Gas separating membranes from polyimide polymers
US5042993A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1990 |
| Grant date | Aug 27, 1991 |
| Priority date | — |
| Expiry date | Jul 24, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2379/08
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention is a class of semi-permeable polyimide membranes and a process for using such membranes to separate one or more components of a gaseous mixture. The membranes are prepared from a polyimide having surface-modifiable functionalities comprising repeating units formed from an aromatic dianhydride and an alkyl-substituted phenylenediamine having at least one hydrogen atom located on a ring position ortho to an amine nitrogen. The membranes formed therefrom are contacted in the presence of an oxygen source with an activating force such as high energy electromagnetic irradiation to effect modification of the polymer surface. The surface-modified polyimide membranes exhibit high gas perm-selectivities and are especially useful in effecting the separation of oxygen and nitrogen from air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.