Modified polysulfone and hollow fiber membrane and preparation method thereof

Abstract

The present invention belongs to the technical field of modified polysulfones, and particularly relates to a modified polysulfone and a preparation method thereof, as well as a heparin-modified polysulfone hollow fiber membrane and a preparation method thereof. The modified polysulfone is mainly composed of a sulfonated polysulfone main chain and covalently grafted heparin side chains. By sulfonating the polysulfone, the mechanical properties and anti-coagulant properties of the polysulfone material are improved to a certain extent. The sulfonated polysulfone is then heparinized to maintain the excellent mechanical properties of the polysulfone material and significantly improve the anti-coagulant properties of the polysulfone material. The prepared heparin-modified sulfonated polysulfone is blended with a spinning solution to prepare a hollow fiber membrane. The membrane material improves the ultrafiltration rate while maintaining the sieving coefficient, significantly increases the membrane life, and prevents the shedding of membrane components. The hollow fiber membrane is particularly suitable for hemodialysis equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of modified polysulfones, and in particular relates to a heparin-modified sulfonated polysulfone and a preparation method thereof, as well as a heparin-modified polysulfone hollow fiber membrane and a preparation method thereof. Background Art

[0002] Hemodialysis devices place high demands on the membrane material, as their separation performance directly impacts the effectiveness of dialysis. Excellent hemodialysis membrane materials must meet the following basic requirements: non-toxicity and no side effects; good biocompatibility; good solute permselectivity; high mechanical strength; and suitable surface properties.

[0003] Polysulfone, the primary material for dialysis membranes, has a low ultrafiltration coefficient due to its inherent performance characteristics, making it susceptible to adsorption of macromolecules such as blood proteins, leading to membrane fouling. Modification of the material's hydrophilicity and hydrophobicity can improve the ultrafiltration coefficient of dialysis membranes, significantly reducing membrane fouling and extending their service life. Currently, the main modification methods are blending and grafting.

[0004] Grafting modification uses chemical bonds to fix chemical substances containing the required functional groups on the membrane surface. Usually, small molecule compounds rich in hydrophilic groups such as vitamins and their derivatives are grafted on the membrane surface. They have good stability and long life, but the production process is complicated and requires additional production steps, which significantly increases the difficulty and cost of production. Blending modification allows the target chemical substances to enter the product by mixing chemical substances containing the required functional groups into the spinning solution. Usually, macromolecular organic substances rich in hydrophilic groups such as polyvinyl pyrrolidone and polyethylene glycol are doped into the spinning solution. The process is simple, but the combination of raw materials relies only on organic cross-linking, which has problems such as poor stability, easy shedding, and change in the viscosity of the original formula of the spinning solution.

[0005] Since the residual coagulation phenomenon that occurs during the dialysis process will have a certain adverse effect on the dialysis effect and dialysis safety, a simple and efficient modification method for the hydrophilicity and antioxidant properties of the membrane is particularly important. Traditional modification methods usually use heparin as an additive, added into the spinning solution formula, and blended modification is performed. However, due to the small molecular weight of the heparin molecule itself, it is easy to fall off from the dialysis membrane, causing the membrane performance to drop sharply with the dialysis time. The problem of heparin shedding can be significantly improved by chemically bonding heparin to the membrane surface through a grafting method, but its production process is extremely complicated, which greatly increases the production cost of the dialysis membrane. Therefore, a simple and efficient membrane modification and its preparation method are particularly important. Summary of the Invention

[0006] According to one aspect of the present invention, a modified polysulfone and a preparation method thereof are provided, wherein the mechanical properties and anticoagulant properties of the polysulfone membrane are significantly improved by sequentially subjecting the polysulfone to sulfonation modification and heparinization modification.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A modified polysulfone mainly consists of a sulfonated polysulfone backbone and covalently grafted heparin side chains, and its chemical structure is as follows:

[0009]

[0010] or

[0011]

[0012] or

[0013]

[0014] or

[0015]

[0016] or

[0017]

[0018] Wherein n=50~300.

