A method for modifying electrospun aqueous polyurethane waterproof and moisture permeable film based on click chemistry

Abstract

This invention discloses a method for preparing an electrospun waterborne polyurethane waterproof and breathable membrane based on click chemistry modification, relating to textile material technology. The preparation method includes the following steps: (1) Preparation of electrospinning solution: waterborne polyurethane, spinning aid, and click chemistry modified polymer components A and B are dissolved in a solvent and stirred thoroughly to obtain a spinning solution, and electrospinning is performed through the electrospinning solution; (2) Preparation of electrospun waterproof and breathable membrane: the above electrospinning solution is electrospun to prepare an electrospun waterproof and breathable membrane, and then click chemistry crosslinking treatment is performed. This invention uses waterborne polyurethane as raw material to prepare an electrospun waterborne polyurethane waterproof and breathable membrane in one step, and adopts click chemistry to improve its water contact angle and hydrostatic pressure resistance. No harmful solvents or hydrophobic agents harmful to the human body are used in the electrospinning process. The water contact angle and hydrostatic pressure resistance of the click chemistry modified waterborne polyurethane nanofiber membrane are significantly increased; the whole process is short and environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of textile materials technology, and particularly relates to a method for developing a waterborne polyurethane waterproof and breathable membrane based on click chemical modification electrospun waterborne polyurethane. Background Technology

[0002] While electrospun nanofiber membranes have become one of the mainstream waterproof and breathable membranes, the electrospinning process inevitably involves the use of organic solvents. Furthermore, to improve the hydrostatic pressure of the membrane, most researchers employ fluorinated hydrophobic agents. The degradation processes of organic solvents such as DMF and THF, as well as fluorinated hydrophobic agents, produce harmful substances such as perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonate (PFOS), which can cause harm to human health and the environment. Therefore, developing a waterproof and breathable membrane that uses green solvents without fluorinated hydrophobic agents is one direction to consider for promoting green and sustainable development.

[0003] Waterborne polyurethane is a novel polyurethane system synthesized using water instead of organic solvents. It is an ideal green and environmentally friendly material, possessing advantages such as being pollution-free, safe and reliable, having excellent mechanical properties, good compatibility, and easy modification. Most waterborne polyurethanes are commonly used as adhesives, finishing agents, and surface treatment agents, but rarely as raw materials for electrospinning to prepare electrospun waterproof and breathable membranes. Click chemistry is a highly selective organic reaction that can be carried out under mild conditions to achieve the bonding of carbon heteroatoms. Click chemistry has advantages such as high yield, harmless byproducts, and wide applicability, and is widely used in many fields such as medicine, chemical synthesis, and material modification.

[0004] This patent aims to broaden the application of waterborne polyurethane in textile materials and provides a method for preparing a waterproof and breathable membrane based on click chemistry-modified electrospinning: a method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry.

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

[0007] A method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry includes the following steps:

[0008] S1. Preparation of electrospinning solution: Dissolve waterborne polyurethane, spinning aid, and click chemical modified polymer components A and B in a solvent, stir thoroughly to obtain a spinning solution, and perform electrospinning through the electrospinning solution.

[0009] S2. Preparation of electrospun waterproof and breathable membrane: The above electrospun solution is electrospun to prepare an electrospun waterproof and breathable membrane, which is then subjected to click chemical crosslinking treatment.

[0010] Preferably, in S1, the click-modified polymer A component is one or more of pentaerythritol tetra-3-mercaptopropionic acid, γ-mercaptopropyltriethoxysilane, n-octadecyl mercaptan, 1-hexadecyl mercaptan, and polydimethylsiloxane; the click-modified polymer B component is one or more of vinyl-terminated polydimethylsiloxane, tetramethyltetravinylcyclotetrasiloxane, vinyl MQ resin, and octavinyl-POSS; and the solvent is one or more of water and anhydrous ethanol.

[0011] Preferably, the click chemistry method in S2 can be one of the following: cycloaddition reaction of terminal alkyne group with azide, cycloaddition reaction of cycloalkyne group with azide, condensation reaction of non-alcohol carbonyl compound, and addition reaction of mercapto group with carbon-carbon multibond. The electrospinning process parameters in S2 are: spinning voltage 10–30 kV, solution injection rate 0.5–5 ml / h, receiving distance 10–20 cm, ambient temperature 10–30 °C, and relative humidity 20–60% RH.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] This invention uses waterborne polyurethane as raw material to prepare electrospun waterborne polyurethane waterproof and breathable membranes in a one-step electrospinning process. Click chemistry is used to improve its water contact angle and hydrostatic pressure resistance. No harmful solvents or hydrophobic agents harmful to the human body are used in the electrospinning process. The waterborne polyurethane nanofiber membrane modified by click chemistry has significantly increased water contact angle and hydrostatic pressure resistance. The entire process is short and environmentally friendly. Attached Figure Description

[0014] Figure 1 This is a flowchart illustrating the preparation process of the present invention.

