Porous composite fiber filter element and preparation method thereof

Abstract

The invention relates to a porous composite fiber filter element and a preparation method thereof, and belongs to the technical field of fiber filter elements. The porous composite fiber filter element is prepared by taking degradable composite fibers as raw materials, the degradable composite fibers comprise the following components: degradable resin, a glycidyl methacrylate-ethylene copolymer, modified caragana microphylla fibers, fumed silica and an antioxidant, and the degradable resin is one or more of PBS, PBAT, PHB, PES, PHA, PBT, PLA, PPC, PHV, PHBV, PCL, PBSA, PVA and PBAD; according to the porous composite fiber filter element disclosed by the invention, the preparation process is not limited to use of degradable materials, and on the basis, the prepared fibers can be ensured to have good mechanical strength. The development of the porous composite fiber filter element aims to provide a fiber filter element which is environment-friendly and practical.

Description

Technical Field

[0001] The present invention belongs to the technical field of fiber filters, and relates to a porous composite fiber filter and a preparation method thereof. Background Art

[0002] In the production process of filters, materials such as PP, PA, PE, and PET that are not easily decomposed are usually used. However, the non-degradable characteristics of these materials cause their large-scale use to cause permanent damage to the environment. In addition, the filter materials are also used to manufacture components such as the water absorption rods of humidifiers, the fragrance volatilization rods, the filter tips of electronic cigarettes, and the integrated oil storage cotton, which requires the filter materials to have excellent filtering ability and good mechanical strength at the same time.

[0003] Caragana korshinskii, as a kind of wood, can extract natural fibers from it. Due to the presence of a large number of hydroxyl groups in cellulose, Caragana korshinskii can be used as a modifier for some adsorption materials. Due to the hard inner core of Caragana korshinskii, it can be speculated that its fibers will have good toughness, and Caragana korshinskii fibers can be used as a reinforcing agent for polymer materials to enhance the mechanical properties of the materials. However, the compatibility between Caragana korshinskii fibers and polymers is poor, and it is often difficult to obtain an ideal binding effect by direct mixing. Summary of the Invention

[0004] The purpose of the present invention is to provide a porous composite fiber filter and a preparation method thereof. The porous composite fiber filter involved in the present invention not only limits the use of degradable materials in the preparation process, but also on this basis, can ensure that the prepared fibers have good mechanical strength. The development of this porous composite fiber filter aims to provide an environmentally friendly and practical fiber filter.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A porous composite fiber filter is prepared from degradable composite fibers as raw materials. The degradable composite fibers include the following components in parts by weight: 90-110 parts of degradable resin, 7-10 parts of glycidyl methacrylate-ethylene copolymer, 12-16 parts of modified Caragana korshinskii fibers, 2-3 parts of fumed silica, and 1.0-1.5 parts of antioxidant.

[0007] As a preferred technical solution of the present invention, the degradable resin is one or more of PBS, PBAT, PHB, PES, PHA, PBT, PLA, PPC, PHV, PHBV, PCL, PBSA, PVA, and PBAD.

[0008] As a preferred technical solution of the present invention, the antioxidant is composed of antioxidant 1010, antioxidant 1076 and antioxidant 168 mixed in a mass ratio of 1.6 - 2.0:1.0 - 1.2:0.6 - 0.8.

[0009] The preparation method of the modified Caragana korshinskii includes the following steps:

[0010] Step 1: Place the Caragana korshinskii fiber in the activation solution for heat treatment, ultrasonic treatment, filter and then wash, and vacuum dry to obtain prefabricated Caragana korshinskii fiber;

[0011] Step 2: Ultrasonically treat the prefabricated Caragana korshinskii fiber and the chitosan solution, heat and stir, then filter to obtain the solid, and vacuum dry to obtain the composite;

[0012] Step 3: Stir and mix the composite and the ethanol solution, preheat, add the mixed monomers and stir at a constant temperature, filter, wash, and vacuum dry to obtain the modified Caragana korshinskii fiber.

[0013] As a preferred technical solution of the present invention, in Step 1, the heat treatment is heating at 70 - 75 °C for 15 - 20 min; the ultrasonic treatment is treating at a power of 600 - 800 W for 2 - 3 min; the vacuum drying is vacuum drying at 70 °C to constant weight.

