Thermoplastic polyester elastomer

Abstract

The invention discloses a thermoplastic polyester elastomer, and particularly relates to the technical field of thermoplastic polyester elastomers. The elastomer is prepared from purified terephthalic acid, 1, 4-butanediol, 1, 6-adipic acid, bio-based polytetrahydrofuran polyol, a hydrolysis-resistant catalyst and an antioxidant according to a specific ratio. The preparation method comprises the following steps: firstly, respectively carrying out esterification reaction on PTA and BDO as well as AA and BDO, controlling the esterification rate to be 95-97%, then mixing the obtained T ester and A ester with bio-based PTMEG and the antioxidant, carrying out gradient pressure reduction at 245-250 DEG C to-100 kPa, and carrying out deep polycondensation under the conditions that the temperature is 260-265 DEG C and the vacuum degree is less than or equal to 1.01 mmHg, thereby finally preparing the thermoplastic polyester elastomer with regular molecular chain structure and balanced performance. The material shows excellent tensile strength and elongation at break. The invention effectively solves the problems that the foaming structure is influenced by too fast crystallization of TPEE and the melt strength is insufficient.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic polyester elastomer technology, and specifically to thermoplastic polyester elastomers. Background Technology

[0002] Thermoplastic polyester elastomers (TPEEs), as an important engineering material combining the elasticity of rubber and the processability of plastics, are widely used in automotive parts, electronic cables, sporting goods, and high-end packaging. However, traditional TPEEs still face several common technical bottlenecks in practical applications: First, their hard segment crystallization rate is too fast and the crystallization morphology is difficult to control, easily leading to uneven cell structure and poor dimensional stability during foaming, affecting the lightweight and balanced mechanical properties of the products; second, the melt strength of the material is generally low, making it prone to melt fracture and sag during high shear or tensile processing, restricting its molding stability and product integrity in blow molding, thermoforming, and other processes; third, existing TPEEs mostly rely on petroleum-based raw materials, with stable chemical structures that are difficult to biodegrade naturally, making recycling complex and energy-intensive, and failing to meet the current development requirements of green, low-carbon, and circular economy. These intertwined problems limit the application expansion and industrial upgrading of TPEEs in the direction of high performance and sustainability.

[0003] Specifically, the uncontrollable crystallization behavior directly affects the cell morphology and distribution of TPEE foam materials. In traditional materials, the excessively rapid crystallization of hard segments prevents uniform nucleation and growth of gas during foaming, resulting in large or closed cell structures. This not only reduces the material's buffering and insulation properties but also affects the appearance and dimensional accuracy of the finished product. Simultaneously, insufficient melt strength makes it difficult for the material to maintain stable ductility and shape retention during high-temperature processing. This is particularly problematic when preparing films, hollow containers, and complex irregular parts, easily leading to pores, uneven thickness, and molding defects, severely limiting its processing applicability and product yield. Furthermore, with increasingly stringent global environmental regulations and the deepening of sustainable development concepts, traditional petroleum-based TPEE is difficult to efficiently degrade or recycle after disposal. Its recycling process often requires energy-intensive physical or chemical treatments, and the performance of recycled materials deteriorates significantly, resulting in resource waste and environmental burden.

[0004] Therefore, developing a thermoplastic polyester elastomer with tunable crystallization behavior, excellent melt strength, and environmental friendliness has become an urgent need for technological upgrading and material innovation in this field. An ideal TPEE material should achieve controllable adjustment of the hard segment crystallization rate and morphology in its molecular structure design to optimize foaming behavior and cell quality; simultaneously, it should possess high melt strength and ductile stability to adapt to diverse processing techniques and improve product performance; furthermore, it should reflect green and sustainable characteristics in raw material sourcing and material lifecycle, such as using bio-based monomers, improving material biodegradability, or simplifying recycling processes. Against this backdrop, this invention addresses the shortcomings of existing TPEEs in crystallization control, melt strengthening, and environmental compatibility by proposing a novel thermoplastic polyester elastomer system with significantly improved overall performance through formulation optimization and process innovation. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide thermoplastic polyester elastomers that solve the problems of existing thermoplastic polyester elastomers having crystallization behavior that affects cell structure, insufficient melt strength, and increased difficulty in recycling.

[0006] To achieve the above objectives, the present invention provides the following technical solution: Thermoplastic polyester elastomer, specifically comprising the following components: 601.2–801.2g PTA (purified terephthalic acid), 397.4–471.4g BDO (1,4-butanediol), 159.2–221.4g 1,6-adipic acid, 784.6–1512.2g bio-based PTMEG, 78–372ppm hydrolysis-resistant catalyst TC220, 3.6–6.4g antioxidant KY-168, 3.6–6.4g Irganox 1076.

[0007] Preferably, bio-based PTMEG is a bio-based polyether polyol whose main component is polytetrahydrofuran polyol.

[0008] Preferably, the main components of the hydrolysis-resistant catalyst TC220 are organotin compounds and titanate catalysts.

[0009] Preferably, the main component of antioxidant KY-168 is tris[2,4-di-tert-butylphenyl]phosphite.

[0010] Preferably, the specific synthesis of thermoplastic polyester elastomer includes the following steps: S1: Place PTA+BDO and TC220 in a reactor and purge with nitrogen four times. Then start stirring and set the esterification temperature, stirring speed and pressure. Then increase the temperature and pressure of the reactor. S2: Control the esterification rate. Then, the water, tetrahydrofuran and unreacted BDO produced by the esterification reaction are released from the top of the esterification vessel in the form of steam. The remaining T esterification product enters the esterification separation tower for separation. S3: Place AA+BDO and TC220 in a reactor and purge with nitrogen four times. Then start stirring and set the esterification temperature, stirring speed, and pressure. Then increase the temperature and pressure of the reactor. S4: Control the esterification rate. Subsequently, the water, tetrahydrofuran and unreacted BDO produced by the esterification reaction escape from the top of the esterification vessel in the form of steam, and the remaining A esterification product enters the esterification separation tower for separation. S5: Add T ester, A ester, antioxidant KY-168, Irganox1076, and bio-based PTMEG to the hopper, then purge with nitrogen four times before adding to the reactor, maintaining temperature and gradient pressure reduction, and then heating it up. S6: Under high vacuum conditions, small molecule oligomers and BDO are continuously released, followed by further condensation reaction, and finally discharged and pelletized through the discharge port at the bottom of the reactor.

[0011] Preferably, in step S1, PTA+BDO and TC220 are placed in a reactor, the esterification temperature is set to 170-190°C, the stirring speed is 40-50 Hz, the pressure is 70-75 kPa and maintained for 1 hour, and finally the temperature of the reactor is raised to 230-235°C and the pressure is maintained at 75-80 kPa for 2 hours.

[0012] Preferably, the esterification rate in S2 is controlled at 95-97%.

[0013] Preferably, in step S3, AA+BDO and TC220 are added to the reactor and the esterification temperature is set to 170-190°C. The mixture is maintained at a stirring speed of 40-50 Hz and a pressure of 70-75 kPa for 1-2 hours. Finally, the temperature of the reactor is raised to 230-235°C and maintained at 75-80 kPa for 2 hours.

[0014] Preferably, the esterification rate in S4 is controlled at 95-97%.

[0015] Preferably, in step S5, the added substance is placed in the reactor and maintained at 245–250°C, while the pressure is reduced at a gradient of 10 kPa / min until it reaches -100 kPa. Then, the temperature is raised to 260–265°C and the vacuum degree is less than 1.01 mmHg.

[0016] The technical effects and advantages of the thermoplastic polyester elastomer of this invention are as follows: 1. This invention uses a hydrolysis-resistant catalyst to prevent the catalyst from being hydrolyzed, thereby reducing the use of catalyst by 50%, reducing catalyst residue in the material, and thus improving the weather resistance of the material.

[0017] 2. This invention innovates the design of raw material formulations to improve the performance of materials, better meet the needs of different application scenarios, and enable materials to have both high melt strength and biodegradability to protect the environment.

[0018] 3. The material exhibits excellent comprehensive mechanical properties, maintaining a high elongation at break of 576% while possessing a tensile strength of 18 MPa and a tensile modulus of 59 MPa, achieving an ideal balance between high elasticity, good toughness, and moderate rigidity.

[0019] 4. This invention employs an optimized process that combines stepwise esterification with high-vacuum polycondensation. By separately esterifying PTA and AA and strictly controlling the esterification rate at 95%–97%, and then performing deep polycondensation at 260–265°C and a vacuum of ≤1.01 mmHg, the regularity and integrity of the molecular chains are significantly improved, thereby giving the material higher melt strength and thermal stability.

[0020] 5. This invention introduces bio-based PTMEG as the core soft segment raw material, which significantly reduces the dependence on traditional petroleum-based materials, embodies the concept of green chemistry and sustainable development, and the material shows clear biodegradability potential, with outstanding environmental friendliness.

[0021] 6. This invention uses hydrolysis-resistant organotin / titanium ester catalyst TC220, whose excellent hydrolytic stability allows for a reduction of approximately 50% in catalyst usage. This not only reduces production costs but also reduces the amount of metal ions remaining in the final product, significantly improving the long-term weather resistance and safety of the material.

[0022] 7. This invention, through structural characterization methods such as infrared spectroscopy, clearly verifies the integrity of the polymer chain structure and the accuracy of the chemical functional groups, at 1725 cm⁻¹. -1 1105 cm -1 and 1602 cm -1 Clear characteristic absorption peaks of ester bonds, ether bonds, and benzene rings were observed at the respective locations, proving that the synthesis reaction was complete and the product had high purity. Attached Figure Description

[0023] Figure 1 This is the infrared spectrum of the thermoplastic polyester elastomer proposed in this invention; Figure 2 This is the TGA spectrum of the thermoplastic polyester elastomer proposed in this invention; Figure 3 This is the tensile-stress-strain curve of the thermoplastic polyester elastomer proposed in this invention; Figure 4 The polymer DSC curve of the thermoplastic polyester elastomer proposed in this invention; Figure 5 This is a diagram of the equipment for synthesizing the thermoplastic polyester elastomer proposed in this invention; Figure 6 It is the polymer backbone molecular formula of the thermoplastic polyester elastomer proposed in this invention. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] Example 1 This embodiment provides a thermoplastic polyester elastomer, and the specific implementation steps include: Experimental materials: 701.2g PTA purified terephthalic acid, 437.2g BDO 1,4-butanediol, 180.4g 1,6-adipic acid, 861.2g bio-based PTMEG, 89ppm hydrolysis-resistant catalyst TC220, 4.6g antioxidant KY-168, 4.6g Irganox1076.

[0027] Experimental objective: Synthesis of thermoplastic polyester elastomers.

[0028] Experimental steps: S1: Place PTA+BDO and TC220 in a reactor and purge with nitrogen four times. Then start stirring and set the esterification temperature to 190℃, the stirring speed to 50Hz, and the pressure to 75Kpa and maintain for 1 hour. Raise the temperature of the reactor to 235℃ and the pressure to 80Kpa and maintain for another 2 hours. S2: The esterification rate is controlled at 97%. The water, tetrahydrofuran (THF) and unreacted BDO produced by the esterification reaction escape from the top of the esterification vessel in the form of steam. The remaining T esterification product enters the esterification separation tower for separation. S3: Place AA+BDO and TC220 in a reactor and purge with nitrogen four times. Then start stirring and set the esterification temperature to 190℃, the stirring speed to 50Hz, and the pressure to 75Kpa and maintain for 1 hour. Raise the temperature of the reactor to 235℃ and the pressure to 80Kpa and maintain for 2 hours. S4: The esterification rate is controlled at 97%. The water, tetrahydrofuran (THF) and unreacted BDO produced by the esterification reaction escape from the top of the esterification vessel in the form of steam. The remaining A esterification product enters the esterification separation tower for separation. S5: Add T ester, A ester, antioxidant KY-168, Irganox1076, and bio-based PTMEG to the hopper, then purge with nitrogen four times before adding to the reactor. Maintain the temperature at 250℃, reduce the pressure at a gradient of 10 kPa / min until it drops to -100 kPa, then raise the temperature to 265℃ and maintain a vacuum of ≤1.01 mmHg. S6: Under high vacuum conditions, small molecule oligomers and BDO are continuously extracted, followed by further polycondensation reaction to reach a certain polymer end, and finally discharged and pelletized through the discharge port at the bottom of the reactor.

[0029] Experimental results: See Table 1 for details.

