ANION EXCHANGE MEMBRANES

GOVERNMENT LICENSE RIGHTS

[0001] This invention was partly made wit Government support under grant DE-AR000G814 awarded by Advanced Research Projects Agency - Energy of the United States Department of Energy. The Government has certain rights in the invention.

FIELD OF THE INVENTION

[0002] Anion exchange polymers capable of forming anion -exchange membranes {AEMs) an ionomers (AESs) are provided for use in anion exchange membrane fuel cells (AEMFCs), More specifically, hydroxide exchange polymers are provided which are capable of forming hydroxide-exchange membranes (HEMs), and ionomers (HEIs} for use in various applications such as hydroxide exchange membrane fuel ceiis (HE FCs) and hydroxide exchange membrane electrolyzers (HEMEL).

BACKGROUND OF THE INVENTION

[0003] Proton exchange membrane fuel ceils (PEMFCs) are considered to be clean and efficient power sources. Sfeeie et a!., Nature 2001, 414, 345. However, the high cost and unsatisfactory durability of catalysts are major barriers for large- scale commercialization of PEMFCs. Borup et aL Chem Rev 2007, 107, 3904. By switching the polymer electrolyte from an“acidic" condition to a“basic" one,

HEMFCs are able to work with non-precious metsS catalysts and the catalysts are expected to be more durable. Other cheaper fuel cel! components are also possible such as metal bipolar plates. Varcoe, et a! _f Fuel Cells 2005, 5, 187; Gu et a!.,

Angew Chem Int Edit 2009, 48, 6499; Gu et aL, Chem Common 2013, 49, 131. However, currently available HEMs and HEIs exhibit low alkaline/chemical stability, iow hydroxide conductivity, high water uptake, and low mechanical Integrity under dry conditions, especially after wet-dry cycles.

[0004] The biggest challenge for HEMs/HEIs at present is achieving a high chemical stability at desired operation temperatures of 80 °C or more, and ideally 95 °C or more e.g. _« in the presence of nucleophilic hydroxide ions). Varcoe et a!., Energ Environ Sci 2014, 7, 3135. The most commonly encountered cationic functions! groups (e.g., benzyl trimethyl ammonium and alkyl chain ammonium) ca undergo a number of degradation processes in the presence of hydroxide ions nucleophiles by direct nucleophilic substitution and Hofmann elimination. Moreover, the polymer backbone of most base polymers for HEIWHE1 applications (e.g., poSysulfone and polyCphenyiene oxide)) unavoidably contains ether linkages along the backbone, which makes the HEMs/HEIs potentially labile under high pH conditions, Lee et a!., Acs Macro Lett 2015, 4, 453; Lee et a!., Acs Macro Let 2015, 4, 814 The strongly nucleophilic hydroxide ions attack these wea bonds and degrade the polymer backbone. Thus, alternative cationic groups, organic tethers, and polymer backbones are needed to enhance chemical stability of HEMs/HEIs.

[0005] Another concern regarding current HEMs/HEIs is their hydroxide conductivity. In comparison to Nation, HEMs have intrinsically lower ionic

conductivities under similar conditions, because the mobility of OH- is lower than that of H+. Hibbs et al., Chem Mater 2008, 20, 2586. Greater ion -exchange capacity (I EC) is needed for HEMs/HEIs to achieve greater hydroxide conductivity. However, high IEC usuall leads to a membrane having high water uptake a high swelling ratio), decreasing the morphological stability and mechanical strength of the membrane, especially after repeated wet-dry cycles. This highly swollen state when wet Is a major reason for decreased flexibility and brittleness of HEMs when dry. The removal of the trade-off between high hydroxide conductivity and low water uptake has been a major setback in designing high-performance HEMs/HEIs. Pan et al., Energ Environ Sci 2013, 6, 2912. Chemical cross-linking, physical reinforcement, side-chain polymerization, and block-copolymer architecture have been tried to reduce water uptake white maintaining acceptable hydroxide conductivity, but these techniques bring challenging problems, e.g., reduced mechanical flexibility, decreased alkaline stability, and/or increased cost. Gu et al., Chem Commun 2011, 47, 2856; Park et at, Electrochem Solid St 2012, 15, B27; Wang et al.,

Chemsuscbem 2015, 8, 4229; Ran et al., Sci Rep-Uk 2014, 4; Tanaka et al., J Am Chem Soc 2011, 133, 10646. Additionally, almost all side-chain or block-copolymer HEMs are based on flexible aliphatic polymer chains due to limited available synthesis methods. As a result, the membranes still cannot provide morphological stability (low swell ratio) at high SECs and high temperature. Wang et a!., Chemsuschem 2015, 8, 4229; Ran et al., Sci Rep-Uk 2014, 4; Marino et al.,

Chemsuschem 2015, 8, 513; U et al, ML Macromolecules 2015, 48, 6523.

[0006] An additional obstacle to using HEMs is achievement of mechanical flexibility and Strength in an ambient dry state. Most HEMs exhibit low mechanical strength and are ver brittle in a completely dry state especially after being

completely swollen, it is difficult to obtain and handle thin membranes that are large in size as needed for commercial use of HEMs. Without good mechanical properties, the ionomers cannot form and keep an adequate triple phase structure in the fuel cell electrode at high temperature, such as at or above 80 °C. U et al, J Am Chem Soc 2013, 135, 10124.

[0007] Another highly desirable feature of an HE! is that the polymer be soluble in a mixture of lower boiling alcohol and water but insoluble In pure alcohol or water so that the HE!s can be readily incorporated into an electrode catalyst layer yet not be dissolved away by water or alcohol.

[0008] PEMFCs have recently been deployed as zero-emission power sources in commercially sold automobiles, with demonstrated Song driving range and short refuelling time, which are two features preferred for customer acceptance.

However, PEMFCs use platinum electrocataiysts and are not yet cost competitive with gasoline engines. Major approaches to PEMFC cost reduction include

development of Sow-p!atinum-foading, high power density membrane electrode assemblies (MEAs), and platinum-group-metal-free (FGM-free) cathode catalysts. A fundamentally different pathway to lo cost fuel cells is to switch fro PEMFCs to hydroxide exchange membrane fuel cells (HEMFCs) that, due to their basic operating environment, can work with PGM~free anode and cathode catalysts, and thus are potentially economically viable. To replace PEMFCs, however, HEMFCs have to provide a performance that matches PE MFC’s, performance which in turn requires highly active anode and cathode cata!ysts as well as the highly chemically stable, tonicaSSy conductive, and mechanically robust hydroxide exchange

membranes (HEMs)/hydroxide exchange ionomers {HEfs) to build an efficient triple phase boundary an thus drastically improve the utilization of the catalyst particles and reduce the internal resistance.

[0009] BEMs/H Els are typically composed of organic cations tethered on a polymer backbone, with OH- being the balancing anion. A chemically stable HEM/HE! requires a stable organic cation and a stable polymer backbone. These hydroxide conductive organic cations have been obtained by introducing quaternary ammonium, imidazolium, guanidinium, phosphonium, sulfonium, ruthenium and cobaftocenium using eh!oromeihySation of aromatic rings or bromination on the benzyltc methyl groups of the polymers. Various polymer backbone

structures-poiy(oiefins), poiy(styrenes) polyphenylene oxides), poiy(phenylenes), poly(arylene ethers) -have been investigated recently. So far, most of HEMs/HEis based on traditional cation groups (such as benzyl trimethyl ammonium) and aromatic polymer backbones (such as poiysulfone have low alkaline/chemical stability, iow hydroxide conductivity, high water uptake, an poor mechanical properties when dry.

[0010] Polymer backbones with ether linkages are generaSiy vulnerable in alkaline medium and thus HEM/HE! having ether-free polymers backbones are highly desirable. Acid catalyzed hydroxylation reactions have been demonstrated to efficiently produce ether-free polymers backbones, and HEM/HEI with such backbones have proven to have good alkaline stability and mechanicai properties. Zoiotukhfn et al. Chem. Comm. 2004, 1030. Diaz et al. Macromol. Rapid Commun. 2007, 28, 183. Lee et al. ACS Macro Let. 2015, 4, 814. Bae et al. US Patent, App. 15/527,967.

[O011]To further enhance the aSkaSine stability of HEM/HEI under both high temperature and low relative humidity, cations other than the conventional ammonium cations are highly needed !midazolium cations, when properly

substituted, have shown improved alkaline stability Gu et ai. Macromolecules, 2014, 47, 208. Wang et ak ChemSusChem 2013, 6, 2070. Hugar et al J, Am. Chem. Soc. 2015, 137, 8730.

SUMMARY OF THE INVENTION

[0012] A polymer is provided which comprises structural units of Formulae (1 A); (3A) or (3'A); and optionally (4A), wherein the structural units of Formulae (1A), (3A), (3’A) and (4A) have the structures:

wherein:

Rii are each independently a quaternary ammonium or phosphonium group or a nitrogen-containing heterocyclic group or a salt thereof, the quaternary ammonium or phosphonium group having the formula (5A):

an the nitrogen-containing heterocyclic group being an optionally substituted pyrrole, pyrroiine, pyrazoie, pyrazoline, imidazole, imidazoline, triazoSe, pyridine, triazine, pyrazine, pyridazine, pyrimidine, azepine, quinoline, piperidine, pyrrolidine, pyrazolidine, imidazoisdine, azepane, isoxazole, isoxazoltne, oxazoie, oxazoiine, oxadiazole, oxatrsazoie, dioxazole, oxazine, oxadiazine, isoxazolidine, morpholine, thiazole, isothiazoie, oxathlazoie, oxathiazine, or caprolactam, wherein each substituent is independently alkyl, alkenyl, alkynyl, aryl, or aralkyl;

R20, f¾o, R40, Rto, Reo, RTO, R«O, RSO, RISO, R140. Riso, Rieo, and Ri?o are each independently hydrogen, halide, alkyl, alkenyl, alkynyl or aryl, and the alkyl, alkenyl, alkyny! or aryl are optionally substituted with halide, and wherein Rso and Rso are optionally linked to form a five membered ring optionally substituted with halide or alkyl;

each Ru ) is independently alkyl, alkenyl, alkynyl, or a substituent having formula (4B):

and the alkyl, alkenyl, or alkynyl are optionally substituted with fluoride;

Riso and R240 are each independently aSkylene;

R 190 , R200, R210, R220, and R230 are each independently alkyl, alkenyl, or alkynyl;

q is 0, 1, 2, 3, 4, 5, 8, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 18, 17, 18, 19, or 20; m is 0, 1, 2, 3, 4, 5 or 6;

n is O, 1 , 2 or 3;

each m ⁵ and each n’ is independently 0, 1 or 2;

X ^' is an anion; and Z is P when the structural unit of formula (3A) is present in the polymer but the structural unit of formula (3 ^! A) is not present in the polymer, and Z is N or P when the structural unit of formula (3 ^! A) is present in the polymer.

[0013] Also provided is a poiymer comprising a reaction product of a polymerization mixture comprising:

(i) a cation-functionalized tnfluoroketone monomer having the formula:

(ii) an aromatic monomer having the formula:

or a crown ether monomer having the formula:

(Hi) optionally, a trifiuoromethyl ketone monomer having the formula:

Ri are each independently a quaternary ammonium or phosphoniurn group or a nitrogen-containing heterocyclic group or a salt thereof, the quaternary ammonium or phosphoniurn group having the formula (5A):

and the nitrogen-containing heterocyclic group being an optionally substituted pyrrole, pyrroline, pyrazole, pyrazoiine, Imidazole, imidazoline, triazole, pyridine, triazine, pyrazine, pyridazine, pyrimidine, azepine, quinoline, piperidine, pyrrolidine, pyrazolidine, imidazoildine, azepane, isoxazoSe, isoxazoline, oxazole, oxazoltne, oxadiazole, oxatriazole, dioxazole, oxazine, oxadiazine, isoxazolidine, morpholine, thiazote, isothiazole, oxathiazoSe, oxathiazine, or caprolactam, wherein each substituent is independently alkyl, alkenyl, alkynyl, aryl, or aralkyl;

R 2, Rs, R4, Rs, Re, R?, Rs, Rs, Rto, R13, Ri4, Rts, Rts, and Ri?are each independently hydrogen, halide, alkyl, alkenyl, alkynyl or aryl, and the alkyl, alkenyl, alkynyl or aryl are optionally substituted with halide, and wherein Rs and Re are optionally linked to form a five membered ring optionally substituted with halide or alkyl;

each R12 is independently alkyl, alkenyl, alkynyl, or a substituent of formula

(4C);

and the alkyl, alkenyl, or alkynyl are optionaily substituted with fluoride;

RISG and R240 are each independently aikylene;

RI9O, R200, R210, R220, and R23G are each independently alkyl, alkenyl, or alkynyl;

is 0, 1 , 2, 3, 4, 5 or 6;

n is 0, 1 , 2 or 3; a each m and each n’ is independently 0, 1 or 2;

q is 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, ID, 11 , 12, 13, 14, 15, 16, 17, 18, 19, or 20;

X ^' is an anion; and

Z is P when the aromatic monomer of formula (3) is present in the

polymerization mixture but the crown ether monomer of formula (3’) is not present in the polymerization mixture, and Z is N or P when the crown ether monomer of formula (3 ^! ) is present in the polymerization mixture.

[0014] Another polymer is provided which comprises a second reaction product of a second polymerization mixture comprising:

a quaternar ammonium or phosphonium compound or a nitrogen-containing heterocycle or a salt thereof; and

an intermediate polymer;

wherein:

the intermediate polymer comprises a first reaction product of a first polymerization mixture comprising:

(i) a hafogenated trifluoromethyf ketone monomer having the formula:

(is) an aromatic monomer having the formula (3) as shown above, or a crown ether monomer having the formula (3’> as shown above; and

(til) optionally, a trifluoromethyl ketone monomer having the formula (4) as shown above, wherein:

the quaternary phosphonium compound has the formula (5):

the nitrogen-containing heterocycle, m’, n’, n, q, f¾, R¾ R4, Rs, Re, Ry, Re, Rs,

Rto, Ri2, RI3, RI4, Ris, Rig, and Rr? are as described above;

Ris and RZ4 are each independently aikyiene;

Rig, R20, R21, R22, and R23 are each independently alkyl, alkenyl, or aSkynyl; R111 is a halide;

m is 0, 1 , 2, 3, 4, 5 or 6; X- is an anion; and

Z is P when the aromatic monomer of formula (3) is present in the first polymerization mixture but the crown ether monomer of formula (3’) is not present in the first polymerization mixture, arid Z is N or P when the crown ether monomer of formula (3’) is present in the first polymerization mixture.

[0015] An anion exchange polymer is also provided, which comprises a reaction product of a base and any one of the polymers as described above.

[0018] A method of making an anion exchange polymer membrane comprising the anion exchange polymer is also provided. The method comprises: reacting the cation-functionalized trifluoroketone monomer, the optional trifSuoromethyl ketone monomer, and the aromatic monomer or the crown ether monomer in the presence of an organic solvent and a polymerization catalyst to form a cation-functionalized polymer;

dissolving the cation-functionalized polymer in a solvent to form a polymer solution;

casting the polymer solution to form a polymer membrane; and

exchanging anions of the polymer membrane with hydroxide, bicarbonate, or carbonate ions or a combination thereof to form the anion exchange polymer membrane.

[0017] Another method of making an anion exchange polymer membrane comprising the anion exchange polymer is provided, The method comprises:

reacting the hafogenated trifluoroketone monomer, the optional trifieoromethyi ketone monomer, and the aromatic monomer in the presence of an organic solvent an a polymerization catalyst to form a halogen-functionalize polymer;

reacting the halogen-functionalized polymer with the quaternary phosphonium compound or the nitrogen-containing hetenocyc!e or a salt thereof in the presence of an organic solvent to form a cafion-functionaSized polymer;

dissolving the cation-functionalized polymer in a solvent to form a polymer solution;

casting the polymer solution to form a polymer membrane; and

exchanging anions of the polymer membrane with hydroxide, bicarbonate, or carbonate Ions or a combination thereof to form the anion exchange polymer membrane. [0018] Another method of making an anion exchange polymer membrane comprising the anion exchange polymer is provided. The method comprises:

reacting the hafogenated trifluoroketone monomer, the optional trifiuoromethyl ketone monomer, and the crown ether monomer in the presence of an organic solvent and a polymerization catalyst to form a halogen-functionalized polymer; reacting the halogen-functionalized polymer with the quaternary ammonium compound or quaternary phosphonium compound or the nitrogen-containing heterocycle or a salt thereof in the presence of an organic solvent to for a cation- functionalized polymer;

dissolving the cation-functionalized polymer in a solvent to form a polymer solution;

casting the polymer solution to form a polymer membrane; and

exchanging anions of the polymer membrane with hydroxide, bicarbonate, or carbonate ions or a combination thereof to form the anion exchange polymer membrane,

[0019] An anion exchange membrane is also provided, optionally

configured and sized to be suitable for use in a fuel cell, electrolyzer, eiectrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, water purifier, waste water treatment system, ion exchanger, or CO a separator, and the anion exchange membrane comprising the anion exchange polymer

[0020] An anion exchange membrane fuel cell, electrolyzer, eiectrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, water purifier, waste water treatment system, ion exchanger, or CO2 separator is also provided, the fuel cell, electrolyzer, eiectrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, water purifier, waste water treatment system, ion exchanger, or CO2 separator comprising the anion exchange polymer,

[0021] Also provided is a reinforced electrolyte membrane, optionally configured and sized to be suitable for use in a fuel cell, electrolyzer, eiectrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, water purifier, waste water treatment system, ion exchanger, or CO2 separator. The membrane comprises a porous substrate impregnated with the anion exchange polymer. [0022] Other objects and features wi l be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A illustrates an exemplary hydroxide exchange membrane fuel cell

[0024] Figure 1 B illustrates an exemplary hydroxide exchange membrane electrolyzer,

[0025] Figure 2 depicts an 1 H NMR spectrum of BP-CF3-Br-1 in CDCI3.

[0026] Figure 3 depicts an 1 H NMR spectrum of BP-CF3-SM-1 In DMSO-d6.

[0027] Figure 4A shows 1 H NMR spectra of BP-CF3-IM-1 before and after an alkaline stability test for 1200 hours at 130 X in 1 KOH (10% TFA in DMSO- ),

[0028] Figure 4B shows 1 H NMR spectra of TP~OF34M~1 before and after an alkaline stability test for 300 hours at 80 X in 10M KOH. (in DMSG-d6). Figure 4C shows 1 H NMR spectra of TP~CF3~IM~1 before and after an alkaline stability test for 300 hours at 95 with RH of 50.9% and 23 3%, respectively (10% TFA in DMSO-d6).

[0029] Figure 5 depicts an 1 H NMR spectrum of TP~CP3~8r~1 In CDC13.

[0030] Figure 6 shows an 1 H NMR spectrum of TP-CF3-IM-1 in DMSO~d8.

[0031] Figure 7 is a graph depicting tensile stress as a function of elongation for TP-CF3-IM-1 polymers in bicarbonate form.

[0032] Figure 8 illustrates polarization (voltage as a function of current density) and power density (power density as a function of current density) curves of an HEMFC at 95 X. Materials: TP-CF3-IM-1 membrane, sonomer loading of 20 %, catalyst: 0,4 mgPt cm~2 PtRu/C on anode, 0.4 mgPt cm -2 PtRu/C on cathode. Test conditions: 95 , anode humidifier temperature: 90 X, cathode anode humidifier temperature: 97 X, H2 flow rate: 1 0 L/rnin, O2 flow rate; 2 0 L/rnin.

[0033] Figure 9 illustrates polarization (voltage as a function of current density) curves of an HEMEL at 80 X. Materials: TP-GF3-IM-1 membrane, tonomer loading of 30 %, catalyst; 4 0 mgps cm -2 Pt/C on anode, 2.9 mg cm --2 IrOa on cathode. Test conditions: 80 X for water and electrolyzer, water flow rate: 3 0 ml/min. [0034] Figure 10 depicts an t H NIV1R spectrum of PCE-C5-B in CPCI3, [0035] Figure 11 depicts an 1H NMR spectrum of PCE-C5-iM-Br-1 in DMSO-d8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] HEMs/HEIs formed from polymers with various pendant cationic groups and having intrinsic hydroxide conduction channels have been discovered which simultaneously provide Improved chemical stability, conductivity, water uptake, good solubility in selected solvents, mechanical properties, and other attributes relevant to HEM/HEI performance. The attachment of the pendant side chains to the rigid aromatic polymer backbone of the polymer which is free of ether bonds allows fine tuning of the mechanical properties of the membrane and incorporation of aikaiine stable cations, such as tmidazoliums, phosphontums and ammoniums, and provides enhanced stability to the polymer, HEMs/HEIs formed from these polymers exhibit superior chemical stability, anion conductivity, decreased water uptake, good solubility in selected solvents, and improved mechanical properties in an ambient dry state as compared to conventional HEM/HE is. The inventive HEMFCs exhibit enhanced performance and durability at relatively high temperatures.

[0037] As a first aspect of the invention, a polymer Is provided which comprises structural units of Formulae { 1 A); (3A) and/or (3’A); and optionally (4A).

[0038] The structural unit of Formulae (t A) has the structure:

an Rii are each independently a quaternary ammonium or phosphonium group or a nitrogen-containing heterocyclic group or a salt thereof.

[003S] The quaternary ammonium or phosphonium group has the formula

(5A):

wherein Riso and f¾4o are each independently alkylene; Rieo, Rim, Ri :,, R220 _» and R230 are each independently alkyl, alkenyl, or alkynyl; m is 0, 1 , 2, 3, 4, 5 or 8; X is an anion; and 2 is P when the structural unit of formula (3A) is present in the polymer but the structural unit of formula (3Ά) is not present in the polymer, and Z is N or P when the structural unit of formula (3'A) is present in the polymer. Preferably, X comprises a halide, BF4 ^” , PFe , C ¾ ^2' or HCO3 ^' .

100403 For example, the quaternary ammonium or the quaternary phosphonium grou of the formula (5A) can have Riso and R240 each

independently be C 1-C22 alkylene; Riso, Raw, R210, Rz , and R230 can each independently be Ci -Ce alkyl; can be 0, 1 , 2, 3, 4, 5, or 8; and Z is N or P.

[00413 As another example, the quaternary ammonium or the quaternary phosphonium grou of the formula (5A) can have Riso and R240 each

independently be Ci-Ce alkylene; R190, R200, R2io, Rsao, and R230 can each independently be Ci-Ce alkyl; m can be 0, 1 , 2, or 3; and Z is N or P.

[0042|As yet another example, the quaternary ammonium or the quaternary phosphonium group of the formula (SA) can have Rieo and R¾*o each independently be Ce-Cas alkylene; Rtgo, R200, R21D, R22D, and R230 each

independently be Gr-Ce alkyl; m be 0, 1, 2, or 3; and Z is N or P.

[00433 In other instances, the quaternary ammonium or the quaternary phosphonium group of the formula (5A) can have Rieo and R240 each be Ca-Ce alkylene; Rtso, Rsoo, Raio, R220, and R230 each Independently be methyl; m be 1 ; and Z is N or P,

[0044] In yet other instances, the quaternary ammonium or the quaternary phosphonium group of the formula (5A) can have Rieo and R240 each be n~ hexylene; iga, RSOO, Raio, R220. _. and R230 each be methyl; m be 1 ; and Z is N or P,

[0048] The nitrogen-containing heterocyclic group can be an optionally substituted pyrrole, pyrroline, pyrazole, pyrazoline, imidazole, imidazoline, triazole, pyridine, triazine, pyrazine, pyridazine, pyrimidine, azepine, quinoline, piperidine, pyrrolidine, pyrazolidine, tmidazolidine, azepane, isoxazole, isoxazoline, oxazole, oxazoiine, oxadiazole, oxatriazoie, dioxazole, oxazlne, oxadiazioe, isoxazolidine, morpholine, Ihiazoie, isothiazoSe, oxalhiazole, oxathiazine, or caprolactam, wherein each substituent is independently alkyl, alkenyl, alkynyi, aryl, or aralkyl,

|0046] Preferably, the nitrogen-containing heterocyclic group is unsaturated such as pyrrole, pyrroSsne, pyrazoSe, pyrazoSine. imidazole, imidazoline, triazoSe, pyridine, triazine, pyrazine, pyridazsne, pyrimidine, azepine, or quinoline, and each substitutable position of the heterocycle is substituted independently with alkyl (e.g., methyl, ethyl, propyl, n-butyl) or aryl groups (e.g., phenyl with alky! substituents).

[0047] The nitrogen-containing heterocyclic group can comprise an imidazolium having the formula (6A):

wherein: i¾s, Rze, R27, an are each independently hydrogen, halide, alkyl, alkenyl, alkynyi or aryl, an the alkyl, aikenyl, alkyny or aryl are optionally substituted with halide. Preferably, Rzg is 2,4,6-alkyjphenyl, and Ras, R ₂ 6, and R27 are each independentl Ci-Ce alkyl. An example of an imidazole as the nitrogen- containing heterocycle is 1-butyl-2-mesity}-4,5-dimethyh1 /-imidazole-imidazole which has the formula:

[0048] The structural unit of Formulae (3A) has the structure;

wherein n is 0, 1 , 2 or 3; f½, F½, R40, Rso, Reo, R70, Rso, and R« are each independently hydrogen, halide, alkyl, alkenyl, afkynyl or aryl, and the alkyl, alkenyl, aSkyrtyl or aryl are optionally substituted with halide; and wherein R30 and Rso are optionally linked to form a five membered ring optionally substituted with haiide or alkyl,

[0049] For example, in the structural unit of formula (3A), at least one of Rso, Rso, R40, Rso, Reo, R70, Rso, and Rso can be haiide or aryl, and the ary! can be optionally substituted with haiide.

[0050] As another example, in the structural unit of formula (3A), Rm and Reo can be linked to form a five membered ring optionally substituted with halide or alkyl.

[0051] The structural unit of formula (3A) can be derived from an aromatic monomer comprising biphenyl, para-terphenyl, meta-terphenyi, para-quaierphenyS, 9,9-dimethyl-9H-fluorene _! or benzene.

[0052] The structural unit of formula (S’A) has the structure:

wherein R20, F o _* Rso, R?o, Rso, and Rgo are each independently hydrogen, halide, alkyl, alkenyl, aikynyS or aryl, and the alkyl, alkenyl, aSkynyl or aryl are optionally substituted with halide. The benzo ring shown in formula (3’ A) as dashed lines an the Rm group can be present or absent. If the benzo ring shown in formula (3’A) as dashed lines is absent, then the Rso group Is absent since the benzo ring of the structural unit would be bivalent. If the benzo ring shown in formula (3Ά) as dashed lines is present, then the Rao group is present since the benzo ring having the Rso group would be monovalent.

[0053] For example, the structural unit can be derived from a dibenzo~18~ crown-6 polyether as In formula (3Ά-1 ) wherein m’ and n ^* are 0, a dlbenzo-21 -crown- 7 poiyether as In formula {3Ά-1 ) wherein m ^s is 0 and n' is 1 , a dibenzo-24~crown-8 polyether as in formula (3 ^f A~1 ) wherein m' and n are 1 , or a dibenzo~3Q-crown~10 polyether as in formula (3' ~1 ) wherein m ^* and n’ are 2, and R20, R40, Rso, R70, Rso, an Rso are as defined for formula (3 ^! A):

or a benzo-18~crown-6 polyether as in formula (3 ^! A~2) wherein m ^! and rV are 2, and RTO and Rso are as defined for formula (3Ά):

[0054] For example, in the structural unit of any of formuiae (3'A)-(3’A-2), Rso, R40, Rso, RTO, RSO, and Rso, if present, can be hydrogen or halide.

[0055] The structural unit of formula (3Ά-1 } can be derived from: the respective dibenzo-crown ether wherein R20, 40, Rso, TO, RSO, an go are each hydrogen. Dibenzol 8-crown~6 polyether can be made from catechol and bis{chioroethyl) ether as described by Charles J, Pedersen, Org. Synth., 1972, 52, 66, and is commercially available, Dibenzo-21 -crown-7 polyether, dibenzo-24- crown-8 polyether, and dibenzo-30-erown-tO polyether are also commercially available.

[00563 The structural unit of formula (3 ^* A-2) can be derived from benzol 8- crown-6 polyether wherein Rro and Rso are eac hydrogen. Benzo-1 S-cfOwn-6 polyether Is commercially available.

[0057] The optional structural unit of Formula (4A) has the structure:

R 100 wherein each R«e is independently alkyl, alkenyl, alkynyi, or a substituent having the formula (4B):

and the alkyl, alkenyl, or alkynyi are optionally substituted with fluoride; Rise, R o, Riso, Ri8o. and Ri?o are each independently hydrogen, halide, alkyl, aikeny!, alkynyi or aryl, and the alkyl, alkenyl, alkynyi or aryl are optionally substituted with halide.

[0058] For example, in the structural unit of formula (4A), Rioo can be alkyl, alkenyl, or alkynyi, and the alkyl, alkenyl, or alkynyi can be optionally substituted with fluoride.

[0059] As another example, in the structural unit of formula (4A), Rioo can be the substituent of formula (4B) and at least one of Riso, Ruo, Rise, Rieo and Ri?o can be halide or aryl, and the aryl can be optionally substituted with fluoride.

[0060] As yet another example, R20, R40, Rso, Rro, Rso, Rso, Rise _* , Ruo, Riso, Rieo, and I7O can each independently be hydrogen, or alkyl optionally substituted with fluoride, and R100 can be alky! optionally substituted with fluoride or the substituent of formula (4B).

[0061] In other instances, R20, R40, Rso, R?o, Rao, Rso, Riso, R¼o, Riso, Rieo, and Rrro can each independently be hydrogen, methyl, ethy!, propyl, butyl, pentyl, or hexyl, or methyl, ethyl, propyl, butyl, pentyl, or hexyl optionally substituted with fluoride, and Rim can be methyl, ethyl, propyl, butyl, pentyl, or hexyl optionally substituted with fluoride or the substituent of formula (4B).

[0062] A sum of the mole fractions of the structural unit of Formula (1 A) and Formula (4A) in the polymer can be about equal to a sum of th mole fractions of the structural units of Formulae (3A) and (3Ά) in the polymer, and the ratio of the mole fraction of the structural unit of Formula (1A) in the polymer to the sum of the mole fractions of the structural units of Formulae (3A) and (3Ά) in the polymer can be from about 0.01 to 1 . [0063] A mole ratio of a sum of the mole fractions of the structural unit of Formula (1 A) and Formula (4A) to a sum of the mole fractions of Formulae (3A) and (3Ά) in the polymer can be from about 0.95:1 to about 1.4:1 , and the ratio of the mole fraction of the structural unit of Formula (1A) to the sum of the mole f ractions of the structural units of Formulae (3A) and (3Ά) can be from about 0.01 to 1.

[0064] The mole ratio of the sum of the mol fractions of the structural unit of Formula (1 A and Formula (4A) to the sum of the mole fractions of Formulae (3A) and (3Ά) in the polymer can be from about 1 :1 to about 1.2:1.

[0065] As a secon aspect of the invention, a polymer is provide which comprises a reaction product of a polymerization mixture comprising a cation- functionalized trifluoroketone monomer; an aromatic monomer and/or crown ether monomer: and optionally a trifluoromethy! ketone monomer,

[0066] The cation-functionalized trifluoroketone monomer has the formula; wherein q is 0, 1 , 2, 3.4, 5, 6, 7, B, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, or 20; and Ri are each independently a quaternary ammonium or phosphonium group or a nitrogen-containing heterocyclic group or a salt thereof, The quaternary ammonium or phosphonium group and the nitrogen-containing heterocyfic group are as defined above for the first aspect of the Invention.

[0067] The aromatic monomer has the formula;

wherein n Is 0, 1 , 2 or 3; Rz, Rs, RA, RS, Re, Rr, Re, Rs, and Rio are each

independently hydrogen, halide, alkyl, alkenyl, alkynyl or aryl, an the alkyl, alkenyl, alkynyl or aryl are optionally substituted with halide, and wherein Rs and Re are optionally linked to form a five membered ring optionally substitute with halide or alkyl.

[0068] For example, in the aromatic monomer of formula (3), at feast one of Ra, Rs, f¾ _s R¾ Re, Rr _s Rs, R¾ and Rio is halide or aryl, and the aryl is optionally substituted with halide.

1 ^* 0089] As another example, in the aromatic monomer of formula (3), Rs and Re are linked to form a five membered ring optionally substituted with halide or alkyl.

[0070] The aromatic monomer of formula (3) can comprise biphenyl, para- terphenyf, meta-terpbenyS, para-quaterphersyl, 9,9-dimethyl-9Hhfluorene, or benzene.

[0071] The crown ether monomer has the formula;

wherein Ra, R4, Rs, Rr, Rs, Rs, and Rio, if present, are each independently hydrogen, halide, alkyl, alkenyl, aikynyi or aryl, and the alkyl, alkenyl, aikynyi or aryl are optionally substituted with halide and each nf and each n ^* is independently 0, 1 or 2 The benzo ring shown in formula (3 ^! ) as dashed lines can be present or absent

[0072] For example, the crown ether monomer can be a dibenzo-18-crown- 6 poiyether as in formula (3 -1 ) wherein m’ and n are 0, a dibenzo-21 -crown-7 polyether as in formula (3 -1) wherein m ⁵ Is 0 and n' is 1 , a di enzQ~24~crown-8 poiyether as in formula (3’-1) wherein m’ and n’ are 1, or a dibenzo-30-crown-10 poiyether as In formula (3-1) wherein m’ and n ^! are 2, and Ra, R4, Rs, R?, Rs, Rs and

Rio are as defined for formula (3’): or a benzo~18~crown-8 poSyether as in formula (3 -2) wherein m’ and n’ are 2, and

R?, Ra, Rs and Rio are as defined for formula (3’};

[0073] The optional irifSuoromethyi ketone monomer has the formula:

wherein each R12 is independently alkyl, alkenyl, alkynyl, or a substituent of formula (4C):

and the alkyl, alkenyl, or alkynyi are optionally substituted with fluoride; and Ria, Rw Rts, Rie, and Ri? are each independently hydrogen, halide, alkyl, alkenyl, alkynyi or aryl.

[0074] For example, in the trifluoromethyS ketone monomer of formula (4), Ri2 IS alkyl, alkenyl, or alkynyi, and the alkyl, alkenyl, or alkynyi is optionally substituted with fluoride.

[0075] As another example, in the trifluoromethyi ketone monomer of formula (4), R12 is a substituent of formula (4C) and at least one of R13, Ru, R15, Rie and Ri7is halide or aryl, and the aryl is optionally substituted with fluoride.

[0076] As yet another example, R2, Ra, R4, Rs, Re, Rr, Re, Rs, Rio, Ria, Ru, Rts, Ria, and Ri? are each independently hydrogen, or alkyl optionally substituted with fluoride, and R12 is alkyl optionally substituted with fluoride or a substituent of formula (4C).

[0077] In other instances, Ra, Rs, R*. Rs, Re, RT, RS, RS, R10, R13, Ru, Rts, is, and R ₁₇ are each independently hydrogen, methyl, ethyl, propyl, butyl, pentyl, or hexyl, or methyl, ethyl, propyl, butyl, pentyl, or hexyl optionally substituted with fluoride, and R12 is methyl, ethyl, propyl, butyl, pentyl, or hexyl optionally substituted with fluoride or a substituent of formula (4C).

[0078] A third aspect of the invention is a polymer which comprises a second reaction product of a second polymerization mixture. The second

polymerization mixture comprises a quaternary ammonium or phosphonium compound or a nitrogen -containing heterocycle or a salt thereof; and an intermediate polymer.

[0079] The Intermediate polymer comprises a first reaction product of a first polymerization mixture. The first polymerization mixture comprises a ha!ogenatec! trifluoromethy! ketone monomer; an aromatic monomer and/or crown ether monomer; and optionally, a trifluoromethyl ketone monomer.

[0080] The haiogenated trifluoromethy! ketone monomer has the formula: wherein q is O, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20; and Rio is a halide. Preferably, the halide is fluoride, chloride, bromide or iodide.

[0081] The aromatic monomer has the formula (3) and is as described for the polymer in the second aspect of the invention,

[0082] The crown ether has the formula and is as described for the polymer in the second aspect of the invention.

[0083] The trifluoromethyl ketone monomer has the formula (4) and is as described for the polymer in the second aspect of the invention.

[0084] The quaternary ammonium or phosphonium compound has the formula (6):

wherein m is 0, 1 , 2, 3, 4, 5 or 6; R s and R24 are each independently aikylene; Ris, Rgo, R21, R22, and R23 are each independently alkyl, alkenyl, or alkyn l; X is an anion: and Z is P when the aromatic monomer of formula (3) Is present in the first polymerization mixture but the crown ether monomer of formula (3 ^' ) is not present in the first polymerization mixture, and Z is N or P when the crown ether monomer of formula (3 ) is present in the first polymerization mixture. Preferably, X comprises a halide, BF4 ^" , PFs~, CO3 ² or HCQac

[0085] For example, the quaternary ammonium or phosphonium compound of the formula (5) can have Rig and R24 each independently be Ci~C22 aikylene; R s, R20, R21 , R22, and R23 can each independently be Ci-Cs alkyl; m can be 0, 1 , 2, 3, 4, 5, or 8; and 2 is N or P.

[0086] As another example, the quaternary ammonium or phosphonium compound of the formula (5) can have Ris and R24 each independently he Ci-Ce aikyiene; Ris, R20, R21, R22, and R23 can each independently be Ci-Ce alkyl; m can be 0, 1 , 2, or 3; and Z is N or P.

[0087] As yet another example, the quaternary ammonium or phosphonium compound of the formula (5) can have Rig and R24 each independently be C8-C22 aikyiene; R19, R20, R21, R¾ and R23 can each independently be Ci-Ce alkyl; m can be 0, 1 , 2, or 3; and Z is N or P.

[0088] In other instances, the quaternary ammonium or phosphonium compound of the formula (5) can have Ris and R24 each be C2-C8 aikyiene; Ris, R20, R21, R22, and R23 can each independently be methyl; m can be 1 ; and Z is SM or P,

[0089] In yet other instances, the quaternary ammonium or phosphonium compound of the formula {5} can have Rie and R24 each be n-hexySene; R19, Rao,

R21, R22, and R23 can each be methyl; m can be 1; and Z is N or P.

[0090] The nitrogen-containing heterocycle can be an cptlonaliy substituted pyrrole, pyrroline, pyrazole, pyrazoline, imidazole, imidazoline, triazoie, pyridine, triazine, pyrazine, pyridazine, pyrimidine, azepine, quinoline, piperidine, pyrrolidine, pyrazolidine, imidazoiidine, azepane, isoxazoie, isoxazoiine, oxazoie, oxazo!ine, oxadiazo!e, oxatriazoie, dioxazole, oxazine, oxadiazine, isoxazolidine, morpholine, thiazoie, isothiazoSe, oxathiazole, oxathiazine, or caprolactam, wherein each substituent Is independently alkyl, alkenyl, aikynyi, aryl, or aralkyl.

[0091] Preferably, the nitrogen-containing beterocycie is unsaturated such as pyrrole, pyrroline, pyrazole, pyrazoline, imidazole, imidazoline, triazole, pyridine, triazine, pyrazine, pyridazine, pyrimidine, azepirse, or quinoline, and each

substitutable position of the heterocycle is substituted independently with alkyl (e.g., methyl, ethyl, propyl, n-butyl) or aryl groups (e.g,, phenyl with alkyl substituents).

[0092] The nitrogen-containing heterocycle can comprise an imidazole having the formula (6):

wherein; R25, Rae, R27, R¾ _f and Rasare each independently hydrogen, halide, alkyl, alkenyl, alkynyl or aryl, and the alkyl, alkenyl, alkynyl or aryl are optionally

substituted with halide. Preferably, Rss is hydrogen, F½ is 2,4,8~alkylphenyl, and R25, R26, and R27 are each independently Ci-Cg alkyl. An example of an imidazole as the nitrogen-containing heterocycle is 1-butyl~2-mesliyl-4,5-dirnethyl-1 H-lmidazole- imidazoie which has the formula;

[0093] The nitrogen-containing heterocycle can be a optionally substituted pyrrole, pyrroHne, pyrazole, pyrazoisne, imidazole, imidazoline, triazole, pyridine, triazine, pyrazine, pyridazine, pyrimidine, azeplne, quinoline, piperidine, pyrrolidine, pyrazolidine, imidazolidine, azepane, tsoxazole, isoxazofine, oxazoie, oxazofine, oxadiazole, oxatriazoie, dioxazole, oxaztne, oxadiazine, isoxazolidine, morpholine, fhiazole, Isothiazole, oxafhiazole, oxathiazine, or caprolactam, wherein each substituent is independently alkyl, alkenyl, alkynyl, aryl, or aralkyl.

10094] A fourth aspect of the invention is an anion exchange polymer which comprises a reaction product of a base and any one of the polymers as described above in the first, second or third aspects of the invention.

[0095] Preferably, the base comprises a hydroxide-containing base such as sodium hydroxide or potassiu hydroxide; a bicarbonate-containing base such as sodium bicarbonate or potassium bicarbonate; or a carbonate-containing base such as sodiu carbonate or potassiu carbonate.

[0098] Representative anion exchange polymers include the following wherein x is 0.01-1 :

[0097] The in dazo!Sum tethered~poly(ary! aikyiene) polymer or imidazolium tethered-poSy(aryl~crovvn ether-alkylene) polymer can be an hydroxide exchange polymer comprising a poly{ary! aikyiene) or poly( aryl-crown ether-alkylene) backbone free of ether linkages, and having; water uptake of not more than 47% based on the dry weight of the polymer when immersed in pure water at 80 °C; or hydroxide conductivity in pure water at 20 °C of at least 31 mS/cm, Also, the polymer can be; stable to degradation (as evidenced by no change in the Ή NMR spectra) when immersed in 1 1Vt potassium hydroxide at 130 °C for 1 ,200 hours; stable to

degradation (as evidenced by no change in the ^! H NMR spectra) when immersed in 10 M potassium hydroxide at 80 °C for 300 hours; stable to degradation (as evidenced by no change in the ¹ H NMR spectra) when kept at relative humidity of 23.3% and 50.9% at 95 °C for 300 hours; insoluble in pure water and isopropanoi at 100 , but soluble in a 50/60 mixture by weight of water an ethanol at 100 °C.

Also, the polymer can have a tensile strength of at least 30 MPa and/or elongation at break of at least 250%.

[0098] Uptake of the imidazo!ium tethered-polyiaryi-crown ether-alkylene) polymer can be no more than 47% when the polymer is crosslinked with a

crossiinking agent or is chemically bound to a membrane. For example, the water uptake of po!ycrown ethe r-CF3~T A (also known as PCE-C5-QA-1 ) of Example 10 was 384% and of poly(aryl-crown ether-alkylene) -CF3-I of Example 7 was about 200% when measured, but can be decreased by crosslinking or chemically binding the polymer to a membrane.

[0099] Crossiinking agents for use in crosslinking any of the polymers described herein include, for example, dibromoaSkanes (dibromohexanes,

dibromobutane), diiodoaikanes (diiodohexanes, diiodobutane), and ammonium cation-containing dibromoaikaoes and diiodoaikanes.

[00100] The imidazolium tethered-poly(aryl aikyiene) polymer or imidazoSium tethered-po!y(aryi~crown ether-alkylene) polymer can be an hydroxide exchange polymer comprising an imidazoiium-tethered poiy(aryl aikyiene) or poly(aryi~crown ether-alkylene) backbone free of ether Iinkages, and having a peak power density of at least 130 mW/crrt ² when the polymer is used as an hydroxide exchange

membrane of an hydroxide exchange membrane fuel cell and is loaded at 20% as an hydroxide exchange ionomer in cathodic and anodic catalyst layers of the fuel cell, the fuel cell having 0.4 mgpt cm ^-3 PtRu/C on anode, 0.4 mgpi cm ^-3 PtRu/C on cathode and test conditions being hydrogen flow rate of 1 0 L/min, oxygen flow rate of 2.0 L/min, ceil temperature of 95 °C _; and anode and cathode humidifier

temperature at 90 °C, and 97“C, respectively.

[00101] Preferably, the ary! linkages of the imidazoSium tethered-po!y(aryl alkylene) polymer backbone free of ether linkages comprise p-phenyl, and the alkylene linkages comprise hydroxide bicarbonate or carbonate anions, or a combination thereof. The ImidazoSium tefhered~poly{aryl~crown ether-aikylene) polymer backbone free of ether linkages also preferably comprises dibenzo-18~ crown-6, dibenzo-21 -crown-7 polyether, dibenzo-24-crown~8 poiyether, or dibenzo- 30-crown-IO poiyether

[00102] The aryl linkages of the imidazoiium tethered-polyfaryl afky!ene) polymer backbon can be derived, for example, from biphenyl, para-terphenyl, meta- terphsnyi, para-quaterphenyL S,9-dimethyl-9/74iuorene, or benzene monomers. The imidazoiium tethered-poly(ary!-crown ether-aikylene) polymer backbone free of ether linkages can be derived, for example, from d ibenzo- 18-crown~6 , dibenzo-21 -crown-7 poiyether, dibenzo~24~crown-8 poiyether, or dibenzo-30-erown~1O poiyether.

[00103] The alkylene linkages of the imidazoiium teihered-po!y{aryf alkylene) backbone are derived from 7-bromo-l ,1 ,1-tnfluorGheptan-2-one monomers.

[00104] The imidazoiium tethered-polyfaryi alkylene) polymer backbone or imidazoiiu tethered-poly{aryl-crown ether-aikylene) polymer backbone can further comprise 2,2,2-trifluoroethylbenzene linkages derived from 2,2,2- trifSuoroaceiophenone monomer, or or triftuoromethy! methyiene linkages derived from trifluoromethyi ketone monomer, such as 1 ,1 ,1-trifluoropropane linkages derived from 1 ,1,1 -trifluoroacetone.

[0010S] A fifth aspect of the invention is a method of making an anion exchange polymer membrane comprising the anion exchange polymer in the fourth aspect of the invention. The method comprises; reacting the cation-functionalized trifluorokefone monomer, the optional trifluoromethyl ketone monomer, and the aromatic monomer and/or crown ether monomer in the presence of an organic solvent and a polymerization catalyst to form a cation-functionalized polymer;

dissolving the cation-functionalized polymer in a solvent to form a polymer solution; casting the polymer solution to form a polymer membrane; and exchanging anions of the polymer membrane with hydroxide, bicarbonate, or carbonate ions or a

combination thereof to form the anion exchange polymer membrane.

[00106J For example, a cation-functionalized frifluoroketone monomer such as an imtdazolium functionalized 7- bromo-l ,1 ,1 -trifluoroheptan-2-one, a optional trifSuoromethyf ketone monomer such as 2,2,2-trifluoroacetophenone or 1 ,1 ,1- trifSuoroacetone, and an aromatic monomer such as benzene, biphenyl, p-terphenyS, m-terphenyl or p-quaterphenyl or a crown ether monomer such as dibenzo-18- crown-6, dibenzo-21 -crown-7 polyether, dibenzo~24~Grown-8 po!yether, or dibenzo- 3G-crowrv10 polyether can be placed in a stirred container and dissolved or dispersed into an organic solvent A polymerization catalyst in a solvent can then be added dropwise over up to 80 minutes at -78 to 60 °C. Thereafter, the reaction is continued at this temperature for about 1 to about 120 hours. The resulting solution is poured slowly into an aqueous solution of ethanol. The solid obtained is filtered, washe with water and immersed in 1 M K2C03 at roo temperature for about 1 to 48 hours. Finally, the product is filtered, washed with water and dried completely under vacuum to form a cation-functionalized polymer. The cation functionalized polymer is then subjected to anion exchange, for example in 1 M KOH for hydroxide exchange, at about 20 to 100 °C for about 12 to 48 hours, followed by washing and immersion in DS water for about 12 to 48 hours under an oxygen-free atmosphere to remove residual KOH.

[001073 A representative reaction scheme for the fifth aspect of the invention is shown below, wherein Rs, Re, R?, Rs, and Rioo are each independentiy hydrogen, alkyl, aikenyl, phenyi or alkynyS, and the alkyl, aikenyi, phenyl or a! ynyi are optionally substituted with a halide; Rit is phosphoniu or nitrogen-containing heterocyeie; n is the number of repeat units in the polymer; q is 0-20; and x is 0.01-1 :

Ar

[00108] A sixth aspect of the invention is a method of making an anion exchange polymer membrane comprising the anion exchange polymer in the fourth aspect of the invention. The method comprises: reacting the halogenated trifiuoroketone monomer, the optional triftuoromethyl ketone monomer, and the aromatic monomer and/or crown ether monomer in the presence of an organic solvent and: a polymerization catalyst to form a halogen-functionalized polymer; reacting the halogen-functionalized polymer with the quaternary phosphonium compound or the nitrogen-containing heterocycle or a salt thereof in the presence of an organic solvent to form a cation-functionalized polymer; dissolving the cation- functionalized polymer in a solvent to form a polymer solution; casting the polymer solution to form a polymer membrane; and exchanging anions of the polymer membrane with hydroxide, bicarbonate, or carbonate ions or a combination thereof to form the anion exchange polymer membrane.

[00109] For example, a halogenated trifiuoroketone monomer such as 7~ bromo-1,1 ,1 -trifiuoroheptan-2~one, an optional trifluoromethyl ketone monomer such as 2,2,2-trlfluoroacetophenone or 1,1 ,1 -trifluoroacetone, and an aromatic monomer such as benzene, biphenyl, p-terphenyl, m-terphenyi or p-quaterphenyl or crown ether monomer such as dlbenzo-18~crown-8, ctibenzo-21 -crown-7 po!yether, dibenzo-24-crown-8 polyether, or dibenzo~30~crown-10 polyether can be placed in a stirred container and dissolved or dispersed into an organic solvent. A polymerization catalyst in a solvent can then be added dropwise over up to 60 minutes at -78 to 60 °C. Thereafter, the reaction is continued at this temperature for about 1 to about 120 hours. The resulting solution is poured slowly into an aqueous solution of ethanol. The solid obtained is filtered, washed with water and immersed in 1 M K2C03 at room temperature for about 1 to 48 hours. Finally, the product is filtered, washed with water and dried completely under vacuum to form a halogen- functionalized polymer.

[001181 The halogen functionalized polymer is then placed in a stirred container with the quaternary phosphonium compound or the nitrogen-containing heterocycle or a salt thereof such as a functionalized imidazole and dissolved or dispersed into an organic solvent, The reaction is continued at a temperature of about 50 to 100“C for about 1 to about 120 hours. The resulting solution is then cast to form a polymer membrane. The polymer membrane is then subjecte to anion exchange, for example in 1 M KQH for hydroxide exchange, at about 20 to 100 °C for about 12 to 48 hours, followed b washing and immersion in Dt water for about 12 to 48 hours under an oxygen-free atmosphere to remove residual KOH.

[00111] A representative reaction scheme for the sixth aspect of the invention is shown below, wherein Rs, Re, Rz, Rs. and Rico are eac independently hydrogen, alkyl, alkenyl, phenyl or a!kynyl, and the alkyl, alkenyl, phenyl or alkynyl are optionally substituted with a haiide; Rn is a quaternary ammonium or

phosphonium group or nitrogen-containing heterocyclic group as defined in the first aspect of the invention; n is the number of repeat units in the polymer; q is 0-20; and x is 0.01-1:

Ar =

[00112] A seventh aspect of the invention is an anion exchange membrane, optionally configured and sized to be suitable for use in a fuel cell, electrolyzer, electrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer , water purifier, waste water treatment system, ion exchanger, or CO2 separator, and comprising the anion exchange polymer of the fourth aspect of the invention

[00113] The anion exchange polymer can be made into reinforced hydroxide exchange membranes as described below. Such reinforced hydroxide exchange membranes can be prepared by a method which comprises wetting a porous substrate in a liquid to form a wetted substrate; dissolving the poSyfsry! a!ky!ene) polymer In a solvent to form a homogeneous solution; applying the solution onto the wetted substrate to form the reinforced membrane; drying the reinforced membrane; and exchanging anions of the reinforced membrane with hydroxide ions to form the reinforced hydroxide exchange polymer membrane. The solution can be applied to the wetted substrate by any known membrane formation technique such as casting, spraying, or doctor knifing.

[00114] The resulting reinforced membrane can be impregnated with the poSy(aryl atkylene) polymer multiple times if desired by wetting the reinforced membrane again and repeating the dissolving, casting and drying steps.

[00115] The polymerization catalyst used in forming the polymer can comprise trifluoromethanesulfonic acid, pentaf!uoroethanesuSfonic acid, heptafluoro- l-propanesuSfonic acid, trifluoroacetic acid, perfluoropropion c acid,

heptaflucrobutyric acid, or a combination thereof.

[00118] Each of the organic solvents used in the any of the above methods can be independently selected from polar aprotic solvents (e.g , dimethyl sulfoxide, l-methyl-S-pyrrolidinone, 1~methyi~2-pyrroiidone, t-methyS~2-pyrrofidooe, or dimethylformamide) or other suitable solvents including, but are not limited to, methylene chloride, trifluoroacetic acid, trifluoromethanesulfonic acid, chloroform, 1 _; 1,2 2 tetrachioroethane _s dimethySacefamide or a combination thereof.

[001173 The solvent in the dissolving step can comprise methanol, ethanol, n-propanol, isopropanoi, n-butanol, sec-butanol, tert-buianol, a pentanol, a hexanoS, dimethyl sulfoxide, 1 ~methyl-2~pyrrQ!idone, dimethylformamide, chloroform, ethyl lactate, tetrahydrofuran, 2-methyltetrahydrofuran, water, phenol, acetone, or a combination thereof,

[00118] The liqui used to wet the porous substrate can be a iow boiling point solvent such as a lower alcohol (e.g , methanol, ethanol, propanoi, isopropanoi) and/or water. Preferably, the liquid is anhydrous ethanol,

[00110] Additional aspects of the invention are described below.

[00120] An anion exchange membrane such as a hydroxide exchange membrane is also provided. The membrane is configured and sized to be suitable for use in a fuel cell, electrolyzer, electrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, water purifier, waste water treatment system, ion exchanger, or CO2 separator, and comprises any of the poly{aryi alkylene) polymers as described herein.

[00121] A reinforced electrolyte membrane such as a reinforced hydroxide exchange membrane is also provided to increase the mechanical robustness of the anion exchange membrane for stability through numerous wet an dry cycles

{relative humidity cycling) in a fuel cell. The membrane Is configured and sized to be suitable for use in a fuel cell, electrolyzer, electrodiaiyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, wafer purifier, waste water treatment system, ion exchanger, or CO2 separator, and comprises a porous substrate impregnated wit any of the po!y(aryt alkylene) polymers as described herein.

Methods for preparing reinforced membranes are well known to those of ordinary skill in the art such as those disclosed in U.S. Patent Nos. REST, 656 and RE37,701, which are incorporated herein by reference for their description of reinforced membrane synthesis and materials.

[00122] The porous substrate can comprise a membrane comprised of pGiytetrafiuoroefhySene, polypropylene, polyethylene , poly(ether ketone),

poSyaryfetherketone, imidazolium-tethered poiyfaryi alkylene), imidazoSe -tethered poiy(aryf alkylene), poiysuifone, perfluoroalkoxyaikane, or a fiuorinated ethy!ene propylene polymer, or other porous polymers known in the art such as the

dimensionally stable membrane from Gioer for use in preparing reinforced

membranes for fuel cells. Such porous substrates are commercially available, for example, from W. . Gore & Associates.

[00123] The porous substrate can have a porous microstructure of polymeric fibrils. Such substrates comprised of poiytefrafSuoroethylene are commercially available. The porous substrate can comprise a microstructure of nodes

interconnected by fibrils.

[00124] The interior volume of the porous substrate can be rendered substantially occlusive by impregnation with the poly(aryi aikylene) polymer as described herein..

[00125] The porous substrate can have a thickness from about 1 micron to about 10, 15, 20, 25. 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100 microns. Preferably, the porous substrate has a thickness fro about 5 microns to about 30 microns, or from about 7 microns to about 20 microns.

[00126] An anion exchange membrane fuel cell, electrolyzer, electrodia!yzer, solar hydrogen generator, flow battery, desalinator, sensor, demsneralizer, water purifier, waste water treatment system, ion exchanger, or CQ¾ separator is also provided, the fuel cell, electrolyzer, eiectrodialyzer, solar hydrogen generator, flow battery, desalinator, sensor, demineralizer, water purifier, waste water treatment system, ion exchanger, or CO2 separator comprising the anion exchange polymer.

[00127] Polymers of the invention having high water uptake are useful as ionomers in electrolyzers or fuel cells if the polymers are adhered to a catalyst layer so as not to be washed away during operation of the electrolyzer or fuel ceil.

Adherence can be achieved by chemically binding the polymer to a membrane or catalyst layer within the electrolyzer or fuel cell, or by crosslinking the polymer with crosslinkers such as those described above. For example, functional groups on a polymer of the invention such as bromoa!kyi groups can be reacted with functional groups on a membrane, such as amine groups, to bind the polymer sonomer to the membrane,

[00128] When polymers of the invention are used as a membrane, it is preferred that th water uptake of the polymer ranges from about 20 to about 60% to maintain the mechanical strength of the membrane,

[00129] The poiy(aryl a!kySene) polymers or poly(aryS-crown ethen-alkylene) polymers can be used in HEMFCs such as a typical fuel cell 10 as shown in Figure 1A- Figure 1A illustrates a typical fuel cell 10 with an anode portion 12 (illustrated on the left) and a cathode portion 14 (illustrated on the right) whic are separated by an electrolyte membrane 16. The electrolyte membrane 16 can be any membrane comprising any of the polyfaryl alkylene) polymers or poiy(ary!~crown ether-aSkylene) polymers as described herein, an can be a reinforced membrane. Supporting members are not illustrated, The anode portion carries out an anode half-reaction which oxidizes fuel releasing electrons to an external circuit and producing oxidized products. The cathode portion carries out a cathode half-reaction which reduces an oxidizer consuming electrons from the external circuit The gas diffusion layers (GDLs) 18 and 20 serve to deliver the fuel 22 and oxidizer 24 uniformly across the respective catalyst layers 26 and 28. Charge neutrality is maintained by a flow of ions from the anode to the cathode for positive ions and from cathode to anode for negative tons. The dimensions illustrated are not representative, as the electrolyte membrane is usually selected to be as thin as possible while maintaining the membrane’s structural integrity.

[00130] In the case of the illustrated hydroxide exchange membrane fuel ceil (HEMFC), the anode half-reaction consumes fuel and OH- ions arid produces waste water (as well as carbon dioxide in the case of carbon containing fuels). The cathode half reaction consumes oxygen and produces OH- ions, which flow from the cathode to the anode through the electrolyte membrane. Fuels are limited only by the oxidizing ability of the anode catalyst and typically include hydrogen gas, methanol, ethanol, ethylene glycol, and glycerol. Preferably, the fuel is H2 or methanol. Catalysts are usually platinum (Ft), silver (Ag), or one or more transition metals, e.g„ Ni In the case of a PEMFC, the anode half-reaction consumes fuel and produces H+ ions and electrons. The cathode half reaction consumes oxygen, H+ ions, and electrons and produces waste water, and H+ ions (protons) flow from the anode to the cathode through the electrolyte membrane.

