Process for the production of a moisture-permeable polymeric material, and products and uses thereof

Abstract

This invention relates to a method for preparing a moisture-permeable polymer material, its product, and its applications. Chitosan and resin are compounded, and the resulting slurry is dissolved in a supercritical fluid environment through wet grinding. During the jet diffusion process, the precipitated polymeric solutes can aggregate and stretch into filaments under the action of a strong electric field, finally depositing and adhering to a sintering plate to form a web, thus preparing a moisture-permeable polymer material. Due to the addition of chitosan and fumed silica and the special film-forming environment, it possesses a certain amount of micropores, thereby improving air and moisture permeability and providing antibacterial effects, making it suitable for use in clothing, home decoration, and other fields.

Description

Technical Field

[0001] This invention relates to a method for preparing a moisture-permeable polymer material, its products, and applications, belonging to the field of polymer material molding. Background Technology

[0002] Chitin is a polysaccharide found in many organisms, especially in the shells of crustaceans, hence its other name, chitosan. It is a natural macromolecule, and the monomer that makes up this macromolecule is 2-acetamido-2-deoxy-β-D-glucose; therefore, the scientific name of chitin is polyacetylglucosamine.

[0003] Chitin has many different industrial applications. It is used for water and wastewater purification, as a food additive and in pharmaceuticals to thicken and stabilize food and medicine. Chitin can also be used as a dye, in textiles, and as an adhesive. Industrial separation membranes and ion exchange resins can be made from chitin. Chitin is also used in processing paper size and strength. Chitin products, as tough and strong materials, are advantageous for use as surgical sutures. In addition, chitin has some unusual properties; it accelerates wound healing and has even become a standalone wound healing agent. There is extensive research on its applications in biomedical materials, as it possesses advantages such as good biocompatibility, non-toxicity, low cost, easy modification, and good mechanical strength. At room temperature, 100 grams of chitin powder can adsorb 200–225 grams of a 40 wt% sodium hydroxide solution, of which approximately 100 grams is water. The adsorption value of chitin is related to the concentration of the alkaline solution and the adsorption temperature. At 0 degrees Celsius, for a 20-30 wt% sodium hydroxide solution, 100 grams of chitosan powder can adsorb up to approximately 800 grams of water, of which about 600 grams are water. Chitosan has natural antibacterial properties, with a very high broad-spectrum antibacterial rate; over 90% of common bacteria cannot survive on chitosan fibers. Therefore, fabrics made from chitosan fibers, along with colored cotton or pure cotton, are particularly suitable for infant clothing and high-end men's and women's underwear. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a moisture-permeable polymer material.

[0005] Another object of the present invention is to provide a moisture-permeable polymer material product prepared by the above method.

[0006] Another object of the present invention is to provide an application of the above-mentioned product.

[0007] The objective of this invention is achieved through the following scheme: a method for preparing a moisture-permeable polymer material, comprising combining chitin and resin, dissolving them in a supercritical fluid environment after wet grinding, and then, during the jet diffusion process, agglomerating and stretching the polymeric solutes into filaments under the action of a strong electric field, which are then deposited and adhered to a sintering disk to form a web, thereby preparing a moisture-permeable polymer material, including the following steps:

[0008] (1) Ingredients: Weigh 16-33 parts of polyurethane (PU), 0.5-1.8 parts of chitin, 0.2-0.8 parts of fumed silica, and 0.5-1 parts of conditioning additives. Add them to 100 parts of N,N-dimethylformamide (DMF) and stir to disperse and dissolve. Then pour the mixture into a wet grinding equipment. The grinding media is zirconia microspheres. Grind at a speed of 1700-2000 rpm and below 3°C. When the particle size D90 of the material is ≤0.8μm, discharge the material to obtain the grinding slurry.

[0009] (2) Pour the grinding slurry into Figure 1 In reactor A, when the temperature of reactor A is raised to 80℃~120℃, valve k1 is opened, and valve k2 connecting the DMF aqueous solution tank and valve k3 between reactors A and B are closed. High-purity CO2 is pumped into reactor A through compressor C to disperse and dissolve the grinding slurry. When the pressure of reactor A reaches 7.5MPa~50MPa, the mixture is stirred at 700rpm and kept at the temperature and pressure for half an hour to allow the wet grinding slurry to dissolve into the supercritical fluid environment.

