Self-repairing acrylate dielectric material based on dual-mode network as well as preparation method and application of self-repairing acrylate dielectric material

Abstract

The invention discloses a self-repairing acrylate dielectric material based on a dual-mode network as well as a preparation method and application of the self-repairing acrylate dielectric material based on the dual-mode network. According to the material, dynamic covalent chemistry and a synergistic effect of a dual-mode network structure are utilized, a long-chain flexible cross-linking agent and a short-chain chain extender containing dynamic thiocarbamate bonds are adopted, and the self-repairing acrylate dielectric material based on the dual-mode network is prepared. Meanwhile, the proportion of the multifunctional micromolecule TMPTMA or PET4A is optimized, and performance balance and self-repairing are achieved. In the preparation process, click reaction curing is initiated through ultraviolet light, the process is simple, and the cost is low. The tensile strength is 0.3-0.6 MPa, the elongation at break is 350%, the dielectric constant at 1kHz is 7-9, the dielectric loss is 0.047-0.067, and the mechanical property can be completely recovered within 30 minutes at the temperature of 100 DEG C. The device is suitable for bionic flapping wing aircraft muscle systems, muscle-like drivers, repairable artificial heart valves and the like, damage is repaired through dynamic key recombination, the reliability of the device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] The invention belongs to a method for preparing a polymer material, and relates to a self-repairing acrylate dielectric material based on a dual-mode network, a preparation method and application thereof. Background Art

[0002] Dielectric elastomers are a type of electroactive polymer that can produce large deformations under an external electric field. This new type of electroactive polymer smart material has the advantages of large electroinduced deformation, fast response speed, high elasticity, light weight and good flexibility. It has good application prospects in aerospace, mechanical engineering, biomedicine and other fields.

[0003] At present, the methods for improving the dielectric properties of dielectric elastomer materials mainly include material modification and composite strategies. Through molecular structure design, such as the introduction of polar groups (cyano, ester, etc.), dipole polarization can be enhanced, thereby improving the dielectric constant. For example, acrylonitrile-butadiene copolymer (NBR) has higher dielectric properties due to the presence of cyano groups. Adding ceramic fillers with high dielectric constants (such as barium titanate and barium strontium titanate) is a common method. Nanoscale fillers can reduce agglomeration and improve interfacial compatibility, but the content needs to be controlled to avoid a decrease in mechanical properties. Conductive fillers (such as carbon nanotubes and graphene) can significantly improve the dielectric constant through the microcapacitor effect, but it is necessary to prevent seepage from increasing leakage current. In addition, constructing a porous structure or introducing ionic liquids can utilize the interfacial polarization effect to enhance the dielectric response, but attention should be paid to the uniformity and stability of the material. However, existing methods generally find it difficult to achieve the coordinated optimization of the dielectric and mechanical properties of materials, and they are also unable to effectively solve the problem of easy damage and failure of traditional dielectric elastomer materials.

[0004] It is particularly noteworthy that, although in recent years, the introduction of dynamic bonding technology has opened up new ways to optimize the performance of dielectric elastomers, which can give materials self-healing capabilities through reversible covalent bonds (such as disulfide bonds, borate bonds, etc.), these systems often find it difficult to balance high dielectric properties and excellent mechanical properties. Although some elastomers containing dynamic bonds exhibit good self-healing properties, their dielectric constants are generally low; and polar polymers with high dielectric constants often have problems such as insufficient dynamic bond stability and significant performance attenuation at high temperatures. In addition, existing dielectric elastomer materials are difficult to maintain a stable dielectric response over a wide frequency range, and dielectric losses increase significantly when used at high frequencies. This key bottleneck seriously restricts their practical applications in flexible electronics, intelligent drives and other fields. These inherent defects make the development of dielectric elastomer materials with high dielectric properties, excellent mechanical properties and wide-band stability a technical problem that needs to be overcome urgently. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a self-healing acrylate dielectric material based on a dual-mode network, a preparation method and application thereof.

