Antibacterial waterproof packaging material and preparation method thereof

Abstract

The invention relates to the technical field of high-performance polypropylene, and discloses an antibacterial waterproof packaging material and a preparation method thereof.The preparation method of the antibacterial waterproof packaging material comprises the following steps that two-dimensional silylene is prepared and modified, and surface modified silylene is obtained; the preparation method comprises the following steps: preparing ZIF-9, and modifying the ZIF-9 by using polydopamine to obtain ZIF-9 (at) PDA; the ZIF-9 (at) PDA is combined with the surface modified silylene, and a composite micro-nano material is obtained; carrying out modification treatment on the composite micro-nano material to obtain a modified composite micro-nano material; and mixing the modified polypropylene, the modified composite micro-nano material and an auxiliary agent, extruding and granulating to obtain the antibacterial waterproof packaging material. The antibacterial waterproof packaging material disclosed by the invention not only has excellent antibacterial waterproof performance, but also has good mechanical property and anti-aging performance, and can be used for a long time under an outdoor high-temperature condition.

Description

Technical Field

[0001] This invention relates to the field of high-performance polypropylene technology, and in particular to an antibacterial and waterproof packaging material and its preparation method. Background Technology

[0002] Currently, corrugated cardboard boxes are widely used in commodity circulation. However, in recent years, corrugated cardboard boxes have been facing hygiene and environmental problems that must be studied and solved: (1) the problem of "paper dust" generated by corrugated cardboard boxes; (2) they become damp as soon as they come into contact with water, turning the boxes into a breeding ground for bacteria. The above problems have become serious hygiene issues. In order to solve the problem of "paper dust" generated by corrugated cardboard boxes, plastic packaging materials can be used to replace corrugated cardboard boxes. Polypropylene is one of the five major general-purpose plastics. It has the characteristics of low price, easy processing and molding, and excellent comprehensive product performance. However, polypropylene itself has poor antibacterial properties, and the water contact angle of ordinary polypropylene surface is about 100°. It is a general hydrophobic material, and its waterproof performance needs to be improved. In addition, PP material is affected by a variety of complex factors such as light and heat, which can easily cause molecular chain breakage, resulting in degradation of PP material, which cannot meet the needs of long-term outdoor use.

[0003] To address the above issues, Chinese patent application CN107603022A discloses an antibacterial polypropylene film, Chinese patent application CN105885215A discloses a method for preparing an anti-UV polypropylene material, and Chinese patent application CN114395192A discloses a method for preparing a lycopodium powder modified starch-polypropylene waterproof composite material. However, none of the above patent applications can simultaneously improve the waterproof performance, antibacterial performance, and anti-aging performance of polypropylene materials. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing an antibacterial and waterproof packaging material, comprising the following steps: Step 1: Prepare two-dimensional siloxanes using calcium silicide as raw material; modify the two-dimensional siloxanes with 3-chloropropyltrimethoxysilane to obtain surface-modified siloxanes; Step 2: Prepare ZIF-9 and modify it with polydopamine to obtain ZIF-9@PDA; combine ZIF-9@PDA with surface-modified siloxane to obtain composite micro / nano materials; Step 3: The composite micro / nano materials are modified with propylene 3-isocyanate to obtain functionalized composite micro / nano materials; the functionalized composite micro / nano materials are reacted with quaternary ammonium salt compounds, dodecafluoroheptyl methacrylate, and glycidyl methacrylate to obtain modified composite micro / nano materials. Step 4: Mix modified polypropylene, modified composite micro / nano materials, glycerol, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and paraffin in proportion to obtain a mixture; extrude and granulate the mixture to obtain an antibacterial and waterproof packaging material.

[0005] Preferably, in step one, the method for preparing the surface-modified siloxane is as follows: At 23-27℃, calcium silicide was mixed with 37wt% hydrochloric acid at a ratio of (5-6)g:(500-800)mL, and stirred continuously in an ice-water bath for 6-7 days. After centrifugation, washing, and drying, two-dimensional siloxane was obtained. Two-dimensional siloxane, 3-chloropropyltrimethoxysilane, and toluene were mixed in a mass ratio of (3-4):(3-6):(50-80), and stirred at 85-95℃ for 8-12 h. After purification, surface-modified siloxane was obtained. In the above process, two-dimensional siloxanes are prepared using calcium silicide as raw material. Two-dimensional siloxanes have a layered structure with a diameter concentrated in 1-5 micrometers. The layered structure of two-dimensional siloxanes can improve the barrier properties of organic polymers, enhance the mechanical properties and thermal stability of organic polymers, and its surface has abundant hydroxyl groups, which can combine with 3-chloropropyltrimethoxysilane to convert the hydroxyl groups on its surface into chlorine, thereby reducing hydrophilicity.

[0006] Preferably, in step two, the preparation method of the ZIF-9@PDA is as follows: At 23-27℃, benzimidazole was added to ethanol and stirred. Then, 25wt% ammonia solution was added and stirred. Cobalt acetate was added and stirred for 150-200 min. After purification, ZIF-9 was obtained. The average particle size of ZIF-9 was 200-400 nm. The mass ratio of benzimidazole, ethanol, 25wt% ammonia solution and cobalt acetate was (2.4-4.8):(140-300):(1.2-2.4):(2.5-5). ZIF-9 was dispersed in Tris buffer at 23-27℃, sonicated, and then dopamine hydrochloride was added. After stirring at 600-700 r / min for 18-24 h, ZIF-9@PDA was obtained. The ratio of ZIF-9, Tris buffer, and dopamine hydrochloride was (1-1.2) g: 500 mL: (0.5-2) g. In the above process, ZIF-9 was prepared by cobalt ions and benzimidazole. ZIF-9 has a cubic morphology and an average particle size of 200-400 nm. As a MOF material, ZIF-9 has good thermal stability, antibacterial properties and UV resistance. Furthermore, ZIF-9 was modified by polydopamine, which was coated onto ZIF-9. Polydopamine has strong adhesion and UV and antibacterial effects. Therefore, compared with ZIF-9, ZIF-9@PDA has better antibacterial and UV resistance. In addition, the phenolic hydroxyl groups of polydopamine in ZIF-9@PDA can be chemically bonded to the surface-modified siloxane.

[0007] Preferably, in step two, the method for preparing the composite micro / nano material is as follows: In a nitrogen atmosphere, surface-modified siloxane, potassium carbonate, and tetrahydrofuran were mixed at a mass ratio of (2-4):(12.9-25.8):(60-100) to obtain mixture A; ZIF-9@PDA and tetrahydrofuran were mixed at a mass ratio of (1-3):(30-50) and sonicated to obtain mixture B; mixture B was added to mixture A at 0-10℃, heated to reflux, and stirred at 600-700 r / min for 20-30 h, and purified to obtain composite micro / nano materials; In the above process, ZIF-9@PDA is deposited on the surface-modified siloxane through the adhesion of polydopamine and the chemical reaction between phenolic hydroxyl groups and chlorine, which further prolongs the water erosion path and forms a superhydrophobic micro-nano structure on the surface-modified siloxane. Therefore, the composite micro-nano material of the present invention has excellent water resistance and waterproof performance. At the same time, ZIF-9, PDA and modified siloxane work synergistically to show better antibacterial and anti-ultraviolet effects.

[0008] Preferably, in step three, the preparation method of the modified composite micro / nano material is as follows: The composite micro / nanomaterial was added to toluene and stirred. Then, propylene 3-isocyanate and dibutyltin dilaurate were added, and the mixture was heated to 78-82℃ and reacted for 50-70 min. After purification, the functionalized composite micro / nanomaterial was obtained. The mass ratio of the composite micro / nanomaterial, toluene, propylene 3-isocyanate, and dibutyltin dilaurate was (2-4):(50-80):(0.8-1.8):(0.01-0.03). Functionalized composite micro / nanomaterials were added to N,N-dimethylformamide and sonicated. Quaternary ammonium salt compound, dodecafluoroheptyl methacrylate, and glycidyl methacrylate were added, stirred, and azobisisobutyronitrile was added. The mixture was heated to 75-80℃ and reacted for 12-16 h. After purification, modified composite micro / nanomaterials were obtained. The mass ratio of functionalized composite micro / nanomaterials, N,N-dimethylformamide, quaternary ammonium salt compound, dodecafluoroheptyl methacrylate, and glycidyl methacrylate was (2.5-3.5):(100-150):(1.2-1.6):(1.4-2):(0.5-0.7). In the above process, the phenolic hydroxyl groups in the composite micro / nanomaterial react with the isocyanate groups of propylene 3-isocyanate, introducing unsaturated carbon-carbon double bonds on the surface of the composite micro / nanomaterial. These unsaturated carbon-carbon double bonds cause the quaternary ammonium salt compound, dodecafluoroheptyl methacrylate, and glycidyl methacrylate to copolymerize on the surface of the composite micro / nanomaterial, introducing organic polymer chains. These organic polymer chains can crosslink with the organic chains of modified polypropylene, increasing the crosslinking density of the polypropylene system and improving the dispersibility of the composite micro / nanomaterial in the polypropylene system. Furthermore, among the organic polymer chains: the quaternary ammonium salt compound has antibacterial effects; dodecafluoroheptyl methacrylate introduces fluorine-containing chains, exhibiting excellent hydrophobic properties, and the high bond energy of the CF bond provides good thermal stability and resistance to UV damage; the epoxy groups introduced by glycidyl methacrylate can undergo ring-opening reactions with the carboxyl groups in the modified polypropylene, further improving the interfacial compatibility between the composite micro / nanomaterial and the modified polypropylene.

[0009] Furthermore, the method for preparing the quaternary ammonium salt compound is as follows: N-(3-dimethylaminopropyl)methacrylamide was added to dichloromethane, stirred, and heated to 38-42℃. Then, a 50wt% dichloromethane solution of benzyl chloride was added dropwise. The mixture was stirred and reacted at 38-42℃ for 22-26 hours. After purification, a quaternary ammonium salt compound was obtained. The mass ratio of N-(3-dimethylaminopropyl)methacrylamide, dichloromethane, and the 50wt% dichloromethane solution of benzyl chloride was (13.4-26.8):(32.5-65):(20-40). In the above process, N-(3-dimethylaminopropyl)methacrylamide undergoes a quaternization reaction with benzyl chloride to obtain a quaternary ammonium salt compound containing unsaturated carbon-carbon double bonds.

[0010] Preferably, in step four, the content of each component in the mixture, by weight, is as follows: 70-80 parts modified polypropylene, 10-20 parts modified composite micro / nano materials, 3-5 parts glycerol, 1-2 parts 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 1-3 parts paraffin. In the above process, modified polypropylene is used as the organic polymer matrix, and modified composite micro-nano materials are used as functional fillers to improve the thermal stability, mechanical properties, antibacterial properties, waterproof properties and UV resistance of the organic polypropylene matrix; glycerol is used as a plasticizer, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole is used as a light stabilizer, and paraffin is used as a lubricant.

[0011] Preferably, in step four, the extrusion conditions of the mixture are: extrusion temperature 220-230℃ and extrusion speed 200-500rpm.

