Polyether and polyamide block copolymer nanofiber air filter material and method of making

Abstract

The application discloses a kind of polyether and polyamide block copolymer nanofiber air filter material method. The precursor spinning solution is obtained by mixing suitable proportion of Pebax raw material and alcohol solvent, and the block copolymer nanofiber is prepared by using electrostatic spinning device. Under the premise of not having charge, it has good air filtration performance. The advantages of the application are that Pebax itself has good chemical corrosion resistance, excellent mechanical properties, antistatic property and high and low temperature adaptability, and the volatilization of alcohol solvent in the spinning process does not charge the nanofiber, and the obtained Pebax nanofiber can play a stable air filtration role in high temperature and high humidity acidic environment.

Description

Technical Field

[0001] This invention belongs to the field of air filtration, specifically relating to a method for preparing block copolymer nanofiber filter materials based on electrospinning. Background Technology

[0002] Industrial production and daily life have led to severe air pollution, primarily composed of suspended particulate matter, which has had a significant impact on human health and social activities. For example, exhaust gases from various industrial and mining enterprises and power plants contain not only respirable particulate matter (PM2.5) with a diameter of 2.5 μm or less, but also... 2.5 Air pollution is primarily caused by suspended particulate matter, accompanied by acidic gases such as H2S, SO2, NOx, HCl, and CO2, resulting in persistent atmospheric pollution. Existing filter materials often do not simultaneously possess good filtration performance, high and low temperature resistance, and corrosion resistance. Furthermore, in certain special environments, the generation and presence of static electricity can increase the likelihood of fire. Therefore, developing a highly efficient air filter material that can withstand harsh environments and does not generate static electricity is of significant practical importance in air filtration.

[0003] Polyether block amide elastomers are block copolymers made from polyether and polyamide blocks. Among them, Pebax, produced by Arkema in France, has excellent properties such as ultra-light density, excellent antistatic properties, outstanding breathability, chemical corrosion resistance, low-temperature impact resistance, and certain high-temperature resistance. Moreover, the raw materials used in its manufacture contain bio-based polyamide blocks, making it a partially renewable material. It is widely used in high-performance sports materials, biocompatible catheter stents, waterproof and breathable membranes, and subsea oil pipelines.

[0004] Electrospinning technology generates micron- or even nano-sized polymer fibers by charging a polymer solution, stretching and deforming the jet, and then cooling it after solvent evaporation. Electrospun nanofibers have a large specific surface area, high porosity, and easily controllable structure. Moreover, the interconnected channels formed by continuous electrospun nanofibers facilitate the passage of air molecules, greatly reducing energy loss during the filtration process, making them excellent air filtration materials.

[0005] Therefore, the Pebax nanofiber air filter material prepared by electrospinning has the good physicochemical properties of Pebax, such as high temperature resistance and acid and alkali resistance. At the same time, by utilizing the material structure of fine nanofiber diameter and alternating beaded fibers, it achieves excellent air filtration performance and has potential application value. Summary of the Invention

[0006] The purpose of this invention is to provide a copolymer nanofiber air filter material composed of polyether and polyamide blocks. This method allows for the continuous and stable preparation of Pebax nanofibers, maintaining not only Pebax's antistatic properties, chemical resistance, low-temperature impact resistance, and high-temperature resistance, but also allowing for control of the Pebax fiber diameter and morphology by adjusting spinning parameters and ambient temperature and humidity, thus constructing a highly efficient and low-resistance air filtration structure. Therefore, the nanofiber material prepared using the method provided by this invention exhibits great application potential in the field of air filtration in extreme environments.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] (1) Prepare a volume-mass fraction of Pebax (block polyether amide elastomer) solution and stir magnetically at 40-80℃ until completely dissolved;

[0009] (2) Add a certain amount of nonionic surfactant to the solution in step (1) and stir until completely dissolved;

[0010] (3) Transfer the solution in step (2) to the syringe and fix it to the push pump. Use an electrospinning device to spin the solution. Place the nonwoven PP nonwoven fabric on the receiving roller and deposit Pebax nanofibers on its surface.

[0011] (4) Place the sample obtained in step (3) at room temperature to remove excess solvent and obtain Pebax nanofiber filter material.

