Environment-friendly high-elasticity granular material for plastic track and preparation method thereof

Abstract

This invention belongs to the field of materials technology, specifically relating to an environmentally friendly, high-elasticity plastic running track granular material and its preparation method. This material is made from EVA and SEBS as base materials, with inorganic functional fillers as additives, through a mixing and foaming process. The inorganic functional filler is obtained by modifying the surface of nano-molybdenum disulfide with a polymer modifier having an alternating silylbenzene-triazine benzotriazole structure. The polymer modifier improves the compatibility between nano-molybdenum disulfide and the rubber-plastic matrix, allowing nano-molybdenum disulfide to better exert its advantages as an inorganic filler, thus improving the material's mechanical properties and wear resistance. The polymer modifier's structure contains abundant triazine benzotriazole segments and rigid cyclic segments, which not only endow the material with excellent UV aging resistance but also enhance its high-temperature resistance, enabling the prepared material to adapt to harsh outdoor environments.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to an environmentally friendly, highly elastic plastic running track granular material and its preparation method. Background Technology

[0002] Synthetic running tracks are an important component of modern sports venues, widely used in schools, stadiums, and community fitness areas. Synthetic running track materials are generally classified into cast (CPU), permeable, and precast rubber rolls, among others. Granular materials, as the main component of the surface layer or elastic layer, directly affect the track's elasticity, cushioning performance, and the athlete's experience and safety. With the promotion of national fitness activities and increasingly stringent environmental regulations, the market has placed higher demands on the high elasticity, durability, and environmental friendliness of synthetic running track granular materials.

[0003] Existing plastic running track granule materials can be mainly divided into the following categories: EPDM (Extractable Polymer Rubber) granules: This type of material is currently the most widely used plastic track granule on the market. It is made from waste tires through processes such as crushing, desulfurization, and vulcanization. Although it achieves resource reuse, it has obvious drawbacks: First, the odor problem is prominent. Aromatic oils and vulcanization accelerators in waste tires release volatile organic compounds (VOCs) and irritating odors, which are more pronounced in the high temperatures of summer, affecting the health of athletes. Second, there is a risk of heavy metal content. Some inferior EPDM granules may contain heavy metals such as lead, cadmium, and chromium, which do not meet environmental protection requirements. Third, the elasticity is poorly adjustable. Its rebound rate mainly depends on the cross-linking density of the rubber itself, making it difficult to flexibly control through formula design.

[0004] Thermoplastic elastomer granules: Granules prepared using thermoplastic polyurethane (TPU) or styrene-based thermoplastic elastomers (such as SEBS) as the base material have good elasticity and environmental friendliness, but have the problem of high cost.

[0005] Ethylene-vinyl acetate copolymer (EVA) based granules: EVA is an environmentally friendly material with excellent foaming properties, good softness, biodegradability, and moderate price, and is widely used in sports mats, shoe midsoles, and other fields. However, track granules made from EVA alone have disadvantages such as insufficient resilience and large compression set, making it difficult to meet the requirements of high-standard plastic running tracks for high elasticity and long service life.

[0006] To overcome the above-mentioned defects, EVA can be blended with styrene-ethylene-butene-styrene block copolymer (SEBS) to combine their advantages and form an environmentally friendly plastic running track composite material with good elasticity. However, research has found that when the EVA / SEBS blend system is used as a plastic running track material, it has poor UV aging resistance and poor wear resistance. Based on this, the present invention develops an environmentally friendly high-elasticity plastic running track granular material, which can solve the problems existing in the prior art. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an environmentally friendly, highly elastic plastic running track granular material and its preparation method.

[0008] A first aspect of the present invention provides an environmentally friendly, highly elastic plastic running track granular material, comprising the following raw materials measured in parts by weight: EVA: 32-46 servings; SEBS: 18-25 servings; Maleic anhydride grafted with SEBS: 5-10 parts; Inorganic functional fillers: 1.8-4.5 parts; Chlorinated paraffin oil: 10-18 parts; Pigment: 4-8 parts; Polyethylene wax: 5-10 parts; Foaming agent: 6-12 parts; The inorganic functional filler is nano-molybdenum disulfide that has been modified with a surface polymer modifier.

[0009] As a preferred embodiment of the present invention, the method for preparing the inorganic functional filler includes the following steps: Step A: Preparation of surface-functionalized modified nano-molybdenum disulfide Nano-molybdenum disulfide was added to a mixed solution of ethanol and deionized water in a volume ratio of 1:1. After being dispersed evenly, silane modification reagent was added to adjust the pH to 3-4. The temperature was then controlled at 60-70℃ and stirred continuously for 6-9 hours. The mixture was then cooled and discharged. The solid material was centrifuged, washed, and vacuum dried to obtain surface-functionalized modified nano-molybdenum disulfide. Step B: Preparation of inorganic functional fillers Surface-functionalized molybdenum disulfide nanoparticles and toluene were added to a polymerization reactor and ultrasonically dispersed. Nitrogen gas was then introduced for protection. 1,4-Di(dimethylsilyl)benzene and a catalyst were added to the polymerization reactor. After the addition was complete, the temperature was raised to 70-75℃ and held for 2-4 hours. Then, a triazine benzotriazole derivative was added to the polymerization reactor, and the temperature was adjusted to 80-85℃. Stirring and holding were continued for 12-24 hours. The nitrogen gas was removed, heating was stopped, and the solid material was collected by centrifugation after natural cooling. The solid material was then washed and vacuum dried to obtain the inorganic functional filler.

[0010] As a preferred embodiment of the present invention, in step A, the silane modifying agent is methacryloyloxymethyltriethoxysilane or methacryloyloxymethyltrimethoxysilane.

[0011] As a preferred embodiment of the present invention, in step B, the catalyst is a cassette catalyst.

[0012] As a preferred embodiment of the present invention, in step B, the triazine benzotriazole derivative is prepared by the following method: 4-(2H-benzo[D][1,2,3]triazol-2-yl)benzene-1,3-diol, 1-epoxyethylenemethyl-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and N,N-dimethylformamide were added to a reactor, nitrogen gas was introduced, and stirring was started. After the mixture was homogeneous, a promoter was added to the reactor. After the addition was complete, the mixture was heated to 70-80°C and stirred continuously for 4-8 hours. Heating was then stopped, and the mixture was cooled to room temperature. The reaction solution was washed with dilute hydrochloric acid, and the organic phase was dried with anhydrous sodium sulfate. The mixture was filtered to remove impurities, and the solvent was evaporated to remove impurities. The crude product was purified by column chromatography to obtain the triazine benzotriazole derivative.

[0013] As a preferred embodiment of the present invention, the molar ratio of 4-(2H-benzo[D][1,2,3]triazol-2-yl)benzene-1,3-diol and 1-epoxyethylenemethyl-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione is 1:1.

[0014] As a preferred embodiment of the present invention, the accelerator is any one of triethylamine, potassium carbonate, or sodium carbonate.

[0015] As a preferred embodiment of the present invention, in step B, the mass ratio of the surface-functionalized modified nano-molybdenum disulfide, 1,4-bis(dimethylsilyl)benzene and triazine benzotriazole derivative is 1:0.1-0.25:0.2-0.6.

[0016] It should be noted that in the above technical solution, firstly, a silane-modifying agent is used to perform surface organic functionalization modification on nano-molybdenum disulfide, modifying the surface of the nano-molybdenum disulfide with active alkenyl functional groups to obtain surface-functionalized nano-molybdenum disulfide. Then, under the action of a catalyst, the active alkenyl functional groups of the surface-functionalized nano-molybdenum disulfide can undergo a hydrosilylation reaction with the silane-hydrogen bonds in the 1,4-di(dimethylsilyl)benzene structure, while the remaining 1,4-di(dimethylsilyl)benzene in the system can... As an intermediate linker, it undergoes a continuous hydrosilylation reaction with the unsaturated alkenyl substituents in the structure of triazine benzotriazole derivatives, thereby forming a surface-functionalized agent of surface-functionalized molybdenum disulfide nanoparticles as an active initiation site, initiating the in-situ polymerization of 1,4-di(dimethylsilyl)benzene and triazine benzotriazole derivatives on the surface of molybdenum disulfide nanoparticles. This results in the modification of the surface of molybdenum disulfide nanoparticles with a polymer modifier having an alternating silylbenzene-triazine benzotriazole linkage structure, thus preparing an inorganic functional filler.

[0017] Among them, the triazine benzotriazole derivative is prepared by using 4-(2H-benzo[D][1,2,3]triazol-2-yl)phenyl-1,3-diol and 1-epoxyethylenemethyl-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione as raw materials, and the active hydroxyl substituents and epoxy groups in their structures undergo ring-opening addition under the action of a promoter.

[0018] As a preferred embodiment of the present invention, the pigment is carbon black; the foaming agent is AC foaming agent.

[0019] A second aspect of the present invention provides a method for preparing an environmentally friendly, highly elastic plastic running track granular material, comprising the following steps: Step 1: Ingredients Weigh out each ingredient according to the specified weight proportions and set aside. Step 2: Mixing Add EVA, SEBS, maleic anhydride-grafted SEBS, inorganic functional filler, chlorinated paraffin oil, pigment, polyethylene wax and foaming agent to a high-speed mixer, control the mixing speed to 300-500 r / min, and mix evenly to form a mixture. Step 3: Foaming The mixture is fed into an extruder for extrusion, and the extruded rubber is placed in an oven for vulcanization and foaming. After foaming, it is cooled by air cooling.

[0020] Compared with the prior art, the present invention has the following beneficial effects: This invention prepares an inorganic functional filler by modifying the surface of nano-molybdenum disulfide with a polymeric modifier having an alternating silylbenzene-triazine benzotriazole structure. Firstly, the polymeric modifier can form an "organic transition" structure between the nano-molybdenum disulfide and the rubber-plastic matrix. This transition structure effectively improves the compatibility between the nano-molybdenum disulfide and the rubber-plastic matrix, allowing the nano-molybdenum disulfide to better exert its advantages as an inorganic filler, improving the mechanical properties and wear resistance of the material. Secondly, the polymeric modifier contains abundant triazine benzotriazole segments and rigid cyclic segments, which not only endow the material with excellent UV aging resistance but also enhance its high-temperature resistance, enabling the prepared material to withstand harsh outdoor environments. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is an infrared analysis result of a triazine benzotriazole derivative. Detailed Implementation

[0023] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0024] Preparation Example Preparation of inorganic functional fillers: Step 1: Preparation of surface-functionalized modified nano-molybdenum disulfide 2.4 g of nano molybdenum disulfide was added to a mixed solution of ethanol and deionized water with a volume ratio of 1:1. After being dispersed evenly, 0.5 g of methacryloyloxymethyltrimethoxysilane was added to adjust the pH to 4. The temperature was then controlled at 70℃ and stirred continuously for 8 hours. After cooling, the material was discharged, the solid material was centrifuged, washed, and vacuum dried to obtain surface-functionalized modified nano molybdenum disulfide. Step 2: Preparation of triazine benzotriazole derivatives 0.3 g of 4-(2H-benzo[D][1,2,3]triazol-2-yl)benzene-1,3-diol, 0.35 g of 1-epoxyethylenemethyl-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and N,N-dimethylformamide were added to a reactor. Nitrogen gas was introduced and stirring was started. After the mixture was homogeneous, 0.2 g of potassium carbonate was added to the reactor. After the addition was complete, the reactor was heated to 75°C and stirred continuously for 6 hours. Heating was then stopped and the mixture was cooled to room temperature. The reaction solution was washed with dilute hydrochloric acid, and the organic phase was dried with anhydrous sodium sulfate. The mixture was filtered to remove impurities, and the solvent was evaporated to remove impurities. The crude product was purified by column chromatography to obtain the triazine benzotriazole derivative. Figure 1 This is the infrared analysis spectrum of the triazine benzotriazole derivative, where 3334 cm⁻¹... -1 The characteristic absorption peak appearing at 3098 cm⁻¹ is the characteristic absorption peak of hydroxyl groups. -1 The characteristic absorption peak appearing at 3052 cm⁻¹ is a characteristic absorption peak of hydrocarbons in the benzene ring skeleton. -1 The characteristic absorption peak appearing at 1690 cm⁻¹ is the characteristic absorption peak of CH on the unsaturated carbon-carbon double bond. -1 The characteristic absorption peak appearing at 1038 cm⁻¹ is the C=O characteristic absorption peak of the triazine ring. -1 The characteristic absorption peak appearing at this point is the characteristic absorption peak of CO in ether bonds, and no obvious characteristic absorption peak of epoxy is shown in the figure.

