Antibacterial breathable bio-based composite fabric and preparation method thereof

Abstract

The invention relates to the technical field of layered composite fabrics, in particular to an antibacterial breathable bio-based composite fabric and a preparation method thereof. The composite fabric comprises a two-layer structure of an inner-layer fabric and an outer-layer fabric, the inner-layer fabric is prepared from a bio-based material polylactic acid, the outer-layer fabric is prepared from bio-based materials polyamide fibers and polyester fibers, the polylactic acid is subjected to modification treatment, graphene oxide is introduced, quaternary ammonium salt is generated, the composite fabric has excellent antibacterial performance, and the antibacterial performance of the composite fabric is improved. The preparation method of the antibacterial modified polylactic acid comprises the following steps: reacting graphene oxide with 1-dimethoxy (methyl) silicon methyl isocyanate to prepare isocyanate-based graphene oxide; reacting the isocyanate-based graphene oxide with polylactic acid to prepare graphene oxide modified polylactic acid; reacting the graphene oxide modified polylactic acid with epoxidized soybean oil and amino modified graphene oxide to prepare modified polylactic acid; and carrying out quaternization reaction on the modified polylactic acid and bromoethanol to generate the antibacterial modified polylactic acid.

Description

Technical Field

[0001] The invention relates to the technical field of layered composite fabrics, and in particular to an antibacterial and breathable bio-based composite fabric and a preparation method thereof. Background Art

[0002] Bio-based materials are materials made from renewable biomass, including crops and trees, through biological, chemical and physical means. The application and promotion of bio-based materials has effectively reduced the exploitation and utilization of non-renewable resources such as petroleum, and also reduced pollution and damage to the environment. Commonly used bio-based materials include bio-based polylactic acid, bio-based polyamide PA56, bio-based polyester PET, etc. Among them, polylactic acid is made from biomass materials containing sugar, starch, cellulose, etc., fermented into lactic acid, and then polymerized by lactic acid. It is a bio-based material. PA56 is made from biomass materials as raw materials, and 1,5-pentanediamine is prepared by microbial method, and then polymerized with adipic acid. Bio-based polyester PET is prepared by polymerizing bio-based ethylene glycol monomer and fossil-based terephthalic acid prepared by biomass materials through biochemical catalysis.

[0003] The use of bio-based materials to prepare fabrics has excellent biological environmental protection, but there are some defects that need to be overcome, such as the problem of light aging of polyamide materials, the problem of easy static electricity generation of PET materials, and the air permeability of polyamide fabrics and polyester fabrics needs to be improved. For example, polylactic acid fabrics, as skin-friendly fabrics, need to improve their antibacterial properties, and polylactic acid materials have the problem of large brittleness, and need to improve their toughness. Chinese patent CN116252525B discloses a method for preparing antibacterial and wear-resistant textile fabrics, the fabrics include an inner base fabric, a middle base fabric and an outer base fabric, wherein the middle base fabric is an antibacterial layer, chitin fiber and polyacrylonitrile fiber are blended into the middle base fabric, the antibacterial liquid is placed in a steam box, and the middle base fabric is passed through the steam in the steam box, and the antibacterial particles are injected into the middle base fabric to achieve the antibacterial properties of the middle base fabric, but the mode of action between the antibacterial component and the middle base fabric is physical adsorption, and the antibacterial stability needs to be improved. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an antibacterial and breathable bio-based composite fabric and a preparation method thereof, so as to solve the problem that the antibacterial performance and breathability of the fabric in the prior art need to be improved.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for preparing an antibacterial and breathable bio-based composite fabric comprises the following steps: Step 1: adding graphene oxide to N,N-dimethylformamide, and after ultrasonic dispersion, adding 1-dimethoxy(methyl)silylmethyl isocyanate to react. After the reaction is completed, filtering, washing, and drying to obtain isocyanate-based graphene oxide; Step 2: mixing the isocyanate-based graphene oxide with the polylactic acid, and kneading the mixture. After kneading, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain the graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting, after the reaction is completed, adding amino modified graphene oxide, continuing the reaction, after the reaction is completed, precipitating, filtering, washing, and drying to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane; Step 4, adding the modified polylactic acid into dimethyl sulfoxide, adding bromoethanol, reacting, and after the reaction is completed, precipitating, filtering, washing, and drying to obtain the antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, and chopping the polylactic acid filaments to obtain polylactic acid fibers; The polylactic acid fiber is spun into yarn, and the yarn is then spun into fabric through a knitting process to obtain the polylactic acid fabric; Step 6: blending the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber to obtain a blended yarn, and then spinning the blended yarn into a fabric through a knitting process to obtain a nylon / polyester blended fabric; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, and the inner fabric and the outer fabric are compounded to obtain an antibacterial and breathable bio-based composite fabric.

[0006] Preferably, in the step 1, the mass ratio of graphene oxide, N,N-dimethylformamide and 1-dimethoxy(methyl)silylmethyl isocyanate is 10:(800-1000):(16-20), and the reaction conditions are stirring at a speed of 800-1200 r / min and a temperature of 75-85° C. for 6-8 hours.

