Thermoplastic polyester elastomer based on polypropylene glycol with controllable tacticity and method for preparing the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN UNIV OF TECH
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-29
Smart Images
Figure CN122103538A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials technology, specifically relating to a polyester-polyether block copolymer thermoplastic polyester elastomer obtained by polycondensation of diacid or dimethyl diacid, diol and polypropylene glycol with controllable stereoregularity, and its preparation method. Background Technology
[0002] Thermoplastic polyester elastomers (TPEEs) are typically multi-block copolymers composed of alternating polyether soft segments and polyester hard segments. The polyester hard segments are usually high-melting-point polybutylene terephthalate (PET), which crystallizes at service temperatures to form physical cross-linking points, giving the material high strength, modulus, hardness, and heat resistance. The polyether soft segments are typically long-chain diols such as polytetrahydrofuran (PTF) and polypropylene glycol (PPG), which have low glass transition temperatures, imparting good flexibility, low-temperature performance, and elasticity. The hard segments melt upon heating, allowing the material to flow and be processed; upon cooling, the hard segments recrystallize, restoring the material's elastomer properties. Therefore, TPEEs combine thermoplastic processability with rubber elasticity.
[0003] Long-chain diols are key components determining the flexibility and elasticity of TPEE (Polyterpenoid Resin Electrolyte), and their structural design and innovation have a crucial impact on the final performance of TPEE. Invention patent CN104193976A uses terephthalic acid and 1,4-butanediol as hard segment monomers and polytetrahydrofuran as the soft segment raw material, preparing TPEE through esterification-polymerization. Invention patent CN102718973A: Based on a polyester hard segment constructed from terephthalic acid and 1,4-butanediol, the soft segment uses a mixture of polytetrahydrofuran diol and polysiloxane. By introducing a certain proportion of polysiloxane blocks, the overall performance, such as heat resistance and flexibility, is improved without sacrificing the material's mechanical properties as much as possible. Invention patent CN1260268C uses terephthalic acid and 1,4-butanediol as hard segment monomers and selects different proportions of poly(1,3-propylene ether diol) and polytetrahydrofuran as mixed soft segments to prepare TPEE. Its characteristics include mature raw materials and routes, and controllable costs. However, overall, the key properties of this type of system, such as elastic recovery and low-temperature flexibility, are still largely limited by the intrinsic structure of the selected polyether glycol soft segment, and it is difficult to achieve functional breakthroughs using only conventional formulations and processes. In order to advance soft segment design from "simple blending modification" to "molecular structure customization," invention patent CN102652148A, while maintaining the heat resistance and strength provided by the polybutylene terephthalate hard segment, further improves the adjustability of the material in terms of antistatic / hydrophilic properties, processing window, and overall elasticity, proposing the use of random poly(ethylene oxide- coTPEE was prepared using tetrahydrofuran (THF) ether diol as a soft segment. This soft segment essentially "integrates" polyethylene oxide and polytetrahydrofuran into the same soft segment, achieving synergistic performance contributions from both soft segments, and forming a block copolymer structure together with the polybutylene terephthalate (PET) hard segment. This indicates that the TPEE soft segment modification strategy is moving from "formulation stacking" to "structure-performance synergistic design."
[0004] Therefore, it is of great significance to develop a TPEE that can achieve a synergistic improvement in high strength and high elongation through soft segment structure regulation, and to provide a preparation method suitable for industrial scale-up. Summary of the Invention
[0005] The purpose of this invention is to provide a thermoplastic polyester elastomer based on stereoregularity-controlled polypropylene glycol and its preparation method. By introducing stereoregularity-controlled polypropylene glycol and copolymerizing it with various diacids or dimethyl diacid esters and diols, a TPEE material with excellent comprehensive performance and thermoplastic processability is obtained. The stereoregularity-controlled polypropylene glycol used combines the segmental flexibility of traditional commercial polypropylene glycol with the chain regularity and crystallinity tendency of polytetrahydrofuran. This highly regular soft segment structure promotes the formation of more regular and stable soft segment microregions in TPEE, thereby significantly improving the degree of microphase separation between soft and hard segments, ultimately enhancing the performance of TPEE.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A thermoplastic polyester elastomer based on stereoregularity-controllable polypropylene glycol, wherein the thermoplastic polyester elastomer is obtained by polycondensation of a diacid, a diol, and stereoregularity-controllable polypropylene glycol, or by polycondensation of a dimethyl diacid, a diol, and stereoregularity-controllable polypropylene glycol, wherein the diacid or dimethyl diacid and the diol constitute the hard segment, and the stereoregularity-controllable polypropylene glycol constitutes the soft segment. The general formula of the thermoplastic polyester elastomer is shown below: .
