Moisture-permeable hydrolysis-resistant antibacterial polyurethane synthetic leather and application thereof

Abstract

According to the moisture-permeable hydrolysis-resistant antibacterial polyurethane synthetic leather and the application thereof provided by the invention, the synthetic leather takes isophorone diisocyanate and castor oil as raw materials, and a modified two-dimensional nano material and quaternized carboxymethyl chitosan are introduced to construct a three-dimensional cross-linked network structure, so that a polyurethane frame structure is stable; the isophorone diisocyanate and the tannic acid form covalent cross-linking, and the polyurethane and the quaternized carboxymethyl chitosan generate hydrogen bonds so as to form secondary cross-linking; quaternized carboxymethyl chitosan has biodegradability, not only provides a moisture supply channel, but also provides antibacterial factors. Through innovative molecular structure design and a functional modification process, collaborative optimization of three key properties, namely moisture permeability, hydrolysis resistance and antibacterial property, is realized. According to the invention, a gas-liquid transmission path is reconstructed on a microscopic level, the limitation that the air permeability and the water resistance of bio-based polyurethane cannot be realized at the same time is broken through, and an innovative solution is provided for a high-performance environment-friendly vamp material.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic leather preparation, and particularly relates to moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather and applications thereof. Background Art

[0002] Polyurethane (PU), also known as polyurethane, contains numerous carbamate groups (-NHCOO-) in its molecular backbone. It is a block polymer composed of alternating soft segments (composed of polyols) and hard segments (composed of polyisocyanates and chain extenders). This structure imparts properties intermediate between those of plastics and rubbers, such as high elasticity, wear resistance, oil resistance, and a wide range of hardness.

[0003] Polyurethane (PU) has become the fifth largest plastic material in the world due to its outstanding mechanical properties, wear resistance and molecular designability, and is widely used in the fields of footwear, textiles, automobiles, etc. Among traditional shoe upper materials, petroleum-based waterborne polyurethane (WPU) is widely used due to its excellent mechanical properties and controllable costs. However, it relies on non-renewable fossil resources, and the volatile organic compounds and waste emitted during its production process are difficult to degrade, which is in significant conflict with the global circular economy goals. Bio-based waterborne polyurethane (BWPU) has become an alternative due to its renewable characteristics, but it faces many challenges in the actual industrialization process: First, the hydroxyl group in the castor oil molecular chain has low activity and insufficient reaction efficiency with isocyanate, resulting in low crosslinking density and weak mechanical properties (such as tear strength and water resistance); second, polyurethane (PU) synthetic leather is easily corroded by microorganisms (bacteria and mold) during wear. The reason is that the nutrient base required for microbial growth exists in the molecular structure of polyurethane resin. On the other hand, various additives added to the resin slurry, such as plasticizers and heat stabilizers, , light stabilizers, fillers, waxes, etc., can also serve as a nutrient source for microorganisms. Under suitable conditions, bacteria and molds will multiply in large numbers, causing polyurethane synthetic leather to mold and deteriorate. In order to give the material antibacterial properties, physical blending of silver nanoparticles or quaternary ammonium salts is often used, but nanoparticles are easy to agglomerate, resulting in uneven dispersion and a high risk of dissolution after long-term use, and chemical modifications (such as grafting antibacterial groups) can easily destroy the air permeability of the material itself; thirdly, traditional PU synthetic leather mostly relies on dense coatings to achieve water resistance, and it is difficult to balance air permeability and hydrostatic pressure resistance, and high temperature and high pressure during processing can easily lead to degradation of bio-based components.

[0004] In response to the above problems, there is an urgent need to develop a new bio-based polyurethane system that can synergistically improve the material's air permeability, water resistance, and antibacterial properties through molecular design and process optimization, while ensuring processing feasibility and environmental friendliness. Therefore, the present invention proposes a moisture-permeable, hydrolysis-resistant, and antibacterial polyurethane synthetic leather and its application. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather and applications thereof.

