Blends of low equivalent molecular weight PFSA ionomers with Kynar 2751
View Patent ↗A polymer blend useful as an ion conductor in fuel cells includes a first polymer that includes a non-ionic segment and a second polymer that includes a sulfonic acid group.
1. A polymer blend comprising:
a first polymer including a nonionic polymer segment, the first polymer being a fluoroelastomer that is prepared by copolymerizing at least one fluoro-monomer and at least one non-fluoro-monomer wherein the fluoroelastomer has a glass transition temperature below about 25° C.; and
a second polymer having the following chemical moiety:
2. The polymer blend of claim 1 wherein the first polymer exhibits an elongation at break in a tensile mode of at least 50%.
3. The polymer blend of claim 1 wherein the fluoro-elastomer is be prepared by polymerizing at least one fluoro-monomer selected from the group consisting of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, vinylfluoride, chlorotrifluoroethylene, perfluorovinylmethyl ether, and trifluoroethylene.
4. The polymer blend of claim 1 wherein the non-fluoro monomer is selected from the group consisting of ethylene, propylene, methyl methacrylate, ethyl acrylate, styrene, vinyl chloride and combinations thereof.
5. The polymer blend of claim 1 wherein the fluoro-elastomer is selected from the group consisting of poly(tetrafluoroethlyene-co-ethylene), poly(tetrafluoroethylene-co-propylene), and terpolymer of ethylene, tetrafluoroethylene and perfluoromethylvinylether.
6. The polymer blend of claim 1 wherein the second polymer is a perfluorosulfonic acid polymer.
7. The polymer blend of claim 1 wherein the second polymer comprises the following repeat unit:
(CF 2 —CF)—(OCF 2 CFX) m —O p —(CF 2 ) n —SO 3 H,
wherein:
X is fluorine or trifluoromethyl;
m is 0 to 3,
n is 1 to 12; and
p is 0 or 1.
8. The polymer blend of claim 1 wherein the second polymer comprises the following repeat unit:
(CF 2 —CF)—(OCF 2 CFX) m —O p —(CF 2 ) n —SO 3 H
wherein m=1, X═CF 3 , p=1, and n=2.
9. The polymer blend of claim 8 wherein the second polymer comprises the following repeat unit:
(CF 2 —CF)—(OCF 2 CFX) m —O p —(CF 2 ) n —SO 3 H
wherein m=0, p=1, and n=2.
10. The polymer blend of claim 8 wherein the second polymer comprises the following repeat unit:
(CF 2 —CF)—(OCF 2 CFX) m —O p —(CF 2 ) n —SO 3 H
wherein m=0, p=1, and n=4.
11. The polymer blend of claim 1 wherein the first polymer is present in an amount from about 1 to about 80 weight percent.
12. The polymer blend of claim 1 wherein the first polymer is present in an amount from about 5 to about 50 weight percent.
13. The polymer blend of claim 1 wherein the first polymer is present in an amount from about 10 to about 30 weight percent.
14. The polymer blend of claim 1 wherein the second polymer is present in an amount from about 50 to about 95 weight percent.
15. The polymer blend of claim 1 wherein the second polymer is present in an amount from about 70 to about 90 weight percent.
16. The polymer blend of claim 1 wherein the second polymer is present in an amount from about 20 to about 99 weight percent.