Hydrophilic porous polytetrafluoroethylene membrane (ii)

Patent metadata

Field	Value
Publication number	US-2017028362-A1
Application number	US-201514815578-A
Country	US
Kind code	A1
Filing date	Jul 31, 2015
Priority date	Jul 31, 2015
Publication date	Feb 2, 2017
Grant date	—

Abstract

Disclosed are hydrophilic porous PTFE membranes comprising PTFE and an amphiphilic copolymer of the formula (I):

wherein Rf, Rh 1 , Rh 2 , Y, m, n, and o are as described herein. Also disclosed are a method of preparing hydrophilic porous PTFE membranes and a method of filtering fluids through such membranes.

First claim

1 . A hydrophilic porous membrane comprising polytetrafluoroethylene (PTFE) and an amphiphilic copolymer of formula (I):

wherein the amphiphilic copolymer is a random or block copolymer, Rf is a perfluoro-substituted group, whereas Rh 1 and Rh 2 are hydrophilic groups or chlorine, m and n are independently from 0 to 1000, provided m+n+o is greater than or equal to 10, and Y is hydroxyl.

2 . The hydrophilic porous membrane of claim 1 , wherein Rf is perfluoro-substituted alkyl, where alkyl chain may optionally contain one or more oxygen atoms in the chain.

3 . The hydrophilic porous membrane of claim 1 , wherein Rf is C p F 2p+1 —(CH 2 ) q (OCH 2 ) r , wherein p is 1 to 12, q is 0 to 3, and r is 0 to 2.

4 . The hydrophilic porous membrane of claim 3 , wherein Rf is independently selected from C 8 F 17 CH 2 , C 6 F 13 (CH 2 ) 2 OCH 2 , C 4 F 9 CH 2 and CF 3 .

5 . The hydrophilic porous membrane of claim 4 , wherein Rf is selected from C 8 F 17 CH 2 and C 6 F 13 (CH 2 ) 2 OCH 2 .

6 . The hydrophilic porous membrane of claim 1 , wherein Rh 1 and Rh 2 are independently selected from hydroxyl, acyloxy, trifluoroacetyl, alkyloxy, chlorine, allyloxy, alkylthio, and alkylthiopropyloxy, wherein the alkyl portion of alkylthio and alkylthiopropyloxy are optionally substituted with hydroxyl, carboxylic acid, sulfonic acid, phosphonic acid, quaternary ammonium, alkylsulfonyl, or heterocyclyl.

7 . The hydrophilic porous membrane of claim 6 , wherein Rh 1 and Rh 2 are selected from hydroxyl and trifluoroacetyl.

8 . The hydrophilic porous membrane of claim 1 , wherein the amphiphilic copolymer is selected from:

9 . A method of preparing a hydrophilic porous PTFE membrane comprising:
(i) preparing a blend comprising PTFE and a amphiphilic copolymer, and optionally a lubricant; (ii) extruding the blend into a tape; (iii) biaxially stretching the tape to obtain a hydrophilic porous membrane;
optionally
(iv) reacting the hydrophilic porous membrane with an agent to modify the chemical structure of the amphiphilic copolymer; and optionally
(v) annealing the hydrophilic porous membrane;
wherein the amphiphilic copolymer is of formula (I):

wherein the amphiphilic copolymer is a random or block copolymer, Rf is a perfluoro-substituted group, whereas Rh 1 and Rh 2 are hydrophilic groups or chlorine, m, n and o are independently from 0 to 1000, provided m+n+o is greater than or equal to 10, and Y is hydroxyl.

10 . A hydrophilic porous membrane produced by the method of claim 9 .

11 . A method of filtering a fluid, the method comprising passing the fluid through the hydrophilic porous membrane of claim 1 .

12 . A method of filtering a fluid, the method comprising passing the fluid through the hydrophilic porous membrane of claim 10 .

Assignees

• Pall Corp

Inventors

• Stasiak Marcin
• Ait-Haddou Hassan
• Onyemauwa Frank O
• Singh Amarnauth

Classifications

• B01D2325/36

  Hydrophilic membranes · CPC title

• B01D71/76

  Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74 (rubbers in general B01D71/24) · CPC title

• B01D67/0009

  by phase separation, sol-gel transition, evaporation or solvent quenching · CPC title

• B01D67/0027

  by stretching · CPC title

• B01D69/02

  characterised by their properties · CPC title