ASYMMETRIC POLY(PHENYLENE ETHER) CO-POLYMER MEMBRANE, SEPARATION MODULE THEREOF AND METHODS OF MAKING

1 . A porous membrane, wherein the porous membrane comprises a poly(phenylene ether) copolymer, wherein the porous membrane has at least one of a molecular weight cut off of less than 40 kilodaltons and a surface pore size of 0.001 to 0.1 micrometers.

2 . The porous membrane of claim 1 , wherein the poly(phenylene ether) copolymer comprises first and second repeat units having the structure:

wherein each occurrence of Z 1 is independently halogen, unsubstituted or substituted C 1 -C 12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C 1 -C 12 hydrocarbylthio, C 1 -C 12 hydrocarbyloxy, or C 2 -C 12 halohydrocarbyloxy, wherein at least two carbon atoms separate the halogen and oxygen atoms,

wherein each occurrence of Z 2 is independently hydrogen, halogen, unsubstituted or substituted C 1 -C 12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C 1 -C 12 hydrocarbylthio, C 1 -C 12 hydrocarbyloxy, or C 2 -C 12 halohydrocarbyloxy, wherein at least two carbon atoms separate the halogen and oxygen atoms, and

wherein the first repeat units and second repeat units are not the same.

3 . The porous membrane of claim 1 , wherein the poly(phenylene ether) copolymer comprises:

99 to 20 mole percent repeat units derived from 2,6-dimethylphenol; and

1 to 80 mole percent repeat units derived from a second monohydric phenol having the structure

wherein Z is C 1 -C 12 alkyl or cycloalkyl, or a monovalent radical having the structure

wherein q is 0 or 1, and R 1 and R 2 are independently hydrogen or C 1 -C 6 alkyl;

wherein all mole percents are based on the total moles of all repeat units.

4 . The porous membrane of claim 3 , wherein the copolymer comprises:

80 to 20 mole percent repeat units derived from 2,6-dimethylphenol; and

20 to 80 mole percent repeat units derived from the second monohydric phenol.

5 . The porous membrane of claim 4 , wherein the second monohydric phenol is 2-methyl-6-phenylphenol.

6 . The porous membrane of claim 1 , wherein the poly(phenylene ether) copolymer has an intrinsic viscosity of 0.7 to 1.5 deciliters per gram, when measured in chloroform at 25° C.

7 . The porous membrane of claim 1 , wherein the poly(phenylene ether) copolymer has a weight average molecular weight of 100,000 to 500,000 daltons, as measured in chloroform by gel permeation chromatography against polystyrene standards.

8 . The porous membrane of claim 1 , wherein the poly(phenylene ether) copolymer has a solubility of 50 to 400 grams per kilogram in N-methyl-2-pyrrolidone at 25° C. in, based on the combined weight of the poly(phenylene ether) copolymer and N-methyl-2-pyrrolidone.

9 . The porous membrane of claim 1 , comprising 20 to 99 weight percent of the poly(phenylene ether) copolymer and 1 to 80 weight percent of poly(2, 6-dimethyl-1,4-phenylene ether), polyethersulfone, polysulfone, polyphenylsulfone, or a combination comprising at least one of the foregoing, based on the total weight of the porous membrane.

10 . A porous membrane-forming composition for making the porous membrane of claim 1 , comprising:

a poly(phenylene ether) copolymer comprising the first and second repeat units; and

a water-miscible polar aprotic solvent, wherein the poly(phenylene ether) copolymer is dissolved in the water-miscible polar aprotic solvent.

11 . A method of making the porous membrane of claim 1 , comprising:

dissolving the poly(phenylene ether) copolymer in a water-miscible polar aprotic solvent to form a porous membrane-forming composition; and

phase-inverting the porous asymmetric membrane forming-composition in a first non-solvent composition to form the porous membrane.

12 . The method of claim 11 , wherein hydrophilic and amphiphilic polymers are absent from the membrane-forming composition and the first non-solvent composition.

13 . The method of claim 11 , further comprising washing the porous membrane in a second non-solvent composition.

14 . The method of claim 11 , further comprising drying the porous membrane.

15 . A porous membrane made by the method of claim 11 .

16 . A method of making a hollow fiber by coextrusion through a spinneret comprising an annulus and a bore, wherein the method comprises coextruding:

a membrane-forming composition comprising a poly(phenylene ether) copolymer, dissolved in a water-miscible polar aprotic solvent through the annulus, and

a first non-solvent composition comprising water, a water-miscible polar aprotic solvent, or a combination comprising at least one of the foregoing, through the bore,

into a second non-solvent composition comprising water, a water-miscible polar aprotic solvent, or a combination comprising at least one of the foregoing, to form the hollow fiber.

17 . The method of claim 16 , wherein hydrophilic and amphiphilic polymers are absent from the membrane-forming composition and the first non-solvent composition.

18 . A separation module comprising the porous membrane of claim 1 .

19 . A hollow fiber made by the method of claim 16 .

20 . A separation module comprising the hollow fiber of claim 19 .