Sulfonated polyphenylene ether and method for producing same

Abstract

The present application describes a sulfonated polyphenylene ether. The sulfonated polyphenylene ether has a sulfonation degree of 15% to 50%. At least 90% of the sulfonated polyphenylene ether repeat units of the sulfonated polyphenylene ether are monosubstituted. Methods for making the sulfonated polyphenylene ether and articles made therefrom are also disclosed.

Description

[0001] CITATION OF RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of European Patent Application No. 23170792.8, filed April 28, 2023, the contents of which are incorporated by reference in their entirety. TECHNICAL FIELD

[0003] Disclosed herein are sulfonated polyphenylene ethers and methods for making sulfonated polyphenylene ethers. BACKGROUND

[0004] Polyphenylene ethers are commercially attractive materials due to their unique combination of physical, chemical, and electrical properties. In addition, combinations of polyphenylene ethers with other polymers or additives provide blends that result in improved overall properties, including chemical resistance, high strength, and high flow. As new commercial applications are explored, various sulfonated grades of polyphenylene ether materials are desired.

[0005] Conventional methods for sulfonating polyphenylene ethers can produce non-uniformity as the degree of sulfonation is increased, which can affect the reaction system such that further sulfonation is not possible.

[0006] Accordingly, there remains a continuing need in the art for an improved sulfonation method that can provide a high level of sulfonation (e.g., up to 50%) and can further provide a high percentage of mono-substituted repeat units. It would be further advantageous if the sulfonated polyphenylene ethers could be provided with reduced levels of residual components, such as residual solvents. SUMMARY

[0007] One aspect of the present disclosure is a sulfonated polyphenylene ether comprising repeat units of the formula:

[0008] wherein, in the above formula, Z 1 independently at each occurrence is a sulfonic acid group, a sulfonyl chloride group, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarboxy group, or a C 2-12 halohydrocarboxy group, wherein at least two carbon atoms separate the halogen and oxygen atoms; Z 2 independently at each occurrence is a sulfonic acid group, a sulfonyl chloride group, a hydrogen, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarboxy group, or a C 2-12haloalkoxy, wherein at least two carbon atoms separate the halogen and oxygen atoms; and wherein the sulfonated polyphenylene ether has a degree of sulfonation of 15% to 50% as determined by nuclear magnetic resonance spectroscopy; and wherein at least 90% of the sulfonated polyphenylene ether repeat units are mono-substituted.

[0009] Another aspect of the present disclosure is a membrane comprising the sulfonated polyphenylene ether.

[0010] Another aspect of the present disclosure is a method of making a sulfonated polyphenylene ether, the method comprising: contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a co-solvent comprising ethyl acetate under conditions effective to provide a mixture comprising the sulfonated polyphenylene ether; and isolating the sulfonated polyphenylene ether from the mixture; wherein the polyphenylene ether is present in an amount greater than or equal to 8 weight percent, preferably wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent, based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent; the co-solvent is present in an amount of 7 to 15 weight percent, based on the total weight of the solvent and the co-solvent; and wherein the sulfonating agent is present in a weight ratio of sulfonating agent to polyphenylene ether of less than 0.5: 1, preferably 0.1: 1 to 0.45: 1.

[0011] The above described and other features are exemplified by the following drawings and detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0012] The following drawings represent exemplary embodiments.

[0013] Figure 1 A chemical structure of an exemplary sulfonated polyphenylene ether according to one aspect of the present disclosure is shown. DETAILED DESCRIPTION

[0014] The present inventors have unexpectedly discovered that by selecting particular method conditions for making a sulfonated polyphenylene ether, it is possible to provide a sulfonated polyphenylene ether having a high degree of sulfonation. In further advantageous features, the sulfonated polyphenylene ether can have a high degree of mono-substitution (i.e., the sulfonated repeat units have at least 90% only one sulfonate group). With the ability to effectively produce polyphenylene ethers at sulfonation levels of 15% to 50%, a wide variety of different products are possible. For example, ion exchange membranes for dialysis, proton conducting membranes for polymer electrolyte membrane fuel cells, ion exchange membranes for flow batteries, hollow fiber membranes, precursors for molecular sieve carbon membranes for gas separation, precursors for carbon electrodes for fuel cells, carbon membrane reactors, and the like. Thus, the present disclosure provides significant improvements.

[0015] Accordingly, one aspect of the present disclosure is a method of making a sulfonated polyphenylene ether. The degree of sulfonation can be controlled by adjusting the amounts of solvent and co-solvent in the method, by adjusting the amount of sulfonating agent used, and by adjusting the concentration of polyphenylene ether in the reaction mixture.

[0016] The process according to the present disclosure includes contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent and a co-solvent to sulfonate the polyphenylene ether. The solvent includes 1,2-dichloroethane. The co-solvent includes at least one of methyl ethyl ketone, diethyl ether, methyl ethyl sulfone, ethyl acetate (EA), or tetramethylene sulfone. In one aspect, the co-solvent includes at least one of ethyl acetate or tetramethylene sulfone. In a particular aspect, the co-solvent includes ethyl acetate.

[0017] The polyphenylene ether includes those comprising recurring structural units having the formula:

[0018] wherein each occurrence of Z 1 independently includes a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group wherein at least two carbon atoms separate the halogen and oxygen atoms; and each occurrence of Z 2 independently includes a hydrogen, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group wherein at least two carbon atoms separate the halogen and oxygen atoms. 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 can optionally contain heteroatoms in addition to 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, amino, hydroxy, etc., groups, or it can contain heteroatoms within the backbone of the hydrocarbyl residue. As one example, Z 1 may be a dibutylaminomethyl group formed from the reaction of the terminal 3,5-dimethyl-1,4-phenyl group with the dibutylamine component of the oxidation polymerization catalyst.

[0019] In an aspect, the polyphenylene ether comprises 2,6-dimethyl-1,4-phenylene ether units, 2,3,6-trimethyl-1,4-phenylene ether units, or a combination thereof. In an aspect, the polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene ether). In an aspect, the polyphenylene ether comprises poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.03 to 2 deciliters per gram (dl / g). For example, the polyphenylene ether can have an intrinsic viscosity of 0.25 to 1.7 dl / g, especially 0.25 to 0.7 dl / g, more especially 0.35 to 0.55 dl / g, even more especially 0.35 to 0.50 dl / g, measured using an Ubbelohde viscometer in chloroform at 25 °C.

[0020] In an aspect, the polyphenylene ether can comprise molecules having end groups that are amino group-containing alkyl groups, typically located ortho to the hydroxyl groups. Also frequently present are tetramethyl diphenylquinone (TMDQ) end groups, typically obtained from a 2,6-dimethyl phenol-containing reaction mixture in which tetramethyl diphenylquinone byproducts are present. The polyphenylene ether can be in the form of a homopolymer, copolymer, graft copolymer, ionomer, block copolymer, or oligomer, and combinations thereof.

