Antibacterial polyacrylate aqueous emulsion and preparation method thereof

Abstract

The invention relates to the technical field of high-performance coatings, and discloses an antibacterial polyacrylate water-based emulsion and a preparation method thereof.The preparation method of the antibacterial polyacrylate water-based emulsion comprises the following steps that firstly, a phosphorus-containing spiro compound is prepared, then the phosphorus-containing spiro compound reacts with 3, 5-diamino-1, 2, 4-triazole, and a nitrogen-containing phosphorus spiro compound is obtained; the preparation method comprises the following steps: sequentially reacting a nitrogen and phosphorus containing spiro compound with 4-hydroxynonenal and hexamethylene diisocyanate to obtain a modified multifunctional spiro compound; combining the modified multifunctional spiro compound with carboxymethyl chitosan to obtain a multifunctional modifier; copolymerizing the mixed monomer and a multifunctional modifier to obtain a polyacrylate water-based emulsion; adding the composite modified BiOCl (at) Cu-MOF into a polyacrylate water-based emulsion, so as to obtain an antibacterial polyacrylate water-based emulsion; the antibacterial polyacrylate water-based emulsion disclosed by the invention has excellent thermal stability, mechanical properties and lasting antibacterial and flame-retardant properties.

Description

Technical Field

[0001] This invention relates to the field of high-performance coatings technology, specifically to an antibacterial polyacrylate aqueous emulsion and its preparation method. Background Technology

[0002] Polyacrylate emulsions, as a type of high-performance polymer emulsion, possess excellent light transmittance, mechanical properties, acid and alkali resistance, and weather resistance. Furthermore, their production process is simple, flexible, and inexpensive, making them widely used in textiles, papermaking, coatings, leather, construction, and aerospace materials. The natural world contains numerous bacteria, fungi, viruses, and other microorganisms that can directly or indirectly cause various diseases, significantly impacting human production and life. Therefore, to better meet application needs, polyacrylate emulsions with antibacterial functions have emerged.

[0003] For example, Chinese patent application CN114672215A discloses a method for preparing a nano-ZnO modified polyacrylate emulsion composite coating, which improves the antibacterial properties of the polyacrylate emulsion by modifying it. However, the nano-ZnO in Chinese patent application CN114672215A, as an inorganic material, has poor interfacial compatibility with the polyacrylate emulsion, resulting in poor dispersion of nano-ZnO. This leads to an unsatisfactory antibacterial modification effect of the polyacrylate emulsion and also affects its mechanical properties. In addition, polyacrylate is easily decomposed at high temperatures and is highly flammable, which can easily cause serious fire safety hazards, thus limiting the application range of polyacrylate. Therefore, improving the flame retardant properties of polyacrylate emulsion is also crucial. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing an antibacterial aqueous polyacrylate emulsion, comprising the following steps: Step 1: Pentaerythritol reacts with phosphorus oxychloride to give a phosphorus-containing spirocyclic compound; the phosphorus-containing spirocyclic compound reacts with 3,5-diamino-1,2,4-triazole to give a nitrogen-containing phosphorus-containing spirocyclic compound. Step 2: The nitrogen- and phosphorus-containing spirocyclic compound reacts with 4-hydroxynonenal to obtain a multifunctional spirocyclic compound; the multifunctional spirocyclic compound is modified with hexamethylene diisocyanate to obtain a modified multifunctional spirocyclic compound; the modified multifunctional spirocyclic compound is combined with carboxymethyl chitosan to obtain a multifunctional modifier. Step 3: Methyl methacrylate, n-butyl acrylate, methacrylic acid and multifunctional modifier are polymerized to obtain an aqueous polyacrylate emulsion; the composite modified BiOCl@Cu-MOF is added to the aqueous polyacrylate emulsion and reacted to obtain an antibacterial aqueous polyacrylate emulsion.

[0005] Preferably, in step one, the preparation method of the nitrogen-phosphorus spirocyclic compound is as follows: Pentaerythritol and phosphorus oxychloride were mixed in a mass ratio of (12-20):(105.2-131.6), and stirred at 75-85℃ for 50-70 min. Then the temperature was raised to 104-106℃ and maintained for 11-13 h. After purification, a phosphorus-containing spirocyclic compound was obtained. In a nitrogen atmosphere, a phosphorus-containing spirocyclic compound was added to N,N-dimethylformamide and stirred. Then, 3,5-diamino-1,2,4-triazole was added, and the mixture was heated to 108-112℃ and reacted for 3.5-4.5 h. After purification, a nitrogen-containing phosphorus-containing spirocyclic compound was obtained. The mass ratio of the phosphorus-containing spirocyclic compound, N,N-dimethylformamide, and 3,5-diamino-1,2,4-triazole was (7.4-14.8):(120-150):(4.9-9.9). In the above process, the hydroxyl group of pentaerythritol reacts with the two chlorine atoms of phosphorus oxychloride to form a spirocyclic ring, introducing flame-retardant phosphorus. Next, the remaining chlorine in the phosphorus-containing spirocyclic compound reacts with the amino groups at both ends of the nitrogen-containing phosphorus spirocyclic compound to obtain a nitrogen-containing phosphorus spirocyclic compound containing a spirocyclic ring, a triazole group, and flame-retardant nitrogen and phosphorus elements. Among these, phosphorus and nitrogen have a synergistic flame-retardant effect, the presence of the spirocyclic structure and the triazole group can improve the mechanical properties of the polymer matrix, and the triazole group also has a good antibacterial effect.

