PBO hollow fiber membrane and preparation method thereof

Abstract

The invention belongs to the field of high-performance fiber materials, and discloses a PBO hollow fiber membrane and a preparation method thereof.The preparation method specifically comprises the steps that firstly, a PBO spinning solution is synthesized, then a hydrophilic film-forming agent is added, the mixture is stirred and mixed to be uniform, then mixed, conveyed and filtered through an extruder in sequence, then quantitatively metered and conveyed to a hollow spinneret plate head through a metering pump, and finally the PBO hollow fiber membrane is obtained. And carrying out circular blowing stretching forming and coagulating bath cooling shaping, and finally, carrying out soaking, drying and winding to obtain the hollow fiber membrane. The method is easy to operate, and the prepared PBO hollow fiber membrane is high in strength and resistant to acid and alkali and has wide application and popularization value under complex working conditions.

Description

Technical Field

[0001] The present invention belongs to the field of high-performance new materials, and specifically provides a PBO hollow fiber membrane and a preparation method thereof. Background Art

[0002] A hollow fiber membrane is a separation membrane material with a hollow tubular structure. Its diameter is usually in the micrometer to millimeter range, and the wall thickness is from dozens of nanometers to hundreds of micrometers. Its core feature is that the interior is a continuous hollow cavity, and the exterior is a dense or porous functional layer, which can achieve the separation, filtration, or mass transfer of substances through physical or chemical actions. Hollow fiber membranes have extensive application values in fields such as sewage treatment, chemical filtration, biomedicine, and material separation. Research and development as well as industrial preparation of new high-performance membrane materials are the keys to improving membrane performance. However, hollow fiber membranes of general materials have poor durability under extreme conditions such as high temperature, strong acid, and strong alkali.

[0003] PBO fiber is a polyaryl heterocyclic liquid crystal high-performance fiber, which has the characteristics of high strength, high modulus, high temperature resistance, and high flame retardancy. Its strength reaches 5.8 GPa, the modulus can reach 280 GPa, the highest decomposition temperature can reach 650 °C, and it has excellent resistance to strong acid and alkali corrosion and high temperature resistance, and has extensive applications in military and civilian fields. However, PBO is usually applied as a filament.

[0004] Whether it is possible to develop a hollow fiber membrane with better durability under extreme conditions such as high temperature, strong acid, and strong alkali by combining the excellent properties of PBO fiber has become a problem that the inventor endeavors to solve. Summary of the Invention

[0005] In view of the problems existing in the above technologies, the present invention provides a PBO hollow fiber membrane and a preparation method thereof. Specifically, first, a PBO spinning dope is synthesized, then a hydrophilic film-forming agent is added, and after stirring and mixing evenly, it is successively subjected to extrusion machine mixing and conveying, filtration, and then quantitatively metered and conveyed to a hollow spinneret head by a metering pump. After forming by annular air blowing and stretching and cooling and shaping in a coagulation bath, finally, it is soaked, dried, and wound to obtain a hollow fiber membrane. The above method is simple to operate, and the prepared PBO hollow fiber membrane has high strength, acid and alkali resistance, and has extensive application and popularization values under complex working conditions.

[0006] The biggest difference between the present invention and the prior art lies in: On the basis of the conventional PBO polymer preparation method, the inventor introduced a hydrophilic film-forming agent into the PBO spinning dope. By utilizing the hydrophilicity of the film-forming agent and its phase inversion ability with the non-solvent, the hydrophilicity and porosity of the PBO hollow fiber membrane are increased, and the water flux and filtration efficiency of the membrane are improved. Based on the above concept, the PBO hollow fiber membrane prepared by the present invention has the characteristics of high strength, high temperature resistance, and acid and alkali resistance.