[0021] As used herein, polyphenylene ether can also refer to lower molecular weight phenylene ether oligomers. In an aspect, the phenylene ether oligomer comprises 2,6-dimethyl-1,4-phenylene ether units, 2,3,6-trimethyl-1,4-phenylene ether units, or a combination thereof. In an aspect, the phenylene ether oligomer can have an intrinsic viscosity of 0.03 to 0.13 dl / g, or 0.05 to 0.1 dl / g, or 0.1 to 0.15 dl / g, measured using an Ubbelohde viscometer in chloroform at 25 °C. The polyphenylene ether oligomer can have a number average molecular weight of 500 to 7,000 grams per mole (g / mol) and a weight average molecular weight of 500 to 15,000 g / mol, as determined by gel permeation chromatography using polystyrene standards. In an aspect, the number average molecular weight can be 750 g / mol to 4,000 g / mol and the weight average molecular weight can be 1,500 g / mol to 9,000 g / mol, as determined by gel permeation chromatography using polystyrene standards.

[0022] The phenylene ether oligomer can be mono- or di-functional. In an aspect, the phenylene ether oligomer can be mono-functional. For example, it can have a functional group at one end of the polymer chain. The functional group can be, for example, a hydroxyl group or a (meth)acrylate group, preferably a (meth)acrylate group. In an aspect, the phenylene ether oligomer comprises poly(2,6-dimethyl-1,4-phenylene ether).

[0023] In one aspect, the phenylene ether oligomer can be difunctional. For example, it can have functional groups at both ends of the oligomer chain. The functional groups can be, for example, hydroxyl groups or (meth)acrylate groups, preferably (meth)acrylate groups. Difunctional polymers having functional groups at both ends of the polymer chain are also referred to as "telechelic" polymers. In one aspect, the phenylene ether oligomer includes a difunctional phenylene ether oligomer having the following structure:

[0024] wherein Q 1 and Q 2 each independently comprises a halogen, an unsubstituted or substituted C 1-12 primary or secondary hydrocarbyl group, a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, and a C 2-12 halohydrocarbyloxy group in which at least two carbon atoms separate the halogen and oxygen atoms; Q 3 and Q 4 each occurrence independently includes a hydrogen, a halogen, an unsubstituted or substituted C 1-12 primary or secondary hydrocarbyl group, a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, and a C 2-12 halohydrocarbyloxy group in which at least two carbon atoms separate the halogen and oxygen atoms; Z is a hydrogen or a (meth)acrylate; x and y are independently 0 to 30, or 0 to 20, or 0 to 15, or 0 to 10, or 0 to 8, with the proviso that the sum of x and y is at least 2, or at least 3, or at least 4; and L has the following structure: ; wherein each occurrence of R 3 and R 4 and R 5 and R 6 independently includes a hydrogen, a halogen, an unsubstituted or substituted C 1-12 primary or secondary hydrocarbyl group, a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, and a C 2-12 halohydrocarbyloxy group in which at least two carbon atoms separate the halogen and oxygen atoms; z is 0 or 1 ; and Y has the following structure: and

[0025] wherein each occurrence of R 7 independently includes a hydrogen and a C 1-12 hydrocarbyl group, and each occurrence of R 8 and R 9 independently includes a hydrogen, a C 1-12 hydrocarbyl group, and a C 1-6 hydrocarbylene group, wherein R8 and R 9 together form a C 4-12 alkylene group.

[0026] In one aspect, the phenylene ether oligomer includes a difunctional phenylene ether oligomer having the structure:

[0027] wherein each occurrence of Q 1 , Q 2 , Q 3 , Q 4 , L, x, and y are as defined above, and R 10 is methyl or hydrogen.

[0028] In the above (meth)acrylate-terminated phenylene ether structure, there are restrictions on the variables x and y, which correspond to the number of phenylene ether repeat units in the two different positions in the difunctional phenylene ether oligomer. In this structure, x and y are independently 0 to 30, or 0 to 20, or 0 to 15, or 0 to 10, or 0 to 8. The sum of x and y is at least 2, or at least 3, or at least 4. The phenylene ether oligomer can be analyzed by proton nuclear magnetic resonance spectroscopy (1H NMR) to determine whether the average meets these restrictions. Specifically, 1 1H NMR can distinguish between protons associated with internal and terminal phenylene ether groups, with internal and terminal residues of the polyhydric phenol, and also with terminal residues. Thus, the average number of phenylene ether repeat units per molecule, and the relative abundance of internal and terminal residues derived from the dihydric phenol, can be determined. 1

[0029] In one aspect, the phenylene ether oligomer includes a difunctional phenylene ether oligomer having the structure:

[0030] wherein each occurrence of Q 5 and Q 6 independently comprises a methyl group, a di-n-butylaminomethyl group, or a morpholinomethyl group; and each occurrence of a and b independently is 0 to 20, with the proviso that the sum of a and b is at least 2; and each occurrence of R 10 is methyl or hydrogen. An exemplary difunctional phenylene ether oligomer includes NORYL TM resin SA9000, available from SABIC.

[0031] In one aspect, the phenylene ether oligomer includes a difunctional phenylene ether oligomer having the structure:

[0032] wherein each occurrence of Q 5 and Q 6 ​independently contains a methyl group, a di-n-butylaminomethyl group, or a morpholinomethyl group; and each occurrence of a and b is independently 0 to 20, provided that the sum of a and b is at least 2. Exemplary bifunctional phenylene ether oligomers include NORYL TM Resin SA90, available from SABIC.

[0033] In one aspect, the polyphenylene ether comprises a polyphenylene ether homopolymer, an oligomer, or a combination thereof. The polyphenylene ether can preferably comprise poly(2,6-dimethyl-1,4-phenylene ether).

[0034] The method for sulfonating a polyphenylene ether comprises contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent and a co-solvent. In one aspect, the method comprises dissolving a polyphenylene ether in a solvent and a co-solvent to form a polyphenylene ether mixture. The mixing of the components of the mixture can be carried out at a temperature of 10 °C to 60 °C, such as 25 °C to 40 °C. The solvent comprises 1,2-dichloroethane and is present in an amount sufficient to dissolve the polyphenylene ether. The amount of co-solvent is sufficient to prevent precipitation of the sulfonated polyphenylene ether prior to the desired degree of sulfonation having been achieved.

[0035] The solvent mixture can comprise greater than or equal to 8 weight percent of the polyphenylene ether, or greater than 10 weight percent of the polyphenylene ether, or greater than 12 weight percent of the polyphenylene 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 polyphenylene ether, each based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent.

[0036] The solvent (i.e., 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 polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent.

[0037] The co-solvent 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 co-solvent. For example, the co-solvent can be present in an amount of 8 to 12 weight percent. In one aspect, the co-solvent can be present in an amount of at least 10 weight percent, such as 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 co-solvent.

[0038] The polyphenylene ether is reacted with a sulfonating agent to sulfonate the polyphenylene ether. The sulfonation can be carried out at a temperature of up to 85 °C, such as 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 polyphenylene ether of less than 0.5: 1. For example, the weight ratio of sulfonating agent to polyphenylene ether can be 0.1: 1 to 0.45: 1, or 0.2: 1 to 0.4: 1. In one aspect, the sulfonating agent can be added slowly to the reaction mixture, for example, over a period of 15 minutes (min) to 60 minutes (e.g., over 30 minutes). Once the sulfonating agent is added to the solvent mixture, the solvent mixture can be stirred for a period of time, for example, 60 to 210 minutes, before isolation of the sulfonated product is carried out.

