Gas separation articles composed of amorphous crosslinked fluorinated copolymers and methods of making and using thereof
Described herein are articles for separating gases. The article includes a selective layer consisting of a crosslinked amorphous fluorinated copolymer containing one or more types of fluorinated ring monomers, with crosslinking between the fluorinated copolymer chains. The crosslinking improves the mechanical properties of the fluoropolymer, thereby permitting use of polymer types which would otherwise be excessively brittle. The resulting crosslinked polymer membranes have superior selectivity and reliability performance compared with previous compositions known to the art. Methods for making and using the article described are also provided.
1. A separation article comprising a first surface and a second surface and a layer comprising an amorphous crosslinked fluorinated copolymer adjacent to at least one of the first surface or the second surface,
wherein the amorphous crosslinked fluorinated copolymer is produced by (a) copolymerizing one or more fluorinated ring monomers in the amount of 1 mol % to 99.5 mol %, wherein the fluorinated ring monomer is at least a five membered ring, and a crosslinker in the amount of from 0.2 mol % to 40 mol % to produce a first copolymer and (b) crosslinking the first copolymer to produce the amorphous crosslinked fluoropolymer.
2. The separation article of claim 1 , wherein the fluorinated ring monomer is perfluorinated.
3. The separation article of claim 1 , wherein the fluorinated ring monomer is an olefinic compound.
4. The separation article of claim 1 , wherein the fluorinated ring monomer comprises a five or six membered ring.
5. The separation article of claim 1 , wherein the fluorinated ring monomer is produced by a cyclopolymerization of a linear monomer that has an olefin on one end of the monomer and a vinyl ether on the other end of the monomer.
6. The separation article of claim 1 , wherein the fluorinated ring monomer comprises one or more of the following compounds:
wherein
R 1 and R 2 are independently F, CF 3 , CF 2 CF 3 , CF 2 H, CF 2 CF 2 H, CFHCF 3 , CFHCF 2 H;
R 3 and R 4 are independently F, CF 3 , or CF 2 CF 3 , CF 2 H, CF 2 CF 2 H, CFHCF 3 , CFHCF 2 H;
R 5 , R 6 , R 7 , and R 8 are independently F, CF 3 , or CF 2 CF 3 , CF 2 H, CF 2 CF 2 H, CFHCF 3 , CFHCF 2 H and R 6 and R 7 can be contained within a 5- or 6-membered ring; and
R 9 is F, CF 3 , or CF 2 CF 3 .
7. The separation article of claim 1 , wherein the fluorinated ring monomer is:
or a combination thereof.
8. The separation article of claim 1 , wherein the fluorinated ring monomer is in the amount of 80 mol % to 99 mol %.
9. The separation article of claim 1 , wherein the crosslinker comprises a perfluorinated olefinic compound comprising at least one crosslinkable group.
10. The separation article of claim 1 , wherein the crosslinkable group comprises a photoactive group or a thermally active group.
11. The separation article of claim 9 , wherein the crosslinkable group comprises an alkyl ester group, a cyano group, or a fluorinated vinyl ether group.
12. The separation article of claim 1 , wherein the crosslinker comprises one or more compounds having the structure I-III:
wherein R F is a perfluoroalkyl group having from 1 to 6 carbon atoms with optionally 1 or 2 ether oxygen atoms, and
R 9 is a linear or branched alkyl group having from 1 to 6 carbon atoms.
13. The separation article of claim 1 , wherein the crosslinker is:
or any combination thereof.
14. The separation article of claim 1 , wherein the crosslinker is in the amount of 0.2 mol % to 20 mol %.
15. The separation article of claim 1 , wherein the fluorinated ring monomer comprises one or more of the following compounds:
wherein
R 1 and R 2 are independently F, CF 3 , CF 2 CF 3 , CF 2 H, CF 2 CF 2 H, CFHCF 3 , CFHCF 2 H;
R 3 and R 4 are independently F, CF 3 , or CF 2 CF 3 , CF 2 H, CF 2 CF 2 H, CFHCF 3 , CFHCF 2 H;
R 6 , R 6 , R 7 , and R 8 are independently F, CF 3 , or CF 2 CF 3 , CF 2 H, CF 2 CF 2 H, CFHCF 3 , CFHCF 2 H and R 6 and R 7 can be contained within a 5- or 6-membered ring; and
R 9 is F, CF 3 , or CF 2 CF 3 ; and
the crosslinker comprises one or more compounds having the following structure:
wherein R F is a perfluoroalkyl group having from 1 to 6 carbon atoms with optionally 1 or 2 ether oxygen atoms, and
R 9 is a linear or branched alkyl group having from 1 to 6 carbon atoms.
