EVA / POE composite high-resilience foaming material and preparation method thereof

Abstract

The invention belongs to the technical field of foam material manufacturing, and particularly relates to an EVA / POE composite high-resilience foam material and a preparation method thereof, and the EVA / POE composite high-resilience foam material is prepared by mixing EVA, POE, a foaming agent, a foaming promoter, a foaming stabilizer and a cross-linking agent, extruding, vulcanizing and secondarily foaming. The modified nucleating flame retardant prepared by loading the modified flame retardant on the porous metal framework and polydimethylsiloxane are mixed to serve as a foaming stabilizer, so that a large number of gas nucleating sites are provided, and the size of foam pores is refined and distributed more uniformly; the modified flame retardant is fixed in micropores of a porous metal frame through hydrogen bonds, so that the modified nucleation flame retardant has bubble nucleation stability and flame retardance at the same time. The high-resilience foaming material prepared by the invention is ideal in foaming quality, and has excellent resilience, impact resilience and flame retardance.

Description

Technical Field

[0001] The invention belongs to the technical field of foam material manufacturing, and particularly relates to an EVA / POE composite high-resilience foam material and a preparation method thereof. Background Art

[0002] Ethylene-vinyl acetate copolymer (EVA) is a non-toxic foam material with excellent mechanical properties and elasticity. By introducing vinyl acetate segments into low-density polyethylene, it achieves low crystallinity and high melt strength. Polyolefin elastomers (POE) are primarily classified into three categories: ethylene / α-olefin copolymers, propylene / α-olefin copolymers, and ethylene-propylene copolymers. POE contains no unsaturated double bonds and has a relatively low content of tertiary carbon atoms, resulting in excellent aging resistance. Furthermore, its relatively narrow molecular weight distribution imparts good fluidity, making it less susceptible to deflection during injection and extrusion, resulting in excellent processing and mechanical properties. Low-density polyethylene (LDPE) foam materials and products are widely used in the flexible packaging field on the market due to their low density, light weight, large volume, strong energy absorption capacity, good shock absorption, sound insulation and heat insulation properties. However, with the fierce market competition, the requirements for the resilience of foamed LDPE products are getting higher and higher. At present, the resilience of foamed composite materials prepared by LDPE cannot meet its technical requirements, and the melt strength is low and the processability is poor at high shear rates, which limits its application in industry. Therefore, the existing technology generally improves LDPE foam materials by adding EVA to blend to improve the processing performance and foaming performance of the foam material.

[0003] Chinese invention patent publication number CN118359837B discloses a high-resilience polyolefin foam material and its preparation method. The preparation of the foam material comprises the following steps: preparing a polyolefin resin blend, preparing a thermoplastic elastomer blend, preparing a foaming precursor, and preparing the foam material. Through mechanical coating and solution casting, the invention produces a core-shell structure composed of a polyolefin core and nanoparticles and a thermoplastic resin shell. The porous nanoparticles in the prepared core-shell structure act as gas diffusion channels during the foaming process, effectively increasing the gas diffusion rate. They also play a heterogeneous nucleation role, effectively reducing the cell nucleation energy barrier. The core-shell structure is not destroyed during hot pressing and is well preserved.

[0004] The Chinese invention patent with publication number CN119039651B discloses a method for preparing a wear-resistant modified EVA foam sole material. Ethylene-vinyl acetate copolymer, POE grafted microcrystalline cellulose, EPDM rubber, additives, fillers, cross-linking agents, and foaming agents are placed in an open mill, mixed, and then molded and foamed in a flat vulcanizer to obtain a wear-resistant modified EVA foam sole material.

[0005] Although existing technologies can improve the resilience and wear resistance of EVA / POE composite foam materials, there are still technical problems such as it is difficult to achieve both high rebound and flame retardant functions, and direct addition of flame retardants is prone to phase separation. Therefore, further research is needed on the flame retardant composition and structure of EVA / POE composite foam materials to further improve the foaming performance and rebound performance of EVA / POE composite foam materials while maintaining flame retardant properties. Summary of the Invention

[0006] The purpose of the present invention is to provide a high-resilience foam material involving an EVA / POE composite and a preparation method thereof, so as to solve the technical problems in the prior art that it is difficult to achieve both high rebound and flame retardancy and that phase separation is easily caused by directly adding a flame retardant.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: The EVA / POE composite high-resilience foam material comprises the following components in parts by mass: 45-48 parts of EVA, 50-53 parts of POE, 0.2-0.4 parts of a cross-linking agent, 13-18 parts of a foaming agent, 0.8-1.1 parts of a foaming aid, and 4-6 parts of a foaming stabilizer; The foaming stabilizer is prepared by mixing a nucleating flame retardant and polydimethylsiloxane in a mass ratio of (5-8):1; The nucleating flame retardant is prepared by loading a modified flame retardant onto a porous metal frame, wherein the mass ratio of the porous metal frame to the modified flame retardant is (2-3): (3.2-4.5); The modified flame retardant is prepared by grafting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with 4-terpene alcohol through a carbon-carbon double bond reaction; The cross-linking agent is dicumyl peroxide, the foaming agent is an azodicarbonamide foaming agent, and the foaming aid is prepared by mixing zinc oxide and zinc stearate in a mass ratio of 1:(2-3).

[0008] The preparation method of the foaming stabilizer comprises the following steps: S11, dissolving zinc nitrate in deionized water and then adding dropwise to an aqueous solution of 2-methylimidazole, stirring at room temperature for reaction, filtering, washing, and drying to obtain a porous metal frame; S12, adding 4-terpene alcohol and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to toluene, adding azobisisobutyronitrile as an initiator, heating the mixture in a nitrogen atmosphere for reaction, filtering, washing, and drying to obtain a modified flame retardant, adding a porous metal frame and the modified flame retardant to ethanol, ultrasonically stirring, and removing the ethanol by rotary evaporation to obtain a nucleated flame retardant; S13. Mixing the nucleating flame retardant and polydimethylsiloxane to prepare a foaming stabilizer.

[0009] Preferably, the reaction principle of the modified flame retardant is as follows:

[0010] The modified flame retardant was analyzed by mass spectrometry, and the results were as follows: m / z: 370.17 (100.0%), 371.17 (23.9%), 372.18 (2.8%).

[0011] Preferably, the ratio of zinc nitrate to 2-methylimidazole in S11 is (1.2-1.5) g: (4-8) g, and the mixture is stirred at room temperature at a speed of 200-300 rpm for 1-2 hours, and allowed to react for 8-10 hours.

[0012] Preferably, the amount ratio of 4-terpene alcohol, DOPO, toluene and azobisisobutyronitrile in the S12 is (14-15) g: (20-22) g: (400-500) mL: (0.8-1) g, the temperature is raised to 65-75° C. in a nitrogen atmosphere and the reaction is carried out for 36-48 hours, the mixture is centrifuged at a speed of 10000-12000 rpm for 10-15 minutes, washed with deionized water, and vacuum dried at 50-60° C. to obtain a modified flame retardant.

[0013] Preferably, the mass ratio of the porous metal frame to the modified flame retardant in S12 is (2-3): (3.2-4.5), and ultrasonic stirring is performed at a power of 300-500 W for 20-40 minutes.

[0014] The preparation method of the EVA / POE composite high-resilience foam material comprises the following steps: S1. Mixing ingredients: Add EVA, POE, cross-linking agent, foaming agent and foaming stabilizer into a mixer, heat and mix, and then add into a mixer to mix to obtain a mixture; S2, extrusion vulcanization: adding the mixed material into the extruder, hot pressing and extruding, placing it into the vulcanizing machine for vulcanization and foaming to obtain the pre-foamed material; S3. Secondary foaming: Grind off the surface of the pre-foamed material and press it into a mold for secondary foaming to obtain an EVA / POE composite high-resilience foam material.

[0015] Preferably, the temperature in S1 is raised to 60-70° C., mixed and stirred at a speed of 300-500 rpm for 5-10 minutes, and banburyed at 90-105° C. for 5-10 minutes.

[0016] Preferably, the temperatures of the temperature zones of the hot pressing extrusion of the extruder in S2 are set as follows: the head temperature is 130~145°C, zone 1 is 105~115°C, zone 2 is 125~135°C, zone 3 is 135~140°C, zone 4 is 140~150°C, zone 5 is 145~155°C, and zone 6 is 140~150°C.

[0017] Preferably, the hot pressing temperature of the vulcanizer in S2 is 150-165° C., the pressure is 10-20 MPa, and the foaming time is 10-20 min.

[0018] Preferably, the temperature of the secondary foaming in S3 is 160-175° C., and the foaming time is 5-10 minutes.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The EVA / POE composite high-resilience foam material of the present invention is prepared by mixing EVA, POE, a foaming agent, a foaming aid, a foaming stabilizer and a cross-linking agent, followed by extrusion vulcanization and secondary foaming. EVA and POE improve the resilience of the product through a compatibility mechanism; zinc oxide and zinc stearate are used as foaming aids to increase the gas production rate and gas production; a modified nucleating flame retardant and polydimethylsiloxane are used as foaming stabilizers to broaden the decomposition temperature range of the foaming agent; polydimethylsiloxane reduces the surface tension of the polymer melt and inhibits the merging of bubbles; the porous metal frame of the modified nucleating flame retardant contains a rich microporous structure, which provides a large number of gas nucleation sites, makes the bubble size refined and distributed more evenly, stabilizes the material, and improves the melt strength of the foaming matrix material, thereby improving its resilience.

[0020] 2. The modified nucleating flame retardant of the present invention is prepared by loading the modified flame retardant on a porous metal frame. The modified flame retardant is prepared by grafting DOPO with 4-terpene alcohol through a carbon-carbon double bond reaction. The cyclic group of 4-terpene alcohol introduced into the modified flame retardant has a similar non-polar structure to the EVA / POE matrix material, thereby improving the compatibility of the modified flame retardant in the EVA / POE material. The phosphorus element in DOPO promotes the formation of a carbon layer, and the carbon chain structure of 4-terpene alcohol serves as a supplementary carbon source, thereby enhancing the continuity and strength of the carbon layer. The microporous structure of the porous metal frame provides a loading reaction site, and the modified flame retardant is fixed in the micropores through hydrogen bonds formed by intermolecular hydroxyl groups. The microporous structure has an adsorption effect, and can reduce the taste of the material by adsorbing formamide produced by the decomposition of the foaming agent, so that the modified nucleating flame retardant has both bubble nucleation stability and flame retardancy. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 any creative efforts are within the scope of protection of the present invention.

[0022] The EVA of the present invention has a vinyl acetate content of 18 wt% and a density of 0.936 g / cm 3, melt flow rate is 10g / 10min; POE is ethylene / α-olefin copolymer, density is 0.873g / cm 3 , the melt flow rate is 1.115g / 10min; the foaming agent is azodicarbonamide foaming agent, the decomposition temperature is 165℃, the gas evolution volume is 160±5mL / g, and the average particle size is 7μm.

[0023] Example 1. The EVA / POE composite high-resilience foam material of this example is prepared from the following components: 47g of EVA, 53g of POE, 0.3g of diisopropylbenzene peroxide cross-linking agent, 15g of azodicarbonamide foaming agent, 0.9g of a foaming aid prepared by mixing zinc oxide and zinc stearate in a mass ratio of 1:3, and 5g of a foaming stabilizer.

[0024] The preparation method of the foaming stabilizer of this embodiment comprises the following steps: S11, dissolving 1.2 g of zinc nitrate in 10 mL of deionized water and then adding the solution dropwise to an aqueous solution prepared by adding 6.7 g of 2-methylimidazole to 40 mL of deionized water, stirring at room temperature at 200 rpm for 1 h, allowing the reaction to stand for 9 h, filtering, washing, and drying to obtain a porous metal framework; S12, adding 14 g of 4-terpene alcohol and 21 g of DOPO to 450 mL of toluene, adding 0.8 g of initiator azobisisobutyronitrile, heating to 65° C. in a nitrogen atmosphere for reaction for 36 h, centrifuging at 10,000 rpm for 10 min, washing with deionized water, and vacuum drying at 50° C. to obtain a modified flame retardant, adding 2 g of the porous metal framework and 3.2 g of the modified flame retardant to 50 mL of ethanol, ultrasonically stirring at a power of 300 W for 20 min, and removing ethanol by rotary evaporation to obtain a nucleated flame retardant; S13. Mix 0.8 g of polydimethylsiloxane and 4.2 g of a nucleating flame retardant to prepare a foaming stabilizer.

[0025] The preparation method of the EVA / POE composite high-resilience foam material of this embodiment comprises the following steps: S1. Mixing ingredients: EVA, POE, cross-linking agent, foaming agent and foaming stabilizer were added to a mixer, heated to 70°C and mixed at 300 rpm for 8 minutes, and then added to a mixer and mixed at 100°C for 5 minutes to obtain a mixture; S2, extrusion vulcanization: the mixed material is added to the extruder, the temperature of each temperature zone is set to: the head temperature is 145 ° C, the first zone is 110 ° C, the second zone is 125 ° C, the third zone is 135 ° C, the fourth zone is 145 ° C, the fifth zone is 150 ° C, and the sixth zone is 140 ° C. The mixed material is hot-pressed and extruded into a vulcanizing machine for vulcanization and foaming. The hot pressing temperature of the vulcanizing machine is 165 ° C, the pressure is 10 MPa, and the foaming time is 10 min to obtain a pre-foamed material; S3. Secondary foaming: Grind off the surface of the pre-foamed material and press it into a mold for secondary foaming. The secondary foaming temperature is 170° C. and the foaming time is 5 minutes to obtain an EVA / POE composite high-resilience foaming material.

[0026] Example 2. The EVA / POE composite high-resilience foam material of this example is prepared from the following components: 45g of EVA, 50g of POE, 0.2g of diisopropylbenzene peroxide cross-linking agent, 13g of azodicarbonamide foaming agent, 0.8g of a foaming aid prepared by mixing zinc oxide and zinc stearate in a mass ratio of 1:2, and 6g of a foaming stabilizer.

[0027] The preparation method of the foaming stabilizer of this embodiment comprises the following steps: S11, dissolving 1.5 g of zinc nitrate in 10 mL of deionized water and then adding the solution dropwise to an aqueous solution prepared by adding 4.2 g of 2-methylimidazole to 40 mL of deionized water, stirring at 300 rpm for 1 h at room temperature, allowing the reaction to stand for 10 h, filtering, washing, and drying to obtain a porous metal framework; S12. Add 15 g of 4-terpene alcohol and 22 g of DOPO to 500 mL of toluene, add 1 g of initiator azobisisobutyronitrile, heat to 70° C. in a nitrogen atmosphere and react for 48 h, centrifuge at 12,000 rpm for 10 min, wash with deionized water, and vacuum dry at 60° C. to obtain a modified flame retardant. Add 2.27 g of the porous metal framework and 3.7 g of the modified flame retardant to 50 mL of ethanol, ultrasonically stir at a power of 500 W for 20 min, and remove ethanol by rotary evaporation to obtain a nucleated flame retardant. S13. Mix 1 g of polydimethylsiloxane and 5 g of a nucleating flame retardant to prepare a foaming stabilizer.

[0028] The preparation method of the EVA / POE composite high-resilience foam material of this embodiment comprises the following steps: S1. Mixing ingredients: EVA, POE, cross-linking agent, foaming agent and foaming stabilizer were added to a mixer, heated to 60°C and mixed at 300 rpm for 5 minutes, and then added to a mixer and mixed at 90°C for 5 minutes to obtain a mixture; S2, extrusion vulcanization: the mixed material is added to the extruder, the temperature of each temperature zone is set to: the head temperature is 130 ° C, the first zone is 105 ° C, the second zone is 125 ° C, the third zone is 135 ° C, the fourth zone is 140 ° C, the fifth zone is 145 ° C, and the sixth zone is 140 ° C. The mixed material is hot-pressed and extruded into a vulcanizing machine for vulcanization and foaming. The hot pressing temperature of the vulcanizing machine is 165 ° C, the pressure is 16 MPa, and the foaming time is 20 min to obtain a pre-foamed material; S3. Secondary foaming: Grind off the surface of the pre-foamed material and press it into a mold for secondary foaming. The secondary foaming temperature is 170° C. and the foaming time is 10 min to obtain an EVA / POE composite high-resilience foaming material.

