A method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane

Abstract

This invention relates to the field of gas separation membrane technology and provides a method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane. The preparation method includes the following steps: (1) synthesizing a polyimide polymer by chemical imine method using a carboxylic acid-containing diamine monomer and a dianhydride monomer in a certain proportion. (2) Preparing a spinning solution by mixing the polymer with an organic solvent, a metal salt, and a non-solvent in a certain proportion. (3) Spinning the prepared spinning solution into a membrane under certain conditions, immersing it in pure water for a certain time, and then washing it several times with methanol and n-hexane to remove the solvent. (4) Drying the cleaned hollow fiber membrane and packaging it into a membrane module for gas separation testing. The hollow fiber membrane obtained by this invention can be applied to the removal of acidic gases from natural gas and the extraction of helium from natural gas, while exhibiting excellent anti-plasticization ability and gas separation performance. Advantages of this invention: stable process, simple operation, and excellent gas separation and anti-plasticization performance of the membrane. This invention enriches the research and development and preparation ideas for anti-plasticization hollow fiber membranes used for gas separation, and the prepared anti-plasticization hollow fiber membrane material has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of gas separation membrane technology, and more specifically to a method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane. Background Technology

[0002] Gas separation is widely used in chemical production, energy resources, and environmental protection, such as natural gas decarbonization, carbon dioxide capture, hydrogen separation and purification, oxygen and nitrogen separation, natural gas helium extraction, and olefin and alkane separation. Compared to cryogenic distillation and pressure swing adsorption, membrane separation technology has advantages such as high separation efficiency, low energy consumption, small environmental footprint, and low equipment investment cost, leading to its rapid development in the gas separation field. Polymer membranes, in particular, offer advantages such as low cost and high processability, and can be designed in various forms. Asymmetric hollow fiber membranes, in particular, are favored in industrial applications due to their high specific surface area. However, currently available commercial hollow fiber membranes for gas separation are prone to plasticization by gases such as carbon dioxide under high-pressure operating conditions, resulting in reduced separation performance. Therefore, developing novel, plasticization-resistant hollow fiber membranes is of great significance.

[0003] Patent (CN116272441B) discloses a gas separation membrane material for helium extraction from natural gas with anti-plasticization effect. It uses two diamine monomers and one dianhydride monomer to synthesize a polyimide polymer, which is then used to prepare the gas separation membrane. At a certain temperature, the carboxyl groups on the polymer molecular chain can be removed through heat treatment, resulting in bidirectional transesterification crosslinking to form a stable crosslinked structure. However, this patent is limited to the preparation of flat sheet membranes and does not cover the preparation process of hollow fiber membranes. Furthermore, the heat treatment crosslinking method can easily reduce the gas permeability coefficient of hollow fiber membranes.

[0004] Patent (CN117101428A) discloses a process for preparing chlorinated polyvinyl chloride hollow fiber membranes. The hollow fiber membranes prepared by this patent have good toughness, high filtration flux, high strength of the inner and outer skin layers, and good durability. However, the hollow fiber membrane material prepared by this patent is mainly used for liquid-solid separation and liquid-liquid separation, and does not involve gas separation. Furthermore, the raw material components used are mainly chlorinated polyvinyl chloride and styrene-ethylene-styrene block copolymers, styrene-ethylene-butene-styrene block copolymers, and styrene-butene-propylene-styrene block copolymers, without any research on anti-plasticization properties.

[0005] Patent (CN116943460 B) discloses a method for preparing a rare-earth-coordinated hollow fiber composite membrane. The method involves immersing a purchased hollow fiber membrane in an organic solvent, generating amino groups on the membrane surface under ultraviolet light, and then immersing it in a mixed solution of metal salts to prepare the rare-earth-coordinated hollow fiber composite membrane. However, this patent only relates to the preparation of the rare-earth-coordinated hollow fiber composite membrane and does not conduct research on the anti-plasticization properties of the hollow fiber membrane.

