Polyurethane microporous moisture-permeable film and dry preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials and coatings, and discloses a polyurethane microporous moisture-permeable film and a dry preparation method thereof, the moisture permeability of the polyurethane microporous moisture-permeable film is not less than 10000 g / (m < 2 >. 24 h), the down penetration resistance is less than 5, the resistivity is less than 6.2 * 10 < 5 > omega.cm, the maximum thermal weight loss percentage w / % is less than 15.7%, and the tensile strength is not less than 45.5 MPa; the preparation method comprises the following steps: in the process of synthesizing polyurethane, firstly adding a hydroxylated fullerene epoxy compound, stirring for reaction, then adding ferulic acid, continuously stirring for reaction to obtain modified polyether polyurethane, then mixing the modified polyether polyurethane with N, N-dimethylformamide I to obtain a glue solution, coating base cloth with the glue solution, and drying to obtain the polyurethane composite material. The polyurethane microporous moisture-permeable film is obtained. The mechanical property, moisture permeability, air permeability, antistatic property, thermal stability and down-proof property of the polyurethane microporous moisture-permeable film are effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical fields of polymer materials and coating technologies, and relates to a polyurethane microporous moisture-permeable membrane and a dry preparation method thereof. Background Art

[0002] With the increasing improvement of people's living standards, consumers have higher and higher requirements for the use performance of outdoor clothing. In particular, the clothing for outdoor sports such as leisure travel must have special functions such as rainproof, windproof, heat preservation, cold resistance, and moisture permeability. The early waterproof coating processing was to coat a continuous plastic film that was impermeable to water and insoluble in water on the fabric surface. Therefore, the fabric was not breathable and did not allow sweat to pass through. Wearing a raincoat made of such fabric would make people feel stuffy, so it was mainly used for making tents, umbrellas and other products. The subsequent fabrics with the ability of wet and hot steam exchange were composed of a breathable PTFE microporous membrane and a base fabric. However, the PTFE membrane cannot be degraded, so it is easy to pollute the earth environment. The microporous moisture-permeable polyurethane membrane material refers to that the pore diameter of the polyurethane polymer microporous membrane material is between the diameters of water vapor and liquid water droplets, and does not allow liquid such as water droplets to pass through. At the same time, it can ensure that the sweat emitted by the human body freely passes through in the form of water vapor, and will not form condensation accumulation between the human body surface and the fabric, so as to truly achieve the effect of waterproof and breathable.

[0003] With the development of science and technology, the preparation method of polyurethane microporous membranes has gradually transitioned from the traditional dry film-forming method to the wet film-forming process. Although the pore size of the polyurethane microporous membranes prepared by the wet film-forming method is controllable, the wet film-forming process has problems such as a long process cycle, low efficiency, and complex operating conditions, making it difficult to achieve large-scale production. Therefore, the industry still hopes to adopt the dry film-forming method to reduce costs and achieve large-scale production of waterproof and moisture-permeable fabrics in large quantities. Moreover, fabrics with such moisture-permeability can not only meet the wearing needs of people when they are active in special working environments (such as harsh environments like severe cold, rain, snow, strong winds, deserts, etc.) (such as field operations, etc.), but also meet the requirements of people for leather clothes, shoes, bags, and various high-grade clothing fabrics in daily life, and have broad development prospects. However, there are still many defects in the existing dry film-forming methods. For example, the patent application with the publication number CN101929081A discloses a high water pressure resistance and high moisture permeability coating fabric obtained by dry coating. After calendering treatment on a base fabric that has undergone water repellency treatment, a microporous layer is then coated, and finally a protective layer is formed on the microporous layer. Although this invention improves the water pressure resistance, moisture permeability, and washing durability, the problem of air permeability still exists, and the processing technology is relatively complex. The patent application with the publication number CN103866579A discloses a breathable, waterproof, and moisture-permeable wet coating fabric, its processing method, and uses. This wet coating fabric is coated with two layers of wet microporous coatings on the fabric. Although it solves the defects of the dry coating, such as a relatively hard handfeel and easy to make noises, in fact, due to the secondary coating, the air permeability cannot be improved, and there are great limitations in the selection of different fabric processing.

[0004] Textile fabrics belong to insulating materials and generally have a very high specific resistance. Therefore, during the textile processing process, the close contact and friction between fibers and fibers or between fibers and machine parts can easily cause the transfer of surface charges on the fibers, thus generating static electricity. Static electricity is also generated during the wearing process of clothing, making the clothing more likely to adsorb dust, causing dirt, and also causing discharge phenomena between the clothing and the human body, as well as between clothing and clothing, reducing the comfort of people wearing the clothing. When the static electricity phenomenon is severe, the static voltage can reach several thousand volts, and sparks can be generated due to discharge, causing fires and serious consequences. For this reason, people have never stopped researching antistatic fabrics. The antistatic treatment of fabrics in the existing technology mainly uses composite additive antistatic agents, which are mainly composed of inorganic materials such as graphite, metals, and metal oxides. The addition amount in polyurethane materials generally needs to reach about 30% to achieve a better antistatic effect, and the addition of a large amount of antistatic agents has a greater impact on the physical properties of polyurethane materials. In addition, during the use of the antistatic agent in the material, it continuously migrates to the surface and is continuously consumed and lost. After a period of time, when the active ingredients are exhausted, its antistatic effect basically disappears. For example: The patent application with the application number CN201320187689.4 discloses an antistatic functional fabric. The antistatic functional fabric is coated with an upper antistatic coating and a lower antistatic coating on the upper and lower surfaces of the fabric base layer respectively, so that the fabric has antistatic properties. However, its antistatic coating is formed by coating with an antistatic finishing agent, so the antistatic effect is not permanent. As the antistatic coating wears, the antistatic effect is easily gradually weakened until it completely fails.

[0005] Thermal stability refers to the ability of textiles to maintain their structure and performance in a high-temperature environment. Textiles are often affected by high temperatures during use, such as ironing clothes, drying, etc. Therefore, studying the thermal stability performance of textiles is of great significance for improving the quality and service life of textiles.

[0006] As a kind of textile, the mechanical properties of fabrics have an important impact on their use effect, safety, and service life. Among many mechanical property parameters, the tensile strength of fabrics is the most basic property. The tensile strength can evaluate the tensile strength of fabrics and reflects the maximum tensile force that the fabric can withstand under external forces. Therefore, studying the mechanical properties of textiles is of great significance for improving the quality and service life of textiles.

[0007] Therefore, it is of great significance to study a polyurethane microporous moisture-permeable membrane coated on fabrics and its dry preparation method to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the problems existing in the prior art and provide a polyurethane microporous moisture-permeable membrane and its dry preparation method.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A dry preparation method of a polyurethane microporous moisture-permeable membrane, which comprises mixing a modified polyether polyurethane and N,N-dimethylformamide I (DMF) to obtain a glue solution, coating the glue solution on a PET base fabric with a coater, and after drying, removing the PET base fabric to obtain the polyurethane microporous moisture-permeable membrane;

[0011] The preparation method of the modified polyether polyurethane is as follows: during the synthesis of polyurethane, hydroxylated fullerene epoxide is first added, and after stirring and reacting, ferulic acid is added, and after continuing to stir and react, the modified polyether polyurethane is obtained.

[0012] The hydroxylated fullerene epoxide surface contains a large number of hydroxyl groups and has multiple reactive centers. The present invention utilizes the structural characteristics of the hydroxylated fullerene epoxide molecule chain rich in a large number of hydroxyl groups to prepare a hydroxylated fullerene epoxide-modified polyether polyurethane by modifying the polyether polyurethane with hydroxylated fullerene epoxide. The spherical structure of the hydroxylated fullerene epoxide can increase the crosslinking density of the polyurethane, thereby improving the thermal stability of the polyurethane film. At the same time, the hydroxylated fullerene epoxide contains many unreacted hydroxyl groups and a large number of conjugated double bonds. These hydroxyl groups will undergo thermal crosslinking when heated, and the free radicals generated during the thermal degradation of the polyurethane can react with these conjugated double bonds and be eliminated, thereby delaying the thermal degradation process of the polyurethane film and improving the thermal stability of the polyurethane film. And the large number of hydrophilic hydroxyl groups on the surface of the hydroxylated fullerene epoxide can play a bridging role for water vapor, accelerating the transmission speed of water vapor in the polyurethane film, and having better moisture permeability and air permeability than the traditional polyurethane dry coagulation film; at the same time, these polar hydroxyl groups can absorb moisture in the air to form a conductive thin film, thereby improving the conductivity of the material and contributing to the dissipation of static electricity, making the polyurethane microporous moisture-permeable membrane have excellent antistatic performance.

[0013] Ferulic acid has a broad-spectrum inhibitory effect on bacteria. It has been found that ferulic acid can inhibit pathogenic bacteria such as Shigella sonnei, Klebsiella pneumoniae, Enterobacter, Escherichia coli, Citrobacter, and Pseudomonas aeruginosa. There is currently no research report on the compounding of ferulic acid and polyurethane. In the present invention, the addition of ferulic acid during the synthesis of polyurethane can improve the antibacterial properties of the PU membrane. The modification of polyether polyurethane with hydroxylated fullerene epoxide can improve the thermal stability of the PU membrane, but cannot enhance the mechanical strength of the PU membrane; if the modification with hydroxylated fullerene epoxide is not carried out, directly adding ferulic acid to the polyether polyurethane system cannot improve the mechanical strength of the PU membrane. However, in the present invention, it was unexpectedly found that adding ferulic acid to the system of hydroxylated fullerene epoxide-modified polyether polyurethane significantly improved the mechanical strength of the polyurethane microporous moisture-permeable membrane. After analysis, this is because ferulic acid can be connected to a large number of hydroxyl groups on the surface of hydroxylated fullerene epoxide and covalently incorporated into the modified polyether polyurethane system to make the prepared PU membrane layer more compact.

[0014] As a preferred technical solution:

[0015] For the dry preparation method of a polyurethane microporous moisture-permeable membrane as described above, the drying temperature is 85 - 125 °C, and the drying time is 35 - 65 min.

[0016] For the dry preparation method of a polyurethane microporous moisture-permeable membrane as described above, the mass ratio of modified polyether polyurethane to N,N-dimethylformamide I (DMF) is 40 - 50:40 - 50.

[0017] A dry preparation method of a polyurethane microporous moisture-permeable membrane as described above. The preparation process of the modified polyether polyurethane is as follows: by weight, first, 10 - 20 parts of isopropyl glycol are subjected to vacuum dehydration treatment at 110 - 130 °C for 1 - 4 h in a reaction kettle. Then, after the temperature is lowered to 75 - 85 °C, 50 - 70 parts of isophorone diisocyanate, 10 - 20 parts of N,N-dimethylformamide II (DMF), 30 - 50 parts of 1,4-dioxane, and 3 - 6 parts of dibutyltin dilaurate are added under nitrogen protection. Then, the mixture is stirred and reacted at a stirring speed of 250 - 450 r / min for 3 - 6 h. Next, after the temperature is lowered to 50 - 65 °C, 3 - 12 parts of 1,4-butanediol are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 200 - 400 r / min for 2 - 5 h. Then, the temperature is raised to 65 - 75 °C, and 5 - 10 parts of hydroxylated fullerene epoxide are added to the reaction kettle. Then, methyl ethyl ketone is added to adjust the viscosity of the reaction system to 6000 - 9000 mPa·s. After that, the mixture is stirred and reacted at a stirring speed of 250 - 400 r / min for 2 - 5 h. Then, after the temperature is lowered to 50 - 65 °C, 0.5 - 2 parts of ferulic acid are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 350 - 500 r / min for 15 - 20 h. Finally, the product is poured into methanol, filtered, and then dried in vacuum to obtain the modified polyether polyurethane.

[0018] A dry preparation method of a polyurethane microporous moisture-permeable membrane as described above. The preparation process of the hydroxylated fullerene epoxide is as follows: by weight, first, 5 - 10 parts of fullerene epoxide and 300 - 500 parts of toluene are placed in a reaction kettle, and the mixture is stirred at a stirring speed of 200 - 300 r / min at 35 - 45 °C for 1 - 3 h. Then, after the temperature is raised to 50 - 65 °C, 50 - 80 parts of hydrogen peroxide and 25 - 50 parts of aqueous tetrabutylammonium hydroxide solution are added, and the mixture is continuously stirred at a stirring speed of 300 - 500 r / min for 10 - 20 h to obtain a two-layered mixture. The lower liquid phase is taken, and 350 - 600 parts of isopropyl alcohol, 200 - 400 parts of n-hexane, and 300 - 500 parts of anhydrous ether are added thereto. Then, the mixture is centrifuged at a centrifugal rotation speed of 7000 - 20000 r / min for 20 - 70 min to obtain a precipitate. Finally, the precipitate is washed 3 - 6 times with anhydrous ether and dried in a vacuum oven at 50 - 80 °C for 12 - 20 h to obtain the hydroxylated fullerene epoxide.

[0019] Fullerene epoxide is a hollow molecule composed entirely of carbon, with good photoactivity and chemical reactivity. Introducing the main chain or side chain of polymers into fullerene epoxide has been widely and deeply studied in recent years; a large number of hydroxyl groups in hydroxylated fullerene epoxide are randomly distributed on the surface of the carbon cage of hydroxylated fullerene epoxide, forming multiple reactive centers; moreover, hydroxylated fullerene epoxide has lower biological toxicity compared to fullerene epoxide and has good application prospects in the fields of biochemistry, medicine, and polymer material chemistry.

[0020] For the dry preparation method of a polyurethane microporous moisture-permeable membrane as described above, the glue solution further contains carboxylated collagen fibers; the mass ratio of modified polyether polyurethane to carboxylated collagen fibers is 1 - 4:2 - 5;

[0021] Collagen fiber is the main component of livestock animal skins and is one of the largest renewable animal biomass resources. Due to its excellent biodegradability and special multi-level fiber structure, it also shows great application potential in non-tanning fields; carboxyl is a typical hydrophilic acidic group. Grafting carboxyl can enhance the negative charge of collagen fibers and also increase the hydrogen bond and electrostatic attraction between collagen fibers and water molecules, enhancing the water adsorption capacity of collagen fibers;

[0022] By introducing carboxylated collagen fibers into the PU membrane system, the synergistic effect of hydroxylated fullerene epoxide and carboxylated collagen fibers can significantly improve the water vapor permeability and transmission rate of the PU membrane. The combined action of hydroxyl and carboxyl groups can significantly improve the moisture permeability of the PU moisture-permeable microporous membrane more than a single component. The synergistic effect of hydroxyl and carboxyl groups can absorb moisture in the air faster and more easily form a conductive thin film on the surface of the PU membrane, significantly improving the antistatic performance of the polyurethane microporous moisture-permeable membrane. The thermal stability of the PU membrane can be greatly improved through the synergistic effect of carboxylated collagen fibers and hydroxylated fullerene epoxide.

[0023] For the dry preparation method of a polyurethane microporous moisture-permeable membrane as described above, the preparation process of carboxylated collagen fibers is as follows: by weight, first place 3 - 7 parts of glyoxylic acid and 25 - 45 parts of deionized water in a reaction kettle, stir at a stirring speed of 200 - 450 r / min at 40 - 55 °C for 1 - 4 h, then add 15 - 25 parts of collagen fibers, continue to stir at a stirring speed of 250 - 500 r / min for 2 - 6 h, then raise the temperature to 55 - 65 °C and slowly add 0.5 - 3 parts of genipin, continue to stir at a stirring speed of 250 - 500 r / min for 2 - 6 h, then filter, then wash with distilled water 4 - 9 times, and finally dry in a vacuum oven at 60 - 80 °C for 3 - 8 h to obtain carboxylated collagen fibers;

[0024] The collagen fibers crosslinked with genipin have better thermal stability. Inside the collagen fibers, crosslinking occurs between genipin and the carboxyl groups of collagen, greatly improving the thermal stability of the collagen fibers against high-temperature degradation.

[0025] In the dry preparation method of the polyurethane microporous moisture-permeable membrane as described above, the glue solution further contains an antifoaming agent and a dispersant; the mass ratio of the modified polyether polyurethane, the antifoaming agent and the dispersant is 40-50:1-3:1-3.

[0026] The present invention also provides a polyurethane microporous moisture-permeable membrane prepared by using the preparation method described in any one of the above. The thickness of the polyurethane microporous moisture-permeable membrane is 30-35 μm, the average pore diameter is 1-3 μm, the moisture permeability is not less than 10000 g / (m 2 ·24 h), the hydrostatic pressure is not less than 8500 mm H 2 O, the anti-feather penetration property is less than 5 roots, the resistivity is lower than 6.2×10 5 Ω·cm, the maximum thermal decomposition temperature T max is not less than 335.8 °C, the maximum thermal weight loss percentage w / % is lower than 15.7%, the waterproof and moisture permeability is grade 3, and the tensile strength is not less than 45.5 MPa; among them, the average pore diameter is controlled at 1-3 μm, which can prevent light fog and water droplets from passing through but allow water vapor molecules to pass through freely, constituting a flow channel for water and air, realizing the dual functions of physical moisture removal and moisture absorption and desorption by functional groups, thereby obtaining very high waterproof and breathable performance.

[0027] Beneficial effects:

[0028] (1) By adding ferulic acid to the system of hydroxylated fullerene epoxide modified polyether polyurethane in the present invention, ferulic acid can be connected to a large number of hydroxyl groups on the surface of hydroxylated fullerene epoxide and covalently bonded to the modified polyether polyurethane system, making the prepared PU film layer more compact and significantly improving the mechanical strength of the polyurethane microporous moisture-permeable membrane.

[0029] (2) The pore diameter of the polyurethane microporous moisture-permeable membrane of the present invention is uniformly controlled at 1-3 μm, so that it can prevent light fog and water droplets from passing through but allow water vapor molecules to pass through freely, constituting a flow channel for water and air, realizing the dual functions of physical moisture removal and moisture absorption and desorption by functional groups, thereby obtaining very high waterproof and breathable performance. At the same time, due to the small and uniform pore diameter, it is easier for fluff to block the pores,

[0030] and it is difficult to drill through, so the coating has excellent anti-feather penetration effect;

[0031] (3) The spherical structure of the hydroxylated fullerene epoxide prepared by the present invention can increase the crosslinking density of the polyurethane, thereby improving the thermal stability of the polyurethane film. At the same time, the hydroxylated fullerene epoxide contains many unreacted hydroxyl groups and a large number of conjugated double bonds. These hydroxyl groups will undergo thermal crosslinking when heated, and the free radicals generated during the thermal degradation of the polyurethane can react with these conjugated double bonds and be eliminated, thereby delaying the thermal degradation process of the polyurethane film and improving the thermal stability of the polyurethane film.

[0032] (4) The large number of hydrophilic hydroxyl groups on the surface of the hydroxylated fullerene epoxide prepared by the present invention can play a bridging role for water vapor, accelerating the transmission rate of water vapor in the polyurethane film, and having better moisture permeability and air permeability than traditional polyurethane dry coagulation films; at the same time, these polar hydroxyl groups can absorb moisture in the air to form a conductive thin film, thereby improving the conductivity of the material, contributing to the dissipation of static electricity, and enabling the polyurethane microporous moisture-permeable film to have excellent antistatic performance. The method of the present invention avoids the problem that the antistatic effect gradually weakens with the increase of the use time caused by the traditional formation of an antistatic coating by coating.

[0033] (5) By introducing carboxylated collagen fibers into the PU film system in the present invention, the synergistic effect of the hydroxylated fullerene epoxide and the carboxylated collagen fibers can significantly improve the water vapor permeability and transmission rate of the PU film. The combined action of hydroxyl and carboxyl can significantly improve the moisture permeability of the PU microporous moisture-permeable film more than a single component.

[0034] (6) The collagen fibers crosslinked with genipin in the present invention have better thermal stability. Inside the collagen fibers, crosslinking occurs between genipin and collagen carboxyl, greatly improving the thermal stability of the collagen fibers during high-temperature degradation. And the crosslinked collagen fibers require more energy to break these crosslinking bonds when heated, so an obvious heat absorption peak will be generated. At the same time, the synergistic effect of the carboxylated collagen fibers and the hydroxylated fullerene epoxide can greatly improve the thermal stability of the polyurethane microporous moisture-permeable film.

[0035] (7) The present invention effectively improves the mechanical properties, waterproof, breathable, moisture-permeable, antistatic, thermal stability, and anti-down leakage properties of the polyurethane microporous film, can achieve large-scale production, and the prepared polyurethane microporous moisture-permeable film belongs to the micron level, which can replace the traditional PTFE microporous film and avoid the pollution of the F component in the PTFE microporous film material to the earth environment. Description of the Drawings

[0036] Figure 1 and Figure 2 are SEM images of the front side of the polyurethane microporous moisture-permeable film prepared in Example 1 at different magnifications;

[0037] Figure 3 The infrared spectra of ferulic acid and the modified polyether polyurethane prepared in Example 1 and Comparative Example 3; in the figure, A is ferulic acid, B is the polyether polyurethane modified by ferulic acid binding to hydroxylated fullerene epoxide in Example 1, and C is the hydroxylated fullerene epoxide modified polyether polyurethane in Comparative Example 3. Detailed implementation manners

[0038] The present invention will be further described below in conjunction with specific implementation manners. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0039] To ensure that the performance of the substances used in each example and comparative example is disclosed sufficiently, the manufacturers and grades of the substances are stated. Products of other manufacturers and grades that meet the limitations of the present invention are also feasible.