[0010] (3) Depressurization film formation: The reactor B is preheated to 80℃~120℃. The reactor A and reactor B are controlled by valve k3. The interior of reactor B is a cylindrical space with an open outlet. After the pressure and temperature of reactor A and reactor B reach the preset value and remain constant for a period of time, valve k3 between the two reactors is opened. The solution in reactor A that has been fully dissolved by supercritical CO2 enters reactor B and is sprayed at high speed into the cavity of reactor B through a metal capillary tube with an inner diameter of 50μm. Due to the sudden decrease in pressure in the cavity of reactor B, the supercritical gas expands and generates gas, which rapidly reduces the solubility of the solute and causes it to precipitate. The nozzle is connected to a high-voltage power supply, and a metal powder sintered disc with the same diameter as the inner cavity of reactor B is placed at the outlet and grounded. In this way, the high-temperature precipitated high-temperature precipitate during the spray diffusion process is effectively reduced. Under the influence of a strong electric field, the molecular solute aggregates and stretches into filaments, which then deposit and adhere to the sintering plate to form a membrane. During this process, CO2 carries most of the solvent through the sintering plate and is discharged from reactor B, serving a drying function. Throughout the depressurization film formation process, the injection flow rate is controlled by valve k3, and compressor C continuously replenishes CO2 into reactor A through valve k1, keeping the pressure drop of reactor A within 0.2 MPa and the temperature drop within 1°C. Once the slurry in reactor A is consumed, valve k2 is opened, and the high-pressure pump pumps DMF aqueous solution from the bypass pipe into the CO2 pipe, which is then carried by CO2 into reactor B to flush and solidify the membrane material. Finally, a moisture-permeable polymer material with a certain porosity and thickness is obtained on the sintering plate of reactor B.

[0011] The polyurethane is one of polyether polyurethane, polyester polyurethane, and polyester polyether polyurethane, and the additive component is a polyurethane coagulation regulator.

[0012] The pipe between valve k3 and reactor B is made of non-conductive and high-pressure resistant material; reactor B is made of non-conductive and high-temperature resistant material, and the inner cavity length of reactor B is 100mm~300mm, which can be customized.

[0013] The metal powder sintering disk can block most particles with a diameter of not less than 50 nm from passing through.

[0014] The mass fraction of DMF in the bypass aqueous solution is 8%~25%.

[0015] The high-purity carbon dioxide is required to have a purity of ≥99.9%.

[0016] This invention provides a moisture-permeable polymer material prepared according to any of the methods described above. The obtained moisture-permeable polymer material has a certain amount of micropores due to the addition of chitin and fumed silica and a special film-forming environment, which improves air and moisture permeability and has antibacterial effect.

[0017] This invention provides an application of a breathable polymer material in the fields of clothing and home decoration.

[0018] Due to the addition of chitin and fumed silica and the special film-forming environment, it has a certain amount of micropores, which improves air and moisture permeability and has antibacterial effect, making it suitable for use in clothing, home decoration and other fields. Attached Figure Description

[0019] Figure 1 Schematic diagram of the preparation process of moisture-permeable polymer materials;

[0020] Explanation of the labels in the diagram:

[0021] C – Compressor;

[0022] Valve k1; Valve k2; Valve k3;

[0023] 2—DMF aqueous solution; 21—High-pressure unidirectional pump;

[0024] Reactor A; 31—Stirring shaft;

[0025] Reactor B; 41—Metal nozzle; 42—Metal powder sintering plate. Detailed Implementation

[0026] The present invention is further illustrated by the following embodiments, but the present invention is not limited to the specific content of the following embodiments.

[0027] Example 1

[0028] A moisture-permeable polymer material is prepared by combining chitin and resin, which are then dissolved in a supercritical fluid environment after wet grinding. During the jet diffusion process, the polymeric solute precipitated is aggregated and stretched into filaments under the action of a strong electric field, and then deposited and adhered on a sintering disk to form a web, thus producing a moisture-permeable polymer material. The preparation steps are as follows:

[0029] (1) Ingredients: Weigh 160g of polyether polyurethane, 5g of chitin, 2g of fumed silica, and 5g of conditioning agent, add them to 1000g of N,N-dimethylformamide (DMF), stir and disperse them thoroughly, then pour them into a wet grinding equipment. The grinding media is zirconia microspheres. The grinding speed is 1700~2000rpm, and the material temperature is controlled below 3℃ during grinding. When the particle size D90 in the material is ≤0.8μm, the material is discharged to obtain the grinding slurry.