[0006] Patent (CN202310158174.X) discloses a method for preparing a high-strength, anti-plasticization gas separation membrane. The hollow fiber membrane's polymer is synthesized from diamines such as 6FDA (hexafluorodianhydride) and DABA (3,5-diaminobenzoic acid), BPDA (3,3',4,4'-biphenyltetracarboxylic dianhydride), and PMDA (1,2,4,5-pyromellitic dianhydride). This process reduces polymer chain fluidity and improves the polymer's anti-plasticization properties and mechanical strength. The hollow fiber membrane obtained by spinning this polyimide exhibits advantages such as high strength, anti-plasticization, and good thermal stability during gas separation. This hollow fiber membrane maintains good selectivity for CO2 / N2 and CO2 / CH4 while improving permeability. However, the preparation method of this patent is complex, and the anti-plasticization performance needs further improvement.

[0007] This invention provides a metal-coordinated hollow fiber membrane material. This hollow fiber membrane exhibits high gas separation selectivity and excellent resistance to plasticization under high pressure. Summary of the Invention

[0008] In view of this, the present invention provides a method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane. This method is simple and easy to implement, and the prepared hollow fiber membrane has strong resistance to carbon dioxide plasticization, which is of great significance for maintaining the gas selectivity of hollow fiber membranes in real environments.

[0009] The metal coordination crosslinking anti-plasticization hollow fiber membrane of the present invention is characterized by:

[0010] 1. The polymer used in the metal coordination crosslinking anti-plasticization hollow fiber membrane has the structure of formula (I):

[0011]

[0012] Formula (I)

[0013] In formula (I), R1 is a dianhydride monomer, which is selected from R a R b R c Any one of the groups; R2 is a diamine monomer that does not contain a carboxyl group, selected from R d R e Rf R g Any one of the groups; R3 is a diamine monomer containing a carboxyl group, selected from R h R i R j Any one of the groups.

[0014]

[0015] 2. The non-solvent metal salts used in the metal coordination crosslinking anti-plasticization hollow fiber membrane include, but are not limited to, ferric chloride, aluminum chloride, lanthanum chloride, europium chloride, cerium chloride, and yttrium chloride.

[0016] 3. The method for preparing the metal coordination crosslinking antiplasticizing hollow fiber membrane adopts a dry-jet-wet spinning process.

[0017] One objective of this invention is to provide a method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane, the technical solution of which is as follows:

[0018] (1) The polymer, solvent, metal salt and non-solvent are mixed in a stirred tank according to a certain component ratio and stirred until completely dissolved to obtain a spinning solution. The spinning solution is degassed under vacuum to maintain the vacuum degree in the tank at 10-50 kPa. After degassed completely, nitrogen gas is introduced into the tank until the pressure is 0.4-0.8 MPa.

[0019] (2) Mix the solvent and deionized water in a certain proportion to prepare the core liquid, and simultaneously perform vacuum degassing for later use.

[0020] (3) The prepared spinning solution and core solution are squeezed into a core of a specific size through a spinning pump at a certain flow rate and simultaneously extruded from the core. Under the stretching of gravity and guide rollers, they pass through a certain air gap height and then enter the coagulation bath to solidify into a hollow fiber membrane.

[0021] (4) The initially formed hollow fiber membrane is collected on the take-up wheel at a certain pulling speed under the traction of the guide wheel;

[0022] (5) The collected hollow fiber membranes are post-treated under certain conditions. First, soak them in pure water for several days, and change the pure water every once in a while. Then, wash them several times with non-solvent A and non-solvent B, and change the non-solvent every once in a while.

[0023] (6) The processed hollow fiber membrane is placed in a vacuum drying oven and dried at a specified temperature for a certain period of time.

[0024] The solvents described in step (1) above include, but are not limited to, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc) and tetrahydrofuran (THF), and the non-solvents include, but are not limited to, water, ethanol, ethyl acetate and acetic acid.

[0025] The proportions of the spinning solution components described in step (1) above are as follows: the polymer component content is 20-30 wt%, the solvent component content is 40-60 wt%, the non-solvent component content is 10-20 wt%, and the metal salt component content is 2-5 wt%.

[0026] Preferably, in step (1), the proportions of polymer, solvent, non-solvent, and metal salt in the spinning solution are 27 wt%, 55 wt%, 15 wt%, and 3 wt%, respectively.

