High-elongation-strength anti-fatigue TPU blended material and preparation method thereof

Abstract

The application discloses a high-elongation-strength anti-fatigue TPU blended material and a preparation method thereof, and relates to the field of polymer materials. In the preparation of the high-elongation-strength anti-fatigue TPU blended material, phosphorus chloride is reacted with 4'-vinyl-[1,1'-biphenyl]-4-alcohol and p-phenylphenol to obtain a phosphite antioxidant; nano-silicon dioxide is sequentially reacted with trimethoxysilane and the phosphite antioxidant to obtain modified silicon dioxide; a modified polyurethane elastomer is prepared by reacting hydroxyl-terminated polysiloxane, 1,4-butanediol, isophorone diisocyanate and adipic dihydrazide; polyether amide elastomer and the modified polyurethane elastomer are mixed, mixed with a compatilizer, modified silicon dioxide and antioxidant 1010, dried, mechanically mixed, and melt-blended to obtain the high-elongation-strength anti-fatigue TPU blended material. The high-elongation-strength anti-fatigue TPU blended material prepared by the application has the abilities of self-repairing, durability and flame resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a fatigue-resistant TPU blend material with high tensile strength and its preparation method. Background Technology

[0002] Thermoplastic polyurethane elastomer (TPU) is widely used in many fields such as automobile manufacturing, electronic packaging, medical devices, and sports equipment due to its excellent elasticity, wear resistance, weather resistance and processing adaptability. As downstream industries develop towards high performance, lightweight and long life, higher requirements are placed on the mechanical properties of TPU materials, especially tensile strength and fatigue resistance, which directly affect the service life and reliability of products under long-term dynamic stress environment. However, traditional single-component TPU materials have performance limitations: pure polyester TPU has good fatigue resistance but low tensile strength and is prone to permanent deformation under high-intensity stress; pure polyether TPU has high tensile strength but insufficient fatigue resistance and is prone to cracking after long-term repeated stress. To balance tensile strength and fatigue resistance, the industry often uses elastomer blending modification technology. However, the compatibility between different elastomers is poor, and phase separation is prone to occur, resulting in unstable mechanical properties of the blended material and difficulty in achieving the expected modification effect. At the same time, the addition of modified silica is an effective means to improve tensile strength during the blending modification process, but nano-scale modified silica... Silica is prone to agglomeration, which not only fails to fully exert its reinforcing effect but may also reduce the fatigue resistance of the material. In addition, moisture in the raw materials can cause TPU degradation during melt processing, affecting the mechanical properties and processing stability of the material. In the existing technology, there is still room for optimization in the selection of compatibilizers, improvement of filler dispersibility, and raw material pretreatment processes. There is an urgent need to develop a TPU blend material and its preparation method that can achieve synergistic improvement of tensile strength and fatigue resistance through reasonable formulation design and process control, so as to meet the urgent market demand for high-performance TPU materials. Therefore, this application introduces a fatigue-resistant TPU blend material with high tensile strength and its preparation method. Summary of the Invention

[0003] The purpose of this invention is to provide a fatigue-resistant TPU blend material with high tensile strength and its preparation method, so as to solve the problems existing in the prior art.

[0004] A high elongation strength anti-fatigue TPU blend material is prepared by mixing polyether amide elastomer and modified polyurethane elastomer, then mixing with compatibilizer, modified silica and antioxidant 1010, drying, mechanically mixing and melt blending. The polyurethane elastomer is prepared by reacting hydroxyl-terminated polysiloxane, 1,4-butanediol, and isophorone diisocyanate, followed by reaction with adipamide hydrazine. The modified silica is prepared by reacting nano-silica sequentially with trimethoxysilane and phosphite antioxidant; The phosphite antioxidant is prepared by reacting phosphorus chloride with 4'-vinyl-[1,1'-biphenyl]-4-ol and p-phenylphenol.

