High-wear-resistance anti-aging TPU composite material and preparation method thereof

Abstract

The invention discloses a high-wear-resistance anti-aging TPU composite material and a preparation method thereof, and relates to the technical field of TPU composite materials. The TPU composite material with high wear resistance and aging resistance is prepared from the following raw materials in parts by weight: 90 to 100 parts of thermoplastic polyurethane elastomer, 5 to 12 parts of modified nano silicon dioxide, 8 to 15 parts of modified basalt fiber, 0.2 to 0.5 part of antioxidant 1010, 0.3 to 0.6 part of ultraviolet light absorber UV-531, 0.5 to 1.0 part of zinc stearate and 0.8 to 1.5 parts of trimethylolpropane triacrylate. According to the high-wear-resistance anti-aging TPU composite material, the raw material ratio is scientific, and the compatibility is enhanced through multi-step modification of the modified nano silicon dioxide and the basalt fibers; the preparation process is standard, and the melt blending, secondary water cooling and other processes guarantee the quality; the material has excellent wear resistance and aging resistance, good mechanical properties and great application potential.

Description

Technical Field

[0001] This invention relates to the field of TPU composite material technology, specifically to a high wear-resistant and anti-aging TPU composite material and its preparation method. Background Technology

[0002] Thermoplastic polyurethane elastomer (TPU), a polymer material combining the high elasticity of rubber and the processability of plastics, has been widely used in various fields such as automotive manufacturing, electronics, medical devices, and sporting goods due to its excellent mechanical strength, flexibility, oil resistance, and environmental recyclability. However, in complex application scenarios such as outdoor use, high-frequency friction, and harsh working conditions, traditional TPU materials have significant shortcomings. Their insufficient wear resistance and weak aging resistance are particularly prominent, greatly limiting their application range and service life.

[0003] In terms of abrasion resistance, traditional TPU materials are prone to surface wear, cracking, and even failure under long-term friction, especially in high-contact applications such as automotive sealing strips, transmission components, and shoe sole materials. The performance degradation caused by wear directly affects the user experience and safety of the product. Regarding aging resistance, TPU materials exposed to sunlight, oxygen, and temperature changes for extended periods are susceptible to oxidative degradation and molecular chain breakage, resulting in yellowing, hardening, and embrittlement. This leads to decreased elasticity and deterioration of mechanical properties, severely impacting the product's appearance and reliability.

[0004] While existing technologies have attempted to improve TPU performance by adding inorganic fillers, antioxidants, and UV absorbers, these methods generally suffer from several shortcomings. For example, unmodified inorganic fillers have poor compatibility with the TPU matrix and are prone to agglomeration, which not only fails to effectively improve wear resistance but may also lead to a decline in the material's mechanical properties. The effect of adding a single anti-aging additive is limited and cannot simultaneously resist the dual effects of oxidation and UV aging. Some modification processes are complex, costly, or pose environmental risks, making industrial-scale mass production difficult.

[0005] With the increasing demands for material performance across various industries, the market urgently needs a TPU composite material that combines excellent wear resistance with long-lasting anti-aging capabilities and a stable and controllable manufacturing process to meet the stringent requirements of outdoor products, the automotive industry, and high-end equipment. Therefore, developing a high-wear-resistant and anti-aging TPU composite material with a scientifically formulated, rationally modified, and synergistically improved performance to address the performance deficiencies of traditional TPU materials is of significant practical importance and has broad application prospects. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high wear-resistant and anti-aging TPU composite material and its preparation method, solving the problems of poor wear resistance, weak anti-aging properties, insufficient compatibility of inorganic fillers, and limited effectiveness of anti-aging additives in traditional TPU materials.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A high wear-resistant and anti-aging TPU composite material comprises the following raw materials in parts by weight: 90-100 parts thermoplastic polyurethane elastomer, 5-12 parts modified nano silica, 8-15 parts modified basalt fiber, 0.2-0.5 parts antioxidant 1010, 0.3-0.6 parts ultraviolet absorber UV-531, 0.5-1.0 parts zinc stearate, and 0.8-1.5 parts trimethylolpropane triacrylate.

[0008] Furthermore, the thermoplastic polyurethane elastomer has a Shore hardness of 85-95A, ensuring that the matrix has sufficient load-bearing capacity to adapt to wear-resistant applications, as well as good processing fluidity for easy molding. The number average molecular weight is 20,000-30,000, and its NCO / OH molar ratio is 1.05-1.15. The precise control of the number average molecular weight and NCO / OH molar ratio ensures the stability of the interfacial bonding with the modified filler, avoiding the degradation of the mechanical properties of the composite material due to deviations in matrix properties.

