High-temperature-resistant TPU material and preparation method thereof

Abstract

The application discloses a kind of high-temperature-resistant TPU materials and preparation method thereof, it is related to high polymer material technical field.The application when preparing high-temperature-resistant TPU material, polyether dihydric alcohol, toluene-2, 4-diisocyanate prepolymerization is used with soybean glycitein dianhydride monomer chain extension and is obtained functional polyurethane;Polyphosphazene microspheres, 4-allyl-2, 6-di-tert-butyl phenol reaction and are obtained modified polyphosphazene microspheres;Nanometer calcium carbonate is sequentially reacted with chloropropyl triethoxysilane, 3-hydroxy-beta-ionone and is obtained modified nanometer calcium carbonate;Functional polyurethane, modified polyphosphazene microspheres, modified nanometer calcium carbonate are mixed evenly, and extrusion molding is obtained high-temperature-resistant TPU material.The high-temperature-resistant TPU material prepared by the application has excellent high-temperature resistance, flame retardant and anti-aging performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a high-temperature-resistant TPU material and a preparation method thereof. BACKGROUND

[0002] As an important part of the high polymer material field, thermoplastic polyurethane has been widely used in high-end fields such as aerospace, construction, new energy vehicle manufacturing and electronic devices since its first synthesis, due to its special structure of soft and hard segments and many advantages such as high elasticity, low temperature resistance, wear resistance, recyclability and processability. In recent years, with the rapid development of the new energy vehicle field and the electronic and electrical industry, the market of thermoplastic polyurethane is becoming more and more open, and has broad development space. However, thermoplastic polyurethane is still limited by its major defects of flammability, easy aging and poor thermal stability.

[0003] When thermoplastic polyurethane is at a temperature above 80℃ for a long time, some main mechanical properties such as modulus and strength will decrease, and when the processing temperature reaches or exceeds 200℃, the polyurethane will undergo thermal degradation, which cannot meet the requirements of high-temperature-resistant materials. The limiting oxygen index value LOI of thermoplastic polyurethane is only 17%~19%, which belongs to flammable materials, and a large amount of toxic gases will be released during combustion, threatening people's life and property safety, so it is abandoned in many application fields. The urethane bond and ether bond in thermoplastic polyurethane are sensitive to ultraviolet light, and long-term exposure will cause photo-oxidation reaction, leading to molecular chain rupture and structure damage, which finally manifests as surface powdering, cracking and decrease of mechanical properties.

[0004] In view of the problems existing in thermoplastic polyurethane, a thermoplastic polyurethane material with anti-aging, flame-retardant and high-temperature-resistant properties is invented to improve the comprehensive performance of thermoplastic polyurethane and meet the growing market demand. SUMMARY

[0005] The present application aims to provide a high-temperature-resistant TPU material and a preparation method thereof to solve the problems in the prior art.

[0006] To solve the above technical problems, the present application provides the following technical scheme:

[0007] A high-temperature-resistant TPU material is prepared by pre-polymerizing polyether diol and toluene-2,4-diisocyanate, and then chain extending with soybean genin dianhydride monomer to obtain functionalized polyurethane; modifying polyphosphazene microspheres by reacting polyphosphazene microspheres and 4-allyl-2,6-di-tert-butyl phenol to obtain modified polyphosphazene microspheres; modifying nano calcium carbonate by reacting pre-modified nano calcium carbonate and 3-hydroxy-beta-ionone to obtain modified nano calcium carbonate; and mixing the functionalized polyurethane, the modified polyphosphazene microspheres and the modified nano calcium carbonate uniformly, and then extruding and molding to obtain the high-temperature-resistant TPU material.

[0008] The daidzein dianhydride monomer is prepared by reacting daidzein and phthalic anhydride-4-formyl chloride;

[0009] The polyphosphazene microspheres are prepared by reacting hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol;

[0010] The pre-modified nano calcium carbonate is prepared by reacting nano calcium carbonate and chloropropyl triethoxysilane.

[0011] A preparation method of a high-temperature-resistant TPU material, comprising the following preparation steps:

[0012] (1) A polyether diol, daidzein dianhydride monomer, and toluene-2,4-diisocyanate are weighed according to a molar ratio of 1:(0.5-0.6):(1.8-2.0); the daidzein dianhydride monomer and N,N-dimethylformamide are mixed uniformly according to a mass ratio of 1:(5-6) to prepare a dianhydride solution; the polyether diol and N,N-dimethylformamide are mixed uniformly according to a mass ratio of 1:(8-10), heated to 70-80°C, and then toluene-2,4-diisocyanate and 0.04-0.06 times the mass of the polyether diol of dibutyltin dilaurate are sequentially added under a nitrogen atmosphere, and stirred at 70-80°C and 200-300 r / min for 50-60 min; the dianhydride solution is added, and stirring is continued at 75-85°C for 1-2 h; the temperature is raised to 110°C, and stirring is continued for 2-3 h; and drying is performed under vacuum at 60-70°C for 18-20 h to obtain a functional polyurethane;

