Method of making a crosslinked fiber membrane from a high molecular weight, monoesterified polyimide polymer

摘要

The present disclosure relates to a high molecular weight, monoesterified polyimide polymer. Such high molecular weight, monoesterified polyimide polymers are useful in forming crosslinked polymer membranes for the separation of fluid mixtures. According to its broadest aspect, the method of making a crosslinked membrane comprises the following steps: (a) preparing a polyimide polymer comprising carboxylic acid functional groups from a reaction solution comprising monomers and at least one solvent; (b) treating the polyimide polymer with a diol at esterification conditions in the presence of dehydrating conditions to form a monoesterified polyimide polymer; and (c) subjecting the monoesterified fiber to transesterification conditions to form a crosslinked fiber membrane, wherein the dehydrating conditions at least partially remove water produced during step (b). The crosslinked membranes can be used to separate at least one component from a feed stream including more than one component.