[0009] Furthermore, the modified nano-silica is prepared using the following specific steps: A1. Take nano-silica, add anhydrous ethanol, and ultrasonically disperse for 30 min; add 0.5 mol / L dilute sulfuric acid solution, heat to 60-70℃, and stir for 2 h; then add silane coupling agent KH550 to the system, and continue to keep warm for 3 h; after the reaction is completed, centrifuge, wash 3-4 times with anhydrous ethanol, and dry in an 80℃ vacuum drying oven for 6 h to obtain the first modified nano-silica; through dispersion, surface activation and coupling agent grafting, break the agglomeration of nano-silica, introduce organic functional groups, initially improve its compatibility with the organic matrix, and lay the foundation for subsequent modification.

[0010] A2. Take the first modified nano-silica, add toluene, ultrasonically disperse for 20 min, and heat to 80-85℃; add a polyurethane prepolymer composed of isophorone diisocyanate and polyethylene adipate dropwise to the system at a dropping rate of 1-2 ml / min; after the dropwise addition is complete, add dibutyltin dilaurate and keep the reaction at the temperature for 4 h; then add n-butanol, add 0.01-0.02 g of dibutyltin dilaurate, heat to 85℃ and continue the reaction for 2 h; after the reaction is complete, centrifuge, wash twice with toluene, and vacuum dry at 60℃ for 8 h to obtain the second modified nano-silica; graft a flexible polyurethane brush onto the surface of the nano-silica, and end-cap the brush structure with n-butanol to lock the ends, avoiding excessive reaction with the TPU matrix and subsequent agglomeration, while significantly improving the interfacial bonding force with the matrix through segment interpenetration, ensuring dispersion stability.

[0011] A3. Take the second modified nano-silica, add N,N-dimethylformamide, ultrasonically disperse for 15 min, and heat to 75-80℃; add antioxidant 1076 and adipic acid dihydrazide, keep the reaction at this temperature for 5 h, cool to room temperature, centrifuge, wash three times with acetone, and vacuum dry at 90℃ for 10 h to obtain modified nano-silica. Using adipic acid dihydrazide, antioxidant 1076 is anchored to the polyurethane graft layer via hydrogen bonds / hydrazone bonds, forming a slowly released antioxidant layer. This allows the nano-silica to possess both wear-resistant reinforcement and antioxidant functions, while also limiting the antioxidant migration path, ensuring the long-lasting anti-aging properties of the composite material.

[0012] Furthermore, the ratio of nano-silica, anhydrous ethanol, dilute sulfuric acid solution, and silane coupling agent KH550 in A1 is 100g: 500-600ml: 80-100ml: 15-20ml.

[0013] Furthermore, in A2, the ratio of the first modified nano-silica, toluene, isophorone diisocyanate, polyethylene adipate, dibutyltin dilaurate, and n-butanol is 100g:400-500ml:25-30ml:40-50g:0.31-0.52g:10-15ml; wherein, the total amount of dibutyltin dilaurate is 0.31-0.52g, which is added in two stages: 0.30-0.50g is added in the first stage of the polyurethane prepolymer grafting reaction, and 0.01-0.02g is added in the second stage of the n-butanol end-capping reaction; the polyethylene adipate has hydroxyl groups at both ends and a molecular weight of 1000.

[0014] Furthermore, the ratio of the second modified nano-silica, N,N-dimethylformamide, antioxidant 1076, and adipic acid dihydrazide in A3 is 100g: 350-450ml: 20-25g: 10-15g.

[0015] Furthermore, the modified basalt fiber is prepared using the following specific steps: B1. Basalt fiber was placed in a muffle furnace and heated to 450°C at a rate of 5°C / min, and held for 2 hours to remove the surface organic sizing agent, thus obtaining degummed basalt fiber. The degummed basalt fiber was then taken and a 1 mol / L sodium hydroxide solution was added, and the mixture was stirred at room temperature for 1.5 hours. Then, silane coupling agent KH560 was added to the system, and the temperature was raised to 50-60°C, and the mixture was stirred for 3 hours. After the reaction was completed, the fiber was washed with deionized water until neutral and dried at 100°C for 4 hours to obtain the first modified basalt fiber. The fiber surface sizing agent was removed, and the fiber was encapsulated by etching and grafted with a coupling agent to improve the dispersibility and interfacial bonding between the fiber and the organic matrix, thus laying a solid foundation for subsequent modification.

