Cyclodextrin grafted polyquaternary phosphonium salt eugenol ester antibacterial material and synthesis method thereof

Abstract

The invention relates to a cyclodextrin grafted polyquaternary phosphonium salt eugenol ester antibacterial material, which has the following structure: m is the number of structural units of cyclodextrin, namely m = 1, m = 2 or m = 3; r1 is-CN or-CH3; r2 is phenyl or butyl; the anion X is one of Br <->, F <->, Cl <->, I <->, OH <->, CN <->, SCN <->, BF4 <->, PF6 <->, SO4 < 2->, CO3 < 2-> or AlCl4 <->, and X refers to the type of the anion; p is 0 or 2; x is 0 or 2; n is the grafting degree; y is the number of structural units of the quaternary phosphonium salt eugenol ester monomer; the product of y and n is the degree of polymerization, and P in-P-(R2) 3 refers to phosphorus element and is positive charge of quaternary phosphonium salt. Meanwhile, the invention further discloses a synthesis method of the antibacterial material. The cyclodextrin grafted polyquaternary phosphonium salt eugenol ester prepared by the invention has excellent antibacterial performance and good biocompatibility, can be applied to antibacterial coatings, medical devices or surface bacteriostasis of daily necessities and the like, and is a novel antibacterial material with potential application prospects.

Description

Technical Field

[0001] This invention relates to the fields of materials science and antibacterial technology, and in particular to a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material and its synthesis method. Background Technology

[0002] Globally, bacterial infections have become a key factor in triggering various diseases and increasing the risk of illness, and their severity cannot be underestimated. According to a study published in The Lancet in 2024, between 1990 and 2021, one million people died annually worldwide from drug-resistant infections, and this number may rise to nearly two million by 2050; it is projected that by 2050, the number of deaths directly caused by antibiotic resistance will rise to 1.91 million, with an additional 8.22 million deaths related to it. Bacterial infections have become the second leading cause of death globally, second only to ischemic heart disease, seriously threatening human life and health. The overuse of antibiotics has led to an increasingly prominent problem of bacterial resistance, and the emergence of superbugs poses a huge challenge to the treatment of bacterial infections, making the development of new and effective antibacterial materials urgent. Currently, existing antibiotic alternatives such as inorganic nanoparticles, organic small molecules, and natural polymers, while each with their own characteristics, also have significant limitations, such as high cost, high toxicity, easy volatility and decomposition, poor chemical stability, and weak antibacterial properties, which limit their widespread application. In contrast, synthetic polymeric antibacterial materials have shown broad application prospects due to their good chemical stability, excellent antibacterial properties, low cost, and high utilization rate. However, current synthetic polymeric antibacterial materials still have shortcomings in terms of biocompatibility. Some materials are toxic to human cells, and their metabolic and degradation performance in vivo needs to be improved, which is also an urgent problem to be faced.

[0003] Among synthetic polymeric antimicrobial materials, quaternary ammonium compounds (QACs) stand out due to their superior bactericidal ability and unique bactericidal mechanism (through cation adsorption of bacterial cell membranes and disruption of membrane structure leading to leakage of cell contents) (Y. Qiu, et al. Quaternary-ammoniumchitosan, a promising packaging material in the food industry. Carbohyd. Polym., 2024, 323: 121384.). However, QACs suffer from poor drug resistance, slow biodegradation, and cytotoxicity, limiting their further applications (S. Mohapatra, et al. Quaternary ammonium compounds of emerging concern: Classification, occurrence, fate, toxicity and antimicrobial resistance. J. Hazard. Mater., 2023, 445: 130393.). To address the inherent limitations of QACs, researchers have turned their attention to quaternary phosphonium salts (QPS), which have a structure extremely similar to QACs. Both belong to cationic antibacterial groups, but the core difference lies in the central atom. P has a lower electronegativity (2.19) than N (3.04) and a larger atomic radius (110 pm) than N (75 pm), resulting in QPS having a stronger polarizability. This difference in atomic structure endows QPS with unique physicochemical properties and antibacterial performance (J.Lu, et al. Antibacterial performance of cationic quaternaryphosphonium-modified chitosan polymer in water. Chinese Chem. Lett., 2024,35(9): 109406.).Compared to QACs, QPS is a weakly associated cation with a stronger electrostatic interaction with the negatively charged bacterial cell membrane, enabling it to adsorb and bind to the bacterial surface more efficiently (Y. Xue, et al. Antimicrobial polymeric materials with quaternary ammonium and phosphonium salts. Int. J.Mol. Sci., 2015, 16(2): 3626-3655.). It also exhibits more reliable chemical stability, higher antibacterial activity, stronger resistance to bacterial resistance, and a wider range of applications (X. Sun, et al. Poly (phosphonium)-functionalized double-armed β-CD antimicrobial material via RAFT. Macromolecules, 2023, 56(23): 9498-9508.). Therefore, QPS has greater advantages and potential than QACs in addressing bacterial resistance. However, QPS still faces challenges such as high cytotoxicity and low polymerization rate (B. Nunes, et al. Antimicrobial activity and cytotoxicity of novel quaternary ammonium and phosphonium salts. J. Mol. Liq., 2024, 401: 124616.). Existing research focuses primarily on the specific functionalization applications of quaternary phosphonium salts. For example, invention patent CN 120554587A discloses a method for preparing a polymeric organic flocculant using tannic acid and quaternary phosphonium salts as raw materials, applicable to the fields of solid waste resource utilization and water treatment agents; invention patent CN120424119A discloses the preparation of a hydroxyl-functionalized quaternary phosphonium salt polyionic liquid hypercrosslinked heterogeneous catalyst and its catalytic application in the cycloaddition reaction of CO2 and epoxides. Therefore, effectively balancing the relationship between antibacterial activity and cytotoxicity has become a core challenge in the development of novel quaternary phosphonium salt antibacterial materials, while also providing significant opportunities for technological innovation in this field.

