Packaging material with antibacterial activity and preparation method thereof

Abstract

The invention belongs to the technical field of packaging materials, and particularly relates to a packaging material with antibacterial activity and a preparation method thereof. The packaging material with antibacterial activity is prepared from the following raw materials in parts by weight: 60 to 70 parts of polylactic acid, 10 to 20 parts of poly (butylene succinate), 3 to 5 parts of modified montmorillonite, 0.5 to 1 part of a bacteriostatic agent, 0.5 to 1 part of a lubricating agent, 1 to 3 parts of a compatilizer and 1 to 1.5 parts of functional filler. The packaging material provided by the invention has excellent barrier property, antibacterial property and mechanical property, stable fixation and synergistic interaction of functional components such as the modified montmorillonite and the functional filler are realized, and the packaging material has important significance in promoting technical progress of the packaging industry and meeting the requirements of the market on high-performance packaging materials.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of packaging materials, and particularly relates to a packaging material with antibacterial property and a preparation method thereof. BACKGROUND

[0002] With the increasing demand of consumers for food safety, quality maintenance and shelf life extension, the development of new packaging materials with excellent mechanical properties, high barrier properties and high-efficiency antibacterial function has become a research hotspot. Traditional plastic packaging materials, such as polyethylene (PE) and polypropylene (PP), have good processing performance and certain barrier properties, but their non-biodegradable characteristics have brought serious environmental pollution problems. Therefore, biodegradable green packaging materials, especially polylactic acid (PLA), have attracted widespread attention due to their advantages of being derived from renewable resources and being capable of being degraded by composting.

[0003] However, polylactic acid itself has some inherent defects, which limit its direct application in high-end packaging field: first, PLA material has high brittleness and poor impact resistance, which is prone to breakage during transportation or use; second, its barrier properties to water vapor and oxygen are general, which is not conducive to the long-term preservation of humidity or oxygen-sensitive products; third, PLA itself does not have antibacterial activity and cannot effectively inhibit the growth and reproduction of microorganisms on the surface of food, which may lead to food spoilage and safety risks.

[0004] In order to improve the performance of PLA, researchers often use the method of adding nano fillers for composite modification. However, there are obvious problems in directly introducing nano fillers into the PLA matrix: first, the surface energy of nano particles (such as montmorillonite and carbon nanotubes) is high, which is easy to agglomerate in the hydrophobic PLA matrix, resulting in stress concentration and damaging the mechanical properties of the material; second, the unmodified nano fillers have poor interfacial compatibility with PLA, weak interface bonding, which affects stress transfer and performance improvement effect; third, they do not have or only have weak antibacterial function, which cannot meet the demand of packaging materials for active antibacterial function.

[0005] Therefore, it is of great significance to develop a new type of packaging material with excellent barrier properties, antibacterial properties and mechanical properties, and to realize the stable fixation and synergistic effect of functional components, in order to promote the technological progress of the packaging industry and meet the demand of the market for high-performance packaging materials. SUMMARY

[0006] The first object of the present application is to provide a packaging material with antibacterial property. The material matches polylactic acid, modified montmorillonite, functional filler and antibacterial agent, etc. to simultaneously improve the toughness, strength and barrier property of the material, and endow it with high-efficiency and stable antibacterial function, which fully meets the comprehensive requirements of modern packaging materials for performance, safety and environmental protection.

[0007] The second object of the present application is to provide a preparation method of the packaging material with bacteriostasis.

[0008] In order to achieve the above object, the technical scheme adopted by the present application is: The packaging material with bacteriostasis comprises the following raw materials by weight: polylactic acid 60-70 parts, polybutylene succinate 10-20 parts, modified montmorillonite 3-5 parts, bacteriostatic agent 0.5-1 part, lubricant 0.5-1 part, compatible agent 1-3 parts, and functional filler 1-1.5 parts.

[0009] Further, the preparation process of the modified montmorillonite is as follows: (1) Take the montmorillonite and add it to deionized water, then add the surfactant and zinc chloride, heat the reaction, and then filter, wash, dry, and calcine to obtain the pretreated montmorillonite; (2) Add the pretreated montmorillonite of step (1) to an ethanol aqueous solution, then add the silane coupling agent, and heat the reaction to obtain the silane coupling agent modified montmorillonite; (3) Take the silane coupling agent modified montmorillonite of step (2) and add it to deionized water, then add the fritillary cyclic peptide C, and heat the reaction to obtain the modified montmorillonite.

[0010] Further, the preparation process of the functional filler is as follows: take the carbon nanotube and immerse it in a nitric acid solution at 40-50°C for 1-2h, then add the treated carbon nanotube to an ethanol aqueous solution, and then add triethylenetetramine, EDC, and NHS, and react at 40-50°C for 3-5h to obtain the functional filler.

[0011] Further, in step (1), the mass ratio of the montmorillonite, surfactant, zinc chloride, and deionized water is 10:(0.18-0.3):(0.8-1):(80-100), and the surfactant is cetyltrimethylammonium bromide; the temperature of the heating reaction is 70-80°C, and the time is 1-3h; the temperature of the calcination is 500-550°C, and the time is 1-3h.

[0012] Further, in step (2), the mass ratio of the pretreated montmorillonite, silane coupling agent, and ethanol aqueous solution is 1:(0.15-0.2):(40-50); the ethanol aqueous solution is prepared by mixing ethanol and water at a volume ratio of 4:1; the silane coupling agent is KH560; the temperature of the heating reaction is 70-80°C, and the time is 3-5h.

[0013] Further, the mass ratio of the silane coupling agent modified montmorillonite, the cowslip cyclic peptide C and the deionized water in step (3) is 10:(30-40):100; the heating reaction temperature is 80-90 DEG C, and the heating reaction time is 3-5h.

[0014] Further, the mass ratio of the carbon nanotube and the nitric acid solution is (5-7):90; the concentration of the nitric acid solution is 70wt%; the mass ratio of the treated carbon nanotube, the triethylenetetramine, the EDC and the NHS is 10:(0.5-1):(0.2-0.5):(0.2-0.5); the dosage ratio of the treated carbon nanotube and the aqueous solution of ethanol is 1g:8-10mL; the aqueous solution of ethanol is prepared by mixing ethanol and water according to a volume ratio of 4:1.

[0015] Further, the bacteriostatic agent is chitosan; the compatible agent is a mixture of maleic anhydride grafted polypropylene and ethylene-methyl acrylate copolymer according to a mass ratio of (2-4):(1.5-2.5); and the lubricant is calcium stearate.

[0016] A preparation method of the packaging material with bacteriostasis, comprising the following steps: uniformly mixing polylactic acid, polybutylene succinate, modified montmorillonite, bacteriostatic agent, lubricant, compatible agent and functional filler according to a proportion, and melt blending at 185-195 DEG C for 5-8min.

[0017] The beneficial technical effects of the present application are as follows: 1. The present application provides a packaging material with bacteriostasis, wherein the modified montmorillonite is treated by a surfactant cetyltrimethylammonium bromide, which can increase the interlayer spacing of the montmorillonite; zinc ions enter the interior of the montmorillonite through ion exchange and are converted into stable zinc oxide after calcination. The abundant void structure of the montmorillonite can adsorb water vapor and reduce the environmental humidity; the zinc oxide can react with water to generate hydroxide, thereby improving the water vapor barrier property of the packaging material and inhibiting the growth of bacteria. The surface of the montmorillonite modified by the silane coupling agent is introduced with epoxy groups, and the amino groups in the cowslip cyclic peptide C can undergo ring-opening reaction with the epoxy groups to form covalent bonds or can form coordination bonds with the zinc ions, so that the cowslip cyclic peptide C is stably grafted on the surface of the montmorillonite, thereby avoiding migration and precipitation. The covalently crosslinked interface structure can further hinder the penetration of oxygen and water molecules. The flexible chain segments of the cowslip cyclic peptide C can not only improve the brittleness of polylactic acid and enhance the impact resistance of the packaging material, but also form hydrogen bonds with the molecular chains of polylactic acid, so that the modified montmorillonite is uniformly dispersed in the packaging material and the mechanical properties are not reduced due to agglomeration.

[0018] 2. This invention provides a packaging material with antibacterial properties, wherein the introduced functional filler is carbon nanotubes with a large number of carboxyl groups on their surface after nitric acid treatment, which are then covalently grafted with triethylenetetramine molecules to form stable amide bonds. Introducing a large number of amino groups onto the surface of the carbon nanotubes can, on the one hand, improve the interfacial compatibility between the carbon nanotubes and the polylactic acid matrix, thereby increasing the material's strength and impact resistance; on the other hand, the multi-amino structure of triethylenetetramine can disrupt microbial cell membranes, further improving the antibacterial properties of the packaging material. Attached Figure Description

[0019] Figure 1 This is a SEM image of the modified montmorillonite obtained in Example 1 of the present invention; Figure 2 This is a SEM image of the functional filler obtained in Example 1 of the present invention. Detailed Implementation

[0020] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0021] Example 1 A packaging material with antibacterial properties comprises the following raw materials in parts by weight: Polylactic acid (weight average molecular weight 1.8 × 10⁻⁶) 5 65 parts of polybutylene succinate (weight average molecular weight 1.0 × 10⁻⁶ g / mol) and 65 parts of polybutylene succinate (weight average molecular weight 1.0 × 10⁻⁶ g / mol). 5 15 parts (g / mol) of modified montmorillonite, 4 parts of antibacterial agent (chitosan), 0.8 parts of lubricant (calcium stearate), 2 parts of compatibilizer (maleic anhydride grafted polypropylene and ethylene-methyl acrylate copolymer mixed at a mass ratio of 3:2), and 1.2 parts of functional filler.

[0022] The preparation process of modified montmorillonite is as follows: (1) Add montmorillonite to deionized water, then add surfactant (hexadecyltrimethylammonium bromide) and zinc chloride, and control the mass ratio of montmorillonite, surfactant, zinc chloride and deionized water to be 10:0.25:0.9:90. Then heat the reaction at 75°C for 2 hours. After the reaction is completed, filter, wash and dry the reaction solution, and then calcine it at 530°C for 2 hours to obtain pretreated montmorillonite. (2) Add the pretreated montmorillonite from step (1) to an ethanol aqueous solution (anhydrous ethanol and water are prepared in a volume ratio of 4:1), and then add silane coupling agent (KH560). The mass ratio of the pretreated montmorillonite, silane coupling agent and ethanol aqueous solution is 1:0.18:45. Heat the reaction at 75°C for 4 hours. Filter, wash and dry the reaction solution to obtain silane coupling agent modified montmorillonite. (3) Take the silane coupling agent modified montmorillonite from step (2) and add it to deionized water, then add Vaccaria segetalis cyclic peptide C, wherein the mass ratio of silane coupling agent modified montmorillonite, Vaccaria segetalis cyclic peptide C, and deionized water is 10:35:100; then heat the reaction at 85℃ for 4 hours. After the reaction is completed, filter, wash, and dry the reaction solution to obtain modified montmorillonite. The SEM image of the modified montmorillonite is shown below. Figure 1 As shown.

[0023] The preparation process of the functional filler is as follows: Carbon nanotubes were immersed in a 70wt% nitric acid solution at 45℃ for 1.5h, with a mass ratio of carbon nanotubes to nitric acid solution of 6:90. Then, the treated carbon nanotubes were added to an aqueous ethanol solution (anhydrous ethanol and water were prepared at a volume ratio of 4:1), with a volume ratio of 1g:9mL. Triethylenetetramine, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), and N-hydroxysuccinimide (NHS) were added, with a mass ratio of 10:0.8:0.4:0.4. The pH was adjusted to 6.5, and the reaction was carried out at 45℃ for 4h. After the reaction was completed, the reaction solution was filtered, washed, and dried to obtain the functional filler. The SEM image of the functional filler is shown below. Figure 2 As shown.

