Self-polymerized microporous polymer hollow fiber ultrafiltration membrane, its preparation method and application

Abstract

This invention provides a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, its preparation method, and its application, belonging to the field of ultrafiltration membrane technology. This invention mixes a self-polymerizing microporous polymer (PIM), a plasticizer, and an organic solvent to obtain a spinning solution. The spinning solution is then used for wet spinning to obtain a hollow fiber ultrafiltration membrane in one step. In this invention, the self-polymerizing microporous polymer (PIM) is added during the spinning process. The PIM material cross-links internally through aromatic ether bonds (C-O-C) to form a network structure, while micropores are generated during the network weaving process, thus forming a continuous pore network structure, thereby improving the performance of the ultrafiltration membrane. The hollow fiber ultrafiltration membrane prepared by this invention using a self-polymerizing microporous polymer with a specific structure exhibits good hydrophilicity, with a permeability coefficient of over 100 μm. ‑2 h ‑1 The above features enable efficient filtration under low pressure, reducing energy consumption.

Description

A self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, its preparation method and application Technical Field

[0001] This invention relates to the field of ultrafiltration membrane technology, and in particular to a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, its preparation method, and its application. Background Technology

[0002] With the increasing global demand for water resources, environmental pollution control, and the rapid development of the biopharmaceutical industry, membrane separation technology, as a highly efficient and energy-saving separation method, is experiencing unprecedented development opportunities. In water treatment, ultrafiltration membranes, due to their nanoscale pore size (typically 1-100 nm) and pore size sieving effect, have become one of the core technologies in the membrane separation field. Ultrafiltration membranes can effectively remove suspended solids, bacteria, and large organic molecules from water; in food processing, they aid in liquid concentration, purification, and separation; and in the biopharmaceutical industry, ultrafiltration membranes are widely used in important processes such as cell separation and protein purification. However, traditional ultrafiltration membrane production methods typically face problems such as low production efficiency, unstable membrane performance, severe membrane fouling, and environmental pollution, limiting their further development in practical applications. Summary of the Invention

[0003] The purpose of this invention is to provide a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, its preparation method and application, which can improve the production efficiency of ultrafiltration membranes, obtain ultrafiltration membranes with stable performance, and have strong environmental protection.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, comprising the following steps:

[0006] A spinning solution is obtained by mixing a self-polymerizing microporous polymer, a plasticizer, and an organic solvent.

[0007] Water and glycerin are mixed to obtain the core fluid;

[0008] After wet spinning of the spinning solution and core solution, solidification is carried out in a coagulation bath to obtain a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane.

[0009] The monomers for preparing the self-polymerizing microporous polymer include tetrafluoroterephthalonitrile and 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene.

[0010] Preferably, the plasticizer includes diethylene glycol, glycerol, polydimethylsiloxane, or dioctyl phthalate; the organic solvent includes tetrahydrofuran, chloroform, or N,N-dimethylacetamide.

[0011] Preferably, the content of each component in the spinning solution is: 22-30 wt% self-polymerizing microporous polymer, 7-10 wt% plasticizer, and 60-70 wt% organic solvent.

[0012] Preferably, the mass ratio of water to glycerol in the core fluid is 80:20 to 20:80.

[0013] Preferably, the method for preparing the self-polymerizing microporous polymer includes the following steps:

[0014] Tetrafluoroterephthalonitrile, 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene, potassium carbonate and N,N-dimethylacetamide were mixed and subjected to polymerization. After polymerization, the mixture was subjected to precipitation, boiling water treatment and vacuum drying to obtain a self-polymerized microporous polymer.

[0015] Preferably, the molar concentration of the tetrafluoroterephthalonitrile in N,N-dimethylacetamide is 10-30 mmol / L, the molar concentration of the 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene in N,N-dimethylacetamide is 15-50 mmol / L, and the molar concentration of the potassium carbonate in N,N-dimethylacetamide is 50-100 mmol / L.

[0016] Preferably, the polymerization reaction is carried out at a temperature of 100-200°C for a time of 30-60 minutes.

[0017] The present invention provides a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared by the preparation method described above, with an inner diameter of 0.5~0.8 mm and an outer diameter of 1.0~1.3 mm.

