An antibacterial modified plastic and a method for preparing the same
By adding phosphorus-modified imidazoline and modified borate esters to plastics, the problem of insufficient antibacterial and flame-retardant properties of existing antibacterial plastics is solved, the tensile effect is improved, and efficient antibacterial and flame-retardant effects are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANJING TAIYU MATERIAL TECH CO LTD
- Filing Date
- 2025-05-16
- Publication Date
- 2026-06-12
AI Technical Summary
The antibacterial and flame-retardant properties of existing antibacterial plastics need to be improved, and traditional modification methods have failed to effectively enhance their tensile properties.
Using polypropylene as the base material, phosphorus-modified imidazoline, modified borate ester, antioxidant 1010, plasticizer polyethylene glycol and talc are added. After being mixed in a high-speed mixer, the mixture is extruded and granulated in a twin-screw extruder and then molded in an injection molding machine to form an antibacterial modified plastic.
It improves the antibacterial and flame-retardant properties of plastics, while also enhancing their tensile properties, achieving better mechanical properties.
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer material modification technology, specifically to an antibacterial modified plastic and its preparation method. Background Technology
[0002] Plastics are one of the greatest material innovations of the 20th century. However, due to their performance limitations and environmental problems, plastic modification has become a core direction in materials science. Antimicrobial plastics are modified materials that inhibit or kill microorganisms (such as bacteria, fungi, and viruses) by adding antimicrobial agents or using special surface treatment techniques. Their core objective is to reduce the growth of microorganisms on plastic surfaces, avoid cross-contamination, and extend the lifespan of products, which is particularly important in fields with high hygiene requirements such as medical, food, and home appliances. With increasing demands for hygiene and safety, traditional plastics lack antimicrobial properties; therefore, avoiding this problem is key to solving the issue. For example, patent CN102617912A discloses a shielding flame-retardant plastic, which comprises the following components by weight: 100 parts of plastic substrate, 5-25 parts of doped polyaniline, 0.5-3 parts of curing agent, 10-30 parts of polyphosphatidic acid, 0.5-3.5 parts of crosslinking agent, 1-6 parts of lubricant, 5-15 parts of flame retardant, 0.5-1.5 parts of antioxidant, 0.1-1 parts of stabilizer, and 0.2-1 parts of metal passivator. This invention's shielding flame-retardant plastic has low manufacturing cost, high shielding performance, and good safety performance, but its antibacterial properties need improvement. Summary of the Invention
[0003] (a) Technical problems to be solved
[0004] To address the shortcomings of existing technologies, this invention provides an antibacterial modified plastic and its preparation method, which exhibits good antibacterial, flame-retardant, and tensile properties.
[0005] (II) Technical Solution
[0006] To achieve the above objectives, the present invention provides the following technical solution: an antibacterial modified plastic, comprising the following weight components: 60-75 parts by weight of polypropylene, 2-4 parts by weight of phosphorus-modified imidazoline, 3-5 parts by weight of modified borate ester, 0.2-0.3 parts by weight of antioxidant 1010, 0.1-0.3 parts by weight of plasticizer polyethylene glycol, and 1-2 parts by weight of talc.
[0007] Furthermore, the preparation method of the phosphorus-modified imidazoline is as follows:
[0008] S1. Add oleic acid and diethylenetriamine to xylene solvent, stir evenly at room temperature, maintain at 150-160℃ for 2-2.5h, and then carry out cyclization reaction at 200-220℃ for 1.5-2h. After the reaction is completed, cool and dry to obtain intermediate 1.
[0009] S2. Add 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 4-bromomethylbenzyl alcohol, and triethylamine to acetonitrile solvent. First, react at 10-15℃ for 30-60 min, and then react at 65-75℃ for 4-6 h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2.
[0010] S3. Add intermediate 1 and intermediate 2 to N,N-dimethylformamide solvent, stir and mix, continue to add triethylamine catalyst, and react at 60-80℃. After the reaction is completed, purify by vacuum distillation to obtain phosphorus-modified imidazoline.