[0019] Some technical solutions include the following steps:

[0020] Sulfonation of polysulfone: dissolve polysulfone in a polar solvent, and under an inert atmosphere, use a complex of silicon halide and halosulfonic acid or halosulfonic acid as a sulfonating agent to introduce sulfonic acid groups on the aromatic ring of polysulfone to obtain sulfonated polysulfone;

[0021] Chlorination of sulfonated polysulfone: Under the protection of inert gas, sulfuryl chloride or thionyl chloride is used as a chlorinating agent to replace the hydrogen atom of the sulfonic acid group on the aromatic ring of polysulfone, and then a sulfonyl chloride group is introduced on the aromatic ring of polysulfone to obtain chlorinated sulfonated polysulfone;

[0022] Heparin-modified sulfonated polysulfone: Heparin is dissolved in a polar solvent, mixed with a NaH suspension, and then added to a chlorinated sulfonated polysulfone solution under an inert atmosphere to covalently bond heparin molecules to the polysulfone side chains to obtain heparin-modified sulfonated polysulfone.

[0023] Some technical solutions also include the following steps:

[0024] A mixed system of isopropyl alcohol and water is used to purify the sulfonation product of polysulfone and the chlorination product of sulfonated polysulfone.

[0025] In some technical solutions, the polar solvent is one or more combinations of dichloromethane, chloroform, toluene, acetone and methanol; and / or,

[0026] The mass ratio of isopropyl alcohol to water in the sulfonation step of polysulfone is 9:1, and the mass ratio of isopropyl alcohol to water in the chlorination step of sulfonated polysulfone is 50:50; and / or,

[0027] In the sulfonation step of polysulfone, the purity of the obtained sulfonated polysulfone is above 99%.

[0028] In some technical solutions, the preparation method of the modified polysulfone is specifically as follows:

[0029] The polysulfone is fully dissolved in a polar solvent, a sulfonating agent is added at 0-5°C to carry out a full sulfonation reaction, the reaction mixture is allowed to settle, and a precipitate is left. The precipitate is washed with a polar solvent and then poured into a mixture of isopropyl alcohol and water. The alcohol layer is removed, and the precipitate is diluted with isopropyl alcohol for an appropriate amount and length of time to obtain a free-flowing solid. The sulfonated polysulfone is obtained after extraction and drying.

[0030] The sulfonated polysulfone is dissolved in a polar solvent in an inert atmosphere, gently heated, a chlorinating agent is added dropwise, heated and stirred to dissolve, and then the temperature is increased to reflux the solvent, the residue obtained after rotary evaporation is added to chilled isopropanol and stirred, the precipitate is taken out, and the precipitate is added to a mixture of chilled water and isopropanol with a mass ratio of 50:50 and stirred for an appropriate amount of time, filtered and rinsed with chilled water to obtain a neutral filtrate, and dried to obtain chlorinated sulfonated polysulfone;

[0031] Heparin is dissolved in a polar solvent, followed by dissolving NaH in a non-polar solvent, removing the wax layer, and adding the mixture to a dry organic solvent to prepare a NaH suspension. The heparin solution is stirred in the organic solvent and continued to stir at room temperature. The solution is added to a chlorinated sulfonated polysulfone solution and stirred under an inert atmosphere. The mixture is then poured into ether, mixed, and washed with K2CO3 and brine in sequence. The solvent is evaporated in vacuo, and the compound is solidified with cooled isopropanol to obtain a viscous solid, i.e., heparin-modified sulfonated polysulfone.

[0032] According to another aspect of the present invention, the present invention further provides a heparin-modified polysulfone hollow fiber membrane and a preparation method thereof, which can improve the ultrafiltration rate while ensuring the sieving coefficient, and at the same time greatly increase the membrane life and avoid the shedding of membrane components.

[0033] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0034] A method for preparing a heparin-modified polysulfone hollow fiber membrane comprises the following steps:

[0035] Dissolving polysulfone in an organic solvent, adding polyvinyl pyrrolidone as an additive, and stirring and mixing uniformly to form a homogeneous organic solution;

[0036] adding the heparin-modified sulfonated polysulfone into the homogeneous organic solution to obtain a spinning solution;

[0037] The spinning solution is vacuum degassed and poured into the spinning device, and pushed to the spinneret for forming by a metering pump. At the same time, the core liquid enters the spinneret under pressure, passes through a certain air gap and enters the gel tank. The hollow fiber membrane is solidified and formed under the action of a non-solvent, washed with pure water and then dried to obtain the heparin-modified polysulfone hollow fiber membrane.

[0038] In some technical solutions, the content of the organic solvent accounts for 40wt% to 90wt% of the spinning solution, the content of the polyvinyl pyrrolidone accounts for 0.5wt% to 30wt% of the spinning solution, and the content of the heparin-modified sulfonated polysulfone accounts for 0.1wt% to 30wt% of the spinning solution; and / or,

[0039] The organic solvent is N,N-dimethylacetamide.

