Degradable antibacterial plastic product and preparation method thereof

Abstract

The invention discloses a degradable antibacterial plastic product and a preparation method thereof, and relates to the technical field of plastics. The high-strength plastic product is prepared through a double-layer plastic sintering technology. The surface layer is made of biodegradable copolymer, and the bottom layer is made of rigid modified copolymer reinforced plastic layer, so that the overall mechanical property is improved. In addition, a composite natural antibacterial agent composed of zanthoxylum oil resin and a tea leaf extract is utilized, so that the applicability of the plastic product is improved, and the mechanical property of a surface layer structure is enhanced through a cross-linked network. The composite antibacterial agent is environment-friendly, has biodegradability, can be decomposed by microorganisms after being discarded, and participates in natural carbon circulation.

Description

Technical Field

[0001] The present invention relates to the technical field of plastics, in particular to a degradable antibacterial plastic product and a preparation method thereof. Background Art

[0002] It's reported that the world consumes an average of approximately 90 kg of synthetic polymers per person annually, the majority of which is neither biodegradable nor recyclable. Over 270 million tons of plastic are produced annually, 18 million tons of which end up in the oceans, and a cumulative 244,000 tons have already accumulated. Plastic has become a major environmental disaster. While many products, such as plastic bags and bottles, are labeled "recyclable" or "degradable," the reality is that these plastics are only recyclable to a limited extent.

[0003] As plastic products are used more and more widely in human life and production, they have also caused a series of problems to the environment: the plastic products used now are generally petroleum-based plastics, which have a low recycling rate and are difficult to degrade in nature or have a long degradation cycle, which can easily cause "white pollution", causing a series of damages to the soil and the environment, and seriously damaging the ecological environment system.

[0004] To address increasingly serious environmental issues, a growing number of researchers are exploring and developing green, environmentally friendly materials that can be degraded quickly. Biodegradable materials, with their excellent biodegradability and environmental friendliness, hold significant research value and broad market prospects. Summary of the Invention

[0005] The purpose of the present invention is to provide a degradable antibacterial plastic product and a preparation method thereof, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a degradable antibacterial plastic product, comprising, by weight, 100 to 150 parts of a copolymer, 70 to 95 parts of a modified copolymer, 15 to 22 parts of polystyrene, 12 to 25 parts of a composite natural antibacterial agent, and 6 to 20 parts of an antioxidant;

[0007] The copolymer is prepared by polymerizing diallyl pyrocarbonate and 3-butene-1-amine in a mass ratio of 1-5:1-5;

[0008] The modified copolymer is prepared by subjecting the copolymer to plasma pretreatment, immersing the copolymer in a grafting monomer solution, and then subjecting the grafting monomer to ultraviolet radiation treatment.

[0009] The composite natural antibacterial agent is prepared from Zanthoxylum bungeanum oleoresin, water-soluble starch and tea extract.

[0010] Furthermore, the Zanthoxylum bungeanum oleoresin is produced by a supercritical method with a purity of 60%.

[0011] Furthermore, the relative molecular mass of the polystyrene is 3000 g / mol.

[0012] Furthermore, the preparation method of the copolymer is: under the protection of high-purity nitrogen, adding a solvent, 3-butene-1-amine, and diallyl pyrocarbonate, heating to 50-70°C, adding an initiator, reacting for 2-3 hours, adding isopropanol to terminate the reaction, removing the solvent by rotary evaporation, and then drying at 60°C to constant weight to obtain a copolymer.

[0013] Furthermore, the solvent is butyl acetate.

[0014] Furthermore, the mass ratio of the solvent, 3-butene-1-amine, and initiator is 120-200:25-33:0.01.

[0015] Furthermore, the grafting monomer is 1-phenyl-2-propenyl-1-ketone.

[0016] Furthermore, the preparation method of the composite natural antibacterial agent is as follows: 60 to 85 parts by weight of Zanthoxylum bungeanum oleoresin is heated to 30 to 70° C., 6 to 10 parts by weight of an oil-soluble emulsifier is added, and the mixture is stirred until dissolved to obtain an oil phase; 60 to 80 parts by weight of water-soluble starch and 40 to 70 parts by weight of tea extract are added to 200 to 450 parts by weight of water and heated to 50 to 90° C., and then 1 to 10 parts by weight of a water-soluble emulsifier and 0.5 to 3 parts by weight of a stabilizer are added to obtain an aqueous phase; the aqueous phase and the oil phase are mixed, emulsified and homogenized at a pressure of 20 MPa to 80 MPa to form an emulsion with a particle size of 100 nm to 2000 nm, and spray-dried.