[0007] Preferably, in the step 1: the ultrasonic dispersion condition is ultrasonic dispersion at an ultrasonic dispersion frequency of 40-60 kHz for 30-60 min, washing includes using acetone to wash multiple times to remove residual solvent N,N-dimethylformamide and unreacted 1-dimethoxy(methyl)silylmethyl isocyanate, and drying includes using a vacuum oven to remove residual acetone.

[0008] Preferably, in step 2: the mass ratio of isocyanate-based graphene oxide to polylactic acid is (4.5-5):100, and the banburying conditions are banburying at a stirring speed of 60-80 r / min and a temperature of 175-185° C. for 15-20 min.

[0009] Preferably, in the step three, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino modified graphene oxide is 100:(800-1000):(10-20):(6-10), the reaction conditions are under the protection of inert gas and at a temperature of 65-75°C for 28-36h, and the conditions for continuing the reaction are under the protection of inert gas and at a temperature of 65-75°C for 30-36h.

[0010] Preferably, in the step three, the precipitation comprises adding ethanol 3-5 times the mass of dimethyl sulfoxide for precipitation, and the washing comprises washing with ethanol 3-5 times.

[0011] Preferably, the amino-modified graphene oxide in step 3 is prepared by the following steps: Adding N-aminoethyl-3-aminopropylmethyldimethoxysilane to an ethanol aqueous solution to obtain an N-aminoethyl-3-aminopropylmethyldimethoxysilane solution, adding graphene oxide to the N-aminoethyl-3-aminopropylmethyldimethoxysilane solution, reacting, filtering, washing, and drying after the reaction is completed to obtain amino-modified graphene oxide; The mass ratio of N-aminoethyl-3-aminopropylmethyldimethoxysilane, ethanol aqueous solution and graphene oxide is (15-20):(800-1000):(3-6), and the reaction conditions are reflux reaction at 75-85°C for 20-30h.

[0012] Preferably, in step 4, the mass ratio of modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:(800-1000):(18-24), and the reaction is carried out under the protection of an inert gas at a temperature of 65-75° C. for 110-130 hours.

[0013] Preferably, in step 4: precipitation comprises adding ethanol in an amount 3-5 times the mass of dimethyl sulfoxide for precipitation, and washing comprises washing with ethanol 3-5 times.

[0014] Preferably, in the step 5: the content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 10-15wt%, the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1, the spinning temperature is 20-40°C, and the coagulation bath is deionized water; The diameter of the obtained polylactic acid fiber is 40-60 μm.

[0015] Preferably, in step 5: the yarn count of the yarn is 30-50S (English count), and the weight of the polylactic acid fabric is 150-180g / m 2 .

[0016] Preferably, in step six: the mass ratio of the light-resistant bio-based nylon fiber to the antistatic bio-based polyester fiber is 1:1, the yarn count of the blended yarn is 35-45S, and the gram weight of the polylactic acid fabric is 220-250g / m 2 .

[0017] Preferably, the light-resistant bio-based nylon fiber in step six is ​​prepared by the following steps: The bio-based polyamide resin PA56 and epoxy-modified nano zinc oxide are melt-kneaded to obtain a melt, and the melt is spun to obtain a light-resistant bio-based nylon fiber; The mass ratio of bio-based polyamide resin PA56 to epoxy-modified nano zinc oxide is 100:(8-12), the melt mixing conditions are melt mixing at a temperature of 260-280° C. for 15-20 min, a spinning pressure of 4-8 MPa, and a spinning speed of 800-1600 m / min; Epoxy-modified nano zinc oxide is prepared by the following steps: Adding nano zinc oxide to an ethanol aqueous solution, after ultrasonic dispersion, adding γ-glycidyloxypropyltrimethoxysilane, continuing ultrasonic dispersion, after the reaction is completed, filtering, washing, and drying to obtain epoxy-modified nano zinc oxide; The mass ratio of γ-glycidyloxypropyltrimethoxysilane, ethanol aqueous solution and nano zinc oxide is (5-10):(500-800):(8-12), and the reaction conditions are reflux reaction at 75-85°C for 3-5h; The antistatic bio-based polyester fiber is prepared by the following steps: The bio-based polyester resin PET (polyethylene terephthalate) is mixed with an antistatic agent and melt-spun to obtain antistatic bio-based polyester fiber; The mass ratio of bio-based polyester resin PET to antistatic agent is 100:(6-8), and the melt spinning temperature is 270-290°C; The antistatic agent is prepared by the following steps: Mix fatty amine polyoxyethylene ether, polyethylene glycol glycidyl ether and sodium dodecylbenzene sulfonate, add silane coupling agent and wetting dispersant in sequence, stir and obtain an antistatic agent; Among them, the mass ratio of fatty amine polyoxyethylene ether, polyethylene glycol glycidyl ether, sodium dodecylbenzene sulfonate, silane coupling agent and wetting dispersant is (40-60):(10-20):(5-10):(3-5):(0.5-1).

