.alpha., .beta., .beta.-trifluorostyrene-based composite membranes
AssigneeBallard Power Systems Inc.
InventorsAlfred E. Steck, Charles Stone
Life of this patent
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Abstract
A composite membrane is provided in which a porous substrate is impregnated with a polymeric composition comprising various combinations of .alpha.,.beta.,.beta.-trifluorostyrene, substituted .alpha.,.beta.,.beta.-trifluorostyrene and ethylene-based monomeric units. Where the polymeric composition includes ion-exchange moieties, the resultant composite membranes are useful in electrochemical applications, particularly as membrane electrolytes in electrochemical fuel cells.
Claims32
A composite membrane that is flexible in the dry state, the composite membrane comprising a flexible porous sheet material impregnated with a polymeric composition consisting predominantly of:
- ##STR16## wherein each of m, n, r and s is zero or an integer greater than zero, and at least one of m and n is an integer greater than zero;
- X is selected from the group consisting of SO.sub.3 H, PO.sub.2 H.sub.2, PO.sub.3 H.sub.2, CH.sub.2 PO.sub.3 H.sub.2, COOH, OSO.sub.3 H, OPO.sub.2 H.sub.2, OPO.sub.3 H.sub.2, OArSO.sub.3 H where Ar is an aryl, NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls) and CH.sub.2 NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls);
- Z is selected from the group consisting of hydrogen, SO.sub.2 F, halogens, C.sub.x H.sub.y F.sub.z (where x is an integer greater than zero and y+z=2x+1), SO.sub.3 H, PO.sub.2 H.sub.2, PO.sub.3 H.sub.2, CH.sub.2 PO.sub.3 H.sub.2, COOH, OSO.sub.3 H, OPO.sub.2 H.sub.2, OPO.sub.3 H.sub.2, OArSO.sub.3 H where Ar is an aryl, NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls) and CH.sub.2 NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls);
- and
- E is selected from the group consisting of CH.sub.2 --CH.sub.2, CH.sub.2 --CHF, CFH--CFH, CF.sub.2 --CH.sub.2, CF.sub.2 --CHF, CF.sub.2 --CF.sub.2.
A composite membrane that is flexible in the dry state, the composite membrane comprising a flexible porous sheet material impregnated with a polymeric composition consisting essentially of:
- ##STR17## wherein each of m, n, n, r and s is zero or an integer greater than zero, and at least one of m and n is an integer greater than zero;
- X is selected from the group consisting of SO.sub.3 H, PO.sub.2 H.sub.2, PO.sub.3 H.sub.2, CH.sub.2 PO.sub.3 H.sub.2, COOH, OSO.sub.3 H, OPO.sub.2 H.sub.2, OPO.sub.3 H.sub.2, OArSO.sub.3 H where Ar is an aryl, NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls) and CH.sub.2 NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls);
- Z is selected from the group consisting of hydrogen, SO.sub.2 F, halogens, C.sub.x H.sub.y F.sub.z (where x is an integer greater than zero and y+z=2x+1), SO.sub.3 H, PO.sub.2 H.sub.2, PO.sub.2 H.sub.2, CH.sub.2 PO.sub.2 H.sub.2, COOH, OSO.sub.3 H, OPO.sub.2 H.sub.2, OPO.sub.3 H.sub.2, OArSO.sub.2 H where Ar is an aryl, NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls) and CH.sub.2 NR.sub.3.sup.+ (where R is selected from the group consisting of alkyls, perfluoroalkyls and aryls);
- and
- E is selected from the group consisting of CH.sub.2 --CH.sub.2, CH.sub.2 --CHF, CFH--CFH, CF.sub.2 --CH.sub.2, CF.sub.2 --CHF, CF.sub.2 --CF.sub.2.
Dependencies are inferred from the claim text.