[0024] A method for preparing a packaging material with antibacterial properties includes the following steps: according to the formula, polylactic acid, polybutylene succinate, modified montmorillonite, antibacterial agent, lubricant, compatibilizer and functional filler are mixed evenly and melt-blended at 190°C for 6 minutes to obtain the final product.

[0025] Example 2 A packaging material with antibacterial properties comprises the following raw materials in parts by weight: Polylactic acid (weight average molecular weight 1.8 × 10⁻⁶) 5 60 parts of polybutylene succinate (weight average molecular weight 1.0 × 10⁻⁶ g / mol) and 60 parts of polybutylene succinate (weight average molecular weight 1.0 × 10⁻⁶ g / mol). 510 parts (g / mol) of modified montmorillonite, 4 parts of antibacterial agent (chitosan), 0.8 parts of lubricant (calcium stearate), 1 part of compatibilizer (maleic anhydride grafted polypropylene and ethylene-methyl acrylate copolymer mixed at a mass ratio of 2:1.5), and 1 part of functional filler.

[0026] The preparation process of modified montmorillonite is as follows: (1) Add montmorillonite to deionized water, then add surfactant (hexadecyltrimethylammonium bromide) and zinc chloride, and control the mass ratio of montmorillonite, surfactant, zinc chloride and deionized water to be 10:0.18:0.8:80. Then heat the reaction at 70°C for 3 hours. After the reaction is completed, filter, wash and dry the reaction solution, and then calcine it at 500°C for 3 hours to obtain pretreated montmorillonite. (2) Add the pretreated montmorillonite from step (1) to an ethanol aqueous solution (anhydrous ethanol and water are prepared in a volume ratio of 4:1), and then add silane coupling agent (KH560), wherein the mass ratio of the pretreated montmorillonite, silane coupling agent and ethanol aqueous solution is 1:0.15:40; heat the reaction at 70°C for 5 hours, filter, wash and dry the reaction solution to obtain silane coupling agent modified montmorillonite; (3) Take the silane coupling agent modified montmorillonite from step (2) and add it to deionized water, then add Wangbuliu cyclic peptide C, wherein the mass ratio of silane coupling agent modified montmorillonite, Wangbuliu cyclic peptide C and deionized water is 10:30:100; then heat the reaction at 80℃ for 5h. After the reaction is completed, filter, wash and dry the reaction solution to obtain modified montmorillonite.

[0027] The preparation process of the functional filler is as follows: Carbon nanotubes are immersed in a 70wt% nitric acid solution at 40℃ for 2 hours, with a mass ratio of carbon nanotubes to nitric acid solution of 5:90; then the treated carbon nanotubes are added to an aqueous ethanol solution (anhydrous ethanol and water are prepared at a volume ratio of 4:1), with a volume ratio of 1g:8mL for the treated carbon nanotubes to the aqueous ethanol solution; then triethylenetetramine, EDC, and NHS are added, with a mass ratio of 10:0.5:0.2:0.2 for the treated carbon nanotubes; the pH is adjusted to 6.5, and then the reaction is carried out at 40℃ for 5 hours. After the reaction is completed, the reaction solution is filtered, washed, and dried to obtain the functional filler.

[0028] A method for preparing a packaging material with antibacterial properties includes the following steps: according to the formula, polylactic acid, polybutylene succinate, modified montmorillonite, antibacterial agent, lubricant, compatibilizer and functional filler are mixed evenly, and melt-blended at 185°C for 8 minutes to obtain the final product.