[0006] Preferably, the method for preparing the modified multifunctional spirocyclic compound is as follows: In a nitrogen atmosphere, a nitrogen- and phosphorus-containing spirocyclic compound was added to N,N-dimethylformamide, stirred, and then 4-hydroxynonenal was added. The mixture was heated to 60-80℃ and reacted for 8-10 hours. After purification, a multifunctional spirocyclic compound was obtained. The mass ratio of the nitrogen- and phosphorus-containing spirocyclic compound, N,N-dimethylformamide, and 4-hydroxynonenal was (8.4-16.8):(120-150):(3.8-8.8). The multifunctional spirocyclic compound was added to N,N-dimethylformamide and stirred. Then, hexamethylene diisocyanate and dibutyltin dilaurate were added, and the mixture was heated to 75-85℃ and reacted for 7-9 hours. After purification, the modified multifunctional spirocyclic compound was obtained. The mass ratio of the multifunctional spirocyclic compound, N,N-dimethylformamide, hexamethylene diisocyanate, and dibutyltin dilaurate was (3.5-7):(120-150):(1.7-3.4):(0.03-0.05). In the above process, the amino group in the nitrogen-phosphorus spirocyclic compound reacts with the aldehyde group of 4-hydroxynonenal to form an antibacterial Schiff base bond, and introduces a carbon-carbon double bond and a hydroxyl group into the structure of the nitrogen-phosphorus spirocyclic compound to obtain a multifunctional spirocyclic compound; the hydroxyl group in the multifunctional spirocyclic compound reacts with the isocyanate group at one end of hexamethylene diisocyanate to introduce an isocyanate group into the multifunctional spirocyclic compound, thus obtaining a modified multifunctional spirocyclic compound.

[0007] Preferably, in step two, the preparation method of the multifunctional modifier is as follows: Carboxymethyl chitosan was added to ethanol and stirred. Then, the modified multifunctional spirocyclic compound was added. The mixture was heated to 70-80℃ under a nitrogen atmosphere and stirred for 8-12 hours. After purification, the multifunctional modifier was obtained. The mass ratio of carboxymethyl chitosan, ethanol, and modified multifunctional spirocyclic compound was (16-24):(300-500):(0.5-0.9). In the above process, carboxymethyl chitosan exhibits excellent water solubility, antibacterial properties, film-forming ability, and antioxidant activity, as well as biocompatibility and biodegradability. The amino and hydroxyl groups in carboxymethyl chitosan can react with the isocyanate groups in the modified multifunctional spirocyclic compound, thereby grafting the modified multifunctional spirocyclic compound onto the carboxymethyl chitosan side chain to obtain a multifunctional modifier. The multifunctional modifier in this invention combines the advantages of carboxymethyl chitosan and the modified multifunctional spirocyclic compound, and can improve the mechanical properties, antibacterial properties, and flame retardant properties of the polymer matrix.

[0008] Preferably, in step three, the preparation method of the polyacrylate aqueous emulsion is as follows: Methyl methacrylate, n-butyl acrylate, and methacrylic acid were mixed to obtain a mixed monomer. A multifunctional modifier was mixed with deionized water and stirred at 35-45°C for 20-40 minutes to obtain a multifunctional modifier mixture. Under a nitrogen atmosphere, deionized water, sodium dodecyl sulfate, and alkylphenol polyoxyethylene ether OP-10 were mixed, stirred, and heated to 70-80°C. Potassium persulfate was added, and simultaneously, 10% by mass of the above mixed monomer and 10% by mass of the above multifunctional modifier mixture were added dropwise, controlling the dropwise addition time to 10-20 minutes. After the addition was complete... Continue the reaction for 20-30 minutes; then, simultaneously add the remaining mixed monomers, multifunctional modifier mixture and 0.5 wt% potassium persulfate aqueous solution, controlling the addition time to 2-3 hours. After the addition is complete, raise the temperature to 75-85℃ and continue the reaction for 1-2 hours. After the reaction is complete, lower the product temperature to ambient temperature, filter and discharge to obtain an aqueous polyacrylate emulsion; wherein, the mass ratio of methyl methacrylate, n-butyl acrylate, methacrylic acid and multifunctional modifier is (27-54):(25-45):(1-2):(8-14).

[0009] Preferably, in step three, the antibacterial aqueous polyacrylate emulsion is prepared by the following method: the composite modified BiOCl@Cu-MOF and the aqueous polyacrylate emulsion are mixed at a mass ratio of (5-12):(50-60), and stirred at 70-80℃ for 1-2 hours to obtain the antibacterial aqueous polyacrylate emulsion.

[0010] In the above process, potassium persulfate was used as an initiator, methyl methacrylate, n-butyl acrylate, and methacrylic acid were used as polymerizing monomers, and a multifunctional modifier was used as a functional monomer. Aqueous polyacrylate emulsions were prepared by emulsion polymerization. The epoxy groups of the composite modified BiOCl@Cu-MOF in the aqueous polyacrylate emulsion can combine with the amino and carboxyl groups in the polyacrylate. In addition, the composite modified BiOCl@Cu-MOF can also form hydrogen bond interactions and electrostatic interactions with the polyacrylate. Therefore, the composite modified BiOCl@Cu-MOF and polyacrylic acid can be combined through chemical covalent bonds and physical interactions, which improves the dispersibility of the composite modified BiOCl@Cu-MOF and thus endows the polyacrylate emulsion with better performance.