[0012] Furthermore, in step four, the method for preparing the modified polypropylene includes the following steps: Step S1: In a nitrogen atmosphere, 5-hexene-1-amine and benzoyl peroxide are added to xylene and stirred. Then, polypropylene particles are added, the temperature is raised to 85-95℃ and the mixture is stirred for 5-7 hours. The mixture is then purged with nitrogen to obtain surface-modified polypropylene. The mass ratio of 5-hexene-1-amine, benzoyl peroxide, xylene, and polypropylene particles is (1-1.7):(0.06-0.08):(100-150):(20-30). Step S2: Under a nitrogen atmosphere, 3,4,9,10-perylenetetracarboxylic dianhydride, levodopa, and pyrazole are mixed and heated to 125-130℃ for 6-7 h. Then, ethanol is added, and the mixture is refluxed for 6-8 h and purified to obtain a diimine compound. The mass ratio of 3,4,9,10-perylenetetracarboxylic dianhydride, levodopa, pyrazole, and ethanol is (1-2):(1.5-2.5):(8-16):(80-160). Diimino compound was added to N,N-dimethylformamide and stirred. Then, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added and stirred for 1-2 hours. Then, surface-modified polypropylene was added and reacted at 115-125℃ for 20-30 hours. After purification, modified polypropylene was obtained. The mass ratio of diimino compound, N,N-dimethylformamide, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide and surface-modified polypropylene was (11.3-18.7):(300-400):(1.8-2.2):(7-8.4):(20-30). In the above process, under the initiation of benzoyl peroxide, 5-hexen-1-amine reacts with polypropylene, introducing amino-containing branches into the polypropylene; the anhydride of 3,4,9,10-perylenetetracarboxylic acid dianhydride reacts with the amino group of levodopa (without ring opening) to obtain a diimine compound. The diimine compound combines with the surface-modified polypropylene through an amidation reaction, introducing the diimine compound into the branches of the modified polypropylene. The diimine structure in the diimine compound has excellent mechanical properties, thermal stability, and hydrophobicity. Levodopa introduces a catechol structure into the diimine compound, endowing it with antibacterial and anti-UV aging properties. Furthermore, levodopa also introduces carboxyl groups into the diimine compound. The carboxyl groups can combine with the polymer chains on the surface of the modified composite micro / nanomaterial through hydrogen bonds and chemical bonds, improving the dispersibility of the modified composite micro / nanomaterial and increasing the crosslinking density of the polypropylene matrix.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The composite micro / nanomaterial of this invention combines ZIF-9@PDA with surface-modified siloxane through the adhesion of polydopamine and chemical bonds. The synergistic effect of ZIF-9, PDA, and modified siloxane effectively improves the mechanical properties, antibacterial properties, waterproof properties, and anti-aging properties of the antibacterial and waterproof packaging material. Furthermore, the introduction of organic polymer chains containing quaternary ammonium salt compounds, dodecyl fluoroheptyl methacrylate, and glycidyl methacrylate into the composite micro / nanomaterial increases the crosslinking density of the polypropylene system and improves the dispersibility of the composite micro / nanomaterial within the polypropylene system. The quaternary ammonium salt compounds in the organic polymer chains also exhibit antibacterial effects. The dodecyl fluoroheptyl methacrylate in the organic polymer chains introduces a fluorine-containing chain, exhibiting excellent hydrophobic properties. Simultaneously, the high bond energy of the CF bond provides excellent thermal stability and resistance to UV damage. The glycidyl methacrylate in the organic polymer chains introduces epoxy groups, which can undergo ring-opening reactions with the carboxyl groups in the modified polypropylene, further improving the interfacial compatibility between the composite micro / nanomaterial and the modified polypropylene. 2. This invention modifies polypropylene by using diimine compounds, introducing non-polar branches into the non-polar polypropylene chain. The presence of hydroxyl, carboxyl, and other groups in the branches allows the modified polypropylene to bond with the polymer chains on the surface of the modified composite micro / nano materials through hydrogen bonds and chemical bonds. Furthermore, the presence of diimine compounds in the branches improves the antibacterial, waterproof, and anti-aging properties of polypropylene. 3. This invention introduces functional branches into the polypropylene polymer chain, endowing the modified polypropylene with intrinsic antibacterial, waterproof, and anti-aging properties. Furthermore, it forms physical and chemical interactions between the modified polypropylene and the modified composite micro / nano materials, improving the dispersibility and anti-migration ability of the modified composite micro / nano materials. By synergistically combining the modified polypropylene and the modified composite micro / nano materials, the antibacterial and waterproof packaging material of this invention has durable antibacterial, waterproof, and anti-aging properties, thus extending its service life. 4. This invention discloses an antibacterial and waterproof packaging material based on polypropylene plastic, which can replace traditional corrugated cardboard box packaging materials and solve the problems of corrugated cardboard boxes being prone to producing "paper dust" and having poor waterproof and antibacterial properties. Furthermore, the antibacterial and waterproof packaging material of this invention also has excellent mechanical properties and long-lasting antibacterial, waterproof, and anti-aging properties, and can be used for a long time outdoors and under high temperature conditions. Attached Figure Description

[0014] Figure 1 This is a comparison chart of the antibacterial rates of Escherichia coli and Staphylococcus aureus (0 days and 3 months) of the antibacterial and waterproof packaging materials prepared in Examples 2-4 and Comparative Examples 1-5 of the present invention. Figure 2 This is a comparison chart of the water absorption rate tests of the antibacterial and waterproof packaging materials prepared in Examples 2-4 and Comparative Examples 1-5 of the present invention; Figure 3 This is a comparison chart of the tensile strength tests of the antibacterial and waterproof packaging materials prepared in Examples 2-4 and Comparative Examples 1-5 of the present invention; Figure 4 This is a comparison chart of the tensile strength retention rate (after thermo-oxidative aging and after UV aging) of the antibacterial and waterproof packaging materials prepared in Examples 2-4 and Comparative Examples 1-5 of the present invention. Detailed Implementation

[0015] 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.

[0016] Example 1 This embodiment discloses a method for preparing modified polypropylene, including the following steps: Step S1: In a nitrogen atmosphere, 1.4g of 5-hexene-1-amine and 0.07g of benzoyl peroxide were added to 125g of xylene and stirred for 30min. Then, 25g of polypropylene particles were added, the temperature was raised to 90℃ and stirred for 6h. After the reaction was completed, the mixture was purged with nitrogen, filtered, washed and dried to obtain surface-modified polypropylene. Step S2: Under a nitrogen atmosphere, 1.5 g of 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2 g of levodopa and 12 g of pyrazole were mixed and heated to 128 °C for 6.5 h. Then, 120 g of ethanol was added to the reaction system, and the mixture was refluxed for 7 h. After standing to precipitate, the mixture was filtered. The resulting solid product was washed four times with ethanol and then dried under vacuum at 70 °C to obtain a diimine compound. 15g of the diimine compound was added to 350g of N,N-dimethylformamide and stirred for 30min. Then, 2g of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and 7.7g of N-hydroxysuccinimide were added and stirred for 1.5h. Then, 25g of surface-modified polypropylene was added and reacted at 120℃ for 25h. After the reaction was completed, the mixture was filtered, and the resulting product was washed successively with N,N-dimethylformamide and ethanol and then dried to obtain modified polypropylene.