[0017] Furthermore, the antioxidant is prepared by mixing dilauryl thiodipropionate and gallic acid in a mass ratio of 4-7:10-15.

[0018] Furthermore, a method for preparing an antibacterial plastic product includes the following preparation steps:

[0019] (1) The copolymer, the composite natural antimicrobial agent, and 1 / 2 of the weight of the antioxidant are fully mixed in proportion to obtain a surface plastic powder;

[0020] (2) Fully mixing the modified copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant to obtain a bottom layer powder;

[0021] (3) The bottom layer powder is spread flat in the mold, covered with an aramid fiber mesh cloth of the same area and thickness of 0.1 to 1 mm, and then the surface layer plastic powder is spread flat, pressurized and sintered, and demolded to obtain an antibacterial plastic product.

[0022] Furthermore, the pressure in the pressure sintering is 3-35 MPa, and the sintering temperature is 160-220°C.

[0023] Furthermore, the aramid fiber mesh has a gram weight of 80 to 100 g / m 2 .

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention uses two layers of plastic to be flatly sintered without mixing with each other to obtain a high-strength plastic product. The surface plastic is based on a copolymer formed by the polymerization of diallyl pyrocarbonate and 3-butene-1-amine. Aliphatic ester bonds are introduced into the main chain of the copolymer molecule, making it biodegradable and giving the degradable plastic excellent degradability. The bottom plastic uses a rigid modified copolymer as the base material to form a reinforced plastic layer, thereby improving the overall mechanical properties of the plastic. The modified copolymer uses 1-phenyl-2-propenyl-1-ketone grafted onto the polypropylene molecular chain, introducing an oxidation-sensitive unit vinyl ketone, so that the surface plastic can accelerate the degradation of polypropylene during composting or soil burial, thereby making the overall plastic have excellent degradability.

[0026] (2) The present invention uses Zanthoxylum bungeanum oleoresin as the oil phase and water-soluble starch and tea extract as the water phase, and emulsifies and encapsulates to form a composite natural antimicrobial agent. The addition of tea extract masks the irritating taste of Zanthoxylum bungeanum oleoresin, improving the applicability of plastic products. The polar groups of water-soluble starch and tea extract as the encapsulating layer can covalently bind to the copolymer to form a cross-linked network, inhibiting the relative slip between the copolymer molecular chains and imparting excellent mechanical properties to the surface structure. The composite natural antimicrobial agent used in the present invention is environmentally friendly and can be decomposed into carbon dioxide and water by microorganisms in nature after being discarded, and then absorbed and utilized by plants, participating in the carbon cycle, and having biodegradability. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] In order to more clearly illustrate the method provided by the present invention, the following examples are provided in detail. The test methods for various indicators of the antibacterial plastic products prepared in the following examples are as follows:

[0029] The antibacterial performance is tested in accordance with QB / T2591-2003 "Antibacterial Plastics - Test Methods for Antibacterial Performance and Antibacterial Effect" (film method).

[0030] The tensile properties were tested according to GB / T1040.3-2006 using a universal material testing machine at a test speed of 10 mm / min.

[0031] Degradation performance: Soil burial degradation: Cut a certain size of film, dry it thoroughly to constant weight (W0), mark it and bury it about 10 cm below the ground surface. Take it out after 3 months, wash it with water and ethanol, weigh it after drying (W1), and calculate the weight loss rate. Weight loss rate (%) = (W1-W0) / W0×100%; take 5 test samples and take the average value of the final result.

[0032] Example 1

[0033] A biodegradable antibacterial plastic product comprises, by weight, 100 parts of a copolymer, 70 parts of a modified copolymer, 15 parts of polystyrene, 12 parts of a composite natural antibacterial agent, and 6 parts of an antioxidant; the antioxidant is prepared by mixing dilauryl thiodipropionate and gallic acid in a mass ratio of 4:10;

[0034] The preparation method of the antibacterial plastic product is:

[0035] (1) Under the protection of high-purity nitrogen, butyl acetate, 3-butene-1-amine, and diallyl pyrocarbonate were added, heated to 50°C, n-butyl lithium was added, and the reaction was continued for 2 hours. Then, isopropanol was added to terminate the reaction, the solvent was removed by rotary evaporation, and the copolymer was dried at 60°C to constant weight; the mass ratio of butyl acetate, 3-butene-1-amine, initiator, and isopropanol was 120:25:0.01:0.5;

