High plasticization-resistant cross-linked polymeric membranes for separations

• US 8,816,003 B2
• Filed: 06/24/2008
• Issued: 08/26/2014
• Est. Priority Date: 06/24/2008
• Status: Expired due to Fees

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Liu, Chunqing, Wilson, Stephen T., Lesch, David A.
• Primary Examiner(s): Jagannathan, Vasu
• Assistant Examiner(s): HU, HENRY S
• Application Number:
  US12/145,153
• Publication Number:
  US 20090318620A1
• Time in Patent Office: 2,254 Days
• Field of Search: 525/56, 525/403, 525/343, 525/374
• US Class Current: 525/56
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 2325/30 Chemical resistance
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 67/0093 Chemical modification
• CPC Class Codes: B01D 67/00931 by introduction of specific groups after membrane formation, e.g. by grafting
• CPC Class Codes: B01D 71/16 Cellulose acetate
• CPC Class Codes: C08B 15/10 Crosslinking of cellulose
• CPC Class Codes: C08G 18/6484 Polysaccharides and derivatives thereof
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: C08L 81/06 Polysulfones; Polyethersulfones
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

This invention involves a composition, a method of making, and an application of high plasticization-resistant chemically cross-linked polymeric membranes such as cross-linked cellulose acetate (CA) membrane. These cross-linked polymeric membranes with covalently interpolymer-chain-connected rigid networks showed no decrease in CO₂/CH₄ ideal selectivity under 690 kPa (100 psig) pure CO₂ pressure and also no CO₂ plasticization up to 3447 kPa (500 psig) pure CO₂ pressure. By using the method of chemical cross-linking as described in this invention, the separation characteristics of the polymeric membranes can be decisively improved. These new cross-linked polymeric membranes can be used not only for gas separations such as CO₂/CH₄ and CO₂/N₂ separations, O₂/N₂ separation, olefin/paraffin separations (e.g. propylene/propane separation), iso/normal paraffins separations, but also for liquid separations such as pervaporation and desalination.

Claims

1. A process for preparation of a cross-linked plasticization-resistant gas separation membrane comprising first reacting a polymeric membrane material with a cross-linking agent in an organic solvent and then drying the cross-linked polymeric membrane material by removing the organic solvent to form the cross-linked plasticization-resistant gas separation membrane wherein said polymeric membrane material is selected from the group consisting of poly(ethylene glycol)s, poly(ethylene oxide)s, cellulose acetate, cellulose triacetate, poly(vinyl alcohol), poly(p-hydroxystyrene), poly(ethylene imine)s, poly(vinyl amine), poly(allyl amine), poly(propylene oxide)s, co-block-poly(ethylene oxide)-poly(propylene oxide)s, tri-block-poly (propylene oxide)-poly(ethylene oxide)-poly(propylene oxide)s, poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminepropyl ether)s, polyamic acids, and mixtures thereof and wherein said cross-linking agent is selected from the group consisting of tolylene-2,4-diisothiocyanate, tolylene 2,6-diisothiocyanate, tolylene-2,4-diisocyanate, tolylene-2,5-diisocyanate, tolylene-2,6-diisocyanate, tolylene-α

, 4-diisocyanate, terephthaldehyde, ethyleneglycol diglycidyl ether, 1,3-phenylene diisocyanate, 4,4′

-methylenebis(phenyl isocyanate), and 1,4-phenylene diisocyanate.

2. The process of claim 1 wherein said polymeric membrane material is selected from the group consisting of poly(ethylene glycol)s, poly(ethylene oxide)s, cellulose acetate, cellulose triacetate, poly(vinyl alcohol), poly(p-hydroxystyrene), poly(propylene oxide)s, co-block-poly(ethylene oxide)-poly(propylene oxide)s, tri-block-poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide)s, poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminepropyl ether)s, and mixtures thereof.

3. The process of claim 1 wherein said polymeric membrane material is cellulose acetate, cellulose triacetate, or a mixture of cellulose acetate and cellulose triacetate.

4. The process of claim 1 wherein said cross-linking agent is selected from the group consisting of terephthaldehyde and ethyleneglycol diglycidyl ether.

5. The process of claim 1 wherein said cross-linking agent is tolylene-2,4diisocyanate or 4,4′

-methylenebis(phenyl isocyanate).

6. The process of claim 1 wherein said cross-linked plasticization-resistant gas separation membrane is in a form selected from the group consisting of sheets, tubes or hollow fibers.

7. The process of claim 1 wherein said cross-linked plasticization-resistant gas separation membrane is a cross-linked inter-polymer-chain network.