TPU football leather capable of being fully recycled and preparation method thereof

Abstract

The invention relates to the technical field of TPU, in particular to TPU football leather capable of being fully recycled and a preparation method of the TPU football leather. The TPU football leather capable of being fully recycled comprises a TPU foaming film and a TPU film arranged at the upper end of the TPU foaming film, wherein the TPU film is prepared from the following components in parts by weight: 60 to 80 parts of TPU particles, 35 to 45 parts of TPU-pineapple leaf residue fiber composite material, 15 to 25 parts of maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer, 7 to 12 parts of reinforcing filler, 5 to 8 parts of lubricating agent and 6 to 9 parts of antioxidant. The TPU football leather can be fully recycled, has excellent wear resistance, bending resistance, aging resistance, tensile strength, impact resistance and blasting resistance, is convenient to use and wide in application range, and the preparation method of the TPU football leather is simple in process, easy to operate and control, stable in quality, low in reject ratio and high in yield, has very high economic effects and is beneficial to industrial large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of TPU, and particularly relates to a fully recyclable TPU football leather and a preparation method thereof. Background Art

[0002] Recently, with the progress of synthetic leather technology and the improvement of processing techniques, various synthetic leather materials have emerged. Currently, the widely used ones in the market are PU synthetic leather and PVC synthetic leather. During their production process, waste water and waste gas are discharged with sulfides, chlorides, phthalates, DMF, etc. as the main solvents. Although people have carried out recycling and treatment, it is difficult to meet the environmental protection requirement of "zero emission", which causes great harm to the ecological environment and human life.

[0003] Thermoplastic polyurethane elastomer (hereinafter referred to as TPU) is a new type of elastomer material that has emerged in recent years. The environmental protection characteristics and unique physical and chemical properties of TPU are beyond the reach of other polymer materials. Thermoplastic polyurethane elastomer is a material that has elasticity at room temperature and can be plastified and processed at high temperature. Its structure is composed of thermodynamically incompatible thermoplastic hard segments and elastic soft segments, which overcomes the disadvantage that traditional rubber cannot be repeatedly processed and recycled, and can replace traditional rubber. Under the pressure of current resources and pollution, TPU has received wide attention due to its great economic value and environmental protection role.

[0004] At the same time, generally common synthetic leather has poor degradation performance and requires hundreds of years for natural degradation. Pineapple leaf residue fiber is mainly composed of lignin, hemicellulose, cellulose, and a small amount of pectin / wax, and is a relatively high-quality natural fiber. Researchers at Mahidol University in Thailand made leather from pineapple leaf fiber, which can be comparable to genuine leather and has better performance than other existing plant-based leathers. In this application, TPU football leather is prepared by filling TPU with pineapple leaf residue fiber, which can reduce the cost of materials and improve the biodegradability of materials, and is of great significance to environmental protection. However, pineapple leaf residue fiber belongs to bio-based polymers and has great differences in properties from thermoplastic polyurethane. How to improve the interfacial compatibility between pineapple leaf residue fiber and polyurethane substrate, and the prepared TPU football leather can be recycled, and has good abrasion resistance, tensile strength, is an urgent problem to be solved in this application. Summary of the Invention

[0005] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide a fully recyclable TPU football leather, which is fully recyclable, and also has excellent abrasion resistance, flex resistance, aging resistance, tensile strength, impact resistance, and burst resistance, is convenient to use, has stable quality, good economic effects, and a wide range of applications.

[0006] The preparation method of the fully recyclable TPU football leather of the present invention has a simple process, easy operation control, high output, which is conducive to large-scale industrial production. The obtained TPU football leather has stable quality, can be fully recycled, has excellent wear resistance, and also has excellent aging resistance, tensile strength, flexural resistance, impact resistance and bursting resistance, with superior comprehensive performance.

[0007] The object of the present invention is achieved by the following technical solutions: A fully recyclable TPU football leather, including a TPU foam film and a TPU film provided on the upper end of the TPU foam film. The TPU film includes the following components in parts by weight: 60-80 parts of TPU particles, 35-45 parts of TPU-pineapple leaf residue fiber composite material, 15-25 parts of maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, 7-12 parts of reinforcing filler, 5-8 parts of lubricant and 6-9 parts of antioxidant.

[0008] Further, the TPU particles are Huntsman A85P4394.

