Preparation method of PBT-RSF melt-blown-electrospun composite material

Abstract

The application discloses a preparation method of PBT-RSF melt-blown-electrostatic spinning composite material and belongs to the technical field of composite non-woven fabrics. The preparation method is composed of the following steps: preparing PBT melt-blown cloth, modifying, preparing PBT-RSF composite spinning liquid, and compounding. In the compounding, the composite spinning liquid is injected into an electrostatic spinning machine for electrostatic spinning, and the modified PBT melt-blown cloth is used for receiving, so that the PBT-RSF melt-blown-electrostatic spinning composite material is obtained after the electrostatic spinning is completed. The application can improve the strength, wear resistance, high-temperature resistance and high-humidity resistance of the prepared PBT-RSF melt-blown-electrostatic spinning composite material, avoid hair raising, reduce the filtration resistance of the PBT-RSF melt-blown-electrostatic spinning composite material, and improve the filtration efficiency and chemical resistance of the PBT-RSF melt-blown-electrostatic spinning composite material.

Description

Technical Field

[0001] This invention relates to the field of composite nonwoven fabric technology, specifically to a method for preparing a PBT-RSF meltblown-electrospun composite material. Background Technology

[0002] In medicine, blood transfusion is an effective clinical treatment and plays an irreplaceable role in modern medicine. However, blood transfusion also carries some safety risks. The human body often develops leukocyte antibodies due to the transfusion of blood or blood components containing leukocytes, leading to various transfusion reactions such as non-hemolytic fever and adult respiratory distress syndrome. It can also trigger some leukocyte-related viral infections, such as cytomegalovirus and human immunodeficiency disease. Therefore, in clinical medicine, it is necessary to remove leukocytes from the blood in order to reduce these side effects.

[0003] Currently, the internationally accepted method for removing white blood cells from blood is through filtration using blood filtration materials. These materials are typically biomedical polymers that come into direct or indirect contact with the human body to remove harmful components or substances. They hold significant promise for applications in novel medical devices such as white blood cell filters, platelet filters, and artificial kidneys (kidney dialysis machines). Meltblown nonwoven fabrics possess an ultra-fine fiber structure, which increases the surface area and porosity of the fibers, and the pores are evenly distributed. This results in high filtration efficiency, large capacity, low filtration resistance, and good chemical resistance, making nonwoven filter media an excellent blood filtration material.

[0004] Biocompatible polybutylene terephthalate (PBT)-regenerated silk fibroin (RSF) meltblown-electrospun composite material prepared by pore size gradient structure technology results in a white blood cell count far below the national standard after blood filtration, solving the problem of low filtration efficiency of traditional materials and reducing blood filtration time by half. However, when PBT is combined with RSF, RSF affects the strength and abrasion resistance of PBT, resulting in a decrease in the strength and abrasion resistance of the composite material. Moreover, since meltblown nonwoven fabric itself has problems such as low strength, poor high temperature resistance, poor high humidity resistance, and easy pilling, it not only further affects the strength of the composite material, but also reduces the high temperature resistance and high humidity resistance of the composite material and makes it prone to pilling.

[0005] To address these issues, the most common method currently is to add reinforcing fillers. However, reinforcing fillers have limited effect on improving the strength of composite materials and can also increase the filtration resistance, reduce the filtration efficiency, and decrease the chemical resistance of composite materials. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing PBT-RSF meltblown-electrospun composite materials. This method can improve the strength, abrasion resistance, high temperature resistance, and high humidity resistance of the prepared PBT-RSF meltblown-electrospun composite materials, while avoiding fuzzing, reducing the filtration resistance of the PBT-RSF meltblown-electrospun composite materials, and improving the filtration efficiency and chemical resistance of the PBT-RSF meltblown-electrospun composite materials.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a PBT-RSF meltblown-electrospun composite material comprises the following steps: preparing PBT meltblown fabric, modifying it, preparing a PBT-RSF composite spinning solution, and combining them.

[0009] The preparation of PBT meltblown fabric involves mixing reinforcing filler and PBT chips at a mass ratio of 15-18:100, followed by blending and granulation to obtain PBT mixed chips. These PBT mixed chips are then fed into a twin-screw extruder for meltblown extrusion and spinning. High-speed hot air is used for blowing, stretching the meltblown fibers to obtain meltblown microfibers. The meltblown microfibers are then subjected to negative pressure agglomeration and roller winding to obtain PBT meltblown fabric.

