Elastomer and preparation method and application thereof

Abstract

The invention relates to an elastomer and a preparation method and application thereof, the structure of the elastomer is shown as a general formula I. The elastomer has excellent self-healing efficiency, high tensile strength and toughness, low surface energy and remarkable reprocessability.

Description

Technical Field

[0001] The present invention belongs to the field of elastomeric materials, and particularly relates to an elastomer and its preparation method and application. Background Art

[0002] Due to their excellent elasticity and flexibility, elastomers have been widely used in the fields of biomedicine, wearable electronics, and soft robotics. With the increasing emphasis on sustainable development and the growing demand for high-performance materials, self-healing elastomers with both puncture resistance and damage tolerance, as well as high strength and high toughness, are attracting more and more attention. However, there are inherent contradictions among these properties, and it is a major challenge to simultaneously improve the above properties in a single material system. To enhance the mechanical strength and dynamic self-healing performance of elastomers, researchers have adopted various strategies, including introducing dynamic hard phases, hierarchical hydrogen bonds, and rigid-flexible supramolecular segments, but these methods often reduce their toughness. Other methods, such as designing non-covalent interactions, including metal coordination, cation-π interactions, and introducing organic imine cages, sequential polymerization, and multi-dynamic crosslinking units, although enhancing the strength and toughness of elastomers, reduce their healing efficiency. Therefore, there is an urgent need for efficient molecular engineering strategies to simultaneously improve these conflicting properties. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an elastomer and its preparation method and application.

[0004] The present invention provides an elastomer represented by the general formula I, and the structural general formula is as follows:

[0005]

[0006] Wherein R1 is a diisocyanate residue; R2 is a bisphenol residue; R3 is a diamine residue; wherein n = 50 - 500;

[0007] Wherein the wavy line indicates that the structure of the repeating unit is omitted.

[0008] Note: The R1 diisocyanate residue is the remaining group after removing the isocyanate group (-NCO) from the diisocyanate; the R2 bisphenol residue is the group after removing the phenolic hydroxyl group from the bisphenol; the R3 diamine residue is the group after removing the amino group from the diamine.

[0009] Preferably, the diisocyanate includes one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI); the diphenol includes one or more of hydroquinone, catechol, resorcinol, octafluorobiphenol, biphenol, hexafluorobisphenol A, bisphenol A, bisphenol F, 4,4'-sulfonyldiphenol; the diamine includes one or more of ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, adipic dihydrazide, isophthalic dihydrazide.

[0010] Preferably, the structure includes:

[0011]

[0012] one or more of; wherein R is a diisocyanate residue;

[0013] Further, the diisocyanate includes one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI).

[0014] The present invention provides a method for preparing an elastomer, comprising:

[0015] (1) Mixing polytetramethylene ether glycol, diisocyanate, and a catalyst, reacting under a protective gas condition, cooling, and then adding a chain extender and a solvent, and stirring to react;

[0016] (2) Adding hexamethylene diisocyanate trimer and a solvent, stirring to react, and drying to obtain an elastomer.

[0017] Preferably, in step (1), the diisocyanate includes one or more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI); the catalyst includes dibutyltin dilaurate;

[0018] Preferably, the chain extender includes bisphenol (diphenol) and diamine; the solvent includes N,N-dimethylacetamide.

[0019] Preferably, the molar ratio of bisphenol to diamine in the chain extender is 1:1 to 1:10;

[0020] Preferably, the phenol includes one or more of hydroquinone, catechol, resorcinol, octafluorobiphenol, biphenol, hexafluorobisphenol A, bisphenol A, bisphenol F, 4,4'-sulfonyldiphenol; the diamine includes one or more of ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, adipic dihydrazide, isophthalic dihydrazide.

[0021] Preferably, the molar ratio of the polytetramethylene ether glycol, diisocyanate, chain extender, and hexamethylene diisocyanate trimer is 2.5:(5 - 8):(3 - 5):(0.5 - 0.8); the catalyst is 0.01 - 1% of the total mass of the reactants.

[0022] Preferably, in step (1), after vacuum drying the polytetramethylene ether glycol, it is cooled to 40 - 90 °C, then the diisocyanate and the catalyst are added, and the reaction is carried out for 1 - 24 h under a protective gas condition, cooled to 25 - 80 °C, and the chain extender solution is added, and the stirring reaction is carried out for 1 - 24 h.