[0013] (2) The polyphosphazene microspheres, 4-allyl-2,6-di-tert-butylphenol, and N,N-dimethylformamide are mixed uniformly according to a mass ratio of 1:(3-4):(20-30), 0.06-0.08 times the mass of the polyphosphazene microspheres of azobisisobutyronitrile is added, stirring is performed at 70-80°C and 300-500 r / min for 4-5 h, filtration is performed, washing is performed with anhydrous ethanol 5 times, and drying is performed under vacuum at 50-60°C for 18-20 h to obtain modified polyphosphazene microspheres;

[0014] (3) The pre-modified nano calcium carbonate, 3-hydroxy-β-ionone, triethylamine, and N,N-dimethylformamide are mixed uniformly according to a mass ratio of 1:(3-4):(0.1-0.2):(20-30), stirring is performed at 55-65°C and 300-500 r / min for 5-6 h, filtration is performed, washing is performed with anhydrous ethanol and deionized water 3 times each, and drying is performed under vacuum at 60-70°C for 16-18 h to obtain modified nano calcium carbonate;

[0015] (4) by mass parts, take 98~100 parts of functional polyurethane, 5~6 parts of modified polyphosphazene microspheres, 4~5 parts of modified nano calcium carbonate; the functional polyurethane, modified polyphosphazene microspheres, modified nano calcium carbonate are mixed uniformly, placed in the extruder, the extrusion temperature is 190~210℃, the screw rotation speed is 20~30r / min, and the high temperature resistant TPU material is prepared.

[0016] As an optimization, the type of polyether diol in step (1) is PPG-1000.

[0017] As an optimization, the preparation method of the daidzein dianhydride monomer in step (1) is: daidzein, phthalic anhydride-4-formyl chloride are added to toluene with a mass of 20~30 times of daidzein, and pyridine with a mass of 0.06~0.08 times of daidzein is added, stirring at room temperature at 300~500r / min for 60~70min, heating to 100~110℃, continuing to stir under nitrogen atmosphere for 4~5h, drying at 55~65℃ under vacuum for 10~12h, and obtaining daidzein dianhydride monomer; the reaction mechanism is as follows:

[0018] .

[0019] As an optimization, the preparation method of the polyphosphazene microspheres in step (2) is: mix hexachlorocyclotriphosphazene and acetonitrile uniformly in a mass ratio of 1:(50~60), ultrasonic at room temperature for 1~2h, add 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine with a molar amount of 1~1.2 times of hexachlorocyclotriphosphazene, add 2-(mercaptomethyl)benzene-1,4-diol with a molar amount of 0.7~0.8 times of hexachlorocyclotriphosphazene, continue to ultrasonic for 10~20min, add triethylamine with a mass of 0.06~0.08 times of hexachlorocyclotriphosphazene, stir at 30~40℃ at 200~300r / min for 5~6h, naturally cool to room temperature, stand for 6~8h, filter, wash with anhydrous ethanol and deionized water for 3 times respectively, dry at 50~60℃ under vacuum for 12~14h, and obtain polyphosphazene microspheres.

[0020] As an optimization, the CAS number of the 2-(mercaptomethyl)benzene-1,4-diol is 5273-75-6; the structural formula is: .

[0021] As an optimization, the preparation method of the pre-modified nano-calcium carbonate in step (3) is as follows: nano-calcium carbonate and anhydrous ethanol are mixed evenly at a mass ratio of 1:(60~70), and ultrasonicated at room temperature for 1~2h. Chloropropyltriethoxysilane with a mass of 5~6 times that of nano-calcium carbonate is added, the temperature is raised to 70~80℃, and ultrasonication is continued for 8~10min. Oxalic acid aqueous solution with a concentration of 1mol / L with a mass of 7~8 times that of nano-calcium carbonate is added dropwise at a uniform rate within 10min. After the addition is completed, the reaction is stirred for 3~4h. The mixture is filtered, washed 3 times each with anhydrous ethanol and deionized water, and dried at 60~70℃ for 10~12h under vacuum conditions to obtain pre-modified nano-calcium carbonate.

[0022] As an optimization, the CAS number of the 3-hydroxy-β-ionone in step (3) is 116296-75-4; the structural formula is: .

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0024] In preparing high-temperature resistant TPU materials, this invention involves reacting daidzein and phthalic anhydride-4-formyl chloride to obtain daidzein dianhydride monomer; prepolymerizing polyether diol and toluene-2,4-diisocyanate, and then extending the chain with daidzein dianhydride monomer to obtain functionalized polyurethane; reacting hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol to obtain polyphosphazene microspheres; reacting the polyphosphazene microspheres with 4-allyl-2,6-di-tert-butylphenol to obtain modified polyphosphazene microspheres; reacting nano-calcium carbonate sequentially with chloropropyltriethoxysilane and 3-hydroxy-β-ionone to obtain modified nano-calcium carbonate; and mixing the functionalized polyurethane, modified polyphosphazene microspheres, and modified nano-calcium carbonate uniformly, followed by extrusion molding to obtain the high-temperature resistant TPU material.

[0025] First, daidzein and phthalic anhydride-4-formyl chloride are reacted to prepare daidzein dianhydride monomer; polyether diol and toluene-2,4-diisocyanate are prepolymerized, and then the daidzein dianhydride monomer is used for chain extension to prepare functionalized polyurethane; imide groups and daidzein are introduced into the main chain of functionalized polyurethane; the introduction of imide groups can improve the high-temperature resistance of high-temperature resistant TPU materials, and daidzein contains deoxybenzoin structure, which has a high carbon-forming ability, enabling the material to form a dense char layer structure during combustion, thereby improving the flame retardant properties of high-temperature resistant TPU materials.

[0026] Secondly, polyphosphazene microspheres were prepared by reacting hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol, resulting in polyphosphazene microspheres containing a cyclotriphosphazene skeleton, a pyromellitic triazine structure, and thiol groups. The thiol groups on the polyphosphazene microspheres were then reacted with the carbon-carbon double bonds on 4-allyl-2,6-di-tert-butylphenol to prepare modified polyphosphazene microspheres. A 2,6-di-tert-butylphenol structure was then grafted onto the modified polyphosphazene microspheres. The pyromellitic triazine structure can improve the flame retardancy and high-temperature resistance of high-temperature resistant TPU materials, while the cyclotriphosphazene skeleton can improve the flame retardancy. The grafted 2,6-di-tert-butylphenol structure is a hindered phenolic light stabilizer, which can delay photoaging of materials and improve the anti-aging properties of high-temperature resistant TPU materials by capturing free radicals and interrupting the oxidation chain reaction.

[0027] Finally, pre-modified nano-calcium carbonate was prepared by reacting nano-calcium carbonate with chloropropyltriethoxysilane, and chlorine atoms were introduced onto the pre-modified nano-calcium carbonate. The chlorine atoms introduced onto the pre-modified nano-calcium carbonate were then reacted with the hydroxyl groups on 3-hydroxy-β-ionone to prepare modified nano-calcium carbonate, and a β-ionone structure was introduced onto the modified nano-calcium carbonate. The β-ionone structure has photoisomerization, changing from the trans conformation to the cis conformation under ultraviolet light and returning to the trans conformation under light-shielded conditions. This reversible cis-trans isomerization gives β-ionone the property of ultraviolet absorption, converting ultraviolet light energy into chemical energy, thereby improving the anti-aging performance of high-temperature resistant TPU materials. Adding nano-calcium carbonate to polyurethane can improve the dimensional stability and heat resistance of the material, thereby improving the high-temperature resistance of high-temperature resistant TPU materials. Detailed Implementation

[0028] 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.

[0029] Example 1: A method for preparing a high-temperature resistant TPU material, the method comprising the following preparation steps:

[0030] (1) Add daidzein and phthalic anhydride-4-formyl chloride to toluene at a molar ratio of 1:2, which is 20 times the mass of daidzein. Add pyridine at a molar ratio of 0.06 times the mass of daidzein. Stir at 300 r / min for 70 min at room temperature, raise the temperature to 100 °C, and continue stirring for 5 h under a nitrogen atmosphere. Dry at 55 °C for 12 h under vacuum to obtain daidzein dianhydride monomer. Weigh polyether diol, daidzein dianhydride monomer, and toluene-2,4-diisocyanate in a molar ratio of 1:0.5:1.8. Add daidzein dianhydride monomer, N, N-Dimethylformamide was mixed evenly at a mass ratio of 1:5 to prepare a dianhydride solution. Polyether diol and N,N-Dimethylformamide were mixed evenly at a mass ratio of 1:8 and heated to 70°C. Under a nitrogen atmosphere, toluene-2,4-diisocyanate and dibutyltin dilaurate (0.04 times the mass of polyether diol) were added sequentially. The mixture was stirred at 70°C and 200 r / min for 60 min. The dianhydride solution was added, and the mixture was stirred at 75°C for 2 h. The temperature was raised to 110°C, and the mixture was stirred for 3 h. The mixture was dried at 60°C under vacuum for 20 h to obtain the functionalized polyurethane.