[0004] Traditional methods for constructing QPS polymers involve functionalizing QPS using petroleum-based monomers (such as acrylics, acrylamides, and phenyl groups) (X. Sun, et al. Poly(phosphonium)-functionalized double-armed β-CD antimicrobial material via RAFT. Macromolecules, 2023, 56(23): 9498-9508.). Patent CN 120399159A discloses an antibacterial polyurethane acrylate film material with embedded N-substituted benzisothiazolinone and alkenyl functionalized quaternary phosphonium salts, exhibiting significant antibacterial activity against Escherichia coli and Staphylococcus aureus. The corresponding antibacterial coating can be used for surface modification of substrates. Furthermore, patent CN120329470A relates to the field of antibacterial functional polymer materials, disclosing a quaternary phosphonium salt-type isobutyl cationic polymer and its preparation method and application. The polymer obtained by this method has high purity and a high content of quaternary phosphonium salt groups, resulting in higher antibacterial activity. However, with the gradual depletion of petroleum resources, the increase in CO2 emissions, and the difficulty in degrading petroleum-based materials, the search for new sustainable development strategies and alternatives to petroleum-based polymers has become a current development trend. In recent years, bio-based compounds have attracted much attention due to their biodegradability, renewability, environmental friendliness, and non-toxicity. Utilizing bio-based compounds to improve the biocompatibility and sustainability of materials has become a novel strategy (Y. Wu, et al. Interdisciplinary-inspired smart antibacterial materials and their biomedical applications. Adv. Mater.,2023, 36(17): 2305940.). Eugenol is a phenolic monoterpene compound extracted from various natural products such as clove oil and lignin. It has unique allyl and phenolic functional groups and is easy to chemically modify (L. Zhang, et al. Asustainable waterborne vanillin-eugenol-acrylate miniemulsion with suitable antibacterial properties as a substitute for the styrene–acrylate emulsion. Green. Chem., 2021, 23: 7576-7588.).Furthermore, the phenolic hydroxyl groups of eugenol endow it with excellent antibacterial activity and the ability to scavenge reactive oxygen species (J. Sha, et al. Surface hydrolysis-anchored eugenol self-polishing marine antifouling coating. J. Colloid Interf. Sci., 2023, 637: 67-75.). Based on this, eugenol is considered a functional unit for constructing bio-based antibacterial polymers (R. Morales-Cerrada, et al. Eugenol, a promising building block for biobased polymers with cutting-edge properties. Biomacromolecules, 2021, 22(9): 3625-3648.). For example, grafting polyeugenol onto the surface of cellulose gives it strong antioxidant properties (Y. Li, et al. Poly-eugenolgrafting from cellulose surface for robust antioxidation. Food Hydrocolloid., 2024, 156: 110296.), while also exhibiting excellent biocompatibility, making it suitable for food or cosmetic packaging. Invention patent CN 120004748A provides an eugenol quaternary ammonium salt compound and its preparation method, as well as its application in wood preservation. Using eugenol as the core framework, the carbon chain is bridged with alkyl tertiary amines to form a bromide salt, which significantly inhibits the growth of wood-decaying fungi. Furthermore, as a natural product, eugenol avoids threats to the ecological environment, thus improving its safety and efficiency in the wood preservation process. In addition to ensuring antibacterial effects, invention patent CN119039517A discloses a method of functionalizing QPS groups with higher antibacterial activity using renewable and biodegradable eugenol, further reducing the cytotoxicity of QPS materials, thereby endowing them with better biocompatibility and environmental friendliness, achieving a "win-win" goal. It is worth noting that the hydroxyl groups of eugenol-derived monomers endow them with antibacterial, antioxidant, and preservative functions. Despite exhibiting various properties, eugenol-based homopolymers suffer from severe aggregation due to the stacking of their benzene ring structures (π-π interactions), which causes most of the active groups to be encapsulated within the homopolymer and unable to function.It is well known that the hydrophobic benzene ring structure of eugenol has poor solubility in aqueous media (Y.Li, et al. Poly-eugenol grafting from cellulose surface for robust antioxidation. FoodHydrocolloid., 2024, 156: 110296.). In particular, with the continuous increase and stacking of benzene rings after polymerization, the homopolymer exhibits significant insolubility in aqueous media, failing to fully expose its active groups. Therefore, designing materials that can reduce the stacking of benzene ring structures and improve the water solubility of eugenol homopolymers to fully expose the active sites on the benzene rings is currently a research hotspot.

[0005] Macrocyclic host molecules with a hydrophilic outer layer and a hydrophobic inner cavity can efficiently bind to hydrophobic guests through host-guest interactions. Cyclodextrins, with their excellent biocompatibility, are a typical example. Their binding to hydrophobic guests mainly relies on enantioselective size-matching effects, forming classic host-guest encapsulation systems. For instance, studies have shown that hydrophobic interactions between cyclodextrin and styrene have enabled the construction of inclusion complexes, achieving aqueous dispersion polymerization of polymers (X. Chen, et al. Direct synthesis of polymer nanotubes by aqueous dispersion polymerization of a cyclodextrin / styrene complex. Angew. Chem. Int. Ed., 2017, 56: 16541-16545.). Similarly, the dynamic cross-linked network formed by cyclodextrin and adamantane through host-guest interactions endows them with potential self-healing properties (CN115160454A). Furthermore, invention patent CN 120605344A uses cyclodextrin and microcrystalline cellulose as the main components, combined with modified calcium carbonate and other ingredients, to obtain a cyclodextrin composition that improves drug solubility, significantly enhancing product solubility and resulting in better release. The cyclodextrin-mediated host-guest interaction not only significantly improves the solubility of hydrophobic substances in aqueous media, but more importantly, it can flexibly adjust the rigidity of hydrophobic guests on the polymer chain, thereby spontaneously assembling into high-performance nanocomponents through host-guest interactions. Invention patent CN 117243367A discloses a method for preparing and applying a cyclodextrin-polyphenol-oil molecule self-assembled ternary particle-stabilized high-antioxidant Pickering emulsion, which features simple preparation, strong oxidative stability, non-toxicity, and good biocompatibility, and can be widely used in the food industry, pharmaceutical industry, and daily chemical products. Invention patent CN120399250A discloses a multi-substituted cyclodextrin supramolecular material, its preparation method and uses, and a pharmaceutical composition, which has strong drug loading capacity and exhibits excellent protective effects against unstable drugs. Furthermore, the hydroxyl-rich structure of cyclodextrin molecules allows them to serve as the core of star polymers. Through chemical modification, they can form multi-armed bridging bonds with carboxyl-containing chain transfer agents, thereby enabling the embedding of functionalized monomers onto the chain transfer agent (CN116693721A). Notably, materials with nanochannels also offer novel pathways for polymer synthesis due to their spatial confinement effect.For example, it can limit the formation of long-sized linear polymers by benzene ring monomers at high conversion rates (H. Pan, et al. Synthesis of narrowly distributed cyclic polymers by suzuki cross-coupling polycondensation under nanoconfinement. Macromolecules. 2023, 56(23): 9523-9529.). Furthermore, the invention patent CN 120173193A describes a polyrotaxylated covalent organic framework material and its application, which utilizes the cavity of γ-cyclodextrin to significantly increase the interlayer spacing of the polyrotaxylated covalent organic framework material, exhibiting excellent therapeutic effects on wounds infected with Staphylococcus aureus.