[0030] (2) A schematic diagram of the preparation process of the moisture-permeable polymer material is shown below. Figure 1 Pour the grinding slurry into the following container: Figure 1In the reactor A shown, when the reactor A is heated to 80°C, valve k1 is opened and valve k2 connecting the DMF aqueous solution tank and valve k3 between reactors A and B are closed. High-purity CO2 is pumped into reactor A through compressor C to disperse and dissolve the grinding slurry until the pressure in reactor A reaches 45MPa. At the same time, stirring shaft 31 stirs at 700rpm and keeps the temperature and pressure maintained for half an hour, so that the wet grinding slurry is dissolved in the supercritical fluid environment.

[0031] (3) Depressurization film formation: The reactor B is preheated to 80°C. After the pressure and temperature of reactors A and B reach the preset value and remain constant for a period of time, the valve k3 between the two reactors is opened. The solution in reactor A that has been fully dissolved by supercritical CO2 enters reactor B and is sprayed at high speed into the cavity of reactor B through a metal nozzle 41 with an inner diameter of 50 μm. Due to the sudden decrease in pressure in the cavity of reactor B, the supercritical gas expands and generates gas, which rapidly reduces the solubility of the solute and causes it to precipitate. The metal nozzle 41 is connected to a high-voltage power supply, and a metal powder sintering plate 42 with the same diameter as the inner cavity of reactor B is placed at the outlet and grounded. In this way, the high molecular weight solute precipitated during the spray diffusion process is aggregated and stretched into filaments under the action of a strong electric field, and then deposited and adhered to the metal powder. A membrane is formed on the sintering disc 42. During this process, CO2 carries most of the solvent through the metal powder sintering disc 42 and is discharged from the reactor B, which serves a drying function. Throughout the depressurization film formation process, the injection flow rate is controlled by valve k3, and the compressor C continuously replenishes CO2 into the reactor A through valve k1, keeping the pressure drop of the reactor A within 0.2 MPa and the temperature drop within 1°C. After the slurry in the reactor A is consumed, valve k2 is opened, and DMF aqueous solution 2 is pumped from the bypass pipe into the CO2 pipe through the high-pressure one-way pump 21 and carried into the reactor B by CO2 to flush and solidify the membrane material. Finally, a moisture-permeable polymer material sample 1 with a certain porosity and thickness is obtained on the metal powder sintering disc 42 of the reactor B.

[0032] After simple post-treatment, its moisture permeability was tested. The moisture permeability reached 1470 g / m³. 2 ·24h.

[0033] Example 2

[0034] A moisture-permeable polymer material, prepared using a process similar to that in Example 1, is prepared according to the following steps:

[0035] (1) Ingredients: Weigh 260g of polyester polyurethane, 12g of chitin, 5g of fumed silica, and 7g of conditioning additives and add them to 1000g of N,N-dimethylformamide. After stirring and dissolving thoroughly, pour the mixture into a wet grinding equipment. The grinding media is zirconia microspheres. The grinding speed is 1700~2000rpm. During the grinding process, the material temperature is controlled below 3℃. When the particle size D90 in the material is ≤0.8μm, the material is discharged to obtain the grinding slurry.

[0036] (2) Pour the grinding slurry into Figure 1 In reactor A, the temperature of reactor A is raised to 100°C. At the same time, valve k1 is opened and valves k2 and k3 are closed. High-purity CO2 is pumped into reactor A through compressor C to dissolve the aforementioned grinding slurry. The mixture is stirred at 700 rpm under a pressure of 25 MPa and kept at the temperature and pressure for half an hour to dissolve the wet grinding slurry into the supercritical fluid environment.