[0009] Further, the maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer is selected from Kraton FG1901GT.

[0010] Further, the lubricant is zinc stearate; the antioxidant is butylated hydroxytoluene.

[0011] Further, the thickness of the TPU film is 0.1-0.3 cm, the thickness of the TPU foam film is 0.4-1.2 cm, and the density of the TPU foam film is 0.2-0.4 g / cm 3 。

[0012] Further, the preparation method of the TPU-pineapple leaf fiber composite material includes the following steps:

[0013] A1. Place polytetrahydrofuran diol in a reaction vessel, stir and heat up to 115-130 °C, control the pressure in the reaction vessel to -0.02-0.06 MPa for dehydration; then fill with nitrogen, cool down to 75-85 °C, add isophorone diisocyanate and a catalyst, catalyze the reaction for 1-3 h, then cool down to 65-75 °C, add 1,4-butanediol for chain extension reaction for 1-2 h, and the reaction is completed to obtain mixture one;

[0014] A2. Raise the temperature to 70-80 °C, add pineapple leaf residue fiber to mixture one and stir for reaction for 1-2 h to obtain the TPU-pineapple leaf fiber composite material.

[0015] Further, the molar ratio of polytetrahydrofuran diol, 1,4-butanediol to isophorone diisocyanate is 1:

[0016] (2.8 - 3.2) : (3.8 - 4.2).

[0017] Further, the polytetrahydrofuran diol is polytetrahydrofuran diol 1000.

[0018] Further, the catalyst is at least one of dibutyltin dilaurate and stannous octoate. The addition amount of the catalyst is 0.03 - 0.08% of the total mass of polytetrahydrofuran diol, 1,4 - butanediol and isophorone diisocyanate.

[0019] Further, the addition amount of the pineapple leaf residue fiber is 10 - 15% of the total mass of polytetrahydrofuran diol, 1,4 - butanediol and isophorone diisocyanate.

[0020] Further, the preparation method of the pineapple leaf residue fiber includes the following steps:

[0021] B1. Take pineapple leaves, crush the pineapple leaves into powder to obtain pineapple leaf powder;

[0022] B2. Steam a part of the pineapple leaf powder at 80 - 120 °C for 40 - 70 min, then immerse it in water for 15 - 30 h for fermentation treatment, and then perform suction filtration and dry to constant weight to obtain the first pretreated product;

[0023] B3. Add another part of the pineapple leaf powder to a 0.3 - 0.8 mol / L potassium hydroxide solution, mix evenly, stir and react at 85 - 95 °C for 3 - 4 h, then perform suction filtration and wash to neutrality, and dry to constant weight to obtain the second pretreated product;

[0024] B4. Mix the first pretreated product and the second pretreated product evenly, add KH - 550 coupling agent and stir evenly, place it in an oven at 85 - 95 °C for 1 - 2 h, seal and reserve to obtain the pineapple leaf residue fiber.

[0025] Further, in step B1, the mesh number of the pineapple leaf powder is 100 - 200 mesh.

[0026] Further, in step B4, the weight ratio of the first pretreated product, the second pretreated product and the KH - 550 coupling agent is (0.8 - 1.2) : 1.5 : (0.07 - 0.12).

[0027] Further, the reinforcing filler is silicon dioxide - coated silicon carbide nanoparticles, and the preparation method of the silicon dioxide - coated silicon carbide nanoparticles includes the following steps:

[0028] C1. Prepare tetraethyl orthosilicate, deionized water, and absolute ethanol in a molar ratio of 1:3.8 - 4.2:3.8 - 4.2, then adjust the pH value to 1 - 2 with concentrated hydrochloric acid, and stir at 280 - 320 r / min for 25 - 40 min at a temperature of 30 - 40 °C to obtain silica sol;

[0029] C2. Disperse silicon carbide in the silica sol, perform ultrasonic treatment for 1 - 2 h, and then place it in an oven at 80 - 100 °C for 35 - 50 h to obtain composite gel powder;

[0030] C3. Place the composite gel powder in a muffle furnace, heat it at a heating rate of 8 - 12 °C / min, sinter it for 2 - 4 h after reaching 500 - 700 °C to obtain silicon carbide nanoparticles coated with silica.

[0031] Further, the silicon carbide is silicon carbide whiskers with a diameter of 0.1 - 2.5 μm and a length of 10 - 50 μm.

