Fully-recycled renewable TPU (thermoplastic polyurethane) basketball shoe sole piece and preparation method thereof

Abstract

The invention particularly relates to a fully-recycled and renewable TPU basketball shoe sole piece and a preparation method thereof. The TPU basketball shoe sole piece is prepared from the following raw materials in parts by weight: 60 to 75 parts of TPU prepolymer, 0.5 to 2 parts of chain extender, 10 to 20 parts of recycled TPU waste, 5 to 10 parts of reinforcing filler, 3 to 8 parts of elasticity regulator, 0.5 to 2 parts of antioxidant, 5 to 10 parts of anti-skid modifier, 1 to 3 parts of cross-linking agent and 0.5 to 1 part of lubricant. According to the basketball shoe sole piece, TPU obtained through the design of a bio-based poly (4-hydroxybutyrate) soft segment and the cooperation of the elasticity regulator has excellent elasticity, and meanwhile, the TPU is jointly cooperated with the reinforcing filler and the anti-skid modifier, so that the anti-skid performance, the thermal wear resistance and the tearing strength of the basketball shoe sole piece are improved. In addition, recycling of part of resources is achieved by recycling TPU waste, and meanwhile the prepared TPU basketball shoe sole piece has good renewability and biocompatibility.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of basketball sole sheet materials, and particularly relates to a fully recyclable and renewable TPU basketball sole sheet and a preparation method thereof. Background Art

[0002] Polyurethane can achieve customized design of the internal structure by adjusting the types of soft and hard segments and chain extenders, and is widely used in many fields such as aerospace, electronic automobiles, biomedical, and sports shoe materials due to its high flexibility. At present, most of the raw materials for polyurethane synthesis come from petroleum-based raw materials, and the highly stable chemical bonds of polyurethane materials make them difficult to recycle and reuse. Even if a small part can be recycled by physical or chemical methods, the recycling process has problems such as high energy consumption and low recycling efficiency. Therefore, it is necessary to develop raw materials from biological sources for the synthesis of polyurethane. Among them, biomass-derived poly(4-hydroxybutyrate) has good biodegradability and biocompatibility, and it is a completely renewable polymer material. Using it for the synthesis of recyclable TPU materials has great environmental protection advantages. However, when it is used for the preparation of sports shoe sole materials, due to the high flexibility of the molecular weight and high regularity of poly(4-hydroxybutyrate), it is easy to crystallize, resulting in problems such as a narrow processing temperature range and insufficient wear resistance of the material. At the same time, in order to improve the wear resistance and anti-slip performance of the sole, some wear-resistant fillers usually need to be added, but the high melt viscosity and polarity difference of poly(4-hydroxybutyrate) easily lead to filler agglomeration and reduce the reinforcement effect. Summary of the Invention

[0003] The purpose of the present invention is to provide a fully recyclable and renewable TPU basketball sole sheet and a preparation method thereof to solve the above-mentioned deficiencies of the prior art.

[0004] The purpose of the present invention is achieved by the following technical solutions: a fully recyclable and renewable TPU basketball sole sheet, comprising the following raw materials in parts by weight: 60-75 parts of TPU prepolymer, 0.5-2 parts of chain extender, 10-20 parts of recycled TPU waste, 5-10 parts of reinforcing filler, 3-8 parts of elastic regulator, 0.5-2 parts of antioxidant, 3-5 parts of anti-slip modifier, 1-3 parts of cross-linking agent, and 0.5-1 part of lubricant.

[0005] Further, the preparation method of the TPU prepolymer comprises the following steps: vacuum dehydrating poly(4-hydroxybutyrate) at 70-80°C for 2-4 hours, then adding diisocyanate and organotin catalyst thereto and continuously stirring, and gradually heating to 80-85°C and reacting for 2-3 hours to obtain the TPU prepolymer for standby.

