A bio-based antibacterial hydrophobic polyester and its preparation method and application

Abstract

The application discloses a kind of bio-based antibacterial hydrophobic polyester and its preparation method and application.The polyester is with natural magnolol as antibacterial source, through its with cyanuric chloride, ethanol amine gradually reaction, again with linear mercaptan through click chemistry grafting, synthesis out with antibacterial and hydrophobic structure's polymerizable monomer;Further, the monomer is used as third component, with terephthalic acid, ethylene glycol is in situ copolymerization, and bio-based antibacterial hydrophobic polyester is prepared;Finally, it is blended with conventional polyester chip and is spun, and functional terylene fiber is obtained.The functional unit is embedded in polyester main chain by chemical bonding in the application, and the integration and durability of antibacterial and hydrophobic performance are realized.Testing shows that the obtained fiber is greater than 90% to escherichia coli and staphylococcus aureus antibacterial rate, still greater than 87% after 50 times washing;Its water contact angle is greater than 130 ° and stable, and excellent comprehensive performance is shown.The process of the application is reliable, and product is environment-friendly, suitable for the development of high-end functional textiles.

Description

Technical Field

[0001] This invention belongs to the field of polyester fiber technology, specifically relating to a bio-based antibacterial hydrophobic polyester, its preparation method, and its application. Background Technology

[0002] Polyethylene terephthalate (PET, polyester) fiber, as the world's most produced synthetic fiber, is widely used in clothing, home textiles, and industrial textiles due to its excellent mechanical properties, dimensional stability, wrinkle resistance, and ease of processing. However, the dense molecular chain structure of polyester fiber and the lack of hydrophilic groups result in poor moisture absorption and wicking properties. In actual wear, sweat tends to remain on the hydrophobic fiber surface, providing a moist environment for the growth of bacteria, fungi, and other microorganisms. This can even lead to microbial proliferation more easily than with some hydrophilic fibers, producing odors and potentially posing health risks. Therefore, multifunctional modification of polyester fiber, including antibacterial and hydrophobic properties, to improve its wearing comfort and hygiene has become an important direction in the functionalization research and development of textiles.

[0003] Currently, the technical approaches to imparting antibacterial properties to polyester fibers mainly fall into two categories: blending modification and surface modification. Blending modification involves physically blending antibacterial agents with polyester chips followed by melt spinning, and is one of the simplest methods to achieve functionalization. Commonly used antibacterial agents include nano-metal (oxide) particles (such as silver, copper, and zinc-based) and quaternary ammonium salt organic antibacterial agents. For example, Chinese patent application CN118600586A discloses a method for preparing antibacterial fibers by blending nano-flower-like zinc oxide, hexadecyltrimethylammonium chloride, and sepiolite with polyester and then spinning the resulting blend. However, in such methods, the compatibility between the antibacterial agent and the polyester matrix is ​​usually poor, and the two mainly bond through physical interactions. During long-term use and repeated washing, the antibacterial agent easily migrates and dissolves from the fiber interior, leading to a rapid decline in antibacterial efficacy and making it difficult to achieve a long-lasting and stable antibacterial effect. In addition, the addition of a large number of inorganic particles may affect the spinnability and mechanical properties of the fiber.

[0004] To overcome the shortcomings of insufficient durability in blend modification, surface grafting modification technology has emerged. This technology involves etching and activating the fiber surface to introduce active groups, and then grafting antibacterial functional monomers through chemical reactions. For example, Chinese patent application CN107759779A discloses a method of introducing amino side groups onto the polyester molecular chain and then using amino complexation to fix metal ions such as silver and copper to obtain durable antibacterial properties. Although this method improves the durability of antibacterial properties, it still has significant limitations: First, polyester fiber surfaces are highly inert, and the etching pretreatment before grafting inevitably damages the fiber surface, increasing its roughness, which may negatively affect the fiber's mechanical properties (such as strength) and feel; second, the grafted antibacterial functional groups are mainly limited to the outermost layer of the fiber, and during use, the residues of dead microorganisms may cover and shield these surface active sites, affecting the effectiveness of its long-term action; third, using metal ions as the antibacterial source raises potential concerns about biocompatibility and the risk of heavy metal accumulation in the environment.