[0017] Example 2 This embodiment discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 23℃, add 5g of calcium silicide to 500mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 6 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 5 times at 8000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 40h to obtain two-dimensional siloxane. 3g of two-dimensional siloxane and 3g of 3-chloropropyltrimethoxysilane were added to 50g of toluene and stirred at 85℃ for 12h. After the reaction was completed, the mixture was filtered, and the filter residue was washed with toluene and ethanol and then dried under vacuum at 60℃ to obtain surface-modified siloxane. Step 2: At 23℃, add 2.4g benzimidazole to 140g ethanol and stir. Add 1.2g 25wt% ammonia solution and continue stirring. Then add 2.5g cobalt acetate and continue stirring for 150min. After the reaction is complete, centrifuge to collect the precipitate, wash it three times with ethanol, and dry it to obtain ZIF-9. At 23℃, 1g ZIF-9 was dispersed in 500mL of Tris buffer at pH 8 and sonicated for 40min. Then, 0.5g of dopamine hydrochloride was added and stirred at 600r / min for 18h. The precipitate was collected by centrifugation, washed three times with deionized water, and freeze-dried to obtain ZIF-9@PDA. In a nitrogen atmosphere, 2g of surface-modified siloxane and 12.9g of potassium carbonate were added to 60g of tetrahydrofuran and stirred in an ice-water bath for 1h to obtain mixture A; 1g of ZIF-9@PDA was added to 30g of tetrahydrofuran and sonicated for 20min to obtain mixture B; at 0℃, mixture B was added dropwise to mixture A at a rate of 1mL / min, heated to reflux and stirred at 600r / min for 20h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite micro / nano materials. Step 3: Add 13.4g of N-(3-dimethylaminopropyl)methacrylamide to 32.5g of dichloromethane, stir, heat to 38℃, and then add 20g of 50wt% benzyl chloride solution in dichloromethane at a rate of 1mL / min. After the addition is complete, stir the reaction at 38℃ for 22h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. 2g of composite micro / nano materials were added to 50g of toluene and stirred for 40min. Then, 0.8g of propylene 3-isocyanate and 0.01g of dibutyltin dilaurate were added and heated to 78℃ for 50min. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the functionalized composite micro / nano materials. 2.5g of functionalized composite micro / nanomaterials were added to 100g of N,N-dimethylformamide and sonicated for 30min. Then, 1.2g of quaternary ammonium salt compound, 1.4g of dodecafluoroheptyl methacrylate, and 0.5g of glycidyl methacrylate were added and stirred. Then, 0.03g of azobisisobutyronitrile was added and heated to 75℃ for 12h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified composite micro / nanomaterials. Step 4: By weight, 70 parts of modified polypropylene, 10 parts of modified composite micro / nano materials, 3 parts of glycerol, 1 part of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 1 part of paraffin are blended to obtain a mixture; the mixture is then extruded and granulated in a twin-screw extruder to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 220℃ and extrusion speed 200 rpm.

[0018] Example 3 This embodiment discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 27℃, add 6g of calcium silicide to 800mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 7 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 8 times at 12000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 50h to obtain two-dimensional siloxane. 4g of two-dimensional siloxane and 6g of 3-chloropropyltrimethoxysilane were added to 80g of toluene and stirred at 95℃ for 12h. After the reaction was completed, the mixture was filtered, and the filter residue was washed with toluene and ethanol and then dried under vacuum at 60℃ to obtain surface-modified siloxane. Step 2: At 27℃, add 4.8g benzimidazole to 300g ethanol and stir. Add 2.4g 25wt% ammonia solution and continue stirring. Then add 5g cobalt acetate and continue stirring for 200min. After the reaction is complete, centrifuge to collect the precipitate, wash it 5 times with ethanol, and dry it to obtain ZIF-9. At 27℃, 1.2g ZIF-9 was dispersed in 500mL Tris buffer at pH 8 and sonicated for 60min. Then, 2g dopamine hydrochloride was added and stirred at 700r / min for 24h. The precipitate was collected by centrifugation, washed 5 times with deionized water, and freeze-dried to obtain ZIF-9@PDA. In a nitrogen atmosphere, 4g of surface-modified siloxane and 25.8g of potassium carbonate were added to 100g of tetrahydrofuran and stirred in an ice-water bath for 2h to obtain mixture A; 3g of ZIF-9@PDA was added to 50g of tetrahydrofuran and sonicated for 40min to obtain mixture B; at 10℃, mixture B was added dropwise to mixture A at a rate of 2mL / min, heated to reflux and stirred at 700r / min for 30h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite micro / nano materials. Step 3: Add 26.8g of N-(3-dimethylaminopropyl)methacrylamide to 65g of dichloromethane, stir, heat to 42℃, and then add 40g of 50wt% benzyl chloride solution in dichloromethane at a rate of 2mL / min. After the addition is complete, stir the reaction at 42℃ for 26h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. 4g of composite micro / nano materials were added to 80g of toluene and stirred for 60min. Then 1.8g of propylene 3-isocyanate and 0.03g of dibutyltin dilaurate were added and heated to 82℃ for 70min. After the reaction was completed, the mixture was filtered, washed and dried to obtain the functionalized composite micro / nano materials. 3.5g of functionalized composite micro / nanomaterials were added to 150g of N,N-dimethylformamide and sonicated for 60min. Then, 1.6g of quaternary ammonium salt compound, 2g of dodecafluoroheptyl methacrylate, and 0.7g of glycidyl methacrylate were added and stirred. Then, 0.04g of azobisisobutyronitrile was added and heated to 80℃ for 16h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified composite micro / nanomaterials. Step 4: By weight, 80 parts of modified polypropylene, 20 parts of modified composite micro / nano materials, 5 parts of glycerol, 2 parts of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 3 parts of paraffin are blended to obtain a mixture; the mixture is then extruded and granulated in a twin-screw extruder to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 230℃ and extrusion speed 500 rpm.

[0019] Example 4 This embodiment discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 25℃, add 5.5g of calcium silicide to 650mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 6.5 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 7 times at 10000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 45h to obtain two-dimensional siloxane. 3.5g of two-dimensional siloxane and 4.5g of 3-chloropropyltrimethoxysilane were added to 65g of toluene and stirred at 90℃ for 10h. After the reaction was completed, the mixture was filtered, and the filter residue was washed with toluene and ethanol and then dried under vacuum at 60℃ to obtain surface-modified siloxane. Step 2: At 25℃, add 3.6g benzimidazole to 220g ethanol and stir. Add 1.8g 25wt% ammonia solution and continue stirring. Then add 3.8g cobalt acetate and continue stirring for 175min. After the reaction is complete, centrifuge to collect the precipitate, wash it 4 times with ethanol, and dry it to obtain ZIF-9. At 25℃, 1.1g ZIF-9 was dispersed in 500mL Tris buffer at pH 8 and sonicated for 50min. Then, 1.3g dopamine hydrochloride was added and stirred at 65r / min for 21h. The precipitate was collected by centrifugation, washed 4 times with deionized water, and freeze-dried to obtain ZIF-9@PDA. In a nitrogen atmosphere, 3g of surface-modified siloxane and 19.4g of potassium carbonate were added to 80g of tetrahydrofuran and stirred in an ice-water bath for 1.5h to obtain mixture A; 2g of ZIF-9@PDA was added to 40g of tetrahydrofuran and sonicated for 30min to obtain mixture B; at 5℃, mixture B was added dropwise to mixture A at a rate of 1.5mL / min, heated to reflux and stirred at 650r / min for 25h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite micro / nano materials. Step 3: Add 20.1g of N-(3-dimethylaminopropyl)methacrylamide to 48.8g of dichloromethane, stir, heat to 40℃, and then add 30g of 50wt% benzyl chloride solution in dichloromethane at a rate of 1.5mL / min. After the addition is complete, stir the reaction at 40℃ for 24h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. Add 3g of composite micro / nano materials to 65g of toluene and stir for 50min. Then add 1.3g of propylene 3-isocyanate and 0.02g of dibutyltin dilaurate. Heat to 80℃ and react for 60min. After the reaction is complete, filter, wash and dry to obtain functionalized composite micro / nano materials. 3g of functionalized composite micro / nanomaterials were added to 125g of N,N-dimethylformamide and sonicated for 45min. Then, 1.4g of quaternary ammonium salt compound, 1.7g of dodecafluoroheptyl methacrylate, and 0.6g of glycidyl methacrylate were added and stirred. Then, 0.04g of azobisisobutyronitrile was added and heated to 78℃ for 14h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified composite micro / nanomaterials. Step 4: By weight, mix 70-80 parts of modified polypropylene, 15 parts of modified composite micro / nano materials, 4 parts of glycerol, 1.5 parts of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2 parts of paraffin to obtain a mixture; put the mixture into a twin-screw extruder for extrusion and granulation to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 225℃ and extrusion speed 350rpm.