[0025] Step 3: Preparation of Inorganic Functional Fillers 1.8 g of surface-functionalized molybdenum disulfide nanoparticles and toluene were added to the polymerization reactor and ultrasonically dispersed. Nitrogen gas was then introduced for protection. 0.4 g of 1,4-di(dimethylsilyl)benzene and 2 mg of caster catalyst were added to the polymerization reactor. After the addition was complete, the temperature was raised to 70 °C and held for 4 h. Then, 1 g of triazine benzotriazole derivative was added to the polymerization reactor, the temperature was adjusted to 80 °C, and stirring and holding were continued for 18 h. The nitrogen gas was removed, heating was stopped, and the solid material was collected by centrifugation after natural cooling. After washing and vacuum drying, the inorganic functional filler was obtained.

[0026] The mass fraction of the cassiterite catalyst is 2%, and the solvent is xylene.

[0027] Example 1

[0028] This embodiment provides an environmentally friendly, high-elasticity plastic running track granule material, comprising the following raw materials measured in parts by weight: EVA: 32 portions; SEBS: 18 copies; Maleic anhydride grafted with SEBS: 5 parts; Inorganic functional filler: 1.8 parts; Chlorinated paraffin oil: 10 parts; Pigment: 4 parts; Polyethylene wax: 5 parts; Foaming agent: 6 parts; The preparation method of the material includes the following steps: Step 1: Ingredients Weigh out each ingredient according to the specified weight proportions and set aside. Step 2: Mixing EVA, SEBS, maleic anhydride-grafted SEBS, inorganic functional filler, chlorinated paraffin oil, pigment, polyethylene wax and foaming agent are added to a high-speed mixer, and the mixing speed is controlled at 300 r / min. The mixture is stirred and mixed evenly to form a mixture. Step 3: Foaming The mixture is fed into an extruder for extrusion, and the extruded rubber is placed in an oven for vulcanization and foaming. After foaming, it is cooled by air cooling.

[0029] The preparation method of the inorganic functional filler is shown in the preparation example; carbon black is selected as the pigment; and AC foaming agent is selected as the foaming agent.

[0030] Example 2

[0031] This embodiment provides an environmentally friendly, high-elasticity plastic running track granule material, comprising the following raw materials measured in parts by weight: EVA: 35 portions; SEBS: 20 copies; Maleic anhydride grafted with SEBS: 8 parts; Inorganic functional fillers: 4 parts; Chlorinated paraffin oil: 12 parts; Pigment: 5 parts; Polyethylene wax: 6 parts; Foaming agent: 8 parts; The preparation method of the material includes the following steps: Step 1: Ingredients Weigh out each ingredient according to the specified weight proportions and set aside. Step 2: Mixing EVA, SEBS, maleic anhydride-grafted SEBS, inorganic functional filler, chlorinated paraffin oil, pigment, polyethylene wax and foaming agent are added to a high-speed mixer, and the mixing speed is controlled at 400 r / min. The mixture is stirred and mixed evenly to form a mixture. Step 3: Foaming The mixture is fed into an extruder for extrusion, and the extruded rubber is placed in an oven for vulcanization and foaming. After foaming, it is cooled by air cooling.