[0006] However, the application of cyclodextrin-based materials still faces significant bottlenecks: on the one hand, the nanocavities of cyclodextrin-based macromolecular chain transfer agents are limited, making it difficult to effectively form host-guest interactions with the hydrophobic blocks of the chain transfer agent, especially when the degree of polymerization of the hydrophobic units is high; on the other hand, the multi-branched structure of cyclodextrin-based star polymers leads to increased chain entanglement and steric hindrance, further hindering the bonding between the hydrophobic components on the chain transfer agent and the cyclodextrin cavities. Therefore, controlling the low degree of polymerization of the hydrophobic blocks in the cyclodextrin arms and the low degree of branching of the cyclodextrin itself will become an innovative strategy to achieve a synergistic improvement in the grafting degree and polymerization degree of cyclodextrin-based macromolecular chain transfer agents. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a high-performance cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material.

[0008] Another technical problem to be solved by the present invention is to provide a method for synthesizing the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material.

[0009] To address the above problems, the present invention provides a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material, characterized in that the antibacterial material has the following structure: Where: m is the number of structural units of the cyclodextrin, i.e., m=1, m=2, or m=3; R1 is -CN or -CH3; R2 is phenyl or butyl; and the anion X... ϴ For Br - F - Cl - I - OH - CN - SCN - BF4- PF6 - SO4 2- CO3 2- Or AlCl4 - In the formula, X refers to the type of anion; p is 0 or 2; x is 0 or 2; n is the degree of grafting; y is the number of structural units of the quaternary phosphonium salt eugenol ester monomer; the product of y and n is the degree of polymerization; P in -P-(R2)3 refers to phosphorus; and ⊕ is the positive charge of the quaternary phosphonium salt.

[0010] The method for synthesizing a cyclodextrin-grafted polyquaternium eugenol ester antibacterial material as described above includes the following steps: (1) Preparation of cyclodextrin-based macromolecular chain transfer agents: In container A, equipped with a heating bath, stirring, and nitrogen gas protection device, an amide solvent and cyclodextrin are added. Under a nitrogen atmosphere, the mixture is heated to 45-65 °C and slowly stirred until completely dissolved. After the resulting cyclodextrin solution is allowed to stand at room temperature, RAFT chain transfer agent, carbodiimide condensing agent, and pyridine catalyst are added sequentially. After sealing, the mixture is first magnetically stirred at 20-50 °C for 20-36 h, and then cooled in an ice-water bath at -5-5 °C for 0.5-2 h to stop the reaction. The mixed solution is then vacuum filtered to obtain a bright yellow liquid. Finally, the bright yellow liquid is added dropwise to a precipitant, and the precipitate is obtained by vacuum filtration. The precipitate is then vacuum dried at 40-75 °C to constant weight to obtain a yellow precipitate, which is the cyclodextrin-based macromolecular chain transfer agent. (2) Preparation of quaternary phosphonium salt eugenol ester monomer: First, eugenol, triethylamine, and excess solvent are added to container B. The mixture is cooled and stirred in an ice bath for 5-20 minutes. Then, the acylation reagent is added to the system. After magnetic stirring at -10 to 10 °C for 0.5-2 hours, the temperature is raised to room temperature and the reaction continues for 4-8 hours. After the reaction is complete, the system is cooled to 0-5 °C, and deionized water is added to quench the reaction. Next, excess solvent is added to the reaction solution. The organic phase is collected after liquid-liquid extraction, and excess solvent is removed. The solution is then purified by column chromatography to obtain an oily liquid, namely acylated eugenol ester. Subsequently, acylated eugenol ester, quaternary phosphonium salt, and excess solvent are added to container C, which is equipped with a heating bath, stirring, and gas protection device. The reaction is carried out at 50-80 °C for 20-36 hours. After the reaction is complete, the reaction solution is cooled to room temperature, excess solvent is removed, and the solution is purified by column chromatography to obtain an oily liquid, which is the product, quaternary phosphonium salt eugenol ester monomer. (3) Preparation of cyclodextrin-grafted polyquaternary phosphonate eugenol ester antibacterial material: Cyclodextrin-based macromolecular chain transfer agent, quaternary phosphonium salt eugenol ester monomer, oil-soluble initiator, and amide solvent were added to a Schlenk tube and magnetically stirred to mix the reaction substrate evenly. Then, the sealed Schlenk tube was immersed in liquid nitrogen and subjected to several freeze-thaw cycles, with the final cycle filling the system with inert gas. The specific freeze-thaw process was as follows: after the solvent was completely frozen, the stopcock was opened to evacuate for 1-10 minutes; the reaction flask was closed, and thawing was allowed until the solvent was completely thawed, repeating this process 1-5 times; then, the reaction was stirred at 60-90 °C for 15-30 h; after the reaction was complete, the Schlenk tube was immersed in liquid nitrogen to quench the reaction; after thawing, the reaction mixture was dialyzed in deionized water for 2-5 days, the product was collected, and freeze-dried at -75 to -40 °C to obtain the cyclodextrin-grafted polyquaternary phosphonium salt eugenol ester antibacterial material.

[0011] In step (1), the ratio of amide solvent to cyclodextrin is 25-50 mL: 3.10-4.60 g; the mass ratio of RAFT chain transfer agent to cyclodextrin is 2.90-3.80 g: 3.10-4.60 g; the mass ratio of carbodiimide condensing agent to cyclodextrin is 2.00-5.50 g: 3.10-4.60 g; the mass ratio of pyridine catalyst to cyclodextrin is 0.35-0.55 g: 3.10-4.60 g; and the ratio of precipitant to cyclodextrin is 90-180 mL: 3.10-4.60 g.

[0012] The carbodiimide condensing agent is one of N,N-diisopropylcarbodiimide, N,N-dicyclohexylcarbodiimide, or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide; the pyridine catalyst is pyridine or 4-dimethylaminopyridine; and the precipitant is one of acetone, diethyl ether, petroleum ether, or ethyl acetate.

[0013] In step (2), the mass ratio of triethylamine to eugenol is 2.00 ~ 5.50 g: 2.00 ~ 4.50 g; the mass ratio of acylation reagent to eugenol is 4.00 ~ 6.50 g: 2.00 ~ 4.50 g; and the mass ratio of quaternary phosphonium salt to eugenol is 1.50 ~ 3.50 g: 2.00 ~ 4.50 g.

[0014] The acylation reagent is one of acyl halide, acyl azide, acid anhydride or carboxylic acid ester; the quaternary phosphonium salt is a phenyl quaternary phosphonium salt or a butyl quaternary phosphonium salt.

[0015] The solvent in step (2) is one of acetonitrile, n-hexane, or dichloromethane.

[0016] In step (3), the mass ratio of quaternary phosphonium salt eugenol ester monomer to cyclodextrin-based macromolecular chain transfer agent is 500~1000 mg: 50~250 mg; the mass ratio of oil-soluble initiator to cyclodextrin-based macromolecular chain transfer agent is 1~10 mg: 50~250 mg; and the mass ratio of amide solvent to cyclodextrin-based macromolecular chain transfer agent is 1.00~4.50 g: 50~250 mg.

[0017] The amide solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylformamide.