[0006] To achieve the above object, the present invention proposes the following technical solution: a moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather, wherein the polyurethane synthetic leather is a polyurethane microfiber synthetic leather;

[0007] The polyurethane microfiber synthetic leather comprises a microfiber base fabric and a synthetic leather surface layer;

[0008] The preparation method of the polyurethane microfiber synthetic leather comprises the following steps: dipping the microfiber base cloth into a bio-based polyurethane emulsion, drying, washing, and hot pressing after dipping to obtain a moisture-permeable, hydrolysis-resistant, and antibacterial bio-based polyurethane microfiber synthetic leather;

[0009] Furthermore, the bio-based polyurethane emulsion comprises the following raw material components in parts by weight:

[0010] 40-50 parts of isophorone diisocyanate;

[0011] 48-60 parts of castor oil;

[0012] 5-9 parts of modified two-dimensional nanomaterials;

[0013] 0.1-0.5 parts of dibutyltin dilaurate;

[0014] 11-14 parts of 2,2-dihydroxybutyric acid;

[0015] 8-10 parts of triethylamine;

[0016] 5-8 parts of quaternized carboxymethyl chitosan;

[0017] The balance was acetone.

[0018] Furthermore, the modified two-dimensional nanomaterial is obtained by modifying the two-dimensional nanomaterial via polyphenol.

[0019] Furthermore, the polyphenol is tannic acid, and the two-dimensional nanomaterial is one of lithium terephthalate, zirconium phosphate, and MXene.

[0020] Furthermore, the preparation method of the modified two-dimensional nanomaterial is: adding the two-dimensional nanomaterial to deionized water, ultrasonically treating it to obtain a dispersion, adding a surfactant aqueous solution to the dispersion, stirring at room temperature and then centrifuging, discarding the supernatant, and freeze-drying the precipitate to obtain the modified two-dimensional nanomaterial.

[0021] Furthermore, the surfactant is one of 3-aminopropyltriethoxysilane and dopamine.

[0022] Furthermore, the preparation method of the quaternized carboxymethyl chitosan comprises:

[0023] A1. Dissolve chitosan in 2-4% acetic acid solution, add chloroacetic acid at 60-70°C and react for 6-7 hours. Prepare carboxymethyl chitosan by the mass ratio of chitosan to chloroacetic acid (4-5):1.

[0024] A2. Glycidyl trimethylammonium chloride is prepared into a solution with a pH of 8.0-8.5, and the carboxymethyl chitosan is added thereto at a molar ratio of (1.1-1.2):1, and the mixture is reacted for 11-12 hours under the following conditions to obtain the quaternized carboxymethyl chitosan.

[0025] Furthermore, the preparation method of the bio-based polyurethane emulsion comprises the following steps:

[0026] S1, vacuum drying the isophorone diisocyanate and the castor oil to remove moisture;

[0027] S2, dispersing the modified two-dimensional nanomaterial in the castor oil and transferring the mixture to a three-necked flask equipped with a condenser reflux apparatus, sequentially adding isophorone diisocyanate, dibutyltin dilaurate, and acetone, raising the temperature to 80-90° C., and stirring the mixture at 300-500 rpm in an inert gas atmosphere for 2-3 hours;

[0028] S3, continue to add the 2,2-dihydroxybutyric acid to the reaction system and react for 2-3 hours;

[0029] S4, lowering the temperature of the reaction system to room temperature, then adding triethylamine and quaternized carboxymethyl chitosan, and stirring at 200-400 rpm for 45-50 min for neutralization to obtain a polyurethane prepolymer;

[0030] S5. Add deionized water to the polyurethane prepolymer in S4 and stir at a speed of 1500-2000 rpm for 2-3 hours for emulsification to obtain the bio-based polyurethane emulsion.

[0031] Furthermore, the preparation method of the polyurethane microfiber synthetic leather includes: stirring the bio-based polyurethane emulsion and the modified two-dimensional nanomaterial dispersion at room temperature for 1 to 2 hours to obtain a composite solution, then soaking the microfiber base cloth in the composite solution, and then drying it, repeating the operation until the dry weight gain value of the microfiber base cloth is 15 to 18%, then washing it with deionized water until the washing liquid is neutral, and hot pressing it at 80 to 90°C and 5 to 8 MPa pressure for 5 to 10 minutes to obtain the polyurethane microfiber synthetic leather.

[0032] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0033] The present invention provides a moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather and its application. The synthetic leather uses isophorone diisocyanate and castor oil as raw materials, and constructs a three-dimensional cross-linked network structure by introducing modified two-dimensional nanomaterials and quaternized carboxymethyl chitosan, so that the polyurethane framework structure is stable, isophorone diisocyanate and tannic acid form covalent crosslinks, and polyurethane and quaternized carboxymethyl chitosan generate hydrogen bonds to form secondary crosslinks; quaternized carboxymethyl chitosan has biodegradable properties, not only provides a moisture supply channel, but also provides antibacterial factors. The present invention achieves synergistic optimization of the three key properties of moisture permeability, hydrolysis resistance and antibacterial properties through innovative molecular structure design and functional modification processes. The present invention reconstructs the gas-liquid transmission path at the microscopic level, breaking through the limitation that bio-based polyurethane cannot have both air permeability and water resistance, and provides an innovative solution for high-performance environmentally friendly shoe upper materials.

[0034] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, to the extent such concepts are not mutually inconsistent, can be considered to be part of the present subject matter disclosure.

[0035] The foregoing and other aspects, embodiments and features of the present invention will be more fully understood from the following description. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will become apparent from the following description or will be learned from the practice of the specific embodiments according to the present invention. DETAILED DESCRIPTION

[0036] The following embodiments of the present invention are intended only to illustrate the technical features of the present invention and do not constitute a limitation on the scope of protection of the claims. Those skilled in the art should understand that any technical variations or parameter adjustments based on the basic principles of the present invention, without departing from the core concept of the present invention, are deemed to fall within the scope of protection of the claims of the present invention.

[0037] Unless otherwise specified, the experimental methods or test methods described in the following examples / comparative examples are conventional methods; the reagents and materials described are obtained from conventional commercial channels or prepared by conventional methods unless otherwise specified.

[0038] Example 1

[0039] A moisture-permeable, hydrolysis-resistant, and antibacterial polyurethane synthetic leather, wherein the polyurethane synthetic leather is a polyurethane microfiber synthetic leather; the polyurethane microfiber synthetic leather comprises a microfiber base fabric and a synthetic leather surface layer; and a method for preparing the polyurethane microfiber synthetic leather comprises the following steps: impregnating the microfiber base fabric in a bio-based polyurethane emulsion, and drying, washing, and hot-pressing the impregnation to obtain the moisture-permeable, hydrolysis-resistant, and antibacterial bio-based polyurethane microfiber synthetic leather;

[0040] Furthermore, the bio-based polyurethane emulsion comprises the following raw material components in parts by weight:

[0041] 40 parts of isophorone diisocyanate;

[0042] 48 parts of castor oil;

[0043] 5 parts of modified two-dimensional nanomaterials;

[0044] 0.1 part of dibutyltin dilaurate;

[0045] 2,2-dihydroxybutyric acid 11 parts;

[0046] 8 parts of triethylamine;

[0047] 5 parts of quaternized carboxymethyl chitosan;

[0048] The balance was acetone.

[0049] Preferably, the modified two-dimensional nanomaterial of this embodiment is obtained by modifying lithium talc with tannic acid. The specific preparation method is as follows: 0.5 g of lithium talc is added to 50 mL of deionized water and ultrasonically treated to obtain a dispersion; then 50 mL of a 1.5% aqueous solution of 3-aminopropyltriethoxysilane is added to the dispersion, stirred at room temperature, and then centrifuged. The supernatant is discarded and the precipitate is freeze-dried to obtain the modified two-dimensional nanomaterial.

[0050] Furthermore, the preparation method of the quaternized carboxymethyl chitosan comprises:

[0051] A1. Dissolve chitosan in 2% acetic acid solution, add chloroacetic acid and react at 60°C for 6 hours. Prepare carboxymethyl chitosan by chitosan and chloroacetic acid in a mass ratio of 4:1.

[0052] A2. Glycidyl trimethylammonium chloride was prepared into a solution with a pH of 8.0, and the carboxymethyl chitosan was added thereto at a molar ratio of 1.1:1 and reacted for 11 hours under the following conditions to obtain the quaternized carboxymethyl chitosan.

[0053] Furthermore, the preparation method of the bio-based polyurethane emulsion comprises the following steps:

[0054] S1, vacuum drying the isophorone diisocyanate and the castor oil to remove moisture;

[0055] S2, dispersing the modified two-dimensional nanomaterial in the castor oil and transferring the mixture to a three-necked flask equipped with a condenser reflux apparatus, sequentially adding isophorone diisocyanate, dibutyltin dilaurate, and acetone, raising the temperature to 80° C., and stirring the mixture at 300 rpm in an inert gas atmosphere for 2 h;

[0056] S3, continue to add the 2,2-dihydroxybutyric acid to the reaction system and react for 2 hours;

[0057] S4, lowering the temperature of the reaction system to room temperature, then adding triethylamine and quaternized carboxymethyl chitosan, and stirring at 200 rpm for 45 min for neutralization to obtain a polyurethane prepolymer;

[0058] S5. Add deionized water to the polyurethane prepolymer in S4 and stir at a speed of 1500 rpm for 2 hours for emulsification to obtain the bio-based polyurethane emulsion.

[0059] Furthermore, the preparation method of the polyurethane microfiber synthetic leather includes: stirring the bio-based polyurethane emulsion and the modified two-dimensional nanomaterial dispersion at room temperature for 1 to 2 hours to obtain a composite solution, then soaking the microfiber base cloth in the composite solution, and then drying it, repeating the operation until the dry weight gain value of the microfiber base cloth is 15%, and then washing it with deionized water until the washing liquid is neutral, and hot pressing it at 80°C and 5 MPa pressure for 5 minutes to obtain the polyurethane microfiber synthetic leather.

[0060] Example 2

[0061] Different from the above-mentioned Example 1, the bio-based polyurethane emulsion includes the following raw material components in parts by weight:

[0062] 45 parts of isophorone diisocyanate;

[0063] 54 parts of castor oil;

[0064] 7 parts of modified two-dimensional nanomaterials;

[0065] 0.3 parts of dibutyltin dilaurate;

[0066] 13 parts of 2,2-dihydroxybutyric acid;

[0067] 9 parts of triethylamine;

[0068] 7 parts of quaternized carboxymethyl chitosan;

[0069] The balance was acetone.

[0070] Furthermore, the preparation method of the quaternized carboxymethyl chitosan comprises:

[0071] A1. Dissolve chitosan in 3% acetic acid solution, add chloroacetic acid at 65°C and react for 6.5 hours. Prepare carboxymethyl chitosan by chitosan and chloroacetic acid in a mass ratio of 4.5:1.

[0072] A2. Glycidyl trimethylammonium chloride was prepared into a solution with a pH of 8.3, and the carboxymethyl chitosan was added thereto at a molar ratio of 1.15:1 and reacted for 11.5 hours under the following conditions to obtain the quaternized carboxymethyl chitosan.

[0073] Furthermore, the preparation method of the bio-based polyurethane emulsion comprises the following steps:

[0074] S1, vacuum drying the isophorone diisocyanate and the castor oil to remove moisture;

[0075] S2, dispersing the modified two-dimensional nanomaterial in the castor oil and transferring the mixture to a three-necked flask equipped with a condenser reflux apparatus, sequentially adding isophorone diisocyanate, dibutyltin dilaurate, and acetone, raising the temperature to 85° C., and stirring the mixture at 400 rpm in an inert gas atmosphere for 2.5 hours;

[0076] S3, continue to add the 2,2-dihydroxybutyric acid to the reaction system and react for 2.5 hours;

[0077] S4, lowering the temperature of the reaction system to room temperature, then adding triethylamine and quaternized carboxymethyl chitosan, and stirring at 300 rpm for 47 min for neutralization to obtain a polyurethane prepolymer;

[0078] S5. Add deionized water to the polyurethane prepolymer in S4 and stir at a speed of 1800 rpm for 2.5 hours for emulsification to obtain the bio-based polyurethane emulsion.

[0079] Furthermore, the preparation method of the polyurethane microfiber synthetic leather includes: stirring the bio-based polyurethane emulsion and the modified two-dimensional nanomaterial dispersion at room temperature for 1.5 hours to obtain a composite solution, then soaking the microfiber base cloth in the composite solution, and then drying it, repeating the operation until the dry weight gain value of the microfiber base cloth is 17%, then washing it with deionized water until the washing liquid is neutral, and hot pressing it at 85°C and 7 MPa pressure for 7 minutes to obtain the polyurethane microfiber synthetic leather.

[0080] For other steps, refer to Example 1.

[0081] Example 3

[0082] Different from the above-mentioned Example 1, the bio-based polyurethane emulsion includes the following raw material components in parts by weight:

[0083] 50 parts of isophorone diisocyanate;

[0084] 60 parts of castor oil;

[0085] 9 parts of modified two-dimensional nanomaterials;

[0086] 0.5 parts of dibutyltin dilaurate;

[0087] 14 parts of 2,2-dihydroxybutyric acid;

[0088] 10 parts of triethylamine;

[0089] 8 parts of quaternized carboxymethyl chitosan;

[0090] The balance was acetone.

[0091] Furthermore, the preparation method of the quaternized carboxymethyl chitosan comprises:

[0092] A1. Dissolve chitosan in 4% acetic acid solution, add chloroacetic acid and react at 70°C for 7 hours. Prepare carboxymethyl chitosan with chitosan and chloroacetic acid in a mass ratio of 5:1.

[0093] A2. Glycidyl trimethylammonium chloride was prepared into a solution with a pH of 8.5, and the carboxymethyl chitosan was added thereto at a molar ratio of 1.2:1 and reacted for 12 hours under the following conditions to obtain the quaternized carboxymethyl chitosan.

[0094] Furthermore, the preparation method of the bio-based polyurethane emulsion comprises the following steps:

[0095] S1, vacuum drying the isophorone diisocyanate and the castor oil to remove moisture;

[0096] S2, dispersing the modified two-dimensional nanomaterial in the castor oil and transferring the mixture to a three-necked flask equipped with a condenser reflux apparatus, sequentially adding isophorone diisocyanate, dibutyltin dilaurate, and acetone, raising the temperature to 90° C., and stirring the mixture at 500 rpm in an inert gas atmosphere for 3 hours;

[0097] S3, continue to add the 2,2-dihydroxybutyric acid to the reaction system and react for 3 hours;

[0098] S4, lowering the temperature of the reaction system to room temperature, then adding triethylamine and quaternized carboxymethyl chitosan, and stirring at 400 rpm for 50 min for neutralization to obtain a polyurethane prepolymer;

[0099] S5. Add deionized water to the polyurethane prepolymer in S4 and stir at a speed of 2000 rpm for 3 hours for emulsification to obtain the bio-based polyurethane emulsion.

[0100] Furthermore, the preparation method of the polyurethane microfiber synthetic leather includes: stirring the bio-based polyurethane emulsion and the modified two-dimensional nanomaterial dispersion at room temperature for 2 hours to obtain a composite solution, then soaking the microfiber base cloth in the composite solution, and then drying it, repeating the operation until the dry weight gain value of the microfiber base cloth reaches 18%, then washing it with deionized water until the washing liquid is neutral, and hot pressing it at 90°C and 8 MPa pressure for 10 minutes to obtain the polyurethane microfiber synthetic leather.

