Antibacterial high-elasticity foam and preparation method thereof

Abstract

The invention relates to the technical field of foam, and discloses antibacterial high-elasticity foam and a preparation method thereof, and the foam is prepared from the following raw materials: low-density polyethylene, aminated polyethylene, an epichlorohydrin modified ethylene-octene copolymer, a foaming agent, a sensitizing agent and an antioxidant. Aminated polyethylene and an epichlorohydrin modified ethylene-octene copolymer are introduced into raw material components of the antibacterial high-elasticity foam, an irradiation crosslinking process is combined, quaternization reaction of the aminated polyethylene and the epichlorohydrin modified ethylene-octene copolymer forms an antibacterial active center, and quaternary ammonium salt provides lasting antibacterial property; the epoxy-amido ring-opening reaction of the two is carried out to construct a covalent cross-linked structure to enhance the compressive deformation resistance of the material; the epoxy chloropropane modified ethylene-octylene copolymer and the low-density polyethylene matrix form an island structure, impact energy is absorbed through elastic deformation, and the rebound resilience of the material is improved. Through mutual cooperation of the raw materials, the antibacterial property, antibacterial durability and rebound resilience of the foam are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of foams, and in particular to an antibacterial and highly elastic foam and a preparation method thereof. Background Art

[0002] Foams primarily include polyurethane foam, electron radiation cross-linked polyethylene (IXPE) foam, and ethylene-vinyl acetate copolymer (EVA) foam. Cross-linked polyethylene foam is a new type of foam material with a closed-cell structure that lies between soft polyurethane foam and rigid polystyrene foam. It combines strength, elasticity, wear resistance, chemical resistance, and insulation properties, making it an ideal material for insulation, heat insulation, cushioning, and buoyancy. Currently, antibacterial polyethylene foam materials are widely used in mechanical shock absorption, floor mats, automotive interiors, electronic equipment, and other fields. As market demand escalates, the demand for antibacterial properties in materials is also increasing.

[0003] In existing technology, the main method for improving the antimicrobial properties of polyethylene foam materials is to add antimicrobial agents. However, this method has significant drawbacks: first, the cost of antimicrobial agents is high; second, antimicrobial agents have poor compatibility with the polyethylene matrix and tend to migrate to the material surface over time, resulting in insufficient persistence of the antimicrobial effect and difficulty meeting the performance requirements for long-term use.

[0004] Furthermore, currently industrially produced chemically cross-linked foam materials, such as polyethylene electronic cross-linked foam and EVA foam, commonly use azodicarbonamide (AC) as a blowing agent. This foaming agent is highly polluting during its production process and is inherently toxic. Decomposition produces formamide and dimethylformamide residues, posing potential health risks. Furthermore, these foam materials frequently come into contact with the external environment during packaging, storage, and transportation, increasing the risk of infection by pathogens. Furthermore, the material itself lacks antimicrobial properties, further limiting its application. Summary of the Invention

[0005] In order to solve the problems existing in the background technology, the present invention provides an antibacterial and highly elastic foam and a preparation method thereof, which can simultaneously improve the antibacterial property, antibacterial durability and resilience of the foam and is not easy to migrate and lose.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] Disclosed is an antibacterial and highly elastic foam, comprising the following raw materials in parts by weight: 75-90 parts by weight of low-density polyethylene, 5-12 parts by weight of aminated polyethylene, 8-15 parts by weight of epichlorohydrin-modified ethylene-octene copolymer, 2-6 parts by weight of a foaming agent, 1-3 parts by weight of a sensitizer, and 0.5-2 parts by weight of an antioxidant; the foam is prepared by electron radiation cross-linking reaction.

[0008] Preferably, the mass ratio of the aminated polyethylene to the epichlorohydrin-modified ethylene-octene copolymer is 1:1.2-1.8; further, the mass ratio of the aminated polyethylene to the epichlorohydrin-modified ethylene-octene copolymer is 1:1.5.

[0009] Preferably, the mass ratio of epichlorohydrin modified ethylene-octene copolymer to low-density polyethylene is 1:5-7.5; further, the mass ratio of epichlorohydrin modified ethylene-octene copolymer to low-density polyethylene is 1:5.

