POLYMER BLEND PROTON EXCHANGE MEMBRANE AND METHOD FOR MANUFACTURING THE SAME

• US 20110136016A1
• Filed: 06/23/2010
• Published: 06/09/2011
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: VRB Enery Inc.
• Original Assignee: Beijing Prudent Century Technology Company Limited
• Inventors: LI, Linlin, HUANG, Mianyan, ZHAO, Yanling
• Granted Patent: US 8,486,579 B2
• Time in Patent Office: Days
• US Class Current: 429/309
• CPC Class Codes: C08G 2261/722 Sulfonation
• CPC Class Codes: C08G 65/48 Polymers modified by chemical after-treatment
• CPC Class Codes: C08J 2381/06 Polysulfones; Polyethersulfones
• CPC Class Codes: C08J 5/2275 Heterogeneous membranes
• CPC Class Codes: C08L 71/00 Compositions of polyethers obtained by reactions forming an ether link in the main chain of polyacetals C08L59/00; of epoxy resins C08L63/00; of polythioether-ethers C08L81/02; of polyether-sulfones C08L81/06; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 81/06 Polysulfones; Polyethersulfones
• CPC Class Codes: H01M 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1025 having only carbon and oxygen, e.g. polyethers, sulfonated polyetheretherketones [S-PEEK], sulfonated polysaccharides, sulfonated celluloses or sulfonated polyesters
• 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 8/1044 Mixtures of polymers, of which at least one is ionically conductive
• CPC Class Codes: H01M 8/1081 starting from solutions, dispersions or slurries exclusively of polymers
• CPC Class Codes: H01M 8/188 by recharging of redox couples containing fluids; Redox flow type batteries
• CPC Class Codes: H01M 8/20 Indirect fuel cells, e.g. fuel cells with redox couple being irreversible H01M8/18 takes precedence
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention relates to a polymer blend proton exchange membrane comprising a soluble polymer and a sulfonated polymer, wherein the soluble polymer is at least one polymer selected from the group consisting of polysulfone, polyethersulfone and polyvinylidene fluoride, the sulfonated polymer is at least one polymer selected from the group consisting of sulfonated poly(ether-ether-ketone), sulfonated poly(ether-ketone-ether-ketone-ketone), sulfonated poly(phthalazinone ether keton), sulfonated phenolphthalein poly(ether sulfone), sulfonated polyimides, sulfonated polyphosphazene and sulfonated polybenzimidazole, and wherein the degree of sulfonation of the sulfonated polymer is in the range of 96% to 118%. The present invention further relates to a method for manufacturing the polymer blend proton exchange membrane.

Claims

1. A polymer blend proton exchange membrane comprising a soluble polymer and a sulfonated polymer, wherein the soluble polymer is at least one polymer selected from the group consisting of polysulfone, polyethersulfone and polyvinylidene fluoride, the sulfonated polymer is at least one polymer selected from the group consisting of sulfonated poly(ether-ether-ketone), sulfonated poly(ether-ketone-ether-ketone-ketone), sulfonated poly(phthalazinone ether keton), sulfonated phenolphthalein poly(ether sulfone), sulfonated polyimide, sulfonated polyphosphazene and sulfonated polybenzimidazole, and wherein the degree of sulfonation of the sulfonated polymer is in the range of 96% to 118%.

2. The polymer blend proton exchange membrane according to claim 1, wherein the degree of sulfonation is 98 to 116%, preferably 100 to 114%, more preferably 106 to 110%.

3. The polymer blend proton exchange membrane according to claim 1, wherein the sulfonated polymer is made from an unsulfonated polymer with melt viscosity of 100 to 550 centipoise, preferably 300 to 450 centipoise, more preferably 350 to 400 centipoise, at 300 to 500°

C.

4. The polymer blend proton exchange membrane according to claim 1, wherein the sulfonated polymer is prepared by directly dissolving the unsulfonated polymer in concentrated sulfuric acid, Nordhausen acid, or chlorosulfonic acid and sulfonating the unsulfonated polymer.

5. The polymer blend proton exchange membrane according to claim 1, wherein the sulfonated polymer is prepared by directly dissolving the unsulfonated polymer in concentrated sulfuric acid and sulfonating the unsulfonated polymer, the concentrated sulfuric acid is used in an amount of 2 to 15 ml of concentrated sulfuric acid per gram of unsulfonated polymer, preferably 5 to 7 ml of concentrated sulfuric acid per gram of unsulfonated polymer.

6. The polymer blend proton exchange membrane according to claim 4, wherein the sulfonated polymer is prepared by two steps:

the first step is to carry out reaction for 3 to 5 hours at 20 to 40°

C.;

the second step is to carry out reaction for 1 to 4 hours at 70 to 100°

C.