[0039] The method further includes isolating the sulfonated polyphenylene ether from the mixture. For example, once the polyphenylene ether has been sulfonated, a counter solvent mixture, for example, comprising deionized (DI) water and an organic solvent, can be used to precipitate the sulfonated polyphenylene ether from the solvent mixture. As the organic solvent, hexane, heptane, cyclopentane, or cycloheptane (along with deionized water) can be used to precipitate the sulfonated polyphenylene ether out of the reaction solvent mixture. The present inventors have advantageously found that particular organic solvents can be especially useful. For example, the organic solvent should be immiscible with water and not form an azeotrope with 1,2-dichloroethane or ethyl acetate. Preferably, the organic solvent comprises cyclopentane or cycloheptane. In a certain particular manner, the organic solvent is cyclopentane.

[0040] The reaction solvent mixture can be added (e.g., slowly) to the counter solvent mixture, where the counter solvent mixture can be used in an amount sufficient to cause precipitation. For example, 100 grams (g) of the reaction mixture can be added to 300 to 700 g, preferably 390 to 595 g, of the counter solvent mixture. In one aspect, the counter solvent can have a weight ratio of organic solvent to water of 1: 1 to 1: 1, or 1:2 to 1:5, or 1:3 to 1:4.5.

[0041] The precipitated sulfonated polyphenylene ether can be filtered, and optionally washed and dried. The filtrate can be biphasic, having 1,2-dichloroethane, a cosolvent, and optionally one or more organics (e.g., cyclohexane or cycloheptane) that are part of the antisolvent mixture as the organic phase and water as the aqueous phase. Thus, the filtrate can be further processed to recover at least one of 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 water. The recovered materials can include decanting the biphasic filtrate to form an aqueous stream and an organic stream. The organic stream can be further processed (e.g., distilled) to recover 1,2-dichloroethane or the cosolvent. The recovered materials can be recycled. As described herein, the selection of an antisolvent that does not form an azeotrope with 1,2-dichloroethane or ethyl acetate can advantageously result in increased recovery of solvents or cosolvents for recycling and reuse in subsequent processes.

[0042] The methods described herein can provide sulfonated polyphenylene ethers having high degrees of sulfonation and high monosulfonated repeat units. Thus, the sulfonated polyphenylene ethers represent another aspect of the present disclosure.

[0043] Sulfonated polyphenylene ether as used herein refers to a polymer comprising repeat units according to the formula:

[0044] wherein, in the above formula, Z 1 independently at each occurrence is a sulfonic acid group, a sulfonyl chloride group, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group in which at least two carbon atoms separate the halogen and oxygen atoms; and Z 2 independently at each occurrence is a sulfonic acid group, a sulfonyl chloride group, a hydrogen, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group in which at least two carbon atoms separate the halogen and oxygen atoms. In one aspect, at least one occurrence of Z 2 is a sulfonic acid group or a sulfonyl chloride group. In one aspect, each occurrence of Z 1 is a C 1-6 alkyl group, preferably a methyl group. In one aspect, the sulfonated polyphenylene ether can be derived from poly(2,6-dimethyl-1,4-phenylene ether).

[0045] The sulfonated polyphenylene ether has a degree of sulfonation of 15% to 50%. The degree of sulfonation can be determined, for example, using nuclear magnetic resonance (NMR) spectroscopy. In an aspect, the sulfonated polyphenylene ether can have a degree of sulfonation of 15 to 40%, or 15 to 30%. Thus, the sulfonated polyphenylene ether can further comprise non-sulfonated repeat units.

[0046] In an advantageous feature, the sulfonated polyphenylene ether according to the present disclosure can have a high degree of mono-substitution. In other words, a majority of the sulfonated repeat units of the sulfonated polyphenylene ether can have a single sulfonate group (i.e., mono-substituted repeat units). For example, at least 90% of the sulfonated polyphenylene ether repeat units are mono-substituted. It is noted that the term "mono-substituted" as used herein is not equivalent to "uniformly substituted." The term "uniformly substituted" refers to a sulfonated polyphenylene ether product having a certain degree of sulfonation that is uniform across the mass of the product. In contrast, as used herein, "mono-substituted" refers to a sulfonated polyphenylene ether product having a certain (uniform) degree of sulfonation across the mass of the product, and further, at least 90% of the repeat units bearing a sulfonate group have only one sulfonate group. For example, a sulfonated polyphenylene ether product having a uniform degree of substitution of 20% refers to a substitution degree of 20% across the entire mass of the product. In the present application, a mono-sulfonated polyphenylene ether product having a degree of substitution of 20% refers, for example, to at least 90% of the 20 repeat units that are sulfonated (assuming a total of 100 repeat units in the polymer for ease of calculation) having only one sulfonate group (i.e., at least 18 of the 20 repeat units having only one sulfonate group).

[0047] The sulfonated polyphenylene ether can further have a total residual solvent content of less than 0.2 weight percent, based on the total weight of the sulfonated polyphenylene ether. The residual solvent content can be determined using gas chromatography. In an aspect, the sulfonated polyphenylene ether can have a total residual ethyl acetate content of less than 0.05 weight percent, based on the total weight of the sulfonated polyphenylene ether, as determined using gas chromatography.

[0048] The present disclosure is further illustrated by the following examples, which are non-limiting.

[0049] Example

[0050] The sulfonated polyphenylene ether was prepared and isolated according to the following procedure.

[0051] Example 1

[0052] A 500 ml glass reactor (9 cm internal diameter) with 45° pitched blade turbine stir paddle (6 cm diameter) was used to dissolve polyphenylene ether (PPO, 42 g) in 1,2-dichloroethane (EDC, 378 g) and ethyl acetate (EA, 42 g) with stirring at 45 °C for 30 minutes. Once the solution was uniform and clear, chlorosulfonic acid (CSA, 17.22 g) was slowly added over a period of 30-40 min, maintaining the temperature at 45 °C. The reaction was carried out for 3.5 hours under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA. A portion of the reaction mass (100 g) was quenched in a cooled demineralized (DM) water (400 g) and n-hexane (100 g) mixture maintained at 10-12 °C. The quenched reaction mass was then filtered off using a Buchner funnel to separate the solvents and sulfonated PPE (sPPE). The wet cake of sPPE (40 g) containing 80-85% water and hexane was then dried under vacuum (12 mm Hg) at room temperature (e.g., 25-30 °C) for 48 hours to obtain a residual water content of less than 5 weight percent.

[0053] Example 2

[0054] A 500 ml glass reactor (9 cm internal diameter) with 45° pitched blade turbine stir paddle (6 cm diameter) was used to dissolve PPO (75 g) in 1,2-dichloroethane (300 g) and ethyl acetate (33.38 g) with stirring at 45 °C for 30 minutes. Once the solution was uniform and clear, chlorosulfonic acid (28.84 g) was slowly added over a period of 30-40 min, maintaining the temperature of the reactor at 45 °C. The reaction was carried out for 3.5 hours under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA. A portion of the reaction mass (100 g) was quenched in a cooled demineralized (DM) water (400 g) and n-hexane (100 g) mixture maintained at 10-12 °C. The quenched reaction mass was then filtered off using a Buchner funnel to separate the solvents and sulfonated PPE (sPPE). The wet cake of sPPE (96 g) containing 80-85% water and hexane was then dried under vacuum (12 mm Hg) at room temperature (25-30 °C) for 48 hours to obtain a residual water content of less than 5 weight percent.

