A method for preparing antibacterial and anticorrosive polyethylene packaging film

Abstract

The invention belongs to the field of polyethylene technology, and is particularly a method for preparing an antibacterial and anticorrosive polyethylene packaging film, comprising 100 parts by weight of polyethylene resin, 1-12 parts by weight of polyphenyl polyquaternary ammonium salt modified starch, 0.3-4 parts by weight of compatibilizer, and 0.2-0.4 parts by weight of antioxidant. The present invention utilizes polyphenyl polyquaternary ammonium salt modified starch and polyethylene resin to carry out melt granulation and blown film forming to obtain an antibacterial and anticorrosive polyethylene packaging film; starch and trimesic acid quaternary ammonium salt contain more hydroxyl groups, and esterification reaction occurs with trimesic acid chloride, and the three form a cross-linked network structure, while polyphenyl polyquaternary ammonium salt modified starch contains a large amount of rigid benzene ring structures, which has a significant reinforcing effect on polyethylene, and improves the tensile properties of the packaging film. Polyphenyl polyquaternary ammonium salt modified starch contains a large amount of quaternary ammonium salt groups, so that the packaging film has excellent antibacterial and anti-biological corrosion performance.

Description

Technical Field

[0001] The invention belongs to the technical field of polyethylene, and in particular relates to a method for preparing an antibacterial and anticorrosive polyethylene packaging film. Background Art

[0002] Polyethylene can be made into film materials through blow molding, cast film and other methods. It has good barrier properties, transparency, weather resistance and other properties, and is widely used in packaging, agriculture, construction and other fields. Improving the antibacterial, anti-biological corrosion, mechanical strength and other properties of polyethylene will help expand the use of polyethylene film in the packaging of food, medicine, medical supplies and other fields.

[0003] Excessive use of petroleum-based plastics such as polyethylene will lead to serious environmental problems such as "white pollution"; in recent years, the development of bio-based green energy and biosolvable materials has been a research hotspot. Starch is cheap, easy to obtain, green, pollution-free, and biodegradable, and is widely used in molecular materials such as polyethylene. Chinese patent CN114561044B discloses a starch / polyethylene degradable film and a preparation method thereof, which forms a double network structure by forming a hydrophilic-hydrophilic network structure constructed between starch molecules and a hydrophilic-hydrophobic network structure constructed between plasticized starch and polyethylene, which work together to greatly improve the mechanical properties of the film material, but the patent does not improve the antibacterial properties of polyethylene. It is not conducive to the practical application of polyethylene film materials in the fields of products, medicines, and medical supplies. Summary of the invention

[0004] 1. Technical problems solved:

[0005] In view of the deficiencies in the prior art, the present invention provides a method for preparing an antibacterial and antiseptic polyethylene packaging film, which solves the problem that the polyethylene packaging film has no antibacterial properties and poor mechanical properties.

[0006] (II) Technical solution:

[0007] An antibacterial and antiseptic polyethylene packaging film comprises the following raw materials: 100 parts by weight of polyethylene resin, 1-12 parts by weight of polyphenyl polyquaternary ammonium salt modified starch, 0.3-4 parts by weight of a compatibilizer, and 0.2-0.4 parts by weight of an antioxidant;

[0008] The preparation method of polyphenyl polyquaternary ammonium salt modified starch is as follows: N, N-dimethylformamide, pyridine and starch are added into a reaction container, heated and stirred to mix, then trimesoyl chloride and trimesoyl quaternary ammonium salt are added, stirred to react, filtered and washed with ethanol and water, and then extracted with acetone in a Soxhlet extractor to obtain polyphenyl polyquaternary ammonium salt modified starch.

[0009] The quaternary ammonium salt of trimesic acid has the chemical structure of the following formula (I):

[0010]

[0011] Preferably, the temperature for heating, stirring and mixing is 100-110° C. and the time is 1-2 h; the temperature for stirring the reaction is 60-90° C. and the time is 8-15 h.