[0032] The present invention also provides a method for preparing the fully recyclable TPU football leather, including the following steps:

[0033] S1. Take a TPU foamed film, and perform plasma surface activation on the upper surface of the TPU foamed film using a plasma device under nitrogen protection;

[0034] S2. According to parts by weight, send TPU particles, TPU - pineapple leaf residue fiber composite material, maleic anhydride - grafted styrene - ethylene - butene - styrene block copolymer, reinforcing filler, lubricant, and antioxidant to the hopper of a casting machine. After heating by the casting machine, a TPU molten mixture is obtained, and then it is extruded from the die head of the casting machine by a rotating screw and cast onto the upper end of the TPU foamed film, so that a TPU film is attached to the TPU foamed film. After embossing and cooling the TPU film with a pressure roller, TPU football leather is obtained; the melting temperature is 210 - 220 °C; the temperature for casting into a film is 180 - 190 °C.

[0035] Further, in step S1, the plasma treatment power is 80 - 130 W, the pressure is 10 - 50 Pa, and the treatment time is 90 - 150 s.

[0036] Further, the TPU foamed film uses a TPU foamed film with the model ZD - 85A from Guangdong Zhongding Technology Development Co., Ltd., with a thickness of 1 cm and a density of 0.3 g / cm 2 .

[0037] The preparation method of the TPU football leather of the present invention has a simple process and is easy to control, which is conducive to large-scale industrial production. The obtained TPU football leather has stable quality, excellent wear resistance, and also has excellent aging resistance, tensile strength, flexural resistance, impact resistance and anti-burst performance, with superior comprehensive performance.

[0038] The beneficial effects of the present invention are as follows: The fully recyclable TPU football leather of the present invention fills TPU with pineapple leaf residue fiber to prepare TPU football leather, which can reduce the cost of materials and improve the biodegradability of materials. By subjecting pineapple leaf powder to enzyme treatment, alkali treatment and coupling agent modification to improve the interfacial compatibility between pineapple leaf residue fiber and polyurethane substrate, and in-situ reacting the pineapple leaf residue fiber with the raw materials of the first mixture - PU prepolymerization reaction, a TPU-pineapple leaf fiber composite material is prepared, and then combined with TPU particles, maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, reinforcing filler, lubricant and antioxidant, the obtained TPU football leather has excellent wear resistance, aging resistance, tensile strength, impact resistance and flexural resistance, and the quality is stable. The preparation method of the TPU football leather has a simple process and is easy to control, which is conducive to large-scale industrial production. Detailed implementation mode

[0039] 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 implementation mode does not limit the present invention.

[0040] Example 1

[0041] In this embodiment, a fully recyclable TPU football leather includes a TPU foamed film and a TPU film provided on the upper end of the TPU foamed film. The TPU film includes the following components in parts by weight: 60 parts of TPU particles, 35 parts of TPU-pineapple leaf residue fiber composite material, 15 parts of maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, 7 parts of reinforcing filler, 5 parts of lubricant and 6 parts of antioxidant.

[0042] Further, the TPU particles are Huntsman A85P4394.

[0043] Further, the maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer is selected from Kraton FG1901GT.

[0044] Further, the lubricant is zinc stearate; the antioxidant is butylated hydroxytoluene.

[0045] Further, the thickness of the TPU film is 0.2 cm

[0046] Further, the preparation method of the TPU-pineapple leaf fiber composite material includes the following steps:

[0047] A1. Place polytetrahydrofuran diol in a reaction vessel, stir and heat up to 120 °C, control the pressure in the reaction vessel at -0.04 MPa for dehydration; then fill with nitrogen, cool down to 80 °C, add isophorone diisocyanate and a catalyst, after catalytic reaction for 1.5 h, cool down to 70 °C, add 1,4-butanediol for chain extension reaction for 1 - 2 h, and the mixture one is obtained after the reaction is completed;

[0048] A2. Raise the temperature to 75 °C, add pineapple leaf residue fiber to the mixture one and stir for 1.5 h to obtain the TPU - pineapple leaf fiber composite material.

[0049] Further, the molar ratio of the polytetrahydrofuran diol, 1,4-butanediol to isophorone diisocyanate is 1:3:4.

[0050] Further, the polytetrahydrofuran diol uses polytetrahydrofuran diol 1000.