[0040] In some technical solutions, the gel tank contains pure water, and the core liquid is an N,N-dimethylacetamide aqueous solution; and / or,

[0041] The air gap is 40 cm.

[0042] In some technical solutions, the heparin-modified polysulfone hollow fiber membrane is suitable for hemodialysis equipment.

[0043] The present invention adopts the above technical solution to have at least the following beneficial effects:

[0044] 1. Heparin, which is rich in hydrophilic groups, is grafted onto sulfonated polysulfone, which is then added to the spinning solution for blending. The more complex structure and chemical bonds effectively increase the modification strength, making it easier to industrialize while ensuring stability.

[0045] 2. The addition of heparin derivatives can effectively increase the ultrafiltration coefficient and service life of the dialysis membrane;

[0046] 3. The presence of heparin derivatives can effectively improve blood compatibility, prevent the occurrence of coagulation, and reduce the risk of dialysis;

[0047] 4. The porosity of heparin modified polysulfone hollow fiber membrane is 40% to 85%, the breaking strength is 0.5 to 15 MPa, and the pure water flux is 10 to 400 mL / (m 2 ·h·mmHg), and the clearance rates of urea and creatinine in the blood reached 333 and 301 mL / min respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of the preparation principle of heparin-modified sulfonated polysulfone in an embodiment of the present invention;

[0049] Figure 2 This is a comparison chart of the static anti-protein adsorption results of the membrane material prepared in Example 4 of the present invention;

[0050] Figure 3 This is a comparison chart of the DPPH free radical and ABTS+ free radical scavenging capabilities of the membrane material prepared in Example 4 of the present invention;

[0051] Figure 4 This is a graph showing changes in ultrafiltration rate of membrane materials prepared in Examples 4-8 of the present invention as a function of additive dosage. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application. The various commonly used reagents used in the examples are all commercially available products.

[0053] Example 1

[0054] See Figure 1 , provides a heparin-modified sulfonated polysulfone, which is mainly composed of a sulfonated polysulfone main chain and a covalently grafted heparin side chain. The chemical structure is as follows, where n=50-300.

[0055]

[0056] or

[0057]

[0058] or

[0059]

[0060] or

[0061]

[0062] or

[0063]

[0064] It should be noted that the polysulfone in the present application refers to polysulfone materials, including but not limited to synthetic membranes with good biocompatibility and high permeability, such as polyether, polyethersulfone and polyarylsulfone.

[0065] Example 2

[0066] See Figure 1 , provides a method for preparing heparin-modified sulfonated polysulfone, comprising the following steps:

[0067] Sulfonation of polysulfone: PSU (polysulfone) was dissolved in dry DCM (dichloromethane) at room temperature for 8 hours. Chlorosulfonic acid was added at 0-5°C and stirred vigorously at a stirrer speed for more than 2 hours, and then stirred at room temperature for more than 12 hours to ensure complete sulfonation. The reaction mixture was allowed to settle and the upper organic layer was removed, leaving a dark brown precipitate. The precipitate was washed with DCM and then poured into a mixture of isopropanol / water (9:1) and stirred vigorously. The alcohol layer was removed and the precipitate was diluted with isopropanol overnight to obtain a free-flowing solid. The alcohol was removed by vacuum filtration and the product was dried in a vacuum at 40°C for 24 hours to obtain the sulfonated polysulfone.

[0068] Chlorination of sulfonated polysulfone: The sulfonated polysulfone product obtained in the above step is dissolved in dry DCM in an inert atmosphere and heated gently. Thionyl chloride is added dropwise and stirred at 60-70°C to dissolve, and then the temperature is increased to reflux the solvent. The dark brown residue obtained after rotary evaporation is added to chilled isopropanol and stirred vigorously. The precipitate is removed and the precipitate is frozen again with a mixture of water: isopropanol (50:50) and stirred overnight. Filter and rinse with chilled water to a neutral filtrate. The obtained compound is vacuum dried at 70°C for 2 days. Chlorinated sulfonated polysulfone is obtained.

[0069] Heparin-modified sulfonated polysulfone: Dissolve heparin in anhydrous THF and purge with dry nitrogen for 1 hour to remove any dissolved oxygen. Dissolve the sodium hydroxide (NaH) in dry n-hexane. Remove the hexane wax layer and add dry THF to create a NaH suspension. Stir the heparin solution in THF and continue stirring at room temperature for 2 hours. This solution is added to a solution of the chlorinated sulfonated polysulfone in anhydrous tetrahydrofuran (THF) and stirred under nitrogen for 24 hours. The mixture is then poured into diethyl ether, mixed, and washed sequentially with 10% potassium carbonate (KCO) and then brine. The solvent is evaporated in vacuo, and the compound is solidified with cold isopropanol to yield a sticky solid, the heparin-modified sulfonated polysulfone.