[0029] Example 3. The EVA / POE composite high-resilience foam material of this example is prepared from the following components: 45g of EVA, 53g of POE, 0.4g of diisopropylbenzene peroxide cross-linking agent, 15g of azodicarbonamide foaming agent, 1.1g of a foaming aid prepared by mixing zinc oxide and zinc stearate in a mass ratio of 1:3, and 4g of a foaming stabilizer.

[0030] The preparation method of the foaming stabilizer of this embodiment comprises the following steps: S11, dissolving 1.4 g of zinc nitrate in 10 mL of deionized water and then adding the solution dropwise to an aqueous solution prepared by adding 5.1 g of 2-methylimidazole to 40 mL of deionized water, stirring at room temperature at 200 rpm for 1 h, allowing the reaction to stand for 9 h, filtering, washing, and drying to obtain a porous metal framework; S12, adding 14 g of 4-terpene alcohol and 20 g of DOPO to 400 mL of toluene, adding 0.8 g of initiator azobisisobutyronitrile, heating to 65° C. in a nitrogen atmosphere and reacting for 48 h, centrifuging at 12,000 rpm for 15 min, washing with deionized water, and vacuum drying at 50° C. to obtain a modified flame retardant, adding 3 g of the porous metal framework and 4.5 g of the modified flame retardant to 50 mL of ethanol, ultrasonically stirring at a power of 400 W for 30 min, and removing ethanol by rotary evaporation to obtain a nucleated flame retardant; S13. Mix 0.75 g of polydimethylsiloxane and 5.25 g of a nucleating flame retardant to prepare a foaming stabilizer.

[0031] The preparation method of the EVA / POE composite high-resilience foam material of this embodiment comprises the following steps: S1. Mixing ingredients: EVA, POE, cross-linking agent, foaming agent and foaming stabilizer were added to a mixer, heated to 65°C and mixed at a speed of 300 rpm for 8 minutes, and then added to a mixer and mixed at 90°C for 10 minutes to obtain a mixture; S2, extrusion vulcanization: the mixed material is added to the extruder, the temperature of each temperature zone is set to: the head temperature is 140 ° C, the first zone is 115 ° C, the second zone is 130 ° C, the third zone is 135 ° C, the fourth zone is 150 ° C, the fifth zone is 145 ° C, and the sixth zone is 140 ° C. The mixed material is hot-pressed and extruded into a vulcanizing machine for vulcanization and foaming. The hot pressing temperature of the vulcanizing machine is 155 ° C, the pressure is 20 MPa, and the foaming time is 20 min to obtain a pre-foamed material; S3. Secondary foaming: Grind off the surface of the pre-foamed material and press it into a mold for secondary foaming. The secondary foaming temperature is 160° C. and the foaming time is 5 minutes to obtain an EVA / POE composite high-resilience foaming material.

[0032] Example 4. The EVA / POE composite high-resilience foam material of this example is prepared from the following components: 48g of EVA, 50g of POE, 0.3g of diisopropylbenzene peroxide cross-linking agent, 17g of azodicarbonamide foaming agent, 0.8g of a foaming aid prepared by mixing zinc oxide and zinc stearate in a mass ratio of 1:2.5, and 4g of a foaming stabilizer.

[0033] The preparation method of the foaming stabilizer of this embodiment comprises the following steps: S11, dissolving 1.3 g of zinc nitrate in 10 mL of deionized water and then adding the solution dropwise to an aqueous solution prepared by adding 7.2 g of 2-methylimidazole to 40 mL of deionized water, stirring at room temperature at 250 rpm for 2 h, allowing the mixture to react for 10 h, filtering, washing, and drying to obtain a porous metal framework; S12. 15 g of 4-terpene alcohol and 21 g of DOPO were added to 400 mL of toluene, and 1 g of azobisisobutyronitrile as an initiator was added. The mixture was heated to 65° C. in a nitrogen atmosphere and reacted for 48 h. The mixture was centrifuged at 11,000 rpm for 10 min, washed with deionized water, and vacuum-dried at 55° C. to obtain a modified flame retardant. 2.5 g of the porous metal framework and 3.8 g of the modified flame retardant were added to 50 mL of ethanol, and ultrasonically stirred at a power of 300 W for 40 min. The ethanol was removed by rotary evaporation to obtain a nucleated flame retardant. S13. Mix 0.5 g of polydimethylsiloxane and 3.5 g of a nucleating flame retardant to prepare a foaming stabilizer.

