Patent ID: 8241501
Filing Date: 2012-08-14
Classification: B01D,C08G,C08L,Y02C

Abstract:
1. A process for separating at least one gas or liquid from a mixture of gases or liquids using a polymer membrane made from subjecting aromatic polyimide membranes first to a thermal treatment step followed by a crosslinking step wherein said aromatic polyimide membranes comprise at least one aromatic polyimide polymer comprising cross-linkable functional groups in a polymer backbone of said aromatic polyimide polymer and pendent —OH or —SH functional groups ortho to a heterocyclic imide nitrogen within said aromatic polyimide polymer wherein said polymer membrane is a cross-linked polybenzoxazole or polybenzothiazole polymer membrane and wherein said aromatic polyimide polymer has a structure represented by a plurality of first repeating units of a formula (I), wherein said formula (I) is: where —X or mixtures thereof, —X or mixtures thereof, —X or mixtures thereof, —Z—, —Z′—, and —Z″— are independently —O— or —S—, and —R— is or mixtures thereof, said process comprising: