Bio-based microporous membrane and preparation method thereof

Abstract

The invention relates to the technical field of microporous membranes, and discloses a bio-based microporous membrane and a preparation method thereof.The bio-based microporous membrane is prepared from 4, 4-diisocyanate dicyclohexylmethane, polycaprolactone diol and a chain extender, the polycaprolactone diol serves as a bio-based raw material, the chain extender is composed of hydrogen-containing eugenol functional siloxane and 1, 4-butanediol, and the chain extender is a chain extender composed of hydrogen-containing eugenol functional siloxane and 1, 4-butanediol. The hydrogen-containing eugenol functional siloxane is prepared by carrying out a reaction on a bio-based raw material eugenol, 1, 3-divinyl tetramethyl disiloxane and phenylsilane; the preparation method comprises the following steps: covalent bonding of alkenyl functionalized antibacterial nanoparticles and hydrogen-containing eugenol functionalized siloxane is realized through a platinum-catalyzed hydrosilylation reaction, and the bio-based microporous membrane is prepared by taking bio-based polyurethane as a raw material through a wet membrane forming method. The antibacterial rate of the prepared membrane product reaches 99% or above, and the bio-based carbon content of the membrane product reaches 60% or above.

Description

Technical Field

[0001] This invention relates to the field of microporous membrane technology, and in particular to a bio-based microporous membrane and its preparation method. Background Technology

[0002] A microporous membrane is a thin film material filled with tiny pores. Its working principle is as follows: external liquid water, being much larger than the micropores, is blocked, thus achieving waterproofing; moisture emitted by the human body can diffuse out through the micropores due to concentration differences, achieving breathability. This efficient water vapor removal capability prevents moisture from condensing and accumulating between the skin and fabric, keeping the wearer dry. Combining microporous membranes with fabrics through lamination and other technologies can endow fabrics with excellent waterproof and breathable properties, making them promising for applications in outdoor sportswear, professional protective equipment, and other fields.

[0003] Key monomers in traditional polyurethanes (such as polyols and isocyanates) are primarily derived from non-renewable petroleum-based materials. Faced with the increasing depletion of petroleum resources and related environmental problems, the development of bio-based polyurethanes has become a research hotspot. Bio-based refers to raw materials derived from renewable biomass resources (such as plants and microorganisms), possessing low-carbon and environmentally friendly characteristics. Developing bio-based polyurethanes aligns with the demands of green consumption and sustainable development.

[0004] Based on this, the present invention aims to first synthesize a novel bio-based polyurethane, and then use it as a basis to prepare a bio-based microporous membrane, which will eventually be applied to the field of functional textiles. Summary of the Invention

[0005] This invention uses polycaprolactone diol, 1,4-butanediol, hydrogen-containing eugenol-functionalized siloxane, 4,4-diisocyanate dicyclohexylmethane, and alkenyl-functionalized antibacterial nanoparticles as raw materials. Bio-based polyurethane is prepared through urethane reaction and hydrosilylation reaction. A bio-based microporous membrane is then prepared using a wet film-forming method. The antibacterial properties of this membrane product meet the technical requirements of GB / T20944.3-2008 "Evaluation of Antibacterial Properties of Textiles Part 3: Shaking Method" regarding an inhibition rate of ≥70% against Staphylococcus aureus and Escherichia coli.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A bio-based microporous membrane, wherein the bio-based carbon content of the bio-based microporous membrane is >60%, and the bio-based microporous membrane comprises the following raw materials in parts by weight:

[0008] 9.0-9.5 parts of 4,4-diisocyanate dicyclohexylmethane;

[0009] 18-22 parts of polycaprolactone diol, which is a bio-based raw material;

[0010] 5.5-10.5 parts of chain extender, which is composed of hydrogen-containing eugenol-functionalized siloxane and 1,4-butanediol, wherein the mass ratio of hydrogen-containing eugenol-functionalized siloxane to 1,4-butanediol is 0.3-1:1;

[0011] Hydrogen-containing eugenol-functionalized siloxanes are prepared by reacting bio-based raw material eugenol, 1,3-divinyltetramethyldisiloxane, and phenylsilane.

[0012] 0.1-0.5 parts of alkenyl-functionalized antibacterial nanoparticles, which are covalently bonded to hydrogen-containing eugenol-functionalized siloxanes via a platinum-catalyzed hydrosilylation reaction.

[0013] Preferably, the method for preparing the hydrogen-containing eugenol-functionalized siloxane is as follows:

[0014] Based on the hydrosilylation reaction mechanism, under the action of a platinum catalyst, the alkenyl functional group of 1 molar equivalent of 1,3-divinyltetramethyldisiloxane reacts with the silane-hydrogen bond functional group of 2 molar equivalent of phenylsilane to prepare a silane-hydrogen bond-terminated siloxane. Then, the silane-hydrogen bond functional group of 1 molar equivalent of the silane-hydrogen bond-terminated siloxane reacts with the alkenyl functional group of 2 molar equivalent of eugenol to prepare a hydrogen-containing eugenol-functionalized siloxane.

[0015] Preferably, the platinum catalyst is a chloroplatinic acid isopropanol solution with a platinum mass fraction of 0.5-2.5%.

[0016] Preferably, the method for preparing the alkenyl-functionalized antibacterial nanoparticles is as follows: surface modification of antibacterial nanoparticles is performed using an alkenyl-functionalized silane coupling agent to obtain alkenyl-functionalized antibacterial nanoparticles.

[0017] Preferably, the alkenyl-functionalized silane coupling agent is one of vinyltrimethoxysilane, allyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane.

[0018] Preferably, the antibacterial nanoparticles are one of nano zinc oxide, nano copper oxide, and nano magnesium oxide.

[0019] Preferably, the antibacterial nanoparticles have a particle size of 20-80 nm.

[0020] Preferably, the mass ratio of the antibacterial nanoparticles to the alkenyl-functionalized silane coupling agent is 1:0.01-0.10.

[0021] Preferably, the thickness of the bio-based microporous membrane is 50-100 μm.

[0022] A method for preparing a bio-based microporous membrane includes the following steps:

[0023] Polycaprolactone diol was prepared using ε-caprolactone and 1,4-butanediol as raw materials.

[0024] Polycaprolactone diol was subjected to an amino esterification reaction with 4,4-diisocyanate dicyclohexylmethane to prepare an isocyanate prepolymer.

[0025] A hydrosilicone-functionalized polyurethane was prepared by reacting 1,4-butanediol and hydrogen-containing eugenol-functionalized siloxane with isocyanate prepolymer to obtain a chain extension reaction.

[0026] Alkenyl-functionalized antibacterial nanoparticles undergo a hydrosilylation reaction with hydrosilane-functionalized polyurethane to prepare bio-based polyurethane.

[0027] Bio-based microporous membranes were prepared by a wet film-forming method using bio-based polyurethane as raw material, N,N-dimethylformamide as solvent, and anhydrous ethanol as coagulation bath.

[0028] The beneficial effects of this invention are as follows:

[0029] Hydrogen-containing eugenol-functionalized siloxanes were prepared by hydrosilylation reaction of eugenol, a bio-based raw material, with phenylsilane and 1,3-divinyltetramethyldisiloxane.

[0030] Alkenyl-functionalized silane coupling agents and antibacterial nanoparticles were prepared using alkenyl-functionalized silane coupling agents and antibacterial nanoparticles as raw materials.

[0031] Bio-based polycaprolactone diol was prepared using bio-based ε-caprolactone and 1,4-butanediol as raw materials.

[0032] Bio-based polyurethane was prepared by using hydrogen-containing eugenol-functionalized siloxane and 1,4-butanediol as chain extenders, and bio-based polycaprolactone diol, 4,4-diisocyanate dicyclohexylmethane, and alkenyl-functionalized antibacterial nanoparticles as raw materials through urethane reaction and hydrosilylation reaction. Based on the principle of non-solvent-induced phase separation, a bio-based microporous membrane was prepared by wet film formation method using bio-based polyurethane as raw material, N,N-dimethylformamide as solvent, and anhydrous ethanol as coagulation bath.

[0033] Experimental results confirm that the bio-based microporous membrane prepared by this invention has a bio-based carbon content of over 60%, and the antibacterial rate of the membrane product reaches over 99%. Its antibacterial performance meets the technical requirements of GB / T 20944.3-2008 "Evaluation of Antibacterial Properties of Textiles - Part 3: Shaking Method" regarding an antibacterial rate of ≥70% against Staphylococcus aureus and Escherichia coli. Detailed Implementation

[0034] Example 1:

[0035] The reaction mechanism for preparing hydrogen-containing eugenol-functionalized siloxanes is as follows:

[0036] Based on the hydrosilylation reaction mechanism, under the action of a platinum catalyst, the alkenyl functional group of 1 molar equivalent of 1,3-divinyltetramethyldisiloxane reacts with the silanium-hydrogen bond functional group of 2 molar equivalent of phenylsilane to prepare a silanium-hydrogen bond-terminated siloxane. Then, the silanium-hydrogen bond functional group of 1 molar equivalent of the silanium-hydrogen bond-terminated siloxane reacts with the alkenyl functional group of 2 molar equivalent of eugenol to prepare a hydrogen-containing eugenol-functionalized siloxane.

[0037] The chemical structural formula of hydrogen-containing eugenol-functionalized siloxanes is as follows:

[0038] ;

[0039] The specific preparation steps for hydrogen-containing eugenol-functionalized siloxanes are as follows:

[0040] Trace amounts of water in the isopropanol solution were adsorbed and removed. 0.53 g of chloroplatinic acid hexahydrate and 12 mL of isopropanol solution were added to prepare a 2% platinum isopropanol chloroplatinic acid solution.

[0041] Add 20 mL of toluene, 2.3 mL of 1,3-divinyltetramethyldisiloxane, and 2 drops of 2% platinum isopropanol chloroplatinate solution to a three-necked flask and mix well. Add 2.5 mL of phenylsilane and 20 mL of toluene to a constant-pressure dropping funnel and mix well. Heat to 60 °C under nitrogen protection and slowly add the solution from the funnel to the three-necked flask. The addition should be completed within 1 hour. Heat again to 75 °C and react for 5 hours. Then cool to 60 °C and add 3.1 mL of eugenol and 20 mL of toluene to the constant-pressure dropping funnel. Mix well and slowly add to the three-necked flask. The addition should be completed within 1 hour. Heat to 80 °C and react for 6 hours to obtain the crude product. Remove toluene by rotary evaporation. Wash with deionized water and ethanol successively, and dry at 60 °C for 12 hours to obtain hydrogen-containing eugenol-functionalized siloxane.

[0042] The 1H NMR characterization results of hydrogen-containing eugenol-functionalized siloxanes are as follows:

[0043] 1 H NMR (400MHz, DMSO-D6, δ, ppm): 0.05 (s, 12H), 0.87-0.91 (t, 4H), 1.07-1.15 (m, 8H), 1.63-1.69 (m, 4H), 2.54-2.67 (m, 4H), 3.82(s, 6H), 4.18-4.23(m, 2H), 6.04(s, 2H), 6.63-6.65(d, 4H), 6.75-6.77(d, 2H), 7.28-7.34(m, 6H), 7.49-7.54(m, 4H);

[0044] The reaction mechanism for preparing alkenyl-functionalized antibacterial nanoparticles is as follows:

[0045] Alkenyl-functionalized silane coupling agent is hydrolyzed to generate Si-OH, which undergoes a condensation reaction with the hydroxyl groups on the surface of antibacterial nanoparticles to prepare alkenyl-functionalized antibacterial nanoparticles.

[0046] The alkenyl-functionalized silane coupling agent is one of vinyltrimethoxysilane, allyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane. In this embodiment, 3-(methacryloyloxy)propyltriethoxysilane is selected.

[0047] The antibacterial nanoparticles are one of nano zinc oxide, nano copper oxide, and nano magnesium oxide; in this embodiment, nano zinc oxide is selected.

[0048] The specific preparation steps for alkenyl-functionalized antibacterial nanoparticles are as follows:

[0049] 30 mL of ethanol solution was mixed with 10 mL of deionized water, and then 0.12 mL of 3-(methacryloyloxy)propyltriethoxysilane was added. The mixture was magnetically stirred for 30 min, and then 2 g of nano-zinc oxide (particle size 50 nm) was added. The mixture was magnetically stirred for 30 min and ultrasonically dispersed for 25 min to form a uniform dispersion. The dispersion was then transferred to a magnetically stirred oil bath and the temperature was set to 85 °C. After reacting for 1 h, the mixture was cooled to room temperature, filtered, washed, and vacuum dried at 65 °C for 10 h to obtain alkenyl-functionalized antibacterial nanoparticles.

[0050] Example 2:

[0051] A bio-based microporous membrane comprises the following raw materials in parts by weight:

[0052] With the molar ratio of isocyanate to hydroxyl groups set at 1.03:1, the raw material formula for the bio-based microporous membrane is obtained as follows:

[0053] 9.4 g of 4,4-diisocyanate dicyclohexylmethane;

[0054] 20g of polycaprolactone diol;

[0055] 1.7g of bio-based 1,4-butanediol;

[0056] 4.4g of hydrogen-containing eugenol-functionalized siloxane;

[0057] 0.3g of alkenyl-functionalized antibacterial nanoparticles;

[0058] A method for preparing a bio-based microporous membrane includes the following steps:

[0059] 4.25 parts by weight of ε-caprolactone were placed in a three-necked flask, and 0.2 parts by weight of 1,4-butanediol were added and mixed thoroughly. Then, 0.01 g of stannous octoate was added, and the mixture was purged with nitrogen and reacted at 150 °C for 24 h. The temperature was then lowered to 60 °C, the precipitate was washed with methanol, cooled, filtered, and dried under vacuum at 50 °C for 24 h to obtain polycaprolactone diol. According to m2=m1M2 / (M n The formula is -M2), where m2 is the mass of 1,4-butanediol, m1 is the mass of ε-caprolactone, M2 is the relative molecular weight of 1,4-butanediol, and M... n The relative molecular mass of polycaprolactone diol is calculated to be approximately 2000.

[0060] According to the formulation dosage, under nitrogen protection, polycaprolactone diol and 4,4-diisocyanate dicyclohexylmethane were mixed, heated to 50°C, and mechanically stirred for 1 hour. Then, the temperature was raised to 80°C and stirred for another 2 hours to form an isocyanate prepolymer. Subsequently, 1,4-butanediol and hydrogen-containing eugenol-functionalized siloxane were added to 30 mL of anhydrous N,N-dimethylformamide and mixed evenly. The mixture was then slowly added to the isocyanate prepolymer and reacted at 70°C for 1 hour. Then, 0.1 g of dibutyltin dilaurate was added, the temperature was raised to 80°C, and the reaction was carried out for 4 hours to obtain silane-functionalized polyurethane. Alkenyl-functionalized antibacterial nanoparticles and 4 drops of a 2% platinum isopropanol chloroplatinate solution were added to the silane-functionalized polyurethane, the temperature was raised to 85°C, and the reaction was maintained for 5 hours. After cooling to room temperature, the mixture was placed in a vacuum drying oven at 80°C to obtain bio-based polyurethane.

[0061] Bio-based polyurethane was added to N,N-dimethylformamide and stirred thoroughly. The mixture was then placed in a 60°C constant temperature water bath and stirred for 2 hours to prepare a 20% polyurethane casting solution. The solution was degassed under vacuum at room temperature. A dry and clean glass plate was used as a template, and the polyurethane casting solution was evenly coated onto the film using a wire rod coater. The film was then immersed in an anhydrous ethanol coagulation bath to form a film. The formed film was transferred from the glass plate to deionized water and soaked for 2 hours. The film was then removed and allowed to dry naturally to obtain a bio-based microporous membrane a with a thickness of 65 μm.

[0062] Example 3:

[0063] The preparation method of bio-based microporous membrane b differs from that of bio-based microporous membrane a only in that it contains 1.5 g of 1,4-butanediol and 6 g of hydrogen-containing eugenol-functionalized siloxane.

[0064] Example 4:

[0065] The preparation method of bio-based microporous membrane c differs from that of bio-based microporous membrane a only in that 1.2 g of 1,4-butanediol and 8.4 g of hydrogen-containing eugenol-functionalized siloxane are used.

[0066] Comparative example:

[0067] A bio-based microporous membrane comprises the following raw materials in parts by weight:

[0068] With the molar ratio of isocyanate to hydroxyl groups set at 1.03:1, the raw material formula for the bio-based microporous membrane is obtained as follows:

[0069] 5.8g of 4,4-diisocyanate dicyclohexylmethane;

[0070] 20g of polycaprolactone diol;

[0071] 1g of 1,4-butanediol;

[0072] The preparation method of polycaprolactone diol with a relative molecular mass of approximately 2000 is the same as that in Example 2;

[0073] According to the formulation dosage, under nitrogen protection, polycaprolactone diol and 4,4-diisocyanate dicyclohexylmethane were mixed, heated to 50°C, and mechanically stirred for 1 hour. Then, the temperature was raised to 80°C and stirred for another 2 hours to form an isocyanate prepolymer. Subsequently, 1,4-butanediol was added to 30 mL of anhydrous N,N-dimethylformamide and mixed evenly. The mixture was then slowly added to the isocyanate prepolymer and reacted at 70°C for 1 hour. Then, 0.1 g of dibutyltin dilaurate was added, the temperature was raised to 80°C, and the reaction was carried out for 4 hours. After cooling to room temperature, the mixture was placed in a vacuum drying oven at 80°C and dried to obtain bio-based polyurethane.

[0074] Bio-based polyurethane was added to N,N-dimethylformamide and stirred thoroughly. The mixture was then placed in a 60°C constant temperature water bath and stirred for 2 hours to prepare a 20% polyurethane casting solution. The solution was degassed under vacuum at room temperature. Using a dry and clean glass plate as a template, the polyurethane casting solution was evenly coated onto the film using a wire rod coater. The film was then immersed in an anhydrous ethanol coagulation bath to form a membrane. The formed film was transferred from the glass plate to deionized water and soaked for 2 hours. The film was then removed and allowed to dry naturally to obtain a bio-based microporous membrane with a thickness of 65 μm.

[0075] Performance testing:

[0076] I. Mechanical property testing of bio-based microporous membranes

[0077] The tensile properties and elongation at break of the bio-based microporous membrane were tested using an electronic fabric tensile tester. The bio-based microporous membrane was prepared into strip-shaped samples of 25 mm × 150 mm with a sample clamping length of 100 mm and a tensile speed of 10 mm / min. The samples were tested three times and the average value was taken.

[0078] Table 1. Experimental results of mechanical properties of bio-based microporous membranes

[0079] Product No. Tensile strength (MPa) Elongation at break (%) Bio-based microporous membrane a 18.7 334.2 Bio-based microporous membrane b 20.5 354.3 Bio-based microporous membrane c 19.8 342.4 Comparative Example 11.4 237.9

[0080] II. Moisture permeability test of bio-based microporous membranes

[0081] According to the method in GB / T 12704.1-2009 "Textiles - Test Methods for Moisture Permeability of Fabrics - Part 1: Moisture Absorption Method", the moisture permeability of the bio-based microporous membrane was tested using a moisture permeability tester, and the moisture permeability was calculated.

[0082] Table 2. Results of the moisture permeability test of bio-based microporous membranes

[0083] Product No. moisture permeability [g / (m 2 ·24h) Bio-based microporous membrane a 4132 Bio-based microporous membrane b 4495 Bio-based microporous membrane c 4258

[0084] III. Antibacterial Test of Bio-based Microporous Membranes

[0085] The samples were sterilized, and then Escherichia coli (ATCC8739) and Staphylococcus aureus (ATCC6538) were used as test strains. The bacteria were cultured at 37°C for 24 hours and diluted to 106 colony-forming units (CFU) per milliliter.

[0086] Add 0.1g of sample to 10mL of bacterial dilution solution, irradiate at room temperature for 2h under 40W UV lamp, then drop 0.1mL of solution onto AGAR plate and spread evenly, and place at 37℃ for 12h.

[0087] The antibacterial rate is calculated as (PM) / P × 100%, where P and M are the average number of bacteria in the control group and experimental group samples, respectively.

[0088] Table 3. Experimental results of antibacterial properties of bio-based microporous membranes

[0089] Product No. Bacteriostatic rate against E. coli (%) Bacteriostatic rate against S. aureus (%) Bio-based microporous membrane a ≥99.9 ≥99.9 Bio-based microporous membrane b ≥99.9 ≥99.9 Bio-based microporous membrane c ≥99.9 ≥99.9

[0090] The antibacterial rate of the bio-based microporous membrane prepared by this invention meets the technical requirements of GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method" regarding the antibacterial rate of Staphylococcus aureus and Escherichia coli ≥70%, and the sample has antibacterial effect.

[0091] IV. Testing of Bio-based Carbon Content

[0092] Biomass contains 100% C14, while fossil raw materials do not contain C14 (0%). The bio-based carbon content in bio-based microporous membranes, i.e. the percentage of bio-based carbon in total organic carbon, is measured by ASTM D68866 method and accelerator mass spectrometry (AMS).

[0093] Table 4. Experimental results of bio-based carbon content in bio-based microporous membranes.

[0094] Product No. Bio-based carbon content (%) Bio-based microporous membrane a 61.2 Bio-based microporous membrane b 61.7 Bio-based microporous membrane c 62.3

[0095] The experimental results above show that the membrane product prepared by this invention has excellent antibacterial properties, and its bio-based carbon content reaches 60%, which is a bio-based microporous membrane.

Claims

1. A bio-based microporous membrane, characterized in that, The bio-based microporous membrane has a bio-based carbon content >60%, and the bio-based microporous membrane comprises the following raw materials in parts by weight: 9.0-9.5 parts of 4,4-diisocyanate dicyclohexylmethane; 18-22 parts of polycaprolactone diol, which is a bio-based raw material; 5.5-10.5 parts of chain extender, which is composed of hydrogen-containing eugenol-functionalized siloxane and 1,4-butanediol, wherein the mass ratio of hydrogen-containing eugenol-functionalized siloxane to 1,4-butanediol is 0.3-1:1; Hydrogen-containing eugenol-functionalized siloxanes are prepared by reacting bio-based raw material eugenol, 1,3-divinyltetramethyldisiloxane, and phenylsilane. The chemical structural formula of the hydrogen-containing eugenol-functionalized siloxanes is as follows: ； 0.1-0.5 parts of alkenyl-functionalized antibacterial nanoparticles, which are covalently bonded to hydrogen-containing eugenol-functionalized siloxanes via a platinum-catalyzed hydrosilylation reaction.

2. The bio-based microporous membrane according to claim 1, characterized in that, The preparation method of the hydrogen-containing eugenol functionalized siloxane is as follows: Based on the hydrosilylation reaction mechanism, under the action of a platinum catalyst, the alkenyl functional group of 1 molar equivalent of 1,3-divinyltetramethyldisiloxane reacts with the silane-hydrogen bond functional group of 2 molar equivalent of phenylsilane to prepare a silane-hydrogen bond-terminated siloxane. Then, the silane-hydrogen bond functional group of 1 molar equivalent of the silane-hydrogen bond-terminated siloxane reacts with the alkenyl functional group of 2 molar equivalent of eugenol to prepare a hydrogen-containing eugenol-functionalized siloxane.

3. The bio-based microporous membrane according to claim 2, characterized in that, The platinum catalyst is a chloroplatinic acid isopropanol solution with a platinum mass fraction of 0.5-2.5%.

4. The bio-based microporous membrane according to claim 1, characterized in that, The method for preparing the alkenyl-functionalized antibacterial nanoparticles is as follows: surface modification of antibacterial nanoparticles is performed using an alkenyl-functionalized silane coupling agent to obtain alkenyl-functionalized antibacterial nanoparticles.

5. A bio-based microporous membrane according to claim 4, characterized in that, The alkenyl-functionalized silane coupling agent is one of vinyltrimethoxysilane, allyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, and 3-(methacryloyloxy)propyltriethoxysilane.

6. A bio-based microporous membrane according to claim 4, characterized in that, The antibacterial nanoparticles are one of nano zinc oxide, nano copper oxide, and nano magnesium oxide.

7. A bio-based microporous membrane according to claim 4, characterized in that, The antibacterial nanoparticles have a particle size of 20-80 nm.

8. A bio-based microporous membrane according to claim 4, characterized in that, The mass ratio of the antibacterial nanoparticles to the alkenyl-functionalized silane coupling agent is 1:0.01-0.

10.

9. A bio-based microporous membrane according to claim 1, characterized in that, The thickness of the bio-based microporous membrane is 50-100 μm.

10. A method for preparing a bio-based microporous membrane as described in claim 1, characterized in that, Includes the following steps: Polycaprolactone diol was prepared using ε-caprolactone and 1,4-butanediol as raw materials. Polycaprolactone diol was subjected to an amino esterification reaction with 4,4-diisocyanate dicyclohexylmethane to prepare an isocyanate prepolymer. A hydrosilicone-functionalized polyurethane was prepared by reacting 1,4-butanediol and hydrogen-containing eugenol-functionalized siloxane with isocyanate prepolymer to obtain a chain extension reaction. Alkenyl-functionalized antibacterial nanoparticles undergo a hydrosilylation reaction with hydrosilane-functionalized polyurethane to prepare bio-based polyurethane. Bio-based microporous membranes were prepared by a wet film-forming method using bio-based polyurethane as raw material, N,N-dimethylformamide as solvent, and anhydrous ethanol as coagulation bath.

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