[0006] Furthermore, the molecular weight of the poly(4-hydroxybutyrate) is 1000 - 3000, and the diisocyanate is 4,4'-diphenylmethane diisocyanate (MDI) or hexamethylene diisocyanate (HDI). In this prepolymer system, the molar ratio of -NCO to -OH is 2.0 - 2.5, and the dosage of the organotin catalyst is 0.1 - 0.3 wt%.

[0007] It has good renewability and biocompatibility. At the same time, by utilizing the excellent molecular chain flexibility of poly(4-hydroxybutyrate) and cooperating with the chain extender, the TPU prepolymer is given good resilience.

[0008] Furthermore, the chain extender is 1,4-butanediol.

[0009] Furthermore, the preparation method of the recycled TPU waste includes the following steps: sorting and crushing the TPU waste from the soles, heating and dissolving it in dimethyl sulfoxide, adding 5 - 10 wt% of the alcoholysis agent and 0.2 - 0.5 wt% of the organotin catalyst, controlling the reaction temperature at 75 - 85 °C for 4 - 6 h, and finally filtering to obtain the recycled TPU waste. Preferably in the present invention, the alcoholysis agent is ethylene glycol or propylene glycol.

[0010] In the present invention, by partially depolymerizing the TPU waste, the depolymerized TPU can participate in the polymerization again, which can improve its compatibility in the system, avoid phase separation caused by direct blending, and effectively improve the problems of uneven crosslinking degree and impaired mechanical properties of the TPU waste.

[0011] Furthermore, the reinforcing filler is at least one of nano-silica, nano-silicon nitride, and carbon nanotubes. In the present invention, the reinforcing filler is preferably nano-silica.

[0012] Furthermore, the elasticity regulator is poly(butylene adipate). By adding the elasticity regulator, the glass transition temperature of the material can be reduced, thereby improving the low-temperature elasticity of the TPU basketball sole sheet and overcoming the problem of hardening of traditional TPU soles at low temperatures.

[0013] Furthermore, the anti-slip modifier is at least one of micron-scale silica, micro-nano mixed-scale silica, and surface-grafted modified graphene. Specifically, the specific preparation method of the surface-grafted modified graphene is as follows: dispersing graphene oxide in an ethanol aqueous solution, adding 3-aminopropyltriethoxysilane and mixing evenly, and refluxing and reacting at 75 - 80 °C for 5 - 6 h. The product obtained after centrifugation, washing, and drying is placed in toluene, adding hydroxyl-terminated polydimethylsiloxane and dicyclohexylcarbodiimide and continuing to react for 10 - 12 h, and finally adding hydrazine hydrate and reacting for 5 - 6 h. After completion, it is centrifuged, washed, and dried to obtain the surface-grafted modified graphene.

[0014] In the present invention, on the one hand, the lamellar structure of graphene can be utilized to increase the surface roughness of the TPU basketball sole sheet. On the other hand, by surface grafting and modifying graphene, the surface energy can be reduced by grafting polydimethylsiloxane, preventing the formation of a water film on the surface of the TPU basketball sole sheet, thereby enhancing the wet grip of the sole sheet. In addition, the addition of surface grafted and modified graphene can improve the heat resistance of the material, contributing to the improvement of the hot processing performance of the TPU basketball sole sheet.

[0015] Further, the crosslinking agent is trimethylolpropane and / or triallyl isocyanurate.

[0016] Further, the antioxidant is a hindered phenol antioxidant and / or a phosphite antioxidant.

[0017] Further, the lubricant is at least one of zinc stearate, glyceryl stearate, and methyl silicone oil.

[0018] Step S1: A chain extender and recycled TPU waste are fully mixed into the TPU prepolymer, and then a pretreated reinforcing filler and an elastic regulator are added and fully mixed. Then, an anti-slip modifier and a crosslinking agent are added and stirred at high speed to obtain a mixture.

[0019] Step S2: The mixture obtained in Step S1 is poured into a preheated mold for curing, and the cured TPU is annealed.

[0020] Step S3: The annealed TPU block obtained in Step S2 is put into a twin-screw extruder for melt granulation to obtain TPU particles.

