Waterproof and moisture-permeable fiber membrane, and preparation method and application thereof

Abstract

This invention discloses a waterproof and breathable fiber membrane, its preparation method, and its application. The waterproof and breathable fiber membrane has a core-shell structure, and its surface is coated with a water-based hydrophobic agent. The core material of the core-shell structure is polyurethane, and the shell material is selected from at least one of polyethylene glycol, high molecular weight polyacrylamide, polyvinyl alcohol, and polyvinylpyrrolidone. The water-based hydrophobic agent is fused and adhered to the surface of the shell material. The water-based hydrophobic agent and the shell material of this invention fuse to form a highly adhesive outer layer. The hydrophobic agent molecules are tightly coated on the surface of the waterproof and breathable fiber membrane through physical adhesion, resulting in a strong bond between the hydrophobic agent and the waterproof and breathable fiber membrane, and the waterproof and breathable fiber membrane exhibits good durability, high elongation, and elasticity.

Description

Technical Field

[0001] This invention relates to the field of textile materials technology, and in particular to a waterproof and breathable fiber membrane, its preparation method, and its application. Background Technology

[0002] Waterproof and breathable membranes combine waterproof and breathable functions and are widely used in fields such as cold-weather clothing, outdoor clothing, special military uniforms, and medical protective equipment.

[0003] The relevant technology is to prepare waterproof and breathable fiber membranes using a one-step electrospinning method. However, this method has limited improvement in the hydrophobicity of PU fiber membranes, resulting in poor adhesion and durability. Alternatively, a method can be used to first obtain a hydrophilic fiber membrane through electrospinning, then coat it with a hydrophobic emulsion, and finally dry it at high temperature to obtain a waterproof and breathable membrane. This method results in defects such as high brittleness, low elongation, and poor elasticity in the fiber membrane.

[0004] Therefore, it is necessary to develop a waterproof and breathable fiber membrane with strong bonding, good durability, and excellent elongation and elasticity. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention provides a waterproof and breathable fiber membrane, which has strong bonding force, good durability, and high elongation and elasticity.

[0006] A second aspect of the present invention also provides a method for preparing a waterproof and breathable fiber membrane.

[0007] A third aspect of the present invention also provides an application of a waterproof and breathable fiber membrane.

[0008] A waterproof and breathable fiber membrane is provided according to a first aspect of the present invention, wherein the waterproof and breathable fiber membrane has a core-shell structure and the surface of the waterproof and breathable fiber membrane is coated with an aqueous hydrophobic agent;

[0009] The core material of the core-shell structure is polyurethane, and the shell material of the core-shell structure is selected from at least one of polyethylene glycol, high molecular weight polyacrylamide, polyvinyl alcohol, and polyvinylpyrrolidone; the water-based hydrophobic agent is fused and adhered to the surface of the shell material.

[0010] The waterproof and breathable fiber membrane according to embodiments of the present invention has at least the following beneficial effects:

[0011] The core layer of this invention is made of polyurethane (PU) with excellent elastic properties, forming a tough support layer. The shell layer is made of one of polyethylene glycol (PEG), high molecular weight polyacrylamide (PAM), polyvinyl alcohol (PVA), or polyvinylpyrrolidone (PVP), forming an outer hygroscopic adhesive, thus preparing nanofibers with a core-shell structure. The aqueous hydrophobic agent and shell material of this invention are fused to form a highly adhesive outer layer. The hydrophobic agent molecules are tightly coated on the surface of the waterproof and breathable fiber membrane through physical adhesion, resulting in a strong bond between the hydrophobic agent and the waterproof and breathable fiber membrane, and the waterproof and breathable fiber membrane exhibits good durability, high elongation, and elasticity.

[0012] According to some embodiments of the present invention, the aqueous hydrophobic agent is selected from at least one of paraffin-based hydrophobic agents, organosilicon-based hydrophobic agents, acrylic resins, polyester-based hydrophobic agents, and polymethyl methacrylate.

[0013] According to some embodiments of the present invention, the thickness of the waterproof and breathable fiber membrane is 15 μm to 25 μm.

[0014] According to some embodiments of the present invention, the average pore size of the waterproof and breathable fiber membrane is 0.7 μm to 1.5 μm.

[0015] The method for preparing a waterproof and breathable fiber membrane according to a second aspect embodiment of the present invention includes the following steps:

[0016] S1. Inject the core layer spinning solution into the core layer solution channel of the coaxial electrospinning device, and inject the shell layer spinning solution into the shell layer solution channel of the coaxial electrospinning device. Adjust the spinning parameters to perform coaxial electrospinning. At the same time as electrospinning, spray the aqueous hydrophobic agent solution onto the surface of the waterproof and breathable fiber membrane through a spraying device.

