Preparation method of polyarylether sulfone resin

Abstract

The invention relates to a preparation method of polyarylether sulfone resin, which comprises the following steps: introducing split phases into a reaction liquid, extracting low-molecular-weight polyarylether sulfone through liquid-liquid split phases, and in a rapid precipitation and solidification process, solidifying the extracted low-molecular-weight part into superfine powder while solidifying a high-molecular-weight product into larger particles, thereby obtaining the polyarylether sulfone resin. And removing the superfine powder through screening. The weight-average molecular weight of the prepared polyarylether sulphone resin is between 25000 and 60000, the content of cyclic dimer is less than 1wt%, and the molecular weight distribution (PD) is less than 3. Compared with the prior art, the preparation method disclosed by the invention has the advantages that repeated washing and purification are not needed, and the polyarylether sulfone with low cyclic dimer content and narrow molecular weight distribution can be prepared.

Description

Technical Field

[0001] This invention relates to the field of polymer synthesis technology, and in particular to a method for preparing polyarylether sulfone resin. Background Technology

[0002] Polyarylethersulfone (hereinafter referred to as polysulfone) is a high-performance polymer with excellent heat resistance, good mechanical properties, and flame retardancy. It is widely used in automobiles, aerospace, medical devices, household appliances, and separation membranes. Currently, commercially successful polysulfones include bisphenol A polysulfone (PSU), polyethersulfone (PES), and polyphenylsulfone (PPSU). The industrial synthesis method involves the stepwise polymerization of aromatic bisphenols with 4,4'-dichlorodiphenyl sulfone under alkaline catalysis via a high-temperature solution method. Bisphenol A is used to generate PPSU, bisphenol S is used to generate PES, and bisphenol A is used to generate PSU. Specific information on the synthesis methods can be found in references such as RN Johnson et al., J. Polym. Sci. A-1 5 (1967) 2375, and JEMc Grathet. al., Polymer 25 (1984) 1827.

[0003] As can be seen from the literature, for example, Savariar et al., Desalination 144 (2002) 15-20, polysulfone resins contain a large amount of cyclic oligomers, resulting in a wide molecular weight distribution, mainly due to the unavoidable chain cyclization reaction during solution polymerization. The presence of cyclic oligomers affects various aspects of the product's performance, such as increased mold fouling during injection molding and decreased mechanical properties. Particularly when applied to the preparation of downstream polysulfone separation membranes, cyclic oligomers in the membrane-forming solution easily crystallize and precipitate, causing turbidity and affecting the membrane preparation process and the performance of the resulting membrane. Therefore, it is essential to develop a method for preparing polysulfone resins with low cyclic oligomer content.

[0004] Patent CN116178719A provides a purification and molecular weight fractionation process for polysulfone. After the reaction is completed and cooled, the reaction solution is first appropriately diluted, and then water is added in batches as a precipitant. After each addition of the precipitant, the precipitated polysulfone particles are separated, followed by further washing and purification to obtain a group of polysulfone resins with a narrow molecular weight distribution (PD<2). The purification process involves numerous steps. Patent CN1057783C discloses a synthesis technology for narrow-distribution polyethersulfone (PES) resin. This invention uses KOH instead of NaOH, and the post-treatment involves cooling the reaction solution to room temperature for curing. After pulverization, the resin is boiled and washed eight times with distilled water, producing PES resin with a molecular weight distribution between 2 and 3. Patent WO2024 / 008502 describes a method that optimizes the initial concentration of the two monomers at 2.2-2.7 mol / L and the heating rate to above 0.4 K / min. After the reaction is completed and cooled to room temperature, the reaction solution is purified by precipitation in water. The resulting product contains less than 1.1 wt% cyclic dimers, and the turbidity of the film-forming solution after standing for 7 days is less than 1.95. However, this method has drawbacks, such as numerous purification steps or long purification times. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing polyarylether sulfone resin to solve the above-mentioned problems. This invention introduces phase separation into the reaction solution, extracts low molecular weight polysulfone through liquid-liquid phase separation, and then solidifies the extracted low molecular weight fraction into fine powder during rapid precipitation and solidification. This powder is then effectively removed by sieving. The resulting polysulfone resin has a weight-average molecular weight between 25,000 and 60,000, a cyclic dimer content of less than 1 wt%, and a molecular weight distribution (PD) of less than 3. The method of this invention can effectively remove low molecular weight polyarylether sulfone, including cyclic oligomers, without the need for repeated washing and purification, and produces polyarylether sulfone with low cyclic dimer content and narrow molecular weight distribution.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] The purpose of this invention is to provide a method for preparing polyarylene ether sulfone resin, the method comprising the following steps:

[0008] (1) Using dihalogen monomers and diphenol monomers as reaction monomers, polar organic reaction solvents as reaction solvents, and alkali metal basic salts as catalysts, polyarylether sulfone reaction solution is obtained through polymerization reaction.

[0009] (2) Under closed stirring conditions, water is added to the polyarylether sulfone reaction solution obtained in step (1), cooled to 140-180℃, and stirred continuously to obtain a phase-separated reaction solution.

[0010] (3) The phase-separated reaction liquid obtained in step (2) is not cooled down, but is placed in a low-temperature precipitation solvent for cooling and precipitation to obtain a precipitate mixture. Then, the precipitate mixture is sieved with a sieve, and the sieve residue is taken. Water is added to disperse the residue, and the residue is sieved again. The sieve residue is taken again, and the sieve residue is mixed with water and then heated and washed multiple times. After each heating and washing, the residue is cooled and filtered. Water is added again for the next heating and washing. Finally, the filter cake is dried to obtain polyarylene ether sulfone resin. The obtained polyarylene ether sulfone resin is a polyarylene ether sulfone resin with narrow distribution and low cyclic oligomer content.

[0011] Further, in step (1), preferably after feeding, the molar ratio of the dihalomonomer to the diphenol monomer is 0.98-1.06.

[0012] Further, in step (1), preferably after feeding, the molar ratio of the protons consumed by the alkali metal basic salt through acid-base neutralization to the phenolic hydroxyl groups in the diphenol monomer is 1.00-1.2. For example, when the alkali metal basic salt is potassium carbonate and the diphenol monomer is bisphenol A, the molar ratio of potassium carbonate to bisphenol A is 1.00-1.2.

[0013] Further, in step (1), the dihalogen monomer is preferably one or more of 4,4'-dichlorodiphenyl sulfone, 4,4'-dibromodiphenyl sulfone, and 4,4'-difluorodiphenyl sulfone.

[0014] More preferably, in step (1), the dihalogen monomer is 4,4'-dichlorodiphenyl sulfone.

[0015] Furthermore, in step (1), the diphenol monomer is preferably one or more of bisphenol A, bisphenol S and biphenyl diphenol.

[0016] Further, in step (1), the alkali metal basic salt is selected from one or more of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, potassium hydroxide, and sodium hydroxide.

[0017] Further, in step (1), the polar organic reaction solvent is preferably one or more of N-methylpyrrolidone (NMP), N,N-dimethylformamide, dimethyl sulfoxide (DMSO), N,N-dimethylacetamide, etc.

[0018] Further, in step (1), the molar ratio of the polar organic reaction solvent to the polymer repeating unit in the polyarylether sulfone reaction solution is between 7 and 15, preferably between 7 and 12.

[0019] Further, in step (1), the temperature of the polymerization reaction is 160-250℃, preferably 180-220℃.

[0020] Further, in step (2), after adding water to the polyarylether sulfone reaction solution obtained in step (1), the molar ratio of water to polymer repeating units is between 10 and 20, and the mixture is stirred evenly.

[0021] Further, in step (3), the low-temperature precipitation solvent is preferably one or more of methanol, ethanol, and water; the temperature of the low-temperature precipitation solvent is -20 to 25°C.

[0022] Furthermore, the mesh size of the sieve used is 50-200 mesh, preferably 50-100 mesh.

[0023] Furthermore, the polyarylethersulfone resin preferably has a weight-average molecular weight between 25,000 and 60,000, a cyclic dimer content of less than 1.0 wt%, and a molecular weight distribution (PD) of less than 3. That is, a narrow distribution refers to a molecular weight distribution of less than 3, and a low cyclic oligomer content refers to a cyclic dimer content of less than 1.0 wt%.