[0027] As described in step (2) above, the solvent content of the core fluid component is 10-30 wt%; the solvent is selected from one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and tetrahydrofuran;

[0028] Preferably, the volume percentage of solvent in the core fluid described in step (2) is 80%;

[0029] As described in step (3) above, the liquid flow rate is 10-15 ml / min, the core liquid flow rate is 5-10 ml / min; the outer diameter of the spray core is 0.5-1.0 mm, the inner diameter is 0.3-0.8 mm; and the air gap height is 5-15 cm.

[0030] Preferably, the flow rate of the feed liquid in step (3) is 10 ml / min, the flow rate of the core liquid is 5 ml / min, and the air gap height is 7 cm;

[0031] As described in step (4) above, the stretching speed is 15-40 meters per minute;

[0032] Preferably, the stretching speed described in step (4) is 30 m / min;

[0033] The post-treatment conditions described in step (5) above are as follows: soaking time in pure water is 3-5 days, with water changed every 6-12 hours; non-solvent A and non-solvent B are each washed 3-5 times, with water changed every 30-60 minutes; non-solvent A is selected from methanol, ethanol and isopropanol; non-solvent B is selected from n-hexane and n-heptane.

[0034] As described in step (6) above, the drying temperature is 50-100°C. o C, drying time is 12-18 hours;

[0035] Preferably, the drying temperature in step (6) is 100°C. o C, drying time is 15 hours.

[0036] The second objective of this application is to provide a metal coordination crosslinked anti-plasticization hollow fiber membrane product, characterized in that the metal coordination crosslinked anti-plasticization hollow fiber membrane synthesized by this invention has good gas separation performance.

[0037] The third objective of this application is to provide an application for a metal coordination crosslinked anti-plasticization hollow fiber membrane for gas separation. The membrane, prepared according to the method described in this invention, can be used for natural gas purification, carbon dioxide capture, hydrogen separation and purification, air separation, helium extraction from natural gas, gas dehumidification, and olefin and alkane separation. Compared to existing technologies, the hollow fiber membrane prepared by this invention possesses strong anti-plasticization capabilities, and its gas separation performance remains stable even under high CO2 content and high-pressure inlet conditions.

[0038] Example 1

[0039] A metal coordination crosslinked anti-plasticization hollow fiber membrane is prepared by the following method:

[0040] (1). Under nitrogen protection, in a 30 L reactor equipped with a mechanical stirrer, DABA (199.5 g), TFMB (70.0 g), and MPDA (307.3 g) were first added, followed by anhydrous NMP (10 L). After the diamine monomer was completely dissolved, the temperature inside the reactor was lowered to 5 °C. o C, then 6 FDA (1942 g) was added for polymerization. After 8 h, the reaction was complete, yielding the corresponding polyamic acid solution. Then, 2113 mL of pyridine and 2479 mL of acetic anhydride were added for imine reaction at 20 °C. o After reacting at C for 24 h, a polyimide solution was obtained. The obtained polyimide solution was precipitated in pure water. The precipitated polyimide material was then poured into an aqueous solution containing 50% ethanol and stirred. The completely precipitated polymer was washed three times with a 50% ethanol solution and then... o Dry polyimide polymer can be obtained by vacuum drying at C for 12 h.

[0041] (2). Take 400 g of the polyimide polymer (PI) obtained in step (1) and dissolve it in anhydrous NMP (667 g). Place it in a spinning kettle, add 222 g of anhydrous ethanol, 148 g of THF and 44.5 g of cerium chloride, stir for 48 h to obtain the spinning solution, degas under vacuum and let it stand for 12 h. Fill the kettle with nitrogen until the pressure is 0.4 MPa.

[0042] (3). The polyimide spinning solution obtained in step (2) is spun, and the spinning diagram is shown below. Figure 1 As shown in the diagram, the spinning solution is first fed into the spinning pump through a pipeline under a nitrogen pressure of 0.4 MPa inside the reactor. The spinning pump simultaneously extrudes the spinning solution and core solution from the spinneret at a controlled feed rate. After passing through a certain air gap height, they solidify in a coagulation bath to form a metal-coordinated crosslinked hollow fiber membrane. The spinning solution discharge rate is 10 mL / min, the core solution discharge rate is 5 mL / min, and the core solution composition is 80 wt% NMP and 20 wt% H2O. The spinneret temperature is controlled at 50°C. o C. The distance between the spinneret and the air gap in the coagulation bath is 7 cm to ensure the formation of the outer layer of the hollow fiber membrane. Finally, the hollow fiber membrane completes basic solidification in the coagulation bath, with the temperature of the coagulation bath controlled at 20°C. o C; The hollow fiber membrane is finally collected on the winding wheel, and the winding speed of the wheel is controlled at 30 m / min.

