Environment-friendly degradable functional school uniform fabric and preparation method thereof

Abstract

The application discloses an environment-friendly degradable functional school uniform fabric and a preparation method thereof, and particularly relates to the technical field of textiles, and relates to an environment-friendly degradable functional school uniform fabric and a preparation method thereof; the environment-friendly degradable functional school uniform fabric is prepared from polylactic acid chips, polyethylene glycol, dicumyl peroxide, quaternary ammonium chitosan derivative, tea polyphenol, baicalin, citric acid, butanetetrol, cotton pulp and N-methylmorpholine-N-oxide; the application constructs a fabric matrix by using fully biodegradable cellulose and hydrophilic modified polylactic acid, and matches a natural degradable functional system, so that the fabric can be completely decomposed by microorganisms in a compost environment, and the degradation performance of the application is improved.

Description

Technical Field

[0001] This invention relates to the field of textile technology, and more specifically, to an environmentally friendly, biodegradable functional school uniform fabric and its preparation method. Background Technology

[0002] As students' daily clothing, the choice of fabric for school uniforms directly affects the wearer's health and wearing experience. With the increasing environmental awareness of the whole society and the growing attention of parents to students' health, modern school uniform fabrics not only need to meet basic wearing performance such as wear resistance and wrinkle resistance, but also have higher requirements for functionality and environmental friendliness. Therefore, it is of great significance to provide a school uniform fabric that combines environmental protection and biodegradability with other functions.

[0003] The school uniform fabrics in related technologies include a synthetic fiber main component, a natural fiber component, and a chemical finishing agent coating. The synthetic fiber main component generally includes polyester or nylon, which typically accounts for 65-100% of the fabric. Its function is to utilize the high strength and excellent elastic recovery of synthetic fibers to ensure that the school uniforms maintain their shape and are not easily damaged after frequent activities and multiple washes. The natural fiber component generally includes cotton fibers, which utilize the hydrophilicity of cotton fibers to improve the fabric's moisture absorption and breathability, alleviating the stuffiness caused by pure synthetic fibers. The chemical finishing agent coating is used to address the problem of students being active and prone to sweating. Antibacterial and UV-resistant finishing agents are added in the finishing stage through a padding process, giving the fabric the function of inhibiting bacterial growth and blocking ultraviolet rays.

[0004] However, in practical use, it still has some drawbacks, such as poor biodegradability. Traditional fabrics use a large amount of non-degradable petrochemical-based synthetic materials such as polyester fibers, which are difficult to decompose in the natural environment after being discarded. The disposal of discarded school uniforms mainly relies on incineration or landfill, which will cause long-term pollution and waste of resources. Poor durability. Traditional fabrics rely on chemical antibacterial agents added in the finishing process, which have poor durability. The functional additives in the traditional process only stay on the surface of the fiber and have poor bonding force. In the finishing process, the additives are difficult to penetrate into the tight polyester molecular arrangement. The antibacterial layer of physical adsorption or weak cross-linking will have a significant decrease or even disappear of function after washing many times. Poor moisture absorption. In traditional polyester-cotton blended school uniforms, polyester does not absorb water, and cotton absorbs water but does not dry easily. After students sweat, the cotton fibers expand and become coarser, causing the fabric to stick to the skin, and the moisture evaporates slowly, which can easily lead to catching a cold or discomfort. Summary of the Invention

[0005] To improve the above-mentioned problems and reduce the issues of poor biodegradability, poor durability, and poor moisture absorption in school uniform fabrics in related technologies, this invention provides an environmentally friendly biodegradable functional school uniform fabric and its preparation method to solve the problems mentioned in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An environmentally friendly, biodegradable functional school uniform fabric and its preparation method include the following steps: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 170-190℃ and a screw speed of 150-220rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum-dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at a temperature of 75-85℃ to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at a speed of 2500rpm for 20min. Degas under vacuum for 2h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 85-95℃ and a spinning speed of 600-1000m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into a constant temperature water bath at 80-90℃ for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 10-20 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 75-85℃, and relaxed and heat-set at 95-105℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0007] Preferably, the environmentally friendly and biodegradable functional school uniform fabric is prepared from polylactic acid chips, polyethylene glycol, dicumyl peroxide, quaternized chitosan derivatives, tea polyphenols, baicalin, citric acid, butylenetetroxide, cotton pulp, and N-methylmorpholine-N-oxide through hydrophilic modification of polylactic acid chips, preparation of antibacterial dispersion, preparation of antibacterial stock solution, preparation of antibacterial cellulose fibers, spinning of blended yarns, fabric weaving, and finished product finishing. The raw materials for its preparation include: 100 parts polylactic acid chips, 10-15 parts polyethylene glycol, 0.15-0.3 parts dicumyl peroxide, 8-18 parts 2-hydroxypropyltrimethylammonium chloride chitosan, 1.78-4 parts tea polyphenols, 0.89-2 parts baicalin, 0.64-1.44 parts citric acid, 0.32-0.72 parts butylenetetrol, 100 parts cotton pulp, and 1150 parts N-methylmorpholine-N-oxide.

[0008] Preferably, the polylactic acid chips are specifically L-polylactic acid chips, and the polyethylene glycol is specifically polyethylene glycol 4000.

[0009] Preferably, the volume fraction of the glacial acetic acid aqueous solution in S2 is 1%.

[0010] Preferably, the mass concentration of the quaternized chitosan solution in S2 is 20%.

[0011] Preferably, the mass concentration of the N-methylmorpholine-N-oxide aqueous solution in S3 is 85%.

[0012] Preferably, the mass concentration of the N-methylmorpholine-N-oxide aqueous solution in S3 is 85%.