[0101] For other steps, refer to Example 1.

[0102] Comparative Example 1

[0103] The difference from Example 1 is that the surfactant 3-aminopropyltriethoxysilane is not added during the treatment of the modified two-dimensional nanomaterial. The other steps refer to Example 1.

[0104] Comparative Example 2

[0105] The difference from Example 1 is that in the process of modifying the two-dimensional nanomaterial, the surfactant 3-aminopropyltriethoxysilane is replaced by dopamine, and the other steps refer to Example 1.

[0106] Comparative Example 3

[0107] Different from Example 1, polyphenol is not added in the preparation method of the modified two-dimensional nanomaterial, and other steps refer to Example 1.

[0108] Comparative Example 4

[0109] The difference from Example 1 is that no modified two-dimensional nanomaterial is added to the bio-based polyurethane emulsion component, and the other steps refer to Example 1.

[0110] Comparative Example 5

[0111] The difference from Example 1 is that quaternized carboxymethyl chitosan is not added to the bio-based polyurethane emulsion component, and the other steps are the same as those of Example 1.

[0112] Performance Testing

[0113] Antibacterial performance test

[0114] Refer to QB / T4341-2012, "Test Methods and Antimicrobial Effects of Antimicrobial Polyurethane Synthetic Leather." The test method is to evenly apply or drip the prepared inoculum solution onto the surface of the specimen, ensuring full contact between the solution and the surface. After the specified incubation time, calculate the antimicrobial rate of the specimen. The test bacteria are Staphylococcus aureus and Escherichia coli.

[0115] Moisture permeability test

[0116] Refer to GB / T12704.1-2009 "Test method for water vapor permeability of textile fabrics - Part 1: Moisture absorption method". Test method: Place a water vapor permeability cup filled with desiccant and sealed with a fabric sample in a sealed environment at specified temperature and humidity. Calculate the sample's water vapor permeability, moisture permeability and water vapor permeability coefficient based on the change in the cup's mass over a certain period of time.

[0117] Hydrolysis resistance test

[0118] Refer to QB / T5754-2022 "Water-based / Solvent-free Polyurethane Composite Artificial Leather" light industry standard and conduct tests.

[0119] Mechanical properties testing

[0120] The tensile breaking properties of the samples were tested with reference to GB / T24218.3-2010 “Test methods for textiles and nonwoven materials - Part 3: Determination of breaking strength and elongation at break (strip method)”.

[0121] Table 1 Test results analysis table

[0122] From the comparative results in Table 1 above, it can be seen that the bio-based polyurethane synthetic leather prepared in the embodiments of the present invention exhibits excellent moisture permeability, hydrolysis resistance, antibacterial properties and mechanical properties.

[0123] The present invention provides a moisture-permeable, hydrolysis-resistant, and antibacterial polyurethane synthetic leather and its applications. Specifically, castor oil-derived polyols are used as bio-based polyols, and isophorone diisocyanate is used as the polyisocyanate. The isophorone diisocyanate forms covalent crosslinks with tannic acid, while secondary crosslinks are formed with quaternized carboxymethyl chitosan via hydrogen bonds. The quaternized carboxymethyl chitosan provides moisture supply channels, resulting in a moisture permeability of up to 2280 g / m² / 24h. The quaternized carboxymethyl chitosan is biodegradable and not only provides moisture supply channels but also provides antibacterial properties. Furthermore, a three-dimensional crosslinked network is constructed by introducing tannic acid and quaternized carboxymethyl chitosan. The reducing properties of tannic acid inhibit bacterial and fungal growth, resulting in antibacterial activity and imparting antibacterial properties to the polyurethane. Through innovative molecular structure design and functional modification processes, the present invention achieves synergistic optimization of three key properties: moisture permeability, hydrolysis resistance, and antibacterial properties.