[0005] In addition, another type of research (such as Chinese patent application CN121023681A) involves blending natural mineral powders such as tourmaline with polyester after complex surface modification, aiming to achieve both antibacterial durability and flame retardancy. However, this method is essentially still within the category of physical blending, and challenges remain in achieving the interfacial bonding between the functional components and the polyester matrix, long-term stability, and the synergistic realization of multiple functions (such as antibacterial and high hydrophobicity).

[0006] In summary, existing technologies have not yet adequately addressed the following issue: how to simultaneously introduce highly efficient and safe (especially non-metallic ionic) antibacterial and hydrophobic components into polyester fibers in a stable and durable manner without compromising the fiber's intrinsic properties, thus achieving a long-lasting and highly efficient integration of antibacterial and hydrophobic properties. Therefore, developing a method for preparing polyester fibers based on novel molecular design principles, capable of in-situ constructing biomass-based antibacterial and long-lasting hydrophobic functions at the polymer molecular structure level, has significant theoretical and practical value. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a bio-based antibacterial hydrophobic polyester, its preparation method, and its application. By molecularly designing and in-situ bonding of biomass antibacterial units (magnolin) and hydrophobic units (long-chain alkyl groups) to the polyester backbone, a polyester fiber with both long-lasting and highly effective antibacterial properties, excellent hydrophobicity, and maintenance of matrix properties is successfully prepared, providing an innovative solution for the development of high-performance sustainable textiles.

[0008] This invention is achieved through the following technical solution:

[0009] A bio-based antibacterial hydrophobic polyester having the structure shown in formula (1):

[0010]

[0011] Equation (1);

[0012] In equation (1): n and m are each an integer from 10 to 150; x is an odd number from 9 to 19.

[0013] Preferably, the polyester has a number-average molecular weight of 14,000 to 21,000, a weight-average molecular weight of 18,000 to 32,000, and a polydispersity index of 1.2 to 1.5.

[0014] The above-mentioned method for preparing bio-based antibacterial hydrophobic polyester includes the following steps:

[0015] Step 1) Using magnolol as the starting material, it is reacted sequentially with cyanuric chloride and ethanolamine. The resulting intermediate is then reacted with a straight-chain thiol through a click chemical reaction to obtain a polymerizable monomer (IV).

[0016] Step 2) In the presence of a catalyst and a dehydrating agent, terephthalic acid, ethylene glycol and the polymerizable monomer (IV) obtained in step 1) are subjected to a copolymerization reaction to obtain the bio-based antibacterial hydrophobic polyester (I).

[0017] Preferably, the specific steps of step 1) are as follows:

[0018] Step 1-1) Under an inert atmosphere and at -5 to 5°C, magnolol, cyanuric chloride and pyridine derivatives were reacted in anhydrous xylene for 15 to 24 h, and the intermediate product (II) was obtained after separation; wherein, the molar ratio of magnolol, cyanuric chloride and pyridine derivatives was 1:(1.02 to 1.32):(1.05 to 1.20);

[0019] Step 1-2) The intermediate product (II) obtained in step 1-1) is reacted with ethanolamine in dichloromethane at 40-65℃ for 10-15 h, and the intermediate product (III) is obtained after separation; wherein, the molar ratio of intermediate product (II) to ethanolamine is 1:(2.15-2.35);

[0020] Steps 1-3) The intermediate product (III) obtained in step 1-2) is reacted with a straight-chain thiol in toluene at 100-120°C for 4-6 h by click chemistry to obtain a polymerizable monomer (IV); wherein the molar ratio of intermediate product (III) to straight-chain thiol is 1:(2.05-2.35).

[0021] Preferably, the straight-chain thiols in steps 1-3) are selected from straight-chain alkyl thiols with 10 to 20 carbon atoms.