[0013] Preferably, the mass concentration of the cellulase working solution in S7 is 2%.

[0014] Preferably, the mass concentration of the citric acid aqueous solution in S8 is 1%.

[0015] Preferably, the mass concentration of the soybean oil-based polyethylene glycol softener working solution in S8 is 3%.

[0016] This invention uses fully biodegradable cellulose and hydrophilically modified polylactic acid to construct the fabric matrix, combined with a natural biodegradable functional system, so that the fabric can be completely decomposed by microorganisms in a composting environment, thereby improving the degradation performance of this invention. This invention utilizes a low-temperature in-situ esterification and crosslinking process to enable antibacterial components to form stable covalent bonds with cellulose molecular chains. This, combined with inter-fiber interface crosslinking, enhances structural stability, prevents loss of functional components, and improves the durability of school uniform fabrics. This invention breaks the hydrophobic crystalline structure of polylactic acid by melt grafting polyethylene glycol, and combines it with highly hydrophilic cellulose to construct a continuous hydrophilic moisture-wicking network, thereby improving the moisture absorption and evaporation capacity of the fabric and enhancing the moisture absorption of school uniform fabric. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the embodiments of the present invention. Unless otherwise specified below, the raw materials used in the various examples and embodiments of the present invention are all commercially available common materials. Preparation Examples 1-5 An environmentally friendly and biodegradable functional school uniform fabric, the components of which and their corresponding proportions are shown in the table below, is prepared using the following method: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 180℃ and a screw speed of 180rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. The polylactic acid chips are specifically L-polylactic acid chips; Specifically, polyethylene glycol is polyethylene glycol 4000; S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. The volume fraction of the glacial acetic acid aqueous solution is 1%; The mass concentration of the quaternized chitosan solution was 20%. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 80°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Vacuum degassing is performed for 2 h to obtain the antibacterial stock solution. The mass concentration of the N-methylmorpholine-N-oxide aqueous solution was 85%. The solid content of the cellulose solution is 8%; S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 90℃ and a spinning speed of 800m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into an 85℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 15 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 80℃, and relaxed and heat-set at 100℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. The mass concentration of the cellulase working solution was 2%. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0018] The mass concentration of the citric acid aqueous solution was 1%. The mass concentration of the soybean oil-based polyethylene glycol softener working solution is 3%; Table: Components and their mass ratios (g) of the raw materials used in Preparation Examples 1-5 Preparation Example 6 A method for preparing an environmentally friendly, biodegradable functional school uniform fabric differs from that in Example 1 in that the preparation method is as follows: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 170°C and a screw speed of 150 rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum-dried at a temperature of 80°C and a vacuum degree of ≤-0.09 MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 80°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Vacuum degassing is performed for 2 h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 90℃ and a spinning speed of 800m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into an 85℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 15 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 80℃, and relaxed and heat-set at 100℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0019] Preparation Example 7 A method for preparing an environmentally friendly, biodegradable functional school uniform fabric differs from that in Example 1 in that the preparation method is as follows: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 190℃ and a screw speed of 220rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 80°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Vacuum degassing is performed for 2 h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 90℃ and a spinning speed of 800m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into an 85℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 15 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 80℃, and relaxed and heat-set at 100℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0020] Preparation Example 8 A method for preparing an environmentally friendly, biodegradable functional school uniform fabric differs from that in Example 1 in that the preparation method is as follows: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 180℃ and a screw speed of 180rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 75°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Degas under vacuum for 2 h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 90℃ and a spinning speed of 800m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into an 85℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 15 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 80℃, and relaxed and heat-set at 100℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0021] Preparation Example 9 A method for preparing an environmentally friendly, biodegradable functional school uniform fabric differs from that in Example 1 in that the preparation method is as follows: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 180℃ and a screw speed of 180rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 85°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Vacuum degassing is performed for 2 h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 90℃ and a spinning speed of 800m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into an 85℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 15 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 80℃, and relaxed and heat-set at 100℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0022] Preparation Example 10 A method for preparing an environmentally friendly, biodegradable functional school uniform fabric differs from that in Example 1 in that the preparation method is as follows: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 180℃ and a screw speed of 180rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 80°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Vacuum degassing is performed for 2 h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 85℃ and a spinning speed of 600m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into an 80℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 10 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 75℃, and relaxed and heat-set at 95℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0023] Preparation Example 11 A method for preparing an environmentally friendly, biodegradable functional school uniform fabric differs from that in Example 1 in that the preparation method is as follows: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 180℃ and a screw speed of 180rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at 80°C to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at 2500 rpm for 20 min. Vacuum degassing is performed for 2 h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 95℃ and a spinning speed of 1000m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into a 90℃ constant temperature water bath for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 20 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 85℃, and relaxed and heat-set at 105℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

[0024] Performance testing The environmentally friendly and biodegradable functional school uniform fabrics prepared in each embodiment were selected for testing. The test subjects were 110 samples of the environmentally friendly and biodegradable functional school uniform fabrics, with 10 samples in each group. Their degradation performance, durability, and moisture absorption were tested, and the specific testing steps are as follows: Degradation performance: First, samples were taken from the environmentally friendly, biodegradable functional school uniform fabric prepared in the examples. The fabric was cut into 5mm × 5mm samples and buried in activated soil. The temperature was controlled at 56-60℃, and the relative humidity at 50-55%. The samples were continuously tested for 180 days. The degradation rate was calculated by continuously measuring the carbon dioxide release, thus characterizing the degradation performance of the environmentally friendly, biodegradable functional school uniform fabric. The test results and evaluation criteria are as follows: Degradation rate > 75% (considered high degradation performance); Degradation rate <75% (considered as low degradation performance).