[0007] In the formula: x, n, and m are all integers greater than 0; R and R' represent substituents, which are respectively substituents of the dicarboxylic acid. diols The substituents on it correspond to the substituents.
[0008] Furthermore, the thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol has a melting point of 150~230 ℃ (preferably 172~216 ℃), a glass transition temperature of -71~-40 ℃ (preferably -70~-58 ℃), a maximum tensile strength of 15~35 MPa (preferably 18~35 MPa), and an elongation at break of 400~1200% (preferably 480~1100%).
[0009] Furthermore, the main configuration of the stereoregularity-controlled polypropylene glycol is as follows: R - Polypropylene glycol or S - Polypropylene glycol, the stereoregularity of which is 70-100%, and the number-average molecular weight of which is controllable. M n The main configurations of polypropylene glycol with a concentration of 500–5000 g / mol and controllable stereoregularity are as follows: .
[0010] Further, the dicarboxylic acid is selected from at least one of terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,5-furandicarboxylic acid, and the dimethyl ester of the dicarboxylic acid is selected from at least one of dimethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylic acid, and dimethyl 2,5-furandicarboxylic acid, with the following structural formula: .
[0011] Further, the diol comprises at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, 1,4-cyclohexanediethanol, isosorbide, and 2,5-tetrahydrofurandiethanol, with the following structural formula: .
[0012] The preparation method of thermoplastic polyester elastomer based on polypropylene glycol with controllable stereoregularity includes the following reaction formula: Dicarboxylic acid or dimethyl diacid, diol, stereoregular polypropylene glycol, catalyst, antioxidant and stabilizer are added to a reactor and esterification or transesterification reaction is carried out under nitrogen protection. After completion, the temperature is raised and vacuum is drawn to carry out polycondensation reaction to obtain thermoplastic polyester elastomer.
[0013] Further, the molar ratio of the diacid or dimethyl diacid to the diol is 1:(1.1~1.8); the mass ratio of the stereoregularity-controlled polypropylene glycol to the total mass of the diacid or dimethyl diacid and the diol is 1:(0.5~5); the mass ratio of the catalyst to the diacid or dimethyl diacid is 1:(400~1000); the mass ratio of the antioxidant to the diacid or dimethyl diacid is 1:(100~200); and the mass ratio of the stabilizer to the diol is 1:(10000~12000).
[0014] Furthermore, the esterification reaction is carried out at a temperature of 180-250 °C for 3-6 h; the transesterification reaction is carried out at a temperature of 180-250 °C for 3-6 h; and the polycondensation reaction is carried out at a temperature of 200-280 °C for 2-6 h.
[0015] Furthermore, the polycondensation reaction includes pre-polycondensation and final polycondensation. The absolute pressure of the pre-polycondensation reaction system is 800-1500 Pa. After the pre-polycondensation is completed, the pressure is further reduced to enter the final polycondensation reaction system. The absolute pressure of the final polycondensation reaction system is 30-100 Pa.
[0016] Further, the catalyst is any one or a combination of at least two of titanium-containing compounds, tin-containing compounds, or antimony-containing compounds; the antioxidant includes any one or a combination of at least two of antioxidant 1010, antioxidant 168, antioxidant 1098, or antioxidant 1076; the stabilizer includes any one or a combination of at least two of phosphite compounds, phosphate compounds, or aminourea compounds.
[0017] Furthermore, polypropylene glycol with controllable stereoregularity can be added during esterification or transesterification reactions, or it can be added in batches after esterification or transesterification reactions or during pre-condensation. This invention does not limit the method of addition, but adding in batches is beneficial to reduce the risk of thermal degradation caused by high-temperature residence and improve dispersion uniformity.