[0005] A method for preparing a fatigue-resistant TPU blend material with high tensile strength, the method mainly includes the following preparation steps: (1) Prepare a chloroplatinic acid solution with a concentration of 0.009~0.011 g / ml by mixing chloroplatinic acid and isopropanol; mix pre-modified silica, phosphite antioxidant, isopropanol and chloroplatinic acid solution in a mass ratio of 1:2~3:7~8:0.018~0.022, stir at 60~64℃ and 200~300 r / min for 4~5 h, filter, wash with deionized water 4~6 times, and vacuum dry at 30~40℃ for 24~26 h to obtain modified silica; (2) Zinc perchlorate hexahydrate, methanol and dichloromethane are mixed evenly in a mass ratio of 1:6-8:6-8 to obtain a zinc solution; hydroxyl-terminated polysiloxane, 1,4-butanediol, isophorone diisocyanate and dibutyltin dilaurate are mixed in a mass ratio of 2-3:4-6:18-20:0.2-0.3, stirred for 2-3 hours at 75-85℃ and 200-300 r / min under nitrogen protection, then 0.1-0.2 times the mass of 1,4-butanediol adipamide is added, and stirring is continued for 7-9 hours. After cooling to room temperature, the mixture is soaked in the zinc solution for 46-48 hours and dried at 75-85℃ for 12-14 hours to obtain a modified polyurethane elastomer. (3) Mix polyether amide elastomer and modified polyurethane elastomer evenly at a mass ratio of 2~5:5~8 to obtain elastomer; mix elastomer, compatibilizer and modified silica according to the ratio, add 1wt% antioxidant 1010 to elastomer, and dry and mechanically mix in sequence to obtain premix; melt blend the premix to obtain blend material.

[0006] As an optimization, the phosphite antioxidant mentioned in step (1) is prepared by mixing phosphorus chloride and chloroform at a mass ratio of 1:35-45 and sonicating for 4-6 min to obtain a phosphorus mixture; 4'-vinyl-[1,1'-biphenyl]-4-ol, p-phenylphenol and chloroform at a mass ratio of 1:2:40-50 and stirring at 200-300 r / min for 2-3 min, and then adding 4'-vinyl-[1,1'-biphenyl]-4-ol. Add 1 to 1.2 molar amounts of triethylamine, continue stirring for 2 to 3 minutes, raise the temperature to 65 to 75°C, and uniformly add an equimolar amount of phosphorus chloride-corresponding phosphorus mixture of 4'-vinyl-[1,1'-biphenyl]-4-ol over 14 to 16 minutes. Continue stirring for 4 to 5 hours, vacuum dry at 60 to 70°C for 10 to 12 hours, wash with deionized water 4 to 5 times, and vacuum dry again at 60 to 70°C for 10 to 12 hours to obtain the final product.

[0007] As an optimization, the pre-modified silica mentioned in step (1) is prepared by mixing trimethoxysilane, ethanol, deionized water and nano silica in a mass ratio of 1:7-8:2-3:1, sonicating for 20-30 min, adjusting the pH to 4-5 with 0.1 mol / L hydrochloric acid aqueous solution, heating to 45-55℃, stirring at 300-400 r / min for 5-7 h, filtering, washing with deionized water 6-8 times, and vacuum drying at 60-70℃ for 10-12 h.

[0008] As an optimization, the hydroxyl-terminated polysiloxane in step (2) is prepared by adding dimethoxydimethylsilane, 2-(4-pyridylethyl)triethoxysilane, 1,3-di(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane and cation exchange resin IR120 to a 250 mL three-necked flask, mixing them in a molar ratio of 4-6:1:1-2:0.1-0.2, and stirring for 15-16 min at 95-105 °C, 200-300 r / min, under nitrogen protection.

[0009] As an optimization, the specific process of drying in step (3) is as follows: vacuum drying at 80~100℃ for 6~8h.

[0010] As an optimization, the amount of compatibilizer added is 5 wt% of the elastomer.

[0011] As an optimization, the amount of modified silica added is 1wt% to 9wt% of the elastomer.

[0012] As an optimization, the compatibilizer includes one or more of POE-g-MAH, POE-g-GMA, and SEBA-g-MAH.

[0013] As an optimization, the specific parameters for melt blending in step (3) are: setting the screw speed to 40~60 rpm, the temperature to 170~190℃, and the melt blending time to 10 min.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are: In preparing a fatigue-resistant TPU blend material with high tensile strength, this invention involves reacting phosphorus chloride with 4'-vinyl-[1,1'-biphenyl]-4-ol and p-phenylphenol to obtain a phosphite antioxidant; reacting nano-silica sequentially with trimethoxysilane and the phosphite antioxidant to obtain modified silica; reacting hydroxyl-terminated polysiloxane, 1,4-butanediol, and isophorone diisocyanate, followed by reaction with adipamide, to obtain a modified polyurethane elastomer; mixing the polyetheramide elastomer and the modified polyurethane elastomer, then mixing with a compatibilizer, modified silica, and antioxidant 1010, drying, mechanically mixing, and melt blending to obtain a fatigue-resistant TPU blend material with high tensile strength.

