TPE damping foam material and method for producing the same

Abstract

The application relates to the technical field of shock-absorbing foaming materials, and particularly discloses a novel TPE shock-absorbing foaming material and a preparation method thereof. The novel TPE shock-absorbing foaming material is obtained after pre-mixed material is subjected to open mixing and mold foaming forming, the pre-mixed material is a mixture of a base material, a filler and an additive, the base material is obtained by mixing SEBS powder, EVA foaming material powder and mineral oil and then standing and aging, and the additive comprises a foaming agent, dicumyl peroxide, zinc oxide and zinc stearate. When production is carried out according to the formula process of the application, the total amount of mineral oil that needs to be absorbed by SEBS powder in the oil filling process is reduced, and the mineral oil mainly composed of naphthenic oil reduces the difficulty of SEBS powder absorbing paraffin oil, so that the time required in the oil filling process can be fully reduced, and the production efficiency of the TPE shock-absorbing foaming material can be fully improved.

Description

Technical Field

[0001] This application relates to the field of shock-absorbing foam materials technology, and more specifically, it relates to a novel TPE shock-absorbing foam material and its preparation method. Background Technology

[0002] TPE is short for thermoplastic elastomer, which refers to a class of elastomer materials that have the elasticity of rubber at room temperature and can be plasticized and molded at high temperatures. Adding foaming components to a basic TPE formulation can produce foamed materials with shock-absorbing properties. These foamed materials are often used in the production of products such as insoles and yoga mats.

[0003] Among the related technologies, there is a SEBS / EVA blend material, which belongs to a type of TPE shock-absorbing foam material. The material is prepared according to the following process: (1) Take 14kg of SEBS powder and 27kg of paraffin oil, and mix them for 12min under the conditions of controlling the rotation speed at 1455 rpm and the mixing temperature at 40℃. Then let it stand for 48h of oil filling, and then mix it for 8min under the conditions of rotating speed at 2850 rpm and mixing temperature at 65℃ to obtain SEBS high-mixed material; (2) Mix 40kg of SEBS high-mixed material, 10kg of EVA powder, 50kg of filler, 25kg of foaming agent, 7kg of diisopropylbenzene peroxide, 1kg of zinc oxide, and 4kg of zinc stearate, and then knead them at 110℃ for 14min. Then, after one open milling, two open milling, cooling and sheeting, and molding foaming, the SEBS / EVA blend material is obtained.

[0004] Regarding the aforementioned technologies, the inventors believe that although the processes in these technologies have enabled the production of TPE shock-absorbing foam materials, these processes require more than 48 hours for SEBS powder and mineral oil to be fully mixed, which is not conducive to fully improving the production efficiency of TPE shock-absorbing foam materials. Summary of the Invention

[0005] In related technologies, the time required for thorough mixing of SEBS powder and paraffin oil is relatively long, which is not conducive to fully improving the production efficiency of TPE shock-absorbing foam materials. To overcome this deficiency, this application provides a novel TPE shock-absorbing foam material and its preparation method.

[0006] In the first aspect, this application provides a novel TPE shock-absorbing foam material, which adopts the following technical solution:

[0007] A novel TPE shock-absorbing foam material is disclosed, wherein the novel TPE shock-absorbing foam material is obtained by open mixing and compression molding of a premix. The premix is ​​a mixture of base material, filler and additives. The base material is formed by mixing the following components in parts by weight and then allowing them to stand for aging: 13.7-14.2 parts of SEBS powder, 13-15 parts of EVA foaming material powder, and 26-28 parts of mineral oil. The mineral oil contains 50-70% naphthenic oil, with the remainder made up to 100% by paraffin oil. The additives include a foaming agent, dicumyl peroxide, zinc oxide and zinc stearate.

