Sulfonated poly(phenylene ether) and method for producing the same

Abstract

Sulfonated poly(phenylene ether) has repeating units of phenylene ether and has a sulfonation degree of 20 to 50% and a molar ratio of sulfonyl chloride (-SO2Cl) to sulfonic acid (-SO3H) of 0.06 or less. Sulfonated poly(phenylene ether) can be used, for example, in membranes for separation based on gas and ion exchange. A method for producing sulfonated poly(phenylene ether) is also described.

Description

Technical Field

[0001] This specification discloses sulfonated poly(phenylene ether) and a method for producing the same.

[0002] (Cross-reference to related applications) This application claims the priority and benefit of European Patent Application Publication No. 22178729.4, filed on June 13, 2022, the content of which is incorporated herein by reference in its entirety.

Background Art

[0003] Poly(phenylene ether) is a commercially attractive material due to its unique combination of physical, chemical, and electrical properties. Furthermore, combinations of poly(phenylene ether) with other polymers or additives can achieve blends that improve overall properties such as chemical resistance, high strength, and high fluidity. As new commercial applications are sought, poly(phenylene ether) materials with various degrees of sulfonation are desired.

[0004] In conventional methods of sulfonating poly(phenylene ether), the sulfonation level becomes non-uniform as the reaction progresses, affecting the reaction system and making further sulfonation difficult. Also, sulfonating poly(phenylene ether) can lead to a decrease in molecular weight and the presence of residual reaction by-products.

Summary of the Invention

Problems to be Solved by the Invention

[0005] It is desirable to provide an improved method for sulfonating poly(phenylene ether) that can achieve a high sulfonation level (e.g., up to 50%) and a reduction in the sulfonyl chloride content. It would be further advantageous to retain a high molecular weight polymer with a low oligomer content after sulfonation.

Means for Solving the Problems

[0006] Sulfonated poly(phenylene ether) represents one aspect of the present disclosure. The sulfonated poly(phenylene ether) has the following formula

Chemical formula

[0007] Another aspect is a method for producing sulfonated poly(phenylene ether), which includes the steps of dissolving poly(phenylene ether) in 1,2-dichloroethane to form a mixture, combining a sulfonating agent and a co-solvent, preferably ethyl acetate, with the mixture to form sulfonated poly(phenylene ether), passing nitrogen gas through the mixture at a flow rate of 30 milliliters or more per minute per mole of the sulfonating agent, precipitating the sulfonated poly(phenylene ether), and separating the precipitated sulfonated poly(phenylene ether).

[0008] Another aspect is a membrane comprising sulfonated poly(phenylene ether).

[0009] Another aspect is a precursor of porous carbon, which is a precursor comprising sulfonated poly(phenylene ether).

[0010] The above and other features are illustrated by the following detailed description.

Brief Description of the Drawings

[0011] Here, reference is made to the drawings, which are exemplary and non-limiting.

[0012]

Figure 1

Embodiments for Carrying Out the Invention

[0013] A method has been developed to reliably sulfonate poly(phenylene ether) to a sulfonation degree in the range of 20 - 50%. Advantageously, the sulfonated poly(phenylene ether) contains a low level of sulfonyl chloride and a small amount of oligomeric impurities. The sulfonated poly(phenylene ether) can retain a low oligomer content (e.g., less than 1 weight percent) and a high molecular weight (e.g., a number average molecular weight exceeding 60,000 grams / mole). The sulfonated poly(phenylene ether) with a low sulfonyl chloride content can improve the ion exchange capacity (IEC). Also, this method is scalable and enables the production of poly(phenylene ether) with various sulfonation levels. Moreover, uniform sulfonation is possible.

[0014] Accordingly, one aspect of the present disclosure is a sulfonated poly(phenylene ether). The sulfonated poly(phenylene ether) has the following formula

Chemical formula

[0015] In one aspect, x in the aforementioned formula may be 1, and the sulfonated poly(phenylene ether) has the following formula [Chemical formula] (wherein Z 1 and Z 2 are as defined above) and has a repeating unit.

[0016] In one aspect, x in the aforementioned formula may be 2, and the sulfonated poly(phenylene ether) may have the following formula [Chemical formula] (wherein Z 1 and Z 2 are as defined above) and may have a repeating unit.

[0017] The sulfonated poly(phenylene ether) of the present disclosure is sulfonated, and thus at least a part of Z 1 or Z 2 is understood to be substituted with a sulfo group (for example, a sulfonic acid group or a sulfonyl chloride group).

[0018] In one aspect, the poly(phenylene ether) may include 2,6-dimethyl-1,4-phenylene ether repeating units, 2,3,6-trimethyl-1,4-phenylene ether units, 2,5-dimethyl-1,4-phenylene ether repeating units, 2,2’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether repeating units, 2-methyl-6-phenyl-1,4-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-1,4-phenylene ether repeating units, 2,2’-6,6’-tetramethoxy-4,4’-dihydroxybiphenyl ether, 3,3’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether units, their sulfonated derivatives, or combinations thereof. As used herein, the term “their sulfonated derivatives” refers to the aforementioned repeating units having at least one substituent substituted with a sulfo group. For example, sulfonated poly(phenylene ether) may have 2,6-dimethyl-3-sulfo-1,4-phenylene ether repeating units, 2,5-dimethyl-3-sulfo-1,4-phenylene ether repeating units, 2,2’,5,5’-tetramethyl-3-sulfo-4,4’-dihydroxybiphenyl ether repeating units, 2-methyl-6-phenyl-3-sulfo-1,4-phenylene ether repeating units, 2,2’-dimethyl-6,6’-3-sulfo-diphenyl-4,4’-dihydroxybiphenyl ether repeating units, 2,6-diphenyl-3-sulfo-1,4-phenylene ether repeating units, 2,2’,6,6’-tetraphenyl-3-sulfo-3-sulfo-4,4’-dihydroxybiphenyl ether repeating units, 2,6-dimethoxy-3-sulfo-1,4-phenylene ether repeating units, 2,2’-6,6’-tetramethoxy-3-sulfo-4,4’-dihydroxybiphenyl ether, or combinations thereof.

