Waterproof antibacterial polyester multi-layer composite fabric and preparation process thereof

Abstract

The present application relates to the technical field of multilayer composite fabric, in particular to a waterproof and antibacterial polyester multilayer composite fabric and a preparation process thereof.The waterproof and antibacterial polyester multilayer composite fabric comprises a core layer fabric and a waterproof and antibacterial fiber layer on the front and back surfaces of the core layer fabric.In the present application, alkaloids in bamboo culms are separated, combined with polyamide amine PAMAM-G3-NH2 through a reaction to obtain a PAMAM-alkaloid compound, and then combined with vanillin amine hydrochloride and bamboo cellulose nanocrystal through a Schiff base reaction, which significantly improves the bonding strength of natural alkaloids and the fiber base, and the prepared composite antibacterial agent is spun together with a polyurethane polymer solution, so that the composite antibacterial agent can be uniformly dispersed and stably embedded in the waterproof and antibacterial fiber layer, thereby effectively avoiding the shedding of the antibacterial components in the daily rubbing, folding and repeated washing processes, and ensuring the stability of the long-acting antibacterial performance.

Description

Technical Field

[0001] This invention relates to the field of multilayer composite fabric technology, specifically to a waterproof and antibacterial polyester multilayer composite fabric and its preparation process. Background Technology

[0002] Currently, polyester fabric, as a widely used synthetic fiber, occupies an important position in the fields of clothing, home textiles, and industrial textiles. However, when it absorbs sweat, sebum, and other bodily secretions, it easily creates a favorable environment for the growth of bacteria, fungi, and other microorganisms, leading not only to hygiene problems such as odor and discoloration, but also potentially causing skin allergies and even the risk of infection.

[0003] To enhance the antibacterial properties of polyester, existing technologies often involve adding inorganic antibacterial agents, such as silver, copper, or zinc ions and their compounds, to inhibit microorganisms through the slow-release effect of metal ions; using organic synthetic antibacterial agents, such as quaternary ammonium salts and chlorophenol compounds, to disrupt the structure of microorganisms through contact; and introducing natural plant-derived antibacterial substances, such as utilizing the natural antibacterial components carried or loaded on bio-based fibers like Juncao.

[0004] Among these technologies, plant-based antibacterial technologies have attracted considerable attention due to their environmental friendliness, low biotoxicity, and good biocompatibility. These technologies directly utilize the antibacterial properties of natural plants or extract their active substances (such as alkaloids) to construct an antibacterial layer, avoiding the ecological burden and potential irritation that may arise from inorganic or chemically synthesized antibacterial agents. However, in these natural antibacterial methods, plant active substances mainly bind to fibers through physical adsorption or simple encapsulation. This not only results in weak binding forces with plant fiber carriers but also makes it difficult to achieve good compatibility with synthetic fibers. During subsequent physical and mechanical processes such as rubbing, folding, and especially machine washing, and repeated washing, these antibacterial active molecules are easily shed and lost, leading to a rapid decline in antibacterial effect and making it difficult to guarantee the stability of long-term antibacterial performance.

[0005] In order to ensure waterproof performance, existing polyester fabrics are often coated with a hydrophobic coating. Although this can achieve a certain waterproof effect, the waterproof performance of such a hydrophobic coating is often negatively correlated with the moisture permeability. While the waterproof performance is good, the moisture permeability of the fabric will be reduced. Summary of the Invention

[0006] To address the aforementioned technical deficiencies, this invention presents a waterproof and antibacterial polyester multilayer composite fabric and its preparation process. The prepared multilayer composite fabric exhibits excellent waterproof performance and long-lasting antibacterial properties.

[0007] A waterproof and antibacterial polyester multilayer composite fabric includes a core fabric and waterproof and antibacterial fiber layers on both sides of the core fabric.

[0008] The core layer fabric is made by spraying polyurethane adhesive onto the front and back surfaces of polyester fabric;

[0009] The waterproof and antibacterial fiber layer is made by electrospinning a composite spinning solution containing a composite antibacterial agent, a palm oil-erucic acid-based polyurethane polymer solution and acetone onto the surface of the core fabric.

[0010] The compound antibacterial agent is prepared by reacting PAMAM-alkaloid complex, vanillinamine hydrochloride and reed oxidized cellulose nanocrystals dispersed in deionized water.

[0011] A process for preparing a waterproof and antibacterial polyester multilayer composite fabric includes the following steps:

[0012] S1. Separation of Reed Alkaloids: After washing and crushing the Reed stems, the Reed extract was refluxed and extracted with alcohol. The solid and liquid were separated to obtain Reed residue and Reed ethanol extract. The Reed ethanol extract was concentrated under reduced pressure until there was no alcohol odor. Then the pH was adjusted to acidic and ethyl acetate was used to extract the fat-soluble components. Then the pH was adjusted to alkaline and ethyl acetate was used for extraction. The organic phase was collected, evaporated and concentrated to obtain Reed alkaloid extract.

[0013] Preparation of S2, PAMAM-alkaloid complex: PAMAM-G3-NH2 was frozen and placed in an aqueous acetic acid solution. Formaldehyde aqueous solution was slowly added dropwise, and then Rehmannia glutinosa alkaloid extract was added in batches. The reaction was then heated and stirred. The reaction solution was dialyzed with deionized water and then freeze-dried to obtain PAMAM-alkaloid complex.

[0014] S3. Preparation of oxidized cellulose nanocrystals of Reed Bamboo: The Reed Bamboo filter residue was treated with alkali and bleached, washed and dried, and then placed in sulfuric acid aqueous solution for acid hydrolysis. It was then placed in an ice water bath for ultrasonic treatment. The precipitate was collected by centrifugation and dialyzed with deionized water until neutral. Sodium periodate was added for oxidation. After dialyzing and freeze drying, Reed Bamboo oxidized cellulose nanocrystals were obtained.

[0015] S4. Preparation of composite antibacterial agent: PAMAM-alkaloid complex, vanillinamine hydrochloride, arundinium oxidized cellulose nanocrystals and deionized water are mixed and reacted. The lower solid layer is collected by centrifugation and washed. Then, sodium cyanoborohydride methanol solution is added and stirred. The lower solid layer is collected by centrifugation and washed. The mixture is then air-dried to obtain composite antibacterial agent.

[0016] S5. Preparation of palm oil-erucic acid-based polyurethane: Under a nitrogen atmosphere, diethanolamine is slowly added to erucic acid while the temperature is slowly raised to 180-185℃ and then kept at the temperature to react and obtain erucic acid diethanolamide. Under a nitrogen atmosphere, palm oil and diethanolamine are mixed and reacted at 120-125℃ with sodium methoxide as a catalyst, then extracted and separated, and obtained by rotary evaporation. Using palm oil diethanolamide as a polyol, erucic acid diethanolamide as a chain extender, and N,N-dimethylformamide as a solvent, palm oil-erucic acid-based polyurethane polymer solution is prepared by high-temperature reaction with hexamethylene diisocyanate and dibutyltin dilaurate.

[0017] S6. Spinning construction of waterproof and antibacterial fiber layer: A composite spinning solution is prepared by combining a composite antibacterial agent, palm oil-erucic acid-based polyurethane polymer solution and acetone. Then, spinning is performed on the front and back surfaces of polyester fabric coated with polyurethane adhesive to form a waterproof and antibacterial fiber layer. After drying and hot pressing, a waterproof and antibacterial polyester multilayer composite fabric is obtained.

[0018] Furthermore, the separation of reed alkaloids in step S1 specifically includes the following steps:

[0019] S1.1: After cleaning and drying the stems of Reed Bamboo, crush them through a 30-50 mesh sieve, and then place them in a reflux condenser. Use a 90-95% ethanol aqueous solution for reflux extraction, repeat 3-4 times, each time for 2-2.5 hours. Then filter to separate the solid and liquid, and obtain Reed Bamboo filter residue and Reed Bamboo ethanol extract.

[0020] S1.2: Take the ethanol extract of Reed Bamboo and concentrate it under reduced pressure until there is no alcohol odor. Then dilute it with 8-10 times the volume of distilled water, and then add sulfuric acid aqueous solution to adjust the pH to 2-3 to obtain acidic Reed Bamboo ethanol extract.