[0021] Step S4: The TPU particles obtained in Step S3 are put into an injection molding machine to be injection molded into the shape of a basketball sole sheet, thus obtaining the TPU basketball sole sheet.

[0022] Even further, the chain extender is 1,4-butanediol.

[0023] Even further, the pretreatment method of the reinforcing filler is: placing the reinforcing filler in poly(4-hydroxy diacid ester) with a mass ratio of 1:1 and ultrasonically dispersing it for 15 - 30 min.

[0024] Even further, in Step S2, the curing is divided into two steps. The first step has a curing temperature of 100 - 110 °C and a time of 2 - 3 h; the second step has a curing temperature of 110 - 120 °C and a time of 3 - 4 h; the annealing treatment temperature is 80 - 85 °C and the time is 20 - 24 h.

[0025] Even further, in Step S3, the temperature of the twin-screw extruder is 160 - 180 °C.

[0026] Furthermore, in step S4, the temperature of the injection barrel is 180 - 200 °C, the temperature of the mold is 60 - 80 °C, and the injection pressure is 80 - 100 MPa.

[0027] In the present invention, through the prepolymerization of poly(4-hydroxybutyrate) and diisocyanate, and simultaneously introducing the recycled TPU waste after depolymerization for repolymerization, the effective recycling and reuse of some waste materials are realized, and at the same time, the phase separation problem caused by direct use can be avoided. Meanwhile, through the ingenious cooperation of reinforcing fillers, elastic regulators, and anti-slip modifiers, the elasticity, wear resistance, and anti-slip performance of the TPU basketball sole sheet are synergistically improved. Subsequently, through the combination of stepwise curing and annealing treatment, the TPU crosslinking network is optimized, and the mechanical properties of the sole sheet are effectively improved by adjusting its crystallization state.

[0028] The beneficial effects of the present invention are as follows: The fully recycled and renewable TPU basketball sole sheet prepared by the present invention has good renewable and biocompatible properties. Adding recycled TPU waste in the TPU polymerization process realizes the recycling of resources. As a basketball sole sheet, through the design of the bio-based poly(4-hydroxybutyrate) soft segment, the TPU obtained by cooperating with diisocyanate, chain extender, and elastic regulator has excellent elasticity. At the same time, in cooperation with reinforcing fillers and anti-slip modifiers, the anti-slip performance, wear resistance, and tear strength of the basketball sole sheet are improved, especially the anti-wet-slip performance and thermal wear resistance. Specific Embodiments

[0029] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments. The content mentioned in the embodiments does not limit the present invention.

[0030] This embodiment provides a fully recycled and renewable TPU basketball sole sheet, including the following raw materials in parts by weight: 60 parts of TPU prepolymer, 0.7 part of chain extender, 11 parts of recycled TPU waste, 6 parts of reinforcing filler, 3.5 parts of elastic regulator, 1 part of antioxidant, 3 parts of anti-slip modifier, 1.5 parts of crosslinking agent, and 0.5 part of lubricant.

[0031] Furthermore, the preparation method of the TPU prepolymer includes the following steps: Vacuum dehydrate poly(4-hydroxybutyrate) at 70 °C for 4 h, then add diisocyanate and dibutyltin dilaurate thereto and continuously stir, and gradually raise the temperature to 80 °C and react for 3 h to obtain the TPU prepolymer for standby.

[0032] Furthermore, the molecular weight of the poly(4-hydroxybutyrate) is 2000, and the diisocyanate is hexamethylene diisocyanate (HDI). In this prepolymerization system, the molar ratio of -NCO to -OH is 2.0, and the dosage of dibutyltin dilaurate is 0.12 wt%.

[0033] Further, the chain extender is 1,4-butanediol.

[0034] Further, the preparation method of the recycled TPU waste includes the following steps: sorting and crushing the TPU waste from the soles, heating and dissolving it in dimethyl sulfoxide, adding 6 wt% ethylene glycol and 0.5 wt% stannous octoate, controlling the reaction temperature at 80 °C for 6 h, and finally filtering to obtain the recycled TPU waste.

[0035] Further, the reinforcing filler is nano-silica.