[0019] In one aspect, the sulfonated poly(phenylene ether) may have 2,6-dimethyl-1,4-phenylene ether units and 2,6-dimethyl-3-sulfo-1,4-phenylene ether repeating units. In other words, the sulfonated poly(phenylene ether) may be sulfonated poly(2,6-dimethyl-1,4-phenylene ether).

[0020] The sulfonated poly(phenylene ether) has a sulfonation degree of 20 to 50%. As will be described in more detail below, the sulfonation degree may be measured using, for example, proton nuclear magnetic resonance ( 1 1H NMR) spectroscopy. Thus, at least one occurrence of Z 1 or Z 2 is a sulfo group in at least 20% of the repeating units of the sulfonated poly(phenylene ether). Within this range, the sulfonated poly(phenylene ether) may have a sulfonation degree of 20 to 50%, or 20 to 45%, or 20 to 40%, or 20 to 35%.

[0021] The sulfonated poly(phenylene ether) may optionally contain molecules having aminoalkyl-containing end groups typically located ortho to the hydroxy groups. Also, tetramethyldiphenoquinone (TMDQ) end groups are often present, which are typically obtained from a 2,6-dimethylphenol-containing reaction mixture in which tetramethyldiphenoquinone by-products are present.

[0022] The poly(phenylene ether) from which the sulfonated poly(phenylene ether) can be prepared may be in the form of a homopolymer, copolymer, graft copolymer, ionomer, block copolymer, or oligomer and combinations thereof. In one aspect, the poly(phenylene ether) from which the sulfonated poly(phenylene ether) can be prepared may be poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.03 to 2 deciliters / gram (dl / g). For example, the poly(phenylene ether) may have an intrinsic viscosity of 0.25 to 1.7 dl / g, specifically 0.25 to 0.7 dl / g, more specifically 0.35 to 0.55 dl / g, and even more specifically 0.35 to 0.50 dl / g, measured at 25 °C in chloroform using an Ubbelohde viscometer.

[0023] The sulfonated poly(phenylene ether) preferably has a low content of sulfonyl chloride. Specifically, the sulfonated poly(phenylene ether) has a molar ratio of sulfonyl chloride (-SO2Cl) to sulfonic acid (-SO3H) of 0.06 or less. For example, the molar ratio of sulfonyl chloride (-SO2Cl) to sulfonic acid (-SO3H) can be 0.05 or less, or less than 0.05, or 0.04 or less, or more than 0 to 0.04, or 0.001 to 0.04, or 0.01 to 0.04, or 0.02 to 0.04, or 0.03 to 0.04.

[0024] In one aspect, with respect to the sulfonyl chloride groups of the sulfonated poly(phenylene ether), it may have a sulfonation degree of less than 1.25%. In other words, the sulfonated poly(phenylene ether) contains less than 1.25 sulfonyl chloride groups per 100 repeating units. Within this range, with respect to the sulfonyl chloride groups of the sulfonated poly(phenylene ether), it may have a sulfonation degree of 1.2% or less, for example, 0.1 to 1.2%.

[0025] Sulfonated poly(phenylene ether) can have a number average molecular weight of 60,000 to 100,000 grams / mol, a weight average molecular weight of 130,000 to 200,000 grams / mol, and a dispersity of 1.8 to 2.5. The number average molecular weight, weight average molecular weight, and dispersity are measured using gel permeation chromatography in dimethylformamide relative to polystyrene standards, as further described in the following examples.

[0026] Sulfonated poly(phenylene ether) can contain low levels of oligomers. As used herein, the term "oligomer" refers to a phenylene ether molecule having a molecular weight of less than 1000 atomic mass units (amu, interchangeably used with daltons (Da) or grams / mol (g / mol)). For example, sulfonated poly(phenylene ether) may contain less than 1 weight percent, or less than 0.75 weight percent, or less than 0.5 weight percent of oligomers having a molecular weight of less than 1,000 grams / mol, where the weight percent is based on the total weight of the sulfonated poly(phenylene ether). In one aspect, sulfonated poly(phenylene ether) may contain less than 0.7 weight percent, or less than 0.5 weight percent, or less than 0.4 weight percent of oligomers having a molecular weight of less than 500 grams / mol, where the weight percent is based on the total weight of the sulfonated poly(phenylene ether).

[0027] Sulfonated poly(phenylene ether) can advantageously exhibit an ion exchange capacity (IEC) of 1.2 to 2.5, or 1.5 to 2.5 milliequivalents per gram of sulfonated poly(phenylene ether). Unexpectedly, the inventors have discovered that reducing the level of sulfonyl chloride in sulfonated poly(phenylene ether) can improve the IEC. Reduction of the sulfonyl chloride content has advantageously been found to correlate with the flow rate of an overhead nitrogen sweep, as further described below.

[0028] In certain embodiments, the sulfonated poly(phenylene ether) may have sulfonated 2,6-dimethyl-1,4-phenylene ether units. The sulfonated poly(phenylene ether) may have a sulfonation degree of 20 to 35%. The sulfonated poly(phenylene ether) may have a molar ratio of sulfonyl chloride (-SO2Cl):sulfonic acid (-SO3H) of 0.01 to 0.04. In one embodiment, the sulfonated poly(phenylene ether) may have a content of sulfonyl chloride (-SO2Cl) of less than 1.2%, preferably less than 0.1 to 1.2%. The sulfonated poly(phenylene ether) may contain less than 0.5 weight percent of oligomers having a molecular weight of less than 1,000 grams / mol, where the weight percent is based on the total weight of the sulfonated poly(phenylene ether). The sulfonated poly(phenylene ether) may have a number average molecular weight of 60,000 to 100,000 grams / mol, a weight average molecular weight of 130,000 to 200,000 grams / mol, a dispersity of 1.8 to 2.5, and an ion exchange capacity of 1.2 to 2.5 milliequivalents per gram of sulfonated poly(phenylene ether), preferably 1.5 to 2.5 milliequivalents per gram of sulfonated poly(phenylene ether).

