CH₂ CH₂ CH₂ O)_n, wherein R³ is H or CH₃, and n is at least 5.

37. The method of claim 36, wherein R¹ and R² are the same and are each H or CH₃, and A is (CH₂ CH₂ O)_n or (CH₂ CH(CH₃)O)_n.

38. The method of claim 24, wherein said hydrophilic polyalkylene glycol diacrylate is selected from the group consisting of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, and combinations thereof.

39. The method of claim 24, wherein said thermal polymerization initiator is selected from the group consisting of sodium persulfate and ammonium persulfate.

40. The method of claim 24, wherein said temperature is from about 27°

C. to about 50°

C.