[0012] In some embodiments of the present invention, the Pebax polymer in step (1) may be one of Pebax2533, Pebax3533, and Pebax1657.

[0013] In some embodiments of the present invention, the mass volume fraction of Pebax in step (1) is 5%-20%. When the Pebax content or proportion is low, the fiber diameter is small, exhibiting a spider web-like connection, with more beads, which is beneficial to improving the air filtration efficiency of the material. When the Pebax content or proportion is high, the fiber diameter is large, the beads are reduced, and the filtration resistance is low.

[0014] In some embodiments of the present invention, the solvent in step (1) is one or more of isopropanol, n-butanol, and isobutanol.

[0015] In some embodiments of the present invention, the nonionic surfactant in step (2) is one of alkylphenol polyoxyethylene ether, Triton, polysorbate, sorbitan, and alkylolamide.

[0016] In some embodiments of the present invention, the nonwoven PP nonwoven fabric used in step (3) is a common nonwoven fabric with a basis weight of 30-100 g / m². 2 .

[0017] In some embodiments of the present invention, the electrospinning voltage in step (3) is controlled to be 10-25 kV, the distance between the needle and the roller is 10-20 cm, and the liquid pushing speed is 0.5-3 ml / h.

[0018] The advantages of this invention are: the Pebax nanofiber air filter material prepared by this invention has the good chemical corrosion resistance, excellent mechanical properties, antistatic properties and high and low temperature adaptability of Pebax itself, and can adapt to relatively harsh working environments.

[0019] This invention achieves continuous preparation of Pebax nanofibers by adjusting the concentration of Pebax polymer and spinning parameters, while also adjusting the diameter and morphology of the nanofibers. The prepared nanofibers have good air filtration performance.

[0020] The Pebax nanofibers prepared by this invention do not generate static electricity due to the volatilization of alcohol solvents during the spinning process and their own permanent antistatic properties. Therefore, the Pebax nanofibers obtained will not pose any potential risks due to static electricity during air filtration. Attached Figure Description

[0021] Figure 1 This is a SEM image of the block copolymer nanofibers prepared in Example 1.

[0022] Figure 2 The images show a comparison of the air filtration effects of the block copolymer nanofibers prepared in Example 1 (the left image shows the filtration effect of the nonwoven PP substrate alone; the right image shows the filtration effect after Pebax nanofiber deposition).

[0023] Figure 3 This is a pore size distribution diagram of the block copolymer nanofiber air filter material prepared in Example 1.

[0024] Figure 4 This is a SEM image of the block copolymer nanofibers prepared in Example 2. Detailed Implementation

[0025] To more clearly illustrate the specific technical solution of the present invention, the following examples further illustrate the method for preparing block copolymer nanofiber air filter materials.

[0026] Example 1

[0027] 2.4 g of Pebax raw material was dissolved in 20 ml of n-butanol solution to prepare a 12 wt% precursor spinning solution. 0.3 ml of Triton surfactant was added, and the solution was then stirred at 80°C for 5 hours in a water bath. After standing at room temperature until the spinning solution was completely homogeneous, the solution was injected into a 10 mL syringe and fixed to a syringe pump. Smooth copper foil was then pressed tightly against a roller, and a weight of 50 g / m² was applied. 2 PP nonwoven fabric was fixed on copper foil to serve as a collection device. The electrospinning process parameters were 15 kV, receiving distance of 15 cm, and spinning time of 180 min. The prepared composite nanofiber membrane was dried at room temperature for 24 h to remove excess solvent.

[0028] The Pebax nanofibers prepared in Example 1 have a diameter of approximately 120 nm and exhibit a small amount of beaded structure. Figure 1 SEM image of the block copolymer nanofibers prepared in Example 1; Figure 2 This is a comparison chart of the air filtration effects of the block copolymer nanofibers prepared in Example 1; at an air velocity of 32 L / min, the effect on PM2.5... 2.5 The effective filtration efficiency was 98.39%, and the filtration resistance was 100 Pa. Surface potential testing showed that the Pebax nanofibers prepared in Example 1 had a surface potential of 0.