[0043] (4) Completely immerse the hollow fiber membrane obtained in step (3) in pure water, changing the water every 12 hours. After 72 hours of soaking, clean the membrane by first soaking it in methanol for 30 minutes, then rinsing it with n-hexane for 30 minutes, repeating this process three times. Place the cleaned hollow fiber membrane in a vacuum drying oven at 100°C. o Vacuum was applied for 15 hours. The dried hollow fiber composite film encapsulated assembly was then tested.

[0044] The cross-sectional morphology of the metal coordination crosslinked anti-plasticization hollow fiber membrane prepared in this embodiment was analyzed by EDS energy dispersive spectroscopy, and the analysis is shown in the attached figure. Figure 2 As shown in the figure, the EDS energy dispersive spectroscopy results show that the metallic Ce element is uniformly distributed in the cross section of the hollow fiber membrane, and no aggregation phenomenon is observed in the cross section of the membrane. This indicates that the 72-hour immersion in pure water did not leach the rare earth Ce out of the membrane, and the metallic Ce exists in the hollow fiber membrane.

[0045] Compare with Example 1

[0046] An uncoordinated crosslinked hollow fiber membrane was prepared under similar conditions and methods as in Example 1. The difference between Example 1 and Example 2 is that cerium chloride, an inorganic salt in the spinning solution, was replaced with lithium nitrate; all other preparation conditions and methods were the same as in Example 1.

[0047] Infrared spectroscopy analysis and gas performance testing were performed on the uncoordinated crosslinked hollow fiber membrane prepared in this comparative example, and it was compared with the metal-coordinated crosslinked anti-plasticization hollow fiber membrane prepared in Example 1. The infrared spectrum is shown below. Figure 3 As shown, at a wavenumber of 1650 cm⁻¹ −1At the same location, the hollow fiber membrane prepared in Comparative Example 1 has a characteristic peak of carboxyl groups, while the metal coordination crosslinking anti-plasticization hollow fiber membrane prepared in the example does not have this peak. This indicates that the carboxyl groups on the hollow fiber membrane of the example have undergone coordination crosslinking reaction with metal Ce ions.

[0048] Gas performance tests were conducted on the hollow fiber membranes prepared in Example 1 and Comparative Example 1. The test results are shown in Table 1. Compared with the uncoordinated crosslinked hollow fiber membrane, the gas permeability of the metal-coordinated crosslinked antiplasticized hollow fiber membrane decreased slightly, but the selectivity was improved.

[0049] The anti-plasticization performance of two hollow fiber membranes was tested using a He / CO2 / CH4 mixture (0.3:49.4:50.3, v / v / v). The test results are as follows: Figure 4 As shown in the figure. The results indicate that when the feed pressure containing carbon dioxide reaches 400 PSIA, the He / CH4 selectivity of the uncoordinated crosslinked hollow fiber membrane decreases significantly, while the He / CH4 selectivity of the metal-coordinated crosslinked anti-plasticization hollow fiber membrane remains essentially unchanged, indicating that the metal-crosslinked hollow fiber membrane has a certain anti-plasticization ability.

[0050] Example 2

[0051] (1) A metal coordination crosslinked anti-plasticizing hollow fiber membrane, prepared by the method of Example 1, and spun using the following parameters: PI / NMP / THF / EtOH / LiNO3 (27 / 45 / 10 / 15 / 3, wt%) as the feed solution mass ratio, H2O / NMP (80 / 20, v / v%) as the core solution formulation, and pure water (20% v / v%) as the coagulation bath. o C), the feed flow rate is fixed at 10 ml / min, the air gap height is 7 cm, and the spinneret temperature is 50°C. o Spinning is carried out under the condition of C and a stretching speed of 30 m / min.

[0052] (2) The difference from Example 1 is that a different core fluid flow rate of 10 ml / min is used for spinning.