[0011] Preferably, in step three, the preparation method of the composite modified BiOCl@Cu-MOF includes the following steps: Step S1: Under stirring, the ligand mixture is added to the metal salt mixture at a rate of 1-2 mL / min, stirred for 20-40 min, heated to 136-144℃ and maintained for 20-30 h, cooled to ambient temperature, purified, and BiOCl@Cu-MOF is obtained. In the above process, copper nitrate trihydrate was used as a metal precursor and trimesic acid as a ligand to grow Cu-MOF in situ on BiOCl nanosheets, thus obtaining BiOCl@Cu-MOF. The BiOCl nanosheets and Cu-MOF in BiOCl@Cu-MOF exhibit synergistic flame retardant and antibacterial effects. Specifically, in terms of flame retardancy, BiOCl@Cu-MOF shows strong catalytic activity (derived from copper and Bi) at the initial stage of combustion, promoting the conversion of pyrolysis products into residual carbon. Furthermore, due to the porous structure of Cu-MOF anchored on the BiOCl surface, it can adsorb some toxic fumes, thus playing a role in smoke suppression. As the temperature increases, BiOCl... The @Cu-MOF begins to decompose and absorb a large amount of heat, forming a protective barrier on the carbonized body. These compounds inhibit the transfer of heat and oxygen, delay the decomposition of the matrix, and reduce toxic fumes. At the same time, the decomposition products of BiOCl and other non-combustible gases can dilute oxygen, thereby inhibiting combustion. The interaction of these mechanisms enhances the flame retardant and smoke-reducing effects of BiOCl@Cu-MOF. In terms of antibacterial properties: the Cu-MOF anchored on the sheet-like BiOCl can induce the generation of reactive oxygen species in bacteria and cause mechanical damage to the bacterial membrane through the nanostructure of Cu-MOF. At the same time, Cu-MOF releases a large amount of copper ions, thus exhibiting excellent antibacterial effects. Step S2: Mix ethanol, deionized water, 28wt% ammonia solution, and BiOCl@Cu-MOF, stir, then add dopamine hydrochloride solution, stir and react for 6-8 hours, purify, and obtain polydopamine modified BiOCl@Cu-MOF; wherein, the ratio of ethanol, deionized water, 28wt% ammonia solution, BiOCl@Cu-MOF, and dopamine hydrochloride solution is (32-64)g:(45-90)g:(0.4-0.8)mL:(3-5)g:(15-25)mL; At 23-25℃, polydopamine-modified BiOCl@Cu-MOF was added to N,N-dimethylformamide and sonicated. Then epichlorohydrin and tetrabutylammonium bromide were added, followed by the dropwise addition of a mixed NaOH solution. After the addition was complete, the mixture was stirred for 7-9 hours and purified to obtain the composite modified BiOCl@Cu-MOF. The mass ratio of the polydopamine-modified BiOCl@Cu-MOF, N,N-dimethylformamide, epichlorohydrin, tetrabutylammonium bromide, and the mixed NaOH solution was (3-5):(100-150):(40-50):(0.4-0.6):(72.7-90.9). The mixed NaOH solution was obtained by mixing sodium hydroxide, tetrabutylammonium bromide, and deionized water in a mass ratio of 21.8:0.9:50. In the above process, BiOCl@Cu-MOF is modified with polydopamine to obtain polydopamine-modified BiOCl@Cu-MOF. The introduction of organic functional groups such as phenolic hydroxyl groups on the surface of BiOCl@Cu-MOF can improve the dispersibility of BiOCl@Cu-MOF in the organic matrix. Furthermore, the introduction of polydopamine endows polydopamine-modified BiOCl@Cu-MOF with better antibacterial and flame retardant properties, and also improves its UV resistance. In addition, epoxy groups are introduced into polydopamine-modified BiOCl@Cu-MOF through the substitution reaction between chlorine in epichlorohydrin and phenolic hydroxyl groups in polydopamine-modified BiOCl@Cu-MOF.

[0012] Furthermore, the BiOCl nanosheets in step S1 are prepared by the following method: Bismuth nitrate pentahydrate and ethylene glycol were mixed at a mass ratio of (4.85-9.7):(22.26-44.52) under the combined action of magnetic stirring and ultrasonic treatment to obtain solution A; NaCl and ethylene glycol were mixed at a mass ratio of (0.58-1.16):(22.26-44.52) to obtain solution B; under stirring, solution B was added dropwise to solution A, and the pH was adjusted to 5-7 to obtain solution C; solution C was subjected to isothermal crystallization treatment at 135-145℃ for 2.5-3.5h, cooled to ambient temperature, and purified to obtain BiOCl nanosheets; the thickness of the BiOCl nanosheets was 20-30nm.

[0013] Further, in step S1, the metal salt mixture is obtained by mixing copper nitrate trihydrate, ethanol, and BiOCl nanosheets in a mass ratio of (5-10):(60-120):(2.5-5); the ligand mixture is obtained by mixing trimesic acid, ethanol, and deionized water in a mass ratio of (2.9-5.8):(18-36):(10-20).

[0014] In the above process, BiOCl nanosheets were prepared by solvothermal method using bismuth nitrate pentahydrate and NaCl as raw materials. The BiOCl nanosheets have a two-dimensional layered structure and have good mechanical properties, thermal stability and flame retardant and smoke suppression effects.

[0015] The antibacterial aqueous polyacrylate emulsion was prepared using the method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses potassium persulfate as an initiator, methyl methacrylate, n-butyl acrylate, and methacrylic acid as polymerizing monomers, and a multifunctional modifier as a functional monomer to prepare an aqueous polyacrylate emulsion via emulsion polymerization. The multifunctional modifier is obtained by grafting a modified multifunctional spirocyclic compound onto a carboxymethyl chitosan branch chain. Carboxymethyl chitosan possesses excellent water solubility, antibacterial properties, and film-forming ability. The modified multifunctional spirocyclic compound, due to the presence of spirocyclic rings, triazole groups, Schiff base bonds, and flame-retardant nitrogen and phosphorus elements in its structure, exhibits a synergistic effect with carboxymethyl chitosan. Furthermore, this invention introduces the multifunctional modifier into the polyacrylate polymer chain in the form of a functional monomer, avoiding the migration problem of additives such as flame retardants and antibacterial agents in traditional polyacrylate emulsions, thus endowing the aqueous polyacrylate emulsion with excellent thermal stability, mechanical properties, and long-lasting antibacterial and flame-retardant properties.

[0017] This invention provides an antibacterial aqueous polyacrylate emulsion by adding a composite modified BiOCl@Cu-MOF to an aqueous polyacrylate emulsion. The composite modified BiOCl@Cu-MOF is obtained by modifying BiOCl@Cu-MOF with polydopamine and epichlorohydrin. BiOCl@Cu-MOF can effectively improve the mechanical properties and thermal stability of the aqueous polyacrylate emulsion, and the BiOCl nanosheets and Cu-MOF in BiOCl@Cu-MOF have synergistic flame retardant and antibacterial effects. Furthermore, the modification of BiOCl@Cu-MOF with polydopamine and epichlorohydrin not only enhances its antibacterial and flame retardant properties, but also enables it to form chemical bonds and physical interactions with the polyacrylate matrix, promoting the uniform dispersion of BiOCl@Cu-MOF in the polyacrylate matrix, thereby improving the overall performance of the antibacterial aqueous polyacrylate emulsion. Attached Figure Description