[0034] The preparation method of the EVA / POE composite high-resilience foam material of this embodiment comprises the following steps: S1. Mixing ingredients: EVA, POE, cross-linking agent, foaming agent and foaming stabilizer were added to a mixer, heated to 70°C and mixed at a speed of 500 rpm for 10 minutes, and then added to a mixer and mixed at 105°C for 10 minutes to obtain a mixture; S2, extrusion vulcanization: the mixed material is added to the extruder, the temperature of each temperature zone is set to: the head temperature is 145 ° C, the first zone is 115 ° C, the second zone is 135 ° C, the third zone is 140 ° C, the fourth zone is 150 ° C, the fifth zone is 155 ° C, and the sixth zone is 150 ° C. The mixed material is hot-pressed and extruded into a vulcanizing machine for vulcanization and foaming. The hot pressing temperature of the vulcanizing machine is 165 ° C, the pressure is 20 MPa, and the foaming time is 20 min to obtain a pre-foamed material; S3. Secondary foaming: Grind off the surface of the pre-foamed material and press it into a mold for secondary foaming. The secondary foaming temperature is 175° C. and the foaming time is 10 min to obtain an EVA / POE composite high-resilience foaming material.

[0035] Comparative Example 1: The difference between this comparative example and Example 1 is that the foaming stabilizer is replaced by talc.

[0036] Comparative Example 2: The difference between this comparative example and Example 1 is that the modified nucleating flame retardant is not added to the foaming stabilizer.

[0037] Comparative Example 3: The difference between this comparative example and Example 1 is that the modified nucleating flame retardant is replaced by a porous metal frame.

[0038] Comparative Example 4: This comparative example differs from Example 1 in that no EVA is added.

[0039] Performance Testing The tensile strength and elongation at break of the foamed materials obtained in each embodiment and comparative example were measured according to GB / T 528-2009 “Vulcanized rubber or thermoplastic rubber — Determination of tensile stress-strain properties”. The impact rebound rate of the foamed materials obtained in each embodiment and comparative example was measured according to GB / T 1681-2009 “Determination of rebound resilience of vulcanized rubber”; The limiting oxygen index of the foamed materials prepared in each embodiment and comparative example was determined according to GB / T 2406.2-2021 "Plastics - Determination of combustion behavior by oxygen index method - Part 2: Room temperature test"; The formamide content of the foaming materials prepared in each example and comparative example was measured according to GB / T 33390-2016 “Determination of the limited substance dimethylformamide in footwear, footwear and footwear components”.

[0040] The test results are shown in Table 1 below: Table 1 Foam material performance test results

[0041] It can be seen from the data in the above table that the tensile strength of the high rebound foam material obtained in Examples 1 to 4 is 2.7 to 2.8 MPa, the elongation at break is 270% to 276%, and the impact rebound rate is 18.3% to 19.1%, indicating that the high rebound foam material obtained in the present invention has excellent impact rebound elasticity; the limiting oxygen index of the high rebound foam material obtained in Examples 1 to 4 is 27.8% to 28.1%, indicating that the high rebound foam material obtained in the present invention has excellent flame retardant properties; the formamide content of the high rebound foam material obtained in Examples 1 to 4 is 43 to 46 mg / kg, the foaming stabilizer in Comparative Example 1 is replaced with talc, and its formamide content is 123 mg / kg, and the foaming stabilizer in Comparative Example 2 does not add a modified nucleating flame retardant, and its formamide content is 119 mg / kg, further illustrating that the high rebound foam material obtained in the present invention has excellent deodorization performance.