[0031] (2) Mix hexachlorocyclotriphosphazene and acetonitrile at a mass ratio of 1:50, sonicate at room temperature for 1 h, add 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine at a molar weight of 1 times that of hexachlorocyclotriphosphazene, add 2-(mercaptomethyl)benzene-1,4-diol at a molar weight of 0.7 times that of hexachlorocyclotriphosphazene, continue sonicating for 10 min, add triethylamine at a mass weight of 0.06 times that of hexachlorocyclotriphosphazene, stir at 30℃ and 200 r / min for 6 h, cool naturally to room temperature, let stand for 6 h, and filter. The polyphosphazene microspheres were prepared by washing the microspheres three times each with anhydrous ethanol and deionized water, and drying them at 50°C for 14 hours under vacuum. The polyphosphazene microspheres, 4-allyl-2,6-di-tert-butylphenol, and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:3:20. Azobisisobutyronitrile (AIB) was added at 0.06 times the mass of the polyphosphazene microspheres. The mixture was stirred at 70°C and 300 r / min for 5 hours. After filtration, the microspheres were washed five times with anhydrous ethanol and dried at 50°C for 20 hours under vacuum to obtain modified polyphosphazene microspheres.

[0032] (3) Mix nano-calcium carbonate and anhydrous ethanol at a mass ratio of 1:60, sonicate at room temperature for 1 h, add chloropropyltriethoxysilane at a mass ratio of 5 times that of nano-calcium carbonate, heat to 70 °C, continue sonicating for 10 min, and add oxalic acid aqueous solution at a concentration of 1 mol / L at a uniform rate at a mass ratio of 7 times that of nano-calcium carbonate within 10 min. After the addition is complete, continue stirring and reacting for 4 h, filter, wash with anhydrous ethanol and deionized water 3 times each, and dry at 60 °C for 12 h under vacuum to obtain pre-modified nano-calcium carbonate; mix pre-modified nano-calcium carbonate, 3-hydroxy-β-ionone, triethylamine, and N,N-dimethylformamide at a mass ratio of 1:3:0.1:20, stir and react at 55 °C and 300 r / min for 6 h, filter, wash with anhydrous ethanol and deionized water 3 times each, and dry at 60 °C for 18 h under vacuum to obtain modified nano-calcium carbonate;

[0033] (4) Weigh 98 parts of functionalized polyurethane, 5 parts of modified polyphosphazene microspheres, and 4 parts of modified nano-calcium carbonate by mass. Mix the functionalized polyurethane, modified polyphosphazene microspheres, and modified nano-calcium carbonate evenly, place them in an extruder for extrusion molding, and extrude at a temperature of 190°C and a screw speed of 20 r / min to obtain high-temperature resistant TPU material.

[0034] Implementation 2: A method for preparing a high-temperature resistant TPU material, the method comprising the following preparation steps:

[0035] (1) Add daidzein and phthalic anhydride-4-carboxyl chloride in a molar ratio of 1:2 to 25 times the mass of daidzein in toluene, add 0.07 times the mass of daidzein in pyridine, stir at 400 r / min for 65 min at room temperature, raise the temperature to 105 °C, continue stirring for 4.5 h under a nitrogen atmosphere, and dry at 60 °C for 11 h under vacuum to obtain daidzein dianhydride monomer; weigh polyether diol, daidzein dianhydride monomer, and toluene-2,4-diisocyanate in a molar ratio of 1:0.55:1.9; add daidzein dianhydride monomer, N,N- Dimethylformamide was mixed evenly at a mass ratio of 1:5.5 to prepare a dianhydride solution. Polyether diol and N,N-dimethylformamide were mixed evenly at a mass ratio of 1:9 and heated to 75°C. Under a nitrogen atmosphere, toluene-2,4-diisocyanate and dibutyltin dilaurate (0.05 times the mass of polyether diol) were added sequentially. The mixture was stirred at 250 r / min for 55 min at 75°C. The dianhydride solution was added, and the mixture was stirred and reacted at 80°C for 1.5 h. The temperature was raised to 110°C, and the mixture was stirred and reacted for 2.5 h. The mixture was dried at 65°C under vacuum for 19 h to obtain the functionalized polyurethane.

[0036] (2) Mix hexachlorocyclotriphosphazene and acetonitrile at a mass ratio of 1:55 until homogeneous, sonicate at room temperature for 1.5 h, add 1.1 times the molar amount of 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine of hexachlorocyclotriphosphazene, add 0.75 times the molar amount of 2-(mercaptomethyl)benzene-1,4-diol of hexachlorocyclotriphosphazene, continue sonicating for 15 min, add 0.07 times the molar amount of triethylamine of hexachlorocyclotriphosphazene, stir at 35℃ and 250 r / min for 5.5 h, cool naturally to room temperature, let stand for 7 h, and strain. The mixture was filtered, washed three times each with anhydrous ethanol and deionized water, and dried at 55°C for 13 hours under vacuum to obtain polyphosphazene microspheres. Polyphosphazene microspheres, 4-allyl-2,6-di-tert-butylphenol, and N,N-dimethylformamide were mixed uniformly at a mass ratio of 1:3.5:25. Azobisisobutyronitrile (AIB) was added at 0.07 times the mass of the polyphosphazene microspheres, and the mixture was stirred at 75°C and 400 r / min for 4.5 hours. The mixture was then filtered, washed five times with anhydrous ethanol, and dried at 55°C for 19 hours under vacuum to obtain modified polyphosphazene microspheres.

