Claims
- 1. A process for the preparation of a porous poly(aryl ether ketone) article comprising:
a. forming a blend of poly(aryl ether ketone) polymer with a polyimide, b. forming a shaped article from said blend, c. decomposing said polyimide in said shaped article into low molecular weight fragments by chemical means, d. removing said low molecular weight fragments from said article.
- 2. The process of claim 1 wherein said step b) is accomplished by extrusion, casting or molding.
- 3. The process of claim 1 wherein said step d) comprises solvent washing.
- 4. The process of claim 1 wherein said steps c) and d) take place concurrently in a common liquid media.
- 5. The process of claim 1 further comprising drying the porous article under conditions that substantially preserves the porous structure.
- 6. The process of claim 5 wherein said drying process is carried out from a hydrocarbon or a fluorocarbon solvent.
- 7. The process of claim 6 wherein said hydrocarbon is pentane, hexane, cyclohexane, heptane, octane or a mixture thereof, and said flouorocarbon is a chlorofluorocarbon or a perfluorocarbon.
- 8. The process of claim 1 wherein said poly(aryl ether ketone) is poly(ether ether ketone) or poly(ether ketone).
- 9. The process of claim 8 wherein polyimide in said poly(aryl ether ketone)/polyimide blend is poly(ether imide) of the following repeat unit:
- 10. The process of claim 9 wherein said poly(ether imide) has a molecular weight between 1,000 and 500,000.
- 11. The process of claim 9 wherein said poly(ether imide) is a copolymer or block copolymer of poly(ether imide).
- 12. The process of claim 11 wherein said poly(ether ether ketone) or poly(ether ketone) comprises from 20 to 80 weight percent of said blend.
- 13. The process of claim 8 wherein polyimide in said poly(aryl ether ketone)/polyimide blend is the phenylindane containing polyimide of the following repeat unit:
- 14. The process of claim 13 wherein said phenylindane containing polyimide has a molecular weight between 1,000 and 500,000.
- 15. The process of claim 14 wherein said poly(ether ether ketone) or poly(ether ketone) comprises from 20 to 80 weight percent of said blend.
- 16. The process of claim 1 wherein said porous article is a flat sheet, a fiber, a tube, or a hollow fiber.
- 17. The process of claim 1 wherein said polyimide is decomposed by contacting the shaped article with ammonia, tetraalkylammonium hydroxide, hydrazine, alkylhydrazine, hydroxyalkylhydrazine, primary aliphatic amine, secondary aliphatic amine, or a mixture thereof.
- 18. The process of claim 17 wherein said tetraalkyammonium hydroxide is tetramethylammonium hydroxide.
- 19. The process of claim 17 wherein said primary aliphatic amine is monoethanolamine, ethylamine, propylamine, butylamine, or a mixture thereof.
- 20. The process of claim 17 wherein said ammonia, tetraalkylammonium hydroxide, hydrazine, alkylhydrazine, hydroxyalkylhydrazine, primary aliphatic amine, secondary aliphatic amine are in a solution of alcohol, hydrocarbon, ketone, water, aprotic solvent or a mixture thereof.
- 21. The process of claim 20 wherein said alcohol is methanol, ethanol, isopropanol, or butanol.
- 22. The process of claim 16 wherein said flat sheet, said fiber, said tube, or said hollow fiber is drawn prior to step c), after step d) or both.
- 23. The process of claim 16 wherein said flat sheet, said tube, or said hollow fiber is a fluid separation membrane.
- 24. The process of claim 16 wherein said article is a battery separator.
- 25. The process of claim 1 wherein said shaped poly(aryl ether ketone) article is a multilayer article formed from two or more poly(aryl ether ketone) polymer polyimide blends that differ in blend chemical composition.
- 26. The process of claim 25 wherein the poly(aryl ether ketone) polymer weight content in said blends differ by at least 1 percent.
- 27. The process of claim 9 wherein the average pore diameter of said shaped article is about 0.25 micrometers or less.
- 28. The process of claim 1 wherein said blend of poly(aryl ether ketone) with polyimide contains an additive.
- 29. The process of claim 28 wherein said additive is a solvent, a plasticizer, or a filler.
- 30. The process of claim 1 wherein the specific surface area of said article is above 20 m2/g.
- 31. A method for separating a fluid mixture into a fraction enriched in a first component and a fraction depleted in the first component, comprising the step of contacting said fluid mixture with a fluid separation membrane, said membrane having been formed by a process including the steps of:
a. forming a blend of poly(aryl ether ketone) polymer with a polyimide, b. forming a shaped article from said blend by extrusion or molding, c. decomposing said polyimide in said shaped article into lower molecular weight fragments by chemical means, d. removing said low molecular weight fragments from said article; whereby said fraction enriched in the first component and said fraction depleted in the first component are generated by preferentially permeating a portion of said fluid mixture through said fluid separation membrane.
- 32. The method of claim 31 wherein said fluid mixture is a solution of one or more components and said first component is a solute dissolved in said solution.
- 33. The method of claim 31 wherein said method for separating a fluid mixture is a micro filtration, an ultrafiltration, a nano-filtration, or a gas separation process.
- 34. The method of claim 31 wherein said fluid separation membrane is a hollow fiber, a tube, or a flat sheet.
- 35. The method of claim 34 wherein said fluid separation membrane further contains a separation layer formed on said hollow fiber, said tube, or said flat sheet.
- 36. The method of claim 31 wherein said blend of poly(aryl ether ketone) polymer with a polyimide is poly(ether ether ketone)/poly(ether imide) or poly(ether ketone)/poly(ether imide) blend.
- 37. The method of claim 36 wherein said fluid separation membrane is a multilayer membrane formed from two or more blends that differ in blend chemical composition.
- 38. The method of claim 37 wherein said fluid separation membrane contains two or more layers that differ in the average pore size.
- 39. The method of claim 38 wherein the layer comprised of a smaller average pore size is supported by or sandwiched between layers with a larger average pore size.
- 40. The method of claim 36 wherein said blend contains an additive.
- 41. The method of claim 40 wherein said additive is a solvent, a plasticizer, or a filler.
- 42. The method of claim 31 wherein the average pore size of said fluid separation membrane is about 0.25 micrometer or less.
- 43. The method of claim 31 wherein said first component is a solid matter suspended in said fluid mixture.
- 44. The method of claim 31 wherein said method is a cross-flow filtration or a dead-end filtration process.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of, under 35 U.S.C. §119(e), U.S. Provisional Patent Application No. 60/468,013, filed May 5, 2003.
Provisional Applications (1)
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Number |
Date |
Country |
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60468013 |
May 2003 |
US |