[0055] Comparative Example 3

[0056] PPO (42 g) was dissolved in 1,2-dichloroethane (394.38 g) and ethyl acetate (25.62 g) using a 500 ml glass reactor (9 cm internal diameter) with a 45 °C pitched blade turbine agitator paddle (6 cm diameter) for 30 minutes at 45 °C. Once the solution was uniform and clear, chloro-sulfonic acid (23.94 g) was added slowly over a period of 30-40 min, maintaining the temperature of the reactor at 45 °C. The reaction was carried out for 3.5 hours under continuous stirring (300 rpm, tip line speed = 0.94 m / s) after the addition of CSA. A portion of the reaction mass (100 g) was quenched in a mixture of chilled demineralized (DM) water (400 g) and n-hexane (100 g) maintained at 10-12 °C. The quenched reaction mass was then filtered off using a Buchner funnel to separate the solvents and sulfonated PPE (sPPE). The wet cake of sPPE (40 g) containing 80-85% water and hexane was then dried under vacuum (12 mmHg) at room temperature (25-30 °C) for 48 hours to obtain a residual water content of less than 5 weight percent.

[0057] The results of Examples 1-3 are provided in Table 1. As shown in Table 1, using a uniform reaction mixture with polyphenylene oxide present in the reaction mixture in an amount of up to 20 weight percent and a CSA / PPE ratio of less than 0.5, a degree of sulfonation in the range of 20 to 30%, or 25 to 30% can be achieved.

[0058] Table 1 In the current process, hexane is typically used as an anti-solvent to precipitate the sulfonated product. Hexane forms an azeotrope with ethyl acetate, dichloroethane, and water, which makes solvent recovery difficult. For example, when hexane is used as an anti-solvent, in order to recover pure solvents, an entrainer would be required in the distillation. Therefore, alternative co-solvents were investigated in order to provide an improved separation procedure. The criteria for selecting a suitable anti-solvent include: (1) an organic solvent that is immiscible with water; (2) does not dissolve sulfonated polyphenylene oxide; (3) is capable of extracting ethyl acetate and dichloroethane; (4) does not form an azeotrope with ethyl acetate or dichloroethane; and (5) can form an azeotrope with water.

[0059] The following solvents were investigated for use in isolating sulfonated polyphenylene oxide: hexane, cyclopentane, heptane, cycloheptane, n-octane, and iso-octane. Table 2 summarizes the azeotropic behavior of each of these solvents with the solvents used in the reaction.

[0060] Table 2 Extraction of EDC and EA in the various organic solvents described above was simulated at 25°C using a decanter model in ASPEN PLUS. The simulated extraction amounts are provided in Table 3. In the simulation, the organic and aqueous layers were separated using a decanter model. The theoretical composition of the organic layers in each supernatant is given in Table 3. The composition of the organic layers in each supernatant determined by the simulation is given in Table 4. Based on the simulated and theoretical weight percentages of each solvent in the organic layers, the recovery percentages of the corresponding solvents were estimated, as compiled in Table 5.

[0061] Table 3 Table 4 Table 5 Based on the quantities shown in Table 6, the theoretical composition of the organic layer in the supernatant was calculated. The actual composition of the organic layer consists of... 1 The results were confirmed by ¹H NMR analysis, as shown in Table 7. The recovery rates (%) of each solvent were determined based on the actual and theoretical weight percentages of each solvent in the organic layer, as shown in Table 8.

[0062] Table 6 Table 7 Table 8 Determination of the substitution pattern of sulfonated PPE The sPPE sample prepared as described above 1 H NMR is used to measure the degree of substitution (DS), but it is insufficient to determine the substitution mode (monosubstitution vs. disubstitution). This is because 1 The low signal dispersion in the 1H NMR spectrum. The inventors have solved this problem by analyzing the 13C spectrum, which has a much higher signal dispersion. Since the 1H resonance is well resolved, 2D... 1 H- 13 C-gradient-assisted heteronuclear single quantum coherence (gHSQC) experiments were conducted to link proton signals with corresponding carbon resonances. C from substituted sPPE rings... 13 carbon peak (in) Figure 1 (as shown in) 13 A well-resolved peak was produced at approximately 14.6 ppm in the C18 NMR. The signal intensity of this peak was compared with that of the aromatic resonance of C6 in the substituted ring.

[0063] The ratio is the apparent degree of mono-substitution, shown in Table 9. DS (%) is also given in Table 9. It is clear that mono-substitution is 90% or greater over the entire range of sulfonation degree (20%-35%) in the 11 samples analyzed.

[0064] Table 9 After determining the conditions and solvents described above for obtaining sulfonated polyphenylene ether, the following examples were conducted to further determine the composition of the final sulfonated polyphenylene ether product.

[0065] Example 15

[0066] In a laboratory set-up, a 500 ml glass reactor (9 cm internal diameter) with a 45° pitched blade turbine agitator paddle (6 cm diameter) was used to dissolve polyphenylene ether (PPO, 75 g) in 1,2-dichloroethane (EDC, 300 g) and ethyl acetate (EA, 33 g) at 60 °C with stirring for 60 minutes. Once the solution was homogeneous and clear, chlorosulfonic acid (CSA, 28.875 g) was added slowly over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target sulfonation degree (DS, %) of 28-30%. The reaction was carried out for 2 hours after the addition of CSA under continuous stirring (300 rpm, blade tip linear velocity = 0.94 m / s).

[0067] After completion of the reaction, 90 g of the reaction mass from the above reaction was quickly charged into a 1 liter baffled precipitation reactor with a pitched blade turbine agitator paddle containing 360 g of water and 90 g of n-hexane, maintained at 8-10 °C and 420 rpm. The slurry formed was maintained under stirring for 1 h, followed by filtration of the solids. The resulting wet cake was further washed using the same reactor with 216 g of water and 54 g of n-hexane at 300 rpm stirring for 1 h at 25 °C to remove the residual material. This washing process was carried out five times to achieve the desired residual solvent content in the final product. The washed wet cake was dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 hours to obtain the final sulfonated PPE powder with <5 wt% moisture.

[0068] Example 16

[0069] In a laboratory set up, PPO (100 g) was dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) in a 1 liter glass reactor (9 cm internal diameter) with 45° pitched blade turbine stirrer paddle (6 cm diameter) at 60 °C with stirring for 60 minutes. Once the solution was uniform and clear, 38.5 g of CSA was added slowly over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS of 28-30%. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA.

