Antifouling polylactic acid fiber fabric and preparation method thereof

Abstract

The invention discloses an antifouling polylactic acid fiber fabric and a preparation method thereof, and relates to the technical field of textile materials. When the antifouling polylactic acid fiber fabric is prepared, firstly, polypyrrole nanoparticles react with KH590 to obtain modified polypyrrole nanoparticles; synthesizing methacrylamide guanidine hydrochloride, grafting methacrylamide guanidine hydrochloride with polylactic acid, and reacting methacrylamide guanidine hydrochloride with KH560 to prepare silanized antibacterial grafted polylactic acid; silanized antibacterial grafted polylactic acid, the modified polypyrrole nanoparticles and KH570 are subjected to blending electrostatic spinning and weaving, and a modified polylactic acid fiber fabric is obtained; the preparation method comprises the following steps: carrying out hydrolytic polycondensation on trifluoropropane trimethoxysilane serving as a precursor, and then reacting with dimethylchlorosilane to prepare fluorinated hydrogen-containing polysilsesquioxane; and treating a modified polylactic acid fiber fabric with a KH570 treating fluid, immersing the treated modified polylactic acid fiber fabric in a coating solution containing the fluorinated hydrogen-containing polysilsesquioxane, and performing heat treatment to obtain the antifouling polylactic acid fiber fabric. The fabric has excellent antifouling, antibacterial and antistatic properties.

Description

Technical Field

[0001] This invention relates to the field of textile materials technology, specifically to a stain-resistant polylactic acid fiber fabric and its preparation method. Background Technology

[0002] Polylactic acid (PLA) is a widely used biodegradable material with good mechanical properties and processing stability at room temperature. It is non-toxic, odorless, and resistant to general chemical corrosion. Its raw materials are derived from renewable plant resources such as corn and sugarcane, and it is considered an environmentally friendly alternative to petroleum-based plastics. Currently, it is used in packaging materials, daily necessities, medical devices, and textile fibers. However, PLA itself has limited antibacterial and stain-resistant properties, and its surface is prone to stains and microorganisms, affecting its hygiene and durability in high-end clothing and medical textiles, and also limiting its further application in high-performance textiles.

[0003] In recent years, with the increasing demand for green materials and healthy textiles, the use of polylactic acid (PLA) in clothing, home textiles, and industrial textiles has been growing, making its functional modification increasingly urgent. In practical use, PLA fabrics are easily stained with oil, sweat, and bacteria, making cleaning and maintenance difficult. After long-term use, their surface properties deteriorate, affecting appearance and hygiene. Therefore, to enhance the added functions of PLA textiles, extend their service life, and expand their application in high-end stain-resistant and antibacterial textiles, it is necessary to systematically functionalize PLA fibers through surface modification, functional grafting, and composite finishing techniques. Summary of the Invention

[0004] The purpose of this invention is to provide a stain-resistant polylactic acid fiber fabric and its preparation method, so as to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A stain-resistant polylactic acid fiber fabric is obtained by treating modified polylactic acid fiber fabric with KH570 treatment solution and fluorinated hydrogen-containing polysilsesquioxane coating.

[0006] As an optimization, the modified polylactic acid fiber fabric is prepared by electrospinning and weaving a blend of silanized antibacterial grafted polylactic acid, modified polypyrrole nanoparticles and KH570.

[0007] As an optimization, the antibacterial grafted polylactic acid is prepared by grafting methylacrylamide guanidine hydrochloride onto polylactic acid and then reacting it with KH560.

[0008] As an optimization, the fluorinated hydrogen-containing polysilsesquioxane is prepared by hydrolysis and condensation of trifluoropropanetrimethoxysilane as a precursor, followed by reaction with dimethylchlorosilane.