[0020] The modified polypropylene in Examples 2-4 above is the modified polypropylene prepared in Example 1.

[0021] Comparative Example 1 This comparative example discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 25℃, add 5.5g of calcium silicide to 650mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 6.5 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 7 times at 10000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 45h to obtain two-dimensional siloxane. 3.5g of two-dimensional siloxane and 4.5g of 3-chloropropyltrimethoxysilane were added to 65g of toluene and stirred at 90℃ for 10h. After the reaction was completed, the mixture was filtered, and the filter residue was washed with toluene and ethanol and then dried under vacuum at 60℃ to obtain surface-modified siloxane. Step 2: At 25℃, add 3.6g benzimidazole to 220g ethanol and stir. Add 1.8g 25wt% ammonia solution and continue stirring. Then add 3.8g cobalt acetate and continue stirring for 175min. After the reaction is complete, centrifuge to collect the precipitate, wash it 4 times with ethanol, and dry it to obtain ZIF-9. At 25℃, 1.1g ZIF-9 was dispersed in 500mL Tris buffer at pH 8 and sonicated for 50min. Then, 1.3g dopamine hydrochloride was added and stirred at 65r / min for 21h. The precipitate was collected by centrifugation, washed 4 times with deionized water, and freeze-dried to obtain ZIF-9@PDA. In a nitrogen atmosphere, 3g of surface-modified siloxane and 19.4g of potassium carbonate were added to 80g of tetrahydrofuran and stirred in an ice-water bath for 1.5h to obtain mixture A; 2g of ZIF-9@PDA was added to 40g of tetrahydrofuran and sonicated for 30min to obtain mixture B; at 5℃, mixture B was added dropwise to mixture A at a rate of 1.5mL / min, heated to reflux and stirred at 650r / min for 25h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite micro / nano materials. Step 3: Add 20.1g of N-(3-dimethylaminopropyl)methacrylamide to 48.8g of dichloromethane, stir, heat to 40℃, and then add 30g of 50wt% benzyl chloride solution in dichloromethane at a rate of 1.5mL / min. After the addition is complete, stir the reaction at 40℃ for 24h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. Add 3g of composite micro / nano materials to 65g of toluene and stir for 50min. Then add 1.3g of propylene 3-isocyanate and 0.02g of dibutyltin dilaurate. Heat to 80℃ and react for 60min. After the reaction is complete, filter, wash and dry to obtain functionalized composite micro / nano materials. 3g of functionalized composite micro / nanomaterials were added to 125g of N,N-dimethylformamide and sonicated for 45min. Then, 1.4g of quaternary ammonium salt compound, 1.7g of dodecafluoroheptyl methacrylate, and 0.6g of glycidyl methacrylate were added and stirred. Then, 0.04g of azobisisobutyronitrile was added and heated to 78℃ for 14h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified composite micro / nanomaterials. Step 4: By weight, 70-80 parts of the surface-modified polypropylene prepared in Example 1, 15 parts of the modified composite micro / nano material, 4 parts of glycerol, 1.5 parts of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2 parts of paraffin are blended to obtain a mixture; the mixture is then extruded and granulated in a twin-screw extruder to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 225℃ and extrusion speed 350 rpm.

[0022] Comparative Example 2 This comparative example discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 25℃, add 5.5g of calcium silicide to 650mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 6.5 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 7 times at 10000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 45h to obtain two-dimensional siloxane. 3.5g of two-dimensional siloxane and 4.5g of 3-chloropropyltrimethoxysilane were added to 65g of toluene and stirred at 90℃ for 10h. After the reaction was completed, the mixture was filtered, and the filter residue was washed with toluene and ethanol and then dried under vacuum at 60℃ to obtain surface-modified siloxane. Step 2: At 25℃, add 3.6g benzimidazole to 220g ethanol and stir. Add 1.8g 25wt% ammonia solution and continue stirring. Then add 3.8g cobalt acetate and continue stirring for 175min. After the reaction is complete, centrifuge to collect the precipitate, wash it 4 times with ethanol, and dry it to obtain ZIF-9. At 25℃, 1.1g ZIF-9 was dispersed in 500mL Tris buffer at pH 8 and sonicated for 50min. Then, 1.3g dopamine hydrochloride was added and stirred at 65r / min for 21h. The precipitate was collected by centrifugation, washed 4 times with deionized water, and freeze-dried to obtain ZIF-9@PDA. In a nitrogen atmosphere, 3g of surface-modified siloxane and 19.4g of potassium carbonate were added to 80g of tetrahydrofuran and stirred in an ice-water bath for 1.5h to obtain mixture A; 2g of ZIF-9@PDA was added to 40g of tetrahydrofuran and sonicated for 30min to obtain mixture B; at 5℃, mixture B was added dropwise to mixture A at a rate of 1.5mL / min, heated to reflux and stirred at 650r / min for 25h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite micro / nano materials. Step 3: Add 20.1g of N-(3-dimethylaminopropyl)methacrylamide to 48.8g of dichloromethane, stir, heat to 40℃, and then add 30g of 50wt% benzyl chloride solution in dichloromethane at a rate of 1.5mL / min. After the addition is complete, stir the reaction at 40℃ for 24h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. Add 3g of composite micro / nano materials to 65g of toluene and stir for 50min. Then add 1.3g of propylene 3-isocyanate and 0.02g of dibutyltin dilaurate. Heat to 80℃ and react for 60min. After the reaction is complete, filter, wash and dry to obtain functionalized composite micro / nano materials. 3g of functionalized composite micro / nanomaterials were added to 125g of N,N-dimethylformamide and sonicated for 45min. Then, 1.4g of quaternary ammonium salt compound, 1.7g of dodecafluoroheptyl methacrylate, and 0.6g of glycidyl methacrylate were added and stirred. Then, 0.04g of azobisisobutyronitrile was added and heated to 78℃ for 14h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified composite micro / nanomaterials. Step 4: By weight, mix 70-80 parts of polypropylene, 15 parts of modified composite micro / nano materials, 4 parts of glycerol, 1.5 parts of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2 parts of paraffin to obtain a mixture; put the mixture into a twin-screw extruder for extrusion and granulation to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 225℃ and extrusion speed 350rpm.