[0070] After completion of the reaction, 520 g of the reaction mass from the above reaction was quickly charged into a 5 liter un-baffled precipitation reactor with pitched blade turbine stirrer paddle containing 2080 g of water and 520 g of cyclopentane (CP) maintained at 8-10 °C and 750 rpm. The slurry formed was maintained under stirring for 2 h, followed by filtration of the solids. The resulting wet cake was further washed using the same reactor with 1248 g of water and 312 g of cyclopentane under stirring at 170 rpm for 2 h at 25 °C to remove the residual material. This washing process was carried out five times to achieve the desired residual solvent content in the final wet cake. The cake was further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 hours to obtain the final sulfonated PPE powder having < 5 wt% moisture.

[0071] Example 17

[0072] In a laboratory set up, PPO (100 g) was dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) in a 1 liter glass reactor (9 cm internal diameter) with 45° pitched blade turbine stirrer paddle (6 cm diameter) at 60 °C with stirring for 60 minutes. Once the solution was uniform and clear, 38.5 g of CSA was added slowly over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS of 28-30%. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA.

[0073] After the reaction is complete, 520 g of the reaction mass from the above reaction is quickly charged to a 5 liter un-baffled precipitation reactor with pitched blade turbine agitator paddle containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed is maintained under agitation for 2 h, after which the solids are filtered. The resulting wet cake is further washed using the same reactor with 1248 g of water and 312 g of cyclopentane, under agitation at 170 rpm, for 2 h at 25 °C to remove the residual solvents. This washing process is carried out five times to achieve the desired residual solvent content in the final wet cake. The cake is further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 h to obtain the final sulfonated PPE powder with <5 wt% moisture.

[0074] Example 18

[0075] In a laboratory set-up, PPO (100 g) is dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) using a 1 liter glass reactor (9 cm internal diameter) with a 45° pitched blade turbine agitator paddle (6 cm diameter) stirred at 60 °C for 60 minutes. Once the solution is homogeneous and clear, 35.35 g of chlorosulfonic acid (CSA) is slowly added over a period of 30-40 min, maintaining the temperature of the reactor at 60 °C to achieve a target DS% of 24-26. The reaction is carried out under continuous agitation (300 rpm, blade tip linear velocity = 0.94 m / s) for 2 h after the addition of CSA.

[0076] After the reaction is complete, 520 g of the reaction mass from the above reaction is quickly charged to a 5 liter un-baffled precipitation reactor with pitched blade turbine agitator paddle containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed is maintained under agitation for 2 h, after which the solids are filtered. The resulting wet cake is further washed using the same reactor with 1248 g of water and 312 g of cyclopentane, under agitation at 170 rpm, for 2 h at 25 °C to remove the residual solvents. This washing process is carried out five times to achieve the desired residual solvent content in the final wet cake. The cake is further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 h to obtain the final sulfonated PPE powder with <5 wt% moisture.

[0077] Example 19

[0078] In a laboratory set-up, PPO (100 g) was dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) in a 1 liter glass reactor (9 cm internal diameter) with a 45° pitched blade turbine stirrer paddle (6 cm diameter) at 60 °C with stirring for 60 minutes. Once the solution was uniform and clear, 35.0 g of CSA was added slowly over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS% of 24-26. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA.

[0079] After completion of the reaction, 520 g of the reaction mass from the above reaction was quickly charged into a 5 liter un-baffled precipitation reactor with a pitched blade turbine stirrer paddle containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed was maintained under stirring for 2 h, followed by filtration of the solids. The resulting wet cake was further washed using the same reactor with 1248 g of water and 312 g of cyclopentane at 170 rpm stirring for 2 h at 25 °C to remove the residual material. This washing process was carried out five times to achieve the desired residual solvent content in the final wet cake. The cake was further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 hours to obtain the final sulfonated PPE powder with < 5 wt% moisture.

[0080] Example 20

[0081] In a laboratory set-up, PPO (100 g) was dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) in a 1 liter glass reactor (9 cm internal diameter) with a 45° pitched blade turbine stirrer paddle (6 cm diameter) at 60 °C with stirring for 60 minutes. Once the solution was uniform and clear, 35.0 g of CSA was added slowly over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS% of 24-26. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA.

[0082] After the reaction is complete, 520 g of the reaction mass from the above reaction is quickly added to a 5 liter un-baffled precipitation reactor with pitched blade turbine agitator paddle containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed is maintained under agitation for 2 h, after which the solids are filtered. The resulting wet cake is further washed using the same reactor with 1248 g of water and 312 g of cyclopentane, under agitation at 170 rpm, at 25 °C for 2 h to remove the residual solvents. This washing process is carried out five times to achieve the desired residual solvent content in the final wet cake. The cake is further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 hours to obtain the final sulfonated PPE powder with <5 wt% moisture.

[0083] Example 21

[0084] In a laboratory set-up, PPO (100 g) was dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) using a 1 liter glass reactor (9 cm internal diameter) with a 45° pitched blade turbine agitator paddle (6 cm diameter) stirred at 60 °C for 60 minutes. Once the solution was homogeneous and clear, 27.67 g of CSA was slowly added over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS% of 20-22. The reaction was carried out under continuous agitation (300 rpm, blade tip linear velocity = 0.94 m / s) for 2 h after the addition of CSA.

[0085] After the reaction is complete, 520 g of the reaction mass from the above reaction is quickly added to a 5 liter un-baffled precipitation reactor with pitched blade turbine agitator paddle containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed is maintained under agitation for 2 h, after which the solids are filtered. The resulting wet cake is further washed using the same reactor with 1248 g of water and 312 g of cyclopentane, under agitation at 170 rpm, at 25 °C for 2 h to remove the residual solvents. This washing process is carried out five times to achieve the desired residual solvent content in the final wet cake. The cake is further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 hours to obtain the final sulfonated PPE powder with <5 wt% moisture.

[0086] Example 22

[0087] In a laboratory set-up, PPO (100 g) was dissolved in 1,2-dichloroethane (400 g) and ethyl acetate (33 g) using a 1 liter glass reactor (9 cm internal diameter) with a 45° pitched blade turbine stirrer paddle (6 cm diameter) stirred at 60 °C for 60 minutes. Once the solution was homogeneous and clear, 27.67 g of CSA was slowly added over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS of 20-22%. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA.

[0088] After completion of the reaction, 520 g of the reaction mass from the above reaction was quickly added to a 5 liter un-baffled precipitation reactor with a pitched blade turbine stirrer paddle containing 2080 g of water and 520 g of cyclopentane, maintained at 8-10 °C and 750 rpm. The slurry formed was maintained under stirring for 2 h, followed by filtration of the solids. The resulting wet cake was further washed using the same reactor with 1248 g of water and 312 g of cyclopentane under stirring at 170 rpm for 2 h at 25 °C to remove the residual material. This washing process was carried out five times to achieve the desired residual solvent content in the final wet cake. The cake was further dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 hours to obtain the final sulfonated PPE powder having < 5 wt% moisture.

[0089] Example 23

[0090] In a laboratory set-up, PPO (75 g) was dissolved in 1,2-dichloroethane (300 g) and ethyl acetate (33 g) using a 500 ml glass reactor (9 cm internal diameter) with a 45° pitched blade turbine stirrer paddle (6 cm diameter) stirred at 60 °C for 60 minutes. Once the solution was homogeneous and clear, 21.6 g of CSA was slowly added over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS of 20-22%. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip linear velocity = 0.94 m / s) after the addition of CSA.