[0010] Preferably, the foaming agent is one of 4,4-oxobisbenzenesulfonylhydrazide, benzenesulfonylhydrazide, toluenesulfonylhydrazide, or a combination of two or more thereof.

[0011] Preferably, the sensitizer is at least one of zinc stearate, zinc acetate, and zinc oxide.

[0012] Preferably, the antioxidant is a phosphite antioxidant.

[0013] Furthermore, the preparation method of the epichlorohydrin-modified ethylene-octene copolymer (epichlorohydrin-modified POE) comprises the following steps:

[0014] Ⅰ: Dissolve the POE base material in xylene, add tetrabutylammonium bromide, epichlorohydrin and dicumyl peroxide in sequence, and react at 85-90° C. for 4-6 hours to obtain a reaction solution;

[0015] II: Hydroquinone is added to the reaction solution to terminate the reaction, and then the reaction solution is poured into methanol at 0-5°C to precipitate the polymer, which is washed and dried to obtain epichlorohydrin-modified POE.

[0016] Preferably, the reaction in step I is carried out under nitrogen protection with a stirring rate of 200 to 300 rpm; epichlorohydrin is added dropwise for 30 minutes.

[0017] Preferably, the addition amount of tetrabutylammonium bromide is 0.5-1% of the weight of the POE base material, the addition amount of epichlorohydrin is 8-12% of the weight of the POE base material, and the addition amount of dicumyl peroxide is 0.1-0.3% of the weight of the POE base material.

[0018] Preferably, in step II, washing is performed three times with a methanol / water mixed solvent, and the drying condition is vacuum drying at 60° C. for 12 hours.

[0019] Preferably, the amount of hydroquinone added is 0.05% by weight of the POE base material.

[0020] Dicumyl peroxide triggers the formation of macromolecular free radicals from tertiary carbon and hydrogen atoms on the POE molecular chain. This radical action causes the epichlorohydrin ring to open, and its epoxy group (-CH(O)CH2-) undergoes a grafting reaction with the double bond on the POE chain. This reaction also preserves the chlorine atom (-CH2Cl) in the epichlorohydrin molecule, providing the product with active sites for halogenation reactions. Tetrabutylammonium bromide acts as a phase transfer catalyst, promoting the interfacial reaction between the non-polar POE (organic phase) and the polar epichlorohydrin (aqueous phase precursor), improving grafting efficiency.

[0021] Furthermore, the preparation method of the aminated polyethylene comprises the following steps:

[0022] The ethylene-acrylamide copolymer is dissolved in deionized water and heated with stirring until completely dissolved; after cooling, a mixed solution of sodium hypochlorite and sodium hydroxide is added dropwise, and the reaction temperature is controlled to continue the low-temperature reaction; sodium bisulfite is added to terminate the reaction, and the reaction solution is poured into cold methanol to precipitate the polymer, which is filtered, washed, and then dried to obtain the aminated polyethylene.

[0023] Under alkaline conditions, sodium hypochlorite acts as an oxidant to convert the amide groups in the ethylene-acrylamide copolymer into primary amine groups -NH2 through a Hofmann rearrangement reaction, while removing a carbonyl group to generate Na2CO3 by-product.

[0024] A method for preparing the above-mentioned antibacterial and highly elastic foam comprises the following steps:

[0025] S1. Add low-density polyethylene, aminated polyethylene, epichlorohydrin-modified ethylene-octene copolymer, foaming agent, sensitizer and antioxidant into a mixer, stir mechanically until uniform, add into a screw extruder for extrusion, set the extrusion section operating temperature to 100-140° C., the screw speed to 50-150 r / min, and extrude a sheet with a thickness of 0.4-0.8 mm to obtain a mother sheet;

[0026] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator, with an irradiation dose of 50 to 80 kGy;

[0027] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment, set the temperature of the foaming furnace to 200-240° C., the foaming time to 6-10 minutes, and then perform molding processing to obtain foam.

