Metal salt of poly(arylene ether) and uses thereof

Abstract

A copolymer includes a metal salt of a sulfonated poly(arylene ether) including particular amounts of repeating units of the formulas (I) wherein Z1, Z2, and X are as defined herein. The copolymer can be particularly useful as a selectively permeable separation membrane, for example for separating an olefin from an olefin-paraffin stream.

Description

METAL SALT OF POLY( ARYLENE ETHER) AND USES THEREOFCROSS REFERENCE TO RELATED APPLICATIONThis application claims priority to and the benefit of European Patent Application No. 24176888.6 filed May 20, 2024, the contents of which are hereby incorporated by reference in their entirety.BACKGROUND

[0001] Disclosed herein is a copolymer comprising a metal salt of a sulfonated poly(arylene ether) and methods for the manufacture thereof. Membranes and systems comprising the copolymer are also described.

[0002] Light olefins, such as propylene and ethylene, are produced as co-products from a variety of feedstocks in a number of different processes in the chemical, petrochemical, and petroleum refining industries. Various petrochemical streams contain olefins and other saturated hydrocarbons. Typically, these streams are from stream cracking units (ethylene production), catalytic cracking units (motor gasoline production), or the dehydrogenation of paraffins.

[0003] Previous methods of separating olefins from the streams include cryogenic distillation, which is expensive and energy intensive due to the low relative volatilities of the components. Large capital expense and energy costs have created incentives for extensive research in this area of separations, and low energy-intensive membrane separations have been considered as an attractive alternative.

[0004] Accordingly, there remains a continuing need in the art for improved selectively permeable separation membranes.SUMMARY

[0005] An aspect is a copolymer comprising a metal salt of a sulfonated poly(arylene ether) comprising 49 to 89 mole percent (mol%), preferably 55 to 85 mol%, more preferably 60 to 80 mol% of a first repeating unit of the formula10 to 50 mol%, preferably 15 to 40 mol%, more preferably 20 to 28 mol% of a second repeating unit of the formula1 mol% or less of a third repeating unit of the formula1 mol% or less of a fourth repeating unit of the formulawherein mole percent is based on the total moles of repeating units in the copolymer; and wherein in the foregoing formulas, Z1is independently at each occurrence hydrogen, a halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; Z2is independently at each occurrence a hydrogen, halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; and X is hydrogen, potassium, sodium, ammonium, or a transition metal having an electronegativity of 1.8 to 2.9; wherein in at least 90% of repeating units comprising a -SO3X moiety, X is the transition metal having an electronegativity of 1.8 to 2.9.

[0006] Another aspect is a selectively permeable separation membrane comprising the copolymer. The selectively permeable separation membrane can have a porosity of 0.5 cm3thO / gram of dry membrane or less.

[0007] Another aspect is a separation system for separating an olefin from an olefinparaffin stream, the separation system comprising the membrane.

[0008] Another aspect is a method for separating an olefin from an olefin-paraffin stream, the method comprising: contacting a first side of a membrane comprising the copolymerwith the olefin-paraffin stream; applying a pressure to cause the olefin to selectively permeate to a second side of the membrane; and collecting an olefin-enriched product stream.

[0009] The above described and other features are exemplified by the following figure and detailed description.BRIEF DESCRIPTION OF THE DRAWING

[0010] The following figure is an exemplary embodiment wherein the like elements are numbered alike.

[0011] The Figure is a schematic illustration of a separation system according to an aspect.DETAILED DESCRIPTION

[0012] To date, separation of olefins from paraffins via conventional polymer membranes has not been commercially successful due to inadequate selectivities and permeabilities of the polymer membrane materials, as well as due to plasticization issues. Polymers that are more permeable are generally less selective compared to less permeable polymers. Various polymers and techniques have been used, but without much success in terms of improving the membrane selectivity.

[0013] There have been efforts to form selectively permeable membranes by incorporation of metal ions. The high selectivity for olefin / paraffin separations can be achieved by the incorporation of metal ions such as silver (I) or copper (I) cations into the solid nonporous polymer matrix layer on top of the highly porous membrane support layer or directly into the pores of the highly porous support membrane that results in the formation of a reversible metal cation complex with the pi bond of olefins, whereas no interaction occurs between the metal cations and the paraffins. Addition of water, plasticizer, or humidification of the olefin / paraffin feed streams can often be necessary to obtain reasonable olefin permeances and high olefin / paraffin selectivities. Development of new stable, high permeance, and highly selective permeable membranes is still desired for the use of such membranes for olefin / paraffin separations.

[0014] Poly(arylene ether)s are commercially attractive materials because of their unique combination of physical, chemical, and electrical properties. Furthermore, the combination of poly(arylene ether)s with other polymers or additives provides blends which result in improved overall properties including chemical resistance, high strength, and high flow. As new commercial applications are explored, various sulfonated grades of poly(arylene ether) materialsare desired. The present inventors have discovered that sulfonated poly(arylene ether)s can be useful in providing the corresponding transition metal salt. The metal salt-containing poly(arylene ethers) were found to be particularly well suited for formation of robust membranes, and demonstrated to be useful in conducting olefin-paraffin separations. A significant improvement is therefore provided by the present disclosure.

[0015] Accordingly, an aspect of the present disclosure is a copolymer comprising a metal salt of a sulfonated poly(arylene ether). The copolymer comprises a first repeating unit having the structure (I)wherein Z1is independently at each occurrence hydrogen, a halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms and Z2is independently at each occurrence a hydrogen, halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms. In some aspects, each occurrence of Z1is not hydrogen. In an aspect, each occurrence of Z1is a methyl group. In an aspect, each occurrence of Z2is hydrogen.

[0016] The copolymer comprises 49 to 89 mole percent of the first repeating units according to the foregoing structure (I), wherein mole percent is based on the total moles of repeating units in the copolymer. Within this range, the copolymer can comprise 55 to 85 mole percent, or 60 to 80 mole percent of the first repeating units.

[0017] The copolymer further comprises a second repeating unit of the structure (II)wherein Z1and Z2can be as defined for the first repeating unit, and X is hydrogen, potassium, sodium, ammonium, or a transition metal having an electronegativity of 1.8 to 2.9, or an electronegativity of 1.8 to 2.6. At least a portion of X is the transition metal, for example in at least 90% of repeating units comprising a -SO3X moiety, X is the transition metal. It will beunderstood that the presence of potassium, sodium, or ammonium as X can be due to incomplete exchange of a potassium, sodium, or ammonium precursor material to the transition metal. In an aspect, each occurrence of Z1is a methyl group. In an aspect, each occurrence of Z2is hydrogen. In an aspect, the transition metal comprises silver, copper, gold, or a combination thereof, preferably silver.