[0018] Preferably, at 0.1 MPa, the permeability coefficient of the self-polymerizing microporous polymer hollow fiber ultrafiltration membrane is >100 μm. -2 h -1 .

[0019] This invention provides the application of the self-polymerizing microporous polymer hollow fiber ultrafiltration membrane described above in the fields of water treatment, food separation, or pharmaceutical separation.

[0020] This invention provides a method for preparing a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane. The method involves mixing a self-polymerizing microporous polymer (PIM), a plasticizer, and an organic solvent to obtain a spinning solution. The spinning solution is then subjected to wet spinning to obtain the hollow fiber ultrafiltration membrane in one step. In this invention, the self-polymerizing microporous polymer (PIM) is added during the spinning process. The PIM material cross-links internally through aromatic ether bonds (COC) to form a network structure, while micropores are generated during the network weaving process, thus forming a continuous pore network structure and improving the performance of the ultrafiltration membrane. The hollow fiber ultrafiltration membrane prepared by this invention using a self-polymerizing microporous polymer with a specific structure exhibits good hydrophilicity, with a permeability coefficient of over 100 μm. -2 h -1 The above features enable efficient filtration under low pressure, reducing energy consumption.

[0021] Furthermore, this invention employs a one-step method to prepare hollow fiber ultrafiltration membranes, which is relatively simple in preparation, has low production costs, and offers high cost-effectiveness, making it suitable for large-scale production. Moreover, it generates less waste during production, thus exhibiting strong environmental friendliness. The method of this invention simplifies the multiple steps required in traditional membrane formation processes, reduces system complexity, and improves production efficiency. Simultaneously, the simplified process flow is more conducive to automated production, thus offering significant advantages in industrial production.

[0022] This invention can adjust the physicochemical properties of the core liquid according to the specific requirements of the membrane, thereby optimizing the membrane formation process and performance.

[0023] The hollow fiber ultrafiltration membrane prepared by this invention can be widely used in a variety of application fields, such as water treatment, food separation and medicine. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the synthesis process of the self-polymerizing microporous polymer in Example 1;

[0025] Figure 2 shows the XRD pattern of the self-polymerizing microporous polymer prepared in Example 1;

[0026] Figure 3 is the FTIR spectrum of the self-polymerizing microporous polymer prepared in Example 1;

[0027] Figure 4 is a thermogravimetric diagram of the self-polymerizing microporous polymer prepared in Example 1;

[0028] Figure 5 is a schematic diagram of the process of preparing hollow fiber ultrafiltration membrane in Example 1;

[0029] Figure 6 is a SEM image of the inner surface of the hollow fiber ultrafiltration membrane prepared in Example 1;

[0030] Figure 7 is a cross-sectional SEM image of the hollow fiber ultrafiltration membrane prepared in Example 1;

[0031] Figure 8 shows the contact angle of the hollow fiber ultrafiltration membrane prepared in Example 1. Detailed Implementation

[0032] In this invention, unless otherwise specified, the raw materials or reagents required for preparation are all commercially available products well known to those skilled in the art.

[0033] This invention provides a method for preparing a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, comprising the following steps:

[0034] A spinning solution is obtained by mixing a self-polymerizing microporous polymer, a plasticizer, and an organic solvent.

[0035] Water and glycerin are mixed to obtain the core fluid;

[0036] After wet spinning of the spinning solution and core solution, solidification is carried out in a coagulation bath to obtain a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane.

[0037] The monomers for preparing the self-polymerizing microporous polymer include tetrafluoroterephthalonitrile and 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene.

[0038] In this invention, the method for preparing the self-polymerizing microporous polymer (PIM) preferably includes the following steps:

[0039] Tetrafluoroterephthalonitrile, 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene, potassium carbonate and N,N-dimethylacetamide were mixed and subjected to polymerization. After polymerization, the mixture was subjected to precipitation, boiling water treatment and vacuum drying to obtain a self-polymerized microporous polymer.

[0040] In this invention, the molar concentration of the tetrafluoroterephthalonitrile in N,N-dimethylacetamide is preferably 10-30 mmol / L, more preferably 10-20 mmol / L; the molar concentration of the 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene in N,N-dimethylacetamide is 15-50 mmol / L, more preferably 30 mmol / L; and the molar concentration of the potassium carbonate in N,N-dimethylacetamide is 50-100 mmol / L, more preferably 70-80 mmol / L.