[0011] In the above reaction process, oleic acid and diethylenetriamine were cyclized to introduce a tertiary amine and an amino group, thereby obtaining intermediate 1; the chlorine in 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and the hydroxyl group in 4-bromomethylbenzyl alcohol were reacted to introduce a bromine group, thereby obtaining intermediate 2; the tertiary amine in intermediate 1 and the bromine in intermediate 2 were quaternized to obtain phosphorus-modified imidazoline.
[0012] Furthermore, the ratio of xylene, oleic acid, and diethylenetriamine in S1 is 20-40 mL: 4-4.2 g: 2.1-2.3 g.
[0013] Furthermore, the stirring time in S1 is 20-30 minutes.
[0014] Further, the ratio of acetonitrile, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 4-bromomethylbenzyl alcohol, and triethylamine in S2 is 20-35 mL: 2-2.2 g: 3.1-3.4 g: 0.02-0.03 g.
[0015] Further, the ratio of N,N-dimethylformamide solvent, intermediate 1, intermediate 2, and triethylamine in S3 is 25-40 mL: 3.6-3.8 g: 1.5-1.8 g: 0.01-0.02 g.
[0016] Furthermore, the reaction time in S3 is 6-8 hours.
[0017] Further, the method for modifying the borate ester is as follows: 2,6-dihydroxy-3,7-dibromonaphthalene and pinacol diboronate are dissolved in 1,4-dioxane solvent, and [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and sodium carbonate are added to the solvent. Under a nitrogen atmosphere, the mixture is heated to the reaction temperature and reacted for 1.5-2.5 hours. After the reaction is completed, the solvent is removed by rotary evaporation to obtain the modified borate ester.
[0018] Further, the ratio of 2,6-dihydroxy-3,7-dibromonaphthalene, pinacol diborate, 1,4-dioxane, [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride, and sodium carbonate is 3.5-3.9g:2.8-3.2g:80-90mL:0.3-0.4g:4.4.2g.
[0019] Furthermore, the method for preparing the antibacterial modified plastic is characterized in that the method for preparing the antibacterial modified plastic is as follows: polypropylene, phosphorus-modified imidazoline, modified borate ester, antioxidant 1010, plasticizer polyethylene glycol, and talc are placed in a high-speed mixer and mixed evenly, extruded and granulated in a twin-screw extruder, with a blending temperature of 180-190℃ and an extrusion temperature of 170-180℃, dried, and injection molded to obtain the antibacterial modified plastic.
[0020] (III) Beneficial Technical Effects
[0021] This invention involves mixing polypropylene, phosphorus-modified imidazoline, modified borate ester, antioxidant 1010, plasticizer polyethylene glycol, and talc in a high-speed mixer until homogeneous, extruding and granulating the mixture in a twin-screw extruder, drying it, and then injection molding it to obtain an antibacterial modified plastic.
[0022] During the blending extrusion process, the chains of phosphorus-modified imidazoline and modified borate ester entangle with polypropylene, resulting in a tighter bond and forming a cross-linked network that enhances its tensile properties. The imidazoline and quaternary ammonium groups in the phosphorus-modified imidazoline exhibit good antibacterial effects. The phosphorus and nitrogen elements in the phosphorus-modified imidazoline and the boron elements in the modified borate ester together constitute a flame-retardant system, providing good flame retardant performance. Furthermore, the reaction between intermediate 2 and intermediate 1 increases the degree of substitution of the imidazoline, further enhancing its antibacterial effect. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] To better understand the above technical solutions, specific embodiments will be used to describe the technical solutions in detail below.
[0025] Example 1
[0026] (1) Add 4g of oleic acid and 2.1g of diethylenetriamine to 20mL of xylene solvent, stir at room temperature for 20min, keep at 150℃ for 2h, and then carry out cyclization reaction at 200℃ for 1.5h. After the reaction is completed, cool and dry to obtain intermediate 1.
