Functional zinc oxide modified polypropylene antibacterial plastic and preparation method thereof

Abstract

The invention relates to the technical field of antibacterial plastics, and discloses a functional zinc oxide modified polypropylene antibacterial plastic, and compared with pure-phase polypropylene plastic, the functional zinc oxide modified polypropylene plastic has better antibacterial performance and mechanical performance, and the antibacterial performance is better. Zinc oxide serving as a non-toxic and harmless antibacterial inorganic matter with an antibacterial effect not only increases the antibacterial property of the polypropylene plastic, but also improves the mechanical property of the polypropylene plastic when being added into the polypropylene plastic, the benzimidazole derivative has good biological activity and antibacterial effect, and the antibacterial property of the polypropylene plastic is improved by grafting the benzimidazole derivative on the surface of zinc oxide. According to the present invention, by adding the benzimidazole derivative and the zinc oxide to the polypropylene plastic, the escape and the loss of the small molecules are avoided, the antibacterial effect of the polypropylene plastic is increased through the synergistic effect between the benzimidazole derivative and the zinc oxide, and the mechanical property of the polypropylene is further improved when the polyethylene is added into the polypropylene in the blending manner.

Description

Technical Field

[0001] The invention relates to the technical field of antibacterial plastics, in particular to a functional zinc oxide modified polypropylene antibacterial plastic and a preparation method thereof. Background Art

[0002] Polypropylene (PP) is one of the five conventional plastics that are corrosion-resistant, electrically insulating, non-toxic, easy to process and inexpensive. It is widely used in our daily lives, so high requirements are placed on PP with high strength and antibacterial properties for various uses, such as household appliances, filters, packaging materials, and various forms of textile industries, such as non-woven films and fibers. However, the lack of antibacterial properties on the surface of polypropylene limits the application of polypropylene in these fields. For this reason, researchers have conducted a lot of research, such as the Chinese patent publication number CN103059405B, which discloses antibacterial polypropylene plastics, and the Chinese patent publication number CN106995557B, which discloses an antibacterial polypropylene masterbatch and a preparation method thereof. Although both increase the antibacterial properties of polypropylene, they still have the problem of large amount of antibacterial substances added and unsatisfactory antibacterial effect.

[0003] As an inorganic metal oxide, nano zinc oxide has unique physical and chemical stability, ultraviolet absorption, antibacterial and non-toxic properties. Therefore, nano zinc oxide has been used in various applications, such as food packaging, cosmetics and drugs. Benzimidazole is a useful intermediate for developing new molecules with biological or pharmaceutical significance. Benzimidazole derivatives have been found to have good activity and have good applications in anti-tumor, antibacterial, anthelmintic, antibacterial, analgesic, anti-inflammatory and other fields. However, benzimidazole derivatives are mostly small molecules, which are easy to precipitate when directly added to polypropylene, reducing the antibacterial stability of polypropylene. Grafting it on the surface of zinc oxide can not only avoid the reduction of the antibacterial stability of polypropylene, but also increase the antibacterial ability of polypropylene through synergistic effects. According to the method of Xu Zhixian's "Synthesis and Characterization of New Block and Graft Copolymers of Polyethylene", single-end carboxyl polyethylene is prepared with flexible long chains, which can not only improve the mechanical properties of polypropylene, but also serve as a grafting medium, so that the benzimidazole derivatives are grafted on the surface of zinc oxide to avoid its shedding and precipitation during use.

[0004] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides a functional zinc oxide modified polypropylene antibacterial plastic and a preparation method thereof, which solves the problem that the polypropylene plastic has no antibacterial property and low mechanical strength.