[0070] The solvents selected in this embodiment include but are not limited to: polar solvents such as one or more combinations of dichloromethane, chloroform, toluene, acetone and methanol; non-polar solvents such as n-hexane or benzene; and organic reagents such as THF.

[0071] The reaction steps of this embodiment are carried out in an inert atmosphere, which is beneficial to the controllability of the reaction steps.

[0072] In the preparation step of sulfonated polysulfone of this embodiment, polysulfone is used as raw material and chlorosulfonic acid is used as sulfonating agent to carry out sulfonation reaction, and the crude product of the sulfonation reaction is purified by recrystallization through a mixture of isopropyl alcohol and water. The purity of the prepared sulfonated polysulfone is above 99%.

[0073] In this embodiment, polysulfone is sulfonated to improve the mechanical properties and anticoagulant properties of the polysulfone material. The sulfonated polysulfone is then heparinized to maintain the excellent mechanical properties of the polysulfone material and significantly improve the anticoagulant properties of the polysulfone material.

[0074] Example 3

[0075] Provided are a heparin-modified polysulfone hollow fiber membrane and a preparation method thereof, the preparation method comprising the following steps:

[0076] Dissolving polysulfone in an organic solvent, adding polyvinyl pyrrolidone (PVP) as an additive, and mechanically stirring and mixing to form a homogeneous organic solution;

[0077] The heparin-modified sulfonated polysulfone prepared in Example 2 is added to a homogeneous organic solution to obtain a spinning solution;

[0078] The spinning solution is vacuum degassed and poured into the spinning device, and pushed to the spinneret for forming by a metering pump. At the same time, the core liquid enters the spinneret under pressure, passes through a certain air gap and enters the gel tank. The hollow fiber membrane is solidified and formed under the action of a non-solvent, washed with pure water and then dried to obtain the heparin-modified polysulfone hollow fiber membrane.

[0079] The organic solvent in this embodiment can be selected from N,N-dimethylacetamide (DMAC), whose content accounts for 40wt% to 90wt% of the spinning solution, the content of polyvinyl pyrrolidone accounts for 0.5wt% to 30wt% of the spinning solution, and the content of heparin-modified sulfonated polysulfone accounts for 0.1wt% to 30wt% of the spinning solution.

[0080] In some specific embodiments, the gel tank contains pure water, the core liquid is an N,N-dimethylacetamide aqueous solution, and the air gap is 40 cm.

[0081] In this embodiment, a hollow fiber membrane is prepared by mixing an appropriate amount of sulfonated polysulfone covalently grafted with heparin hydrophilic groups into the spinning solution. The hollow fiber membrane is particularly suitable for use in hemodialysis equipment. The more complex structure and chemical bonds effectively increase the modification strength, making the membrane material easier to industrialize while ensuring stability. The addition of heparin derivatives can effectively increase the ultrafiltration coefficient and service life of the dialysis membrane.

[0082] Comparative Example 1

[0083] The difference from Example 3 is that no heparin-modified sulfonated polysulfone is added, only the spinning membrane step is retained, and the mass ratio of PSU:PVP:DMAC is controlled to be 23:4:73. The membrane prepared by Control Example 1 is denoted as M0.

[0084] Comparative Example 2

[0085] The difference from Example 3 is that heparin was directly blended during the spinning and membrane-forming step, and the mass ratio of PSU:PVP:DMAC:X was controlled to be 15:1:76:8, where X represents the additive, specifically heparin in this control example. The membrane prepared from Control Example 2 is designated M1.

[0086] Comparative Example 3

[0087] The difference from Example 3 is that chitosan-modified sulfonated polysulfone was added to the spinning membrane process, and the mass ratio of PSU:PVP:DMAC:X was controlled to be 15:1:76:8, where X represents the additive, specifically chitosan-modified sulfonated polysulfone in this control example. The membrane prepared from Control Example 3 is designated M2.

[0088] Example 4

[0089] This example builds on the preparation steps of Examples 2 and 3, but with a mass ratio of PSU:PVP:DMAC:X of 15:1:76:8, where X represents an additive. Specifically, in all examples herein, it is heparin-modified sulfonated polysulfone. The covalent grafting method is employed, resulting in a more complex structure and chemical bonds that effectively increase the strength of the modification. The membrane material prepared in Example 4 is designated M3.