[0029] Example 2

[0030] Weigh 1.2 g of Pebax raw material and dissolve it in 20 ml of isopropanol solution to prepare a 6 wt% precursor spinning solution. Then, place the solution on a water bath stirrer and stir at 60°C for 3 hours. After standing at room temperature until the spinning solution is completely mixed, inject it into a 10 mL syringe and fix it to the syringe pump. Place a smooth copper foil tightly against the roller and apply a weight of 50 g / m². 2 PP nonwoven fabric was fixed on copper foil to serve as a collection device. The electrospinning process parameters were 10 kV, receiving distance of 10 cm, and spinning time of 100 min. The prepared composite nanofiber membrane was dried at room temperature for 24 h to remove excess solvent.

[0031] The Pebax nanofibers prepared in Example 2 have a diameter of approximately 60 nm. At a wind speed of 32 L / min, they effectively inhibit PM2.5 buildup. 2.5 The effective filtration efficiency is 83.4%, and the filtration resistance is 30 Pa.

[0032] Example 3

[0033] Weigh 3.7 g of Pebax raw material and dissolve it in 20 ml of n-butanol solution to prepare a precursor spinning solution with a mass / volume fraction of 18.5 wt%. Add 0.5 ml of Triton surfactant, then place the solution on a water bath stirrer and stir at 80°C for 5 hours. Let it stand at room temperature until the spinning solution is completely mixed. Inject the solution into a 10 mL syringe and fix it to the syringe pump. Place a smooth copper foil tightly against the roller and apply a weight of 50 g / m². 2 PP nonwoven fabric was fixed on copper foil to serve as a collection device. The electrospinning process parameters were 20 kV, receiving distance of 15 cm, and spinning time of 180 min. The prepared composite nanofiber membrane was dried at room temperature for 24 h to remove excess solvent.

[0034] The Pebax nanofibers prepared in Example 3 have a diameter of approximately 300 nm. At a wind speed of 32 L / min, they effectively control PM2.5. 2.5 The effective filtration efficiency is 94.47%, and the filtration resistance is 233 Pa.

Claims

1. A method for preparing a copolymer nanofiber air filter material of polyether and polyamide blocks, characterized in that... The specific preparation steps are as follows: (1) Prepare a block polyether amide elastomer solution and stir it magnetically at 40-80℃ until it is completely dissolved. The block polyether amide elastomer has a mass volume fraction of 5%-20%, and the organic solvent used in the block polyether amide elastomer solution is one or more of isopropanol, n-butanol, and isobutanol. (2) Add a certain amount of nonionic surfactant to the solution in step (1) and stir until completely dissolved; (3) Transfer the solution in step (2) to the syringe and fix it to the push pump. Use an electrospinning device to spin the solution. Place the nonwoven PP nonwoven fabric on the receiving roller and deposit block polyether amide elastomer nanofibers on its surface. (4) Place the sample obtained in step (3) at room temperature to remove excess solvent and obtain nanofiber air filter material, wherein the nanofiber air filter material has no surface charge and has a hierarchical structure of alternating nanofibers and beads.

2. The method for preparing a polyether and polyamide block copolymer nanofiber air filter material as described in claim 1, characterized in that, The block polyether amide elastomer in step (1) is one of Pebax2533, Pebax3533, and Pebax1657.

3. The method for preparing a polyether and polyamide block copolymer nanofiber air filter material as described in claim 1, characterized in that, The nonionic surfactant used in the solution of step (2) is one of alkylphenol polyoxyethylene ether, Triton, polysorbate, sorbitan, and alkylolamide.

4. The method for preparing a polyether and polyamide block copolymer nanofiber air filter material as described in claim 1, characterized in that, The nonwoven PP fabric used in step (3) is ordinary nonwoven fabric with a basis weight of 30-100 g / m². 2 .

5. The method for preparing a polyether and polyamide block copolymer nanofiber air filter material as described in claim 1, characterized in that, In step (3), the voltage of the electrospinning process is 15-25 kV, the distance between the needle and the roller is 10-20 cm, and the liquid pushing speed is 0.5-3 ml / h.

6. A nanofiber air filter material prepared by the method for preparing a copolymer nanofiber air filter material of polyether and polyamide blocks as described in any one of claims 1-5, characterized in that, The nanofiber air filter material has no surface charge and has a hierarchical structure with alternating nanofibers and beads.

7. The nanofiber air filter material as described in claim 6, characterized in that, The nanofibers in the nanofiber air filter material have a diameter of 60-300 nm.

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