[0017] S2. The waterproof and breathable fiber membrane prepared in step S1 is dried to obtain the final product.

[0018] According to some embodiments of the present invention, the concentration of the core spinning solution is 12 wt.% to 16 wt.%.

[0019] According to some embodiments of the present invention, the concentration of the shell spinning solution is 10 wt.% to 27 wt.%.

[0020] According to some embodiments of the present invention, the concentration of the aqueous hydrophobic agent solution is 3 wt.% to 7 wt.%.

[0021] According to some embodiments of the present invention, the number average molecular weight of the high molecular weight polyacrylamide is 8,000,000 to 1,200,000.

[0022] According to some embodiments of the present invention, the number-average molecular weight of the polyethylene glycol is 600 to 1500.

[0023] According to some embodiments of the present invention, the number-average molecular weight of the polyvinylpyrrolidone is 45,000 to 55,000.

[0024] According to some embodiments of the present invention, the drying temperature is 20°C to 80°C.

[0025] According to some embodiments of the present invention, in step S1, the parameters of the electrospinning include:

[0026] Voltage 15kV~20kV, receiving distance 20cm~25cm, core perfusion rate 0.6mL / h~2mL / h, shell perfusion rate 1mL / h~3mL / h, temperature 37℃~43℃, relative humidity 20%~35%.

[0027] A third aspect of the present invention provides an application of the above-described waterproof and breathable fiber membrane in clothing products.

[0028] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0029] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0030] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0031] Example 1

[0032] This example provides a waterproof and breathable fiber membrane with a thickness of 15 μm and a pore size of 0.7 μm. The membrane has a core-shell structure, and its surface is coated with a water-based hydrophobic agent. The preparation method is as follows:

[0033] Preparation of core spinning solution: Polyurethane (number average molecular weight of 77,000) was dissolved in N,N-dimethylformamide to prepare a solution with a mass fraction of 12 wt%.

[0034] Preparation of shell spinning solution: Polyethylene glycol (number average molecular weight of 600) was dissolved in acetone to prepare a 10 wt% solution;

[0035] Preparation of aqueous hydrophobic agent solution: Aqueous acrylic resin (purchased from Shandong Li'ang New Material Technology Co., Ltd.) was diluted with deionized water to a certain concentration to prepare aqueous acrylic resin with a mass fraction of 5wt%.

[0036] S1. Using hydrophobic aluminum foil as the receiving substrate, the core layer spinning solution is injected into the core layer solution channel of the coaxial electrospinning device, and the shell layer spinning solution is injected into the shell layer solution channel of the coaxial electrospinning device. The spinning parameters are adjusted to perform coaxial electrospinning (electrospinning parameters are: voltage 16kV, receiving distance 22cm, core layer infusion rate 1mL / h, shell layer infusion rate 2mL / h, temperature 40℃, relative humidity 20%). At the same time as electrospinning, an aqueous hydrophobic agent solution is sprayed onto the surface of the waterproof and breathable fiber membrane through a spraying device.

[0037] S2. The waterproof and breathable fiber membrane prepared in step S1 is dried (drying at 80℃ for 40 minutes) to obtain the final product.

[0038] Example 2

[0039] This example provides a waterproof and breathable fiber membrane with a thickness of 19 μm and a pore size of 1.1 μm. The membrane has a core-shell structure, and its surface is coated with a water-based hydrophobic agent. The preparation method is as follows:

[0040] Preparation of core spinning solution: Polyurethane (number average molecular weight of 77,000) was dissolved in N,N-dimethylformamide to prepare a solution with a mass fraction of 14 wt%.

[0041] Preparation of shell spinning solution: Polyvinyl alcohol (number average molecular weight of 1200) was dissolved in dimethyl sulfoxide to prepare a solution with a mass fraction of 12 wt%.

[0042] Preparation of aqueous hydrophobic agent solution: The aqueous hydrophobic agent of organosilicon (Beijing Qifei Technology Development Co., Ltd., aqueous organosilicon hydrophobic agent F-3100) was diluted with deionized water to a certain concentration to prepare a solution with a mass fraction of 7wt%.

[0043] S1. Using hydrophobic aluminum foil as the receiving substrate, the core layer spinning solution is injected into the core layer solution channel of the coaxial electrospinning device, and the shell layer spinning solution is injected into the shell layer solution channel of the coaxial electrospinning device. The spinning parameters are adjusted to perform coaxial electrospinning (electrospinning parameters are: voltage 20kV, receiving distance 23cm, core layer injection rate 0.8mL / h, shell layer injection rate 1.5mL / h, temperature 41℃, relative humidity 30%). Simultaneously with electrospinning, an aqueous hydrophobic agent solution is sprayed onto the surface of the waterproof and breathable fiber membrane through a spraying device.