[0012] Preferably, the volume ratio of N,N-dimethylformamide to pyridine is 1:(0.7-1).

[0013] Preferably, the mass ratio of starch, trimesoyl chloride and trimesoyl quaternary ammonium salt is 1:(0.03-0.2):(0.1-0.6).

[0014] Preferably, the compatibilizer is maleic anhydride grafted polyethylene; and the antioxidant is antioxidant 1010.

[0015] Preferably, the preparation method of trimesic acid quaternary ammonium salt is as follows:

[0016] Step (1), at 0-5°C, add dichloromethane, pyridine, 4-dimethylaminopyridine, trimesoyl chloride, and glycidol in a molar ratio of (3-3.3):(0.15-0.18):1:(3-3.3) to a reaction container, stir and mix, then react at 20-25°C for 12-24h, concentrate under reduced pressure, wash with water, and then recrystallize from ethyl acetate to obtain trimesoyl triglycidyl ester. The reaction formula is as follows:

[0017]

[0018] Step (2), add ethanol, triethylamine hydrochloride and trimesylic acid ester in a molar ratio of (3-3.6):1 to a reaction vessel, stir and react at 30-45°C for 5-8h, concentrate under reduced pressure, and recrystallize from ethyl acetate to obtain trimesylic acid ester quaternary ammonium salt. The reaction formula is as follows:

[0019]

[0020] Preferably, the method for preparing the antibacterial and antiseptic polyethylene packaging film comprises adding polyethylene resin, polyphenyl polyquaternary ammonium salt modified starch, compatibilizer, and antioxidant into a twin-screw extruder, melt-extruding, and pelletizing; and then using a single-screw film blowing machine to blow-mold the film to obtain the antibacterial and antiseptic polyethylene packaging film.

[0021] (III) Technical effect: The present invention uses pyridine as an acid binding agent and 4-dimethylaminopyridine as a catalyst to carry out an acyl chloride esterification reaction on trimesoyl chloride and glycidol, and then carries out a ring-opening reaction with triethylamine hydrochloride to obtain a trimesoyl ester quaternary ammonium salt containing multiple quaternary ammonium salts and hydroxyl groups. Further, using trimesoyl chloride as a cross-linking agent, starch and trimesoyl ester quaternary ammonium salt are subjected to an esterification cross-linking reaction to obtain a polyphenyl polyquaternary ammonium salt modified starch. Thus, a large number of quaternary ammonium salt groups and rigid benzene ring structures are introduced into the starch matrix.

[0022] The invention utilizes polyphenyl polyquaternary ammonium salt modified starch and polyethylene resin to carry out melt granulation and blow molding to prepare antibacterial and anticorrosive polyethylene packaging film; starch and trimesic acid ester quaternary ammonium salt contain more hydroxyl groups, and esterification reaction occurs with trimesic acid chloride, and the three form a cross-linked network structure, and maleic anhydride is added to graft polyethylene, and its maleic anhydride group can react with the hydroxyl group in the polyphenyl polyquaternary ammonium salt modified starch, so that it can be used as a compatibilizer, improve the compatibility between the modified starch and the polyethylene resin, and will not affect the mechanical properties of the polyethylene packaging film. At the same time, the polyphenyl polyquaternary ammonium salt modified starch contains a large amount of rigid benzene ring structure, which has a significant reinforcing effect on polyethylene, thereby improving the tensile properties of the packaging film.

[0023] The polyphenyl polyquaternary ammonium salt modified starch in the polyethylene packaging film of the present invention contains a large number of quaternary ammonium salt groups, presents positive charge, can generate electrostatic interaction with negatively charged substances in bacterial cell membranes, can change the permeability and integrity of cell membranes, make genetic materials such as DNA and RNA in cells overflow, lead to cell death, show very high inhibition zone diameter to Escherichia coli, Staphylococcus aureus and Candida albicans, and have excellent antibacterial and biocorrosion inhibition performance. DETAILED DESCRIPTION

[0024] In order to make the technical solution of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. It should be noted that the following embodiments are only used to better understand the technical solution of the present invention and should not be understood as limiting the present invention.