[0091] After completion of the reaction, 90 g of the reaction mass from the above reaction was quickly added to a 1 liter baffled precipitation reactor with a pitched blade turbine stirrer paddle containing 360 g of water and 90 g of cyclopentane, maintained at 8-10 °C and 420 rpm. The slurry formed was maintained under stirring for 1 h, followed by filtration of the solids. The resulting wet cake was analyzed for residual solvent without drying it.

[0092] Example 24

[0093] In a laboratory set-up, PPO (75 g) was dissolved in 1,2-dichloroethane (300 g) and ethyl acetate (33 g) using a 500 ml glass reactor (9 cm internal diameter) with a 45° pitched blade turbine stirrer paddle (6 cm diameter) at 60 °C for 60 minutes. Once the solution was homogeneous and clear, 21.6 g of CSA was added slowly over a period of 30-40 min, maintaining the temperature of the reactor to 60 °C to achieve a target DS% of 20-22. The reaction was carried out for 2 h under continuous stirring (300 rpm, tip line speed = 0.94 m / s) after the addition of CSA.

[0094] After completion of the reaction, 90 g of the reaction mass from the above reaction was quickly added to a 1 liter baffled precipitation reactor with a pitched blade turbine stirrer paddle containing 360 g of water and 90 g of cyclopentane, maintained at 8-10 °C and 420 rpm. The slurry formed was maintained under stirring for 1 h, followed by filtration of the solids. The resulting wet cake was dried in a vacuum oven at 25 °C and 10-20 mbar vacuum for 70-90 h to obtain the final sulfonated PPE powder with <5 wt% moisture.

[0095] The samples were analyzed using an Agilent headspace gas chromatography (GC) instrument equipped with a CP-waX-52cb column size of 50 m x 320 µm x 1.2 µm, with ultra-pure helium gas as the carrier gas with a column flow rate of 2 milliliters per minute (ml / min), a split ratio of 20:1, and an inlet temperature of 240 °C. A flame ionization detector was used. The headspace sampler was maintained at 80 °C and equilibrated with the headspace vial for 30 minutes prior to injection.

[0096] For quantitative analysis of residual solvent content, calibration was performed using external solvents of known concentration. The vapors generated in each calibration sample were injected into the column to record their response using a flame ionization detector, and a calibration curve was generated using the known concentrations and the area under the curve of the specified chromatogram peak. The detection limit for this analysis was 5 ppm.

[0097] Samples of sulfonated polyphenylene ether (sPPE) according to the above examples were prepared by dissolving 0.5 grams of sPPE in 5 milliliters of NMP and analyzing the samples using gas chromatography. A calibration curve was used to determine the concentration of residual solvent in each sample.

[0098] The experimental conditions and the resulting residual solvent content for each example are summarized in Table 10.

[0099] Table 10 Comparative Example As shown in Table 1, it can be seen that no EDC was detected in any of the examples. Both EA and CP were observed to be present in amounts within acceptable ranges.

[0100] The present invention further encompasses the following aspects.

[0101] Aspect 1 : A sulfonated polyphenylene ether comprising: recurring units of the formula

[0102] wherein, in the above formula, Z 1 independently at each occurrence, is a sulfonic acid group, a sulfonyl chloride group, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group wherein at least two carbon atoms separate the halogen and oxygen atoms; Z 2 independently at each occurrence, is a sulfonic acid group, a sulfonyl chloride group, a hydrogen, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group (with the proviso that the hydrocarbyl group is not a tertiary hydrocarbyl group), a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group wherein at least two carbon atoms separate the halogen and oxygen atoms; and wherein the sulfonated polyphenylene ether has a degree of sulfonation of 15% to 50% as determined by nuclear magnetic resonance spectroscopy; and wherein at least 90% of the sulfonated polyphenylene ether recurring units of the sulfonated polyphenylene ether are monosubstituted.

[0103] Aspect 2: The sulfonated polyphenylene ether according to Aspect 1, wherein the sulfonated polyphenylene ether has a total residual solvent content of less than 0.2 weight percent, as determined using gas chromatography, based on the total weight of the sulfonated polyphenylene ether.

[0104] Aspect 3: The sulfonated polyphenylene ether according to Aspect 1 or 2, wherein the sulfonated polyphenylene ether is prepared by a process comprising: contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a co-solvent comprising ethyl acetate to provide a mixture comprising the sulfonated polyphenylene ether; wherein, based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent, the polyphenylene ether is present in an amount greater than or equal to 8 weight percent, preferably wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent; the co-solvent is present in an amount of 7 to 15 weight percent, based on the total weight of the solvent and the co-solvent; and wherein the sulfonating agent is present in a weight ratio of sulfonating agent to polyphenylene ether of less than 0.5: 1, preferably 0.1 : 1 to 0.45: 1.

[0105] Aspect 4: The sulfonated polyphenylene ether of aspect 3, wherein the sulfonated polyphenylene ether is prepared by a method further comprising adding the mixture comprising the sulfonated polyphenylene ether to an anti-solvent 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 precipitated sulfonated polyphenylene ether; and isolating the sulfonated polyphenylene ether.

[0106] Aspect 5: The sulfonated polyphenylene ether according to any one of aspects 1 to 4, wherein at least one of Z 2 is a sulfonic acid group or a sulfonyl chloride group.

[0107] Aspect 6: The sulfonated polyphenylene ether according to any one of aspects 1 to 5, wherein each Z 1 is a methyl group.

[0108] Aspect 7: The sulfonated polyphenylene ether according to any one of aspects 1 to 6, wherein the sulfonated polyphenylene ether has a total residual ethyl acetate content of less than 0.05 weight percent, as determined using gas chromatography, based on the total weight of the sulfonated polyphenylene ether.

[0109] Aspect 8: The sulfonated polyphenylene ether according to aspect 1, wherein the sulfonated polyphenylene ether comprises repeat units of the formula: ; wherein the sulfonated polyphenylene ether has a degree of sulfonation of 15 to 40%, as determined by nuclear magnetic resonance spectroscopy; wherein at least 90% of the sulfonated polyphenylene ether repeat units of the sulfonated polyphenylene ether are monosubstituted; wherein the sulfonated polyphenylene ether has a total residual solvent content of less than 0.2 weight percent, as determined using gas chromatography, based on the total weight of the sulfonated polyphenylene ether; and wherein the sulfonated polyphenylene ether is prepared by a method comprising: contacting a polyphenylene 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 polyphenylene ether, wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent based on the total weight of the polyphenylene 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 polyphenylene ether of 0.1 : 1 to 0.45 : 1; adding the mixture comprising the sulfonated polyphenylene ether to an anti-solvent 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 precipitated sulfonated polyphenylene ether; and isolating the precipitated sulfonated polyphenylene ether.

[0110] Aspect 9: A film comprising the sulfonated polyphenylene ether according to any one of aspects 1 to 8.