[0028] Beneficial effects of the present invention:

[0029] 1. The present invention introduces aminated polyethylene and epichlorohydrin-modified ethylene-octene copolymer into the raw material components of the antibacterial and highly elastic foam, and combines them with an irradiation cross-linking process to produce a cross-linked polyethylene foam material. Through the mutual coordination of the raw materials, the antibacterial properties, antibacterial durability and resilience of the foam are effectively improved, thereby obtaining an antibacterial and highly elastic foam, avoiding the problems of poor compatibility and insufficient persistence of the antibacterial effect caused by achieving the antibacterial properties of polyethylene foam materials by adding antibacterial agents.

[0030] 2. The aminated polyethylene prepared in this invention and the epichlorohydrin-modified ethylene-octene copolymer undergo a quaternization reaction under irradiation / heating conditions, generating a quaternary ammonium salt structure and forming an antimicrobial active center. These centers are chemically bonded within the polymer network, resisting migration and loss, and providing long-lasting antimicrobial properties. Sensitizers such as zinc stearate, zinc acetate, and zinc oxide release zinc ions during irradiation, which interact with the quaternary ammonium salt to enhance antimicrobial efficacy, inhibit biofilm formation, and effectively prevent microbial adhesion in long-term use, such as automotive interiors and medical underlays.

[0031] 3. Epichlorohydrin-modified ethylene-octene copolymer undergoes an epoxy-amine ring-opening reaction with aminated polyethylene, forming β-hydroxyamine bonds and building a three-dimensional crosslinked network. This covalent crosslinking structure enhances the material's compression set resistance. The epichlorohydrin-modified ethylene-octene copolymer acts as an "island phase" dispersed within the low-density polyethylene matrix, forming a sea-island structure. This elastic deformation absorbs impact energy, improving the material's resilience. The epoxy groups also enhance interfacial adhesion and inhibit phase separation.

[0032] 4. The foaming agent used in the present invention is environmentally friendly, and its decomposition products are harmless nitrogen and carbon dioxide. The products are clean and harmless, contain zero formamide and zero azodicarbonamide, are suitable for use in medical and children's settings, and have a killing effect on conventional Escherichia coli, Staphylococcus aureus, Salmonella, etc. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] It should be noted that:

[0035] (1) The present invention adopts the AATCC-100 bacterial count determination method to test the antibacterial property of the antibacterial high-elastic foam, and evaluates the antibacterial performance of the sample by calculating the inhibition rate.

[0036] Prepare a 1.8 cm × 1.8 cm square sample. Dilute the bacterial solution to 1 × 10 5 ~2×10 5CFU / mL: Add 1 mL of bacterial solution to the sample surface, ensuring complete infiltration, and incubate at 37°C for 24 hours. Wash with 20 mL of 0.85% ice-cold saline for 1 minute, then spread on TSA plates after serial dilutions and incubate at 37°C for 24 hours.

[0037] The antibacterial activity of the sample was calculated using the following formula:

[0038] Inhibition rate = (number of viable bacteria in blank control sample - number of viable bacteria in test sample) / number of viable bacteria in blank control sample × 100%.

[0039] (2) The present invention performs a rebound resilience test on the antibacterial high-elasticity foam according to the ASTM D 3574 standard, and evaluates the rebound resilience of the sample by calculating the rebound rate.

[0040] Prepare a 100mm x 100mm x 50mm specimen. Calibrate the equipment to confirm that the steel ball diameter of 16mm and the drop height of 500mm meet the standards. Check the sensor accuracy and verify that the rebound rate error is less than 1.5%. Place the specimen on a horizontal base, release the steel ball, and allow it to fall freely. Record the rebound height. Repeat the test five times and take the average value.

[0041] Rebound rate = (rebound height / 500 mm) × 100%.

[0042] Example 1

[0043] 1. Preparation of epichlorohydrin modified ethylene-octene copolymer

[0044] Ⅰ: Dissolve 100g of POE pellets in 250ml of xylene under nitrogen protection, stir at 60°C for 2h until completely dissolved, add 0.8g of tetrabutylammonium bromide, 10g of epichlorohydrin and 0.2g of diisopropylbenzene peroxide to the dissolved POE solution in sequence, and stir at 250rpm at 90°C for 5h to obtain a reaction solution; epichlorohydrin is added dropwise for 30 minutes.