[0025] The polyethylene resin of the present invention has the model number DFDA-7042. The maleic anhydride grafted polyethylene has the brand number XR-14L.

[0026] Preparation method of trimesic acid quaternary ammonium salt:

[0027] Step (1), at 0-5° C., add dichloromethane, pyridine, 4-dimethylaminopyridine, trimesoyl chloride, and glycidol in a molar ratio of (3-3.3):(0.15-0.18):1:(3-3.3) into a reaction container, stir and mix, then react at 20-25° C. for 12-24 hours, concentrate under reduced pressure, wash with water, and then recrystallize from ethyl acetate to obtain trimesoyl chloride.

[0028] Step (2), adding ethanol, triethylamine hydrochloride and trimesylic acid triglycidyl ester in a molar ratio of (3-3.6):1 into a reaction container, stirring and reacting at 30-45° C. for 5-8 hours, concentrating under reduced pressure, and recrystallizing with ethyl acetate to obtain trimesylic acid quaternary ammonium salt.

[0029] The preparation method of polyphenyl polyquaternary ammonium salt modified starch is as follows: N, N-dimethylformamide and pyridine in a volume ratio of 1: (0.7-1) are added into a reaction container, and starch is added, heated to 100-110° C., stirred and mixed for 1-2 hours for gelatinization, cooled to room temperature, and then trimesoyl chloride and trimesoyl ester quaternary ammonium salt are added, wherein the mass ratio of starch, trimesoyl chloride and trimesoyl ester quaternary ammonium salt is 1: (0.03-0.2): (0.1-0.6), heated to 60-90° C., stirred and reacted for 8-15 hours, filtered, washed with ethanol and water, and then extracted with acetone in a Soxhlet extractor to obtain polyphenyl polyquaternary ammonium salt modified starch.

[0030] The preparation method of the antibacterial and anticorrosive polyethylene packaging film is as follows: 100 parts by weight of polyethylene resin, 1-12 parts by weight of polyphenyl polyquaternary ammonium salt modified starch, 0.3-4 parts by weight of compatibilizer maleic anhydride grafted polyethylene, and 0.2-0.4 parts by weight of antioxidant 1010 are added into a twin-screw extruder, melt-extruded, and pelletized; then a single-screw film blowing machine is used to blow-form the film to obtain the antibacterial and anticorrosive polyethylene packaging film.

[0031] Example 1

[0032] (1) At 0°C, add 80 mL of dichloromethane, 66 mmol of pyridine, 3 mmol of 4-dimethylaminopyridine, 20 mmol of trimesoyl chloride, and 60 mmol of glycidol into a reaction container, stir and mix, and then react at 20°C for 18 hours, concentrate under reduced pressure, wash with water, and then recrystallize with ethyl acetate to obtain trimesoyl triglycidyl ester.

[0033] (2) Add 50 mL of ethanol, 96 mmol of triethylamine hydrochloride, and 30 mmol of trimesylic acid triglycidyl ester to a reaction vessel, stir and react at 30° C. for 8 h, concentrate under reduced pressure, and recrystallize with ethyl acetate to obtain trimesylic acid triglycidyl ester quaternary ammonium salt.

[0034] (3) Add 150 mL of N,N-dimethylformamide, 105 mL of pyridine, and 20 g of starch to a reaction container, heat to 110°C, stir and mix for 1 hour to gelatinize, then cool to room temperature, add 0.6 g of trimesoyl chloride and 2 g of trimesoyl quaternary ammonium salt, heat to 60°C, stir and react for 15 hours, filter, wash with ethanol and water, and then extract with acetone in a Soxhlet extractor to obtain polyphenyl polyquaternary ammonium salt modified starch.