[0005] (II) Technical solution To achieve the above object, the present invention provides the following technical solution: a functional zinc oxide modified polypropylene antibacterial plastic, the preparation method of the functional zinc oxide modified polypropylene antibacterial plastic comprises the following steps: (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: maleic anhydride, an interfacial agent xylene and an initiator azobisisobutyronitrile are placed in a reaction bottle, stirred evenly, and then carboxyl-terminated polyethylene is added. The mixture is continuously stirred and reacted under a nitrogen atmosphere. After the reaction is completed, maleic anhydride grafted carboxyl-terminated polyethylene is obtained. (2) Preparation of amino zinc oxide: Add zinc oxide and γ-aminopropyltriethoxysilane to an acetone solvent at a mass ratio of 100:1-3:1800-4000, and react at 70-100°C for 3-8h. When the reaction is completed, amino zinc oxide is obtained; (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: Aminated zinc oxide and maleic anhydride grafted carboxyl-terminated polyethylene are ultrasonically dispersed in an ether solvent, stirred evenly and reacted. After the reaction is completed, carboxyl-terminated polyethylene grafted zinc oxide is obtained; (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: ultrasonically disperse the carboxyl-terminated polyethylene grafted zinc oxide in tetrahydrofuran, then add 2-hydroxymethylbenzimidazole, dicyclohexylcarbodiimide and 4-dimethylaminopyridine, stir evenly, and react. After the reaction is completed, benzimidazole-based polyethylene grafted zinc oxide is obtained; (5) Preparation of functionalized zinc oxide modified polypropylene antibacterial plastic: Add benzimidazole polyethylene grafted zinc oxide and polypropylene into a high-speed mixer, mix evenly, and then transfer to a twin-screw extruder for granulation, and then use an injection molding machine for preparation and shaping to obtain functionalized zinc oxide modified polypropylene antibacterial plastic.

[0006] Preferably, in step (1), the mass ratio of maleic anhydride, xylene, azobisisobutyronitrile and carboxyl-terminated polyethylene is 3-8:8-20:0.2-0.5:100.

[0007] Preferably, in step (1), the reaction temperature is 80-120° C. and the reaction time is 2-6 h.

[0008] Preferably, in step (3), the mass ratio of the amino zinc oxide, the maleic anhydride grafted carboxyl-terminated polyethylene and the ether is 100:120-200:1800-3000.

[0009] Preferably, in step (3), the reaction temperature is 20-50° C. and the reaction time is 6-15 h.

[0010] Preferably, in step (4), the mass ratio of the carboxyl-terminated polyethylene grafted zinc oxide, tetrahydrofuran, 2-hydroxymethylbenzimidazole, dicyclohexylcarbodiimide and 4-dimethylaminopyridine is 100:2500-6000:8-15:60-100:8-12.

[0011] Preferably, in step (4), the reaction temperature is 120-150° C. and the reaction time is 4-10 h.

[0012] Preferably, in step (5), the mass ratio between the benzimidazole-based polyethylene grafted zinc oxide and the polypropylene is 1.5-6:100.

[0013] 3. Beneficial technical effects Compared with the prior art, the present invention has the following experimental principles and beneficial technical effects: The functionalized zinc oxide modified polypropylene antibacterial plastic comprises the following steps: firstly, xylene is used as an interface agent and azobisisobutyronitrile is used as an initiator to make a graft reaction between carboxyl-terminated polyethylene and maleic anhydride to obtain maleic anhydride grafted carboxyl-terminated polyethylene; secondly, γ-aminopropyltriethoxysilane is used as a modifier to modify zinc oxide to obtain amino zinc oxide; then, the high activity of maleic anhydride in the maleic anhydride grafted carboxyl-terminated polyethylene is used to react with the amino group of the amino zinc oxide to obtain carboxyl-terminated polyethylene grafted zinc oxide; then, under the catalytic system of dicyclohexylcarbodiimide and 4-dimethylaminopyridine, the carboxyl end of the carboxyl-terminated polyethylene grafted zinc oxide is subjected to an esterification reaction with the hydroxyl group of 2-hydroxymethylbenzimidazole to obtain benzimidazole-based polyethylene grafted zinc oxide; and finally, the functionalized zinc oxide modified polypropylene antibacterial plastic is prepared by blending.