[00131 J It can, therefore, be appreciated how an electrolyte membrane made from a po!y(aryl aikylene) polymer or pQiy{aryi~crown ether-alkylene) polymer significantly improves fuel ceil performance. First, greater fuel cell efficiency requires Sow internal resistance, and therefore, electrolyte membranes with greater ionic conductivity (decreased ionic resistance) are preferred. Second, greater power requires greater fuel ceil currents, and therefore, electrolyte membranes with greater ion-current carrying capacity are preferred. Also, practical electrolyte membranes resist chemical degradation and are mechanically stable In a fuel cell environment, and also should be readily manufactured.

[00132] The poly(aryl aikylene) polymers or poiy(aryl~crown ether-alkylene) polymers can be used In HEMELs such as an electrolyzer 30 as shown in Figure IB, Figure 18 illustrates an electrolyzer 30 with an anode portion 32 (illustrated on the left) and a cathode portion 34 (illustrate on the right) which are separated by an electrolyte membrane 38 The electrolyte membrane 36 can be any membrane comprising any of the polyiaryl aikylene) polymers or poly(aryl~crown ether-alkylene) polymers as described herein, and can be a reinforced membrane. Supporting members are not illustrated. The anode portion carries out an anode half-reaction which oxidizes ions releasing electrons to an external circuit and producing oxidized products. The cathode portion carries out a cathode half-reaction which reduces an oxidizer consuming electrons from the external circuit. The gas diffusion layers (GDIs) 38 and 40 serve to release the oxidizer 42 and fuel 44 uniformly across the respective catalyst layers 46 and 48, Charge neutrality is maintained by a flow of ions from the anode to the cathode for positive tons and from cathode to anode for negative ions. The dimensions illustrated are not representative, as the electrolyte membrane is usually selected to be as thin as possible while maintaining the membrane’s structural integrity.

[00133] In the case of the illustrated hydroxide exchange membrane fuel cell (HEMFG), the anode haif-reaction consumes OH- ions and produces oxygen. The cathode half reaction consumes water and produces hydrogen and OH~ ions, which flow from the cathode to the anode through the electrolyte membrane. Fuels are limited only by the oxidizing abilit of the cathode catalyst and typically include hydrogen gas, methanol, ethanol, ethylene glycol, and glycerol. Preferably, the fuel is Ffe or methanol. Catalysts are usually platinum (Ft), silver (Ag), or one or more transition metals, e.g., Ni.

[00134] It can, therefore, be appreciated how an electrolyte membrane made from a poiyfaryf alkylene) polymer or poly{aryl-crown ether-alkylene) polymer significantly improves electrolyzer performance. First, greater electrolyzer efficiency requires low internal resistance, and therefore, electrolyte membranes with greater ionic conductivity (decreased ionic resistance) are preferred. Second, greater fuel production requires greater electrolyzer currents, and therefore, electrolyte membranes with greater ion-current carrying capacity are preferred. Also, practical electrolyte membranes resist chemical degradation and are mechanically stable in an electrolyzer environment, and also should be readily manufactured.

[80135] Although a principal application for the poty{ary! alkylene) polymers or polyCaryhcrown ether-alkylene) polymers is for energy conversion such as in use in anion exchange membranes, hydroxide exchange membranes, anion exchange membrane fuel cells, and hydroxide exchange membrane fuel ceils, the

anion/hydroxide exchange tonomers an membranes can be used for many other purposes such as use in fuel ceils (e.g., hydrogen/atcoho!/ammonia fuel cells);

electrolyzers (e.g., water/carbon dioxide/ammonia electrolyzers), eiectrodia!yzers; ion-exchangers; solar hydrogen generators; desalinators (e.g., desalination of sea/brackish water); demineralizers (e.g,, demineralization of water); water purifiers (e.g., ultra-pure water production); waste water treatment systems; concentration of electrolyte solutions in the food, drug, chemical, and biotechnology fields; electrolysis (e.g., chlor-aikaSi production and H2/G2 production); energy storage (e.g,, super capacitors, metal air batteries and redox flow batteries); sensors (e.g., pH/RH sensors); and i other applications where an anion-conductive lonomer is

advantageous.

[08136] Also provided is a reinforced electrolyte membrane, optionally configured and sized to be suitable for use in a fuel ceil, electrolyzer, eSectrodialyzer, solar hydrogen generator, flow battery, desalinator, sensor, deminerailzer, water purifier, waste water treatment system, Jon exchanger, or CO2 separator. The membrane comprises a porous substrate impregnated with the anion exchange polymer. [00137] Having described the invention in detail, It will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims,

EXAMPLES

[00138] The following non-limiting examples are provided to further illustrate the present invention

EXAMPLE 1

[00139] An Imidazolium-tethered polyiaryi alkylene) polymer was prepared from 7-bromo~1 ,1,t~infiuoroheptan~2-one, 1 ,1.1-tritluoroacetone and biphenyl (referred to as BP~CF3~iM~x, wherein x is the mole ratio of 7-bromo-l ,1 ,1- trifluoroheptan~2-one to biphenyl and is from 1 to 100), BP~CF3-l -x was prepared by three major steps: (1) synthesis of a bromide-functionalized polymer, (2) synthesis of an imidazolium-functionaSized polymer, and (3) membrane casting and hydroxide exchange. The reaction scheme is depicte below, wherein n is the number of repeat units in the polymer:

[00140] (1 ) Synthesis of the bromide-functionalized polymer CF3-Br-1 ).

To a 100 ml three-necked flask equipped with overhead mechanical stirrer, 7- bromo~1 A1~trifluoroheptan-2-one (3 000 g, 12,1 mmol) and biphenyl (1.560 g, 10.1 mmol) were dissolved Into methylene chloride (6,7 ml), Thfluorameihanesulfonie acid (TFSA) (6.7 ml) were then added dropwise over 30 minutes at 0 "C

Thereafter, the reaction was continued at this temperature for 24 hours. The resulting viscous, brown solution was poured slowly into ethanol The precipitated solid was filtered, washed with water and immersed in 1 M K2CO3 at room:

temperature for 12 hours. Finally, the product was filtered, washed with water and dried completely at 60 °G under vacuum. The yield of the polymer was nearly 100% ¹ H WMR (CDCIs, ¾ ppm): 7.58 (Hz, 4H), 7,36 (Hi, 4H), 3.33 (Hs, 2H), 2.45 (FU, 2H), 1.80 (Hs, 2H), 1.45 (H?, 2H) and 1.27 (He, 2H) (see Figure 2).

[00141] (2) Synthesis of lmidazoSium-functionafized polymer (BP-CF3-IM-1) To a 50 mL one-necked flask equipped with magnetic bar. the bromide- functionalized polymer (2,0 g, 5.2 mmol) and the imidazole (1.7 g, 6.3 mmol) were added into NMP (37 ml). The solution was stirred over 12 hours 75 ^':, C, The resulting yellow solution was used to cast a membrane. The membrane was washed consequently three times with hydrochloride solution (pH 1) and DI water, and dried completely at 80 ^a O under vacuum. The yield of the polymer BP-CF3-SM-1 was almost 100%. 1 H NMR {DMSO~d6, d, ppm): 7.70 (H2, 4H), 7.29 (H1, 4H), 7.02 (H3, 2H), 3.67 (H4, 4H), 2.27-2.19 (H5, H6, H12, 11 H), 1.89 (H7, 6H), 1.38-107 (H8 _S H9, HI 0, 10H), 0.68 (H11 3H) (see Figure 3),

[001423 (8) BP-CF3-IM-1 membrane casting and hydroxide exchange.

Membrane was prepared by dissolving the BP-CF3-IM-1 polymer (1.0 g) in NMP (10 ml) and casting on a clear glass plat at 80 ^ft C for 8 hours. The membrane (in bromide form) was peeled off from a glass plate in contact with deionized (DI) water. The membrane in hydroxide form was obtained by ion exchange in 1 M KOH at 60 °C for 24 hours, followed by washing and immersion in DI water for 48 hours under argon to remove residual KOH,

[00143J Other BP-CFS-SM-x membranes are prepared by using different mole ratios of 7-bromo-1,1,1-ihfluoroheptan-2-one to biphenyl,

[00144J (4) Alkaline stability. Alkaline stability of the imidazoliem containing polymer was evaluated under various conditions to probe its high chemical stability. BP-CF3-IM-1 membrane was immersed into 1 M KOH water solution at 130 °C for 1200h and the 1 H NMR spectra showed no change before and after the alkaline test (Figure 4A). TP-CF3-I -1 membrane was immersed into 10 M KOH solution at 80 °C for 300h and no degradation was observed based on the 1 H HMR spectra shown in Figure 4B. Moreover, TP-CF3-SM-1 membrane kept for 30Gh at 95 ^'5 C under low relative humidity (RH) of 23.3% and 50.9%, respectively, also di not shown sign of degradation as shown in Figure 4C These results strongly suggested that highly alkaline stable imidazofium cation tethered to a rigid poiyfaryl alkylene) polymer backbone structure can indeed yield remarkable chemical stability HEMs,

[00145] (5) Water uptake and hydroxide conductivity. An ideal material for HEMs/HE is should have good Ion conductivity with low water uptake. All membranes are expecte to show very high conductivity in pure water. For example, at 20 °C the hydroxide conductivity of a BP-CF3~IM-x polymer is expected to be much greater than PSFQN (the benchmark HEM) which has an JEC value of 36 mS/cm. PSFQN is derived from benzyl fhmethy! ammonium polysulfone and has the formula:

[00145] Increasing the temperature also enhances the hydroxide conductivity of the membrane samples.

[00147] (6) Solubility and mechanical properties. The BP-CF3-IM-X polymers are expected to exhibit excellent solubility in dsmethylformamide, - methyi pyrrol idone, dimethyl sulfoxide, and isopropanoS/water (1/1 weight ratio), but are expected not to dissolve in pure water and isopropanol.

[00148] (?) Hydroxide exchange membrane fuel cell (HEMFG) performance. Although BP-CF3-IM-X polymer membranes are expected to have superior chemical stability, hydroxide conductivity, low water uptake, good solubility and mechanical properties, the most practical evaluation of these materials is their performance in HEMFG single cells as an HEI in the catalyst layer and as the HEM. Membrane- electrode assemblies (MEAs) can be fabricated by depositing 5 cm ³ electrode onto both sides of a BP-CF3-IM-X polymer membrane with a robotic sprayer (Sono-Tek ExactaCoat), The electrode ink is prepared by adding 250 g of catalyst (Tanaka Kiksnzoku Kogyo, or TKK, 50% Pt on hsgh-surfaoe-area C) and a desired amount of ionomer (a BP-GF3-IM-X polymer, prepared by dissolving the BP-CFS-IM-x polymer In a water and isopropanol mixture) to 10 g of water an 10 g of isopropanol, followed by sonicating for 1 hour. The catalyst loading is 0.4 mg Pt/cm ² . The sandwich is completed by adding a rubber gasket, a GDI (SGL25CC), and a graphite flow field (ElectroGhem) to each side of the MBA Performance is

characterized with a fuel ceil test system equipped wit a bac pressure module (Scribner S50e). Normally, the cell is activated for 30 minutes at 100 m A/cm ² and another 30 minutes at 200 m A/cm ² . After activation, performance is recorded by scanning current.