[0008] By adopting the above technical solution, compared with related technologies, this application replaces EVA powder with EVA foaming material powder and adjusts the oil filling method. EVA foaming material powder, SEBS powder, and mineral oil are mixed and then allowed to stand for aging, achieving oil filling during this process. The EVA foaming material powder can be a pulverized product of waste EVA foaming material or debris collected during EVA foaming material production. Its porous structure can adsorb and store a portion of the mineral oil, thereby reducing the total amount of mineral oil that the SEBS powder needs to absorb during the oil filling process. Simultaneously, this application also preferably uses a 50-70% proportion of naphthenic oil in the mineral oil, resulting in a mineral oil with naphthenic oil as the main component. After entering the molecular chains of SEBS, the cyclic structure of the naphthenic oil molecules increases the distance between the SEBS molecular chains, which not only facilitates the subsequent penetration of naphthenic oil molecules into the SEBS molecular chains but also facilitates the penetration of chain-structured paraffin oil molecules into the SEBS molecular chains, thus reducing the difficulty for the SEBS powder to absorb paraffin oil. Since the total amount of mineral oil that SEBS powder needs to absorb during the oil filling process is reduced, and the mineral oil with naphthenic oil as the main component reduces the difficulty for SEBS powder to absorb paraffin oil, the time required for the oil filling process can be significantly reduced, which is conducive to significantly improving the production efficiency of TPE shock-absorbing foam materials.

[0009] Preferably, the filler comprises biochar, and the amount of biochar is 12-16% of the weight of the foaming agent.

[0010] By adopting the above technical solution, during the molding and foaming process, while the foaming agent generates gas, the pore structure on the surface of the biochar can continuously receive gas diffused from the melt, allowing bubble nuclei to continuously form within the pores of the biochar. This phenomenon promotes bubble nucleation, which in turn helps increase the porosity of the TPE shock-absorbing foam material. When the biochar content is too low, the bubble nucleation effect is poor. Conversely, when the biochar content is too high, the melt fluidity decreases significantly, which inhibits bubble nucleation. After optimization, when the biochar content is 12-16% of the foaming agent weight, the porosity of the TPE shock-absorbing foam material is higher.

[0011] Preferably, the biochar is prepared according to the following method:

[0012] (1) After drying and crushing the reeds, the reed powder is obtained. The reed powder is mixed with ammonia water and then aged in a closed environment. After aging, the mixture is heated in a water bath and centrifuged and filtered. The filter residue is then dried to obtain modified reed powder.

[0013] (2) The modified reed powder was pyrolyzed, and the pyrolysis product was cooled, washed, dried and ground, and then sieved to obtain biochar.

[0014] By adopting the above technical solution, this application uses reed powder as raw material. Ammonia water is mixed with dried reed powder, and the powder is allowed to fully absorb the ammonia water during static aging. The ammonia water decomposes during pyrolysis to produce gas, promoting the formation of pore structures and contributing to the obtaining of biochar with a richer surface pore structure.

[0015] Preferably, the pyrolysis temperature is 300-400℃.

[0016] While increasing the temperature can increase the porosity of biochar using the above-mentioned technical solutions, excessively high temperatures lead to excessive mass loss of reed powder, which not only affects the biochar's role in promoting bubble nucleation but also hinders the improvement of biochar yield. A pyrolysis temperature of 300-400℃ helps to obtain biochar with a better promoting effect on bubble nucleation while minimizing the mass loss of reed powder.

[0017] Preferably, the mass concentration of the ammonia water is 3-10%.

[0018] By adopting the above technical solution, the optimal mass concentration of ammonia water was determined. When the mass concentration of ammonia water is too low, the gas produced by the decomposition of ammonia water is insufficient to adequately increase the porosity of the biochar surface. When the mass concentration of ammonia water is too high, the ammonia water decomposes too violently during pyrolysis, easily damaging the pore structure of the biochar surface and affecting the biochar's role in promoting bubble nucleation. When the mass concentration of ammonia water is 3-10%, the resulting biochar exhibits a relatively good effect in promoting bubble nucleation.

[0019] Preferably, the reed powder and ammonia water are mixed at a weight ratio of 1:(2.8-3.2).

