Proton-conducting membrane and use thereof

Patent metadata

Field	Value
Publication number	US-9812725-B2
Application number	US-201313742774-A
Country	US
Kind code	B2
Filing date	Jan 16, 2013
Priority date	Jan 17, 2012
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A membrane obtainable by
A) mixing:
(vii) aromatic tetraamino compounds and (viii) aromatic carboxylic acids or esters thereof which contain at least two acid groups per carboxylic acid monomer, or (ix) aromatic and/or heteroaromatic diaminocarboxylic acids, in polyphosphoric acid to form a solution and/or dispersion
B) heating the mixture from step A), and polymerizing until an intrinsic viscosity of at least 0.8 dl/g, is obtained for the polymer being formed, C) adding polyazole polymers, D) heating the mixture from step C), E) applying a membrane layer using the mixture according to step D) on a carrier or an electrode, F) treating the membrane formed in the presence of water and/or moisture, G) removing the membrane from the carrier;

wherein the content of all polyazole polymers in the membrane is between 5% to 25% by weight and wherein the membrane has a Young Modulus is at least 2.0 MPa.

First claim

What is claimed is:

1. A proton-conducting polymer membrane based on polyazoles, obtainable by a process comprising steps of
A) providing a monomer solution and/or dispersion including
(i) one or more aromatic tetraamino compounds and
either (ii) one or more aromatic carboxylic acids or esters thereof which contain at least two acid groups per carboxylic acid monomer,
or (iii) one or more aromatic and/or heteroaromatic diaminocarboxylic acids, in polyphosphoric acid to form a solution and/or dispersion

B) heating the monomer solution and/or dispersion from step A), and polymerizing until a formed polyazole polymer having an intrinsic viscosity of at least 0.8 dl/g is obtained,
C) adding of one or more polyazole polymer to the polyphosphoric acid and the formed polyazole polymer of step B), the added one or more polyazole polymer being different from the formed polyazole polymer of step B),
D) heating the mixture from step C),
E) applying a membrane layer using the mixture heated according to step D) on a carrier,
G) treating the membrane layer formed in the presence of water and/or moisture to provide a membrane including at least a formed polyazole and an added polyazole being different from the formed polyazole, and
H) removing the membrane from the carrier;
wherein a total content of all polyazole polymers in the membrane is at least 10% by weight and up to about 25% by weight and said total content includes any acids and water being present, said total content excluding however any optional additives and wherein the membrane has a Young Modulus of at least 4.5 MPa, and
wherein the monomers in the monomer solution and/or dispersion of step A accounts for less than 10% by weight of the total solid content of all polyazole polymers in the membrane.

2. The membrane as claimed in claim 1 , wherein the aromatic and heteroaromatic tetraamino compounds are selected from 2,3,5,6-tetraaminopyridine, 3,3′,4,4′-tetraaminodiphenylsulfone, 3,3′,4,4′-tetraaminodiphenyl ether, 3,3′,4,4′-tetraaminobiphenyl, 1,2,4,5-tetraaminobenzene, 3,3′,4,4′-tetraaminobenzophenone, 3,3′,4,4′-tetraaminodiphenylmethane, 3,3′,4,4′-tetraaminodiphenyldimethyl-methane, or the salts of the aforementioned compounds.

3. The membrane as claimed in claim 1 , wherein the diaminocarboxylic acids are selected from diaminobenzoic acid and the mono and dihydrochloride derivatives of said acid, or 1,2-diamino-3′-carboxy acid 4,4′-diphenyl ether.

4. The membrane as claimed in claim 1 , wherein the one or more aromatic carboxylic acids or esters thereof includes an aromatic tricarboxylic acid selected from 1,3,5-benzenetricarboxylic acid (trimesic acid), 1,2,4-benzenetricarboxylic acid (trimellitic acid), (2-carboxyphenyl)iminodiacetic acid, 3,5,3′-biphenyltricarboxylic acid, 3,5,4′-biphenyltricarboxylic acid, or any one mixture thereof.

5. The membrane as claimed in claim 1 , wherein the one or more, aromatic carboxylic acids or esters thereof includes an aromatic tetracarboxylic acid selected from 3,5,3′,5′-biphenyltetracarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid, benzophenonetetracarboxylic acid, 3,3′,4,4′-biphenyltetracarboxylic acid, 2,2′,3,3′-biphenyltetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, or any one mixture thereof.

