High-performance transparent self-healing conductive elastomer and preparation method thereof

Abstract

The application belongs to the technical field of transparent self-repairing conductive elastomer materials, and discloses a high-performance transparent self-repairing conductive elastomer and a preparation method thereof.The method comprises the following steps: 1) reacting polyester diols and diisocyanate under the action of a catalyst to obtain an isocyanate-terminated polyurethane prepolymer; and 2) mixing a diacylhydrazine containing a benzene ring and the polyurethane prepolymer, carrying out chain extension reaction, adding lithium bis(trifluoromethanesulfonyl)imide, and curing to obtain a polyurethane-urea conductive elastomer; the diacylhydrazine is one or more than one of isophthalic acid dihydrazide or terephthalic acid dihydrazide.The method is simple, the obtained elastomer material has high transparency and high mechanical properties, good self-repairing performance, good conductivity and excellent tensile resilience, and can be used as an excellent stretchable conductor material, and has great application potential in monitoring human dynamic activities, monitoring mechanical movement and human-computer interaction processes.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of conductive elastomer materials, and particularly relates to a high-performance transparent self-repairing conductive elastomer and a preparation method thereof. BACKGROUND

[0002] With the rapid development of flexible electronic materials, flexible stretchable conductors with intrinsic stretchability, electrical conductivity and good resilience are indispensable basic materials for developing flexible electronic devices. Stretchable conductor materials can be divided into three types: hydrogel, ionic gel and ionically conductive elastomer. The problems of water loss and low mechanical properties of hydrogel hinder the practical use of hydrogel-based electronic devices in open environments. The problem of leakage of toxic ionic liquid after compression and stretching deformation of ionic gel hinders the practical application of ionic gel in human wearable electronic devices, and also limits the long-term stable service of ionic gel-based electronic devices. As one of the stretchable conductors, ionically conductive elastomer has become a reliable alternative to gel-based ionic conductors, solving the drawbacks of water loss and ionic liquid leakage of the former, but still has the disadvantage of relatively low mechanical properties, which is prone to damage during use, ultimately leading to the failure of flexible electronic devices. Therefore, the main goal of further developing such materials is to simultaneously improve the mechanical properties and self-repairing properties of the materials on the basis of introducing ionically conductive properties and intrinsic stretchability, to prepare a high-performance self-repairing ionically conductive elastomer material, and to realize the high performance and conductive functionalization of self-repairing elastomers.

[0003] Chinese patent CN 116496436 A discloses a preparation method and application of a multi-hydrogen bond network-based self-repairing high-transparency conductive elastomer. By constructing a polymerizable low-eutectic solvent system of choline chloride / acrylic acid-imidazole alkyl urea, a dense hydrogen bond network is introduced, which gives the elastomer material good electrical conductivity, mechanical properties, self-repairing properties and transparency, with a tensile strength of 1.02 MPa and a room temperature self-repairing efficiency of 100%. Chinese patent application CN 117924647 A discloses a preparation method and application of a polyurethane and a polyurethane-based ionically conductive elastomer. By introducing the interaction force of double dynamic covalent bonds and non-covalent bonds, multiple and multi-level hydrogen bonds, disulfide bonds and dynamic D-A bonds are simultaneously introduced into the polyurethane system, to prepare a polyurethane-based ionically conductive elastomer with good mechanical properties, ideal ionic conductivity, excellent self-healing ability and recyclability. Moreover, the polyurethane-based ionically conductive elastomer has excellent sensing stability and sensitivity, and can be applied to high-sensitivity flexible sensors to monitor human motion. However, the comprehensive performance of the above-mentioned elastomers needs to be improved.

