Heterocycle grafted monomers and related polymers and hybrid inorganic-organic polymer membranes

• US 20060111530A1
• Filed: 01/26/2005
• Published: 05/25/2006
• Est. Priority Date: 01/27/2004
• Status: Active Grant

• Current Assignee: Toyota Motor Corporation, Georgia Institute of Technology (University System of Georgia)
• Original Assignee: Toyota Motor Corporation
• Inventors: Zhou, Zhen, Li, Siwen, Li, Wen, Liu, Meilin, Hase, Kohai
• Granted Patent: US 7,576,165 B2
• Time in Patent Office: Days
• US Class Current: 526/258
• CPC Class Codes: C07D 233/64 with substituted hydrocarbon radicals attached to ring carbon atoms, e.g. histidine
• CPC Class Codes: C07D 239/38 One sulfur atom
• CPC Class Codes: C07D 249/04 1,2,3-Triazoles; Hydrogenated 1,2,3-triazoles
• CPC Class Codes: C07D 249/12 Oxygen or sulfur atoms
• CPC Class Codes: C07F 7/1804 Compounds having Si-O-C linkages Si-O-acyl linkages C07F7/1896
• CPC Class Codes: C08F 226/06 by a heterocyclic ring containing nitrogen
• CPC Class Codes: C08F 228/02 by a bond to sulfur
• CPC Class Codes: C08G 75/20 Polysulfones
• CPC Class Codes: C08G 77/26 nitrogen-containing groups
• CPC Class Codes: C08J 2379/06 Polyhydrazides; Polytriazoles; Polyamino-triazoles; Polyoxadiazoles
• CPC Class Codes: C08J 5/2231 based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds
• CPC Class Codes: C08L 81/06 Polysulfones; Polyethersulfones
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 8/1027 having carbon, oxygen and other atoms, e.g. sulfonated polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/103 having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh]
• CPC Class Codes: H01M 8/1032 having sulfur, e.g. sulfonated-polyethersulfones [S-PES]
• CPC Class Codes: H01M 8/1037 having silicon, e.g. sulfonated crosslinked polydimethylsiloxanes
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: H01M 8/1067 characterised by their physical properties, e.g. porosity, ionic conductivity or thickness
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Polymers, polymer precursors, and other materials are described, having at least one heterocycle and being useful for fabrication of proton-exchange membranes (PEMs). In representative examples, the heterocycle is a fluorinated imidazole ring. The heterocycle can be chosen to have a low value of pKa, and may be a triazole ring, other nitrogen-containing heterocycle, or derivative thereof. Polymers and composites were prepared having excellent proton conductivity. Applications of these materials include fuel cells and other ion-conducting applications.

Claims

1. A compound of the structure X-Y-Z, where:

X includes a heterocycle;

Y is a linking group; and

Z is a polymerizable group or a polymer backbone.

2. The compound of claim 1, wherein X has a pKa of less than 7.

3. The compound of claim 1, wherein X has a pKa of less than 5.

4. The compound of claim 1, wherein X has a pKa equal to or less than 2.6.

5. The compound of claim 1, wherein X includes a nitrogen-containing heterocycle, an oxygen-containing heterocycle, or a sulfur-containing heterocycle.

6. The compound of claim 1, wherein X includes a nitrogen-containing heterocycle selected from a group consisting of 1,2,4-triazole, 1,2,3-triazole, 1H-benzotriazole, pyrimidine, pyrazine, purine, imidazole, pyrazole, pyridine, and derivatives thereof.

7. The compound of claim 6, wherein X includes a nitrogen-containing heterocycle having an electron-withdrawing group attached thereto.

8. The compound of claim 7, wherein the electron-withdrawing group is a group containing at least one fluorine atom.

9. The compound of claim 6, wherein X includes a fluorinated imidazole ring having a pKa of less than approximately 2.6.

10. The compound of claim 6, wherein Y includes an alkyl chain having two or more carbon atoms.

11. The compound of claim 6, wherein Z is a polymerizable group.

12. The compound of claim 11, wherein Z is a vinyl group, epoxy group, or hydrolyzable silicon-containing group.

13. The compound of claim 6, wherein Z is a polymer backbone.

14. The compound of claim 6, wherein Z includes a hybrid inorganic-organic matrix including silicon atoms.

15. The compound of claim 14, wherein the hybrid inorganic-organic matrix has acid groups bound thereto.

16. The compound of claim 6, wherein Z is a polymer backbone having acid groups attached thereto.

17. The compound of claim 16, wherein the acid groups are phosphonic acid groups.

18. The compound of claim 6, wherein the nitrogen-containing heterocycle has at least one substituent including a fluorine group.

19. The compound of claim 1, wherein Z is a poly(vinyl) polymer backbone, and X includes a pyrimidine, pyrazole, or triazole group.

20. A proton-conducting polymer, the polymer including:

a polymer backbone;

a nitrogen-containing heterocycle attached to the polymer backbone or included in the polymer backbone,

the nitrogen-containing heterocycle having a pKa of less than approximately 5.

21. The proton-conducting polymer of claim 20, wherein the nitrogen-containing heterocycle is selected from a group consisting of 1,2,4-triazole, 1,2,3-triazole, pyrimidine, 1H-benzotriazole, purine, imidazole, pyrazole, pyrazine, pyridine, and derivatives thereof.

22. The proton-conducting polymer of claim 20, wherein the nitrogen-containing heterocycle is a halogenated imidazole or a halogenated pyridine.

23. The proton-conducting polymer of claim 20, wherein the polymer backbone is a poly(vinyl) polymer, and the nitrogen-containing heterocycle is a triazole.

24. A proton-conducting composite comprising:

an acid compound, wherein the acid compound is an inorganic acid, or an inorganic acid group containing compound; and

a compound having the structure H1-L-H2, where;

H1 includes a first nitrogen-containing heterocycle;

H2 includes a second nitrogen-containing heterocycle; and

L is a linking group, the linking group having between 2 and 20 atoms.

25. The composite of claim 24, wherein the acid compound is a sulfonated polymer.

26. The composite of claim 24, wherein the first nitrogen-containing heterocycle is selected from a group consisting of 1,2,4-triazole, 1,2,3-triazole, 1H-benzotriazole, pyrimidine, pyrazine, purine, imidazole, pyrazole, and derivatives thereof.

27. A proton-conducting polymer including:

a hybrid inorganic-organic matrix including silicon atoms;

an acid group attached to the hybrid inorganic-organic matrix; and

a nitrogen-containing heterocycle attached to the hybrid inorganic-organic matrix,

wherein the nitrogen-containing heterocycle is selected from a group consisting of 1,2,4-triazole, 1,2,3-triazole, 1H-benzotriazole, pyrimidine, pyrazine, purine, imidazole, pyrazole, and pyridine.

28. The proton-conducting polymer of claim 27, wherein the nitrogen-containing heterocycle has at least one halogenated substituent group attached thereto.