[0021] S1.3: Add 1-1.5 times the volume of ethyl acetate to the acidic Reed ethanol extract and shake and stir for 4-5 minutes. Then centrifuge at 6000-8000 rpm to separate the components. Discard the upper organic phase and extract the fat-soluble components. Collect the aqueous phase and extract the fat-soluble components with ethyl acetate in the same way. Repeat 5-6 times. Add ammonia to the last collected aqueous phase to adjust the pH to 9-10. Extract with ethyl acetate and then centrifuge to collect the organic phase. Evaporate and concentrate to a viscous state to obtain Reed alkaloid extract.

[0022] Furthermore, the preparation of step S2PAMAM-alkaloid complex specifically includes the following steps:

[0023] S2.1: Freeze 7-8 parts by weight of polyamidoamine PAMAM-G3-NH2 to -3 to -5℃, then place it in a container that has been treated with an ice bath at 3-5℃, add 18-20 parts by weight of an aqueous acetic acid solution with a pH of 6-6.5, and then slowly add 0.65-0.7 parts by weight of an aqueous formaldehyde solution with a mass concentration of 36-37%. After mixing and stirring for 30-50 minutes, add 1.4-1.5 parts by weight of Reed alkaloid extract in 4-6 batches to obtain a pre-reaction solution;

[0024] S2.2: Heat the pre-reaction solution to 50-55℃ and stir at 150-200 rpm for 7-9 hours. Then cool it to room temperature and put it into a dialysis bag with a molecular weight cutoff of 3000-5000 Da. Dialyze the solution with deionized water at 4-5℃ for 32-40 hours, changing the deionized water every 8 hours. Then collect the solution in the dialysis bag to obtain PAMAM-alkaloid complex solution. Freeze-dry and then pulverize to obtain PAMAM-alkaloid complex.

[0025] Furthermore, step S3, the preparation of *Arundo donax* oxidized cellulose nanocrystals, specifically includes the following steps:

[0026] S3.1: Mix the Reed Fibers filter residue obtained in step S1.1 with a sodium hydroxide solution of 8-10% by mass at a material-to-liquid ratio of 1:(20-25)g / mL. Treat the mixture at 85-90℃ for 1-1.5h, then place it in an environment of -10 to -15℃ and stir at 800-900rpm for 4-5h. Then filter and collect the filter cake and wash it with clean water 2-3 times to obtain Reed Fibers lignocellulose microfibers.

[0027] S3.2: Soak the lignocellulose microfibers of Reed Bamboo in a bleaching solution at a material-to-liquid ratio of 1:(15-20)g / mL, treat at 70-75℃ for 5-6h, then filter and collect the filter cake, wash it with water 3-4 times, soak it in anhydrous ethanol for 3-5min, filter it and dry it at 45-50℃ to obtain Reed Bamboo cellulose microfibers.

[0028] S3.3: Disperse the cellulose microfibers of *Arundinaria salsa* in a 55-60% sulfuric acid aqueous solution at a material-to-liquid ratio of 1:(18-20) g / mL. Acid hydrolyze the solution at 50-55℃ for 40-45 min. After cooling to room temperature, place the solution in an ice-water bath for ultrasonic treatment with an ultrasonic power of 250-300W. Then dilute the solution with 10-15 times the volume of deionized water. Centrifuge the solution at 8-12℃ and 10000-12000 rpm for 10-15 min. Remove the supernatant and collect the precipitate. Place the precipitate in a dialysis bag with a molecular weight cutoff of 8000-10000 Da and dialyze it with deionized water until the pH is neutral to obtain a dispersion of *Arundinaria salsa* cellulose nanocrystals.

[0029] S3.4: Add sodium periodate to the dispersion of Arundo donax cellulose nanocrystals, with the mass ratio of sodium periodate to Arundo donax cellulose nanocrystals in the dispersion being (0.8-1.2):1. Stir the reaction at 35-45℃ in the dark for 1-1.5 h, then add 0.8-1 wt% ethylene glycol and stir for 40-60 min to terminate the reaction. Place the reaction solution into a dialysis bag with a molecular weight cutoff of 8000-10000 Da and dialyze for 2-3 days to obtain an oxidized cellulose nanocrystal dispersion. Freeze-dry the dispersion to obtain Arundo donax oxidized cellulose nanocrystals.

[0030] Furthermore, the preparation of the composite antibacterial agent in step S4 specifically includes the following steps:

[0031] S4.1: Mix PAMAM-alkaloid complex, vanillinamine hydrochloride, atractylodes oxidized cellulose nanocrystals and deionized water in a container and stir for 25-30 min to prepare a mixed reaction solution. The mass concentration of PAMAM-alkaloid complex in the mixed reaction solution is 4-5 g / L, the mass concentration of vanillinamine hydrochloride is 0.6-0.8 g / L, and the mass concentration of atractylodes oxidized cellulose nanocrystals is 8-10 g / L. Then, react at 30-40℃ for 20-30 min, centrifuge to collect the precipitate, and wash with deionized water 3-4 times to obtain a solid reactant.

[0032] S4.2: Add the solid reactants to a 0.1-0.15 mol / L sodium cyanoborohydride methanol solution at a material-to-liquid ratio of 1:(800-1000) g / mL, stir at room temperature for 5-6 h, then centrifuge to collect the lower solid layer, wash with deionized water 3-4 times, and air dry to obtain the composite antibacterial agent.

[0033] Furthermore, the preparation of palm oil-erucic acid-based polyurethane in step S5 specifically includes the following steps:

[0034] S5.1: Place erucic acid in a reaction vessel and heat it to 80-90℃ at a heating rate of 4-5℃ / min under a nitrogen atmosphere. Then, start adding diethanolamine dropwise at a uniform rate. Control the heating to 180-185℃ so that the diethanolamine is completely added to the reaction vessel. The molar ratio of erucic acid to diethanolamine is 1:(1.1-1.2). Then, keep it at this temperature for 4-5 hours. As the reaction vessel cools down to 50-60℃, remove it to obtain erucic acid diethanolamide.

[0035] S5.2: Under a nitrogen atmosphere, sodium methoxide and diethanolamine are added to a container, heated to 80-85℃, and mixed at 150-170 rpm for 10-15 min. Then, palm oil is added and the temperature is raised to 120-125℃. The molar ratio of sodium methoxide, diethanolamine and palm oil is 1:(40-42):(6-8). Under a nitrogen atmosphere, the mixture is stirred for 4-5 h to obtain a reaction solution. An equal volume of ethyl acetate is added to the reaction solution and transferred to a separatory funnel. The solution is extracted 3-5 times with saturated sodium chloride solution until the aqueous phase is clear. The organic phase is filtered and the filtrate is rotary evaporated at a water bath temperature of 60-65℃ and a vacuum of -0.1 MPa for 3-3.5 h to obtain palm oil diethanolamide.

[0036] S5.3: Under a dry nitrogen atmosphere, place palm oil diethanolamide, hexamethylene diisocyanate and dibutyltin dilaurate in a container, then add 3-4 times the mass of N,N-dimethylformamide, stir at 250-300 rpm for 10-15 min, then heat to 70-75℃ and keep warm for 3-3.5 h, then add erucic acid diethanolamide and stir for 15-20 min, heat to 90-95℃ and stir for 7-9 h to obtain a palm oil-erucic acid-based polyurethane polymer solution, wherein the molar ratio of hexamethylene diisocyanate, palm oil diethanolamide, erucic acid diethanolamide and dibutyltin dilaurate is 1:(8.1-8.15):(1.42-1.45):(0.06-0.07).

[0037] Furthermore, the spinning construction of the waterproof and antibacterial fiber layer in step S6 specifically includes the following steps:

[0038] S6.1: Place acetone and palm oil-erucic acid-based polyurethane polymer solution in a container at a mass ratio of 1:(0.8-1), add 5-6wt% of composite antibacterial agent and mix evenly to obtain composite spinning solution. Load the composite spinning solution into the syringe of the electrospinning machine. The syringe orifice diameter is 0.07-0.12mm, the preset spinning voltage is 20-25kV, and the spinning solution output rate is 0.1-0.12mm / min.

[0039] S6.2: Take a polyester fabric with a thickness of 0.1-0.3mm, and spray polyurethane adhesive onto both sides of the polyester fabric, with an adhesive application rate of 15-20g / m². 2 This yields the core fabric.

[0040] S6.3: Place the core fabric under the electrospinning machine preset in step S6.1, adjust the distance from the syringe nozzle to 15-20cm, start the electrospinning machine to spin, and spin evenly on both sides of the core fabric to form a waterproof and antibacterial fiber layer with a thickness of 25-30μm. After drying, hot press at 1-2MPa and 90-95℃ for 3-5min to obtain a waterproof and antibacterial polyester multilayer composite fabric.