[0041] In this invention, tetrafluoroterephthalonitrile, 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene, anhydrous potassium carbonate, and N,N-dimethylacetamide are added to the reaction vessel, stirred evenly at room temperature, and the reaction apparatus is transferred to an oil bath for heating and mechanical stirring to carry out the polymerization reaction.

[0042] In this invention, the temperature of the polymerization reaction is preferably 100~200℃, more preferably 200℃, and the time is preferably 30~60 min, more preferably 30 min.

[0043] After the polymerization reaction is completed, the present invention preferably cools the reaction product, pours the PIM reaction product into anhydrous methanol to precipitate, filters the obtained precipitate, dissolves it with chloroform, precipitates it again into anhydrous methanol, treats the obtained fluorescent yellow solid with boiling water, and then vacuum dries it in a vacuum drying oven to obtain self-polymerizing microporous polymer (PIM) powder.

[0044] In this invention, based on 50-100 g of the PIM reaction product, the volume of anhydrous methanol required for precipitation in anhydrous methanol is 300-600 mL, more preferably 400 mL; the volume of chloroform required for dissolution in chloroform is 50-100 mL, more preferably 50 mL; and the volume of anhydrous methanol required for reprecipitation in anhydrous methanol is 300-600 mL, more preferably 400 mL.

[0045] In this invention, the boiling water treatment time is preferably 6 to 12 hours, more preferably 10 hours; the vacuum drying temperature is preferably 80 to 100 °C, more preferably 80 °C, and the time is preferably 12 to 24 hours, more preferably 12 hours.

[0046] In this invention, the preferred content of each component in the spinning solution is: 22-30 wt% self-polymerizing microporous polymer, 7-10 wt% plasticizer, and 60-70 wt% organic solvent.

[0047] In this invention, the content of the self-polymerizing microporous polymer in the spinning solution is more preferably 25-30 wt%, the content of the plasticizer is more preferably 8-10 wt%, and the content of the organic solvent is more preferably 62-67 wt%.

[0048] In this invention, the plasticizer preferably includes diethylene glycol, glycerol, polydimethylsiloxane, or dioctyl phthalate; the organic solvent preferably includes tetrahydrofuran, chloroform, or N,N-dimethylacetamide.

[0049] In this invention, the self-polymerizing microporous polymer provides the matrix structure framework of the membrane, the plasticizer improves the flexibility and stability of the membrane, and the organic solvent fully dissolves and uniformly disperses other components, ensuring the consistency, flowability and stability of the spinning solution.

[0050] In this invention, the self-polymerizing microporous polymer, plasticizer, and organic solvent are mixed and then crushed to form a spinning solution. This invention does not have a specific limitation on the crushing process; any method well-known in the art can be used to crush and mix the materials.

[0051] In this invention, the mass ratio of water to glycerol in the core fluid is preferably 80:20 to 20:80, more preferably 40:60 or 60:40. The addition of glycerol helps adjust the viscosity and permeability of the core fluid, thereby affecting the formation of the membrane pore structure and the final membrane separation performance. By adjusting the water-to-glycerol ratio, the properties of the core fluid can be optimized to meet the requirements of different membrane preparations.

[0052] In this invention, the spinning solution is preferably extruded through the casting solution spinneret at room temperature, while the core solution is injected through the core solution orifice and fills the hollow fiber structure. The extruded membrane fibers fall vertically into the coagulation bath to complete the initial formation of the membrane. The formed membrane fibers are collected by a fiber take-up device and dried to obtain a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane.

[0053] In this invention, the coagulation bath is preferably water, the temperature of the coagulation bath is preferably 20~70 ℃, more preferably 30~50 ℃, and the coagulation time is preferably 1~15 minutes, more preferably 10 minutes.

[0054] This invention utilizes a microporous polymer as the high-molecular material, ensuring the structural uniformity and high separation efficiency of the hollow fiber membrane, while also possessing high production stability and controllability. By optimizing the temperature and time of the coagulation bath, the pore structure and physical properties of the membrane can be precisely controlled, improving the final performance of the membrane. This spinning process has low cost and a high level of automation, making it suitable for large-scale industrial production.

[0055] The present invention provides a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared by the preparation method described above, with an inner diameter of 0.5~0.8 mm, more preferably 0.7 mm, and an outer diameter of 1.0~1.3 mm, more preferably 1.2 mm.