[0007] The specific technical solution of the present invention is as follows: A preparation method of PBO hollow fiber membrane, the specific steps are as follows: (1) Preparation of PBO polymer spinning dope Add 4,6-diaminoresorcinol dihydrochloride, terephthalic acid, phosphorus pentoxide, antioxidant stannous chloride and solvent into the reaction kettle according to the proportion. Under the reaction condition of nitrogen, keep a certain stirring speed, and control the polymer viscosity by gradually increasing the reaction temperature, then the PBO polymer spinning dope can be obtained; The above steps can refer to the monomer ratio of the PBO polymerization reaction in the applicant's prior patent CN 112760737 B. The input amount of 4,6-diaminoresorcinol dihydrochloride accounts for 10-18 wt% in the mass of the PBO reaction system. The molar ratio of the input amount of terephthalic acid to 4,6-diaminoresorcinol dihydrochloride is 1:1. The input mass of phosphorus pentoxide accounts for 15-23 wt% in the mass of the PBO reaction system. The input mass of the solvent accounts for 58-67 wt% in the mass of the PBO reaction system. The input mass of stannous chloride accounts for 0.01-0.05 wt% in the mass of the PBO reaction system; Among them, the stirring speed is maintained at 30-80 r / min, the temperature is controlled at 80-120 °C, and the time is controlled at 10-20 h; the reaction solvent is one or two of polyphosphoric acid, sulfuric acid, methanesulfonic acid and aluminum trichloride-based methane, preferably polyphosphoric acid or sulfuric acid. The viscosity of the finally obtained PBO spinning dope is in the range of 500-1000 Pa·s, and the PBO solid content is 10-15 wt%.

[0008] (2) Mixing of PBO polymer spinning dope and hydrophilic film-forming agent Add a certain amount of hydrophilic film-forming agent into the PBO polymer spinning dope prepared in step (1), and stir for 1-3 h under the condition of a rotation speed of 30-80 r / min to make it evenly mixed to obtain a PBO spinning mixture; Among them, the hydrophilic film-forming agent is selected from one or two of polyethylene glycol and polyvinylpyrrolidone, preferably polyethylene glycol. The proportion of the hydrophilic film-forming agent in the PBO polymer spinning dope is 5-15 wt%.

[0009] The addition of the above hydrophilic film-forming agent can adjust the thermodynamic properties of the PBO spinning dope, promote the formation of specific pore structures such as finger-like pores or sponge-like pores during the phase inversion process. Its hydrophilicity can accelerate the exchange rate of the solvent and the non-solvent, thereby regulating the porosity and pore size distribution of the membrane. In addition, it also has a pore-forming function, which is removed by water washing after the membrane is formed, leaving uniformly distributed micropores to improve the water permeability of the membrane. The hydrophilicity of the hydrophilic film-forming agent can reduce the hydrophobicity of the membrane surface, inhibit the excessive densification of the skin layer, and balance the permeability and selectivity of the membrane. Excessive addition amount will cause the pore size of the hollow fiber membrane to be too large to play its role in filtering impurities. In addition, excessive addition will cause the strength of the hollow fiber membrane to decrease and reduce its service life.

[0010] (3) Transportation and filtration The PBO spinning mixture obtained in step (2) is further mixed and transported to a filter through an extruder, where the rotation speed of the extruder is controlled at 10 - 30 r / min and the temperature is controlled at 150 - 200 °C. Then, impurities are further filtered out through the filter. The pore size of the filter element is 5 - 50 μm, preferably a filter element with a pore size of 10 μm.

[0011] (4) Formation of PBO hollow fiber membrane The filtered PBO spinning mixture is metered and transported to the hollow spinneret head through a metering pump, and at the same time, the core liquid is also metered and transported to the hollow spinneret head through a metering pump. The flow rate ratio of the PBO spinning mixture to the core liquid is 2 - 5:1. After stretching and forming by ring blowing and cooling and shaping in the coagulation bath, and finally through soaking, drying and winding, a hollow fiber membrane is obtained.

[0012] Among them, the rotation speed of the metering pump is 5 - 10 cc / min; the pore diameter of the hollow spinneret is 200 - 1000 μm, and the length-diameter ratio is 3:1; the temperature of the ring blowing is 40 - 80 °C; the coagulation bath and the core liquid are one or two of water, ethanol and glycerol; the drying temperature is 150 - 200 °C; the temperature of all pipelines for transporting the PBO spinning dope is controlled at 150 - 200 °C.