[0018] The copolymer comprises 10 to 50 mole percent of the second repeating units according to the foregoing structure, wherein mole percent is based on the total moles of repeating units in the polymer. Within this range, the copolymer can comprise 15 to 40 mole percent, or 20 to 28 mole percent of the second repeating units. In an aspect, the copolymer comprises 0.1 to 30 weight percent of the transition metal. Within this range, the copolymer can comprise at least 0.5 weight percent, or 1 weight percent or 5 weight percent of the transition metal. Also within this range, the copolymer can comprise at most 25 most weight percent, at most 20 weight percent, or at most 15 weight percent, or at most 10 weight percent, or at most 5 weight percent.

[0019] The copolymer optionally further comprises a third repeating unit of the structure(III)wherein Z1and Z2can be as defined for the first repeating unit. In an aspect, each occurrence of Z1is a methyl group. In an aspect, each occurrence of Z2is hydrogen.

[0020] The copolymer comprises 1 mole percent or less of the third repeating units according to the foregoing formula. In an aspect, the copolymer may comprise zero mole percent of the third repeating units (i.e., the third repeating units are not present). In an aspect, the copolymer may comprise greater than 0 to 1 mole percent of the third repeating units.

[0021] The copolymer optionally further comprises a fourth repeating unit of the structure (IV)wherein Z1, Z2, and X can be as defined above. In an aspect, each occurrence of Z1is a methyl group. In an aspect, each occurrence of Z2is hydrogen. In an aspect, the transition metal comprises silver, copper, gold, or a combination thereof, preferably silver.

[0022] The copolymer comprises 1 mole percent or less of the fourth repeating units according to the foregoing formula. In an aspect, the copolymer may comprise zero mole percent of the fourth repeating units (i.e., the fourth repeating units are not present). In an aspect, the copolymer may comprise greater than 0 to 1 mole percent of the fourth repeating units.

[0023] Of the units comprising a -SO3X group (e.g., units according to formula (II) or (IV)), at least 90% comprise X being the transition metal having an electronegativity of 1.8 to 2.9, or an electronegativity of 1.8 to 2.6.

[0024] As used herein, the term “sulfonate repeating unit” refers to any repeating unit having a -SO3X group bound thereto, and include the sulfonate metal salt and other sulfonate derivatives (e.g., precursors to the sulfonate metal salt). In an aspect, the copolymer of the present disclosure has a high degree of monosulfonated repeating units. Stated another way, a majority of sulfonated repeating units of the sulfonated poly(phenylene ether) can have a single sulfonate / sulfonic acid group (i.e., a monosubstituted repeating unit). For example, at least 90% of the sulfonated poly(phenylene ether) repeating units are monosubstituted. It is noted that the term “monosubstituted” as used herein is not equivalent to “uniformly substituted”. The term “uniform substitution” refers to a sulfonated poly(phenylene ether) product having a certain degree of sulfonation that is uniform throughout the mass of the product. In contrast, “monosubstituted” as used herein means that a sulfonated poly(phenylene ether) product has a certain (uniform) degree of sulfonation across the mass of the product (for example, as determined byNMR), and further that at least 90% of the repeat units bearing a sulfonate group have only one sulfonate group. For example, a sulfonated poly(phenylene ether) product having a uniform degree of substitution of 20% means that the degree of substitution is 20% across the entire mass of the product. In the present application, a monosulfonated poly(phenylene ether) product having a degree of substitution of 20% means that, for example, out of the 20 repeat units which are sulfonated (assuming 100 repeat units total in the polymer for each of calculation), at least 90% of those 20 repeat units have only one sulfonate group (i.e., at least 18 of the 20 repeat units have one sulfonate group).

[0025] In some aspects, the polyphenylene ether (PPE) substrate comprises: 2,6- dimethyl-l,4-phenylene ether repeating units, 2,3,6-trimethyl-l,4-phenylene ether repeating units, 2,5-dimethyl-l,4-phenylene ether repeating units, 2,2’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether repeating units, 2- methyl-6-phenyl-l,4-phenylene ether repeating units, 2,2’-dimethyl-6,6’-diphenyl-4,4’- dihydroxybiphenyl ether repeating units, 2,6-diphenyl- 1 ,4-phenylene ether repeating units, 2,2’,6,6’-tetraphenyl-4,4’-dihydroxybiphenyl ether repeating units, 2,6-dimethoxy-l,4- phenylene ether repeating units, 2,2’ -6,6’ -tetramethoxy - 4,4’ -dihydroxybiphenyl ether, 3,3 ’,5,5’- tetramethyl-4, 4’ -dihydroxybiphenyl ether units, or a combination thereof. In some aspects, the sulfonated polyphenylene ether (sPPE) product comprises: 2,6-dimethyl-l,4-phenylene ether repeating units, 2,3,6-trimethyl-l,4-phenylene ether units, 2,5-dimethyl-l,4-phenylene ether repeating units, 2,2’,5,5’-tetramethyl-4,4’- dihydroxybiphenyl ether repeating units, 2- methyl-6-phenyl-l,4-phenylene ether repeating units, 2,2’-dimethyl-6,6’-diphenyl-4,4’- dihydroxybiphenyl ether repeating units, 2,6-diphenyl- 1 ,4-phenylene ether repeating units, 2,2’,6,6’-tetraphenyl-4,4’-dihydroxybiphenyl ether repeating units, 2,6-dimethoxy-l,4- phenylene ether repeating units, 2,2’ -6,6’ -tetramethoxy - 4,4’ -dihydroxybiphenyl ether, 3,3 ’,5,5’- tetramethyl-4, 4’ -dihydroxybiphenyl ether units, sulfonated derivatives of the same repeat units, or a combination thereof.

[0026] The copolymer can further have a total residual solvent content of less than 0.2 weight percent, based on the total weight of the copolymer. Residual solvent content can be determined using gas chromatography. In an aspect, the copolymer can have a total residual ethyl acetate content of less than 0.05 weight percent, based on the total weight of the copolymer, as determined using gas chromatography.

[0027] In a specific aspect, the copolymer can comprise 49 to 89 mole percent, preferably 55 to 85 mole percent, more preferably 60 to 80 mole percent of a first repeating unit of the structure (I)10 to 50 mole percent, preferably 15 to 40 mole percent, more preferably 20 to 28 mole percent of a second repeating unit of the structure (II)1 mole percent or less of a third repeating unit of the structure (III)1 mole percent or less of a fourth repeating unit of the structure (IV)wherein mole percent is based on the total moles of repeating units in the copolymer; and wherein X is hydrogen or silver, provided that at least 90% of the total occurrences of X is silver. In an aspect, the copolymer can have a total residual solvent content of less than 0.2 weight percent, based on the total weight of the copolymer, as determined using gas chromatography.

[0028] Poly(arylene ethers), sulfonated poly(phenylene ethers), and copolymers can be analyzed by proton nuclear magnetic resonance spectroscopyNMR) to determine whether structural details of the compositions. Specifically,NMR can distinguish between protons associated with internal and terminal phenylene ether groups, and with internal and terminal residues. It is therefore possible to determine the average number of phenylene ether repeating units per molecule, the degree of sulfonation, and the relative abundance of internal and terminal residues.

[0029] In an aspect, the copolymer according to the present disclosure can be made by a particular method. For example, the copolymer can be made by a method comprising contacting the poly(phenylene ether) with a sulfonating agent in the presence of a solvent and a cosolvent. In an aspect, the method comprises dissolving the poly(phenylene ether) in the solvent and the cosolvent to form a poly (phenylene ether) mixture. Mixing of the components of the mixture can be performed at temperatures of 10 to 60°C, for example 25 to 40°C. The solvent comprises 1 ,2-dichloroethane and is present in a sufficient quantity to dissolve the poly(phenylene ether). The amount of cosolvent is sufficient to prevent precipitation of the sulfonated poly(phenylene ether) before the desired degree of sulfonation has been attained.

[0030] The solvent mixture can comprise greater than or equal to 8 weight percent of the poly (phenylene ether), or greater than 10 weight percent of poly(phenylene ether), or greater than 12 weight percent of the poly(phenylene ether). Within this range, the solvent mixture can comprise 8 to 25 weight percent, preferably 8 to 20 weight percent, or 10 to 25 weight percent,or greater than 10 to 25 weight percent, or 10 to 20 weight percent, or 15 to 25 weight percent, or 15 to 20 weight percent of the poly(phenylene ether), each based on the total weight of the poly(phenylene ether), the sulfonating agent, the solvent, and the cosolvent.

[0031] The solvent (i.e., the 1 ,2-dichloroethane) can be present in the reaction in an amount of 60 to 99 weight percent, or 70 to 95 weight percent, or 70 to 85 weight percent, each based on the total weight of the poly(phenylene ether), the sulfonating agent, the solvent, and the cosolvent.

[0032] The cosolvent can be present in the reaction in an amount of 7 to 15 weight percent based on the total weight of the solvent and the cosolvent. For example, the cosolvent can be present in an amount of 8 to 12 weight percent. In an aspect, the cosolvent can be present in an amount of at least 10 weight percent, for example 10 to 15 weight percent, or greater than 10 to 15 weight percent, or 11 to 15 weight percent, or 12 to 15 weight percent, each based on the total weight of the solvent and the cosolvent.

[0033] The poly(phenylene ether) is reacted with a sulfonating agent to sulfonate the poly(phenylene ether). The sulfonation can be performed at a temperature of up to 85°C, e.g., 10 to 60°C, or 25 to 40°C. The amount of sulfonating agent added to the reaction mixture can be selected to provide a weight ratio of sulfonating agent to poly(phenylene ether) of less than 0.5:1. For example, a weight ratio of sulfonating agent to poly(phenylene ether) can be 0.1:1 to 0.45:1, or 0.2:1 to 0.4:1. In an aspect, the sulfonating agent can be added slowly to the reaction mixture, e.g., added over a period of 15 minutes (min.) to 60 min., (e.g., over a period of 30 mins.). Once the sulfonating agent is added to the solvent mixture, the solvent mixture can be stirred, e.g., for a period of time of 60 to 210 mins., prior to proceeding to isolation of the sulfonated product or to formation of the corresponding metal salt.

[0034] The sulfonated poly(phenylene ether) can optionally be isolated from the mixture prior to forming the metal salt. Alternatively, the mixture can be used directly without purification of the sulfonated poly(phenylene ether) intermediate.

[0035] The method further comprises contacting the mixture comprising the sulfonated poly(phenylene ether) with a transition metal precursor to provide the metal salt of a sulfonated poly(arylene ether). Contacting with the transition metal precursor can be, for example, 5 to 25°C, or 5 to 15°C. The mixture can be stirred e.g., for a period of time of 60 to 210 minutes, prior to proceeding to isolation of the metal salt product. Suitable transition metal precursors can be selected by a person having skill in the art and guided by the present disclosure. For example, when a silver salt of a sulfonated poly(phenylene ether) is desired, AgNCh can be used as the silver precursor.

[0036] The method can further comprise isolating the metal salt of the sulfonated poly(phenylene ether) from the mixture. For example, once the poly(phenylene ether) has been sulfonated, the sulfonated poly(phenylene ether) can be precipitated from the solvent mixture using an anti-solvent mixture, e.g., containing de-ionized (DI) water and an organic solvent. As the organic solvent, hexane, heptane, cyclopentane, or cycloheptane can be used (along with deionized water) to cause the sulfonated poly(phenylene ether) to precipitate out of the reaction solvent mixture. In an aspect, the organic solvent should be immiscible with water and does not form an azeotrope with 1 ,2-dichloroethane or ethyl acetate. Preferably, the organic solvent comprises cyclopentane or cycloheptane. In a specific aspect, the organic solvent is cyclopentane.

[0037] The reaction solvent mixture can be (e.g., slowly) added to the anti-solvent mixture, wherein the anti-solvent mixture can be used in an amount sufficient to induce precipitation. For example, 100 grams (g) reaction mixture can be added to 300 to 700 g, preferably 390 to 595 g, of the anti-solvent mixture. In an aspect, the antisolvent can have an organic solvent to water weight ratio of 1:1 to 1:1, or 1:2 to 1:5, or 1:3 to 1:4.5.

[0038] The precipitated metal salt of the sulfonated poly(phenylene ether) can be filtered, and optionally washed and dried. The filtrate can be diphasic with the 1 ,2- dichloroethane, cosol vent, and optionally organic(s) (e.g., cyclohexane or cycloheptane) that were part of the anti-solvent mixture, as the organic phase and water as the aqueous phase. Hence, the filtrate can be further processed to recover at least one of the 1,2-dichloroethane, the cosolvent, or water; preferably to recover 1,2-dichloroethane and the cosolvent, more preferably to recover 1,2-dichloroethane, the cosolvent, and the water. Recovering the materials can comprise decanting the diphasic filtrate to form an aqueous stream and an organic stream. The organic stream can be further processed, e.g., distilled, to recover the 1,2-dichloroethane or the cosolvent. The recovered materials can be recycled. Selection of the antisolvent so as not to form an azeotrope with 1 ,2-dichloroethane or ethyl acetate as described herein can advantageously result in increased recovery of solvent or cosolvent for recycling and reuse in subsequent processes.

[0039] Acidity of the copolymers influences their properties and suitability for applications such as use in membranes. Table 1 illustrates how degree of sulphonation (DS) and formation of metal salts relate to acidity of the compositions as measured by ion exchange capacity (IEC).Table 1:IEC is a measure of the acidity from the -SO3H groups in pure protonic form of sulphonated poly (phenylene ether). The IEC values indicate that the exemplary sulphonated poly (phenylene ethers) have acidity in the range of 1.3 to 1.6 milliequivalents per gram. After conversion to the silver salts, the -SO3H groups were converted to the corresponding silver salts thereby reducing the acidity to 0.002 to 0.04 milliequivalents per gram. This change in acidity demonstrates that at least 90% of the -SO3H group acidic hydrogens were exchanged for metal ions. In some aspects, the sulphonated poly(arylene ether) has an IEC of less than 2.5, less than 2.1, less than 2, less than 1.8, less than 1.6, or less than 1.5 meq / g. In some aspects, the metal salt of the sulphonated poly(arylene ether) has an IEC of less than 1, less than 0.1, less than 0.06, less than 0.05, or less than 0.04 meq / g.

[0040] The IEC of sulfonated PPE is the maximum amount of ion (H+) that the polymer can exchange in a solution. The IEC indicates the number of milli-equivalents of ions in 1 g of the dry polymer. The method involves stirring a known quantity of sPPE in known volume of 2M sodium chloride solution for 2-3 hours (hr). During this process all the H+ ions are replaced by sodium ion from the sodium chloride solution and form hydrochloric acid, which can be quantified by titration with a known standard of sodium hydroxide. From the volume of hydrochloric acid generated the ion exchange capacity is determined.

[0041] The copolymer of the present disclosure comprising repeating units comprising a sulfonate metal salt can be particularly well suited for use as a selectively permeable separation membrane. A membrane can be formed, for example, by preparing a solution comprising the copolymer and forming a thin layer of the copolymer solution using any suitable layer- forming technique. The layer can be dried to provide a free-standing polymer membrane comprising the copolymer.

[0042] The selectively permeable membrane comprising the copolymer according to the present disclosure can have, for example, a density of 1 to 1.5 grams per cubic centimeter (g / cc), for example 1.1 to 1.3 g / cc, or 1.15 to 1.25 g / cc, or 1.2 g / cc and a porosity of 0.25 to 1 cm3FEO / gm dry membrane, for example 0.35 to 0.65 cm3FEO / gm dry membrane, or 0.4 to 0.6 cm3EEO / gm dry membrane, or 0.45 to 0.55 cm3EEO / gm dry membrane, or 0.48 to 0.52 cm3EEO / gm dry membrane, or 0.5 cm3EEO / gm dry membrane.

[0043] The selectively permeable membrane comprising the copolymer according to the present disclosure can be particularly well suited for use in a method for separating an olefin from an olefin-paraffin stream. The olefin-paraffin stream can be a liquid stream or a gaseous stream, and comprises an olefin and a corresponding paraffin. Exemplary olefin-paraffin streams can be, for example, gaseous streams comprising 1 to 99 mole percent of a C2-8 olefin and 1 to 99 mole percent of a C1-8 paraffin. Liquid olefin-paraffin streams are also contemplated. Exemplary liquid olefin-paraffin streams can be, for example, liquid streams comprising 1 to 99 mole percent of a C5-20 olefin and 1 to 99 mole percent of a C5-20 paraffin. The streams can be produced from, for example, stream cracking, catalytic cracking, the dehydrogenation of paraffins, and the like. In an aspect, the olefin may comprise, for example, ethylene, propylene, butylene, or heptane and the paraffin may comprise ethane, propane, butane, or heptane, respectively. The olefin / paraffin feed comprises a first concentration of olefin and a first concentration of paraffin depending on the application for which the membrane separation is used.

[0044] The method comprises contacting a first side of the membrane comprising the copolymer with the olefin-paraffin stream, and applying a pressure to cause the olefin to selectively permeate to the second, opposite side of the membrane. Contacting the first side of the membrane with the olefin-paraffin stream can be, for example, at a temperature of less than 50°C, for example 10 to 40°C, or 20 to 30°C. A pressure differential is maintained between the first and second sides of the membrane. For example, the second side can be maintained at vacuum or at any pressure that is less than the pressure of the first side. In an aspect, the pressure differential can be 1 to 5 bar, for example 2 to 3 bar.

[0045] The olefin enriched product stream can be collected (e.g., from the second side of the membrane). The olefin-depleted (i.e., paraffin rich) stream can be collected (e.g., from the first side of the membrane. The olefin-depleted stream has a concentration of olefin that is significantly lower than the initial concentration of the olefin-paraffin stream, and that is much lower than the olefin concentration in the olefin-enriched stream. The olefin-depleted stream also has a concentration of paraffin that is higher than the initial concentration of paraffin in the feed stream.

[0046] Advantageously, the olefin-enriched product stream resulting from the present method can have a high degree of purity, for example a purity of at least 95 volume percent, based on the total volume of the product stream. Stated another was, the olefin-enriched productstream can comprise at least 95 volume percent of the olefin, based on the total volume of the olefin-enriched product stream. Conversely, 5 volume percent or less of the total volume of the product stream can be the paraffin.

[0047] A separation system for separating an olefin from an olefin-paraffin stream represents another aspect of the present disclosure. The separation system comprises the membrane comprising the copolymer according to the present disclosure.

[0048] For example, referring to the Figure, a separation system (100) can comprise a first fluid chamber (101) adjacent to a first side (104) of the membrane (103), and a second fluid chamber (102) adjacent to a second, opposite side (105) of the membrane (103). A first fluid port (106) is in fluid communication with the first fluid chamber (101) and is configured to provide the olefin-paraffin stream to the first fluid chamber. A second fluid port (107) is in fluid communication with the first fluid chamber and configured to remove a paraffin-enriched stream from the first chamber. A third fluid port (108) is in fluid communication with the second fluid chamber (102) and configured to remove an olefin-enriched stream from the second fluid chamber.

[0049] This disclosure is further illustrated by the following examples, which are nonlimiting.EXAMPLESExample 1

[0050] Poly(2,6-dimethyl-, 1,4-phenylene ether) (75 grams (g)) was dissolved in 1,2- dichloroethane (300 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 500 milliliter (ml) glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 28.875 g chloro-sulfonic acid (CSA) was added slowly over a period of 30-40 minutes maintaining the temperature of the reactor at 60 °C to achieve the target degree of sulfonation (DS %) of 28 to 30%. The degree of sulfonation can be determined byNMR. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 meters per second (m / s)).