[0037] (3) Mix nano-calcium carbonate and anhydrous ethanol at a mass ratio of 1:65, sonicate at room temperature for 1.5 h, add chloropropyltriethoxysilane at a mass ratio of 5.5 times that of nano-calcium carbonate, heat to 75 °C, continue sonication for 9 min, and add oxalic acid aqueous solution at a concentration of 1 mol / L at a uniform rate at a mass ratio of 7.5 times that of nano-calcium carbonate within 10 min. After the addition is complete, continue stirring and reacting for 3.5 h, filter, wash with anhydrous ethanol and deionized water 3 times each, and dry at 65 °C for 11 h under vacuum to obtain pre-modified nano-calcium carbonate; mix pre-modified nano-calcium carbonate, 3-hydroxy-β-ionone, triethylamine, and N,N-dimethylformamide at a mass ratio of 1:3.5:0.15:25, stir and react at 60 °C and 400 r / min for 5.5 h, filter, wash with anhydrous ethanol and deionized water 3 times each, and dry at 65 °C for 17 h under vacuum to obtain modified nano-calcium carbonate;

[0038] (4) Weigh 99 parts of functionalized polyurethane, 5.5 parts of modified polyphosphazene microspheres, and 4.5 parts of modified nano-calcium carbonate by mass. Mix the functionalized polyurethane, modified polyphosphazene microspheres, and modified nano-calcium carbonate evenly, place them in an extruder and extrude them. The extrusion temperature is 200℃ and the screw speed is 25r / min to obtain high-temperature resistant TPU material.

[0039] Example 3: A method for preparing a high-temperature resistant TPU material, the method comprising the following preparation steps:

[0040] (1) Add daidzein and phthalic anhydride-4-formyl chloride to toluene at a molar ratio of 1:2, which is 30 times the mass of daidzein. Add pyridine at a molar ratio of 0.08 times the mass of daidzein. Stir at 500 r / min for 70 min at room temperature, raise the temperature to 110 °C, and continue stirring for 4 h under a nitrogen atmosphere. Dry at 65 °C for 10 h under vacuum to obtain daidzein dianhydride monomer. Weigh polyether diol, daidzein dianhydride monomer, and toluene-2,4-diisocyanate in a molar ratio of 1:0.6:2.0. Add daidzein dianhydride monomer, N,N N,N-Dimethylformamide was mixed uniformly at a mass ratio of 1:6 to prepare a dianhydride solution; polyether diol and N,N-dimethylformamide were mixed uniformly at a mass ratio of 1:10, heated to 80°C, and under a nitrogen atmosphere, toluene-2,4-diisocyanate and dibutyltin dilaurate (0.06 times the mass of polyether diol) were added sequentially. The mixture was stirred at 300 r / min for 50 min at 80°C, the dianhydride solution was added, and the mixture was stirred at 85°C for 1 h. The temperature was raised to 110°C and the mixture was stirred for 3 h. The mixture was dried at 70°C under vacuum for 18 h to obtain the functionalized polyurethane.

[0041] (2) Mix hexachlorocyclotriphosphazene and acetonitrile at a mass ratio of 1:60, sonicate at room temperature for 2 hours, add 1.2 times the molar amount of 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine and 0.8 times the molar amount of 2-(mercaptomethyl)benzene-1,4-diol, continue sonicating for 20 minutes, add 0.08 times the molar amount of triethylamine, stir at 300 r / min for 5 hours at 40°C, cool naturally to room temperature, let stand for 8 hours, and strain. The mixture was filtered, washed three times each with anhydrous ethanol and deionized water, and dried at 60°C for 12 hours under vacuum to obtain polyphosphazene microspheres. The polyphosphazene microspheres, 4-allyl-2,6-di-tert-butylphenol, and N,N-dimethylformamide were mixed uniformly at a mass ratio of 1:4:30. Azobisisobutyronitrile (AIB) was added at 0.08 times the mass of the polyphosphazene microspheres, and the mixture was stirred at 80°C and 500 r / min for 4 hours. The mixture was then filtered, washed five times with anhydrous ethanol, and dried at 60°C for 18 hours under vacuum to obtain modified polyphosphazene microspheres.