[0004] The present application aims at the problem of how to realize the high performance and conductive function of self-repairing elastomer at the same time, introduces lithium ions into the polyurethane-urea elastomer, forms the ionic coordination of lithium ions and oxygen atoms of carbonyl and the cation-π interaction of lithium ions and benzene ring, constructs the conductive channel based on lithium ions in the elastomer system, and further constructs a high molecular network with multiple non-covalent interactions by combining the multiple hydrogen bond interactions between polymer segments, thereby successfully preparing a polyurethane-urea conductive elastomer material with high conductivity, high strength, excellent resilience, self-repairing performance, transparency and stable tensile sensing performance. SUMMARY

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the present application aims to provide a polyurethane-urea conductive elastomer with high conductivity, high strength, excellent resilience, self-repairing performance, transparency and stable tensile sensing performance and a preparation method (i.e. a high-performance transparent self-repairing conductive elastomer and a preparation method thereof). The present application constructs a multiple non-covalent interaction, including the ionic coordination of lithium ions and oxygen atoms of carbonyl, the cation-π interaction of lithium ions and benzene ring and the multiple hydrogen bond interaction, by carrying out a polymerization reaction of polyester diol, diisocyanate and benzene ring-containing dihydrazide, and then adding lithium bis(trifluoromethanesulfonyl)imide, so as to obtain a series of high-performance conductive elastomer materials. The polyurethane-urea conductive elastomer prepared by the method of the present application exhibits very excellent comprehensive performance: high tensile strength (68.7 MPa), excellent resilience, high light transmittance (91.01%), high ionic conductivity (1.32 x 10 -5 S / cm), excellent self-repairing ability and stable tensile sensing performance.

[0006] The object of the present application is achieved by the following technical solutions.

[0007] A preparation method of a high-performance transparent self-repairing conductive elastomer, comprising the following steps:

[0008] 1) reacting polyester diol and diisocyanate under the action of a catalyst to obtain an isocyanate-terminated polyurethane prepolymer;

[0009] 2) mixing benzene ring-containing dihydrazide and the polyurethane prepolymer, and carrying out chain extension reaction to obtain a polyurethane-urea reaction solution;

[0010] 3) uniformly mixing lithium bis(trifluoromethanesulfonyl)imide and the polyurethane-urea reaction solution, and curing to form a polyurethane-urea conductive elastomer.

[0011] The polyester diol is one or two of polybutylene adipate diol (PBA), polycaprolactone diol (PCL) and polycarbonate diol (PCDL).

[0012] The number average molecular weight of the polyester diol in step 1) is 650-3000 g / mol.

[0013] The diisocyanate in step 1) is one or more of 4,4'-dicyclohexylmethane diisocyanate (HMDI), i.e. dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI) and toluene diisocyanate (TDI).

[0014] The molar ratio of isocyanate groups in the diisocyanate to hydroxyl groups in the polyester diol is 1.9 / 1-2.5 / 1.

[0015] The catalyst in step 1) is one or more of triethylamine, stannous octoate or dibutyl tin dilaurate, and the catalyst is added in an amount of 0.5%-1% by weight of the polyester diol.

[0016] The polyester diol in step 1) is subjected to a dehydration treatment before the reaction, and the polyester diol and the diisocyanate are reacted under the protection of N2 atmosphere.

[0017] The reaction temperature in step 1) is 60-80°C, and the reaction time is 3-5 h.

[0018] The dihydrazide in step 2) is one of isophthalic dihydrazide or terephthalic dihydrazide.

[0019] The molar ratio of amino groups in the dihydrazide chain extender to isocyanate groups in the diisocyanate in step 2) is (0.9-1.5):(1.9-2.5).

[0020] An organic solvent is added in the chain extension reaction in step 2), or the organic solvent is mixed with the polyurethane prepolymer, and then mixed with the dihydrazide to perform the chain extension reaction.

[0021] The organic solvent in step 2) is one or more of N,N-dimethylformamide and N,N-dimethylacetamide.

[0022] The ratio of the amount of the organic solvent to the amount of the dihydrazide is (30-60) mL:0.01 mol.

[0023] The temperature of the chain extension reaction in step 2) is 30-50°C, and the reaction time is 4-9 h.