[0051] Once the reaction was completed, the product was isolated. The reaction mass from the Example 1 (90 g) was quickly added to a 1 liter baffled precipitation reactor with pitched blade turbine containing 360 g of water and 90 g of n-hexane, maintained at 8 to 10 °C and 420 rpm. The slurry formed was maintained under agitation for 1 hour followed by filtration of the solid. Wet cake produced by filtration was further washed using the same reactor having216 g of water and 54 g of n-hexane under an agitation of 300 rpm for 1 hour to remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final product. After washing, the wet cake was dried in a vacuum oven at 25 °C and a pressure of 10 to 20 millibar (mbar) vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 2

[0052] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45° pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 38.5 g chloro-sulfonic acid (CSA) was added slowly over a period of 30-40 min maintaining the temperature of the reactor at 60 °C to achieve the target DS % of 28 to 30%, as determined by NMR. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 m / s).

[0053] Once the reaction was completed, the product was isolated. Reaction mass from Example 2 (520 g) was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of water and 520 g of cyclopentane, maintained at 8 to 10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm for 2 hours to remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final wet cake. The washed cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 3

[0054] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 38.04 g chloro-sulfonic acid (CSA) was added slowly over a period of 30 to 40 minutes maintaining temperature of reactor to 60 °C to achieve target DS % of 28 to 30%, as determined by NMR. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 m / s).

[0055] Once the reaction was completed, the product was isolated. Reaction mass from the Example 3 (520 g) was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of water and 520 g of cyclopentane, maintained at 8 to 10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm, 2 hours remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final wet cake. This cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 4

[0056] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 35.35 g chloro-sulfonic acid (CSA) was added slowly over a period of 30-40 minutes maintaining temperature of reactor to 60 °C to achieve target DS % of 24 to 26%. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 m / s).

[0057] Once the reaction was completed, the product was isolated. Reaction mass from Example 4 (520 g), was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm, 2 hours remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final wet cake. This cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 5

[0058] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 35.0 gchloro-sulfonic acid (CSA) was added slowly over a period of 30-40 minutes maintaining temperature of reactor to 60 °C to achieve target DS % of 24 to 26%. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 m / s).

[0059] Once the reaction was completed, the product was isolated. Reaction mass from the Example 5 (520 g), was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of water and 520 g of cyclopentane, maintained at 8 to 10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm for 2 hours remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final wet cake. This cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 h to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 6

[0060] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60 °C for 60 min under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 26.35 g chloro-sulfonic acid (CSA) was added slowly over a period of 30 to 40 minutes maintaining temperature of reactor to 60 °C to achieve target DS % of 20 to 22%. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 m / s).

[0061] Once the reaction was completed, the product was isolated. Reaction mass from the Example 6 (520 g), was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of IM silver nitrate in water having and 520 g of cyclopentane, maintained at 8 to 10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm for 2 hours remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final wet cake. This cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 7

[0062] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 27.67 g chloro-sulfonic acid (CSA) was added slowly over a period of 30-40 min maintaining temperature of reactor to 60 °C to achieve target DS % of 20 to 22%. The reaction was conducted for 2 h after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94 m / s).

[0063] Once the reaction was completed, the product was isolated. Reaction mass from the Example 7 (520 g) was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of IM silver nitrate in water and 520 g of cyclopentane, maintained at 8 to 10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm for 2 hours remove the residuals at 25 °C. This washing process was carried out five times to get the desired residual solvent content in the final wet cake. This cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 8

[0064] Poly(2,6-dimethyl-, 1,4-phenylene ether) (100 g) was dissolved in 1,2- dichloroethane (400 g) and ethyl acetate (33 g) at 60° C for 60 minutes under stirring using a 1 liter glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 27.67 g chloro-sulfonic acid (CSA) was added slowly over a period of 30-40 minutes maintaining temperature of reactor to 60° C to achieve target DS % of 20 to 22%. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94m / s).

[0065] Once the reaction was completed, the product was isolated. Reaction mass from the Example 8 (520 g) was quickly added to a 5 liter non-baffled precipitation reactor with pitched blade turbine containing 2080 g of IM silver nitrate in water and 520 g of cyclopentane, maintained at 8 to 10 °C and 750 rpm. The slurry formed was maintained under agitation for 2 hours followed by filtration of the solid. Wet cake produced was further washed using the same reactor having 1248 g of water and 312 g of cyclopentane under an agitation of 170 rpm for 2 hours remove the residuals at 25 °C. This washing process was carried out five times to get thedesired residual solvent content in the final wet cake. This cake was further dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.Example 9

[0066] Poly(2,6-dimethyl-, 1,4-phenylene ether) (75 g) was dissolved in 1,2- dichloroethane (300 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 500 ml glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 21.6 g chloro-sulfonic acid (CSA) was added slowly over a period of 30 to 40 minutes maintaining temperature of reactor to 60 °C to achieve target DS % of 20 to 22%. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94m / s).

[0067] Once the reaction was completed, the product was isolated. Reaction mass from the Example 9 (90 g) was quickly added to a 1 liter baffled precipitation reactor with pitched blade turbine containing 360 g of IM silver nitrate in water and 90 g of cyclopentane, maintained at 8 to 10 °C and 420 rpm. The slurry formed was maintained under agitation for 1 hour followed by filtration of the solid. Wet cake produced was analyzed for residual solvents without subsequent drying.Example 10

[0068] Poly(2,6-dimethyl-, 1,4-phenylene ether) (75 g) was dissolved in 1,2- dichloroethane (300 g) and ethyl acetate (33 g) at 60 °C for 60 minutes under stirring using a 500 ml glass reactor (inner diameter = 9 centimeters (cm)) with a 45°pitched blade turbine impeller (diameter = 6 cm) in a laboratory setup. Once the solution was homogeneous and clear, 21.6 g chloro-sulfonic acid (CSA) was added slowly over a period of 30 to 40 minutes maintaining temperature of reactor to 60 °C to achieve target DS % of 20 to 22%. The reaction was conducted for 2 hours after addition of CSA with continuous agitation (300 rpm, tip spccd=0.94m / s).

