CN215539887U

CN215539887U - Preparation device of poly 4-methyl-1-pentene hollow fiber membrane for ECMO

Info

Publication number: CN215539887U
Application number: CN202120500544.XU
Authority: CN
Inventors: 崔朝亮; 何金晖; 何婷; 周玥; 汪朝晖; 汪效祖; 邢卫红; 范益群
Original assignee: Nanjing Tech University
Current assignee: Jiangsu Aike Film High Tech Co ltd
Priority date: 2021-03-09
Filing date: 2021-03-09
Publication date: 2022-01-18
Anticipated expiration: 2031-03-09

Abstract

The utility model relates to a preparation device of a poly 4-methyl-1-pentene hollow fiber membrane for ECMO. The method comprises the following steps: the extruder is used for mixing and extruding the poly-4-methyl-1-pentene, the diluent and the additive to obtain thermally induced phase separation casting solution; the spinning nozzle is arranged at a material outlet of the casting solution extruding device and is used for extruding thermally induced phase separation casting solution film filaments; the quenching bath is used for receiving and cooling the film filaments obtained in the spinneret; the rinsing bath is used for receiving the membrane filaments obtained in the quenching bath and heating and stretching the membrane filaments; the deposition tank is used for depositing and coating rubber materials on the surfaces of the membrane filaments obtained in the rinsing bath tank; and the wire winding groove is used for winding the film wire obtained from the deposition groove. Thereby obtaining the poly 4-methyl-1-pentene hollow fiber with certain pore size distribution and good micropore structure.

Description

Preparation device of poly 4-methyl-1-pentene hollow fiber membrane for ECMO

Technical Field

The utility model relates to a preparation device of a poly 4-methyl-1-pentene hollow fiber membrane for ECMO.

Background

The Extracorporeal Membrane Oxygenation (ECMO) is a combination of an artificial lung and an artificial heart, is a medical emergency treatment technical device, and the most core part is a Membrane lung and a blood pump which respectively play roles of the artificial lung and the artificial heart, can support the cardiopulmonary function of a patient with severe cardiopulmonary failure for a short time, and wins precious time for the rescue of critical patients. ECMO support is an adjuvant therapy that is currently difficult to replace by other medical techniques, and represents to some extent the level of rescue of critically ill patients in hospitals. According to the Marketsanind Markets research report, the McKewei, Meidun force and Riono Fang (the ECMO brand is Sonin) are the first three names of the global ECMO equipment market. The membrane material suitable for ECMO is currently the best material made globally by the company Membrana, which is currently purchased by the company 3M.

The qi-blood exchange membrane is a core component of the membrane oxygenator, serves as a barrier for separating blood from gas phase, and also provides a place for blood oxidation. Wherein the structure and distribution of the surface pores of the membrane layer have a very important influence on the gas permeability and the prevention of plasma leakage. The core materials of the membrane oxygenator commonly used at present comprise polypropylene (PP) and poly-4-methyl-1-pentene (PMP), and compared with PMP, PMP has higher oxygen permeability, lower blood flow resistance in the process due to better hydrophobic property of PMP and reduces blood permeation phenomenon. However, PMP membrane products are currently monopolized by 3M corporation in the united states worldwide.

Poly 4-methyl-1-pentene (PMP) is a thermoplastic polyolefin with good mechanical and thermal stability. PMP also has excellent air permeability, which is 12 times higher than that of polypropylene (PP). Thus, PMP is an excellent gas permeable membrane material, especially in the oxygen-rich field. At present, PMP hollow fiber membranes with compact surfaces and high air permeability can be prepared by a thermal induced phase separation method, a melt spinning-cold drawing method and a solvent casting method.

The poly-4-methyl-1-pentene is used as a semi-crystalline polymer, and provides conditions for preparing a PMP hollow fiber membrane by a melt extrusion method. Chinese patent CN104857864A reports a method for preparing a poly 4-methyl-1-pentene hollow fiber membrane by using an extrusion casting-melt stretching method, wherein the membrane forming process comprises the steps of passing molten poly 4-methyl-1-pentene (TPX) through a melt extrusion casting machine, casting to obtain a poly 4-methyl-1-pentene base membrane, performing heat treatment on the poly 4-methyl-1-pentene base membrane, performing cold and hot stretching on the heat-treated membrane to generate micropores, and then performing heat setting treatment to obtain a poly 4-methyl-1-pentene microporous membrane with a good microporous structure; no second component organic solvent is added in the preparation process, no pollutant is generated, and the environment-friendly production concept is met. Although the method avoids adding a large amount of solvent, the method has the disadvantages of more control conditions, more complex process production process, difficult regulation and control of the pore size and high processing temperature.

At present, the preparation technology for preparing the poly 4-methyl-1-pentene hollow fiber membrane with regular structure by a melt extrusion method with respect to the poly 4-methyl-1-pentene applied to ECMO is also lacked.

SUMMERY OF THE UTILITY MODEL

The purpose of the utility model is: a novel method for preparing a poly (4-methyl-1-pentene) hollow fiber membrane for ECMO is provided, which can obtain a membrane material having a regular pore morphology; the production process of the utility model uses poly-4-methyl-1-pentene and different diluents to prepare poly-4-methyl-1-pentene hollow fiber membranes with different membrane pore forms, the membrane forming principle is that poly-4-methyl-1-pentene powder and diluents are mixed, then the mixture is melted by a double screw, and then the mixture is stretched and extruded by a spinneret to form, and then the poly-4-methyl-1-pentene hollow fiber membrane is prepared by two steps of cold and hot stretching, and the diluents are extracted to generate different membrane pore forms and porous structures.

The technical scheme is as follows:

the poly (4-methyl-1-pentene) hollow fiber membrane applied to ECMO comprises a base layer and a coating layer on the surface of the base layer, wherein the base layer comprises the following components in percentage by weight:

20-50% of poly-4-methyl-1-pentene;

30-75% of a diluent;

5-20% of an additive;

the coating layer is used for reducing the leakage of the hollow fiber membrane.

The poly-4-methyl-1-pentene is TPX, and the melt flow rate is 5-30 g/10min (the test condition is that the temperature is 260 ℃ and 5Kg is multiplied); the coating layer is made of a rubber material; the thickness of the coating layer is 10-500 nm; the rubber material is one or a mixture of more than one of fluorocarbon rubber, fluorosilicone rubber, nitrile rubber and silicon rubber.

The additive is selected from one or a mixture of more of a pore-foaming agent, an antioxidant or a nucleating agent.

The diluent is one or a mixture of more than one of phthalate, citrate, phosphate or aliphatic dicarboxylic acid ester.

The base layer has an aperture of 100nm to 1000nm, the hollow fiber membrane-based membrane has a tensile strength of at least 10Mpa and an elongation at break of 150%, the outer diameter of the hollow fiber membrane-based membrane filaments is 350 ± 50nm, the inner diameter is 150 ± 50nm, and a contact angle of at least 90 °; a minimum of 50% porosity.

The preparation method of the poly 4-methyl-1-pentene hollow fiber membrane applied to ECMO comprises the following steps:

(1) mixing poly 4-methyl-1-pentene, a diluent and an additive, adding into a melt extruder, and carrying out melt extrusion through a spinning nozzle;

(2) after the poly 4-methyl-1-pentene initial extruded film passes through a section of air section, the poly 4-methyl-1-pentene initial extruded film is subjected to cold treatment for a period of time in a quenching bath to obtain a poly 4-methyl-1-pentene treated film with a further complete structure;

(3) drawing and stretching the quenching bath treatment film to generate micropores;

(4) then, thermally stretching the processing membrane with the micropores under a rinsing bath;

(5) after the poly 4-methyl-1-pentene microporous membrane is subjected to cold drawing, collection and shaping by a filament winding groove, a deposition rubber material is coated in a deposition groove, and the poly 4-methyl-1-pentene hollow fiber membrane with certain pore size distribution and good microporous structure is obtained.

In the step (1), the extruder is a single-screw extruder or a double-screw extruder.

In the step (1), the rotating speed of a screw is 50-200 r/min, and the temperature is 150-250 ℃; the residence time of the whole extrusion process is 5-10 minutes, and the pressure is 5-10 MPa.

In the step (1), the melt extrusion temperature of a spinning nozzle is 200-250 ℃; the extrusion frequency of the spinneret is 1-10 Hz.

In the step (2), the temperature of the quenching bath is 0-100 ℃.

In the step (3), the drawing and stretching frequency is 20-50 Hz.

In the step (4), the hot stretching frequency of the rinsing bath is 20-50 Hz.

In the step (5), the cold drawing frequency of the wire winding groove is 20-50 Hz.

In the step (5), the hot stretching conditions of the rinsing bath are as follows: stretching the steel sheet at 30-150 ℃ by 40-120%; the temperature of the deposition tank is 20-120 ℃.

In the step (5), the coating step includes: preparing a solution containing siloxane monomers, immersing the base film in the solution, taking out and drying.

The concentration of the siloxane monomer solution is 1-10 wt%.

The siloxane monomer can be polydimethylsiloxane, and the solvent adopted by the solution is selected from n-heptane, n-hexane, water and the like.

A method for testing the leakage of a hollow fiber membrane comprises the following steps:

assembling hollow fiber membrane filaments in a membrane component, wherein the outer surface of each hollow fiber membrane filament is the shell pass of the membrane component, and the inner surface of each hollow fiber membrane filament is the tube pass of the membrane component;

flowing an aqueous solution within the shell side of the membrane filaments;

flowing a sweep gas in the tube side of the membrane filaments;

the chromogenic material contacted with water is contacted with the purge gas flowing out of the membrane filaments, and the leakage of the membrane filaments is judged according to the change of the color.

The color developing substance contacted with water is anhydrous copper sulfate; the purge gas is nitrogen.

Advantageous effects

The utility model has the beneficial effects that: 1. the PMP hollow fiber membrane prepared by the extrusion melting method has the advantages of easy regulation and control, simple process and good continuity. 2. The hollow fiber membrane prepared by two-step cold and hot stretching has more stable structure and more uniform surface pore structure distribution. 3. The hollow fiber microporous membrane with uniform pore size distribution and different inner and outer diameters of the hollow fiber membrane can be obtained by changing the stretching condition. 4. The process from feeding to collection of the hollow fiber membrane is completely and automatically continuous, the hollow fiber membrane with different pore size distribution and the porosity of 30-70 percent can be obtained only by changing the drawing parameters, and the continuous production of the ECMO core membrane material can be realized. 5. The hollow fiber composite membrane prepared by coating the rubber material has good anti-seepage performance and meets the long-term stability operation standard of ECMO.

Drawings

Fig. 1 is a diagram of a production apparatus of a PMP hollow fiber membrane.

FIG. 2 is a diagram of a detection apparatus.

FIG. 3 is a diagram showing the distribution of aperture in examples and comparative examples

FIG. 4 is a graph showing the measurement of contact angle in examples and comparative examples

FIG. 5 is a graph showing mechanical properties of examples and comparative examples

FIG. 6 is a comparison of leak test results

Wherein, 1, an extruder; 2. a spinneret; 3. an air bath; 4. a quenching bath; 5. rinsing bath; 6. a deposition tank; 7. a wire winding groove; 8. a first pulling roll; 9. a second pulling roll; 10. a third pulling roll; 11. a membrane module; 12. membrane silk; 13. a gas inlet; 14. an aqueous solution inlet; 15. a gas outlet; 16. an aqueous solution outlet; 17. a developer storage tank; 18. and a seal.

Detailed Description

The adopted equipment is shown in figure 1, and comprises a set of polymer and diluent extrusion equipment, wherein the equipment is used for preparing a hollow fiber membrane by a thermally induced phase separation method, a membrane casting solution system forms hollow fibers through a spinning nozzle, the hollow fibers are immersed in quenching water bath to generate phase separation, and the phase separation is carried out rapidly through cooling and forming to obtain a base membrane; in the thermally induced phase separation method, the adopted diluent is phthalate diluent, or single or mixed diluent such as citric acid ester, phosphate ester, aliphatic dicarboxylic acid ester and the like which can be used for preparing the polymer separation membrane by the thermally induced phase separation method.