[0015] Figure 2 The images show SEM images of the electrospun waterborne polyurethane waterproof and breathable membrane before and after chemical modification in this invention.

[0016] Figure 3 The values ​​represent a comparison of the water contact angle and hydrostatic pressure of the electrospun waterborne polyurethane waterproof and breathable membrane before and after modification according to this invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1:

[0019] See Figure 1 This invention discloses a method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry, comprising the following steps:

[0020] Step 1: Preparation of electrospinning solution: Add waterborne polyurethane and polyethylene oxide to deionized water and stir for 4 hours to obtain waterborne polyurethane aqueous solution. Add γ-mercaptopropyltriethoxysilane, vinyl MQ resin and 2-hydroxy-2-methylphenylacetone to anhydrous ethanol and stir. After the solution is stirred well, mix them together.

[0021] Step 2: Preparation of electrospun waterproof and breathable membrane: The above electrospinning solution was electrospun. The electrospinning process parameters were: spinning voltage 15kV, receiving distance 15cm, solution injection rate 1mL / h, ambient temperature 25℃, and relative humidity 20%; ultraviolet irradiation was carried out for 6h using mercapto-olefin click chemistry.

[0022] Compare with Example 1:

[0023] The blank control group consisted of electrospun waterborne polyurethane nanofiber membranes that had not undergone click chemical crosslinking treatment.

[0024] Experimental results:

[0025] like Figure 2 As shown, based on the samples in Example 1 and Comparative Example 1, the number of bonding nodes between the fibers in Example 1 significantly increased after UV crosslinking treatment via a mercapto-olefin click chemistry method. Figure 3 As shown, based on the samples in Example 1 and Comparative Example 1, the water contact angle and hydrostatic pressure of the electrospun waterborne polyurethane waterproof and breathable membrane of Example 1 significantly increased after being treated with ultraviolet crosslinking via mercapto-olefin click chemistry.

[0026] The above description is merely a preferred embodiment of the present invention and is only used to help understand the method and core essence of the present invention. However, the scope of protection of the present invention is not limited thereto. For those skilled in the art, within the technical scope disclosed in the present invention, any equivalent substitutions or modifications made according to the technical solution and inventive concept of the present invention should be covered within the scope of protection of the present invention. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry, characterized in that, Includes the following steps: S1. Preparation of electrospinning solution: Dissolve waterborne polyurethane, spinning aid, and click chemical modified polymer components A and B in a solvent, stir thoroughly to obtain a spinning solution, and perform electrospinning through the electrospinning solution; S2. Preparation of electrospun waterproof and breathable membrane: The above electrospun solution is electrospun to prepare an electrospun waterproof and breathable membrane, which is then subjected to click chemical crosslinking treatment.

2. A method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry, as described in claim 1, is characterized in that... In S1, the click-modified polymer A component is one or more of pentaerythritol tetra-3-mercaptopropionic acid, γ-mercaptopropyltriethoxysilane, n-octadecyl mercaptan, 1-hexadecyl mercaptan, and polydimethylsiloxane; the click-modified polymer B component is one or more of vinyl-terminated polydimethylsiloxane, tetramethyltetravinylcyclotetrasiloxane, vinyl MQ resin, and octavinyl-POSS; and the solvent is one or more of water and anhydrous ethanol.

3. A method for preparing a waterproof and breathable membrane using waterborne polyurethane as the spinning raw material and employing a one-step electrospinning method based on click chemistry, as described in claim 1, is characterized in that... The click chemistry method in S2 can be one of the following: cycloaddition reaction of terminal alkyne group with azide, cycloaddition reaction of cycloalkyne group with azide, condensation reaction of non-alcohol carbonyl compound, and addition reaction of mercapto group with carbon-carbon multibond. The electrospinning process parameters in S2 are: spinning voltage 10–30 kV, solution injection rate 0.5–5 ml / h, receiving distance 10–20 cm, ambient temperature 10–30 °C, and relative humidity 20–60% RH.

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