[0029] The sulfonated poly(phenylene ether) can be prepared by a method including the step of dissolving poly(phenylene ether) in 1,2-dichloroethane to form a mixture. The poly(phenylene ether) starting material has the following formula

Chemical formula

[0030] In one aspect, the poly(phenylene ether) may include 2,6-dimethyl-1,4-phenylene ether repeating units, 2,3,6-trimethyl-1,4-phenylene ether units, 2,5-dimethyl-1,4-phenylene ether repeating units, 2,2’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether repeating units, 2-methyl-6-phenyl-1,4-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-1,4-phenylene ether repeating units, 2,2’-6,6’-tetramethoxy-4,4’-dihydroxybiphenyl ether, 3,3’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether units, or combinations thereof, and preferably may include 2,6-dimethyl-1,4-phenylene ether units (i.e., in one aspect, the poly(phenylene ether) is poly(2,6-dimethyl-1,4-phenylene ether)). For example, the poly(phenylene ether) may include poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.03 to 2 deciliters / gram (dl / g). Within this range, the poly(phenylene ether) may have an intrinsic viscosity of 0.25 to 1.7 dl / g, specifically 0.25 to 0.7 dl / g, more specifically 0.35 to 0.55 dl / g, and even more specifically 0.35 to 0.50 dl / g (measured at 25 °C in chloroform using an Ubbelohde viscometer).

[0031] In one aspect, the poly(phenylene ether) can include molecules having aminoalkyl-containing end groups typically located ortho to the hydroxy group. Also, tetramethyldiphenoquinone (TMDQ) end groups are often present, which are typically obtained from a reaction mixture containing 2,6-dimethylphenol in which tetramethyldiphenoquinone by-products are present. The poly(phenylene ether) can be in the form of a homopolymer, copolymer, graft copolymer, ionomer, block copolymer, or oligomer, and combinations thereof.

[0032] The mixture of poly(phenylene ether) and solvent can be provided at a temperature of 10 to 85 °C, such as 10 to 60 °C, or 25 to 40 °C. 1,2-Dichloroethane can be present in an amount sufficient to dissolve the poly(phenylene ether). In one aspect, the mixture can contain 1 to 20 wt% of poly(phenylene ether) and 80 to 99 wt% of 1,2-dichloroethane.

[0033] The solvent mixture can then be combined with a sulfonating agent to sulfonate the poly(phenylene ether). Combining the solvent mixture with the sulfonating agent is further carried out in the presence of a co-solvent, preferably ethyl acetate. Alternative exemplary co-solvents can be, for example, as described in WO 2020 / 254885, the content of which is incorporated herein in its entirety.

[0034] The sulfonation reaction can be carried out at a temperature of up to 85 °C, for example, at a temperature of 10 to 85 °C, or 10 to 60 °C, or 25 to 40 °C. The amount of the sulfonating agent added to the solvent mixture may be 0.5 to 1 mole, preferably 0.25 to 0.9 mole, per mole of poly(phenylene ether) dissolved in the solvent mixture. The specific amount of the sulfonating agent added varies depending on the desired sulfonation level of the sulfonation reaction product. The sulfonating agent may be added slowly to the solvent mixture, for example, over 15 to 60 minutes (min) (for example, 30 minutes). After combining the sulfonating agent and the co-solvent with the solvent mixture, the resulting reaction mixture may be stirred for, for example, 60 to 210 minutes before proceeding to precipitation. The stirring can be carried out at a stirring speed effective to keep the reaction mixture homogeneous, for example, at a stirring speed of 50 to 1,000 revolutions per minute (RPM). In one embodiment, the stirring speed may be selected such that the tip speed of the blade is 1 to 8 meters per second (m / s), or 1 to 5 m / s, or 2 to 4 m / s.

[0035] The sulfonating agent is preferably added together with a co-solvent that can desirably prevent the precipitation of the sulfonated poly(phenylene ether) before reaching the desired degree of sulfonation. The sulfonating agent and the co-solvent can preferably be present in a weight ratio of 1:1.5 to 1.5:1, preferably 1:1.1 to 1.1:1.

[0036] During the sulfonation reaction, nitrogen gas can be flowed into the reaction mixture. Without wishing to be bound by theory, it is believed that flowing nitrogen gas into the reaction mixture at a specific flow rate can promote the reduction of the amount of sulfonyl chloride groups in the sulfonation product, for example, by removing HCl by-products. In one aspect, nitrogen gas can be passed through the mixture at a flow rate of 20 milliliters per minute or more per mole of the sulfonating agent. Within this range, the nitrogen gas can be passed through the reaction mixture at a flow rate of 20 to 1500 milliliters per mole of the sulfonating agent, or 25 to 1500 milliliters per mole of the sulfonating agent, or 25 to 1300 milliliters per mole of the sulfonating agent, or 25 to 1050 milliliters per mole of the sulfonating agent, or 25 to 250 milliliters per mole of the sulfonating agent. The aforementioned flow rate of nitrogen gas may also be the case when the occupancy of the reactor is 30% or more.

[0037] The sulfonated poly(phenylene ether) may be precipitated from the solvent mixture, for example, using a poor solvent mixture containing deionized (DI) water. In one aspect, at least one of hexane and heptane can be used, for example, together with deionized water, to precipitate the sulfonated poly(phenylene ether) from the reaction mixture. The reaction mixture may be added (e.g., slowly) to the poor solvent mixture, and the poor solvent mixture can be used in an amount sufficient to induce precipitation. For example, 100 grams (g) of the reaction mixture may be added to 300 to 700 g, preferably 390 to 595 g, of a poor solvent mixture having a weight ratio of hexane to water in the range of 0 to 1.15.

[0038] The precipitated sulfonated poly(phenylene ether) can be filtered and optionally washed and dried. The filtrate can be biphasic with an organic phase that is 1,2-dichloroethane, a co-solvent, and optionally an organic (e.g., hexane) that was part of the poor solvent mixture, and an aqueous phase that is water. Thus, the filtrate can be further processed to recover at least one of 1,2-dichloroethane, the co-solvent, or water, preferably recovering 1,2-dichloroethane and the co-solvent, and more preferably recovering 1,2-dichloroethane, the co-solvent, and water. Recovering the materials can include decanting the biphasic filtrate to form aqueous and organic streams. The organic stream can be further processed, e.g., by distillation, to recover 1,2-dichloroethane and / or the co-solvent. The recovered materials can be reused.