[0018] Figure 1 This is a comparison chart of the antibacterial rate tests of the antibacterial polyacrylate aqueous emulsions prepared in Examples 2-4 and Comparative Examples 3-6 of the present invention. Figure 2 This is a comparison chart of the LOI test results of the antibacterial polyacrylate aqueous emulsions prepared in Examples 2-4 and Comparative Examples 3-6 of the present invention. Figure 3 This is a comparison chart of the tensile strength tests of the antibacterial polyacrylate aqueous emulsions prepared in Examples 2-4 and Comparative Examples 3-6 of the present invention. Figure 4 This is a schematic diagram illustrating the synthesis of the phosphorus-containing spirocyclic compound of the present invention; Figure 5 This is a schematic diagram illustrating the synthesis of the nitrogen- and phosphorus-containing spirocyclic compounds of the present invention; Figure 6 This is a schematic diagram illustrating the synthesis of the multifunctional spirocyclic compound of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Example 1 This embodiment discloses a method for preparing composite modified BiOCl@Cu-MOF, including the following steps: Step S1: Under the combined action of magnetic stirring and ultrasonic treatment, 7.28g of bismuth nitrate pentahydrate was dissolved in 33.39g of ethylene glycol to obtain solution A; 0.87g of NaCl was dissolved in 33.39g of ethylene glycol to obtain solution B; under stirring, solution B was added dropwise to solution A, and the pH was adjusted to 6 with 1mol / L sodium hydroxide aqueous solution to obtain solution C; solution C was subjected to isothermal crystallization treatment at 140℃ for 3h, cooled to ambient temperature, centrifuged, and the obtained solid product was subjected to alternating ultrasonic dispersion and washing with deionized water and ethanol for 3 cycles, and then dried at 80℃ for 12h to obtain BiOCl nanosheets; 7.5 g of copper nitrate trihydrate was dissolved in 90 g of ethanol, and then 3.8 g of BiOCl nanosheets were added. The mixture was stirred for 30 min to obtain a metal salt mixture. 4.4 g of trimesic acid, 27 g of ethanol, and 15 g of deionized water were mixed and stirred until dissolved to obtain a ligand mixture. Under stirring, the ligand mixture was added to the above metal salt mixture at a rate of 1.5 mL / min. The mixture was stirred for 30 min, heated to 140 °C and maintained for 25 h, cooled to ambient temperature, centrifuged, and the resulting solid product was washed three times with ethanol and dried at 80 °C for 12 h to obtain BiOCl@Cu-MOF. Step S2: Mix 48g ethanol, 67.5g deionized water, 0.6mL 28wt% ammonia solution, and 4g BiOCl@Cu-MOF, stir at 24℃ for 30min, then add 20mL of 0.05g / mL dopamine hydrochloride solution, stir and react for 7h. After the reaction is complete, filter, wash the obtained solid product three times with ethanol, and dry at 70℃ for 12h to obtain polydopamine modified BiOCl@Cu-MOF; At 24℃, 4g of polydopamine-modified BiOCl@Cu-MOF was added to 125g of N,N-dimethylformamide and sonicated for 30min. Then, 45g of epichlorohydrin and 0.5g of tetrabutylammonium bromide were added, followed by the dropwise addition of 81.8g of a mixed NaOH solution at a rate of 2.5mL / min. After the addition was complete, the mixture was stirred for 8h. After the reaction was completed, the mixture was centrifuged, and the resulting solid product was washed three times with ethanol and dried at 60℃ for 14h to obtain the composite modified BiOCl@Cu-MOF. The NaOH mixed solution was prepared by mixing sodium hydroxide, tetrabutylammonium bromide, and deionized water in a mass ratio of 21.8:0.9:50.

[0021] Example 2 This embodiment discloses a method for preparing an antibacterial aqueous polyacrylate emulsion, comprising the following steps: Step 1: Mix 12g pentaerythritol and 105.2g phosphorus oxychloride and stir at 75℃ for 70min. Then raise the temperature to 104℃ and maintain it for 13h. At the same time, keep the reaction mixture boiling until no more hydrogen chloride gas is produced. After the reaction is completed, wash the precipitate with anhydrous diethyl ether and chloroform and dry it under vacuum at 58℃ to obtain a phosphorus-containing spirocyclic compound. In a nitrogen atmosphere, 7.4 g of a phosphorus-containing spirocyclic compound was added to 120 g of N,N-dimethylformamide and stirred. Then, 4.9 g of 3,5-diamino-1,2,4-triazole was added, and the mixture was heated to 108 °C and reacted for 4.5 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the nitrogen-containing phosphorus-containing spirocyclic compound. Step 2: In a nitrogen atmosphere, 8.4g of nitrogen- and phosphorus-containing spirocyclic compound was added to 120g of N,N-dimethylformamide and stirred. Then, 3.8g of 4-hydroxynonenal was added, and the mixture was heated to 60°C and reacted for 10h. After the reaction was completed, the solvent and remaining reactants were removed by rotary evaporation to obtain the multifunctional spirocyclic compound. 3.5g of the multifunctional spirocyclic compound was added to 120g of N,N-dimethylformamide and stirred. Then, 1.7g of hexamethylene diisocyanate and 0.03g of dibutyltin dilaurate were added. The mixture was heated to 75℃ and reacted for 9h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified multifunctional spirocyclic compound. 16g of carboxymethyl chitosan was added to 300g of ethanol and stirred for 30min. Then 0.5g of the modified multifunctional spirocyclic compound was added. The mixture was heated to 70℃ under a nitrogen atmosphere and stirred for 12h. After the reaction was completed, the solvent was evaporated to obtain the multifunctional modifier. Step 3: Mix 27g methyl methacrylate, 25g n-butyl acrylate, and 1g methacrylic acid to obtain a mixed monomer; mix 8g of multifunctional modifier with 80g deionized water and stir at 35℃ for 40min to obtain a multifunctional modifier mixture; under a nitrogen atmosphere, mix 40g deionized water, 0.5g sodium dodecyl sulfate, and 1g alkylphenol polyoxyethylene ether OP-10, stir at 100r / min, and heat to 70℃. Add 0.2g potassium persulfate, and simultaneously add 10% by mass of the above mixed monomer and 10% by mass of the above multifunctional modifier mixture, controlling the dropping time to 10min. After the dropping is complete, continue the reaction for 30min; then, simultaneously add the remaining mixed monomer, multifunctional modifier mixture, and 25g... Add 0.5wt% potassium persulfate aqueous solution, control the dropping time to 2.0h. After the dropping is completed, raise the temperature to 75℃ and continue to keep the temperature for 2h. After the reaction is completed, lower the product temperature to the ambient temperature, filter and discharge to obtain polyacrylate aqueous emulsion. Add 5g of the composite modified BiOCl@Cu-MOF prepared in Example 1 to 50g of aqueous polyacrylate emulsion, and stir at 70℃ for 2h to obtain antibacterial aqueous polyacrylate emulsion.