[0013] In the above preparation method, PBO fibers have excellent corrosion resistance to strong acids and alkalis and high temperature resistance. By using the existing mature PBO polymerization and spinning technologies and combining with the preparation method of hollow fiber membranes, PBO hollow fiber membranes can be obtained. Since the filtration ability of pure PBO hollow fiber membranes is relatively low, on this basis, by introducing a water-forming film-forming agent, the film-forming agent can promote the formation of specific pore structures such as finger-like pores or sponge-like pores during the phase inversion process. Its hydrophilicity can accelerate the exchange rate of the solvent and the non-solvent, thereby regulating the porosity and pore size distribution of the membrane. In addition, it also has a pore-forming function and is removed by water washing after the membrane is formed, leaving uniformly distributed micropores to improve the water permeability of the membrane. The hydrophilicity of the hydrophilic film-forming agent can reduce the hydrophobicity of the membrane surface, inhibit the excessive densification of the skin layer, and balance the above characteristics of the permeability and selectivity of the membrane. By controlling the addition amount of the film-forming agent, the porosity of the PBO hollow fiber membrane is regulated, so as to obtain PBO hollow fiber membranes with different water fluxes, thereby meeting the performance requirements of different usage scenarios.

[0014] The inventors also claim to protect the PBO hollow fiber membranes prepared by the above method. The obtained PBO hollow fiber membranes can be specifically used for the separation of corrosive media in the chemical and petroleum industries, such as for the filtration, concentration or purification of strong acid and alkali solutions such as sulfuric acid, nitric acid, and sodium hydroxide, the separation of catalysts or the recovery of valuable substances in dye synthesis and petroleum refining; and for the cyclic filtration or gas separation of high-temperature acid solutions in high-temperature and high-pressure environments; for industrial wastewater treatment in environmental protection and water treatment, mainly including the treatment of strong acid and alkali wastewater containing heavy metal ions in industries such as electroplating and metallurgy, and recovering precious metals or neutralizing acids and alkalis and then discharging through membrane separation; for the filtration of strong acid and alkali reaction solutions in the pharmaceutical and bioengineering fields, such as separating strong acidic or alkaline reaction products (such as in antibiotic production) in drug synthesis, to avoid the corrosion of traditional membrane materials. It can be seen that the PBO hollow fiber membranes obtained in this application have a wide range of applications and can be better promoted and applied.

[0015] In summary, the PBO hollow fiber membranes and their preparation methods provided by the present invention have universality, simple operation, low requirements for equipment conditions, are green and pollution-free, the process is controllable, and the addition amount of the hydrophilic film-forming agent can be adjusted according to needs, so as to regulate the porosity of the PBO hollow fiber membrane. It is a very promising method for preparing high-temperature and strong acid and alkali-resistant hollow fiber membranes. Description of the Drawings

[0016] Figure 1 Schematic diagram of the technical process for preparing PBO hollow fiber membranes in Example 1. Detailed Embodiments

[0017] The following will further illustrate the present solution in conjunction with specific embodiments, which can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0018] Example 1 A method for preparing a PBO hollow fiber membrane, the specific steps are as follows: (1) Preparation of PBO polymer spinning dope: Add 2.3 kg of 4,6-diaminoresorcinol hydrochloride, 1.8 kg of terephthalic acid, 3.5 kg of phosphorus pentoxide, 0.19 kg of antioxidant stannous chloride and 12 kg of polyphosphoric acid solvent into a reaction kettle. Under the reaction condition of nitrogen, the rotation speed of the reaction kettle is maintained at 50 r / min for stirring, and the reaction is carried out at 80 °C for 5 h and at 120 °C for 10 h. Finally, the viscosity of the obtained PBO spinning dope is 600 Pa·s, and the PBO solid content is 13.9 wt%. (2) Mixing of PBO polymer spinning dope and hydrophilic film-forming agent: Add 1 kg of hydrophilic film-forming agent polyethylene glycol into the PBO polymer spinning dope prepared in step (1), and stir at a rotation speed of 50 r / min for 3 h to make it uniformly mixed to obtain a PBO spinning mixture. (3) Transportation and filtration: Transport the PBO spinning mixture obtained in step (2) to a filter through an extruder for further mixing, wherein the rotation speed of the extruder is controlled at 10 r / min and the temperature is controlled at 180 °C. Then, further filter out impurities through the filter, and the pore diameter of the filter element is 10 μm. (4) Formation of PBO hollow fiber membrane: Meter and transport the filtered PBO spinning mixture to the hollow spinneret head through a metering pump, and at the same time meter and transport the core liquid to the hollow spinneret head through a metering pump. The flow rate ratio of the PBO spinning mixture to the core liquid is 5:1. After stretching and forming by ring blowing and cooling and shaping by a coagulation bath, finally through soaking, drying and winding, a hollow fiber membrane is obtained.