[0036] Further, the elastic regulator is poly(butylene adipate).

[0037] Further, the anti-slip modifier is surface-grafted modified graphene. Specifically, the specific preparation method of the surface-grafted modified graphene is as follows: dispersing graphene oxide in an ethanol aqueous solution, adding 2 wt% of 3-aminopropyltriethoxysilane and mixing evenly, refluxing and reacting at 75 °C for 6 h, placing the product obtained by centrifugation, washing and drying in toluene, adding hydroxyl-terminated polydimethylsiloxane and dicyclohexylcarbodiimide in a mass ratio of 1:2:0.7 and continuing to react at 80 °C for 12 h, and finally adding an equimolar amount of hydrazine hydrate to the product obtained by centrifugation, washing and drying for reaction for 6 h, and after centrifugation, washing and drying, the surface-grafted modified graphene is obtained.

[0038] Further, the crosslinking agent is trimethylolpropane.

[0039] Further, the antioxidant is compounded from antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1.

[0040] Further, the lubricant is zinc stearate.

[0041] The preparation method of the fully recycled and renewable TPU basketball sole sheet provided in this embodiment includes the following steps:

[0042] Step S1: Fully mix the chain extender and the recycled TPU waste into the TPU prepolymer, then add the pretreated reinforcing filler and elastic regulator and mix well, and then add the anti-slip modifier and crosslinking agent and stir at high speed to obtain a mixture;

[0043] Step S2: Pour the mixture obtained in Step S1 into a preheated mold for curing, and perform Step S3 on the cured TPU. Anneal the TPU block obtained in Step S2 and put it into a twin-screw extruder for melt granulation to obtain TPU particles;

[0044] Step S4: Put the TPU particles obtained in step S3 into an injection molding machine to be injection molded into the shape of a basketball sole sheet, thereby obtaining the TPU basketball sole sheet.

[0045] Furthermore, the pretreatment method of the reinforcing filler is as follows: Place the reinforcing filler in poly(4-hydroxy diacid ester) with a mass ratio of 1:1 and ultrasonically disperse it for 20 min.

[0046] Furthermore, in step S2, the curing is divided into two steps. The temperature of the first step of curing is 100 °C and the time is 3 h; the temperature of the second step of curing is 110 °C and the time is 4 h; the temperature of the annealing treatment is 80 °C and the time is 24 h.

[0047] Furthermore, in step S3, the temperature of the twin-screw extruder is 160 °C (feeding zone) - 180 °C (metering zone).

[0048] Furthermore, in step S4, the temperature of the injection barrel is 185 °C, the temperature of the mold is 65 °C, and the injection pressure is 90 MPa.

[0049] Example 2

[0050] This example provides a fully recyclable and renewable TPU basketball sole sheet, which comprises the following raw materials in parts by weight: 70 parts of TPU prepolymer, 0.9 part of chain extender, 16 parts of recycled TPU waste, 7 parts of reinforcing filler, 6 parts of elastic regulator, 1.5 parts of antioxidant, 4 parts of anti-slip modifier, 2 parts of crosslinking agent, and 0.7 part of lubricant.

[0051] Further, the preparation method of the TPU prepolymer comprises the following steps: Vacuum dehydrate poly(4-hydroxybutyrate) at 75 °C for 3 h, then add diisocyanate and dibutyltin dilaurate thereto and continuously stir, and gradually raise the temperature to 80 °C and react for 3 h to obtain the TPU prepolymer, and set it aside.

[0052] Furthermore, the molecular weight of the poly(4-hydroxybutyrate) is 2000, and the diisocyanate is 4,4'-diphenylmethane diisocyanate (MDI). In this prepolymer system, the molar ratio of -NCO to -OH is 2.2, and the dosage of dibutyltin dilaurate is 0.2 wt%.

[0053] Further, the chain extender is 1,4-butanediol.