[0023] Comparative Example 3 This comparative example discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 25℃, add 5.5g of calcium silicide to 650mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 6.5 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 7 times at 10000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 45h to obtain two-dimensional siloxane. Step 2: Add 20.1g of N-(3-dimethylaminopropyl)methacrylamide to 48.8g of dichloromethane, stir, heat to 40℃, and then add 30g of 50wt% benzyl chloride solution in dichloromethane at a rate of 1.5mL / min. After the addition is complete, stir the reaction at 40℃ for 24h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. Add 3g of two-dimensional siloxane to 65g of toluene and stir for 50min. Then add 1.3g of propylene 3-isocyanate and 0.02g of dibutyltin dilaurate. Heat to 80℃ and react for 60min. After the reaction is complete, filter, wash and dry to obtain functionalized two-dimensional siloxane. 3g of functionalized two-dimensional siloxane was added to 125g of N,N-dimethylformamide and sonicated for 45min. Then, 1.4g of quaternary ammonium salt compound, 1.7g of dodecafluoroheptyl methacrylate, and 0.6g of glycidyl methacrylate were added and stirred. Then, 0.04g of azobisisobutyronitrile was added and heated to 78℃ for 14h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified two-dimensional siloxane. Step 3: By weight, 70-80 parts of modified polypropylene, 15 parts of modified two-dimensional siloxane, 4 parts of glycerol, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2 parts of paraffin are blended to obtain a mixture; the mixture is then extruded and granulated in a twin-screw extruder to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 225℃ and extrusion speed 350rpm.

[0024] Comparative Example 4 This comparative example discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 25℃, add 3.6g benzimidazole to 220g ethanol and stir. Add 1.8g 25wt% ammonia solution and continue stirring. Then add 3.8g cobalt acetate and continue stirring for 175min. After the reaction is complete, centrifuge to collect the precipitate, wash it 4 times with ethanol, and dry it to obtain ZIF-9. At 25℃, 1.1g ZIF-9 was dispersed in 500mL Tris buffer at pH 8 and sonicated for 50min. Then, 1.3g dopamine hydrochloride was added and stirred at 65r / min for 21h. The precipitate was collected by centrifugation, washed 4 times with deionized water, and freeze-dried to obtain ZIF-9@PDA. Step 2: Add 20.1g of N-(3-dimethylaminopropyl)methacrylamide to 48.8g of dichloromethane, stir, heat to 40℃, and then add 30g of 50wt% benzyl chloride solution in dichloromethane at a rate of 1.5mL / min. After the addition is complete, stir the reaction at 40℃ for 24h. After the reaction is completed, concentrate, precipitate, and dry to obtain the quaternary ammonium salt compound. Add 3g ZIF-9@PDA to 65g toluene and stir for 50min. Then add 1.3g propylene 3-isocyanate and 0.02g dibutyltin dilaurate. Heat to 80℃ and react for 60min. After the reaction is complete, filter, wash and dry to obtain functionalized ZIF-9@PDA. 3g of functionalized ZIF-9@PDA was added to 125g of N,N-dimethylformamide and sonicated for 45min. Then, 1.4g of quaternary ammonium salt compound, 1.7g of dodecafluoroheptyl methacrylate, and 0.6g of glycidyl methacrylate were added and stirred. Then, 0.04g of azobisisobutyronitrile was added and heated to 78℃ for 14h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain modified ZIF-9@PDA. Step 3: By weight, mix 70-80 parts of modified polypropylene, 15 parts of modified ZIF-9@PDA, 4 parts of glycerol, 1.5 parts of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2 parts of paraffin to obtain a mixture; put the mixture into a twin-screw extruder for extrusion and granulation to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 225℃ and extrusion speed 350rpm.

[0025] Comparative Example 5 This comparative example discloses a method for preparing an antibacterial and waterproof packaging material, including the following steps: Step 1: At 25℃, add 5.5g of calcium silicide to 650mL of 37wt% hydrochloric acid and stir continuously in an ice-water bath for 6.5 days. When the solution color changes from black to olive green, it indicates that the calcium silicide has been converted into siloxane nanosheets. Decant the reaction mixture and centrifuge it 7 times at 10000rpm. Wash the centrifuged product with deionized water and freeze-dry it for 45h to obtain two-dimensional siloxane. 3.5g of two-dimensional siloxane and 4.5g of 3-chloropropyltrimethoxysilane were added to 65g of toluene and stirred at 90℃ for 10h. After the reaction was completed, the mixture was filtered, and the filter residue was washed with toluene and ethanol and then dried under vacuum at 60℃ to obtain surface-modified siloxane. Step 2: At 25℃, add 3.6g benzimidazole to 220g ethanol and stir. Add 1.8g 25wt% ammonia solution and continue stirring. Then add 3.8g cobalt acetate and continue stirring for 175min. After the reaction is complete, centrifuge to collect the precipitate, wash it 4 times with ethanol, and dry it to obtain ZIF-9. At 25℃, 1.1g ZIF-9 was dispersed in 500mL Tris buffer at pH 8 and sonicated for 50min. Then, 1.3g dopamine hydrochloride was added and stirred at 65r / min for 21h. The precipitate was collected by centrifugation, washed 4 times with deionized water, and freeze-dried to obtain ZIF-9@PDA. In a nitrogen atmosphere, 3g of surface-modified siloxane and 19.4g of potassium carbonate were added to 80g of tetrahydrofuran and stirred in an ice-water bath for 1.5h to obtain mixture A; 2g of ZIF-9@PDA was added to 40g of tetrahydrofuran and sonicated for 30min to obtain mixture B; at 5℃, mixture B was added dropwise to mixture A at a rate of 1.5mL / min, heated to reflux and stirred at 650r / min for 25h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite micro / nano materials. Step 3: By weight, 70-80 parts of modified polypropylene, 15 parts of composite micro / nano materials, 4 parts of glycerol, 1.5 parts of 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, and 2 parts of paraffin are blended to obtain a mixture; the mixture is then extruded and granulated in a twin-screw extruder to obtain an antibacterial and waterproof packaging material; wherein the extrusion conditions are: extrusion temperature 225℃ and extrusion speed 350rpm.

