Hydrophilic porous polytetrafluoroethylene membrane (I)

Patent metadata

Field	Value
Publication number	US-9643131-B2
Application number	US-201514815554-A
Country	US
Kind code	B2
Filing date	Jul 31, 2015
Priority date	Jul 31, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

Disclosed are hydrophilic porous PTFE membranes comprising PTFE and an amphiphilic copolymer, for example, a copolymer of the formula:

wherein m and n 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

The invention claimed is:

1. A hydrophilic porous membrane comprising a blend of polytetrafluoroethylene (PTFE) and an amphiphilic copolymer, wherein the amphiphilic copolymer comprises repeat units A and B, wherein A is selected from one or more of the following structures:

and B is of the formula:

wherein:
the amphiphilic copolymer is a block copolymer or a random copolymer; and
the number of repeat units of each of A and B are m and n, and range from 1 to about 1000, provided the sum of n and m is equal to or greater than 10.

2. The hydrophilic porous membrane of claim 1 , wherein the amphiphilic copolymer has chain end groups selected from aryl groups and alkoxy groups.

3. The hydrophilic porous membrane of claim 1 , wherein the amphiphilic copolymer is of one of the following formulae:

wherein m 1 +m 2 =m.

4. A method of preparing a hydrophilic porous membrane comprising:
(i) preparing a blend comprising PTFE and an amphiphilic copolymer, optionally with a lubricant;
(ii) extruding the blend into a tape;
(iii) biaxially stretching the tape to obtain the hydrophilic porous membrane; optionally
(iv) reacting the hydrophilic porous membrane with an agent to modify the chemical structure of the copolymer; and optionally
(v) annealing the hydrophilic porous membrane;
wherein the amphiphilic copolymer comprises repeat units A and B, wherein A is selected from one or more of the following structures:

and B is of the formula:

wherein:
the amphiphilic copolymer is a block copolymer or a random copolymer; and
the number of repeat units of each of A and B are m and n, and range from 1 to about 1000, provided the sum of n and m is equal to or greater than 10.

5. The method of claim 4 , wherein the agent in (iv) is a base.

6. A hydrophilic porous membrane prepared by the method of claim 4 .

7. A hydrophilic porous membrane prepared by the method of claim 5 .

Assignees

• Pall Corp

Inventors

• Aamer Khaled Abdel-Hakim Helmy
• Ait-Haddou Hassan
• Stasiak Marcin
• Singh Amarnauth

Classifications

• C08G2261/122

  statistical · CPC title

• C08G2261/146

  Side-chains containing halogens · CPC title

• C08G2261/126

  block · CPC title

• C08G61/12

  Macromolecular compounds containing atoms other than carbon in the main chain of the macromolecule · CPC title

• C08G2261/1426

  containing carboxy groups (COOH) and/or -C(=O)O-moieties · CPC title