Gas separation membranes from chemically and UV treated polymers of intrinsic microporosity
The invention is a process of making a chemically and UV treated polymer of intrinsic microporosity membrane comprising preparing a polymer of intrinsic microporosity, chemically cross-linking said polymer of intrinsic microporosity with a cross-linking compound to produce a chemically cross-linked polymer of intrinsic microporosity and then treating said chemically cross-linked polymer with UV radiation for a period of time sufficient to provide a product membrane. This product membrane is useful in the separation of C3 and higher hydrocarbons, as well as CO 2 , from natural gas and other gas streams.
1. A process of making a chemically cross-linked and UV cross-linked polymer of intrinsic microporosity membrane comprising preparing a polymer of intrinsic microporosity, chemically cross-linking said polymer of intrinsic microporosity with a chemical cross-linking compound to produce a chemically cross-linked polymer of intrinsic microporosity and then UV cross-linking said chemically cross-linked polymer of intrinsic microporosity with a UV cross-linking compound and UV radiation for a period of time sufficient to provide said chemically cross-linked and UV cross-linked polymer of intrinsic microporosity membrane.
2. The process of claim 1 wherein said cross-linking compound is
wherein R 1 is a divalent moiety consisting of carbon, oxygen, sulfur, or nitrogen; R 2 is a divalent moiety that contains an azide.
3. The process of claim 1 wherein said UV cross-linking compound has a general structure
wherein R3 and R4 comprise substituents that are sensitive to UV light and are selected from a group consisting of aldehyde, ketone, sulfone, and mixtures thereof.
4. The process of claim 1 wherein said cross-linking compound is selected from the group consisting of
and mixtures thereof.
5. The process of claim 3 wherein said group that is sensitive to UV light is a carbonyl or sulfonyl group.
6. The process of claim 2 wherein said UV cross-linking compound is selected from the group consisting of
and mixtures thereof, wherein R5 is selected from a group consisting of —(CH 2 ) n CH 3 , C 6 H 5 , C 6 H 4 CH 3 , and Cl and mixtures thereof; wherein R6 is selected from a group consisting of —(CH 2 ) m CH 3 , C 6 H 5 , and C 6 H 4 CH 3 , and mixtures thereof; wherein n and m are independent integers from 0 to 9.
7. The process of claim 1 wherein said polymer of intrinsic microporosity comprises a reaction product of 3,3′,3′-tetramethyl-1,1″-spirobisindane-5,5′,6,6′-tetrol and 2,3,5,6-tetrafluoroterephthalonitrile.