[0035] (4) Add 1000g of polyethylene resin, 10g of polyphenyl polyquaternary ammonium salt modified starch, 3g of compatibilizer maleic anhydride grafted polyethylene, and 4g of antioxidant 1010 into a twin-screw extruder for melt extrusion. The temperatures of zones 1-6 are 160°C, 165°C, 170°C, 175°C, 175°C, 175°C, and the screw speed is 60r / min. Pellets are cut. Then, a single-screw film blowing machine is used for blow molding into a film. The temperatures of zones 1 to 4 are 170°C, 180°C, 185°C, and 180°C. The pulling roller speed is 10r / min. To obtain an antibacterial and antiseptic polyethylene packaging film.

[0036] Example 2

[0037] (1) Prepare trimesic acid quaternary ammonium salt according to the method of Example 1.

[0038] (2) Add 150 mL of N,N-dimethylformamide, 130 mL of pyridine, and 20 g of starch to a reaction container, heat to 100°C, stir and mix for 2 hours to gelatinize, then cool to room temperature, add 2.5 g of trimesoyl chloride and 8 g of trimesoyl quaternary ammonium salt, heat to 90°C, stir and react for 8 hours, filter, wash with ethanol and water, and then extract with acetone in a Soxhlet extractor to obtain polyphenyl polyquaternary ammonium salt modified starch.

[0039] (3) Add 1000g of polyethylene resin, 10g of polyphenyl polyquaternary ammonium salt modified starch, 3g of compatibilizer maleic anhydride grafted polyethylene, and 2g of antioxidant 1010 into a twin-screw extruder for melt extrusion. The temperatures of zones 1-6 are 160°C, 165°C, 170°C, 175°C, 175°C, 175°C, and the screw speed is 60r / min. Pellets are cut. Then, a single-screw film blowing machine is used for blow molding into a film. The temperatures of zones 1 to 4 are 170°C, 180°C, 185°C, and 180°C. The pulling roller speed is 10r / min. To obtain an antibacterial and antiseptic polyethylene packaging film.

[0040] Example 3

[0041] (1) Prepare trimesic acid quaternary ammonium salt according to the method of Example 1.

[0042] (2) Add 150 mL of N,N-dimethylformamide, 150 mL of pyridine, and 20 g of starch to a reaction container, heat to 100° C., stir and mix for 2 hours to gelatinize, then cool to room temperature, add 4 g of trimesoyl chloride and 12 g of trimesoyl quaternary ammonium salt, heat to 70° C., stir and react for 15 hours, filter, wash with ethanol and water, and then extract with acetone in a Soxhlet extractor to obtain polyphenyl polyquaternary ammonium salt modified starch.

[0043] (3) Add 1000g of polyethylene resin, 10g of polyphenyl polyquaternary ammonium salt modified starch, 3g of compatibilizer maleic anhydride grafted polyethylene, and 2g of antioxidant 1010 into a twin-screw extruder for melt extrusion. The temperatures of zones 1-6 are 160°C, 165°C, 170°C, 175°C, 175°C, 175°C, and the screw speed is 60r / min. Pellets are cut. Then, a single-screw film blowing machine is used for blow molding into a film. The temperatures of zones 1 to 4 are 170°C, 180°C, 185°C, and 180°C. The pulling roller speed is 10r / min. To obtain an antibacterial and antiseptic polyethylene packaging film.

[0044] Comparative Example 1

[0045] (4) Add 1000 g of polyethylene resin, 3 g of compatibilizer maleic anhydride grafted polyethylene, and 4 g of antioxidant 1010 into a twin-screw extruder for melt extrusion. The temperatures of zones 1 to 6 are 160°C, 165°C, 170°C, 175°C, 175°C, 175°C, and the screw speed is 60 r / min. Pellets are cut into pellets. A single-screw film blowing machine is then used for blow molding into a film. The temperatures of zones 1 to 4 are 170°C, 180°C, 185°C, and 180°C. The pulling roller speed is 10 r / min. A polyethylene packaging film is obtained.