[0020] By adopting the above technical solution, the weight ratio of reed powder to ammonia water was further optimized based on the optimized ammonia water concentration. When the ammonia water concentration is 3-10%, the weight ratio of reed powder to ammonia water has a certain impact on the biochar yield and the biochar's effect on promoting bubble nucleation. When reed powder and ammonia water are mixed at a weight ratio of 1:(2.8-3.2), it is beneficial to obtain biochar with a better promoting effect on bubble nucleation without significantly reducing the yield.

[0021] Preferably, the filler comprises modified steel slag powder, which is prepared according to the following method:

[0022] (1) Mix silane coupling agent with water and ethanol to obtain silane modified liquid; crush and grind steel slag to obtain steel slag powder;

[0023] (2) Mix steel slag powder with silane modification liquid to obtain a mixture. Heat the mixture at 65-75℃ for 2-3 hours. Filter to recover the solid in the mixture and dry the solid to obtain modified steel slag powder.

[0024] By adopting the above technical solution, this application obtains modified steel slag powder by treating steel slag powder with a silane coupling agent. The modified steel slag powder has good compatibility with SEBS and EVA, and is easier to uniformly disperse in TPE damping foam materials compared to steel slag powder.

[0025] Preferably, the silane coupling agent is a phenylsilane coupling agent.

[0026] By adopting the above technical solution, the phenylsilane coupling agent, after modifying steel slag powder, can yield modified steel slag powder with benzene rings on its surface, which is beneficial for the adsorption of aromatic components in naphthenic oil. Through the adsorption of aromatic components in naphthenic oil, the probability of contact between the PS phase of SEBS and the aromatic components in naphthenic oil is reduced, limiting the dissolution of the PS phase of SEBS by aromatic components, and thus helping to improve the mechanical properties of TPE damping foam materials.

[0027] Preferably, in step (2) of preparing the modified steel slag powder, salicylic acid is mixed together with the steel slag powder and the silane modification liquid.

[0028] By adopting the above technical solution, salicylic acid can erode the silicates in steel slag, which helps to increase the roughness of the steel slag surface. At the same time, it provides more reaction sites for the grafting modification of silane coupling agents, which is conducive to increasing the total amount of phenyl groups on the surface of modified steel slag powder and improving the adsorption effect of modified steel slag powder on aromatic components in naphthenic oil.

[0029] Secondly, this application provides a method for preparing a novel TPE shock-absorbing foam material, which adopts the following technical solution.

[0030] A method for preparing a novel TPE shock-absorbing foam material includes the following steps:

[0031] (1) Mix mineral oil, SEBS powder and EVA foaming material powder, and let it stand and age in a closed environment for 6-8 hours to obtain base material; (2) Mix base material, filler and additives to obtain premix, and then perform intensive mixing on the premix, followed by primary open milling, secondary open milling, cooling and sheeting and molding foaming to obtain new TPE shock-absorbing foam material.

[0032] By adopting the above technical solution, the method of this application can fully achieve oil filling in 6-8 hours of static aging, which significantly shortens the time required for the oil filling step compared to 48 hours in related technologies, and improves the production efficiency of TPE shock-absorbing foam materials.

[0033] In summary, this application has the following beneficial effects:

[0034] 1. When producing according to the formulation and process of this application, since the total amount of mineral oil that SEBS powder needs to absorb during the oil filling process is reduced, and the mineral oil with naphthenic oil as the main component reduces the difficulty for SEBS powder to absorb paraffin oil, the time required for the oil filling process can be significantly reduced, which is conducive to significantly improving the production efficiency of TPE shock-absorbing foam material.

[0035] 2. The preferred filler in this application includes biochar, and the degree of aromatization of the biochar is increased by modification with ammonia water, thereby enhancing its ability to adsorb aromatic components. By adsorbing aromatic components in naphthenic oil, the probability of contact between the benzene ring of SEBS and the aromatic components in naphthenic oil is reduced, limiting the dissolution of the benzene ring of SEBS by aromatic components, which helps to improve the mechanical properties of TPE shock-absorbing foam material.