[0019] Among them, the rotation speed of the metering pump is 5 cc / min; the pore diameter of the hollow spinneret is 900 μm, and the length-diameter ratio is 3:1; the temperature of the ring blowing is 60 °C; the coagulation bath and the core liquid are both water; the drying temperature is 150 °C; the temperature of all pipelines for transporting PBO spinning dope is controlled at 180 °C; The test results show that the breaking strength of the membrane is 1.8 MPa; at 0.1 MPa, the water flux of pure water is 120 L / (m 2 h).

[0020] Example 2 A method for preparing a PBO hollow fiber membrane, the specific steps are as follows: (1) The same as in Example 1; (2) Mixing the PBO polymer spinning dope with a hydrophilic film-forming agent: Add 2 kg of the hydrophilic film-forming agent polyethylene glycol to the PBO polymer spinning dope prepared in step (1), and stir at a rotation speed of 50 r / min for 3 h to obtain a uniformly mixed PBO spinning mixture; (3)-(4) The same as in Example 1; The test results show that the breaking strength of this membrane is 1.7 MPa; at 0.1 MPa, the water flux of pure water is 150 L / (m 2 h).

[0021] Example 3 A method for preparing a PBO hollow fiber membrane, the specific steps are as follows: (1) The same as in Example 1; (2) Mixing the PBO polymer spinning dope with a hydrophilic film-forming agent: Add 2.97 kg of the hydrophilic film-forming agent polyethylene glycol to the PBO polymer spinning dope prepared in step (1), and stir at a rotation speed of 50 r / min for 3 h to obtain a uniformly mixed PBO spinning mixture; (3)-(4) The same as in Example 1; The test results show that the breaking strength of this membrane is 1.5 MPa; at 0.1 MPa, the water flux of pure water is 180 L / (m 2 h).

[0022] Comparing Examples 1-3, it can be seen that under the same experimental conditions, in Example 3, when the addition amount of the hydrophilic film-forming agent polyethylene glycol is 15 wt%, the water flux of pure water of the PBO hollow fiber membrane is the highest, but its breaking strength is the lowest. In the actual application process, it is necessary to select a PBO hollow fiber membrane with appropriate breaking strength and water flux according to the working conditions.

[0023] Example 4 A method for preparing a PBO hollow fiber membrane, the specific steps are as follows: (1) Preparation of PBO polymer spinning dope: Add 2.3 kg of 4,6-diaminoresorcinol dihydrochloride, 1.8 kg of terephthalic acid, 3.5 kg of phosphorus pentoxide, 0.19 kg of antioxidant stannous chloride and 12 kg of sulfuric acid solvent to the reaction kettle. Under the reaction condition of nitrogen, the rotation speed of the reaction kettle is kept at 50 r / min and stirred. React at a reaction temperature of 80 °C for 5 h and at a reaction temperature of 120 °C for 10 h. Finally, the viscosity of the obtained PBO spinning dope is 600 Pa·s, and the PBO solid content is 13.9 wt%; (2)-(4) The same as in Example 1; The test results show that the breaking strength of the membrane is 1.8 MPa; at 0.1 MPa, the water flux of pure water is 110 L / (m 2 h).

[0024] Comparing Example 4 with Example 1, it can be seen that under the same experimental conditions, when the reaction solvent is sulfuric acid in Example 4, its water flux is lower than that when the reaction solvent is polyphosphoric acid in Example 1.

[0025] Example 5 A method for preparing a PBO hollow fiber membrane, the specific steps are as follows: (1) The same as Example 1; (2) Mixing the PBO polymer spinning dope with a hydrophilic film-forming agent: Add 1 kg of the hydrophilic film-forming agent polyvinylpyrrolidone to the PBO polymer spinning dope prepared in step (1), and stir at a rotation speed of 50 r / min for 3 h to make it uniformly mixed to obtain a PBO spinning mixture; (3)-(4) The same as Example 1; The test results show that the breaking strength of the membrane is 1.7 MPa; at 0.1 MPa, the water flux of pure water is 110 L / (m 2 h).

[0026] Comparing Example 5 with Example 1, it can be seen that under the same experimental conditions, when the hydrophilic film-forming agent is polyvinylpyrrolidone in Example 5, its water flux is lower than that of polyethylene glycol in Example 1.