[0041] Furthermore, in step S1, the mass concentration of the sulfuric acid aqueous solution is 1-1.5%, and the mass concentration of the ammonia solution is 10-15%.

[0042] Further, in step S3.2, the bleaching solution is prepared by mixing acetic acid and a 3% NaClO2 solution at a volume ratio of 1:(100-105).

[0043] Beneficial effects

[0044] 1. This invention separates the alkaloids from the stems of *Arundinaria lobata* and reacts them with polyamide amine PAMAM-G3-NH2 to obtain a PAMAM-alkaloid complex. This complex is then combined with vanillin amine hydrochloride and *Arundinaria lobata* oxidized cellulose nanocrystals prepared from *Arundinaria lobata* filter residue. The *Arundinaria lobata* oxidized cellulose nanocrystals have a high specific surface area and abundant aldehyde active sites, enabling them to undergo a Schiff base reaction with the amine groups of the PAMAM-alkaloid complex. Simultaneously, the active amine groups contained in vanillin amine hydrochloride can also undergo a Schiff base reaction with the *Arundinaria lobata* oxidized cellulose nanocrystals, further increasing the number of binding sites. This constructs strong chemical anchoring points on the fiber surface, significantly improving the bonding strength between the natural alkaloids, vanillin amine hydrochloride, and the fiber substrate. Furthermore, the prepared composite antibacterial agent is spun together with a palm oil-erucic acid-based polyurethane polymer solution. The composite antibacterial agent can be uniformly dispersed and stably embedded in the waterproof antibacterial fiber layer, effectively preventing the loss of antibacterial components during daily rubbing, folding, and repeated washing, ensuring the stability of long-lasting antibacterial performance.

[0045] 2. This invention involves a composite reaction of vanillin amine hydrochloride and PAMAM-alkaloid complex with Rehmannia glutinosa oxidized cellulose nanocrystals. Vanillin amine hydrochloride enables the grafting of antibacterial vanillin amide groups onto the Rehmannia glutinosa oxidized cellulose nanocrystals, while the PAMAM-alkaloid complex enables the grafting of antibacterial Rehmannia glutinosa oxidized cellulose nanocrystals with Rehmannia glutinosa alkaloids. This creates a dual antibacterial functional unit within the fiber network. Rehmannia glutinosa alkaloids exert their antibacterial effect by disrupting the microbial cell membrane, while the vanillin amide groups of vanillin amine hydrochloride can better penetrate the bacterial cell membrane, inactivating the bacterial metabolic proteins and enzymes. The two complement each other in their antibacterial mechanism, and this synergistic effect enhances the killing efficiency against common pathogenic microorganisms, thereby significantly optimizing the overall antibacterial capability of the fabric.

[0046] 3. This invention prepares erucic acid diethanolamide and palm oil diethanolamide through an amidation reaction, and introduces erucic acid diethanolamide as a chain extender into the skeleton of palm oil-based polyurethane. Due to the ultra-long hydrophobic chains contained in the erucic acid chain extender, a large number of amorphous, flexible, ultra-long linear alkyl chains can be introduced into the polyurethane skeleton. These alkyl chains are low surface energy groups, which can significantly increase the molar ratio of hydrophobic groups in the molecule, reduce the overall surface energy of the polyurethane, reduce the spreading and adsorption of water molecules on the surface of palm oil-erucic acid-based polyurethane, making it difficult for water to penetrate into the material. Its amorphous, flexible arrangement structure avoids the formation of a dense crystalline hydrophobic film that blocks water vapor channels, ensuring that the waterproof and antibacterial fiber layer prepared by spinning has good waterproof performance while having breathable pores, giving polyester multilayer composite fabric strong waterproof and breathable capabilities. Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] A waterproof and antibacterial polyester multilayer composite fabric includes a core fabric and waterproof and antibacterial fiber layers on both sides of the core fabric. The preparation method includes the following steps:

[0050] S1: Isolation of Reed Alkaloids

[0051] S1.1: After cleaning and drying the stems of Reed Bamboo, crush them through a 30-mesh sieve, and then place them in a reflux condenser. Extract them by reflux using a 90% ethanol aqueous solution. Repeat this process 3 times, each time for 2 hours. Then filter to separate the solid and liquid components, and obtain Reed Bamboo residue and Reed Bamboo ethanol extract.

[0052] S1.2: Take the ethanol extract of Reishi mushroom and concentrate it under reduced pressure until there is no alcohol odor. Then dilute it with 8 times the volume of distilled water, and then add 1% sulfuric acid aqueous solution to adjust the pH to 2 to obtain acidic Reishi mushroom ethanol extract.

[0053] S1.3: Add 1 volume of ethyl acetate to the acidic Reed ethanol extract and shake and stir for 4 min. Then centrifuge at 6000 rpm to separate the components. Discard the upper organic phase and extract the fat-soluble components. Collect the aqueous phase and extract the fat-soluble components with ethyl acetate in the same way. Repeat 5 times. Add 10% ammonia to the last collected aqueous phase to adjust the pH to 9. Extract with ethyl acetate and then centrifuge to collect the organic phase. Evaporate and concentrate to a viscous state to obtain Reed alkaloid extract.

[0054] S2: Preparation of PAMAM-alkaloid complex

[0055] S2.1: Freeze 7 parts by weight of polyamidoamine PAMAM-G3-NH2 to -5℃, then place it in a container treated with an ice bath at 3℃, add 18 parts by weight of acetic acid aqueous solution with pH 6, and then slowly add 0.65 parts by weight of formaldehyde aqueous solution with a mass concentration of 36%. After mixing and stirring for 30 minutes, add 1.4 parts by weight of reed alkaloid extract in 4 batches to obtain a pre-reaction solution.

[0056] S2.2: The pre-reaction solution was heated to 50℃ and stirred at 150 rpm for 7 hours. After cooling to room temperature, it was placed into a dialysis bag with a molecular weight cutoff of 3000 Da and dialyzed with deionized water at 4℃ for 32 hours. The deionized water was replaced every 8 hours. The solution in the dialysis bag was then collected to obtain the PAMAM-alkaloid complex solution. After freeze-drying, it was pulverized to obtain the PAMAM-alkaloid complex.

[0057] S3: Preparation of Reed Fiber Oxidized Cellulose Nanocrystals

[0058] S3.1: Mix the Reed Fibers filter residue obtained in step S1.1 with an 8% sodium hydroxide solution at a material-to-liquid ratio of 1:20 g / mL. Treat the mixture at 85℃ for 1 hour, then place it in a -15℃ environment and stir at 800 rpm for 4 hours. Filter the mixture and collect the filter cake. Wash the filter cake twice with clean water to obtain Reed Fibers wood cellulose microfibers.

[0059] S3.2: The lignocellulose microfibers of Reishi mushroom were soaked in a bleaching solution at a material-to-liquid ratio of 1:15 g / mL. The bleaching solution was prepared by mixing acetic acid and 3% NaClO2 solution at a volume ratio of 1:100. The mixture was treated at 70℃ for 5 h, then filtered and the filter cake was collected and washed three times with water. It was then soaked in anhydrous ethanol for 3 min, filtered, and dried at 45℃ to obtain Reishi mushroom cellulose microfibers.

[0060] S3.3: Disperse the cellulose microfibers of *Arundinaria salsa* in a 55% sulfuric acid aqueous solution at a material-to-liquid ratio of 1:18 g / mL. Heat the solution to 50℃ and acid hydrolyze for 40 min. After cooling to room temperature, place it in an ice-water bath for ultrasonic treatment with an ultrasonic power of 250W. Then dilute with 10 times the volume of deionized water. Centrifuge at 8℃ and 10000 rpm for 10 min. Remove the supernatant and collect the precipitate. Place the precipitate in a dialysis bag with a molecular weight cutoff of 8000 Da and dialyze with deionized water until the pH is neutral to obtain a dispersion of *Arundinaria salsa* nanocrystals.

[0061] S3.4: Sodium periodate was added to the dispersion of Arundo donax cellulose nanocrystals. The mass ratio of sodium periodate to Arundo donax cellulose nanocrystals in the dispersion was 0.8:1. The mixture was stirred for 1 hour under light-protected conditions at 35°C. Then, 0.8 wt% ethylene glycol was added and stirred for 40 minutes to terminate the reaction. The reaction solution was then placed in a dialysis bag with a molecular weight cutoff of 8000 Da and dialyzed for 2 days to obtain an oxidized cellulose nanocrystal dispersion. After freeze-drying, Arundo donax oxidized cellulose nanocrystals were obtained.