[0036] 3. The method of this application can fully achieve oil filling through 6-8 hours of static aging, which improves the production efficiency of TPE shock-absorbing foam material. Detailed Implementation

[0037] The present application will be further described in detail below with reference to the embodiments, preparation examples and comparative examples. All raw materials involved in the present application can be obtained commercially. The aromatic mass fraction of the naphthenic oil is 10.42%, and the EVA foaming material powder is 100 mesh, which is the crushed product of waste EVA foaming material (average pore size 45 μm).

[0038] Example of biochar preparation

[0039] The following explanation uses Preparation Example 1 as an example.

[0040] Preparation Example 1

[0041] In this preparation example, biochar was prepared according to the following method:

[0042] (1) After drying and crushing the reeds, the reed powder is obtained. The reed powder is mixed with ammonia water at a weight ratio of 1:2.5 and then aged in a closed environment at 25°C for 12 hours. After aging, the mixture is heated in a water bath and centrifuged and filtered. The filter residue is then dried at 105°C to obtain modified reed powder. In this step, the mass concentration of ammonia water is 2.5%.

[0043] (2) Starting from 25℃, the temperature is increased at a rate of 10℃ / min. The temperature is stopped at 420℃, and the modified reed powder is pyrolyzed for 2 hours. The pyrolysis product is then cooled to 25℃ and washed. After drying at 105℃, it is ground. The ground product is passed through a 100-mesh sieve to obtain biochar.

[0044] As shown in Table 1, the difference between preparation examples 1-5 is that the maximum temperature (T) of the modified reed powder pyrolysis is different.

[0045] Table 1. Maximum pyrolysis temperature (T) of modified reed powder

[0046]

[0047] As shown in Table 2, the difference between Preparation Examples 6-9 and Preparation Example 3 is that the mass concentration of ammonia water is different.

[0048] Table 2 Mass concentration of ammonia water

[0049]

[0050] As shown in Table 3, the difference between Preparation Examples 10-13 and Preparation Example 7 is that the reed powder and ammonia water are mixed in different weight ratios.

[0051] Table 3 Weight ratio of reed powder to ammonia water

[0052]

[0053] Preparation Example 14

[0054] The difference between this preparation example and preparation example 1 is that, in step (1) of preparing biochar, ammonia water is replaced with pure water.

[0055] Preparation example of modified steel slag powder

[0056] The following explanation uses Preparation Example 15 as an example.

[0057] Preparation Example 15

[0058] In this preparation example, the modified steel slag powder was prepared according to the following method:

[0059] (1) Mix silane coupling agent with water and ethanol in a weight ratio of 1:9:10 to obtain silane modified liquid; crush and grind steel slag to obtain steel slag powder with an average particle size of 3.5μm; in this step, methyltriethoxysilane is selected as the silane coupling agent.

[0060] (2) Steel slag powder and silane modified liquid are mixed at a weight ratio of 1:3 to obtain a mixed liquid. The mixed liquid is stirred and heated at 70°C for 2.5 hours. The solid in the mixed liquid is filtered and the solid is dried to obtain modified steel slag powder.

[0061] Preparation Example 16

[0062] The difference between this preparation example and preparation example 15 is that the silane coupling agent used is phenyltriethoxysilane.

[0063] Preparation Example 17

[0064] The difference between this preparation example and preparation example 16 is that in step (2) of preparing modified steel slag powder, salicylic acid is mixed together with steel slag powder and silane modification liquid, and the ratio of the weight (g) of salicylic acid to the volume (mL) of silane modification liquid is 0.025 g / mL.

[0065] Example

[0066] Examples 1-5

[0067] The following description uses Example 1 as an example.