6. The membrane as claimed in claim 1 , wherein the aromatic carboxylic acids include heteroaromatic carboxylic acids, including their respective esters, or the acid anhydrides of said heteroaromatic acids, or the acid chlorides of said heteroaromatic acids, wherein the heteroaromatic carboxylic acids include at least one nitrogen in the aromatic moiety.

7. The membrane as claimed in claim 6 , wherein,the heteroaromatic carboxylic acids are selected from pyridine-2,5-dicarboxylic acid, pyridine-3,5-dicarboxylic acid, pyridine-2,6-dicarboxylic acid, pyridine-2,4-dicarboxylic acid, 4-phenyl-2,5-pyridinedicarboxylic acid, 3,5-pyrazoledicarboxylic acid, 2,6-pyrimidinedicarboxylic acid, 2,5-pyrazinedicarboxylic acid, 2,4,6-pyridinetricarboxylic acid, benzimidazole-5,6-dicarboxylic acid, each of their C1-C20-alkyl esters, their C5-C12-aryl esters, their acid anhydrides or their acid chlorides, or any one mixture thereof.

8. The membrane as claimed in claim 1 , wherein the polyphosphoric acid are concentrated grades of phosphoric acid (H 3 PO 4 ) above 95% in which the individual PO 4 units are polymerized and the polyphosphoric acids can be expressed by the formula H n+2 P n O 3n+1 (n>1).

9. The membrane as claimed in claim 8 , wherein the polyphosphoric acid [H n+2 P n O 3n+1 (n>1)] have a content, calculated as P 2 O 5 (by acidimetry), of at least 70% by weight and not more than 86% by weight.

10. The membrane as claimed in claim 1 , wherein the monomers in the monomer soltution and/or dispersion of step A accounts for less than 10% by weight, of the of the total content of all polyazole polymers in the membrane.

11. The membrane as claimed in claim 1 , wherein the polymers based on polyazole being formed in step B) comprise repeat units of the general formula (I) and/or (II) and/or (III) and/or (IV) and/or (V) and/or (VI) and/or (VII) and/or (VIII) and/or (IX) and/or (X) and/or (XI) and/or (XII) and/or (XIII) and/or (XIV) and/or (XV) and/or (XVI) and/or (XVII) and/or (XVIII) and/or (XIX) and/or (XX) and/or (XXI) and/or (XXII)

in which
Ar are the same or different and are each a tetravalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 1 are the same or different and are each a divalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 2 are the same or different and are each a di- or trivalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 3 are the same or different and are each a trivalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 4 are the same or different and are each a trivalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 5 are the same or different and are each a tetravalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 6 are the same or different and are each a divalentaromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 7 are the same or different and are each a divalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 8 are the same or different and are each a trivalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 9 are the same or different and are each a di- or tri- or tetravalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 10 are the same or different and are each a di- or trivalent aromatic or heteroaromatic group which may be mono- or polycyclic,
Ar 11 are the same or different and are each a divalent aromatic or heteroaromatic group which may be mono- or polycyclic,
X are the same or different and are each oxygen, sulfur or an amino group which bears a hydrogen atom, a group having 1-20 carbon atoms, preferably a branched or unbranched alkyl or alkoxy group, or an aryl group as further radical,
R is the same or different and is hydrogen, an alkyl group or an aromatic group, with the proviso that R in formula (XX) is not hydrogen, and
n, m are each an integer greater than or equal to 10.

12. The membrane as claimed in claim 1 , wherein the polymers based on polyazole be

Assignees

• Basf Se

Inventors

• Benicewicz Brian
• Bräuninger Sigmar
• Calundann Gordon
• Qian Guoqing

Classifications

• Y02P70/56

  Cross-Sectional Technologies · mapped topic

• H01M8/103 Primary

  having nitrogen, e.g. sulfonated polybenzimidazoles [S-PBI], polybenzimidazoles with phosphoric acid, sulfonated polyamides [S-PA] or sulfonated polyphosphazenes [S-PPh] · CPC title

• H01M8/1086

  After-treatment of the membrane other than by polymerisation · CPC title

• C08J5/22

  Films, membranes or diaphragms · CPC title

• H01M8/1069

  characterised by the manufacturing processes · CPC title