[0062] S4: Preparation of compound antibacterial agents

[0063] S4.1: PAMAM-alkaloid complex, vanillinamine hydrochloride, atractylodes oxidized cellulose nanocrystals and deionized water were mixed in a container and stirred for 25 min to prepare a mixed reaction solution. The mass concentration of PAMAM-alkaloid complex in the mixed reaction solution was 4 g / L, the mass concentration of vanillinamine hydrochloride was 0.6 g / L, and the mass concentration of atractylodes oxidized cellulose nanocrystals was 8 g / L. Then, the mixture was placed at 30 °C for 20 min, the precipitate was collected by centrifugation, and the precipitate was washed three times with deionized water to obtain a solid reactant.

[0064] S4.2: Add the solid reactants to a 0.1 mol / L sodium cyanoborohydride methanol solution at a material-to-liquid ratio of 1:800 g / mL, stir at room temperature for 5 h, then centrifuge to collect the lower solid layer, wash three times with deionized water, and air dry to obtain the composite antibacterial agent.

[0065] S5: Preparation of Palm Oil-Eucolic Acid-Based Polyurethane

[0066] S5.1: Erucic acid is placed in a reaction vessel and heated to 80°C at a heating rate of 4°C / min under a nitrogen atmosphere. Then, diethanolamine is added dropwise at a uniform rate. When the temperature reaches 180°C, the diethanolamine is completely added to the reaction vessel. The molar ratio of erucic acid to diethanolamine is 1:1.1. The temperature is then maintained for 4 hours. After the reaction vessel is cooled to 50°C, it is removed to obtain erucic acid diethanolamide.

[0067] S5.2: Under a nitrogen atmosphere, sodium methoxide and diethanolamine were added to a container, heated to 80°C, and mixed at 150 rpm for 10 min. Then, palm oil was added and the temperature was raised to 120°C. The molar ratio of sodium methoxide, diethanolamine, and palm oil was 1:40:6. Under a nitrogen atmosphere, the mixture was stirred for 4 h to obtain a reaction solution. An equal volume of ethyl acetate was added to the reaction solution, and the mixture was transferred to a separatory funnel. The solution was extracted three times with saturated sodium chloride solution until the aqueous phase was clear. The organic phase was filtered, and the filtrate was rotary evaporated at a water bath temperature of 60°C and a vacuum of -0.1 MPa for 3 h to obtain palm oil diethanolamide.

[0068] S5.3: Under a dry nitrogen atmosphere, palm oil diethanolamide, hexamethylene diisocyanate, and dibutyltin dilaurate were placed in a container, and then 3 times the mass of N,N-dimethylformamide was added. The mixture was stirred at 250 rpm for 10 min, then heated to 70 °C and kept at that temperature for 3 h. Then, erucic acid diethanolamide was added and stirred for 15 min. The temperature was then raised to 90 °C and stirred for 7 h to obtain a palm oil-erucic acid-based polyurethane polymer solution, wherein the molar ratio of hexamethylene diisocyanate, palm oil diethanolamide, erucic acid diethanolamide, and dibutyltin dilaurate was 1:8.1:1.42:0.06.

[0069] S6: Spinning construction of waterproof and antibacterial fiber layer

[0070] S6.1: Place acetone and palm oil-erucic acid-based polyurethane polymer solution in a container at a mass ratio of 1:0.8, add 5wt% of composite antibacterial agent and mix evenly to obtain composite spinning solution. Load the composite spinning solution into the syringe of the electrospinning machine. The syringe orifice diameter is 0.07mm, the preset spinning voltage is 20kV, and the spinning solution output rate is 0.1mm / min.

[0071] S6.2: Take a 0.1mm thick polyester fabric and spray polyurethane adhesive onto both sides of the fabric, with an adhesive application rate of 15g / m². 2 This yields the core fabric.

[0072] S6.3: Place the core layer fabric under the electrospinning machine preset in step S6.1, adjust the distance from the syringe nozzle to 15cm, start the electrospinning machine to spin, and spin evenly on both sides of the core layer fabric to form a waterproof and antibacterial fiber layer with a thickness of 25μm. After drying, hot press at 1MPa and 90℃ for 3min to obtain a waterproof and antibacterial polyester multilayer composite fabric.

[0073] Example 2

[0074] A waterproof and antibacterial polyester multilayer composite fabric includes a core fabric and waterproof and antibacterial fiber layers on both sides of the core fabric. The preparation method includes the following steps:

[0075] S1: Isolation of Reed Alkaloids

[0076] S1.1: After cleaning and drying the stems of Reed Bamboo, crush them through a 40-mesh sieve and then place them in a reflux condenser. Extract them by reflux with a 93% ethanol aqueous solution. Repeat the extraction 4 times, each time for 2.3 hours. Then filter to separate the solid and liquid, and obtain Reed Bamboo filter residue and Reed Bamboo ethanol extract.

[0077] S1.2: Take the ethanol extract of Reed Bamboo and concentrate it under reduced pressure until there is no alcohol odor. Then add 9 times the volume of distilled water to dilute it. Then add a 1.2% sulfuric acid aqueous solution to adjust the pH to 2.5 to obtain acidic Reed Bamboo ethanol extract.

[0078] S1.3: Add 1.25 times the volume of ethyl acetate to the acidic Reed ethanol extract and shake and stir for 4.5 min. Then centrifuge at 7000 rpm, discard the upper organic phase, extract and remove the fat-soluble components, and collect the aqueous phase. Repeat the same steps with ethyl acetate to remove the fat-soluble components. Repeat 6 times. Add 12.5% ​​ammonia to the last collected aqueous phase to adjust the pH to 9.5, extract with ethyl acetate, centrifuge and collect the organic phase, evaporate and concentrate to a viscous state to obtain Reed alkaloid extract.

[0079] S2: Preparation of PAMAM-alkaloid complex

[0080] S2.1: Freeze 7.5 parts by weight of polyamidoamine PAMAM-G3-NH2 to -4°C, then place it in a container that has been treated with an ice bath at 4°C, add 19 parts by weight of an aqueous acetic acid solution with a pH of 6.5, and then slowly add 0.68 parts by weight of an aqueous formaldehyde solution with a mass concentration of 36.5%. After mixing and stirring for 40 minutes, add 1.45 parts by weight of Reed alkaloid extract in 5 batches to obtain a pre-reaction solution;

[0081] S2.2: The pre-reaction solution was heated to 52.5℃ and stirred at 175 rpm for 8 hours. After cooling to room temperature, it was placed into a dialysis bag with a molecular weight cutoff of 4000 Da and dialyzed with deionized water at 4℃ for 36 hours, with the deionized water being replaced every 8 hours. The solution in the dialysis bag was then collected to obtain the PAMAM-alkaloid complex solution. After freeze-drying, it was pulverized to obtain the PAMAM-alkaloid complex.

[0082] S3: Preparation of Reed Fiber Oxidized Cellulose Nanocrystals

[0083] S3.1: Mix the Reed Fibers filter residue obtained in step S1.1 with a 9% sodium hydroxide solution at a material-to-liquid ratio of 1:22.5 g / mL. Treat the mixture at 87℃ for 1.3 h, then place it in an environment at -12℃ and stir at 850 rpm for 5 h. Then filter and collect the filter cake, wash it three times with clean water to obtain Reed Fibers lignocellulose microfibers.

[0084] S3.2: The lignocellulose microfibers of Reishi mushroom were soaked in a bleaching solution at a material-to-liquid ratio of 1:17.5 g / mL. The bleaching solution was prepared by mixing acetic acid and 3% NaClO2 solution at a volume ratio of 1:103. The mixture was treated at 72℃ for 5.5 h, then filtered and the filter cake was washed 4 times with water and then soaked in anhydrous ethanol for 4 min. After filtration, the mixture was dried at 47℃ to obtain Reishi mushroom cellulose microfibers.

[0085] S3.3: The cellulose microfibers of *Arundinaria lobata* were dispersed in a 57.5% sulfuric acid aqueous solution at a material-to-liquid ratio of 1:19 g / mL. The solution was heated to 52℃ and acidified for 43 min. After cooling to room temperature, the solution was placed in an ice-water bath for ultrasonic treatment with an ultrasonic power of 275 W. Then, 13 times the volume of deionized water was added for dilution. The solution was centrifuged at 10℃ and 11000 rpm for 12 min. The supernatant was removed and the precipitate was collected. The precipitate was placed in a dialysis bag with a molecular weight cutoff of 9000 Da and dialyzed with deionized water until the pH was neutral to obtain a dispersion of *Arundinaria lobata* nanocrystals.