[0018] The present invention also discloses an antibacterial and breathable bio-based composite fabric prepared by the above-mentioned method for preparing the antibacterial and breathable bio-based composite fabric.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The composite fabric in the present invention comprises a two-layer structure of an inner fabric and an outer fabric. The inner fabric is made of a bio-based material, polylactic acid, and the outer fabric is made of bio-based materials, nylon fiber and polyester fiber, which reduces the use of non-renewable resources and is environmentally friendly. The inner fabric and the outer fabric are both spun by a knitting process, and the coil structure makes the arrangement of the yarns not tight enough, leaving large gaps between the yarns, which is convenient for the passage of gas molecules and the fabric has good air permeability. The polylactic acid fabric as the inner fabric has good skin affinity. The polylactic acid is modified to enhance its toughness and improve its antibacterial properties, and can avoid the problem of bacterial breeding caused by the humid environment provided by sweating when in contact with the skin. The outer fabric is made of a blend of light-resistant bio-based nylon fiber and antistatic bio-based polyester fiber, and has excellent wear resistance, light resistance and antistatic properties. In the present invention, when preparing antibacterial modified polylactic acid, adding antibacterial material graphene oxide can effectively improve the antibacterial property of polylactic acid, using 1-dimethoxy (methyl) silyl methyl isocyanate to modify graphene oxide to obtain isocyanate-based graphene oxide, and then the isocyanate group introduced on the surface reacts with the terminal hydroxyl group and the terminal carboxyl group on the polylactic acid molecular chain respectively to generate carbamate bonds and amide bonds respectively, thereby realizing the chemical bonding of graphene oxide and polylactic acid to obtain graphene oxide-modified polylactic acid; the introduction of epoxy soybean oil can improve the toughness of polylactic acid, and the graphene oxide-modified polylactic acid molecules The imino groups on the carbamate bonds and amide bonds can react with the epoxy groups on the epoxy soybean oil molecules to achieve chemical bonding between the epoxy soybean oil and the graphene oxide modified polylactic acid. Since the epoxy soybean oil is a multi-epoxy material, it can further react with the amino and imino groups on the graphene oxide molecules modified by N-aminoethyl-3-aminopropylmethyldimethoxysilane to introduce more graphene oxide, thereby further improving the antibacterial properties. The imino groups are converted into tertiary amines through a ring-opening reaction with epoxy groups. Under the action of the tertiary amine and the quaternizing agent bromoethanol, an antibacterial quaternary ammonium salt is formed, thereby further improving the antibacterial properties of the polylactic acid. In the present invention, when preparing the outer fabric, both nylon fiber and polyester fiber have good wear resistance, which can improve the service life of the fabric. The nylon fiber is modified to improve the problem that it is easy to age and harden under long-term light exposure, and the polyester fiber is modified to improve the problem that it is easy to generate static electricity due to friction, so that the outer fabric has wear resistance, light resistance and antistatic properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a process flow chart of the preparation of the antibacterial modified polylactic acid in the present invention; Figure 2 This is a bar chart showing the test results of the antibacterial properties of the polylactic acid fabrics prepared in Examples 3-7 of the present invention and Comparative Examples 1-2. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] Example 1 This embodiment discloses a method for preparing light-resistant bio-based nylon fiber, comprising the following steps: The bio-based polyamide resin PA56 and epoxy-modified nano zinc oxide were melt-mixed at 270°C for 18 minutes, with the mass ratio of light-resistant bio-based polyamide resin PA56 to epoxy-modified nano zinc oxide being 100:10, to obtain a melt, and the melt was spun at a spinning pressure of 6 MPa and a spinning speed of 1200 m / min to obtain light-resistant bio-based nylon fiber; The epoxy-modified nano zinc oxide is prepared by the following steps: Add nano zinc oxide to 90wt% ethanol aqueous solution, ultrasonically disperse it at an ultrasonic dispersion frequency of 30kHz for 30 minutes, add γ-glycidyloxypropyltrimethoxysilane, the mass ratio of γ-glycidyloxypropyltrimethoxysilane, 90wt% ethanol aqueous solution, and nano zinc oxide is 8:600:10, continue to ultrasonically disperse it at an ultrasonic dispersion frequency of 30kHz for 30 minutes, reflux at 80°C for 4 hours, and after the reaction is completed, filter, wash, and dry to obtain epoxy-modified nano zinc oxide.

[0023] Example 2 This embodiment discloses a method for preparing an antistatic bio-based polyester fiber, comprising the following steps: Fatty amine polyoxyethylene ether AC-1200, polyethylene glycol glycidyl ether PEG-26 glyceryl ether, and sodium dodecylbenzene sulfonate were mixed, and γ-methacryloxypropyl methyl dimethoxy silane and polyurethane wetting and dispersing agent Efka4010 were added in sequence, and stirred at room temperature for 30 minutes to obtain an antistatic agent; Among them, the mass ratio of fatty amine polyoxyethylene ether, polyethylene glycol glycidyl ether, sodium dodecylbenzene sulfonate, silane coupling agent, and wetting and dispersing agent is (40-60):(10-20):(5-10):(3-5):(0.5-1); The bio-based polyester resin PET is mixed with an antistatic agent, the mass ratio of the bio-based polyester resin PET to the antistatic agent is 100:(6-8), and melt spinning is performed at a melt spinning temperature of 270-290° C. to obtain antistatic bio-based polyester fibers.