[0022] Preferably, the specific steps of step 2) are as follows: under an inert atmosphere, terephthalic acid, the polymerizable monomer (IV), ethylene glycol, stannous octoate catalyst, and N,N-diisopropylcarbodiimide dehydrating agent are mixed and reacted at 210~235℃ for 2~4 h, then heated to 250℃ and reacted under vacuum for 2~6 h to obtain the bio-based antibacterial hydrophobic polyester (I); wherein, the molar ratio of terephthalic acid, polymerizable monomer (IV), and ethylene glycol is 1:(0.1~0.35):(0.68~0.92).

[0023] Preferably, the amount of the catalyst stannous octoate is 0.05% to 0.33% of the weight of terephthalic acid; and the amount of the dehydrating agent N,N-diisopropylcarbodiimide is 0.3% to 10.0% of the weight of terephthalic acid.

[0024] An antibacterial hydrophobic polyester fiber is obtained by melt spinning a composition comprising the above-mentioned bio-based antibacterial hydrophobic polyester.

[0025] Preferably, the composition is formed by blending the bio-based antibacterial hydrophobic polyester with conventional polyester chips at a weight ratio of 1:(10~20).

[0026] The above-mentioned method for preparing antibacterial and hydrophobic polyester fibers includes the following steps:

[0027] The bio-based antibacterial hydrophobic polyester was vacuum dried with conventional polyester chips for 2-10 h, then melt-blended and extruded at 170-270°C. The resulting masterbatch was then melt-spun at 260-270°C at a spinning speed of 1200-4000 m / min.

[0028] The beneficial effects of this invention are as follows:

[0029] (1) The core of this invention lies in the molecular structure design, which uses a chemical reaction to directly embed biomass antibacterial units (magnolin) and hydrophobic units (long-chain alkyl groups) as comonomers into the polyester backbone to form chemical bonds. This fundamentally solves the problem of easy migration and dissolution of functional components in physical blending modification. Test data shows that after 50 simulated washes, the fiber obtained in this way still maintains an antibacterial rate of over 87% against Escherichia coli and Staphylococcus aureus, while its high water contact angle (>130°) remains stable, achieving simultaneous and long-lasting antibacterial and hydrophobic properties.

[0030] (2) The hydrophobic long-chain alkyl group introduced in this invention not only endows the fiber surface with excellent water repellency, but also has a synergistic effect with the magnolol antibacterial unit. The long-chain alkyl group can be embedded in the cell membrane of microorganisms, interfering with their material exchange, thereby enhancing the antibacterial efficacy of magnolol; at the same time, the dense hydrophobic layer can "block" the migration channels of water molecules into the fiber interior, inhibiting the growth of microorganisms from the physical environment, and achieving dual protection of "physical barrier" and "chemical sterilization".

[0031] (3) The present invention selects magnolol, an effective component of the traditional Chinese medicine Magnolia officinalis, as the antibacterial structural unit. It is derived from natural plants, has good biocompatibility and degradability potential, avoids the environmental accumulation and ecotoxicity risks that may be caused by the use of antibacterial agents such as silver and copper metal ions, and also avoids the biosafety issues of some organic antibacterial agents, which is in line with the green and sustainable development concept of textile chemicals.

[0032] (4) The present invention adopts an in-situ copolymerization synthesis route, in which the functional groups are located on the polymer molecular chain and can be evenly distributed throughout the fiber through blending and spinning. This method does not require surface etching or finishing of the finished fiber, thus fully preserving the original excellent mechanical strength, wrinkle resistance and durability of polyester fiber, and overcoming the defects of surface grafting modification that may damage the fiber body and affect the hand feel.

[0033] (5) By adjusting the feed ratio of polymerizable monomer (IV) and the carbon chain length (x value) of linear thiol, the present invention can precisely control the density of antibacterial and hydrophobic groups and the length of hydrophobic segments in the final copolyester molecule, thereby achieving controllable design and optimization of fiber antibacterial efficacy and hydrophobic grade, and meeting the differentiated needs of different application scenarios. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to specific embodiments.

[0035] Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art, and the experimental methods without specific conditions are all conventional methods in the art.

[0036] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0037] A bio-based antibacterial hydrophobic polyester, the structural formula of which is shown in formula (1):

[0038]

[0039] Equation (1)

[0040] In equation (1): n and m are repeating polyester units, each taking an integer value of 10 to 150; x is the number of straight-chain -CH2- in the sulfur-containing monomer, taking an odd number of 9 to 19.