[0054] Further, the preparation method of the recycled TPU waste comprises the following steps: Sort and crush the TPU waste from the sole, heat and dissolve it in dimethyl sulfoxide, add 8 wt% ethylene glycol and 0.4 wt% stannous octoate, control the reaction temperature at 80 °C and react for 6 h, and finally filter to obtain the recycled TPU waste.

[0055] Further, the reinforcing filler is nano silicon nitride.

[0056] Further, the elastic regulator is polybutylene adipate.

[0057] Further, the anti-slip modifier is surface-grafted modified graphene. Specifically, the surface-grafted modified graphene is uniformly mixed with silane, and the resulting product after reflux reaction at 75 °C for 6 h and centrifugation, washing and drying is placed in toluene. Hydroxyl-terminated polydimethylsiloxane and dicyclohexylcarbodiimide are added in a mass ratio of 1:2:0.7 and the reaction continues at 80 °C for 12 h. Finally, an equimolar amount of hydrazine hydrate is added to the product obtained after centrifugation, washing and drying for reaction for 6 h. After completion, the surface-grafted modified graphene is obtained through centrifugation, washing and drying.

[0058] Further, the crosslinking agent is triallyl isocyanurate.

[0059] Further, the antioxidant is compounded from antioxidant 1010 and antioxidant 168 at a mass ratio of 1:2.

[0060] Further, the lubricant is glyceryl stearate.

[0061] This embodiment provides a method for preparing the fully recyclable and renewable TPU basketball sole sheet, including the following steps:

[0062] Step S1: A chain extender and recycled TPU waste are fully mixed with the TPU prepolymer, and then the pretreated reinforcing filler and elastic regulator are added and fully mixed. Then, an anti-slip modifier and a crosslinking agent are added thereto and stirred at high speed to obtain a mixture.

[0063] Step S2: The mixture obtained in Step S1 is poured into a preheated mold for curing, and the cured TPU is annealed.

[0064] Step S3: The annealed TPU block obtained in Step S2 is put into a twin-screw extruder for melt granulation to obtain TPU particles.

[0065] Step S4: The TPU particles obtained in Step S3 are put into an injection molding machine to be injection molded into the shape of a basketball sole sheet, and thus the TPU basketball sole sheet is obtained.

[0066] Furthermore, the pretreatment method of the reinforcing filler is: The reinforcing filler is ultrasonically dispersed in poly(4-hydroxy diacid ester) with a mass ratio of 1:1 for 25 min.

[0067] Further, in step S2, the curing is divided into two steps. The curing temperature in the first step is 105°C and the time is 2.5 h; the curing temperature in the second step is 115°C and the time is 3.5 h; the annealing treatment temperature is 80°C and the time is 24 h.

[0068] Further, in step S3, the temperature of the twin-screw extruder is 160 (feeding zone) - 180°C (metering zone).

[0069] Further, in step S4, the injection barrel temperature is 190°C, the mold temperature is 70°C, and the injection pressure is 100 MPa.

[0070] Example 3

[0071] This example provides a fully recyclable and renewable TPU basketball sole sheet, which comprises the following raw materials in parts by weight: 75 parts of TPU prepolymer, 1.2 parts of chain extender, 18 parts of recycled TPU waste, 9 parts of reinforcing filler, 7.5 parts of elasticity regulator, 2 parts of antioxidant, 5 parts of anti-slip modifier, 2.8 parts of cross-linking agent, and 1 part of lubricant.

[0072] Further, the preparation method of the TPU prepolymer comprises the following steps: poly(4-hydroxybutyrate) is vacuum dehydrated at 80°C for 3 h, then diisocyanate and dibutyltin dilaurate are added thereto and continuously stirred, and the temperature is gradually raised to 85°C and reacted for 2.5 h to obtain the TPU prepolymer, which is reserved for use.

[0073] Further, the molecular weight of the poly(4-hydroxybutyrate) is 2000, and the diisocyanate is hexamethylene diisocyanate (HDI). In this prepolymer system, the molar ratio of -NCO to -OH is 2.4, and the dosage of dibutyltin dilaurate is 0.15 wt%.

[0074] Further, the chain extender is 1,4-butanediol.