16. The separation article of claim 1 , wherein the fluorinated ring monomer and the crosslinker are copolymerized with a third monomer comprising a fluorinated vinyl compound or a fluorinated vinyl ether compound.
17. The separation article of claim 16 , wherein the third monomer has the structure:
wherein n and m are independently 1, 2, or 3, and x is 1 or 2.
18. The separation article of claim 16 , wherein the third monomer is
19. The separation article of claim 1 , wherein the first copolymer is produced by solution or aqueous emulsion polymerization.
20. The separation article of claim 1 , wherein the copolymerization is conducted in the presence of an initiator.
21. The separation article of claim 20 , wherein the initiator comprises a hydrocarbon peroxide, a fluorocarbon peroxide, a hydrocarbon peroxydicarbonate, an inorganic fluorocarbon initiator, or any combination thereof.
22. The separation article of claim 1 , wherein the first copolymer is crosslinked by exposing the first copolymer to UV radiation at a wavelength of less than 300 nm from about 0.5 hours to about 48 hours.
23. The separation article of claim 1 , wherein the first copolymer is crosslinked by exposing the first copolymer to UV radiation at a wavelength of about 250 nm to about 300 nm from about 0.5 hours to about 48 hours.
24. The separation article of claim 1 , wherein the first copolymer is crosslinked by heating the first copolymer at a temperature of from about 300° C. to about 350° C. for 0.5 minutes to 60 minutes.
25. The separation article of claim 1 , wherein the amorphous crosslinked fluorinated copolymer has a glass transition temperature of from 0° C. to 300° C.
26. The separation article of claim 1 , wherein the amorphous crosslinked fluorinated copolymer has a M n of from 10 kDa to 2,000 kDa.
27. The separation article of claim 1 , wherein the amorphous crosslinked fluorinated copolymer has a M w of from 10,000 g/mol to 3,000,000 g/mol.
28. The separation article of claim 1 , wherein the separation article comprises a multi-layer structured article, wherein at least one layer of the structure comprises the copolymer.
29. The separation article of claim 1 , wherein the article comprises a film, membrane, tube, or fiber.
30. The separation article of claim 1 , wherein the separation article comprises a layer of the amorphous crosslinked fluorinated copolymer, wherein the layer has a thickness of less than or equal to 1 μm.
31. A method for separating a first gaseous component from a gaseous mixture said process comprising passing the gaseous mixture across a separation article of claim 1 .
32. The method of claim 31 , wherein the method comprises
(a) passing the gaseous mixture across the separation article having a feed side and a permeate side, the separation article having the layer that is selectively permeable to at least the first gaseous component, said selective layer comprising the amorphous crosslinked fluorinated copolymer;
(b) providing a driving force sufficient to provide for permeation of at least a portion of the gaseous mixture from the feed side to the permeate side of the separation article, resulting in a gaseous permeate stream on the permeate side of the separation article and a gaseous retentate stream on the feed side of the separation article, wherein the gaseous permeate stream comprises the first gaseous component.
33. The method of claim 32 , wherein the permeate stream has a concentration of first component that is greater than a concentration of the first component in the retentate stream.
34. The method of claim 32 , further comprising withdrawing the permeate stream from the permeate side of the separation article.
35. The method of claim 32 , further comprising withdrawing the retentate stream from the feed side of the separation article.
36. The method of claim 32 , wherein the first gaseous component is carbon dioxide, hydrogen sulfide, helium, or any combination thereof.
37. The method of claim 32 , wherein the gaseous mixture comprises methane and carbon dioxide.
38. The method of claim 32 , wherein more than about 50% or more of the first gaseous component in the gaseous mixture permeates through the separation article.