[0010] The temperature of the melt extrusion is 280-300℃;

[0011] The temperature of the high-speed hot airflow is 270-280℃;

[0012] The diameter of the meltblown ultrafine fiber is 2-3 μm;

[0013] The preparation method of the reinforcing filler is as follows: Calcium chloride dihydrate is added to anhydrous ethanol and stirred until completely dissolved to obtain an ethanol solution of calcium chloride dihydrate; then, the ethanol solution of calcium chloride dihydrate and ammonium bicarbonate are added to a reactor, and stirred at 180-200 rpm for 15-20 min at 2-5℃, and then allowed to stand at 40-45℃ for 20-22 h, followed by centrifugation. The centrifugation speed is controlled at 8000-10000 rpm for 8-10 min, and amorphous calcium carbonate is obtained after centrifugation; a 25-30% (w / w) aqueous solution of hydrogen peroxide, amorphous calcium carbonate, and anhydrous ethanol are added. Add the material to the reactor and stir at 100-120 rpm for 40-45 min at 40-45℃. Then centrifuge at 8000-10000 rpm for 10-12 min. After centrifugation, dry the material at 110-115℃ to obtain the primary reinforcing filler. Mix the primary reinforcing filler with the precursor sol at a mass ratio of 10:1-1.2 and freeze-dry at -40℃ to -30℃ for 7-8 h. After freeze-drying, grind the material to a particle size of 100-200 nm to obtain the reinforcing filler.

[0014] In the preparation of the reinforcing filler, the mass ratio of calcium chloride dihydrate to anhydrous ethanol in the calcium chloride dihydrate ethanol solution is 1.5-2:1000.

[0015] The mass ratio of calcium chloride dihydrate ethanol solution to ammonium bicarbonate is 100:10-12;

[0016] The mass ratio of a 25-30% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol is 30-32:0.3-0.4:9-10.

[0017] The precursor sol is prepared as follows: propionic acid and water are added to a reactor and stirred at 100-120 rpm for 45-55 min at 30-35℃. Magnesium oxide is slowly added, and the addition time is controlled at 30-40 min. After the addition is completed, stirring is continued for 40-50 min. Then, the mixture is allowed to stand at room temperature for 1.5-2 h, filtered, and the filtrate is concentrated to a viscosity of 50-52 Pa·s at 25℃ to obtain the precursor sol.

[0018] In the preparation of the precursor sol, the mass ratio of propionic acid, water, and magnesium oxide is 180-200:130-140:42-45.

[0019] The modification involves uniformly blowing cellulose short fibers onto PBT meltblown fabric using a high-speed hot air stream, controlling the temperature of the high-speed hot air stream at 220-230℃, and the mass ratio of PBT meltblown fabric to cellulose short fibers at 100:10-30. After blowing, a high-voltage electret treatment of 50,000-60,000 volts is performed to obtain the modified PBT meltblown fabric.

[0020] The method for preparing the cellulose short fibers is as follows: chitosan, water, and acetic acid are added to a reaction vessel and stirred at 180-200 rpm for 30-40 min at 60-70℃. γ-(2,3-epoxypropoxy)propyltrimethoxysilane is added dropwise at a rate of 6-8 g / min. After the addition is complete, the temperature is raised to 90-95℃ and stirred at 90-95℃ for 3-4 h. The pH is adjusted to 8-9 using a 6-8% sodium hydroxide aqueous solution to obtain a mixed solution. Cotton fibers are soaked in the mixed solution at a mass ratio of 40-45:100 and allowed to stand at 50-60℃ for 4-5 h. The cotton fibers are then removed, drained, dehydrated, dried at 110-120℃, and cut to a length of 10-20 mm to obtain cellulose short fibers.

[0021] In the preparation of the cellulose short fibers, the mass ratio of chitosan, water, acetic acid, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 8-9:60-65:1-1.1:2-2.2.

[0022] To prepare the PBT-RSF composite spinning solution, PBT chips and RSF are mixed evenly and then added to hexafluoroisopropanol and stirred until completely dissolved to obtain the composite spinning solution.

[0023] In the preparation of the PBT-RSF composite spinning solution, the mass ratio of PBT chips, RSF, and hexafluoroisopropanol is 100:20-50:800-900.

[0024] The composite process involves injecting the composite spinning solution into an electrospinning machine for electrospinning, and using modified PBT meltblown fabric as the receiver. The syringe volume is controlled at 30 mL, the needle inner diameter at 0.8-1 mm, the feed speed at 0.9-1 mL / h, the receiving distance at 12-15 cm, and the spinning voltage at 15-20 kV. After electrospinning, the PBT-RSF meltblown-electrospun composite material is obtained.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) The method for preparing the PBT-RSF meltblown-electrospun composite material of the present invention can improve the strength and wear resistance of the prepared PBT-RSF meltblown-electrospun composite material by adding reinforcing fillers to the preparation of PBT meltblown fabric. The longitudinal tensile strength of the prepared PBT-RSF meltblown-electrospun composite material is 385-394 N / 5cm, the transverse tensile strength is 275-282 N / 5cm, the longitudinal breaking strength is 42-45 N / 5cm, the transverse breaking strength is 26-29 N / 5cm, and the friction coefficient is 1.2-1.5.