[0014] As a preferred technical solution of the present invention, in Step 1, the mass ratio of the Caragana korshinskii fiber to the activation solution is 8 - 10:40 - 45; the activation solution is composed of propylene glycol, acetic acid and deionized water mixed in a mass ratio of 4.8 - 5.2:0.5 - 0.7:20 - 24.

[0015] As a preferred technical solution of the present invention, in a high-temperature environment, the Caragana korshinskii fiber will experience swelling and become soft, which helps to remove impurities. In addition, ultrasonic treatment can improve the efficiency of the acetic acid reaction and further remove impurities in lignin. At the same time, the combined use of propylene glycol and ultrasonic waves can significantly increase the hydroxyl content on the surface of the Caragana korshinskii fiber.

[0016] As a preferred technical solution of the present invention, in Step 2, the ultrasonic treatment is ultrasonic treatment at a power of 800 - 1000 W for 3 - 5 min; the heat stirring is stirring at a temperature of 50 - 60 °C and a rotation speed of 500 - 600 rpm for 30 - 45 min; the vacuum drying is vacuum drying at 80 °C to constant weight.

[0017] As a preferred technical solution of the present invention, in Step 2, the mass ratio of the prefabricated Caragana korshinskii fiber to the chitosan solution is 12 - 15:50 - 60; the chitosan solution is composed of chitosan and 2 wt% acetic acid aqueous solution in a mass ratio of 1.0 - 1.3:35 - 40.

[0018] As a preferred technical solution of the present invention, under the action of ultrasound, chitosan forms small-molecule water-soluble chitosan, enabling more free amino groups, promoting the combination of chitosan and the hydroxyl groups on the surface of korshinskii komarovii fiber through hydrogen bonds and electrostatic interactions, facilitating the entry of chitosan into the porous structure of korshinskii komarovii fiber to form a multi-dimensional network structure, and significantly improving the mechanical strength of the filter element.

[0019] As a preferred technical solution of the present invention, in step three, the stirring and mixing is carried out at a rotation speed of 800 - 1000 rpm for 20 - 30 min; the preheating is to raise the temperature to 40 °C; the constant-temperature stirring is carried out at a temperature of 45 - 55 °C and a rotation speed of 400 - 600 rpm for 4 - 6 h; the washing is to rinse 3 times with anhydrous ethanol; the vacuum drying is to vacuum dry at a temperature of 80 - 90 °C until constant weight.

[0020] As a preferred technical solution of the present invention, in step three, the mass ratio of the composite, ethanol solution, and mixed monomer is 15 - 16:50 - 60:2.5 - 3.0; the mixed monomer is composed of 2-furylacrolein and coniferyl aldehyde mixed in a mass ratio of 1.5 - 1.8:2.5 - 3.0; the concentration of the ethanol solution is 30 wt%.

[0021] As a preferred technical solution of the present invention, the present invention conducts surface modification treatment on korshinskii komarovii fiber with chitosan, 2-furylacrolein, and coniferyl aldehyde, and uses glycidyl methacrylate-ethylene copolymer as a compatibilizer to introduce functional groups that can chemically react with the polymer, thereby significantly enhancing the interfacial bonding force between korshinskii komarovii fiber and the polymer. This modified korshinskii komarovii fiber can not only be better dispersed in the polymer matrix, but also effectively enhance the mechanical strength of the filter element while maintaining its good filtration performance.

[0022] As a preferred technical solution of the present invention, the GMA content of glycidyl methacrylate-ethylene copolymer is 6 wt%.

[0023] A preparation method of a porous composite fiber filter element includes the following steps: placing a degradable resin, glycidyl methacrylate-ethylene copolymer, modified korshinskii komarovii fiber, fumed silica, and antioxidant in an extruder and carrying out twin-screw spinning at a temperature of 190 - 210 °C, obtaining a degradable composite fiber, forming a fiber web from the degradable composite fiber, strengthening it into a non-woven fabric, heating and melting it, and then carrying out shaping treatment in a filter element mold to obtain the product.