[0023] Preferably, in step (2), the solvent includes N,N-dimethylacetamide; the stirring reaction time is 0.5 - 2 h; the drying is carried out in an oven at 60 - 100 °C for 12 - 48 h, and then vacuum dried at 60 - 80 °C for 12 - 48 h.

[0024] Natural spider silk is renowned for its excellent mechanical properties and has long been a model for the design and development of high-performance elastomers. In addition to the β-sheet nanocrystals and amorphous phase composed of polypeptide chains connected by hydrogen bonds, the intact spider silk fiber also has a unique locked nano-phase to maintain the integrity of the β-sheet nanocrystals (as shown in Figure 1 a). These properties together endow spider silk with excellent strength and toughness. Notably, molecular dynamics simulations and experimental studies have confirmed that reducing the size of the β-sheet nanocrystals can increase energy dissipation, thereby significantly improving the mechanical strength and damage resistance of spider silk. In addition, the reversibility of the hydrogen bond array in the β-sheet nanocrystals and the stick-slip deformation of the amorphous chains jointly promote the self-healing of spider silk defects. Overall, leveraging the small-sized biomimetic hydrogen bond nano-phase observed in spider silk represents a promising strategy for simultaneously enhancing the mechanical strength, toughness, and self-healing ability of elastomers.

[0025] Based on this, the present invention draws inspiration from and surpasses the spider silk nano-confinement, and proposes a molecular engineering strategy using fluorine hydrogen bonds to confine dynamic nano-domains to address the typical contradiction among strength, toughness, and self-healing, while endowing the elastomer with excellent puncture and tear resistance (as shown in Figure 1As shown in Fig. b). Specifically, the hydrazide group rich in hydrogen bond donors and acceptors easily forms unique hard domains with a high density of hydrogen bonds. The fluorinated groups participating in the formation of fluorine-hydrogen bonds can effectively reduce the size of the hard domains. These smaller and denser hydrogen bond array nanophases act as strong but reversible crosslinkers, contributing to a large amount of energy dissipation, thereby enhancing mechanical strength, toughness, puncture resistance, and damage tolerance. It is worth noting that the strong electron-withdrawing ability of the fluorinated groups accelerates the dynamic dissociation and association of the phenolic urethane bonds in the hard domains, cooperating with the reversible hydrogen bond array to further improve the self-healing efficiency of the elastomer. The resulting fluorinated poly(urethane-urea) (such as CPUU-FA) elastomer exhibits the highest puncture energy among polymer elastomers and the highest fracture energy among all reported thermosetting elastomers, while also having excellent self-healing efficiency, high tensile strength, low surface energy, and remarkable reprocessability.

[0026] Beneficial effects

[0027] The elastomer of the present invention has excellent self-healing efficiency, high tensile strength and toughness, low surface energy, and remarkable reprocessability. Brief Description of the Drawings

[0028] Figure 1 (a) Schematic diagram of the structure of spider silk, showing the microstructure with β-sheet nanocrystals, locked phases, and polypeptide chains; (b) Microstructure diagram of the bionic elastomer, including F-H bonds, nanoassemblies of hydrogen bond arrays, and amorphous polytetrahydrofuran (PTMG) chains;

[0029] Figure 2 For the synthesis of fluorinated elastomers and their controls;

[0030] Figure 3 Shows the mechanical properties, self-healing properties, and reprocessing properties of poly(urethane-urea) elastomers; specifically including: (a) Typical stress-strain curves of CPUU-FA and CPUU-BA elastomers, and (b) Force-displacement curves, with the inset in (b) showing the puncture resistance of CPUU-FA; (c) Comparison of the puncture energies of CPUU-FA with other reported elastomers, and the results show that 887 mJ is the highest puncture energy among all polymer elastomers; (d-e) Show the typical engineering stress-strain curves of intact and slotted CPUU-FA elastomers, indicating that its fracture energy has created a new world record for thermosetting elastomers; (f) Shows the hysteresis area corresponding to each loading-unloading cycle; (g) Describes the relationship between the self-healing efficiency (measured by the tensile strength recovery rate) of CPUU-FA and CPUU-BA elastomers and the repair time at 100 °C; (h) Shows the relationship between the tensile strength recovery rate of CPUU-FA and CPUU-BA elastomers and the number of reprocessing cycles;