[0042] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

[0043] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. EVA / POE composite high resilience foam material, characterized in that: The components include the following by mass: 45-48 parts of EVA, 50-53 parts of POE, 0.2-0.4 parts of cross-linking agent, 13-18 parts of foaming agent, 0.8-1.1 parts of foaming aid and 4-6 parts of foaming stabilizer; The foaming stabilizer is prepared by mixing a nucleating flame retardant and polydimethylsiloxane in a mass ratio of (5-8):1; The nucleating flame retardant is prepared by loading a modified flame retardant onto a porous metal frame, wherein the mass ratio of the porous metal frame to the modified flame retardant is (2-3): (3.2-4.5); The modified flame retardant is prepared by grafting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide onto 4-terpene alcohol through a carbon-carbon double bond reaction.

2. The EVA / POE composite high resilience foam material according to claim 1, characterized in that: The cross-linking agent is dicumyl peroxide, the foaming agent is an azodicarbonamide foaming agent, and the foaming aid is prepared by mixing zinc oxide and zinc stearate in a mass ratio of 1:(2-3).

3. The EVA / POE composite high resilience foam material according to claim 1, characterized in that: The preparation method of the foaming stabilizer comprises the following steps: S11, dissolving zinc nitrate in deionized water and then adding dropwise to an aqueous solution of 2-methylimidazole, stirring at room temperature for reaction, filtering, washing, and drying to obtain a porous metal frame; S12, adding 4-terpene alcohol and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to toluene, adding azobisisobutyronitrile as an initiator, heating the mixture in a nitrogen atmosphere, filtering, washing, and drying to obtain a modified flame retardant, adding a porous metal frame and the modified flame retardant to ethanol, ultrasonically stirring, and removing the ethanol by rotary evaporation to obtain a nucleated flame retardant; S13. Mix the nucleating flame retardant and polydimethylsiloxane in a mass ratio of (5-8):1 to prepare a foaming stabilizer.

4. The EVA / POE composite high resilience foam material according to claim 3, characterized in that: The ratio of zinc nitrate to 2-methylimidazole in S11 is (1.2-1.5) g: (4-8) g. The mixture is stirred at room temperature at a speed of 200-300 rpm for 1-2 hours and allowed to react for 8-10 hours.

5. The EVA / POE composite high resilience foam material according to claim 3, characterized in that: The amount ratio of 4-terpene alcohol, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, toluene and azobisisobutyronitrile in the S12 is (14-15) g: (20-22) g: (400-500) mL: (0.8-1) g. The temperature is raised to 65-75° C. in a nitrogen atmosphere and the reaction is carried out for 36-48 hours. The mixture is centrifuged at a speed of 10,000-12,000 rpm for 10-15 minutes, washed with deionized water, and vacuum-dried at 50-60° C. to obtain a modified flame retardant. The porous metal frame and the modified flame retardant are added to ethanol and ultrasonically stirred at a power of 300-500 W for 20-40 minutes.

6. The method for preparing the EVA / POE composite high resilience foam material according to any one of claims 1 to 5, characterized in that: The steps include: S1. Mixing ingredients: Add EVA, POE, cross-linking agent, foaming agent and foaming stabilizer into a mixer, heat and mix, and then add into a mixer to mix to obtain a mixture; S2, extrusion vulcanization: adding the mixed material into the extruder, hot pressing and extruding, placing it into the vulcanizing machine for vulcanization and foaming to obtain the pre-foamed material; S3. Secondary foaming: Grind off the surface of the pre-foamed material and press it into a mold for secondary foaming to obtain an EVA / POE composite high-resilience foam material.

7. The method for preparing the EVA / POE composite high resilience foam material according to claim 6, characterized in that: In the S1, the temperature is raised to 60-70°C and mixed at a speed of 300-500 rpm for 5-10 minutes, and banburying is performed at 90-105°C for 5-10 minutes; the temperature of each temperature zone of the extruder hot pressing extrusion in the S2 is set to: the head temperature is 130-145°C, the first zone is 105-115°C, the second zone is 125-135°C, the third zone is 135-140°C, the fourth zone is 140-150°C, the fifth zone is 145-155°C, and the sixth zone is 140-150°C; the hot pressing temperature of the vulcanizer is 150-165°C, the pressure is 10-20 MPa, and the foaming time is 10-20 minutes; the temperature of the secondary foaming in the S3 is 160-175°C, and the foaming time is 5-10 minutes.

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