[0040] The test methods for relevant performance indicators in the following examples and comparative examples are as follows:

[0041] Moisture permeability: The polyurethane microporous moisture permeable membranes prepared in each example and each comparative example were used as specimens, and then the moisture permeability of the specimens was measured with reference to the standard of GB / T 12704.1-2009.

[0042] Hydrostatic pressure: The polyurethane microporous moisture permeable membranes prepared in each example and each comparative example were used as specimens, and the hydrostatic pressure of the specimens was measured with reference to the standard of JIS L1092-2009.

[0043] Down-proof property: The polyurethane microporous moisture permeable membranes prepared in each example and each comparative example were used as specimens, and then the down-proof property of the specimens was measured with reference to the standard of GB / T 14272-2011.

[0044] Maximum thermal decomposition temperature T max : The polyurethane microporous moisture permeable membranes prepared in each example and each comparative example were used as specimens, and then the maximum thermal decomposition temperature of the specimens was measured with reference to the standard of GB / T 31850-2015.

[0045] Maximum thermal weight loss percentage w / %: The polyurethane microporous moisture permeable membranes prepared in each example and each comparative example were used as specimens, and then the maximum thermal weight loss percentage (that is, the percentage of the mass loss of the sample in the fastest stage of the mass decrease of the sample during the entire test thermal weight loss process) of the specimens was measured with reference to the standard of GB / T 27761-2011.

[0046] Waterproof and moisture permeability: The polyurethane microporous moisture-permeable membranes prepared in each example and each comparative example were used as specimens, and then the waterproof and moisture permeability of the specimens was measured with reference to the standard of GB / T40910-2021.

[0047] Tensile strength: The polyurethane microporous moisture-permeable membranes prepared in each example and each comparative example were used as specimens, and then the tensile strength of the specimens was measured with reference to the standard of GBT1040.1-2018; among them, the tensile speed was set at 200mm / min.

[0048] Resistivity: The polyurethane microporous moisture-permeable membranes prepared in each example and each comparative example were used as specimens, and then the samples were measured with reference to the interelectrode equivalent resistance (F method) in the standard of GB / T12703-1991.

[0049] The fullerene epoxide used in each of the following examples and comparative examples was prepared in the literature (Rapid preparation of C60(OH)n and its mechanism study [J]. Chemical Journal of Chinese Universities, 1998(06):27-29. DOI: 10.3321 / j.issn:0251-0790.1998.06.030.).

[0050] Example 1

[0051] A dry preparation method of a polyurethane microporous moisture-permeable membrane comprises the following steps:

[0052] (1) Prepare hydroxylated fullerene epoxide;

[0053] By weight, first put 5 parts of fullerene epoxide and 300 parts of toluene into a reaction kettle, stir at a stirring speed of 200r / min at 35°C for 3h, then raise the temperature to 50°C and add 50 parts of hydrogen peroxide and 25 parts of an aqueous solution of tetrabutylammonium hydroxide with a concentration of 40wt%, continue to stir at a stirring speed of 300r / min for 10h to obtain a liquid mixture with upper and lower layers, take the lower liquid phase and add 350 parts of isopropanol, 200 parts of n-hexane and 300 parts of anhydrous ether thereto, then centrifuge at a centrifugal speed of 7000r / min for 20min to obtain a precipitate, and finally wash the precipitate with anhydrous ether three times and dry it in a vacuum oven at 50°C for 12h to obtain hydroxylated fullerene epoxide;

[0054] (2) Prepare modified polyether polyurethane;

[0055] By weight parts, first, 10 parts of isopropyl glycol are vacuum dehydrated at 110 °C for 1 h in a reaction kettle, then the temperature is lowered to 75 °C, and 50 parts of isophorone diisocyanate, 10 parts of N,N-dimethylformamide II, 30 parts of 1,4-dioxane and 3 parts of dibutyltin dilaurate are added under nitrogen protection. Then, the mixture is stirred and reacted at a stirring speed of 250 r / min for 3 h. After the temperature is lowered to 50 °C, 3 parts of 1,4-butanediol are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 200 r / min for 2 h. Then, the temperature is raised to 65 °C, and 5 parts of the hydroxylated fullerene epoxide prepared in step (1) are added to the reaction kettle. Methyl ethyl ketone is added to adjust the viscosity of the reaction system to 6000 mPa·s. Then, the mixture is stirred and reacted at a stirring speed of 250 r / min for 2 h. Then, the temperature is lowered to 50 °C, and 0.5 part of ferulic acid is added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 350 r / min for 15 h. Finally, the product is poured into methanol, filtered, and vacuum dried at 50 °C for 12 h to obtain the modified polyether polyurethane;

[0056] (3) The modified polyether polyurethane prepared in step (2) and N,N-dimethylformamide I are mixed to obtain a glue solution, and the glue solution is coated on a PET base fabric (manufacturer: Dongguan Chuanminyu Textile Co., Ltd., brand: XH1040GSXVFX) with a film coater. After drying, the PET base fabric is removed to obtain a polyurethane microporous moisture-permeable membrane; wherein, the drying temperature is 85 °C, the drying time is 35 min, and the mass ratio of the modified polyether polyurethane to N,N-dimethylformamide I is 40:50.

[0057] The finally prepared polyurethane microporous moisture-permeable membrane (whose SEM images are as shown in Figure 1 、 Figure 2 ) has a thickness of 30 μm, an average pore size of 3 μm, a moisture permeability of 10600 g / (m 2 ·24 h), a hydrostatic pressure of 9000 mm H 2 O, a down-proof property of 4 roots, a resistivity of 5.9×10 5 Ω·cm, a maximum thermal decomposition temperature T max of 345.3 °C, a maximum thermal weight loss percentage w / % of 14.9%, a waterproof and moisture-permeable property of grade 3, and a tensile strength of 46.8 MPa.

[0058] Comparative Example 1

[0059] A dry preparation method of a polyurethane microporous moisture-permeable membrane is basically the same as that of Example 1, except that: step (1) is not carried out, and the hydroxylated fullerene epoxide in step (2) is replaced with an equal mass of fullerene epoxide.

[0060] The moisture permeability of the finally prepared polyurethane microporous moisture-permeable membrane is 8500 g / (m 2· 24 h), the resistivity is 9.3×10 5 Ω·cm, the maximum thermal decomposition temperature T max is 302.5 °C, and the maximum percentage of thermal weight loss w / % is 17.3%.