[0042] (3) Mix nano-calcium carbonate and anhydrous ethanol at a mass ratio of 1:70, sonicate at room temperature for 2 hours, add chloropropyltriethoxysilane at a mass ratio of 6 times that of nano-calcium carbonate, heat to 80°C, continue sonicating for 8 minutes, and add oxalic acid aqueous solution at a concentration of 1 mol / L at a uniform rate at a mass ratio of 8 times that of nano-calcium carbonate within 10 minutes. After the addition is complete, continue stirring and reacting for 3 hours, filter, wash with anhydrous ethanol and deionized water 3 times each, and dry at 70°C for 10 hours under vacuum to obtain pre-modified nano-calcium carbonate; mix pre-modified nano-calcium carbonate, 3-hydroxy-β-ionone, triethylamine, and N,N-dimethylformamide at a mass ratio of 1:4:0.2:30, stir and react at 65°C and 500 r / min for 5 hours, filter, wash with anhydrous ethanol and deionized water 3 times each, and dry at 70°C for 16 hours under vacuum to obtain modified nano-calcium carbonate;

[0043] (4) Weigh 100 parts of functionalized polyurethane, 6 parts of modified polyphosphazene microspheres, and 5 parts of modified nano-calcium carbonate by mass. Mix the functionalized polyurethane, modified polyphosphazene microspheres, and modified nano-calcium carbonate evenly, place them in an extruder and extrude them. The extrusion temperature is 210℃ and the screw speed is 30r / min to obtain high-temperature resistant TPU material.

[0044] Comparative Example 1:

[0045] The difference between the preparation method of the high-temperature resistant TPU material in Comparative Example 1 and Example 2 lies in the different step (1). Step (1) is modified as follows: Weigh polyether diol, 1,4-butanediol, and toluene-2,4-diisocyanate in a molar ratio of 1:0.55:1.9; mix 1,4-butanediol and N,N-dimethylformamide in a mass ratio of 1:5.5 to prepare a butanediol solution; mix polyether diol and N,N-dimethylformamide... The mixture was thoroughly mixed at a mass ratio of 1:9, heated to 75°C, and under a nitrogen atmosphere, toluene-2,4-diisocyanate and dibutyltin dilaurate (0.05 times the mass of polyether diol) were added sequentially. The mixture was stirred at 250 rpm for 55 min at 75°C. A butanediol solution was then added, and the mixture was stirred at 80°C for 1.5 h. The temperature was then raised to 110°C, and the mixture was stirred for another 2.5 h. The mixture was then dried at 65°C under vacuum for 19 h to obtain the functionalized polyurethane. The remaining steps were the same as in Example 2.

[0046] Comparative Example 2:

[0047] The difference between the preparation method of the high-temperature resistant TPU material in Comparative Example 2 and Example 2 lies in step (2). Step (2) is modified as follows: Hexachlorocyclotriphosphazene and acetonitrile are mixed evenly at a mass ratio of 1:60, and sonicated at room temperature for 2 hours. Then, 1.2 times the molar amount of 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine and 0.8 times the molar amount of 2-(mercaptomethyl)benzene-1,4-diol are added. The mixture is sonicated for another 20 minutes. Then, 0.08 times the mass of triethylamine is added. The mixture is stirred at 300 r / min at 40°C for 5 hours, naturally cooled to room temperature, and allowed to stand for 8 hours. The mixture is then filtered, washed three times each with anhydrous ethanol and deionized water, and dried at 60°C for 12 hours under vacuum to obtain modified polyphosphazene microspheres. The remaining steps are the same as in Example 2.

[0048] Comparative Example 3:

[0049] The preparation method of the high-temperature resistant TPU material in Comparative Example 3 differs from that in Example 2 in that step (2) is omitted, and step (4) is modified as follows: 99 parts of functionalized polyurethane and 4.5 parts of modified nano-calcium carbonate are weighed by mass; the functionalized polyurethane and modified nano-calcium carbonate are mixed evenly and extruded in an extruder at a temperature of 200°C and a screw speed of 25 r / min to obtain the high-temperature resistant TPU material. The remaining steps are the same as in Example 2.

[0050] Comparative Example 4:

[0051] The preparation method of the high-temperature resistant TPU material in Comparative Example 4 differs from that in Example 2 in that step (3) is omitted, and step (4) is modified as follows: 99 parts by mass of functionalized polyurethane, 5.5 parts by mass of modified polyphosphazene microspheres, and 4.5 parts by mass of nano-calcium carbonate are weighed; the functionalized polyurethane, modified polyphosphazene microspheres, and nano-calcium carbonate are mixed evenly and extruded in an extruder at a temperature of 200°C and a screw speed of 25 r / min to obtain the high-temperature resistant TPU material. The remaining steps are the same as in Example 2.

[0052] Comparative Example 5:

[0053] The preparation method of the high-temperature resistant TPU material in Comparative Example 5 differs from that in Example 2 in that step (3) is omitted, and step (4) is modified as follows: 99 parts by mass of functionalized polyurethane and 5.5 parts by mass of modified polyphosphazene microspheres are weighed; the functionalized polyurethane and modified polyphosphazene microspheres are mixed evenly and extruded in an extruder at a temperature of 200°C and a screw speed of 25 r / min to obtain the high-temperature resistant TPU material. The remaining steps are the same as in Example 2.

[0054] Test Example 1

[0055] High temperature resistance test

[0056] Test method: The thermal stability of the sample was tested using a Q50 thermogravimetric analyzer from TA Instruments (USA). 5 mg of sample was placed in a crucible under a nitrogen atmosphere. The temperature was increased from 30℃ to 600℃ at a rate of 10℃ / min. The 5% thermogravimetric temperature T of the sample was recorded. 5% and the 10% thermogravimetric temperature T of the sample 10% The results are shown in Table 1.