[0009] A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution are mixed at a mass ratio of 1:(0.8~1.2):(6~7), stirred at 25~30℃ and 300~500rpm for 2~3h, and washed by centrifugation with deionized water to obtain polypyrrole nanoparticles; polypyrrole nanoparticles, triethylamine and anhydrous ethanol are mixed at a mass ratio of 1:(13~17):(95~105), stirred at 25~30℃ and 300~500rpm for 15~25min, KH590 with a mass of 9~11 times that of polypyrrole nanoparticles is added, and stirring is continued for 12~14h, and washed by centrifugation with deionized water to obtain modified polypyrrole nanoparticles; (2) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water at a mass ratio of 1:(0.9~1.1):(3~3.5) until homogeneous. Stir at 0~5℃ and 300~500rpm for 15~25min. Add 1~1.5 times the mass of 1,3-diaminoguanidine hydrochloride in methacryloyl chloride and continue stirring for 2.5~3.5h. Extract with ethyl acetate, wash the organic layer with brine, and rotary evaporate. Then, mix with water at a volume ratio of 1:(0.9~1.1):(3~3.5). 4) Dissolve in acetone, add 1.5-2.5 times the mass of concentrated hydrochloric acid to 1,3-diaminoguanidine hydrochloride, stir at 25-30℃ and 300-500 rpm for 1.5-2.5 h, filter, wash with acetone, and dry under reduced pressure at 40°C to obtain guanidine methacrylamide hydrochloride; mix polylactic acid, guanidine methacrylamide hydrochloride, and tert-butyl peroxide in a mass ratio of 1:(0.15-0.25):(0.002-0.004). The mixture was uniformly reacted at 170-180℃ for 8-12 min to obtain antibacterial grafted polylactic acid (PLA). The PLA was then dissolved in anhydrous N,N-dimethylformamide at 5-10 wt%, and 0.15-0.25 times its weight of KH560 was added. The mixture was stirred at 65-75℃ and 300-500 rpm for 18-24 h. Ethanol precipitation, filtration, and drying were then performed to obtain silanized antibacterial grafted PLA. The silanized PLA was then... Antibacterial grafted polylactic acid, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide and dichloromethane were mixed in a mass ratio of 1:(0.02~0.03):(0.015~0.025):(4~6):(4~6), stirred at 25~30℃ and 300~500rpm for 20~28h, and then electrospun to obtain modified polylactic acid fiber yarn. The modified polylactic acid fiber was then woven to obtain modified polylactic acid fiber fabric. (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide are mixed in a mass ratio of 1:(4.5~5.5):(0.1~0.11):(0.075~0.085), refluxed and stirred at 65~75℃ and 300~500rpm for 4.5~5.5h, rotary evaporated, washed with tetrahydrofuran, and dried to obtain fluorinated polysilsesquioxane intermediate; fluorinated... In a nitrogen atmosphere, a fluorinated hydrogen-containing polysilsesquioxane intermediate and a dimethylchlorosilane intermediate were prepared by adding a 25wt% to 26wt% solution of dimethylchlorosilane / 1,2-dichloroethane to a 6wt% to 7wt% solution of fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane. The mixture was stirred at 45 to 50°C and 300 to 500 rpm for 4.5 to 5.5 hours. The organic phase was separated, and the mixture was washed with distilled water, rotary evaporated, and dried to obtain the fluorinated hydrogen-containing polysilsesquioxane. (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 8wt%~12wt%, add 0.5%~1.5% of platinum complex catalyst based on the mass of fluorinated hydrogen-containing polysilsesquioxane, stir at 25~30℃ and 300~500rpm for 20~40min to obtain a coating solution; immerse the modified polylactic acid fiber fabric in KH570 treatment solution for 20~30min, dry at 50~60℃, then immerse in the coating solution for 20~40min, take it out and heat treat at 100~120°C for 20~40min, wash with water to obtain a stain-resistant polylactic acid fiber fabric.

[0010] As an optimization, the reaction process of polylactic acid modified polypyrrole nanoparticles in step (1) is as follows:

[0011] As an optimization, the polylactic acid type in step (2) is 4032D.

[0012] As an optimization, the silanization antibacterial grafted polylactic acid reaction process in step (2) is as follows:

[0013] As an optimization, the electrospinning in step (2) uses a conjugate spinning machine with the following main process parameters: spinning voltage of 6.5~8.5kV, receiving distance of 10~14cm, spinning solution propulsion rate of 0.4μL / min, needle spacing of 18~22cm, needle inner diameter of 0.5mm, bell mouth rotation speed of 400r / min, winding roller rotation speed of 5.3r / min, relative humidity of 30%~40%, and temperature of 25~30℃; the modified polylactic acid fiber fabric is a single-layer plain weave fabric with a warp density of 450 threads / 10cm, a weft density of 350 threads / 10cm, and a weight per square meter of 98g / m². 2 .

[0014] As an optimization, the structure of the fluorinated hydrogen-containing polysilsesquioxane in step (3) is as follows:

[0015] As an optimization, the preparation method of the KH570 treatment solution in step (4) is as follows: Ethanol and deionized water are mixed evenly at a volume ratio of 70:30, and the pH is adjusted to 4 with 0.2M acetic acid to obtain a mixed solvent; KH570 is added to the mixed solvent at a concentration of 50wt%~70wt%, and stirred at 25~30℃ and 300~500rpm for 20~40min to obtain the KH570 treatment solution.

[0016] As an optimization, the platinum complex catalyst in step (4) is a Karstedt catalyst (platinum in the form of a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex).

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are: In preparing stain-resistant polylactic acid (PLA) fiber fabric, the present invention first reacts polypyrrole nanoparticles with KH590 to obtain modified polypyrrole nanoparticles; synthesizes guanidine methacrylamide hydrochloride and grafts it onto PLA, then reacts it with KH560 to prepare silanized antibacterial grafted PLA; blends the silanized antibacterial grafted PLA, modified polypyrrole nanoparticles, and KH570, electrospun, and weaves to obtain modified PLA fiber fabric; after hydrolysis and polycondensation of trifluoropropanetrimethoxysilane as a precursor, it reacts with dimethylchlorosilane to obtain fluorinated hydrogen-containing polysilsesquioxane; treats the modified PLA fiber fabric with a silane treatment solution, immerses it in a coating solution containing the above-mentioned fluorinated hydrogen-containing polysilsesquioxane, and then heat-treats it to obtain stain-resistant PLA fiber fabric.

[0018] First, in the fiber preparation stage, 3-mercaptopropyltriethoxysilane was grafted onto the surface of polypyrrole nanoparticles via a mercapto-Michael addition reaction to obtain modified polypyrrole possessing both conductive and antibacterial properties as well as silane reactivity. Simultaneously, silanized polylactic acid with antibacterial function and silane coupling sites was prepared by grafting guanidine hydrochloride with methacrylamide and end-capping with γ-glycidoxypropyltrimethoxysilane. Both were then electrospun into fiber fabric, providing an active substrate with abundant reaction sites for subsequent functional finishing.