[0068] Example 1

[0069] In this embodiment, the novel TPE shock-absorbing foam material is prepared according to the following steps:

[0070] (1) Mix 26kg mineral oil, 13.7kg SEBS powder and 13kg EVA foaming material powder, and let it stand and age in a closed environment for 6 hours to obtain the base material; In this step, the proportion of naphthenic oil in the mineral oil is 50%, and the rest is paraffin oil;

[0071] (2) The base material obtained in step (1), 50 kg of filler and additives are mixed to obtain a premix. The premix is ​​then subjected to internal mixing, followed by a first open milling, a second open milling, cooling and sheeting, and molding foaming to obtain a new type of TPE shock-absorbing foam material. In this step, the additives include 25 kg of AC foaming agent, 7 kg of dicumyl peroxide, 1 kg of zinc oxide and 4 kg of zinc stearate, and the filler is calcium carbonate powder.

[0072] As shown in Table 4, the main difference between Examples 1-5 lies in the different proportions of the base material.

[0073] Table 4. Proportioning of base materials

[0074] sample SEBS powder / kg EVA foaming material powder / kg Mineral oil / kg Example 1 13.7 13 26 Example 2 13.8 13.5 26.5 Example 3 14.0 14 27 Example 4 14.1 14.5 27.5 Example 5 14.2 15 28

[0075] Example 6

[0076] The difference between this embodiment and embodiment 5 is that after the mineral oil, SEBS powder and EVA foaming material powder are mixed, they are left to stand and age in a closed environment for 7 hours.

[0077] Example 7

[0078] The difference between this embodiment and embodiment 5 is that after the mineral oil, SEBS powder and EVA foaming material powder are mixed, they are left to stand and age in a closed environment for 8 hours.

[0079] Example 8

[0080] The difference between this embodiment and Embodiment 5 is that the proportion of naphthenic oil in the mineral oil is 60%, and the remainder is paraffin oil.

[0081] Example 9

[0082] The difference between this embodiment and Embodiment 5 is that the proportion of naphthenic oil in the mineral oil is 70%, and the remainder is paraffin oil.

[0083] Example 10

[0084] The difference between this embodiment and Example 9 is that the filler is a mixture of calcium carbonate powder and biochar from Preparation Example 1, and the amount of biochar is 10% of the weight of the foaming agent.

[0085] As shown in Table 5, the difference between Examples 10-14 is that the percentage of biochar used to the weight of the foaming agent (hereinafter referred to as biochar percentage) is different.

[0086] Table 5 Biochar Proportion

[0087] sample Example 10 Example 11 Example 12 Example 13 Example 14 Biochar percentage 10 12 14 16 18

[0088] As shown in Table 6, the difference between Examples 15-27 and Example 12 is that the preparation methods of biochar are different.

[0089] Table 6 Examples of biochar preparation

[0090]

[0091] Example 28

[0092] The difference between this embodiment and Embodiment 9 is that the filler is a mixture of calcium carbonate powder and steel slag powder, with the steel slag powder accounting for 5% of the filler.

[0093] Example 29

[0094] The difference between this embodiment and Example 28 is that the filler is made by mixing calcium carbonate powder with the modified steel slag powder of Preparation Example 15, and the modified steel slag powder accounts for 5% of the filler.

[0095] Example 30

[0096] The difference between this embodiment and Example 29 is that the calcium carbonate powder is mixed with the modified steel slag powder of Preparation Example 16.

[0097] Example 31

[0098] The difference between this embodiment and Example 29 is that the calcium carbonate powder is mixed with the modified steel slag powder of Preparation Example 17.

[0099] Comparative Example

[0100] Comparative Example 1

[0101] This comparative example provides a SEBS / EVA blend material, which belongs to a type of TPE shock-absorbing foam material. This material is prepared according to the following process:

[0102] (1) Take 14 kg of SEBS powder and 27 kg of paraffin oil, and mix them for 12 min at a speed of 1455 rpm and a mixing temperature of 40℃. Then let them stand and fill with oil for 48 h, and then mix them for 8 min at a speed of 2850 rpm and a mixing temperature of 65℃ to obtain high-mixed SEBS material.

[0103] (2) Mix 40kg of SEBS high-mix material, 10kg of EVA powder, 50kg of filler, 25kg of foaming agent, 7kg of dicumyl peroxide, 1kg of zinc oxide and 4kg of zinc stearate and then knead at 110℃ for 14min. Then, after one open milling, two open milling, cooling and sheeting and molding foaming, the SEBS / EVA blend material is obtained.