In the preparation method of the present invention, binary diluents are preferably used, wherein one of the diluents is preferably compatible with poly-4-methyl-1-pentene, such as dioctyl phthalate; while another diluent is less compatible with poly-4-methyl-1-pentene, such as: dibutyl sebacate, triethyl phosphate, triethyl citrate, and the like. The monobasic diluent and PMP have good dissolution, high interaction force and narrow phase separation region, and are easy to generate S-L phase separation to generate lace-shaped or crystalline structures. By adopting a second diluent with poor compatibility, the cloud point curve is moved upwards, the phase separation area is widened, L-L phase separation is easy to occur, a honeycomb or continuous pore structure is generated, and the permeation flux is improved.

The purpose of the additive can be to enhance the overall viscosity of the casting solution, and the uniformity of the hollow fiber obtained by the casting solution system through the spinning nozzle is improved. Meanwhile, due to the addition of the pore-forming agent, the porosity is integrally enhanced, and the flux is obviously improved. The additive comprises one or more of pore-foaming agent, antioxidant and nucleating agent. The mass fraction of the additive is 5-20%. The poly 4-methyl-1-pentene hollow fiber membrane is subjected to surface treatment by depositing a coating rubber material on the surface. The treated hollow fiber membrane has a coating of about 300nm, no surface defects and a leak-proof time of at least 10 hours.

When the hollow fiber membrane is applied to an ECMO system, on one hand, the regular porous base membrane has good gas permeability, so that N in the system is ensured₂、O₂、CO₂Etc. for fast transmission; on the other hand, because the blood cannot permeate into the membrane, the effect of preventing the blood from permeating is achieved through the compactness of the coating layer, and the coating layer shows better hydrophobicity, so that the blood is further prevented from depositing on the surface and forming thrombus.

The device provided by the utility model is shown in figure 1:

a high-strength hollow fiber membrane production apparatus comprising:

the extruder 1 is used for mixing and extruding the poly-4-methyl-1-pentene, the diluent and the additive to obtain thermally induced phase separation casting solution;

the spinning nozzle 2 is arranged at a material outlet of the casting solution extruding device and is used for extruding thermally induced phase separation casting solution film filaments;

a quenching bath 4 for receiving and cooling the film filaments obtained from the spinneret 2;

a rinsing bath 5 for receiving the film filaments obtained in the quenching bath 4 and heating and stretching the film filaments;

a deposition tank 6 for depositing a coating rubber material on the surface of the membrane wire obtained in the rinsing bath 5;

and the wire winding groove 7 is used for winding the film wire obtained from the deposition groove 6.

The extruder 1 is a single-screw extruder or a double-screw extruder.

An air bath 3 is also connected to the outlet of the spinneret 2 for air-bathing the film filaments obtained in the spinneret 2.

The rinsing bath 5 is also provided with a first pulling roller 8 for pulling the membrane filaments in the rinsing bath 5.

A second drawing roller 9 is also arranged in the deposition groove 6 and is used for drawing the film wire in the deposition groove 6.

A third drawing roller 10 is further arranged in the filament winding groove 7 and is used for drawing the film filament in the filament winding groove 7.

The present invention also provides a device for testing the leakage of a hollow fiber membrane applied to ECMO, comprising:

a membrane module 11 in which membrane filaments 12 are mounted in the membrane module 11;

the membrane module 11 is also provided with a gas inlet 13 and a gas outlet 15, and the gas inlet 13 and the gas outlet 15 are respectively communicated with two ends of the membrane filaments 12;

the membrane module 11 is also provided with a water solution inlet 14 and a water solution outlet 16, and the water solution inlet 14 and the water solution outlet 16 are respectively communicated with the shell side of the membrane filaments 12;

and a developer storage tank 17 connected to the gas outlet 15 and filled with a substance capable of developing color when it is in contact with water.

And a gas cylinder connected to the gas inlet 13 for supplying a purge gas to the tube side of the membrane wire 12.

The gas steel cylinder is filled with nitrogen.

A delivery pump is also included, connected to the aqueous solution inlet 14, for supplying the aqueous solution into the aqueous solution inlet 14.

The aqueous solution is a PBS buffer solution.

The developer storage tank 17 is filled with anhydrous copper sulfate.

And a sealing member 18, which is arranged in the membrane module 11 and is used for separating the tube side and the shell side of the membrane wires 12.