[0024] Furthermore, step (1) specifically includes the following process:

[0025] (1-1) Add bisphenol monomer, alkali metal basic salt, and polar organic reaction solvent to the reaction vessel. An azeotropic agent (dehydrating azeotropic aid) can also be added to help remove water quickly. The azeotropic agent can be selected from one or more of toluene and chlorobenzene. Nitrogen gas is continuously introduced into the reaction vessel under stirring to remove oxygen. Then, the temperature is raised to carry out the salt formation reaction and remove water and azeotropic agent.

[0026] (1-2) Add dihalogen monomer to the reactor, seal it and heat it to above 160°C to carry out the polymerization reaction. After the polymerization reaction is completed (that is, when the viscosity of the reaction solution basically stops rising), add an appropriate amount of polar organic reaction solvent for appropriate dilution, and then introduce the end-capping agent. After the end-capping reaction is completed, polyarylether sulfone reaction solution is obtained.

[0027] Furthermore, the capping agent can be chloromethane.

[0028] Further, in step (1-1), preferably after feeding, the molar ratio of the polar organic reaction solvent to the bisphenol monomer is 4-8. In step (1-2), a polar organic reaction solvent is also added. Combined with the polar organic reaction solvent added in step (1-1), the molar ratio of the polar organic reaction solvent to the polymer repeating unit in the polyarylene ether sulfone reaction solution is between 7-15.

[0029] Furthermore, the reactor is a stainless steel reactor equipped with a thermometer, a stirrer, an air inlet pipe, and a water separator, and a bottom discharge pipe is connected to the bottom of the reactor. The type of reactor used is not crucial, as long as it meets the process requirements. From a convenience perspective, it is best to use a reactor known to those skilled in the art.

[0030] Furthermore, step (3) specifically includes the following process:

[0031] (3-1) The phase-separated reaction liquid obtained in step (2) is not cooled down. It is placed in a precipitation tank containing a low-temperature precipitation solvent for cooling and precipitation. After the material is discharged, the precipitated mixture is sieved through a 50-100 mesh screen and the solvent and fine powder are removed. The material on the sieve is mixed with 6 times the weight of deionized water. The precipitated mixture is sieved through a 50-100 mesh screen and the material on the sieve is mixed with 6 times the weight of deionized water again. The temperature is raised to 70°C and washed with water. After filtration, the filter cake is washed with 6 times the weight of deionized water again, then boiled. After filtration and rinsing, the filter cake is dried at 120°C for 4 hours to obtain the dried resin, which is the polyarylether sulfone resin. The obtained polyarylether sulfone resin is a polyarylether sulfone resin with narrow distribution and low cyclic oligomer content.

[0032] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects:

[0033] 1) This invention introduces phase separation into the reaction solution, extracts low molecular weight polysulfone through liquid-liquid phase separation, and then solidifies the extracted low molecular weight part into fine powder, which is effectively removed by sieving. The polysulfone resin obtained thereby has a weight average molecular weight between 25,000 and 60,000, a cyclic dimer content of less than 1 wt%, and a molecular weight distribution (PD) of less than 3.

[0034] 2) In this invention, after phase separation is introduced into the reaction solution, the product is enriched in the precipitated phase, the viscosity of the reaction solution decreases, and there is no need to add a large amount of solvent for dilution and then pour it into the precipitation bath for precipitation, which reduces solvent consumption and the product particle morphology is also better.

[0035] 3) In this invention, the reaction solution after phase separation is not further cooled, but is directly precipitated in a low-temperature precipitation solvent, which can avoid the aggregation of the precipitated phase during the cooling process to room temperature, as well as the aggregation of large particles of the target product during precipitation. Detailed Implementation

[0036] The present invention will now be described in detail with reference to specific embodiments, but this is by no means a limitation thereof. Any preparation methods, materials, structures, or compositional ratios not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0037] The technical concept and technical solution of this invention are as follows:

[0038] To effectively remove unreacted monomers and low molecular weight polyarylether sulfones, including cyclic oligomers, from the reaction solution, this invention preferably maintains a molar ratio of polar organic reaction solvent to polymer repeating units between 7 and 15 at the end of the reaction. After the reaction, an appropriate amount of water is added to the reactor (the molar ratio of water to polymer repeating units after adding water is between 10 and 20), and the temperature is lowered to 140-180°C. The mixture is stirred until the system is redispersed and equilibrated. At this point, phase separation occurs in the reaction solution, with the high molecular weight fraction "precipitating" into droplets, while the low molecular weight polysulfones remain dissolved in the solvent. Without further cooling, the high-temperature reaction solution is directly placed into a dispersion vessel with a cooling jacket containing a low-temperature precipitating solvent (-20-25°C). At this point, the high molecular weight polysulfone droplets that "precipitate" first solidify into larger particles, while the low molecular weight polysulfones precipitate and solidify into extremely fine powder. After feeding, the dispersion is sieved through a 50-100 mesh screen to remove solvent and fine particles. The residue is collected, dispersed in deionized water, and sieved again. The residue is then collected again. The residue is mixed with water and subjected to multiple heating and washing cycles. After each heating and washing, the residue is cooled and filtered. Water is added again for the next heating and washing cycle. Finally, the filter cake is dried to obtain a polyarylene ether sulfone resin with a narrow distribution and low cyclic oligomer content.

[0039] This invention does not require specific process parameters or formulations for the polymerization reaction steps, but preferably, after the dihalogen monomer is fed, the molar ratio of the dihalogen monomer to the bisphenol monomer is 0.98-1.06, the molar ratio of the reaction solvent to the bisphenol monomer is 4-8, and the molar ratio of the protons consumed by the alkali metal basic salt through acid-base neutralization to the phenolic hydroxyl groups in the bisphenol monomer is 1.00-1.2, more preferably 1.00-1.10. The dihalogen monomer is preferably one or more of 4,4'-dichlorodiphenyl sulfone, 4,4'-dibromodiphenyl sulfone, and 4,4'-difluorodiphenyl sulfone; the bisphenol monomer is preferably one or more of bisphenol A, bisphenol S, and biphenyl hydroquinone; the polar organic reaction solvent is preferably one or more of N-methylpyrrolidone, N,N-dimethylformamide, DMSO, and N,N-dimethylacetamide; and the precipitation solvent is preferably one or a mixture of methanol, ethanol, and water.

[0040] The polysulfone resin obtained is preferably between 25,000 and 60,000 in weight average molecular weight, with the content of cyclic dimers below 1.0 wt% and the molecular weight distribution (PD) below 3.

[0041] The experimental methods described in the following embodiments of the present invention, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0042] The molecular weight and content of cyclic oligomers of the product were determined by size exclusion chromatography using dimethylacetamide as a solvent.

[0043] In the following examples, the raw materials such as bisphenol A, bisphenol S, and powdered potassium carbonate are all commercially available products.

[0044] Example 1

[0045] This embodiment provides a method for preparing polyarylene ether sulfone resin, comprising the following steps:

[0046] In a 3L stainless steel reactor equipped with a thermometer, stirrer, air inlet, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, 595g (6mol) of N-methylpyrrolidone (NMP), and 184g (2mol) of toluene were added. Stirring was started at 200 rpm, and nitrogen gas was continuously introduced into the reactor for 15 minutes. The temperature was then gradually increased to 160°C to remove moisture and the azeotropic agent toluene. Then, 290g (1.01mol) of 4,4'-dichlorodiphenyl sulfone was added, and the reactor was sealed and heated to 200°C to begin the polymerization reaction. After 6 hours of reaction, 396g (4mol) of NMP was added, followed by the introduction of 500mL of chloromethane gas and a reaction time of 15 minutes. Then, under sealed conditions, 252g (14mol) of deionized water was added, and the mixture was stirred and cooled to 160°C while maintaining the temperature.

[0047] All the reaction solution was directly discharged through the bottom discharge pipe into a precipitation tank containing a 40wt% methanol-water solution (low-temperature precipitation solvent) at -10℃ for cooling and precipitation. After discharge, the precipitated mixture was vibrated and sieved through a 50-mesh sieve to remove the solvent and fine powder. The residue was mixed with 6 times its weight of deionized water, and the mixture was vibrated and sieved again through a 50-mesh sieve. The residue was again mixed with 6 times its weight of deionized water, heated to 70℃ for washing, filtered, and the filter cake was again mixed with 6 times its weight of deionized water, then boiled and washed. After filtration and rinsing, the filter cake was dried at 120℃ for 4 hours to obtain dry PSU resin powder PSU-1. Testing showed that PSU-1 had a weight-average molecular weight of 48,000, a molecular weight distribution index of 2.6, and a cyclic dimer content of 0.82wt%.