[0029] Example 3 A packaging material with antibacterial properties comprises the following raw materials in parts by weight: Polylactic acid (weight average molecular weight 1.8 × 10⁻⁶) 5 70 parts of polybutylene succinate (weight average molecular weight 1.0 × 10⁻⁶ g / mol) and 70 parts of polybutylene succinate (weight average molecular weight 1.0 × 10⁻⁶ g / mol). 5 20 parts (g / mol) of modified montmorillonite, 5 parts of antibacterial agent (chitosan), 1 part of lubricant (calcium stearate), 3 parts of compatibilizer (maleic anhydride grafted polypropylene and ethylene-methyl acrylate copolymer mixed at a mass ratio of 4:2.5), and 1.5 parts of functional filler.

[0030] The preparation process of modified montmorillonite is as follows: (1) Add montmorillonite to deionized water, then add surfactant (hexadecyltrimethylammonium bromide) and zinc chloride, and control the mass ratio of montmorillonite, surfactant, zinc chloride and deionized water to be 10:0.3:1:100. Then heat the reaction at 80℃ for 1h. After the reaction is completed, filter, wash and dry the reaction solution, and then calcine it at 550℃ for 1h to obtain pretreated montmorillonite. (2) Add the pretreated montmorillonite from step (1) to an ethanol aqueous solution (anhydrous ethanol and water are prepared in a volume ratio of 4:1), and then add silane coupling agent (KH560). The mass ratio of the pretreated montmorillonite, silane coupling agent and ethanol aqueous solution is 1:0.2:50. Heat the reaction at 80°C for 3 hours. Filter, wash and dry the reaction solution to obtain silane coupling agent modified montmorillonite. (3) Take the silane coupling agent modified montmorillonite from step (2) and add it to deionized water, then add Vaccaria segetalis cyclic peptide C, wherein the mass ratio of silane coupling agent modified montmorillonite, Vaccaria segetalis cyclic peptide C and deionized water is 10:40:100; then heat the reaction at 90℃ for 3 hours. After the reaction is completed, filter, wash and dry the reaction solution to obtain modified montmorillonite.

[0031] The preparation process of the functional filler is as follows: Carbon nanotubes are immersed in a 70wt% nitric acid solution at 50℃ for 1 hour, with a mass ratio of carbon nanotubes to nitric acid solution of 7:90; then the treated carbon nanotubes are added to an aqueous ethanol solution (anhydrous ethanol and water are prepared at a volume ratio of 4:1), with a volume ratio of 1g:10mL; then triethylenetetramine, EDC, and NHS are added, with a mass ratio of 10:1:0.5:0.5; the pH is adjusted to 6.5, and the reaction is carried out at 50℃ for 3 hours. After the reaction is completed, the reaction solution is filtered, washed, and dried to obtain the functional filler.

[0032] A method for preparing a packaging material with antibacterial properties includes the following steps: according to the formula, polylactic acid, polybutylene succinate, modified montmorillonite, antibacterial agent, lubricant, compatibilizer and functional filler are mixed evenly, and melt-blended at 195°C for 5 minutes to obtain the product.

[0033] Comparative Example 1 Compared with Example 1, the modified montmorillonite in Comparative Example 1 was replaced with montmorillonite; all other aspects remained the same as in Example 1.

[0034] Comparative Example 2 Compared with Example 1, Comparative Example 2 replaces Vaccaria segetalis cyclic peptide C with Vaccaria segetalis cyclic peptide A in step (3) of the modified montmorillonite preparation process; all other steps remain the same as in Example 1.

[0035] Comparative Example 3 Compared with Example 1, Comparative Example 3 replaces the functional filler with carbon nanotubes; everything else remains the same as Example 1.

[0036] Experimental Example 1 1. The tensile strength and elongation at break of the materials obtained in Examples 1-3 and Comparative Examples 1-3 were tested according to GB / T1040.1-2018 "Determination of Tensile Properties of Plastics". The tensile rate was set to 50 mm / min. Each group of samples was tested in 5 parallel experiments. The average value was taken as the final experimental result, as shown in Table 1.