The percentages recited in the present invention refer to mass percentages unless otherwise specified.

Examples 1-5 are provided to illustrate the preparation of base films.

Example 1

Aiming at the preparation of a polymer-based membrane by a thermally induced phase separation method, the content and the processing method of each substance in a membrane forming system are as follows,

the polymer adopts poly 4-methyl-1-pentene (PMP) for chemical production of Mitsui Japan, the commodity type is TPX, the mass content is 50%, the diluent adopts dioctyl phthalate with good compatibility with the TPX as a single diluent, the mass content is 40%, and the additive adopts a pore-foaming agent PEG-400, the mass content is 10%.

Putting the mixed raw materials into a double-screw extruder for extrusion, wherein the temperature is 250 ℃; the residence time of the whole extrusion process was 5 minutes and the pressure was 5 MPa. Extruding the mixture by a spinning nozzle, cooling the mixture in a quenching bath after passing through an air section of 10cm to generate phase separation, cooling the mixture, quickly solidifying the mixture to form a film, stretching the film by a godet wheel, and then carrying out hot stretching in a rinsing bath, wherein the poly 4-methyl-1-pentene microporous film is subjected to cold stretching, collection and shaping by a filament winding groove to obtain the poly 4-methyl-1-pentene hollow fiber film.

The base film finally prepared had an outer diameter of about 1.3mm and an inner diameter of about 0.7 mm.

Example 2

the polymer adopts poly 4-methyl-1-pentene (PMP) for chemical production of Mitsui Japan, the commodity type is TPX, the mass content is 50%, the diluent adopts dioctyl phthalate with good compatibility with TPX and dibutyl phthalate with poor compatibility with TPX as binary diluent, the mass content of the dioctyl phthalate is 15%, the mass content of the dibutyl phthalate is 25%, and the mass fraction of the additive is 10% of a pore-forming agent PEG-400.

The base film finally prepared had an outer diameter of about 1.11mm and an inner diameter of about 0.67 mm.

Example 3

the polymer adopts poly 4-methyl-1-pentene (PMP) for chemical production of Japan three-well, the commodity type is TPX, the mass content is 50%, the diluent adopts dioctyl phthalate with good compatibility with TPX and dibutyl sebacate with poor compatibility with TPX as binary diluent, the mass content of the dioctyl phthalate is 20%, the mass content of the dibutyl sebacate is 20%, the additive adopts PEG-400 and silicon dioxide, the mass content of the PEG-400 is 5%, and the mass content of the silicon dioxide is 5%.

The base film finally prepared had an outer diameter of about 0.8mm and an inner diameter of about 0.4 mm.

Example 4

the polymer adopts poly 4-methyl-1-pentene (PMP) for chemical production of the Japan three-well, the commodity type is TPX, the mass content is 50%, the diluent adopts dioctyl phthalate with good compatibility with the TPX and triethyl phosphate with poor compatibility with the TPX as binary diluents, the mass content of the dioctyl phthalate is 20%, the mass content of the triethyl phosphate is 20%, the additive adopts PEG-400 and silicon dioxide, the mass content of the PEG-400 is 5%, and the mass content of the silicon dioxide is 5%.

The base film finally prepared had an outer diameter of about 0.52mm and an inner diameter of about 0.26 mm.

Example 5

the polymer adopts poly 4-methyl-1-pentene (PMP) for chemical production of Mitsui Japan, the commodity type is TPX, the mass content is 50%, the diluent adopts dioctyl phthalate with good compatibility with TPX and triethyl citrate with poor compatibility with TPX as binary diluent, the mass content of the dioctyl phthalate is 20%, the mass content of the triethyl citrate is 20%, the additive adopts PEG-400 and silicon dioxide, the mass content of the PEG-400 is 5%, and the mass content of the silicon dioxide is 5%.

The base film finally prepared had an outer diameter of about 0.37mm and an inner diameter of about 0.2 mm.