[0025] Durability: First, samples of the environmentally friendly and biodegradable functional school uniform fabric prepared in the examples were taken and subjected to 50 consecutive washes simulating a standard household washing machine wash. After washing, the samples were hung to dry, and then the antibacterial rate against Escherichia coli was tested to characterize the durability of the environmentally friendly and biodegradable functional school uniform fabric. The test results and evaluation criteria are as follows: Antibacterial rate > 90% (considered as high durability); Antibacterial rate <90% (considered as poor durability).

[0026] Hygroscopicity: First, samples were taken from the environmentally friendly and biodegradable functional school uniform fabric prepared in the examples. The samples were immersed in water for a certain period of time, and after dripping water, the water absorption per unit mass was calculated. The rate of water evaporation over time in a standard environment was measured after the samples were wetted. This was used to characterize the hygroscopicity of the environmentally friendly and biodegradable functional school uniform fabric. The test results and evaluation criteria are as follows: Water absorption rate > 100%, evaporation rate > 0.15 g / h (considered as highly hygroscopic); Water absorption rate <100%, evaporation rate <0.15g / h (considered as weak hygroscopicity).

[0027] It should be specifically noted that the environmentally friendly and biodegradable functional school uniform fabric obtained above is produced in accordance with normal production methods. Any defective environmentally friendly and biodegradable functional school uniform fabric produced is disregarded. Examples 1-5

[0028] The corresponding relationship of the preparation methods used in an environmentally friendly and biodegradable functional school uniform fabric is shown in the table below.

[0029] Table: Comparison of the use of environmentally friendly and biodegradable functional school uniform fabrics in Examples 1-5 The environmentally friendly and biodegradable functional school uniform fabrics from Examples 1-5 were extracted and their degradation rate, water droplet diffusion time, evaporation rate, and peel strength retention rate were tested according to the above measurement steps and standards. The average value of the test results was recorded in the table below.