[0039] An exemplary method for manufacturing a sulfonated poly(phenylene ether) according to the present disclosure is schematically shown in FIG. 1. As shown, in this method, it is necessary to introduce poly(phenylene ether) and 1,2-dichloroethane into a mixing vessel 10. The mixing vessel 10 can be maintained at a temperature from room temperature to a maximum of 85° C., for example, 30° C. to 85° C., or 30 to 60° C., preferably 30° C. to 45° C. Inside the mixing vessel 10, the poly(phenylene ether) and 1,2-dichloroethane can be mixed, for example, until homogeneous to form a solvent mixture. Optionally, mixing may be continued until a homogeneous and transparent solution is obtained. The solvent mixture from the mixing vessel 10 can be treated in a reaction vessel 20 with a sulfonating agent and a co-solvent (for example, ethyl acetate). By passing nitrogen gas through the reaction mixture in the reaction vessel 20, the degree of sulfuryl chloride can be kept low. Then, for example, when the desired degree of sulfonation is reached, the sulfonated poly(phenylene ether) can be precipitated from the mixture in a precipitation unit 30. For example, the reaction solvent mixture can be slowly added to a poor solvent mixture (for example, a poor solvent mixture of hexane and DI water) to induce precipitation of the sulfonated poly(phenylene ether). The precipitated sulfonated poly(phenylene ether) can be separated from the liquid phase, for example, in a filtration unit 40, and then the sulfonated poly(phenylene ether) can be washed, for example, in washing units 50, 52 (for example, using DI water), and dried, for example, in a dryer 54. The washing liquid from the washing units 50, 52 can optionally be separated into a water stream and a hexane stream in a decantation unit 56. The hexane stream can optionally be reused in a recycle unit 50. On the other hand, the liquid phase from the filtration unit 40 can be treated, for example, in a decantation unit 60 using liquid-liquid separation to remove water. The recovered aqueous phases from the decantation unit 60 and the decantation unit 56 can be treated in a multiple effect evaporator (MEE) 70 to recover water. The obtained water can optionally be reused, for example, in a recycle unit 50, a washing unit 52, or a precipitation unit 30, preferably in a recycle unit 50.The 1,2-dichloroethane (EDC) stream from the decantation unit 60 can be further processed to separate EDC by distillation in unit 80. The separated EDC can optionally be reused, for example, in the mixing vessel 10.

[0040] Sulfonated poly(phenylene ether) can be useful in a variety of products. For example, sulfonated poly(phenylene ether) can be useful in ion exchange membranes (e.g., for dialysis), proton conducting membranes (e.g., 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. Accordingly, membranes containing sulfonated poly(phenylene ether) represent another aspect of the present disclosure. Membranes containing sulfonated poly(phenylene ether) can be prepared, for example, by casting a film containing sulfonated poly(phenylene ether), optionally onto a substrate. Exemplary substrates include, for example, synthetic woven fabrics (e.g., polypropylene cloth, polyacrylonitrile cloth, polyacrylonitrile-vinyl chloride copolymer cloth, polyvinyl chloride cloth, polyester cloth, etc.), glass filter cloth, polyvinylidene chloride screen, abrasive paper, treated cellulose battery paper, polystyrene-coated glass fiber mat, polyvinyl chloride battery paper, and the like. Any suitable casting method, such as solution casting, drop casting, spin coating, doctor blade, roller coating, etc., or combinations thereof, may be used. The membrane preferably includes at least one layer containing sulfonated poly(phenylene ether). Precursors for porous carbon represent another aspect of the present disclosure. Porous carbon can be useful, for example, as a molecular sieve carbon membrane for gas separation. Porous carbon molecular sieve membranes can be produced, for example, by pyrolyzing a precursor polymer containing the sulfonated poly(phenylene ether) of the present disclosure. The porous carbon may have micropores (e.g., with a diameter of 0.01 micrometer or less), macropores (e.g., with a diameter of 0.01 - 100 micrometers), or a combination thereof.

Example

[0041] The present disclosure is further illustrated by the following examples, which are not limiting.

[0042] Sulfonated poly(phenylene ether) was prepared using the following exemplary procedure.

[0043] A reactor equipped with a stirrer was maintained at 40 °C. Poly(phenylene ether) (PPE) resin (10 parts by weight) was dissolved in 1,2-dichloroethane (93.9 parts by weight) until a homogeneous and clear solution was obtained (e.g., for 60 minutes). The relative ratio of poly(phenylene ether) and 1,2-dichloroethane can be varied as further described below. The temperature was maintained at 40 °C. Chlorosulfonic acid (5.7 parts by weight) and ethyl acetate (6.1 parts by weight) were transferred to the reactor over 40 minutes with vigorous stirring. The relative ratio of chlorosulfonic acid and ethyl acetate can also be varied according to the desired degree of sulfonation, as further described below. A nitrogen purge was maintained through the headspace of the reaction mixture, and rapid stirring was maintained. The amount of nitrogen flow through the headspace of the reaction mixture was varied as further described below. When the desired degree of sulfonation was obtained as measured by proton nuclear magnetic resonance ( 1 1H NMR) spectroscopy, the reaction mixture was then slowly transferred to a washing container containing DI water (500 milliliters) at a temperature of 10 °C and equipped with four stirring blades with a diameter of about 60 mm, and operated at 1,000 rpm such that the tip speed of the blades was 3.14 m / s. Subsequently, the temperature was raised to 25 °C after 1 hour. Stirring was continued for a total of 30 minutes. Filtration was then carried out. The residue (sPPE) was then reslurried with a DI water / hexane mixture (200 milliliters of DI water, 19.7 milliliters of hexane) and refiltered. The residue was thoroughly washed with DI water (200 milliliters for each wash) until a neutral pH was obtained as measured by potentiometric titration. The sulfonated material was then dried under vacuum at room temperature (e.g., 25 °C) for up to 72 hours.

[0044] The degree of substitution (also called the sulfonation degree or sulfonation level) indicates the proportion of repeating units having sulfonic acid groups along the molecular chain of the sulfonated polymer. The degree of substitution (DS) was measured by nuclear magnetic resonance (NMR) spectroscopy. The sample was dissolved in dimethyl sulfoxide-d6 (DMSO-d6, also known as deuterated DMSO) (using overnight shaking on a reciprocating shaker), and 32 scans were averaged with a delay time of 5 seconds. If there was an undissolved portion, the solvent vial was sonicated in a 45 °C water bath for 15 - 30 minutes.