[0027] (2) Add 2g of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 3.1g of 4-bromomethylbenzyl alcohol, and 0.02g of triethylamine to 20mL of acetonitrile solvent. First, react at 10℃ for 30min, and then react at 65℃ for 4h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2;
[0028] (3) Add 3.6-3.8g of intermediate 1 and 1.5g of intermediate 2 to 25mL of N,N-dimethylformamide solvent, stir and mix, and continue to add 0.01g of triethylamine catalyst. React at 60℃ for 6h. After the reaction is completed, distill under reduced pressure and purify to obtain phosphorus-modified imidazoline.
[0029] (4) Dissolve 3.5g of 2,6-dihydroxy-3,7-dibromonaphthalene and 2.8g of pinacol diborate in 80mL of 1,4-dioxane solvent, add 0.3g of [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and 4g of sodium carbonate, and heat to the reaction temperature for 1.5h under a nitrogen atmosphere. After the reaction is completed, remove the solvent by rotary evaporation to obtain the modified borate ester.
[0030] (5) 60 parts by weight of polypropylene, 2 parts by weight of phosphorus-modified imidazoline, 3 parts by weight of modified borate ester, 0.2 parts by weight of antioxidant 1010, 0.1 parts by weight of plasticizer polyethylene glycol, and 1 part by weight of talc are placed in a high-speed mixer and mixed evenly. The mixture is then extruded and granulated in a twin-screw extruder at a blending temperature of 180°C and an extrusion temperature of 170°C. After drying, the mixture is injection molded to obtain antibacterial modified plastic.
[0031] Example 2
[0032] (1) Add 4.2 g of oleic acid and 2.3 g of diethylenetriamine to 40 mL of xylene solvent, stir at room temperature for 30 min, keep at 160 °C for 2.5 h, and then carry out cyclization reaction at 220 °C for 2 h. After the reaction is completed, cool and dry to obtain intermediate 1.
[0033] (2) Add 2.2 g of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 3.4 g of 4-bromomethylbenzyl alcohol, and 0.03 g of triethylamine to 35 mL of acetonitrile solvent. First, react at 15 °C for 60 min, and then react at 75 °C for 6 h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2.
[0034] (3) Add 3.8g of intermediate 1 and 1.8g of intermediate 2 to 40mL of N,N-dimethylformamide solvent, stir and mix, and continue to add 0.02g of triethylamine catalyst. React at 80℃ for 8h. After the reaction is completed, distill under reduced pressure and purify to obtain phosphorus-modified imidazoline.
[0035] (4) Dissolve 3.9 g of 2,6-dihydroxy-3,7-dibromonaphthalene and 3.2 g of pinacol diborate in 90 mL of 1,4-dioxane solvent, add 0.4 g of [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and 4.2 g of sodium carbonate, and heat to the reaction temperature for 2.5 h under a nitrogen atmosphere. After the reaction is completed, remove the solvent by rotary evaporation to obtain the modified borate ester.
[0036] (5) 75 parts by weight of polypropylene, 4 parts by weight of phosphorus-modified imidazoline, 5 parts by weight of modified borate ester, 0.3 parts by weight of antioxidant 1010, 0.3 parts by weight of plasticizer polyethylene glycol, and 2 parts by weight of talc are placed in a high-speed mixer and mixed evenly. The mixture is then extruded and granulated in a twin-screw extruder at a blending temperature of 190°C and an extrusion temperature of 180°C. After drying, the mixture is injection molded to obtain antibacterial modified plastic.
[0037] Example 3
[0038] (1) Add 4.1 g of oleic acid and 2.2 g of diethylenetriamine to 30 mL of xylene solvent, stir at room temperature for 25 min, keep at 155 °C for 2.2 h, and then carry out cyclization reaction at 210 °C for 1.5 h. After the reaction is completed, cool and dry to obtain intermediate 1.