[0032] The preparation method of the inorganic functional filler is shown in the preparation example; carbon black is selected as the pigment; and AC foaming agent is selected as the foaming agent.

[0033] Example 3

[0034] This embodiment provides an environmentally friendly, high-elasticity plastic running track granule material, comprising the following raw materials measured in parts by weight: EVA: 46 units; SEBS: 25 copies; Maleic anhydride grafted with SEBS: 10 parts; Inorganic functional filler: 4.5 parts; Chlorinated paraffin oil: 18 parts; Pigment: 8 parts; Polyethylene wax: 10 parts; Foaming agent: 12 parts; The preparation method of the material includes the following steps: Step 1: Ingredients Weigh out each ingredient according to the specified weight proportions and set aside. Step 2: Mixing EVA, SEBS, maleic anhydride-grafted SEBS, inorganic functional filler, chlorinated paraffin oil, pigment, polyethylene wax and foaming agent are added to a high-speed mixer, and the mixing speed is controlled at 500 r / min. The mixture is stirred and mixed evenly to form a mixture. Step 3: Foaming The mixture is fed into an extruder for extrusion, and the extruded rubber is placed in an oven for vulcanization and foaming. After foaming, it is cooled by air cooling.

[0035] The preparation method of the inorganic functional filler is shown in the preparation example; carbon black is selected as the pigment; and AC foaming agent is selected as the foaming agent.

[0036] Comparative Example 1 The difference between this comparative example and Example 2 is that the inorganic functional filler is replaced with surface-functionalized modified nano-molybdenum disulfide, while all other aspects are the same.

[0037] The preparation method of surface functionalized modified nano-molybdenum disulfide is shown in the preparation example.

[0038] Comparative Example 2 The difference between this comparative example and Example 2 is that the inorganic functional filler is replaced with nano-molybdenum disulfide, while all other aspects are the same.

[0039] Comparative Example 3 The difference between this comparative example and Example 2 is that the inorganic functional filler is removed, while the rest are the same.

[0040] The materials provided in the above embodiments and comparative examples were used to prepare test specimens that met the specifications, and performance tests were conducted. The test methods are as follows: (1) Conduct a rebound rate test according to standard ISO8307; (2) Compressive strength test was conducted according to standard GB / T 8813-2020; after the test, test samples of the same batch and specifications were placed in an accelerated aging chamber and subjected to 300mJ / cm 2 The test samples were irradiated with mercury lamps, removed after 72 hours, and the compressive strength was tested again. The rate of decrease in compressive strength was calculated to evaluate the anti-ultraviolet aging performance. Generally speaking, the lower the rate of decrease, the better the anti-aging performance, and vice versa. (3) Place test samples of the same weight in a thermogravimetric analyzer, purge with nitrogen for protection, and raise the temperature from room temperature to 600℃ at a heating rate of 5℃ / min. Record the temperature at which the test sample loses 5% of its weight as the initial decomposition temperature and evaluate the high temperature resistance. (4) Conduct abrasion resistance tests according to standard GB / T 5478-2008; The performance test data above are shown in Table 1.

[0041] Table 1 Performance Test Results

[0042] As can be seen from the above, the materials prepared in the embodiments of the present invention have good performance in various aspects. After replacing the inorganic functional filler with surface functionalized modified nano molybdenum disulfide, it can be seen that the nano molybdenum disulfide modified by the silane coupling agent can be relatively uniformly dispersed in the material and play a certain role. However, it loses the advantages of the polymer modifier, resulting in a significant decline in the various properties of the material, especially the high temperature resistance and UV aging resistance.

[0043] After replacing the inorganic functional filler with nano-molybdenum disulfide, the material's various properties further declined due to dispersibility issues.

[0044] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention, including the best mode, and also to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. An environmentally friendly, highly elastic plastic running track granular material, characterized in that, Includes the following raw materials measured in parts by weight: EVA: 32-46 servings; SEBS: 18-25 servings; Maleic anhydride grafted with SEBS: 5-10 parts; Inorganic functional fillers: 1.8-4.5 parts; Chlorinated paraffin oil: 10-18 parts; Pigment: 4-8 parts; Polyethylene wax: 5-10 parts; Foaming agent: 6-12 parts; The inorganic functional filler is nano-molybdenum disulfide that has been modified with a surface polymer modifier.