[0045] The sulfonation degree can be calculated from either aliphatic protons or aromatic protons. Considering aromatic protons, it is as follows: [Number] Considering aliphatic protons, it is as follows: [Number] where I is the integral value of the NMR chemical shift at a given ppm.

[0046] The molecular weight of the sulfonated poly(phenylene ether) was measured by gel permeation chromatography (GPC) using dimethylformamide as the mobile phase and 0.1 wt% lithium bromide as an additive based on the weight of the mobile phase. Two Agilent (e.g., 2 columns) PLgel 5 micrometers (μm) MIXED-B, 300 × 7.5 mm, one with a guard, were used for elution of sPPE at a flow rate of 1 milliliter per minute (ml / min) and a column temperature of 50 °C. An ultraviolet (UV) detector (275 nanometers (nm)) was used to record the GPC chromatogram of sPPE at an elution time of 30 minutes. The sample was slowly dissolved in a dimethylformamide solvent at a concentration of 3 milligrams per milliliter (mg / ml) for about 4 - 6 hours using a reciprocating shaker. The solution was filtered through a 0.45 μm PTFE filter, placed in a GPC autosampler vial, and analyzed. The GPC system was calibrated with polystyrene standards in the range of 580 Daltons (Da) to 6570 kDa. Shimadzu's Labsolution software was used for baseline point setting. The dispersity ( [Number] ) was measured as follows. [Number]

[0047] The oligomer content was measured using the slice data generated by the GPC software and the GPC chromatograms obtained for each sample using the above method. This software was used to "slice" the chromatogram and calculate the molecular weight and content of each slice. For each sample, the oligomer content of oligomers with a molecular weight less than 1000 amu and less than 500 amu was measured.

[0048] As shown in Table 2 below, by the procedure described herein, a sulfonated poly(phenylene ether) was obtained that has a high degree of sulfonation (e.g., greater than 15%), retains a high molecular weight (e.g., Mn greater than 60,000 grams / mole), and has a low level of residual oligomers.

[0049]

Table 1

[0050]

Table 2

[0051] Without wishing to be bound by theory, the presence of sulfonyl chloride groups in the sulfonated poly(phenylene ether) is thought not to contribute to the ion exchange capacity of the material. Thus, it would be advantageous to provide a sulfonated poly(phenylene ether) with a reduced sulfonyl chloride content in order to provide a material with improved ion exchange capacity.

[0052] For this purpose, the inventors attempted to reduce the sulfonyl chloride content using an overhead nitrogen sweep to minimize or remove the formation of sulfonyl chloride in the sulfonated poly(phenylene ether) product. As shown in Table 3, the inventors unexpectedly discovered that the flow rate of nitrogen passing through the reaction mixture can affect the sulfonyl chloride content in the resulting sulfonated poly(phenylene ether). Advantageously, it was discovered that the sulfonated poly(phenylene ether) with reduced sulfonyl chloride content improves the IEC.

[0053] IEC indicates the number of milliequivalents of ions in 1 g of dry polymer. IEC was measured by dissolving sPPE in a mixture of dimethylacetamide / isopropyl alcohol and titrating with alcoholic potassium hydroxide by the potentiometric method. This non-aqueous titration was carried out using a Solvotrode (commercially available from Metrohm USA) as the electrode. This method uses a two-solvent system. This gives a sharp and reproducible endpoint.

[0054] The sample was dissolved in dimethylacetamide and diluted with isopropyl alcohol to obtain a reproducible ion exchange capacity. With only dimethylacetamide, there was significant variation in the repeated analysis and a sharp endpoint could not be obtained. Without being limited by theory, this two-solvent system is thought to be useful for controlling polarity and reaching a sharp and reproducible endpoint. [Number] Wherein, A = volume in ml of 0.1N potassium hydroxide (KOH) solution required for titration, B = volume in ml of 0.1N KOH solution required for the blank, F = normality of 0.1N KOH solution, and S = weight of the sample in grams.

[0055] The concentrations of sulfonic acid (SO3H) and sulfonyl chloride (SO2Cl) groups were measured by measuring the total concentrations of elemental sulfur (S) and chlorine (Cl) using elemental analysis using CHNS and combustion ion chromatography, respectively. Free amounts of elemental S (measured as sulfate) and Cl (measured as chloride) were measured using extraction ion chromatography.

[0056] Table 3 below provides the amounts or ratios of various reaction components of Examples 2 to 12 and further investigates the effect of the flow rate of nitrogen sweep on the sulfonyl chloride content. The amounts of various residual components, degree of sulfonation, and ion exchange capacity (IEC) of each example are provided.

[0057]

Table 3

[0058]

Table 4

[0059] As shown in Tables 2 and 3, sulfonated poly(phenylene ether) products with a sulfonation degree (DS) of 16.8 - 31.8% were obtained by the method described herein. The total of this sulfonation degree includes -SO3H groups and -SO2Cl groups. By analyzing the total amount and free amount of elements S and Cl using the above CHNS, combustion ion chromatography, and extraction ion chromatography, the sulfonation degree can be further decomposed into the percentage of -SO3H and the percentage of -SO2Cl contributing to the total DS.

[0060] Table 3 further shows the relationship between the flow rate of nitrogen sweep in the headspace during the sulfonation reaction and the resulting -SO2Cl content. In Examples 2 - 8, an N2 sweep with a flow rate of 50 - 100 ml / min was used (corresponding to a standardized N2 sweep flow rate of 81.8 - 204.4 ml / min per mole of CSA1), showing a -SO2Cl content of less than 1.2% (e.g., 0.77 - 1.17%). Each of Examples 2 - 8 showed a -SO2Cl:-SO3H molar ratio of 0.04 or less (e.g., 0.03 - 0.04).

[0061] In each of these examples, as shown in Table 2, a high molecular weight was further maintained with Mn of 77,000 - 97,000 grams / mole, Mw of 158,000 - 190,000, and a dispersity of 2.0 - 2.1. The oligomer content was also advantageously minimized, with each example having an oligomer with a molecular weight of 1000 amu or less of 0.5 weight percent or less. The oligomer with a molecular weight of 500 amu or less was limited to 0.4 weight percent or less.

