Method of making a crosslinked fiber membrane from a high molecular weight, monoesterified polyimide polymer
First Claim
1. A method of making a crosslinked membrane, comprising:
- (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 polyimide polymer to transesterification conditions to form a crosslinked membrane,wherein the dehydrating conditions at least partially remove water produced during step (b), and with the concentration of water in a solution comprising the polyimide polymer and the diol in step (b) maintained at between about 0 weight % and 0.08 weight %.
2 Assignments
0 Petitions
Accused Products
Abstract
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.
25 Citations
36 Claims
-
1. A method of making a crosslinked membrane, comprising:
-
(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 polyimide polymer to transesterification conditions to form a crosslinked membrane, wherein the dehydrating conditions at least partially remove water produced during step (b), and with the concentration of water in a solution comprising the polyimide polymer and the diol in step (b) maintained at between about 0 weight % and 0.08 weight %. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. A method of making a crosslinked membrane, comprising:
-
(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 polyimide polymer to transesterification conditions to form a crosslinked membrane, wherein the dehydrating conditions at least partially remove water produced during step (b), and with the dehydrating conditions of step (b) being sufficient to reduce scissioning of the monoesterified polyimide polymer. - View Dependent Claims (35)
-
-
36. A method of making a crosslinked membrane, comprising:
-
(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 polyimide polymer to transesterification conditions to form a crosslinked membrane, wherein the dehydrating conditions at least partially remove water produced during step (b), and the average molecular weight of the monoesterified polyimide polymer of step (b) is equal to or greater than the average molecular weight of the polyimide polymer of step (a).
-
Specification