[0030] Table 1: Test Results of Example 1

[0031] Example 1 successfully synthesized a thermoplastic polyester elastomer with good overall properties. This experiment used purified terephthalic acid, 1,4-butanediol, 1,6-adipic acid, and bio-based PTMEG as the main raw materials, and under the action of the hydrolysis-resistant catalyst TC220 and antioxidants, [reference needed]. Figure 5 The diagram shows the equipment used to prepare thermoplastic polyester elastomers through a stepwise esterification and high-vacuum polycondensation process (see [reference]). Figure 6 The materials synthesized through this process exhibit complete ester bonds, ether bonds, and benzene ring characteristics in their structure (see...). Figure 1 Infrared spectrum), good thermal stability ( Figure 2 (TGA curve), and possesses excellent mechanical properties: tensile modulus of 59 MPa, tensile strength of 18 MPa, elongation at break of 576%, Shore D hardness of 38, density of 1159 kg / m³, and melting temperature of 150℃. Figure 3 , Figure 4The process design of Example 1 optimized the control of reaction temperature, pressure, vacuum degree and time, ensuring the integrity and regularity of the polymer chain structure, and finally obtained a thermoplastic polyester elastomer with high toughness, moderate strength and clear melting behavior, which is suitable for engineering and packaging materials fields that require good comprehensive performance.

[0032] Example 2 This embodiment provides a thermoplastic polyester elastomer, and the specific implementation steps include: Experimental objective: Test the properties of thermoplastic polyester elastomers.

[0033] Experimental steps: S1: The thermoplastic polyester elastomer particles obtained in Example 1 were vacuum dried at 80°C for 4 hours, and then injection molded into standard test strips and sample blocks required for hardness and density testing using an injection molding machine. S2: Condition the specimen in a standard environment of 23±2℃ and 50±10% relative humidity for at least 16 hours, and use a universal testing machine with the tensile speed set to 50 mm / min to test the tensile modulus of elasticity, tensile strength and elongation at break of the specimen. S3: Place the flat sample on the hardness tester platform, use the Shore D hardness tester, and read the hardness value within 1 second after the indenter makes perpendicular contact with the sample surface. Take the average value after 5 measurements at different positions on the sample. S4: Using the liquid displacement method, a precision electronic balance and density measuring kit are used to weigh the sample in air, then immerse it in distilled water and weigh it again. The density is calculated using Archimedes' principle. S5: Using a differential scanning calorimeter, take 5-10 mg of sample and place it in a crucible. Under a nitrogen atmosphere, heat the sample from 30℃ to 200℃ at a rate of 10℃ / min. Record the melting endothermic curve and take the peak temperature as the melting temperature. S6: Record the raw data of each test item, calculate the average value and standard deviation, compile them into a table, and combine them with infrared structural analysis to comprehensively evaluate the material performance.

[0034] Experimental results:

[0035] This material maintains a high elongation at break (576%) while possessing moderate tensile strength (18 MPa) and modulus (59 MPa), a Shore D hardness of 38, a density of 1159 kg / m³, and a melting temperature of 150℃. Combined with infrared spectroscopy... Figure 1-4The clear ester bonds, ether bonds, and benzene ring characteristic peaks in the sample demonstrate that the thermoplastic polyester elastomer of this invention has a complete structure, good flexibility, mechanical strength, and well-defined melting behavior, and its overall performance is superior to that of traditional petroleum-based or incompletely processed comparative materials.

[0036] Comparative Example 1 This embodiment provides a thermoplastic polyester elastomer, and the specific implementation steps include: Experimental materials: PTA (purified terephthalic acid): 701.2 g, BDO (1,4-butanediol): 437.2 g, 1,6-adipic acid (AA): 180.4 g, bio-based PTMEG: 861.2 g, hydrolysis-resistant catalyst TC220: 89 ppm, antioxidant KY-168: 4.6 g, antioxidant Irganox1076: 4.6 g.

[0037] Experimental objective: The vibrational characteristic peaks of ester bonds, ether bonds, and benzene ring skeleton in the thermoplastic polyester elastomer synthesized under standard process conditions were verified to confirm the integrity of the polymer structure.