[0041] The specific steps for preparing the above-mentioned bio-based antibacterial hydrophobic polyester are as follows:

[0042] (1) Synthesis of polymerizable monomer (IV), the reaction formula is shown in formula (2), and the specific details are as follows:

[0043]

[0044] Equation (2)

[0045] Magnolol, cyanuric chloride, and pyridine derivatives were reacted in anhydrous xylene for 15–24 h under an inert atmosphere and at -5–5 °C. After the reaction was completed, the intermediate product (II) was obtained by extraction with petroleum ether. The molar ratio of magnolol, cyanuric chloride, and pyridine derivatives was 1:(1.02–1.32):(1.05–1.20).

[0046] Intermediate product (II) was reacted with ethanolamine in dichloromethane at 40–65 °C for 10–15 h. After washing with water and vacuum distillation, intermediate product (III) was obtained. The molar ratio of intermediate product (II) to ethanolamine was 1:(2.15–2.35).

[0047] Intermediate product (III) and a linear thiol were reacted in toluene at 100–120 °C for 4–6 h via click chemistry to obtain polymerizable monomer (IV). The molar ratio of intermediate product (III) to linear thiol was 1:(2.05–2.35).

[0048] (2) The synthesis of bio-based antibacterial hydrophobic polyester (I) is shown in the reaction formula (3), as follows:

[0049]

[0050] Equation (3)

[0051] Under an inert atmosphere, terephthalic acid (PTA), polymerizable monomer (IV), ethylene glycol, stannous octoate catalyst (0.05%–0.33% by weight of PTA), and dehydrating agent N,N-diisopropylcarbodiimide (0.3%–10.0% by weight of PTA) are mixed and reacted at 210–235°C for 2–4 h, then the temperature is raised to 250°C and the reaction continues under vacuum for 2–6 h to obtain the bio-based antibacterial hydrophobic polyester (I). The molar ratio of terephthalic acid, polymerizable monomer (IV), and ethylene glycol is 1:(0.1–0.35):(0.68–0.92).

[0052] The molecular weight of the prepared bio-based antibacterial hydrophobic polyester (I) was determined by gel permeation chromatography (GPC). Its number average molecular weight (Mn) was 14,000 to 21,000, its weight average molecular weight (Mw) was 18,000 to 32,000, and its polydispersity index (PDI) was 1.2 to 1.5.

[0053] The specific steps of the method for preparing antibacterial hydrophobic polyester fibers based on the above-mentioned bio-based antibacterial hydrophobic polyester are as follows:

[0054] The bio-based antibacterial hydrophobic polyester (I) is blended with conventional polyester chips at a weight ratio of 1:(10~20), and then vacuum dried for 2~10 h. The blended and extruded granules are then melt-blended in a twin-screw extruder at 170~270℃. The resulting masterbatch is then melt-spun on a high-speed composite spinning machine at 260~270℃ at a spinning speed of 1200~4000 m / min.

[0055] Example 1: Preparation of antibacterial and hydrophobic polyester fibers using standard processes

[0056] A method for preparing antibacterial hydrophobic polyester fiber, the specific steps of which are as follows:

[0057] 1. Synthesis of polymerizable monomers (IV)

[0058] (1) Synthetic intermediate product (II)

[0059] Under nitrogen protection, 2.7 g (approximately 10.14 mmol) of magnolol was dissolved in 50 mL of anhydrous xylene. 1.1 mL (approximately 11.30 mmol) of 4-methylpyridine was added, and the mixture was cooled to 0°C in an ice bath. 2.0 g (approximately 10.84 mmol) of cyanuric chloride was dissolved in 50 mL of anhydrous xylene and slowly added dropwise to the above solution. The mixture was stirred at 0°C for 20 h. After the reaction was complete, the product was extracted with petroleum ether, separated, and dried to obtain intermediate product (II) in 87.2% yield.