[0056] In this invention, at 0.1 MPa, the permeability coefficient of the self-polymerizing microporous hollow fiber ultrafiltration membrane is >100 μm. -2 h -1 .

[0057] This invention provides the application of the self-polymerizing microporous polymer hollow fiber ultrafiltration membrane described above in the fields of water treatment, food separation, or pharmaceutical separation. This invention does not impose any particular limitation on the method of application; any method well-known in the art can be used.

[0058] Furthermore, the modular design of the hollow fiber membrane for batch spinning allows for easy integration and expansion by optimizing the spinning process and membrane pore structure design, thus meeting operational requirements of different scales and needs.

[0059] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods.

[0060] Unless otherwise specified, the experimental and testing methods described below are conventional methods; unless otherwise specified, the reagents and raw materials described below are commercially available.

[0061] In this invention, the permeability coefficient P w Defined as: the mass flowing out per unit time per unit area per unit volume under certain conditions. P w =Δm / (ρ A Δt), unit Lm -2 h -1 Where Δm (kg) is the mass increment of the filtrate during the separation time Δt (h), and ρ is the density of the filtrate (kg L). -1 ), A(m 2 () represents the effective filtration area.

[0062] Example 1

[0063] As shown in Figure 1, 10 mmol tetrafluoroterephthalonitrile, 30 mmol 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene, 70 mmol anhydrous potassium carbonate, and 1000 mL N,N-dimethylacetamide were added to the reactor of the water separator. The mixture was stirred at room temperature for 60 min. After stirring until homogeneous, the reaction apparatus was transferred to an oil bath at 200 °C and mechanically stirred for 30 min. After the reaction system cooled, 50 g of the reaction product was poured into 400 mL of anhydrous methanol to precipitate. The precipitate was filtered, dissolved in 50 mL of chloroform, and then precipitated again in 400 mL of anhydrous methanol. The resulting fluorescent yellow solid was treated in boiling water for 10 h and dried in a vacuum drying oven at 80 °C for 12 h to obtain self-polymerizing microporous polymer (PIM) powder, denoted as PIM-1.

[0064] According to the formula, 22 wt% of the self-polymerizing microporous polymer, 8 wt% of diethylene glycol and 70 wt% of tetrahydrofuran prepared above were mixed at room temperature to obtain a spinning solution;

[0065] Water and glycerin were mixed at a mass ratio of 80:20 to obtain the core fluid;

[0066] As shown in Figure 4, at room temperature, the spinning solution is extruded through the casting solution spinneret orifice, while the core solution is simultaneously injected through the core solution orifice. The extruded membrane fibers fall vertically into a 20°C coagulation bath (tap water) for 10 minutes. After coagulation, the fibers are collected by a winding device and dried to obtain a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane. The inner diameter is 0.7 mm, the outer diameter is 1.2 mm, and the permeability coefficient is 120 μm. -2 h -1 .

[0067] Figure 1 is a schematic diagram of the synthesis process of the self-polymerizing microporous polymer in Example 1. The self-polymerizing microporous polymer PIM was synthesized by reacting monomers 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene and tetrafluoroterephthalonitrile.

[0068] Figure 2 shows the XRD pattern of the self-polymerizing microporous polymer prepared in Example 1. The XRD pattern shows two polymer peaks with 2θ of 14.0 degrees and 22.6 degrees, corresponding to d-intervals of 6.5 Å and 4.0 Å, respectively, which are attributed to the micropores and effective segments between polymer chains.

[0069] Figure 3 shows the FTIR spectrum of the self-polymerizing microporous polymer prepared in Example 1. The FTIR spectrum is displayed at 1600 cm⁻¹. - ¹ Absorption peak near the carbonyl group (C=O). In the 3000-3100 cm⁻¹ range. -1 and 1600-1450 cm -1 Characteristic peaks of the CH vibration of the aromatic ring within the range of 700-900 cm⁻¹. -1 The rigid framework (such as spirocyclic structures) of nearby PIMs passed through characteristic peaks, indicating the successful synthesis of the self-polymerizing microporous polymer.