[0018] The present invention has the following beneficial effects: By introducing polypropylene glycol with controllable stereoregularity into the soft segment structure, the present invention combines the segmental flexibility of traditional polypropylene glycol with the chain regularity and crystallization tendency of polytetrahydrofuran. This highly regular soft segment structure not only endows the material with excellent low-temperature toughness, but also promotes the formation of more regular and stable soft segment microregions in TPEE, thereby significantly improving the degree of microphase separation between soft and hard segments, which is conducive to achieving a comprehensive improvement in strength, elongation and elastic recovery performance. Attached Figure Description
[0019] Figure 1 The results of the 1H NMR spectrum test of the thermoplastic polyester elastomer prepared in Example 1 are shown below. Figure 2 The results of differential scanning calorimetry (DSC) testing of the thermoplastic polyester elastomer prepared in Example 1 are shown below. Figure 3 The longitudinal tensile stress-strain curves of the thermoplastic polyester elastomers prepared in Examples 1, 17, and Comparative Example 1 are shown. Detailed Implementation
[0020] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0021] 1. Terminology and Parameter Description (1) The term "stereoregularity" as used in this specification is used to characterize the degree of stereoregularity of the polypropylene glycol segments with controllable stereoregularity. Preferably, carbon nuclear magnetic resonance spectroscopy (NMR) can be used. 13 C NMR was used to analyze the stereoregularity of polypropylene glycol segments, and the stereoregularity was characterized by the content of isotactic triplets (mm) or equivalent stereoregular sequence parameters, with values ranging from 70 to 100%.
[0022] (2) The “pre-condensation and final condensation” described in this specification are both different vacuum range controls of the condensation reaction: pre-condensation removes low molecular weight compounds and excess diols at 800-1500 Pa; final condensation further reduces the pressure to 30-100 Pa to increase the number average molecular weight and complete the polymerization.
[0023] (3) Based on the mass of the dicarboxylic acid or dimethyl diacid ( ); mass of diol ( The quality of polypropylene glycol with controllable stereoregularity ( ); Ignoring the removal of small-molecule water or alcohol in the system, the hard segment content in the final thermoplastic polyester elastomer can be roughly calculated. w H The calculation formula is as follows: (4) The prepared TPEE is granulated to obtain thermoplastic polyester elastomer particles. These particles are directly used for differential scanning calorimetry testing of TPEE. Then, these particles are injection molded into dumbbell-shaped specimens for mechanical property testing of TPEE.
[0024] 2. Performance Testing (1) Melting point and glass transition temperature: Tested according to the test method provided in ASTM D3418; (2) Longitudinal tensile strength and elongation at break: Tested according to the test method provided in ASTM D638.
[0025] Example 1 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... RPolypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0026] Example 2 1.33 kg of dimethyl terephthalate; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Ester exchange was carried out at 190 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0027] Example 3 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... S Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0028] Example 4 1.03 kg of 2,6-naphthalenedicarboxylic acid; 0.77 kg of 1,6-hexanediol; 1.61 kg of... RPolypropylene glycol (number average molecular weight 1500 g / mol, stereoregularity >99%), 2.39 g catalyst (dibutyltin dilaurate), 9.01 g antioxidant 1076, and 0.07 g stabilizer (tris(2-ethylhexyl) phosphate) were added to the reactor and stirred. Esterification was carried out at 235℃ for 4.5 h under nitrogen protection. The temperature was raised to 265℃ and vacuum was applied. The pre-condensation absolute pressure was controlled at about 1100 Pa and the reaction was carried out for 1.3 h. The pressure was further reduced to 60 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0029] Example 5 0.66 kg of 2,5-furandicarboxylic acid; 0.35 kg of ethylene glycol; 1.21 kg of... R Polypropylene glycol (number average molecular weight 1800 g / mol, stereoregularity 80%), 0.89 g catalyst (antimony glycol), 4.01 g antioxidant 1098 and 1.02 g antioxidant 168, and 0.03 g stabilizer (1,3-diphenylurea) were added to the reactor and stirred. Esterification was carried out at 210 °C for 3.5 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation absolute pressure was controlled at about 1000 Pa and the reaction was carried out for 1.0 h. The pressure was further reduced to 30 Pa for final condensation for 2.6 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0030] Example 6 Add 0.78 kg of dimethyl 2,5-furandicarboxylate; 0.35 kg of ethylene glycol; and 1.21 kg of... R Polypropylene glycol (number average molecular weight 1800 g / mol, stereoregularity 80%), 1.05 g catalyst (antimony glycol), 4.48 g antioxidant 1098 and 1.12 g antioxidant 168, and 0.03 g stabilizer (1,3-diphenylurea) were added to the reactor and stirred. Ester exchange was performed at 210 °C for 3.5 h under nitrogen protection. The temperature was then raised to 255 °C and a vacuum was