[0024] The molar ratio of lithium bis(trifluoromethanesulfonyl)imide to polyester diol in step 3) is (1-1.75):1.

[0025] The solidification molding condition in step 3) is to place the system after reaction in a mold, remove the organic solvent, and then heat treat at 60-100 DEG C for 6-12 h.

[0026] The conductive elastomer is a conductive elastomer film.

[0027] The repair method of the high-performance transparent self-repairing conductive elastomer film is to treat the film with a fracture or crack at 60-80 DEG C for 24-48 h.

[0028] The principle of the high-performance transparent self-repairing conductive elastomer film of the application is that a polymerization reaction is carried out by using polyester diol, diisocyanate, and two different dihydrazide chain extenders, and then lithium bis(trifluoromethanesulfonyl)imide is added to construct a multiple non-covalent interaction, including ionic coordination of lithium ion and oxygen atom of carbonyl group, cation-π interaction of lithium ion and benzene ring, and multiple hydrogen bond interaction. The multiple non-covalent interaction plays an important role in the mechanical property, conductive property, rebound property, and self-repairing property of the conductive elastomer. For the mechanical property, the higher the multiple non-covalent interaction between polymer chains in the system, the greater the stress required for stretching of the polymer chain segment, and the greater the corresponding tensile strength. For the conductive property, the coordination of lithium ion and oxygen atom of carbonyl group and the cation-π interaction of benzene ring construct enough conductive paths, which promote migration of lithium ion under the action of an external electric field, and endow the elastomer material with good conductive property. For the rebound property, the formation of multiple non-covalent interaction increases the physical crosslinking degree of the polymer network, which limits the residual orientation of the molecular chain, and endows the elastomer material with good rebound property. For the self-repairing property, the increase of temperature causes dissociation of the multiple non-covalent interaction, and the ionic coordination, cation-π interaction, and multiple hydrogen bond interaction in the system are constantly exchanged until a dynamic equilibrium is reached, so that the polymer network is reconstructed, and the elastomer material is endowed with excellent self-repairing property.

[0029] Compared with the prior art, the application has the following advantages:

[0030] 1) The polyurethane-urea film prepared in the application has high conductivity, high strength, excellent rebound property, self-repairing property, transparency, and stable tensile sensing performance, the tensile strength reaches 68.7 MPa, the ionic conductivity reaches 1.32 x 10 - 5S / cm, and has high light transmittance (91.01%), and has excellent resilience and self-repairing ability. In addition, the elastomer also has excellent tensile sensing performance, and can be applied to strain sensors as a stretchable conductor, and has great application value in monitoring human joint activity, mechanical movement and human-computer interaction process. For mechanical movement with larger deformation and larger driving force, the stretchable conductor material used for monitoring is more prone to breakage, and the conductive elastomer material prepared in the application has high strength, self-repairing performance and stable tensile sensing performance, and is more suitable for monitoring this type of movement than other materials.

[0031] 2) The synthesis condition of the present application is mild, the preparation process is simple, and the raw materials are easy to obtain. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the stress-strain curve diagram of examples 1-4 and comparative examples;

[0033] Figure 2 is the ion conductivity curve diagram of examples 1-4;

[0034] Figure 3 is the ion conductivity comparison diagram of example 4 and comparative example;

[0035] Figure 4 is the cyclic loading-unloading tensile curve diagram of examples 1-4 under 50% and 200% strain; a, e are example 1; b, f are example 2; c, g are example 3; d, h are example 4;

[0036] Figure 5 is the light transmittance curve diagram of example 1 in the visible light range;

[0037] Figure 6 is the stress-strain curve diagram of examples 1-4 after repair;

[0038] Figure 7 is the ion conductivity comparison diagram of examples 1-4 before and after repair;

[0039] Figure 8 is the tensile sensing performance diagram of example 1;

[0040] Figure 9 is the sensing signal change diagram of example 1 applied to human joint movement monitoring and mechanical joint movement monitoring. DETAILED DESCRIPTION

[0041] In order to better illustrate the present application, the technical solutions of the present application are further described in combination with specific examples and drawings, but the scope of protection of the present application is not limited thereto.