[0027] Example 6 A method for preparing a PBO hollow fiber membrane, the specific steps are as follows: (1)-(3) The same as Example 1; (4) Forming the PBO hollow fiber membrane: Meter and transport the filtered PBO spinning dope to the hollow spinneret head through a metering pump, and at the same time meter and transport the core liquid to the hollow spinneret head through a metering pump. After being stretched and formed by ring blowing and cooled and shaped in a coagulation bath, finally through soaking, drying and winding, a hollow fiber membrane is obtained.

[0028] Among them, the rotation speed of the metering pump is 5 cc / min; the aperture of the hollow spinneret is 500 μm, and the length-diameter ratio is 3:1; the temperature of the ring blowing is 60 °C; the coagulation bath and the core liquid are water; the drying temperature is 150 °C; the temperature of all pipelines for transporting the PBO spinning dope is controlled at 180 °C; The test results show that the breaking strength of the membrane is 1.2 MPa; at 0.1 MPa, the water flux of pure water is 190 L / (m 2 h).

[0029] Comparing Example 6 with Example 1, it can be seen that under the same experimental conditions, when the aperture of the hollow spinneret is 500 μm in Example 6, its water flux is higher than that of Example 1.

[0030] Comparative Example 1 The preparation of a polyvinylidene fluoride hollow fiber membrane is as follows: Prepare the polymer required for preparing the casting solution in proportion. Put polyvinylidene fluoride into a vacuum drying oven in advance and dry it at 40 °C for 24 h, then take it out after completion; then weigh 1 kg of polyvinylidene fluoride and 9 kg of triacetin solvent, add the weighed polyvinylidene fluoride and triacetin solvent into the reaction kettle, under the reaction condition of nitrogen, keep the rotation speed of the reaction kettle at 50 r / min and stir, under the condition of a reaction temperature of 80 °C, stir and mix for 5 h to make it evenly mixed, and then adjust the temperature of the above-mentioned material liquid kettle to 170 °C; Subsequently, add the core liquid triethylene glycol to the core liquid kettle, adjust the temperature of the core liquid kettle to 80 °C, and heat up and preheat the screw and the corresponding pipeline, and the temperature is 170 °C; Then, further mix and convey the spinning mixture through an extruder to a filter, where the rotation speed of the extruder is controlled at 10 r / min and the temperature is controlled at 180 °C, and then further filter out impurities through the filter, and the pore diameter of the filter element is 10 μm; Convey the filtered spinning mixture to the hollow spinneret head through a metering pump, and at the same time convey the core liquid to the hollow spinneret head through a metering pump. The flow ratio of the PBO spinning mixture to the core liquid is 5:1. After being stretched and formed by ring blowing and cooled and shaped by a coagulation bath, finally, it is soaked, dried and wound to obtain a hollow fiber membrane.

[0031] Among them, the rotation speed of the metering pump is 5 cc / min; the pore diameter of the hollow spinneret is 900 μm, and the length-diameter ratio is 3:1; the temperature of the ring blowing is 60 °C; the coagulation bath and the core liquid are both water; the drying temperature is 150 °C; the temperature of all pipelines for conveying the spinning dope is controlled at 180 °C.

[0032] The test results show that: the breaking strength of the membrane is 0.8 MPa; under 0.1 MPa, the water flux of pure water is 110 L / (m 2 h).

[0033] From the above tests, it can be seen that the breaking strength of the examples of the present application is higher than that of the comparative example, and the performance is significantly improved compared with the comparative example.

[0034] Experimental Example Take the PBO hollow fiber membrane and polyvinylidene fluoride hollow fiber membrane prepared in Example 1 and Comparative Example 1, conduct performance tests on the hollow fiber membrane, under 0.1 MPa, adjust the pH value of the test pure water to 3, 7.5 and 12 respectively, and under the condition of 100 hours, the test results are shown in Table 1.

[0035] Table 1 Comparison of the performance of hollow fiber membranes PBO hollow fiber membrane Polyvinylidene fluoride hollow fiber membrane Breaking strength (pH = 3) 1.8 0.3 Breaking strength (pH = 7.5) 1.8 0.8 Breaking strength (pH = 12) 1.7 0.4 Water flux (pH = 3) 123 153 Water flux (pH = 7.5) 120 110 Water flux (pH = 7.5) 121 147 It can be seen from the test results that: (1) For the PBO hollow fiber membrane obtained in this application, the breaking strength performance is basically stable in acidic and alkaline environments; while for the polyvinylidene fluoride hollow fiber membrane, the breaking strength decreases to a large extent.