[0030] Table: Performance test results of degradation rate, antibacterial rate, water absorption rate, and evaporation rate in Examples 1-5 As can be seen from the table above, the preparation processes of environmentally friendly and biodegradable functional school uniform fabrics in Examples 1-5 all effectively improve the production results of these fabrics. Polylactic acid (PLA) chips, as the core synthetic matrix material, possess complete biodegradability and can be completely decomposed into carbon dioxide and water by microorganisms in a composting environment. This ensures the overall degradation performance of the fabric at the matrix level, while also providing stable mechanical support and wrinkle resistance, avoiding the wrinkle-prone shrinkage defects of cellulose matrices. Polyethylene glycol, as a hydrophilic grafting monomer for PLA, under the initiation of dicumyl peroxide, grafts hydrophilic polyethers onto the PLA molecular chains through a melt grafting reaction, breaking the regular crystalline structure of the PLA molecular chains. The structure is modified to reduce its crystallinity, while introducing a large number of hydrophilic hydroxyl groups and ether bonds, significantly improving the hydrophilicity and moisture absorption and wicking capacity of polylactic acid (PLA). This addresses the industry pain points of poor moisture absorption and static electricity generation in pure PLA. Furthermore, the grafted PLA retains its complete biodegradable molecular structure, without affecting its biodegradability. Dicumyl peroxide, acting as a free radical initiator in the melt grafting reaction, decomposes in the molten state to generate free radicals, which capture active hydrogen atoms from the PLA molecular chain, forming active free radical sites. These sites provide active sites for the grafting reaction between polyethylene glycol and PLA, ensuring the smooth progress of the grafting reaction and improving the grafting efficiency and the stability of the modification effect. Cotton pulp, as a natural cellulose matrix raw material for fabrics, has a large number of hydrophilic hydroxyl groups on its molecular chain, possessing excellent natural... With excellent hygroscopic and biodegradable properties, it can be completely degraded by cellulase in the natural environment. It synergistically forms a fully biodegradable fabric matrix with modified polylactic acid, while providing numerous active hydroxyl sites for the covalent grafting of antibacterial components, ensuring a stable load of antibacterial function. N-methylmorpholine-N-oxide, as a green solvent for cellulose, can directly dissolve the cellulose macromolecules in cotton pulp, breaking the hydrogen bonds between cellulose molecules and allowing the cellulose molecular chains to fully unfold, forming a uniform and stable cellulose spinning solution, ensuring the smooth progress of subsequent spinning processes. Furthermore, this solvent can be completely recycled, and the production process emits no toxic or harmful pollutants, meeting environmental protection requirements. Glacial acetic acid aqueous solution, as the dissolving medium for quaternized chitosan derivatives, can be adjusted by regulating the pH of the system. The pH value ensures the complete protonation of the quaternized chitosan molecular chains, achieving complete and uniform dissolution of the quaternized chitosan. This provides a stable liquid environment for the uniform dispersion of the antibacterial system, without damaging the molecular structure and antibacterial activity of the antibacterial components. The quaternized chitosan derivative, as the core antibacterial functional component, is itself a modified natural chitosan product with complete biodegradability and no heavy metal or toxic residues. The quaternary ammonium groups on its molecular chains can disrupt bacterial cell membrane structures through charge interaction, achieving a broad-spectrum and highly effective antibacterial effect. Simultaneously, the molecular chains contain numerous active hydroxyl groups, which can be grafted onto cellulose molecular chains through cross-linking reactions, preventing the physical shedding of antibacterial components and significantly improving the wash resistance and durability of the antibacterial properties. Tea polyphenols and baicalin serve as plant-derived auxiliary antibacterial components.Both are biodegradable active substances extracted from natural plants. They synergistically construct a dual-effect antibacterial system with quaternized chitosan, achieving antibacterial effects by disrupting the enzyme system and genetic material of bacteria. This compensates for the insufficient antibacterial activity of quaternized chitosan against certain strains. Simultaneously, the phenolic hydroxyl groups on both molecules can serve as active sites for cross-linking reactions, forming stable bonds with cellulose molecular chains, further enhancing the durability of the antibacterial system. Furthermore, the phenolic hydroxyl groups possess excellent antioxidant and UV protection properties, additionally imparting anti-aging and UV protection functions to the fabric. Citric acid, as a formaldehyde-free bifunctional cross-linking agent, has multiple carboxyl groups on its molecule, which can react with cellulose, quaternized chitosan, tea polyphenols, and Scutellaria baicalensis under heating conditions. The hydroxyl groups on the glycoside undergo esterification, forming stable covalent bonds between the antibacterial component and the cellulose molecular chain. This firmly fixes the antibacterial component inside and on the surface of the fiber, fundamentally solving the problem of easy washing and shedding of antibacterial components in traditional physical impregnation processes. This significantly improves the long-term durability of the fabric's antibacterial performance and function. Meanwhile, citric acid is a natural, biodegradable organic acid that releases no formaldehyde or toxic substances, thus not affecting the overall biodegradability of the fabric. Butylenetetrol, as a cross-linking promoter, has multiple hydroxyl groups on its molecule and can undergo esterification with the carboxyl groups of citric acid, forming a multi-dimensional cross-linking network between the cellulose molecular chain and the antibacterial component, improving the uniformity and grafting efficiency of the cross-linking reaction. This process avoids the stress concentration problem of molecular chains caused by single citric acid crosslinking, and further seals the free carboxyl groups after the crosslinking reaction, reducing the acidity of the fabric and improving its pH stability and wearing safety. N-methylmorpholine-N-oxide aqueous solution, used as the coagulation bath medium in wet and dry spinning, allows the solvent in the cellulose spinning solution to rapidly diffuse and precipitate through a concentration gradient, causing the cellulose molecular chains to reform hydrogen bonds and solidify, achieving continuous and stable fiber preparation. Simultaneously, the microporous structure and cross-sectional morphology of the fiber can be controlled by adjusting the coagulation bath parameters, further improving the fiber's moisture absorption and wicking properties. Cellulase working solution is used for the bio-enzymatic polishing and finishing of the fabric greige, allowing for selective... This process breaks down protruding fiber fuzz on the fabric surface, resulting in a smooth and even surface, improving the fabric's anti-pilling properties and appearance durability. Simultaneously, cellulase, a natural biological agent, is completely biodegradable, with no pollutant emissions during production. It does not damage the fiber structure or the fabric's degradation properties. Citric acid aqueous solution is used for interfacial cross-linking treatment in the fabric finishing process. Under heating conditions, it further promotes the esterification and cross-linking reaction between the terminal hydroxyl groups on the modified polylactic acid molecular chains and the hydroxyl groups on the cellulose molecular chains, forming covalent cross-linking bridges between the two blended fibers, significantly enhancing the cohesion and bonding strength between the fibers. This achieves the goal of improving the production effect of environmentally friendly, biodegradable, functional school uniform fabrics. Its degradation rate is 91.7-95.2%, which is considered to be high degradation performance; its antibacterial rate is 93.5-98.7%, which is considered to be strong durability; its water absorption rate is 185-248%, and its evaporation rate is 0.16-0.25g / h, which is considered to be strong hygroscopicity. It is evident that, given a fixed amount of raw materials, the production effect of environmentally friendly and biodegradable functional school uniform fabrics can be enhanced by adjusting the proportions of these materials. Based on the data in the table above, it is clear that when preparing environmentally friendly and biodegradable functional school uniform fabrics, the following ingredients are used: 100 parts polylactic acid chips, 15 parts polyethylene glycol, 0.3 parts dicumyl peroxide, 12 parts 2-hydroxypropyltrimethylammonium chloride chitosan, 2.67 parts tea polyphenols, 1.33 parts baicalin, 0.96 parts citric acid, 0.48 parts butylene tert-butylene glycol, 100 parts cotton pulp, and 1150 parts N-methylmorpholine-N-oxide. The obtained environmentally friendly biodegradable functional school uniform fabric exhibited the strongest degradation performance and moisture absorption. The reason for this is that the addition amounts of polyethylene glycol and the initiator dicumyl peroxide were the highest among all groups. Under the initiation effect of dicumyl peroxide, more polyethylene glycol molecules could be stably grafted onto the polylactic acid (PLA) molecular chain, effectively breaking the original regular crystalline structure of PLA and significantly reducing its crystallinity. Simultaneously, a large number of hydrophilic ether bonds and terminal hydroxyl groups were introduced into the PLA molecular chain, fundamentally improving the inherent defect of poor moisture absorption in pure PLA at the molecular structure level and significantly enhancing the hydrophilicity of the PLA matrix. In addition to its moisture-wicking capabilities, the fabric utilizes the abundant active hydrophilic hydroxyl groups inherent in the cellulose molecular chains of cotton pulp to synergistically construct continuous and abundant hydrophilic conduction channels. This allows the fabric to quickly absorb and conduct moisture from the skin's surface. Simultaneously, it optimizes the microporous structure within the fiber, accelerating the evaporation rate of absorbed moisture. Ultimately, this results in optimal moisture-wicking and quick-drying performance. Furthermore, the high grafting amount of polyethylene glycol further disrupts the regular arrangement of polylactic acid (PLA) molecular chains, significantly increasing the proportion of amorphous PLA regions. This allows microorganisms in the composting environment to more easily attach to, erode, and decompose PLA molecular chains, effectively accelerating the drying process. The degradation rate of the polylactic acid matrix is ​​moderate under this ratio, with the addition of both the antibacterial system and the cross-linking system being appropriate. This ensures that the antibacterial component forms a stable covalent graft with the cellulose molecular chain, achieving long-lasting antibacterial function, while avoiding the formation of an overly dense three-dimensional cross-linking network that hinders the decomposition of cellulose molecules by microorganisms. A good synergistic matching of degradation rates is achieved between the fully biodegradable cellulose matrix and the modified polylactic acid matrix, avoiding the problem of degradation lag in a single matrix. The moderate cross-linking density also does not affect the decomposition of cellulose molecular chains by cellulase secreted by microorganisms, as obtained from Examples 1-5.