[0036] (2) The copolymer was subjected to plasma treatment, vacuumed to 100 Pa, and then argon gas was introduced at a flow rate of 20 cm 3 / s, at a power of 20KW, a voltage of 380V, and a treatment time of 30s; immersing the treated copolymer in 5wt% 1-phenyl-2-propenyl-1-one / cyclohexane, placing the copolymer in a 60°C water bath, adding 0.001 times the mass of 1-phenyl-2-propenyl-1-one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and performing ultraviolet irradiation treatment at a wavelength of 300nm, a power of 500W, and a treatment time of 30min; rinsing the copolymer after ultraviolet irradiation with deionized water three times, and drying at 60°C for 3h to obtain a modified copolymer;

[0037] (3) heating 60 parts by weight of Zanthoxylum bungeanum oleoresin to 50° C., adding 6 parts by weight of phospholipid, and stirring until dissolved to obtain an oil phase; adding 60 parts by weight of water-soluble starch and 40 parts by weight of tea extract to 200 parts by weight of water and heating to 50° C., and then adding 1 part by weight of sodium caseinate and 0.5 parts by weight of citric acid to obtain an aqueous phase; mixing the aqueous phase and the oil phase, emulsifying and homogenizing the mixture under a pressure of 40 MPa to form an emulsion with a particle size of 250 nm, and drying the emulsion in a spray drying tower under the conditions of an inlet air temperature of 200° C. and an outlet air temperature of 100° C. to obtain a composite natural antibacterial agent;

[0038] (4) The copolymer, the composite natural antimicrobial agent, and 1 / 2 of the weight of the antioxidant are fully mixed in proportion to obtain a surface plastic powder;

[0039] (5) Fully mix the modified copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant to obtain a bottom layer powder;

[0040] (6) Spread the bottom layer of powder in the mold, cover it with an aramid fiber mesh cloth of the same area and thickness of 0.5 mm, and then spread the surface plastic powder. Maintain the pressure at 10 MPa and the sintering temperature at 200 ° C for 2.5 hours, demold, and obtain the antibacterial plastic product.

[0041] Example 2

[0042] A biodegradable antibacterial plastic product comprising, by weight, 125 parts of a copolymer, 85 parts of a modified copolymer, 18 parts of polystyrene, 20 parts of a composite natural antibacterial agent, and 13 parts of an antioxidant; the antioxidant being a mixture of dilauryl thiodipropionate and gallic acid in a mass ratio of 7:10;

[0043] The preparation method of the antibacterial plastic product is:

[0044] (1) Under the protection of high-purity nitrogen, butyl acetate, 3-butene-1-amine, and diallyl pyrocarbonate were added, heated to 60°C, n-butyl lithium was added, and the reaction was continued for 3 hours. Then, isopropanol was added to terminate the reaction, the solvent was removed by rotary evaporation, and the copolymer was dried at 60°C to constant weight; the mass ratio of butyl acetate, 3-butene-1-amine, initiator, and isopropanol was 160:30:0.01:0.5;

[0045] (2) The copolymer was subjected to plasma treatment, vacuumed to 150 Pa, and then argon gas was introduced at a flow rate of 30 cm 3 / s, at a power of 60KW, a voltage of 380V, and a treatment time of 65s; immersing the treated copolymer in 12wt% 1-phenyl-2-propenyl-1-one / cyclohexane, placing the copolymer in a 70°C water bath, adding 0.001 times the mass of 1-phenyl-2-propenyl-1-one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and performing ultraviolet irradiation treatment at a wavelength of 300nm, a power of 500W, and a treatment time of 45min; rinsing the copolymer after ultraviolet irradiation with deionized water three times, and drying at 60°C for 3h to obtain a modified copolymer;

[0046] (3) heating 72 parts by weight of Zanthoxylum bungeanum oleoresin to 50° C., adding 8 parts by weight of phospholipid, and stirring until dissolved to obtain an oil phase; adding 70 parts by weight of water-soluble starch and 55 parts by weight of tea extract to 315 parts by weight of water and heating to 50° C., and then adding 6 parts by weight of sodium caseinate and 1.8 parts by weight of citric acid to obtain an aqueous phase; mixing the aqueous phase and the oil phase, emulsifying and homogenizing at a pressure of 40 MPa to form an emulsion with a particle size of 250 nm, and drying the emulsion in a spray drying tower under the conditions of an inlet air temperature of 200° C. and an outlet air temperature of 100° C. to obtain a composite natural antibacterial agent;