[0027] (2) The preparation method of the PBT-RSF meltblown-electrospun composite material of the present invention, by modifying the prepared PBT meltblown cloth to prepare the modified PBT meltblown cloth, can improve the high temperature resistance of the prepared PBT-RSF meltblown-electrospun composite material. The prepared PBT-RSF meltblown-electrospun composite material is placed in an environment with a temperature of 50°C and a humidity of 60% for 30 days. The longitudinal tensile strength is 381-391 N / 5cm, the transverse tensile strength is 273-279 N / 5cm, the longitudinal breaking strength is 40-45 N / 5cm, and the transverse breaking strength is 24-28 N / 5cm.

[0028] (3) The preparation method of the PBT-RSF meltblown-electrospun composite material of the present invention, by modifying the prepared PBT meltblown cloth to prepare the modified PBT meltblown cloth, can improve the high humidity resistance of the prepared PBT-RSF meltblown-electrospun composite material. The prepared PBT-RSF meltblown-electrospun composite material is placed in an environment with a temperature of 20°C and a humidity of 90% for 30 days. The longitudinal tensile strength is 384-392 N / 5cm, the transverse tensile strength is 272-280 N / 5cm, the longitudinal breaking strength is 40-44 N / 5cm, and the transverse breaking strength is 24-27 N / 5cm.

[0029] (4) The method for preparing the PBT-RSF meltblown-electrospun composite material of the present invention modifies the prepared PBT meltblown fabric to prepare the modified PBT meltblown fabric, which can prevent the prepared PBT-RSF meltblown-electrospun composite material from fuzzing. After the prepared PBT-RSF meltblown-electrospun composite material is placed in an environment with a temperature of 23°C and a humidity of 60% for 100 days, there is no fuzzing.

[0030] (5) The preparation method of the PBT-RSF meltblown-electrospun composite material of the present invention, by modifying the prepared PBT meltblown cloth to produce a modified PBT meltblown cloth, can reduce the filtration resistance of the PBT-RSF meltblown-electrospun composite material and improve the filtration efficiency of the PBT-RSF meltblown-electrospun composite material. When the PBT-RSF meltblown-electrospun composite material prepared by the present invention is used to filter white blood cells in blood, the filtration resistance is 22-25 Pa and the filtration efficiency is 99.81-99.88%.

[0031] (6) The preparation method of the PBT-RSF meltblown-electrospun composite material of the present invention improves the chemical resistance of the prepared PBT-RSF meltblown-electrospun composite material by adding reinforcing fillers to the preparation of PBT meltblown fabric. The PBT-RSF meltblown-electrospun composite material prepared according to the present invention is completely immersed in a 10% hydrochloric acid aqueous solution at 23°C for 10 days. After this immersion, the longitudinal tensile strength is 378-384 N / 5 cm, and the transverse tensile strength is 271-277 N / 5 cm. The longitudinal tensile strength is 39-43 N / 5 cm, and the transverse tensile strength is 24-27 N / 5 cm. When the PBT-RSF meltblown-electrospun composite material prepared in this invention is completely immersed in a 10% sodium hydroxide aqueous solution at 23°C for 10 days, the longitudinal tensile strength is 380-391 N / 5 cm, the transverse tensile strength is 272-279 N / 5 cm, the longitudinal tensile strength is 41-44 N / 5 cm, and the transverse tensile strength is 24-28 N / 5 cm. Detailed Implementation

[0032] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0033] Example 1

[0034] A method for preparing a PBT-RSF meltblown-electrospun composite material, specifically as follows:

[0035] 1. Preparation of PBT meltblown fabric: Reinforcing filler and PBT chips are mixed at a mass ratio of 15:100 and then granulated to obtain PBT mixed chips. The PBT mixed chips are then fed into a twin-screw extruder for meltblown extrusion and spinning. High-speed hot air is used for blowing, and the meltblown fibers are stretched to obtain meltblown microfibers. The meltblown microfibers are then subjected to negative pressure coagulation and roller winding to obtain PBT meltblown fabric.

[0036] The temperature of the melt extrusion is 280°C;

[0037] The temperature of the high-speed hot airflow is 270°C;

[0038] The diameter of the meltblown ultrafine fiber is 2 μm;

[0039] The preparation method of the reinforcing filler is as follows: Calcium chloride dihydrate is added to anhydrous ethanol and stirred until completely dissolved to obtain an ethanol solution of calcium chloride dihydrate; then, the ethanol solution of calcium chloride dihydrate and ammonium bicarbonate are added to a reactor, stirred at 180 rpm for 15 min at 2°C, and then allowed to stand at 40°C for 20 h. After centrifugation, the centrifugation speed is controlled at 8000 rpm for 8 min, and amorphous calcium carbonate is obtained after centrifugation; a 25% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol are added to the reactor, stirred at 100 rpm for 40 min at 40°C, and then centrifuged at 8000 rpm for 10 min. After centrifugation, the mixture is dried at 110°C to obtain the primary reinforcing filler; the primary reinforcing filler and the precursor sol are mixed evenly at a mass ratio of 10:1, and then freeze-dried at -40°C for 7 h. After freeze-drying, the mixture is ground to a particle size of 100 nm to obtain the reinforcing filler.