[0024] Example 3 This embodiment discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 60 minutes at an ultrasonic dispersion frequency of 40 kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:800:16, and reacting at a stirring speed of 800 r / min and a temperature of 75°C for 8 hours. After the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid at a mass ratio of 4.5:100, and kneading at a temperature of 175° C. for 20 min at a stirring speed of 60 r / min. After the kneading is completed, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting at 65 ° C for 36 hours under nitrogen protection, adding amino-modified graphene oxide after the reaction, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino-modified graphene oxide is 100:800:10:6, and the reaction is continued at 65 ° C for 36 hours under nitrogen protection. After the reaction, ethanol 3 times the mass of dimethyl sulfoxide is added for precipitation, filtering, washing with ethanol 3 times, and drying in a vacuum drying oven at 50 ° C for 24 hours to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane, and the preparation method comprises the following steps: N-aminoethyl-3-aminopropylmethyldimethoxysilane was added to a 95wt% ethanol aqueous solution to obtain an N-aminoethyl-3-aminopropylmethyldimethoxysilane solution, graphene oxide was added to the N-aminoethyl-3-aminopropylmethyldimethoxysilane solution, the mass ratio of N-aminoethyl-3-aminopropylmethyldimethoxysilane, 95wt% ethanol aqueous solution, and graphene oxide was 15:800:3, and refluxed at 80°C for 24h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried in a vacuum drying oven at 60°C for 20h to obtain amino-modified graphene oxide; Step 4: Add the modified polylactic acid to dimethyl sulfoxide and bromoethanol, wherein the mass ratio of the modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:800:18, and react at 65°C for 130 hours under nitrogen protection. After the reaction, add ethanol 3 times the mass of dimethyl sulfoxide for precipitation, filter, wash with ethanol 3 times, and dry in a vacuum drying oven at 50°C for 24 hours to obtain antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, and subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature is 30° C., the coagulation bath is deionized water, and the polylactic acid filaments are chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 10wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 30S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 180g / m 2 ; Step 6: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 35S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 250g / m 2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0025] Example 4 This embodiment discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 30 minutes at an ultrasonic dispersion frequency of 60kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:1000:20, reacting at a stirring speed of 1200r / min and a temperature of 85°C for 6h, after the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid in a mass ratio of 5:100, and kneading at a temperature of 185° C. for 15 minutes at a stirring speed of 80 r / min. After the kneading is completed, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting for 28 hours at 75°C under nitrogen protection, adding amino-modified graphene oxide after the reaction, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino-modified graphene oxide is 100:1000:20:10, and continuing to react for 30 hours at 75°C under nitrogen protection. After the reaction, adding ethanol 5 times the mass of dimethyl sulfoxide for precipitation, filtering, washing with ethanol 5 times, and drying in a 50°C vacuum drying oven for 24 hours to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane, and the preparation method is the same as that in Example 3; Step 4: Add the modified polylactic acid to dimethyl sulfoxide and bromoethanol, wherein the mass ratio of the modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:1000:24, and react at 75°C for 110 hours under nitrogen protection. After the reaction, add ethanol 5 times the mass of dimethyl sulfoxide for precipitation, filter, wash with ethanol 5 times, and dry in a vacuum drying oven at 50°C for 24 hours to obtain antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, and subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature is 30° C., the coagulation bath is deionized water, and the polylactic acid filaments are chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 15wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 50S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 150g / m 2 ; Step 6: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 45S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 220g / m 2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0026] Example 5 This embodiment discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 45 minutes at an ultrasonic dispersion frequency of 50 kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:850:17, reacting at a stirring speed of 1000 r / min and a temperature of 80° C. for 7 hours, after the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid at a mass ratio of 4.6:100, and kneading at a temperature of 180° C. for 12 minutes at a stirring speed of 70 r / min. After the kneading is completed, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting for 32 hours at 70°C under nitrogen protection, adding amino-modified graphene oxide after the reaction, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino-modified graphene oxide is 100:850:13:7, and continuing to react for 34 hours at 70°C under nitrogen protection. After the reaction, adding ethanol 4 times the mass of dimethyl sulfoxide for precipitation, filtering, washing with ethanol 4 times, and drying in a vacuum drying oven at 50°C for 24 hours to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane, and the preparation method is the same as that in Example 3; Step 4: Add the modified polylactic acid to dimethyl sulfoxide and bromoethanol, wherein the mass ratio of the modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:850:19.5, and react at 70°C for 120 hours under nitrogen protection. After the reaction, add ethanol 4 times the mass of dimethyl sulfoxide for precipitation, filter, wash with ethanol 4 times, and dry in a vacuum drying oven at 50°C for 24 hours to obtain antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, and subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature is 30° C., the coagulation bath is deionized water, and the polylactic acid filaments are chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 11.5wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 40S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 170g / m 2 ; Step 6: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 40S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 240g / m 2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0027] Example 6 This embodiment discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 45 minutes at an ultrasonic dispersion frequency of 50 kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:900:18, reacting at a stirring speed of 1000 r / min and a temperature of 80° C. for 7 hours, after the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid in a mass ratio of 4.75:100, and kneading at a temperature of 180° C. for 12 min at a stirring speed of 70 r / min. After kneading, extruding the obtained melt, cooling, drying, and pelletizing to obtain graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting for 32 hours at 70°C under nitrogen protection, adding amino-modified graphene oxide after the reaction, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino-modified graphene oxide is 100:900:15:8, and continuing to react for 34 hours at 70°C under nitrogen protection. After the reaction, adding ethanol 4 times the mass of dimethyl sulfoxide for precipitation, filtering, washing with ethanol 4 times, and drying in a vacuum drying oven at 50°C for 24 hours to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane, and the preparation method is the same as that in Example 3; Step 4: Add the modified polylactic acid to dimethyl sulfoxide and bromoethanol, wherein the mass ratio of the modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:900:21, and react at 70°C for 120 hours under nitrogen protection. After the reaction, add ethanol 4 times the mass of dimethyl sulfoxide for precipitation, filter, wash with ethanol 4 times, and dry in a vacuum drying oven at 50°C for 24 hours to obtain antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, and subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature is 30° C., the coagulation bath is deionized water, and the polylactic acid filaments are chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 13wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 40S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 170g / m 2 ; Step 6: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 40S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 240g / m 2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0028] Example 7 This embodiment discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 45 minutes at an ultrasonic dispersion frequency of 50 kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:950:19, reacting at a stirring speed of 1000 r / min and a temperature of 80° C. for 7 hours, after the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid at a mass ratio of 4.9:100, and kneading at a temperature of 180° C. for 12 minutes at a stirring speed of 70 r / min. After the kneading is completed, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting for 32 hours at 70°C under nitrogen protection, adding amino-modified graphene oxide after the reaction, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino-modified graphene oxide is 100:950:18:9, and continuing to react for 34 hours at 70°C under nitrogen protection. After the reaction, adding ethanol 4 times the mass of dimethyl sulfoxide for precipitation, filtering, washing with ethanol 4 times, and drying in a vacuum drying oven at 50°C for 24 hours to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane, and the preparation method is the same as that in Example 3; Step 4: Add the modified polylactic acid to dimethyl sulfoxide and bromoethanol, the mass ratio of modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:950:22.5, react at 70°C for 120h under nitrogen protection, and after the reaction, add ethanol 4 times the mass of dimethyl sulfoxide for precipitation, filter, wash with ethanol 4 times, and dry in a vacuum drying oven at 50°C for 24h to obtain antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, and subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature is 30° C., the coagulation bath is deionized water, and the polylactic acid filaments are chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 14wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 40S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 170g / m 2 ; Step 6: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 40S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 240g / m2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0029] In Example 3-7, the graphene oxide used in step 1 is the same as that used in step 3.