[0015] First, phosphorus chloride is reacted with 4'-vinyl-[1,1'-biphenyl]-4-ol and p-phenylphenol to prepare a phosphite antioxidant. Then, nano-silica is reacted sequentially with trimethoxysilane and the phosphite antioxidant to prepare modified silica. Phosphite is prepared by reacting phosphorus chloride with 4'-vinyl-[1,1'-biphenyl]-4-ol and p-phenylphenol. Under high temperature or flame conditions, the phosphite decomposes to generate phosphorus-containing free radicals. These free radicals can effectively capture highly reactive hydrogen and hydroxyl radicals in the combustion chain reaction, interrupting the chain reaction and thus inhibiting flame propagation. Simultaneously, the formed phosphite structure possesses antioxidant properties and can act as an auxiliary antioxidant in conjunction with antioxidant 1010 to extend the material's service life.

[0016] Secondly, hydroxyl-terminated polysiloxane, 1,4-butanediol, and isophorone diisocyanate are reacted, followed by reaction with adipic hydrazide to prepare modified polyurethane elastomer. The monomer of hydroxyl-terminated polysiloxane contains pyridine, which can form coordination bonds with zinc ions. After the bonds break, these coordination bonds are reconstructed under external stimuli, giving the material self-healing ability and achieving a self-repairing effect. During the preparation of polyurethane, due to the presence of amide urea, its six hydrogen bonds can act as strong crosslinking sites, forming a hydrogen bond crosslinking network structure, which improves tensile strength.

[0017] Finally, the polyetheramide elastomer and modified polyurethane elastomer are mixed, then mixed with a compatibilizer, modified silica, and antioxidant 1010, dried, mechanically mixed, and melt-blended to obtain a fatigue-resistant TPU blend material with high tensile strength. Through scientific formulation, the tensile strength of the material is significantly improved, achieving complementary synergy between fatigue resistance and strength, while ensuring elastic recovery under long-term dynamic stress. The selection of specific compatibilizers effectively improves the compatibility of the elastomer and inhibits phase separation. Combined with the raw material drying and dehydration process and optimized melt blending parameters, the material's mechanical properties are stable and its processing is consistent. Moreover, the preparation process is simple, requires no special equipment, and is convenient for industrial production. Attached Figure Description

[0018] Figure 1 The cyclic tensile test curve of Example 1; Figure 2 The cyclic tensile test curve for Example 2; Figure 3 The curve for the cyclic tensile test in Example 3 is shown. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] The compatibilizer used in the following examples and comparative examples is POE-g-MAH; the polyether amide elastomer is PEBAX4033, purchased from Arkema, France. Example 1