[0090] Example 5

[0091] The difference from Example 4 is that the mass ratio of PSU:PVP:DMAC:X is controlled to be 13:1:76:10. The membrane material prepared in Example 5 is denoted as M4.

[0092] Example 6

[0093] The difference from Example 4 is that the mass ratio of PSU:PVP:DMAC:X is controlled to be 14:1:76:9. The membrane material prepared in Example 6 is denoted as M5.

[0094] Example 7

[0095] The difference from Example 4 is that the mass ratio of PSU:PVP:DMAC:X is controlled to be 16:1:76:7. The membrane material prepared in Example 7 is denoted as M6.

[0096] Example 8

[0097] The difference from Example 4 is that the mass ratio of PSU:PVP:DMAC:X is controlled to be 17:1:76:6. The membrane material prepared in Example 8 is denoted as M7.

[0098] Experimental results analysis

[0099] The test results of the membranes prepared from Control Examples 2-3 and Examples 4-5 are shown in the following table.

[0100] Table 1. Test results of membrane ultrafiltration rate and clearance rate

[0101]

[0102] It can be seen from the test results in Table 1 that the membrane material prepared by blending the heparin-modified sulfonated polysulfone obtained by covalent grafting with the spinning solution in the present application significantly improves the ultrafiltration rate while ensuring the sieving coefficient, can effectively improve blood compatibility, prevent the occurrence of coagulation, and reduce the risk of dialysis.

[0103] See Figure 2 , for static anti-protein adsorption research. Figure 2 As can be seen, compared to membrane M0, membranes M1, M2, and M3 with heparin or heparin-like structures showed significantly lower BSA adsorption per unit area. This suggests that membranes modified with heparin or heparin-like structures exhibit superior antifouling properties. This is likely due to the presence of hydrophilic groups such as hydroxyl and carbonyl groups on SLB. These hydrophilic groups form a hydration layer with the BSA aqueous solution on the membrane surface. This hydration layer isolates the hydrophobic BSA protein from the blended membrane, significantly reducing the potential for complement activation during dialysis and improving the membrane's antioxidant properties. The membrane modified with sulfonated polysulfone-heparin grafting exhibited the lowest BSA adsorption rate.

[0104] See Figure 3 , is the ability of the membrane to scavenge DPPH free radicals and ABTS+ free radicals. Figure 3 It can be seen that the membrane modified with sulfonated polysulfone-heparin can greatly improve the membrane's antioxidant properties, thereby improving the oxidative stress state caused by its application in hemodialysis membranes and having better blood compatibility.

[0105] See Figure 4 The effect of the addition of heparin-modified sulfonated polysulfone on ultrafiltration rate was analyzed. With increasing heparin-modified sulfonated polysulfone content, the membrane's ultrafiltration rate initially increased and then decreased, while flux recovery gradually improved while maintaining a high BSA retention rate. In particular, the membrane's ultrafiltration rate reached its maximum when the sulfonated polysulfone content reached 8%. All performance characteristics were improved.

[0106] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A modified polysulfone, characterized in that It is mainly composed of a sulfonated polysulfone main chain and a covalently grafted heparin side chain. The chemical structure is as follows: or or or or Wherein n=50~300.

2. The method for preparing modified polysulfone according to claim 1, wherein Including steps: Sulfonation of polysulfone: dissolve polysulfone in a polar solvent, and under an inert atmosphere, use a complex of silicon halide and halosulfonic acid or halosulfonic acid as a sulfonating agent to introduce sulfonic acid groups on the aromatic ring of polysulfone to obtain sulfonated polysulfone; Chlorination of sulfonated polysulfone: Under the protection of inert gas, sulfuryl chloride or thionyl chloride is used as a chlorinating agent to replace the hydrogen atom of the sulfonic acid group on the aromatic ring of polysulfone, and then a sulfonyl chloride group is introduced on the aromatic ring of polysulfone to obtain chlorinated sulfonated polysulfone; Heparin-modified sulfonated polysulfone: Heparin is dissolved in a polar solvent, mixed with a NaH suspension, and then added to a chlorinated sulfonated polysulfone solution under an inert atmosphere to covalently bond heparin molecules to the polysulfone side chains to obtain heparin-modified sulfonated polysulfone.

3. The method for preparing modified polysulfone according to claim 2, wherein Also includes the steps: A mixed system of isopropyl alcohol and water is used to purify the sulfonation product of polysulfone and the chlorination product of sulfonated polysulfone.