[0014] The functionalized zinc oxide modified polypropylene antibacterial plastic has better antibacterial properties and mechanical properties than pure polypropylene plastic. Zinc oxide is a non-toxic and harmless antibacterial inorganic substance with antibacterial effect. When added to polypropylene plastic, it not only increases the antibacterial property of polypropylene plastic, but also improves its mechanical properties. In polypropylene, when zinc oxide is exposed to light, the electrons in the valence band are excited with high energy and jump to the conduction band, thereby forming photogenerated hole-electron pairs in the valence band and the conduction band, wherein the photogenerated electrons have strong reducing properties and the photogenerated holes have strong oxidizing properties. When an oxidation reaction occurs with hydroxyl radicals or water molecules on the surface of the substance, highly reactive substances such as OH are generated, which can photocatalytically inactivate bacteria, viruses or other pollutants, thereby increasing the antibacterial property of polypropylene plastic. In addition, zinc oxide acts on inorganic substances to form an organic-inorganic network structure in the polypropylene structure, which is exposed to external light. When the external force is affected by stress, it is dispersed inside the polypropylene through the network structure, avoiding the damage caused by stress concentration, increasing the elongation at break of the polypropylene plastic, and slowly reducing the tensile strength. The benzimidazole derivatives have good biological activity and antibacterial effects, inhibiting the formation of DNA topoisomerase and HIV reverse transcriptase in bacterial cells, reducing the reproduction of bacterial cells, and achieving the effect of inhibiting bacterial growth. By grafting the benzimidazole derivatives on the surface of zinc oxide, not only the escape and loss of small molecules are avoided, but also the antibacterial effect of the polypropylene plastic is increased through the synergistic effect between the benzimidazole derivatives and zinc oxide. When polyethylene is added to polypropylene by blending, polyethylene inserts into the crystal structure of polypropylene, co-crystallizes, etc., which increases the crystallization point between polypropylene and polyethylene, forms a network structure with a higher degree of cross-linking, enhances the interaction between the two, and further improves the mechanical properties of polypropylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the reaction formula of maleic anhydride and carboxyl-terminated polyethylene; Figure 2 It is the reaction formula of amino zinc oxide and maleic anhydride grafted carboxyl-terminated polyethylene; Figure 3 It is the reaction formula of carboxyl-terminated polyethylene grafted with zinc oxide and 2-hydroxymethylbenzimidazole. DETAILED DESCRIPTION

[0016] To achieve the above object, the present invention provides the following specific implementation methods and examples: A functional zinc oxide modified polypropylene antibacterial plastic, the preparation method of which comprises the following steps: (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: maleic anhydride, interfacial agent xylene and initiator azobisisobutyronitrile (AIBN) are placed in a reaction bottle in a mass ratio of 3-8:8-20:0.2-0.5:100, stirred evenly, and then carboxyl-terminated polyethylene is added, stirred continuously under a nitrogen atmosphere, and reacted at 80-120°C for 2-6 hours. After the reaction is completed, cooled, extracted for 4-8 hours, and vacuum dried at 40-60°C to obtain maleic anhydride grafted carboxyl-terminated polyethylene; (2) Preparation of amino zinc oxide: Add zinc oxide and γ-aminopropyltriethoxysilane to acetone solvent at a mass ratio of 100:1-3:1800-4000, react at 70-100°C for 3-8h, and extract with ethanol and dry to obtain amino zinc oxide after the reaction is completed; (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: according to the mass ratio of 100:120-200:1800-3000, amino zinc oxide and maleic anhydride grafted carboxyl-terminated polyethylene are ultrasonically dispersed in ether solvent, stirred evenly and reacted at 20-50°C for 6-15h. After the reaction is completed, filter and wash with ether and deionized water to obtain carboxyl-terminated polyethylene grafted zinc oxide; (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: ultrasonically disperse the carboxyl-terminated polyethylene grafted zinc oxide in tetrahydrofuran at a mass ratio of 100:2500-6000:8-15:60-100:8-12, then add 2-hydroxymethylbenzimidazole, dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP), stir evenly, react at 120-150°C for 4-10 hours, and after the reaction is completed, filter to obtain benzimidazole-based polyethylene grafted zinc oxide; (5) Preparation of functionalized zinc oxide modified polypropylene antibacterial plastic: Add benzimidazole polyethylene grafted zinc oxide and polypropylene into a high-speed mixer at a mass ratio of 1.5-6:100, mix evenly, and then transfer to a twin-screw extruder for granulation, and then use an injection molding machine for preparation and shaping to obtain functionalized zinc oxide modified polypropylene antibacterial plastic.