[0018] The oil-soluble initiator is one of azobisisobutyronitrile, azobisisoheptanenitrile, or dimethyl azobisisobutyrate.

[0019] Compared with the prior art, the present invention has the following advantages: 1. This invention uses eugenol, a plant essential oil with excellent biocompatibility, as the core, quaternary phosphonium salt as the main antibacterial component, and haloacetyl halide as the connecting bridge between the two. First, a biocompatible cyclodextrin-based macromolecular chain transfer agent is prepared by chemically modifying cyclodextrin. Then, a novel cyclodextrin-grafted polyquaternary phosphonium salt eugenol ester antibacterial material with excellent biocompatibility is prepared by using RAFT polymerization technology.

[0020] 2. This invention uses organic solvents as reaction media and achieves the expansion from aqueous phase self-assembly to organic phase self-assembly of cyclic polymers through host-guest interactions. It also achieves a breakthrough in the self-assembly of cyclodextrin-based macromolecular chain transfer agents and quaternary phosphonate eugenol esters on polymer chains into tail-shaped cyclic polymers.

[0021] 3. This invention utilizes the host-guest interaction between low grafting degree and low polymerization degree to reduce the accumulation of quaternary phosphonium salt eugenol ester structure, thereby embedding the benzene ring structure in the cyclodextrin cavity, which greatly improves the water solubility of the quaternary phosphonium salt eugenol ester homopolymer, fully exposes the active sites of cyclodextrin-grafted polyquaternary phosphonium salt eugenol ester, and significantly enhances its antibacterial properties.

[0022] 4. The antibacterial material prepared by this invention has the advantages of being non-toxic, harmless, and renewable, and has excellent biocompatibility. It can be widely used in many fields such as antibacterial coatings, antibacterial treatment of medical devices and surface antibacterial treatment of daily necessities. Attached Figure Description

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0024] Figure 1 The proton nuclear magnetic resonance spectrum of the cyclodextrin-based macromolecular chain transfer agent prepared in Example 1 of this invention ( 1 (H NMR) image.

[0025] Figure 2 The infrared spectrum (FT-IR) of the cyclodextrin-based macromolecular chain transfer agent prepared in Example 1 of this invention.

[0026] Figure 3 The infrared spectrum (FT-IR) of the quaternary phosphonium salt eugenol ester monomer prepared in Example 1 of this invention.

[0027] Figure 4 The 1H NMR spectrum of the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material prepared in Example 1 of this invention (… 1 (H NMR) image.

[0028] Figure 5 The image shows the Fourier transform infrared (FT-IR) spectrum of the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material prepared in Example 1 of this invention.

[0029] Figure 6 The image shows a scanning electron microscope (SEM) image of the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material prepared in Example 1 of this invention.

[0030] Figure 7 This is a photograph of an antibacterial plate of the cyclodextrin-grafted polyquaternium salt eugenol ester material prepared in Example 1 of this invention. Detailed Implementation

[0031] A cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material has the following structure: Where: m is the number of structural units of the cyclodextrin, i.e., m=1, m=2, or m=3; R1 is -CN or -CH3; R2 is phenyl or butyl; and the anion X... ϴ For Br - F - Cl - I - OH - CN - SCN - BF4 - PF6 - SO4 2- CO3 2- Or AlCl4 - In the formula, X refers to the type of anion; p is 0 or 2; x is 0 or 2; n is the degree of grafting; y is the number of structural units of the quaternary phosphonium salt eugenol ester monomer; the product of y and n is the degree of polymerization; P in -P-(R2)3 refers to phosphorus; and ⊕ is the positive charge of the quaternary phosphonium salt.

[0032] Its synthesis method includes the following steps: (1) Preparation of cyclodextrin-based macromolecular chain transfer agents: In container A, equipped with a heating bath, stirring, and nitrogen gas protection device, an amide solvent and cyclodextrin are added. The ratio of amide solvent to cyclodextrin is 25-50 mL: 3.10-4.60 g. Under a nitrogen atmosphere, the mixture is heated to 45-65°C and slowly stirred until completely dissolved. After the resulting cyclodextrin solution is allowed to stand at room temperature, a RAFT chain transfer agent, a carbodiimide condensing agent, and a pyridine catalyst are added sequentially. The mass ratio of RAFT chain transfer agent to cyclodextrin is 2.90-3.80 g: 3.10-4.60 g, the mass ratio of carbodiimide condensing agent to cyclodextrin is 2.00-5.50 g: 3.10-4.60 g, and the mass ratio of pyridine catalyst to cyclodextrin is 0.35-0.55 g: 3.10-4.60 g. After sealing, the mixture was first magnetically stirred at 20–50 °C for 20–36 h, then cooled in an ice-water bath at -5–5 °C for 0.5–2 h to stop the reaction. The mixed solution was then vacuum filtered to obtain a bright yellow liquid. Finally, the bright yellow liquid was added dropwise to a precipitant at a ratio of 90–180 mL: 3.10–4.60 g of precipitant to cyclodextrin. The precipitate was obtained by vacuum filtration and then vacuum dried at 40–75 °C to constant weight to obtain a yellow precipitate, which is the cyclodextrin-based macromolecular chain transfer agent.

[0033] The amide solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylformamide; the carbodiimide condensing agent is one of N,N-diisopropylcarbodiimide, N,N-dicyclohexylcarbodiimide, or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide; the pyridine catalyst is pyridine or 4-dimethylaminopyridine; and the precipitant is one of acetone, diethyl ether, petroleum ether, or ethyl acetate.

[0034] (2) Preparation of quaternary phosphonium salt eugenol ester monomer: First, eugenol, triethylamine, and excess solvent are added to container B, with a triethylamine to eugenol mass ratio of 2.00–5.50 g: 2.00–4.50 g. The mixture is cooled and stirred in an ice bath for 5–20 min. Then, an acylation reagent is added to the system, with an acylation reagent to eugenol mass ratio of 4.00–6.50 g: 2.00–4.50 g. The mixture is magnetically stirred at -10 to 10 °C for 0.5–2 h, then heated to room temperature and the reaction continues for 4–8 h. After the reaction is complete, the system is cooled to 0 °C. The reaction was quenched with deionized water at 5℃. Next, excess solvent was added to the reaction solution, and the organic phase was collected after liquid-liquid extraction. Excess solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid, namely acylated eugenol ester. Subsequently, the acylated eugenol ester, quaternary phosphonium salt, and excess solvent were added to container C equipped with a heating bath, stirring, and gas protection device. The mass ratio of quaternary phosphonium salt to eugenol was 1.50 ~ 3.50 g: 2.00 ~ 4.50 g. The reaction was carried out at 50 ~ 80 ℃ for 20 ~ 36 h. After the reaction, the reaction solution was cooled to room temperature, excess solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid, which was the product, quaternary phosphonium salt eugenol ester monomer.