[0111] Aspect 10: A method of making a sulfonated polyphenylene ether, the method comprising: contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a co-solvent comprising ethyl acetate under conditions effective to provide a mixture comprising sulfonated polyphenylene ether; and isolating the sulfonated polyphenylene ether from the mixture; wherein the polyphenylene ether is present in an amount greater than or equal to 8 weight percent, based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent, preferably wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent; the co-solvent is present in an amount of 7 to 15 weight percent, based on the total weight of the solvent and the co-solvent; and wherein the sulfonating agent is present in a weight ratio of sulfonating agent to polyphenylene ether of less than 0.5: 1, preferably 0.1: 1 to 0.45: 1.

[0112] Aspect 11: The method according to Aspect 10 or 11, further comprising adding the mixture comprising sulfonated polyphenylene ether to an anti-solvent 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 precipitated sulfonated polyphenylene ether; isolating the sulfonated polyphenylene ether; and optionally washing the isolated sulfonated polyphenylene ether with the anti-solvent.

[0113] Aspect 12: The method according to Aspect 11, wherein the organic solvent comprises cyclopentane or cycloheptane, preferably cyclopentane.

[0114] Aspect 13: The method according to any one of Aspects 10 to 12, wherein the isolated sulfonated polyphenylene ether has a degree of sulfonation of 15 to 50% as determined by nuclear magnetic resonance spectroscopy; wherein at least 90% of the sulfonated repeat units of the sulfonated polyphenylene ether are mono-substituted; and optionally wherein the isolated sulfonated polyphenylene ether has a combined residual solvent content of less than 0.2 weight percent as determined using gas chromatography, based on the total weight of the sulfonated polyphenylene ether.

[0115] Aspect 14: The method according to Aspect 10, comprising: contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a co-solvent comprising ethyl acetate under conditions effective to provide a mixture comprising sulfonated polyphenylene ether, wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent; the co-solvent is present in an amount of 7 to 15 weight percent based on the total weight of the solvent and the co-solvent; and the sulfonating agent is present in a weight ratio of sulfonating agent to polyphenylene ether of 0.1 : 1 to 0.45: 1; adding the mixture comprising sulfonated polyphenylene ether to an anti-solvent 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 precipitated sulfonated polyphenylene ether; isolating the precipitated sulfonated polyphenylene ether; and optionally washing the isolated sulfonated polyphenylene ether with the anti-solvent; wherein the organic solvent comprises cyclopentane or cycloheptane; and wherein the isolated sulfonated polyphenylene ether has a degree of sulfonation of 15 to 50% as determined by nuclear magnetic resonance spectroscopy; wherein at least 90% of the sulfonated repeat units of the sulfonated polyphenylene ether are monosubstituted; and optionally wherein the isolated sulfonated polyphenylene ether has a combined residual solvent content of less than 0.2 weight percent as determined using gas chromatography based on the total weight of the sulfonated polyphenylene ether.

[0116] Aspect 15: A sulfonated polyphenylene ether prepared by the method of any one of Aspects 10 to 14.

[0117] Alternatively, the compositions, methods, and articles can 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 of, or substantially devoid of, any material (or species), step, or component that is otherwise unnecessary for the achievement of the function or achievement of the compositions, methods, and articles.

[0118] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. “Combination” is inclusive of blends, mixtures, alloys, reaction products, or 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. Unless otherwise specified, the terms “a” and “an” and “the” include plural referents. Unless otherwise specified, the term “or” means “and / or.” References to “an aspect” are meant to refer to a particular element described in connection with that aspect, and are not necessarily intended to be limiting of other aspects. As used herein, the term “combinations thereof’ is inclusive of one or more of the listed elements and is open, allowing for the presence of one or more additional like elements. Furthermore, it is to be understood that the described elements can be combined in any suitable manner in the various aspects.

[0119] Unless specified to the contrary otherwise in this document, 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.

[0120] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary 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 prevails. In addition, the bibliographic data

[0121] 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 or a hydrogen atom as indicated. A dash ("-") that is not between two letters or symbols is used to indicate a point of attachment in a substituent. For example, -CHO is attached through carbon of the carbonyl group.

[0122] As used herein, the term "hydrocarbyl," whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue comprising only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also comprise combinations of aliphatic, aromatic, straight-chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when the hydrocarbyl residue is described as substituted, it can optionally comprise heteroatoms in addition to and in place of carbon and hydrogen members of the residue. Thus, when specifically described as substituted, the hydrocarbyl residue can also comprise one or more carbonyl, amino, hydroxyl, etc., groups, or it can comprise heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" refers to a branched or straight-chain, saturated aliphatic hydrocarbyl group, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, and n-hexyl and s-hexyl. "Alkenyl" refers to a straight-chain or branched-chain monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HC=CH2)). "Alkoxy" refers to an alkyl group attached to the rest of the molecule by an oxygen (i.e., alkyl-O-), for example, methoxy, ethoxy, and s-butyloxy. "Alkylene" refers to a straight-chain or branched-chain, saturated, divalent aliphatic hydrocarbyl group (e.g., methylene (-CH2-) or propylene (-(CH2)3-)). "Cycloalkylene" refers to a divalent cyclic alkylene group, -C n H 2n-x wherein x is the number of hydrogens replaced by cyclization. "Cycloalkenyl" refers to 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" refers to an aromatic hydrocarbyl group including the indicated number of carbon atoms, such as phenyl, cycloheptatrienyl, indanyl, or naphthyl. "Arylene" refers to a divalent aryl group. "Alkylidenearylene" refers to an arylene group substituted with an alkyl group. "Arylidenealkylene" refers to an alkylene group substituted with an aryl group (e.g., benzyl). The prefix "halo" refers to a group or compound including one or more of a fluorine, chlorine, bromine, or iodine substituents. Combinations of different halogen atoms (e.g., bromine and fluorine) or only chlorine atoms can be present. The prefix "hetero" refers to a compound or group including at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatoms), wherein the heteroatoms are 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 which can each independently be C 1-9 alkoxy, C 1-9 haloalkoxy, nitro (-NO2), cyano (-CN), C 1-6 alkylsulfonyl (-S(=O)2-alkyl), C 6-12Arylsulfonyl (-S(=O)2-aryl), thiol (-SH), thiocyanate (-SCN), toluenesulfonyl (CH3C6H4SO2-), C 3-12 cycloalkyl, C 2-12 alkenyl, C 5-12 Cycloalkenyl, C 6-12 Aryl, C 7-13 Arylalkylene, C 4-12 Heterocyclic alkyl groups, and C 3-12 A heteroaryl group can replace hydrogen, provided that the valence of the substituted atom does not exceed the normal valence of the substituted atom. The number of carbon atoms indicated in the group does not include any substituents. For example, -CH2CH2CN is a C2 alkyl group substituted with a nitrile.