[0070] Figure 4 shows the thermogravimetric analysis (TGA) of the self-polymerizing microporous polymer prepared in Example 1. As shown in Figure 3, it mainly includes two weight loss processes. The mass loss of PIM is 5% between 50-120 °C, primarily due to the loss of surface organic solvents. Subsequently, starting at 480 °C, PIM undergoes 30% decomposition, leading to structural collapse. This TGA result indicates that PIM possesses relatively high thermal stability.

[0071] Figure 5 is a schematic diagram of the process for preparing the hollow fiber ultrafiltration membrane in Example 1, illustrating the membrane fiber production process. The inner and outer diameters of the membrane fibers are precisely measured using a computer-controlled automatic dimensional analyzer. This automated system can monitor the dimensional changes of the membrane fibers in real time and ensure that each fiber meets design requirements during preparation through high-precision measurement technology, thereby guaranteeing the membrane's uniformity and performance stability. This precise measurement method effectively improves the overall quality of the hollow fiber ultrafiltration membrane and ensures that the membrane's filtration efficiency and antifouling performance reach optimal levels.

[0072] Figure 6 is a SEM image of the inner surface of the hollow fiber ultrafiltration membrane prepared in Example 1. As shown in Figure 6, the inner surface of the hollow fiber of the ultrafiltration membrane has a dense structure.

[0073] Figure 7 is a cross-sectional SEM image of the hollow fiber ultrafiltration membrane prepared in Example 1. As shown in Figure 7, its interior exhibits a porous network with uniform pore distribution, forming a microporous structure similar to a sponge. This effectively increases the surface area of ​​the membrane and improves the separation performance while maintaining low fluid resistance.

[0074] Figure 8 shows the contact angle of the hollow fiber ultrafiltration membrane prepared in Example 1. As shown in Figure 8, the contact angle of the inner surface of the self-porous polymer is 58°, indicating that the ultrafiltration membrane has good hydrophilicity. The smaller contact angle means that water molecules can more easily contact the membrane surface, thereby improving the hydrophilicity of the membrane, which plays an important role in improving the performance of the ultrafiltration membrane.

[0075] Example 2

[0076] The only difference from Example 1 is that the spinning solution formulation is: 25 wt% self-polymerizing microporous polymer, 8 wt% diethylene glycol, and 67 wt% tetrahydrofuran.

[0077] Everything else is the same as in Example 1.

[0078] The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared in this embodiment has an inner diameter of 0.7 mm, an outer diameter of 1.2 mm, and a permeability coefficient of 170 μm. -2 h -1 .

[0079] Example 3

[0080] The only difference from Example 1 is that the spinning solution formulation is: 30 wt% self-polymerizing microporous polymer, 8 wt% diethylene glycol, and 62 wt% tetrahydrofuran.

[0081] Everything else is the same as in Example 1.

[0082] The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared in this embodiment has an inner diameter of 0.8 mm, an outer diameter of 1.3 mm, and a permeability coefficient of 198 μm. -2 h -1 .

[0083] Example 4

[0084] The only difference from Example 1 is that the spinning solution formulation is: 22 wt% self-polymerizing microporous polymer, 10 wt% diethylene glycol, and 68 wt% tetrahydrofuran.

[0085] Everything else is the same as in Example 1.

[0086] The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared in this embodiment has an inner diameter of 0.8 mm, an outer diameter of 1.3 mm, and a permeability coefficient of 178 μm. -2 h -1 .

[0087] Example 5

[0088] The only difference from Example 1 is that the spinning solution formulation is: 22 wt% self-polymerizing microporous polymer, 8 wt% diethylene glycol, and 70 wt% tetrahydrofuran.

[0089] Core fluid formulation: Water and glycerin are mixed in a mass percentage ratio of 60:40.

[0090] Everything else is the same as in Example 1.

[0091] The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared in this embodiment has an inner diameter of 0.8 mm, an outer diameter of 1.3 mm, and a permeability coefficient of 188 μm. -2 h -1 .

[0092] Example 6

[0093] The only difference from Example 1 is that the spinning solution formulation is: 22 wt% self-polymerizing microporous polymer, 8 wt% diethylene glycol, and 70 wt% tetrahydrofuran.

[0094] Core fluid formulation: Water and glycerin are mixed in a mass percentage ratio of 40:60.

[0095] Everything else is the same as in Example 1.