[0006] The preparation method of self-healing dielectric materials based on a dual-mode network proposed in this study is innovative in that by integrating dynamic covalent chemistry and a dual-mode network structure, effective regulation of the electromechanical properties and self-healing properties of the materials is achieved. Specifically, by introducing two crosslinking agents / chain extenders with significant molecular weight differences, while optimizing the electrical properties of the materials, their mechanical properties are significantly improved. In addition, through molecular design, dynamic covalent bonds are introduced, enabling the materials to have good self-healing ability while maintaining excellent dielectric properties, providing reliable theoretical and methodological support for the combination of high dielectric properties and autonomous damage repair. This method has the advantages of simple preparation process, convenient post-treatment, strong versatility, and low cost, showing good application prospects.

[0007] The first aspect of the present invention protects a self-healing acrylate dielectric material based on a dual-mode network, and the dielectric material is prepared by ultraviolet curing reaction from the following components:

[0008] Long-chain crosslinking agent (25 - 45 wt%): Aliphatic polyurethane diacrylate CN9021ns is used, and its molecular chain is composed of a flexible polyether diol segment and an aliphatic diisocyanate segment, forming a continuous flexible network, endowing the material with high elasticity and large deformation ability;

[0009] Short-chain chain extender (30 - 50 wt%): Selected from polyurethane acrylate IE6000 (IPDI-EDDET) containing dynamic ethyl thiocarbamate bonds, with a molecular weight Mn≈6000 g / mol, endowing self-healing function through dynamic bonds (infrared characteristic peak 1195 cm -1 ) and optimizing dielectric properties;

[0010] Acrylate monomer (20 - 35 wt%): Trimethylolpropane trimethacrylate (TMPTMA) or pentaerythritol triacrylate (PET4A) is selected, with a functionality ≥3, enhancing the crosslinking density to balance strength and flexibility;

[0011] Photoinitiator (0.2 wt%): Composed of 2,2-dimethoxy-2-phenylacetophenone (DMPA) and benzophenone (BP) compounded at a mass ratio of 0.8 - 1.2:1 to ensure efficient ultraviolet curing. The most preferred compounding ratio is a mass ratio of 1:1.

[0012] For the above technical solution, it is further preferred that: the long-chain crosslinking agent accounts for 30 - 40 wt%, the short-chain chain extender accounts for 32 - 42 wt%, and the acrylate monomer accounts for 23 - 28 wt%. For example, in Example 3, CN9021ns accounts for 35 wt%, IE6000 accounts for 38.88 wt%, and TMPTMA accounts for 25.92 wt%, achieving the synergistic optimization of a dielectric constant of 7.68 and an elongation at break of 300%;

[0013] The dynamic ethyl thiocarbamate bond can achieve self - healing assisted by heating (as Figure 5 shown), and the mechanical property recovery rate after self - healing is > 85%;

[0014] The dielectric constant of the material is 5.5 - 8.6, the dielectric loss is 0.047 - 0.081 at a frequency of 1 kHz, the tensile strength is 0.2 - 32 MPa, and the elongation at break is 150 - 570%.

[0015] For the above - mentioned technical solution, further preferably: The material of the present invention is composed of two cross - linkers at the molecular scale - CN9021ns (Mn is 30000*(1 ± 5%) g / mol) composed of long - chain flexible polyether diol segments and aliphatic diisocyanate segments, and a short - chain chain extender (Mn is 6000*(1 ± 5%) g / mol) containing dynamic ethyl thiocarbamate bonds, plus small - molecule comonomers such as trimethylolpropane trimethacrylate or pentaerythritol triacrylate. During the preparation process, the proportions of each component are adjusted according to different requirements. For example, in the system using only long - chain cross - linkers, the content of CN9021ns is 10% - 40% to explore the optimal ratio suitable for the dual - mode system; while in the dual - mode system, the content of the long - chain cross - linker is adjusted to 25% - 45%, and it is mixed with the short - chain chain extender and small - molecule comonomers in a specific ratio to achieve the best performance.

[0016] The second aspect of the present invention protects the preparation method of the dielectric material, which specifically includes the following steps:

[0017] Raw material mixing: Dissolve CN9021ns, IE6000, acrylate monomer and photo - initiator in anhydrous tetrahydrofuran (THF) according to the ratio, and stir to form a homogeneous solution;

[0018] UV curing: Inject the solution into a mold, and irradiate it with ultraviolet light (365 nm, irradiation intensity 10 - 50 mW / cm 2 ) for 1 - 5 minutes under nitrogen protection to trigger the click reaction between double bonds and between thiol and double bonds;

[0019] Post - treatment: The cured product is successively dried in vacuum at 40 °C for 12 hours and at 60 °C for 24 hours to completely remove the solvent and stabilize the dual - mode network structure.