[0069] Once the reaction was completed, the product was isolated. Reaction mass from the Example 10 (90 g) was quickly added to a 1 liter baffled precipitation reactor with pitched blade turbine containing 360 g of IM silver nitrate in water and 90 g of cyclopentane, maintained at 8 to 10 °C and 420 rpm. The slurry formed was maintained under agitation for 1 hour followed by filtration of the solid. Wet cake produced was dried in a vacuum oven at 25 °C and 10 to 20 mbar vacuum for 70 to 90 hours to get the final sulfonated PPE powder with a moisture content of less than 5 weight percent.

[0070] Degree of sulfonation (DS) or sulfonation level of the sulfonated PPE powders can be calculated fromNMR measurement of the aliphatic or aromatic protons. For example, after assigning the DMSO solvent peak at 2.5 ppm, integrating the resonance of the aromatic protons of unsubstituted poly(phenylene oxide) at 6.47 ppm (I2) and aromatic protons of the substituted poly(phenylene oxide) units at 6.05 ppm (I3), and integrating the resonance of the aliphatic protons of unsubstituted poly(phenylene oxide) at 2.01 ppm (I7) and aliphatic protons of the substituted poly(phenylene oxide) units (E & E’ at 2.4 and 1.89 ppm, respectively). The DS can be calculated by either of the following equations:DS (%) = 7- -TT - (considering aromatic hydrogens) (i)(0.5+Z2)+^3DS2(%) = “ (considering aliphatic hydrogens) (ii)I&+I?Table 2 shows a representative calculation for a sample with a DS% near 20, such as Examples 6-10 where DS% is 20-22%. The integrals I2 and I3 correspond to the mole percents of unsubstituted and substituted moieties of the sulfonated PPO. Calculated DS% relates to IEC of pure protonic form and IEC of metal salt form as illustrated in Table 1. Examples 1-3 are correlated with DS% 28.1 and 29.9 in Table 1, Examples 4 and 5 are correlated with DS% 24.6 and 25.6 in Table 1, and Examples 6-10 are correlated with DS% 19.7 and 21.4 in Table 1.Table 2:

[0071] Membranes comprising the foregoing sulfonated poly(phenylene ethers) and silver salts thereof were prepared according to the following general procedure. For Examples 1-5, appropriate solutions of the sulfonated poly(phenylene ether) or their corresponding sodium salts were prepared in a 90:10 (by weight) mixture of N-methyl-2-pyrrolidone:acetone mixture at 15 wt% solids. The solutions were cast into 200 micron films using a thin film applicator using a doctor's blade. The dried films were immersed into 10% percent aqueous silver nitrate solutions overnight and then washed with deionized water. For Examples 6-10, appropriate solutions of the silver salts of sulfonated polyphenylene ether resins were prepared in a 90:10 (by weight) mixture of N-methyl-2-pyrrolidone:acetone mixture at 15 wt% solids. The solutionswere cast into 200 micron films using a thin film applicator using a doctor's blade. The dried films were then washed with deionized water.

[0072] Olefin separation using a membrane comprising a silver salt of a sulfonated poly(phenylene ether) according to Example 9 was performed. The performance and process conditions are shown in Table 3.Table 3

[0073] As shown in Table 3, the silver salts of the sulfonated poly(phenylene ether) according to the present disclosure can provide effective olefin separation membranes. In particular, the silver salts of sulfonated poly(phenylene ether) were observed to be particularly promising for use in ethylene separation from ethane, yielding high purity of the isolated ethylene. For use in propylene separation, moderate purity of the isolated propylene was observed.

[0074] This disclosure further encompasses the following aspects.

[0075] Aspect 1: A copolymer comprising a metal salt of a sulfonated poly(arylene ether) comprising 49 to 89 mol%, preferably 55 to 85 mol%, more preferably 60 to 80 mol% of a first repeating unit of the formula10 to 50 mol%, preferably 15 to 40 mol%, more preferably 20 to 28 mol% of a second repeating unit of the formula1 mol% or less of a third repeating unit of the formula1 mol% or less of a fourth repeating unit of the formulawherein mole percent is based on the total moles of repeating units in the copolymer; and wherein in the foregoing formulas, Z1is independently at each occurrence hydrogen, a halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; Z2is independently at each occurrence a hydrogen, halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; and X is hydrogen, potassium, sodium, ammonium, or a transition metal having an electronegativity of 1.8 to 2.9; wherein in at least 90% of repeating units comprising a -SO3X moiety, X is the transition metal having an electronegativity of 1.8 to 2.9, preferably wherein the copolymer has an ion exchange capacity less than 1, more preferably less than 0.1, even more preferably less than 0.05.

[0076] Aspect 2: The copolymer of aspect 1, wherein at least 90% of repeating units comprising a -SO3X moiety have a single -SO3X moiety per repeating units.

[0077] Aspect 3: The copolymer of aspect 1 or 2, wherein the copolymer comprises 0.1 to 30 weight percent of the transition metal.

[0078] Aspect 4: The copolymer of any of aspects 1 to 3, wherein the transition metal comprises silver, copper, gold, or a combination thereof, preferably silver.

[0079] Aspect 5: The copolymer of any of aspects 1 to 4, wherein the copolymer is made by a method comprising: contacting a poly(phenylene ether) with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a cosolvent comprising ethyl acetate to provide a mixture comprising the sulfonated poly(phenylene ether); and contacting the mixture comprising the sulfonated poly(phenylene ether) with a transition metal precursor to provide the metal salt of a sulfonated poly( arylene ether); wherein the poly(phenylene ether) is present in an amount of greater than or equal to 8 weight percent, based on the total weight of the poly(phenylene ether), the sulfonating agent, the solvent, and the cosolvent, preferably wherein the poly(phenylene ether) is present in an amount of 8 to 25 weight percent; the cosolvent is present in an amount of 7 to 15 weight percent based on the total weight of the solvent and the cosolvent; and wherein the sulfonating agent is present in a weight ratio of sulfonating agent to poly(phenylene ether) of less than 0.5:1, preferably 0.1:1 to 0.45:1.

[0080] Aspect 6: The copolymer of aspect 5, wherein contacting the mixture with the metal precursor is further in the presence of an antisolvent comprising water and an organic solvent that is immiscible with water and does not form an azeotrope with 1 ,2-dichloroethane or ethyl acetate to form a slurry comprising a precipitated metal salt of the sulfonated poly(phenylene ether); and isolating the metal salt of the sulfonated poly(phenylene ether).

[0081] Aspect 7: The copolymer any of aspects 1 to 6, wherein each occurrence of Z2is hydrogen; and each of Z1is a methyl group.