[0022] Example 3 This embodiment discloses a method for preparing an antibacterial aqueous polyacrylate emulsion, comprising the following steps: Step 1: Mix 20g pentaerythritol and 131.6g phosphorus oxychloride, stir at 85℃ for 50min, then raise the temperature to 106℃ and maintain it for 11h. At the same time, keep the reaction mixture boiling until no more hydrogen chloride gas is produced. After the reaction is completed, wash the precipitate with anhydrous diethyl ether and chloroform, and then dry it under vacuum at 58℃ to obtain a phosphorus-containing spirocyclic compound. In a nitrogen atmosphere, 14.8 g of a phosphorus-containing spirocyclic compound was added to 150 g of N,N-dimethylformamide and stirred. Then, 9.9 g of 3,5-diamino-1,2,4-triazole was added, and the mixture was heated to 112 °C and reacted for 3.5 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the nitrogen-containing phosphorus-containing spirocyclic compound. Step 2: In a nitrogen atmosphere, 16.8g of nitrogen- and phosphorus-containing spirocyclic compound was added to 150g of N,N-dimethylformamide and stirred. Then, 8.8g of 4-hydroxynonenal was added, and the mixture was heated to 80℃ and reacted for 8 hours. After the reaction was completed, the solvent and the remaining reactants were removed by rotary evaporation to obtain the multifunctional spirocyclic compound. 7g of the multifunctional spirocyclic compound was added to 150g of N,N-dimethylformamide and stirred. Then, 3.4g of hexamethylene diisocyanate and 0.05g of dibutyltin dilaurate were added. The mixture was heated to 85℃ and reacted for 7h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified multifunctional spirocyclic compound. 24g of carboxymethyl chitosan was added to 500g of ethanol and stirred for 40min. Then, 0.9g of the modified multifunctional spirocyclic compound was added. The mixture was heated to 80℃ under a nitrogen atmosphere and stirred for 8h. After the reaction was completed, the solvent was evaporated to obtain the multifunctional modifier. Step 3: Mix 54g methyl methacrylate, 45g n-butyl acrylate, and 2g methacrylic acid to obtain a mixed monomer; mix 14g of multifunctional modifier with 100g deionized water and stir at 45℃ for 20min to obtain a multifunctional modifier mixture; under a nitrogen atmosphere, mix 80g deionized water, 1g sodium dodecyl sulfate, and 2g alkylphenol polyoxyethylene ether OP-10, stir at 200r / min, and heat to 80℃. Add 0.3g potassium persulfate, and simultaneously add 10% by mass of the above mixed monomer and 10% by mass of the above multifunctional modifier mixture, controlling the adding time to 20min. After the addition is complete, continue the reaction for 20min; then, simultaneously add the remaining mixed monomer, multifunctional modifier mixture, and 50g... Add 0.5wt% potassium persulfate aqueous solution, control the dropping time to 3h. After the dropping is completed, raise the temperature to 85℃ and continue to keep the temperature for 1h. After the reaction is completed, lower the product temperature to the ambient temperature, filter and discharge to obtain polyacrylate aqueous emulsion. 12g of the composite modified BiOCl@Cu-MOF prepared in Example 1 was added to 60g of aqueous polyacrylate emulsion, and the mixture was stirred at 80°C for 1 hour to obtain an antibacterial aqueous polyacrylate emulsion.

[0023] Example 4 This embodiment discloses a method for preparing an antibacterial aqueous polyacrylate emulsion, comprising the following steps: Step 1: Mix 16g pentaerythritol and 118.4g phosphorus oxychloride and stir at 80℃ for 60min. Then raise the temperature to 105℃ and maintain it for 12h. At the same time, keep the reaction mixture boiling until no more hydrogen chloride gas is produced. After the reaction is completed, wash the precipitate with anhydrous diethyl ether and chloroform and dry it under vacuum at 58℃ to obtain a phosphorus-containing spirocyclic compound. In a nitrogen atmosphere, 11.1 g of a phosphorus-containing spirocyclic compound was added to 135 g of N,N-dimethylformamide and stirred. Then, 7.4 g of 3,5-diamino-1,2,4-triazole was added, and the mixture was heated to 110 °C and reacted for 4 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the nitrogen-containing phosphorus-containing spirocyclic compound. Step 2: In a nitrogen atmosphere, 12.6g of nitrogen- and phosphorus-containing spirocyclic compound was added to 135g of N,N-dimethylformamide and stirred. Then, 6.3g of 4-hydroxynonenal was added, and the mixture was heated to 70°C and reacted for 9 hours. After the reaction was completed, the solvent and remaining reactants were removed by rotary evaporation to obtain the multifunctional spirocyclic compound. 5.3 g of the multifunctional spirocyclic compound was added to 135 g of N,N-dimethylformamide and stirred. Then, 2.6 g of hexamethylene diisocyanate and 0.04 g of dibutyltin dilaurate were added. The mixture was heated to 80 °C and reacted for 8 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain the modified multifunctional spirocyclic compound. 20g of carboxymethyl chitosan was added to 400g of ethanol and stirred for 35min. Then 0.7g of the modified multifunctional spirocyclic compound was added. The mixture was heated to 75℃ under a nitrogen atmosphere and stirred for 10h. After the reaction was completed, the solvent was evaporated to obtain the multifunctional modifier. Step 3: Mix 40.5g methyl methacrylate, 35g n-butyl acrylate, and 1.5g methacrylic acid to obtain a mixed monomer; mix 11g of multifunctional modifier with 90g deionized water and stir at 40℃ for 30min to obtain a multifunctional modifier mixture; under a nitrogen atmosphere, mix 60g deionized water, 0.8g sodium dodecyl sulfate, and 1.5g alkylphenol polyoxyethylene ether OP-10, stir at 150r / min, and heat to 75℃. Add 0.3g potassium persulfate, and simultaneously add 10% by mass of the above mixed monomer and 10% by mass of the above multifunctional modifier mixture, controlling the adding time to 15min. After the addition is complete, continue the reaction for 25min; then, simultaneously add the remaining mixed monomer, multifunctional modifier mixture, and 37.5g... Add 0.5wt% potassium persulfate aqueous solution, control the dropping time to 2.5h. After the dropping is completed, raise the temperature to 80℃ and continue to keep the temperature for 1.5h. After the reaction is completed, lower the product temperature to the ambient temperature, filter and discharge to obtain polyacrylate aqueous emulsion. 8.5g of the composite modified BiOCl@Cu-MOF prepared in Example 1 was added to 55g of aqueous polyacrylate emulsion, and the mixture was stirred at 75°C for 1.5h to obtain an antibacterial aqueous polyacrylate emulsion.