[0038] Experimental steps: S1: Add PTA, BDO and TC220 to the reactor, purge with nitrogen 4 times, start stirring, set the esterification temperature to 190℃, stirring speed to 50 Hz and pressure to 75 kPa, and maintain for 1 hour. S2: Heat to 235℃, adjust the pressure to 80 kPa, maintain for 2 hours, and control the esterification rate to 97%; S3: Add AA, BDO and TC220 to another reactor, and repeat steps S1 to S2 to obtain esterified A. S4: Mix T ester, A ester, antioxidant KY-168, Irganox1076 and bio-based PTMEG, replace with nitrogen and add to the reactor, maintain 250℃, and depressurize to -100 kPa at a rate of 10 kPa / min. S5: Heat to 265℃, vacuum degree ≤1.01 mmHg, and carry out polycondensation reaction; S5: After reaching the predetermined degree of polymerization, the material is discharged and granulated to obtain thermoplastic polyester elastomer granules.

[0039] Experimental results: refer to Figure 1 The infrared spectrum shows that at 1725 cm⁻¹ -1 A strong C=O stretching vibration peak appears at 1105 cm⁻¹. -1 A characteristic peak for COC ether bonds appears at 1602 cm⁻¹. -1 The presence of a benzene ring skeleton vibration peak indicates that the polymer structure meets the design expectations.

[0040] Comparative Example 2 This embodiment provides a thermoplastic polyester elastomer, and the specific implementation steps include: Experimental materials: PTA (purified terephthalic acid): 750.0 g, BDO (1,4-butanediol): 450.0 g, 1,6-adipic acid (AA): 200.0 g, bio-based PTMEG: 900.0 g, hydrolysis-resistant catalyst TC220: 100 ppm, antioxidant KY-168: 5.0 g, antioxidant Irganox1076: 5.0 g.

[0041] Experimental objective: By optimizing the esterification and polycondensation process parameters, the regularity of polymer molecular chains is enhanced, the melt strength is improved, and the structural integrity and functional group characteristics are verified by infrared spectroscopy.

[0042] Experimental steps: S1: PTA and BDO were esterified at 185 °C and 76 kPa for 1.5 hours under TC220 catalysis; S2: Heat to 237℃, maintain pressure at 82 kPa for 2.5 hours, and control the esterification rate at 98%; S3: AA and BDO are esterified under the same conditions to obtain esterified A. S4: Mix the two esters with PTMEG and antioxidants, and slowly depressurize to -100 kPa at 252°C. S5: Final polycondensation is carried out at 267℃ and a vacuum degree ≤0.8 mmHg, with the time extended to 3 hours; S6: Discharge and pelletize to obtain a high melt strength elastomer.

[0043] Experimental results: refer to Figure 1 The infrared spectrum shows an ester bond peak (1722 cm⁻¹). -1 The intensity was significant, with the ether bond peak at 1110 cm⁻¹. -1 The benzene ring peak (1605 cm⁻¹) is clearly visible. -1 The clarity indicates a complete molecular structure, high chain segment regularity, and conforms to the structural characteristics of high melt strength materials.

[0044] Comparative Example 3 This embodiment provides a thermoplastic polyester elastomer, and the specific implementation steps include: Experimental materials: PTA (purified terephthalic acid): 650.0 g, BDO (1,4-butanediol): 400.0 g, 1,6-adipic acid (AA): 150.0 g, petroleum-based PTMEG (non-bio-based): 800.0 g, hydrolysis-resistant catalyst TC220: 80 ppm, antioxidant KY-168: 4.0 g, antioxidant Irganox 1076: 4.0 g.

[0045] Experimental objective: To verify whether thermoplastic polyester elastomers synthesized in formulations with bio-based content below 20% still meet the bio-based material labeling requirements, and to compare their structural characteristics and performance differences with those of materials with high bio-based content.

[0046] Experimental steps: S1: Add PTA, BDO and TC220 to the reactor, purge with nitrogen 4 times, start stirring, set the esterification temperature to 190℃, stirring speed to 50 Hz and pressure to 75 kPa, and maintain for 1 hour. S2: Heat to 235℃, adjust the pressure to 80 kPa, maintain for 2 hours, and control the esterification rate to 97%; S3: Add AA, BDO and TC220 to another reactor, and repeat steps S1 to S2 to obtain esterified A. S4: Mix T ester, A ester, antioxidant KY-168, Irganox1076 and petroleum-based PTMEG, replace with nitrogen and add to the reactor, maintain 250℃, and reduce the pressure to -100 kPa at a rate of 10 kPa / min. S5: Heat to 265℃, vacuum degree ≤1.01 mmHg, and carry out polycondensation reaction; S6: After reaching the predetermined degree of polymerization, the material is discharged and granulated to obtain thermoplastic polyester elastomer granules.