[0017] Example 1

[0018] (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: 0.15 g of maleic anhydride, 0.4 g of interfacial agent xylene and 0.01 g of initiator azobisisobutyronitrile (AIBN) were placed in a reaction bottle, stirred evenly, and then 5 g of carboxyl-terminated polyethylene was added. The mixture was stirred continuously under a nitrogen atmosphere and reacted at 80°C for 2 h. After the reaction was completed, the mixture was cooled, extracted for 4 h, and vacuum dried at 40°C to obtain maleic anhydride grafted carboxyl-terminated polyethylene. (2) Preparation of amino zinc oxide: 5 g zinc oxide and 0.05 g γ-aminopropyltriethoxysilane were added to 115 mL acetone solvent and reacted at 70 °C for 3 h. After the reaction was completed, ethanol was used for extraction and drying to obtain amino zinc oxide. (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: 4 g of amino zinc oxide and 4.8 g of maleic anhydride grafted carboxyl-terminated polyethylene were ultrasonically dispersed in 105 mL of solvent, stirred evenly and reacted at 20°C for 6 h. After the reaction was completed, the mixture was filtered and washed with ether and deionized water to obtain carboxyl-terminated polyethylene grafted zinc oxide. (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: 4 g of carboxyl-terminated polyethylene grafted zinc oxide was ultrasonically dispersed in 115 mL of tetrahydrofuran, and then 0.32 g of 2-hydroxymethylbenzimidazole, 2.4 g of dicyclohexylcarbodiimide (DCC) and 0.32 g of 4-dimethylaminopyridine (DMAP) were added. After stirring evenly, the mixture was reacted at 120°C for 4 h. After the reaction was completed, the mixture was filtered to obtain benzimidazole-based polyethylene grafted zinc oxide. (5) Preparation of functional zinc oxide modified polypropylene antibacterial plastic: 0.15 g of benzimidazole polyethylene grafted zinc oxide and 10 g of polypropylene were added to a high-speed mixer and mixed evenly. The mixture was then transferred to a twin-screw extruder for granulation, and then an injection molding machine was used for preparation and shaping to obtain functional zinc oxide modified polypropylene antibacterial plastic.

[0019] Example 2

[0020] (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: 0.2 g of maleic anhydride, 0.6 g of interfacial agent xylene and 0.015 g of initiator azobisisobutyronitrile (AIBN) were placed in a reaction bottle, stirred evenly, and then 5 g of carboxyl-terminated polyethylene was added. The mixture was stirred continuously under a nitrogen atmosphere and reacted at 90°C for 3 h. After the reaction was completed, the mixture was cooled, extracted for 5 h, and vacuum dried at 45°C to obtain maleic anhydride grafted carboxyl-terminated polyethylene. (2) Preparation of amino zinc oxide: 5 g zinc oxide and 0.08 g γ-aminopropyltriethoxysilane were added to 150 mL acetone solvent and reacted at 80 °C for 4 h. After the reaction was completed, ethanol was used for extraction and drying to obtain amino zinc oxide. (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: 4 g of amino zinc oxide and 5 g of maleic anhydride grafted carboxyl-terminated polyethylene were ultrasonically dispersed in 125 mL of solvent, stirred evenly and reacted at 25 °C for 8 h. After the reaction was completed, the mixture was filtered and washed with ether and deionized water to obtain carboxyl-terminated polyethylene grafted zinc oxide. (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: 4 g of carboxyl-terminated polyethylene grafted zinc oxide was ultrasonically dispersed in 150 mL of tetrahydrofuran, and then 0.4 g of 2-hydroxymethylbenzimidazole, 2.8 g of dicyclohexylcarbodiimide (DCC) and 0.36 g of 4-dimethylaminopyridine (DMAP) were added. After stirring evenly, the mixture was reacted at 125 °C for 6 h. After the reaction was completed, the mixture was filtered to obtain benzimidazole-based polyethylene grafted zinc oxide. (5) Preparation of functional zinc oxide modified polypropylene antibacterial plastic: 0.2 g of benzimidazole polyethylene grafted zinc oxide and 10 g of polypropylene were added to a high-speed mixer and mixed evenly. The mixture was then transferred to a twin-screw extruder for granulation, and then an injection molding machine was used for preparation and shaping to obtain a functional zinc oxide modified polypropylene antibacterial plastic.

[0021] Example 3

[0022] (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: 0.3 g of maleic anhydride, 0.8 g of interfacial agent xylene and 0.02 g of initiator azobisisobutyronitrile (AIBN) were placed in a reaction bottle, stirred evenly, and then 5 g of carboxyl-terminated polyethylene was added. The mixture was stirred continuously under a nitrogen atmosphere and reacted at 100°C for 5 h. After the reaction was completed, the mixture was cooled, extracted for 6 h, and vacuum dried at 55°C to obtain maleic anhydride grafted carboxyl-terminated polyethylene. (2) Preparation of amino zinc oxide: 5 g zinc oxide and 0.12 g γ-aminopropyltriethoxysilane were added to 200 mL acetone solvent and reacted at 90 °C for 6 h. After the reaction was completed, ethanol was used for extraction and drying to obtain amino zinc oxide. (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: 4 g of amino zinc oxide and 7 g of maleic anhydride grafted carboxyl-terminated polyethylene were ultrasonically dispersed in 155 mL of solvent, stirred evenly and reacted at 45 °C for 12 h. After the reaction was completed, the mixture was filtered and washed with ether and deionized water to obtain carboxyl-terminated polyethylene grafted zinc oxide. (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: 4 g of carboxyl-terminated polyethylene grafted zinc oxide was ultrasonically dispersed in 220 mL of tetrahydrofuran, and then 0.48 g of 2-hydroxymethylbenzimidazole, 3.6 g of dicyclohexylcarbodiimide (DCC) and 0.42 g of 4-dimethylaminopyridine (DMAP) were added. After stirring evenly, the mixture was reacted at 145 °C for 8 h. After the reaction was completed, the mixture was filtered to obtain benzimidazole-based polyethylene grafted zinc oxide. (5) Preparation of functional zinc oxide modified polypropylene antibacterial plastic: 0.5 g of benzimidazole polyethylene grafted zinc oxide and 10 g of polypropylene were added to a high-speed mixer and mixed evenly. The mixture was then transferred to a twin-screw extruder for granulation, and then an injection molding machine was used for preparation and shaping to obtain functional zinc oxide modified polypropylene antibacterial plastic.