[0036] (2) For the PBO hollow fiber membrane obtained in this application, the water flux performance is basically stable in acidic and alkaline environments; while for the polyvinylidene fluoride hollow fiber membrane, the water flux increases to a large extent, indicating that in a strong acid or alkaline environment, the polyvinylidene fluoride hollow fiber membrane has swollen and the pore structure has been damaged.

[0037] It can be seen that the hollow fiber membrane prepared from PBO fibers in this application has higher strength, longer service life and can be applied in more complex working conditions.

[0038] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a PBO hollow fiber membrane, comprising: (1) preparing a PBO polymer spinning solution; characterized in that: The following steps are also included: (2) PBO polymer spinning solution mixed with hydrophilic film-forming agent Add a certain amount of hydrophilic film-forming agent to the PBO polymer spinning solution prepared in step (1), stir for 1-3 h at a speed of 30-80 r / min to mix them evenly to obtain a PBO spinning mixed solution; (3) Transportation and filtration The PBO spinning mixture obtained in step (2) is further mixed and transported to a filter through an extruder, wherein the speed of the extruder is controlled at 10-30 r / min and the temperature is controlled at 150-200 °C, and then the impurities are further filtered out through a filter, wherein the pore size of the filter element is 5-50 μm; (4) PBO hollow fiber membrane molding The filtered PBO spinning mixture is metered and delivered to the hollow spinneret head by a metering pump, and the core liquid is also metered and delivered to the hollow spinneret head by a metering pump. The flow ratio of the PBO spinning mixture to the core liquid is 2-5:

1. After that, it is stretched by annular blowing, cooled and shaped in a coagulation bath, and finally soaked, dried and wound to obtain a hollow fiber membrane.

2. The method for preparing the PBO hollow fiber membrane according to claim 1, characterized in that: Step (1) Preparation of PBO polymer spinning solution, the specific steps are as follows: A certain proportion of 4,6-diaminoresorcinol hydrochloride, terephthalic acid, phosphorus pentoxide, antioxidant stannous chloride and solvent are added into a reactor. Under nitrogen reaction conditions, a certain stirring speed is maintained, and the reaction temperature is gradually increased to control the polymer viscosity to obtain a PBO polymer spinning solution. The viscosity of the PBO spinning solution is in the range of 500-1000 Pa·s, and the PBO solid content is 10-15wt%.

3. The method for preparing the PBO hollow fiber membrane according to claim 2, characterized in that: In step (1), the stirring speed is maintained at 30-80 r / min, the temperature is controlled at 80-120° C., and the time is controlled at 10-20 h; the reaction solvent is one or two of polyphosphoric acid, sulfuric acid, methanesulfonic acid and trichloroaluminum methane.

4. The method for preparing the PBO hollow fiber membrane according to claim 1, characterized in that: In step (2), the hydrophilic film-forming agent is selected from one or both of polyethylene glycol and polyvinyl pyrrolidone, and the proportion of the hydrophilic film-forming agent in the PBO polymer spinning solution is 5-15 wt%.

5. The method for preparing the PBO hollow fiber membrane according to claim 4, characterized in that: The hydrophilic film-forming agent in step (2) is polyethylene glycol.

6. The method for preparing the PBO hollow fiber membrane according to claim 1, characterized in that: The pore size of the filter element in step (3) is 5-50 μm.

7. The method for preparing the PBO hollow fiber membrane according to claim 1, characterized in that: In step (3), the metering pump speed is 5-10 cc / min, the annular air temperature is 40-80°C, the drying temperature is 150-200°C, and the temperature of all pipelines conveying PBO spinning solution is controlled at 150-200°C.

8. The method for preparing a PBO hollow fiber membrane according to claim 1 or 7, characterized in that: In step (3), the pore size of the hollow spinneret is in the range of 200-1000 μm, and the aspect ratio is 3:1; in step (3), the coagulation bath and the core liquid are one or two of water, ethanol and propylene glycol.

9. The method for preparing the PBO hollow fiber membrane according to claim 8, characterized in that: In step (3), both the coagulation bath and the core liquid are water.

10. A PBO hollow fiber membrane obtained by using the method for preparing a PBO hollow fiber membrane according to any one of claims 1 to 9.

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