[0104] Comparative Example 2

[0105] The difference between this comparative example and Comparative Example 1 is that the settling and oil filling time in step (1) of Comparative Example 1 is adjusted to 8 hours.

[0106] Comparative Example 3

[0107] The difference between this comparative example and Example 5 is that the EVA foaming material powder is replaced with the same weight of EVA powder.

[0108] Comparative Example 4

[0109] The difference between this comparative example and Example 5 is that the mineral oil contains 40% naphthenic oil and the remainder is paraffin oil.

[0110] Comparative Example 5

[0111] The difference between this comparative example and Example 5 is that the mineral oil contains 80% naphthenic oil and the remainder is paraffin oil.

[0112] Performance testing methods

[0113] I. Evaluation of Oil Filling Effect

[0114] Since the degree of oil filling affects the tear strength of TPE materials, the oil filling effect is characterized by comparing the tear strength under different oil filling time conditions.

[0115] In this test, an experimental group and a control group were set up. The experimental group was produced and processed according to the formulas and process conditions of each embodiment and comparative example. The difference between the control group and the experimental group was that the static aging (static oil filling) time of the control group was extended by 48 hours compared with that of the experimental group.

[0116] Test reference standard: ASTM D624-2000 General purpose vulcanized rubber and thermoplastic elastomers – Test method for tear resistance.

[0117] After measuring the tear strength of the experimental group and the control group, the ratio R1 between the tear strength of the experimental group and the tear strength of the control group was calculated. The results are shown in Table 7.

[0118] Table 7R1

[0119] sample <![CDATA[R1 / %]]> sample <![CDATA[R1 / %]]> Example 1 92.9 Example 8 97.2 Example 2 93.0 Example 9 99.9 Example 3 93.2 Comparative Example 1 99.9 Example 4 93.3 Comparative Example 2 42.4 Example 5 93.5 Comparative Example 3 78.6 Example 6 97.8 Comparative Example 4 81.2 Example 7 99.9 Comparative Example 5 99.9

[0120] II. Optimal Selection of Biochar

[0121] Production and processing were carried out according to the formulations and process conditions of each embodiment and comparative example. Then, the true density ρ1 of the sample made of foamed material was measured by the specific gravity method described in GB / T 1033.1-2008, and the apparent density ρ2 of the sample made of foamed material was tested by the method described in GB / T 6343-2009. Then, the porosity was calculated according to the following formula:

[0122]

[0123] After obtaining the porosity calculation results, the ratio of the porosity measured in the samples of Examples 10-27 to the porosity measured in the sample of Example 9 was calculated, and the result was defined as the relative porosity. The results are shown in Table 7.

[0124] The yield is the weight ratio of biochar obtained after pyrolysis and carbonization to reed powder before pyrolysis and carbonization. The ratio of the yield of Preparation Examples 1-14 to the yield of Preparation Example 1 is the relative yield.

[0125] Table 8 Relative Porosity

[0126]

[0127]

[0128] Table 9 Relative Yield

[0129] sample Relative yield / % sample Relative yield / % Preparation Example 1 100.0 Preparation Example 8 110.5 Preparation Example 2 104.6 Preparation Example 9 110.7 Preparation Example 3 109.7 Preparation Example 10 109.2 Preparation Example 4 114.1 Preparation Example 11 108.5 Preparation Example 5 118.2 Preparation Example 12 107.9 Preparation Example 6 110.2 Preparation Example 13 107.3 Preparation Example 7 110.4 Preparation Example 14 116.9

[0130] III. Evaluation of the Adsorption Effect of Aromatic Components

[0131] Production and processing were carried out according to the formulation and process conditions of each embodiment, and the tear strength of the TPE shock-absorbing foam material was tested with reference to ASTM D624-2000. The ratio between the tear strength of Examples 28-31 and the tear strength of Example 28 was calculated and recorded as R2. The results are shown in Table 10.