[0060] (2) Synthetic intermediate product (III)

[0061] 3.4 g (approximately 8.21 mmol) of intermediate product (II) was dissolved in 50 mL of dichloromethane. 1.1 g (approximately 18.01 mmol) of ethanolamine was dissolved in 40 mL of dichloromethane and added dropwise. The mixture was heated to 60 °C and reacted for 10 h. The reaction solution was washed with water and the solvent was removed by vacuum distillation to obtain intermediate product (III) in 97.3% yield.

[0062] (3) Click chemical reaction

[0063] 4.0 g (approximately 9.23 mmol) of intermediate product (III) was dissolved in 100 mL of xylene solution. 6.1 g (approximately 21.29 mmol) of octadecyl mercaptan was added. The mixture was heated to 120 °C and reacted for 4 h. The solvent was removed by vacuum distillation to give polymerizable monomer (IV) in 78.7% yield.

[0064] 2. Synthesis of Bio-based Antibacterial Hydrophobic Polyester (I)

[0065] (1) Under nitrogen protection, add 16.5 g (about 99.32 mmol) PTA, 10.0 g (about 9.94 mmol) polymerizable monomer (IV), 5.0 g (about 80.55 mmol) ethylene glycol, 0.04 g stannous octoate (catalyst, accounting for about 0.24% of the weight of PTA) and 0.83 g N,N-diisopropylcarbodiimide (dehydrating agent, accounting for about 5.0% of the weight of PTA) to a three-necked flask.

[0066] (2) Seal the three-necked flask, turn on the oil bath and heat to 210°C, and react at a constant temperature for 2 h.

[0067] (3) Then the temperature was raised to 250°C and the vacuum pump was started to draw the vacuum to 10 kPa. The reaction continued for 3.5 h under vacuum conditions until no distillate flowed out.

[0068] (4) Stop heating and cool to room temperature. The solid product in the three-necked flask is the bio-based antibacterial hydrophobic polyester (I). According to GPC testing, its Mn is 15873, Mw is 23492, and PDI is 1.48.

[0069] 3. Preparation of antibacterial and hydrophobic polyester fibers

[0070] (1) 5.0 kg of bio-based antibacterial hydrophobic polyester (I) and 50.0 kg of conventional polyester chips (weight ratio 1:10) were vacuum dried at 70°C for 2 h.

[0071] (2) The dried mixture is fed into a twin-screw extruder. The temperatures of each zone are set as follows: Zone 1 170℃, Zone 2 230℃, Zone 3 240℃, Zone 4 260℃, Die head 265℃, and screw speed 300 r / min. After melt blending, the mixture is extruded, cooled, and pelletized to obtain functional masterbatch.

[0072] (3) The masterbatch is melt-spun at 270°C on a high-speed composite spinning machine at a spinning speed of 2450 m / min. The fiber is then wound into shape after being stretched in three steps at 80~110°C by a parallel stretching machine to obtain antibacterial hydrophobic polyester fiber.

[0073] Example 2

[0074] A method for preparing antibacterial hydrophobic polyester fiber, the specific steps of which are as follows:

[0075] 1. Synthesis of polymerizable monomers (IV)

[0076] The specific steps are the same as in Example 1.

[0077] 2. Synthesis of Bio-based Antibacterial Hydrophobic Polyester (I)

[0078] (1) Under nitrogen protection, add 1.65 kg of PTA (about 9.93 mol), 1.0 kg of polymerizable monomer (IV) (about 0.99 mol), 0.55 kg of ethylene glycol (about 8.86 mol), 3.5 g of stannous octoate (about 0.21% of the weight of PTA) and 82.5 g of N,N-diisopropylcarbodiimide (5% of the weight of PTA) to the reactor.

[0079] (2) Seal the reactor, turn on the electric heating, and react at a constant temperature of 210~235℃ for 2 h. Then raise the temperature to 250℃ and evacuate to 20 kPa. Continue the reaction for 3.5~5.0 h until the actual collected water output reaches 98% of the theoretical water output.

[0080] (3) Turn off the heating, cool down to room temperature, open the reactor, discharge the material, granulate it, and take out the solid product, which is the bio-based antibacterial hydrophobic polyester (I). According to GPC testing, its Mn is 16872, Mw is 23790, and PDI is 1.41.