[0045] II: 0.05 g of hydroquinone was added to the reaction solution to terminate the reaction. The reaction solution was then poured into cold methanol at 0°C to precipitate the polymer. After filtration, the polymer was washed three times with a methanol / water mixed solvent and finally dried in vacuo at 60°C for 12 hours to obtain white granular epichlorohydrin-modified POE.

[0046] 2. Preparation of Aminated Polyethylene

[0047] 100g of ethylene-acrylamide copolymer was added to a reactor, followed by deionized water. The temperature was raised to 60°C and stirred for 1.5 hours until completely dissolved. The mixture was cooled to 0°C in an ice-water bath and a mixed solution of sodium hypochlorite and sodium hydroxide was slowly added dropwise. The molar ratio of sodium hypochlorite to sodium hydroxide was 1:1.2, and the addition time was controlled to 30 minutes. The reaction temperature was maintained at ≤5°C for a low-temperature reaction. The reaction was stirred and kept at 0°C for 2 hours, followed by the addition of 2g of sodium bisulfite to neutralize any residual sodium hypochlorite. The reaction solution was poured into 3 volumes of cold methanol to precipitate the polymer. After filtration, the polymer was washed three times with methanol and water, followed by vacuum drying at 60°C for 12 hours to obtain a white powder of aminated polyethylene.

[0048] 3. Preparation of antibacterial high elastic foam

[0049] S1. Add 75 parts of low-density polyethylene, 10 parts of aminated polyethylene, 15 parts of epichlorohydrin-modified ethylene-octene copolymer, 4 parts of 4,4-oxybisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant into a mixer by weight. After mechanical stirring, add the mixture into a screw extruder for extrusion. Set the operating temperature of the extrusion section to 120°C and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet.

[0050] Among them, the density of low-density polyethylene is 0.924g / cm 3 , tensile yield strength ≥10 MPa, elongation at break ≥600%, compliant with RoHS / FDA / PAHs / Reach standards. 4,4'-Oxybisbenzenesulfonylhydrazine decomposes at 152-162°C, with a gas evolution rate of 125 ml / g. It is a white powder with a purity of ≥99%. It exhibits foaming properties, producing a fine, uniform cell structure. The zinc stearate is Zhenghao brand X-36 aqueous zinc stearate dispersion.

[0051] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator, with an irradiation dose of 60 kGy.

[0052] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0053] Example 2

[0054] The difference between this embodiment and embodiment 1 is that a method for preparing an antibacterial and highly elastic foam comprises the following steps:

[0055] S1. Add 90 parts of low-density polyethylene, 10 parts of aminated polyethylene, 15 parts of epichlorohydrin-modified ethylene-octene copolymer, 4 parts of 4,4-oxybisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant to a mixer by weight. After mechanical stirring, add the mixture to a screw extruder for extrusion. Set the extrusion section operating temperature to 120° C. and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet.

[0056] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator at an irradiation dose of 60 kGy;

[0057] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0058] Example 3

[0059] The difference between this embodiment and embodiment 1 is that a method for preparing an antibacterial and highly elastic foam comprises the following steps:

[0060] S1. Add 75 parts of low-density polyethylene, 8 parts of aminated polyethylene, 15 parts of epichlorohydrin-modified ethylene-octene copolymer, 4 parts of 4,4-oxybisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant to a mixer by weight. After mechanical stirring, add the mixture to a screw extruder for extrusion. Set the extrusion section operating temperature to 120° C. and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet.

[0061] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator at an irradiation dose of 60 kGy;

[0062] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0063] Example 4

[0064] The difference between this embodiment and embodiment 1 is that a method for preparing an antibacterial and highly elastic foam comprises the following steps:

[0065] S1. Add 84 parts of low-density polyethylene, 8 parts of aminated polyethylene, 12 parts of epichlorohydrin-modified ethylene-octene copolymer, 4 parts of 4,4-oxybisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant to a mixer by weight. After mechanical stirring, add the mixture to a screw extruder for extrusion. Set the extrusion section operating temperature to 120° C. and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet.