[0039] (2) Add 2.1 g of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 3.3 g of 4-bromomethylbenzyl alcohol, and 0.02 g of triethylamine to 30 mL of acetonitrile solvent. First, react at 12 °C for 45 min, and then react at 70 °C for 5 h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2.
[0040] (3) Add 3.7g of intermediate 1 and 1.6g of intermediate 2 to 35mL of N,N-dimethylformamide solvent, stir and mix, and continue to add 0.02g of triethylamine catalyst. React at 70℃ for 7h. After the reaction is completed, distill under reduced pressure and purify to obtain phosphorus-modified imidazoline.
[0041] (4) Dissolve 3.7g of 2,6-dihydroxy-3,7-dibromonaphthalene and 3g of pinacol diborate in 85mL of 1,4-dioxane solvent, add 0.3g of [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and 4.1g of sodium carbonate, and heat to the reaction temperature for 2h under a nitrogen atmosphere. After the reaction is completed, remove the solvent by rotary evaporation to obtain the modified borate ester.
[0042] (5) 65 parts by weight of polypropylene, 3 parts by weight of phosphorus-modified imidazoline, 4 parts by weight of modified borate ester, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of plasticizer polyethylene glycol, and 1 part by weight of talc are placed in a high-speed mixer and mixed evenly. The mixture is then extruded and granulated in a twin-screw extruder at a blending temperature of 185°C and an extrusion temperature of 175°C. After drying, the mixture is injection molded to obtain antibacterial modified plastic.
[0043] Example 4
[0044] (1) Add 4g of oleic acid and 2.1g of diethylenetriamine to 28mL of xylene solvent, stir at room temperature for 25min, keep at 155℃ for 2h, and then carry out cyclization reaction at 200℃ for 1.5h. After the reaction is completed, cool and dry to obtain intermediate 1.
[0045] (2) Add 2g of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 3.2g of 4-bromomethylbenzyl alcohol, and 0.02g of triethylamine to 25mL of acetonitrile solvent. First, react at 10℃ for 40min, and then react at 65℃ for 5h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2;
[0046] (3) Add 3.6 g of intermediate 1 and 1.6 g of intermediate 2 to 30 mL of N,N-dimethylformamide solvent, stir and mix, and continue to add 0.01 g of triethylamine catalyst. React at 70 °C for 6 h. After the reaction is completed, distill under reduced pressure and purify to obtain phosphorus-modified imidazoline.
[0047] (4) Dissolve 3.6g of 2,6-dihydroxy-3,7-dibromonaphthalene and 3g of pinacol diborate in 80mL of 1,4-dioxane solvent, add 0.3g of [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and 4g of sodium carbonate, and heat to the reaction temperature for 2h under a nitrogen atmosphere. After the reaction is completed, remove the solvent by rotary evaporation to obtain the modified borate ester.
[0048] (5) 65 parts by weight of polypropylene, 2 parts by weight of phosphorus-modified imidazoline, 4 parts by weight of modified borate ester, 0.2 parts by weight of antioxidant 1010, 0.2 parts by weight of plasticizer polyethylene glycol, and 1 part by weight of talc are placed in a high-speed mixer and mixed evenly. The mixture is then extruded and granulated in a twin-screw extruder at a blending temperature of 180°C and an extrusion temperature of 175°C. After drying, the mixture is injection molded to obtain antibacterial modified plastic.
[0049] Example 5
[0050] (1) Add 4.2 g of oleic acid and 2.2 g of diethylenetriamine to 40 mL of xylene solvent, stir at room temperature for 30 min, keep at 155 °C for 2.5 h, and then carry out cyclization reaction at 220 °C for 2 h. After the reaction is completed, cool and dry to obtain intermediate 1.
[0051] (2) Add 2.1 g of 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 3.3 g of 4-bromomethylbenzyl alcohol, and 0.03 g of triethylamine to 35 mL of acetonitrile solvent. First, react at 15 °C for 50 min, and then react at 75 °C for 6 h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2.