[0086] S3.4: Sodium periodate was added to the dispersion of Arundo donax cellulose nanocrystals, with a mass ratio of sodium periodate to Arundo donax cellulose nanocrystals in the dispersion of Arundo donax cellulose nanocrystals of 1:1. The mixture was stirred and reacted for 1.3 h at 40 °C in the dark. Then, 0.9 wt% ethylene glycol was added and stirred for 50 min to terminate the reaction. The reaction solution was placed in a dialysis bag with a molecular weight cutoff of 9000 Da and dialyzed for 2.5 days to obtain an oxidized cellulose nanocrystal dispersion. After freeze-drying, Arundo donax oxidized cellulose nanocrystals were obtained.

[0087] S4: Preparation of compound antibacterial agents

[0088] S4.1: PAMAM-alkaloid complex, vanillinamine hydrochloride, atractylodes oxidized cellulose nanocrystals and deionized water were mixed in a container and stirred for 28 min to prepare a mixed reaction solution. The mass concentration of PAMAM-alkaloid complex in the mixed reaction solution was 4.5 g / L, the mass concentration of vanillinamine hydrochloride was 0.7 g / L, and the mass concentration of atractylodes oxidized cellulose nanocrystals was 9 g / L. The mixture was then placed at 35 °C and reacted for 25 min. The precipitate was collected by centrifugation and washed 4 times with deionized water to obtain a solid reactant.

[0089] S4.2: Add the solid reactants to a 0.125mol / L sodium cyanoborohydride methanol solution at a material-to-liquid ratio of 1:900g / mL, stir at room temperature for 5.5h, then centrifuge to collect the lower solid layer, wash with deionized water 4 times, and air dry to obtain the composite antibacterial agent.

[0090] S5: Preparation of Palm Oil-Eucolic Acid-Based Polyurethane

[0091] S5.1: Erucic acid was placed in a reaction vessel and heated to 85°C at a heating rate of 4.5°C / min under a nitrogen atmosphere. Then, diethanolamine was added dropwise at a uniform rate. When the temperature was controlled to reach 182°C, the diethanolamine was completely added to the reaction vessel. The molar ratio of erucic acid to diethanolamine was 1:1.15. The mixture was then kept at this temperature for 5 hours. After the temperature of the reaction vessel was lowered to 55°C, the mixture was removed to obtain erucic acid diethanolamide.

[0092] S5.2: Under a nitrogen atmosphere, sodium methoxide and diethanolamine were added to a container, heated to 83°C, and mixed at 160 rpm for 12 min. Then, palm oil was added and the temperature was raised to 122°C. The molar ratio of sodium methoxide, diethanolamine, and palm oil was 1:41:7. Under a nitrogen atmosphere, the mixture was stirred for 5 h to obtain a reaction solution. An equal volume of ethyl acetate was added to the reaction solution, and the mixture was transferred to a separatory funnel. The solution was extracted five times with saturated sodium chloride solution until the aqueous phase was clear. The organic phase was filtered, and the filtrate was rotary evaporated at a water bath temperature of 63°C and a vacuum of -0.1 MPa for 3.5 h to obtain palm oil diethanolamide.

[0093] S5.3: Under a dry nitrogen atmosphere, palm oil diethanolamide, hexamethylene diisocyanate, and dibutyltin dilaurate were placed in a container, and then 3.5 times the mass of N,N-dimethylformamide was added. The mixture was stirred at 275 rpm for 12 min, then heated to 72 °C and kept at that temperature for 3 h. Then, erucic acid diethanolamide was added and stirred for 18 min. The temperature was then raised to 93 °C and stirred for 8 h to obtain a palm oil-erucic acid-based polyurethane polymer solution, wherein the molar ratio of hexamethylene diisocyanate, palm oil diethanolamide, erucic acid diethanolamide, and dibutyltin dilaurate was 1:8.13:1.44:0.065.

[0094] S6: Spinning construction of waterproof and antibacterial fiber layer

[0095] S6.1: Place acetone and palm oil-erucic acid-based polyurethane polymer solution in a container at a mass ratio of 1:0.9, add 5.5wt% of composite antibacterial agent and mix evenly to obtain composite spinning solution. Load the composite spinning solution into the syringe of the electrospinning machine. The syringe orifice diameter is 0.095mm, the preset spinning voltage is 22kV, and the spinning solution output rate is 0.11mm / min.

[0096] S6.2: Take a polyester fabric with a thickness of 0.2mm, spray polyurethane adhesive onto the front and back surfaces of the polyester fabric, with an adhesive application amount of 17.5g / m², to obtain the core layer fabric.

[0097] S6.3: Place the core layer fabric under the electrospinning machine preset in step S6.1, adjust the distance from the syringe nozzle to 17cm, start the electrospinning machine to spin, and spin evenly on both sides of the core layer fabric to form a waterproof and antibacterial fiber layer with a thickness of 28μm. After drying, hot press at 1.5MPa and 92℃ for 4min to obtain a waterproof and antibacterial polyester multilayer composite fabric.

[0098] Example 3

[0099] A waterproof and antibacterial polyester multilayer composite fabric includes a core fabric and waterproof and antibacterial fiber layers on both sides of the core fabric. The preparation method includes the following steps:

[0100] S1: Isolation of Reed Alkaloids

[0101] S1.1: After cleaning and drying the stems of Reed Bamboo, crush them through a 50-mesh sieve and then place them in a reflux condenser. Extract them by reflux using a 95% ethanol aqueous solution. Repeat the extraction 4 times, each time for 2.5 hours. Then filter to separate the solid and liquid, and obtain Reed Bamboo filter residue and Reed Bamboo ethanol extract.

[0102] S1.2: Take the ethanol extract of Reed Bamboo and concentrate it under reduced pressure until there is no alcohol odor. Then dilute it with 10 times the volume of distilled water, and then add 1.5% sulfuric acid aqueous solution to adjust the pH to 3 to obtain acidic Reed Bamboo ethanol extract.

[0103] S1.3: Add 1.5 times the volume of ethyl acetate to the acidic Reed ethanol extract and shake and stir for 5 min. Then centrifuge at 8000 rpm to separate the components. Discard the upper organic phase and extract the fat-soluble components. Collect the aqueous phase and extract the fat-soluble components with ethyl acetate in the same way. Repeat 6 times. Add 15% ammonia water to the aqueous phase collected in the last time to adjust the pH to 10. Extract with ethyl acetate and then centrifuge to collect the organic phase. Evaporate and concentrate to a viscous state to obtain Reed alkaloid extract.

[0104] S2: Preparation of PAMAM-alkaloid complex

[0105] S2.1: Freeze 8 parts by weight of polyamidoamine PAMAM-G3-NH2 to -3℃, then place it in a container that has been treated with an ice bath at 5℃, add 20 parts by weight of acetic acid aqueous solution with pH 6.5, and then slowly add 0.7 parts by weight of formaldehyde aqueous solution with a mass concentration of 37%. After mixing and stirring for 50 minutes, add 1.5 parts by weight of Reed alkaloid extract in 6 batches to obtain a pre-reaction solution;

[0106] S2.2: The pre-reaction solution was heated to 55℃ and stirred at 200 rpm for 9 hours. After cooling to room temperature, it was placed into a dialysis bag with a molecular weight cutoff of 5000 Da and dialyzed with deionized water at 5℃ for 40 hours, with the deionized water being replaced every 8 hours. The solution in the dialysis bag was then collected to obtain the PAMAM-alkaloid complex solution. After freeze-drying, it was pulverized to obtain the PAMAM-alkaloid complex.

[0107] S3: Preparation of Reed Fiber Oxidized Cellulose Nanocrystals

[0108] S3.1: Mix the Reed Fibers filter residue obtained in step S1.1 with a 10% sodium hydroxide solution at a material-to-liquid ratio of 1:25 g / mL. Treat the mixture at 90℃ for 1.5 h, then place it in a -10℃ environment and stir at 900 rpm for 5 h. Filter the mixture and collect the filter cake. Wash the filter cake three times with clean water to obtain Reed Fibers lignocellulose microfibers.

[0109] S3.2: The lignocellulose microfibers of Reishi mushroom were soaked in a bleaching solution at a material-to-liquid ratio of 1:20 g / mL. The bleaching solution was prepared by mixing acetic acid and 3% NaClO2 solution at a volume ratio of 1:105. The mixture was treated at 75℃ for 6 hours, then filtered and the filter cake was collected and washed 4 times with water. It was then soaked in anhydrous ethanol for 5 minutes, filtered, and dried at 50℃ to obtain Reishi mushroom cellulose microfibers.