[0030] Comparative Example 1 This comparative example discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 60 minutes at an ultrasonic dispersion frequency of 40 kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:800:16, and reacting at a stirring speed of 800 r / min and a temperature of 75°C for 8 hours. After the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid at a mass ratio of 4.5:100, and kneading at a temperature of 175° C. for 20 min at a stirring speed of 60 r / min. After the kneading is completed, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain graphene oxide-modified polylactic acid; Step 3: Add graphene oxide modified polylactic acid to dimethyl sulfoxide, add epoxy soybean oil, react at 65°C for 36 hours under nitrogen protection, add ethanol 3 times the mass of dimethyl sulfoxide for precipitation after the reaction, filter, wash with ethanol 3 times, and dry in a vacuum drying oven at 50°C for 24 hours to obtain modified polylactic acid; Step 4: Add the modified polylactic acid to dimethyl sulfoxide and bromoethanol, wherein the mass ratio of the modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:800:18, and react at 65°C for 130 hours under nitrogen protection. After the reaction, add ethanol 3 times the mass of dimethyl sulfoxide for precipitation, filter, wash with ethanol 3 times, and dry in a vacuum drying oven at 50°C for 24 hours to obtain antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, and subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature is 30° C., the coagulation bath is deionized water, and the polylactic acid filaments are chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 10wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 30S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 180g / m 2 ; Step 6: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 35S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 250g / m 2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0031] Comparative Example 2 This comparative example discloses a method for preparing an antibacterial and breathable bio-based composite fabric, comprising the following steps: Step 1, adding graphene oxide to N, N-dimethylformamide, ultrasonically dispersing for 60 minutes at an ultrasonic dispersion frequency of 40 kHz, adding 1-dimethoxy (methyl) silyl methyl isocyanate, the mass ratio of graphene oxide, N, N-dimethylformamide, and 1-dimethoxy (methyl) silyl methyl isocyanate is 10:800:16, and reacting at a stirring speed of 800 r / min and a temperature of 75°C for 8 hours. After the reaction is completed, filtering, washing with acetone to remove residual solvent N, N-dimethylformamide and unreacted 1-dimethoxy (methyl) silyl methyl isocyanate, washing for 5 times, and using a vacuum oven to remove residual acetone to obtain isocyanate-based graphene oxide; Step 2: mixing isocyanate-based graphene oxide with polylactic acid at a mass ratio of 4.5:100, and kneading at a temperature of 175° C. for 20 min at a stirring speed of 60 r / min. After the kneading is completed, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting at 65 ° C for 36 hours under nitrogen protection, adding amino-modified graphene oxide after the reaction, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino-modified graphene oxide is 100:800:10:6, and the reaction is continued at 65 ° C for 36 hours under nitrogen protection. After the reaction, ethanol 3 times the mass of dimethyl sulfoxide is added for precipitation, filtering, washing with ethanol 3 times, and drying in a vacuum drying oven at 50 ° C for 24 hours to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane, and the preparation method is the same as that in Example 3; Step 4: adding the modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, the spinning temperature being 30° C., the coagulation bath being deionized water, and the polylactic acid filaments being chopped to obtain polylactic acid fibers; The diameter of the obtained polylactic acid fiber is 40 μm and the length is 38 mm; The content of modified polylactic acid in the polylactic acid spinning solution is 10wt%, and the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1. The polylactic acid fiber is spun into yarn, the yarn count of the yarn is 30S, and then the yarn is spun into fabric through a knitting process to obtain a polylactic acid fabric, the weight of the polylactic acid fabric is 180g / m 2 ; Step 5: Blend the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber in a mass ratio of 1:1 to obtain a blended yarn with a yarn count of 35S. Then, the blended yarn is spun into a fabric through a knitting process to obtain a nylon / polyester blended fabric. The weight of the polylactic acid fabric is 250g / m 2 ; Wherein, the light-resistant bio-based nylon fiber is the light-resistant bio-based nylon fiber prepared in Example 1; the antistatic bio-based polyester fiber is the antistatic bio-based polyester fiber prepared in Example 2; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, the inner fabric and the outer fabric are compounded by polyester sewing thread to obtain an antibacterial and breathable bio-based composite fabric.