[0042] Example 1

[0043] A method for preparing a high-performance transparent self-repairing conductive elastomer film, comprising the following steps:

[0044] 5.27g 4,4-dicyclohexyl methane diisocyanate and 10g polybutylene adipate glycol with a molecular weight of 1000 were mixed and stirred uniformly, 0.1g dibutyltin dilaurate was added, and the mixture was heated and stirred in an 80°C oil bath for 3h to obtain a prepolymer; 1.94g isophthalic dihydrazide was added to the prepolymer, and the mixture was reacted at 45°C for 8h, during which 40ml N,N-dimethylacetamide was added for dilution; then 3.59g lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 8ml N,N-dimethylacetamide (DMAC), and the mixture was added to the reaction solution and stirred for 2h; then the reaction product was poured into a polytetrafluoroethylene mold, the organic solvents used were removed in a vacuum oven at 40-60°C, and then the mixture was treated in a forced air oven at 80°C for 12h to obtain a polyurethane-urea film.

[0045] Example 2

[0046] A method for preparing a high-performance transparent self-repairing conductive elastomer film, comprising the following steps:

[0047] 5.27g 4,4-dicyclohexyl methane diisocyanate and 10g polybutylene adipate glycol with a molecular weight of 1000 were mixed and stirred uniformly, 0.1g dibutyltin dilaurate was added, and the mixture was heated and stirred in an 80°C oil bath for 3h to obtain a prepolymer; 1.94g isophthalic dihydrazide was added to the prepolymer, and the mixture was reacted at 45°C for 8h, during which 40ml N,N-dimethylacetamide was added for dilution; then 3.59g lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 8ml N,N-dimethylacetamide (DMAC), and the mixture was added to the reaction solution and stirred for 2h; then the reaction product was poured into a polytetrafluoroethylene mold, the organic solvents used were removed in a vacuum oven at 40-60°C, and then the mixture was treated in a forced air oven at 80°C for 12h to obtain a polyurethane-urea film.

[0048] Example 3

[0049] A method for preparing a high-performance transparent self-repairing conductive elastomer film, comprising the following steps:

[0050] 5.27g 4,4-dicyclohexylmethane diisocyanate and 10g polybutylene adipate glycol with molecular weight 1000 were mixed and stirred uniformly, 0.1g dibutyltin dilaurate was added, and the mixture was heated and stirred in an 80°C oil bath for 3h to obtain a prepolymer; 1.94g isophthalic dihydrazide was added to the prepolymer, and the mixture was reacted at 45°C for 8h, during which 40ml N,N-dimethylacetamide was added for dilution; then 5.02g lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 12ml N,N-dimethylacetamide (DMAC) and added to the reaction solution, and the mixture was stirred for another 2h; the reaction product was then poured into a polytetrafluoroethylene mold, and the organic solvents used were removed in a vacuum oven at 40-60°C, and then the product was treated in a forced air oven at 80°C for 12h to obtain a polyurethane-urea film.

[0051] Example 4

[0052] A method for preparing a high-performance transparent self-repairing conductive elastomer film, comprising the following steps:

[0053] 5.27g 4,4-dicyclohexylmethane diisocyanate and 10g polybutylene adipate glycol with molecular weight 1000 were mixed and stirred uniformly, 0.1g dibutyltin dilaurate was added, and the mixture was heated and stirred in an 80°C oil bath for 3h to obtain a prepolymer; 1.94g isophthalic dihydrazide was added to the prepolymer, and the mixture was reacted at 45°C for 8h, during which 40ml N,N-dimethylacetamide was added for dilution; then 5.02g lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 12ml N,N-dimethylacetamide (DMAC) and added to the reaction solution, and the mixture was stirred for another 2h; the reaction product was then poured into a polytetrafluoroethylene mold, and the organic solvents used were removed in a vacuum oven at 40-60°C, and then the product was treated in a forced air oven at 80°C for 12h to obtain a polyurethane-urea film.