[0066] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator at an irradiation dose of 60 kGy;

[0067] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0068] Comparative Example 1

[0069] The only difference between this comparative example and Example 1 is that in the preparation of the foam, aminated polyethylene and epichlorohydrin-modified ethylene-octene copolymer are not added.

[0070] Specifically, a method for preparing an antibacterial and highly elastic foam comprises the following steps:

[0071] S1. Add 75 parts of low-density polyethylene, 4 parts of 4,4-oxobisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant to a mixer by weight, stir them mechanically until uniform, and then add them to a screw extruder for extrusion. Set the extrusion section operating temperature to 120°C and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet;

[0072] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator at an irradiation dose of 60 kGy;

[0073] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0074] Comparative Example 2

[0075] The only difference between this comparative example and Example 1 is that no aminated polyethylene is added in the preparation of the foam.

[0076] Specifically, a method for preparing an antibacterial and highly elastic foam comprises the following steps:

[0077] S1. Add 75 parts of low-density polyethylene, 15 parts of epichlorohydrin-modified ethylene-octene copolymer, 4 parts of 4,4-oxybisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant to a mixer by weight. After mechanical stirring, add the mixture to a screw extruder for extrusion. Set the extrusion section operating temperature to 120° C. and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet.

[0078] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator at an irradiation dose of 60 kGy;

[0079] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0080] Comparative Example 3

[0081] The only difference between this comparative example and Example 1 is that epichlorohydrin-modified ethylene-octene copolymer is not added in the preparation of the foam.

[0082] Specifically, a method for preparing an antibacterial and highly elastic foam comprises the following steps:

[0083] S1. Add 75 parts of low-density polyethylene, 10 parts of aminated polyethylene, 4 parts of 4,4-oxybisbenzenesulfonylhydrazine, 2 parts of zinc stearate and 1 part of antioxidant to a mixer by weight. After mechanical stirring, add the mixture to a screw extruder for extrusion. Set the extrusion section operating temperature to 120°C and the screw speed to 100 r / min. Extrude a sheet with a thickness of 0.6 mm to obtain a mother sheet.

[0084] S2. The master sheet obtained in S1 is subjected to irradiation cross-linking using an electron accelerator at an irradiation dose of 60 kGy;

[0085] S3. Add the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment. Set the temperature of the foaming furnace to 220° C. and the foaming time to 8 minutes. Then perform molding processing to obtain foam.

[0086] Performance testing:

[0087] The foams prepared in Examples 1-4 and Comparative Examples 1-3 of the present invention were made into samples that met the specifications. The antibacterial properties of the antibacterial high-elasticity foams were tested using the AATCC-100 bacterial count method, and the antibacterial properties of the samples were evaluated by calculating the antibacterial rate. The resilience of the antibacterial high-elasticity foams was tested according to the ASTM D 3574 standard, and the resilience of the samples was evaluated by calculating the rebound rate. The specific test results are shown in Table 1:

[0088] Table-1 Performance Test

[0089] Antibacterial activity / % Antibacterial activity after 6 months / % Resilience / % Example 1 98 98 85 Example 2 95 93 82 Example 3 98 97 85 Example 4 98 97 80 Comparative Example 1 30 25 64 Comparative Example 2 35 30 72 Comparative Example 3 75 69 65

[0090] As shown in Table 1, the foams prepared in Examples 1 to 4 all have good antibacterial properties, antibacterial durability and resilience, with an antibacterial rate of more than 95%. The antibacterial effect has hardly decayed after 6 months, and the rebound rate is more than 80%. Among them, the performance of Example 1 is the best.