[0032] In the above embodiments and comparative examples, bio-based polyamide resin PA56 was purchased from bio-based polyamide, item number: 41724-56-5, appearance: white powder; nano zinc oxide was purchased from Shanghai Yaotian New Material Technology Co., Ltd., item number: YT-Oy-02-2, average particle size: 50nm; bio-based polyester resin PET was purchased from Jiangmen Danpule Rubber and Plastic Co., Ltd., product model: N1B, melting point: 247±2°C; fatty amine polyoxyethylene ether AC-1200 was purchased from Yixing Jiateng Chemical Co., Ltd., model: AC-1200; polyethylene glycol glycidyl Oil ether PEG-26 glycerol ether was purchased from Hai'an Petrochemical Plant, Jiangsu Province, CAS: 32694-55-0; polyurethane wetting and dispersing agent Efka4010 was purchased from Foshan Zhitu New Materials Co., Ltd., item number: EFKA-4010; graphene oxide is graphene oxide nanosheets purchased from Shanghai Naio Nano Technology Co., Ltd., item number: NO-C-068-1, thickness <2nm, diameter <20μm; polylactic acid was purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd., CAS number: 26100-51-6, with an average molecular weight of 100,000.

[0033] Test example: (1) Antibacterial performance: The antibacterial rate of the inner layer fabric (polylactic acid fabric) prepared in Examples 3-7 and Comparative Examples 1-2 after washing 50 times was measured with reference to the standard FZ / T73023-2006 "Antibacterial Knitwear". The measurement results are shown in Table 1: Table 1