4. The method for preparing modified polysulfone according to claim 3, wherein The polar solvent is one or more combinations of dichloromethane, chloroform, toluene, acetone and methanol; and / or, The mass ratio of isopropyl alcohol to water in the sulfonation step of polysulfone is 9:1, and the mass ratio of isopropyl alcohol to water in the chlorination step of sulfonated polysulfone is 50:50; and / or, In the sulfonation step of polysulfone, the purity of the obtained sulfonated polysulfone is above 99%.

5. The method for preparing the modified polysulfone according to any one of claims 2 to 4, wherein: The preparation method of the modified polysulfone is specifically as follows: The polysulfone is fully dissolved in a polar solvent, a sulfonating agent is added at 0-5°C to carry out a full sulfonation reaction, the reaction mixture is allowed to settle, and a precipitate is left. The precipitate is washed with a polar solvent and then poured into a mixture of isopropyl alcohol and water. The upper organic phase is removed, and the lower precipitate phase is diluted for an appropriate amount of time to obtain a free-flowing solid. The sulfonated polysulfone is obtained after extraction and drying. The sulfonated polysulfone is dissolved in a polar solvent in an inert atmosphere, gently heated, a chlorinating agent is added dropwise, heated and stirred to dissolve, and then the temperature is increased to reflux the solvent, the residue obtained after rotary evaporation is added to chilled isopropanol and stirred, the precipitate is taken out, and the precipitate is added to a mixture of chilled water and isopropanol with a mass ratio of 50:50 and stirred for an appropriate amount of time, filtered and rinsed with chilled water to obtain a neutral filtrate, and dried to obtain chlorinated sulfonated polysulfone; Heparin is dissolved in a polar solvent, followed by dissolving NaH in a non-polar solvent, removing the wax layer, and adding the mixture to a dry organic solvent to prepare a NaH suspension. The heparin solution is stirred in the organic solvent and continued to stir at room temperature. The solution is added to a chlorinated sulfonated polysulfone solution and stirred under an inert atmosphere. The mixture is then poured into ether, mixed, and washed with K2CO3 and brine in sequence. The solvent is evaporated in vacuo, and the compound is solidified with cooled isopropanol to obtain a viscous solid, i.e., heparin-modified sulfonated polysulfone.

6. A method for preparing a heparin-modified polysulfone hollow fiber membrane, characterized in that: Based on the steps of the preparation method of modified polysulfone according to any one of claims 2 to 5, the method further comprises the following steps: Dissolving polysulfone in an organic solvent, adding polyvinyl pyrrolidone as an additive, and stirring and mixing uniformly to form a homogeneous organic solution; adding heparin-modified sulfonated polysulfone into the homogeneous organic solution to obtain a spinning solution; The spinning solution is vacuum degassed and poured into the spinning device, and pushed to the spinneret for forming by a metering pump. At the same time, the core liquid enters the spinneret under pressure, passes through a certain air gap and enters the gel tank. The hollow fiber membrane is solidified and formed under the action of a non-solvent, washed with pure water and then dried to obtain the heparin-modified polysulfone hollow fiber membrane.

7. The method for preparing the heparin-modified polysulfone hollow fiber membrane according to claim 6, characterized in that: The content of the organic solvent accounts for 40wt% to 90wt% of the spinning solution, the content of the polyvinyl pyrrolidone accounts for 0.5wt% to 30wt% of the spinning solution, and the content of the heparin-modified sulfonated polysulfone accounts for 0.1wt% to 30wt% of the spinning solution; and / or, The organic solvent is N,N-dimethylacetamide.

8. The method for preparing the heparin-modified polysulfone hollow fiber membrane according to claim 6, characterized in that: The gel tank contains pure water, and the core liquid is an N,N-dimethylacetamide aqueous solution; and / or, The air gap is 40 cm.

9. A heparin-modified polysulfone hollow fiber membrane, characterized in that: The heparin-modified polysulfone hollow fiber membrane is prepared by the preparation method of any one of claims 6 to 8 and is suitable for hemodialysis equipment.

10. The heparin-modified polysulfone hollow fiber membrane according to claim 9, characterized in that The porosity of the heparin-modified polysulfone hollow fiber membrane is 40% to 85%, the breaking strength is 0.5 to 15 MPa, and the pure water flux at 500 mmHg is 10 to 400 mL / (m 2 ·h·mmHg), and the clearance rates of urea and creatinine in the blood reached 333mL / min and 301mL / min respectively.

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