[0082] Aspect 8: The copolymer of any of aspects 1 to 7, wherein the copolymer comprises 49 to 89 mol%, preferably 55 to 85 mol%, more preferably 60 to 80 mol% of a first repeating unit of the formula10 to 50 mol%, preferably 15 to 40 mol%, more preferably 20 to 28 mol% of a second repeating unit of the formula1 mol% or less of a third repeating unit of the formula1 mol% or less of a fourth repeating unit of the formulawherein mole percent is based on the total moles of repeating units in the copolymer; and wherein X is hydrogen or silver, provided that at least 90% of the total occurrences of X is silver.

[0083] Aspect 9: The copolymer of aspect 8, wherein the copolymer has a total residual solvent content of less than 0.2 weight percent, based on the total weight of the copolymer, as determined using gas chromatography; and wherein the copolymer is made by a method comprising: contacting a poly (phenylene ether) with a sulfonating agent in the presence of a solvent comprising 1 ,2-dichloroethane and a cosolvent ethyl acetate to provide a mixture comprising the sulfonated poly (phenylene ether), wherein the poly (phenylene ether) is present in an amount of 8 to 25 weight percent, based on the total weight of the poly(phenylene ether), the sulfonating agent, the solvent, and the cosolvent; the cosolvent is present in an amount of 7 to 15 weight percent based on the total weight of the solvent and the cosolvent; and the sulfonating agent is present in a weight ratio of sulfonating agent to poly(phenylene ether) of 0.1:1 to 0.45:1; and adding the mixture comprising the sulfonated poly(phenylene ether) to an antisolvent comprising water, an organic solvent that is immiscible with water and does not form an azeotrope with 1 ,2-dichloroethane or ethyl acetate, and a metal precursor to form a slurry comprising a precipitated copolymer comprising the metal salt of the sulfonated poly(phenylene ether); and isolating the precipitated copolymer comprising the metal salt of the sulfonated poly (phenylene ether).

[0084] Aspect 10: A selectively permeable separation membrane comprising the copolymer of any of aspects 1 to 9, wherein the selectively permeable separation membrane has a porosity of 0.5 cm3tfcO / gram of dry membrane or less.

[0085] Aspect 11: A separation system for separating an olefin from an olefin-paraffin stream, the separation system comprising the membrane of aspect 10.

[0086] Aspect 12: The separation system of aspect 11, comprising a first fluid chamber adjacent to a first side of the membrane; a second fluid chamber adjacent to a second, opposite side of the membrane; a first fluid port in fluid communication with the first fluid chamber and configured to provide the olefin-paraffin stream to the first fluid chamber; a second fluid port in fluid communication with the first fluid chamber and configured to remove a paraffin-enriched stream from the first chamber; and a third fluid port in fluid communication the second fluid chamber and configured to remove an olefin-enriched stream from the second fluid chamber.

[0087] Aspect 13: A method for separating an olefin from an olefin-paraffin stream, the method comprising: contacting a first side of a membrane comprising the copolymer of any of aspects 1 to 9 with the olefin-paraffin stream; applying a pressure to cause the olefin to selectively permeate to a second side of the membrane; and collecting an olefin-enriched product stream.

[0088] Aspect 14: The method of aspect 13, wherein the olefin-enriched product stream comprises the olefin in an amount of at least 95 volume percent, based on the total volume of the olefin-enriched product stream.

[0089] Aspect 15: The method of aspect 13 or 14, wherein the olefin-paraffin stream comprises a pair of compounds selected from ethane and ethylene, propane and propylene, butane and butylene, and heptane and heptene.

[0090] The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate materials, steps, or components herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any materials (or species), steps, or components, that are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

[0091] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and / or” unless clearly stated otherwise. Reference throughout the specification to “an aspect” means that a particular element described in connection with the aspect is included in at least one aspect described herein, and may or may not be present in other aspects. The term “combination thereof’ as used herein includes one ormore of the listed elements, and is open, allowing the presence of one or more like elements not named. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various aspects.

[0092] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0093] Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0094] Compounds are described using standard nomenclature. For example, any position not substituted by any indicated group is understood to have its valency filled by a bond as indicated, or a hydrogen atom. A dash that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -CHO is attached through carbon of the carbonyl group.

[0095] As used herein, the term “hydrocarbyl”, whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue that contains only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when the hydrocarbyl residue is described as substituted, it may, optionally, contain heteroatoms over and above the carbon and hydrogen members of the substituent residue. Thus, when specifically described as substituted, the hydrocarbyl residue can also contain one or more carbonyl groups, amino groups, hydroxyl groups, or the like, or it can contain heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" means a branched or straight chain, saturated aliphatic hydrocarbon group, e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n- pentyl, s-pentyl, and n- and s-hexyl. “Alkenyl” means a straight or branched chain, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HC=CH2)). “Alkoxy” means an alkyl group that is linked via an oxygen (i.e., alkyl-O-), for example methoxy, ethoxy, and sec-butyloxy groups. "Alkylene" means a straight or branched chain, saturated, divalent aliphatic hydrocarbon group (e.g., methylene (-CH2-) or, propylene (-(CH2)3- )). “Cycloalkylene” means a divalent cyclic alkylene group, -CnH2n-x, wherein x is the numberof hydrogens replaced by cyclization(s). “Cycloalkenyl” means a monovalent group having one or more rings and one or more carbon-carbon double bonds in the ring, wherein all ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing the specified number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. “Arylene” means a divalent aryl group. “Alkylarylene” means an arylene group substituted with an alkyl group. “Arylalkylene” means an alkylene group substituted with an aryl group (e.g., benzyl). The prefix "halo" means a group or compound including one more of a fluoro, chloro, bromo, or iodo substituent. A combination of different halo atoms (e.g., bromo and fluoro), or only chloro atoms can be present. The prefix “hetero” means that the compound or group includes at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatom(s)), wherein the heteroatom(s) is each independently N, O, S, Si, or P. “Substituted” means that the compound or group is substituted with at least one (e.g., 1, 2, 3, or 4) substituents that can each independently be a C1-9 alkoxy, a C1-9 haloalkoxy, a nitro (-NO2), a cyano (-CN), a C1-6 alkyl sulfonyl (-S(=O)2-alkyl), a C6-12 aryl sulfonyl (-S(=O)2-aryl), a thiol (-SH), a thiocyano (-SCN), a tosyl (CH3C6H4SO2-), a C3-12 cycloalkyl, a C2-12 alkenyl, a C5-12 cycloalkenyl, a C6-12 aryl, a C7- 13 arylalkylene, a C4-12 heterocycloalkyl, and a C3-12 heteroaryl instead of hydrogen, provided that the substituted atom’s normal valence is not exceeded. The number of carbon atoms indicated in a group is exclusive of any substituents. For example -CH2CH2CN is a C2 alkyl group substituted with a nitrile.