[0034] As shown in Table 1, the inner layer fabric prepared by the present invention has excellent antibacterial properties. When preparing antibacterial modified polylactic acid, adding the antibacterial material graphene oxide can effectively improve the antibacterial properties of polylactic acid. The graphene oxide reacts with 1-dimethoxy (methyl) silylmethyl isocyanate to introduce isocyanate groups, and then the isocyanate groups react with the terminal hydroxyl groups and terminal carboxyl groups on the polylactic acid molecular chain to form carbamate bonds and amide bonds, thereby obtaining graphene oxide modified polylactic acid, thereby achieving chemical bonding between graphene oxide and polylactic acid; the introduction of epoxy soybean oil can improve the toughness of polylactic acid, through the imino groups on the carbamate bonds and amide bonds and the epoxy groups on the epoxy soybean oil molecules. Reaction, imino group is converted into tertiary amine, and the chemical bonding of epoxy soybean oil and graphene oxide modified polylactic acid is realized; epoxy soybean oil is a polyepoxy material, which can further react with amino and imino groups on graphene oxide molecules modified by N-aminoethyl-3-aminopropylmethyldimethoxysilane, introduce more graphene oxide, and further improve the antibacterial performance of the modified polylactic acid obtained, and imino group is also converted into tertiary amine by ring-opening reaction with epoxy group, and tertiary amine in modified polylactic acid molecules forms antibacterial quaternary ammonium salt under the action of quaternizing agent, thereby improving the antibacterial performance of polylactic acid again. Compared with Example 1, when preparing modified polylactic acid in Comparative Example 1, amino-modified graphene oxide is not added, the antibacterial performance is reduced, and the tertiary amine that can be formed is reduced, resulting in a reduction in the quaternary ammonium salt formed, and the antibacterial performance is further reduced; in Comparative Example 2, the modified polylactic acid is not quaternized, and the antibacterial performance is weakened.

[0035] (2) Air permeability: The air permeability of the nylon / polyester blended fabrics prepared in Examples 3-7 and Comparative Examples 1-2 was measured with reference to the standard GB / T5453-1997 "Determination of Air Permeability of Textile Fabrics". The results are shown in Table 2: Table 2

[0036] It can be seen from Table 2 that the bio-based composite fabric prepared by the present invention has good air permeability. The inner layer fabric and the outer layer fabric are both spun by knitting technology, and the coil structure makes the arrangement between the yarns not tight enough, leaving large gaps between the yarns, which is convenient for the passage of gas molecules, and the fabric has good air permeability.

[0037] (3) Anti-ultraviolet performance: The ultraviolet protection factor (UPF) of the nylon / polyester blended fabrics prepared in Examples 3-7 and Comparative Examples 1-2 was measured with reference to the standard GB / T18830-2009 "Evaluation of the anti-ultraviolet performance of textiles". The measurement results are shown in Table 3: Table 3

[0038] It can be seen from Table 3 that the outer layer fabric prepared in the present invention has good anti-ultraviolet performance. The outer layer fabric is made of bio-based materials nylon fiber and polyester fiber, and the nylon fiber is modified to improve its anti-ultraviolet performance.

[0039] (4) Antistatic performance: The antistatic performance of the nylon / polyester blended fabrics prepared in Examples 3-7 and Comparative Examples 1-2 was measured with reference to the standard GB / T12703.2-2009 "Evaluation of electrostatic properties of textiles Part 2: Charge surface density". The results are shown in Table 4: Table 4

[0040] It can be seen from Table 4 that the outer layer fabric prepared in the present invention has good antistatic performance. The outer layer fabric is made of bio-based materials nylon fiber and polyester fiber, and the polyester fiber is modified to improve its antistatic performance.

[0041] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial and breathable bio-based composite fabric, characterized in that: The following steps are involved: Step 1: adding graphene oxide to N,N-dimethylformamide, and after ultrasonic dispersion, adding 1-dimethoxy(methyl)silylmethyl isocyanate to react. After the reaction is completed, filtering, washing, and drying to obtain isocyanate-based graphene oxide; Step 2: mixing the isocyanate-based graphene oxide with the polylactic acid, and kneading the mixture. After kneading, the obtained melt is extruded, cooled, blown dry, and pelletized to obtain the graphene oxide-modified polylactic acid; Step 3, adding graphene oxide modified polylactic acid to dimethyl sulfoxide, adding epoxy soybean oil, reacting, after the reaction is completed, adding amino modified graphene oxide, continuing the reaction, after the reaction is completed, precipitating, filtering, washing, and drying to obtain modified polylactic acid; Wherein, the amino-modified graphene oxide is prepared by reacting graphene oxide with N-aminoethyl-3-aminopropylmethyldimethoxysilane; Step 4, adding the modified polylactic acid into dimethyl sulfoxide, adding bromoethanol, reacting, and after the reaction is completed, precipitating, filtering, washing, and drying to obtain the antibacterial modified polylactic acid; Step 5, adding the antibacterial modified polylactic acid into a chloroform / acetone mixed solvent, stirring and dissolving to obtain a polylactic acid spinning solution, subjecting the polylactic acid spinning solution to a wet spinning process to obtain polylactic acid filaments, and chopping the polylactic acid filaments to obtain polylactic acid fibers; The polylactic acid fiber is spun into yarn, and the yarn is then spun into fabric through a knitting process to obtain the polylactic acid fabric; Step 6: blending the light-resistant bio-based nylon fiber and the antistatic bio-based polyester fiber to obtain a blended yarn, and then spinning the blended yarn into a fabric through a knitting process to obtain a nylon / polyester blended fabric; Polylactic acid fabric is used as the inner fabric, nylon / polyester blended fabric is used as the outer fabric, and the inner fabric and the outer fabric are compounded to obtain an antibacterial and breathable bio-based composite fabric.

2. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In the step 1, the mass ratio of graphene oxide, N,N-dimethylformamide and 1-dimethoxy(methyl)silylmethyl isocyanate is 10:(800-1000):(16-20), and the reaction conditions are stirring at a speed of 800-1200 r / min and a temperature of 75-85° C. for 6-8 hours.

3. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In the step 2, the mass ratio of isocyanate-based graphene oxide to polylactic acid is (4.5-5):100, and the banburying conditions are banburying at a stirring speed of 60-80 r / min and a temperature of 175-185° C. for 15-20 min.

4. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In the step 3, the mass ratio of graphene oxide modified polylactic acid, dimethyl sulfoxide, epoxy soybean oil, and amino modified graphene oxide is 100:(800-1000):(10-20):(6-10), the reaction conditions are: under the protection of inert gas, at a temperature of 65-75° C. for 28-36 hours, and the conditions for continuing the reaction are: under the protection of inert gas, at a temperature of 65-75° C. for 30-36 hours; The amino-modified graphene oxide is prepared by the following steps: Adding N-aminoethyl-3-aminopropylmethyldimethoxysilane to an ethanol aqueous solution to obtain an N-aminoethyl-3-aminopropylmethyldimethoxysilane solution, adding graphene oxide to the N-aminoethyl-3-aminopropylmethyldimethoxysilane solution, reacting, filtering, washing, and drying after the reaction is completed to obtain amino-modified graphene oxide; The mass ratio of N-aminoethyl-3-aminopropylmethyldimethoxysilane, ethanol aqueous solution and graphene oxide is (15-20):(800-1000):(3-6), and the reaction conditions are reflux reaction at 75-85°C for 20-30h.

5. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In the step 4, the mass ratio of modified polylactic acid, dimethyl sulfoxide and bromoethanol is 100:(800-1000):(18-24), and the reaction conditions are to react at a temperature of 65-75° C. for 110-130 hours under the protection of an inert gas.

6. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In the step 5, the content of antibacterial modified polylactic acid in the polylactic acid spinning solution is 10-15wt%, the chloroform / acetone mixed solvent is prepared by mixing chloroform and acetone in a volume ratio of 2:1, the spinning temperature is 20-40° C., and the coagulation bath is deionized water; The diameter of the obtained polylactic acid fiber is 40-60 μm.

7. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In step 5: the yarn count of the yarn is 30-50S, and the weight of the polylactic acid fabric is 150-180g / m 2 .

8. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: In step 6, the mass ratio of the light-resistant bio-based nylon fiber to the antistatic bio-based polyester fiber is 1:1, the yarn count of the blended yarn is 35-45S, and the weight of the polylactic acid fabric is 220-250g / m 2 .

9. The method for preparing an antibacterial and breathable bio-based composite fabric according to claim 1, characterized in that: The light-resistant bio-based nylon fiber in step 6 is prepared by the following steps: The bio-based polyamide resin PA56 and epoxy-modified nano zinc oxide are melt-kneaded to obtain a melt, and the melt is spun to obtain a light-resistant bio-based nylon fiber; The mass ratio of bio-based polyamide resin PA56 to epoxy-modified nano zinc oxide is 100:(8-12), the melt mixing conditions are melt mixing at a temperature of 260-280° C. for 15-20 min, a spinning pressure of 4-8 MPa, and a spinning speed of 800-1600 m / min; Epoxy-modified nano zinc oxide is prepared by the following steps: Adding nano zinc oxide to an ethanol aqueous solution, after ultrasonic dispersion, adding γ-glycidyloxypropyltrimethoxysilane, continuing ultrasonic dispersion, after the reaction is completed, filtering, washing, and drying to obtain epoxy-modified nano zinc oxide; The mass ratio of γ-glycidyloxypropyltrimethoxysilane, ethanol aqueous solution and nano zinc oxide is (5-10):(500-800):(8-12), and the reaction conditions are reflux reaction at 75-85°C for 3-5h; The antistatic bio-based polyester fiber is prepared by the following steps: The bio-based polyester resin PET is mixed with an antistatic agent, and melt-spinned to obtain antistatic bio-based polyester fibers; The mass ratio of bio-based polyester resin PET to antistatic agent is 100:(6-8), and the melt spinning temperature is 270-290°C; The antistatic agent is prepared by the following steps: Mix fatty amine polyoxyethylene ether, polyethylene glycol glycidyl ether and sodium dodecylbenzene sulfonate, add silane coupling agent and wetting dispersant in sequence, stir and obtain an antistatic agent; Among them, the mass ratio of fatty amine polyoxyethylene ether, polyethylene glycol glycidyl ether, sodium dodecylbenzene sulfonate, silane coupling agent and wetting dispersant is (40-60):(10-20):(5-10):(3-5):(0.5-1).

10. An antibacterial and breathable bio-based composite fabric prepared by the method for preparing an antibacterial and breathable bio-based composite fabric as claimed in any one of claims 1 to 9.

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