[0019] Secondly, in the finishing stage of the fabric, the base fabric is first treated with a γ-methacryloxypropyltrimethoxysilane treatment solution. After hydrolysis, the silane coupling agent's silanol groups can undergo dehydration condensation reactions with the silane on the surface of silanized polylactic acid fibers and the silane ends of modified polypyrrole nanoparticles, forming a stable Si-O-Si covalent cross-linked network inside and on the fiber surface, which greatly enhances the structural integrity and interfacial strength of the matrix. Subsequently, under the action of a platinum catalyst, the silicon-hydrogen bonds (Si-H) in the fluorinated hydrogen-containing polysilsesquioxane coating undergo a hydrosilylation reaction with the carbon-carbon double bonds of the γ-methacryloxypropyltrimethoxysilane that has been firmly bonded to the fiber surface in the first step, thereby permanently grafting the low surface energy fluorinated polysilsesquioxane onto the fiber surface in a covalent manner. This not only endows the fabric with excellent hydrophobic, oleophobic, and stain-resistant properties, but also ensures superior durability and washability of antibacterial and stain-resistant functions through full chemical bonding from the fiber matrix to the stain-resistant coating. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] To more clearly illustrate the method provided by the present invention, the following embodiments will be described in detail. Example 1:

[0022] A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1:0.8:6 and stirred at 25℃ and 300rpm for 2h. The mixture was then washed by centrifugation with deionized water to obtain polypyrrole nanoparticles. Polypyrrole nanoparticles, triethylamine and anhydrous ethanol were mixed at a mass ratio of 1:13:95 and stirred at 25℃ and 300rpm for 15min. KH590 was added at a mass ratio of 9 times that of polypyrrole nanoparticles and stirred for 12h. The mixture was then washed by centrifugation with deionized water to obtain modified polypyrrole nanoparticles. (2) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water at a mass ratio of 1:0.9:3 until homogeneous. Stir at 0°C and 300 rpm for 15 min. Add methacryloyl chloride at a mass ratio of 1:1 that of 1,3-diaminoguanidine hydrochloride and continue stirring for 2.5 h. Extract with ethyl acetate. Wash the organic layer with brine. Dissolve the organic layer in acetone at a volume ratio of 1:3 after rotary evaporation. Add concentrated hydrochloric acid at a mass ratio of 1:1.5 that of 1,3-diaminoguanidine hydrochloride dropwise. Stir at 25°C and 300 rpm for 1.5 h. Filter, wash with acetone, and dry under reduced pressure at 40°C to obtain methacrylamide guanidine hydrochloride. Mix polylactic acid, methacrylamide guanidine hydrochloride, and tert-butyl peroxide at a mass ratio of 1:0.15:0.002 until homogeneous. The mixture was stirred at 170℃ for 8 min to obtain antibacterial grafted polylactic acid (PLA). The antibacterial grafted PLA was dissolved in anhydrous N,N-dimethylformamide at 5 wt%, and KH560 (0.15 times the mass of the antibacterial grafted PLA) was added. The mixture was stirred at 65℃ and 300 rpm for 18 h, precipitated with ethanol, filtered, and dried to obtain silanized antibacterial grafted PLA. The silanized antibacterial grafted PLA, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide, and dichloromethane were mixed at a mass ratio of 1:0.02:0.015:4:4, stirred at 25℃ and 300 rpm for 20 h, and then electrospun to obtain modified PLA fiber yarn. The modified PLA fiber yarn was then woven to obtain modified PLA fiber fabric. (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide were mixed in a mass ratio of 1:4.5:0.1:0.075 and stirred under reflux at 65°C and 300 rpm for 4.5 h. The mixture was then rotary evaporated, washed with tetrahydrofuran, and dried to obtain a fluorinated polysilsesquioxane intermediate. Fluorinated polysilsesquioxane intermediate and dimethylchlorosilane were weighed in a mass ratio of 1:1.4. Under a nitrogen atmosphere, 25 wt% dimethylchlorosilane / 1,2-dichloroethane solution was added dropwise to a 6 wt% fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane solution. The mixture was stirred at 45°C and 300 rpm for 4.5 h. The organic phase was separated, washed with distilled water, rotary evaporated, and dried to obtain a fluorinated hydrogen-containing polysilsesquioxane. (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%, add 0.5% of platinum complex catalyst of fluorinated hydrogen-containing polysilsesquioxane by mass, stir at 25°C and 300 rpm for 20 min to obtain coating solution; immerse modified polylactic acid fiber fabric in KH570 treatment solution for 20 min, dry at 50°C, immerse in coating solution for 20 min, take it out and heat treat at 100°C for 20 min, wash with water to obtain stain-resistant polylactic acid fiber fabric. Example 2:

[0023] A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1:1:6.5 and stirred at 27℃ and 400rpm for 2.5h. The mixture was then washed by centrifugation with deionized water to obtain polypyrrole nanoparticles. Polypyrrole nanoparticles, triethylamine and anhydrous ethanol were mixed at a mass ratio of 1:15:100 and stirred at 27℃ and 400rpm for 20min. KH590 with a mass of 10 times that of polypyrrole nanoparticles was added and stirred for 13h. The mixture was then washed by centrifugation with deionized water to obtain modified polypyrrole nanoparticles. (2) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water in a mass ratio of 1:1:3.3 until homogeneous. Stir at 3°C ​​and 400 rpm for 20 min. Add 1.25 times the mass of 1,3-diaminoguanidine hydrochloride in methacryloyl chloride and continue stirring for 3 h. Extract with ethyl acetate. Wash the organic layer with brine. Dissolve in acetone at a volume ratio of 1:3.5 after rotary evaporation. Add concentrated hydrochloric acid in a volume ratio of 2 times the mass of 1,3-diaminoguanidine hydrochloride. Stir at 27°C and 400 rpm for 2 h. Filter, wash with acetone, and dry under reduced pressure at 40°C to obtain methacrylamide guanidine hydrochloride. Mix polylactic acid, methacrylamide guanidine hydrochloride, and tert-butyl peroxide in a mass ratio of 1:0.2:0.003 until homogeneous. Antibacterial grafted polylactic acid (PLA) was prepared by reacting at 175℃ for 10 min. The antibacterial grafted PLA was dissolved in anhydrous N,N-dimethylformamide at 7.5 wt%, and KH560 (0.2 times the mass of the antibacterial grafted PLA) was added. The mixture was stirred at 70℃ and 400 rpm for 20 h, precipitated with ethanol, filtered, and dried to obtain silanized antibacterial grafted PLA. The silanized antibacterial grafted PLA, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide, and dichloromethane were mixed at a mass ratio of 1:0.025:0.02:5:5, stirred at 27℃ and 400 rpm for 24 h, and then electrospun to obtain modified PLA fiber yarn. The modified PLA fiber yarn was then woven to obtain modified PLA fiber fabric. (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide were mixed in a mass ratio of 1:5:0.1:0.08 and stirred under reflux at 70℃ and 400 rpm for 5 h. The mixture was then evaporated, washed with tetrahydrofuran, and dried to obtain a fluorinated polysilsesquioxane intermediate. The fluorinated polysilsesquioxane intermediate and dimethylchlorosilane were weighed in a mass ratio of 1:1.45. Under a nitrogen atmosphere, 25.5 wt% dimethylchlorosilane / 1,2-dichloroethane solution was added dropwise to a 6.5 wt% fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane solution. The mixture was stirred at 47℃ and 400 rpm for 5 h. The organic phase was separated, washed with distilled water, evaporated, and dried to obtain a fluorinated hydrogen-containing polysilsesquioxane. (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%, add 1% of platinum complex catalyst of fluorinated hydrogen-containing polysilsesquioxane by mass, stir at 27°C and 400 rpm for 30 min to obtain coating solution; immerse modified polylactic acid fiber fabric in KH570 treatment solution for 25 min, dry at 55°C, immerse in coating solution for 30 min, take it out and heat treat at 110°C for 30 min, wash with water to obtain stain-resistant polylactic acid fiber fabric. Example 3:

[0024] A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1:1.2:7 and stirred at 30℃ and 500rpm for 3h. The mixture was then washed by centrifugation with deionized water to obtain polypyrrole nanoparticles. Polypyrrole nanoparticles, triethylamine and anhydrous ethanol were mixed at a mass ratio of 1:17:105 and stirred at 30℃ and 500rpm for 25min. KH590 with a mass of 11 times that of polypyrrole nanoparticles was added and stirred for 14h. The mixture was then washed by centrifugation with deionized water to obtain modified polypyrrole nanoparticles. (2) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water in a mass ratio of 1:1.1:3.5 until homogeneous. Stir at 500 rpm for 25 min at 5 °C. Add 1.5 times the mass of 1,3-diaminoguanidine hydrochloride in methacryloyl chloride and continue stirring for 3.5 h. Extract with ethyl acetate. Wash the organic layer with brine. Dissolve in acetone at a volume ratio of 1:4 after rotary evaporation. Add concentrated hydrochloric acid in a volume ratio of 2.5 times the mass of 1,3-diaminoguanidine hydrochloride. Stir at 500 rpm for 2.5 h at 30 °C. Filter, wash with acetone, and dry under reduced pressure at 40 °C to obtain methacrylamide guanidine hydrochloride. Mix polylactic acid, methacrylamide guanidine hydrochloride, and tert-butyl peroxide in a mass ratio of 1:0.25:0.004. The mixture was uniformly reacted at 180℃ for 12 min to obtain antibacterial grafted polylactic acid (PLA). The antibacterial grafted PLA was dissolved in anhydrous N,N-dimethylformamide at 10 wt%, and KH560 (0.25 times the mass of the antibacterial grafted PLA) was added. The mixture was stirred at 75℃ and 500 rpm for 24 h, precipitated with ethanol, filtered, and dried to obtain silanized antibacterial grafted PLA. The silanized antibacterial grafted PLA, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide, and dichloromethane were mixed at a mass ratio of 1:0.03:0.025:6:6, stirred at 30℃ and 500 rpm for 28 h, and then electrospun to obtain modified PLA fiber yarn. The modified PLA fiber yarn was then woven to obtain modified PLA fiber fabric. (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide were mixed in a mass ratio of 1:5.5:0.11:0.085 and stirred under reflux at 75°C and 500 rpm for 5.5 h. The mixture was then rotary evaporated, washed with tetrahydrofuran, and dried to obtain a fluorinated polysilsesquioxane intermediate. The fluorinated polysilsesquioxane intermediate and dimethylchlorosilane were weighed in a mass ratio of 1:1.5. Under a nitrogen atmosphere, 26 wt% dimethylchlorosilane / 1,2-dichloroethane solution was added dropwise to a 7 wt% fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane solution. The mixture was stirred at 50°C and 500 rpm for 5.5 h. The organic phase was separated, washed with distilled water, rotary evaporated, and dried to obtain a fluorinated hydrogen-containing polysilsesquioxane. (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%, add 1.5% of platinum complex catalyst of fluorinated hydrogen-containing polysilsesquioxane by mass, stir at 30°C and 500 rpm for 40 min to obtain coating solution; immerse modified polylactic acid fiber fabric in KH570 treatment solution for 30 min, dry at 60°C, immerse in coating solution for 40 min, take it out and heat treat at 120°C for 40 min, wash with water to obtain stain-resistant polylactic acid fiber fabric.