EXAMPLE 2

[00149] An imidazoSium-tethered poly(aryl aSkylene) polymer was prepared from 7-brorno-1 ,1,1-trlfluorohepian-2~one, 1 ,1,1~trifJuoroacetone and p-lerphenyl (referred to as TP~CF3~flV1~x, wherein x is the mole ratio of 7~bromo~1 ,1 ,1- trif!uoroheptan-2-one to p-terphenyl and Is from 1 to 100). TP~CF3~HVi~x was prepared by three major steps: (1 ) synthesis of a bromide-functionalized polymer, (2) synthesis of an imidazoliurn-functionalized polymer, and (3) membrane casting and hydroxide exchange. The reaction scheme is depicted below, wherein n is the number of repeat units in the polymer:

[00150] (1) Synthesis of a bromide-functionalized polymer (TP~CF3~Br-1 .

To a 100 ml three-necked flask equipped with overhead mechanical stirrer, 7- bromo-1 , 1 ,1-¾ifiuoroheptan-2-one (3.600 g _t 14.6 mmol) and p~ terphenyl (2197 g, 12.1 mmol) were dissolved into methylene chloride (30 mL). TrifiuoromethanesuSfonic add (TFSA) (30 ml) was then added dropwise over 30 minutes at 0 °C, Thereafter, the reaction was continued at this temperature for 24 hours. The resulting viscous, brown solution was poured slowly into ethanol. The precipitated solid was filtered, washed with water and immersed in 1 M K2CO3 at room temperature for 12 hours. Finally, the product was filtered, washed with water and dried completely at 60 °C under vacuum. The yield of the polymer was nearly 100%. ¹ H NMR (CDCia, 6, ppm): 7 O (His, 4H), 7.62 (Hi, 4H), 7.40 (H¾ 4H), 3.34 (H4, 2H), 2.47 (H12, 2H), 1.82 (He, 2H), 1.47 (H10, 2H), 1.30 (He, 2H) (Figure 5).

[001513 (2) Synthesis of imidazolium-functionalized polymer (TP-CF3-iM-T). To a 50 ml one-necke flask equippe wit magnetic bar, the bromide- functionalized polymer (2.0 g, 4,4 mmol) and the functionalized imidazole (1.5 g, 5 5 mmol) were adde into NMP (25 ml). The solution was slimed over 12 hours 75°C. The resulting yellow solution was used to cast a membrane. The membrane was washed consequently three times with hydrochloride solution (PH ~ 1 ) and Dl water, and dried completely at 60 °C under vacuum. The yield of the polymer TP~GF3-IM-x was almost 100%. tH NMR (DMSO~d6, d, ppm): 7.80 (H13. 4H), 7J2 (H1 , 4H), 7.30 (H2, 4H), 7.05 (H3, 4H), 3.69-3.67 (H4, 4H), 2.29-2 23 (H5, H6, H12, 11H), 1.91 (H7, 6H), 1.38-1.01 (H8, H9, H10, 10H), 0.68 (H11, 3H) (Figure 6).

[00152] (3) TP-GF3-IM-X membrane casting and hydroxide exchange.

Membrane was prepared by dissolving the TP-CF3-iM-x polymer (1.0 g) in NMP (10 ml) and casting on a clear glass plate at 80 °C for 8 hours. The membrane (in bromide form) was peeled off from a glass plate in contact with deionized (Dl) water. The membrane in hydroxide form was obtaine by ion exchange in 1 M KOH at 60 ^:' G for 24 hours, followed by washing and immersion in Dl water for 48 hours under argon to remove residual KOH.

[00153] (4) Water uptake and hydroxide conductivity. When x -1 , TP~CF3~ IM-1 has conductivity of 31.4 mS/cm at 20 ' C. It has low water uptake and

dimensional swelling ratio in bicarbonate form (as shown in Table 1 } in pure water fro 20 °C to 80 °C. TABLE 1. Water uptake and dimensional swelling ratio of TP~CF3~1M~1 membrane

[001543 (5) Hydroxide exchange membrane fuel cell (HEMFCI performance. Although TP-CF3-IM-X polymer membranes are expected to Have superior chemical stability, hydroxide conductivity, low water uptake, good solubility and mechanical properties, the most practical evaluation of these materials is their performance in HEMFC single cells as an HEl in the catalyst layer an as the HEM. Membrane- electrode assemblies (MEAs) can be fabricated by depositing 5 cm ² electrode onto both sides of a TP-CF3~iM~x polymer membrane with a robotic sprayer (Sono-Tek ExactaCoat) The electrode ink is prepared by adding 250 mg of catalyst (Tanaka Kikinzoku Kogyo, or TKK, 50% Ft o high-surface-area C) and a desired amount of ionomer (a TP-CF3-IM-x polymer, prepared by dissolving the BP-CF3-IM-X polymer in a water and isopropanol mixture} to 10 g of water and 10 g of isopropanol, followed by sonicating for 1 hour. The catalyst loading is 0.4 gpt cm ² PtRu/C on anode, 0.4 mgpt cm ^"2 PtRu/C on cathode. The sandwich Is completed by adding a rubber gasket, a GDI (SGL25CC), and a graphite flow field (ESectroGhem) to each side of the MEA. Performance is characterized with a fuel cell test system equipped with a back pressure module (Scribner B50e}( Materials: TP100-CF3-iM-1

membrane, ionomer loading of 20 %, catalyst: 0.4 mgpt cm ^"2 PtRu/C on anode, 0.4 mgpt cm ² PtRu/C on cathode. Test conditions: 95 °C, anode humidifier temperature: 90 , cathode anode humidifier temperature; 97 X, Hz How rate; 1.0 l/min, O2 flow rate: 2.0 L/min.). Normally, the cell is activated for 30 minutes at 100 mA/cm ² and another 30 minutes at 200 mA/cm ² . After activation, performance is recorded by scanning current. Results are shown in Figure 8.

[00155J (8¾ Hydroxide exchange membrane electrolyzer fHEMEU

performance. Although TP~CF3~IM~x polymer membranes are expected to have superior chemical stability, hydroxide conductivity, tow water uptake, good solubility an mechanical properties, the most practical evaluation of these materials is their performance in HEMEL cells as an HEl in the catalyst layer and as the HEM.

Membrane-electrode assemblies (MEAs) were fabricated by depositing 5 cm ² electrode onto both sides of a TP~CF3~!M~x polymer membrane with a robotic sprayer (Sono-Tek ExactaCoat) The electrode ink was prepared by adding 250 mg of catalyst {Tanaka Kikinzoku Kogyo, or TKK, 50% Pt on high-surface-area C) and a desired amount of ionomer (a TP-CFS-IM-x polymer, prepared by dissolving the TP- CF3-IM-X polymer in a water and ethano! mixture) to 10 g of water and 10 g of ethanol, followed by sonicating for 1 hour. The catalyst loading was 4 mg Pi/cm ² . Pt- coated Ti plate and TGF-H-060 Toray carbon paper (5% wet proofing) were the gas diffusion layers for the anode and cathode sides, respectively. The cell and deionized water temperatures were kept at a constant temperature. Performance was characterized with an Arbin testing system (Materials: TP100-GF3-IM-1 membrane, ionomer loading of 30 %, catalyst: 4.0 gas cm ^"2 Pt/C on anode, 2.9 mg cm ^'2 Ir0 ₂ on cathode. Test conditions: 80 for water and electrolyzer, water flow rate: 3.0 mL/nm). Normally, the cell was activated for 30 minutes at 100 mA/cm ² and another 30 minutes at 200 mA/cm ² . After activation, performance was recorded by scanning current. Resuits are shown in Figure 9.

EXAMPLE 3

[00156] Another im idazoii u m -tethered poly (aryl alkylene) polymer is prepared from 7 -bromo-1 _; 1 , l-tnik.iaroheptan-2-one, 1,1 ,1 -trifiuoroacefone and m- terphenyi (referred to as mTF-CF3-IMi-x, wherein x is the mole ratio of 7-bromo- 1 ,1 _s 1-trifluoroheptan-2-one to biphenyl and is from 1 to 100). mTP-CF3-!M-x is prepared by three major steps similar to that of TP-CFS-IM-x: (1 ) synthesis of a bromide-functionalized polymer, (2) synthesis of a imidazolium-functsonalized polymer, and (3) membrane casting and hydroxide exchange. The reaction scheme is depicted below, wherein n is the number of repeat units in the polymer:

EXAMPLE 4

Another method of preparing the BP-CF3-IM-X polymer of Example 1 is from the reaction of imidazoSium functlonai!zed 7~bromo-1 ,1 _> 1-trifluoraheptan-2-one, 1 ,1 ,1- trifluoroacetone and biphenyl (referred to as BP~CF3~I ~x, wherein x is the mole ratio of imidazolium functionalized 7-bromo-1 ,1 ,1 -trifluoroheptan-2-one to biphenyl and is from 1 to 100), BP-CF3-1M-X is prepared by two major steps: (1) synthesis of an imidazoiium-functionaSized polymer, and (2) membrane casting and hydroxide exchange. The reaction scheme is depicte below, wherein n is the number of repeat units in the polymer:

EXAMPLE 5

[00157] Another method of preparing the TP-CF3-SM-X polymer of Example 2 is from the reaction of imidazolium functionalized 7~bromo-1 _t 1 ,1-trifluoroheptan-2- one, 1,1 ,1 -trifluoroacetone and p-terphenyi (referred to as TP-CFSdM-x, wherein x is the mole ratio of imidazolium functionalized 7~bromo-1 ,1,1 -tri l uorohep tan -2-one to p- terphenyl and is from 1 to 100). TP-CF3-IM-X is prepared by two major steps: (1) synthesis of an imidazolium -functionalized polymer, and (2) membrane casting and hydroxide exchange. The reaction scheme is depicted below, wherein n is the number of repeat units in the polymer:

EXAMPLE 6

[00158] Another method of preparing the m-TP~CF3-IM-x of Example 3 is from the reaction of imi azoiium functionalized 7-bromo-l ,1 _f 1-trifiuoroheptan-2-one, 1 _; 1 ,1 -trifiuoroacetone and m-terphenyi (referred to as mlP-CFS-IM-x, wherein x is the mole ratio of imidazoiium functionalized 7~bromo~1 ,1 ,1~tnfiuoroheptan~2-one to m-terpbenyl and is from 1 to 100). mTP-CF3~!M~x is prepared by two major steps: (1 ) synthesis of an imidazo!ium-functiona!ized poiymer, and (2) membrane casting and hydroxide exchange. The reaction scheme is depicte below, wherein n is the number of repeat units in the poiymer:

EXAMPLE 7

[00159| An imidazoiium-tethered poly{crown ether) polymer was prepared from 7~bromO _" 1 ,1 , 1-infiuoroheptan-2~one, 1 ,1 ,1 -trifl uoroace!one and dibenzo-18- crown-6 (referred to as PCE-CS-IM-x, wherein x is the mole ratio of 7-bromo-1 ,1 ,1- trif!uoroheptan-2~one to dibenzo~18~crown~6 and is from 1 to 100). PCE~C5~SM~x was prepared by three major steps: (1 ) synthesis of a bromide-functionalized polymer, (2) synthesis of an irnidazo!ium-fundionalized polymer, and (3) membrane casting and hydroxide exchange. The reaction scheme is depicted below, wherein n is the number of repeat units in the polymer:

[00160] Synthesis of a bromide-functionalized polymer (PCE-C5-B ). To a mL three-necked flask equipped with overhead mechanical stirrer, dibenzo-18- crown-6 (7.2082 g, 20.00 mmol) and 7-bromQ~l1 -tj1fiuoroheptan-2~one (5.9294 g, 24.00 mmol) were suspended into chloroform (35 ml). TFSA (30 mL) was then added dropwtse slowly at -15 °C, Thereafter, the reaction was continued at 0 °C for 8 h. The resulting viscous solution was poured slowly into ethanol. The white fibrous solid was filtered, washed with water and Immersed in 1 M K2C03 at 50 ^S C for 12 h. Finally, the white fibrous product was filtered, washed with water and dried completely at 60 °0 under vacuum. The yield of the polymer was 95%. ¹ H NMR (CDCls, 5, ppm): 6.82-6.68 (6H), 4.15-3.96 (16H), 3.33(2H), 2.27 (2H), 1.76 (2H) _S 1.38 (2H), 115 (2 H) (see Figure 10)

