US 2015/0328596 A1Published application

Polybenzoxazole membranes from self-cross-linkable aromatic polyimide membranes

AssigneeUop LLC

InventorsChunqing Liu, Zara Osman, Angela N. Troxell

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Abstract

A method of making a polybenzoxazole (PBO) membrane from a self-cross-linked aromatic polyimide polymer membrane is provided. These membranes are useful in the separation of gas mixtures and liquid mixtures. The PBO membrane is made by fabricating a self-cross-linkable aromatic polyimide polymer membrane comprising both hydroxyl functional groups and carboxylic acid functional groups; cross-linking the polymer to form a self-cross-linked aromatic polyimide polymer membrane by heating the membrane at 250° to 300° C. under an inert atmosphere; and thermal heating the self-cross-linked aromatic polyimide polymer membrane at a temperature from about 350° to 500° C. under an inert atmosphere to convert the self-cross-linked aromatic polyimide polymer membrane into a PBO membrane. A membrane coating step may be added by coating the selective layer surface of the PBO membrane with a thin layer of high permeability material.

Claims11

Dependent claims

A process for separation of liquid mixtures by pervaporation comprising contacting said liquid mixture with a polybenzoxazole membrane of formula (III) comprising wherein said formula (III) is:

wherein X1 is selected from the group consisting of
and mixtures thereof;
wherein X3 is selected from the group consisting of
and mixtures thereof;
wherein X4 is selected from the group consisting of
and mixtures thereof;
Y1 is selected from the group consisting of
and mixtures thereof;
Y2 is selected from the group consisting of
and mixtures thereof, and —R′— is selected from the group consisting of
and mixtures thereof;
o and q are independent integers from 2 to 500 contacting the mixture of liquids to one side of the polybenzoxazole membrane of formula (III) to cause at least one gas to permeate said membrane;
and removing from an opposite side of said polybenzoxazole membrane of formula (III) a permeate liquid composition comprising a portion of said at least one liquid that permeated said membrane.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/812,609Filed 29 Jul 2015
Priority: 27 Sep 2013
Published: 19 Nov 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B01D 61/362
Pervaporation; Membrane distillation; Liquid permeation: pervaporation
B01D 67/0006
Organic membrane manufacture: by chemical reactions
B01D 71/62
Other polymers having nitrogen in the main chain, with or without oxygen or carbon only: polycondensates having nitrogen-containing heterocyclic…
C07C 27/28
Purification; Separation; Stabilisation: by distillation

Family

Application14/039,545Division · filed 27 Sep 2013
Application14/812,609Division
US 2015/0094500 A1Published application
US 9,126,152 B2Related patent
US 9,308,503 B2Related patent
US 2015/0328596 A1This patent

From the US filing history. Foreign family members aren’t listed.