[0062] Examples 1 and 9 - 12 each showed a -SO2Cl content of 0.92 - 1.86 and a -SO2Cl:-SO3H molar ratio of 0.05 - 0.06. It should be noted that the N2 sweep flow rates for Examples 1 and 9 - 12 were lower than those for Examples 2 - 8 at equivalent reaction yields (see, for example, "Normalized N2 sweep" in Table 3, where the N2 sweep flow rate is normalized based on the amount (e.g., moles) of CSA used).

[0063] Table 3 also generally shows an increase in IEC (e.g., IEC of 1.87 meq / gram or more) for samples with a decreased -SO2Cl content (e.g., DS SO2Cl is 0.77 - 1.17%, -SO2Cl:-SO3H molar ratio of 0.04 or less). Examples with a high -SO2Cl content (e.g., DS SO2Cl is 0.92 - 1.86%) generally showed a decrease in IEC (e.g., 1.17 - 1.77 meq / gram or less).

[0064] Accordingly, the present disclosure advantageously provides a sulfonated poly(phenylene ether) having a combination of a sulfonation degree of 20 - 50%, a number average molecular weight of 60,000 - 100,000 grams / mole, a dispersity of 2.0 - 2.1, and a reduced amount of -SO2Cl.

[0065] The present disclosure further encompasses the following aspects.

[0066] Aspect 1: The following formula

Chemical formula

[0067] Aspect 2: The sulfonated poly(phenylene ether) according to Aspect 1, wherein the sulfonyl chloride (-SO2Cl):sulfonic acid (-SO3H) molar ratio is 0.05 or less, or less than 0.05, or 0.04 or less, or more than 0 to 0.04, or 0.001 to 0.04, or 0.01 to 0.04, or 0.02 to 0.04, or 0.03 to 0.04.

[0068] Aspect 3: A sulfonated poly(phenylene ether) according to Aspect 1 or 2, comprising a 2,6-dimethyl-1,4-phenylene ether repeating unit, a 2,3,6-trimethyl-1,4-phenylene ether unit, a 2,5-dimethyl-1,4-phenylene ether repeating unit, a 2,2’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether repeating unit, a 2-methyl-6-phenyl-1,4-phenylene ether repeating unit, a 2,2’-dimethyl-6,6’-diphenyl-4,4’-dihydroxybiphenyl ether repeating unit, a 2,6-diphenyl-1,4-phenylene ether repeating unit, a 2,2’,6,6’-tetraphenyl-4,4’-dihydroxybiphenyl ether repeating unit, a 2,6-dimethoxy-1,4-phenylene ether repeating unit, a 2,2’-6,6’-tetramethoxy-4,4’-dihydroxybiphenyl ether, a 3,3’,5,5’-tetramethyl-4,4’-dihydroxybiphenyl ether unit, a sulfonated derivative thereof, or a combination thereof.

[0069] Aspect 4: A sulfonated poly(phenylene ether) according to any one of Aspects 1 to 3, having a number average molecular weight of 60,000 to 100,000 grams / mol, a weight average molecular weight of 130,000 to 200,000 grams / mol, and a dispersity of 1.8 to 2.5, wherein the number average molecular weight, weight average molecular weight, and dispersity are measured using gel permeation chromatography in dimethylformamide relative to polystyrene standards.

[0070] Aspect 5: A sulfonated poly(phenylene ether) according to any one of Aspects 1 to 4, containing less than 1 weight percent, or less than 0.75 weight percent, or less than 0.5 weight percent of an oligomer having a molecular weight of less than 1,000 grams / mol, wherein the weight percent is based on the total weight of the sulfonated poly(phenylene ether).

[0071] Aspect 6: A sulfonated poly(phenylene ether) according to any one of Aspects 1 to 5, containing less than 0.7 wt%, or less than 0.5 wt%, or less than 0.4 wt% of an oligomer having a molecular weight of less than 500 g / mol, based on the total weight of the sulfonated poly(phenylene ether).

[0072] Aspect 7: A sulfonated poly(phenylene ether) according to any one of Aspects 1 to 6, showing an ion exchange capacity of 1.5 to 2.5 milliequivalents per gram of the sulfonated poly(phenylene ether).

[0073] Aspect 8: A sulfonated poly(phenylene ether) according to Aspect 1, having sulfonated 2,6-dimethyl-1,4-phenylene ether units, a sulfonation degree of 20 to 35%, a molar ratio of sulfonyl chloride (-SO2Cl) to sulfonic acid (-SO3H) of 0.01 to 0.04, and less than 0.5 wt% of an oligomer having a molecular weight of less than 1000 g / mol, based on the total weight of the sulfonated poly(phenylene ether), a number average molecular weight of 60,000 to 100,000 g / mol, a weight average molecular weight of 130,000 to 200,000 g / mol, a dispersity of 1.8 to 2.5, and an ion exchange capacity of 1.2 to 2.5 milliequivalents per gram of the sulfonated poly(phenylene ether).

[0074] Aspect 9: A sulfonated poly(phenylene ether) according to any one of Aspects 1 to 8, produced by a method comprising the steps of dissolving poly(phenylene ether) in 1,2-dichloroethane to form a mixture, combining a sulfonating agent and a co-solvent, preferably ethyl acetate, with the mixture to form a sulfonated poly(phenylene ether), passing nitrogen gas through the mixture at a flow rate of 25 milliliters per minute or more per mole of the sulfonating agent, precipitating the sulfonated poly(phenylene ether), and separating the precipitated sulfonated poly(phenylene ether).

[0075] Aspect 10: A method for producing a sulfonated poly(phenylene ether) according to any one of Aspects 1 to 9, comprising the steps of dissolving the poly(phenylene ether) in 1,2-dichloroethane to form a mixture, combining a sulfonating agent and a co-solvent, preferably ethyl acetate, with the mixture to form the sulfonated poly(phenylene ether), passing nitrogen gas through the mixture at a flow rate of 30 milliliters or more per minute per mole of the sulfonating agent, precipitating the sulfonated poly(phenylene ether), and separating the precipitated sulfonated poly(phenylene ether).

[0076] Aspect 11: The method according to Aspect 10, wherein the dissolving step is carried out at a temperature of 30°C to 85°C.