[0035] Wherein: the acylating agent is one of acyl halide, acyl azide, acid anhydride or carboxylic acid ester; the quaternary phosphonium salt is phenyl quaternary phosphonium salt or butyl quaternary phosphonium salt; the solvent is one of acetonitrile, n-hexane or dichloromethane.

[0036] (3) Preparation of cyclodextrin-grafted polyquaternary phosphonate eugenol ester antibacterial material: A cyclodextrin-based macromolecular chain transfer agent, a quaternary phosphonium salt eugenol ester monomer, an oil-soluble initiator, and an amide solvent were added to a Schlenk tube. The mass ratio of the quaternary phosphonium salt eugenol ester monomer to the cyclodextrin-based macromolecular chain transfer agent was 500–1000 mg: 50–250 mg; the mass ratio of the oil-soluble initiator to the cyclodextrin-based macromolecular chain transfer agent was 1–10 mg: 50–250 mg; and the mass ratio of the amide solvent to the cyclodextrin-based macromolecular chain transfer agent was 1.00–4.50 g: 50–250 mg. The reaction substrate was mixed uniformly by magnetic stirring. Then, a sealed Schlenk tube was immersed in liquid nitrogen and subjected to several freeze-thaw cycles, with the final cycle involving the filling of the system with inert gas. The specific freeze-thaw process was as follows: after the solvent was completely frozen, the stopcock was opened to create a vacuum for 1-10 minutes; the reaction flask was closed, and thawing was allowed until the solvent was completely thawed, repeating this process 1-5 times; then, the reaction was stirred at 60-90 °C for 15-30 h; after the reaction was complete, the Schlenk tube was immersed in liquid nitrogen to quench the reaction; after thawing, the reaction mixture was dialyzed in deionized water for 2-5 days, the product was collected, and freeze-dried at -75 to -40 °C to obtain the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material.

[0037] The amide solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylformamide; the oil-soluble initiator is one of azobisisobutyronitrile, azobisisoheptanenitrile, or dimethyl azobisisobutyrate.

[0038] Example 1: A method for synthesizing a cyclodextrin-grafted polyquaternium phosphonate eugenol ester antibacterial material, comprising the following steps: (1) Preparation of cyclodextrin-based macromolecular chain transfer agents: In a round-bottom flask equipped with a stirrer, heating bath, and gas protection device, 37 mL of N,N-dimethylformamide and 4.20 g of α-cyclodextrin were added. The mixture was heated to 50 °C under a nitrogen atmosphere and slowly stirred until completely dissolved. After the solution cooled to room temperature, 1.45 g of 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, 2.50 g of N,N-diisopropylcarbodiimide, and 0.41 g of pyridine were weighed and added to the round-bottom flask. The flask was sealed and magnetically stirred at 30 °C for 22 h. Subsequently, the round-bottom flask was placed in a water bath at 5 °C for 0.5 h to complete the reaction. The precipitate was removed by vacuum filtration, and the bright yellow liquid was collected. The bright yellow liquid was added dropwise to 110 mL of ethyl acetate to precipitate the product, and the precipitate was collected by vacuum filtration. Finally, the precipitate was dried in a vacuum oven at 50 °C until constant weight, yielding a yellow precipitate, which is the cyclodextrin-based macromolecular chain transfer agent.

[0039] (2) Preparation of quaternary phosphonium salt eugenol ester monomer: Eugenol and triethylamine were added to a container, cooled and stirred in an ice bath for 6 min, then the acyl halide was added to the system, and the mixture was magnetically stirred at -3 ℃ for 0.7 h. The temperature was then raised to room temperature and the reaction continued for 4 h. After the reaction was complete, the temperature was lowered to 0-5 ℃, and deionized water was added to quench the reaction. The organic phase was collected after liquid-liquid extraction, the solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid acylated eugenol ester. Subsequently, the acylated eugenol ester and quaternary phosphonium salt were added to a container equipped with a heating bath, stirring, and gas protection device, and reacted at 50 ℃ for 21 h. After the reaction was complete, the solution was cooled to room temperature, solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid, which was the quaternary phosphonium salt eugenol ester monomer.

[0040] (3) Preparation of cyclodextrin-grafted polyquaternary phosphonate eugenol ester antibacterial material: 70 mg of cyclodextrin-based macromolecular chain transfer agent, 510 mg of quaternary phosphonium salt eugenol ester monomer, 3.50 mg of azobisisobutyronitrile (AIB), and 1.70 g of N-methylformamide were added to a Schlenk tube and magnetically stirred to mix the reaction substrate thoroughly. The sealed Schlenk tube was then immersed in liquid nitrogen. After the solvent was completely frozen, the stopcock was opened to create a vacuum for 3 minutes. The reaction flask was then closed, and the mixture was thawed until the solvent was completely thawed. This process was repeated three times, with the last thaw cycle filled with an inert gas. The mixture was then placed in an oil bath at 65 °C and stirred for 17 h. After the reaction was complete, the reaction tube was immersed in liquid nitrogen to quench the reaction. After thawing, the mixture was dialyzed in deionized water for 2 days, and the precipitate was collected and freeze-dried at -70 °C to obtain the cyclodextrin-grafted polyquaternary phosphonium salt eugenol ester antibacterial material.

[0041] The cyclodextrin-grafted polyquaternium salt eugenol ester prepared in Example 1 was characterized and analyzed, and its antibacterial properties were tested.

[0042] [Hydrogen NMR Spectroscopy] By nuclear magnetic resonance hydrogen spectrum ( 1 The prepared cyclodextrin-based macromolecular chain transfer agent was characterized and analyzed by 1H NMR, such as... Figure 1 As shown. Wherein, 0.84 ppm corresponds to the terminal -C of the RAFT chain transfer agent. H 3 (-C H 3, a), 1.25 ppm of CH3-(C) attributed to RAFT chain transfer agents H 2)9-(CH3-(C H 2) 9-, b), 1.68 ppm of -S-CH2-C attributed to RAFT chain transfer agents H 2-(-S-CH2-C) H 2-, c), 3.43 ppm corresponds to -SC of the RAFT chain transfer agent. H2-(-SC H 2-, d), 1.53 ppm corresponds to the R1-CC of the RAFT chain transfer agent. H 3 (R1-CC) H 3, e). 2.49 and 2.65, 2.81 ppm correspond to amide solvents and DMSO-d6, respectively. 3.51 ~ 3.73 ppm correspond to the -OC of cyclodextrin. H 2 -CH-(-OC H 2 -CH-, f), -CH-C H 2-(-CH-C) H 2-, m), -C H -CH-O-(-C H -CH-O-, j), -CH-C H - O-(-CH-C H -O-, l), 4.45 ppm, attributed to the -CH2-O of cyclodextrins. H (-CH2-O) H , g), 4.83 ppm corresponds to the -OC of cyclodextrin H -O-(-OC H -C-, h), 5.61 ~ 5.81 ppm, attributed to the -O group of cyclodextrins. H (-O) H Furthermore, through infrared spectroscopy (FT-IR, n, n'), Figure 2 The characteristic peaks of the functional groups in the cyclodextrin further verified its successful synthesis. In summary, the presence of chemical structures in cyclodextrin and RAFT chain transfer agents indicates that cyclodextrin-based macromolecular chain transfer agents have been successfully prepared.