[0052] (3) Add 3.8 g of intermediate 1 and 1.8 g of intermediate 2 to 35 mL of N,N-dimethylformamide solvent, stir and mix, and continue to add 0.02 g of triethylamine catalyst. React at 80 °C for 7 h. After the reaction is completed, distill under reduced pressure and purify to obtain phosphorus-modified imidazoline.
[0053] (4) Dissolve 3.7 g of 2,6-dihydroxy-3,7-dibromonaphthalene and 3.2 g of pinacol diborate in 90 mL of 1,4-dioxane solvent, add 0.4 g of [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and 4.2 g of sodium carbonate, and heat to the reaction temperature for 2.5 h under a nitrogen atmosphere. After the reaction is completed, remove the solvent by rotary evaporation to obtain the modified borate ester.
[0054] (5) 75 parts by weight of polypropylene, 3 parts by weight of phosphorus-modified imidazoline, 5 parts by weight of modified borate ester, 0.3 parts by weight of antioxidant 1010, 0.2 parts by weight of plasticizer polyethylene glycol, and 2 parts by weight of talc are placed in a high-speed mixer and mixed evenly. The mixture is then extruded and granulated in a twin-screw extruder at a blending temperature of 190°C and an extrusion temperature of 175°C. After drying, the mixture is injection molded to obtain antibacterial modified plastic.
[0055] Comparative Example 1
[0056] The difference between this comparative example and Example 5 is that intermediate 1 was used instead of phosphorus-modified imidazoline.
[0057] Comparative Example 2
[0058] The difference between this comparative example and Example 5 is that intermediate 2 was used instead of phosphorus-modified imidazoline.
[0059] Comparative Example 3
[0060] The difference between this comparative example and Example 5 is that no modified borate ester was added.
[0061] Performance testing:
[0062] The antibacterial modified plastics prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests.
[0063] (1) The antibacterial performance test method is as follows: The antibacterial performance test was conducted according to GB / T 31402-2015 "Test Method for Antibacterial Performance of Plastic Surfaces". The test strains were Escherichia coli AS1.90 and Staphylococcus aureus ACTT6538P. The test results are shown in Table 1.
[0064] Table 1: Antibacterial Performance Test
[0065] Group Escherichia coli (%) Staphylococcus aureus (%) Example 1 99.2 99.3 Example 2 99.7 99.8 Example 3 99.5 99.4 Example 4 99.3 99.3 Example 5 99.5 99.6 Comparative Example 1 92.3 91.5 Comparative Example 2 95.1 94.6 Comparative Example 3 99.4 99.3
[0066] As can be seen from Table 1, the antibacterial modified plastics prepared in Examples 1-5 all have an antibacterial rate of more than 99% against Escherichia coli and Staphylococcus aureus, which is better than that of Comparative Examples 1-2.
[0067] (2) The flame retardant performance test methods are as follows: the oxygen index of the material is tested using an oxygen index meter, and the flammability rating of the material is tested using a horizontal and vertical combustion tester. The test results are shown in Table 2.
[0068] Table 2: Flame retardant performance test
[0069] Group Oxygen index (%) UL-94 Example 1 36.8 V-0 Example 2 38.2 V-0 Example 3 37.4 V-0 Example 4 37.1 V-0 Example 5 37.8 V-0 Comparative Example 1 20.6 V-1 Comparative Example 2 21.2 V-1 Comparative Example 3 22.9 V-1
[0070] As can be seen from Table 2, the antibacterial modified plastics prepared in Examples 1-5 have better flame retardant effects compared with Comparative Examples 1-2.
[0071] (3) The mechanical properties were tested according to GB / T 1040-2006, with a tensile rate of 5 mm / min. The test results are shown in Table 3.
[0072] Table 3: Mechanical Performance Tests
[0073] Group Tensile strength (MPa) Example 1 41.5 Example 2 43.2 Example 3 42.1 Example 4 41.6 Example 5 42.7 Comparative Example 1 34.5 Comparative Example 2 33.2 Comparative Example 3 35.9
[0074] As can be seen from Table 3, the antibacterial modified plastics prepared in Examples 1-5 have better mechanical properties than those in Comparative Examples 1-2.