[0021] A method for preparing a fatigue-resistant TPU blend material with high tensile strength mainly includes the following preparation steps: (1) Trimethoxysilane, ethanol, deionized water, and nano silica were mixed in a mass ratio of 1:7:2:1, sonicated for 20 min, and the pH was adjusted to 4 with 0.1 mol / L hydrochloric acid aqueous solution. The temperature was raised to 45 °C, stirred at 300 r / min for 5 h, filtered, washed 6 times with deionized water, and vacuum dried at 60 °C for 10 h to obtain pre-modified silica. Phosphorus chloride and chloroform were mixed in a mass ratio of 1:35 and sonicated for 4 min to obtain a phosphorus mixture. 4'-vinyl-[1,1'-biphenyl]-4-ol, p-phenylphenol, and chloroform were mixed in a mass ratio of 1:2:40 and stirred at 200 r / min for 2 min. Trimethoxysilane was added in a mass ratio of 1:7:2:1. Amine was stirred for 2 minutes, and the temperature was raised to 65°C. An equimolar amount of phosphorus chloride-containing phosphorus mixture of 4'-vinyl-[1,1'-biphenyl]-4-ol was added over 14 minutes. Stirring continued for 4 hours, followed by vacuum drying at 60°C for 10 hours. The mixture was washed four times with deionized water and then vacuum dried again at 60°C for 10 hours to obtain the phosphite antioxidant. A chloroplatinic acid solution with a concentration of 0.009 g / ml was prepared by mixing chloroplatinic acid and isopropanol. The pre-modified silica, phosphite antioxidant, isopropanol, and chloroplatinic acid solution were mixed at a mass ratio of 1:2:7:0.018 and stirred at 200 r / min for 4 hours at 60°C. The mixture was filtered, washed four times with deionized water, and vacuum dried at 30°C for 24 hours to obtain the modified silica. (2) Dimethoxydimethylsilane, 2-(4-pyridylethyl)triethoxysilane, 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, and cation exchange resin IR120 were added to a 250 mL three-necked flask and mixed in a molar ratio of 4:1:1:0.1. The mixture was stirred for 15 min at 95 °C, 200 r / min, and nitrogen protection to obtain hydroxyl-terminated polysiloxane. Zinc perchlorate hexahydrate, methanol, and dichloromethane were mixed in a mass ratio of 1... A zinc solution was prepared by mixing the 6:6 ratio of polysiloxane, 1,4-butanediol, isophorone diisocyanate, and dibutyltin dilaurate in a mass ratio of 2:4:18:0.2. The mixture was stirred for 2 hours at 75°C and 200 r / min under nitrogen protection. Then, 0.1 times the mass of adipic hydrazide of 1,4-butanediol was added, and the mixture was stirred for another 7 hours. The mixture was cooled to room temperature, immersed in the zinc solution for 46 hours, and dried at 75°C for 12 hours to obtain the modified polyurethane elastomer. (3) The polyether amide elastomer and the modified polyurethane elastomer are mixed evenly at a mass ratio of 2:5 to obtain the elastomer; the elastomer, compatibilizer and modified silica are mixed at a mass ratio of 3:5:100, and 1 wt% of antioxidant 1010 is added to the elastomer. The mixture is vacuum dried at 80°C for 6 hours and mechanically mixed to obtain the premix; the premix is ​​melt-blended, and the screw speed is set to 40 rpm, the temperature is set to 170°C and the melt-blending time is set to 10 min to obtain the blended material. Example 2

[0022] A method for preparing a fatigue-resistant TPU blend material with high tensile strength mainly includes the following preparation steps: (1) Trimethoxysilane, ethanol, deionized water, and nano-silica were mixed in a mass ratio of 1:7.5:2.5:1, sonicated for 25 min, and the pH was adjusted to 4.5 with 0.1 mol / L hydrochloric acid aqueous solution. The temperature was raised to 50 °C, stirred at 350 r / min for 6 h, filtered, washed 7 times with deionized water, and vacuum dried at 65 °C for 11 h to obtain pre-modified silica; phosphorus chloride and chloroform were mixed in a mass ratio of 1:40 and sonicated for 5 min to obtain phosphorus mixture; 4'-vinyl-[1,1'-biphenyl]-4-ol, p-phenylphenol, and chloroform were mixed in a mass ratio of 1:2:45, stirred at 250 r / min for 2.5 min, and triethylamine with a molar amount of 1.1 times that of 4'-vinyl-[1,1'-biphenyl]-4-ol was added. Continue stirring for 2.5 min, raise the temperature to 70℃, and add an equimolar amount of phosphorus mixture corresponding to phosphorus chloride of 4'-vinyl-[1,1'-biphenyl]-4-ol at a uniform rate over 15 min. Continue stirring for 4.5 h, vacuum dry at 65℃ for 11 h, wash with deionized water 4.5 times, and vacuum dry again at 65℃ for 11 h to obtain phosphite antioxidant; prepare a chloroplatinic acid solution with a concentration of 0.01 g / ml by dissolving chloroplatinic acid and isopropanol; mix pre-modified silica, phosphite antioxidant, isopropanol and chloroplatinic acid solution at a mass ratio of 1:2.5:7.5:0.02, stir at 62℃ and 250 r / min for 4.5 h, filter, wash with deionized water 5 times, and vacuum dry at 35℃ for 24~26 h to obtain modified silica; (2) Dimethoxydimethylsilane, 2-(4-pyridylethyl)triethoxysilane, 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane and cation exchange resin IR120 were added to a 250 mL three-necked flask and mixed in a molar ratio of 5:1:1.5:0.1.5. The mixture was stirred at 100 °C, 250 r / min and nitrogen protection for 15.5 min to obtain hydroxyl-terminated polysiloxane. Zinc perchlorate hexahydrate, methanol and dichloromethane were added in a mass ratio of A zinc solution was prepared by mixing the 1:7:7 ratio of polysiloxane, 1,4-butanediol, isophorone diisocyanate, and dibutyltin dilaurate in a mass ratio of 2.5:5:19:0.25. The mixture was stirred for 2.5 h at 80 °C and 250 r / min under nitrogen protection. Then, 0.15 times the mass of 1,4-butanediol adipamide was added, and the mixture was stirred for another 8 h. The mixture was cooled to room temperature, immersed in the zinc solution for 47 h, and dried at 80 °C for 13 h to obtain the modified polyurethane elastomer. (3) The polyether amide elastomer and the modified polyurethane elastomer are mixed evenly at a mass ratio of 4:7 to obtain the elastomer; the elastomer, compatibilizer and modified silica are mixed at a mass ratio of 4:5:100, and 1 wt% of antioxidant 1010 is added to the elastomer. The mixture is vacuum dried at 90°C for 7 hours and mechanically mixed to obtain the premix; the premix is ​​melt-blended, with the screw speed set at 50 rpm, the temperature at 180°C and the melt-blending time at 10 min to obtain the blended material. Example 3