[0054] Comparative Example

[0055] A method for preparing a high-performance transparent self-repairing conductive elastomer film, comprising the following steps:

[0056] 5.27 g 4,4-dicyclohexylmethane diisocyanate and 10 g polybutylene adipate glycol with molecular weight 1000 were mixed and stirred uniformly, 0.1 g dibutyltin dilaurate was added, and the mixture was heated and stirred in an 80 °C oil bath for 3 h to obtain a prepolymer; 1.74 g adipic acid dihydrazide was added to the prepolymer, and the mixture was reacted at 45 °C for 8 h, during which 30 ml N,N-dimethylacetamide was added for dilution; then 4.31 g lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 10 ml N,N-dimethylacetamide (DMAC) and added to the reaction solution, and the mixture was stirred for another 2 h; then the reaction product was poured into a polytetrafluoroethylene mold, and the organic solvents used were removed in a vacuum oven at 40-60 °C, and then the product was treated in a forced air oven at 80 °C for 12 h to obtain a polyurethane-urea film.

[0057] Tensile property test method of the high-performance transparent self-repairing conductive elastomer film: a tensile testing machine was used to test the tensile strength and elongation at break.

[0058] Cyclic tensile property test method of the high-performance transparent self-repairing conductive elastomer film: a cyclic tensile test was performed at a constant loading-unloading rate of 50 mm min -1 to evaluate the elastic recovery ability of the conductive elastomer. During the test, the sample was stretched to produce a strain of 50% and 200%, respectively, and then immediately released to complete stress unloading. After unloading, a 30-second waiting period was allowed before the next loading-unloading cycle. The cyclic tensile test was performed 5 times.

[0059] Repair method of the high-performance transparent self-repairing conductive elastomer film: the film was cut into dumbbell-shaped or rectangular samples, which were cut with a scalpel and placed in a 60-80 °C environment for 24-48 h. Then the tensile strength and ionic conductivity of the samples were tested.

[0060] Conductivity test method of the high-performance transparent self-repairing conductive elastomer film: a resistance digital source meter was used to test the ionic conductivity of the elastomer. The sample was in the shape of a cuboid with dimensions of 10 mm x 10 mm x 1 mm. Copper foil was wrapped around the left and right ends of the sample, and then a test wire interface was clamped on the copper foil to test the resistance of the sample. The ionic conductivity was calculated according to the following formula:

[0061]

[0062] where σ is the conductivity, L is the sample length, R is the sample resistance, and S is the sample cross-sectional area.

[0063] Tensile sensing performance test method of the high-performance transparent self-repairing conductive elastomer film: the ionic elastomer was assembled with a stretchable conductor material to form a strain resistance sensor. Copper wires were wrapped around the sample and connected to a resistance digital source meter. The sample was stretched at a rate of 50 mm min-1 The ionic elastomer was subjected to different tensile strains at varying stretching rates, and its relative resistance was measured during this process. Simultaneously, the ionic elastomer was worn on different joints of the human body and on a robotic arm, and its relative resistance was measured using a resistive digital source meter during fixed joint movements and mechanical motion.

[0064] The overall performance of the above embodiments and comparative examples was tested respectively, and the results are shown in Tables 1 and 2. Figures 1-9 As shown.

[0065] Figure 1 These are stress-strain curves of Examples 1-4 and the comparative examples; Figure 2 These are the ionic conductivity curves for Examples 1-4; Figure 3 This is a comparison chart of the ionic conductivity of Example 4 and the comparative example; Figure 4 These are the cyclic loading-unloading tensile curves of Examples 1-4 at 50% and 200% strain; Figure 5 This is a transmittance curve of Example 1 in the visible light range; Figure 6 These are the stress-strain curves after repair in Examples 1-4;

[0066] Figure 7 These are comparison graphs of ionic conductivity before and after repair in Examples 1-4; Figure 8 This is a graph showing the tensile sensing performance of Example 1; Figure 9 This is a graph showing the changes in sensor signals applied to human joint motion monitoring and mechanical joint motion monitoring in Example 1.

