Claims
- 1. A gas separation membrane prepared by the process comprising the steps of:
- a. dissolving first polymer or polymers in a suitable solvent to form a core solution;
- b. dissolving second polymer or polymers in a solvent to form a sheath solution having at least 27-35 weight percent of said second polymer or polymers;
- c. coextruding the core and sheath solutions at a temperature of 85.degree.-100.degree. C. through a spinneret having at least one hollow fiber spinning orifice to provide at least one nascent multicomponent hollow fiber membrane;
- d. drawing said nascent multicomponent hollow fiber membrane through an air gap of 7-9 cm at a draw ratio of 3.0-6.0;
- e. introducing said nascent multicomponent hollow fiber membrane into a coagulation bath at a temperature of 0.degree.-20.degree. C. to solidify the nascent multicomponent hollow fiber membrane into a hollow fiber membrane.
- 2. The gas separation membrane of claim 1, wherein the selectivity for two gases in a mixture of gases is at least 80% of the relative selectivity of the corresponding single gases in the mixture.
- 3. A gas separation membrane prepared by the process comprising the steps of:
- a. dissolving polymer or polymers in a solvent to form a sheath solution having 27-35 weight percent of said polymer or polymers;
- b. extruding the solution at a temperature of 85.degree.-100.degree. C. through a spinneret having at least one hollow fiber spinning orifice to provide at least one nascent hollow fiber membrane;
- c. drawing said nascent hollow fiber membrane through an air gas of 7-9 cm at a draw ratio of 3.0-6.0;
- d. introducing said nascent hollow fiber membrane into a coagulation bath at a temperature of 0.degree.-20.degree. C. to solidity the nascent hollow fiber membrane into a hollow fiber asymmetric membrane, wherein the selectivity for two gases in a mixture of gases is at least 65% of the relative selectivity of the corresponding single gases in the mixture.
Parent Case Info
This is a divisional of application Ser. No. 08/465,304, filed Jun. 5, 1995, (now U.S. Pat. No. 5,618,332) which is a divisional of U.S. Ser. No. 08/246,201, filed May 19, 1994, issued Nov. 21, 1995 as U.S. Pat. No. 5,468,430.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5085676 |
Ekiner et al. |
Feb 1992 |
|
5085774 |
Ekiner et al. |
Feb 1992 |
|
Divisions (2)
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Number |
Date |
Country |
Parent |
465304 |
Jun 1995 |
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Parent |
246201 |
May 1994 |
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