Membrane comprising oxyethylene groups
The present invention relates to a membrane wherein said membrane comprises a continuous non-porous layer comprising a polymerized composition that comprised prior to polymerization at least one type of compound having a molecular weight of at least 1500 Da and comprising at least 75 weight % of oxyethylene groups and at least two polymerizable groups each comprising a non-substituted vinyl group. The invention further relates to the use of this membrane for separating polar gases and vapors.
1. Membrane comprising a continuous substantially non-porous layer comprising the polymerization product of a composition comprising a compound, which compound comprises at least 75 weight % of —(—CH 2 —CH 2 —O—)— (oxyethylene) groups and has a molecular weight of at least 1500 Da and has at least two polymerizable groups, each polymerizable group comprising a CH 2 ═CH— (non-substituted vinyl) group, wherein the oxyethylene groups form an uninterrupted chain of formula —(CH 2 CH 2 O) n — wherein n is at least 25.
2. Membrane according to claim 1 wherein said polymerizable groups are selected from acrylate groups, acrylamide groups, vinyl ether groups, vinyl ester groups, vinyl amide groups, allyl ether groups, allyl ester groups, allyl amine groups, allyl amide groups, styryl groups and combinations thereof.
3. Membrane according to claim 1 wherein at least one of said polymerizable groups is an acrylate group.
4. Membrane according to claim 1 wherein at least two of said polymerizable groups are acrylate groups.
5. Membrane according to claim 1 wherein said composition comprises 3-80 weight % of said compound.
6. Membrane according to claim 1 wherein said composition comprises 5-60 weight % of said compound.
7. Membrane according to claim 1 wherein said continuous substantially non-porous layer comprises at least 60 weight % of oxyethylene groups.
8. Membrane according to claim 1 wherein the pure water permeance of the membrane at 20° C. is less than 6.10 −8 m 3 /m 2 .s.kPa.
9. Membrane according to claim 1 joined to a porous support.
10. Membrane according to claim 1 wherein the compound has more than 90 weight % of oxyethylene groups.
11. Membrane according to claim 1 wherein at least two of said polymerizable groups are acrylate groups, the compound has more than 90 weight % of oxyethylene groups and the pure water permeance of the membrane at 20° C. is less than 6.10 −8 m 3 /m 2 .s.kPa.
12. A module comprising at least one cartridge and at least one membrane according to claim 1 .
13. A module comprising at least one cartridge and at least one membrane according to claim 10 .
14. A module comprising at least one cartridge and at least one membrane according to claim 11 .
15. A module according to claim 12 wherein the membrane has a flatsheet, spiral-wound or hollow fiber geometry.
16. A module according to claim 13 wherein the membrane has a flatsheet, spiral-wound or hollow fiber geometry.
17. A module according to claim 14 wherein the membrane has a flatsheet, spiral-wound or hollow fiber geometry.
18. Process for making a membrane according to claim 1 comprising the steps of:
a. providing said composition;
b. applying said composition to a support;
c. polymerizing said composition thereby forming a substantially non-porous polymer film;
d. optionally separating the polymer film from the support; and
e. optionally washing and/or drying the polymer film.
19. Process according to claim 18 wherein the coating step is continuous.
20. Process according to claim 18 wherein the polymerization step comprises exposure of the applied layer to radiation for less than 1 second.
21. Membrane according to claim 1 for separation of polar gases and/or vapors from non-polar gases and/or vapors.