[0040] In the ethanol solution of calcium chloride dihydrate, the mass ratio of calcium chloride dihydrate to anhydrous ethanol is 1.5:1000.

[0041] The mass ratio of calcium chloride dihydrate ethanol solution to ammonium bicarbonate is 100:10.

[0042] The mass ratio of 25% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol is 30:0.3:9.

[0043] The precursor sol is prepared as follows: propionic acid and water are added to a reactor and stirred at 100 rpm for 45 min at 30 °C. Magnesium oxide is slowly added over a time of 30 min. After addition, stirring is continued for 40 min. The mixture is then allowed to stand at room temperature for 1.5 h, filtered, and the filtrate is concentrated to a viscosity of 50 Pa·s at 25 °C to obtain the precursor sol.

[0044] The mass ratio of propionic acid, water, and magnesium oxide is 180:130:42.

[0045] 2. Modification: High-speed hot air is used to uniformly blow cellulose short fibers onto PBT meltblown fabric. The temperature of the high-speed hot air is controlled at 220℃. The mass ratio of PBT meltblown fabric to cellulose short fibers is 100:10. After blowing, a 50,000-volt high-voltage electret treatment is performed to obtain the modified PBT meltblown fabric.

[0046] The method for preparing the cellulose short fibers is as follows: chitosan, water, and acetic acid are added to a reaction vessel and stirred at 180 rpm for 30 min at 60°C. γ-(2,3-epoxypropoxy)propyltrimethoxysilane is added dropwise at a rate of 6 g / min. After the addition is complete, the temperature is raised to 90°C and stirred at 90°C for 3 h. The pH is adjusted to 8 using a 6% sodium hydroxide aqueous solution to obtain a mixed solution. Cotton fibers are soaked in the mixed solution at a mass ratio of 40:100 and allowed to stand at 50°C for 4 h. The cotton fibers are then removed, drained, dehydrated, dried at 110°C, and cut to a length of 10 mm to obtain cellulose short fibers.

[0047] The mass ratio of chitosan, water, acetic acid, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 8:60:1:2.

[0048] 3. Preparation of PBT-RSF composite spinning solution: PBT chips and RSF are mixed evenly and then added to hexafluoroisopropanol and stirred until completely dissolved to obtain the composite spinning solution;

[0049] The mass ratio of PBT slices, RSF, and hexafluoroisopropanol is 100:20:800.

[0050] 4. Composite: The composite spinning solution is injected into an electrospinning machine for electrospinning, and modified PBT meltblown fabric is used as the receiver. The volume of the syringe is controlled at 30mL, the inner diameter of the needle is 0.8mm, the feed speed is 0.9mL / h, the receiving distance is 12cm, and the spinning voltage is 15kV. After electrospinning, the PBT-RSF meltblown-electrospun composite material is obtained.

[0051] Example 2

[0052] A method for preparing a PBT-RSF meltblown-electrospun composite material, specifically as follows:

[0053] 1. Preparation of PBT meltblown fabric: Reinforcing filler and PBT chips are mixed at a mass ratio of 16:100 and then granulated to obtain PBT mixed chips. The PBT mixed chips are then fed into a twin-screw extruder for meltblown extrusion and spinning. High-speed hot air is used for blowing, and the meltblown fibers are stretched to obtain meltblown microfibers. The meltblown microfibers are then subjected to negative pressure coagulation and roller winding to obtain PBT meltblown fabric.

[0054] The temperature of the melt extrusion is 290°C;

[0055] The temperature of the high-speed hot airflow is 275°C;

[0056] The diameter of the meltblown ultrafine fiber is 2 μm;

[0057] The preparation method of the reinforcing filler is as follows: Calcium chloride dihydrate is added to anhydrous ethanol and stirred until completely dissolved to obtain an ethanol solution of calcium chloride dihydrate; then, the ethanol solution of calcium chloride dihydrate and ammonium bicarbonate are added to a reactor, stirred at 190 rpm for 18 min at 4°C, and then allowed to stand at 42°C for 21 h. After centrifugation, the centrifugation speed is controlled at 9000 rpm for 9 min, and amorphous calcium carbonate is obtained after centrifugation; a 28% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and... Anhydrous ethanol was added to the reactor and stirred at 110 rpm for 42 min at 42 °C. The mixture was then centrifuged at 9000 rpm for 11 min. After centrifugation, the mixture was dried at 112 °C to obtain the primary reinforcing filler. The primary reinforcing filler was then mixed with the precursor sol at a mass ratio of 10:1.1 and freeze-dried at -35 °C for 7.5 h. After freeze-drying, the mixture was ground to a particle size of 150 nm to obtain the reinforcing filler.