[0026] In the above examples and comparative examples, benzoyl peroxide, xylene, 3,4,9,10-perylenetetracarboxylic acid dianhydride, levodopa, ethanol, pyrazole, N,N-dimethylformamide, N-hydroxysuccinimide, 37wt% hydrochloric acid, 3-chloropropyltrimethoxysilane, toluene, benzimidazole, 25wt% ammonia, cobalt acetate, dopamine hydrochloride, potassium carbonate, tetrahydrofuran, N-(3-dimethylaminopropyl)methacrylamide, dichloromethane, benzyl chloride, dibutyltin dilaurate, dodecafluoroheptyl methacrylate, glycidyl methacrylate, azobisisobutyronitrile, glycerol, and paraffin were obtained from Sinopharm Chemical Reagent Co., Ltd. The following materials were supplied: 2-(2'-hydroxy-3',5'-dicyclopentadienylphenyl)benzotriazole, from Zhejiang Wanfeng Chemical Co., Ltd.; 5-hexene-1-amine, from Shanghai Anmic Chemical Co., Ltd.; calcium silicide, from Shanghai Yaotian New Material Technology Co., Ltd.; Tris buffer solution with pH 8, from Hubei Xinjiecheng Chemical Technology Co., Ltd.; propylene 3-isocyanate, from Shandong Senya New Material Co., Ltd.; N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.; and polypropylene granules, grade T30s, from Dongguan Tongyi Plastic Raw Materials Co., Ltd.

[0027] Experimental Example Samples of antibacterial and waterproof packaging materials prepared in Examples 2-4 and Comparative Examples 1-5 were taken, and performance tests were performed on each group of samples. I. Antibacterial performance test: The test was conducted in accordance with the standard GB / T 31402-2023 "Test method for antibacterial properties of plastic surfaces". Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC 6538P) were used as test objects. The test was conducted immediately after the preparation of each group of antibacterial and waterproof packaging material samples (0 days) and after each group of antibacterial polypropylene plastics were placed at room temperature for 3 months. II. Waterproof performance test: Each group of samples was immersed in distilled water at 40℃ for 12 hours, and the water absorption rate was calculated. Water absorption rate = (mass of sample after immersion - mass of sample before immersion) / mass of sample before immersion × 100%; III. Mechanical property testing: Tensile strength tests were conducted in accordance with GB / T 1040.1-2018 "Determination of tensile properties of plastics - Part 1: General rules" and GB / T 1040.2-2022 "Determination of tensile properties of plastics - Part 2: Test conditions for molded and extruded plastics". The specimen size was 1A type and the test speed was 50 mm / min. IV. Anti-aging performance test: Each group of samples was made into strips with a size of 80mm×10mm×4mm and placed in a UV aging test chamber and a thermal aging test chamber for 10 days of aging treatment. The UV aging was performed using a xenon lamp with a power of 35W, and the thermal aging test was performed at a temperature of 50℃. After the treatment, the samples were taken out and the tensile strength of the treated samples was tested. The tensile strength retention rate was calculated as follows: tensile strength retention rate = tensile strength of the aged sample / tensile strength of the sample before aging × 100%.

[0028] The test results are shown in Table 1: Table 1 As can be seen from the test results in Table 1, the antibacterial and waterproof packaging materials prepared in Examples 2-4 of the present invention have excellent long-lasting antibacterial properties, waterproof properties, anti-aging properties and mechanical properties. A comparison of Comparative Examples 1-2 and Example 4 shows that surface modification of polypropylene with 5-hexene-1-amine followed by grafting with diimine compounds improves the interfacial compatibility between polypropylene and the modified composite micro / nanomaterials. The presence of diimine and catechol structures in the diimine compounds enhances the overall performance of the antibacterial and waterproof packaging material. A comparison of Comparative Examples 3-4 and Example 4 shows that ZIF-9@PDA and two-dimensional siloxanes have a positive impact on the mechanical properties and thermal stability of the antibacterial and waterproof packaging material. Depositing ZIF-9@PDA on two-dimensional siloxanes extends the water erosion path and forms a superhydrophobic micro / nanostructure, improving the waterproof performance of the antibacterial and waterproof packaging material. Furthermore, ZIF-9@PDA also enhances the antibacterial properties and UV resistance of the antibacterial and waterproof packaging material. Aging performance: As can be seen from the comparison between Comparative Example 5 and Example 4, introducing organic polymer chains onto the surface of the composite micro / nanomaterials allows the organic polymer chains to crosslink with the organic chains of the modified polypropylene, increasing the crosslinking density of the polypropylene system and improving the dispersibility of the composite micro / nanomaterials in the polypropylene system. Furthermore, among the organic polymer chains: quaternary ammonium salt compounds have antibacterial effects; dodecyl fluoroheptyl methacrylate introduces fluorine-containing chains, exhibiting excellent hydrophobic properties, and the high bond energy of the CF bond provides good thermal stability and resistance to UV damage; glycidyl methacrylate introduces epoxy groups that can undergo ring-opening reactions with the carboxyl groups in the modified polypropylene, further improving the interfacial compatibility between the composite micro / nanomaterials and the modified polypropylene. Therefore, introducing organic polymer chains onto the surface of the composite micro / nanomaterials improves the overall performance of the antibacterial and waterproof packaging material.

[0029] 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 producing an antibacterial waterproof packaging material, characterized by, It comprises the following steps: Step one, two-dimensional siloxene is prepared with calcium silicide as raw material; the two-dimensional siloxene is modified by 3-chloropropyl trimethoxysilane to obtain surface-modified siloxene; Step two, ZIF-9 is prepared and modified with polydopamine to obtain ZIF-9@PDA; ZIF-9@PDA is combined with surface-modified siloxene to obtain composite micro-nano material; Step three, the composite micro-nano material is modified by 3-isocyanate acrylate to obtain functionalized composite micro-nano material; the functionalized composite micro-nano material is reacted with quaternary ammonium salt compound, dodecafluoroheptyl methacrylate and glycidyl methacrylate to obtain modified composite micro-nano material; Step four, modified polypropylene, modified composite micro-nano material, glycerol, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and paraffin are blended in proportion to obtain a mixture; the mixture is extruded and granulated to obtain an antibacterial and waterproof packaging material.