[0051] Further, the catalyst is dibutyltin dilaurate. The addition amount of the catalyst is 0.05% of the total mass of the polytetrahydrofuran diol, 1,4-butanediol and isophorone diisocyanate.

[0052] Further, the addition amount of the pineapple leaf residue fiber is 12% of the total mass of the polytetrahydrofuran diol, 1,4-butanediol and isophorone diisocyanate.

[0053] Further, the preparation method of the pineapple leaf residue fiber includes the following steps:

[0054] B1. Take pineapple leaves, crush the pineapple leaves into powder to obtain pineapple leaf powder;

[0055] B2. Steam a part of the pineapple leaf powder at 100 °C for 50 min, then immerse it in water for 24 h for fermentation treatment, and then filter and dry to constant weight to obtain the first pretreatment product;

[0056] B3. Add another part of the pineapple leaf powder to a 0.5 mol / L potassium hydroxide solution, mix evenly, stir and react at 90 °C for 3.5 h, then filter and wash until neutral, and dry to constant weight to obtain the second pretreatment product;

[0057] B4. Mix the first pretreatment product and the second pretreatment product evenly, add KH-550 coupling agent and stir evenly, place it in an oven at 90 °C for 1.5 h, seal and reserve to obtain the pineapple leaf residue fiber.

[0058] Further, in step B1, the mesh number of the pineapple leaf powder is 150 mesh.

[0059] Further, in step B4, the weight ratio of the first pre-treated material, the second pre-treated material and the KH-550 coupling agent is 1:1.5:0.09.

[0060] Further, the reinforcing filler is silicon dioxide-coated silicon carbide nanoparticles, and the preparation method of the silicon dioxide-coated silicon carbide nanoparticles comprises the following steps:

[0061] C1. Tetraethyl orthosilicate, deionized water and absolute ethanol are formulated according to a molar ratio of 1:4:4, and then the pH value is adjusted to 1.5 with concentrated hydrochloric acid. At a temperature of 35 °C, stirring is carried out at 300 r / min for 30 min to obtain a silicon dioxide sol;

[0062] C2. Silicon carbide is dispersed in the silicon dioxide sol, and ultrasonic treatment is carried out for 1.5 h, and then it is placed in an oven at 90 °C for 45 h to obtain a composite gel powder;

[0063] C3. The composite gel powder is placed in a muffle furnace, and the temperature is raised to 600 °C at a heating rate of 10 °C / min and sintered for 3 h to obtain silicon dioxide-coated silicon carbide nanoparticles.

[0064] Further, the silicon carbide is silicon carbide whiskers with a diameter of 0.5 μm and a length of 10 μm.

[0065] The present invention also provides a preparation method of the fully recyclable TPU football leather, comprising the following steps:

[0066] S1. Take a TPU foamed film, and perform plasma surface activation on the upper surface of the TPU foamed film by using a plasma device under nitrogen protection;

[0067] S2. By weight, TPU particles, a TPU-pineapple leaf residue fiber composite material, a maleic anhydride-grafted styrene-ethylene-butene-styrene block copolymer, a reinforcing filler, a lubricant and an antioxidant are sent to the hopper of a casting machine. After being heated by the casting machine, a TPU molten mixture is obtained, and then it is pushed by a rotating screw and extruded from the die head of the casting machine and cast onto the upper end of the TPU foamed film, so that a TPU film is attached to the TPU foamed film. The TPU film is embossed and cooled by a pressing roller to obtain TPU football leather; the melting temperature is 215 °C; the temperature for film casting is 185 °C.

[0068] Further, in step S1, the plasma treatment power is 100 W, the pressure is 30 Pa, and the treatment time is 120 s.

[0069] Further, the TPU foamed film is a TPU foamed film of model ZD-85A produced by Guangdong Zhongding Technology Development Co., Ltd., with a thickness of 1 cm and a density of 0.3 g / cm 3 。

[0070] Example 2

[0071] In this example, the fully recyclable TPU football leather comprises a TPU foam film and a TPU film disposed on the upper end of the TPU foam film. The TPU film comprises the following components in parts by weight: 70 parts of TPU particles, 40 parts of TPU-pineapple leaf residue fiber composite material, 20 parts of maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, 10 parts of reinforcing filler, 6 parts of lubricant, and 7 parts of antioxidant.