[0037] 2. The notched impact strength of the cantilever beam was tested according to the GB / 1843-2008 standard, as shown in Table 1.

[0038] Table 1 Mechanical performance test results As shown in Table 1, the tensile strength, elongation at break, and impact strength of the products obtained in Examples 1-3 of this invention are all superior to those in Comparative Examples 1-3. In Comparative Example 1, compared to Example 1, replacing modified montmorillonite with montmorillonite significantly reduced the mechanical properties, indicating that modified montmorillonite can improve the mechanical properties of the packaging material. This is because the flexible segments of the Wangbuliuxing cyclic peptide C can improve the brittleness of polylactic acid, enhance the impact resistance of the packaging material, and form hydrogen bonds with polylactic acid molecules. In Comparative Example 3, replacing the functional filler with carbon nanotubes resulted in inferior mechanical properties compared to Example 1. This is because the functional filler introduces a large number of amino groups on its surface, which improves the interfacial compatibility between carbon nanotubes and the polylactic acid matrix, thereby enhancing the mechanical properties and impact resistance of the packaging material and endowing it with excellent mechanical properties.

[0039] 3. Antibacterial rate: The antibacterial properties of the materials obtained in Examples 1-3 and Comparative Examples 1-3 were tested according to the test method of GB / T31402-2023. The results are shown in Table 2.

[0040] Table 2 Results of Antibacterial Rate Test As shown in Table 2, the products obtained in Examples 1-3 of this invention exhibit better antibacterial rates against two common pathogenic bacteria (Staphylococcus aureus and Escherichia coli) than those in Comparative Examples 1-3, demonstrating highly efficient and broad-spectrum antibacterial capabilities. The decrease in the antibacterial rate in Comparative Example 1 compared to Example 1 indicates that the zinc ions / zinc oxides in the modified montmorillonite can react with moisture in the environment, slowly releasing zinc ions, interfering with bacterial enzyme systems and disrupting their metabolism, thus inhibiting bacterial growth. Vaccaria segetalis cyclic peptide C is firmly grafted onto the surface of montmorillonite through covalent and coordination bonds, preventing the migration and loss of small-molecule antibacterial agents and ensuring the durability of the antibacterial effect. Comparative Example 2, which replaced Vaccaria segetalis cyclic peptide C with Vaccaria segetalis cyclic peptide A, showed a higher antibacterial rate, but still differed from the examples. Comparative Example 3 replaced the functional filler with carbon nanotubes; compared with Example 1, its antibacterial rate against both bacteria was significantly reduced, indicating that the functional filler can improve the antibacterial performance of the material compared with carbon nanotubes. This may be because the polyamino structure of triethylenetetramine in the functional filler can destroy the microbial cell membrane and further improve the antibacterial properties of the packaging material.

[0041] 4. Water vapor barrier properties: The water vapor barrier properties of the packaging materials obtained in Examples 1-3 and Comparative Examples 1-3 were determined according to the evaporation method in GB / T1037-2021. The experimental results are shown in Table 3.

[0042] Table 3 Results of water vapor transmission rate test Water vapor transmission rate (WVTR) is an important indicator for evaluating the ability of packaging to preserve freshness and prevent moisture. The lower the value, the better the barrier properties.

[0043] As shown in Table 3, the water vapor permeability of Examples 1-3 is significantly lower than that of Comparative Examples 1-3, indicating that the packaging material of the present invention has excellent water vapor barrier properties. Comparative Example 1 has the worst barrier properties compared to Example 1, possibly because it contains a large number of defects or pores caused by poor compatibility, providing a rapid channel for water vapor. The barrier properties of Comparative Examples 2 and 3 are improved, but still far inferior to the examples, indicating that the modified montmorillonite sheets with increased interlayer spacing and uniform dispersion, as well as carbon nanotubes, form a tortuous and complex path in the PLA matrix, greatly extending the diffusion channel of water vapor molecules; furthermore, the rich porosity structure of montmorillonite can physically adsorb water molecules; and at the same time, zinc oxide can react with the permeated water molecules, further consuming and blocking water vapor.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A packaging material with antibacterial properties, characterized in that, The raw materials include the following parts by weight: 60-70 parts of polylactic acid, 10-20 parts of polybutylene succinate, 3-5 parts of modified montmorillonite, 0.5-1 part of antibacterial agent, 0.5-1 part of lubricant, 1-3 parts of compatibilizer, and 1-1.5 parts of functional filler.