[0058] In the ethanol solution of calcium chloride dihydrate, the mass ratio of calcium chloride dihydrate to anhydrous ethanol is 1.8:1000.

[0059] The mass ratio of calcium chloride dihydrate ethanol solution to ammonium bicarbonate is 100:11.

[0060] The mass ratio of 28% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol is 31:0.3:9.5.

[0061] The precursor sol is prepared as follows: propionic acid and water are added to a reactor and stirred at 110 rpm for 50 min at 32 °C. Magnesium oxide is slowly added and the addition time is controlled to be 35 min. After the addition is completed, stirring is continued for 45 min. Then, the mixture is allowed to stand at room temperature for 1.8 h, filtered, and the filtrate is concentrated to a viscosity of 51 Pa·s at 25 °C to obtain the precursor sol.

[0062] The mass ratio of propionic acid, water, and magnesium oxide is 190:135:43.

[0063] 2. Modification: High-speed hot air is used to uniformly blow cellulose short fibers onto PBT meltblown fabric. The temperature of the high-speed hot air is controlled at 225℃. The mass ratio of PBT meltblown fabric to cellulose short fibers is 100:20. After blowing, a 50,000-volt high-voltage electret treatment is performed to obtain the modified PBT meltblown fabric.

[0064] The method for preparing the cellulose short fibers is as follows: chitosan, water, and acetic acid are added to a reaction vessel and stirred at 190 rpm for 35 min at 65°C. γ-(2,3-epoxypropoxy)propyltrimethoxysilane is added dropwise at a rate of 7 g / min. After the addition is complete, the temperature is raised to 92°C and stirred at 92°C for 3.5 h. The pH is adjusted to 8 using a 7% sodium hydroxide aqueous solution to obtain a mixed solution. Cotton fibers are soaked in the mixed solution at a mass ratio of 42:100 and allowed to stand at 55°C for 4.5 h. The cotton fibers are then removed, drained, dehydrated, dried at 115°C, and cut to a length of 15 mm to obtain cellulose short fibers.

[0065] The mass ratio of chitosan, water, acetic acid, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 8.5:62:1.1:2.1.

[0066] 3. Preparation of PBT-RSF composite spinning solution: PBT chips and RSF are mixed evenly and then added to hexafluoroisopropanol and stirred until completely dissolved to obtain the composite spinning solution;

[0067] The mass ratio of PBT slices, RSF, and hexafluoroisopropanol was 100:30:850.

[0068] 4. Composite: The composite spinning solution is injected into an electrospinning machine for electrospinning, and modified PBT meltblown fabric is used as the receiver. The volume of the syringe is controlled at 30mL, the inner diameter of the needle is 0.9mm, the feed speed is 0.9mL / h, the receiving distance is 14cm, and the spinning voltage is 18kV. After electrospinning, the PBT-RSF meltblown-electrospun composite material is obtained.

[0069] Example 3

[0070] A method for preparing a PBT-RSF meltblown-electrospun composite material, specifically as follows:

[0071] 1. Preparation of PBT meltblown fabric: Reinforcing filler and PBT chips are mixed at a mass ratio of 18:100 and then granulated to obtain PBT mixed chips. The PBT mixed chips are then fed into a twin-screw extruder for meltblown extrusion and spinning. High-speed hot air is used for blowing, and the meltblown fibers are stretched to obtain meltblown microfibers. The meltblown microfibers are then subjected to negative pressure coagulation and roller winding to obtain PBT meltblown fabric.

[0072] The temperature of the melt extrusion is 300°C;

[0073] The temperature of the high-speed hot airflow is 280°C;

[0074] The diameter of the meltblown ultrafine fiber is 3 μm;

[0075] The preparation method of the reinforcing filler is as follows: Calcium chloride dihydrate is added to anhydrous ethanol and stirred until completely dissolved to obtain an ethanol solution of calcium chloride dihydrate; then, the ethanol solution of calcium chloride dihydrate and ammonium bicarbonate are added to a reactor, stirred at 200 rpm for 20 min at 5°C, and then allowed to stand at 45°C for 22 h. After centrifugation, the centrifugation speed is controlled at 10000 rpm for 10 min, and amorphous calcium carbonate is obtained after centrifugation; a 30% (w / w) hydrogen peroxide aqueous solution and amorphous calcium carbonate are then added. Anhydrous ethanol was added to the reactor and stirred at 120 rpm for 45 min at 45℃. The mixture was then centrifuged at 10000 rpm for 12 min. After centrifugation, it was dried at 115℃ to obtain the primary reinforcing filler. The primary reinforcing filler was then mixed with the precursor sol at a mass ratio of 10:1.2 and freeze-dried at -30℃ for 8 h. After freeze-drying, the filler was ground to a particle size of 200 nm to obtain the reinforcing filler.

