Amphiphilic block copolymer; composition, membrane, and separation module thereof; and methods of making same

1. An amphiphilic block copolymer, comprising

a hydrophobic block comprising a poly(phenylene ether) block or a poly(phenylene ether) copolymer block having repeat units of the structure:

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

a hydrophilic block or graft comprising a polymerized hydrophilic ethylenically unsaturated monomer.

2. The amphiphilic block copolymer of claim 1 , comprising 20 to 50 weight percent of the hydrophobic block and 50 to 80 weight percent of the hydrophilic block or graft.

3. The amphiphilic block copolymer of claim 1 , wherein the hydrophobic block comprises a poly(phenylene ether) copolymer comprising:

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

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

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

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

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

wherein the poly(phenylene ether) copolymer block has an intrinsic viscosity of 0.1 to 0.5 deciliters per gram, measured in chloroform at 25° C.

4. The amphiphilic block copolymer of claim 1 , wherein the hydrophobic block of the amphiphilic copolymer comprises a poly(phenylene ether) copolymer comprising:

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 amphiphilic block copolymer of claim 4 , wherein the second monohydric phenol comprises 2-methyl-6-phenylphenol.

6. The amphiphilic block copolymer of claim 1 , wherein the hydrophilic ethylenically unsaturated monomer comprises methoxy-capped poly(ethylene oxide) methacrylate, 4-vinylpyridine, N-vinylpyrrolidone, N,N-dimethylacrylamide, 4-acryloylmorpholine, or a combination comprising at least one of the foregoing.

7. A method of making the amphiphilic block copolymer of claim 1 , comprising polymerization of the hydrophilic ethylenically unsaturated monomer in the presence of a hydrophobic polymer comprising a poly(phenylene ether) or a poly(phenylene ether) copolymer having repeat units of the structure:

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

8. The method of claim 7 , wherein the polymerization is controlled radical polymerization.

9. The method of claim 8 , wherein the controlled radical polymerization is atom transfer radical polymerization, reversible addition fragmentation transfer polymerization, or stable free radical polymerization.

10. The method of claim 7 , wherein the polymerization is graft polymerization.

11. The method of claim 7 , wherein the hydrophilic ethylenically unsaturated monomer comprises methoxy-capped poly(ethylene oxide) methacrylate, 4-vinylpyridine, vinyl pyrrolidone, N,N-dimethylacrylamide, 4-acryloylmorpholine, or a combination comprising at least one of the foregoing.

12. A porous asymmetric membrane comprising:

a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer; and

an amphiphilic block copolymer comprising

an amphiphilic block copolymer comprising

a hydrophobic block comprising a poly(phenylene ether) or poly(phenylene ether) copolymer having repeat units of the structure:

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

a hydrophilic block or graft comprising a polymerized hydrophilic ethylenically unsaturated monomer,

in a water-miscible polar aprotic solvent to form a porous asymmetric membrane-forming composition;

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

optionally washing the porous asymmetric membrane in a second non-solvent; and

optionally drying the porous asymmetric membrane to form the porous asymmetric membrane.

13. A porous asymmetric membrane-forming composition comprising:

a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer;

the amphiphilic block copolymer of claim 1 ; and

a water-miscible polar aprotic solvent,

wherein the hydrophobic polymer and amphiphilic block copolymer are dissolved in the water-miscible polar aprotic solvent.

14. A method of forming a porous asymmetric membrane, the method comprising:

dissolving

a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer and

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

15. The porous asymmetric membrane of claim 12 , wherein the hydrophobic polymer comprises a poly(phenylene ether) having repeat units having the structure:

a hydrophobic block comprising a poly(phenylene ether) block or a poly(phenylene ether) copolymer block having repeat units of the structure:

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

a hydrophilic block or graft comprising a polymerized hydrophilic ethylenically unsaturated monomer.

16. The porous asymmetric membrane of claim 12 , wherein the hydrophobic polymer comprises a poly(phenylene ether) copolymer comprising:

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

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

wherein Z is C 1-12 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 1-6 alkyl;

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

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

17. The porous asymmetric membrane of claim 12 , wherein the hydrophobic polymer comprises a poly(phenylene ether) copolymer comprising: 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.

18. The porous asymmetric membrane of claim 17 , wherein the second monohydric phenol comprises 2-methyl-6-phenylphenol.

19. The amphiphilic block copolymer of claim 1 , wherein the hydrophobic block of the amphiphilic copolymer comprises the poly(phenylene ether) copolymer block.

20. The porous asymmetric copolymer of claim 12 , wherein the hydrophobic block of the amphiphilic copolymer comprises the poly(phenylene ether) copolymer block.

21. A method of making the amphiphilic block copolymer of claim 14 , wherein the hydrophobic block of the amphiphilic copolymer comprises the poly(phenylene ether) copolymer block.