WATER FLUX POLYMER MEMBRANES

• US 20110207841A1
• Filed: 10/09/2009
• Published: 08/25/2011
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Arkema Incorporated (Arkema)
• Original Assignee: Arkema Incorporated (Arkema)
• Inventors: Biscarat, Jennifer, Ness, Jason S., Schmidt, Scott C., Kosar, Walter, Macy, Noah E.
• Granted Patent: US 9,707,524 B2
• Time in Patent Office: Days
• US Class Current: 521/134
• 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 69/02 characterised by their properties
• CPC Class Codes: B01D 71/34 Polyvinylidene fluoride
• 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 71/4011 Polymethylmethacrylate
• CPC Class Codes: B01D 71/402 Polymers based on the polymerisation of fumaric acid or derivatives thereof
• CPC Class Codes: B01D 71/403 Polymers based on the polymerisation of maleic acid or derivatives thereof
• CPC Class Codes: B01D 71/80 Block polymers
• CPC Class Codes: C08L 27/16 Homopolymers or copolymers or vinylidene fluoride
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers

Abstract

The invention relates to a polymer membrane composition having improved water flux and stable pore size. The water flux is improved by increasing the hydrophilicity of the membrane using a matrix polymer blended with controlled architecture amphiphilic block copolymers. Preferred membranes are those having a fluoropolymer matrix and acrylic amphiphilic block copolymers. The addition of the amphiphilic block copolymers are especially useful in microfiltration and ultra filtration membranes when used in water filtration.

Claims

1. A polymeric membrane comprising:

a) 99-20 weight percent of a hydrophobic matrix polymer, and

b) 1-80 weight percent of an amphiphilic block copolymer having at least one hydrophilic block and at least one hydrophobic block compatible with said polymer matrix.

2. The polymeric membrane of claim 1 wherein said block copolymer is a di-, tri- or multiblock copolymer.

3. The polymeric membrane of claim 2 wherein said block copolymer is a controlled radical polymerized copolymer.

4. The polymeric membrane of claim 3 wherein said amphiphilic block copolymer comprises residual nitroxide end-groups.

5. The polymeric membrane of claim 2 wherein said block copolymer contains at least one segment that is a gradient copolymer.

6. The polymeric membrane of claim 2 wherein said block copolymer is water-soluble.

7. The polymeric membrane of claim 2 wherein said block copolymer is non-water soluble

8. The polymeric membrane of claim 1 wherein said matrix polymer comprises a fluoropolymer.

9. The polymeric membrane of claim 8 wherein said fluoropolymer is a polyvinylidene fluoride homopolymer, or a polyvinylidene copolymer comprising at least 50 mole percent of vinylidene fluoride monomer units.

10. The polymeric membrane of claim 1 having a maximum pore size of less than 0.3 um.

11. The polymeric membrane of claim 1 comprising 99-40 weight percent of hydrophobic matrix polymer and 1-60 weight percent of amphiphilic block copolymer.

12. The polymeric membrane of claim 1 comprising 90-70 weight percent of hydrophobic matrix polymer and 10-30 weight percent of amphiphilic block copolymer.

13. The polymeric membrane of claim 1 further comprising a hydrophilic additive.

14. The polymeric membrane of claim 1, wherein said amphiphilic block copolymer is partially or fully neutralized.

15. The polymeric membrane of claim 1, wherein said hydrophilic and hydrophobic blocks comprise acrylic polymers.

16. The polymeric membrane of claim 1, wherein said hydrophobic matrix polymer and amphiphilic block copolymer form an intimate blend.

17. The polymeric membrane of claim 16, wherein said intimate blend is an interpenetrating polymer network (IPN) or a core-shell morphology.

18. The polymeric membrane of claim 16 wherein said membrane is a polymer electrolyte membrane.

19. A process for forming the intimate blend of claim 16, wherein a latex of said hydrophobic matrix polymer is used as a seed polymer, and said amphiphilic block copolymer is polymerized in the presence of said seed polymer.

20. A hydrophilic-modified polymer coating comprising the hybrid latex of claim 19.