[0024] The beneficial effects of the present invention:

[0025] The porous composite fiber filter element involved in the present invention is not limited to using degradable materials in its preparation process. Moreover, on this basis, it can ensure that the prepared fibers have good mechanical strength. The development of this porous composite fiber filter element aims to provide an environmentally friendly and practical fiber filter element to meet the dual needs of current society for sustainable development and environmental protection. The present invention successfully combines the environmental protection characteristics of degradable materials with the mechanical properties of fibers, thus meeting the environmental protection requirements while ensuring the strength and durability of the fibers in practical applications. Detailed implementation manners

[0026] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with embodiments, details the specific implementation manners, structures, features, and their effects according to the present invention as follows.

[0027] Example 1

[0028] A porous composite fiber filter element, which is prepared from degradable composite fibers as raw materials. The degradable composite fibers include the following components by weight: 90 parts of degradable resin, 7 parts of glycidyl methacrylate-ethylene copolymer, 12 parts of modified Caragana korshinskii fiber, 2 parts of fumed silica, and 1.0 part of antioxidant; the degradable resin is PBS; the antioxidant is composed of antioxidant 1010, antioxidant 1076, and antioxidant 168 in a mass ratio of 1.6:1.0:0.6;

[0029] The preparation method of the modified Caragana korshinskii includes the following steps:

[0030] Step 1: Place the Caragana korshinskii fiber in the activation solution for heat treatment, ultrasonic treatment, filter and then wash, and vacuum dry to obtain prefabricated Caragana korshinskii fiber; among them, the heat treatment is heating at 70 °C for 15 min; the ultrasonic treatment is treating at 600 W power for 2 min; the vacuum drying is vacuum drying at 70 °C until constant weight; the mass ratio of the Caragana korshinskii fiber to the activation solution is 8:40; the activation solution is composed of propylene glycol, acetic acid, and deionized water in a mass ratio of 4.8:0.5:20;

[0031] Step 2: Ultrasonically treat the prefabricated Caragana korshinskii fiber and the chitosan solution, heat and stir, then filter to obtain the solid, and vacuum dry to obtain the composite; the ultrasonic treatment is ultrasonic treatment at 800 W power for 3 min; the heat and stir is stirring at 50 °C and 500 rpm for 30 min; the vacuum drying is vacuum drying at 80 °C until constant weight; the mass ratio of the prefabricated Caragana korshinskii fiber to the chitosan solution is 12:50; the chitosan solution is composed of chitosan and 2 wt% concentration acetic acid aqueous solution in a mass ratio of 1.0:35;

[0032] Step 3: Stir and mix the composite and the ethanol solution, add the mixed monomers after preheating, stir at a constant temperature, perform suction filtration, washing, and vacuum drying to obtain modified Caragana korshinskii fibers; the stirring and mixing is carried out at a speed of 800 rpm for 20 min; the preheating is to raise the temperature to 40 °C; the constant-temperature stirring is carried out at a temperature of 45 °C and a speed of 400 rpm for 4 h; the washing is to rinse with absolute ethanol 3 times; the vacuum drying is to vacuum dry at a temperature of 80 °C until constant weight; the mass ratio of the composite, the ethanol solution, and the mixed monomers is 15:50:2.5; the mixed monomers are composed of 2-furylacrolein and coniferyl aldehyde mixed in a mass ratio of 1.5:2.5; the concentration of the ethanol solution is 30 wt%.

[0033] A preparation method of a porous composite fiber filter element includes placing a degradable resin, a glycidyl methacrylate-ethylene copolymer, modified Caragana korshinskii fibers, fumed silica, and an antioxidant in an extruder and performing twin-screw spinning at a temperature of 190 °C, and then obtaining a degradable composite fiber. The degradable composite fiber is formed into a fiber web, reinforced into a non-woven fabric, heated and melted, and then placed in a filter element mold for shaping treatment to obtain the filter element.