[0047] (4) The copolymer, the composite natural antimicrobial agent, and 1 / 2 of the weight of the antioxidant are fully mixed in proportion to obtain a surface plastic powder;

[0048] (5) Fully mix the modified copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant to obtain a bottom layer powder;

[0049] (6) Spread the bottom layer of powder in the mold, cover it with an aramid fiber mesh cloth of the same area and thickness of 0.5 mm, and then spread the surface plastic powder. Maintain the pressure at 10 MPa and the sintering temperature at 200 ° C for 2.5 hours, demold, and obtain the antibacterial plastic product.

[0050] Example 3

[0051] A biodegradable antibacterial plastic product comprises, by weight, 150 parts of a copolymer, 95 parts of a modified copolymer, 22 parts of polystyrene, 25 parts of a composite natural antibacterial agent, and 20 parts of an antioxidant; the antioxidant is prepared by mixing dilauryl thiodipropionate and gallic acid in a mass ratio of 7:15;

[0052] The preparation method of the antibacterial plastic product is:

[0053] (1) Under the protection of high-purity nitrogen, butyl acetate, 3-butene-1-amine, and diallyl pyrocarbonate were added, heated to 70°C, n-butyl lithium was added, and the reaction was continued for 3 hours. Then, isopropanol was added to terminate the reaction, the solvent was removed by rotary evaporation, and the copolymer was dried at 60°C to constant weight; the mass ratio of butyl acetate, 3-butene-1-amine, initiator, and isopropanol was 200:33:0.01:0.5;

[0054] (2) The copolymer was subjected to plasma treatment, vacuumed to 200 Pa, and then argon gas was introduced at a flow rate of 40 cm 3 / s, at a power of 100KW, a voltage of 380V, and a treatment time of 100s; immersing the treated copolymer in 20wt% 1-phenyl-2-propenyl-1-one / cyclohexane, placing the copolymer in an 80°C water bath, adding 0.001 times the mass of 1-phenyl-2-propenyl-1-one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and performing ultraviolet irradiation treatment at a wavelength of 300nm, a power of 500W, and a treatment time of 50min; rinsing the copolymer after ultraviolet irradiation treatment with deionized water 5 times, and drying at 60°C for 5h to obtain a modified copolymer;

[0055] (3) heating 85 parts by weight of Zanthoxylum bungeanum oleoresin to 50° C., adding 10 parts by weight of phospholipid, and stirring until dissolved to obtain an oil phase; adding 80 parts by weight of water-soluble starch and 70 parts by weight of tea extract to 450 parts by weight of water and heating to 90° C., and then adding 10 parts by weight of sodium caseinate and 3 parts by weight of citric acid to obtain an aqueous phase; mixing the aqueous phase and the oil phase, emulsifying and homogenizing at a pressure of 40 MPa to form an emulsion with a particle size of 250 nm, and drying the emulsion in a spray drying tower under the conditions of an inlet air temperature of 200° C. and an outlet air temperature of 100° C. to obtain a composite natural antibacterial agent;

[0056] (4) The copolymer, the composite natural antimicrobial agent, and 1 / 2 of the weight of the antioxidant are fully mixed in proportion to obtain a surface plastic powder;

[0057] (5) Fully mix the modified copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant to obtain a bottom layer powder;

[0058] (6) Spread the bottom layer of powder in the mold, cover it with an aramid fiber mesh cloth of the same area and thickness of 0.5 mm, and then spread the surface plastic powder. Maintain the pressure at 10 MPa and the sintering temperature at 200 ° C for 2.5 hours, demold, and obtain the antibacterial plastic product.

[0059] Comparative Example 1

[0060] The difference between Comparative Example 1 and Example 3 is that polyethylene is used instead of the copolymer, and the remaining steps are the same as those of Example 1.

[0061] Comparative Example 2

[0062] The difference between Comparative Example 2 and Example 3 is that ethylene-vinyl acetate copolymer is used instead of copolymer, and the remaining steps are the same as Example 1.

