Permanent hydrophilic block structure polyarylether sulfone hemodialysis membrane and preparation method thereof

Abstract

The invention belongs to the field of separation membranes, particularly relates to the field of hemodialysis membranes, and discloses a permanent hydrophilic block structure polyarylether sulfone hemodialysis membrane and a preparation method thereof, and the preparation method comprises the following steps: (1) preparing a block polymer; (2) preparing a membrane casting solution; and (3) preparing the hollow fiber membrane. Hydrophilic / hydrophobic chain segments are synthesized through a step-by-step synthesis method, the amphoteric polyarylether sulfone block copolymer is constructed to serve as a film forming base material, the hydrophilic chain segments are anchored between the hydrophobic chain segments through chemical bonds, permanent hydrophilization is achieved, and the problem of loss of a traditional pore-foaming agent is avoided; the ultrafiltration membrane with uniform pore diameter and high porosity is formed by regulating and controlling the proportion of hydrophilic-hydrophobic chain segments and inducing microphase separation by combining a non-solvent induced phase separation method, so that the removal efficiency of middle molecular toxins is improved, and meanwhile, high flux is maintained.

Description

Technical Field

[0001] The present invention belongs to the field of separation membranes, specifically relates to the field of hemodialysis membranes, and particularly relates to a permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane and a preparation method thereof. Background Art

[0002] In the field of biomedical hemodialysis membrane applications, polyarylethersulfone (such as polysulfone, polyethersulfone, etc.) has been intensively studied as a hollow fiber membrane material due to its excellent chemical stability, good mechanical strength, and high-temperature resistance. However, traditional polyarylethersulfone separation membranes have defects such as high hydrophobicity, insufficient biocompatibility, and poor stability of hydrophilic modification, resulting in problems such as protein adsorption and thrombosis in clinical applications, which affect dialysis efficiency and patient safety (Materials Chemistry and Physics 248 (2020) 122911). The main manifestations are as follows. (1) The problem of easy loss of porogens. Traditional polysulfone dialysis membranes mostly rely on water-soluble porogens (such as polyvinylpyrrolidone) to regulate the membrane pore structure, but these porogens are easily lost during dialysis, leading to a decrease in membrane hydrophilicity, flux attenuation, and even residual toxicity in the body. (2) Insufficient stability of surface modification. Existing technologies often improve hydrophilicity by surface coating (such as heparin, polyphenolic substances) or grafting hydrophilic monomers, but the coating is easily detached and relies on physical adsorption or weak chemical bonding, resulting in performance degradation after long-term use. (3) Poor compatibility of amphiphilic copolymers. Some studies have attempted to improve hydrophilicity by amphiphilic block copolymers (such as polyethylene glycol-polysulfone), but the compatibility of the hydrophobic segment with the substrate is insufficient, resulting in uneven membrane structure or decreased mechanical strength.

[0003] In recent years, researchers have been committed to developing permanently hydrophilic polyarylethersulfone separation membranes. Among them, one of the important directions includes block copolymer design: chemically bonding hydrophilic segments (such as polyethylene glycol, polyglycerol) to the polyarylethersulfone main chain to form a stable block structure, avoiding the migration or loss of additives. In-situ hydrophilization: directly introducing hydrophilic segments during the film-forming process through blending or copolymerization, reducing post-treatment steps and enhancing material homogeneity. The other is biocompatibility optimization: combining the synergistic effects of biomimetic coatings (such as heparin-like structures) and block copolymers to reduce the risk of complement activation and thrombosis (Journal of Membrane Science 618 (2021) 118690).