[0077] Aspect 12: The method according to Aspect 10 or 11, wherein the mixture contains 1 to 20% by weight of poly(phenylene ether) and 80 to 99% by weight of 1,2-dichloroethane.

[0078] Aspect 13: The method according to any one of Aspects 10 to 12, wherein the sulfonating agent and the co-solvent are present in a weight ratio of 1:1.5 to 1.5:1, preferably 1:1.1 to 1.1:1.

[0079] Aspect 14: A membrane comprising a sulfonated poly(phenylene ether) according to any one of Aspects 1 to 9.

[0080] Aspect 15: The membrane according to Aspect 14, which is an ion exchange membrane.

[0081] Aspect 16: A precursor of porous carbon, comprising a sulfonated poly(phenylene ether) according to any one of Aspects 1 to 9.

[0082] Aspect 17: The precursor according to Aspect 16, wherein the porous carbon comprises micropores having a diameter of less than 0.01 micrometer, macropores having a diameter of 0.01 to 100 micrometers, or a combination thereof.

[0083] Compositions, methods, and articles can alternatively include, consist of, or consist essentially of any suitable materials, steps, or components disclosed herein. Compositions, methods, and articles can additionally or alternatively be formulated so as to not include, or substantially not include, any materials (or species), steps, or components that are not necessary to achieve the functions or objectives of the compositions, methods, and articles.

[0084] All ranges disclosed herein include their endpoints, and the endpoints can be combined independently of each other. "Combination" includes blends, mixtures, alloys, reaction products, and the like. Terms such as "first," "second," etc. do not indicate order, quantity, or importance, but are used to distinguish one element from another. The terms "a," "an," and "the" do not indicate a limitation of quantity and should be construed to include both the singular and plural forms unless otherwise indicated herein or clearly contradicted by the context. "Or" means "and / or" unless otherwise specified. References to "one aspect" throughout this specification mean that a particular element described in connection with that aspect is included in at least one aspect described herein and may or may not be present in other aspects. As used herein, the term "combinations thereof" is open-ended and includes one or more of the recited elements and the presence of one or more similar elements not named. Further, it should be understood that the recited elements can be combined in any suitable manner in various aspects.

[0085] Unless otherwise specified herein, all test standards are the latest valid standards as of the filing date of this application, or, if priority is claimed, as of the filing date of the earliest priority application in which the test standard is published.

[0086] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. All patents, patent applications, and other references cited are hereby incorporated by reference in their entirety. However, if the terms of this application conflict or are inconsistent with the terms of the incorporated references, the terms of this application shall control over the conflicting terms of the incorporated references.

[0087] Compounds are described using standard nomenclature. For example, any position not substituted by any indicated group is understood to have its valence satisfied by the indicated bond or hydrogen atom. A dash ("-") not between two letters or symbols is used to indicate the point of attachment of a substituent. For example, -CHO is attached through the carbon of the carbonyl group.

[0088] As used herein, the term "hydrocarbyl," whether used by itself or as a prefix, suffix, or fragment of another term, refers to a residue containing only carbon and hydrogen. The residue may be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched-chain, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight-chain, cyclic, bicyclic, branched-chain, saturated, and unsaturated hydrocarbon moieties. However, when a hydrocarbyl residue is described as being substituted, it may optionally contain heteroatoms in addition to the carbon and hydrogen members of the substituent residue. Thus, especially when described as being substituted, a hydrocarbyl residue can also contain one or more carbonyl groups, amino groups, hydroxyl groups, etc., or can contain heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" means a branched or straight-chain saturated aliphatic hydrocarbon group, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, and n- or s-hexyl. "Alkenyl" means a straight-chain or branched-chain monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HC=CH2)). "Alkoxy" means an alkyl group bonded through oxygen (i.e., alkyl-O-), such as methoxy, ethoxy, and sec-butyloxy groups. "Alkylene" means a straight-chain or branched-chain saturated divalent aliphatic hydrocarbon group (e.g., methylene (-CH2-) or propylene (-(CH2)3-)). "Cycloalkylene" means a divalent cyclic alkylene group, -C n H 2n-xmeans that, in the formula, x is the number of hydrogens replaced by cyclization. "Cycloalkenyl" means a monovalent group having one or more rings and one or more carbon-carbon double bonds within the ring, with all ring members being carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing a specific number of carbon atoms, and examples include 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 containing one or more of fluoro, chloro, bromo, or iodo substituents. Combinations of different halo atoms (e.g., bromo and fluoro), or only chloro atoms can be present. The prefix "hetero" means that a compound or group contains at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatoms), and the heteroatoms are each independently N, O, S, Si, or P. "Substituted" means that a compound or group is each independently substituted with, instead of hydrogen, C1-9 alkoxy, C1-9 haloalkoxy, nitro (-NO2), cyano (-CN), C1-6 alkylsulfonyl (-S(=O)2-alkyl), C6- 12 arylsulfonyl (-S(=O)2-aryl), thiol (-SH), thiocyano (-SCN), tosyl (CH3C6H4SO2-), C3- 12 cycloalkyl, C2- 12 alkenyl, C5- 12 cycloalkenyl, C6- 12 aryl, C7- 13 arylalkylene, C4- 12 heterocycloalkyl, and C3- 12 heteroaryl and is meant to be substituted with at least one (e.g., 1, 2, 3, or 4) substituent that can be, provided that the normal valence of the substituted atom is not exceeded. The number of carbon atoms shown within the group excludes any substituents. For example, -CH2CH2CN is a C2 alkyl group substituted with nitrile.

[0089] Although specific embodiments have been described, applicants or those skilled in the art may conceive of alternatives, variations, modifications, improvements, and substantial equivalents that are not currently foreseeable or possible. Accordingly, the appended claims, which may be filed and amended, are intended to cover all such alternatives, variations, modifications, improvements, and substantial equivalents.