[0034] Example 2

[0035] A porous composite fiber filter element, the porous composite fiber filter element is made of a degradable composite fiber as a raw material, and the degradable composite fiber includes the following components by weight: 97 parts of a degradable resin, 8 parts of a glycidyl methacrylate-ethylene copolymer, 13 parts of modified Caragana korshinskii fibers, 2.3 parts of fumed silica, and 1.2 parts of an antioxidant; the degradable resin is PBS; the antioxidant is composed of antioxidant 1010, antioxidant 1076, and antioxidant 168 mixed in a mass ratio of 1.7:1.1:0.65;

[0036] The preparation method of the modified Caragana korshinskii includes the following steps:

[0037] Step 1: Place the Caragana korshinskii fibers in an activation solution for heat treatment, ultrasonic treatment, filtration, washing, and vacuum drying to obtain prefabricated Caragana korshinskii fibers; wherein, the heat treatment is carried out at a temperature of 72 °C for 15 min; the ultrasonic treatment is carried out at a power of 660 W for 2.5 min; the vacuum drying is to vacuum dry at a temperature of 70 °C until constant weight; the mass ratio of the Caragana korshinskii fibers to the activation solution is 8.7:42; the activation solution is composed of propylene glycol, acetic acid, and deionized water mixed in a mass ratio of 5.0:0.55:21;

[0038] Step 2: Ultrasonically treat the prefabricated Caragana korshinskii fiber and chitosan solution, heat and stir, then filter to obtain the solid, and vacuum dry to obtain the composite; the ultrasonic treatment is carried out at a power of 860 W for 3.5 min; the heating and stirring is carried out at a temperature of 53 °C and a rotation speed of 530 rpm for 35 min; the vacuum drying is carried out at a temperature of 80 °C until constant weight; the mass ratio of the prefabricated Caragana korshinskii fiber to the chitosan solution is 13:53; the chitosan solution is composed of chitosan and 2 wt% acetic acid aqueous solution in a mass ratio of 1.1:37;

[0039] Step 3: Stir and mix the composite and ethanol solution, preheat, then add the mixed monomers and stir at a constant temperature, filter, wash, and vacuum dry to obtain the modified Caragana korshinskii fiber; the stirring and mixing is carried out at a rotation speed of 860 rpm for 25 min; the preheating is to raise the temperature to 40 °C; the constant temperature stirring is carried out at a temperature of 48 °C and a rotation speed of 460 rpm for 4.5 h; the washing is to rinse with anhydrous ethanol 3 times; the vacuum drying is carried out at a temperature of 83 °C until constant weight; the mass ratio of the composite, ethanol solution and mixed monomers is 15.5:53:2.7; the mixed monomers are composed of 2-furylacrolein and coniferyl aldehyde in a mass ratio of 1.6:2.7; the concentration of the ethanol solution is 30 wt%.

[0040] A preparation method of a porous composite fiber filter element includes placing a degradable resin, glycidyl methacrylate-ethylene copolymer, modified Caragana korshinskii fiber, fumed silica and antioxidant in an extruder and carrying out twin-screw spinning at a temperature of 197 °C, then obtaining a degradable composite fiber, forming the degradable composite fiber into a fiber web, strengthening it into a non-woven fabric, heating and melting, and carrying out shaping treatment in a filter element mold to obtain the product.

[0041] Example 3

[0042] A porous composite fiber filter element, the porous composite fiber filter element is made from a degradable composite fiber as the raw material, and the degradable composite fiber includes the following components in parts by weight: 103 parts of degradable resin, 9 parts of glycidyl methacrylate-ethylene copolymer, 15 parts of modified Caragana korshinskii fiber, 2.7 parts of fumed silica and 1.3 parts of antioxidant; the degradable resin is PBS; the antioxidant is composed of antioxidant 1010, antioxidant 1076 and antioxidant 168 in a mass ratio of 1.9:1.15:0.75;

[0043] The preparation method of the modified Caragana korshinskii includes the following steps:

[0044] Step 1: Place the caragana korshinskii fiber in the activation solution for heat treatment, ultrasonic treatment, filter, wash, and vacuum dry to obtain the prefabricated caragana korshinskii fiber. Among them, the heat treatment is heating at 73 °C for 18 min; the ultrasonic treatment is treating at 730 W for 2.5 min; the vacuum drying is vacuum drying at 70 °C until constant weight; the mass ratio of the caragana korshinskii fiber to the activation solution is 9.3:43; the activation solution is composed of propylene glycol, acetic acid, and deionized water mixed according to the mass ratio of 5.1:0.65:23.