[0110] S3.3: Disperse the cellulose microfibers of *Arundo donax* in a 60% sulfuric acid aqueous solution at a material-to-liquid ratio of 1:20 g / mL. Heat to 55℃ and acid hydrolyze for 45 min. After cooling to room temperature, place in an ice-water bath for ultrasonic treatment with an ultrasonic power of 300 W. Then dilute with 15 times the volume of deionized water. Centrifuge at 12℃ and 12000 rpm for 15 min. Remove the supernatant and collect the precipitate. Place it in a dialysis bag with a molecular weight cutoff of 10000 Da and dialyze with deionized water until the pH is neutral to obtain a dispersion of *Arundo donax* cellulose nanocrystals.

[0111] S3.4: Sodium periodate was added to the dispersion of Arundo donax cellulose nanocrystals. The mass ratio of sodium periodate to Arundo donax cellulose nanocrystals in the dispersion was 1.2:1. The mixture was stirred and reacted for 1.5 h at 45 °C in the dark. Then, 1 wt% ethylene glycol was added and stirred for 60 min to terminate the reaction. The reaction solution was then placed in a dialysis bag with a molecular weight cutoff of 10000 Da and dialyzed for 3 days to obtain an oxidized cellulose nanocrystal dispersion. After freeze-drying, Arundo donax oxidized cellulose nanocrystals were obtained.

[0112] S4: Preparation of compound antibacterial agents

[0113] S4.1: PAMAM-alkaloid complex, vanillinamine hydrochloride, atractylodes oxidized cellulose nanocrystals and deionized water were mixed in a container and stirred for 30 min to prepare a mixed reaction solution. The mass concentration of PAMAM-alkaloid complex in the mixed reaction solution was 5 g / L, the mass concentration of vanillinamine hydrochloride was 0.8 g / L, and the mass concentration of atractylodes oxidized cellulose nanocrystals was 10 g / L. Then, the mixture was placed at 40 °C and reacted for 30 min. The precipitate was collected by centrifugation and washed 4 times with deionized water to obtain a solid reactant.

[0114] S4.2: Add the solid reactants to a 0.15 mol / L sodium cyanoborohydride methanol solution at a material-to-liquid ratio of 1:1000 g / mL, stir at room temperature for 6 h, then centrifuge to collect the lower solid layer, wash with deionized water 4 times, and air dry to obtain the composite antibacterial agent.

[0115] S5: Preparation of Palm Oil-Eucolic Acid-Based Polyurethane

[0116] S5.1: Erucic acid is placed in a reaction vessel and heated to 90°C at a heating rate of 5°C / min under a nitrogen atmosphere. Then, diethanolamine is added dropwise at a uniform rate. When the temperature is controlled to reach 185°C, the diethanolamine is completely added to the reaction vessel. The molar ratio of erucic acid to diethanolamine is 1:1.2. The temperature is then maintained for 5 hours. After the reaction vessel is cooled to 60°C, it is removed to obtain erucic acid diethanolamide.

[0117] S5.2: Under a nitrogen atmosphere, sodium methoxide and diethanolamine were added to a container, heated to 85°C, and mixed at 170 rpm for 15 min. Then, palm oil was added and the temperature was raised to 125°C. The molar ratio of sodium methoxide, diethanolamine, and palm oil was 1:42:8. Under a nitrogen atmosphere, the mixture was stirred for 5 h to obtain a reaction solution. An equal volume of ethyl acetate was added to the reaction solution, and the mixture was transferred to a separatory funnel. The solution was extracted five times with saturated sodium chloride solution until the aqueous phase was clear. The organic phase was filtered, and the filtrate was rotary evaporated at a water bath temperature of 65°C and a vacuum of -0.1 MPa for 3.5 h to obtain palm oil diethanolamide.

[0118] S5.3: Under a dry nitrogen atmosphere, palm oil diethanolamide, hexamethylene diisocyanate, and dibutyltin dilaurate were placed in a container, and then 4 times the mass of N,N-dimethylformamide was added. The mixture was stirred at 300 rpm for 15 min, then heated to 75 °C and kept at that temperature for 3.5 h. Then, erucic acid diethanolamide was added and stirred for 20 min. The temperature was then raised to 95 °C and stirred for 9 h to obtain a palm oil-erucic acid-based polyurethane polymer solution, wherein the molar ratio of hexamethylene diisocyanate, palm oil diethanolamide, erucic acid diethanolamide, and dibutyltin dilaurate was 1:8.15:1.45:0.07.

[0119] S6: Spinning construction of waterproof and antibacterial fiber layer

[0120] S6.1: Place acetone and palm oil-erucic acid-based polyurethane polymer solution in a container at a mass ratio of 1:1, add 6wt% of composite antibacterial agent and mix evenly to obtain composite spinning solution. Load the composite spinning solution into the syringe of the electrospinning machine. The syringe orifice diameter is 0.12mm, the preset spinning voltage is 25kV, and the spinning solution output rate is 0.12mm / min.

[0121] S6.2: Take a polyester fabric with a thickness of 0.3mm, spray polyurethane adhesive onto the front and back surfaces of the polyester fabric, with an adhesive application amount of 20g / m², to obtain the core layer fabric.

[0122] S6.3: Place the core layer fabric under the electrospinning machine preset in step S6.1, adjust the distance from the syringe nozzle to 20cm, start the electrospinning machine to spin, and spin evenly on both sides of the core layer fabric to form a waterproof and antibacterial fiber layer with a thickness of 30μm. After drying, hot press at 2MPa and 95℃ for 5min to obtain a waterproof and antibacterial polyester multilayer composite fabric.

[0123] Comparative Example 1: The difference from Example 1 is that steps S1, S2 and S3.4 were removed in Comparative Example 1. The stems of Reed are directly washed, dried and pulverized through a 30-mesh sieve to obtain powder instead of the Reed filter residue in step S3.1. Reed cellulose nanocrystal dispersion is obtained through steps S3.1-S3.3, and Reed cellulose nanocrystal is obtained after freeze-drying.

[0124] In step S4, PAMAM-alkaloid complex was not added, and the oxidized cellulose nanocrystals of Reed arum were replaced with an equal mass of Reed arum cellulose nanocrystals. The remaining steps were the same as in Example 1.

[0125] Comparative Example 2: The difference from Example 1 is that vanillinamine hydrochloride in step S4.1 is replaced with an equal mass of PAMAM-alkaloid complex, while the remaining steps are the same as in Example 1.

[0126] Comparative Example 3: The difference from Example 1 is that in Comparative Example 3, the PAMAM-alkaloid complex in step S4.1 is replaced with an equal mass of vanillinamine hydrochloride, and the remaining steps are the same as in Example 1.

[0127] Comparative Example 4: The difference from Example 1 is that step S5.1 was removed from Comparative Example 4, and erucic acid diethanolamide was not added in step S5.3. All other steps are the same as in Example 1.

[0128] Experiment 1: The multilayer composite fabrics prepared in Examples 1-3 and Comparative Examples 1-3 were used as samples to test their antibacterial properties. The antibacterial rate was determined according to GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method". Staphylococcus aureus, Escherichia coli and Candida albicans were selected as the bacterial strains. Five samples were tested. The initial antibacterial rate was tested and the average value was taken. Then, the samples of Examples 1-3 and Comparative Example 1 were subjected to 100 cycles of conventional rubbing and washing-drying. The antibacterial rate of the multilayer composite fabric after 100 cycles of rubbing and washing-drying was tested and the average value was taken. The data are shown in Table 1.

[0129] Table 1: Antibacterial properties of multilayer composite fabrics

[0130]

[0131] As can be seen from the data in Examples 1-3 in Table 1, the products prepared in the embodiments of this application all have excellent antibacterial properties and antibacterial durability. However, as can be seen from the data in Comparative Example 1, when the alkaloids in the reed stems were not separated and were combined with PAMAM to prepare the PAMAM-alkaloid complex, and then combined with the reed filter residue to prepare reed oxidized cellulose nanocrystals, the antibacterial rate of the prepared multi-layer composite fabric decreased significantly after 100 rubbing and washing cycles. This proves that the preparation of the PAMAM-alkaloid complex and reed oxidized cellulose nanocrystals and the combination of the two to prepare the composite antibacterial agent can significantly improve the bonding strength between the natural alkaloids and the fiber substrate, and enable the composite antibacterial agent to be uniformly dispersed and stably embedded in the waterproof antibacterial fiber layer. This effectively avoids the loss of antibacterial components during daily rubbing, folding and repeated washing, and ensures the stability of long-lasting antibacterial performance.