[0067] from Figure 1 It can be seen that the prepared conductive elastomer film has ultra-high tensile properties. The tensile strength of each embodiment ranges from 53.3 MPa to 68.7 MPa, with a maximum of 68.7 MPa, and the elongation at break is in the range of 682% to 807%.

[0068] from Figure 2 It can be seen that the ionic conductivity of the conductive elastomer is 2.81 × 10⁻⁶. -6 S / cm - 1.32 × 10 -5 Within the range of S / cm, the ionic conductivity of the conductive elastomer film shows an increasing trend with the increase of lithium salt addition.

[0069] from Figure 3 As shown, the conductivity of Example 4 is much higher than that of the comparative example.

[0070] Depend on Figure 4As shown, the stress-strain curves of the five loading-unloading processes in Example 3 almost overlap, and the residual strain of Example 3 is the smallest when the stress value is zero, indicating that Example 3 has the best tensile resilience. Conversely, the stress-strain curves of the loading-unloading processes of the other examples do not overlap, and when the stress value is zero, the residual strain values ​​of the three examples are in the order of smallest to largest as follows: Example 2 < Example 1 < Example 4, indicating that as the amount of lithium salt added increases, the superiority of the tensile resilience of the conductive elastomer film first increases and then decreases.

[0071] Depend on Figure 5 As shown, the average transmittance of Example 1 is greater than 90%, proving that the prepared conductive elastomer film has high transparency.

[0072] From Table 1, Figure 6 and Figure 7 As shown, the mechanical and electrical properties of the samples in each embodiment were restored after repair following damage. The tensile strength of all four embodiments recovered to more than 83% of the original value, with the embodiment showing the best repair capability recovering to approximately 95%. Moreover, the ionic conductivity of all four embodiments remained almost identical to that before repair, indicating that the prepared polyurethane-urea film possesses excellent self-healing properties.

[0073] Depend on Figure 8 As shown, with the increase of strain value, the relative resistance change value of Example 3 increases linearly. The rate of change of relative resistance is equal to the slope of the line, which is called the GF factor, and the GF factor reaches 1.17. Four cyclic tensile tests were conducted on Example 3 at strains of 25%, 50%, 75%, and 100%. The graphs of relative resistance change in each cycle were almost identical under the same strain, indicating that the elastomer has good tensile sensing stability under different strains. To further test whether the conductive elastomer possesses long-term tensile sensing stability, Example 3 was subjected to 1000 cyclic tensile tests at 50% strain. The results showed that the graphs of relative resistance change of the elastomer were similar in 1000 cycles, with only minor errors between the graphs, indicating that the conductive elastomer has excellent sensing stability and reliability. This excellent sensing stability and reliability stems from the elastomer's excellent tensile resilience and stable high ionic conductivity.

[0074] Depend on Figure 9The conductive elastomer is practically applied to the strain sensor, fixed on different parts of the human body and the mechanical arm, and can monitor different human actions and mechanical movements. For the stretching and contraction of the human finger, elbow and knee joint, different stretching and contraction movements correspond to a specific pattern of relative resistance change, and a specific stretching and contraction movement can be distinguished and monitored according to the specific pattern. The relative resistance changes corresponding to the four stretching and contraction movements remain basically consistent in four cycles, indicating that the monitoring process of the sensor has good stability and reliability. For the stretching and contraction of the joints of the mechanical arm with large strain degree and driving force, the monitoring process of the sensor also has good stability and reliability, and the ion conductive elastomer with high mechanical performance has greater bearing capacity for mechanical movements with large driving force and is not easy to be damaged in use.