[0004] Traditional polymer ultrafiltration membranes generally adopt the nonsolvent induced phase separation process, and the pore size distribution of the prepared membrane pores is relatively wide. By combining the nonsolvent induced phase separation method with the self-assembly of hydrophilic / hydrophobic block copolymers, highly porous and relatively uniform membrane pores, that is, homogeneous pore block copolymer porous membranes, can be obtained through the nonsolvent induced phase separation self-assembly technique. By means of the fine design at the molecular level of hydrophilic and hydrophobic block copolymers, the performance of hemodialysis membranes can be comprehensively improved, showing outstanding performance in efficient toxin clearance, biosecurity and long-term stability, which is an important development direction of a new generation of high-performance dialysis materials. With the continuous growth of the global hemodialysis market scale, domestic dialysis membranes still rely on imports (accounting for more than 95%). Therefore, through the design of low-cost and high-performance block copolymers, it is expected to break through the technical barriers and promote the replacement of imported products by domestic dialyzers. It is estimated that the annual market demand for high-flux dialyzers reaches 4 billion to 6 billion yuan, and with the increase in the number of nephropathy patients, the application prospect is broad. Summary of the Invention

[0005] The purpose of the present invention is to provide a permanently hydrophilic block-structured polyarylether sulfone hemodialysis membrane to solve the problems such as the easy loss of water-soluble pore-forming agents in traditional polysulfone dialysis membranes and the poor compatibility of amphiphilic copolymers.

[0006] Another purpose of the present invention is to provide a preparation method of a permanently hydrophilic block-structured polyarylether sulfone hemodialysis membrane, so that it has a symmetric pore structure in the thickness direction, and the pore diameter of the pores is small and the pore size distribution is narrow.

[0007] The present invention includes the following steps:

[0008] (I) Preparation of block polymers

[0009] (1) 4,4'-Difluorodiphenyl sulfone monomer (Formula I) and 2-(3-(dimethylamino)propyl)-3,3'-bis(4-hydroxyphenyl)isoindolinone monomer (Formula II) (synthesis reference: J. Mater. Chem. A, 2025, 13, 9164–9173) are added to N,N'-dimethylacetamide (DMAc), heated to 160 °C with a programmed temperature rise, potassium carbonate is used as a catalyst, and kept for 18 h in a nitrogen atmosphere to obtain an oligomer (Formula III) through co-condensation (method reference: J. Mater. Chem. A, 2025, 13, 9164–9173). Among them, the molar ratio of monomer (Formula I) to monomer (Formula II) is 1 to 1.5:1; the number average molecular weight Mn of the oligomer (Formula III) is 500 to 5000.

[0010]

[0011]

[0012] Preferably, the molar ratio of the monomer (Formula I) to the monomer (Formula I) in step (1) is 1.0 - 1.2:1; preferably 1.05:1.

[0013] Preferably, the programmed temperature heating reaction conditions in step (1) are preferably 140 °C for 6 h, and then changed to 160 °C for 12 h.

[0014] (2) Dissolve the oligomer (Formula III) prepared in step (1) in an organic solvent, and then add sodium 3-bromopropanesulfonate (Formula IV) according to a mass ratio of 10:1.50 - 3.00, stir for a certain period of time, precipitate in a precipitant, and vacuum dry to obtain the oligomer iPESm-F (Formula V), where m is the number of repeating units 30 - 90.

[0015]

[0016] Preferably, the mass ratio in step (2) is 10:1.50 - 3.00; preferably 10:2.5.

[0017] Preferably, the precipitant in step (2) is one or a mixed solvent of water, methanol, ethanol or isopropanol; preferably isopropanol.

[0018] (3) Add 4,4'-difluorodiphenyl sulfone monomer (I) and 4,4'-dihydroxydiphenyl sulfone monomer (Formula VI) to N,N'-dimethylacetamide (DMAc), heat up to 160 °C by programmed temperature, use potassium carbonate as a catalyst, keep for 18 h, and obtain the oligomer PES n -OH (Formula VII), where the molar ratio of the monomer (Formula I) to the monomer (Formula VI) is 1:1 - 1.2, and n is the number of repeating units 20 - 80.

[0019]

[0020] Preferably, the molar ratio of the monomer (Formula I) to the monomer (Formula VI) in step (3) is 1:1 - 1.2; preferably 1:1.05.

[0021] Preferably, the programmed temperature heating reaction conditions in step (3) are preferably 140 °C for 6 h, and then changed to 160 °C for 12 h.

[0022] (4) Mix the oligomer iPES m -F (Formula V) and the oligomer PES n-OH (Formula VII) was added to a liquid with N,N'-dimethylacetamide (DMAc) as the solvent, toluene as the water-carrying agent, and potassium carbonate as the catalyst in a certain proportion. The temperature was raised stepwise to 160 °C, and potassium carbonate was used as the catalyst and maintained for 18 h. In an N₂ atmosphere, an oligomer was obtained through co-polycondensation, and finally dried to obtain a polymer solid, which was a block polymer. By controlling the molar ratio of iPESm-F and PESn-OH, block polymers PESn-b-iPESm-b-PESn-x with different hydrophilic / hydrophobic segment ratios were obtained. Among them, x was the molar ratio of iPESm-F and PESn-OH in the feed of 10-40:60-90. The possible structural formula of the block polymer PESn-b-iPESm-b-PESn-x was as shown in Formula (VIII).

[0023]

[0024] Preferably, in step (4), the stepwise temperature increase heating reaction conditions were preferably 140 °C for 6 h, and then changed to 160 °C for 12 h.

[0025] Preferably, in step (4), the molar ratio of iPESm-F and PESn-OH in the feed was 10-40:60-90; preferably 30:70.

[0026] (II) Preparation of the casting solution

[0027] The block polymer, solvent, and additive obtained in step (I) were placed in a batching container in sequence. They were fully stirred and dissolved at a temperature in the range of 20-110 °C for 3-12 h until a homogeneous solution was formed. After filtering through a stainless steel filter screen and degassing under vacuum or by standing for 6-24 h, it was left to age to prepare the casting solution.

[0028] Preferably, the raw materials were weighed according to the following weight ratio: 5-30 parts of PESn-b-iPESm-b-PESn-x, 0-25 parts of additive, and 55-95 parts of solvent. Further preferably, it was 25 parts of PESn-b-iPESm-b-PESn-x, 5 parts of additive, and 70 parts of solvent.

[0029] Preferably, the solvent used in the above step was one or more of N,N'-dimethylacetamide (DMAc), N,N'-dimethylformamide (DMF), and N-methylpyrrolidone (NMP). Further preferably, it was DMAc.

[0030] Preferably, the additive used in the above step was one or more of pure water, polyethylene glycol, oxalic acid, and water-soluble inorganic salts; the water-soluble inorganic salts were at least one of lithium chloride and lithium nitrate. Further preferably, it was lithium nitrate.

[0031] Preferably, the stirring temperature of the casting solution in the above step is 20-110°C, and the heating time is 3-12h, more preferably 70°C and 6h.

[0032] Preferably, the standing and defoaming time in the above step is 6-24h, more preferably 12h.

[0033] (III) Preparation of hollow fiber membrane

[0034] (1) Control the environmental temperature and humidity to be 18-25°C and 20-50RH% respectively. Extrude the casting solution prepared in step (II) through a spinneret by a metering pump. After passing through an air bath for 10-120s, vertically immerse it in a first coagulation bath at 20-80°C (DMAC / water: DMAC concentration 40-60%, temperature 25-40°C) for a phase separation and curing time of 60-180s, then immerse it in a second coagulation bath (DMAC / water: DMAC concentration 55-70%, temperature 45-80°C) for a phase separation and curing time of 60-240s, and finally wind it into a wire collecting tank. Among them, the core liquid composition is pure water or an aqueous solution containing 5-50% organic solvent by mass concentration to form an as-formed hollow fiber membrane.

[0035] Preferably, the environmental temperature and humidity in the above step are 18-25°C and 20-50RH% respectively, more preferably 25°C and 40RH%.

[0036] Preferably, the air bath time in the above step is 30-80s, the temperature of the first coagulation bath is 20-80°C, the DMAC concentration is 10-60%, and the phase separation and curing time is 30-180s, more preferably 80s, 30°C, 40%, and 120s respectively.

[0037] Preferably, the temperature of the second coagulation bath in the above step is 45-80°C, the DMAc concentration is 55-70%, and the phase separation and curing time is 60-240s, more preferably 50°C, 60%, and 180s respectively.

