Branched and hyperbranched ionomeric polymers and uses thereof

Patent metadata

Field	Value
Publication number	US-2023348659-A1
Application number	US-202318296343-A
Country	US
Kind code	A1
Filing date	Apr 5, 2023
Priority date	Apr 5, 2022
Publication date	Nov 2, 2023
Grant date	—

Abstract

Described herein are branched and hyperbranched anionic phenylene polymers, produced with controlled incorporation of anionic substituents. Applications of such branched ionomeric polymers are also described herein. The branched ionomeric polymers are prepared by a convenient and well-controlled method, permitting tailored properties of catalyst ink formulations, ionomeric polymer membranes, and other applications. Such branched ionomeric polymers have applications in water purification, fuel cells, and battery products.

First claim

1 . A branched or hyperbranched ionomeric polymer, comprising a repeating unit of Formula (I):

comprising an anionic comonomer and a branching comonomer (B),
wherein:
R 1A , R 1B , R 1C , R 1D , R 1E , and R 1F are independently aryl or heteroaryl, each optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from C 1-6 alkyl, halo, nitro, cyano, SO 3 − X + , PO 3 2− X + 2 , and COO − X + , wherein X + is H + or a cation, and provided that at least two of R 1A , R 1B , R 1C , R 1D , R 1E , and R 1F are independently aryl or heteroaryl substituted with 1, 2, 3, 4, or 5 substituents independently selected from SO 3 − X + , PO 3 2− X + 2 , and COO − X + , wherein X + is H + or a cation;
R 1G and R 1H are independently H, aryl, or heteroaryl, wherein said aryl and heteroaryl are each optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from C 1-6 alkyl, halo, nitro, cyano, SO 3 − X + , PO 3 2− X + 2 , and COO − X + , wherein X + is H + or a cation;
A 1 is arylene, heteroarylene, aralkylene, or heteroaralkylene, each optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl; and
A 2 is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each optionally substituted with 1, 2, 3, or 4 substituents independently selected from halo, nitro, cyano, aryl, and heteroaryl;
B is a branching comonomer;
R 2A is a bond; and
wherein a first repeating unit of Formula (I) is bound to a second repeating unit of Formula (I) at R 2A to form a branched structure.

2 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein the polymer is insoluble in a polar solvent.

3 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein a molar ratio of Z:Y in the polymer is from 1:3 to 1:2.

4 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein the branching comonomer (B) comprises a structure of Formula (II):

wherein:
L 3 , at each occurrence, is an optionally substituted multivalent heteroatom (e.g., N, P, B), multivalent aryl, multivalent heteroaryl, multivalent aralkyl, or multivalent heteroaralkyl, wherein said multivalent aryl, multivalent heteroaryl, multivalent aralkyl, and multivalent heteroaralkyl are each optionally substituted with 1, 2, or 3 substituents independently selected from C 1-6 alkyl, halo, nitro, cyano, aryl, and heteroaryl;
L 2 is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C 1-6 alkyl, halo, nitro, cyano, aryl, and heteroaryl; and
L 1 is absent, arylene, or heteroarylene, wherein said arylene and heteroarylene are each optionally substituted with 1, 2, 3, or 4 substituents independently selected from C 1-6 alkyl, halo, nitro, cyano, aryl, and heteroaryl.

5 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein the branching comonomer (B) comprises a structure of Formula (III):

6 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein the anionic comonomer comprises a structure of Formula (VII):

7 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein the repeating unit comprises a structure of Formula (IV):

8 . The branched or hyperbranched ionomeric polymer of claim 1 , wherein the branched or hyperbranched ionomeric polymer is formed by polymerization of a functionalized branching comonomer (B) with a functionalized anionic comonomer, wherein the molar ratio of the functionalized branching comonomer (B) to the functionalized anionic comonomer is greater than 0.2.

9 . The polymer of claim 8 , wherein the molar ratio of the functionalized branching comonomer (B) to the functionalized anionic comonomer is approximately 0.667.

10 . The branched or hyperbranched ionomeric polymer of claim 1 , further comprising a bifunctional monomer C.

11 . A catalyst ink formulation comprising:
a branched or hyperbranched ionomeric polymer having a structure according to claim 1 ; a linear ionomeric polymer; a polar solvent; and a catalyst, wherein the linear ionomeric polymer is dispersed in the polar solvent, and an amount of the linear ionomeric polymer is used which enables the branched or hyperbranched ionomeric polymer to disperse in the polar solvent.

12 . The catalyst ink formulation of claim 11 , wherein the polar solvent comprises an alcohol having a boiling point of less than 120° C.

13 . The catalyst ink formulation of claim 11 , wherein the alcohol is methanol.

14 . The catalyst ink formulation of claim 11 , wherein the polar solvent further comprises water, and wherein a volume-to-volume amount of water to the alcohol is from about 1:3 to about 3:1.

15 . The catalyst ink formulation of claim 11 , wherein the branched or hyperbranched ionomeric polymer is present in the formulation at an amount of from about 0.01 wt % to about 10 wt % of total solids content.

16 . The catalyst ink formulation of claim 11 , wherein the linear ionomeric polymer is a linear sulfonated phenylated poly(phenylene) biphenyl (sPPB-H + ) ionomer, a random copolymer comprising sPPB-H + and a hydrophobic unit, a PFSA material, or a combination thereof.

17 . The catalyst ink formulation of claim 11 , wherein the amount of the linear ionomeric polymer is about equal to or greater than the amount of the branched or hyperbranched ionomeric polymer.

18 . The catalyst ink formulation of claim 11 , wherein the formulation comprises an amount of branched or hyperbranched ionomeric polymer, and an amount of linear ionomeric polymer, wherein the total amount of the branched, hyperbranched, and linear ionomeric polymer dispersed in the polar solvent is from about 0.1% w/v to about 25% w/v.

19 . The catalyst ink formulation of claim 11 , wherein the catalyst is Pt/C, PtCo/C, M-N—C catalyst, or a combination thereof.

20 . The catalyst ink formulation of claim 11 , comprising a catalyst amount of between about 0.1% w/v to about 25% w/v.

21 . An ionomeric polymer membrane comprising:
a mechanical reinforcement; and an ionomeric binder coupled to the mechanical reinforcement, wherein the ionomeric binder comprises:
a linear ionomeric polymer,
a branched or a hyperbranched ionomeric polymer according to claim 1 ,
or a combination thereof.

22 . A catalyst-coated ionomeric polymer membrane comprising:
the ionomeric polymer membrane of claim 21 ; and a catalyst layer in contact with the ionomeric polymer membrane.

23 . The catalyst-coated ionomeric polymer membrane of claim 22 , wherein the catalyst layer is formed from a catalyst ink formulation comprising:
a branched or hyperbranched ionomeric polymer, comprising a repeating unit of Formula (I); a linear ionomeric polymer; a polar solvent; and a catalyst,

Assignees

• Univ Fraser Simon

Inventors

• Adamski Michael
• Balogun Emmanuel
• Cassegrain Simon
• Mardle Peter
• Holdcroft Steven

Classifications

• H01M2300/0082

  Organic polymers · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/926

  on carbon or graphite · CPC title

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M8/1023

  having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes · CPC title