[0132] The data from Comparative Examples 2-3 show that whether vanillinamine hydrochloride in step S4.1 is replaced with PAMAM-alkaloid complex or PAMAM-alkaloid complex is replaced with vanillinamine hydrochloride, the antibacterial rate of the prepared multilayer composite fabric decreases. This proves that the two can complement each other in terms of antibacterial mechanism, thereby improving the killing efficiency against common pathogenic microorganisms.

[0133] Experiment 2: The multilayer composite fabrics prepared in Examples 1-3 and Comparative Example 4 were used as samples. Three samples of each type were taken and their waterproof performance was tested. The hydrostatic pressure was measured according to GB / T4744-2013 "Test and Evaluation of Waterproof Performance of Textiles". The higher the hydrostatic pressure, the better the waterproof performance. The moisture permeability was measured according to GB / T12704-2009 "Test Method for Moisture Permeability of Textile Fabrics Part 1: Moisture Absorption Method". The average value was taken and the data were recorded as shown in Table 2.

[0134] Table 2: Waterproof and breathable properties of multi-layer composite fabrics

[0135]

[0136] As shown in Table 2, the multilayer composite fabric prepared in this application exhibits excellent waterproof performance as well as good moisture permeability. However, as shown in Comparative Example 4, without the addition of erucic acid chain extender to react with palm oil diethanolamide and hexamethylene diisocyanate, the hydrostatic pressure of the multilayer composite fabric decreased from 113 kPa to 95 kPa, indicating a significant decrease in the waterproof performance. This demonstrates that adding erucic acid chain extender to react with palm oil diethanolamide and hexamethylene diisocyanate can significantly improve the waterproof performance of the composite fabric. Furthermore, the moisture permeability of Comparative Example 4 is 12900 g / m²·24h, while that of Example 1 is significantly lower. The wet permeability of the composite fabric is 12600 g / m2·24h. This indicates that when erucic acid chain extender is added and reacts with palm oil diethanolamide and hexamethylene diisocyanate, the moisture permeability of the composite fabric only decreases slightly. Combining the two sets of data, it can be seen that adding erucic acid chain extender and reacting with palm oil diethanolamide and hexamethylene diisocyanate can significantly improve the waterproof performance of the composite fabric while ensuring good moisture permeability. This proves that erucic acid chain extender can reduce the overall surface energy of polyurethane, enhance hydrophobic properties, and avoid the dense crystalline hydrophobic film blocking water vapor channels with an amorphous and flexible arrangement structure, thus giving the polyester multilayer composite fabric strong waterproof and moisture permeability.

[0137] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation process for a waterproof and antibacterial polyester multilayer composite fabric, characterized in that, Includes the following steps: S1. Separation of Reed Alkaloids: After washing and crushing the Reed stems, the Reed extract was refluxed and extracted with alcohol. The solid and liquid were separated to obtain Reed residue and Reed ethanol extract. The Reed ethanol extract was concentrated under reduced pressure until there was no alcohol odor. Then the pH was adjusted to acidic and ethyl acetate was used to extract the fat-soluble components. Then the pH was adjusted to alkaline and ethyl acetate was used for extraction. The organic phase was collected, evaporated and concentrated to obtain Reed alkaloid extract. Preparation of S2, PAMAM-alkaloid complex: PAMAM-G3-NH2 polyamide was frozen and placed in an aqueous acetic acid solution. Formaldehyde aqueous solution was slowly added dropwise, and then Rehmannia glutinosa alkaloid extract was added in batches. The reaction was then heated and stirred. The reaction solution was dialyzed with deionized water and then freeze-dried to obtain PAMAM-alkaloid complex. S3. Preparation of oxidized cellulose nanocrystals of Reed Bamboo: The Reed Bamboo filter residue was treated with alkali and bleached, washed and dried, and then placed in sulfuric acid aqueous solution for acid hydrolysis. It was then placed in an ice water bath for ultrasonic treatment. The precipitate was collected by centrifugation and dialyzed with deionized water until neutral. Sodium periodate was added for oxidation. After dialyzing and freeze drying, Reed Bamboo oxidized cellulose nanocrystals were obtained. S4. Preparation of the composite antibacterial agent: A mixed reaction solution was prepared by combining PAMAM-alkaloid complex, vanillinamine hydrochloride, arundinium oxidized cellulose nanocrystals, and deionized water. After the reaction, the lower solid layer was collected by centrifugation and washed. Then, sodium cyanoborohydride methanol solution was added and stirred. The lower solid layer was collected by centrifugation and washed. The mixture was then air-dried to obtain the composite antibacterial agent. In the mixed reaction solution formed by PAMAM-alkaloid complex, vanillinamine hydrochloride, arundinium oxidized cellulose nanocrystals, and deionized water, the mass concentration of PAMAM-alkaloid complex was 4-5 g / L, the mass concentration of vanillinamine hydrochloride was 0.6-0.8 g / L, and the mass concentration of arundinium oxidized cellulose nanocrystals was 8-10 g / L. S5. Preparation of Palm Oil-Euclidean Acid-Based Polyurethane: Under a nitrogen atmosphere, diethanolamine is slowly added to erucic acid while the temperature is slowly raised to 180-185℃, and then maintained at this temperature to obtain erucic acid diethanolamide. Under a nitrogen atmosphere, palm oil and diethanolamine are mixed and reacted at 120-125℃ with sodium methoxide as a catalyst, followed by extraction and separation, and rotary evaporation to obtain palm oil diethanolamide. Using palm oil diethanolamide as a polyol, erucic acid diethanolamide as a chain extender, and N,N-dimethylformamide as a solvent, it is reacted with hexamethylene diisocyanate and dimethylformamide. A palm oil-erucic acid-based polyurethane polymer solution was prepared by high-temperature reaction of dibutyltin dilaurate. When preparing erucic acid diethanolamide, the molar ratio of erucic acid to diethanolamine was 1:(1.1-1.2). When preparing palm oil diethanolamide, the molar ratio of sodium methoxide, diethanolamine, and palm oil was 1:(40-42):(6-8). The molar ratio of hexamethylene diisocyanate, palm oil diethanolamide, erucic acid diethanolamide, and dibutyltin dilaurate was 1:(8.1-8.15):(1.42-1.45):(0.06-0.07). S6. Spinning Construction of Waterproof and Antibacterial Fiber Layer: A composite spinning solution is prepared by combining a composite antibacterial agent, a palm oil-erucic acid-based polyurethane polymer solution, and acetone. Then, the solution is spun on the front and back surfaces of a polyester fabric coated with polyurethane adhesive to form a waterproof and antibacterial fiber layer. After drying and hot pressing, a waterproof and antibacterial polyester multilayer composite fabric is obtained. In the composite spinning solution, the mass ratio of acetone to palm oil-erucic acid-based polyurethane polymer solution is 1:(0.8-1), and the content of the composite antibacterial agent is 5-6 wt%.

2. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 1, characterized in that, Step S1, the separation of reed alkaloids, specifically includes the following steps: S1.1: After cleaning and drying the stems of Reed Bamboo, crush them through a 30-50 mesh sieve, and then place them in a reflux condenser. Use a 90-95% ethanol aqueous solution for reflux extraction, repeat 3-4 times, each time for 2-2.5 hours. Then filter to separate the solid and liquid, and obtain Reed Bamboo filter residue and Reed Bamboo ethanol extract. S1.2: Concentrate the ethanol extract of *Arundo donax* under reduced pressure until no alcohol odor remains, then dilute with 8-10 times its volume of distilled water, and finally adjust the pH to 2-3 with sulfuric acid solution to obtain acidic *Arundo donax* ethanol extract. S1.3: Add 1-1.5 times the volume of ethyl acetate to the acidic Reed ethanol extract and shake and stir for 4-5 minutes. Then centrifuge at 6000-8000 rpm to separate the components. Discard the upper organic phase and extract the fat-soluble components. Collect the aqueous phase and extract the fat-soluble components with ethyl acetate in the same way. Repeat 5-6 times. Add ammonia to the last collected aqueous phase to adjust the pH to 9-10. Extract with ethyl acetate and then centrifuge to collect the organic phase. Evaporate and concentrate to a viscous state to obtain Reed alkaloid extract.

3. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 2, characterized in that, The preparation of step S2PAMAM-alkaloid complex specifically includes the following steps: S2.1: Freeze 7-8 parts by weight of polyamidoamine PAMAM-G3-NH2 to -3 to -5℃, then place it in a container that has been treated with an ice bath at 3-5℃, add 18-20 parts by weight of an aqueous acetic acid solution with a pH of 6-6.5, and then slowly add 0.65-0.7 parts by weight of an aqueous formaldehyde solution with a mass concentration of 36-37%. After mixing and stirring for 30-50 minutes, add 1.4-1.5 parts by weight of Reed alkaloid extract in 4-6 batches to obtain a pre-reaction solution; S2.2: Heat the pre-reaction solution to 50-55℃ and stir at 150-200 rpm for 7-9 hours. Then cool it to room temperature and put it into a dialysis bag with a molecular weight cutoff of 3000-5000 Da. Dialyze the solution with deionized water at 4-5℃ for 32-40 hours, changing the deionized water every 8 hours. Then collect the solution in the dialysis bag to obtain PAMAM-alkaloid complex solution. Freeze-dry and then pulverize to obtain PAMAM-alkaloid complex.

4. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 2, characterized in that, Step S3, the preparation of *Arundo donax* oxidized cellulose nanocrystals, specifically includes the following steps: S3.1: Mix the Reed Fibers filter residue obtained in step S1.1 with a sodium hydroxide solution of 8-10% by mass at a material-to-liquid ratio of 1:(20-25)g / mL. Treat the mixture at 85-90℃ for 1-1.5h, then place it in an environment of -10 to -15℃ and stir at 800-900rpm for 4-5h. Then filter and collect the filter cake and wash it with clean water 2-3 times to obtain Reed Fibers lignocellulose microfibers. S3.2: Soak the lignocellulose microfibers of Reed Bamboo in a bleaching solution at a material-to-liquid ratio of 1:(15-20)g / mL, treat at 70-75℃ for 5-6h, then filter and collect the filter cake, wash it with water 3-4 times, soak it in anhydrous ethanol for 3-5min, filter it and dry it at 45-50℃ to obtain Reed Bamboo cellulose microfibers. S3.3: Disperse the cellulose microfibers of *Arundo donax* in a 55-60% sulfuric acid aqueous solution at a material-to-liquid ratio of 1:(18-20) g / mL. Acid hydrolyze the solution at 50-55℃ for 40-45 min. After cooling to room temperature, place the solution in an ice-water bath for ultrasonic treatment with an ultrasonic power of 250-300W. Then dilute the solution with 10-15 times the volume of deionized water. Centrifuge the solution at 8-12℃ and 10000-12000 rpm for 10-15 min. Remove the supernatant and collect the precipitate. Place the precipitate in a dialysis bag with a molecular weight cutoff of 8000-10000 Da and dialyze it with deionized water until the pH is neutral to obtain a dispersion of *Arundo donax* cellulose nanocrystals. S3.4: Add sodium periodate to the dispersion of Arundo donax cellulose nanocrystals, with the mass ratio of sodium periodate to Arundo donax cellulose nanocrystals in the dispersion being (0.8-1.2):

1. Stir the reaction at 35-45℃ in the dark for 1-1.5 h, then add 0.8-1 wt% ethylene glycol and stir for 40-60 min to terminate the reaction. Place the reaction solution into a dialysis bag with a molecular weight cutoff of 8000-10000 Da and dialyze for 2-3 days to obtain an oxidized cellulose nanocrystal dispersion. Freeze-dry the dispersion to obtain Arundo donax oxidized cellulose nanocrystals.

5. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 1, characterized in that, The preparation of the composite antibacterial agent in step S4 specifically includes the following steps: S4.1: Mix PAMAM-alkaloid complex, vanillinamine hydrochloride, atractylodes oxidized cellulose nanocrystals and deionized water in a container and stir for 25-30 min to prepare a mixed reaction solution. The mass concentration of PAMAM-alkaloid complex in the mixed reaction solution is 4-5 g / L, the mass concentration of vanillinamine hydrochloride is 0.6-0.8 g / L, and the mass concentration of atractylodes oxidized cellulose nanocrystals is 8-10 g / L. Then, react at 30-40℃ for 20-30 min, centrifuge to collect the precipitate, and wash with deionized water 3-4 times to obtain a solid reactant. S4.2: Add the solid reactants to a 0.1-0.15 mol / L sodium cyanoborohydride methanol solution at a material-to-liquid ratio of 1:(800-1000) g / mL, stir at room temperature for 5-6 h, then centrifuge to collect the lower solid layer, wash with deionized water 3-4 times, and air dry to obtain the composite antibacterial agent.

6. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 1, characterized in that, Step S5, the preparation of palm oil-erucic acid-based polyurethane, specifically includes the following steps: S5.1: Place erucic acid in a reaction vessel and heat it to 80-90℃ at a heating rate of 4-5℃ / min under a nitrogen atmosphere. Then, start adding diethanolamine dropwise at a uniform rate. Control the heating to 180-185℃ so that the diethanolamine is completely added to the reaction vessel. The molar ratio of erucic acid to diethanolamine is 1:(1.1-1.2). Then, keep it at this temperature for 4-5 hours. As the reaction vessel cools down to 50-60℃, remove it to obtain erucic acid diethanolamide. S5.2: Under a nitrogen atmosphere, sodium methoxide and diethanolamine are added to a container, heated to 80-85℃, and mixed at 150-170 rpm for 10-15 min. Then, palm oil is added and the temperature is raised to 120-125℃. The molar ratio of sodium methoxide, diethanolamine and palm oil is 1:(40-42):(6-8). Under a nitrogen atmosphere, the mixture is stirred for 4-5 h to obtain a reaction solution. An equal volume of ethyl acetate is added to the reaction solution and transferred to a separatory funnel. The solution is extracted 3-5 times with saturated sodium chloride solution until the aqueous phase is clear. The organic phase is filtered and the filtrate is rotary evaporated at a water bath temperature of 60-65℃ and a vacuum of -0.1 MPa for 3-3.5 h to obtain palm oil diethanolamide. S5.3: Under a dry nitrogen atmosphere, place palm oil diethanolamide, hexamethylene diisocyanate and dibutyltin dilaurate in a container, then add 3-4 times the mass of N,N-dimethylformamide, stir at 250-300 rpm for 10-15 min, then heat to 70-75℃ and keep warm for 3-3.5 h, then add erucic acid diethanolamide and stir for 15-20 min, heat to 90-95℃ and stir for 7-9 h to obtain a palm oil-erucic acid-based polyurethane polymer solution, wherein the molar ratio of hexamethylene diisocyanate, palm oil diethanolamide, erucic acid diethanolamide and dibutyltin dilaurate is 1:(8.1-8.15):(1.42-1.45):(0.06-0.07).

7. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 1, characterized in that, Step S6, the spinning construction of the waterproof and antibacterial fiber layer, specifically includes the following steps: S6.1: Place acetone and palm oil-erucic acid-based polyurethane polymer solution in a container at a mass ratio of 1:(0.8-1), add 5-6wt% of composite antibacterial agent and mix evenly to obtain composite spinning solution. Load the composite spinning solution into the syringe of the electrospinning machine. The syringe orifice diameter is 0.07-0.12mm, the preset spinning voltage is 20-25kV, and the spinning solution output rate is 0.1-0.12mm / min. S6.2: Take a polyester fabric with a thickness of 0.1-0.3mm, and spray polyurethane adhesive onto both sides of the polyester fabric, with an adhesive application rate of 15-20g / m². 2 This yields the core fabric. S6.3: Place the core fabric under the electrospinning machine preset in step S6.1, adjust the distance from the syringe nozzle to 15-20cm, start the electrospinning machine to spin, and spin evenly on both sides of the core fabric to form a waterproof and antibacterial fiber layer with a thickness of 25-30μm. After drying, hot press at 1-2MPa and 90-95℃ for 3-5min to obtain a waterproof and antibacterial polyester multilayer composite fabric.

8. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 2, characterized in that, In step S1, the mass concentration of the sulfuric acid aqueous solution is 1-1.5%, and the mass concentration of the ammonia solution is 10-15%.

9. The preparation process of a waterproof and antibacterial polyester multilayer composite fabric according to claim 4, characterized in that, In step S3.2, the bleaching solution is prepared by mixing acetic acid and a 3% NaClO2 solution at a volume ratio of 1:(100-105).

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