[0037] (3) Depressurization film formation: The reactor B is preheated to 100°C. After the pressure and temperature of reactor A and reactor B rise to the preset value and remain constant for a period of time, the valve k3 between the two reactors is opened. The solution in reactor A that has been fully dissolved by supercritical CO2 enters reactor B and is ejected at high speed through a metal nozzle 41 with an inner diameter of 50μm. Due to the sudden decrease in pressure in the cavity, the supercritical gas expands to generate gas, thereby rapidly reducing the solubility of the solute and causing it to precipitate. Metal nozzle 41 is connected to a high-voltage power supply. A metal powder sintering disk 42 with the same diameter as the inner cavity of reactor B is placed at the outlet and grounded. In this way, the polymer solute precipitated during the spray diffusion process can be aggregated and stretched into filaments under the action of a strong electric field, and then deposited and adhered on the metal powder sintering disk 42 to form a mesh film. During this process, CO2 carries most of the solvent through the metal powder sintering disk 42 and is discharged from the reactor body, playing a drying role. In the entire depressurization film formation process, the spray flow rate is controlled by valve k3. Compressor C continuously replenishes CO2 to reactor A through k1. The pressure drop of reactor A is kept within 0.2 MPa and the temperature drop is kept within 1°C. After the slurry in reactor A is consumed, valve k2 is opened, and a 18% mass fraction DMF aqueous solution 2 is pumped into the CO2 pipeline through the bypass pipeline by high-pressure one-way pump 21 and carried by CO2 into reactor B to flush and solidify the membrane material. Finally, a moisture-permeable polymer material sample 2 with a certain porosity and thickness is obtained on the metal powder sintering disk 42 of reactor B.

[0038] After simple post-treatment, its moisture permeability was tested. The moisture permeability reached 1510 g / m³. 2 ·24h.

[0039] Example 3

[0040] A moisture-permeable polymer material, prepared using a process similar to that in Example 1, is prepared according to the following steps:

[0041] (1) Ingredients: Weigh 330g of polyester polyether polyurethane, 18g of chitin, 8g of fumed silica, and 10g of conditioning additives and add them to 1000g of N,N-dimethylformamide. Stir and disperse the mixture thoroughly and then pour it into a wet grinding equipment. The grinding medium is zirconia microspheres. The grinding speed is 1700~2000rpm. During the grinding process, the material temperature is controlled below 3℃. When the particle size D90 of the material is ≤0.8μm, the material is discharged to obtain the grinding slurry.

[0042] (2) Pour the grinding slurry into Figure 1 In reactor A, the temperature is raised to 120°C. At the same time, valve k1 is opened and valves k2 and k3 are closed. High-purity CO2 is pumped into reactor A through compressor C to dissolve the grinding slurry. The mixture is stirred at 700 rpm and kept at the temperature and pressure for half an hour under a pressure of 7.5 MPa to allow the wet grinding slurry to dissolve in the supercritical fluid environment.

[0043] Depressurized film formation: Reactor B is preheated to 120℃. After the pressure and temperature of reactors A and B reach the preset values ​​and remain constant for a period of time, valve k3 between the two reactors is opened. The solution in reactor A, which has been fully dissolved in supercritical CO2, enters reactor B and is ejected at high speed through a metal nozzle with an inner diameter of 50μm. Due to the sudden decrease in pressure in the cavity, the supercritical gas expands and generates a gaseous state, thereby rapidly reducing the solubility of the solute and causing it to precipitate. The metal nozzle 41 is connected to a high-voltage power supply, and a metal powder sintering disk 42 with the same diameter as the inner cavity of reactor B is placed at the outlet and grounded. In this way, the high molecular weight solute precipitated during the jet diffusion process can be aggregated and stretched into filaments under the action of a strong electric field, and then deposited and adhered on the metal powder sintering disk 42 to form a mesh film. During this process, CO2, carrying most of the solvent, is discharged from the reactor body through the metal powder sintering plate 42, serving a drying function. Throughout the depressurization film formation process, the injection flow rate is controlled by valve k3, and compressor C continuously replenishes CO2 in reactor A through k1. The pressure drop in reactor A is maintained within 0.2 MPa, and the temperature drop is maintained within 1°C. After the slurry in reactor A is consumed, valve k2 is opened, and a 25% DMF aqueous solution 2 is pumped from the bypass pipe into the CO2 pipe through the high-pressure one-way pump 21. The CO2 carries the solution into reactor B to flush and solidify the membrane material. Finally, a moisture-permeable polymer material sample 3 with a certain porosity and thickness is obtained on the metal powder sintering plate 42 of reactor B. After simple post-treatment, its moisture permeability is tested. See Table 1 for moisture permeability: 1420 g / m³. 2 ·24h:

[0044] .