[0031] It is evident that, given a fixed amount of raw materials, the production effect of environmentally friendly and biodegradable functional school uniform fabrics can be enhanced by adjusting the proportions of these materials. Based on the data in the table above, it is clear that when preparing environmentally friendly and biodegradable functional school uniform fabrics, the following combination of materials—100 parts polylactic acid chips, 12 parts polyethylene glycol, 0.2 parts dicumyl peroxide, 18 parts 2-hydroxypropyltrimethylammonium chloride chitosan, 4 parts tea polyphenols, 2 parts baicalin, 1.44 parts citric acid, 0.72 parts butylene terephthalol, 100 parts cotton pulp, and 1150 parts N-methylmorpholine-N-oxide—results in an environmentally friendly and biodegradable fabric. The functional school uniform fabric exhibits the highest durability. This is attributed to the highest addition levels of antibacterial functional components and the corresponding cross-linking system in this formulation. Sufficient amounts of quaternized chitosan derivatives, tea polyphenols, and baicalin provide ample antibacterial active sites for the fabric. Simultaneously enhanced citric acid and butylene tert-butyl cross-linking systems effectively mediate esterification and cross-linking reactions during fiber forming. This allows the active hydroxyl groups on numerous antibacterial component molecules to form stable covalent bonds with the hydroxyl groups on the cotton pulp cellulose molecular chains, uniformly fixing the antibacterial components throughout the entire cross-section of the fiber's molecular structure, rather than merely adsorbing them onto the fiber surface through physical action. This method fundamentally avoids the loss of antibacterial components due to mechanical friction and water rinsing during repeated washing, ensuring that the fabric maintains excellent antibacterial properties even after long-term washing. Simultaneously, a sufficient amount of cross-linking system forms a uniform and dense multi-dimensional three-dimensional cross-linking network between cellulose molecular chains, significantly improving the structural stability and dry / wet strength of cellulose fibers. This prevents molecular chain breakage and fuzzing during long-term wear and washing, effectively improving the fabric's anti-pilling performance and strength retention. Appropriate amounts of polyethylene glycol and initiator can achieve hydrophilic modification and crystallinity of the polylactic acid matrix. The balance ensures both the mechanical support and wrinkle resistance of polylactic acid fibers, while also improving their interfacial compatibility with cellulose fibers. Combined with the interfacial cross-linking effect during the finishing process, the cohesion between blended fibers can be greatly improved, avoiding fiber slippage and fabric deformation during long-term use. This ensures the dimensional stability and crispness of the fabric after multiple washes. At the same time, the phenolic hydroxyl groups on tea polyphenols and baicalin molecules have excellent antioxidant activity, which can effectively delay the aging and degradation of fibers during light exposure, washing, and daily wear, further extending the service life of the fabric, as obtained from Examples 1-5. Examples 6-11

[0032] The corresponding relationship of the preparation methods used in an environmentally friendly and biodegradable functional school uniform fabric is shown in the table below.

[0033] Table: Comparison of the use of environmentally friendly and biodegradable functional school uniform fabrics in Examples 6-11 The environmentally friendly and biodegradable functional school uniform fabrics from Examples 6-11 above were extracted, and their degradation rate, water droplet diffusion time, evaporation rate, and peel strength retention rate were tested according to the above measurement steps and standards. The average value of the test results was recorded in the table below.