[0043] pass 1 The chemical structure of cyclodextrin-grafted polyquaternium salt eugenol ester was analyzed by ¹H NMR, and the results are as follows: Figure 4 As shown. Of these, 7.87 ~ 7.71 ppm belong to the alkylphosphonium (-) of the quaternary phosphonium salt eugenol ester monomer. R , v), 7.49 ~ 6.46 ppm corresponds to the benzene ring structure (-Ar-) of the quaternary phosphonium salt eugenol ester monomer. H (q, r, s). 5.81 ~ 5.61 ppm belongs to the -O group of cyclodextrins. H (-O) H , n, n'), 5.21 ppm corresponds to the -OC of cyclodextrin H -O-(-OC H -C-, h), 4.98 ppm, attributed to the -CH2-O of cyclodextrin.H (-CH2-O) H The large peak at 4.32 ~ 4.06 ppm corresponds to the phenylcycloalkoxy-OC of the quaternary phosphonium salt eugenol ester monomer. H 3 (-OC) H 3, t). 3.71 ~ 3.62 ppm corresponds to the -OC of cyclodextrin. H 2 -CH-(-OC H 2 -CH-, f), -CH-C H 2-(-CH-C) H 2-, m), -C H -CH-O-(-C H -CH-O-, j), -CH-C H - O-(-CH-C H - O-,l). 3.31 ppm corresponds to -SC of the RAFT chain transfer agent. H 2-(-SC H 2-, d). 2.81 and 2.61, 2.49 ppm correspond to amide solvents and DMSO-d6, respectively. 1.43 ppm is attributed to R1-CC of the RAFT chain transfer agent. H 3 (R1-CC) H 3, e), -S-CH2-C H 2-(-S-CH2-C) H 2-, c), CH3-(C H 2)9-(CH3-(C H 2) 9-, b), 1.02 ppm corresponds to the terminal -C of the RAFT chain transfer agent. H 3 (-C H 3, a). In summary, the chemical structures of the quaternary phosphonium salt eugenol ester monomer, cyclodextrin, and RAFT chain transfer agent are all present, and the C=C peak of the quaternary phosphonium salt eugenol ester monomer disappears after polymerization, indicating that cyclodextrin-grafted polyquaternary phosphonium salt eugenol ester has been successfully prepared.

[0044] Infrared Spectroscopy The prepared quaternary phosphonium salt eugenol ester monomer was characterized by Fourier transform infrared spectroscopy (FT-IR), such as... Figure 3 As shown. The positions of each absorption peak (cm) are shown. -1The corresponding functional groups are: 3073 (-CH3), 2950 (-CH2-), 1752 (-C=O), 1634 (-C=C), 1600 (-Ph), 1450 (-Ph), 1110 (-COC), 1035 (-COC), and 747 (-CP). In summary, the quaternary phosphonium salt eugenol ester monomer has been successfully synthesized.

[0045] The characteristic absorption peaks of cyclodextrin-grafted polyquaternium salt eugenol ester were further analyzed by FT-IR, and the results are as follows: Figure 5 As shown. Among them, 3491 cm -1 Absorption peaks attributable to the stretching vibration of OH in cyclodextrin; 2941 and 2861 cm⁻¹ -1 This absorption peak is attributed to the stretching vibration of saturated CH4 atoms in the polymer backbone. (1693 cm⁻¹) -1 The absorption peak is attributed to the stretching vibration of the carbonyl group (C=O) of cyclodextrin-grafted polyquaternary phosphonate eugenol ester. 1253 cm⁻¹ -1 The absorption peak corresponds to the stretching vibration of Ar-OC in cyclodextrin-grafted polyquaternary phosphonate eugenol ester. 1115 cm⁻¹ -1 The absorption peak at 657 cm⁻¹ corresponds to the stretching vibration of Ar-CP in cyclodextrin-grafted polyquaternium eugenol ester. Furthermore, the absorption peak at 657 cm⁻¹... -1 The absorption peak at [location] corresponds to the stretching vibration of cyclodextrin-grafted polyquaternium eugenol ester-CP. In summary, this demonstrates the successful preparation of cyclodextrin-grafted polyquaternium eugenol ester materials.

[0046] Microscopic morphology The microstructure of the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material prepared in this invention was tested by scanning electron microscopy (SEM) (e.g., ...). Figure 6 Based on SEM characterization results, the cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material prepared in this invention exhibits a stacked ring-like assembly structure with clearly defined dimensions: the inner diameter of the ring structure is approximately 150-250 nm, the outer diameter is approximately 300-500 nm, and the ring width (distance between the inner and outer diameters) is approximately 50 nm. The structural details are clear: the polymer rings have obvious connection sites, and a "tail" is visible at the connection points, exhibiting a tail-like ring structure. 1 Structural analysis by 1H NMR and FT-IR revealed that the primary structure of this material is a linear homopolymer, but it can self-assemble into a secondary ring structure through host-guest interactions in an organic phase environment. This assembly method fully exposes the active sites of the material and increases its specific surface area. The fully exposed active sites can bind to the bacterial surface more efficiently, providing a structural basis for interactions with bacteria (such as cell membrane disruption and metabolic interference), thereby significantly improving its antibacterial efficacy.

[0047] [Antibacterial properties] The antibacterial properties of cyclodextrin-grafted polyquaternium eugenol ester were evaluated using Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus and Streptococcus albus). The results are as follows: Figure 7 As shown, a large number of bacteria were observed in the control groups (Escherichia coli, Staphylococcus aureus, and Streptococcus albus), while almost no bacteria were present in the sample groups (Escherichia coli + cyclodextrin-grafted polyquaternium eugenol ester, Staphylococcus aureus + cyclodextrin-grafted polyquaternium eugenol ester, and Streptococcus albus + cyclodextrin-grafted polyquaternium eugenol ester). Furthermore, the antibacterial rate of cyclodextrin-grafted polyquaternium eugenol ester against Escherichia coli, Staphylococcus aureus, and Streptococcus albus reached 99.9%. Therefore, the antibacterial material of cyclodextrin-grafted polyquaternium eugenol ester can effectively kill and inhibit bacterial growth. This is mainly because the cyclic topology of the homopolymer can fully expose the aldehyde groups and bind to the sulfhydryl groups on the bacterial surface, thereby causing bacterial cell membrane rupture and leading to bacterial death.