applied. The pre-condensation absolute pressure was controlled at approximately 1000 Pa, and the reaction proceeded for 1.0 h. The pressure was further reduced to 30 Pa for final condensation for 2.6 h. The product was then discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0031] Example 7 Add 0.91 kg of terephthalic acid; 0.43 kg of ethylene glycol; and 2.01 kg of... RPolypropylene glycol (number average molecular weight 2000 g / mol, stereoregularity >99%), 1.01 g catalyst (tetraisopropoxytitanium), 5.03 g antioxidant 1010, and 0.04 g stabilizer (tris(nonylphenyl) phosphite) were added to the reactor and stirred. Esterification was carried out at 225 °C for 4 h under nitrogen protection. The temperature was raised to 270 °C and vacuum was applied. The pre-condensation absolute pressure was controlled at about 1300 Pa and the reaction was carried out for 1.2 h. The pressure was further reduced to 70 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0032] Table 1. Thermoplastic polyester elastomers obtained from different formulations and their performance characterization
[0033] Based on the results of the above embodiments, it can be seen that by controlling the stereoregularity of polypropylene glycol, the configuration can be optimized. R or S By controlling the stereoregularity, number-average molecular weight, and the type and ratio of diacid or dimethyl diacid ester and diol, high-quality synthesis of thermoplastic polyester elastomers with controllable stereoregularity can be achieved. Furthermore, comparisons between Examples 1 and 2, and Examples 5 and 6, revealed no significant difference in polymer properties when using dicarboxylic acid or its corresponding dimethyl diacid ester.
[0034] Example 8 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity 90%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0035] Example 9 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... RPolypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity 85%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was then further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0036] Example 10 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity 80%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0037] Example 11 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity 75%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was then further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0038] Comparative Example 1 This is directly compared with Examples 1, 8, 9, 10, and 11, the only difference being that commercially available polypropylene glycol (number-average molecular weight of 1000 g / mol, stereoregularity of 52%) was used instead of the polypropylene glycol used in the above examples. R - Polypropylene glycol (number average molecular weight of 1000 g / mol), and the other raw materials, proportions and process conditions are the same as those in the above examples.
[0039] Table 2. Thermoplastic polyester elastomers obtained from different formulations and their performance characterization
[0040] According to the results shown in Table 2, under the conditions of fixed dicarboxylic acid, diol type, and number-average molecular weight and hard segment content of polypropylene glycol with controllable stereoregularity, the crystallization behavior and mechanical properties of thermoplastic polyester elastomers (TPEEs) can be significantly affected by adjusting the stereoregularity of the polypropylene glycol with controllable stereoregularity. As the stereoregularity of the polypropylene glycol with controllable stereoregularity gradually decreased from >99% to 75%, the melting point and glass transition temperature of TPEEs generally showed a downward trend, the maximum tensile strength gradually decreased, and the elongation at break gradually increased. This indicates that the decreased segmental regularity weakens the ordered arrangement and crystallization ability between the soft and hard segments, thus leading to changes in the overall mechanical properties of TPEEs. In contrast, Comparative Example 1 used commercial polypropylene glycol (stereoregularity of 52%), which further enhanced the disorder of the internal structure of the material. The mechanical properties of the resulting TPEEs were significantly lower than those of the examples, verifying the important role of high stereoregularity in improving TPEE performance.
[0041] Example 12 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 1500 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0042] Example 13 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 2000 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0043] Example 14 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 2500 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0044] Example 15 1.14 kg of terephthalic acid; 1.06 kg of 1,4-butanediol; 1.81 kg of... R Polypropylene glycol (number average molecular weight 3000 g / mol, stereoregularity >99%), 1.89 g catalyst (tetrabutyl titanate), 3.79 g antioxidant 1010 and 3.79 g antioxidant 168, and 0.09 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0045] Comparative Example 2 In direct comparison with Example 1, the only difference is that 1.81 kg of polytetrahydrofuran (number average molecular weight of 1000 g / mol) was used instead of the 1.81 kg of Example 1. R - Polypropylene glycol (number average molecular weight of 1000 g / mol, stereoregularity of 99%), the other raw materials, proportions and process conditions are the same as in Example 1.