Example 6 for illustrating the preparation of a coating layer

In this embodiment, the hollow fiber membrane prepared in embodiment 5 is used as a base membrane, and a polymer PMP base membrane is prepared by a thermal phase separation method using PDMS as an example, a PDMS monomer is dissolved in n-hexane, and the concentrations are 1 wt%, 5 wt%, and 10 wt%, respectively, a PDMS coating solution with a suitable viscosity is coated on the surface of the PMP membrane by an immersion method in a deposition tank, and the PMP anti-leakage composite layer is prepared by taking out and drying the PMP anti-leakage composite layer. The PMP hollow fiber membrane finally prepared had an outer diameter of about 0.4mm and an inner diameter of about 0.2 mm.

SEM characterization

In the membrane structure of example 1 after ethanol extraction and pure water washing, surface defects were observed after 5K surface magnification; the cross section is of a compact structure under 10K times, and the local pores are formed by pore-forming agents and are of a particle accumulation structure as a whole.

In the membrane structure obtained in example 2 after ethanol extraction and pure water washing, small holes were observed on the surface at 10k times magnification; the structure with 10K times of section presents the condition of alternate honeycomb and continuous shapes, the structure is relatively complete on the whole, and the connectivity of the structure is good

In the membrane structure obtained in example 3 after ethanol extraction and pure water washing, a nonuniform small-pore structure on the surface was observed at 5K times magnification; the continuous hole structure with larger aperture can be seen after the section is magnified by 10K times, and the whole structure is looser.

In the membrane structure obtained in example 4 after ethanol extraction and pure water washing, uneven pores appear on the outer surface after 5K times of amplification; the section is stretched after 3K times of amplification, and the film structure is loose.

In the membrane structure of example 5 after ethanol extraction and pure water washing, defects were observed on the outer surface at 10K times; the section is 5K times, the whole structure is in a regular continuous structure, the whole dead holes are fewer, the structural connectivity is better, and the rapid exchange of gas can be guaranteed.

It can be seen from the comparison of electron microscope photos that the two diluents are adopted in the utility model, and the diluent with poor compatibility with the poly-4-methyl-1-pentene is introduced, so that the pore structure of the poly-4-methyl-1-pentene basal membrane can be effectively regulated and controlled, the regular and continuous shape is ensured, and the fast gas exchange in ECMO equipment is facilitated.

In the membrane structure obtained by ethanol extraction and pure water cleaning in example 6, it can be seen that the membrane surface with 22K times of surface amplification presents a compact structure with few defects, and the compact outer surface can effectively prevent leakage; the structure can be observed to be a bicontinuous structure on the section 10K, so that the high flux of gas is ensured; the outer wall magnification of 30K clearly shows that the surface was successfully coated with a coating to prevent leakage and that the underside of the coating appeared as a continuous structure as the cross-section.

Pore size distribution characterization

As can be seen from Table 1 and FIG. 3, the pore diameter of the hollow fiber membrane substrate of poly-4-methyl-1-pentene prepared by the utility model is uniformly distributed and has a pore diameter of 100nm to 1000 nm. Comparing the differences between the different examples, it is clear that the hollow fiber membrane-based membrane prepared using the phthalate diluent and the citrate diluent as the binary diluent has a smaller pore size. In example 6, the film surface after coating was dense, and the pore size distribution of the film surface was not measured by a pore size analyzer.

The comprehensive performance of the material is judged by testing the values of the tensile strength, the elongation at break and the gas flux of the obtained hollow fiber membrane. Examples formulations and various performance test results are shown in the following tables:

table 1 examples 1 to 5 test results, the performance parameters of a PMP hollow fiber membrane as a commercial product were used as comparative examples.

Pore size distribution characterization

As can be seen from FIG. 3, the hollow fiber membrane prepared by the utility model has narrow pore size distribution and large average pore size; in contrast, the commercial hollow fiber membranes of the comparative examples had a dense surface and small pores on the membrane surface due to the surface coating treatment.

Characterization of hydrophobic Properties

As can be seen from Table 1 and FIG. 4, the contact angle values of the poly (4-methyl-1-pentene) hollow fiber membrane prepared by the present invention were all 90 ℃ or more, and the membrane was hydrophobic. And the hydrophobicity is not obviously changed by coating the rubber material on the surface.