[0016] B2. Take the first modified basalt fiber, place it in a high-pressure reactor, add xylene, and heat to 120-130℃ under a nitrogen atmosphere; add maleic anhydride and benzoyl peroxide, keep the reaction at the temperature for 6 hours, cool to room temperature, filter, wash twice with xylene, and vacuum dry at 80℃ for 6 hours to obtain the second modified basalt fiber; by grafting maleic anhydride, an anhydride-carboxylic acid bifunctional group is formed on the fiber surface, which undergoes in-situ amide / imide chemical bonding with the urethane / urea group of TPU during subsequent extrusion, which not only strengthens the fiber reinforcement and material structural stability, but also significantly improves the interfacial hydrolysis resistance under humid and hot conditions.

[0017] B3. Take the second modified basalt fiber, add methyl ethyl ketone (MEK), ultrasonically disperse for 20 min, and heat to 70-75℃; add polycaprolactone diol and p-toluenesulfonic acid, keep the reaction at this temperature for 4 h, filter, wash twice with MEK, and vacuum dry at 100℃ for 8 h to obtain the modified basalt fiber. Grafting MEK optimizes fiber flexibility, avoids embrittlement of the composite material, further improves interfacial bonding quality, and balances overall mechanical properties.

[0018] Furthermore, the ratio of degummed basalt fiber, sodium hydroxide solution, and silane coupling agent KH560 in B1 is 100g: 300-400ml: 20-25ml.

[0019] Furthermore, the ratio of the first modified basalt fiber, xylene, maleic anhydride, and benzoyl peroxide in B2 is 100g: 250-350ml: 30-35g: 1-1.5g.

[0020] Furthermore, the ratio of the second modified basalt fiber, methyl ethyl ketone, polycaprolactone diol, and p-toluenesulfonic acid in B3 is 100g: 300-400ml: 50-60g: 0.5-0.8g.

[0021] A method for preparing a high wear-resistant and anti-aging TPU composite material specifically includes the following steps: S1. Place the thermoplastic polyurethane elastomer in a vacuum drying oven at 80℃ for 4 hours to remove moisture; add the dried thermoplastic polyurethane elastomer to a high-speed mixer, set the speed to 800-1000 r / min, and the temperature to 60-70℃; add 0.5-1.0 parts of zinc stearate, 0.2-0.5 parts of antioxidant 1010, and 0.3-0.6 parts of ultraviolet absorber UV-531 in sequence, and mix for 5 minutes; then add 5-12 parts of modified nano silica, and continue mixing for 8 minutes; finally add 8-15 parts of modified basalt fiber and 0.8-1.5 parts of trimethylolpropane triacrylate, and mix for 10 minutes to obtain a premix; S2. Add the premixed material to the twin-screw extruder and set the temperatures of each section of the extruder as follows: Zone 1 160-170℃, Zone 2 175-185℃, Zone 3 185-195℃, and die head temperature 185-190℃; the screw speed is 200-250 r / min, and the feeding rate is 20-30 kg / h; after melt blending and extrusion, the material is cooled by water and pelletized to obtain TPU composite material particles; S3. Place the composite material particles in an 85℃ vacuum drying oven for 3 hours to remove surface moisture; then use an injection molding machine for injection molding at an injection temperature of 180-195℃, a mold temperature of 40-50℃, an injection pressure of 80-100MPa, a holding pressure of 50-60MPa, and a holding time of 10-15s to obtain high wear-resistant and anti-aging TPU composite material products. Controlling the holding time reduces shrinkage defects, ensures a dense product structure, and fully utilizes the synergistic effect of each functional component.

[0022] Furthermore, the water-cooled pelletizing process in S2 employs a two-stage cooling process. The first stage cooling water temperature is 25-30℃, with a material residence time of 3-5 seconds; the second stage cooling water temperature is 10-15℃, with a material residence time of 5-8 seconds. This two-stage gradient cooling avoids internal stress caused by rapid cooling. The first stage provides initial cooling and shaping, while the second stage provides deep cooling to ensure uniform pellet hardness, prevent pellet adhesion or cracking, and improve the processing stability and dimensional accuracy of subsequent injection molding.

[0023] This invention provides a high wear-resistant and anti-aging TPU composite material and its preparation method, which has the following beneficial effects: 1. The TPU composite material prepared by this invention possesses excellent wear resistance, solving the problem of easy wear and failure of traditional TPU materials under high-frequency friction scenarios. Through multi-step modification of nano-silica and basalt fibers, the compatibility and interfacial bonding between the inorganic filler and the TPU matrix are significantly improved, avoiding filler agglomeration. The modified nano-silica can be uniformly dispersed in the matrix, forming a dense wear-resistant skeleton, while the modified basalt fibers enhance the overall structural strength of the material with a three-dimensional network structure. The synergistic effect of these two components significantly improves the surface hardness and friction resistance of the material, enabling it to withstand long-term high-frequency friction and effectively extending the service life of the product in wear-resistant applications such as automotive transmission components, shoe sole materials, and seals.