Claims

1. A method for preparing a moisture-permeable polymer material, characterized in that, Chitosan and resin are combined, wet-milled, and then dissolved in a supercritical fluid environment. During the jet diffusion process, the precipitated polymeric solutes are aggregated and stretched into filaments under the action of a strong electric field, and then deposited and adhered to a sintering disk to form a web, thus preparing a polymeric moisture-permeable material. The process includes the following steps: (1) Ingredients: Weigh 16-33 parts of polyurethane (PU), 0.5-1.8 parts of chitin, 0.2-0.8 parts of fumed silica, and 0.5-1 parts of conditioning additives. Add them to 100 parts of N,N-dimethylformamide (DMF) and stir to disperse and dissolve. Then pour the mixture into a wet grinding equipment. The grinding medium is zirconia microspheres. Grind at a speed of 1700-2000 rpm and below 3°C. When the particle size D90 of the material is ≤0.8μm, discharge the material to obtain the grinding slurry. (2) Pour the grinding slurry into reactor A. When reactor A is heated to 80℃~120℃, open valve k1 and close valve k2 connecting the DMF aqueous solution tank and valve k3 between reactors A and B. Pump high-purity CO2 into reactor A through compressor C to disperse and dissolve the grinding slurry. When the pressure of reactor A is 7.5MPa~50MPa, stir at 700rpm and keep warm and pressurized for half an hour to dissolve the wet grinding slurry into the supercritical fluid environment. (3) Depressurization film formation: The reactor B is preheated to 80℃~120℃. The reactor A and reactor B are controlled by valve k3. The interior of reactor B is a cylindrical space with an open outlet. After the pressure and temperature of reactor A and reactor B reach the preset value and remain constant for a period of time, valve k3 between the two reactors is opened. The solution in reactor A that has been fully dissolved by supercritical CO2 enters reactor B and is sprayed at high speed into the cavity of reactor B through a metal capillary tube with an inner diameter of 50μm. Due to the sudden decrease in pressure in the cavity of reactor B, the supercritical gas expands to generate gas, which rapidly reduces the solubility of the solute and causes it to precipitate. The nozzle is connected to a high-voltage power supply. A metal powder sintering plate with the same diameter as the inner cavity of reactor B is placed at the outlet and grounded. During the spray diffusion process, the high molecular weight solute precipitated is aggregated and stretched into filaments under the action of a strong electric field, and then deposited and adhered on the sintering plate to form a mesh film. During this process, CO2 The solvent is discharged from reactor B through the sintering plate, which serves as a drying process. During the entire depressurization film formation process, the injection flow rate is controlled by valve k3, and compressor C continuously supplies CO2 to reactor A through valve k1, keeping the pressure drop of reactor A within 0.2 MPa and the temperature drop within 1°C. After the slurry in reactor A is consumed, valve k2 is opened, and the high-pressure pump pumps DMF aqueous solution from the bypass pipe into the CO2 pipe, which is then carried into reactor B by CO2 to flush and solidify the membrane material. Finally, a moisture-permeable polymer material with a certain porosity and thickness is obtained on the sintering plate of reactor B. The polyurethane is one of polyether polyurethane, polyester polyurethane, and polyester polyether polyurethane, and the additive component is a polyurethane curing regulator. The pipe between valve k3 and reactor B is made of non-conductive and high-pressure resistant material; reactor B is made of non-conductive and high-temperature resistant material, and the cavity length is 100mm~300mm. The metal powder sintering disk prevents most particles with a diameter of not less than 50 nm from passing through. The mass fraction of DMF in the bypass aqueous solution is 8%~25%.

2. The method for preparing a moisture-permeable polymer material according to claim 1, characterized in that, The purity of CO2 is ≥99.9%.

3. A moisture-permeable polymer material, characterized in that, The moisture-permeable polymer material prepared according to any one of claims 1-2 has a certain amount of micropores due to the addition of chitin and fumed silica and a special film-forming environment, which improves its air and moisture permeability and has antibacterial effect.

4. The application of the moisture-permeable polymer material according to claim 3 in the fields of clothing and home decoration.

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