[0025] Comparative Example 1: The only difference from Example 2 is step (4), which changes "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%" to "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 5 wt%".

[0026] Comparative Example 2: The only difference from Example 2 is step (4), which changes "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%" to "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 8 wt%".

[0027] Comparative Example 3: The only difference from Example 2 is step (4), which changes "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%" to "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 12 wt%".

[0028] Comparative Example 4: The only difference from Example 2 is step (4), which changes "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%" to "dissolve the fluorinated hydrogen-containing polysilsesquioxane in ethanol at 15 wt%".

[0029] Comparative Example 5: A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1:1:6.5 and stirred at 27℃ and 400rpm for 2.5h. The mixture was then washed by centrifugation with deionized water to obtain polypyrrole nanoparticles. Polypyrrole nanoparticles, triethylamine and anhydrous ethanol were mixed at a mass ratio of 1:15:100 and stirred at 27℃ and 400rpm for 20min. KH590 with a mass of 10 times that of polypyrrole nanoparticles was added and stirred for 13h. The mixture was then washed by centrifugation with deionized water to obtain modified polypyrrole nanoparticles. (2) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water in a mass ratio of 1:1:3.3 until homogeneous. Stir at 3°C ​​and 400 rpm for 20 min. Add 1.25 times the mass of 1,3-diaminoguanidine hydrochloride in methacryloyl chloride and continue stirring for 3 h. Extract with ethyl acetate. Wash the organic layer with brine. Dissolve in acetone at a volume ratio of 1:3.5 after rotary evaporation. Add concentrated hydrochloric acid in a volume ratio of 2 times the mass of 1,3-diaminoguanidine hydrochloride. Stir at 27°C and 400 rpm for 2 h. Filter, wash with acetone, and dry under reduced pressure at 40°C to obtain methacrylamide guanidine hydrochloride. Mix polylactic acid, methacrylamide guanidine hydrochloride, and tert-butyl peroxide in a mass ratio of 1:0.2:0.003 until homogeneous. Antibacterial grafted polylactic acid (PLA) was prepared by reacting at 175℃ for 10 min. The antibacterial grafted PLA was dissolved in anhydrous N,N-dimethylformamide at 7.5 wt%, and KH560 (0.2 times the mass of the antibacterial grafted PLA) was added. The mixture was stirred at 70℃ and 400 rpm for 20 h, precipitated with ethanol, filtered, and dried to obtain silanized antibacterial grafted PLA. The silanized antibacterial grafted PLA, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide, and dichloromethane were mixed at a mass ratio of 1:0.025:0.02:5:5, stirred at 27℃ and 400 rpm for 24 h, and then electrospun to obtain modified PLA fiber yarn. The modified PLA fiber yarn was then woven to obtain modified PLA fiber fabric. (3) The modified polylactic acid fiber fabric is immersed in KH570 treatment solution for 25 minutes, dried at 55°C, and washed with water to obtain a stain-resistant polylactic acid fiber fabric.

[0030] Comparative Example 6: A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1:1:6.5, stirred at 27℃ and 400rpm for 2.5h, and washed by centrifugation with deionized water to obtain polypyrrole nanoparticles. (2) 1,3-Diaminoguanidine hydrochloride, triethylamine, and deionized water were mixed evenly at a mass ratio of 1:1:3.3 and stirred at 3°C ​​and 400 rpm for 20 min. Methacryl chloride (1.25 times the mass of 1,3-diaminoguanidine hydrochloride) was added, and stirring was continued for 3 h. The mixture was extracted with ethyl acetate, and the organic layer was washed with brine. After rotary evaporation, the organic layer was dissolved in acetone at a volume ratio of 1:3.5. Concentrated hydrochloric acid (2 times the mass of 1,3-diaminoguanidine hydrochloride) was added dropwise, and the mixture was stirred at 27°C and 400 rpm for 2 h. The mixture was filtered, washed with acetone, and dried under reduced pressure at 40°C to obtain methacryloyl chloride. Guanidine hydrochloride; polylactic acid, guanidine hydrochloride and tert-butyl peroxide were mixed evenly in a mass ratio of 1:0.2:0.003 and reacted at 175℃ for 10 min to obtain antibacterial grafted polylactic acid; antibacterial grafted polylactic acid, polypyrrole nanoparticles, KH570, N,N-dimethylformamide and dichloromethane were mixed in a mass ratio of 1:0.025:0.02:5:5 and stirred at 27℃ and 400 rpm for 24 h before electrospinning to obtain modified polylactic acid fiber yarn; modified polylactic acid fiber fabric was woven from the modified polylactic acid fiber. (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide were mixed in a mass ratio of 1:5:0.1:0.08 and stirred under reflux at 70℃ and 400 rpm for 5 h. The mixture was then evaporated, washed with tetrahydrofuran, and dried to obtain a fluorinated polysilsesquioxane intermediate. The fluorinated polysilsesquioxane intermediate and dimethylchlorosilane were weighed in a mass ratio of 1:1.45. Under a nitrogen atmosphere, 25.5 wt% dimethylchlorosilane / 1,2-dichloroethane solution was added dropwise to a 6.5 wt% fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane solution. The mixture was stirred at 47℃ and 400 rpm for 5 h. The organic phase was separated, washed with distilled water, evaporated, and dried to obtain a fluorinated hydrogen-containing polysilsesquioxane. (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%, add 1% of platinum complex catalyst of fluorinated hydrogen-containing polysilsesquioxane by mass, stir at 27°C and 400 rpm for 30 min to obtain coating solution; immerse modified polylactic acid fiber fabric in coating solution for 30 min, take it out and heat treat at 110°C for 30 min, wash with water to obtain stain-resistant polylactic acid fiber fabric.