[0076] In the ethanol solution of calcium chloride dihydrate, the mass ratio of calcium chloride dihydrate to anhydrous ethanol is 2:1000.

[0077] The mass ratio of calcium chloride dihydrate ethanol solution to ammonium bicarbonate is 100:12.

[0078] The mass ratio of a 30% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol is 32:0.4:10.

[0079] The preparation method of the precursor sol is as follows: add propionic acid and water into a reactor, stir at 120 rpm for 55 min at 35°C, slowly add magnesium oxide, control the addition time to 40 min, continue stirring for 50 min after the addition is completed, then let stand at room temperature for 2 h, filter, concentrate the filtrate to a viscosity of 52 Pa·s at 25°C to obtain the precursor sol.

[0080] The mass ratio of propionic acid, water, and magnesium oxide is 200:140:45.

[0081] 2. Modification: High-speed hot air is used to uniformly blow cellulose short fibers onto PBT meltblown fabric. The temperature of the high-speed hot air is controlled at 230℃. The mass ratio of PBT meltblown fabric to cellulose short fibers is 100:30. After blowing, a high-voltage electret treatment of 60,000 volts is performed to obtain the modified PBT meltblown fabric.

[0082] The method for preparing the cellulose short fibers is as follows: chitosan, water, and acetic acid are added to a reaction vessel and stirred at 200 rpm for 40 min at 70°C. γ-(2,3-epoxypropoxy)propyltrimethoxysilane is added dropwise at a rate of 8 g / min. After the addition is complete, the temperature is raised to 95°C and stirred at 95°C for 4 h. The pH is adjusted to 9 using an 8% sodium hydroxide aqueous solution to obtain a mixed solution. Cotton fibers are soaked in the mixed solution at a mass ratio of 45:100 and allowed to stand at 60°C for 5 h. The cotton fibers are then removed, drained, dehydrated, dried at 120°C, and cut to a length of 20 mm to obtain cellulose short fibers.

[0083] The mass ratio of chitosan, water, acetic acid, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 9:65:1.1:2.2.

[0084] 3. Preparation of PBT-RSF composite spinning solution: PBT chips and RSF are mixed evenly and then added to hexafluoroisopropanol and stirred until completely dissolved to obtain the composite spinning solution;

[0085] The mass ratio of PBT slices, RSF, and hexafluoroisopropanol is 100:50:900.

[0086] 4. Composite: The composite spinning solution is injected into an electrospinning machine for electrospinning, and modified PBT meltblown fabric is used as the receiver. The volume of the syringe is controlled at 30mL, the inner diameter of the needle is 1mm, the feed speed is 1mL / h, the receiving distance is 15cm, and the spinning voltage is 20kV. After electrospinning, the PBT-RSF meltblown-electrospun composite material is obtained.

[0087] Comparative Example 1

[0088] The same method for preparing PBT-RSF meltblown-electrospun composite material as in Example 2 was used, except that calcium carbonate was used in an equal amount to replace the reinforcing filler in the first step of preparing PBT meltblown fabric.

[0089] Comparative Example 2

[0090] The same method for preparing PBT-RSF meltblown-electrospun composite material as in Example 2 was used, except that the modification step in step 2 was omitted, and in the composite step in step 4, the PBT meltblown fabric prepared in step 1 (preparing PBT meltblown fabric) was used instead of the modified PBT meltblown fabric.

[0091] Experimental Example 1

[0092] The longitudinal tensile strength, transverse tensile strength, longitudinal breaking strength, transverse breaking strength, and coefficient of friction of the PBT-RSF meltblown-electrospun composites prepared in Examples 1-3 and Comparative Examples 1-2 were tested, and the test results are as follows:

[0093]

[0094] The results above show that by adding reinforcing fillers to the preparation of PBT meltblown fabric, the longitudinal tensile strength, transverse tensile strength, longitudinal breaking strength, transverse breaking strength, and coefficient of friction of the prepared PBT-RSF meltblown-electrospun composite material can be improved.

[0095] Analysis revealed that while adding only calcium carbonate as a reinforcing filler can increase strength and abrasion resistance to some extent, calcium carbonate is prone to agglomeration, and the interfacial bonding between calcium carbonate and PBT chips is weak. Under external impact, interfacial defects are easily caused, resulting in poor strength and abrasion resistance of the prepared PBT-RSF meltblown-electrospun composite material. By modifying amorphous calcium carbonate, agglomeration of the reinforcing filler can be avoided, and the interfacial bonding between the reinforcing filler and PBT chips can be improved, thereby enhancing the strength and abrasion resistance of the prepared PBT-RSF meltblown-electrospun composite material.