2. The environmentally friendly, high-elasticity plastic running track granular material according to claim 1, characterized in that, The preparation method of the inorganic functional filler includes the following steps: Step A: Preparation of surface-functionalized modified nano-molybdenum disulfide In a mixed solution of ethanol and deionized water with a volume ratio of 1:1, the surface of molybdenum disulfide nanoparticles was organically functionalized using a silane-modifying agent to obtain surface-functionalized molybdenum disulfide nanoparticles. Step B: Preparation of inorganic functional fillers Using toluene as a medium and the active functional groups of surface-functionalized molybdenum disulfide nanoparticles as initiation sites, 1,4-bis(dimethylsilyl)benzene and triazine benzotriazole derivatives undergo hydrosilylation polymerization under the action of a catalyst to prepare inorganic functional fillers.

3. The environmentally friendly, high-elasticity plastic running track granular material according to claim 2, characterized in that, In step A, the silane modifying agent is methacryloyloxymethyltriethoxysilane or methacryloyloxymethyltrimethoxysilane.

4. The environmentally friendly, high-elasticity plastic running track granular material according to claim 2, characterized in that, In step B, the catalyst is a cassiterite catalyst.

5. The environmentally friendly, high-elasticity plastic running track granular material according to claim 2, characterized in that, In step B, the triazine benzotriazole derivative is prepared using the following method: 4-(2H-benzo[D][1,2,3]triazol-2-yl)benzene-1,3-diol, 1-epoxyethylenemethyl-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and N,N-dimethylformamide were added to a reactor, nitrogen gas was introduced, and stirring was started. After the mixture was homogeneous, a promoter was added to the reactor. After the addition was complete, the mixture was heated to 70-80°C and stirred continuously for 4-8 hours. Heating was then stopped, and the mixture was cooled to room temperature. The reaction solution was washed with dilute hydrochloric acid, and the organic phase was dried with anhydrous sodium sulfate. The mixture was filtered to remove impurities, and the solvent was evaporated to remove impurities. The crude product was purified by column chromatography to obtain the triazine benzotriazole derivative.

6. The environmentally friendly, high-elasticity plastic running track granular material according to claim 5, characterized in that, The molar ratio of 4-(2H-benzo[D][1,2,3]triazol-2-yl)benzene-1,3-diol and 1-epoxyethylenemethyl-3,5-di-2-propenyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione is 1:

1.

7. The environmentally friendly, high-elasticity plastic running track granular material according to claim 5, characterized in that, The accelerator is any one of triethylamine, potassium carbonate, or sodium carbonate.

8. The environmentally friendly, high-elasticity plastic running track granular material according to claim 2, characterized in that, In step B, the mass ratio of the surface-functionalized modified nano-molybdenum disulfide, 1,4-bis(dimethylsilyl)benzene, and triazine benzotriazole derivative is 1:0.1-0.25:0.2-0.

6.

9. The environmentally friendly, high-elasticity plastic running track granular material according to claim 1, characterized in that, The pigment is carbon black; the foaming agent is AC foaming agent.

10. A method for preparing the environmentally friendly, high-elasticity plastic running track granular material as described in claim 1, characterized in that, Includes the following steps: Step 1: Ingredients Weigh out each ingredient according to the specified weight proportions and set aside. Step 2: Mixing Add EVA, SEBS, maleic anhydride-grafted SEBS, inorganic functional filler, chlorinated paraffin oil, pigment, polyethylene wax and foaming agent to a high-speed mixer, control the mixing speed to 300-500 r / min, and mix evenly to form a mixture. Step 3: Foaming The mixture is fed into an extruder for extrusion, and the extruded rubber is placed in an oven for vulcanization and foaming. After foaming, it is cooled by air cooling.

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