[0046] Table 3. Thermoplastic polyester elastomers obtained from different formulations and their performance characterization
[0047] According to the results shown in Table 3, while keeping the types of dicarboxylic acid and diol, the stereoregularity of the stereoregularly controlled polypropylene glycol, and the hard segment content constant, adjusting the number-average molecular weight of the stereoregularly controlled polypropylene glycol has a significant impact on the properties of thermoplastic polyester elastomers (TPEEs). As the number-average molecular weight of the stereoregularly controlled polypropylene glycol gradually increases from 1000 g / mol to 3000 g / mol, the melting point and glass transition temperature of TPEEs slightly increase, the maximum tensile strength generally shows an increasing trend, while the elongation at break gradually decreases. This indicates that the higher number-average molecular weight of the stereoregularly controlled polypropylene glycol enhances molecular chain entanglement and load-bearing capacity, which is beneficial for improving tensile strength, but at the same time limits the deformation capacity of the chain segments, leading to a decrease in material ductility. The performance of Comparative Example 2 further illustrates that, under the same conditions, the stereoregularly controlled polypropylene glycol is more advantageous than polytetrahydrofuran as the soft segment of TPEEs.
[0048] Example 16 Add 0.51 kg of terephthalic acid; 0.47 kg of 1,4-butanediol; and 1.81 kg of... R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 0.84 g catalyst (tetrabutyl titanate), 1.67 g antioxidant 1010 and 1.67 g antioxidant 168, and 0.04 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0049] Example 17 Add 0.76 kg of terephthalic acid; 0.71 kg of 1,4-butanediol; and 1.81 kg of... R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 1.27 g catalyst (tetrabutyl titanate), 2.54 g antioxidant 1010 and 2.54 g antioxidant 168, and 0.06 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was then raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at approximately 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0050] Example 18 1.73 kg of terephthalic acid; 1.61 kg of 1,4-butanediol; 1.81 kg of... RPolypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 2.88 g catalyst (tetrabutyl titanate), 5.76 g antioxidant 1010 and 5.76 g antioxidant 168, and 0.14 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0051] Example 19 3.01 kg of terephthalic acid; 2.81 kg of 1,4-butanediol; 1.81 kg R Polypropylene glycol (number average molecular weight 1000 g / mol, stereoregularity >99%), 4.97 g catalyst (tetrabutyl titanate), 10.01 g antioxidant 1010 and 10.01 g antioxidant 168, and 0.24 g stabilizer (triphenyl phosphite) were added to the reactor and stirred. Esterification was carried out at 230 °C for 4 h under nitrogen protection. The temperature was raised to 255 °C and vacuum was applied. The pre-condensation pressure was controlled at about 1200 Pa for 1.2 h. The pressure was further reduced to 80 Pa for final condensation for 3 h. The product was discharged and granulated to obtain thermoplastic polyester elastomer particles.
[0052] Table 4. Thermoplastic polyester elastomers with different hard segment contents and their performance characterization
[0053] According to the results shown in Table 4, under the conditions of fixed dicarboxylic acid, diol types, and controllable stereoregularity of polypropylene glycol (PPE), the hard segment content plays a key regulatory role in the thermal and mechanical properties of TPEE. As the hard segment content gradually increases from 35% to 75%, the melting point of TPEE increases significantly, the glass transition temperature increases slightly, the maximum tensile strength continues to increase, while the elongation at break gradually decreases. This is because the increased hard segment content promotes the crystallization of hard segments and the formation of physical crosslinking points, thereby enhancing the load-bearing capacity, but at the same time restricts the free movement of soft segments, reducing the ductility of TPEE.
[0054] In summary, the comparison results of the examples and comparative examples show that the stereoregularity level, number-average molecular weight, and hard-segment copolymerization composition of the polypropylene glycol soft segments with controllable stereoregularity used in this invention jointly determine the thermal and mechanical properties of the material. Within the raw material system and process window defined by this invention, key indicators such as melting point, glass transition temperature, strength, and elongation can be synergistically controlled, thereby obtaining thermoplastic polyester elastomers with both high strength and high elongation, providing a reliable basis for material design and engineering preparation in different application scenarios.