[0075] Further, the preparation method of the recycled TPU waste comprises the following steps: the TPU waste from the sole is sorted and crushed, then heated and dissolved in dimethyl sulfoxide, 9 wt% of propylene glycol and 0.4 wt% of organotin catalyst are added, the reaction temperature is controlled at 85°C and reacted for 4.5 h, and finally the recycled TPU waste is obtained through filtration.

[0076] Further, the reinforcing filler is nano-silica.

[0077] Further, the elasticity regulator is poly(butylene adipate).

[0078] Further, the anti-slip modifier is graphene modified by surface grafting. Specifically, the specific preparation method of the surface-grafted modified graphene is as follows: Graphene oxide is dispersed in an ethanol aqueous solution, 2 wt% of 3-aminopropyltriethoxysilane is added and mixed evenly, and the mixture is refluxed at 75 °C for 6 h. The product obtained after centrifugation, washing, and drying is placed in toluene, and hydroxyl-terminated polydimethylsiloxane and dicyclohexylcarbodiimide are added in a mass ratio of 1:2:0.7, and the reaction is continued at 80 °C for 12 h. Finally, an equimolar amount of hydrazine hydrate is added to the product obtained after centrifugation, washing, and drying for reaction for 6 h. After completion, the product is centrifuged, washed, and dried to obtain the surface-grafted modified graphene.

[0079] Further, the cross-linking agent is trimethylolpropane.

[0080] Further, the antioxidant is compounded by antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1.

[0081] Further, the lubricant is methyl silicone oil.

[0082] The present embodiment provides a method for preparing the fully recyclable and renewable TPU basketball sole sheet, including the following steps:

[0083] Step S1: A chain extender and recycled TPU waste are fully mixed with the TPU prepolymer, and then a pretreated reinforcing filler and an elastic regulator are added and fully mixed. Then, an anti-slip modifier and a cross-linking agent are added thereto and stirred at high speed to obtain a mixture.

[0084] Step S2: The mixture obtained in step S1 is poured into a preheated mold for curing, and the cured TPU is annealed.

[0085] Step S3: The annealed TPU block in step S2 is put into a twin-screw extruder for melt granulation to obtain TPU particles.

[0086] Step S4: The TPU particles obtained in step S3 are put into an injection molding machine to be injection molded into the shape of a basketball sole sheet, and thus the TPU is obtained.

[0087] Furthermore, the pretreatment method of the reinforcing filler is as follows: The reinforcing filler is ultrasonically dispersed in poly(4-hydroxy diacid ester) with a mass ratio of 1:1 for 30 min.

[0088] Furthermore, in step S2, the curing is divided into two steps. The first curing temperature is 110 °C and the time is 2 h; the second curing temperature is 120 °C and the time is 3 h; the annealing treatment temperature is 85 °C and the time is 20 h.

[0089] Further, in step S3, the temperature of the twin-screw extruder is 160 (feeding zone) - 180 °C (metering zone).

[0090] Further, in step S4, the temperature of the injection barrel is 195 °C, the temperature of the mold is 75 °C, and the injection pressure is 85 MPa.

[0091] Comparative Example 1

[0092] The difference between this comparative example and Example 1 is that this comparative example uses sorted and crushed TPU waste to replace the recycled TPU waste in Example 1.

[0093] Comparative Example 2

[0094] The difference between this comparative example and Example 1 is that this comparative example does not add the elastic regulator in Example 1.

[0095] Comparative Example 3

[0096] The difference between this comparative example and Example 1 is that this comparative example uses graphene oxide to replace the surface-grafted modified graphene in Example 1 and does not add the reinforcing filler in Example 1.

[0097] Performance Test

[0098] The TPU basketball shoe sole sheets prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests. Among them, the rebound rate test was carried out using ASTM D2632 (vertical rebound test), the DIN wear resistance test was carried out using DIN 53516 (room temperature, 80 °C), the dry and wet anti-slip tests were carried out using ASTM F489, and the tear strength test was carried out using ASTM D624 (DIL-C). The specific test results are shown in the following table.