[0072] The present invention also provides a preparation method of the fully recyclable TPU football leather, comprising the following steps:

[0073] S1. Take the TPU foam film, and perform plasma surface activation on the upper surface of the TPU foam film by using a plasma device under nitrogen protection;

[0074] S2. According to the parts by weight, send the TPU particles, TPU-pineapple leaf residue fiber composite material, maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, reinforcing filler, lubricant, and antioxidant into the hopper of a casting machine. After being heated by the casting machine, a TPU molten mixture is obtained, and then it is extruded from the die head of the casting machine by the pushing of a rotating screw and cast onto the upper end of the TPU foam film, so that the TPU film is attached to the TPU foam film. After the TPU film is embossed and cooled by a pressure roller, TPU football leather is obtained; the melting temperature is 215°C; the temperature for casting into a film is 185°C.

[0075] The remaining content of this example is the same as that of Example 1.

[0076] Example 3

[0077] In this example, the fully recyclable TPU football leather comprises a TPU foam film and a TPU film disposed on the upper end of the TPU foam film. The TPU film comprises the following components in parts by weight: 80 parts of TPU particles, 45 parts of TPU-pineapple leaf residue fiber composite material, 25 parts of maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, 12 parts of reinforcing filler, 58 parts of lubricant, and 9 parts of antioxidant.

[0078] The present invention also provides a preparation method of the fully recyclable TPU football leather, comprising the following steps:

[0079] S1. Take the TPU foam film, and perform plasma surface activation on the upper surface of the TPU foam film by using a plasma device under nitrogen protection;

[0080] S2. By weight, send TPU particles, TPU - pineapple leaf residue fiber composite material, maleic anhydride grafted styrene - ethylene - butene - styrene block copolymer, reinforcing filler, lubricant and antioxidant into the hopper of the casting machine. After heating by the casting machine, a TPU molten mixture is obtained, and then it is extruded from the die head of the casting machine by a rotating screw and cast onto the upper end of the TPU foamed film, so that a TPU film is attached to the TPU foamed film. After embossing and cooling the TPU film by a pressure roller, a TPU football leather is obtained; the melting temperature is 215°C; the temperature for casting into a film is 185°C.

[0081] The remaining content of this example is the same as that of Example 1.

[0082] Comparative Example 1

[0083] The difference between this comparative example and Example 2 is that in the preparation method of the TPU - pineapple leaf fiber composite material, an equal amount of pineapple leaf powder is used to replace the pineapple leaf residue fiber, and the mesh number of the pineapple leaf powder is 150 mesh.

[0084] Comparative Example 2

[0085] The difference between this comparative example and Example 2 is that the reinforcing filler is silicon carbide whiskers with a diameter of 0.5μm and a length of 10μm.

[0086] Performance Test

[0087] Perform performance tests on the fully recyclable TPU football leather prepared in Example 2 and Comparative Examples 1 - 2. Test the tensile strength, abrasion resistance, impact resistance and flexural resistance of the TPU football leather. The test data are shown in Table 1 below:

[0088] Table 1

[0089]

[0090] Among them, for the abrasion resistance test: Cut the TPU foamed film into the shape specified in GB / T1768 - 2006, place it on a TABER abrasion tester (GT - 7012 - T) to observe the surface change of the TPU football leather during friction. The type of grinding wheel is CS - 10, the set rotation speed is 72r / min, and the surface load weight is 1000g;

[0091] The tensile strength test uses a WDT - W type electronic universal material testing machine, and with reference to GB / T1040 - 2006, the tensile rate is 100mm / min.

[0092] For the impact resistance test, the specimen size is 80 mm × 10 mm × 1.13 mm. After drying for 2 - 3 h (at 100 °C), it is cooled and frozen at -20 °C. According to GB / T 16826 - 2008 / ISO 180:2000, the notch type is B. The instrument is the XCJ - 40 cantilever beam impact tester, the pendulum energy is 0.5 J, the span is 60 mm, the notch is placed upright, and the remaining width at the notch is 2 mm.

[0093] Flex resistance test: Cut the TPU football leather into a size of 70 mm × 45 mm, and use a flex tester to conduct a bending test on the semi - finished product at room temperature, and observe the damage condition of the TPU football leather after the bending test.

[0094] For the aging resistance test, it is treated with QUV 340 nm for 1000 hours, and the light intensity is 0.8 W / cm 2 , and after the test, observe the tensile strength of the TPU football leather after the test.