[0046] Comparative Example 2

[0047] (1) Add 150 mL of N,N-dimethylformamide, 105 mL of pyridine, and 20 g of starch to a reaction container, heat to 110°C, stir and mix for 1 hour to gelatinize, then cool to room temperature, add 0.6 g of trimesoyl chloride, heat to 60°C, stir and react for 15 hours, filter, wash with ethanol and water, and then extract with acetone in a Soxhlet extractor to obtain modified starch.

[0048] (2) Add 1000 g of polyethylene resin, 10 g of modified starch, 3 g of compatibilizer maleic anhydride grafted polyethylene, and 4 g of antioxidant 1010 into a twin-screw extruder for melt extrusion. The temperatures of zones 1 to 6 are 160°C, 165°C, 170°C, 175°C, 175°C, 175°C, and the screw speed is 60 r / min. Pellets are cut into pellets. A single-screw film blowing machine is then used for blow molding into a film. The temperatures of zones 1 to 4 are 170°C, 180°C, 185°C, and 180°C. The pulling roller speed is 10 r / min. A polyethylene packaging film is obtained.

[0049] The mechanical properties of polyethylene packaging film were tested according to GB 13022-1991 method, with a test speed of 100 mm / min. The test results are shown in the table below.

[0050]

[0051]

[0052] As shown in the table above, the polyethylene packaging film of Comparative Example 1 has no modified starch added, and its transverse tensile strength is 19.2 MPa, and its elongation at break is 360.5%. Its longitudinal tensile strength is 19.7 MPa, and its elongation at break is 354.2%.

[0053] Polyphenyl polyquaternary ammonium salt modified starch was added in embodiment 1-3, and horizontal and vertical tensile strength was and elongation at break were significantly improved. Mainly because starch and trimesic acid ester quaternary ammonium salt contain more hydroxyl, esterification reaction occurs with trimesic acid chloride, three form cross-linked network structure, and add maleic anhydride grafted polyethylene, its maleic anhydride group can react with the hydroxyl in polyphenyl polyquaternary ammonium salt modified starch, so that it can be used as compatilizer, improve the compatibility between modified starch and polyethylene resin, and will not affect the mechanical property of polyethylene packaging film. Polyphenyl polyquaternary ammonium salt modified starch contains a large amount of rigid benzene ring structures simultaneously, and polyethylene is significantly enhanced, thereby improving the tensile properties of packaging film.

[0054] The starch and trimesoyl chloride in Comparative Example 2 can also undergo esterification and cross-linking reaction. Compared with Comparative Example 1, the tensile properties of the polyethylene packaging film in Comparative Example 2 are also improved to a certain extent.

[0055] Escherichia coli, Staphylococcus aureus, and Candida albicans were cultured and activated in a constant temperature incubator at 37°C for 24 h and diluted to 10 7 cfu / mL bacterial suspension. And spread it on the surface of beef extract peptone agar medium, make the polyethylene packaging film into a circular film with a diameter of 10mm, sterilize it under ultraviolet light, and then stick it on the surface of the culture medium, culture it in a constant temperature incubator at 37℃ for 48h, and measure the diameter of the inhibition zone. The test results are shown in the table below.

[0056]

[0057]

[0058] As can be seen from the above table, the polyethylene packaging films of Examples 1-3 all showed certain inhibition zone diameters for Escherichia coli, Staphylococcus aureus, and Candida albicans, and had excellent antibacterial properties, because the polyphenyl polyquaternary ammonium salt modified starch contained a large number of quaternary ammonium salt groups, which were positively charged and could interact electrostatically with negatively charged substances in bacterial cell membranes, thus changing the permeability and integrity of cell membranes, causing the overflow of genetic materials such as DNA and RNA in cells, leading to cell death, thereby showing good antibacterial properties and biocorrosion inhibition properties.

[0059] Example 4

[0060] (1) Prepare polyphenyl polyquaternary ammonium salt modified starch according to the method of Example 3.