[0031] Comparative Example 7: A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water at a mass ratio of 1:1:3.3 until homogeneous. Stir at 3°C ​​and 400 rpm for 20 min. Add 1.25 times the mass of 1,3-diaminoguanidine hydrochloride in methacryloyl chloride and continue stirring for 3 h. Extract with ethyl acetate. Wash the organic layer with brine. Dissolve in acetone at a volume ratio of 1:3.5 after rotary evaporation. Add concentrated hydrochloric acid at a mass ratio of 2 times the mass of 1,3-diaminoguanidine hydrochloride. Stir at 27°C and 400 rpm for 2 h. Filter, wash with acetone, and dry under reduced pressure at 40°C to obtain methacrylamide guanidine hydrochloride. Antibacterial grafted polylactic acid (PLA) was prepared by uniformly mixing acid, guanidine hydrochloride methacrylamide, and tert-butyl peroxide at a mass ratio of 1:0.2:0.003 and reacting at 175℃ for 10 min. The PLA was then dissolved in anhydrous N,N-dimethylformamide at 7.5 wt%, and KH560 (0.2 times the mass of the PLA) was added. The mixture was stirred at 70℃ and 400 rpm for 20 h, precipitated with ethanol, filtered, and dried to obtain silanized antibacterial grafted PLA. The silanized antibacterial grafted PLA, KH570, N,N-dimethylformamide, and dichloromethane were mixed at a mass ratio of 1:0.02:5:5 and stirred at 27℃ and 400 rpm for 24 h. The mixture was then electrospun to obtain modified PLA fiber yarn. The modified PLA fiber yarn was then woven to obtain modified PLA fiber fabric. (2) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide were mixed in a mass ratio of 1:5:0.1:0.08 and stirred under reflux at 70°C and 400 rpm for 5 h. The mixture was then evaporated, washed with tetrahydrofuran, and dried to obtain a fluorinated polysilsesquioxane intermediate. The fluorinated polysilsesquioxane intermediate and dimethylchlorosilane were weighed in a mass ratio of 1:1.45. Under a nitrogen atmosphere, 25.5 wt% dimethylchlorosilane / 1,2-dichloroethane solution was added dropwise to a 6.5 wt% fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane solution. The mixture was stirred at 47°C and 400 rpm for 5 h. The organic phase was separated, washed with distilled water, evaporated, and dried to obtain a fluorinated hydrogen-containing polysilsesquioxane. (3) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%, add 1% of platinum complex catalyst of fluorinated hydrogen-containing polysilsesquioxane by mass, stir at 27°C and 400 rpm for 30 min to obtain coating solution; immerse modified polylactic acid fiber fabric in KH570 treatment solution for 25 min, dry at 55°C, immerse in coating solution for 30 min, take it out and heat treat at 110°C for 30 min, wash with water to obtain stain-resistant polylactic acid fiber fabric.

[0032] Comparative Example 8: A method for preparing a stain-resistant polylactic acid fiber fabric includes the following preparation steps: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution were mixed at a mass ratio of 1:1:6.5 and stirred at 27℃ and 400rpm for 2.5h. The mixture was then washed by centrifugation with deionized water to obtain polypyrrole nanoparticles. Polypyrrole nanoparticles, triethylamine and anhydrous ethanol were mixed at a mass ratio of 1:15:100 and stirred at 27℃ and 400rpm for 20min. KH590 with a mass of 10 times that of polypyrrole nanoparticles was added and stirred for 13h. The mixture was then washed by centrifugation with deionized water to obtain modified polypyrrole nanoparticles. (2) Polylactic acid, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide and dichloromethane are mixed in a mass ratio of 1:0.025:0.02:5:5 and stirred at 27°C and 400 rpm for 24 h. The mixture is then electrospun to obtain modified polylactic acid fiber yarn. The modified polylactic acid fiber is then woven to obtain modified polylactic acid fiber fabric. (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide were mixed in a mass ratio of 1:5:0.1:0.08 and stirred under reflux at 70℃ and 400 rpm for 5 h. The mixture was then evaporated, washed with tetrahydrofuran, and dried to obtain a fluorinated polysilsesquioxane intermediate. The fluorinated polysilsesquioxane intermediate and dimethylchlorosilane were weighed in a mass ratio of 1:1.45. Under a nitrogen atmosphere, 25.5 wt% dimethylchlorosilane / 1,2-dichloroethane solution was added dropwise to a 6.5 wt% fluorinated polysilsesquioxane intermediate / 1,2-dichloroethane solution. The mixture was stirred at 47℃ and 400 rpm for 5 h. The organic phase was separated, washed with distilled water, evaporated, and dried to obtain a fluorinated hydrogen-containing polysilsesquioxane. (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 10 wt%, add 1% of platinum complex catalyst of fluorinated hydrogen-containing polysilsesquioxane by mass, stir at 27°C and 400 rpm for 30 min to obtain coating solution; immerse modified polylactic acid fiber fabric in KH570 treatment solution for 25 min, dry at 55°C, immerse in coating solution for 30 min, take it out and heat treat at 110°C for 30 min, wash with water to obtain stain-resistant polylactic acid fiber fabric.