[0096] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

Claims

CLAIMS1. A copolymer comprising a metal salt of a sulfonated poly(arylene ether) comprising49 to 89 mol%, preferably 55 to 85 mol%, more preferably 60 to 80 mol% of a first repeating unit of the formula10 to 50 mol%, preferably 15 to 40 mol%, more preferably 20 to 28 mol% of a second repeating unit of the formula1 mol% or less of a third repeating unit of the formula; and1 mol% or less of a fourth repeating unit of the formulawherein mole percent is based on the total moles of repeating units in the copolymer; and wherein in the foregoing formulas,Z1is independently at each occurrence hydrogen, a halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms;Z2is independently at each occurrence a hydrogen, halogen, unsubstituted or substituted C1-12 hydrocarbyl provided that the hydrocarbyl group is not tertiary hydrocarbyl, C1-12 hydrocarbylthio, C1-12 hydrocarbyloxy, or C2-12halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; andX is hydrogen, potassium, sodium, ammonium, or a transition metal having an electronegativity of 1.8 to 2.9; wherein in at least 90% of repeating units comprising a -SO3X moiety, X is the transition metal having an electronegativity of 1.8 to 2.9, preferably wherein the copolymer has an ion exchange capacity less than 1, more preferably less than 0.1, even more preferably less than 0.05.

2. The copolymer of claim 1, wherein at least 90% of repeating units comprising a -SO3X moiety have a single -SO3X moiety per repeating units, as determined byNMR.

3. The copolymer of claim 1 or 2, wherein the copolymer comprises 0.1 to 30 weight percent of the transition metal.

4. The copolymer of any of claims 1 to 3, wherein the transition metal comprises silver, copper, gold, or a combination thereof, preferably silver.

5. The copolymer of any of claims 1 to 4, wherein the copolymer is made by a method comprising: contacting a poly(phenylene ether) with a sulfonating agent in the presence of a solvent comprising 1 ,2-dichloroethane and a cosolvent comprising ethyl acetate to provide a mixture comprising the sulfonated poly(phenylene ether); and contacting the mixture comprising the sulfonated poly(phenylene ether) with a transition metal precursor to provide the metal salt of a sulfonated poly(arylene ether); wherein the poly(phenylene ether) is present in an amount of greater than or equal to 8 weight percent, based on the total weight of the poly(phenylene ether), the sulfonating agent, the solvent, and the cosolvent, preferably wherein the poly(phenylene ether) is present in an amount of 8 to 25 weight percent; the cosolvent is present in an amount of 7 to 15 weight percent based on the total weight of the solvent and the cosolvent; and wherein the sulfonating agent is present in a weight ratio of sulfonating agent to poly(phenylene ether) of less than 0.5:1, preferably 0.1:1 to 0.45:1.

6. The copolymer of claim 5, wherein contacting the mixture with the metal precursor is further in the presence of an antisolvent comprising water and an organic solvent that is immiscible with water and does not form an azeotrope with 1 ,2-dichloroethane or ethyl acetate to form a slurry comprising a precipitated metal salt of the sulfonated poly(phenylene ether); andisolating the metal salt of the sulfonated poly(phenylene ether).

7. The copolymer any of claims 1 to 6, wherein each occurrence of Z2is hydrogen; and each of Z1is a methyl group.

8. The copolymer of any of claims 1 to 7, wherein the copolymer comprises49 to 89 mol%, preferably 55 to 85 mol%, more preferably 60 to 80 mol% of a first repeating unit of the formula10 to 50 mol%, preferably 15 to 40 mol%, more preferably 20 to 28 mol% of a second repeating unit of the formula1 mol% or less of a third repeating unit of the formula1 mol% or less of a fourth repeating unit of the formulawherein mole percent is based on the total moles of repeating units in the copolymer; and wherein X is hydrogen or silver, provided that at least 90% of the total occurrences of X is silver.

9. The copolymer of claim 8, wherein the copolymer has a total residual solvent content of less than 0.2 weight percent, based on the total weight of the copolymer, as determined using gas chromatography; and wherein the copolymer is made by a method comprising:contacting a poly(phenylene ether) with a sulfonating agent in the presence of a solvent comprising 1 ,2-dichloroethane and a cosolvent ethyl acetate to provide a mixture comprising the sulfonated poly (phenylene ether), wherein the poly(phenylene ether) is present in an amount of 8 to 25 weight percent, based on the total weight of the poly(phenylene ether), the sulfonating agent, the solvent, and the cosolvent; the cosolvent is present in an amount of 7 to 15 weight percent based on the total weight of the solvent and the cosolvent; and the sulfonating agent is present in a weight ratio of sulfonating agent to poly(phenylene ether) of 0.1:1 to 0.45:1; and adding the mixture comprising the sulfonated poly(phenylene ether) to an antisolvent comprising water, an organic solvent that is immiscible with water and does not form an azeotrope with 1,2-dichloroethane or ethyl acetate, and a metal precursor to form a slurry comprising a precipitated copolymer comprising the metal salt of the sulfonated poly (phenylene ether); and isolating the precipitated copolymer comprising the metal salt of the sulfonated poly (phenylene ether).

10. A selectively permeable separation membrane comprising the copolymer of any of claims 1 to 9, wherein the selectively permeable separation membrane has a porosity of 0.5 cm3thO / gram of dry membrane or less.

11. A separation system for separating an olefin from an olefin-paraffin stream, the separation system comprising the membrane of claim 10.

12. The separation system of claim 11, comprising a first fluid chamber adjacent to a first side of the membrane; a second fluid chamber adjacent to a second, opposite side of the membrane; a first fluid port in fluid communication with the first fluid chamber and configured to provide the olefin-paraffin stream to the first fluid chamber; a second fluid port in fluid communication with the first fluid chamber and configured to remove a paraffin-enriched stream from the first chamber; and a third fluid port in fluid communication the second fluid chamber and configured to remove an olefin-enriched stream from the second fluid chamber.

13. A method for separating an olefin from an olefin-paraffin stream, the method comprising: contacting a first side of a membrane comprising the copolymer of any of claims 1 to 9 with the olefin-paraffin stream; applying a pressure to cause the olefin to selectively permeate to a second side of the membrane; and collecting an olefin-enriched product stream.

14. The method of claim 13, wherein the olefin-enriched product stream comprises the olefin in an amount of at least 95 volume percent, based on the total volume of the olefin-enriched product stream.

15. The method of claim 13 or 14, wherein the olefin-paraffin stream comprises a pair of compounds selected from ethane and ethylene, propane and propylene, butane and butylene, and heptane and heptene.

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