[0081] 3. Preparation of antibacterial and hydrophobic polyester fibers

[0082] The specific steps are the same as in Example 1.

[0083] Example 3

[0084] A method for preparing antibacterial hydrophobic polyester fiber, the specific steps of which are as follows:

[0085] 1. Synthesis of polymerizable monomers (IV)

[0086] (1) Synthetic intermediate product (II)

[0087] Under nitrogen protection, 2.66 g (approximately 10.0 mmol) of magnolol was dissolved in 50 mL of anhydrous xylene. 1.5 mL (approximately 11.36 mmol) of 2,4,6-trimethylpyridine was added, and the mixture was cooled to 0°C in an ice bath. 2.0 g (approximately 10.84 mmol) of cyanuric chloride was dissolved in 50 mL of anhydrous xylene and slowly added dropwise to the above solution. The mixture was stirred at 0°C for 15 h. After the reaction was complete, the product was extracted with petroleum ether, separated, and dried to obtain intermediate product (II) in 93.5% yield.

[0088] (2) Synthetic intermediate product (III)

[0089] 4.5 g (approximately 10.86 mmol) of intermediate product (II) was dissolved in 50 mL of dichloromethane. 1.52 g (approximately 24.49 mmol) of ethanolamine was dissolved in 40 mL of dichloromethane and added dropwise. The mixture was heated to 60 °C and reacted for 10 h. The reaction solution was washed with water and the solvent was removed by vacuum distillation to obtain intermediate product (III) in 96.1% yield.

[0090] (3) Click chemical reaction

[0091] 5.5 g (approximately 12.69 mmol) of intermediate product (III) was dissolved in 100 mL of xylene solution. 7.0 g (approximately 27.02 mmol) of hexadecyl mercaptan was added. The mixture was heated to 120 °C and reacted for 4 h. The solvent was removed by vacuum distillation to give polymerizable monomer (IV) in 81.4% yield.

[0092] Prepared using the method described above, scaled up 100 times.

[0093] 2. Synthesis of Bio-based Antibacterial Hydrophobic Polyester (I)

[0094] (1) Under nitrogen protection, add 1.65 kg of PTA (about 9.93 mol), 1.10 kg of polymerizable monomer (IV) (about 1.16 mol), 0.56 kg of ethylene glycol (about 9.02 mol), 3.5 g of stannous octoate (about 0.21% of the weight of PTA) and 82.5 g of N,N-diisopropylcarbodiimide (5% of the weight of PTA) to the reactor.

[0095] (2) Seal the reactor, turn on the electric heating, and react at a constant temperature of 210~235℃ for 2 h. Then raise the temperature to 250℃ and evacuate to 20 kPa. Continue the reaction for 3.5~5.0 h until the actual collected water output reaches 98% of the theoretical water output.

[0096] (3) Turn off the heating, cool down to room temperature, open the reactor, discharge the material, granulate it, and take out the solid product, which is the bio-based antibacterial hydrophobic polyester (I). According to GPC testing, its Mn is 20461, Mw is 27622, ​​and PDI is 1.35.

[0097] 3. Preparation of antibacterial and hydrophobic polyester fibers

[0098] The specific steps are the same as in Example 1.

[0099] Comparative Example 1 (Physical Blending)

[0100] A method for preparing polyester fiber, the specific steps of which are as follows:

[0101] (1) Under nitrogen atmosphere, 2.7 g magnolol powder, 6.1 g octadecyl mercaptan, 16.5 g PTA, 5.0 g ethylene glycol, 0.04 g stannous octoate, and 0.83 g N,N-diisopropylcarbodiimide were directly mixed in a three-necked flask, sealed, and heated to 210°C in an oil bath. After reacting at a constant temperature for 2.0 h, the temperature was increased to 250°C while a vacuum pump was used to evacuate to a vacuum level of 10 kPa. The reaction was continued under vacuum for 3.5 h until no more water flowed out of the system. The heating was turned off and the temperature was lowered to room temperature to obtain polyester.

[0102] (2) The subsequent granulation and spinning processes are the same as in Example 1, and the desired result is obtained.

