Self cross-linkable and self cross-linked aromatic polyimide membranes for separations

摘要

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.

主权项

1. 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) comprisingwherein X1 iswherein X2 iswherein X3 iswherein Y1—CO— is; Y2—O— isand mixtures thereof; Y3 is selected from the group consisting ofand mixtures thereof, and —R′— is selected from the group consisting ofand 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.