[0034] Table: Performance test results of degradation rate, antibacterial rate, water absorption rate, and evaporation rate in Examples 1 and 6-11 As can be seen from the table above, the preparation processes of environmentally friendly and biodegradable functional school uniform fabrics in Examples 1-5 all effectively improve the production results of these fabrics. Polylactic acid (PLA) chips, as the core synthetic matrix material, possess complete biodegradability and can be completely decomposed into carbon dioxide and water by microorganisms in a composting environment. This ensures the overall degradation performance of the fabric at the matrix level, while also providing stable mechanical support and wrinkle resistance, avoiding the wrinkle-prone shrinkage defects of cellulose matrices. Polyethylene glycol, as a hydrophilic grafting monomer for PLA, under the initiation of dicumyl peroxide, grafts hydrophilic polyethers onto the PLA molecular chains through a melt grafting reaction, breaking the regular crystalline structure of the PLA molecular chains. The structure is modified to reduce its crystallinity, while introducing a large number of hydrophilic hydroxyl groups and ether bonds, significantly improving the hydrophilicity and moisture absorption and wicking capacity of polylactic acid (PLA). This addresses the industry pain points of poor moisture absorption and static electricity generation in pure PLA. Furthermore, the grafted PLA retains its complete biodegradable molecular structure, without affecting its biodegradability. Dicumyl peroxide, acting as a free radical initiator in the melt grafting reaction, decomposes in the molten state to generate free radicals, which capture active hydrogen atoms from the PLA molecular chain, forming active free radical sites. These sites provide active sites for the grafting reaction between polyethylene glycol and PLA, ensuring the smooth progress of the grafting reaction and improving the grafting efficiency and the stability of the modification effect. Cotton pulp, as a natural cellulose matrix raw material for fabrics, has a large number of hydrophilic hydroxyl groups on its molecular chain, possessing excellent natural... With excellent hygroscopic and biodegradable properties, it can be completely degraded by cellulase in the natural environment. It synergistically forms a fully biodegradable fabric matrix with modified polylactic acid, while providing numerous active hydroxyl sites for the covalent grafting of antibacterial components, ensuring a stable load of antibacterial function. N-methylmorpholine-N-oxide, as a green solvent for cellulose, can directly dissolve the cellulose macromolecules in cotton pulp, breaking the hydrogen bonds between cellulose molecules and allowing the cellulose molecular chains to fully unfold, forming a uniform and stable cellulose spinning solution, ensuring the smooth progress of subsequent spinning processes. Furthermore, this solvent can be completely recycled, and the production process emits no toxic or harmful pollutants, meeting environmental protection requirements. Glacial acetic acid aqueous solution, as the dissolving medium for quaternized chitosan derivatives, can be adjusted by regulating the pH of the system. The pH value ensures the complete protonation of the quaternized chitosan molecular chains, achieving complete and uniform dissolution of the quaternized chitosan. This provides a stable liquid environment for the uniform dispersion of the antibacterial system, without damaging the molecular structure and antibacterial activity of the antibacterial components. The quaternized chitosan derivative, as the core antibacterial functional component, is itself a modified natural chitosan product with complete biodegradability and no heavy metal or toxic residues. The quaternary ammonium groups on its molecular chains can disrupt bacterial cell membrane structures through charge interaction, achieving a broad-spectrum and highly effective antibacterial effect. Simultaneously, the molecular chains contain numerous active hydroxyl groups, which can be grafted onto cellulose molecular chains through cross-linking reactions, preventing the physical shedding of antibacterial components and significantly improving the wash resistance and durability of the antibacterial properties. Tea polyphenols and baicalin serve as plant-derived auxiliary antibacterial components.Both are biodegradable active substances extracted from natural plants. They synergistically construct a dual-effect antibacterial system with quaternized chitosan, achieving antibacterial effects by disrupting bacterial enzyme systems and genetic material. This compensates for the insufficient antibacterial activity of quaternized chitosan against certain strains. Simultaneously, the phenolic hydroxyl groups on both molecules serve as active sites for cross-linking reactions, forming stable bonds with cellulose molecular chains, further enhancing the durability of the antibacterial system. Furthermore, the phenolic hydroxyl groups possess excellent antioxidant and UV protection properties, additionally imparting anti-aging and UV protection functions to the fabric. Citric acid, as a formaldehyde-free bifunctional cross-linking agent, has multiple carboxyl groups on its molecule, which can react with cellulose, quaternized chitosan, tea polyphenols, and yellow... The hydroxyl groups on baicalin undergo esterification, forming stable covalent bonds between the antibacterial component and the cellulose molecular chain. This firmly fixes the antibacterial component inside and on the surface of the fiber, fundamentally solving the problem of easy washing and shedding of antibacterial components in traditional physical impregnation processes. This significantly improves the long-term durability of the fabric's antibacterial performance and function. Meanwhile, citric acid is a natural, biodegradable organic acid that releases no formaldehyde or toxic substances, thus not affecting the overall biodegradability of the fabric. Butylenetetrol, as a cross-linking promoter, has multiple hydroxyl groups on its molecule and can undergo esterification with the carboxyl groups of citric acid, forming a multi-dimensional cross-linking network between the cellulose molecular chain and the antibacterial component, improving the uniformity and grafting effect of the cross-linking reaction. This process avoids the stress concentration problem caused by single citric acid crosslinking, and further seals the free carboxyl groups after the crosslinking reaction, reducing the acidity of the fabric and improving its pH stability and wearing safety. N-methylmorpholine-N-oxide aqueous solution, used as the coagulation bath medium in wet and dry spinning, allows the solvent in the cellulose spinning solution to rapidly diffuse and precipitate through a concentration gradient, causing the cellulose molecular chains to reform hydrogen bonds and solidify, achieving continuous and stable fiber preparation. Furthermore, the microporous structure and cross-sectional morphology of the fiber can be controlled by adjusting the coagulation bath parameters, further improving the fiber's moisture absorption and wicking properties. Cellulase working solution is used for the bio-enzymatic polishing and finishing of the fabric, allowing for selective... This process breaks down protruding fiber fuzz on the fabric surface, resulting in a smooth and even surface, improving the fabric's anti-pilling