[0023] A method for preparing a fatigue-resistant TPU blend material with high tensile strength mainly includes the following preparation steps: (1) Trimethoxysilane, ethanol, deionized water, and nano-silica were mixed in a mass ratio of 1:8:3:1, sonicated for 30 min, and the pH was adjusted to 5 with 0.1 mol / L hydrochloric acid aqueous solution. The temperature was raised to 55 °C, stirred at 400 r / min for 7 h, filtered, washed 8 times with deionized water, and vacuum dried at 70 °C for 12 h to obtain pre-modified silica; phosphorus chloride and chloroform were mixed in a mass ratio of 1:45, sonicated for 6 min to obtain phosphorus mixture; 4'-vinyl-[1,1'-biphenyl]-4-ol, p-phenylphenol, and chloroform were mixed in a mass ratio of 1:2:50, stirred at 300 r / min for 3 min, and 1.2 times the molar amount of 4'-vinyl-[1,1'-biphenyl]-4-ol was added. Amine was stirred for 3 minutes, and the temperature was raised to 75°C. An equimolar amount of phosphorus chloride-containing phosphorus mixture of 4'-vinyl-[1,1'-biphenyl]-4-ol was added at a constant rate over 16 minutes. Stirring continued for 5 hours, followed by vacuum drying at 70°C for 12 hours. The mixture was washed 5 times with deionized water and then vacuum dried again at 70°C for 12 hours to obtain the phosphite antioxidant. A chloroplatinic acid solution with a concentration of 0.011 g / ml was prepared by mixing chloroplatinic acid and isopropanol. The pre-modified silica, phosphite antioxidant, isopropanol, and chloroplatinic acid solution were mixed at a mass ratio of 1:3:8:0.022, stirred at 64°C and 300 r / min for 5 hours, filtered, washed 6 times with deionized water, and vacuum dried at 40°C for 26 hours to obtain the modified silica. (2) Dimethoxydimethylsilane, 2-(4-pyridylethyl)triethoxysilane, 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane and cation exchange resin IR120 were added to a 250 mL three-necked flask and mixed in a molar ratio of 6:1:2:0.2. The mixture was stirred for 16 min at 105 °C, 300 r / min and under nitrogen protection to obtain hydroxyl-terminated polysiloxane. Zinc perchlorate hexahydrate, methanol and dichloromethane were added in a mass ratio of A zinc solution was prepared by mixing the 1:8:8 mixture thoroughly. Hydroxyl-terminated polysiloxane, 1,4-butanediol, isophorone diisocyanate, and dibutyltin dilaurate were mixed in a mass ratio of 3:6:20:0.3 and stirred for 3 hours at 85°C, 300 r / min under nitrogen protection. Then, 0.2 times the mass of 1,4-butanediol (adipylhydrazine) was added, and stirring continued for 9 hours. The mixture was cooled to room temperature, immersed in the zinc solution for 48 hours, and dried at 85°C for 14 hours to obtain the modified polyurethane elastomer. (3) The polyether amide elastomer and the modified polyurethane elastomer are mixed evenly at a mass ratio of 5:8 to obtain the elastomer; the elastomer, compatibilizer and modified silica are mixed at a mass ratio of 5:5:100, and 1 wt% of antioxidant 1010 is added to the elastomer. The mixture is vacuum dried at 100°C for 8 hours and mechanically mixed to obtain the premix; the premix is ​​melt-blended, and the screw speed is set to 60 rpm, the temperature is set to 190°C and the melt-blending time is set to 10 min to obtain the blended material.