[0048] The prepared cyclodextrin-grafted polyquaternium salt eugenol ester achieved an antibacterial rate of 99.9% against Escherichia coli, Staphylococcus aureus, and Streptococcus epidermidis.

[0049] Example 2 A method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material, comprising the following steps: (1) Preparation of cyclodextrin-based macromolecular chain transfer agents: In a round-bottom flask equipped with a stirrer, heating bath, and gas protection device, 48 mL of N,N-dimethylacetamide and 3.70 g of β-cyclodextrin were added. Under a nitrogen atmosphere, the mixture was heated to 60 °C and slowly stirred until completely dissolved. After the solution cooled to room temperature, 3.80 g of 4-cyano-4-[(dodecylthioalkylthiocarbonyl)thioalkyl]valeric acid, 4.10 g of N,N-dicyclohexylcarbodiimide, and 0.51 g of pyridine were weighed and added to the round-bottom flask. The flask was sealed and magnetically stirred at 450 °C for 33 h. The flask was then placed in a water bath at 0 °C for 1.5 h to complete the reaction. The white precipitate was removed by vacuum filtration, and the bright yellow liquid was collected. The bright yellow liquid was added dropwise to 130 mL of petroleum ether to precipitate the product, and the precipitate was collected by vacuum filtration. Finally, the precipitate was dried in a vacuum oven at 60 °C until constant weight, yielding a yellow precipitate, which is the cyclodextrin-based macromolecular chain transfer agent.

[0050] (2) Preparation of quaternary phosphonium salt eugenol ester monomer: Eugenol and triethylamine were added to a container, cooled and stirred in an ice bath for 7 min, then acyl azide was added to the system, and the mixture was magnetically stirred at -1 °C for 0.9 h. The temperature was then raised to room temperature and the reaction continued for 5 h. After the reaction was complete, the temperature was lowered to 0–5 °C, and deionized water was added to quench the reaction. The organic phase was collected after liquid-liquid extraction, the solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid acylated eugenol ester. Subsequently, the acylated eugenol ester and phosphonium salt were added to a container equipped with a heating bath, stirring, and gas protection device, and reacted at 60 °C for 23 h. After the reaction was complete, the solution was cooled to room temperature, the solvent was removed, and the solution was purified by column chromatography to obtain a red oily liquid, which was quaternary phosphonium salt eugenol ester.

[0051] (3) Preparation of cyclodextrin-grafted polyquaternary phosphonate eugenol ester antibacterial material: 180 mg of cyclodextrin-based macromolecular chain transfer agent, 710 mg of quaternary phosphonium acrylate eugenol ester, 5.10 mg of azobisisobutyronitrile, and 4.10 g of N,N-dimethylacetamide were added to a Schlenk tube and magnetically stirred to mix the reaction substrate thoroughly. The sealed Schlenk tube was then immersed in liquid nitrogen. After the solvent was completely frozen, the stopcock was opened to create a vacuum for 7 min. The reaction flask was then closed, and the mixture was thawed until the solvent was completely thawed. This process was repeated four times, with the last thaw cycle filled with inert gas. The mixture was then placed in an oil bath at 80 °C and stirred for 19 h. After the reaction was complete, the reaction tube was immersed in liquid nitrogen to quench the reaction. After thawing, the mixture was dialyzed in deionized water for 3 days, and the precipitate was collected and freeze-dried at -50 °C to obtain the cyclodextrin-grafted polyquaternary phosphonium acrylate antibacterial material.

[0052] The prepared cyclodextrin-grafted polyquaternium salt eugenol ester achieved an antibacterial rate of 99.9% against Escherichia coli, Staphylococcus aureus, and Streptococcus epidermidis.

[0053] Example 3 A method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material, comprising the following steps: (1) Preparation of cyclodextrin-based macromolecular chain transfer agents: In a round-bottom flask equipped with a stirrer, heating bath, and gas protection device, 46 mL of N-methylformamide and 3.30 g of γ-cyclodextrin were added. Under a nitrogen atmosphere, the mixture was heated to 65 °C and slowly stirred until completely dissolved. After the solution cooled to room temperature, 3.60 g of 4-cyano-4-[(dodecylthioalkylthiocarbonyl)thioalkyl]valeric acid, 5.40 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and 0.54 g of pyridine were weighed and added to the round-bottom flask. The flask was sealed and magnetically stirred at 45 °C for 35 h. The flask was then placed in a water bath at -5 °C for 2 h to complete the reaction. The white precipitate was removed by vacuum filtration, and the bright yellow liquid was collected. The bright yellow liquid was added dropwise to 150 mL of diethyl ether to precipitate the product, and the precipitate was collected by vacuum filtration. The precipitate was dried in a vacuum oven at 75 °C until constant weight to obtain a yellow precipitate, which is the cyclodextrin-based macromolecular chain transfer agent.

[0054] (2) Preparation of quaternary phosphonium salt eugenol ester monomer: Eugenol and triethylamine were added to a container, cooled and stirred in an ice bath for 13 min, then the acid anhydride was added to the system, and the mixture was magnetically stirred at 5 °C for 2.5 h. The temperature was then raised to room temperature and the reaction continued for 7 h. After the reaction was complete, the temperature was lowered to 0-5 °C, and deionized water was added to quench the reaction. The organic phase was collected after liquid-liquid extraction, the solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid acylated eugenol ester. Subsequently, the acylated eugenol ester and phosphonium salt were added to a container equipped with a heating bath, stirring, and gas protection device, and reacted at 75 °C for 36 h. After the reaction was complete, the solution was cooled to room temperature, the solvent was removed, and the solution was purified by column chromatography to obtain a red oily liquid, which was quaternary phosphonium salt eugenol ester.

[0055] (3) Preparation of cyclodextrin-grafted polyquaternary phosphonate eugenol ester antibacterial material: 235 mg of cyclodextrin-based macromolecular chain transfer agent, 880 mg of quaternary phosphonium acrylate eugenol ester, 6.30 mg of dimethyl azobisisobutyrate, and 4.30 g of N,N-dimethylformamide were added to a Schlenk tube and magnetically stirred to ensure homogeneous mixing of the reaction substrate. The sealed Schlenk tube was then immersed in liquid nitrogen. After the solvent was completely frozen, the stopcock was opened to create a vacuum for 9 min. The reaction flask was then closed, and the mixture was thawed until the solvent was completely thawed. This process was repeated 5 times, with the last thaw cycle filled with inert gas. The mixture was then placed in an oil bath at 87 °C and stirred for 28 h. After the reaction was complete, the reaction tube was immersed in liquid nitrogen to quench the reaction. After thawing, the mixture was dialyzed in deionized water for 4 days, and the precipitate was collected and freeze-dried at -60 °C to obtain the cyclodextrin-grafted polyquaternary phosphonium acrylate antibacterial material.