[0023] Example 4

[0024] (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: 0.4 g maleic anhydride, 1 g interfacial agent xylene and 0.025 g initiator azobisisobutyronitrile (AIBN) were placed in a reaction bottle, stirred evenly, and then 5 g carboxyl-terminated polyethylene was added. The mixture was stirred continuously under a nitrogen atmosphere and reacted at 120°C for 6 h. After the reaction was completed, the mixture was cooled, extracted for 8 h, and vacuum dried at 60°C to obtain maleic anhydride grafted carboxyl-terminated polyethylene. (2) Preparation of amino zinc oxide: 5 g zinc oxide and 0.15 g γ-aminopropyltriethoxysilane were added to 250 mL acetone solvent and reacted at 100 °C for 8 h. After the reaction was completed, ethanol was used for extraction and drying to obtain amino zinc oxide. (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: 4 g of amino zinc oxide and 8 g of maleic anhydride grafted carboxyl-terminated polyethylene were ultrasonically dispersed in 165 mL of solvent, stirred evenly and reacted at 50 °C for 15 h. After the reaction was completed, the mixture was filtered and washed with ether and deionized water to obtain carboxyl-terminated polyethylene grafted zinc oxide. (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: 4 g of carboxyl-terminated polyethylene grafted zinc oxide was ultrasonically dispersed in 290 mL of tetrahydrofuran, and then 0.6 g of 2-hydroxymethylbenzimidazole, 4 g of dicyclohexylcarbodiimide (DCC) and 0.48 g of 4-dimethylaminopyridine (DMAP) were added. After stirring evenly, the mixture was reacted at 150°C for 10 h. After the reaction was completed, the mixture was filtered to obtain benzimidazole-based polyethylene grafted zinc oxide. (5) Preparation of functional zinc oxide modified polypropylene antibacterial plastic: 0.6 g of benzimidazole polyethylene grafted zinc oxide and 10 g of polypropylene were added to a high-speed mixer and mixed evenly. The mixture was then transferred to a twin-screw extruder for granulation, and then an injection molding machine was used for preparation and shaping to obtain a functional zinc oxide modified polypropylene antibacterial plastic.

[0025] Comparative Example 1 (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: 0.3 g of maleic anhydride, 0.8 g of interfacial agent xylene and 0.02 g of initiator azobisisobutyronitrile (AIBN) were placed in a reaction bottle, stirred evenly, and then 5 g of carboxyl-terminated polyethylene was added. The mixture was stirred continuously under a nitrogen atmosphere and reacted at 100°C for 3 h. After the reaction was completed, the mixture was cooled, extracted for 6 h, and vacuum dried at 45°C to obtain maleic anhydride grafted carboxyl-terminated polyethylene. (2) Preparation of amino zinc oxide: 5 g of zinc oxide and 0.08 g of γ-aminopropyltriethoxysilane were added to 160 mL of acetone solvent and reacted at 80 °C for 5 h. After the reaction was completed, ethanol was used for extraction and drying to obtain amino zinc oxide. (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: 4 g of amino zinc oxide and 6 g of maleic anhydride grafted carboxyl-terminated polyethylene were ultrasonically dispersed in 125 mL of solvent, stirred evenly and reacted at 25 °C for 12 h. After the reaction was completed, the mixture was filtered and washed with ether and deionized water to obtain carboxyl-terminated polyethylene grafted zinc oxide. (4) Preparation of functionalized zinc oxide modified polypropylene antibacterial plastic: 0.5 g of benzimidazole polyethylene grafted zinc oxide and 10 g of polypropylene were added to a high-speed mixer and mixed evenly. The mixture was then transferred to a twin-screw extruder for granulation, and then an injection molding machine was used for preparation and shaping to obtain functionalized zinc oxide modified polypropylene antibacterial plastic.