[0044] S2. The waterproof and breathable fiber membrane prepared in step S1 is dried (drying at 80℃ for 40 minutes) to obtain the final product.

[0045] Example 3

[0046] This example provides a waterproof and breathable fiber membrane with a thickness of 23 μm and a pore size of 1.4 μm. The membrane has a core-shell structure, and its surface is coated with a water-based hydrophobic agent. The preparation method is as follows:

[0047] Preparation of core spinning solution: Polyurethane (number average molecular weight of 77,000) was dissolved in N,N-dimethylformamide to prepare a solution with a mass fraction of 16 wt%.

[0048] Preparation of shell spinning solution: Polyvinylpyrrolidone (number average molecular weight of 8,000,000) was dissolved in dimethyl sulfoxide to prepare a solution with a mass fraction of 25 wt%.

[0049] Preparation of aqueous hydrophobic agent solution: The organosilicon aqueous hydrophobic agent (Beijing Qifei Technology Development Co., Ltd., aqueous organosilicon hydrophobic agent F-3100) was diluted with deionized water to a certain concentration to prepare a solution with a mass fraction of 5 wt%.

[0050] S1. Using hydrophobic aluminum foil as the receiving substrate, the core layer spinning solution is injected into the core layer solution channel of the coaxial electrospinning device, and the shell layer spinning solution is injected into the shell layer solution channel of the coaxial electrospinning device. The spinning parameters are adjusted to perform coaxial electrospinning (electrospinning parameters are: voltage 18kV, receiving distance 22cm, core layer infusion rate 1mL / h, shell layer infusion rate 3mL / h, temperature 40℃, relative humidity 35%). Simultaneously with electrospinning, an aqueous hydrophobic agent solution is sprayed onto the surface of the waterproof and breathable fiber membrane through a spraying device.

[0051] S2. The waterproof and breathable fiber membrane prepared in step S1 is dried (drying at 80℃ for 40 minutes) to obtain the final product.

[0052] Comparative Example 1

[0053] Comparative Example 1 prepared a waterproof and breathable fiber membrane. The preparation method and dosage were the same as in Example 1. The difference was that the shell spinning solution was prepared by dissolving polystyrene (molecular weight 20000) in acetone to prepare a solution with a mass fraction of 10 wt%.

[0054] Comparative Example 2

[0055] Comparative Example 2 provides a waterproof and breathable fiber membrane, which is prepared in the same way as in Example 1, except that the aqueous hydrophobic agent is distributed inside the shell layer. The method involves mixing the shell spinning solution and the aqueous hydrophobic agent solution before electrospinning.

[0056] Performance testing

[0057] The waterproof and breathable fiber membranes prepared in Examples 1-3 and Comparative Examples 1-2 were tested as follows, and the data are shown in Table 1.

[0058] Water resistance: Hydrostatic pressure, as a key indicator of waterproof performance, represents the resistance encountered by water as it passes through the fabric. This test is conducted according to the relevant testing standards of the national standard GB / T4744-1997. The specific steps are as follows: Cut three 18×18cm square sample fiber membranes from the sample fiber membrane, place them on the disc of the hydrostatic pressure tester, cover them with a black fabric, and tighten the ring to compress the fiber membrane. Set the parameter to 6000Pa / min and start the test. Stop the test when the third water droplet appears on the black fabric, record the value, replace the fiber membrane, and repeat the test. After the test is completed, take the average of the three test results, which is the hydrostatic pressure resistance value of the fiber membrane.

[0059] Moisture permeation flux: First, pour approximately 30 mL of deionized water into the permeation cup. Cut the sample fiber membrane to the same size as the permeation cup and place it on the cup (hydrophobic layer facing down). Secure it with rubber rings and washers, and fasten with nuts. After securing, set the instrument parameters: humidity 50%, constant temperature 38℃, and airflow speed 0.44 m / s. When the humidity and temperature in the constant temperature chamber reach the required levels, place the permeation cup inside. After equilibration in the chamber for 1 hour, quickly weigh the permeation cup and record the weight as m1. Immediately place it in the testing instrument for 1 hour and weigh the permeation cup again, recording the weight as m2. Finally, calculate the moisture permeation flux using the formula... Calculate the moisture flux permeable to each fiber membrane. (WVT in the formula represents the moisture flux per square meter per day, kg / m²) 2 ·d;S(m 2 The area of ​​the fiber membrane during the test is 0.00283 m². 2 Δm(g) represents the mass difference of the same fiber membrane, and t(h) represents the testing time of the fiber membrane.