[0024] 2. This composite material exhibits long-lasting and stable anti-aging properties, resisting both oxidation and ultraviolet radiation. The formula scientifically combines antioxidant 1010 with antioxidant 1076 introduced from modified nano-silica, forming a dual antioxidant system that effectively inhibits oxidative degradation and molecular chain breakage during use. Ultraviolet absorber UV-531 efficiently absorbs ultraviolet light, reducing UV damage to the material. Combined with the barrier effect of modified fillers, it delays aging phenomena such as yellowing, hardening, and embrittlement. Whether in long-term outdoor exposure or under conditions of frequent temperature changes, the material maintains good elasticity and mechanical property stability, broadening the application range of TPU materials in outdoor products, automotive exteriors, and other fields.

[0025] 3. The composite material exhibits balanced and excellent mechanical properties, enhancing wear resistance and aging resistance while maintaining good flexibility and structural strength. Thermoplastic polyurethane elastomers inherently possess excellent elasticity; the modified inorganic fillers form a stable composite structure with the matrix, not only preserving the material's flexibility but also improving tensile strength, tear strength, and resistance to deformation through fiber reinforcement and particle filling effects. The product retains the inherent softness and processing fluidity of TPU while possessing stronger structural load-bearing capacity, meeting the diverse mechanical property requirements of different applications. It is suitable for the production of high-end products that require both elasticity and a certain level of structural strength.

[0026] 4. The preparation process of this invention is scientifically sound, highly stable, and easily scalable for industrial mass production, resulting in a high overall cost-performance ratio. The raw material ratios are precisely controllable, the modification process and composite preparation flow are standardized, and the parameters for process steps such as high-speed mixing, twin-screw melt blending, and two-stage water-cooled pelletizing are clearly defined, ensuring the consistency and stability of product quality. The raw materials used are widely available and cost-controllable; the modification process does not require specialized high-end equipment and can be adapted to existing chemical production equipment. Compared to traditional modified TPU materials, the product of this invention offers comprehensive performance improvements without significantly increasing production costs, and the processing flow is environmentally friendly and efficient, meeting the economic and environmental requirements of industrial production and possessing broad market application prospects. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1: Preparation of a high wear-resistant and anti-aging TPU composite material. The specific preparation steps are as follows: S1. Place the thermoplastic polyurethane elastomer in a vacuum drying oven at 80℃ for 4 hours to remove moisture; add the dried thermoplastic polyurethane elastomer to a high-speed mixer, set the speed to 800 r / min and the temperature to 60℃; add 0.5 parts of zinc stearate, 0.2 parts of antioxidant 1010, and 0.3 parts of ultraviolet absorber UV-531 in sequence, and mix for 5 minutes; then add 5 parts of modified nano silica and continue mixing for 8 minutes; finally add 8 parts of modified basalt fiber and 0.8 parts of trimethylolpropane triacrylate, and mix for 10 minutes to obtain a premix. S2. Add the premixed material to the twin-screw extruder and set the temperatures of each section of the extruder as follows: Zone 1 160℃, Zone 2 175℃, Zone 3 185℃, and Die head temperature 185℃; the screw speed is 200 r / min, and the feeding rate is 20 kg / h; after the material is melt-blended and extruded, it is cooled by a two-stage water cooling process. The first stage cooling water temperature is 25℃, and the material residence time is 3s. The second stage cooling water temperature is 10℃, and the material residence time is 5s. Then, it is pelletized to obtain TPU composite material particles. S3. Place the composite material particles in an 85℃ vacuum drying oven for 3 hours to remove surface moisture; use an injection molding machine for injection molding with an injection temperature of 180℃, a mold temperature of 40℃, an injection pressure of 80MPa, a holding pressure of 50MPa, and a holding time of 10s to obtain a high wear-resistant and anti-aging TPU composite material product.