[0024] Comparative Example 1: The preparation method of the high tensile strength fatigue-resistant TPU blend material of Comparative Example 1 differs from that of Example 2 in that the nano-silica is not modified. The remaining steps are the same as in Example 2.

[0025] Comparative Example 2 The difference between the preparation method of the high tensile strength anti-fatigue TPU blend material of Comparative Example 2 and Example 2 lies in the difference in step (2). Step (2) is modified as follows: Dimethoxydimethylsilane, 2-(4-pyridylethyl)triethoxysilane, 1,3-di(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane and cation exchange resin IR120 are added to a 250mL three-necked flask and mixed in a molar ratio of 6:1:2:0.2. The mixture is then heated at 105℃. The hydroxyl-terminated polysiloxane was prepared by stirring at 300 rpm for 16 min under nitrogen protection. The hydroxyl-terminated polysiloxane, 1,4-butanediol, isophorone diisocyanate, and dibutyltin dilaurate were mixed in a mass ratio of 3:6:20:0.3 and stirred at 85°C for 3 h at 300 rpm under nitrogen protection. Then, 0.2 times the mass of 1,4-butanediol (adipylhydrazine) was added, and stirring continued for 9 h. The mixture was then dried at 85°C for 14 h to obtain the modified polyurethane elastomer. The remaining steps were the same as in Example 2.

[0026] Comparative Example 3: The difference between the preparation method of the high tensile strength anti-fatigue TPU blend material of Comparative Example 3 and Example 2 lies in the different step (2). Step (2) is modified as follows: hydroxyl-terminated polysiloxane, 1,4-butanediol, isophorone diisocyanate, and dibutyltin dilaurate are mixed in a mass ratio of 2.5:5:19:0.25 and stirred for 2.5 h at 80 °C, 250 r / min, and nitrogen protection. Then, 0.15 times the mass of 1,4-butanediol adipamide is added, and stirring is continued for 8 h. The mixture is then dried at 80 °C for 13 h to obtain the modified polyurethane elastomer. The remaining steps are the same as in Example 2.

[0027] Test Example 1: Mechanical and cyclic performance testing: Mechanical property testing: The blends prepared in each example and comparative example were pressed into 80mm*80mm*0.5mm sheets using a tablet press at 190℃ and 10MPa. The samples were then cut into specimens using a standard cutter according to GB / T528-2009. After being placed at room temperature for 12 hours, tensile strength and elongation at break were tested using a universal testing machine according to GB / T1040.3-2006. The tensile speed was 100mm / min, and the parallel dimensions of the tensile specimens were 10mm×2mm×0.5mm. The results are shown in Table 1.

[0028] Table 1

[0029] A comparison of the experimental data in Table 1 reveals that the high tensile strength and fatigue-resistant TPU blend material prepared by this invention exhibits excellent mechanical properties.

[0030] As can be seen from Examples 1, 2, and 3 in Table 1, the blend system of PEBAX and TPU provides the material with basic high tensile strength and high toughness. POE-g-MAH, as a compatibilizer, improves the interfacial bonding between the two phases. Nano-silica enhances the rigidity of the material through filling, but excessive addition will sacrifice mechanical properties. KH550, as a coupling agent, although it does not significantly improve tensile strength and toughness, can further enhance rigidity and alleviate some of the negative effects of nano-silica agglomeration. Overall, the core of performance regulation of this system lies in balancing the filling amount of nano-silica and the coupling effect of KH550 to achieve an optimized match between rigidity and toughness. At the same time, in the preparation of polyurethane, due to the presence of amide urea, its six hydrogen bonds can act as strong crosslinking sites, forming a hydrogen bond crosslinking network structure, which improves tensile strength.