[0020] For the above - mentioned technical solution, further preferably:

[0021] After UV curing, the thickness of the material is controlled within 0.3 - 0.6 mm to meet the requirements of dielectric property testing;

[0022] The mass ratio of the short-chain chain extender to the acrylate monomer is 1.5:1. For example, in Example 3, the synergistic effect of IE6000 (38.88%) and TMPTMA (25.92%) significantly improves the dielectric constant and flexibility of the material.

[0023] For the above technical solution, further preferably: To prepare this material, it is first necessary to synthesize a short-chain chain extender. The specific steps include stirring and reacting a stoichiometric ratio of isocyanate compounds (such as hexamethylene diisocyanate or isophorone diisocyanate) with 2,2'-(1,2-ethylenedioxy)bis(ethanethiol) (molar ratio 0.935:1) under nitrogen protection and in the presence of a catalyst for 10 - 12 hours. Subsequently, the final product is obtained through vacuum concentration and purification by washing with petroleum ether. Next, the prepared short-chain chain extender, long-chain crosslinker CN9021ns, and acrylate monomers are dissolved in anhydrous tetrahydrofuran to form a homogeneous solution, which is then transferred to a mold. Under a nitrogen atmosphere, a polymerization reaction is initiated using ultraviolet light. After that, the sample needs to be subjected to solvent evaporation and further curing treatment to obtain a self-healing dielectric material with a dual-mode network structure.

[0024] The third aspect of the present invention protects the application of the dielectric material. This material is very suitable for applications in scenarios such as muscle simulation systems for bionic flapping-wing aircraft in the aerospace field, muscle-like actuators in the field of mechanical engineering, and repairable artificial heart valves in the biomedical field. Further preferably, it includes applications in the aerospace field, in muscle simulation systems for bionic flapping-wing aircraft, whose large strain and rapid response characteristics can achieve the adaptive deformation of the aircraft. At the same time, the self-healing ability of the material can extend the service life in extreme environments. It can also be applied in the field of mechanical engineering, where dielectric elastomer actuators provide muscle-like compliant motion for robots, and its self-healing characteristics significantly improve the system reliability. Applied in the biomedical field, such as in repairable artificial heart valve actuators, its excellent biocompatibility and low modulus characteristics are also suitable for the development of bionic prosthetics and minimally invasive surgical tools.

[0025] Compared with the prior art, the specific beneficial effects of the present invention are:

[0026] 1. The synthesis method of the present invention is simple and the reaction conditions are easy to control. By preparing a short-chain chain extender containing dynamic bonds, selecting the types of acrylic acid and its ester derivatives monomers and adjusting the proportion of the flexible macromolecular crosslinking agent CN9021ns, a dielectric material with excellent performance is prepared, realizing the synchronous optimization of electromechanical properties and dynamic self-healing function. Among them, the long-chain segments in the dual-mode network can ensure that the elastomer maintains a high elongation rate, while the short-chain segments can increase the modulus under medium strain, so as to resist the rapidly increasing Maxwell stress during the actuation process. At the same time, the introduction of dynamic ethyl thiocarbamate bonds endows the material with self-healing characteristics. The use of small molecules further crosslinks the polymer network, effectively reducing the average molecular weight between crosslinking points. This modification enhances the stress transfer kinetics, improves the actuation frequency response of the elastomer, and simultaneously optimizes the hydrogen bond distribution in the dielectric material network. In particular, by precisely controlling the long-chain crosslinking agent CN9021ns in the mass fraction range of 30-35% (Example 3), the optimized construction of the structure is realized, enabling the material to maintain stable dielectric properties (dielectric constant fluctuation <5%) in the 10-10 7 Hz broadband frequency range, which is crucial for the application of high-frequency electronic devices. The synergistic effect of such structure and groups can prepare a dielectric material with good electromechanical properties and self-healing properties.

