Trifluorostyrene containing compounds, and their use in polymer electrolyte membranes
AssigneeE.I. du Pont de Nemours and Company
InventorsBiswajit Choudhury, Mark Gerrit Roelofs, Zhen-Yu Yang
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Abstract
A fluorinated ion exchange polymer is prepared by grafting a monomer onto a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, 1b and mixture thereof; wherein Y is selected from the group consisting of —RFSO2F, —RFSO3M, —RSO2NH2 and —RFSO2N(M)SO2R2F, where in M is hydrogen, an alkali cation or ammonium; and RF and R2F are perfluorinated or partially fluorinated, and may optionally include ether oxygens; and n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b. These ion exchange polymers are useful is preparing catalyst coated membranes and membrane electrode assemblies for fuel cells.
Claims40
A fluorinated ion exchange polymer prepared by grafting a monomer on to a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, structure 1b and mixtures thereof,
- wherein for 1a and 1b, Y is independently selected from the group consisting of —RFSO2F (sulfonyl fluoride), —RFSO3M (fluorosulfonic acid or salt), —RFSO2NH2 (fluorosulfonamide), and —RFSO2N(M)SO2R2F (imide);
- wherein M is H, an alkali cation, or ammonium;
- and RF and R2F groups are perfluorinated or partially fluorinated, and may optionally include ether oxygens;
- and
- n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b.
A fluorinated ion exchange polymer membrane comprising a fluorinated ion exchange polymer prepared by
- grafting a monomer on to a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, structure 1b and mixtures thereof,
- wherein for 1a and 1b, Y is independently selected from the group consisting of —RFSO2F (sulfonyl fluoride), —RFSO3M (fluorosulfonic acid or salt), —RFSO2NH2(fluorosulfonamide), and —RFSO2N(M)SO2R2F (imide);
- wherein M is H, an alkali cation, or ammonium;
- and RF and R2F groups are perfluorinated or partially fluorinated, and may optionally include ether oxygens;
- and
- n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b;
- and
- wherein the base polymer is a partially or completely fluorinated polymer in film form.
A grafting process for making the fluorinated ion exchange polymer membrane comprising:
- forming an monomer composition comprising a grafting monomer, in neat form, emulsion form, or solution form, wherein the grafting monomer is selected from the group consisting of structure 1a, structure 1b and mixtures thereof,
- wherein for for 1a and 1b, Y is independently selected from the group consisting of —RFSO2F (sulfonyl fluoride), —RFSO3M (fluorosulfonic acid or salt), —RFSO2NH2(fluorosulfonamide), and —RFSO2N(M)SO2R2F (imide);
- wherein M is H, an alkali cation, or ammonium;
- and RF and R2F groups are perfluorinated or partially fluorinated, and may optionally include ether oxygens;
- and
- n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b;
- (b) irradiating a base polymer with ionizing radiation, and
- (c) contacting the base polymer with the monomer composition from step (a), at a temperature of about 0° C. to about 120° C. for about 0.1 to about 500 hrs.
A catalyst coated membrane comprising a polymer electrolyte membrane having a first surface and a second surface, wherein the polymer electrolyte membrane comprises a fluorinated ion exchange polymer prepared by grafting a monomer on to a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, structure 1b and mixtures thereof,
- wherein for 1a and 1b, Y is independently selected from the group consisting —RFSO2F (sulfonyl fluoride), —RFSO3M (fluorosulfonic acid or salt), —RFSO2NH2 (fluorosulfonamide), or —RFSO2N(M)SO2R2F (imide);
- wherein M is H, an alkali cation, or ammonium;
- and RF and R2F groups are perfluorinated or partially fluorinated, and may optionally include ether oxygens;
- and
- n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b.
A membrane electrode assembly comprising a polymer electrolyte membrane, having a first surface and a second surface, wherein the polymer electrolyte membrane comprises a fluorinated ion exchange polymer prepared by grafting a monomer on to a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, structure 1b and mixtures thereof,
- wherein for 1a and 1b, Y is independently selected from the group consisting —RFSO2F (sulfonyl fluoride), —RFSO3M (fluorosulfonic acid or salt), —RFSO2NH2 (fluorosulfonamide), or —RFSO2N(M)SO2R2F (imide);
- wherein M is H, an alkali cation, or ammonium;
- and RF and R2F groups are perfluorinated or partially fluorinated, and may optionally include ether oxygens;
- and
- n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b.
An electrochemical cell comprising a membrane electrode assembly, wherein the membrane electrode assembly comprises a polymer electrolyte membrane, having a first surface and a second surface, wherein the polymer electrolyte membrane comprises a fluorinated ion exchange polymer prepared by grafting a monomer on to a base polymer, wherein the grafting monomer is selected from the group consisting of structure 1a, structure 1b and mixtures thereof,
- wherein for 1a and 1b, Y is independently selected from the group consisting —RFSO2F (sulfonyl fluoride), —RFSO3M (fluorosulfonic acid or salt), —RFSO2NH2(fluorosulfonamide), or —RFSO2N(M)SO2R2F (imide);
- wherein M is H, an alkali cation, or ammonium;
- and RF and R2F groups are perfluorinated or partially fluorinated, and may optionally include ether oxygens;
- and
- n is between 1 and 2 for 1a, or n is between 1 and 3 for 1b.
Dependencies are inferred from the claim text.