[0031] Test Example 2: Self-healing test, flame retardancy and aging resistance test: The blends prepared in each embodiment and the comparative example were pressed into sheets of 80mm*80mm*0.5mm using a tablet press at 190°C and 10MPa. The tensile strength was recorded and denoted as N0. Self-healing test method: Make a transverse cut 0.4 cm long and 0.25 mm deep on the surface of the sample, let it stand at 70℃ for 24 h, test the tensile strength and record it as N1, and calculate the self-healing retention rate, where self-healing retention rate = N1 / N0 × 100%; Aging resistance test method: The sample is placed in distilled water at 70℃ for wet heat aging, left to stand for 96 hours, and the tensile strength is tested and recorded as N2. The antioxidant retention rate is calculated, where antioxidant retention rate = N2 / N0 × 100%; Flame retardancy test method: The limiting oxygen index was tested according to GB / T2406.2. The results are shown in Table 2.

[0032] Table 2

[0033] A comparison of the experimental data in Table 2 reveals that the high tensile strength anti-fatigue TPU blend material prepared by this invention has good self-healing, aging resistance and flame retardancy.

[0034] A comparison of the experimental data from Examples 1, 2, 3 and Comparative Example 1 in Table 2 reveals that Examples 1, 2, and 3 have higher limiting oxygen index and antioxidant retention rates. The difference between Comparative Example 1 and Examples 1, 2, and 3 is that the nano-silica was not modified. This indicates that phosphite was prepared by reacting phosphorus chloride with 4'-vinyl-[1,1'-biphenyl]-4-ol and p-phenylphenol. Under high temperature or flame conditions, the phosphite decomposes to generate phosphorus-containing free radicals. These free radicals can effectively capture highly active hydrogen and hydroxyl free radicals in the combustion chain reaction, interrupting the chain reaction and thus inhibiting flame propagation. At the same time, the formed phosphite structure has the effect of an antioxidant and can act as an auxiliary antioxidant in conjunction with antioxidant 1010 to extend the service life of the material. A comparison of the experimental data from Examples 1, 2, 3 and Comparative Example 2 reveals that Examples 1, 2, and 3 exhibit high self-healing retention rates. The difference between Comparative Example 2 and Examples 1, 2, and 3 lies in the absence of a pyridine-zinc coordination structure. This indicates that the monomers of the hydroxyl-terminated polysiloxane contain pyridine, which can form coordination bonds with zinc ions. After these bonds break, they are reconstructed under external stimuli, giving the material self-healing capabilities and achieving a self-repairing effect. A comparison of the experimental data from Examples 1, 2, 3 and Comparative Example 3 reveals that Examples 1, 2, and 3 have higher limiting oxygen indices. The difference between Comparative Example 3 and Examples 1, 2, and 3 is that the polyurethane does not contain polysiloxane. This indicates that polysiloxane undergoes an oxidative cross-linking reaction at high temperatures to form a carbon layer. This carbon layer has excellent thermal stability, oxidation resistance, and oxygen barrier properties, effectively preventing the escape of combustible gases and blocking the transfer of external heat to the interior of the material, thus achieving a flame-retardant effect.

[0035] Test Example 3: Cyclic test: Cyclic tensile test: Examples 1-3 were subjected to cyclic tensile tests, and the data for the 1st, 2nd, 3rd, 5th, 10th, 25th, 50th, 100th, 150th, and 200th cycles were recorded and plotted as curves. The results are shown in the attached figure.

[0036] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fatigue-resistant TPU blend material with high tensile strength, characterized in that, The high tensile strength anti-fatigue TPU blend material is prepared by mixing polyether amide elastomer and modified polyurethane elastomer, then mixing with compatibilizer, modified silica, antioxidant 1010, drying, mechanically mixing, and melt blending. The polyurethane elastomer is prepared by reacting hydroxyl-terminated polysiloxane, 1,4-butanediol, and isophorone diisocyanate, followed by reaction with adipamide hydrazine. The modified silica is prepared by reacting nano-silica sequentially with trimethoxysilane and phosphite antioxidant; The phosphite antioxidant is prepared by reacting phosphorus chloride with 4'-vinyl-[1,1'-biphenyl]-4-ol and p-phenylphenol.