[0024] Comparative Example 1 This comparative example discloses a method for preparing composite modified Cu-MOF, including the following steps: Step S1: Dissolve 7.5g of copper nitrate trihydrate in 90g of ethanol and stir for 30min to obtain a metal salt mixture; mix 4.4g of trimesic acid, 27g of ethanol and 15g of deionized water and stir until dissolved to obtain a ligand mixture; add the ligand mixture to the above metal salt mixture at a rate of 1.5mL / min while stirring, stir for 30min, heat to 140℃ and maintain for 25h, cool to ambient temperature, centrifuge, wash the obtained solid product three times with ethanol, and dry at 80℃ for 12h to obtain Cu-MOF; Step S2: Mix 48g ethanol, 67.5g deionized water, 0.6mL 28wt% ammonia solution, and 4g Cu-MOF, stir at 24℃ for 30min, then add 20mL of 0.05g / mL dopamine hydrochloride solution, stir and react for 7h. After the reaction is complete, filter, wash the obtained solid product three times with ethanol, and dry at 70℃ for 12h to obtain polydopamine modified Cu-MOF; At 24℃, 4g of polydopamine-modified Cu-MOF was added to 125g of N,N-dimethylformamide and sonicated for 30min. Then, 45g of epichlorohydrin and 0.5g of tetrabutylammonium bromide were added, followed by the dropwise addition of 81.8g of a mixed NaOH solution at a rate of 2.5mL / min. After the addition was complete, the mixture was stirred for 8h. After the reaction was completed, the mixture was centrifuged, and the resulting solid product was washed three times with ethanol and dried at 60℃ for 14h to obtain the composite modified Cu-MOF. The NaOH mixed solution was prepared by mixing sodium hydroxide, tetrabutylammonium bromide, and deionized water in a mass ratio of 21.8:0.9:50.

[0025] Comparative Example 2 This comparative example discloses a method for preparing composite modified BiOCl, including the following steps: Step S1: Under the combined action of magnetic stirring and ultrasonic treatment, 7.28g of bismuth nitrate pentahydrate was dissolved in 33.39g of ethylene glycol to obtain solution A; 0.87g of NaCl was dissolved in 33.39g of ethylene glycol to obtain solution B; under stirring, solution B was added dropwise to solution A, and the pH was adjusted to 6 with 1mol / L sodium hydroxide aqueous solution to obtain solution C; solution C was subjected to isothermal crystallization treatment at 140℃ for 3h, cooled to ambient temperature, centrifuged, and the obtained solid product was subjected to alternating ultrasonic dispersion and washing with deionized water and ethanol for 3 cycles, and then dried at 80℃ for 12h to obtain BiOCl nanosheets; Step S2: Mix 48g ethanol, 67.5g deionized water, 0.6mL 28wt% ammonia solution, and 4g BiOCl nanosheets, stir at 24℃ for 30min, then add 20mL of 0.05g / mL dopamine hydrochloride aqueous solution, stir and react for 7h. After the reaction is complete, filter, wash the obtained solid product three times with ethanol, and dry at 70℃ for 12h to obtain polydopamine modified BiOCl nanosheets. At 24℃, 4g of polydopamine-modified BiOCl nanosheets were added to 125g of N,N-dimethylformamide and sonicated for 30min. Then, 45g of epichlorohydrin and 0.5g of tetrabutylammonium bromide were added, followed by the addition of 81.8g of a mixed NaOH solution at a rate of 2.5mL / min. After the addition was complete, the mixture was stirred for 8h. After the reaction was completed, the mixture was centrifuged, and the resulting solid product was washed three times with ethanol and dried at 60℃ for 14h to obtain composite modified BiOCl nanosheets. The NaOH mixed solution was prepared by mixing sodium hydroxide, tetrabutylammonium bromide, and deionized water in a mass ratio of 21.8:0.9:50.

[0026] Comparative Example 3 Compared with Example 4, Comparative Example 3 used the composite modified Cu-MOF prepared in Comparative Example 1 instead of the composite modified BiOCl@Cu-MOF prepared in Example 1 in the process of preparing the antibacterial polyacrylate aqueous emulsion, while other conditions remained unchanged.

[0027] Comparative Example 4 Compared with Example 4, Comparative Example 4 used the composite modified BiOCl nanosheets prepared in Comparative Example 2 instead of the composite modified BiOCl@Cu-MOF prepared in Example 1 in the process of preparing the antibacterial polyacrylate aqueous emulsion, while keeping all other conditions unchanged.

[0028] Comparative Example 5 Compared with Example 4, Comparative Example 5 used BiOCl@Cu-MOF prepared in Example 1 instead of the composite modified BiOCl@Cu-MOF prepared in Example 1 in the process of preparing the aqueous polyacrylate emulsion, while keeping other conditions unchanged.