[0027] 2. The dual-mode network dielectric material provided by the present invention demonstrates a rational design of a dual-mode network dielectric material through the strategic integration of crosslinking agents / chain extenders with different chain lengths, thus realizing the synchronous optimization of electromechanical properties and dynamic self-healing function. This dual-mode network dielectric material exhibits excellent comprehensive properties: its mechanical properties are characterized by low modulus (0.3-0.6 MPa) and high ductility (elongation at break up to 350%), and at the same time it has excellent dielectric properties (at a frequency of 1 kHz, the dielectric constant is between 7 and 9, and the dielectric loss is 0.047-0.067). More notably, while maintaining the above properties, the material exhibits unique frequency response characteristics: the increase in dielectric loss is less than 0.015 in the 10 2 -10 6 Hz frequency range (see Figure 4 ), far superior to traditional acrylate-based dielectric materials (usually the increase >0.05), which is attributed to the efficient regulation of dipole orientation polarization by the dual-mode network. The research has successfully realized the coordinated regulation of the mechanical properties and dielectric properties of the material. It is worth noting that the introduction of dynamic bonds endows the material with good self-healing characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic structural diagram of CN z -B-IE / TMP prepared in Example 3;

[0029] Figure 2 The infrared spectrum of CN z -B-IE / TMP prepared in Example 3;

[0030] Figure 3 Schematic diagrams of uniaxial stretching of the dielectric materials prepared in Examples 1, 2, and 3;

[0031] Figure 4 The dielectric property diagram of CN z -B-IE / TMP prepared in Example 3;

[0032] Figure 5 The self-healing process schematic diagram of CN z -B-IE / TMP prepared in Example 3. Detailed implementation manners

[0033] In order to more clearly understand the above objects, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. Many specific details are set forth in the following description in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of the present invention, rather than all the embodiments.

[0034] The preferred implementation manners of the present invention will be described in detail below in conjunction with the embodiments. It should be understood that the following embodiments are given only for the purpose of illustration, and are not used to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0035] Unless otherwise specified, the experimental methods and calculation methods used in the following embodiments are all conventional methods. The materials, reagents, etc. used in the following embodiments can all be obtained from commercial channels unless otherwise specified. The performance testing instruments used in the embodiments of the present invention: The microstructure is analyzed by a Fourier transform infrared spectrometer.

[0036] In order to test its performance as a dielectric material, including the dielectric constant and dissipation factor, measurements were carried out at 25 °C using a broadband dielectric spectrometer (from Novocontrol, Germany). The dielectric property test electrodes are copper electrodes with a diameter of 10 mm. The samples were prepared into circles with a diameter of 10 mm and a thickness of about 0.5 mm. The measurement frequency range is from 10 to 10 7Hz. Each sample was tested at least five times to ensure repeatability. A rectangular film specimen (5 mm × 5 mm × 0.5 mm) was firmly clamped using a custom fixture. The sample was subjected to an applied voltage through a high-voltage power supply with a slope controlled at 0.1 kV / s. A computer system was used for real-time signal acquisition and processing, and the strain area during the test was calculated simultaneously.

[0037] The tensile property test was carried out in accordance with the standard of GB / T 1040-2018.

[0038] The dielectric constant was calculated using the parallel plate capacitor method and calculated according to the formula ε = C d / (ε0A).

[0039] Example 1:

[0040] Preparation of a single-mode dielectric material with TMPTMA as the monomer and CN9021ns as the long chain

[0041] According to a specific mass fraction ratio, the mass fraction ratio (%) of the long-chain cross-linking agent CN9021ns (Sartomer, aliphatic polyurethane diacrylate) to trimethylolpropane trimethacrylate (TMPTMA) was controlled to be 10:89.8, 20:79.8, 30:69.8, 40:59.8. The initiators DMPA and BP in the system were mixed in a ratio of 1:1, and the total mass fraction ratio was constantly 0.2%. The above compounds were added to a single-necked flask and dissolved with anhydrous THF, and continuously stirred at room temperature until a uniform mixture was obtained. The above mixture was slowly poured into a polytetrafluoroethylene mold and spread flat in the mold. It was reacted in a 365 nm ultraviolet curing oven under a nitrogen atmosphere for 1 - 5 min. The click reaction proceeded quickly in the presence of a catalyst and at a suitable temperature. The cross-linked product obtained from the reaction was vacuumed at 40 °C for 12 h and then heated to 60 °C and vacuumed for 24 h to obtain CN x -L-TMP.