[0047] Experimental results: The material was found to have a bio-based content of <5%, which does not meet the labeling requirement of ≥20%. The infrared spectrum showed an ester bond peak (1725 cm⁻¹). -1 With benzene ring peak (1602 cm) -1 The ether bond region characteristics are still obvious, but they differ from those of the bio-based PTMEG system. Melt strength tests show that its melt tensile properties are lower than those of Example 1.

[0048] Comparative Example 4 This embodiment provides a thermoplastic polyester elastomer, and the specific implementation steps include: Experimental materials: PTA (purified terephthalic acid): 700.0 g, BDO (1,4-butanediol): 440.0 g, 1,6-adipic acid (AA): 185.0 g, bio-based PTMEG (93% content): 850.0 g, hydrolysis-resistant catalyst TC220: 90 ppm, antioxidant KY-168: 5.0 g, antioxidant Irganox1076: 5.0 g.

[0049] Experimental objective: Under the premise that the bio-based content meets the standard, the influence of process conditions on melt strength is verified by shortening the polycondensation time and reducing the vacuum degree, highlighting the necessity of process optimization for high melt strength formulations.

[0050] Experimental steps: S1: PTA and BDO were esterified at 190 °C and 75 kPa for 1 hour under TC220 catalysis; S2: Heat to 235℃, maintain pressure at 80 kPa for 2 hours; S3: AA and BDO are esterified under the same conditions to obtain esterified A. S4: Mix the two esters with bio-based PTMEG and antioxidants, and slowly depressurize to -80 kPa at 250°C. S5: Polycondensation reaction is carried out at 265℃ and a vacuum degree ≤5 mmHg, with the time shortened to 1.5 hours; S6: Discharge and pelletize to obtain elastomer granules.

[0051] Experimental results: The bio-based content was measured to be approximately 68%, which meets the labeling requirements. However, the melt strength test showed that the melt tensile fracture stress and elongation were significantly lower than those of Example 1 and Comparative Example 2. This indicates that insufficient condensation vacuum and shortened time led to a wide molecular weight distribution and decreased chain segment regularity, thereby affecting the melt strength.

[0052] Example 1 successfully prepared a thermoplastic polyester elastomer with complete structure and balanced performance by using a process combining stepwise esterification and high-vacuum polycondensation, combined with bio-based PTMEG and an optimized additive system.

[0053] Example 2 employs a systematic performance testing method that covers mechanical, thermal, and structural characterization, comprehensively verifying the overall performance advantages of the material in Example 1.

[0054] Comparative Example 1 used standard esterification and polycondensation processes, which verified the basic integrity of the polymer structure, but its melt strength and chain segment regularity were not specifically optimized.

[0055] Comparative Example 2 adopted a process optimization strategy of extending the polycondensation time and increasing the vacuum level, which significantly improved the molecular chain regularity and melt strength, but the process complexity and energy consumption were relatively high.

[0056] Comparative Example 3 used petroleum-based PTMEG to replace bio-based PTMEG. Although it retained some structural features, the bio-based content was less than 5%, which did not meet the requirements for sustainable material labeling, and the melt performance was reduced.

[0057] Comparative Example 4 uses a simplified process that employs bio-based PTMEG but shortens the polycondensation time and reduces the vacuum level. Although the bio-based content meets the standard, insufficient polycondensation leads to a wide molecular weight distribution and a significant reduction in melt strength.

[0058] By comprehensively comparing the examples and comparative examples, Example 1 achieves an optimal balance between structural integrity, mechanical properties, melt strength, and bio-based sustainability. It ingeniously enhances the overall performance and processing applicability of the material by synergistically controlling the molecular chain structure through stepwise esterification and high-vacuum polycondensation processes. This makes it suitable for engineering and environmentally friendly packaging applications requiring high flexibility and moderate strength. Although Example 2 did not involve improvements to the synthesis process, it systematically verified the reliability and performance advantages of the material in Example 1. Comparative Example 1 uses a basic process route but does not address key process parameters for performance optimization. Comparative Example 2 uses an enhanced polycondensation process, but its process and time costs are high. Comparative Example 3 uses non-bio-based raw materials but cannot meet the development trend and labeling requirements of green materials. Comparative Example 4 highlights the functional limitations of traditional simplified processes that sacrifice material performance in pursuit of production efficiency. Therefore, the process and formulation system represented by Example 1 has significant advantages in structural design, performance control, and sustainability, providing a high-performance, controllable, and environmentally friendly thermoplastic polyester elastomer preparation scheme for the field.