[0061] Comparing Comparative Example 1 with Example 1, it can be seen that the moisture permeability of the polyurethane microporous moisture-permeable membrane prepared in Comparative Example 1 becomes smaller, the resistivity becomes larger, and the thermal stability decreases. This is because the surface of the hydroxylated fullerene epoxide prepared in Example 1 contains a large number of hydrophilic hydroxyl groups, which can play a bridging role for water vapor and accelerate the transfer rate of water vapor in the polyurethane microporous moisture-permeable membrane. The polyurethane microporous moisture-permeable membrane prepared with it has better moisture permeability and air permeability than the polyurethane microporous moisture-permeable membrane prepared with fullerene epoxide in Comparative Example 1. At the same time, the hydrophilic hydroxyl groups can also absorb moisture in the air to form a conductive thin film, dissipating static electricity, thereby reducing the resistivity of the polyurethane microporous moisture-permeable membrane; in addition, although the spherical structure of the fullerene epoxide used in Comparative Example 1 can also increase the crosslinking density of the polyurethane, thereby improving the thermal stability of the polyurethane membrane, the improvement amplitude is limited.

[0062] Comparative Example 2

[0063] A dry preparation method of a polyurethane microporous moisture-permeable membrane is basically the same as that of Example 1, except that: step (1) is not carried out;

[0064] In step (2), hydroxylated fullerene epoxide and ferulic acid are not added. Specifically: after adding 1,4-butanediol and the reaction is completed, the temperature is not raised and hydroxylated fullerene epoxide is not added. Methyl ethyl ketone is directly added to adjust the viscosity, and after the stirring reaction is completed, the temperature is not lowered and ferulic acid is not added. The product is directly poured into methanol for filtration, and polyether polyurethane is obtained after drying;

[0065] The modified polyether polyurethane in step (3) is replaced with the polyether polyurethane prepared in this comparative example with the same mass.

[0066] The moisture permeability of the finally prepared polyurethane microporous moisture-permeable membrane is 8400 g / (m 2 · 24 h), the resistivity is 9.2×10 5 Ω·cm, the maximum thermal decomposition temperature t max is 251.4 °C, the maximum percentage of thermal weight loss w / % is 21.5%, and the tensile strength is 34.7 MPa.

[0067] Comparing Comparative Example 2 with Example 1, it can be seen that the moisture permeability of the polyurethane microporous moisture-permeable membrane prepared in Comparative Example 2 becomes smaller, the resistivity becomes larger, the thermal stability becomes worse, and the tensile strength decreases. This is because a large number of hydrophilic hydroxyl groups on the surface of the hydroxylated fullerene epoxide prepared in Example 1 can play a bridging role for water vapor, accelerating the transfer rate of water vapor in the polyurethane membrane. Moreover, the hydrophilic hydroxyl groups can also absorb moisture in the air to form a conductive thin film to dissipate static electricity, thereby reducing the resistivity of the polyurethane microporous moisture-permeable membrane. And because the ferulic acid added can be connected to a large number of hydroxyl groups on the surface of the hydroxylated fullerene epoxide and covalently incorporated into the modified polyether polyurethane system, the prepared PU film layer becomes more compact, significantly enhancing the mechanical strength of the polyurethane microporous moisture-permeable membrane. In addition, the hydroxylated fullerene epoxide also contains many unreacted hydroxyl groups and a large number of conjugated double bonds. These hydroxyl groups will undergo thermal cross-linking when heated, and the free radicals generated during the thermal degradation of polyurethane can react with these conjugated double bonds and be eliminated, thereby delaying the thermal degradation process of the polyurethane membrane and improving the thermal stability of the polyurethane membrane.

[0068] Comparative Example 3

[0069] A dry preparation method of a polyurethane microporous moisture-permeable membrane is basically the same as that of Example 1, except that: after adjusting the viscosity of the reaction system and completing the stirring reaction in step (2), without cooling and without adding ferulic acid, the product is directly poured into methanol, filtered and dried.

[0070] The tensile strength of the finally prepared polyurethane microporous moisture-permeable membrane is 35.2 MPa.

[0071] Comparing Comparative Example 3 with Example 1, it can be seen that the tensile strength of the polyurethane microporous moisture-permeable membrane prepared in Comparative Example 3 decreases significantly. This is because the ferulic acid added in Example 1 can be connected to a large number of hydroxyl groups on the surface of the hydroxylated fullerene epoxide and covalently incorporated into the modified polyether polyurethane system, making the prepared PU film layer more compact and significantly enhancing the mechanical strength of the polyurethane microporous moisture-permeable membrane.

[0072] The modified polyether polyurethanes prepared from ferulic acid, Example 1 and Comparative Example 3 were respectively subjected to infrared spectroscopy tests, and the results are as Figure 3 shown. It can be seen from the figure that the absorption peak at 3407 cm -1 of the polyether polyurethane modified by hydroxylated fullerene epoxide is the stretching vibration of -OH. The H in its C-H structure is replaced by ferulic acid, resulting in a blue shift of the characteristic peak of -OH. The absorption peaks of ferulic acid and ferulic acid combined with the polyether polyurethane modified by hydroxylated fullerene epoxide at 1542 cm -1 and 1546 cm -1There are the same characteristic peaks everywhere, but they do not appear in the polyether polyurethane modified by hydroxylated fullerene epoxide. The new absorption band generated by ferulic acid binding to the polyether polyurethane modified by hydroxylated fullerene epoxide at 1731 cm -1 is the characteristic peak of the ester, which further proves that ferulic acid and the polyether polyurethane modified by hydroxylated fullerene epoxide form a copolymer through covalent bonds.

[0073] Example 2

[0074] A dry preparation method of a polyurethane microporous moisture permeable membrane is as follows:

[0075] (1) Prepare hydroxylated fullerene epoxide;

[0076] By weight, first place 7 parts of fullerene epoxide and 400 parts of toluene in a reaction kettle, stir at a stirring speed of 260 r / min at 40 °C for 2 h, then raise the temperature to 60 °C and add 65 parts of hydrogen peroxide and 35 parts of an aqueous solution of tetrabutylammonium hydroxide with a concentration of 40 wt%, continue to stir at a stirring speed of 400 r / min for 15 h to obtain a stratified mixture, take the lower liquid phase and add 480 parts of isopropanol, 300 parts of n-hexane and 400 parts of anhydrous ether to it, then centrifuge at a centrifugal speed of 13000 r / min for 50 min to obtain a precipitate, and finally wash the precipitate 4 times with anhydrous ether and dry it in a vacuum oven at 65 °C for 16 h to obtain hydroxylated fullerene epoxide;

[0077] (2) Prepare modified polyether polyurethane;

[0078] By weight, first subject 15 parts of isopropyl glycol to vacuum dehydration treatment at 120 °C in a reaction kettle for 3 h, then lower the temperature to 80 °C, add 60 parts of isophorone diisocyanate, 15 parts of N,N-dimethylformamide II, 40 parts of 1,4-dioxane and 4 parts of dibutyltin dilaurate under nitrogen protection, then stir and react at a stirring speed of 320 r / min for 5 h, then lower the temperature to 58 °C and add 7 parts of 1,4-butanediol to the reaction kettle, stir and react at a stirring speed of 310 r / min for 4 h, then raise the temperature to 70 °C and add 7 parts of the hydroxylated fullerene epoxide prepared in step (1) to the reaction kettle, add methyl ethyl ketone to adjust the viscosity of the reaction system to 7500 mPa·s, then stir and react at a stirring speed of 340 r / min for 4 h, then lower the temperature to 59 °C and add 1 part of ferulic acid to the reaction kettle, stir and react at a stirring speed of 420 r / min for 17 h, and finally pour the product into methanol for filtration and then vacuum dry it at 70 °C for 7 h to obtain modified polyether polyurethane;