[0060] Contact angle: The contact angle is the angle between a liquid surface and a solid surface at which they just come into contact. The size of the contact angle reflects the hydrophilicity or hydrophobicity of the fiber membrane. The basic steps of the contact angle test are as follows: Cut the prepared sample into 5 pieces of fiber membrane slightly smaller than a coverslip and test them 5 times. Set the contact angle meter to use the seated drop method and select the Young-Laplace equation for the test. Measure the data 5 times and calculate the average value. This average value is taken as the contact angle data of the fiber membrane of that sample.

[0061] Elongation: This test is conducted in accordance with reference standard ISO 2062-2009.

[0062] Bending strength: Bending strength refers to the maximum stress a material can withstand when it breaks under bending load or reaches a specified bending moment. This stress is the maximum normal stress during bending, measured in MPa (megapascals). It reflects the material's resistance to bending and is used to measure its bending performance. This test adopts the domestic standard GB / T 18318-2008 "Test Method for Bending Properties of Textiles". The three-point bending test is an experimental method for verifying the bending mechanical properties of metals. The specimen is placed on two support points at a certain distance. A downward load is applied to the specimen at the midpoint between the two support points. When the three contact points of the specimen form two equal moments, three-point bending occurs, and the specimen will break at the midpoint.

[0063] Table 1 Examples 1-3 and Comparative Examples 1-2

[0064]

[0065] As can be seen from the experimental data in Table 1, the waterproof and breathable fiber membranes provided in Examples 1-3 of this invention have high water resistance, high moisture permeability, high elongation, and good elasticity. Furthermore, the waterproof and breathable fiber membranes of this invention also have strong adhesion and durability; after 30 water-based cycles, the water resistance, moisture permeability, and contact angle are only slightly lower than after the initial cycle.

[0066] Comparative Examples 1 and 2 show that the prepared waterproof and breathable fiber membranes have poor water resistance, moisture permeability, elongation, and elasticity. Furthermore, the performance decline is even greater after 30 washes.

[0067] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preparing a waterproof and breathable fiber membrane, characterized in that, Includes the following steps: S1. Inject the core layer spinning solution into the core layer solution channel of the coaxial electrospinning device, inject the shell layer spinning solution into the shell layer solution channel of the coaxial electrospinning device, and adjust the spinning parameters to perform coaxial electrospinning. During electrospinning, an aqueous hydrophobic agent solution is sprayed onto the surface of the waterproof and breathable fiber membrane through a spraying device. S2. The waterproof and breathable fiber membrane prepared in step S1 is dried to obtain the final product. The waterproof and breathable fiber membrane has a core-shell structure, and the surface of the waterproof and breathable fiber membrane is coated with a water-based hydrophobic agent. The core material of the core-shell structure is polyurethane, and the shell material is selected from at least one of polyethylene glycol, high molecular weight polyacrylamide, polyvinyl alcohol, and polyvinylpyrrolidone; the aqueous hydrophobic agent is fused and adhered to the surface of the shell material. The aqueous hydrophobic agent is selected from at least one of paraffin-based hydrophobic agents, organosilicon hydrophobic agents, acrylic resins, polyester-based hydrophobic agents, and polymethyl methacrylate.

2. The method for preparing the waterproof and breathable fiber membrane according to claim 1, characterized in that, The thickness of the waterproof and breathable fiber membrane is 15μm~25μm.

3. The method for preparing the waterproof and breathable fiber membrane according to claim 1, characterized in that, The average pore size of the waterproof and breathable fiber membrane is 0.7μm~1.5μm.

4. The method for preparing the waterproof and breathable fiber membrane according to claim 1, characterized in that, The concentration of the core spinning solution is 12 wt.% to 16 wt.%.

5. The method for preparing the waterproof and breathable fiber membrane according to claim 1, characterized in that, The concentration of the shell spinning solution is 10 wt.% to 27 wt.%.

6. The method for preparing the waterproof and breathable fiber membrane according to claim 1, characterized in that, The concentration of the aqueous hydrophobic agent solution is 3 wt.% to 7 wt.%.

7. The method for preparing the waterproof and breathable fiber membrane according to claim 1, characterized in that, In step S1, the parameters of the electrospinning include: Voltage 15kV~20kV, receiving distance 20cm~25cm, core perfusion rate 0.6mL / h~2mL / h, shell perfusion rate 1mL / h~3mL / h, temperature 37℃~43℃, relative humidity 20%~35%.

8. The application of the waterproof and breathable fiber membrane prepared by the preparation method according to any one of claims 1 to 7 in clothing products.

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