[0031] Figure 4 Mechanisms for enhanced toughening, self-healing, and improved efficiency; (a) 2D-SAXS patterns of CPUU-FA elastomer at (i) 0%, (ii) 100%, (iii) 300%, (iv) 500%, and (v) 0% strain after unloading; (b) Proposed mechanisms for improving the puncture resistance, tear resistance, tensile strength, and toughness of CPUU-FA elastomer; (c) 2D-WAXD patterns of CPUU-FA elastomer at 0%, 300%, 500%, and 0% strain after unloading; (d) 1D-WAXD curves and their fitting curves of CPUU-FA and CPUU-BA elastomers at 500% strain; (e) Dissociation degrees of phenol-carbamate bonds determined by -NCO / C6H6 ratio at different temperatures with a heating interval of 5 min; (f) In-situ temperature-dependent FT-IR spectra of CPUU-FA in the C=O stretching vibration region (1760 - 1620 cm-1);

[0032] Figure 5 Mechanical and self-healing performance diagrams for CPUU-FA, CPUU-BA, CPUU-FI, CPUU-BI, CPUU-FH, CPUU-BH, CPUU-F, and CPUU-B. Detailed implementation manners

[0033] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0034] Unless otherwise specified, all reagents were used directly without further purification. Polytetramethylene ether glycol (PTMG, number average molecular weight Mn = 2000 g / mol) and 4,4'-diisocyanate (HMDI) were purchased from Aladdin Chemical Reagent Co., Ltd. (China). Ultra-dry tetrahydrofuran (THF, purity 99.9%) was provided by J&K Scientific Co., Ltd. (China). Bisphenol A (B), hexafluorobisphenol AF (F), hexamethylenediamine (H), N,N-dimethylacetamide (DMAc, purity 99.8%) were purchased from Adma Chemical Technology Co., Ltd. (China). Isophthaloyl hydrazide (I) was provided by Macklin Biochemical Technology Co., Ltd. (China), hexamethylene diisocyanate trimer (tri-HT-100) was provided by Wanhua Chemical Group Co., Ltd., adipic dihydrazide (A) was provided by Macklin Biochemical Technology Co., Ltd. (China), and dibutyltin dilaurate (DBTDL, purity 95%) was provided by Sigma-Aldrich (China).

[0035] Related tests:

[0036] The mechanical properties and self-healing properties of the materials were characterized using an electronic universal material testing machine.

[0037] The tensile strength test method is as follows: Select the uniaxial tensile mode of the electronic universal material testing machine to conduct five tests on the same spline, and the results are averaged. The tensile rate is 50 mm / min. -1 。

[0038] The fracture energy test method: Evaluate the notched (notch length of 1 mm) and unnotched rectangular splines (5 mm×0.5 mm×15 mm). According to the formula:

[0039]

[0040] where C is the notch length (1.0 mm), and λC is the fracture elongation of the notched elastomer. W is the integral area of the stress-strain curve of the notched specimen from the strain to λ C 。

[0041] The anti-puncture test method: Use a self-made device to test on an electronic universal testing machine at a rate of 50 mm / min. -1 The force and displacement curves were obtained. The film thickness is about 750 μm.

[0042] The surface energy is calculated according to the following formula:

[0043] The healing efficiency test: Cut the material into rectangles (0.5 mm (T)×5 mm (W)×15 mm (L)), then cut it completely and piece it together, and place it under specific conditions to heal without applying external force. The healing efficiency of the material is characterized by the tensile strength of the specimen before and after healing.