Characterization of mechanical Properties

The results of the mechanical property test of the hollow fiber membranes prepared in the above examples are shown in table 1 and fig. 5 below: the elongation at break is higher by using the phthalate diluent and the phosphate diluent, and the rigidity is higher; the phthalate diluent and the citrate diluent have higher mechanical strength, and the prepared base film has better flexibility. The reason for this analysis may be that citrate based plasticizers are less volatile and therefore mechanically stronger than phthalate based diluents.

Flux characterization

The results of the flux characterization experiments on the hollow fiber membranes prepared in the above examples are shown in table 1: as can be seen from table 1, the use of phthalate diluent and phthalate diluent as binary diluent or phthalate diluent and citrate diluent as binary diluent has the highest flux, because the structure presents a complete bicontinuous structure, the membrane pores have good connectivity, which is favorable for the passage of gas. Example 6 the flux of gas is significantly reduced by coating the surface with a rubber material to form a dense skin layer on the membrane surface.

Leakage prevention test

Taking PDMS as an example, aiming at the preparation of a polymer PMP base membrane by a thermally induced phase separation method, a PDMS coating solution with appropriate viscosity is coated on the surface of the PMP membrane by adopting a method of immersing in a deposition tank, and the PMP anti-leakage composite membrane is prepared. The anti-leakage membrane filaments prepared in the embodiment 5 and the embodiment 6 are glued and assembled into a component, the shell side of the hollow fiber membrane component is filled with PBS buffer solution, and N is introduced into the tube of the membrane component₂The outlet of the purge gas is led to a drying pipe filled with anhydrous copper sulfate. The time elapsed for the anhydrous copper sulfate in the drying tube to start to change color was observed. This time is defined as the leak time.

As can be seen from fig. 6, when the phthalate ester diluent and the citrate ester diluent are used as the binary diluent and the rubber material contents are 1%, 5% and 10% for comparison, it can be seen that when the rubber material content is in the range of 5% to 10%, the leakage time is at least 10 hours; when 1% -5% of rubber material is selected, the surface of the membrane has obvious defects, and the leakage time is not greatly improved compared with the original membrane; when the content of the rubber material is more than 10 percent, the rubber material generates pore permeation, the membrane pore channel is blocked by the rubber material, the permeation time is prolonged, and the flux is obviously reduced.

Claims

1. An apparatus for preparing a poly 4-methyl-1-pentene hollow fiber membrane for ECMO, comprising:

the extruder (1) is used for mixing and extruding the poly-4-methyl-1-pentene, the diluent and the additive to obtain thermally induced phase separation casting solution;

the spinning nozzle (2) is arranged at a material outlet of the casting solution extruding device and is used for extruding thermally induced phase separation casting solution film filaments;

the quenching bath (4) is used for receiving and cooling the film filaments obtained in the spinneret (2);

a rinsing bath (5) for receiving the membrane filaments obtained in the quenching bath (4) and heating and stretching the membrane filaments;

a deposition tank (6) for depositing a coating rubber material on the surface of the membrane wire obtained in the rinsing bath (5);

and the wire winding groove (7) is used for winding the film wire obtained from the deposition groove (6).

2. The apparatus for preparing a poly 4-methyl-1-pentene hollow fiber membrane for ECMO according to claim 1, wherein the extruder (1) is a single screw extruder or a twin screw extruder.

3. The apparatus for preparing a poly 4-methyl-1-pentene hollow fiber membrane for ECMO according to claim 1, wherein an air bath (3) is further connected to the outlet of the spinneret (2) for air-bath of the membrane filaments obtained in the spinneret (2).

4. The apparatus for preparing a poly 4-methyl-1-pentene hollow fiber membrane for ECMO according to claim 1, wherein the rinsing bath (5) further comprises a first drawing roll (8) for drawing the membrane filaments in the rinsing bath (5).

5. The apparatus for preparing a poly 4-methyl-1-pentene hollow fiber membrane for ECMO according to claim 1, wherein a second drawing roll (9) for drawing the membrane filaments in the deposition bath (6) is further provided in the deposition bath (6).

6. The apparatus for preparing a poly 4-methyl-1-pentene hollow fiber membrane for ECMO according to claim 1, wherein a third drawing roll (10) for drawing the membrane wire in the winding groove (7) is further provided in the winding groove (7).