[0038] (2) Immerse the hollow fiber ultrafiltration membrane prepared in the above step in deionized water at 20-40°C for 24-48h for shaping, and rinse it with deionized water to remove residual solvents and additives to form a shaped hollow fiber membrane with an inner and outer diameter of 180-220μm and 250-350μm.

[0039] Preferably, the temperature of the deionized water coagulation bath in the above step is 20-40°C, and the shaping duration is 24-48h, more preferably the temperature and duration are 25°C and 36h respectively.

[0040] Compared with the prior art, the advantages of the present invention are:

[0041] (1) Synthesize hydrophilic / hydrophobic chain segments through a step-by-step synthesis method, and construct an amphiphilic poly(aryl ether sulfone) block copolymer as the film-forming substrate, in which the hydrophilic chain segments are anchored between the hydrophobic chain segments through chemical bonds to achieve permanent hydrophilization and avoid the problem of loss of traditional porogens.

[0042] (2) By regulating the ratio of hydrophilic-hydrophobic chain segments and combining the non-solvent induced phase separation method to induce microphase separation to form an ultrafiltration membrane with uniform pore size and high porosity, the removal efficiency of medium molecular toxins (such as β2-microglobulin) is improved, while maintaining a high flux (>70 mL / h·m 2 ·mmHg).

[0043] (3) The ion pair amphiphilic poly(aryl ether sulfone) has a charge balance and a minimum dipole design at the molecular level, forming a strong hydration layer, effectively blocking the non-specific adsorption of proteins, and the positive and negative charge groups are evenly distributed, avoiding local charge accumulation, thereby reducing the electrostatic interaction with proteins in the blood (such as albumin, fibrinogen). Brief Description of the Drawings Figure 1 It is the SEM morphology diagram of the permanent hydrophilic block structure poly(aryl ether sulfone) hemodialysis membrane of the present invention. Detailed Embodiments

[0044] To further illustrate the technical solution of the present invention, the following describes the preferred implementation schemes of the present invention in combination with some specific embodiments, but it should be understood that these descriptions are only to further illustrate the features and advantages of the present invention, rather than a limitation on the claims of the present invention.

[0045] Example 1

[0046] (I) Preparation of Block Polymer

[0047] (1) Add 210 mmol of 4,4'-difluorodiphenyl sulfone monomer and 200 mmol of 2-(3-(dimethylamine)propyl)-3,3'-bis(4-hydroxyphenyl)isoindolinone monomer to 500 mL of DMAc, and add potassium carbonate as a catalyst. Gradually heat up to 140 °C and maintain for 6 h, then raise the temperature to 160 °C and maintain for 12 h. Maintain for 18 h in an N2 atmosphere, and obtain an oligomer through co-polycondensation.

[0048] (2) Weigh 50 g of the oligomer prepared in step (1) and dissolve it in an organic solvent, then add 12.5 g of 3-bromopropanesulfonic acid sodium, stir for 12 h, precipitate in ethanol, and vacuum dry to obtain the oligomer iPES 42 -F.

[0049] (3) 200 mmol of 4,4'-difluorodiphenyl sulfone monomer and 210 mmol of 4,4'-dihydroxydiphenyl sulfone monomer were added to 500 mL of DMAc, and potassium carbonate was added as a catalyst. The temperature was gradually raised to 140 °C and maintained for 6 h, and then raised to 160 °C and maintained for 12 h. After maintaining for 18 h in an N2 atmosphere, an oligomer PES was obtained by co-polycondensation. 31 -OH.

[0050] (4) The oligomer iPES 32 -F and the oligomer PES 51 -OH were added to a liquid with DMAc as the solvent, toluene as the water-carrying agent, and potassium carbonate as the catalyst in a molar ratio of 1:1 of the terminal groups at both ends. The programmed heating reaction conditions were preferably 140 °C for 6 h, and then changed to 160 °C for 12 h. In an N2 atmosphere, an oligomer was obtained by co-polycondensation, and finally dried to obtain a polymer solid, which was a block polymer; by controlling the molar ratio of iPES 32 -F and PES 31 -OH to 30:70, the block polymer PES 31 -b-iPES 32 -b-PES 31 -30 was obtained.