[0044] Example 1

[0045] Preparation of fluorinated elastomer and its control elastomer

[0046] The preparation method of the elastomer is as Figure 2And Table 1. PTMG was added to a 100 mL round-bottom flask and dried under vacuum at 120 °C for 2 hours, then cooled to 80 °C. Then a mixture of HMDI (1.312 g, 5.000 mmol) and DBTDL (the catalyst dosage was 0.5 wt.% of the total mass of the reactants) was added, and the mixture was stirred for 3 hours under nitrogen protection and then cooled to 40 °C. The chain extender F (0.528 g, 1.570 mmol) and A (0.273 g, 1.570 mmol) were dissolved in 3 mL and 37 mL of DMAc respectively, and then added dropwise to the above reaction solution. After continuous stirring for 17 hours, a mixture containing 5 mL of DMAc and tri-HT-100 was added dropwise to the reaction system, and stirring was continued for 30 minutes to finally obtain a colorless, transparent and viscous polymer. The obtained polymer was poured into a Teflon mold, dried in an oven at 60 °C for 36 hours, and then dried under vacuum at 80 °C for 24 hours to prepare the CPUU-FA film. In addition, by replacing the chain extender F with B and following the above synthesis steps, the CPUU-BA film can be prepared. The synthesis of other elastomers (CPUU-FI, CPUU-BI, CPUU-FH, CPUU-BH, CPUU-F, CPUU-B) follows similar steps, as shown in Table 1 for details.

[0047] Study on the Mechanical, Self-Healing and Reprocessable Properties of Elastomers

[0048] As Figure 3 shown in a and Table 2, the tensile strength of the CPUU-FA elastomer was 42.3 ± 1.9 MPa, the elongation at break was 624.0 ± 28.4%, and the toughness value was 81.5 ± 3.9 MJ m -3 . In contrast, the CPUU-BA elastomer performed worse in terms of tensile strength (32.3 ± 1.5 MPa), elongation at break (574.2 ± 39.2%) and toughness (55.6 ± 2.5 MJ m - 3). It is worth noting that the CPUU-FA elastomer has excellent puncture resistance and can withstand a puncture force of up to 85 N without failure ( Figure 3 shown in b and Table 2). Its puncture energy reached an impressive 887.3 ± 2.4 mJ, which is the highest value among all synthetic elastomers known in the prior art ( Figure 3 shown in c). In addition, the damage tolerance of CPUU-FA was also evaluated. Figure 3 As shown in d and Table 2, the notched sample could be stretched to 427% while maintaining a relatively high tensile strength. The calculated fracture energy of the CPUU-FA elastomer was 117.4 ± 1.5 kJm -2 , which is more than 11 times that of natural rubber and the highest record of the fracture energy of thermosetting elastomers ( Figure 3 shown in e).

[0049] Compared with CPUU-BA, the CPUU-FA elastomer has better elasticity and energy dissipation ability. The hysteresis area reaches the maximum in the first loading-unloading cycle, then decreases, and tends to be stable after the 10th loading-unloading cycle. This indicates that effective energy dissipation mainly occurs in the initial cycle. CPUU-BA also has a similar trend, but the hysteresis area after the first cycle is significantly smaller than that of CPUU-FA. It is worth noting that after 2 h of relaxation, the loading-unloading curve of CPUU-FA basically coincides with the first curve, while CPUU-BA shows obvious residual strain. To further clarify the energy dissipation ability of the elastomer, a series of continuous loading-unloading tests with increasing strain were carried out, and the curve of the hysteresis area versus strain was plotted ( Figure 3 f). At small strains below 300%, the curve slope of CPUU-FA remains almost unchanged, which means that the elastomer mainly undergoes elastic deformation, resulting in minimal energy dissipation. When the strain exceeds 300%, energy can be effectively dissipated, improving the puncture resistance, damage tolerance, and toughness. In contrast, although CPUU-BA has a similar energy dissipation mechanism, its dissipation ability is always lower than that of CPUU-FA throughout the strain range. Under thermal stimulation, the CPUU-FA elastomer exhibits excellent self-healing properties due to the reversible dissociation and recombination of hydrogen bond arrays and phenolurethane bonds, as well as the rapid migration of amorphous chains. With the extension of time, its self-healing efficiency gradually increases from 2 h to 4 h, 8 h, and 16 h, reaching ≈18%, ≈29%, ≈85%, and ≈99% respectively ( Figure 3 g), always higher than the self-healing efficiency of CPUU-BA under the same conditions (≈6%, ≈28%, ≈70%, and ≈85%). This difference is mainly attributed to the fact that fluorinated phenol-carbamate bonds exhibit better kinetics than non-fluorinated phenol-carbamate bonds. The reprocessability of the samples was further characterized by evaluating the tensile strength recovery efficiency. At 120 °C, a transparent and slag-free CPUU-FA film can be obtained after hot pressing at a pressure of 5 MPa for 30 min. The FT-IR spectrum of the post-treated film is consistent with that of the original film, confirming the suitability of the post-treatment conditions. Impressively, after two cycles, the attenuation of the tensile strength of the CPUU-FA elastomer is minimal, while the attenuation of the tensile strength of the CPUU-BA elastomer is obvious ( Figure 3 h).