[0103] Comparative Example 2 (Pure Polyester)

[0104] A method for preparing polyester fiber, the specific steps of which are as follows:

[0105] (1) Polyester was prepared by homopolymerization of 16.5 g of terephthalic acid and 6.0 g of ethylene glycol without adding any functional monomers, using the same catalyst and dehydrating agent as in Example 1.

[0106] (2) The subsequent granulation and spinning processes are the same as in Example 1, and the desired result is obtained.

[0107] Test Example 1

[0108] The polyester fibers obtained in Examples 1-3 and Comparative Examples 1 and 2 were subjected to performance tests, as detailed below:

[0109] 1. Antibacterial performance test

[0110] The antibacterial properties of polyester fibers prepared in each group against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were tested in accordance with the standard GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking bottle method". The results are shown in Table 1.

[0111] Table 1 Antibacterial performance test

[0112]

[0113] Note in Table 1: "-" indicates no antibacterial properties.

[0114] As shown in Table 1, the initial antibacterial rates of the fibers prepared in Examples 1-3 against Escherichia coli and Staphylococcus aureus were all higher than 90%, proving that by chemically bonding magnolol to the polyester chain through molecular design, its broad-spectrum antibacterial activity can be effectively exerted.

[0115] 2. Antibacterial durability test

[0116] Three g of each group of polyester fibers were placed in a 2% sodium dodecyl sulfate aqueous solution for 50 simulated washes. After drying, the washed samples were tested for antibacterial durability according to the standard GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking bottle method". The results are shown in Table 2.

[0117] Table 2 Antibacterial durability performance test

[0118]

[0119] Note in Table 2: "-" indicates no antibacterial properties.

[0120] Comparing Tables 1 and 2, it can be seen that after 50 simulated washes, the antibacterial rate of the fibers obtained in Examples 1-3 remained above 87%, with minimal performance degradation. In contrast, Comparative Example 1, which used simple physical blending, saw its antibacterial rate plummet to approximately 60% after washing. This strongly demonstrates the superior durability of the "in-situ chemical bonding" strategy, fundamentally solving the industry problem of easy migration and dissolution of functional components in physical blending modification.

[0121] 3. Hydrophobicity test

[0122] The hydrophobic properties were evaluated using the dynamic water contact angle measurement method for polyester sheets. The polyester granules extruded from each blend were placed in a flat vulcanizing machine and hot-pressed under the parameters of 20 MPa pressure, 210℃ temperature, 5 min pre-pressing time, and 15 min pressing time to obtain sheets with a thickness of approximately 150 μm. These sheets were cut into 4 cm × 2 cm rectangles and attached to glass slides with double-sided tape. The slides were then placed in an analyzer to measure the water contact angle. The results are shown in Table 3.

[0123] Table 3 Dynamic contact angle of polyester sheets

[0124]

[0125] As shown in Table 3, the water contact angle of the fibers prepared in Examples 1-3 remained highly stable during the observation period of 0.5 s to 30 s. This indicates that their hydrophobic surface is uniform and robust, rather than relying on a fragile temporary coating, which further confirms that the chemical bonding between the function and the fiber body is stable and reliable.

[0126] As shown in Tables 1-3, the fibers prepared in Examples 1-3 all exhibit excellent initial antibacterial properties, high hydrophobicity (contact angle > 130°), and outstanding durability. In contrast, Comparative Example 1 (physical blend) showed lower initial performance values ​​and significant degradation after washing, while Comparative Example 2 showed no function. The data indicates that a hydrophobic surface (high contact angle) coexists with an intrinsic antibacterial structure. This is not merely a simple functional superposition; the hydrophobic long-chain alkyl groups may interfere with the microbial membrane structure, producing a synergistic antibacterial effect with magnolol. Simultaneously, the dense hydrophobic layer physically blocks the adhesion of water and microorganisms, further consolidating the antibacterial effect. This invention, through innovative molecular design, successfully achieves efficient, durable, synergistic, and integrated antibacterial and hydrophobic functions in polyester fibers, with comprehensive performance far exceeding traditional physical blending techniques, possessing outstanding practical value and market potential.

