Water flux polymer membranes

• US 9,707,524 B2
• Filed: 10/09/2009
• Issued: 07/18/2017
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Arkema Incorporated (Arkema)
• Original Assignee: Arkema Incorporated (Arkema)
• Inventors: Kosar, Walter, Macy, Noah E., Ness, Jason S., Biscarat, Jennifer, Schmidt, Scott C.
• Primary Examiner(s): Kaucher, Mark
• Application Number:
  US13/126,670
• Publication Number:
  US 20110207841A1
• Time in Patent Office: 2,839 Days
• 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 having uniform stable hydrophilicity and uniform pore size useful as a water microfiltration or ultrafiltration membrane consisting of a stable, uniform blend of:

a) 99-20 weight percent of a hydrophobic matrix polymer, said matrix polymer comprises a polyvinylidene fluoride homopolymer, or a polyvinylidene copolymer comprising at least 50 mole percent of vinylidene fluoride monomer units,

b) 1-80 weight percent of an amphiphilic block copolymer having

     1) at least one hydrophilic bock and

     2) at least one hydrophobic block compatible with said polymer matrix, wherein said hydrophilic and hydrophobic blocks comprise acrylic polymers, wherein said hydrophilic block is a gradient copolymer having two or more different monomer units, and wherein said hydrophilic block comprises one or more monomer units selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, polyethylene glycol acrylate (PEGA), polyethyeleneglycol-methylether acrylate (MPEGA), polyethylene glycol methacrylate (PEGMA), polyethyleneglycol-methylether-methacrylate (MPEGMA), acrylamido 2-methyl 2-propane sulfonate, styrene sulfonic acid and itaconic acid, and

c) optionally one or more hydrophilic additives selected from the group consisting of polyethylene-glycol (PEG), polyethylene glycol methacrylate (PEGMA), propylene glycol (PG), polyacrylic add (PAA), and polymethacrylic acid (PMA);

wherein said polymeric membrane has a maximum pore size of less than 0.3 um, and wherein said block copolymer is a controlled radical polymerized copolymer.

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

3. The polymeric membrane of claim 1 wherein said amphiphilic block copolymer comprises residual nitroxide end-groups.

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

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

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

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

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

9. The polymeric membrane of claim 8, wherein said intimate blend is an interpenetrating polymer network (IPN) or a core-shell morphology.