[0061] (2) Add 1000 g of polyethylene resin, 30 g of polyphenyl polyquaternary ammonium salt modified starch, 9 g of compatibilizer maleic anhydride grafted polyethylene, and 2 g of antioxidant 1010 into a twin-screw extruder, melt extrude, the temperatures of zones 1-6 are 160° C., 165° C., 170° C., 175° C., 175° C., 175° C., the screw speed is 60 r / min, and pelletize; then use a single-screw film blowing machine to blow film, the temperatures of zones 1 to 4 are 170° C., 180° C., 185° C., 180° C., the traction roller speed is 10 r / min, to obtain an antibacterial and antiseptic polyethylene packaging film.

[0062] Example 5

[0063] (1) Prepare polyphenyl polyquaternary ammonium salt modified starch according to the method of Example 3.

[0064] (2) Add 1000 g of polyethylene resin, 60 g of polyphenyl polyquaternary ammonium salt modified starch, 20 g of compatibilizer maleic anhydride grafted polyethylene, and 2 g of antioxidant 1010 into a twin-screw extruder, melt extrude, the temperatures of zones 1-6 are 160° C., 165° C., 170° C., 175° C., 175° C., 175° C., the screw speed is 60 r / min, and pelletize; then use a single-screw film blowing machine to blow film, the temperatures of zones 1 to 4 are 170° C., 180° C., 185° C., 180° C., the traction roller speed is 10 r / min, to obtain an antibacterial and antiseptic polyethylene packaging film.

[0065] Example 6

[0066] (1) Prepare polyphenyl polyquaternary ammonium salt modified starch according to the method of Example 3.

[0067] (2) Add 1000 g of polyethylene resin, 90 g of polyphenyl polyquaternary ammonium salt modified starch, 30 g of compatibilizer maleic anhydride grafted polyethylene, and 2 g of antioxidant 1010 into a twin-screw extruder, melt extrude, the temperatures of zones 1-6 are 160° C., 165° C., 170° C., 175° C., 175° C., 175° C., the screw speed is 60 r / min, and pelletize; then use a single-screw film blowing machine to blow film, the temperatures of zones 1 to 4 are 170° C., 180° C., 185° C., 180° C., the pulling roller speed is 10 r / min, to obtain an antibacterial and antiseptic polyethylene packaging film.

[0068] Example 7

[0069] (1) Prepare polyphenyl polyquaternary ammonium salt modified starch according to the method of Example 3.

[0070] (2) Add 1000 g of polyethylene resin, 120 g of polyphenyl polyquaternary ammonium salt modified starch, 40 g of compatibilizer maleic anhydride grafted polyethylene, and 2 g of antioxidant 1010 into a twin-screw extruder, melt extrude, the temperatures of zones 1-6 are 160° C., 165° C., 170° C., 175° C., 175° C., 175° C., the screw speed is 60 r / min, and pelletize; then use a single-screw film blowing machine to blow film, the temperatures of zones 1 to 4 are 170° C., 180° C., 185° C., 180° C., the traction roller speed is 10 r / min, to obtain an antibacterial and antiseptic polyethylene packaging film.

[0071] The mechanical properties of polyethylene packaging film were tested according to GB 13022-1991 method, with a test speed of 100 mm / min. The test results are shown in the table below.

[0072]

[0073] As can be seen from the table above, as the amount of polyphenyl polyquaternary ammonium salt modified starch gradually increases, the transverse and longitudinal tensile strength and elongation at break show a trend of first increasing and then decreasing. The transverse strength and elongation at break reach a maximum of 26.5MPa and 422.1%, respectively. The longitudinal strength and elongation at break reach a maximum of 27.3MPa and 416.2%, respectively, showing excellent mechanical properties.

[0074] Escherichia coli, Staphylococcus aureus, and Candida albicans were cultured and activated in a constant temperature incubator at 37°C for 24 h and diluted to 10 7 cfu / mL bacterial suspension. And spread it on the surface of beef extract peptone agar medium, make the polyethylene packaging film into a circular film with a diameter of 10mm, sterilize it under ultraviolet light, and then stick it on the surface of the culture medium, culture it in a constant temperature incubator at 37℃ for 48h, and measure the diameter of the inhibition zone. The test results are shown in the table below.