[0096] The hollow fiber ultrafiltration membrane containing self-polymerizing microporous polymer prepared in this embodiment has an inner diameter of 0.8 mm, an outer diameter of 1.3 mm, and a permeability coefficient of 195 μm. -2 h -1 .

[0097] Example 7

[0098] The only difference from Example 1 is:

[0099] At room temperature, the spinning solution is extruded through the casting solution spinneret orifice, while the core solution is injected through the core solution orifice. The extruded membrane fibers fall vertically into a coagulation bath (deionized water) at 30°C for 10 minutes. After forming, the fibers are collected by a fiber collection device and dried to obtain a self-polymerizing microporous hollow fiber ultrafiltration membrane.

[0100] Everything else is the same as in Example 1.

[0101] The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared in this embodiment has an inner diameter of 0.8 mm, an outer diameter of 1.3 mm, and a permeability coefficient of 106 μm. -2 h-1 .

[0102] Example 8

[0103] The only difference from Example 1 is:

[0104] At room temperature, the spinning solution is extruded through the casting solution spinneret orifice, while the core solution is injected through the core solution orifice. The extruded membrane fibers fall vertically into a coagulation bath (deionized water) at 20°C for 15 minutes. After forming, the fibers are collected by a fiber collection device and dried to obtain a self-polymerizing microporous hollow fiber ultrafiltration membrane.

[0105] Everything else is the same as in Example 1.

[0106] The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared in this embodiment has an inner diameter of 0.8 mm, an outer diameter of 1.3 mm, and a permeability coefficient of 185 μm. -2 h -1 .

[0107] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane, characterized in that, Includes the following steps: A self-polymerizing microporous polymer, a plasticizer, and an organic solvent are mixed to obtain a spinning solution; water and glycerol are mixed to obtain a core solution; the spinning solution and the core solution are wet-spun and then coagulated in a coagulation bath to obtain a self-polymerizing microporous polymer hollow fiber ultrafiltration membrane; the monomers for preparing the self-polymerizing microporous polymer include tetrafluoroterephthalonitrile and 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene.

2. The preparation method according to claim 1, characterized in that, The plasticizer includes diethylene glycol, glycerol, polydimethylsiloxane, or dioctyl phthalate; the organic solvent includes tetrahydrofuran, chloroform, or N,N-dimethylacetamide.

3. The preparation method according to claim 1 or 2, characterized in that, The content of each component in the spinning solution is as follows: 22-30 wt% self-polymerizing microporous polymer, 7-10 wt% plasticizer, and 60-70 wt% organic solvent.

4. The preparation method according to claim 1, characterized in that, The mass ratio of water to glycerol in the core fluid is 80:20 to 20:

80.

5. The preparation method according to claim 1, characterized in that, The preparation method of the self-polymerizing microporous polymer includes the following steps: mixing tetrafluoroterephthalonitrile, 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene, potassium carbonate and N,N-dimethylacetamide, carrying out a polymerization reaction, and then sequentially performing precipitation, boiling water treatment and vacuum drying to obtain the self-polymerizing microporous polymer.

6. The preparation method according to claim 5, characterized in that, The molar concentration of the tetrafluoroterephthalonitrile in N,N-dimethylacetamide is 10–30 mmol / L, the molar concentration of the 5,5',6,6'-tetrahydroxy-3,3',3,3'-tetramethylspirocyclic indene in N,N-dimethylacetamide is 15–50 mmol / L, and the molar concentration of the potassium carbonate in N,N-dimethylacetamide is 50–100 mmol / L.

7. The preparation method according to claim 6, characterized in that, The polymerization reaction is carried out at a temperature of 100–200°C for a time of 30–60 min.

8. The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane prepared by the preparation method according to any one of claims 1 to 7, characterized in that, The inner diameter is 0.5–0.8 mm, and the outer diameter is 1.0–1.3 mm.

9. The self-polymerizing microporous polymer hollow fiber ultrafiltration membrane according to claim 8, characterized in that, At 0.1 MPa, the permeability coefficient of the self-polymerizing microporous polymer hollow fiber ultrafiltration membrane is >100 μm. -2 h -1 .

10. The application of the self-polymerizing microporous polymer hollow fiber ultrafiltration membrane according to claim 8 or 9 in the fields of water treatment, food separation or pharmaceutical separation.

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