[0026] Comparative Example 2 (1) Preparation of zinc oxide modified polypropylene antibacterial plastic: 0.2 g zinc oxide and 10 g polypropylene were added to a high-speed mixer and mixed evenly. The mixture was then transferred to a twin-screw extruder for granulation. The mixture was then prepared and shaped using an injection molding machine to obtain zinc oxide modified polypropylene antibacterial plastic.

[0027] Under light-free conditions, the antibacterial (Staphylococcus aureus) test was carried out on the functionalized zinc oxide modified polypropylene antibacterial plastic in accordance with the national standard GB / T 31402-2015.

[0028]

[0029] Under light conditions, the antibacterial (Staphylococcus aureus) test was carried out on the functionalized zinc oxide modified polypropylene antibacterial plastic in accordance with the national standard GB / T 31402-2015.

[0030]

[0031] Mechanical properties test of functional zinc oxide modified polypropylene antibacterial plastics according to national standard GB / T 2546.2-2003

Claims

1. A functionalized zinc oxide modified polypropylene antibacterial plastic, characterized in that: The preparation method of the functionalized zinc oxide modified polypropylene antibacterial plastic comprises the following steps: (1) Preparation of maleic anhydride grafted carboxyl-terminated polyethylene: maleic anhydride, an interfacial agent xylene and an initiator azobisisobutyronitrile are placed in a reaction bottle, stirred evenly, and then carboxyl-terminated polyethylene is added. The mixture is continuously stirred and reacted under a nitrogen atmosphere. After the reaction is completed, maleic anhydride grafted carboxyl-terminated polyethylene is obtained. (2) Preparation of amino zinc oxide: Add zinc oxide and γ-aminopropyltriethoxysilane to an acetone solvent at a mass ratio of 100:1-3:1800-4000, and react at 70-100°C for 3-8h. When the reaction is completed, amino zinc oxide is obtained; (3) Preparation of carboxyl-terminated polyethylene grafted zinc oxide: Aminated zinc oxide and maleic anhydride grafted carboxyl-terminated polyethylene are ultrasonically dispersed in an ether solvent, stirred evenly and reacted. After the reaction is completed, carboxyl-terminated polyethylene grafted zinc oxide is obtained; (4) Preparation of benzimidazole-based polyethylene grafted zinc oxide: ultrasonically disperse the carboxyl-terminated polyethylene grafted zinc oxide in tetrahydrofuran, then add 2-hydroxymethylbenzimidazole, dicyclohexylcarbodiimide and 4-dimethylaminopyridine, stir evenly, and react. After the reaction is completed, benzimidazole-based polyethylene grafted zinc oxide is obtained; (5) Preparation of functionalized zinc oxide modified polypropylene antibacterial plastic: Add benzimidazole polyethylene grafted zinc oxide and polypropylene into a high-speed mixer, mix evenly, and then transfer to a twin-screw extruder for granulation, and then use an injection molding machine for preparation and shaping to obtain functionalized zinc oxide modified polypropylene antibacterial plastic.

2. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (1), the mass ratio of maleic anhydride, xylene, azobisisobutyronitrile and carboxyl-terminated polyethylene is 3-8:8-20:0.2-0.5:

100.

3. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (1), the reaction temperature is 80-120° C. and the reaction time is 2-6 hours.

4. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (3), the mass ratio of the amino zinc oxide, the maleic anhydride grafted carboxyl-terminated polyethylene and the ether is 100:120-200:1800-3000.

5. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (3), the reaction temperature is 20-50°C and the reaction time is 6-15h.

6. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (4), the mass ratio of the carboxyl-terminated polyethylene grafted with zinc oxide, tetrahydrofuran, 2-hydroxymethylbenzimidazole, dicyclohexylcarbodiimide and 4-dimethylaminopyridine is 100:2500-6000:8-15:60-100:8-12.

7. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (4), the reaction temperature is 120-150° C. and the reaction time is 4-10 h.

8. The functionalized zinc oxide modified polypropylene antibacterial plastic according to claim 1, characterized in that: In the step (5), the mass ratio between the benzimidazole-based polyethylene grafted zinc oxide and the polypropylene is 1.5-6:100.

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