[0132] Table 10R2

[0133] sample <![CDATA[R2 / %]]> Example 28 100.0 Example 29 100.8 Example 30 107.5 Example 31 112.3

[0134] Combining Examples 1-9 and Comparative Examples 1-2 with Table 7, it can be seen that the R1 values ​​measured in Examples 1-5 are all around 93%, which, although still lower than Comparative Example 1, are much higher than Comparative Example 2 with the same oil filling time. This indicates that the scheme of this application helps to improve oil filling efficiency. Examples 6-7 extended the standing aging time, and Examples 8-9 increased the proportion of naphthenic oil, both of which improved the R1 value. Furthermore, Examples 7 and 9 both obtained an R1 value of 99.99%, indicating that Examples 7 and 9 have fully completed oil filling, achieving tear strength close to that of Comparative Example 1, and the oil filling time is much shorter than that of Comparative Example 1, thus significantly improving production efficiency.

[0135] As can be seen from Example 5 and Comparative Example 3, and Table 7, Example 3 absorbs a portion of the mineral oil through the pore structure of the EVA foaming material powder, reducing the total amount of mineral oil that the SEBS powder needs to absorb during the oil filling process. Therefore, it can significantly reduce the time required for the oil filling process, which is beneficial to significantly improving the production efficiency of TPE shock-absorbing foaming material.

[0136] Based on Examples 5, 8-9, and Comparative Examples 4-5, and referring to Table 7, it can be seen that increasing the proportion of naphthenic oil in mineral oil can reduce the difficulty for paraffin oil to enter the SEBS molecular chains. In Comparative Example 4, the proportion of naphthenic oil in mineral oil is relatively small, while the proportion of paraffin oil is relatively large, resulting in low oil filling efficiency. The R1 value of Example 9 has already reached 99.9%, so further increasing the proportion of naphthenic oil (as in Comparative Example 5) is not very meaningful.

[0137] Based on Examples 9, 10-14, and 27, and referring to Table 8, it can be seen that adding biochar helps promote bubble nucleation, and the biochar prepared after ammonia modification has a better promoting effect on bubble nucleation. As the biochar content increases, the relative porosity first increases and then decreases, indicating that when the biochar content is below 12% or above 16% of the blowing agent weight, the effect of biochar in promoting bubble nucleation is relatively poor. However, when the biochar content is 12-16% of the blowing agent weight, bubble nucleation is more complete under the promotion of biochar, resulting in a higher porosity of the TPE shock-absorbing foam material.

[0138] Based on Examples 12 and 15-18, and in conjunction with Tables 8 and 9, it can be seen that when the temperature exceeds 400℃, the mass loss of reed powder is too large, making it difficult to obtain a high yield. As the temperature decreases, the yield of biochar gradually increases, while the porosity also decreases. When the temperature drops below 300℃, the porosity of the biochar is low, which is not conducive to promoting bubble nucleation. At a pyrolysis temperature of 300-400℃, the mass loss of reed powder is relatively small, and biochar with a relatively good promoting effect on bubble nucleation is obtained without significantly reducing the yield.

[0139] Based on Examples 16, 19-22, and Table 8, it can be seen that when the mass concentration of ammonia is below 3%, the gas produced by ammonia decomposition is insufficient to significantly increase the porosity of the biochar surface. When the mass concentration of ammonia is above 10%, the ammonia decomposes too violently during pyrolysis, easily damaging the pore structure of the biochar surface and affecting the biochar's role in promoting bubble nucleation. When the mass concentration of ammonia is between 3% and 10%, the resulting biochar exhibits a relatively better effect in promoting bubble nucleation.

[0140] Based on Examples 20, 23-26, and Tables 8 and 9, it can be seen that the weight ratio of reed powder to ammonia water has a certain impact on the yield of biochar and the promoting effect of biochar on bubble nucleation. Increasing the proportion of ammonia water improves the promoting effect of biochar on bubble nucleation but also reduces the yield. When reed powder and ammonia water are mixed at a weight ratio of 1:(2.8-3.2), it is beneficial to obtain biochar with a relatively good promoting effect on bubble nucleation without a significant decrease in yield.