[0063] Comparative Example 3

[0064] A biodegradable antibacterial plastic product comprising, by weight, 170 parts of a copolymer, 15 parts of polystyrene, 12 parts of a composite natural antibacterial agent, and 6 parts of an antioxidant; the antioxidant being a mixture of dilauryl thiodipropionate and gallic acid in a mass ratio of 4:10;

[0065] The preparation method of the antibacterial plastic product is:

[0066] (1) Under the protection of high-purity nitrogen, butyl acetate, 3-butene-1-amine, and diallyl pyrocarbonate were added, heated to 50°C, n-butyl lithium was added, and the reaction was continued for 2 hours. Then, isopropanol was added to terminate the reaction, the solvent was removed by rotary evaporation, and the copolymer was dried at 60°C to constant weight; the mass ratio of butyl acetate, 3-butene-1-amine, initiator, and isopropanol was 120:25:0.01:0.5;

[0067] (2) heating 60 parts by weight of Zanthoxylum bungeanum oleoresin to 50° C., adding 6 parts by weight of phospholipid, and stirring until dissolved to obtain an oil phase; adding 60 parts by weight of water-soluble starch and 40 parts by weight of tea extract to 200 parts by weight of water and heating to 50° C., and then adding 1 part by weight of sodium caseinate and 0.5 parts by weight of citric acid to obtain an aqueous phase; mixing the aqueous phase and the oil phase, emulsifying and homogenizing the mixture under a pressure of 40 MPa to form an emulsion with a particle size of 250 nm, and drying the emulsion in a spray drying tower under the conditions of an inlet air temperature of 200° C. and an outlet air temperature of 100° C. to obtain a composite natural antibacterial agent;

[0068] (3) 100 parts of the copolymer, the composite natural antibacterial agent, and 1 / 2 of the weight of the antioxidant are fully mixed in proportion to obtain a surface plastic powder;

[0069] (4) 70 parts of the copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant were thoroughly mixed to obtain a bottom layer powder;

[0070] (5) Spread the bottom layer of powder in the mold, cover it with an aramid fiber mesh cloth of the same area and thickness of 0.5 mm, and then spread the surface plastic powder. Maintain the pressure at 10 MPa and the sintering temperature at 200 ° C for 2.5 hours, demold, and obtain the antibacterial plastic product.

[0071] Comparative Example 4

[0072] A biodegradable antibacterial plastic product comprising, by weight, 100 parts of a copolymer, 70 parts of a modified copolymer, 15 parts of polystyrene, 6 parts of an antioxidant, 5 parts of Zanthoxylum bungeanum oleoresin, 5 parts of a tea extract, and 5 parts of a water-soluble starch; the antioxidant being a mixture of dilauryl thiodipropionate and gallic acid in a mass ratio of 4:10;

[0073] The preparation method of the antibacterial plastic product is:

[0074] (1) Under the protection of high-purity nitrogen, butyl acetate, 3-butene-1-amine, and diallyl pyrocarbonate were added, heated to 50°C, n-butyl lithium was added, and the reaction was continued for 2 hours. Then, isopropanol was added to terminate the reaction, the solvent was removed by rotary evaporation, and the copolymer was dried at 60°C to constant weight; the mass ratio of butyl acetate, 3-butene-1-amine, initiator, and isopropanol was 120:25:0.01:0.5;

[0075] (2) The copolymer was subjected to plasma treatment, vacuumed to 100 Pa, and then argon gas was introduced at a flow rate of 20 cm 3 / s, at a power of 20KW, a voltage of 380V, and a treatment time of 30s; immersing the treated copolymer in 5wt% 1-phenyl-2-propenyl-1-one / cyclohexane, placing the copolymer in a 60°C water bath, adding 0.001 times the mass of 1-phenyl-2-propenyl-1-one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and performing ultraviolet irradiation treatment at a wavelength of 300nm, a power of 500W, and a treatment time of 30min; rinsing the copolymer after ultraviolet irradiation with deionized water three times, and drying at 60°C for 3h to obtain a modified copolymer;

[0076] (3) The copolymer, the composite natural antibacterial agent, 1 / 2 of the weight of the antioxidant, the Zanthoxylum oleoresin, the water-soluble starch, and the tea extract are fully mixed in proportion to obtain a surface plastic powder;

[0077] (4) Fully mixing the modified copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant to obtain a bottom layer powder;

[0078] (5) Spread the bottom layer of powder in the mold, cover it with an aramid fiber mesh cloth of the same area and thickness of 0.5 mm, and then spread the surface plastic powder. Maintain the pressure at 10 MPa and the sintering temperature at 200 ° C for 2.5 hours, demold, and obtain the antibacterial plastic product.