[0029] Example 2: Preparation of a high wear-resistant and anti-aging TPU composite material. The specific preparation steps are as follows: S1. Place the thermoplastic polyurethane elastomer in a vacuum drying oven at 80℃ for 4 hours to remove moisture; add the dried thermoplastic polyurethane elastomer to a high-speed mixer, set the speed to 1000 r / min and the temperature to 70℃; add 1.0 part zinc stearate, 0.5 part antioxidant 1010, and 0.6 part ultraviolet absorber UV-531 in sequence, and mix for 5 minutes; then add 12 parts modified nano silica and continue mixing for 8 minutes; finally add 15 parts modified basalt fiber and 1.5 parts trimethylolpropane triacrylate, and mix for 10 minutes to obtain a premix. S2. Add the premixed material to the twin-screw extruder and set the temperatures of each section of the extruder as follows: Zone 1 170℃, Zone 2 185℃, Zone 3 195℃, and Die head temperature 190℃; the screw speed is 250 r / min, and the feeding rate is 30 kg / h; after the material is melt-blended and extruded, it is cooled by a two-stage water cooling process. The first stage cooling water temperature is 30℃, and the material residence time is 5s. The second stage cooling water temperature is 15℃, and the material residence time is 8s. Then, it is pelletized to obtain TPU composite material particles. S3. Place the composite material particles in an 85℃ vacuum drying oven for 3 hours to remove surface moisture; use an injection molding machine for injection molding with an injection temperature of 195℃, a mold temperature of 50℃, an injection pressure of 100MPa, a holding pressure of 60MPa, and a holding time of 15s to obtain a high wear-resistant and anti-aging TPU composite material product.

[0030] Example 3: Preparation of a high wear-resistant and anti-aging TPU composite material. The specific preparation steps are as follows: S1. Place the thermoplastic polyurethane elastomer in an 80℃ vacuum drying oven for 4 hours to remove moisture; add the dried thermoplastic polyurethane elastomer to a high-speed mixer, set the speed to 900 r / min and the temperature to 65℃; add 0.7 parts zinc stearate, 0.3 parts antioxidant 1010, and 0.4 parts ultraviolet absorber UV-531 in sequence, and mix for 5 minutes; then add 8 parts modified nano silica and continue mixing for 8 minutes; finally add 11 parts modified basalt fiber and 1.2 parts trimethylolpropane triacrylate, and mix for 10 minutes to obtain a premix. S2. Add the premixed material to the twin-screw extruder and set the temperatures of each section of the extruder as follows: Zone 1 165℃, Zone 2 180℃, Zone 3 190℃, and Die head temperature 187℃; the screw speed is 225 r / min, and the feeding rate is 25 kg / h; after melt blending and extrusion, the material is cooled by a two-stage water cooling process. The first stage cooling water temperature is 27℃, and the material residence time is 4s. The second stage cooling water temperature is 12℃, and the material residence time is 6s. Then, the material is pelletized to obtain TPU composite material particles. S3. Place the composite material particles in an 85℃ vacuum drying oven for 3 hours to remove surface moisture; use an injection molding machine for injection molding with an injection temperature of 187℃, a mold temperature of 45℃, an injection pressure of 90MPa, a holding pressure of 55MPa, and a holding time of 12s to obtain a high wear-resistant and anti-aging TPU composite material product.

[0031] Example 4: Preparation of modified nano-silica. The specific preparation steps are as follows: A1. Take 100g of nano-silica, add 500ml of anhydrous ethanol, and sonicate for 30min; add 80ml of 0.5mol / L dilute sulfuric acid solution, heat to 60℃, and stir for 2h; then add 15ml of silane coupling agent KH550 to the system, and continue to keep warm for 3h; after the reaction is completed, centrifuge, wash 3 times with anhydrous ethanol, and dry in an 80℃ vacuum drying oven for 6h to obtain the first modified nano-silica; A2. Take 100g of the first-modified nano-silica, add 400ml of toluene, ultrasonically disperse for 20min, and heat to 80℃; add dropwise a polyurethane prepolymer composed of 25ml of isophorone diisocyanate and 40g of polyethylene adipate to the system at a dropping rate of 1ml / min; after the addition is complete, add 0.3g of dibutyltin dilaurate, and keep the reaction at the temperature for 4h; then add 10ml of n-butanol, add 0.01g of dibutyltin dilaurate, and heat to 85℃ to continue the reaction for 2h; after the reaction is complete, centrifuge, wash twice with toluene, and vacuum dry at 60℃ for 8h to obtain the second-modified nano-silica; A3. Take 100g of the second modified nano silica, add 350ml of N,N-dimethylformamide, sonicate for 15min, and heat to 75℃; add 20g of antioxidant 1076 and 10g of adipate dihydrazide, keep the reaction at the temperature for 5h, cool to room temperature, centrifuge, wash 3 times with acetone, and vacuum dry at 90℃ for 10h to obtain modified nano silica.