[0045] Step 2: Ultrasonically treat the prefabricated caragana korshinskii fiber and the chitosan solution, heat and stir, filter to obtain the solid, and vacuum dry to obtain the composite. The ultrasonic treatment is treating at 930 W for 4.5 min; the heat and stir is stirring at 57 °C and 560 rpm for 40 min; the vacuum drying is vacuum drying at 80 °C until constant weight; the mass ratio of the prefabricated caragana korshinskii fiber to the chitosan solution is 14:57; the chitosan solution is composed of chitosan and 2 wt% acetic acid aqueous solution according to the mass ratio of 1.2:38.

[0046] Step 3: Stir and mix the composite and the ethanol solution, preheat, add the mixed monomers, stir at a constant temperature, filter, wash, and vacuum dry to obtain the modified caragana korshinskii fiber. The stir and mix is stirring at 930 rpm for 25 min; the preheating is heating to 40 °C; the constant temperature stirring is stirring at 52 °C and 530 rpm for 5.5 h; the washing is rinsing 3 times with anhydrous ethanol; the vacuum drying is vacuum drying at 87 °C until constant weight; the mass ratio of the composite, the ethanol solution, and the mixed monomers is 15.8:57:2.8; the mixed monomers are composed of 2-furylacrolein and coniferyl aldehyde mixed according to the mass ratio of 1.7:2.8; the concentration of the ethanol solution is 30 wt%.

[0047] A preparation method of a porous composite fiber filter element includes placing a degradable resin, a glycidyl methacrylate-ethylene copolymer, a modified caragana korshinskii fiber, fumed silica, and an antioxidant in an extruder and performing twin-screw spinning at 203 °C to obtain a degradable composite fiber, forming a fiber web from the degradable composite fiber, reinforcing it into a non-woven fabric, heating and melting, and performing a shaping treatment in a filter element mold to obtain the product.

[0048] Example 4

[0049] A porous composite fiber filter element, which is prepared from a degradable composite fiber as a raw material. The degradable composite fiber comprises the following components in parts by weight: 110 parts of a degradable resin, 10 parts of a glycidyl methacrylate-ethylene copolymer, 16 parts of modified Caragana korshinskii fiber, 3 parts of fumed silica, and 1.5 parts of an antioxidant; the degradable resin is PBS; the antioxidant is composed of antioxidant 1010, antioxidant 1076, and antioxidant 168 mixed in a mass ratio of 2.0:1.2:0.8;

[0050] The preparation method of the modified Caragana korshinskii comprises the following steps:

[0051] Step 1: Place the Caragana korshinskii fiber in an activation solution for heat treatment, ultrasonic treatment, filter and then wash, and vacuum dry to obtain a prefabricated Caragana korshinskii fiber; wherein, the heat treatment is heating at 75°C for 20 min; the ultrasonic treatment is treating at 800 W for 3 min; the vacuum drying is vacuum drying at 70°C until constant weight; the mass ratio of the Caragana korshinskii fiber to the activation solution is 10:45; the activation solution is composed of propylene glycol, acetic acid, and deionized water mixed in a mass ratio of 5.2:0.7:24;

[0052] Step 2: Ultrasonically treat the prefabricated Caragana korshinskii fiber and a chitosan solution, heat and stir, then filter to obtain a solid, and vacuum dry to obtain a composite; the ultrasonic treatment is ultrasonic treatment at 1000 W for 5 min; the heat and stir is stirring at 60°C and 600 rpm for 45 min; the vacuum drying is vacuum drying at 80°C until constant weight; the mass ratio of the prefabricated Caragana korshinskii fiber to the chitosan solution is 15:60; the chitosan solution is composed of chitosan and a 2 wt% aqueous acetic acid solution in a mass ratio of 1.3:40;

[0053] Step 3: Stir and mix the composite and an ethanol solution, preheat, then add a mixed monomer and stir at a constant temperature, filter with suction, wash, and vacuum dry to obtain the modified Caragana korshinskii fiber; the stir and mix is stirring at 1000 rpm for 30 min; the preheating is heating to 40°C; the constant temperature stirring is stirring at 55°C and 600 rpm for 6 h; the washing is rinsing 3 times with anhydrous ethanol; the vacuum drying is vacuum drying at 90°C until constant weight; the mass ratio of the composite, the ethanol solution, and the mixed monomer is 16:60:3.0; the mixed monomer is composed of 2-furylacrolein and coniferyl aldehyde mixed in a mass ratio of 1.8:3.0; the concentration of the ethanol solution is 30 wt%.