[0075] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Those skilled in the art should understand that the above descriptions are only some specific embodiments of the present invention, and not all embodiments.
Claims
1. An antibacterial modified plastic, characterized in that, It includes the following components by weight: 60-75 parts by weight of polypropylene, 2-4 parts by weight of phosphorus-modified imidazoline, 3-5 parts by weight of modified borate ester, 0.2-0.3 parts by weight of antioxidant 1010, 0.1-0.3 parts by weight of plasticizer polyethylene glycol, and 1-2 parts by weight of talc. The preparation method of the phosphorus-modified imidazoline is as follows: S1. Add oleic acid and diethylenetriamine to xylene solvent, stir evenly at room temperature, maintain at 150-160℃ for 2-2.5h, and then carry out cyclization reaction at 200-220℃ for 1.5-2h. After the reaction is completed, cool and dry to obtain intermediate 1. S2. Add 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 4-bromomethylbenzyl alcohol, and triethylamine to acetonitrile solvent. First, react at 10-15℃ for 30-60 min, and then react at 65-75℃ for 4-6 h. After the reaction is completed, concentrate, wash and dry to obtain intermediate 2. S3. Add intermediate 1 and intermediate 2 to N,N-dimethylformamide solvent, stir and mix, continue to add triethylamine catalyst, and react at 60-80℃. After the reaction is completed, purify by vacuum distillation to obtain phosphorus-modified imidazoline. The modified borate ester is prepared by dissolving 2,6-dihydroxy-3,7-dibromonaphthalene and pinacol diboronic acid ester in 1,4-dioxane solvent, adding [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride catalyst and sodium carbonate, and heating to the reaction temperature for 1.5-2.5 h under a nitrogen atmosphere. After the reaction is completed, the solvent is removed by rotary evaporation to obtain the modified borate ester.
2. The antibacterial modified plastic according to claim 1, characterized in that, The ratio of xylene, oleic acid, and diethylenetriamine in S1 is 20-40 mL: 4-4.2 g: 2.1-2.3 g.
3. The antibacterial modified plastic according to claim 1, characterized in that, The stirring time in S1 is 20-30 minutes.
4. The antibacterial modified plastic according to claim 1, characterized in that, The ratio of acetonitrile, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, 4-bromomethylbenzyl alcohol, and triethylamine in S2 is 20-35 mL: 2-2.2 g: 3.1-3.4 g: 0.02-0.03 g.
5. The antibacterial modified plastic according to claim 1, characterized in that, The ratio of N,N-dimethylformamide solvent, intermediate 1, intermediate 2, and triethylamine in S3 is 25-40 mL: 3.6-3.8 g: 1.5-1.8 g: 0.01-0.02 g.
6. The antibacterial modified plastic according to claim 1, characterized in that, The reaction time in S3 is 6-8 hours.
7. The antibacterial modified plastic according to claim 1, characterized in that, The ratio of 2,6-dihydroxy-3,7-dibromonaphthalene, pinacol diboronate, 1,4-dioxane, [1,1-bis(diphenylphosphine)ferrocene]palladium dichloride, and sodium carbonate is 3.5-3.9g:2.8-3.2g:80-90mL:0.3-0.4g:4-4.2g.
8. A method for preparing an antibacterial modified plastic as described in any one of claims 1-7, characterized in that, The method for preparing the antibacterial modified plastic is as follows: polypropylene, phosphorus-modified imidazoline, modified borate ester, antioxidant 1010, plasticizer polyethylene glycol, and talc are mixed evenly in a high-speed mixer, extruded and granulated in a twin-screw extruder, with a blending temperature of 180-190℃ and an extrusion temperature of 170-180℃, dried, and injection molded to obtain the antibacterial modified plastic.