[0032] Example 5: Preparation of modified nano-silica. The specific preparation steps are as follows: A1. Take 100g of nano-silica, add 600ml of anhydrous ethanol, and sonicate for 30min; add 100ml of 0.5mol / L dilute sulfuric acid solution, heat to 70℃, and stir for 2h; then add 20ml of silane coupling agent KH550 to the system, and continue to keep warm for 3h; after the reaction is completed, centrifuge, wash 4 times with anhydrous ethanol, and dry in an 80℃ vacuum drying oven for 6h to obtain the first modified nano-silica; A2. Take 100g of the first-modified nano-silica, add 500ml of toluene, ultrasonically disperse for 20min, and heat to 85℃; add dropwise a polyurethane prepolymer composed of 30ml of isophorone diisocyanate and 50g of polyethylene adipate to the system at a dropping rate of 2ml / min; after the addition is complete, add 0.5g of dibutyltin dilaurate, and keep the reaction at the temperature for 4h; then add 15ml of n-butanol, add 0.02g of dibutyltin dilaurate, and heat to 85℃ to continue the reaction for 2h; after the reaction is completed, centrifuge, wash twice with toluene, and vacuum dry at 60℃ for 8h to obtain the second-modified nano-silica; A3. Take 100g of the second modified nano silica, add 450ml of N,N-dimethylformamide, sonicate for 15min, and heat to 80℃; add 25g of antioxidant 1076 and 15g of adipate dihydrazide, keep warm for 5h, cool to room temperature, centrifuge, wash 3 times with acetone, and vacuum dry at 90℃ for 10h to obtain modified nano silica.

[0033] Example 6: Preparation of modified basalt fibers. The specific preparation steps are as follows: B1. Basalt fiber was placed in a muffle furnace and heated to 450°C at a rate of 5°C / min, and kept at that temperature for 2 hours to remove the surface organic wetting agent, thus obtaining degummed basalt fiber. 100g of degummed basalt fiber was added to 300ml of 1mol / L sodium hydroxide solution, and the mixture was stirred at room temperature for 1.5 hours. Then, 20ml of silane coupling agent KH560 was added to the system, the temperature was raised to 50°C, and the mixture was stirred for 3 hours. After the reaction was completed, the fiber was washed with deionized water until neutral and dried at 100°C for 4 hours to obtain the first modified basalt fiber. B2. Take 100g of the first modified basalt fiber, place it in a high-pressure reactor, add 250ml of xylene, and heat to 120℃ under a nitrogen atmosphere; add 30g of maleic anhydride and 1g of benzoyl peroxide, keep the reaction at the temperature for 6h, cool to room temperature, filter, wash twice with xylene, and vacuum dry at 80℃ for 6h to obtain the second modified basalt fiber. B3. Take 100g of the second modified basalt fiber, add 300ml of butanone, ultrasonically disperse for 20min, and heat to 70℃; add 50g of polycaprolactone diol and 0.5g of p-toluenesulfonic acid, keep warm for 4h, filter, wash twice with butanone, and vacuum dry at 100℃ for 8h to obtain the modified basalt fiber.

[0034] Example 7: Preparation of modified basalt fibers. The specific preparation steps are as follows: B1. Basalt fiber was placed in a muffle furnace and heated to 450°C at a rate of 5°C / min, and kept at that temperature for 2 hours to remove the surface organic wetting agent, thus obtaining degummed basalt fiber. 100g of degummed basalt fiber was added to 400ml of 1mol / L sodium hydroxide solution and stirred at room temperature for 1.5 hours. Then, 25ml of silane coupling agent KH560 was added to the system, and the temperature was raised to 60°C and stirred for 3 hours. After the reaction was completed, the fiber was washed with deionized water until neutral and dried at 100°C for 4 hours to obtain the first modified basalt fiber. B2. Take 100g of the first modified basalt fiber, place it in a high-pressure reactor, add 350ml of xylene, and heat to 130℃ under a nitrogen atmosphere; add 35g of maleic anhydride and 1.5g of benzoyl peroxide, keep the reaction at the temperature for 6h, cool to room temperature, filter, wash twice with xylene, and vacuum dry at 80℃ for 6h to obtain the second modified basalt fiber. B3. Take 100g of the second modified basalt fiber, add 400ml of butanone, ultrasonically disperse for 20min, and heat to 75℃; add 60g of polycaprolactone diol and 0.8g of p-toluenesulfonic acid, keep warm for 4h, filter, wash twice with butanone, and vacuum dry at 100℃ for 8h to obtain the modified basalt fiber.

[0035] Comparative Example 1: A high-wear-resistant and anti-aging TPU composite material was prepared. The specific preparation steps are as follows: The remaining steps remain the same, except that the modified nano-silica prepared in Example 4 used in Example 3 is replaced with unmodified nano-silica to prepare a high wear-resistant and anti-aging TPU composite material.