[0033] Experimental Example 1: Determination of the optimal concentration of fluorinated hydrogen-containing polysilsesquioxane Test method: The static contact angle of the stain-resistant polylactic acid fiber fabric was determined by hydrophobic and oleophobic properties. The droplet volume used was 4 μL. Pure water was used for hydrophobicity testing, and glycerin was used for oleophobicity measurement. The results are shown in Table 1.

[0034] Table 1

[0035] A comparison of Example 2 and Comparative Examples 1-4 reveals that the hydrophobic and oleophobic properties of the stain-resistant polylactic acid fiber fabric initially increase significantly with increasing concentration of the fluorinated hydrogen-containing polysilsesquioxane coating, then tend to plateau. When the coating concentration is increased within the range of 8wt% to 12wt%, a continuous, dense, and low-surface-energy fluorinated layer with a micro-nano rough structure can be constructed on the fiber surface, thereby synergistically enhancing the hydrophobic and oleophobic effects. However, when the coating concentration exceeds 10wt%, the performance does not show a significant improvement and decreases slightly due to reduced coating flexibility and difficulty in further improving uniformity. Therefore, selecting a coating concentration of 5wt% to 10wt% achieves the best balance between ensuring excellent stain resistance and material economy and processability.

[0036] Experimental Example 2: Antifouling performance, antibacterial performance, and antistatic performance testing Stain resistance test method: The static contact angle of the stain-resistant polylactic acid fiber fabrics obtained in each example and the fabrics of comparative examples 5-8 before and after 20 water washes was tested. The droplet volume used was 4μL. Pure water was used for hydrophobicity test and glycerin was used for oleophobicity measurement.

[0037] Antibacterial performance test method: The stain-resistant polylactic acid fiber fabrics obtained in each example and the fabrics of comparative examples 5 to 8 were tested for their inhibitory effects on Escherichia coli and Staphylococcus aureus according to GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Vibration method".

[0038] Antistatic performance test method: The surface resistivity of the antifouling polylactic acid fiber fabrics obtained in each example and the fabrics of comparative examples 5 to 8 was tested according to GB / T12703.4—2010 "Evaluation of electrostatic properties of textiles - Part 4: resistivity" standard.

[0039] The results are shown in Table 2.

[0040] Table 2

[0041] A comparison of the experimental data from Examples 1-3 and Comparative Examples 5-8 in Table 2 reveals that the stain-resistant polylactic acid fiber fabric prepared by this invention exhibits excellent stain-resistant properties, antibacterial properties, and antistatic properties.

[0042] By comparing Examples 1-3 and Comparative Example 5, it can be found that treating fabrics with fluorinated hydrogen-containing polysilsesquioxane coating solution can significantly improve their stain resistance. This is because the fluorocarbon segments in the coating give the fabric extremely low surface energy, effectively inhibiting the wetting and spreading of water and oily liquids. At the same time, the polysilsesquioxane component in the coating can form a stable cross-linked network with KH570 on the fabric surface through hydrosilylation reaction during heat treatment, and construct a suitable micro-rough structure, thereby synergistically enhancing the hydrophobic and oleophobic effects of the fabric.

[0043] By comparing Examples 1-3 and Comparative Example 6, it can be found that KH590, KH560 and KH570 silane coupling agents were introduced in steps (1), (2) and (4) respectively, and a complete chemical bonding network from the inside to the surface of the fiber was constructed. Each component was firmly cross-linked and fixed through the dehydration condensation between silanes and the hydrosilylation reaction between the coating and KH570, thereby effectively preventing the modified polypyrrole nanoparticles from falling off and the fluorinated coating from peeling off during multiple washing processes, and significantly improving the retention of the fabric's stain resistance.

[0044] By comparing Examples 1-3 and Comparative Example 7, it can be found that the modified polypyrrole nanoparticle blend spinning can significantly improve the antibacterial and antistatic properties of the fabric. This is because the silanization modification forms a stable Si-O-Si chemical bond network between the particles and the fiber matrix. On the one hand, this network firmly anchors the antibacterial components to prevent them from falling off during washing, thus ensuring antibacterial durability. On the other hand, it provides stable dispersion points for the conjugated conductive structure of polypyrrole, constructing a wash-resistant and durable antistatic pathway.

[0045] By comparing Examples 1-3 and Comparative Example 8, it can be found that grafting polylactic acid with methylacrylamide hydrochloride during the preparation of antibacterial grafted polylactic acid significantly improves its antibacterial properties.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and not restrictive.

Claims

1. A stain-resistant polylactic acid fiber fabric, characterized in that, The fabric is prepared by treating modified polylactic acid fiber fabric with γ-methacryloxypropyltrimethoxysilane (KH570) treatment solution and fluorinated hydrogen-containing polysilsesquioxane coating treatment.