[0050] Mechanism study on enhancement, toughening, and improvement of repair efficiency

[0051] In summary, the CPUU-FA elastomer has improved in terms of tensile strength, mechanical toughness, and self-healing efficiency. To further clarify its underlying mechanism, in-situ SAXS, wide-angle X-ray diffraction (WAXD), and FT-IR were used for in-depth research. When the CPUU-FA strength reached 100% strain, as the strain increased, the scattering rings became gradually shortening spindle shapes along the stretching direction ( Figure 4 a-i-ⅲ). Notably, within the strain range less than 300%, no crystallization peaks were observed in 1D-WAXD ( Figure 5 ). This indicates that the dynamic nanodomains deform without disintegration, and the soft segments are aligned with the stretching direction. When the strain increased to 500%, a new scattering pattern parallel to the stretching direction appeared ( Figure 4 a-ⅳ), and two distinct spots appeared in the 2D-WAXD pattern ( Figure 4 b). The corresponding 1d curve could be deconvoluted into two peaks centered on the scattering vector q, which were 14.3 and 16.8 nm -1 ( Figure 4 c), which are due to the (020) and (110) planes of the crystal methylene, indicating that the dynamic nanodomains gradually disintegrate, accompanied by strain-induced crystallization of PTMG. When the strain recovered to 0%, both the scattering rings and diffraction rings returned to their original isotropic ring states ( Figure 4 a-ⅳ), confirming the reversibility of the nanodomains and crystallization of the elastomer. These findings are consistent with the Figure 3 phenomenon shown in f, where the curve slope remains constant at strains below 300% and gradually increases at strains above 300%. As shown in Figure 4 d, the small and dense dynamic nanoconfinement proposed in this paper is stabilized by F-H bonds, is rigid, and at the same time retains the ability to deform and decompose under external forces. This complex design is crucial for improving the strength and toughness of the CPUU-FA elastomer. Specifically, at small strains (<300%), the amorphous segments expand while the nanodomains deform, causing the PTMG chains to orient along the stretching direction. During this process, the nanostructures remain intact because only a limited number of sacrificial bonds are broken. Therefore, the CPUU-FA elastomer exhibits excellent elasticity. When the strain exceeds 300%, the decomposition of the nanostructures releases the amorphous chains hidden within, thus significantly improving the ductility and toughness of the CPUU-FA. As the strain further increases, strain-induced crystallization of the PTMG soft segments occurs along the stretching direction, enabling the CPUU-FA to have a high fracture energy barrier to resist deformation. Therefore, we propose that the synergistic effects of the extension of PTMG chains, the fracture of sacrificial bonds, the deformation and disintegration of dynamic nanodomains, and the strain-induced crystallization of PTMG segments together improve the mechanical properties of the elastomer.

[0052] By preparing fluorinated polyurethane (CPUU-F) and non-fluorinated polyurethane (CPUU-B), the potential mechanism by which the introduction of fluorinated atoms can effectively enhance the kinetics of the phenol-carbamate bond and thus improve the self-healing efficiency of elastomers was further elucidated. Considering that the reversibility of phenol-carbamate bonds with different structures can be characterized by their initial dissociation temperature, and the lower the dissociation temperature, the stronger the reversibility, variable-temperature FT-IR was used to study these differences. The absorption peak of the dissociating -NCO group in CPUU-F appeared at 2275 cm -1 at 80 °C, while in CPUU-B it appeared at 2275 cm -1 at 90 °C ([[]] Figure 4 Figure 4 e). In addition, whether at different temperatures within a specific time or at different times at a fixed temperature, the degree of dissociation and rate of the phenol-carbamate bond were always higher than those of its counterpart ([[]] Figure 4 Figure 4 e). These results indicate that fluorinated phenol-carbamate bonds have superior reversibility compared to non-fluorinated ones. It is worth noting that FT-IR spectral analysis confirmed that the intensity of ordered N-H in CPUU-FA gradually decreased with increasing temperature, while the intensity of free N-H increased ([[]] Figure 4 Figure 4 f). This phenomenon was also observable in the CPUU-BA spectrum, but to a lesser extent compared to CPUU-FA. The results suggest that fluorinated motifs with strong electron-withdrawing properties are crucial for improving the self-healing efficiency of elastomers. The effect of fluorinated motifs on the reversibility of the phenol-carbamate bond was investigated using variable-temperature stress relaxation experiments.