[0053] The morphology of the metal coordination crosslinked antiplasticization hollow fiber membranes prepared in this embodiment and in Example 1 was analyzed by scanning electron microscopy (SEM). The relevant SEM images are attached below. Figure 5 As shown in the figure, the change in core liquid flow rate (feed / core liquid flow rate ratio) has a significant impact on the morphology of hollow fibers. When the core liquid flow rate is 5 ml / min, the thickness of the hollow fiber membrane wall is 100 micrometers. When the core liquid flow rate increases to 10 ml / min, the thickness of the hollow fiber membrane wall decreases to 50 micrometers.

[0054] Example 3

[0055] (1) A metal coordination crosslinked anti-plasticizing hollow fiber membrane, prepared by the method of Example 1, and spun using the following parameters: PI / NMP / THF / EtOH / LiNO3 (27 / 45 / 10 / 15 / 3, wt%) as the feed solution mass ratio, H2O / NMP (80 / 20, v / v%) as the core solution formulation, and pure water (20% v / v%) as the coagulation bath. o C), the feed liquid flow rate is fixed at 10 ml / min, the core liquid flow rate is 5 ml / min, and the spinneret temperature is 50°C. o Spinning is carried out under the condition of C and a stretching speed of 30 m / min.

[0056] (2) The difference from Example 1 is that different air gap heights are used for spinning, namely 1 cm and 14 cm, and are numbered 3-1 and 3-2 respectively.

[0057] The metal coordination crosslinked antiplasticized hollow fiber membrane prepared in this embodiment was subjected to pure gas testing, and the relevant results are shown in Table 1. As can be seen from the table, the gas flux of the prepared hollow fiber membrane decreases with increasing air gap height. When the air gap height is 1 cm, the selected gas of the prepared hollow fiber membrane is the lowest, with a He / CH4 selectivity of 19.6, which is clearly defective. When the air gap height is 7 cm (Example 1), the metal coordination crosslinked antiplasticized hollow fiber membrane exhibits the best gas separation performance, with He / CH4 and CO2 / CH4 selectivities reaching 257 and 49, respectively.

[0058] Example 4

[0059] (1) A metal coordination crosslinked antiplasticizing hollow fiber membrane, prepared by the method of Example 1, and spun using the following parameters: H2O / NMP (80 / 20, v / v%) as the core liquid formulation and pure water (20%) as the coagulation bath. o C), the feed liquid flow rate is fixed at 10 ml / min, the core liquid flow rate is 5 ml / min, and the spinneret temperature is 50°C. o Spinning is carried out under the condition of C and a stretching speed of 30 m / min.

[0060] (2) The difference from Example 1 is that a different spinning solution formulation is used for spinning. The spinning solution formulation is PI / NMP / THF / EtOH / LiNO3 (22 / 45 / 10 / 20 / 3, wt%).

[0061] The metal coordination crosslinked anti-plasticization hollow fiber membrane prepared in this embodiment was subjected to pure gas testing, and the relevant results are shown in Table 1. The results show that as the polymer content of the spinning solution increases, the gas permeability decreases; when the solid content of the spinning solution is 22 wt%, its gas selectivity is significantly low. This is because the low solid content causes the viscosity of the spinning solution to decrease, which makes the spun hollow fiber membrane prone to defects.

[0062] Example 5

[0063] (1) A metal coordination crosslinked anti-plasticizing hollow fiber membrane, prepared by the method of Example 1, and spun using the following parameters: PI / NMP / THF / EtOH / LiNO3 (27 / 45 / 10 / 15 / 3, wt%) as the feed solution mass ratio, H2O / NMP (80 / 20, v / v%) as the core solution formulation, and pure water (20% v / v%) as the coagulation bath. o C), the feed liquid flow rate is fixed at 10 ml / min, the core liquid flow rate is 5 ml / min, and the spinneret temperature is 50°C. o Spinning is performed under condition C.

[0064] (2) The difference from Example 1 is that different stretching speeds were used for spinning of the core liquid components, namely 22.5 m / min and 15 m / min, respectively, and numbered 5-1 and 5-2.

[0065] The tensile properties of the metal coordination crosslinked anti-plasticization hollow fiber membrane prepared in this embodiment were tested, and the relevant results are shown in Table 2. As can be seen from the table, hollow fibers prepared at higher stretching speeds exhibit higher tensile stress and elastic modulus, and the spun hollow fibers are more compact with lower porosity.