Claims

1. The following formula 【Chemistry 1】 (In the above formula, Z １ However, each instance independently involves a sulfonic acid group, sulfonyl chloride group, halogen, and hydrocarbyl group, which are not tertiary hydrocarbyl unsubstituted or substituted C atoms. １～１２ Hydrocarbil, C １～１２ Hydrocarbylthio, C １～１２ Hydrocarbyl oxy, or C ２～１２ It is a halohydrocarbyloxy, in which at least two carbon atoms separate the halogen atom and the oxygen atom. Z ２ is, independently for each occurrence, a sulfonic acid group, a sulfonyl chloride group, hydrogen, a halogen, a hydrocarbyl group that is not a tertiary hydrocarbyl, an unsubstituted or substituted C １～１２ hydrocarbyl, C １～１２ hydrocarbylthio, C １～１２ hydrocarbyloxy, or C ２～１２ halohydrocarbyloxy, where at least two carbon atoms separate a halogen atom and an oxygen atom, A repeating unit where x is 1 or 2, The degree of sulfonation of 20-50% measured by nuclear magnetic resonance spectroscopy, 0.06 or less sulfonyl chloride (-SO ２ Cl): Sulfonic acid (-SO ３ The molar ratio of H) and A sulfonated poly(phenylene ether) characterized by having the following properties.

2. The sulfonated poly(phenylene ether) according to claim 1, wherein the sulfonyl chloride (-SO ２ Cl): Sulfonic acid (-SO ３ A sulfonated poly(phenylene ether) characterized in that the molar ratio of H) is 0.05 or less, or less than 0.05, or 0.04 or less, or greater than 0 to 0.04, or 0.001 to 0.04, or 0.01 to 0.04, or 0.02 to 0.04, or 0.03 to 0.

04.

3. The sulfonated poly(phenylene ether) according to claim 1, comprising a repeating unit of 2,6-dimethyl-1,4-phenylene ether, a repeating unit of 2,3,6-trimethyl-1,4-phenylene ether, a repeating unit of 2,5-dimethyl-1,4-phenylene ether, a repeating unit of 2,2',5,5'-tetramethyl-4,4'-dihydroxybiphenyl ether, a repeating unit of 2-methyl-6-phenyl-1,4-phenylene ether, a repeating unit of 2,2'-dimethyl-6,6'-diphenyl-4,4'-dihydroxybiphenyl ether, a repeating unit of 2,6-diphenyl-1,4-phenylene ether, a repeating unit of 2,2',6,6'-tetraphenyl-4,4'-dihydroxybiphenyl ether, a repeating unit of 2,6-dimethoxy-1,4-phenylene ether, a repeating unit of 2,2'-6,6'-tetramethoxy-4,4'-dihydroxybiphenyl ether, and 3,3',5,5'-tetramethyl-4,4' A sulfonated poly(phenylene ether) characterized by comprising dihydroxybiphenyl ether units, sulfonated derivatives thereof, or combinations thereof.

4. A sulfonated poly(phenylene ether) according to claim 1, Number-average molecular weight of 60,000 to 100,000 grams / mol, Weight-average molecular weight of 130,000 to 200,000 grams / mol, and 1.8 to 2.5 variance, It has, A sulfonated poly(phenylene ether) characterized by the number-average molecular weight, weight-average molecular weight, and degree of dispersion being measured using gel permeation chromatography with dimethylformamide against a polystyrene standard.

5. A sulfonated poly(phenylene ether) according to claim 1, comprising less than 1 weight percent, less than 0.75 weight percent, or less than 0.5 weight percent of an oligomer having a molecular weight of less than 1,000 grams / mol, wherein the weight percent is based on the total weight of the sulfonated poly(phenylene ether).

6. A sulfonated poly(phenylene ether) according to claim 1, comprising less than 0.7% by weight, less than 0.5% by weight, or less than 0.4% by weight of an oligomer having a molecular weight of less than 500 grams / mol, wherein the weight percentage is based on the total weight of the sulfonated poly(phenylene ether).

7. A sulfonated poly(phenylene ether) according to claim 1, characterized in that it exhibits an ion exchange capacity of 1.5 to 2.5 milliequivalents per gram of sulfonated poly(phenylene ether).

8. A sulfonated poly(phenylene ether) according to claim 1, Sulfonated 2,6-dimethyl-1,4-phenylene ether unit, Sulfonation degree of 20-35%, 0.01 to 0.04 sulfonyl chloride (-SO ２ Cl): Sulfonic acid (-SO ３ The molar ratio of H) and Oligomers having a molecular weight of less than 1,000 grams / mol, less than 0.5 weight percent, It has, The weight percentage is based on the total weight of the sulfonated poly(phenylene ether), Number-average molecular weight of 60,000 to 100,000 grams / mol, Weight-average molecular weight of 130,000 to 200,000 grams / mol, A variance of 1.8 to 2.5, and A sulfonated poly(phenylene ether) characterized by having an ion exchange capacity of 1.2 to 2.5 milliequivalents per gram of sulfonated poly(phenylene ether).

9. A sulfonated poly(phenylene ether) according to claim 1, The steps include: dissolving poly(phenylene ether) in 1,2-dichloroethane to form a mixture; The step of combining a sulfonating agent and a co-solvent with the mixture to form the sulfonated poly(phenylene ether), and the step of passing nitrogen gas through the mixture at a flow rate of 25 milliliters per minute or more per mole of sulfonating agent, The step of precipitating the sulfonated poly(phenylene ether), The steps include separating the precipitated sulfonated poly(phenylene ether) and A sulfonated poly(phenylene ether) characterized by being manufactured by a method comprising the above.

10. A method for producing the sulfonated poly(phenylene ether) described in claim 1, The steps include: dissolving poly(phenylene ether) in 1,2-dichloroethane to form a mixture; The steps include: combining a sulfonating agent and a co-solvent with the mixture to form the sulfonated poly(phenylene ether); passing nitrogen gas through the mixture at a flow rate of 30 milliliters per minute or more per mole of sulfonating agent; The step of precipitating the sulfonated poly(phenylene ether), A method characterized by including the following.

11. A method according to claim 10, characterized in that the dissolving step is performed at a temperature of 30°C to 85°C.

12. The method according to claim 10, wherein the mixture is 1 to 20% by weight of the poly(phenylene ether), and 80 to 99% by weight of the 1,2-dichloroethane, A method characterized by including

13. A method according to claim 10, characterized in that the sulfonating agent and the cosolvent are present in a weight ratio of 1:1.5 to 1.5:

1.

14. A film characterized by containing the sulfonated poly(phenylene ether) described in claim 1.

15. A membrane according to claim 14, characterized in that it is an ion exchange membrane or a gas separation membrane.

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