[0054] A preparation method of a porous composite fiber filter element includes placing a degradable resin, a glycidyl methacrylate-ethylene copolymer, modified Caragana korshinskii fibers, fumed silica, and an antioxidant in an extruder and performing twin-screw spinning at a temperature of 210 °C to obtain a degradable composite fiber. The degradable composite fiber is formed into a fiber web, reinforced into a non-woven fabric, heated and melted, and then placed in a filter element mold for shaping treatment to obtain the product.

[0055] Comparative Example 1

[0056] Compared with Example 3, the difference in Comparative Example 1 is that deionized water is used instead of the activation solution in Step 1, and the other components, preparation steps, and parameters are the same.

[0057] Comparative Example 2

[0058] Compared with Example 3, the difference in Comparative Example 2 is that chitosan is not used in Step 2, and the other components, preparation steps, and parameters are the same.

[0059] Comparative Example 3

[0060] Compared with Example 3, the difference in Comparative Example 3 is that ultrasonic treatment is not performed in Step 2, and the other components, preparation steps, and parameters are the same.

[0061] Comparative Example 4

[0062] Compared with Example 3, the difference in Comparative Example 4 is that coniferyl aldehyde is used instead of 2-furanacrolein in Step 3, and the other components, preparation steps, and parameters are the same.

[0063] Comparative Example 5

[0064] Compared with Example 3, the difference in Comparative Example 5 is that 2-furanacrolein is used instead of coniferyl aldehyde in Step 3, and the other components, preparation steps, and parameters are the same.

[0065] Comparative Example 6

[0066] Compared with Example 3, the difference in Comparative Example 6 is that the mixed monomer is not used in Step 3, and the other components, preparation steps, and parameters are the same.

[0067] Comparative Example 7

[0068] Compared with Example 3, the difference in Comparative Example 7 is that the glycidyl methacrylate-ethylene copolymer is not used, and the other components, preparation steps, and parameters are the same.

[0069] The tensile strength tests were respectively carried out on the degradable composite fibers prepared in Examples 1-4 and Comparative Examples 1-7, and the test results are shown in Table 1.

[0070] Tensile strength test: According to GB / T19975-2005, where the gauge length is 500 mm and the speed is 250 mm / min. The test results are shown in Table 1.

[0071] Table 1

[0072]

[0073]

[0074] From the test results in Table 1, it can be seen that compared with Comparative Examples 1-7, the degradable composite fibers prepared by the present invention have excellent tensile strength, and the mechanical strength of the filters prepared therefrom is relatively high.

[0075] In the present invention, chitosan and korshinsk peashrub fiber form an interpenetrating network structure, which can significantly improve the mechanical strength of the composite fiber. At the same time, amino groups, carboxyl groups and more active hydroxyl groups are introduced. The amino groups can form covalent bond connections with the acrolein in the mixed monomer composed of 2-furylacrolein and coniferyl aldehyde, so that it can form an organic coating modification on the surface of korshinsk peashrub fiber, significantly increasing the dispersibility and interfacial bonding force of korshinsk peashrub fiber in the polymer material. In addition, in the present invention, furylacrolein and coniferyl aldehyde are compounded, and crosslinking points with different sizes and rigidities are formed through the different ring structures of the furan ring and the benzene ring. Moreover, the complementary stacking of different ring structures may reduce structural defects and improve the uniformity of the overall material, thereby forming a denser and more evenly distributed three-dimensional network structure in the composite material, which can more effectively disperse stress and improve the tensile strength. By introducing the acrolein in the mixed monomer, the compatibility between korshinsk peashrub fiber and glycidyl methacrylate-ethylene copolymer and the degradable resin is increased. The epoxy groups of the glycidyl methacrylate-ethylene copolymer can not only react with the carboxyl groups and hydroxyl groups in the modified korshinsk peashrub fiber and fumed silica, but also form chemical grafting with the active groups of the degradable resin, further improving the modification effect of the modified korshinsk peashrub fiber on the degradable resin and enhancing the mechanical strength of the composite fiber.