7. The polymer blend proton exchange membrane according to claim 6, wherein the resulting sulfonated polymer is shaped through water-cooling, preferably through a process in which the resulting sulfonated polymer slurry is poured into a screen with 1 to 4 mm mesh size and flows into deionized water beneath the screen and a strip-shaped sulfonated polymer is obtained after stirring.

8. The polymer blend proton exchange membrane according to claim 7, wherein the resulting strip-shaped sulfonated polymer is washed to remove remaining sulfuric acid, then is dried at a temperature of 100 to 120°

C. for at least 1 hour, preferably at least 4 hours.

9. The polymer blend proton exchange membrane according to claim 1, wherein the weight-average molecular weight of the soluble polymer is in the range of 35000 to 65000, preferably 45000 to 55000, more preferably 48000 to 52000.

10. The polymer blend proton exchange membrane according to claim 1, wherein the content of the soluble polymer is 10% to 50%, preferably 13% to 38%, more preferably 18% to 35%, most preferably 22% to 32%, based on the total weight of the membrane.

11. The polymer blend proton exchange membrane according to claim 1, wherein the thickness of the polymer blend proton exchange membrane is in the range of 30 to 200 μ

m, more preferably 50 to 100 μ

m.

12. A method for manufacturing a polymer proton exchange membrane comprising the following steps:

a) dissolving a soluble polymer in an organic solvent and obtaining a uniform solution, wherein the soluble polymer is at least one polymer selected from the group consisting of polysulfone, polyethersulfone and polyvinylidene fluoride;

b) dissolving a sulfonated polymer in the solution obtained in step a) and obtaining a membrane forming solution, wherein the sulfonated polymer is at least one polymer selected from the group consisting of sulfonated poly(ether-ether-ketone), sulfonated poly(ether-ketone-ether-ketone-ketone), sulfonated poly(phthalazinone ether keton), sulfonated phenolphthalein poly(ether sulfone), sulfonated polyimide, sulfonated polyphosphazene and sulfonated polybenzimidazole, and wherein the degree of sulfonation of the sulfonated polymer is in the range of 96% to 118%;

c) forming a membrane by tape casting the membrane forming solution, then removing the membrane after being dried and heat-treated.

13. The method according to claim 12, wherein the method further includes a step:

d) immersing the membrane in sulfuric acid aqueous solution for a whole day and taking out the membrane for later use.

14. The method according to claim 12, wherein the degree of sulfonation of the sulfonated polymer is 98 to 116%, preferably 100 to 114%, more preferably 106 to 110%.

15. The method according to claim 12, wherein the sulfonated polymer is made from an unsulfonated polymer with melt viscosity of 100 to 550 centipoise, preferably 300 to 450 centipoise, more preferably 350 to 400 centipoise, at 300 to 500°

C.

16. The method according to claim 12, wherein the sulfonated polymer is prepared by directly dissolving the unsulfonated polymer in concentrated sulfuric acid, Nordhausen acid, or chlorosulfonic acid and sulfonating the unsulfonated polymer.

17. The method according to claim 12, wherein the sulfonated polymer is prepared by directly dissolving the unsulfonated polymer in concentrated sulfuric acid and sulfonating the unsulfonated polymer, and wherein the concentrated sulfuric acid is used in an amount of 2 to 15 ml of concentrated sulfuric acid per gram of unsulfonated polymer, preferably 5 to 7 ml of concentrated sulfuric acid per gram of unsulfonated polymer.

18. The method according to claim 16, wherein the sulfonated polymer is prepared by two steps:

the first step is to carry out reaction for 3 to 5 hours at 20 to 40°

C.;

the second step is to carry out reaction for 1 to 4 hours at 70 to 100°

C.

19. The method according to claim 18, wherein the resulting sulfonated polymer is shaped through a water-cooling process, preferably through a process in which the resulting sulfonated polymer slurry is poured into a screen with 1 to 4 mm mesh size and flows into deionized water beneath the screen and a strip-like sulfonated polymer is obtained after stirring.

20. The method according to claim 19, wherein the resulting strip-shaped sulfonated polymer is washed to remove remaining sulfuric acid, then is dried at a temperature of 100 to 120°

C. for at least 1 hour, preferably at least 4 hours.

21. The method according to claim 12, wherein the weight-average molecular weight of the soluble polymer is in the range of 35000 to 65000, preferably 45000 to 55000, more preferably 48000 to 52000.

22. The method according to claim 12, wherein the content of the soluble polymer is 10% to 50%, preferably 13% to 38%, more preferably 18% to 35%, most preferably 22% to 32%, based on the total weight of the membrane.