[0096] Experimental Example 2

[0097] The PBT-RSF meltblown-electrospun composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were placed in an environment with a temperature of 50°C and a humidity of 60% for 30 days. Then, the longitudinal tensile strength, transverse tensile strength, longitudinal breaking strength, and transverse breaking strength were tested. The test results are as follows:

[0098]

[0099] Experimental Example 3

[0100] The PBT-RSF meltblown-electrospun composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were placed in an environment with a temperature of 20°C and a humidity of 90% for 30 days. Then, the longitudinal tensile strength, transverse tensile strength, longitudinal breaking strength, and transverse breaking strength were tested. The test results are as follows:

[0101]

[0102] The results of Experiment 2 and Experiment 3 show that modifying the prepared PBT meltblown fabric to produce modified PBT meltblown fabric can improve the high temperature resistance and high humidity resistance of the prepared PBT-RSF meltblown-electrospun composite material.

[0103] Further analysis revealed that short cellulose fibers were added during the modification of PBT meltblown fabric. These short cellulose fibers can fill and stabilize the interior of the PBT meltblown fabric, thereby avoiding the impact of high temperature and high humidity on the structure of the PBT meltblown fabric.

[0104] Test Example 4

[0105] The PBT-RSF meltblown-electrospun composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were placed in an environment with a temperature of 23°C and a humidity of 60% for 100 days, and then the surface was observed to see if it became fuzzy. The results are as follows:

[0106]

[0107] The above experimental results show that by modifying the prepared PBT meltblown fabric to produce modified PBT meltblown fabric, the fuzzing of the prepared PBT-RSF meltblown-electrospun composite material can be avoided.

[0108] Further analysis revealed that after uniformly spraying short cellulose fibers onto the surface of PBT meltblown fabric, the short cellulose fibers can fill the PBT meltblown fabric, making the structure of the filled PBT meltblown fabric more stable and thus preventing pilling.

[0109] Experimental Example 5

[0110] The PBT-RSF meltblown-electrospun composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were used to filter leukocytes in blood. The filtration resistance and filtration efficiency are as follows:

[0111]

[0112] The above experimental results show that by modifying the prepared PBT meltblown fabric to produce modified PBT meltblown fabric, the filtration resistance of PBT-RSF meltblown-electrospun composite material can be reduced and the filtration efficiency of PBT-RSF meltblown-electrospun composite material can be improved.

[0113] Further analysis revealed that uniformly spraying short cellulose fibers onto the surface of PBT meltblown fabric effectively modifies and fills the fabric, resulting in higher filtration efficiency for white blood cells. Furthermore, although the pore size of the modified PBT meltblown fabric decreases, the presence of amino, acetaminophen, and hydroxyl groups on the surface of the short cellulose fibers after soaking in the mixed solution enhances the filtration rate of white blood cells and reduces filtration resistance.

[0114] Experimental Example 6

[0115] The PBT-RSF meltblown-electrospun composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were completely immersed in a 10% hydrochloric acid aqueous solution at 23°C for 10 days. The longitudinal tensile strength, transverse tensile strength, longitudinal breaking strength, and transverse breaking strength were then tested. The test results are as follows:

[0116]

[0117] Experimental Example 7

[0118] The PBT-RSF meltblown-electrospun composite materials prepared in Examples 1-3 and Comparative Examples 1-2 were completely immersed in a 10% sodium hydroxide aqueous solution at 23°C for 10 days. The longitudinal tensile strength, transverse tensile strength, longitudinal breaking strength, and transverse breaking strength were then tested. The test results are as follows:

[0119]

[0120] The results above show that adding reinforcing fillers to the preparation of PBT meltblown fabric can improve the chemical resistance of the prepared PBT-RSF meltblown-electrospun composite material.

[0121] Further analysis revealed that the reinforcing filler improved the interfacial bonding force with the PBT chips, resulting in higher density and stronger stability of the PBT hybrid chips, thereby enhancing the chemical resistance of the prepared PBT-RSF meltblown-electrospun composite material.