[0079] (3) Prepare carboxylated collagen fibers;

[0080] By weight parts, first place 3 parts of glyoxylic acid and 25 parts of deionized water in a reaction kettle. At 40 °C, stir at a stirring speed of 200 r / min for 1 h. Then add 15 parts of collagen fiber (manufactured by Shanghai Jijing Biotechnology Co., Ltd., grade 9548), and continue to stir at a stirring speed of 250 r / min for 2 h. Then raise the temperature to 55 °C and slowly add 0.5 part of genipin. Continue to stir at a stirring speed of 250 r / min for 2 h. Then filter, and then wash 4 times with distilled water. Finally, dry in a vacuum oven at 60 °C for 3 h to obtain carboxylated collagen fiber;

[0081] (4) Mix the modified polyether polyurethane prepared in step (2), N,N-dimethylformamide I and the carboxylated collagen fiber prepared in step (3) to obtain a glue solution. Coat the glue solution on a PET base fabric (manufactured by Dongguan Chuanminyu Textile Co., Ltd., grade XH1040GSXVFX) with a film applicator. After drying, remove the PET base fabric to obtain a polyurethane microporous moisture-permeable membrane; among them, the drying temperature is 92 °C, the drying time is 40 min, the mass ratio of the modified polyether polyurethane to N,N-dimethylformamide I is 50:40, and the mass ratio of the modified polyether polyurethane to the carboxylated collagen fiber is 1:2.

[0082] The finally prepared polyurethane microporous moisture-permeable membrane has a thickness of 32 μm, an average pore size of 3 μm, a moisture permeability of 11000 g / (m 2 ·24 h), a hydrostatic pressure of 9600 mm H 2 O, a down-proof property of 4 roots, a resistivity of 5.8×10 5 Ω·cm, the maximum thermal decomposition temperature T max is 352.7 °C, the maximum thermal weight loss percentage w / % is 14.2%, the waterproof and moisture permeability is grade 3, and the tensile strength is 47.4 MPa.

[0083] Example 3

[0084] A dry preparation method of a polyurethane microporous moisture-permeable membrane, the steps are as follows:

[0085] (1) Prepare hydroxylated fullerene epoxide;

[0086] By weight, first place 10 parts of fullerene epoxide and 500 parts of toluene in a reaction kettle, stir at a stirring speed of 300 r / min at 45 °C for 1 h, then raise the temperature to 65 °C and add 80 parts of hydrogen peroxide and 50 parts of an aqueous solution of tetrabutylammonium hydroxide with a concentration of 40 wt%, and continue to stir at a stirring speed of 500 r / min for 20 h to obtain a liquid mixture with upper and lower layers. Take the lower liquid phase and add 600 parts of isopropanol, 400 parts of n-hexane and 500 parts of anhydrous ether thereto, and then centrifuge at a centrifugal speed of 20000 r / min for 70 min to obtain a precipitate. Finally, wash the precipitate 6 times with anhydrous ether and dry it in a vacuum oven at 80 °C for 20 h to obtain hydroxylated fullerene epoxide;

[0087] (2) Prepare modified polyether polyurethane;

[0088] By weight, first dehydrate 20 parts of isopropyl glycol in a reaction kettle under vacuum at 130 °C for 4 h, then lower the temperature to 85 °C, add 70 parts of isophorone diisocyanate, 20 parts of N,N-dimethylformamide II, 50 parts of 1,4-dioxane and 6 parts of dibutyltin dilaurate under nitrogen protection, then stir and react at a stirring speed of 450 r / min for 6 h, then lower the temperature to 65 °C and add 12 parts of 1,4-butanediol to the reaction kettle, stir and react at a stirring speed of 400 r / min for 5 h, then raise the temperature to 75 °C and add 10 parts of the hydroxylated fullerene epoxide prepared in step (1) to the reaction kettle, and then add methyl ethyl ketone to adjust the viscosity of the reaction system to 9000 mPa·s, and then stir and react at a stirring speed of 400 r / min for 5 h, then lower the temperature to 65 °C and add 2 parts of ferulic acid to the reaction kettle, stir and react at a stirring speed of 500 r / min for 20 h, and finally pour the product into methanol for filtration and then vacuum dry at 80 °C for 5 h to obtain modified polyether polyurethane;

[0089] (3) Prepare carboxylated collagen fibers;

[0090] By weight, first place 5 parts of glyoxylic acid and 31 parts of deionized water in a reaction kettle, stir at a stirring speed of 310 r / min at 48 °C for 2 h, then add 20 parts of collagen fibers (manufacturer: Shanghai Jijing Biotechnology Co., Ltd., grade: 9548), continue to stir at a stirring speed of 340 r / min for 4 h, then raise the temperature to 60 °C and slowly add 2 parts of genipin, continue to stir at a stirring speed of 340 r / min for 4 h, then filter, then wash 7 times with distilled water, and finally dry in a vacuum oven at 70 °C for 6 h to obtain carboxylated collagen fibers;

[0091] (4) The modified polyether polyurethane prepared in step (2), N,N-dimethylformamide I, the carboxylated collagen fiber prepared in step (3), Hemmingsdeqian defoamer (manufacturer: Shanghai Guangbai New Materials Co., Ltd., brand name: DAPRO AP1622) and Clariant dispersant (manufacturer: Shanghai Kaiyin Chemical Co., Ltd., brand name: Dispersogen FSE) are mixed to obtain a glue solution, and the glue solution is coated on a PET base fabric (manufacturer: Dongguan Chuanminyu Textile Co., Ltd., brand name: XH1040GSXVFX) using a film applicator. After drying, the PET base fabric is removed to obtain a polyurethane microporous moisture permeable membrane; wherein the drying temperature is 125° C., the drying time is 65 min, the mass ratio of the modified polyether polyurethane to N,N-dimethylformamide I is 45:47, the mass ratio of the modified polyether polyurethane to the carboxylated collagen fiber is 4:5, and the mass ratio of the modified polyether polyurethane, Hemmingsdeqian defoamer and Clariant dispersant is 40:1:1.

[0092] The thickness of the polyurethane microporous moisture permeable membrane was 34 μm, the average pore size was 1.5 μm, and the moisture permeability was 11800 g / (m 2 24h), hydrostatic pressure is 11500mm H 2 O, anti-drilling property is 3, resistivity is 5.5×10 5 Ω·cm, maximum thermal decomposition temperature T max It is 366.8℃, the maximum thermal weight loss percentage w / % is 12.9%, the waterproof and breathable property is level 3, and the tensile strength is 50.3MPa.