[0141] As can be seen from Examples 28-31, Example 9, and Table 10, modification with phenyl-free silane coupling agents is beneficial for the uniform dispersion of steel slag fillers and has a certain effect on improving the tear strength of TPE shock-absorbing foam materials, but the improvement rate is limited. However, phenyl-containing silane coupling agents, after modifying steel slag powder, can produce modified steel slag powder with benzene rings on the surface, which is beneficial for adsorbing aromatic components in naphthenic oil. By adsorbing aromatic components in naphthenic oil, the probability of contact between the PS phase of SEBS and the aromatic components in naphthenic oil is reduced, limiting the dissolution of the PS phase of SEBS by aromatic components, thus helping to improve the mechanical properties of TPE shock-absorbing foam materials. Furthermore, the addition of salicylic acid erodes the silicates in the steel slag, increasing the surface roughness of the steel slag and providing more reaction sites for the grafting modification of silane coupling agents. This increases the total amount of phenyl groups on the surface of the modified steel slag powder, improving the adsorption effect of the modified steel slag powder on the aromatic components in naphthenic oil.

[0142] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A TPE shock-absorbing foam material, characterized in that, The TPE shock-absorbing foam material is obtained by open mixing and compression molding of premixed material. The premixed material is a mixture of base material, filler and additives. The base material is made by mixing the following components in parts by weight and then allowing them to stand for aging: 13.7-14.2 parts of SEBS powder, 13-15 parts of EVA foam material powder, and 26-28 parts of mineral oil. The proportion of naphthenic oil in the mineral oil is 50-70%, and the remainder is made up to 100% by paraffin oil. The additives include foaming agent, dicumyl peroxide, zinc oxide and zinc stearate.

2. The TPE shock-absorbing foam material according to claim 1, characterized in that, The filler includes biochar, and the amount of biochar used is 12-16% of the weight of the foaming agent; the biochar is prepared according to the following method: (1) After drying and crushing the reeds, the reed powder is obtained. The reed powder is mixed with ammonia water and then aged in a closed environment. After aging, the mixture is heated in a water bath and centrifuged and filtered. The filter residue is then dried to obtain modified reed powder. (2) The modified reed powder was pyrolyzed, and the pyrolysis product was cooled, washed, dried and ground, and then sieved to obtain biochar.

3. The TPE shock-absorbing foam material according to claim 2, characterized in that, The pyrolysis temperature is 300-400℃.

4. The TPE shock-absorbing foam material according to claim 2, characterized in that, The mass concentration of the ammonia water is 3-10%.

5. The TPE shock-absorbing foam material according to claim 4, characterized in that, The reed powder and ammonia water are mixed at a weight ratio of 1:(2.8-3.2).

6. The TPE shock-absorbing foam material according to claim 1, characterized in that, The filler comprises modified steel slag powder, which is prepared according to the following method: (1) Mix the silane coupling agent with water and ethanol to obtain a silane modified liquid; crush and grind the steel slag to obtain steel slag powder; (2) Mix steel slag powder with silane modification liquid to obtain a mixture. Heat the mixture at 65-75℃ for 2-3 hours. Filter to recover the solid in the mixture and dry the solid to obtain modified steel slag powder.

7. The TPE shock-absorbing foam material according to claim 6, characterized in that, The silane coupling agent is a phenylsilane coupling agent.

8. The TPE shock-absorbing foam material according to claim 7, characterized in that, In step (2) of preparing the modified steel slag powder, salicylic acid is mixed together with steel slag powder and silane modification liquid.

9. The method for preparing the TPE shock-absorbing foam material according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Mix mineral oil, SEBS powder and EVA foaming material powder, and let it stand and age in a closed environment for 6-8 hours to obtain the base material; (2) Mix the base material, filler and additives to obtain a premix, then perform internal mixing on the premix, followed by a first open mill, a second open mill, cooling and sheeting, and molding to obtain TPE shock-absorbing foam material.

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