[0057] Table 1

[0058]

[0059] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 1 reveals that the high-temperature resistant TPU material prepared by this invention has excellent high-temperature resistance.

[0060] By comparison, the 5% and 10% thermogravimetric temperatures of Examples 1-3 are all greater than those of Comparative Example 1, indicating that the daidzein dianhydride monomer is prepared by reacting daidzein and phthalic anhydride-4-formyl chloride; the functionalized polyurethane is prepared by prepolymerizing polyether diol and toluene-2,4-diisocyanate, and then chain-extending with the daidzein dianhydride monomer; and the imide groups are introduced into the main chain of the functionalized polyurethane. The introduction of imide groups can improve the high-temperature resistance of the high-temperature resistant TPU material.

[0061] By comparison, the 5% and 10% thermal weight loss temperatures of Examples 1-3 are all greater than those of Comparative Example 3, indicating that the reaction of hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol to prepare polyphosphazene microspheres results in the presence of a pyromellitic triazine structure in the polyphosphazene microspheres. The pyromellitic triazine structure can improve the flame retardancy and high-temperature resistance of high-temperature resistant TPU materials.

[0062] By comparison, the 5% and 10% thermal weight loss temperatures of Examples 1-3 are all greater than those of Comparative Example 5, indicating that adding nano-calcium carbonate to polyurethane can improve the dimensional stability and heat resistance of the material, thereby improving the high-temperature resistance of the high-temperature resistant TPU material.

[0063] Test Example 2

[0064] Flame retardant performance testing

[0065] Test method: Standard samples were prepared according to GB / T2406-93 for the examples and comparative examples, and the limiting oxygen index of the standard samples was tested. The results are shown in Table 2.

[0066] Table 2

[0067]

[0068] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 2 reveals that the high-temperature resistant TPU material prepared by this invention has good flame retardant properties.

[0069] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 1, indicating that the daidzein dianhydride monomer is prepared by reacting daidzein and phthalic anhydride-4-formyl chloride; the functionalized polyurethane is prepared by prepolymerizing polyether diol and toluene-2,4-diisocyanate and then extending the chain with daidzein dianhydride monomer; and the introduction of daidzein into the main chain of the functionalized polyurethane, which contains deoxybenzoin structure and has a high char-forming ability, enables the material to form a dense char layer structure during combustion, thereby improving the flame retardant performance of the high-temperature resistant TPU material.

[0070] By comparison, the limiting oxygen index of Examples 1-3 is greater than that of Comparative Example 3, indicating that the reaction of hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol to prepare polyphosphazene microspheres results in polyphosphazene microspheres containing a cyclotriphosphazene skeleton and a pyromellitic triazine structure; the pyromellitic triazine structure and the cyclotriphosphazene skeleton can improve the flame retardant properties of high-temperature resistant TPU materials.

[0071] Test Example 3

[0072] Anti-aging performance test

[0073] Test method: Prepare standard specimens according to GB / T1040.3 for the examples and comparative examples. Test the tensile strength M of the standard specimens on an electronic universal testing machine. Irradiate the standard specimens under a UV lamp with a power of 200W and a wavelength of 365nm for 15 days. After the irradiation, test their tensile strength N. Calculate the performance retention rate of the standard specimens after UV aging. Performance retention rate = (N / M) × 100%. The results are shown in Table 3.

[0074] Table 3

[0075]

[0076] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-5 in Table 3 reveals that the high-temperature resistant TPU material prepared by this invention has good anti-aging properties.

[0077] By comparison, the performance retention rates of Examples 1-3 were greater than those of Comparative Examples 2-3, indicating that the polyphosphazene microspheres prepared by reacting hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol contain thiol groups. Modified polyphosphazene microspheres were prepared by reacting the thiol groups on the polyphosphazene microspheres with the carbon-carbon double bonds on 4-allyl-2,6-di-tert-butylphenol. A 2,6-di-tert-butylphenol structure was then grafted onto the modified polyphosphazene microspheres. The grafted 2,6-di-tert-butylphenol structure is a hindered phenolic light stabilizer, which can delay the photoaging of materials and improve the anti-aging performance of high-temperature resistant TPU materials by capturing free radicals and interrupting the oxidation chain reaction.

[0078] By comparison, the performance retention rates of Examples 1-3 were greater than those of Comparative Examples 4-5, indicating that pre-modified nano-calcium carbonate was prepared by reacting nano-calcium carbonate with chloropropyltriethoxysilane, and chlorine atoms were introduced onto the pre-modified nano-calcium carbonate. The chlorine atoms introduced onto the pre-modified nano-calcium carbonate were then reacted with the hydroxyl groups on 3-hydroxy-β-ionone to prepare modified nano-calcium carbonate, and a β-ionone structure was introduced onto the modified nano-calcium carbonate. The β-ionone structure has a photoisomerization effect, changing from the trans conformation to the cis conformation under ultraviolet light and returning to the trans conformation under light-shielded conditions. This reversible cis-trans isomerization gives β-ionone the property of ultraviolet absorption, converting ultraviolet light energy into chemical energy, thereby improving the anti-aging performance of high-temperature resistant TPU materials.