Claims
1. A thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol, characterized in that, The thermoplastic polyester elastomer is obtained by polycondensation of a diacid, a diol, and polypropylene glycol with controllable stereoregularity, or by polycondensation of a dimethyl diacid, a diol, and polypropylene glycol with controllable stereoregularity. The diacid or dimethyl diacid and the diol form the hard segment, and the polypropylene glycol with controllable stereoregularity forms the soft segment. The general formula of the thermoplastic polyester elastomer is shown below: In the formula: x, n, and m are all integers greater than 0; R and R' represent substituents, which are respectively substituents of the dicarboxylic acid. diols The substituents on it correspond to the substituents.
2. The thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol according to claim 1, characterized in that, The thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol has a melting point of 150~230 ℃ and a glass transition temperature of -71~-40 ℃. Its maximum tensile strength is 15~35 MPa; its elongation at break is 400~1200%.
3. The thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol according to claim 1, characterized in that, The main configuration of the stereoregularity-controlled polypropylene glycol is as follows: R - Polypropylene glycol or S - Polypropylene glycol, the stereoregularity of which is 70-100%, and the number-average molecular weight of which is controllable. M n The main configurations of polypropylene glycol with a concentration of 500–5000 g / mol and controllable stereoregularity are as follows: 。 4. The thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol according to claim 1, characterized in that, The dicarboxylic acid is selected from at least one of terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,5-furandicarboxylic acid, and the dimethyl ester of the dicarboxylic acid is selected from at least one of dimethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylic acid, and dimethyl 2,5-furandicarboxylic acid, with the following structural formula: 。 5. The thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol according to claim 1, characterized in that, The diol comprises at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, 1,4-cyclohexanediethanol, isosorbide, and 2,5-tetrahydrofurandiethanol, with the following structural formula: 。 6. A method for preparing a thermoplastic polyester elastomer based on controllable stereoregularity of polypropylene glycol as described in any one of claims 1-5, characterized in that, The reaction formula is as follows: Dicarboxylic acid or dimethyl diacid, diol, stereoregularity controllable polypropylene glycol, catalyst, antioxidant and stabilizer are added to a reactor and esterification or transesterification reaction is carried out under nitrogen protection. After completion, the temperature is raised and vacuum is drawn to carry out polycondensation reaction to obtain thermoplastic polyester elastomer. Among them, stereoregularity controllable polypropylene glycol is added during esterification or transesterification reaction, or after esterification or transesterification reaction and during polycondensation.
7. The preparation method according to claim 6, characterized in that, The molar ratio of the diacid or dimethyl diacid to the diol is 1:(1.1~1.8); the mass ratio of the stereoregularity-controlled polypropylene glycol to the total mass of the diacid or dimethyl diacid and the diol is 1:(0.5~5); the mass ratio of the catalyst to the diacid or dimethyl diacid is 1:(400~1000); the mass ratio of the antioxidant to the diacid or dimethyl diacid is 1:(100~200); and the mass ratio of the stabilizer to the diol is 1:(10000~12000).
8. The preparation method according to claim 6, characterized in that, The esterification reaction is carried out at a temperature of 180-250℃ for 3-6 hours; the transesterification reaction is carried out at a temperature of 180-250℃ for 3-6 hours; and the polycondensation reaction is carried out at a temperature of 200-280℃ for 2-6 hours.
9. The preparation method according to claim 5, characterized in that, The polycondensation reaction includes pre-polymerization and final polymerization. The absolute pressure of the pre-polymerization reaction system is 800-1500 Pa. After the pre-polymerization is completed, the pressure is further reduced to enter the final polymerization. The absolute pressure of the final polymerization reaction system is 30-100 Pa.
10. The preparation method according to claim 6, characterized in that, The catalyst is any one or a combination of at least two of titanium-containing compounds, tin-containing compounds, or antimony-containing compounds; the antioxidant includes any one or a combination of at least two of antioxidant 1010, antioxidant 168, antioxidant 1098, or antioxidant 1076; the stabilizer includes any one or a combination of at least two of phosphite compounds, phosphate compounds, or aminourea compounds.