[0075] Table 1: Stretching properties and repair efficiency of each example after repair

[0076]

[0077] Table 2: Transmittance of each example

[0078]

[0079] It can be seen from Table 1, Table 2 and Figures 1-9 that the elastomer film of the present application has good self-repairing performance, mechanical properties, resilience, conductivity and transmittance. The comprehensive performance is better.

[0080] The above examples are embodiments of the present application for preparing a high-performance transparent self-repairing conductive elastomer film, but the present application is not limited to the above examples, and the embodiments of the present application are not limited by the above examples. Any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. A method for preparing a high-performance transparent self-healing conductive elastomer, characterized in that: Includes the following steps: 1) Polyester diol and diisocyanate are reacted in the presence of a catalyst to obtain isocyanate-terminated polyurethane prepolymer; 2) A polyurethane-urea reaction solution is obtained by mixing a benzene ring-containing dihydrazide with a polyurethane prepolymer and performing a chain extension reaction; wherein the dihydrazide is one or more of isophthalic acid dihydrazide or terephthalic acid dihydrazide. 3) Mix lithium bis(trifluoromethanesulfonyl)imide with the polyurethane-urea reaction solution, cure and mold to obtain polyurethane-urea conductive elastomer; In step 2), the molar ratio of the amino group in the dihydrazide to the isocyanate group in the diisocyanate is (0.9~1.5):(1.9~2.5). The molar ratio of lithium bis(trifluoromethanesulfonyl)imide to polyester diol in step 3) is (1-1.75):1; The molar ratio of isocyanate ions to hydroxyl groups in the polyester diol is 1.9 / 1 to 2.5 / 1. The polyester diol is one or more of poly(1,4-butanediol adipate), polycaprolactone diol, and polycarbonate diol. Step 1) The number-average molecular weight of the polyester diol is 650-3000 g / mol; Step 1) The diisocyanate is one or more of 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, and toluene diisocyanate.

2. The method for preparing the high-performance transparent self-healing conductive elastomer according to claim 1, characterized in that: The reaction temperature in step 1) is 60~80℃, and the reaction time is 3~5 h; The chain extension reaction described in step 2) is carried out at a temperature of 30-50 °C for 4-9 h. In step 2), an organic solvent is added during the chain extension reaction, or the organic solvent is mixed with the polyurethane prepolymer and then mixed with dihydrazide to carry out the chain extension reaction.

3. The method for preparing the high-performance transparent self-healing conductive elastomer according to claim 2, characterized in that: Step 2) The organic solvent is one or more of N,N-dimethylformamide and N,N-dimethylacetamide; The ratio of the organic solvent to dihydrazide is (30~60) mL: 0.01 mol.

4. The method for preparing the high-performance transparent self-healing conductive elastomer according to claim 1, characterized in that: Step 1) The catalyst is one or more of triethylamine, stannous octoate, or dibutyltin dilaurate, and the amount of catalyst added is 0.5% to 1% of the weight of the polyester diol; Step 1) The polyester diol is dehydrated before the reaction; the polyester diol and diisocyanate react under the protection of N2 atmosphere; The curing and molding conditions described in step 3) are as follows: place the reacted system in a mold, remove the organic solvent, and then heat-treat at 60~100℃ for 6~12h.

5. The method for preparing the high-performance transparent self-healing conductive elastomer according to claim 1, characterized in that: The lithium bis(trifluoromethanesulfonyl)imide is first mixed with an organic solvent and then added to a polyurethane-urea reaction solution; the organic solvent is one or more of N,N-dimethylformamide and N,N-dimethylacetamide. The molding process refers to solidifying into a film.

6. A high-performance transparent self-healing conductive elastomer obtained by the preparation method according to any one of claims 1 to 5.

7. The application of the high-performance transparent self-healing conductive elastomer according to claim 6, characterized in that: The high-performance transparent self-healing conductive elastomer is used in strain sensors and tensile conductor materials.

8. The application according to claim 7, characterized in that: The high-performance transparent self-healing conductive elastomer is used to prepare products for monitoring human joint activity, mechanical movement and / or human-computer interaction processes.

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