Self cross-linkable and self cross-linked aromatic polyimide membranes for separations
AssigneeUop LLC
InventorsChunqing Liu, Zara Osman, Angela N. Troxell
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Abstract
This invention relates to self-cross-linkable and self-cross-linked aromatic polyimide polymers, their membranes and methods for making and using these polymers and membranes. The self-cross-linkable aromatic polyimide polymer described in the present invention comprises both hydroxyl functional groups and carboxylic acid functional groups. The self-cross-linked aromatic polyimide was formed via heating the self-cross-linkable aromatic polyimide polymer at ≦300° C. The self-cross-linked aromatic polyimide membranes exhibit high selectivity in separation of mixtures of gases and liquids.
Claims19
A process for separating at least one gas from a mixture of gases comprising providing a self-cross-linked aromatic polyimide membrane of formula (II) comprising
- wherein X1, X2, and X3 are selected from the group consisting of
- and mixtures thereof, respectively;
- X1, X2, and X3 are the same or different from each other;
- Y1—CO— is selected from the group consisting of
- and mixtures thereof;
- Y2—O— is selected from the group consisting of
- and mixtures thereof, and —R′-is selected from the group consisting of
- and mixtures thereof;
- Y3 is selected from the group consisting of
- and mixtures thereof, and —R′-is selected from the group consisting of
- and mixtures thereof, and —R″— is selected from the group consisting of —H, COCH3, and mixtures thereof;
- n, m, and p are independent integers from 2 to 500;
- the molar ratio of (n+m)/p is in a range of 1:20 to 1:0;
- and the molar ratio of n/m is in a range of 1:10 to 10:1 and contacting the mixture of gases to one side of the self-cross-linked aromatic polyimide membrane of formula (II) to cause at least one gas to permeate said membrane;
- and
- removing from an opposite side of said self-cross-linked aromatic polyimide membrane of formula (II) a permeate gas composition comprising a portion of said at least one gas that permeated said membrane.
A process for separation of liquid mixtures by pervaporation comprising contacting said liquid mixture with a membrane comprising self-cross-linked aromatic polyimide membrane of formula (II) comprising
- wherein X1, X2, and X3 are selected from the group consisting of
- and mixtures thereof, respectively;
- X1, X2, and X3 are the same or different from each other;
- Y1—CO— is selected from the group consisting of
- and mixtures thereof;
- Y2—O— is selected from the group consisting of
- and mixtures thereof, and —R′-is selected from the group consisting of
- and mixtures thereof;
- Y3 is selected from the group consisting of
- and mixtures thereof, and —R′-is selected from the group consisting of
- and mixtures thereof, and —R″— is selected from the group consisting of —H, COCH3, and mixtures thereof;
- n, m, and p are independent integers from 2 to 500;
- the molar ratio of (n+m)/p is in a range of 1:20 to 1:0;
- and the molar ratio of n/m is in a range of 1:10 to 10:1.
Dependencies are inferred from the claim text.