[0016 ] Synthesis of imldazolium-functjonallzed polymer (FCE-C5-IM-Br-1 ) To a 50 L one-necked flask equipped with magnetic bar, th bromide- functionalized polymer (1.0 g, 1 7 mmol) and the imidazole (0.5 g, 1.9 mmol) were added into DMSO (20 mi). The solution was stirred over 24 hours 60°C. The resulting yellow solutio was used to cast a membrane. The membrane was washed consequently three times with hydrochloride solution (pH 1 ) and Dl water, and dried completely at 60 ^a O under vacuum. The yield of the polymer PCE-C5-!M-8r-i was 90%. 1H NMR (DMSO-d6, 6, ppm): 7.14 (2H), 6,91-6.61 (6H), 4.06-3.66 (20H), 2.34 (2H), 2.34-2.30 (9H) _f 194 (8H), 1.40-1.38 (6H), 116-1.14(4H) _! 0.72 (3H) (see Figure 11)

[00162] PCE-C5-1M OH-1 membrane casting and hydroxide exchange. Membrane was prepared by dissolving the PCE~C5~IIVf~Br~1 polymer (1 ,0 g) in NMP (10 mL) and casting on a clear glass plate at 80 °C for 8 hours. The membrane (in bromide form) was peeled off from a glass plate in contact with deionized (Dl) water. The membrane in hydroxide form was obtained by ion exchange in 1 M KGH at 60 °C for 24 hours, followed by washing and immersion in Dl water for 48 hours under argon to remove residual KOH. EXAMPLE 8

[00183] Another imidazo!iunvtethered poly {crown ether) polymer Is prepared from 7-bromo-1 ,1 d-thfiuoroheptan^-one, 1 , 1 ,1 drift uoroacetone and dibenzo-18- crown-6 (referred to as PCE~C5~SiVI~x, wherein x is the mole ratio of 7-bromo~1,1 ,1~ trifSuoroheptan-2~one to dibenzo~18~crown~8 and is from 1 to 100). PCE-C5-IM-X is prepared by three major steps similar to that of PCE-C5-IM-1 : (1 } synthesis of a bromide-functionalized polymer, (2) synthesis of an imidazoSium-functtonaSized polymer, and (3) membrane casting and hydroxide exchange. The reaction scheme is depicte below, wherein n is the number of repeat units in the polymer.

EXAMPLE 9

[00164] Another method of preparing the PCE-CS-IM-x of Example 8 is from the reaction of imidazolium functionalized 7 -bromo-1 ,1 ,1 ~trifluoroheptan-2-one , 1 ,1 ,1- trifluoroacetone and dsbenzo-18~crown-6 {referred to as PCE~C5~IM~x, wherein x is the mole ratio of imidazolium functionalized 7~bromo~1 ,1 ,1~tnfluoroheptan~2-one to PCE-CS-IM-x and is from 1 to 100). PCE~C5~ISVI~x is prepared by two major steps; (1) synthesis of an imidazolium -functionalized polymer, and (2) membrane casting and hydroxide exchange. The reaction scheme is depicted below, wherein n is the number of repeat units in the polymer;

EXAMPLE 10

£001853 A quaternary ammonium-tethered poly(crown ether) polymer was prepared from 7-brorno~1,1 ,i~tnfiuorohepfan~2-ane and dtbenzo~18~crown-6

(referred to as PCE~C5~QA-x, wherein x is the mole ratio of 7-bromo-1,1 ,i~ trifSuoroheptan-2~one to ibenzo~18~crown-6 and is from 1 to 100). PCE-C5~GA~x was prepared by three major steps: (1 ) synthesis of a brom ide~f u notion ai ized polymer, (2) synthesis of a quaternary ammonium-functionalized polymer, and (3) membrane easting and hydroxide exchange. The reaction scheme is depicted below, wherein n is the number of repeat units in the polymer:

EXAMPLE 11 [00166] A quaternary ammonium-tethered po!y(erown ether) polymer was prepared from 7 >roroo~1 , 1 , 1-trffiuorohej3tan-2-6ne, 11 ,1 -trifiuoroacetone and dfbenzo-18-crown-6 (referred to as PCE-CS-IM-x, wherein x is the mole ratio of 7- bfomo-i ^I-trifiuoroheptan-S-one to dibenzo-18-crown-6 and is from 1 to 100) PCE-C5-QA-X is prepared by three major steps: (1 ) synthesis of a bromide- funciiona Sized polymer, (2) synthesis of a quaternary ammonium-functionalized polymer, and (3) membrane casting and hydroxide exchange. The reaction scheme is depicted below, wherein is the number of repeat units in the polymer:

PCE-C5-QA_x DEFINITIONS

£001873 The term“suitable substituent,” as used herein, is intended to mean a chemically acceptable functional group, preferably a moiety that does not negate the activity of the inventive compounds. Such suitable substituents include, but are not limited to halo groups, perfluoroaSkyS groups, perfluoroalkoxy groups, alkyl groups, alkenyi groups, alkynyS groups, hydroxy groups, oxo groups, mercapto groups, a!kylthio groups, aSkoxy groups, aryl or heteroaryl groups, arytoxy or heteroaryloxy groups, aralkyl or heteroaralkyl groups, araSkoxy or heteroaralkoxy groups, HO~~{C 0}~~ groups, heterocylic groups, cycloalkyl groups, amino groups, alkyl - and diaikySamino groups, carbamoyl groups, aSkyScarbonyS groups,

alkoxycarbonyl groups, alkySaminocarbonyl groups, dia!kylamino carbonyl groups, arytcarbonyl groups, aryloxycarbonyS groups, alkylsufonyl groups, and arylsulfony! groups. Those skilled in the art will appreciate that many substituents can be substituted by additional substituents.

[001683 The term“alkyl,” as used herein, refers to a linear, branched or cyclic hydrocarbon radical, preferably having 1 to 32 carbon atoms (i.e., 1, 2, 3, 4, 5, 8, 7,

8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 39, 30, 31 , or 32 carbons), and more preferably having 1 to 18 carbon atoms. Alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, secondary-butyl, and tertiary-butyl. Alkyl groups can be unsubstituted or substituted b one or more suitable substituents.

[001893 The term“alkenyl,” as used herein, refers to a straight, branched or cyclic hydrocarbon radical, preferably having 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 39, 30, 31 , or 32 carbons, more preferably having 1 to 18 carbon atoms, and having one or more carbon-carbon double bonds. Alkenyi groups Include, but are not limited to, ethenyl, 1-propenyl, 2- propenyi (ailyl), iso-propenyS, 2-methyi-l -propenyl, 1 -butenyL and 2-butenyl. Alkenyl groups can be unsubstituted or substituted by one or more suitable substituents, as define above.

[601703 The term“alkynyl," as used herein, refers to a straight, branched or cyclic hydrocarbon radical, preferably having 2, 8, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 39, 30, 31 , or 32 carbons, more preferably having 1 to 18 carbon atoms, and having one or more carbon-carbon triple bonds, A!kynyl groups include, but are not limited to, ethynyl, propynyi, and butynyl. Aikynyi groups can be unsubstituted or substituted by one or more suitable substituents, as defined above

[80171] The term“ary!" or‘ ^' ary' as used herein atone or as part of another group (e.g , aralkyl), means monocyclic, bicyciie, or tricyciic aromatic radicals such as phenyl, naphthyl, tetrahydronaphthyi, indanyl and the like; optionally substituted by one or more suitable substituents, preferably 1 to 5 suitable substituents, as defined above. The term’’aryl" also Includes heteroaryl,

[00172] “Aryialkyl” or“aralkyl” means an aryl group attached to the parent molecule through an aikylene group. The number of carbon atoms in the aryl group and the aikylene group is selected such that there is a iota! of about 6 to about 18 carbon atoms in the aryialkyl group. A preferred aryialkyl group is benzyl.

[00173] The term“cycloaikyl," as used herein, refers to a mono, bicyciic or tricyclic carbocyciic radical (e.g„ cyclopropyf, cyclobutyl, cydopentyl, cyctohexyl, cycloheptyi, cyclooctyi, cyciononyf, cyciopentenyS, cyclohexenyl,

bicyclo[2,2.1]heptanyl, bicydo[3.2.1 joctanyl and bicycio[5.2.0]nonanyi, etc.);

optionally containing 1 or 2 double bonds. Cycloaikyl groups can be unsubstituted or substituted by one or more suitable substituents, preferably 1 to 5 suitable

substituents, as defined above.

[00174] The term“-ene” as used as a suffix as part of another group denotes a bivalent radical in which a hydrogen atom is removed from each of two terminal carbons of the group, or if the group is cyclic, from each of two different carbon atoms in the ring. Fo example, aikylene denotes a bivalent alkyl group such as ethylene (-CH2GH2-) or isoprppylene f-GH2{CH3)CH2-}. For clarity, addition of the ~ene sufftx is not intended to alter the definition of the principal wor other than denoting a bivalent radical. Thus, continuing the example above, aikylene denotes an optionally substituted linear saturated bivalent hydrocarbon radical.

[O017S] The term "ether" as used herein represents a bivalent (i.e , difunctionai) group including at least one ether linkage (i.e.,

[00178] The term“heteroaryl," as used herein, refers to a monocyclic, bicyciic, or tricyclic aromatic heterocyclic group containing one or more heteroatoms (e.g., 1 to 3 heteroatoms) selected from 0, S and N In the ring(s). HeteroaryS groups include, but are not limited to, pyridyS, pyrazinyS, pyrimidinyS, pyridazinyi, thienyl, furyl, Imidazolyi, pyrroiyt, oxazoiyi (e.g., 1 ,3-oxazoiyi, 1 ,2-oxazoSyl), thiazolyl (e.g., 1,2- ihiazolyi, 1 /S-thiazolyl), pyrazolyl, ietrazolyl, triazofyi (e.g., 1 ,2,3-triazolyl, 1 ,2,4- iriazolyl), oxadsazolyl (e.g., 1,2,3-oxadiazoiy!), thiadiazolyl (e.g., 1,3,4-thiadiazoSyl), quino!yl, isoqulnoiyl, benzoihienyl, benzofuryl, and indotyL Heteroaryl groups can be unsubstituted or substituted by one or more suitable substituents, preferably 1 to 5 suitable substituents, as defined above.

[00177] The term "hydrocarbon" as used herein describes a compound or radical consisting exclusively of the elements carbon and hydrogen.

[00178] The term 'substituted ' means that in the group in question, at least one hydrogen atom bound to a carbon atom is replaced with one or more substituent groups such as hydroxy (-OH), alkylthio, phosphino, amide (-CON(RA)(RB), wherein RA and RB are independently hydrogen, alkyl, or aryl), amino(~N(RA}(RB), wherein RA and RB are independently hydrogen, aikyi, or aryl), halo (fluoro, chioro, bromo, or iodo), silyt, nitro (-N02), an ether (~ORA wherein RA is alkyl or aryl), an ester OC(0)RA wherein RA is alkyl or aryl), keto (-C(O)RA wherein RA is aikyi or aryl), heterocycio, and the iike. When the term "substituted" introduces or follows a iist of possible substituted groups, il ls intended that the term apply to every member of that group. That is, the phrase“optionally substituted aikyi or ary!” is to be interprete as "optionally substituted alkyl or optionally substituted aryl.” Likewise, the phrase "aikyi or aryl optionally substituted with fluoride" is to be interpreted as "aikyi optionally substituted with fluoride or aryl optionally substituted with fluoride."

[00173] The term "tethered" means that the group in question is bound to the specified polymer backbone. For example, an imldazolium-tetbered poly (aryl alkylene) polymer Is a polymer having imidazo!ium groups bound to a poly (aryl alkylene) polymer backbone.

[00180] When introducing elements of the present invention or the preferred embodiments^) thereof, the articles "a”, "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including” and "having" are intended to be inclusive and mean that there may be additional elements other than the liste elements.

[00181] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. [00182] As various changes could be made in the above products and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.