[0095] The above embodiments are the preferred implementation solutions of the present invention. In addition, the present invention can also be implemented in other ways. 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 TPU football leather, characterized in that: It includes a TPU foamed film and a TPU film provided on the upper end of the TPU foamed film. The TPU film comprises the following components in parts by weight: 60-80 parts of TPU particles, 35-45 parts of a TPU-pineapple leaf residue fiber composite material, 15-25 parts of maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, 7-12 parts of reinforcing filler, 5-8 parts of lubricant, and 6-9 parts of antioxidant.

2. The fully recyclable TPU football leather according to claim 1, characterized in that: The thickness of the TPU film is 0.1-0.3 mm, and the thickness of the TPU foamed film is 0.4-1 cm.

3. The fully recyclable TPU football leather according to claim 1, characterized in that: The preparation method of the TPU-pineapple leaf fiber composite material comprises the following steps: A1. Place polytetrahydrofuran diol in a reaction vessel, stir and heat up to 115-130 °C, control the pressure in the reaction vessel to be -0.02-0.06 MPa, and dehydrate; then fill with nitrogen, cool down to 75-85 °C, add isophorone diisocyanate and a catalyst, catalyze the reaction for 1-3 h, then cool down to 65-75 °C, add 1,4-butanediol for chain extension reaction for 1-2 h, and obtain mixture one after the reaction is completed; A2. Raise the temperature to 70-80 °C, add pineapple leaf residue fiber to mixture one and stir for reaction for 1-2 h to obtain the TPU-pineapple leaf fiber composite material.

4. The fully recyclable TPU football leather according to claim 3, characterized in that: The molar ratio of the polytetrahydrofuran diol, 1,4-butanediol and isophorone diisocyanate is 1:(2.8-3.2):(3.8-4.2).

5. The fully recyclable TPU football leather according to claim 3, characterized in that: The addition amount of the pineapple leaf residue fiber is 10-15% of the total mass of the polytetrahydrofuran diol, 1,4-butanediol and isophorone diisocyanate.

6. A fully recyclable TPU football leather according to claim 3, characterized in that: The preparation method of the pineapple leaf residue fiber comprises the following steps: B1. Take pineapple leaves, crush the pineapple leaves into powder to obtain pineapple leaf powder; B2. Steam a part of the pineapple leaf powder at 80-120 °C for 40-70 min, then immerse it in water for 15-30 h for fermentation treatment, and then filter and dry to constant weight to obtain pretreatment product one; B3. Add another part of the pineapple leaf powder to a 0.3-0.8 mol / L potassium hydroxide solution, mix evenly, stir and react at 85-95 °C for 3-4 h, then filter and wash to neutral, and dry to constant weight to obtain pretreatment product two; B4. Mix the pretreatment product one and pretreatment product two evenly, add KH-550 coupling agent and stir evenly, place it in an oven at 85-95 °C for 1-2 h, seal and reserve to obtain the pineapple leaf residue fiber.

7. The fully recyclable TPU football leather according to claim 6, characterized in that: In step B1, the mesh number of the pineapple leaf powder is 100-200 mesh.

8. The fully recyclable TPU football leather according to claim 6, characterized in that: In step B4, the weight ratio of the pretreatment product one, pretreatment product two and KH-550 coupling agent is (0.8-1.2):1.5:(0.07-0.12).

9. The fully recyclable TPU football leather according to claim 3, wherein: The catalyst is at least one of dibutyltin dilaurate and stannous octoate.

10. A preparation method of the fully recyclable TPU football leather according to any one of claims 1-9, characterized in that: It includes the following steps: S1. Take the TPU foamed film, and perform plasma surface activation on the upper surface of the TPU foamed film by using a plasma device under nitrogen protection; S2. By weight, send TPU particles, TPU-pineapple leaf residue fiber composite material, maleic anhydride grafted styrene-ethylene-butene-styrene block copolymer, reinforcing filler, lubricant and antioxidant into the hopper of the casting machine. After being heated by the casting machine, a TPU molten mixture is obtained, and then it is extruded from the casting machine die with a set opening and uniform thickness by the pushing of a rotating screw, and cast onto the upper end of the TPU foamed film, so that the TPU film adheres to the TPU foamed film. After the TPU film is embossed and cooled by a pressure roller, a TPU football leather is obtained; the melting temperature is 210-220 °C; the temperature for casting into a film is 180-190 °C.

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