[0048] Example 2

[0049] This embodiment provides a method for preparing polyarylene ether sulfone resin. The difference between Example 2 and Example 1 is that the low-temperature precipitation solvent is a mixture of ice and water at 0°C, and PSU resin powder PSU-2 is obtained. Testing showed that PSU-2 has a weight-average molecular weight of 47,600, a molecular weight distribution index of 2.8, and a cyclic dimer content of 0.88 wt%.

[0050] Example 3

[0051] This embodiment provides a method for preparing polyarylether sulfone resin. The difference between Example 3 and Example 1 is that after reacting for 6 hours, the amount of NMP added is 793 g (8 mol), and PSU resin powder PSU-3 is obtained. The weight-average molecular weight of PSU-3 is 46,000, the molecular weight distribution index is 3.0, and the content of cyclic oligomers is 1.0 wt%.

[0052] Example 4

[0053] This embodiment provides a method for preparing polyarylene ether sulfone resin. The only difference between Example 4 and Example 1 is that the amount of deionized water added after the reaction is 360g (18mol), resulting in PSU resin powder PSU-4. Testing showed that PSU-4 has a weight-average molecular weight of 46,600, a molecular weight distribution index of 2.9, and a cyclic oligomer content of 0.96wt%.

[0054] Example 5

[0055] This embodiment provides a method for preparing polyarylene ether sulfone resin, comprising the following steps:

[0056] In a 3L stainless steel reactor equipped with a thermometer, stirrer, air inlet, and water separator, 250.3g (1mol) of bisphenol S, 152g (1.1mol) of powdered potassium carbonate, 595g (6mol) of N-methylpyrrolidone, and 184g (2mol) of toluene were added. Stirring was started at 200 rpm, and nitrogen gas was continuously introduced into the reactor for 15 minutes. The temperature was then gradually increased to 160°C to remove moisture and the azeotropic agent toluene. Then, 290g (1.01mol) of 4,4'-dichlorodiphenyl sulfone was added, and the reactor was sealed and heated to 210°C to begin the polymerization reaction. After 8 hours of reaction, 396g (4mol) of NMP was added, followed by the introduction of 500mL of chloromethane gas and a reaction time of 15 minutes. Then, under sealed conditions, 252g (14mol) of deionized water (14mol) was added, and the mixture was mixed thoroughly while cooling to 160°C and maintaining the temperature.

[0057] All reaction solutions were directly discharged through the bottom discharge pipe into a pressure-resistant settling tank containing a 40wt% methanol aqueous solution at -10℃ for cooling and precipitation. After discharge, the precipitate mixture was vibrated and sieved through a 50-mesh sieve to remove solvent and fine powder. The residue was mixed with 6 times its weight of deionized water, and the mixture was vibrated and sieved again through a 50-mesh sieve. The residue was again mixed with 6 times its weight of deionized water, heated to 70℃ for washing, filtered, and the filter cake was again mixed with 6 times its weight of deionized water, then boiled and washed. After filtration and rinsing, the filter cake was dried at 120℃ for 4 hours to obtain dry PES resin powder PES-5. Testing showed that PES-5 had a weight-average molecular weight of 32,000, a molecular weight distribution index of 2.1, and a cyclic dimer content of 0.69wt%.

[0058] Comparative Example 1

[0059] This comparative example provides a method for preparing polyarylene ether sulfone resin, comprising the following steps:

[0060] In a 3L stainless steel reactor equipped with a thermometer, stirrer, air inlet, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, 595g (6mol) of N-methylpyrrolidone, and 184g (2mol) of toluene were added. Stirring was started at 200 rpm, and nitrogen gas was continuously introduced into the reactor for 15 minutes. The temperature was then gradually increased to 160°C to remove moisture and the azeotropic agent toluene. Then, 290g (1.01mol) of 4,4'-dichlorodiphenyl sulfone was added, and the reactor was sealed and heated to 200°C to initiate the polymerization reaction. After 6 hours of reaction, 396g (4mol) of NMP was added, followed by the introduction of 500mL of chloromethane gas and a 15-minute reaction time. The reactor was then rapidly cooled to room temperature.