properties and appearance durability. Simultaneously, cellulase, a natural biological agent, is completely biodegradable, with no pollutant emissions during production. It does not damage the fiber structure or the fabric's degradation properties. Citric acid aqueous solution is used for interfacial cross-linking treatment in the fabric finishing process. Under heating conditions, it further promotes the esterification and cross-linking reaction between the terminal hydroxyl groups on the modified polylactic acid molecular chains and the hydroxyl groups on the cellulose molecular chains, forming covalent cross-linking bridges between the two blended fibers, significantly enhancing the cohesion and bonding strength between the fibers. This achieves the goal of improving the production effect of environmentally friendly, biodegradable, functional school uniform fabrics. Its degradation rate is 92.7-94.1%, which is considered to be high degradation performance; its antibacterial rate is 94.1-96.2%, which is considered to be strong durability; its water absorption rate is 206-215%, and its evaporation rate is 0.14-0.20 g / h, which is considered to be strong hygroscopicity. It is evident that, given a fixed amount of raw materials, the production effect of environmentally friendly and biodegradable functional school uniform fabrics can be enhanced by adjusting the preparation conditions. Based on the data in the table above, it is clear that when preparing such fabrics, increasing the melt grafting reaction temperature and rotation speed in the hydrophilic modified polylactic acid (PLA) chip preparation process; the dissolution temperature in the antibacterial solution preparation process; and the spinning temperature, speed, constant temperature water bath temperature, duration, hot air drying temperature, and relaxation heat setting temperature in the antibacterial cellulose fiber preparation process will initially increase and then decrease the degradation performance, durability, and moisture absorption of the resulting environmentally friendly and biodegradable functional school uniform fabric. The hydrophilic modified PLA chip preparation process is carried out at a temperature of 180℃ and a screw speed of 180 rpm for the melt grafting reaction; the antibacterial solution... The liquid preparation process involves stirring and dissolving at 80℃. The antibacterial cellulose fiber preparation process involves spinning at 90℃ and 800m / min, followed by secondary stretching in an 85℃ constant temperature water bath, holding at a constant temperature for 15min, and then washing with deionized water in countercurrent flow, drying with hot air at 80℃, and relaxing heat setting at 100℃. The resulting environmentally friendly and biodegradable functional school uniform fabric exhibits the strongest degradation performance, durability, and moisture absorption. The reason for this is that during the preparation of hydrophilic modified polylactic acid chips, the melt grafting reaction temperature and screw speed ensure efficient decomposition of the initiator to generate sufficient active free radicals, enabling a full and uniform grafting reaction between polyethylene glycol and polylactic acid molecular chains. This effectively breaks down the regularity of the polylactic acid molecular chains. By incorporating a complete crystalline structure and introducing sufficient hydrophilic groups to enhance the hydrophilicity of the polylactic acid (PLA) matrix, this method avoids thermal degradation of the PLA molecular chains due to excessively high temperatures or rotation speeds, which could damage the mechanical properties and degradable structure of the matrix. Conversely, it prevents incomplete grafting reactions due to excessively low temperatures or rotation speeds, thus ensuring effective improvement of PLA's hydrophilicity and degradation properties. During the preparation of the antibacterial solution, this stirring and dissolving temperature ensures complete dissolution of cotton pulp cellulose in the solvent, allowing the cellulose molecular chains to fully extend and expose the active hydroxyl groups. Simultaneously, it ensures uniform dispersion of the antibacterial crosslinking system in the spinning solution, preventing the inactivation of natural antibacterial components due to excessively high temperatures and insufficient dissolution of cellulose or exposure of active sites due to excessively low temperatures. The thorough conduct of subsequent cross-linking reactions, during the preparation of antibacterial cellulose fibers, ensures that the spinning temperature and speed maintain optimal rheological properties of the spinning solution, achieving continuous and stable spinning formation. This results in fibers with uniform cross-sections and regular internal microporous structures, creating continuous and unobstructed hydrophilic channels for water adsorption and conduction. Simultaneously, it allows the fiber molecular chains to form a preliminary ordered orientation, laying a good structural foundation for subsequent stretching and shaping. Excessive spinning temperature or speed will not lead to unstable fiber formation, fiber breakage, or structural defects, nor will excessively low temperature or speed result in a loose fiber structure and insufficient mechanical properties. The constant temperature water bath and residence time during the secondary stretching process provide optimal reaction conditions for the citric acid-mediated esterification cross-linking reaction.This process creates a stable and uniform covalent cross-linked network between the antibacterial components and the cellulose molecular chains. This not only firmly fixes the antibacterial components within the fiber, preventing loss after repeated washing and significantly improving the fabric's antibacterial durability, but also, through stretching, achieves high orientation of the fiber molecular chains, significantly enhancing the fiber's dry and wet strength and structural stability, further strengthening the fabric's mechanical durability. It avoids excessive cross-linking due to excessively high temperatures or prolonged times, which could lead to an overly dense network structure that hinders microbial decomposition of the fiber and moisture adsorption and conduction. Conversely, it prevents insufficient cross-linking due to excessively low temperatures or short times, which could result in incomplete cross-linking and prevent stable grafting of the antibacterial components into the fiber. The effective improvement in fiber strength, along with the subsequent hot air drying and relaxation heat setting temperatures, allows for the thorough removal of internal moisture from the fibers while eliminating internal fiber stress. This stabilizes the supramolecular structure of the fibers and the dimensional shape of the fabric, improving the fabric's shape retention and dimensional stability after long-term wear and washing, further enhancing its durability. Simultaneously, it avoids excessive fiber crystallinity due to excessively high temperatures, which could reduce fiber hydrophilicity and microbial accessibility, affecting the fabric's moisture absorption and degradation properties. Conversely, it prevents insufficient setting due to excessively low temperatures, which could lead to insufficient elimination of internal fiber stress and subsequent shrinkage and deformation issues during use, as demonstrated in Examples 1 and 6-11.