[0099]

[0100]

[0101] It can be seen from the data in the above table that in Examples 1-3 of the present invention, high-elastic TPU basketball shoe sole sheets are obtained by the synergistic cooperation of the bio-based poly(4-hydroxybutyrate) soft segment design and the elastic regulator, and the wear resistance, anti-slip performance and tear strength of the bottom sheet are jointly improved by the addition of the reinforcing filler and the anti-slip modifier, especially the anti-wet-slip performance and the thermal wear resistance performance, showing extremely excellent performance. It can be seen from the comparison between Example 1 and Comparative Examples 1-3 that by adjusting the reasonable ratio of the elastic regulator and the reinforcing filler in the present invention, the resilience, wear resistance and anti-slip performance of the TPU basketball shoe sole sheet reach the best balance, and the introduction of the anti-slip modifier more effectively synergistically improves the anti-slip performance and wear resistance of the bottom sheet, especially the anti-wet-slip performance and the thermal wear resistance performance.

[0102] The above specific embodiments further illustrate the technical solution and beneficial effects of the present invention, rather than limiting the implementation manner. For those skilled in the art, any obvious substitution without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A fully recyclable and renewable TPU basketball sole sheet, characterized in that: It comprises the following raw materials in parts by weight: 60-75 parts of TPU prepolymer, 0.5-2 parts of chain extender, 10-20 parts of recycled TPU waste, 5-10 parts of reinforcing filler, 3-8 parts of elasticity regulator, 0.5-2 parts of antioxidant, 5-10 parts of anti-slip modifier, 1-3 parts of crosslinking agent, and 0.5-1 part of lubricant.

2. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, characterized in that: The preparation method of the TPU prepolymer comprises the following steps: Poly(4-hydroxybutyrate) is dehydrated under vacuum at 70-80 °C for 2-4 h, then diisocyanate and organotin catalyst are added thereto and stirred continuously, and the temperature is gradually raised to 80-85 °C and reacted for 2-3 h to obtain the TPU prepolymer.

3. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, characterized in that: The preparation method of the recycled TPU waste comprises the following steps: The TPU waste from soles is sorted and crushed, then heated and dissolved in dimethyl sulfoxide, 5-10 wt% alcoholysis agent and 0.2-0.5 wt% organotin catalyst are added, the reaction temperature is controlled at 75-85 °C and reacted for 4-6 h, and finally the recycled TPU waste is obtained through filtration.

4. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, wherein: The reinforcing filler is at least one of nano-silica, nano-silicon nitride, and carbon nanotubes.

5. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, wherein: The elasticity regulator is poly(butylene adipate).

6. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, wherein: The anti-slip modifier is at least one of micron-scale silica, micro-nano mixed-scale silica, and surface graft-modified graphene.

7. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, wherein: The crosslinking agent is trimethylolpropane and / or triallyl isocyanurate.

8. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, wherein: The antioxidant is a hindered phenol antioxidant and / or a phosphite antioxidant.

9. The fully recyclable and renewable TPU basketball sole sheet according to claim 1, wherein: The lubricant is at least one of zinc stearate, glycerol stearate, and methyl silicone oil.

10. The preparation method of the fully recyclable and renewable TPU basketball sole sheet according to any one of claims 1-9, characterized in that: It comprises the following steps: Step S1: The chain extender and the recycled TPU waste are fully mixed with the TPU prepolymer, then the pretreated reinforcing filler and the elasticity regulator are added and fully mixed, and then the anti-slip modifier and the crosslinking agent are added thereto and stirred at high speed to obtain a mixture. Step S2: The mixture obtained in Step S1 is poured into a preheated mold for curing, and the cured TPU is annealed. Step S3: The annealed TPU block obtained in Step S2 is put into a twin-screw extruder for melt granulation to obtain TPU particles. Step S4: The TPU particles obtained in Step S3 are put into an injection molding machine to be injection molded into the shape of a basketball shoe sole sheet, and thus the TPU basketball shoe sole sheet is obtained.

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