[0036] Comparative Example 2: A high-wear-resistant and anti-aging TPU composite material was prepared. The specific preparation steps are as follows: The remaining steps remain the same, except that the modified basalt fiber prepared in Example 7 used in Example 3 is replaced with unmodified basalt fiber to prepare a high wear-resistant and anti-aging TPU composite material.

[0037] Comparative Example 3: A high-wear-resistant and anti-aging TPU composite material was prepared. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified nano-silica prepared in Example 4 used in Example 3 is replaced with unmodified nano-silica, and the modified basalt fiber prepared in Example 7 is replaced with unmodified basalt fiber, to prepare a high wear-resistant and anti-aging TPU composite material.

[0038] Performance testing

[0039] Performance test results show that the high wear-resistant and anti-aging TPU composite materials prepared in Examples 1-3 are superior to those in Comparative Examples 1-3 in all aspects: Shore hardness is 90-92A, tensile strength is 29.5-32.5MPa, elongation at break is 460%-500%, and Akron abrasion loss is as low as 0.072-0.098cm. 3 / 1.61km, after 120℃×168h heat aging, the tensile strength retention rate was 82%-88%, and the QUV 1000h ultraviolet aging yellowing index ΔE was only 1.6-2.1; while comparative examples 1-3, due to the use of unmodified nano-silica, unmodified basalt fiber, or both, showed a decrease in hardness, tensile strength, and elongation at break, and a significant deterioration in wear resistance. The heat aging tensile strength retention rate was only 62%-72%, and the ultraviolet aging yellowing index was higher (3.4-4.2). This fully demonstrates that multi-step modified nano-silica and basalt fiber can effectively improve the wear resistance, aging resistance, and comprehensive mechanical properties of composite materials.

[0040] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high wear-resistant and anti-aging TPU composite material, characterized in that: It contains the following raw materials in parts by weight: 90-100 parts thermoplastic polyurethane elastomer, 5-12 parts modified nano silica, 8-15 parts modified basalt fiber, 0.2-0.5 parts antioxidant 1010, 0.3-0.6 parts ultraviolet absorber UV-531, 0.5-1.0 parts zinc stearate, and 0.8-1.5 parts trimethylolpropane triacrylate.

2. The high wear-resistant and anti-aging TPU composite material according to claim 1, characterized in that: The thermoplastic polyurethane elastomer has a Shore hardness of 85-95A, a number-average molecular weight of 20,000-30,000, and an NCO / OH molar ratio of 1.05-1.

15.

3. The high wear-resistant and anti-aging TPU composite material according to claim 1, characterized in that: The modified nano-silica is prepared using the following specific steps: A1. Take nano-silica, add anhydrous ethanol, and ultrasonically disperse for 30 min; add 0.5 mol / L dilute sulfuric acid solution, heat to 60-70℃, and stir for 2 h; then add silane coupling agent KH550 to the system, and continue to keep warm for 3 h; after the reaction is completed, centrifuge, wash 3-4 times with anhydrous ethanol, and dry in an 80℃ vacuum drying oven for 6 h to obtain the first modified nano-silica; A2. Take the first modified nano-silica, add toluene, ultrasonically disperse for 20 min, and heat to 80-85℃; add a polyurethane prepolymer composed of isophorone diisocyanate and polyethylene adipate dropwise to the system at a dropping rate of 1-2 ml / min; after the dropwise addition is complete, add dibutyltin dilaurate and keep the reaction at the temperature for 4 h; then add n-butanol, add 0.01-0.02 g of dibutyltin dilaurate, heat to 85℃ and continue the reaction for 2 h; after the reaction is completed, centrifuge, wash twice with toluene, and vacuum dry at 60℃ for 8 h to obtain the second modified nano-silica; A3. Take the second modified nano silica, add N,N-dimethylformamide, ultrasonically disperse for 15 min, heat to 75-80℃; add antioxidant 1076 and adipic acid dihydrazide, keep warm for 5 h, cool to room temperature, centrifuge, wash 3 times with acetone, vacuum dry at 90℃ for 10 h to obtain modified nano silica.