[0122] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0123] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a PBT-regenerated silk fibroin meltblown-electrospun composite material, characterized in that, It consists of the following steps: preparing PBT meltblown fabric, modifying it, preparing PBT-regenerated silk fibroin composite spinning solution, and composite it; The modification involves uniformly blowing cellulose short fibers onto PBT meltblown fabric using a high-speed hot air stream, controlling the temperature of the high-speed hot air stream at 220-230℃, and the mass ratio of PBT meltblown fabric to cellulose short fibers at 100:10-30. After blowing, a high-voltage electret treatment of 50,000-60,000 volts is performed to obtain the modified PBT meltblown fabric. The method for preparing the cellulose short fibers is as follows: chitosan, water, and acetic acid are added to a reaction vessel and stirred at 60-70°C. γ-(2,3-epoxypropoxy)propyltrimethoxysilane is added dropwise at a rate of 6-8 g / min. After the addition is complete, the temperature is raised to 90-95°C and stirred at 90-95°C. The pH is adjusted to 8-9 using a 6-8% sodium hydroxide aqueous solution to obtain a mixed solution. Cotton fibers are soaked in the mixed solution at a mass ratio of 40-45:

100. The mixture is allowed to stand at 50-60°C. The cotton fibers are then removed, drained, dehydrated, dried, and cut to obtain cellulose short fibers. The composite process involves injecting the composite spinning solution into an electrospinning machine for electrospinning, and then receiving it using modified PBT meltblown fabric.

2. The method for preparing the PBT-regenerated silk fibroin meltblown-electrospun composite material according to claim 1, characterized in that, The preparation of PBT meltblown fabric involves mixing reinforcing filler and PBT chips at a mass ratio of 15-18:100, followed by blending and granulation to obtain PBT mixed chips. These PBT mixed chips are then added to a twin-screw extruder for melt extrusion, followed by spinning. High-speed hot air is used for blowing, stretching the meltblown fibers to obtain meltblown microfibers. The meltblown microfibers are then subjected to negative pressure agglomeration and roller winding to obtain PBT meltblown fabric. The temperature of the melt extrusion is 280-300℃; The temperature of the high-speed hot airflow is 270-280℃; The diameter of the meltblown ultrafine fiber is 2-3 μm.

3. The method for preparing the PBT-regenerated silk fibroin meltblown-electrospun composite material according to claim 2, characterized in that, The preparation method of the reinforcing filler is as follows: calcium chloride dihydrate is added to anhydrous ethanol and stirred until completely dissolved to obtain an ethanol solution of calcium chloride dihydrate; then, the ethanol solution of calcium chloride dihydrate and ammonium bicarbonate are added to a reactor, stirred at 2-5℃, and then allowed to stand at 40-45℃ before centrifugation to obtain amorphous calcium carbonate; a 25-30% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol are added to the reactor, stirred at 40-45℃, centrifuged, and dried to obtain the primary reinforcing filler; the primary reinforcing filler and the precursor sol are mixed evenly at a mass ratio of 10:1-1.2, freeze-dried, and then ground to obtain the reinforcing filler; In the preparation of the reinforcing filler, the mass ratio of calcium chloride dihydrate to anhydrous ethanol in the calcium chloride dihydrate ethanol solution is 1.5-2:1000. The mass ratio of calcium chloride dihydrate ethanol solution to ammonium bicarbonate is 100:10-12; The mass ratio of 25-30% hydrogen peroxide aqueous solution, amorphous calcium carbonate, and anhydrous ethanol is 30-32:0.3-0.4:9-10.

4. The method for preparing the PBT-regenerated silk fibroin meltblown-electrospun composite material according to claim 3, characterized in that, The preparation method of the precursor sol is as follows: add propionic acid and water into a reactor, stir at 30-35℃, slowly add magnesium oxide, control the addition time to 30-40 min, continue stirring after the addition is completed, then let stand at room temperature, filter, and concentrate the filtrate to a viscosity of 50-52 Pa·s at 25℃ to obtain the precursor sol. In the preparation of the precursor sol, the mass ratio of propionic acid, water, and magnesium oxide is 180-200:130-140:42-45.

5. The method for preparing the PBT-regenerated silk fibroin meltblown-electrospun composite material according to claim 1, characterized in that, In the preparation of the cellulose short fibers, the mass ratio of chitosan, water, acetic acid, and γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 8-9:60-65:1-1.1:2-2.

2.

6. The method for preparing the PBT-regenerated silk fibroin meltblown-electrospun composite material according to claim 1, characterized in that, To prepare the PBT-regenerated silk fibroin composite spinning solution, PBT chips and regenerated silk fibroin are mixed evenly and then added to hexafluoroisopropanol and stirred until completely dissolved to obtain the composite spinning solution. In the preparation of the PBT-regenerated silk fibroin composite spinning solution, the mass ratio of PBT chips, regenerated silk fibroin, and hexafluoroisopropanol is 100:20-50:800-900.

7. The method for preparing the PBT-regenerated silk fibroin meltblown-electrospun composite material according to claim 1, characterized in that, The composite process involves injecting the composite spinning solution into an electrospinning machine for electrospinning, and using modified PBT meltblown fabric for receiving. The syringe volume is controlled to be 30 mL, the needle inner diameter to be 0.8-1 mm, the feed speed to be 0.9-1 mL / h, the receiving distance to be 12-15 cm, and the spinning voltage to be 15-20 kV. After electrospinning, the PBT-regenerated silk fibroin meltblown-electrospinned composite material is obtained.

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