[0093] Example 4

[0094] A dry method for preparing a polyurethane microporous moisture permeable membrane, the steps are as follows:

[0095] (1) preparing hydroxylated fullerene epoxides;

[0096] By weight, first, 10 parts of fullerene epoxy compound and 47 parts of toluene are placed in a reaction kettle, stirred at 36° C. and 220 r / min for 1.5 hours, then the temperature is raised to 53° C., 55 parts of hydrogen peroxide and 45 parts of a 40wt% tetrabutylammonium hydroxide aqueous solution are added, and the stirring is continued at 330 r / min for 12 hours to obtain a mixed liquid with upper and lower layers, the lower liquid phase is taken and 550 parts of isopropanol, 360 parts of n-hexane and 330 parts of anhydrous ether are added thereto, and then centrifuged at a centrifugal speed of 9000 r / min for 30 minutes to obtain a precipitate, and finally the precipitate is washed 3 times with anhydrous ether and dried in a vacuum oven at 55° C. for 13 hours to obtain a hydroxylated fullerene epoxy compound;

[0097] (2) preparing modified polyether polyurethane;

[0098] By weight parts, first, 12 parts of isopropyl glycol are subjected to vacuum dehydration treatment at 113 °C for 2 h in a reaction kettle. Then, after the temperature is lowered to 77 °C, 65 parts of isophorone diisocyanate, 12 parts of N,N-dimethylformamide II, 33 parts of 1,4-dioxane, and 6 parts of dibutyltin dilaurate are added under nitrogen protection. Then, the mixture is stirred and reacted at a stirring speed of 270 r / min for 4 h. Then, after the temperature is lowered to 53 °C, 12 parts of 1,4-butanediol are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 230 r / min for 3 h. Then, after the temperature is raised to 67 °C, 6 parts of the hydroxylated fullerene epoxide prepared in step (1) are added to the reaction kettle, and methyl ethyl ketone is added to adjust the viscosity of the reaction system to 8800 mPa·s. Then, the mixture is stirred and reacted at a stirring speed of 280 r / min for 3 h. Then, after the temperature is lowered to 53 °C, 2 parts of ferulic acid are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 370 r / min for 16 h. Finally, the product is poured into methanol, filtered, and then vacuum dried at 55 °C for 10 h to obtain the modified polyether polyurethane;

[0099] (3) Prepare carboxylated collagen fibers;

[0100] By weight parts, first, 7 parts of glyoxylic acid and 45 parts of deionized water are placed in a reaction kettle. At 55 °C, the mixture is stirred at a stirring speed of 450 r / min for 4 h. Then, 25 parts of collagen fibers (manufactured by Shanghai Jijing Biotechnology Co., Ltd., grade 9548) are added, and the mixture is continuously stirred at a stirring speed of 500 r / min for 6 h. Then, the temperature is raised to 65 °C, and 3 parts of genipin are slowly added. The mixture is continuously stirred at a stirring speed of 500 r / min for 6 h. Then, it is filtered, and then washed 9 times with distilled water. Finally, it is dried in a vacuum oven at 80 °C for 8 h to obtain the carboxylated collagen fibers;

[0101] (4) Mix the modified polyether polyurethane prepared in step (2), N,N-dimethylformamide I, the carboxylated collagen fibers prepared in step (3), Heiminster Qian defoamer (manufactured by Shanghai Guangbai New Materials Co., Ltd., grade DAPRO AP1622), and Clariant dispersant (manufactured by Shanghai Kayin Chemical Co., Ltd., grade Dispersogen FSE) to obtain a glue solution. The glue solution is coated on a PET base fabric (manufactured by Dongguan Chuanminyu Textile Co., Ltd., grade XH1040GSXVFX) with a film applicator. After drying, the PET base fabric is removed to obtain a polyurethane microporous moisture-permeable membrane; wherein, the drying temperature is 100 °C, the drying time is 45 min, the mass ratio of the modified polyether polyurethane to N,N-dimethylformamide I is 43:50, the mass ratio of the modified polyether polyurethane to the carboxylated collagen fibers is 2:3, and the mass ratio of the modified polyether polyurethane, Heiminster Qian defoamer, and Clariant dispersant is 50:3:2.

[0102] The thickness of the finally obtained polyurethane microporous moisture-permeable membrane is 35 μm, the average pore size is 1 μm, the moisture permeability is 12200 g / (m 2 ·24 h), the hydrostatic pressure is 12000 mm H 2 O, the anti-down leakage property is 3 roots, the resistivity is 5.2×10 5 Ω·cm, the maximum thermal decomposition temperature T max is 370.6 °C, the maximum percentage of thermal weight loss w / % is 12.5%, the waterproof and moisture-permeable property is grade 3, and the tensile strength is 52.7 MPa.

[0103] Example 5

[0104] A dry preparation method of a polyurethane microporous moisture-permeable membrane, the steps are as follows:

[0105] (1) Prepare hydroxylated fullerene epoxide;

[0106] By weight, first place 9 parts of fullerene epoxide and 450 parts of toluene in a reaction kettle, stir at a stirring speed of 250 r / min at 38 °C for 2.5 h, then raise the temperature to 56 °C and add 60 parts of hydrogen peroxide and 40 parts of an aqueous solution of tetrabutylammonium hydroxide with a concentration of 40 wt%, continue to stir at a stirring speed of 360 r / min for 14 h to obtain a stratified mixture, take the lower liquid phase and add 500 parts of isopropanol, 340 parts of n-hexane and 360 parts of anhydrous ether thereto, and then centrifuge at a centrifugal speed of 11000 r / min for 40 min to obtain a precipitate. Finally, wash the precipitate 5 times with anhydrous ether and dry it in a vacuum oven at 60 °C for 15 h to obtain hydroxylated fullerene epoxide;

[0107] (2) Prepare modified polyether polyurethane;

[0108] By weight parts, first, 14 parts of isopropyl glycol are subjected to vacuum dehydration treatment at 116 °C in a reaction kettle for 3 h. Then, after the temperature is lowered to 82 °C, 56 parts of isophorone diisocyanate, 17 parts of N,N-dimethylformamide II, 36 parts of 1,4-dioxane, and 5 parts of dibutyltin dilaurate are added under nitrogen protection. Then, the mixture is stirred and reacted at a stirring speed of 300 r / min for 5 h. Next, after the temperature is lowered to 60 °C, 10 parts of 1,4-butanediol are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 260 r / min for 4 h. Then, the temperature is raised to 72 °C, and 8 parts of the hydroxylated fullerene epoxide prepared in step (1) are added to the reaction kettle. Then, methyl ethyl ketone is added to adjust the viscosity of the reaction system to 8000 mPa·s. After that, the mixture is stirred and reacted at a stirring speed of 300 r / min for 4 h. Then, after the temperature is lowered to 56 °C, 1.5 parts of ferulic acid are added to the reaction kettle, and the mixture is stirred and reacted at a stirring speed of 400 r / min for 18 h. Finally, the product is poured into methanol, filtered, and then vacuum dried at 60 °C for 8 h to obtain the modified polyether polyurethane;

[0109] (3) Prepare carboxylated collagen fibers;

[0110] By weight parts, first, 6 parts of glyoxylic acid and 40 parts of deionized water are placed in a reaction kettle. At 50 °C, the mixture is stirred at a stirring speed of 350 r / min for 3 h. Then, 17 parts of collagen fibers (manufacturer: Shanghai Jijing Biotechnology Co., Ltd., grade: 9548) are added, and the mixture is continuously stirred at a stirring speed of 400 r / min for 3 h. Then, after the temperature is raised to 58 °C, 1.5 parts of genipin are slowly added, and the mixture is continuously stirred at a stirring speed of 400 r / min for 5 h. Then, it is filtered, and then washed 8 times with distilled water. Finally, it is dried in a vacuum oven at 65 °C for 5 h to obtain carboxylated collagen fibers;