[0079] Comparative Example 5

[0080] A degradable antibacterial plastic product comprises, by weight, 100 parts of a copolymer, 70 parts of a modified copolymer, 15 parts of polystyrene, 12 parts of a composite natural antibacterial agent, and 6 parts of an antioxidant. The antibacterial plastic product is obtained by melt-extruding the components. The antioxidant is prepared by mixing dilauryl thiodipropionate and gallic acid in a mass ratio of 4:10.

[0081] Effect Examples

[0082] Table 1 below shows the performance analysis results of the antibacterial plastic products of Examples 1 to 3 of the present invention and Comparative Examples 1 to 5.

[0083] Table 1

[0084]

[0085]

[0086] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A degradable antibacterial plastic product, characterized in that: The composition comprises, by weight, 100 to 150 parts of copolymer, 70 to 95 parts of modified copolymer, 15 to 22 parts of polystyrene, 12 to 25 parts of composite natural antibacterial agent, and 6 to 20 parts of antioxidant; The copolymer is prepared by polymerizing diallyl pyrocarbonate and 3-butene-1-amine in a mass ratio of 1-5:1-5; The modified copolymer is prepared by subjecting the copolymer to plasma pretreatment, immersing the copolymer in a grafting monomer solution, and then subjecting the grafting monomer to ultraviolet radiation treatment. The composite natural antibacterial agent is prepared from Zanthoxylum bungeanum oleoresin, water-soluble starch and tea extract.

2. A degradable antibacterial plastic product according to claim 1, characterized in that: The preparation method of the copolymer comprises the following steps: adding a solvent, 3-butene-1-amine, and diallyl pyrocarbonate under the protection of high-purity nitrogen, heating to 50-70° C., adding an initiator, reacting for 2-3 hours, adding isopropanol to terminate the reaction, removing the solvent by rotary evaporation, and then drying at 60° C. to a constant weight to obtain the copolymer.

3. The degradable antibacterial plastic product according to claim 2, characterized in that: The solvent is butyl acetate.

4. The degradable antibacterial plastic product according to claim 2, characterized in that: The mass ratio of the solvent, 3-butene-1-amine and initiator is 120-200:25-33:0.

01.

5. The degradable antibacterial plastic product according to claim 1, characterized in that: The grafting monomer is 1-phenyl-2-propenyl-1-ketone.

6. The degradable antibacterial plastic product according to claim 1, characterized in that: The preparation method of the composite natural antibacterial agent comprises the following steps: heating 60 to 85 parts by weight of Zanthoxylum bungeanum oleoresin to 30 to 70° C., adding 6 to 10 parts by weight of an oil-soluble emulsifier, and stirring until dissolved to obtain an oil phase; adding 60 to 80 parts by weight of water-soluble starch and 40 to 70 parts by weight of tea extract to 200 to 450 parts by weight of water and heating the mixture to 50 to 90° C., and then adding 1 to 10 parts by weight of the water-soluble emulsifier and 0.5 to 3 parts by weight of a stabilizer to obtain an aqueous phase; mixing the aqueous phase and the oil phase, emulsifying and homogenizing the mixture under a pressure of 20 to 80 MPa to form an emulsion with a particle size of 100 to 2000 nm, and spray drying the mixture.

7. The degradable antibacterial plastic product according to claim 1, characterized in that: The antioxidant is prepared by mixing dilauryl thiodipropionate and gallic acid in a mass ratio of 4-7:10-15.

8. A method for preparing an antibacterial plastic product, characterized in that: The method comprises the following preparation steps: (1) The copolymer, the composite natural antimicrobial agent, and 1 / 2 of the weight of the antioxidant are fully mixed in proportion to obtain a surface plastic powder; (2) Fully mixing the modified copolymer, polystyrene, and 1 / 2 of the weight of the antioxidant to obtain a bottom layer powder; (3) The bottom layer powder is spread flat in the mold, covered with an aramid fiber mesh cloth of the same area and thickness of 0.1 to 1 mm, and then the surface layer plastic powder is spread flat, pressurized and sintered, and demolded to obtain an antibacterial plastic product.

9. The method for preparing an antibacterial plastic product according to claim 8, characterized in that: In the pressurized sintering in step (3), the pressurized pressure is 3 to 35 MPa, and the sintering temperature is 160 to 220°C.

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