[0123] While specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents may be conceived by the applicant or others skilled in the art that are currently unforeseeable or likely to be unforeseeable. Therefore, the appended claims, as filed and as they may be modified, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A sulfonated polyphenylene ether comprising: repeating units of the formula: wherein In the above formula, Z 1 independently at each occurrence is a sulfonic acid group, a sulfonyl chloride group, a halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group - provided that the hydrocarbyl group is not a tertiary hydrocarbyl group, a C 1-12 hydrocarbylthio group, a C 1-12 hydrocarbyloxy group, or a C 2-12 halohydrocarbyloxy group wherein at least two carbon atoms separate the halogen and oxygen atoms; Z 2 independently at each occurrence is a sulfonic acid group, a sulfonyl chloride group, hydrogen, halogen, an unsubstituted or substituted C 1-12 hydrocarbyl group - provided that the hydrocarbyl group is not a tertiary hydrocarbyl group, C 1-12 hydrocarbylthio, C 1-12 hydrocarbyloxy, or C 2-12 halohydrocarbyloxy, wherein at least two carbon atoms separate the halogen and oxygen atoms; and wherein the sulfonated polyphenylene ether has a degree of sulfonation of 15% to 50% as determined by nuclear magnetic resonance spectroscopy; and wherein at least 90% of the sulfonated polyphenylene ether repeating units of the sulfonated polyphenylene ether are monosubstituted.

2. The sulfonated polyphenylene ether of claim 1, wherein the sulfonated polyphenylene ether has a total residual solvent content of less than 0.2 weight percent based on the total weight of the sulfonated polyphenylene ether as determined using gas chromatography.

3. The sulfonated polyphenylene ether of claim 1 or 2, wherein the sulfonated polyphenylene ether is prepared by a method comprising: contacting a polyphenylene 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 polyphenylene ether; wherein, the polyphenylene ether is present in an amount greater than or equal to 8 weight percent based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the cosolvent, preferably wherein the polyphenylene 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 polyphenylene ether of less than 0.5: 1, preferably 0.1: 1 to 0.45:

1.

4. The sulfonated polyphenylene ether of claim 3, wherein the sulfonated polyphenylene ether is prepared by a method further comprising: adding the mixture comprising the sulfonated polyphenylene ether to an anti-solvent 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 precipitated sulfonated polyphenylene ether; and isolating the sulfonated polyphenylene ether.

5. The sulfonated polyphenylene ether of any one of claims 1 to 4, wherein at least one of Z 2 is a sulfonic acid group or a sulfonyl chloride group.

6. The sulfonated polyphenylene ether of any one of claims 1 to 5, wherein each Z 1 is methyl.

7. The sulfonated polyphenylene ether of any one of claims 1 to 6, wherein the sulfonated polyphenylene ether has a total residual ethyl acetate content of less than 0.05 weight percent based on the total weight of the sulfonated polyphenylene ether as determined using gas chromatography.

8. The sulfonated polyphenylene ether of claim 1, wherein the sulfonated polyphenylene ether comprises repeating units of the formula: ； wherein the sulfonated polyphenylene ether has a degree of sulfonation of 15% to 40% as determined by nuclear magnetic resonance spectroscopy; wherein at least 90% of the sulfonated polyphenylene ether repeating units of the sulfonated polyphenylene ether are monosubstituted; wherein the sulfonated polyphenylene ether has a total residual solvent content of less than 0.2 weight percent based on the total weight of the sulfonated polyphenylene ether as determined using gas chromatography; and wherein the sulfonated polyphenylene ether is prepared by a method comprising: contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a cosolvent of ethyl acetate to provide a mixture comprising the sulfonated polyphenylene ether, wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent based on the total weight of the polyphenylene 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 polyphenylene ether of 0.1 : 1 to 0.45: 1; adding the mixture comprising the sulfonated polyphenylene ether to an anti-solvent comprising water and an organic solvent to form a slurry comprising precipitated sulfonated polyphenylene ether, wherein the organic solvent is immiscible with water and does not form an azeotrope with 1,2-dichloroethane or ethyl acetate; and isolating the precipitated sulfonated polyphenylene ether.

9. A membrane comprising the sulfonated polyphenylene ether of any one of claims 1 to 8.

10. A method of making a sulfonated polyphenylene ether, the method comprising: contacting a polyphenylene ether with a sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a co-solvent comprising ethyl acetate under conditions effective to provide a mixture comprising the sulfonated polyphenylene ether; and isolating the sulfonated polyphenylene ether from the mixture; wherein, the polyphenylene ether is present in an amount greater than or equal to 8 weight percent, based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent, preferably wherein the polyphenylene ether is present in an amount greater than 10 to 25 weight percent; the co-solvent is present in an amount of 7 to 15 weight percent, based on the total weight of the solvent and the co-solvent; and wherein the sulfonating agent is present in a weight ratio of sulfonating agent to polyphenylene ether of less than 0.5: 1, preferably 0.1 : 1 to 0.45:

1.

11. The method of claim 10 or 11, further comprising adding the mixture comprising the sulfonated polyphenylene ether to an anti-solvent comprising water and an organic solvent to form a slurry comprising precipitated sulfonated polyphenylene ether, wherein the organic solvent is immiscible with water and does not form an azeotrope with 1,2-dichloroethane or ethyl acetate; isolating the sulfonated polyphenylene ether; and optionally washing the isolated sulfonated polyphenylene ether with the anti-solvent.

12. The method of claim 11, wherein, The organic solvent comprises cyclopentane or cycloheptane, preferably cyclopentane.

13. The process according to any one of claims 10 to 12, wherein the isolated sulfonated polyphenylene ether has a degree of sulfonation of 15% to 50% as determined by nuclear magnetic resonance spectroscopy; wherein, At least 90% of the sulfonated repeat units of the sulfonated polyphenylene ether are mono-substituted; and optionally, wherein the isolated sulfonated polyphenylene ether has a combined residual solvent content of less than 0.2 weight percent, based on the total weight of the sulfonated polyphenylene ether, as determined using gas chromatography.

14. The method of claim 10, comprising: contacting the polyphenylene ether with the sulfonating agent in the presence of a solvent comprising 1,2-dichloroethane and a co-solvent comprising ethyl acetate under conditions effective to provide a mixture comprising the sulfonated polyphenylene ether, wherein the polyphenylene ether is present in an amount of 8 to 25 weight percent, based on the total weight of the polyphenylene ether, the sulfonating agent, the solvent, and the co-solvent; the co-solvent is present in an amount of 7 to 15 weight percent, based on the total weight of the solvent and the co-solvent; and the sulfonating agent is present in a weight ratio of sulfonating agent to polyphenylene ether of 0.1 : 1 to 0.45: 1; adding the mixture comprising the sulfonated polyphenylene ether to an anti-solvent comprising water and an organic solvent to form a slurry comprising precipitated sulfonated polyphenylene ether, wherein the organic solvent is immiscible with water and does not form an azeotrope with 1,2-dichloroethane or ethyl acetate; isolating the precipitated sulfonated polyphenylene ether; and optionally washing the isolated sulfonated polyphenylene ether with the antisolvent; wherein the organic solvent comprises cyclopentane or cycloheptane; and wherein the isolated sulfonated polyphenylene ether has a degree of sulfonation of 15% to 50% as determined by nuclear magnetic resonance spectroscopy; wherein at least 90% of the sulfonated repeat units of the sulfonated polyphenylene ether are monosubstituted; and optionally wherein the isolated sulfonated polyphenylene ether has a combined residual solvent content of less than 0.2 weight percent based on the total weight of the sulfonated polyphenylene ether as determined using gas chromatography.

15. A sulfonated polyphenylene ether prepared by the method of any one of claims 10 to 14.

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