[0127] The embodiments described above are only some, not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. The scope of protection of the present invention is determined by the scope claimed in the claims. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A bio-based antibacterial hydrophobic polyester, characterized in that, It has the structure shown in equation (1): Equation (1); In equation (1): n and m are each an integer from 10 to 150; x is an odd number from 9 to 19.

2. The bio-based antibacterial hydrophobic polyester according to claim 1, characterized in that, The polyester has a number-average molecular weight of 14,000 to 21,000, a weight-average molecular weight of 18,000 to 32,000, and a polydispersity index of 1.2 to 1.

5.

3. A method for preparing a bio-based antibacterial hydrophobic polyester as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1) Using magnolol as the starting material, it is reacted sequentially with cyanuric chloride and ethanolamine. The resulting intermediate is then reacted with a straight-chain thiol through a click chemical reaction to obtain a polymerizable monomer (IV). Step 2) In the presence of a catalyst and a dehydrating agent, terephthalic acid, ethylene glycol and the polymerizable monomer (IV) obtained in step 1) are subjected to a copolymerization reaction to obtain the bio-based antibacterial hydrophobic polyester (I).

4. The preparation method according to claim 3, characterized in that, The specific steps of step 1) are as follows: Step 1-1) Under an inert atmosphere and at -5 to 5°C, magnolol, cyanuric chloride and pyridine derivatives were reacted in anhydrous xylene for 15 to 24 h, and the intermediate product (II) was obtained after separation; wherein, the molar ratio of magnolol, cyanuric chloride and pyridine derivatives was 1:(1.02 to 1.32):(1.05 to 1.20); Step 1-2) The intermediate product (II) obtained in step 1-1) is reacted with ethanolamine in dichloromethane at 40-65℃ for 10-15 h, and the intermediate product (III) is obtained after separation; wherein, the molar ratio of intermediate product (II) to ethanolamine is 1:(2.15-2.35); Steps 1-3) The intermediate product (III) obtained in step 1-2) is reacted with a straight-chain thiol in toluene at 100-120°C for 4-6 h by click chemistry to obtain a polymerizable monomer (IV); wherein the molar ratio of intermediate product (III) to straight-chain thiol is 1:(2.05-2.35).

5. The preparation method according to claim 3, characterized in that, The straight-chain thiols in steps 1-3) are selected from straight-chain alkyl thiols with 10 to 20 carbon atoms.

6. The preparation method according to claim 3, characterized in that, The specific steps of step 2) are as follows: Under an inert atmosphere, terephthalic acid, the polymerizable monomer (IV), ethylene glycol, stannous octoate catalyst, and N,N-diisopropylcarbodiimide dehydrating agent are mixed and reacted at 210~235℃ for 2~4 h, then heated to 250℃ and reacted under vacuum for 2~6 h to obtain the bio-based antibacterial hydrophobic polyester (I); wherein, the molar ratio of terephthalic acid, polymerizable monomer (IV), and ethylene glycol is 1:(0.1~0.35):(0.68~0.92).

7. The preparation method according to claim 6, characterized in that, The amount of the catalyst stannous octoate is 0.05% to 0.33% of the weight of terephthalic acid; the amount of the dehydrating agent N,N-diisopropylcarbodiimide is 0.3% to 10.0% of the weight of terephthalic acid.

8. An antibacterial and hydrophobic polyester fiber, characterized in that, It is prepared by melt spinning from a composition comprising the bio-based antibacterial hydrophobic polyester as described in claim 1 or 2.

9. The antibacterial hydrophobic polyester fiber according to claim 8, characterized in that, The composition is made by blending the bio-based antibacterial hydrophobic polyester with conventional polyester chips at a weight ratio of 1:(10~20).

10. A method for preparing antibacterial hydrophobic polyester fiber as described in claim 8 or 9, characterized in that, Includes the following steps: The bio-based antibacterial hydrophobic polyester was vacuum dried with conventional polyester chips for 2-10 h, then melt-blended and extruded at 170-270°C. The resulting masterbatch was then melt-spun at 260-270°C at a spinning speed of 1200-4000 m / min.

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