[0053]

[0054] Table 1. CPUU-FA monomers and their contents and the corresponding elastomers

[0055]

[0056]

[0057] where F in Table 1 is B is I is H is A is

[0058] Table 2. Summary of the mechanical properties of CPUU-FA and CPUU-BA, all data are expressed as mean ± standard deviation (n ≥ 3)

[0059]

[0060] Table 3. Summary of the mechanical and self-healing properties of all elastomers

[0061]

Claims

1. An elastomer as shown in general formula I, characterized in that: The general structural formula is shown below: Wherein R1 is a diisocyanate residue; R2 is a bisphenol residue; R3 is a diamine residue; wherein n=50-500.

2. The elastic body according to claim 1, characterized in that: The diisocyanate includes one or more of toluene diisocyanate TDI, isophorone diisocyanate IPDI, diphenylmethane diisocyanate MDI, dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, and lysine diisocyanate LDI; the bisphenol includes one or more of hydroquinone, catechol, resorcinol, octafluorobiphenol, biphenol, hexafluorobisphenol A, bisphenol A, bisphenol F, and 4,4′-sulfonyldiphenol; the diamine includes one or more of ethylenediamine, propylenediamine, butanediamine, hexamethylenediamine, adipic dihydrazide, and isophthalic dihydrazide.

3. The elastic body according to claim 1, characterized in that: The structure comprises: One or more of; wherein R is a diisocyanate residue.

4. A method for preparing an elastomer, comprising: (1) polytetramethylene ether glycol, diisocyanate and a catalyst are mixed, reacted under protective gas conditions, cooled, and then a chain extender and a solvent are added and stirred for reaction; (2) adding hexamethylene diisocyanate trimer and a solvent, stirring for reaction, and drying to obtain an elastomer.

5. The preparation method according to claim 4, characterized in that: The diisocyanate in step (1) includes one or more of toluene diisocyanate TDI, isophorone diisocyanate IPDI, diphenylmethane diisocyanate MDI, dicyclohexylmethane diisocyanate HMDI, hexamethylene diisocyanate HDI, and lysine diisocyanate LDI; In step (1), the catalyst comprises dibutyltin dilaurate; In step (1), the chain extender comprises bisphenol and diamine; The solvent in step (1) includes N,N-dimethylacetamide.

6. The preparation method according to claim 5, characterized in that: The molar ratio of bisphenol to diamine in the chain extender is 1:1 to 1:10; The bisphenol includes one or more of hydroquinone, catechol, resorcinol, octafluorobiphenol, biphenol, hexafluorobisphenol A, bisphenol A, bisphenol F, and 4,4′-sulfonyldiphenol; the diamine includes one or more of ethylenediamine, propylenediamine, butanediamine, hexamethylenediamine, adipic dihydrazide, and isophthalic dihydrazide.

7. The preparation method according to claim 4, characterized in that: The molar ratio of the polytetramethylene ether glycol, diisocyanate, chain extender and hexamethylene diisocyanate trimer is 2.5:(5-8):(3-5):(0.5-0.8); the catalyst accounts for 0.01-1% of the total mass of the reactants.

8. The preparation method according to claim 4, characterized in that: In step (1), the polytetramethylene ether glycol is vacuum dried and cooled to 40-90° C., then diisocyanate and a catalyst are added, reacted under protective gas conditions for 1-24 hours, cooled to 25-80° C., a chain extender solution is added, and stirred for reaction for 1-24 hours.

9. The preparation method according to claim 4, wherein the solvent in step (2) comprises N,N-dimethylacetamide; the stirring reaction time is 0.5 to 2 hours; and the drying is performed in an oven at 60 to 100°C for 12 to 48 hours, and then vacuum dried at 60 to 80°C for 12 to 48 hours.

10. Use of the elastomer according to claim 1 in the fields of biomedicine, wearable electronic devices, and soft robotics.

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