4. The high wear-resistant and anti-aging TPU composite material according to claim 3, characterized in that: The ratio of nano-silica, anhydrous ethanol, dilute sulfuric acid solution, and silane coupling agent KH550 in A1 is 100g: 500-600ml: 80-100ml: 15-20ml; The ratio of the first modified nano-silica, toluene, isophorone diisocyanate, polyethylene adipate, dibutyltin dilaurate, and n-butanol in A2 is 100g:400-500ml:25-30ml:40-50g:0.31-0.52g:10-15ml; wherein, the total amount of dibutyltin dilaurate is 0.31-0.52g, added in two stages: 0.30-0.50g is added in the first stage of the polyurethane prepolymer grafting reaction, and 0.01-0.02g is added in the second stage of the n-butanol end-capping reaction; the polyethylene adipate has hydroxyl groups at both ends and a molecular weight of 1000; The ratio of the second modified nano-silica, N,N-dimethylformamide, antioxidant 1076, and adipic acid dihydrazide in A3 is 100g: 350-450ml: 20-25g: 10-15g.

5. The high wear-resistant and anti-aging TPU composite material according to claim 1, characterized in that: The modified basalt fiber is prepared using the following specific steps: B1. Basalt fiber was placed in a muffle furnace and heated to 450°C at a rate of 5°C / min, and kept at that temperature for 2 hours to remove the surface organic wetting agent, thus obtaining degummed basalt fiber. The degummed basalt fiber was then taken and a 1 mol / L sodium hydroxide solution was added, and the mixture was stirred at room temperature for 1.5 hours. Then, silane coupling agent KH560 was added to the system, and the temperature was raised to 50-60°C, and the mixture was stirred for 3 hours. After the reaction was completed, the fiber was washed with deionized water until neutral and dried at 100°C for 4 hours to obtain the first modified basalt fiber. B2. Take the first modified basalt fiber, place it in a high-pressure reactor, add xylene, and heat it to 120-130℃ under a nitrogen atmosphere; add maleic anhydride and benzoyl peroxide, keep it at the temperature for 6 hours, cool it to room temperature, filter it, wash it twice with xylene, and dry it under vacuum at 80℃ for 6 hours to obtain the second modified basalt fiber. B3. Take the second modified basalt fiber, add methyl ethyl ketone, ultrasonically disperse for 20 min, heat to 70-75℃; add polycaprolactone diol and p-toluenesulfonic acid, keep warm for 4 h, filter, wash twice with methyl ethyl ketone, vacuum dry at 100℃ for 8 h to obtain modified basalt fiber.

6. The high wear-resistant and anti-aging TPU composite material according to claim 5, characterized in that: The ratio of degummed basalt fiber, sodium hydroxide solution, and silane coupling agent KH560 in B1 is 100g: 300-400ml: 20-25ml; The ratio of the first modified basalt fiber, xylene, maleic anhydride, and benzoyl peroxide in B2 is 100g: 250-350ml: 30-35g: 1-1.5g; The ratio of the second modified basalt fiber, methyl ethyl ketone, polycaprolactone diol, and p-toluenesulfonic acid in B3 is 100g: 300-400ml: 50-60g: 0.5-0.8g.

7. A method for preparing a high wear-resistant and anti-aging TPU composite material, characterized in that: Specifically, it includes the following steps: S1. Place the thermoplastic polyurethane elastomer in a vacuum drying oven at 80℃ for 4 hours to remove moisture; add the dried thermoplastic polyurethane elastomer to a high-speed mixer, set the speed to 800-1000 r / min, and the temperature to 60-70℃; add 0.5-1.0 parts of zinc stearate, 0.2-0.5 parts of antioxidant 1010, and 0.3-0.6 parts of ultraviolet absorber UV-531 in sequence, and mix for 5 minutes; then add 5-12 parts of modified nano silica, and continue mixing for 8 minutes; finally add 8-15 parts of modified basalt fiber and 0.8-1.5 parts of trimethylolpropane triacrylate, and mix for 10 minutes to obtain a premix; S2. Add the premixed material to the twin-screw extruder and set the temperatures of each section of the extruder as follows: Zone 1 160-170℃, Zone 2 175-185℃, Zone 3 185-195℃, and die head temperature 185-190℃; the screw speed is 200-250 r / min, and the feeding rate is 20-30 kg / h; after melt blending and extrusion, the material is cooled by water and pelletized to obtain TPU composite material particles; S3. Place the composite material particles in an 85℃ vacuum drying oven for 3 hours to remove surface moisture; use an injection molding machine for injection molding with an injection temperature of 180-195℃, a mold temperature of 40-50℃, an injection pressure of 80-100MPa, a holding pressure of 50-60MPa, and a holding time of 10-15s to obtain high wear-resistant and anti-aging TPU composite material products.

8. The method for preparing a high wear-resistant and anti-aging TPU composite material according to claim 7, characterized in that: The water-cooled pelletizing process in S2 adopts a two-stage cooling process. The first-stage cooling water temperature is 25-30℃, and the material residence time is 3-5s; the second-stage cooling water temperature is 10-15℃, and the material residence time is 5-8s.

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