2. A method for preparing a fatigue-resistant TPU blend material with high tensile strength, characterized in that, The preparation method of the high tensile strength fatigue-resistant TPU blend material mainly includes the following preparation steps: (1) Prepare a chloroplatinic acid solution with a concentration of 0.009~0.011 g / ml by mixing chloroplatinic acid with isopropanol; mix pre-modified silica, phosphite antioxidant, isopropanol and chloroplatinic acid solution, stir at 60~64℃ for 4~5 h, filter, wash with deionized water 4~6 times, and vacuum dry at 30~40℃ for 24~26 h to obtain modified silica; (2) Zinc perchlorate hexahydrate, methanol and dichloromethane are mixed evenly to prepare a zinc solution; hydroxyl-terminated polysiloxane, 1,4-butanediol, isophorone diisocyanate and dibutyltin dilaurate are mixed and stirred for 2-3 hours at 75-85℃, 200-300 r / min under nitrogen protection, and then 0.1-0.2 times the mass of 1,4-butanediol adipamide is added and stirred for 7-9 hours. After cooling to room temperature, the mixture is soaked in the zinc solution for 46-48 hours and dried at 75-85℃ for 12-14 hours to obtain a modified polyurethane elastomer; (3) Mix polyether amide elastomer and modified polyurethane elastomer evenly to obtain elastomer; mix elastomer, compatibilizer and modified silica according to the ratio, add 1wt% antioxidant 1010 to elastomer, and dry and mechanically mix in sequence to obtain premix; melt blend the premix to obtain blend material.

3. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The phosphite antioxidant mentioned in step (1) is prepared by mixing phosphorus chloride and chloroform at a mass ratio of 1:35-45 and sonicating for 4-6 minutes to obtain a phosphorus mixture; mixing 4'-vinyl-[1,1'-biphenyl]-4-ol, p-phenylphenol and chloroform at a mass ratio of 1:2:40-50 and stirring at 200-300 r / min for 2-3 minutes; adding triethylamine at a molar amount of 1-1.2 times that of 4'-vinyl-[1,1'-biphenyl]-4-ol and stirring for another 2-3 minutes; heating to 65-75°C and uniformly adding the phosphorus mixture corresponding to an equimolar amount of phosphorus chloride of 4'-vinyl-[1,1'-biphenyl]-4-ol over 14-16 minutes; stirring for another 4-5 hours; vacuum drying at 60-70°C for 10-12 hours; washing with deionized water 4-5 times; and vacuum drying again at 60-70°C for 10-12 hours to obtain the final product.

4. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The pre-modified silica mentioned in step (1) is prepared by mixing trimethoxysilane, ethanol, deionized water and nano silica in a mass ratio of 1:7-8:2-3:1, sonicating for 20-30 min, adjusting the pH to 4-5 with 0.1 mol / L hydrochloric acid aqueous solution, heating to 45-55℃, stirring at 300-400 r / min for 5-7 h, filtering, washing with deionized water 6-8 times, and vacuum drying at 60-70℃ for 10-12 h.

5. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The hydroxyl-terminated polysiloxane described in step (2) is prepared by adding dimethoxydimethylsilane, 2-(4-pyridylethyl)triethoxysilane, 1,3-di(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane and cation exchange resin IR120 to a 250 mL three-necked flask, mixing them in a molar ratio of 4-6:1:1-2:0.1-0.2, and stirring for 15-16 min at 95-105 °C, 200-300 r / min, under nitrogen protection.

6. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The specific process of drying in step (3) is as follows: vacuum drying at 80~100℃ for 6~8h.

7. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The amount of compatibilizer added is 5 wt% of the elastomer.

8. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The amount of modified silica added is 1 wt% to 9 wt% of the elastomer.

9. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 7, characterized in that, The compatibilizer includes one or more of POE-g-MAH, POE-g-GMA, and SEBA-g-MAH.

10. The method for preparing a fatigue-resistant TPU blend material with high tensile strength according to claim 2, characterized in that, The specific parameters for melt blending in step (3) are: screw speed of 40~60 rpm, temperature of 170~190℃, and melt blending time of 10 min.

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