[0035] This specific embodiment is merely an explanation of the present invention and not a limitation thereof. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. An environmentally friendly degradable functional school uniform fabric based on, characterized by, By weight, the environmentally friendly and biodegradable functional school uniform fabric is prepared from polylactic acid chips, polyethylene glycol, dicumyl peroxide, quaternized chitosan derivatives, tea polyphenols, baicalin, citric acid, butylene terephthalol, cotton pulp, and N-methylmorpholine-N-oxide through hydrophilic modification of polylactic acid chips, preparation of antibacterial dispersion, preparation of antibacterial stock solution, preparation of antibacterial cellulose fibers, spinning of blended yarns, fabric weaving, and finished product finishing. The raw materials for its preparation include: 100 parts of polylactic acid chips, 10-15 parts of polyethylene glycol, 0.15-0.3 parts of dicumyl peroxide, 8-18 parts of 2-hydroxypropyltrimethylammonium chloride chitosan, 1.78-4 parts of tea polyphenols, 0.89-2 parts of baicalin, 0.64-1.44 parts of citric acid, 0.32-0.72 parts of butylenetetroxide, 100 parts of cotton pulp, and 1150 parts of N-methylmorpholine-N-oxide.

2. The environment-friendly degradable functional school uniform fabric according to claim 1, characterized in that: The polylactic acid chips are specifically L-polylactic acid chips, and the polyethylene glycol is specifically polyethylene glycol 4000.

3. A method for preparing an environmentally friendly, biodegradable functional school uniform fabric according to claims 1-2, characterized in that, The preparation process of the environmentally friendly and biodegradable functional school uniform fabric includes the following steps: S1. Polylactic acid chips, polyethylene glycol, and dicumyl peroxide are fed into a twin-screw extruder and subjected to a melt grafting reaction at a temperature of 170-190℃ and a screw speed of 150-220rpm. After the reaction is completed, the chips are water-cooled, extruded, and pelletized. They are then vacuum-dried at a temperature of 80℃ and a vacuum degree of ≤-0.09MPa for 6 hours to obtain hydrophilic modified polylactic acid chips. S2. Dissolve 2-hydroxypropyltrimethylammonium chloride chitosan in glacial acetic acid aqueous solution and stir at 2000 rpm for 30 min to prepare quaternized chitosan solution. Then add tea polyphenols and baicalin to the solution and stir at 1500 rpm for 20 min. Then add citric acid and butylenetetroxide and continue stirring until completely dissolved to obtain antibacterial dispersion. S3. After crushing the cotton pulp, add it to an aqueous solution of N-methylmorpholine-N-oxide and stir to dissolve it at a temperature of 75-85℃ to prepare the cellulose stock solution. Then add the antibacterial dispersion obtained in S2 and stir at a speed of 2500rpm for 20min. Degas under vacuum for 2h to obtain the antibacterial stock solution. S4. Using the antibacterial stock solution obtained in S3 as raw material, spinning is carried out at a spinning temperature of 85-95℃ and a spinning speed of 600-1000m / min. The extruded filaments are fed into an N-methylmorpholine-N-oxide coagulation bath to complete coagulation and molding. After a first-stage stretch of 2.2 times, the fibers are introduced into a constant temperature water bath at 80-90℃ for a second-stage stretch, with the total stretch ratio controlled at 4 times. The fibers are held at a constant temperature for 10-20 minutes, then washed with deionized water in a countercurrent flow, dried with hot air at 75-85℃, and relaxed and heat-set at 95-105℃. Finally, the fibers are wound to obtain antibacterial cellulose fibers. S5. The hydrophilic modified polylactic acid chips obtained in S1 are dried in a vacuum drying oven at 90℃ for 8 hours until the water content is less than 50ppm. They are then fed into a screw spinning machine and melt-spun at 180℃. After winding, two-stage stretching, and heat setting at 100℃, hydrophilic modified polylactic acid fibers are obtained. S6. The antibacterial cellulose fiber obtained in S4 and the hydrophilic modified polylactic acid fiber obtained in S5 are put into the blending box and mixed. The mixture is then processed into a sliver by a carding machine and then combined by a three-stage drawing frame. The yarn is then spun on a spinning frame to produce a 32-count blended yarn with a twist coefficient of 360 and a twist direction of Z to obtain the finished blended yarn. S7. Using the blended yarn obtained from S6 as warp and weft yarns, and adopting a 2 / 1 twill weave, the fabric is woven on a rapier loom to form a greige fabric. After desizing, it is placed in cellulase working solution and kept at 50℃ for 35 minutes. Then it is washed sequentially with 85℃ hot water and 25℃ cold water, and then rolled dry to a liquid-pickup ratio of 70% to obtain the greige fabric. S8. The fabric obtained in S7 is immersed in a citric acid aqueous solution for 10 minutes, pre-dried with hot air at 80℃ for 5 minutes to remove free moisture, and then baked at a constant temperature of 100℃ for 8 minutes. After baking, it is washed twice with deionized water, and then immersed in soybean oil-based polyethylene glycol softener working solution. It is then immersed at 40℃ for 15 minutes, with the liquid roll rate controlled at 70%. It is then pre-dried with hot air at 100℃ for 3 minutes and pre-shrinked and shaped at 110℃, with the overfeed rate controlled at 3% during the process, to obtain an environmentally friendly and biodegradable functional school uniform fabric.

4. The method for preparing an environmentally friendly, biodegradable functional school uniform fabric according to claim 3, characterized in that: The volume fraction of the glacial acetic acid aqueous solution in S2 is 1%.

5. The method for preparing an environmentally friendly, biodegradable functional school uniform fabric according to claim 3, characterized in that: The mass concentration of the quaternized chitosan solution in S2 is 20%.

6. The preparation method of the environmentally friendly biodegradable functional school uniform fabric according to claim 3, characterized in that: The mass concentration of the N-methylmorpholine-N-oxide aqueous solution in S3 is 85%.

7. The preparation method of the environmentally friendly biodegradable functional school uniform fabric according to claim 3, characterized in that: The solid content of the cellulose stock solution in S3 is 8%.

8. The method for preparing an environmentally friendly, biodegradable functional school uniform fabric according to claim 3, characterized in that: The mass concentration of the cellulase working solution in S7 is 2%.

9. The method for preparing an environmentally friendly, biodegradable functional school uniform fabric according to claim 3, characterized in that: The mass concentration of the citric acid aqueous solution in S8 is 1%.

10. The method for preparing an environmentally friendly, biodegradable functional school uniform fabric according to claim 3, characterized in that: The mass concentration of the soybean oil-based polyethylene glycol softener working solution in S8 is 3%.

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