[0059] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

[0060] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Thermoplastic polyester elastomer, characterized in that, Specifically comprising the following components: 30.06-40.06 parts by weight PTA purified terephthalic acid, 19.87-23.57 parts by weight BDO 1,4-butanediol, 7.96-11.07 parts by weight 1,6-hexanedioic acid, 39.23-45.62 parts by weight bio-based PTMEG, 78-372 ppm hydrolysis-resistant catalyst TC220, 0.18-0.32 parts by weight antioxidant KY-168, 0.18-0.32 parts by weight Irganox 1076.

2. The thermoplastic polyester elastomer according to claim 1, wherein The bio-based PTMEG is a bio-based polyether polyol whose main component is polytetrahydrofuran polyol.

3. The thermoplastic polyester elastomer of claim 1, wherein The main component of the hydrolysis-resistant catalyst TC220 is an organic tin compound and a titanate catalyst.

4. The thermoplastic polyester elastomer of claim 1, wherein The main component of the antioxidant KY-168 is tris[2,4-di-tert-butylphenyl] phosphite.

5. The thermoplastic polyester elastomer of claim 1, wherein The specific thermoplastic polyester elastomer synthesis steps include: S1: PTA+BDO and TC220 are placed in a reaction kettle, and nitrogen is replaced for 4 times, then stirring is started, and the esterification degree, stirring speed and pressure are set, and then the temperature and pressure of the reaction kettle are increased; S2: the esterification rate is controlled, then water, tetrahydrofuran and unreacted BDO generated in the esterification reaction are escaped from the upper part of the esterification kettle in the form of steam, and the remaining T-esterification product enters an esterification separation tower for separation; S3: AA+BDO and TC220 are placed in a reaction kettle, and nitrogen is replaced for 4 times, then stirring is started, and the esterification temperature, stirring speed and pressure are set, and then the temperature and pressure of the reaction kettle are increased; S4: the esterification rate is controlled, then water, tetrahydrofuran and unreacted BDO generated in the esterification reaction are escaped from the upper part of the esterification kettle in the form of steam, and the remaining A-esterification product enters an esterification separation tower for separation; S5: T-esterification product, A-esterification product, antioxidant KY-168, Irganox 1076 and bio-based PTMEG are added to a hopper, then nitrogen is replaced for 4 times, and then they are added to the reaction kettle, the temperature and gradient pressure are maintained, and then the temperature is increased again; S6: small molecular oligomers and BDO are continuously removed under high vacuum conditions, then further polycondensation reaction occurs, and finally the product is discharged through the discharge port at the bottom of the kettle and is pelletized.

6. The thermoplastic polyester elastomer according to claim 5, wherein In S1, PTA+BDO and TC220 are placed in a reaction kettle, the esterification temperature is set to 170-190°C, the stirring speed is set to 40-50 Hz, the pressure is set to 70-75 Kpa and maintained for 1 hour, and finally the temperature of the reaction kettle is increased to 230-235°C and the pressure is maintained at 75-80 Kpa for 2 hours.

7. The thermoplastic polyester elastomer of claim 5, wherein In S2, the esterification rate is controlled to be 95-97%.

8. The thermoplastic polyester elastomer of claim 5, wherein In S3, AA+BDO and TC220 are added to a reaction kettle, the esterification temperature is set to 170-190°C, the stirring speed is set to 40-50 Hz, the pressure is set to 70-75 Kpa and maintained for 1-2 hours, and finally the temperature of the reaction kettle is increased to 230-235°C and the pressure is maintained at 75-80 Kpa for 2 hours.

9. The thermoplastic polyester elastomer of claim 5, wherein In S4, the esterification rate is controlled to be 95-97%.

10. The thermoplastic polyester elastomer of claim 5, wherein In S5, the added substance is put into the reactor and maintained at 245-250°C, while the pressure is decreased at a gradient of 10 Kpa / min until it is decreased to -100 Kpa, and then it is increased to 260-265°C and the vacuum degree is less than 1.01 mmHg.

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