[0056] The prepared cyclodextrin-grafted polyquaternium salt eugenol ester achieved an antibacterial rate of 99.9% against Escherichia coli, Staphylococcus aureus, and Streptococcus epidermidis.

Claims

1. A cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material, characterized in that... The antibacterial material has the following structure: Where: m is the number of structural units of the cyclodextrin, i.e., m=1, m=2, or m=3; R1 is -CN or -CH3; R2 is phenyl or butyl; and the anion X... ϴ For Br - F - Cl - I - OH - CN - SCN - BF4 - PF6 - SO4 2- CO3 2- Or AlCl4 - In the formula, X refers to the type of anion; p is 0 or 2; x is 0 or 2; n is the degree of grafting; y is the number of structural units of the quaternary phosphonium salt eugenol ester monomer; the product of y and n is the degree of polymerization; P in -P-(R2)3 refers to phosphorus; and ⊕ is the positive charge of the quaternary phosphonium salt.

2. The method for synthesizing a cyclodextrin-grafted polyquaternium eugenol ester antibacterial material as described in claim 1, comprising the following steps: (1) Preparation of cyclodextrin-based macromolecular chain transfer agents: In container A, equipped with a heating bath, stirring, and nitrogen gas protection device, an amide solvent and cyclodextrin are added. Under a nitrogen atmosphere, the mixture is heated to 45-65 °C and slowly stirred until completely dissolved. After the resulting cyclodextrin solution is allowed to stand at room temperature, RAFT chain transfer agent, carbodiimide condensing agent, and pyridine catalyst are added sequentially. After sealing, the mixture is first magnetically stirred at 20-50 °C for 20-36 h, and then cooled in an ice-water bath at -5-5 °C for 0.5-2 h to stop the reaction. The mixed solution is then vacuum filtered to obtain a bright yellow liquid. Finally, the bright yellow liquid is added dropwise to a precipitant, and the precipitate is obtained by vacuum filtration. The precipitate is then vacuum dried at 40-75 °C to constant weight to obtain a yellow precipitate, which is the cyclodextrin-based macromolecular chain transfer agent. (2) Preparation of quaternary phosphonium salt eugenol ester monomer: First, eugenol, triethylamine, and excess solvent were added to container B. The mixture was cooled and stirred in an ice bath for 5–20 min. Then, the acylation reagent was added to the system, and the mixture was magnetically stirred at -10–10 °C for 0.5–2 h. The temperature was then raised to room temperature and the reaction continued for 4–8 h. After the reaction was complete, the system was cooled to 0–5 °C, and deionized water was added to quench the reaction. Next, excess solvent was added to the reaction solution. The organic phase was collected after liquid-liquid extraction, and excess solvent was removed. The solution was purified by column chromatography to obtain an oily liquid, namely acylated eugenol ester. Subsequently, acylated eugenol ester, quaternary phosphonium salt, and excess solvent were added to container C, which was equipped with a heating bath, stirring, and gas protection device. The reaction was carried out at 50–80 °C for 20–36 h. After the reaction was complete, the reaction solution was cooled to room temperature, excess solvent was removed, and the solution was purified by column chromatography to obtain an oily liquid, which was the product, quaternary phosphonium salt eugenol ester monomer. (3) Preparation of cyclodextrin-grafted polyquaternary phosphonate eugenol ester antibacterial material: Cyclodextrin-based macromolecular chain transfer agent, quaternary phosphonium salt eugenol ester monomer, oil-soluble initiator, and amide solvent were added to a Schlenk tube and magnetically stirred to mix the reaction substrate evenly. Then, the sealed Schlenk tube was immersed in liquid nitrogen and subjected to several freeze-thaw cycles, with the final cycle filling the system with inert gas. The specific freeze-thaw process was as follows: after the solvent was completely frozen, the stopcock was opened to evacuate for 1-10 minutes; the reaction flask was closed, and thawing was allowed until the solvent was completely thawed, repeating this process 1-5 times; then, the reaction was stirred at 60-90 °C for 15-30 h; after the reaction was complete, the Schlenk tube was immersed in liquid nitrogen to quench the reaction; after thawing, the reaction mixture was dialyzed in deionized water for 2-5 days, the product was collected, and freeze-dried at -75 to -40 °C to obtain the cyclodextrin-grafted polyquaternary phosphonium salt eugenol ester antibacterial material.

3. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 2, characterized in that: In step (1), the ratio of amide solvent to cyclodextrin is 25-50 mL: 3.10-4.60 g; the mass ratio of RAFT chain transfer agent to cyclodextrin is 2.90-3.80 g: 3.10-4.60 g; the mass ratio of carbodiimide condensing agent to cyclodextrin is 2.00-5.50 g: 3.10-4.60 g; the mass ratio of pyridine catalyst to cyclodextrin is 0.35-0.55 g: 3.10-4.60 g; and the ratio of precipitant to cyclodextrin is 90-180 mL: 3.10-4.60 g.

4. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 3, characterized in that: The carbodiimide condensing agent is one of N,N-diisopropylcarbodiimide, N,N-dicyclohexylcarbodiimide, or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide; the pyridine catalyst is pyridine or 4-dimethylaminopyridine; and the precipitant is one of acetone, diethyl ether, petroleum ether, or ethyl acetate.

5. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 2, characterized in that: In step (2), the mass ratio of triethylamine to eugenol is 2.00 ~ 5.50 g: 2.00 ~ 4.50 g; the mass ratio of acylation reagent to eugenol is 4.00 ~ 6.50 g: 2.00 ~ 4.50 g; and the mass ratio of quaternary phosphonium salt to eugenol is 1.50 ~ 3.50 g: 2.00 ~ 4.50 g.

6. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 5, characterized in that: The acylation reagent is one of acyl halide, acyl azide, acid anhydride or carboxylic acid ester; the quaternary phosphonium salt is a phenyl quaternary phosphonium salt or a butyl quaternary phosphonium salt.

7. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 2, characterized in that: The solvent in step (2) is one of acetonitrile, n-hexane, or dichloromethane.

8. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 2, characterized in that: In step (3), the mass ratio of quaternary phosphonium salt eugenol ester monomer to cyclodextrin-based macromolecular chain transfer agent is 500-1000 mg: 50-250 mg; the mass ratio of oil-soluble initiator to cyclodextrin-based macromolecular chain transfer agent is 1-10 mg: 50-250 mg; and the mass ratio of amide solvent to cyclodextrin-based macromolecular chain transfer agent is 1.00-4.50 g: 50-250 mg.

9. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 3 or 8, characterized in that: The amide solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide, or N-methylformamide.

10. The method for synthesizing a cyclodextrin-grafted polyquaternium salt eugenol ester antibacterial material as described in claim 8, characterized in that: The oil-soluble initiator is one of azobisisobutyronitrile, azobisisoheptanenitrile, or dimethyl azobisisobutyrate.

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