[0076] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments by using the above-disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any indirect modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A porous composite fiber filter element, characterized in that: The porous composite fiber filter element is made of degradable composite fiber as raw material, and the degradable composite fiber comprises the following components by weight: 90-110 parts of degradable resin, 7-10 parts of glycidyl methacrylate-ethylene copolymer, 12-16 parts of modified caragana fiber, 2-3 parts of fumed silica and 1.0-1.5 parts of antioxidant; Wherein, the preparation method of the modified Caragana korshinskii comprises the following steps: Step 1, placing caragana fiber in an activation solution for heating treatment, ultrasonic treatment, filtering, washing, and vacuum drying to obtain prefabricated caragana fiber; Step 2: ultrasonically treat the prefabricated caragana fiber and chitosan solution, filter out the solid after heating and stirring, and vacuum dry to obtain a composite; Step 3: Stir and mix the composite and ethanol solution, add the mixed monomer after preheating, stir at constant temperature, filter, wash, and vacuum dry to obtain modified caragana fiber.

2. A porous composite fiber filter element according to claim 1, characterized in that: The degradable resin is one or more of PBS, PBAT, PHB, PES, PHA, PBT, PLA, PPC, PHV, PHBV, PCL, PBSA, PVA and PBAD; the antioxidant is a mixture of antioxidant 1010, antioxidant 1076 and antioxidant 168 in a mass ratio of 1.6-2.0:1.0-1.2:0.6-0.

8.

3. The porous composite fiber filter element according to claim 1, characterized in that: In step 1, the heating treatment is heating at 70-75°C for 15-20 min; the ultrasonic treatment is treating at 600-800W for 2-3 min; and the vacuum drying is vacuum drying at 70°C to constant weight.

4. The porous composite fiber filter element according to claim 1, characterized in that: In step 1, the mass ratio of the caragana fiber to the activation solution is 8-10:40-45; the activation solution is prepared by mixing propylene glycol, acetic acid and deionized water in a mass ratio of 4.8-5.2:0.5-0.7:20-24.

5. The porous composite fiber filter element according to claim 1, characterized in that: In step 2, the ultrasonic treatment is performed at a power of 800-1000 W for 3-5 min; the heating and stirring is performed at a temperature of 50-60° C. and a speed of 500-600 rpm for 30-45 min; and the vacuum drying is performed at a temperature of 80° C. and vacuum drying until constant weight is achieved.

6. The porous composite fiber filter element according to claim 1, characterized in that: In step 2, the mass ratio of the prefabricated caragana fiber to the chitosan solution is 12-15:50-60; the chitosan solution is composed of chitosan and 2wt% acetic acid aqueous solution in a mass ratio of 1.0-1.3:35-40.

7. The porous composite fiber filter element according to claim 1, characterized in that: In step three, the stirring and mixing is stirring at a speed of 800-1000rpm for 20-30min; the preheating is heating to 40°C; the constant temperature stirring is stirring at a temperature of 45-55°C and a speed of 400-600rpm for 4-6h; the washing is rinsing with anhydrous ethanol for 3 times; and the vacuum drying is vacuum drying at a temperature of 80-90°C to constant weight.

8. The porous composite fiber filter element according to claim 1, characterized in that: In step three, the mass ratio of the complex, ethanol solution and mixed monomer is 15-16:50-60:2.5-3.0; the mixed monomer is prepared by mixing 2-furanpropenal and coniferyl aldehyde in a mass ratio of 1.5-1.8:2.5-3.0; the concentration of the ethanol solution is 30wt%.

9. A method for preparing a porous composite fiber filter element according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: placing a degradable resin, glycidyl methacrylate-ethylene copolymer, modified caragana fiber, fumed silica and an antioxidant in an extruder and spinning them in a twin-screw spinning machine at a temperature of 190-210° C. to obtain degradable composite fibers; forming the degradable composite fibers into a fiber web, reinforcing them into a non-woven fabric, heating and hot-melting them, and placing them in a filter element mold for shaping treatment to obtain the product.

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