[0051] (II) Preparation of the casting solution

[0052] The block polymer PES 31 -b-iPES 32 -b-PES 31 -30, DMAc, and lithium nitrate were placed in a proportion of 20:75:5 in a dosing container and stirred and dissolved at 70 °C for 6 h until a homogeneous solution was formed. After filtration through a stainless steel filter mesh and degassing by vacuum or standing for 12 h, it was allowed to age to obtain a casting solution.

[0053] (III) Preparation of the hollow fiber ultrafiltration membrane

[0054] (1) The environmental temperature and humidity were controlled at 25 °C and 40 RH% respectively. The casting solution was extruded through a spinneret by a metering pump, passed through an air bath for 80 s, and then vertically immersed in a first coagulation bath (DMAc / water: DMAc concentration 40%, temperature 30 °C) for 120 s of phase separation curing, and then immersed in a second coagulation bath (DMAc / water: DMAc concentration 60%, temperature 50 °C) for 180 s of phase separation curing, and finally wound and introduced into a wire collecting tank. Among them, the core liquid composition was pure water or an aqueous solution containing 5-50% by mass of an organic solvent to form a nascent hollow fiber membrane.

[0055] (2) The hollow fiber ultrafiltration membrane prepared in the above step is immersed in deionized water at 25° C. for 36 hours to set the membrane, and then rinsed with deionized water to remove the residual solvent and additives, thereby forming a set hollow fiber membrane.

[0056] (IV) Characterization of hollow fiber ultrafiltration membrane

[0057] Basic property test: see Table 1. SEM morphology Figure 1 Received.

[0058] Dialysis component production: The obtained hollow fiber membrane was gathered and placed in the dialyzer shell. Polyurethane and epoxy resin were used to seal the two ends. After being placed at room temperature for one day, the membrane area was 0.2m 2 Hemodialysis components.

[0059] Filtration performance test: ultrafiltration coefficient (Kuf) test refers to "YY 0053-2016 "Hemodialysis and Related Therapy Hemodialysis Machine"; urea clearance test refers to "YY / T 1493-2016 "Hemodialysis and Related Therapy Concentrates"; β2 microglobulin clearance test refers to "YY / T 0771.3-2020 "Medical Devices for Blood Purification Part 3: Hemodialysis Machine"; biocompatibility test refers to "GB / T 16886.4-2019 "Biological Evaluation of Medical Devices Part 4: Interaction Test with Blood"; mechanical properties test refers to "YY / T0661-2017 "Medical Device Intravascular Catheter Disposable Sterile Catheter Part 5: Hemodialysis Catheter". The test results are shown in Table 1; clotting time test refers to GB / T 16886.4-2019 "Biological Evaluation of Medical Devices Part 4: Interaction Test with Blood".

[0060] Example 2

[0061] (I) Preparation of block polymers

[0062] The same preparation process as in Example 1 was adopted, except that:

[0063] The molar numbers of 4,4'-difluorodiphenyl sulfone monomer (Formula I) and 2-(3-(dimethylamino)propane)-3,3'-di(4-hydroxyphenyl)isoindolinone monomer (Formula II) were 205 mmol and 200 mmol, respectively. Finally, the oligomer iPES was obtained. 41 -F.

[0064] The molar numbers of 4,4'-difluorodiphenyl sulfone monomer and 4,4'-dihydroxydiphenyl sulfone monomer were 205 mmol and 200 mmol respectively. The final oligomer PES was obtained. 35 -OH.

[0065] By controlling iPES 41 -F and PES 35 -OH with a molar ratio of 30:70, the block polymer PES 35 -b-iPES 41 -b-PES 35 -30 is obtained.

[0066] (II) Preparation of the casting solution

[0067] The same preparation process as in Example 1 is adopted.

[0068] (III) Preparation of the hollow fiber ultrafiltration membrane

[0069] The same preparation process as in Example 1 is adopted.

[0070] (IV) Characterization of the hollow fiber ultrafiltration membrane

[0071] The same characterization process as in Example 1 is adopted.

[0072] The test results are shown in Table 1.