[0061] The reaction solution was added to a 40 wt% methanol-water solution under stirring to induce precipitation. The precipitate mixture was then sieved through a 50-mesh screen using vibration. The residue was mixed with 6 times its weight of deionized water, and the mixture was sieved again using vibration. The residue was again mixed with 6 times its weight of deionized water, heated to 70°C, washed with water, filtered, and the filter cake was again mixed with 6 times its weight of deionized water, then boiled and washed. After filtration and rinsing, the filter cake was dried at 120°C for 4 hours to obtain dried PSU resin particles, PSU-6. The weight-average molecular weight of PSU-6 was 45,000, the molecular weight distribution index was 3.2, and the content of cyclic dimers was 1.3 wt%.

[0062] Comparative Example 1 is a conventional implementation in the art. The difference between Comparative Example 1 and Example 1 is that water was not added to initiate phase separation after the reaction, the reaction solution was cooled to room temperature, and precipitation was then carried out in a room-temperature precipitation solvent. The resin obtained in Comparative Example 1 has a molecular weight distribution index greater than 3 and a cyclic dimer content greater than 1 wt%.

[0063] Comparative Example 2

[0064] This comparative example provides a method for preparing polyarylene ether sulfone resin, comprising the following steps:

[0065] In a 3L stainless steel reactor equipped with a thermometer, stirrer, air inlet, and water separator, 228.3g (1mol) of bisphenol A, 152g (1.1mol) of powdered potassium carbonate, 595g (6mol) of N-methylpyrrolidone, and 184g (2mol) of toluene were added. Stirring was started at 200 rpm, and nitrogen gas was continuously introduced into the reactor for 15 minutes. The temperature was then gradually increased to 160°C to remove moisture and the azeotropic agent toluene. Then, 290g (1.01mol) of 4,4'-dichlorodiphenyl sulfone was added, and the reactor was sealed and heated to 200°C to initiate the polymerization reaction. After reacting for 10 hours, 396g (4mol) of NMP was added, followed by the introduction of 500mL of chloromethane gas and a 15-minute reaction. Then, under sealed conditions, 252g of deionized water (14mol) was added, and the mixture was continuously cooled to room temperature while being thoroughly mixed.

[0066] The material was directly discharged through the bottom discharge pipe into a 40wt% methanol-water solution at room temperature for precipitation. The precipitate mixture was passed through a 50-mesh sieve and vibrated for sieving. The residue was mixed with four times its weight of deionized water, and the mixture was passed through a sieve again and vibrated for sieving. The residue was again mixed with deionized water, and the mixture was filtered. The filter cake was then washed with water after boiling, filtered, rinsed, and dried at 120°C for 4 hours to obtain dried PSU resin particles, PSU-7. It should be noted that during the discharge and precipitation process in this comparative example, larger particles were found in the precipitated particles compared to those in Example 1, and material residue remained on the agitator of the reactor. The weight-average molecular weight of PSU-7 was tested to be 65,000, the molecular weight distribution index was 3.6, and the content of cyclic dimers was 1.2wt%.

[0067] The difference between Comparative Example 2 and Example 1 is that the reaction time is longer, and the reaction solution is cooled to room temperature before precipitation in a room-temperature precipitation solvent. When the reaction solution is cooled to room temperature, the viscosity of the precipitated phase is relatively high, making it prone to self-aggregation. Furthermore, during room-temperature precipitation, large particles also agglomerate with the precipitated fine powder, making it difficult to remove the fine powder by sieving. The resin obtained in Comparative Example 2 has a molecular weight distribution index greater than 3, a cyclic dimer content greater than 1 wt%, and a weight-average molecular weight greater than 60,000.

[0068] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing polyarylene ether sulfone resin, characterized in that, The preparation method includes the following steps: (1) Using dihalogen monomers and diphenol monomers as reaction monomers, polar organic reaction solvents as reaction solvents, and alkali metal basic salts as catalysts, polyarylether sulfone reaction solution is obtained through polymerization reaction. (2) Under closed stirring conditions, water is added to the polyarylether sulfone reaction solution obtained in step (1), cooled to 140-180℃, and stirred continuously to obtain a phase-separated reaction solution. (3) The phase-separated reaction liquid obtained in step (2) is not cooled down, but is placed in a low-temperature precipitation solvent for cooling and precipitation to obtain a precipitate mixture. Then, the precipitate mixture is sieved with a sieve, and the sieve residue is taken. Water is added to disperse the residue, and the residue is sieved again. The sieve residue is taken again, and the sieve residue is mixed with water and then heated and washed multiple times. After each heating and washing, the residue is cooled and filtered. Water is added again for the next heating and washing. Finally, the filter cake is dried to obtain polyarylene ether sulfone resin. The obtained polyarylene ether sulfone resin is a polyarylene ether sulfone resin with narrow distribution and low cyclic oligomer content.

2. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, At the end of the reaction in step (1), the molar ratio of the polar organic reaction solvent to the polymer repeating unit in the polyarylether sulfone reaction solution is between 7 and 15. In step (2), after adding water to the polyarylether sulfone reaction solution obtained in step (1), the molar ratio of water to polymer repeating units is between 10 and 20.

3. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, In step (3), the low-temperature precipitation solvent is selected from one or more of methanol, ethanol, and water; The temperature of the low-temperature precipitation solvent is -20 to 25°C; The mesh size of the sieve used is 50-200 mesh.

4. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, In step (1), the molar ratio of the dihalomonomer to the diphenol monomer is 0.98-1.06; The molar ratio of the protons consumed by the alkali metal basic salt through acid-base neutralization to the phenolic hydroxyl groups in the diphenol monomer is 1.00-1.

2.

5. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, The dihalogen monomer is selected from one or more of 4,4'-dichlorodiphenyl sulfone, 4,4'-dibromodiphenyl sulfone, and 4,4'-difluorodiphenyl sulfone; The diphenol monomer is selected from one or more of bisphenol A, bisphenol S and biphenyl diphenol; The polar organic reaction solvent is selected from one or more of N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, and N,N-dimethylacetamide; The alkali metal basic salt is selected from one or more of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, potassium hydroxide, and sodium hydroxide.

6. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, The polyarylene ether sulfone resin has a weight-average molecular weight between 25,000 and 60,000, a cyclic dimer content of less than 1.0 wt%, and a molecular weight distribution of less than 3.

7. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, Step (1) specifically includes the following process: (1-1) Add bisphenol monomer, alkali metal basic salt, and polar organic reaction solvent to the reaction vessel. After continuously introducing nitrogen gas into the reaction vessel to remove oxygen under stirring, raise the temperature to carry out the salt formation reaction and remove the generated water. (1-2) Add dihalogen monomer to the reactor, seal it and heat it to above 160°C to start the polymerization reaction. After the polymerization reaction is completed, add polar organic reaction solvent to dilute it, and then introduce the end-capping agent. After the end-capping reaction is completed, polyarylether sulfone reaction solution is obtained.

8. The method for preparing a polyarylene ether sulfone resin according to claim 7, characterized in that, In step (1-1), in order to help remove moisture quickly, an additional dehydration azeotropic aid is added. After the moisture is removed, the temperature is raised to remove the remaining dehydration azeotropic aid. The dehydration azeotropic aid is selected from one or more of toluene and chlorobenzene.

9. The method for preparing a polyarylene ether sulfone resin according to claim 7, characterized in that, The reactor is a stainless steel reactor equipped with a thermometer, a stirring paddle, an air inlet pipe, and a water separator, and a bottom discharge pipe is connected to the bottom of the reactor.

10. The method for preparing a polyarylene ether sulfone resin according to claim 1, characterized in that, Step (3) specifically includes the following process: (3-1) The phase-separated reaction liquid obtained in step (2) is not cooled down, but placed in a precipitation tank containing a low-temperature precipitation solvent for cooling and precipitation. After the material is discharged, the precipitated mixture is screened through a sieve and vibrated to remove the solvent and fine powder. The material on the sieve is mixed with 6 times the weight of deionized water. The precipitated mixture is screened through a sieve again and vibrated. The material on the sieve is mixed with 6 times the weight of deionized water again. The temperature is raised to 70°C and washed with water. After filtration, the filter cake is added with 6 times the weight of deionized water again, then boiled and washed with water. After filtration and rinsing, the filter cake is dried at 120°C for 4 hours to obtain the dried resin, which is the polyarylether sulfone resin with narrow distribution and low cyclic oligomer content.