[0029] Comparative Example 6 This comparative example discloses a method for preparing an antibacterial polyacrylate aqueous emulsion, including the following steps: Step 1: Add 7.8g of 4-hydroxynonenal to 135g of N,N-dimethylformamide, stir, then add 8.4g of hexamethylene diisocyanate and 0.04g of dibutyltin dilaurate, heat to 80℃, react for 8h, after the reaction is completed, remove the solvent by rotary evaporation to obtain the intermediate product; Add 20g of carboxymethyl chitosan to 400g of ethanol and stir for 35min. Then add 0.7g of intermediate product and heat to 75℃ in a nitrogen atmosphere. Stir and react for 10h. After the reaction is complete, evaporate the solvent to obtain modified carboxymethyl chitosan. Step 2: Mix 40.5g methyl methacrylate, 35g n-butyl acrylate, and 1.5g methacrylic acid to obtain a mixed monomer. Mix 11g modified carboxymethyl chitosan with 90g deionized water and stir at 40℃ for 30min to obtain a modified carboxymethyl chitosan mixture. Under a nitrogen atmosphere, mix 60g deionized water, 0.8g sodium dodecyl sulfate, and 1.5g alkylphenol polyoxyethylene ether OP-10, stir at 150r / min, and heat to 75℃. Add 0.3g potassium persulfate, and simultaneously add 10% by mass of the above mixed monomer and 10% by mass of the above modified carboxymethyl chitosan mixture, controlling the adding time to 15min. After the addition is complete, continue the reaction for 25min. Then, simultaneously add the remaining mixed monomer, modified carboxymethyl chitosan mixture, and 37.5g... Add 0.5wt% potassium persulfate aqueous solution, control the dropping time to 2.5h. After the dropping is completed, raise the temperature to 80℃ and continue to keep the temperature for 1.5h. After the reaction is completed, lower the product temperature to the ambient temperature, filter and discharge to obtain polyacrylate aqueous emulsion. 8.5g of the composite modified BiOCl@Cu-MOF prepared in Example 1 was added to 50-60g of aqueous polyacrylate emulsion, and the mixture was stirred at 75°C for 1.5h to obtain an antibacterial aqueous polyacrylate emulsion.

[0030] In the above examples and comparative examples, the carboxymethyl chitosan, with a molecular weight of 240 kDa, a degree of deacetylation of 90.9%, and a degree of substitution of 90%, was obtained from Shanghai Maclean Biochemical Technology Co., Ltd.

[0031] Experimental Example I. Antibacterial performance test: The antibacterial polyacrylate aqueous emulsions of Examples 2-4 and Comparative Examples 3-6 were respectively coated on the surface of strip samples. The antibacterial effect of each group of samples against Escherichia coli and Staphylococcus aureus was tested according to GB / T21866-2008 "Determination of antibacterial properties and antibacterial effects of antibacterial coatings (films)".

[0032] II. Flame retardant and mechanical property tests: The antibacterial polyacrylate aqueous emulsions of Examples 2-4 and Comparative Examples 3-6 were poured into custom-made polytetrafluoroethylene molds and dried at 40°C to constant weight to obtain antibacterial polyacrylate film samples of each group. The performance of each group of antibacterial polyacrylate film samples was then tested. Flame retardant properties LOI test: Cut the sample into 130mm×10mm×4mm pieces and test it 10 times on a critical oxygen index meter and take the average value. 2. Mechanical properties The sample was cut into dumbbell shapes of 4mm×20mm and tested 5 times on a universal tensile testing machine with a tensile rate of 20mm / min. The average value was taken and the test temperature was 25℃. The test results are shown in Table 1: Table 1

[0033] As shown in Table 1, the antibacterial polyacrylate aqueous emulsions prepared in Examples 2-4 of this invention have excellent mechanical properties, antibacterial properties, and flame retardant properties. A comparison between Comparative Examples 3-5 and Example 4 shows that BiOCl nanosheets and Cu-MOF have synergistic flame retardant and antibacterial effects. Modification of BiOCl@Cu-MOF with polydopamine and epichlorohydrin not only enhances its antibacterial and flame retardant properties but also forms chemical bonds and physical interactions with the polyacrylate matrix, promoting uniform dispersion of BiOCl@Cu-MOF in the polyacrylate matrix, thereby improving the overall performance of the antibacterial polyacrylate aqueous emulsion. A comparison between Comparative Example 6 and Example 4 shows that the modified multifunctional spirocyclic compound, due to the presence of spirocyclic rings, triazole groups, Schiff base bonds, and flame-retardant nitrogen and phosphorus elements in its structure, can synergistically interact with carboxymethyl chitosan, endowing the polyacrylate aqueous emulsion with excellent mechanical properties, antibacterial properties, and flame retardant properties.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial aqueous polyacrylate emulsion, characterized in that, Includes the following steps: Step 1: Pentaerythritol reacts with phosphorus oxychloride to give a phosphorus-containing spirocyclic compound; the phosphorus-containing spirocyclic compound reacts with 3,5-diamino-1,2,4-triazole to give a nitrogen-containing phosphorus-containing spirocyclic compound. Step 2: The nitrogen- and phosphorus-containing spirocyclic compound reacts with 4-hydroxynonenal to obtain a multifunctional spirocyclic compound; A multifunctional spirocyclic compound was modified with hexamethylene diisocyanate to obtain a modified multifunctional spirocyclic compound; the modified multifunctional spirocyclic compound was combined with carboxymethyl chitosan to obtain a multifunctional modifier; Step 3: Methyl methacrylate, n-butyl acrylate, methacrylic acid and multifunctional modifier are polymerized to obtain an aqueous polyacrylate emulsion; the composite modified BiOCl@Cu-MOF is added to the aqueous polyacrylate emulsion and reacted to obtain an antibacterial aqueous polyacrylate emulsion.

2. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 1, characterized in that, In step one, the preparation method of the nitrogen-phosphorus spirocyclic compound is as follows: Pentaerythritol and phosphorus oxychloride were mixed in a mass ratio of (12-20):(105.2-131.6), and stirred at 75-85℃ for 50-70 min. The temperature was then raised to 104-106℃ and maintained for 11-13 h. The mixture was purified to obtain a phosphorus-containing spirocyclic compound. In a nitrogen atmosphere, the phosphorus-containing spirocyclic compound was added to N,N-dimethylformamide and stirred. Then, 3,5-diamino-1,2,4-triazole was added, and the mixture was heated to 108-112℃ and reacted for 3.5-4.5 h. After purification, the nitrogen-containing phosphorus-containing spirocyclic compound was obtained. The mass ratio of the phosphorus-containing spirocyclic compound, N,N-dimethylformamide, and 3,5-diamino-1,2,4-triazole was (7.4-14.8):(120-150):(4.9-9.9).

3. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 1, characterized in that, Preparation method of the modified multifunctional spirocyclic compound: In a nitrogen atmosphere, a nitrogen- and phosphorus-containing spirocyclic compound was added to N,N-dimethylformamide, stirred, and then 4-hydroxynonenal was added. The mixture was heated to 60-80℃ and reacted for 8-10 hours. After purification, a multifunctional spirocyclic compound was obtained. The mass ratio of the nitrogen- and phosphorus-containing spirocyclic compound, N,N-dimethylformamide, and 4-hydroxynonenal was (8.4-16.8):(120-150):(3.8-8.8). The multifunctional spirocyclic compound was added to N,N-dimethylformamide and stirred. Then, hexamethylene diisocyanate and dibutyltin dilaurate were added, heated to 75-85℃, and reacted for 7-9 hours. After purification, the modified multifunctional spirocyclic compound was obtained. The mass ratio of the multifunctional spirocyclic compound, N,N-dimethylformamide, hexamethylene diisocyanate, and dibutyltin dilaurate was (3.5-7):(120-150):(1.7-3.4):(0.03-0.05).

4. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 1, characterized in that, In step two, the preparation method of the multifunctional modifier is as follows: Carboxymethyl chitosan was added to ethanol and stirred. Then, the modified multifunctional spirocyclic compound was added. The mixture was heated to 70-80℃ under a nitrogen atmosphere and stirred for 8-12 hours. After purification, the multifunctional modifier was obtained. The mass ratio of carboxymethyl chitosan, ethanol and modified multifunctional spirocyclic compound was (16-24):(300-500):(0.5-0.9).

5. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 1, characterized in that, In step three, the preparation method of the aqueous polyacrylate emulsion is as follows: Methyl methacrylate, n-butyl acrylate, and methacrylic acid were mixed to obtain a mixed monomer. A multifunctional modifier was mixed with deionized water and stirred at 35-45°C for 20-40 minutes to obtain a multifunctional modifier mixture. Under a nitrogen atmosphere, deionized water, sodium dodecyl sulfate, and alkylphenol polyoxyethylene ether OP-10 were mixed, stirred, and heated to 70-80°C. Potassium persulfate was added, and simultaneously, 10% by mass of the above mixed monomer and 10% by mass of the above multifunctional modifier mixture were added dropwise, controlling the dropwise addition time to 10-20 minutes. After the addition was complete... Continue the reaction for 20-30 minutes; then, simultaneously add the remaining mixed monomers, multifunctional modifier mixture and 0.5 wt% potassium persulfate aqueous solution, controlling the addition time to 2-3 hours. After the addition is complete, raise the temperature to 75-85℃ and continue the reaction for 1-2 hours. After the reaction is complete, lower the product temperature to ambient temperature, filter and discharge to obtain an aqueous polyacrylate emulsion; wherein, the mass ratio of methyl methacrylate, n-butyl acrylate, methacrylic acid and multifunctional modifier is (27-54):(25-45):(1-2):(8-14).

6. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 1, characterized in that, In step three, the antibacterial aqueous polyacrylate emulsion is prepared by the following method: the composite modified BiOCl@Cu-MOF and the aqueous polyacrylate emulsion are mixed at a mass ratio of (5-12):(50-60), and stirred at 70-80℃ for 1-2 hours to obtain the antibacterial aqueous polyacrylate emulsion.

7. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 1, characterized in that, In step three, the preparation method of the composite modified BiOCl@Cu-MOF includes the following steps: Step S1: Under stirring, the ligand mixture is added to the metal salt mixture at a rate of 1-2 mL / min, stirred, heated to 136-144℃ and maintained for 20-30 h, purified, and BiOCl@Cu-MOF is obtained. Step S2: Mix ethanol, deionized water, 28wt% ammonia solution, and BiOCl@Cu-MOF, stir, then add dopamine hydrochloride solution, stir and react for 6-8 hours, purify, and obtain polydopamine modified BiOCl@Cu-MOF; wherein, the ratio of ethanol, deionized water, 28wt% ammonia solution, BiOCl@Cu-MOF, and dopamine hydrochloride solution is (32-64)g:(45-90)g:(0.4-0.8)mL:(3-5)g:(15-25)mL; At 23-25℃, polydopamine-modified BiOCl@Cu-MOF was added to N,N-dimethylformamide and sonicated. Then epichlorohydrin and tetrabutylammonium bromide were added, followed by the dropwise addition of a mixed NaOH solution. After the addition was complete, the mixture was stirred for 7-9 hours and purified to obtain the composite modified BiOCl@Cu-MOF. The mass ratio of the polydopamine-modified BiOCl@Cu-MOF, N,N-dimethylformamide, epichlorohydrin, tetrabutylammonium bromide, and the mixed NaOH solution was (3-5):(100-150):(40-50):(0.4-0.6):(72.7-90.9). The mixed NaOH solution was obtained by mixing sodium hydroxide, tetrabutylammonium bromide, and deionized water in a mass ratio of 21.8:0.9:

50.

8. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 7, characterized in that, The BiOCl nanosheets in step S1 are prepared by the following method: Bismuth nitrate pentahydrate and ethylene glycol were mixed at a mass ratio of (4.85-9.7):(22.26-44.52) under the combined action of magnetic stirring and ultrasonic treatment to obtain solution A; NaCl and ethylene glycol were mixed at a mass ratio of (0.58-1.16):(22.26-44.52) to obtain solution B; under stirring, solution B was added to solution A, and the pH was adjusted to 5-7 to obtain solution C; solution C was subjected to isothermal crystallization treatment at 135-145℃ for 2.5-3.5h, cooled to ambient temperature, and purified to obtain BiOCl nanosheets; the thickness of the BiOCl nanosheets was 20-30nm.

9. The method for preparing the antibacterial polyacrylate aqueous emulsion according to claim 7, characterized in that, In step S1, the metal salt mixture is obtained by mixing copper nitrate trihydrate, ethanol, and BiOCl nanosheets in a mass ratio of (5-10):(60-120):(2.5-5); the ligand mixture is obtained by mixing trimesic acid, ethanol, and deionized water in a mass ratio of (2.9-5.8):(18-36):(10-20).

10. An antibacterial aqueous polyacrylate emulsion prepared by the method for preparing an antibacterial aqueous polyacrylate emulsion as described in any one of claims 1-9.

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