[0073] Example 3

[0074] (I) Preparation of the block polymer

[0075] The same preparation process as in Example 1 is adopted, with the difference that:

[0076] The feed molar amounts of 4,4'-difluorodiphenyl sulfone monomer (Formula I) and 2-(3-(dimethylamine)propyl)-3,3'-bis(4-hydroxyphenyl)isoindolinone monomer (Formula II) are 215 mmol and 200 mmol respectively. The oligomer iPES 52 -F is finally obtained.

[0077] The feed molar amounts of 4,4'-difluorodiphenyl sulfone monomer and 4,4'-dihydroxydiphenyl sulfone monomer are 215 mmol and 200 mmol respectively. The oligomer PES 33 -OH is finally obtained.

[0078] By controlling iPES 52 -F and PES 33 -OH with a molar ratio of 30:70, the block polymer PES 33 -b-iPES 52 -b-PES 33 -30 is obtained.

[0079] (II) Preparation of the casting solution

[0080] The same preparation process as in Example 1 is adopted.

[0081] (III) Preparation of the hollow fiber ultrafiltration membrane

[0082] The same preparation process as in Example 1 was adopted.

[0083] (IV) Characterization of the hollow fiber ultrafiltration membrane

[0084] The same characterization process as in Example 1 was adopted.

[0085] The test results of each example are shown in Table 1.

[0086]

[0087] Table 1 Test results of the membrane.

Claims

1. A preparation method of a permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane, characterized in that It includes the following steps: (I) Preparation of block polymer (1) Add 4,4'-difluorodiphenyl sulfone monomer and 2-(3-(dimethylamino)propyl)-3,3'-bis(4-hydroxyphenyl)isoindolinone monomer into N,N'-dimethylacetamide (DMAc), heat up the temperature in a programmed manner to 160 °C, use potassium carbonate as a catalyst, keep it for 18 h, and obtain an oligomer through co-polycondensation in an N2 atmosphere; among them, the molar ratio of 4,4'-difluorodiphenyl sulfone monomer to 2-(3-(dimethylamino)propyl)-3,3'-bis(4-hydroxyphenyl)isoindolinone monomer is 1-1.5:1; the number-average molecular weight Mn of the oligomer is 500-5000; (2) Dissolve the oligomer prepared in step (1) in an organic solvent, then add sodium 3-bromopropanesulfonate according to a mass ratio of 10:1.50 - 3.00 based on the oligomer, stir for a certain period of time, precipitate in a precipitating agent, and vacuum dry to obtain the oligomer iPES m -F, where m is the number of repeating units 30 - 90; (3) 4,4'-Difluorodiphenyl sulfone monomer and 4,4'-dihydroxydiphenyl sulfone monomer are added to N,N'-dimethylacetamide (DMAc), and the temperature is raised to 160 °C by programmed heating. Potassium carbonate is used as a catalyst and maintained for 18 h in an N2 atmosphere. The oligomer PES is obtained by co-polycondensation. n -OH, where the molar ratio of the feed of 4,4'-difluorodiphenyl sulfone monomer to 4,4'-dihydroxydiphenyl sulfone monomer is 1:1 to 1.2, and n is the number of repeating units from 20 to 80; (4) Add the oligomer iPES m -F and the oligomer PES n -OH into a liquid with N,N'-dimethylacetamide DMAc as the solvent, toluene as the water-carrying agent, and potassium carbonate as the catalyst in a certain proportion. Heat the mixture with a programmed temperature increase to 160 °C. Using potassium carbonate as the catalyst, maintain the temperature for 18 h in an N2 atmosphere. After co-polycondensation, an oligomer is obtained. Finally, dry it to obtain a polymer solid, which is the block polymer. By controlling the molar ratio of iPES m -F and PES n -OH, block polymers PES n -b-iPES m -b-PES n -x are obtained, where the molar ratio of iPES m -F and PES n -OH in the feed is x:100 - x, and x = 10 - 40; (II) Preparation of casting solution Place the block polymer, solvent and additive obtained in step (I) in a batching container in sequence, fully stir and dissolve for 3-12 h within the temperature range of 20-110 °C until a homogeneous solution is formed, filter through a stainless steel filter screen, and carry out vacuum or static defoaming for 6-24 h, and then place it for aging to obtain a casting solution; (III) Preparation of hollow fiber membrane (1) Control the environmental temperature and humidity to be 18-25 °C and 20-50 RH% respectively, extrude the casting solution prepared in step (II) through a metering pump through a spinneret, after passing through an air bath for 10-120 s, vertically immerse it into a first coagulation bath at 20-80 °C for phase separation and solidification for 60-180 s, then immerse it into a second coagulation bath for phase separation and solidification for 60-240 s, and finally wind it into a wire collecting tank; among them, the core liquid composition is pure water or an aqueous solution containing 5-50% organic solvent by mass concentration to form a nascent hollow fiber membrane; (2) Immerse the hollow fiber membrane prepared in the above steps in deionized water at 20-40 °C for 24-48 h for shaping, and rinse with deionized water to remove residual solvent and additive to form a shaped hollow fiber membrane.

2. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane as described in claim 1, wherein: In sub-step (1) of step (I), the molar ratio of the 4,4'-difluorodiphenyl sulfone monomer to the 2-(3-(dimethylamino)propyl)-3,3'-bis(4-hydroxyphenyl)isoindolinone monomer is 1.0-1.2:1; preferably: 1.05:1; The programmed heating reaction conditions are preferably 140 °C, 6 h, and then changed to 160 °C, 12 h.

3. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane as described in claim 1, wherein: In sub-step (2) of step (I), the mass ratio is preferably: 10:2.5; the precipitant is one or a mixed solvent of water, methanol, ethanol or isopropanol.

4. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane as described in claim 1, wherein: In sub-step (3) of step (I), the molar ratio of the 4,4'-difluorodiphenyl sulfone monomer to the 4,4'-dihydroxydiphenyl sulfone monomer is 1:1-1.2; preferably: 1:1.05; the programmed heating reaction conditions are preferably 140 °C, 6 h, and then changed to 160 °C, 12 h.

5. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane according to claim 1, characterized in that: In sub-step (4) of step (i), the programmed temperature rise heating reaction conditions are preferably 140 °C for 6 h, and then changed to 160 °C for 12 h; the molar ratio of iPESm-F to PESn-OH in the feed is 10-40:60-90; preferably 30:

70.

6. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane according to claim 1, characterized in that: In step (ii), PES n -b-iPES m -b-PES n -x is 5 to 30 parts, the additive is 0 to 25 parts, and the solvent is 55 to 95 parts, preferably PES n -b-iPES m -b-PES n -x is 25 parts, the additive is 5 parts, and the solvent is 70 parts; the solvent used is one or more of N,N'-dimethylacetamide (DMAc), N,N'-dimethylformamide (DMF), and N-methylpyrrolidone (NMP); the additive used is one or more of pure water, polyethylene glycol, oxalic acid, and water-soluble inorganic salts; the water-soluble inorganic salt is at least one of lithium chloride and lithium nitrate.

7. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane according to claim 1, characterized in that: In step (ii), the stirring temperature is preferably 70 °C for 6 h, and the standing defoaming time is preferably 12 h.

8. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane according to claim 1, characterized in that: In sub-step (1) of step (iii), the ambient temperature and humidity are preferably 25 °C and 40% RH respectively; the air bath time is 30-80 s, the temperature of the first coagulation bath is 30 °C, the DMAC concentration is 40%, and the phase separation curing time is 120 s; the temperature of the second coagulation bath is 50 °C, the DMAc concentration is 60%, and the phase separation curing time is 60-240 s.

9. The preparation method of the permanently hydrophilic block-structured polyarylethersulfone hemodialysis membrane according to claim 1, characterized in that: In sub-step (2) of step (iii), the temperature of the deionized water coagulation bath is 25 °C, and the shaping duration is 36 h.

10. A polyarylether sulfone hemodialysis membrane with a permanent hydrophilic block structure, characterized in that Prepared by using the preparation method described in any one of claims 1-9.

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