[0042] Example 2:

[0043] Preparation of a single-mode dielectric material with TMPTMA as the monomer and IE6000 as the short chain

[0044] According to a specific mass fraction ratio, control the mass fraction ratio (%) of the short-chain chain extender IE6000 to trimethylolpropane trimethacrylate (TMPTMA) to be 50:49.8, 60:39.8, 70:29.8, 80:19.8, 90:9.8. In the system, the initiators DMPA and BP are mixed in a ratio of 1:1, and the total mass fraction ratio is constantly 0.2%. Add the above compounds into a single-necked flask and dissolve them with anhydrous THF, and continuously stir at room temperature until a uniform mixture is obtained. Slowly pour the above mixture into a polytetrafluoroethylene mold and spread it flat in the mold. React in a 365 nm ultraviolet curing box under a nitrogen atmosphere for 1 - 5 min. The click reaction proceeds rapidly in the presence of a catalyst and at an appropriate temperature. Vacuum the cross-linked product obtained from the reaction at 40 °C for 12 h, and then raise the temperature to 60 °C and vacuum for 24 h to obtain IE m -S-TMP.

[0045] Example 3:

[0046] Preparation of a dual-mode structure dielectric material composed of TMPTMA as the monomer, IE6000 as the short chain, and CN9021ns as the long-chain cross-linking agent

[0047] According to a specific mass fraction ratio, control the mass fraction ratio (%) of the short-chain chain extender IE6000 to trimethylolpropane trimethacrylate (TMPTMA) to be constantly 1.5:1. In the system, the initiators DMPA and BP are mixed in a ratio of 1:1, and the total mass fraction ratio is constantly 0.2%. Adjust the mass fraction of CN9021ns in the system to 25%, 30%, 35%, 40%, 45%. Add the above compounds into a single-necked flask and dissolve them with anhydrous THF, and continuously stir at room temperature until a uniform mixture is obtained. Slowly pour the above mixture into a polytetrafluoroethylene mold and spread it flat in the mold. React in a 365 nm ultraviolet curing box under a nitrogen atmosphere for 1 - 5 min. The click reaction proceeds rapidly in the presence of a catalyst and at an appropriate temperature. Vacuum the cross-linked product obtained from the reaction at 40 °C for 12 h, and then raise the temperature to 60 °C and vacuum for 24 h to obtain CN z -B-IE / TMP.

[0048] Taking CN z -B-IE / TMP as an example, the specific parameter formula is CN9021ns 35 wt%, IE6000 38.88 wt%, TMPTMA 25.92 wt%, DMPA 0.1 wt%, BP 0.1 wt%

[0049] Example 4:

[0050] Preparation of a single-mode structure dielectric material with PET4A as the monomer and CN9021ns as the long chain

[0051] The monomer was changed to pentaerythritol triacrylate (PET4A), the same as in Example 1.

[0052] Example 5:

[0053] Preparation of a single-mode structure dielectric material with PET4A as the monomer and IE6000 with a short chain

[0054] The monomer was changed to pentaerythritol triacrylate (PET4A), the same as in Example 2.

[0055] Example 6:

[0056] Preparation of a dual-mode structure dielectric material with PET4A as the monomer, IE6000 with a short chain, and CN9021ns with a long chain crosslinker

[0057] The monomer was changed to pentaerythritol triacrylate (PET4A), the same as in Example 3.

[0058] Effect Example 1

[0059] The CN z -B-IE / TMP dielectric material prepared in Example 3 was subjected to infrared spectroscopy testing, and the obtained infrared spectrum is shown in Figure 1 . Due to the click reaction of thiol and double bond, in the corresponding infrared spectrum of the prepared CN z -B-IE / TMP material, an absorption peak of S-C appeared at 1195 cm -1 , and at the same time, the C=C peak at 1630 cm -1 disappeared. These results proved the successful preparation of the CN z -B-IE / TMP material.