[0075]

[0076] It can be seen from the above table that with the gradual increase in the dosage of polyphenyl polyquaternary ammonium salt modified starch, the diameter of the inhibition zone of the packaging film against Escherichia coli, Staphylococcus aureus and Candida albicans becomes larger and larger, and the antibacterial property and the inhibition of biocorrosion performance are good. However, when the dosage is too large, the increase in the diameter of the inhibition zone is not obvious.

Claims

1. An antibacterial and antiseptic polyethylene packaging film, characterized in that: The antibacterial and antiseptic polyethylene packaging film comprises the following raw materials: 100 parts by weight of polyethylene resin, 1-12 parts by weight of polyphenyl polyquaternary ammonium salt modified starch, 0.3-4 parts by weight of compatibilizer, and 0.2-0.4 parts by weight of antioxidant; The preparation method of the polyphenyl polyquaternary ammonium salt modified starch comprises: adding N,N-dimethylformamide, pyridine and starch into a reaction container, heating and stirring to mix, then adding trimesoyl chloride and trimesoyl quaternary ammonium salt, stirring to react, filtering and washing, and then extracting in a Soxhlet extractor to obtain the polyphenyl polyquaternary ammonium salt modified starch; The quaternary ammonium salt of trimesic acid ester has the chemical structural formula (I) as follows: Formula (I); The heating, stirring and mixing temperature is 100-110°C for 1-2 hours; the stirring reaction temperature is 60-90°C for 8-15 hours; The mass ratio of the starch, trimesoyl chloride and trimesoyl quaternary ammonium salt is 1:(0.03-0.2):(0.1-0.6); The compatibilizer is maleic anhydride grafted polyethylene.

2. The antibacterial and antiseptic polyethylene packaging film according to claim 1, characterized in that: The volume ratio of the N,N-dimethylformamide to pyridine is 1:(0.7-1).

3. The antibacterial and antiseptic polyethylene packaging film according to claim 1, characterized in that: The antioxidant is antioxidant 1010.

4. The antibacterial and antiseptic polyethylene packaging film according to claim 1, characterized in that: The preparation method of the trimesic acid quaternary ammonium salt is as follows: Step (1), adding dichloromethane, pyridine, 4-dimethylaminopyridine, trimesoyl chloride and glycidol into a reaction container at 0-5°C, stirring and mixing, and then reacting at 20-25°C for 12-24h, concentrating under reduced pressure, washing with water, and then recrystallizing with ethyl acetate to obtain trimesoyl chloride; Step (2), adding ethanol, triethylamine hydrochloride and trimesylic acid ester into a reaction container, stirring for reaction, concentrating under reduced pressure, and recrystallizing with ethyl acetate to obtain trimesylic acid ester quaternary ammonium salt.

5. The antibacterial and antiseptic polyethylene packaging film according to claim 4, characterized in that: In the step (1), the molar ratio of pyridine, 4-dimethylaminopyridine, trimesoyl chloride and glycidol is (3-3.3):(0.15-0.18):1:(3-3.3).

6. The antibacterial and antiseptic polyethylene packaging film according to claim 4, characterized in that: In the step (2), the molar ratio of triethylamine hydrochloride to triglycidyl benzene is (3-3.6):

1.

7. The antibacterial and antiseptic polyethylene packaging film according to claim 4, characterized in that: In the step (2), the reaction temperature is 30-45°C and the reaction time is 5-8h.

8. A method for preparing the antibacterial and antiseptic polyethylene packaging film according to any one of claims 1 to 7, characterized in that: Polyethylene resin, polyphenyl polyquaternary ammonium salt modified starch, compatibilizer and antioxidant are added into a twin-screw extruder, melt-extruded and pelletized; then a single-screw film blowing machine is used to blow-form the film to obtain an antibacterial and antiseptic polyethylene packaging film.

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