[0111] (4) Mix the modified polyether polyurethane prepared in step (2), N,N-dimethylformamide I, the carboxylated collagen fibers prepared in step (3), Heiminster Qian defoamer (manufacturer: Shanghai Guangbai New Materials Co., Ltd., grade: DAPRO AP1622), and Clariant dispersant (manufacturer: Shanghai Kayin Chemical Co., Ltd., grade: Dispersogen FSE) to obtain a glue solution. The glue solution is coated on a PET base fabric (manufacturer: Dongguan Chuanminyu Textile Co., Ltd., grade: XH1040GSXVFX) with a film applicator. After drying, the PET base fabric is removed to obtain a polyurethane microporous moisture-permeable membrane; wherein, the drying temperature is 110 °C, the drying time is 50 min, the mass ratio of the modified polyether polyurethane to N,N-dimethylformamide I is 48:43, the mass ratio of the modified polyether polyurethane to the carboxylated collagen fibers is 1:4, and the mass ratio of the modified polyether polyurethane, Heiminster Qian defoamer, and Clariant dispersant is 46:2:3.

[0112] The thickness of the finally obtained polyurethane microporous moisture-permeable membrane is 34 μm, the average pore diameter is 1.5 μm, the moisture permeability is 11600 g / (m 2 ·24 h), the hydrostatic pressure is 11000 mm H 2 O, the anti-down leakage property is 3 roots, the resistivity is 5.4×10 5 Ω·cm, the maximum thermal decomposition temperature T max is 358.4 °C, the maximum thermal weight loss percentage w / % is 13.6%, the waterproof and moisture-permeable property is grade 3, and the tensile strength is 48.9 MPa.

Claims

1. A dry method for preparing a polyurethane microporous moisture-permeable membrane, characterized in that: The modified polyether polyurethane and N,N-dimethylformamide I are mixed to obtain a glue solution, the glue solution is coated on a base fabric, and after drying, a polyurethane microporous moisture permeable membrane is obtained; The preparation method of the modified polyether polyurethane is as follows: in the process of synthesizing polyurethane, a hydroxylated fullerene epoxy compound is first added, and after stirring for reaction, ferulic acid is added, and after continuing stirring for reaction, the modified polyether polyurethane is obtained.

2. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 1, characterized in that: The drying temperature is 85-125°C, and the drying time is 35-65 minutes.

3. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 2, characterized in that: The mass ratio of the modified polyether polyurethane to N,N-dimethylformamide I is 40-50:40-50.

4. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 3, characterized in that: The preparation process of the modified polyether polyurethane is as follows: first, by weight, 10 to 20 parts of isopropylene glycol are subjected to vacuum dehydration treatment at 110 to 130° C. in a reaction kettle for 1 to 4 hours, then the temperature is reduced to 75 to 85° C., 50 to 70 parts of isophorone diisocyanate, 10 to 20 parts of N,N-dimethylformamide II, 30 to 50 parts of 1,4-dioxane and 3 to 6 parts of dibutyltin dilaurate are added under nitrogen protection, and then the reaction is stirred at a stirring speed of 250 to 450 r / min for 3 to 6 hours, and then 3 to 12 parts of 1,4-butanediol are added to the reaction kettle after the temperature is reduced to 50 to 65° C., The mixture is stirred at a stirring speed of 200 to 400 r / min for 2 to 5 hours, then the temperature is raised to 65 to 75° C., 5 to 10 parts of hydroxylated fullerene epoxy compounds are added to the reaction kettle, butanone is added to adjust the viscosity of the reaction system to 6000 to 9000 mPa·s, and then the mixture is stirred at a stirring speed of 250 to 400 r / min for 2 to 5 hours, then the temperature is lowered to 50 to 65° C., 0.5 to 2 parts of ferulic acid are added to the reaction kettle, and the mixture is stirred at a stirring speed of 350 to 500 r / min for 15 to 20 hours, and finally the product is poured into methanol, filtered, and vacuum dried to obtain a modified polyether polyurethane.

5. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 4, characterized in that: The preparation process of the hydroxylated fullerene epoxy compound is as follows: first, 5 to 10 parts of the fullerene epoxy compound and 300 to 500 parts of toluene are placed in a reaction kettle, stirred at 35 to 45° C. at a stirring speed of 200 to 300 r / min for 1 to 3 hours, then the temperature is raised to 50 to 65° C., 50 to 80 parts of hydrogen peroxide and 25 to 50 parts of tetrabutylammonium hydroxide aqueous solution are added, and the stirring speed is continued at 300 to 500 r / min. The mixture is stirred for 10 to 20 hours to obtain a mixed liquid with upper and lower layers, and the lower liquid phase is taken and 350 to 600 parts of isopropanol, 200 to 400 parts of n-hexane and 300 to 500 parts of anhydrous ether are added thereto, and then centrifuged at a centrifugal speed of 7000 to 20000 r / min for 20 to 70 minutes to obtain a precipitate, and finally the precipitate is washed 3 to 6 times with anhydrous ether and dried in a vacuum oven at 50 to 80° C. for 12 to 20 hours to obtain a hydroxylated fullerene epoxide.

6. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 5, characterized in that: The glue solution also contains carboxylated collagen fibers; the mass ratio of the modified polyether polyurethane to the carboxylated collagen fibers is 1-4:2-5.

7. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 6, characterized in that: The preparation process of carboxylated collagen fiber is as follows: first, by weight, 3 to 7 parts of glyoxylic acid and 25 to 45 parts of deionized water are placed in a reaction kettle, stirred at 40 to 55° C. at a stirring speed of 200 to 450 r / min for 1 to 4 hours, then 15 to 25 parts of collagen fiber are added, and stirring is continued at a stirring speed of 250 to 500 r / min for 2 to 6 hours, then the temperature is raised to 55 to 65° C. and 0.5 to 3 parts of genipin are slowly added, and stirring is continued at a stirring speed of 250 to 500 r / min for 2 to 6 hours, followed by filtering, and then washing with distilled water for 4 to 9 times, and finally drying in a vacuum oven at 60 to 80° C. for 3 to 8 hours to obtain carboxylated collagen fiber.

8. The dry method for preparing a polyurethane microporous moisture-permeable membrane according to claim 7, characterized in that: The adhesive solution also contains a defoamer and a dispersant; the mass ratio of the modified polyether polyurethane, the defoamer and the dispersant is 40-50:1-3:1-3.

9. A polyurethane microporous moisture permeable membrane prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The thickness of the polyurethane microporous moisture permeable membrane is 30-35 μm, the average pore size is 1-3 μm, and the moisture permeability is not less than 10000 g / (m 2 ·24h), hydrostatic pressure not less than 8500mm H2O, anti-drilling property less than 5, resistivity less than 6.2×10 5 Ω·cm, maximum thermal decomposition temperature T max Not less than 335.8℃, the maximum thermal weight loss percentage w / % is less than 15.7%, the waterproof and breathable property is level 3, and the tensile strength is not less than 45.5MPa.

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