2. The method for producing an antibacterial waterproof packaging material according to claim 1, characterized by, In the step one, the preparation method of the surface-modified siloxene is: At 23-27℃, calcium silicide is mixed with 37wt% hydrochloric acid at a dosage ratio of (5-6)g:(500-800)mL, continuously stirred in an ice water bath for 6-7d, centrifuged, washed, and dried to obtain two-dimensional siloxene; The two-dimensional siloxene, 3-chloropropyl trimethoxysilane and toluene are mixed at a mass ratio of (3-4):(3-6):(50-80), stirred at 85-95℃ for 8-12h, and purified to obtain surface-modified siloxene.

3. The method of producing an antibacterial waterproof packaging material according to claim 1, characterized by, In the step two, the preparation method of the ZIF-9@PDA is: At 23-27℃, benzimidazole is added to ethanol, stirred, 25wt% ammonia solution is added, stirred, and cobalt acetate is added, stirred for 150-200min, and purified to obtain ZIF-9; wherein the average particle size of the ZIF-9 is 200-400nm; the mass ratio of the benzimidazole, ethanol, 25wt% ammonia solution and cobalt acetate is (2.4-4.8):(140-300):(1.2-2.4):(2.5-5); At 23-27℃, ZIF-9 is dispersed in Tris buffer solution, ultrasonicated, and then dopamine hydrochloride is added, stirred at a speed of 600-700r / min for 18-24h, and then purified to obtain ZIF-9@PDA; wherein the dosage ratio of ZIF-9, Tris buffer solution and dopamine hydrochloride is (1-1.2)g:500mL:(0.5-2)g.

4. The method of producing an antibacterial waterproof packaging material according to claim 1, characterized by, In the step two, the preparation method of the composite micro-nano material is: Mixing surface modified siloxane, potassium carbonate, tetrahydrofuran in a nitrogen atmosphere, with a mass ratio of (2-4):(12.9-25.8):(60-100), to obtain mixed solution A; mixing ZIF-9@PDA, tetrahydrofuran with a mass ratio of (1-3):(30-50), and ultrasonic, to obtain mixed solution B; adding mixed solution B into mixed solution A at 0-10℃, heating to reflux, and stirring at a speed of 600-700r / min for 20-30h, purifying, to obtain composite micro-nano material.

5. The method of producing an antibacterial waterproof packaging material according to claim 1, characterized by, In the step three, the preparation method of the modified composite micro-nano material: adding the composite micro-nano material into toluene, stirring, then adding 3-isocyanate propylene, dibutyltin dilaurate, heating to 78-82℃ for 50-70min, purifying, to obtain functionalized composite micro-nano material; wherein the mass ratio of composite micro-nano material, toluene, 3-isocyanate propylene, dibutyltin dilaurate is (2-4):(50-80):(0.8-1.8):(0.01-0.03); adding the functionalized composite micro-nano material into N,N-dimethylformamide, ultrasonic, then adding quaternary ammonium salt compound, dodecafluoroheptyl methacrylate, glycidyl methacrylate, stirring, adding azobisisobutyronitrile, heating to 75-80℃, reacting for 12-16h, purifying, to obtain modified composite micro-nano material; wherein the mass ratio of functionalized composite micro-nano material, N,N-dimethylformamide, quaternary ammonium salt compound, dodecafluoroheptyl methacrylate, glycidyl methacrylate is (2.5-3.5):(100-150):(1.2-1.6):(1.4-2):(0.5-0.7).

6. The method of producing an antibacterial waterproof packaging material according to claim 5, characterized by, The preparation method of the quaternary ammonium salt compound: adding N-(3-dimethylaminopropyl) methacrylamide into dichloromethane, stirring, then adding 50wt% benzyl chloride dichloromethane solution dropwise at 38-42℃, stirring at 38-42℃ for 22-26h, purifying, to obtain quaternary ammonium salt compound; wherein the mass ratio of N-(3-dimethylaminopropyl) methacrylamide, dichloromethane, 50wt% benzyl chloride dichloromethane solution is (13.4-26.8):(32.5-65):(20-40).

7. The method of producing an antibacterial waterproof packaging material according to claim 1, characterized by, In the step four, the content of each component in the mixed material is: modified polypropylene 70-80 parts, modified composite micro-nano material 10-20 parts, glycerol 3-5 parts, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole 1-2 parts, paraffin 1-3 parts, by weight.

8. The method of producing an antibacterial waterproof packaging material according to claim 1, characterized by, In the step four, the extrusion conditions of the mixed material are: extrusion temperature 220-230℃, extrusion speed 200-500rpm.

9. The method of producing an antibacterial waterproof packaging material according to claim 1, characterized by, The preparation method of the modified polypropylene in the step four, comprising the following steps: Step S1, under a nitrogen atmosphere, 5-hexene-1-amine, benzoyl peroxide is added into xylene, stirred, then polypropylene particles are added, heated to 85-95℃ and stirred for 5-7h, purged with nitrogen, purified to obtain surface modified polypropylene; wherein the mass ratio of 5-hexene-1-amine, benzoyl peroxide, xylene, polypropylene particles is (1-1.7):(0.06-0.08):(100-150):(20-30); Step S2, under a nitrogen atmosphere, 3,4,9,10-perylenetetracarboxylic dianhydride, levodopa and pyrazole are mixed, heated to 125-130℃, reacted for 6-7h, then ethanol is added, refluxed for 6-8h, purified to obtain diimino compound; wherein the mass ratio of 3,4,9,10-perylenetetracarboxylic dianhydride, levodopa, pyrazole, ethanol is (1-2):(1.5-2.5):(8-16):(80-160); The diimino compound is added into N,N-dimethylformamide, stirred, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added, stirred for 1-2h, then the surface modified polypropylene is added, reacted at 115-125℃ for 20-30h, purified to obtain modified polypropylene; wherein the mass ratio of diimino compound, N,N-dimethylformamide, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, surface modified polypropylene is (11.3-18.7):(300-400):(1.8-2.2):(7-8.4):(20-30).

10. An antibacterial waterproof packaging material prepared by the preparation method of the antibacterial waterproof packaging material according to any one of claims 1-9.

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