[0060] Table 1 summarizes the mechanical properties and dielectric properties of the examples prepared

[0061]

[0062] According to the analysis of the data of the above examples, it can be known that:

[0063] Through the design of the dual-mode network structure, the present invention realizes the collaborative optimization of the mechanical properties and dielectric properties of the dielectric material. The example data shows that the dielectric constant of the composite system of short-chain IE6000 and long-chain CN9021ns (Example 3) reaches 7.68 (1 kHz), approaching 8.33 of the pure short-chain system. At the same time, the elongation at break is increased to 300%, which is significantly better than 150% of the pure long-chain system, proving that the dual-mode structure effectively solves the technical problem of being difficult to balance high dielectric constant and high flexibility. In addition, the introduction of dynamic S-C bonds endows the material with self-healing properties, which cannot be achieved by traditional single-mode structures. Through infrared spectroscopy at 1195 cm -1The characteristic peaks here confirm the successful construction of dynamic bonds. By comparing different monomer systems, it is found that the tetra-functional PET4A can further increase the crosslinking density (tensile strength of 0.57 MPa in Example 6 vs. 0.3 MPa in Example 3), while the tri-functional TMPTMA is more conducive to flexible regulation (elongation rate of 350% vs. 300%), indicating that the performance can be directionally regulated through the molecular design of monomers and crosslinkers. This multi-functional integration strategy based on a dynamic dual-mode network breaks through the performance limitations of existing dielectric materials.

[0064] Comparative Example A: Without using a short-chain chain extender with dynamic bonds (such as in Experimental Example 1, Experimental Example 4, etc.) or using an irreversible crosslinker (neopentyl glycol propoxydiacrylate (PNPDA) instead of IE6000, without self-healing Figure 5 failure), the dielectric loss increases (Experimental Example 1, Experimental Example 4), proving the key role of dynamic bonds in self-healing and loss regulation.

[0065] Comparative Example B: Compared with traditional dielectric materials, the dielectric constant of Silicone is 2.3, that of SEHAS is 3.7, and that of commercial VHB4910 is 4.7; none of the above dielectric materials have self-healing properties, their dielectric constants are much lower than those in Experimental Example 3, etc., and they have no self-repair properties; further highlighting the integrated advantage of high dielectric + self-repair of the present invention.

[0066] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A self-healing acrylic dielectric material based on a dual-mode network, characterized in that: Prepared by UV curing reaction of the following components in mass percentage: (a) long chain crosslinking agent: 25-45 wt% of aliphatic polyurethane diacrylate; (b) short chain extender: 30-50 wt% of polyurethane acrylate containing dynamic thiourethane bonds; (c) acrylate monomer: 20 to 35 wt% of multifunctional acrylate; (d) Photoinitiator: a mixture of 0.2 wt % DMPA and BP in a mass ratio of 0.8 to 1.2:

1.

2. The dielectric material according to claim 1, characterized in that: The long-chain cross-linking agent accounts for 30-40 wt%, the short-chain extender accounts for 32-42 wt%, and the acrylate monomer accounts for 23-28 wt%.

3. The dielectric material according to claim 1, characterized in that: The short chain extender is IE6000.

4. The dielectric material according to claim 1, characterized in that: The long-chain crosslinking agent is CN9021ns, and its molecular chain comprises a flexible polyether diol segment and an aliphatic diisocyanate segment.

5. The dielectric material according to claim 1, characterized in that: The acrylate monomer is trimethylolpropane trimethacrylate.

6. The dielectric material according to claim 1, characterized in that: The acrylate monomer is pentaerythritol triacrylate.

7. The dielectric material according to claim 1, characterized in that: The mass ratio of DMPA to BP in the photoinitiator is 1:1, and the total addition amount is 0.2 wt %.

8. A method for preparing the dielectric material according to claim 1, characterized in that The following steps are involved: (1) dissolving a long-chain crosslinking agent, a short-chain chain extender, an acrylate monomer and a photoinitiator in anhydrous tetrahydrofuran to form a homogeneous solution; (2) The mixed solution is injected into a mold, and then cured and dried by ultraviolet light in a nitrogen atmosphere.

9. The preparation method according to claim 8, characterized in that: The UV curing conditions are wavelength 365nm, irradiation intensity 10-50mW / cm 2 , and the material thickness after curing is 0.3-0.6mm.

10. An application of the dielectric material according to any one of claims 1 to 7 in flexible electronic devices, bionic robot drive systems or self-repairing sensors, characterized in that: The material is applied as a dielectric layer in stretchable capacitors, artificial muscle actuators or pressure sensors, and achieves self-repair of insulation performance after breakdown through dynamic bond recombination.

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