2. The antibacterial packaging material according to claim 1, characterized in that, The preparation process of the modified montmorillonite is as follows: (1) Add montmorillonite to deionized water, then add surfactant and zinc chloride, heat and react, then filter, wash, dry and calcinate to obtain pretreated montmorillonite; (2) Add the montmorillonite pretreated in step (1) to an ethanol aqueous solution, then add a silane coupling agent, and heat the reaction to obtain silane coupling agent modified montmorillonite; (3) Take the silane coupling agent modified montmorillonite from step (2) and add it to deionized water, then add Wangbuliuxing cyclic peptide C, heat the reaction to obtain modified montmorillonite.

3. The antibacterial packaging material according to claim 1, characterized in that, The preparation process of the functional filler is as follows: carbon nanotubes are added to nitric acid solution and impregnated at 40-50℃ for 1-2 hours. Then, the treated carbon nanotubes are added to an aqueous solution of ethanol, followed by the addition of triethylenetetramine, EDC and NHS. The mixture is reacted at 40-50℃ for 3-5 hours to obtain the functional filler.

4. The antibacterial packaging material according to claim 2, characterized in that, In step (1), the mass ratio of montmorillonite, surfactant, zinc chloride, and deionized water is 10:(0.18-0.3):(0.8-1):(80-100), and the surfactant is hexadecyltrimethylammonium bromide; the heating reaction temperature is 70-80℃ and the time is 1-3h; the calcination temperature is 500-550℃ and the time is 1-3h.

5. The antibacterial packaging material according to claim 2, characterized in that, In step (2), the mass ratio of the pretreated montmorillonite, silane coupling agent, and ethanol aqueous solution is 1:(0.15-0.2):(40-50); the ethanol aqueous solution is prepared by mixing ethanol and water in a volume ratio of 4:1; the silane coupling agent is KH560; the heating reaction temperature is 70-80℃ and the time is 3-5h.

6. The antibacterial packaging material according to claim 2, characterized in that, In step (3), the mass ratio of the silane coupling agent-modified montmorillonite, Vaccaria segetalis cyclic peptide C, and deionized water is 10:(30-40):100; the heating reaction temperature is 80-90℃ and the time is 3-5h.

7. The antibacterial packaging material according to claim 3, characterized in that, The mass ratio of carbon nanotubes to nitric acid solution is (5-7):90; the concentration of nitric acid solution is 70wt%; the mass ratio of treated carbon nanotubes, triethylenetetramine, EDC and NHS is 10:(0.5-1):(0.2-0.5):(0.2-0.5); the volume ratio of treated carbon nanotubes to aqueous ethanol solution is 1g:8-10mL; the aqueous ethanol solution is prepared by mixing ethanol and water at a volume ratio of 4:

1.

8. The antibacterial packaging material according to claim 1, characterized in that, The antibacterial agent is chitosan; the compatibilizer is obtained by mixing maleic anhydride-grafted polypropylene and ethylene-methyl acrylate copolymer in a mass ratio of (2-4):(1.5-2.5); the lubricant is calcium stearate.

9. A method for preparing a packaging material with antibacterial properties according to any one of claims 1-8, characterized in that, The process includes the following steps: According to the specified ratio, polylactic acid, polybutylene succinate, modified montmorillonite, antibacterial agent, lubricant, compatibilizer, and functional filler are mixed evenly and melt-blended at 185-195℃ for 5-8 minutes to obtain the final product.

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