[0091] Analysis of Example 1 and Comparative Examples 1-3, specifically comparing Comparative Example 1 and Comparative Example 3, shows that compared to Comparative Example 1, the addition of aminated polyethylene to the foam preparation in Comparative Example 3 significantly increases the antibacterial activity of the foam to 75%, but lacks long-term effectiveness. This indicates that the addition of aminated polyethylene can temporarily inhibit bacteria. Specifically, comparing Comparative Example 1 and Comparative Example 2, it is shown that compared to Comparative Example 1, the addition of epichlorohydrin-modified ethylene-octene copolymer to the foam preparation in Comparative Example 2 increases the resilience of the foam to 72%. This indicates that the addition of epichlorohydrin-modified ethylene-octene copolymer can effectively improve the resilience of the foam.

[0092] By comparison with Example 1, it can be seen that during the preparation of the foam, the amino polyethylene and the epichlorohydrin-modified ethylene-octene copolymer are added simultaneously, and the two cooperate with each other to effectively improve the antibacterial property, antibacterial durability and resilience of the foam.

[0093] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An antibacterial and highly elastic foam, characterized in that: The foam comprises the following raw materials in parts by weight: 75 to 90 parts by weight of low-density polyethylene, 5 to 12 parts by weight of aminated polyethylene, 8 to 15 parts by weight of epichlorohydrin-modified ethylene-octene copolymer, 2 to 6 parts by weight of a foaming agent, 1 to 3 parts by weight of a sensitizer, and 0.5 to 2 parts by weight of an antioxidant; the foam is prepared through an electron radiation cross-linking reaction.

2. The antibacterial and highly elastic foam according to claim 1, characterized in that: The mass ratio of the aminated polyethylene to the epichlorohydrin-modified ethylene-octene copolymer is 1:1.2-1.

8.

3. The antibacterial and highly elastic foam according to claim 1, characterized in that: The mass ratio of epichlorohydrin modified ethylene-octene copolymer to low-density polyethylene is 1:5-7.

5.

4. The antibacterial and highly elastic foam according to claim 1, characterized in that: The preparation method of the epichlorohydrin modified ethylene-octene copolymer is as follows: Ⅰ: dissolving the ethylene-octene copolymer base material in xylene, adding tetrabutylammonium bromide, epichlorohydrin and dicumyl peroxide in sequence, mixing and then performing a ring-opening reaction; II: Add hydroquinone to the reaction system, pour the reaction solution into methanol at 0-5°C to precipitate the product, and obtain epichlorohydrin-modified ethylene-octene copolymer after washing and drying.

5. The antibacterial and highly elastic foam according to claim 4, characterized in that: The added amount of epichlorohydrin is 8-12% of the weight of the ethylene-octene copolymer base material.

6. The antibacterial and highly elastic foam according to claim 4, characterized in that: The reaction in step I is carried out under nitrogen protection; epichlorohydrin is added dropwise over a period of 30 minutes.

7. The antibacterial and highly elastic foam according to claim 1, characterized in that: The preparation method of the aminated polyethylene is as follows: Ethylene-acrylamide copolymer is dissolved in deionized water, heated and stirred until completely dissolved, and after cooling, a mixed solution of sodium hypochlorite and sodium hydroxide is added to carry out Hofmann degradation reaction; then sodium bisulfite is added, and the reaction solution is poured into cold methanol to precipitate solids, which are then washed and dried to obtain aminated polyethylene.

8. The antibacterial and highly elastic foam according to claim 1, characterized in that: The foaming agent is one of 4,4-oxobisbenzenesulfonylhydrazine, benzenesulfonylhydrazine, toluenesulfonylhydrazine, or a combination of two or more thereof.

9. The antibacterial and highly elastic foam according to claim 1, characterized in that: The antioxidant is a phosphite antioxidant.

10. A method for preparing the antibacterial and highly elastic foam according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) adding low-density polyethylene, aminated polyethylene, epichlorohydrin-modified ethylene-octene copolymer, a foaming agent, a sensitizer, and an antioxidant into a screw extruder for extrusion to obtain a sheet having a thickness of 0.4 to 0.8 mm, thereby obtaining a mother sheet; (2) The master sheet obtained in S1 is irradiated and cross-linked using an electron accelerator, and the irradiation dose is controlled at 50 to 80 kGy; (3) Adding the irradiated cross-linked mother sheet into a foaming furnace for foaming treatment to produce foam.