[0066] Table 1 Gas properties corresponding to different air gap heights

[0067]

[0068] Table 2 Effect of different stretching speeds on tensile properties

[0069] Attached Figure Description

[0070] Figure 1 This is a diagram of the hollow fiber membrane spinning process in Example 1;

[0071] Figure 2 The image shows the EDS energy spectrum of the hollow fiber membrane cross-section in Example 1.

[0072] Figure 3 Infrared spectra of hollow fiber membranes prepared in Examples and Comparative Example 1;

[0073] Figure 4 Scanning electron microscope (SEM) images of the cross-sectional morphology of the hollow fiber membranes prepared in Examples and Comparative Example 1;

[0074] Figure 5 The graph shows the test results of the He / CO2 / CH4 (0.3:49.4:50.3, v / v / v) mixture of hollow fiber membranes prepared for Examples and Comparative Example 1.

Claims

1. A method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane for gas separation, characterized in that, The preparation method includes the following steps: (1) The polymer, solvent, metal salt and non-solvent are mixed and stirred in a stirred tank until completely dissolved to obtain a spinning solution. The spinning solution is degassed under vacuum to maintain the vacuum degree in the tank at 10-50 kPa. After degassed completely, nitrogen gas is introduced into the tank until the pressure is 0.4-0.8 MPa. The non-solvent includes any one of water, ethanol, ethyl acetate and acetic acid. (2) Mix the solvent and deionized water evenly to prepare the core solution, and vacuum the core solution to remove bubbles for later use; (3) The prepared spinning solution and core solution are respectively fed into a core of a specific size through a gear pump and simultaneously extruded from the core. Under the stretching of the guide wheel, they pass through an air gap height of 5-15 cm and then enter the coagulation bath to solidify into a hollow fiber membrane. (4) The initially formed hollow fiber membrane is collected on the take-up wheel under the traction and stretching speed of the guide wheel; (5) Soak the collected hollow fiber membrane in pure water for several days, changing the pure water every once in a while. Then wash it several times with non-solvent A and non-solvent B, changing the non-solvent every once in a while. Non-solvent A is selected from methanol, ethanol and isopropanol. Non-solvent B is selected from n-hexane and n-heptane. (6) The treated hollow fiber membrane is placed in a vacuum drying oven to dry; The metal salt is cerium chloride; The polymer is synthesized from diamine monomers and dianhydride monomers via a chemical imine process, and has the following structural formula: Formula (I) In formula (I), R1 is a dianhydride monomer, which is selected from R a R b R c Any one or more combinations of the groups; R2 is a diamine monomer that does not contain a carboxylic acid group, selected from R d R e R f R g Any one or more combinations of the groups; R3 is a diamine monomer containing a carboxylic acid group, selected from R h R i R j Any one of the groups; 。 2. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, The solvent in step (1) comprises any one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and tetrahydrofuran.

3. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, The proportions of the spinning solution components in step (1) are as follows: the polymer component content is 20-30 wt%, the solvent component content is 40-60 wt%, the non-solvent component content is 10-20 wt%, and the metal salt component content is 2-5 wt%.

4. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, The solvent content in the core fluid component described in step (2) is 10-30 wt%; the solvent is selected from one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and tetrahydrofuran.

5. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, In step (3), the flow rate of the liquid is 10-15 ml / min and the flow rate of the core liquid is 5-10 ml / min; the outer diameter of the spray core is 0.5-1.0 mm and the inner diameter is 0.3-0.8 mm.

6. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, The stretching speed in step (4) is 15-30 meters per minute.

7. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, In step (5), the soaking time in pure water is 3-5 days, and the water is changed every 6-12 hours; the non-solvent A and non-solvent B are each washed 3-5 times, and the water is changed every 30-60 minutes.

8. The method for preparing the metal coordination crosslinked anti-plasticization hollow fiber membrane according to claim 1, characterized in that, The drying temperature in step (6) is 50-100°C. o C, the drying time is 12-18 hours.

9. The method for preparing a metal coordination crosslinked anti-plasticization hollow fiber membrane according to any one of claims 1-8, characterized in that, The hollow fiber membrane is used for natural gas purification, carbon dioxide capture, hydrogen separation and purification, air separation, natural gas helium extraction, gas dehumidification, and olefin and alkane separation.

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