2. The stain-resistant polylactic acid fiber fabric according to claim 1, characterized in that, The modified polylactic acid fiber fabric is made by electrospinning and weaving a blend of silanized antibacterial grafted polylactic acid, modified polypyrrole nanoparticles and KH570.

3. The stain-resistant polylactic acid fiber fabric according to claim 2, characterized in that, The antibacterial grafted polylactic acid is prepared by grafting methylacrylamide hydrochloride guanidine onto polylactic acid and then reacting it with γ-glycidoxypropyltrimethoxysilane (KH560).

4. The stain-resistant polylactic acid fiber fabric according to claim 1, characterized in that, The fluorinated hydrogen-containing polysilsesquioxane is prepared by hydrolysis and condensation of trifluoropropanetrimethoxysilane as a precursor, followed by reaction with dimethylchlorosilane.

5. A method for preparing a stain-resistant polylactic acid fiber fabric, characterized in that, The preparation steps include the following: (1) Pyrrole, 0.1M ferric chloride solution and 2wt% polyvinyl alcohol aqueous solution are mixed at a mass ratio of 1:(0.8~1.2):(6~7) and reacted at 25~30℃ to obtain polypyrrole nanoparticles; polypyrrole nanoparticles, triethylamine and anhydrous ethanol are mixed evenly at a mass ratio of 1:(13~17):(95~105), and 3-mercaptopropyltriethoxysilane (KH590) with a mass of 9~11 times that of polypyrrole nanoparticles is added and reacted at 25~30℃ to obtain modified polypyrrole nanoparticles; (2) Mix 1,3-diaminoguanidine hydrochloride, triethylamine, and deionized water in a mass ratio of 1:(0.9~1.1):(3~3.5), add 1~1.5 times the mass of 1,3-diaminoguanidine hydrochloride with methacryloyl chloride at 0~5℃, add 1.5~2.5 times the mass of 1,3-diaminoguanidine hydrochloride with concentrated hydrochloric acid, and react at 25~30℃ to obtain methacrylamide guanidine hydrochloride; mix polylactic acid, methacrylamide guanidine hydrochloride, and tert-butyl peroxide in a mass ratio of 1:(0.15~0.25):(0.002~0.004), and react at 170~180℃. Antibacterial grafted polylactic acid was prepared; antibacterial grafted polylactic acid was dissolved in anhydrous N,N-dimethylformamide at 5wt%~10wt%, and KH560 was added at 0.15~0.25 times the mass of antibacterial grafted polylactic acid. The mixture was reacted at 65~75℃ to prepare silanized antibacterial grafted polylactic acid; silanized antibacterial grafted polylactic acid, modified polypyrrole nanoparticles, KH570, N,N-dimethylformamide and dichloromethane were mixed in a mass ratio of 1:(0.02~0.03):(0.015~0.025):(4~6):(4~6) and then electrospun and woven to obtain modified polylactic acid fiber fabric; (3) Trifluoropropanetrimethoxysilane, tetrahydrofuran, deionized water and sodium hydroxide are mixed in a mass ratio of 1:(4.5~5.5):(0.1~0.11):(0.075~0.085) and reacted at 65~75℃ to obtain a fluorinated polysilsesquioxane intermediate; the fluorinated polysilsesquioxane intermediate and dimethylchlorosilane are mixed in a mass ratio of 1:(1.4~1.5) and reacted at 45~50℃ to obtain a fluorinated hydrogen-containing polysilsesquioxane; (4) Dissolve fluorinated hydrogen-containing polysilsesquioxane in ethanol at 8wt%~12wt%, and add 0.5%~1.5% of platinum complex catalyst by mass of fluorinated hydrogen-containing polysilsesquioxane to prepare coating solution. The modified polylactic acid fiber fabric is immersed in KH570 treatment solution for 20-30 minutes, dried, and then immersed in coating solution for 20-40 minutes. After removal, it is heat-treated at 100-120°C to obtain a stain-resistant polylactic acid fiber fabric.

6. The method for preparing a stain-resistant polylactic acid fiber fabric according to claim 5, characterized in that, The polylactic acid used in step (2) is model 4032D.

7. The method for preparing a stain-resistant polylactic acid fiber fabric according to claim 5, characterized in that, The electrospinning in step (2) uses a conjugate spinning machine with the following main process parameters: spinning voltage of 6.5~8.5kV, receiving distance of 10~14cm, spinning solution propulsion rate of 0.4μL / min, needle spacing of 18~22cm, needle inner diameter of 0.5mm, bell mouth rotation speed of 400r / min, winding roller rotation speed of 5.3r / min, relative humidity of 30%~40%, and temperature of 25~30℃; the modified polylactic acid fiber fabric is a single-layer plain weave fabric with a warp density of 450 threads / 10cm, a weft density of 350 threads / 10cm, and a weight per square meter of 98g / m². 2 .

8. The method for preparing a stain-resistant polylactic acid fiber fabric according to claim 5, characterized in that, The preparation method of KH570 in step (4) is as follows: Ethanol and deionized water are mixed evenly at a volume ratio of 70:30, and the pH is adjusted to 4 with 0.2M acetic acid to obtain a mixed solvent; KH570 is added to the mixed solvent at a concentration of 50wt%~70wt%, and stirred at 25~30℃ and 300~500rpm for 20~40min to obtain KH570 treatment solution.

9. The method for preparing a stain-resistant polylactic acid fiber fabric according to claim 5, characterized in that, The platinum complex catalyst in step (3) is a Karstedt catalyst (a platinum 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex).

Images