[0124] While the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather, characterized by: The polyurethane synthetic leather is polyurethane microfiber synthetic leather; the polyurethane microfiber synthetic leather comprises a microfiber base fabric and a synthetic leather surface layer; The preparation method of the polyurethane microfiber synthetic leather comprises the following steps: dipping the microfiber base cloth into a bio-based polyurethane emulsion, drying, washing, and hot pressing after dipping, and obtaining a synthetic leather surface layer on the microfiber base cloth to obtain the polyurethane microfiber synthetic leather.

2. The moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to claim 1, characterized in that: The bio-based polyurethane emulsion comprises the following raw material components in parts by weight: 40-50 parts of isophorone diisocyanate; 48-60 parts of castor oil; 5-9 parts of modified two-dimensional nanomaterials; 0.1-0.5 parts of dibutyltin dilaurate; 11-14 parts of 2,2-dihydroxybutyric acid; 8-10 parts of triethylamine; 5-8 parts of quaternized carboxymethyl chitosan; The balance was acetone.

3. The moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to claim 2, characterized in that: The modified two-dimensional nanomaterial is obtained by modifying the two-dimensional nanomaterial through polyphenol.

4. The moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to claim 3, characterized in that: The polyphenol is tannic acid, and the two-dimensional nanomaterial is one of lithium algae, zirconium phosphate, and MXene.

5. The moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to claim 2, characterized in that: The preparation method of the quaternized carboxymethyl chitosan comprises: A1. Dissolve chitosan in 2-4% acetic acid solution, add chloroacetic acid at 60-70°C and react for 6-7 hours. Prepare carboxymethyl chitosan by mixing chitosan and chloroacetic acid in a mass ratio of (4-5):

1. A2. Glycidyl trimethylammonium chloride is configured into a solution with a pH of 8.0-8.5, and then the carboxymethyl chitosan is added thereto in a molar ratio of (1.1-1.2):1 and reacted for 11-12 hours under the following conditions to obtain the quaternized carboxymethyl chitosan.

6. The moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to claim 1, characterized in that: The preparation method of the bio-based polyurethane emulsion comprises the following steps: S1, vacuum drying the isophorone diisocyanate and the castor oil to remove moisture; S2, dispersing the modified two-dimensional nanomaterial in the castor oil and transferring the mixture to a three-necked flask equipped with a condenser reflux apparatus, sequentially adding isophorone diisocyanate, dibutyltin dilaurate, and acetone, raising the temperature to 80-90° C., and stirring the mixture at 300-500 rpm in an inert gas atmosphere for 2-3 hours; S3, continue to add the 2,2-dihydroxybutyric acid to the reaction system and react for 2-3 hours; S4, lowering the temperature of the reaction system to room temperature, then adding triethylamine and quaternized carboxymethyl chitosan, and stirring at 200-400 rpm for 45-50 min for neutralization to obtain a polyurethane prepolymer; S5. Add deionized water to the polyurethane prepolymer in S4 and stir at a speed of 1500-2000 rpm for 2-3 hours for emulsification to obtain the bio-based polyurethane emulsion.

7. The moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to claim 2, characterized in that: The preparation method of the polyurethane microfiber synthetic leather comprises: stirring the bio-based polyurethane emulsion and the modified two-dimensional nanomaterial dispersion at room temperature for 1 to 2 hours to obtain a composite solution; then, soaking a microfiber-based cloth in the composite solution, drying, and repeating the operation until the dry weight gain value of the microfiber-based cloth is 15 to 18%; then, washing with deionized water until the washing liquid is neutral; and hot pressing at 80 to 90° C. and a pressure of 5 to 8 MPa for 5 to 10 minutes to obtain the polyurethane microfiber synthetic leather.

8. Use of the moisture-permeable, hydrolysis-resistant and antibacterial polyurethane synthetic leather according to any one of claims 1 to 7 in the preparation of shoe upper materials.

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