[0079] 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 high-temperature resistant TPU material, characterized in that, The high-temperature resistant TPU material is prepared by prepolymerizing polyether diol and toluene-2,4-diisocyanate, followed by chain extension with soybean dianhydride monomer to obtain functionalized polyurethane; by reacting polyphosphazene microspheres with 4-allyl-2,6-di-tert-butylphenol to obtain modified polyphosphazene microspheres; by reacting pre-modified nano-calcium carbonate with 3-hydroxy-β-ionone to obtain modified nano-calcium carbonate; and by uniformly mixing the functionalized polyurethane, modified polyphosphazene microspheres, and modified nano-calcium carbonate, followed by extrusion molding. The daidzein dianhydride monomer is prepared by reacting daidzein with phthalic anhydride-4-formyl chloride. The polyphosphazene microspheres were prepared by reacting hexachlorocyclotriphosphazene, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine, and 2-(mercaptomethyl)benzene-1,4-diol. The pre-modified nano-calcium carbonate is prepared by reacting nano-calcium carbonate with chloropropyltriethoxysilane.

2. A method for preparing a high-temperature resistant TPU material, characterized in that, The preparation method of the high-temperature resistant TPU material includes the following preparation steps: (1) Mix soybean aglycone dianhydride monomer and N,N-dimethylformamide evenly to prepare a dianhydride solution; mix polyether diol and N,N-dimethylformamide evenly, heat to 70~80℃, add toluene-2,4-diisocyanate and dibutyltin dilaurate in sequence under nitrogen atmosphere, react at 70~80℃ for 50~60min, add dianhydride solution, continue to react at 75~85℃ for 1~2h, raise the temperature to 110℃, continue to react for 2~3h to obtain functionalized polyurethane; (2) Mix polyphosphazene microspheres, 4-allyl-2,6-di-tert-butylphenol and N,N-dimethylformamide evenly, add azobisisobutyronitrile, and react at 70~80℃ for 4~5h to obtain modified polyphosphazene microspheres; (3) Mix pre-modified nano-calcium carbonate, 3-hydroxy-β-ionone, triethylamine and N,N-dimethylformamide evenly, and react at 55~65℃ for 5~6h to obtain modified nano-calcium carbonate; (4) The functionalized polyurethane, modified polyphosphazene microspheres and modified nano calcium carbonate are mixed evenly and extruded in an extruder to obtain high temperature resistant TPU material.

3. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The preparation method of the daidzein dianhydride monomer in step (1) is as follows: daidzein and phthalic anhydride-4-formyl chloride are added to toluene in a molar ratio of 1:2, pyridine is added, the mixture is stirred at room temperature for 60-70 min, the temperature is raised to 100-110℃, and the reaction is continued for 4-5 h under a nitrogen atmosphere to obtain the daidzein dianhydride monomer.

4. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The molar ratio of polyether diol, soybean dianhydride monomer, and toluene-2,4-diisocyanate in step (1) is 1:(0.5~0.6):(1.8~2.0).

5. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The preparation method of the polyphosphazene microspheres in step (2) is as follows: hexachlorocyclotriphosphazene and acetonitrile are mixed evenly and ultrasonically dispersed at room temperature. 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine and 2-(mercaptomethyl)benzene-1,4-diol are added and ultrasonic dispersion is continued. Triethylamine is added and the mixture is stirred at 30~40℃ for 5~6h to obtain polyphosphazene microspheres.

6. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The mass ratio of the polyphosphazene microspheres and 4-allyl-2,6-di-tert-butylphenol in step (2) is 1:(3~4).

7. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The preparation method of the pre-modified nano calcium carbonate in step (3) is as follows: mix nano calcium carbonate and anhydrous ethanol evenly, disperse ultrasonically at room temperature, add chloropropyltriethoxysilane, heat to 70~80℃, continue ultrasonic dispersion, add oxalic acid aqueous solution dropwise, and continue reaction for 3~4 hours after the addition is completed to obtain pre-modified nano calcium carbonate.

8. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The amounts of functionalized polyurethane, modified polyphosphazene microspheres, and modified nano-calcium carbonate in step (4) are as follows: by mass parts, functionalized polyurethane 98-100 parts, modified polyphosphazene microspheres 5-6 parts, and modified nano-calcium carbonate 4-5 parts.

9. The method for preparing a high-temperature resistant TPU material according to claim 2, characterized in that, The extrusion temperature in step (4) is 190~210℃ and the screw speed is 20~30r / min.

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