FeCl3 crosslinking-based deep eutectic solvent and polycarbonate double-network conductive elastomer and preparation method thereof

Abstract

The invention belongs to the technical field of flexible sensing, and particularly relates to a poly-deep eutectic solvent and polycarbonate double-network conductive elastomer based on FeCl3 crosslinking and a preparation method of the poly-deep eutectic solvent and polycarbonate double-network conductive elastomer. The preparation method comprises the following steps: mixing polyethylene glycol monomethyl ether, 5-methyl-5-carbobenzoxy trimethylene carbonate, 5-methyl-5-carboxyl trimethylene carbonate and stannous octoate under a vacuum condition, and carrying out a copolymerization reaction to obtain aliphatic polycarbonate; carrying out polymerization reaction on the deep eutectic solvent and a photoinitiator to obtain deep eutectic solvent gel; and stirring aliphatic polycarbonate, the poly deep eutectic solvent gel and ferric trichloride in an organic solvent to obtain the poly deep eutectic solvent and polycarbonate double-network conductive elastomer based on FeCl3 crosslinking. The dual-network conductive elastomer provided by the invention has good mechanical properties, sensing properties, biocompatibility, bacteriostasis and self-repairing properties, and is suitable for the fields of motion monitoring, intelligent health medical treatment and human-computer interaction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flexible sensing and particularly relates to a FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double-network conductive elastomer and a preparation method thereof. BACKGROUND

[0002] With the vigorous development of flexible electronics, wearable electronics and artificial intelligence, flexible wearable devices show broad application prospects in the fields of personal motion monitoring, intelligent health care and human-computer interaction. Flexible sensors for acquiring physiological signals usually require the working material to have good tensile property, stable conductive property and sensitive response to strain or pressure changes. At present, a variety of high molecular conductive elastomers have been used to construct flexible sensors, but such materials often have problems of insufficient mechanical strength, poor cycle stability or limited self-repairing ability under large deformation, which are difficult to meet the comprehensive needs of high strain, long service life and multi-scene use.

[0003] As a new type of green ionic liquid, deep eutectic solvent (DES) has the advantages of wide source, low cost, easy preparation, antibacterial and biodegradable, and strong composition designability, and has been used to construct functional materials such as ionic conductor, electrolyte and ionic gel. The DES ionic gel reported in the prior art usually relies on physical cross-linking or a single hydrogen bond network to maintain the three-dimensional structure, and its mechanical strength and fatigue resistance are relatively weak, which is easily damaged irreversibly under large strain, limiting its further application in high-performance flexible sensors. SUMMARY

[0004] To solve the above technical problems, the application provides a FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double-network conductive elastomer and a preparation method thereof. The application obtains an aliphatic polycarbonate by copolymerization of polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyl trimethylene carbonate and 5-methyl-5-carboxyl trimethylene carbonate under the catalytic action. The deep eutectic solvent is subjected to a photopolymerization reaction to obtain a polydeep eutectic solvent gel. The aliphatic polycarbonate, the polydeep eutectic solvent gel and ferric chloride are mixed and vacuum dried to obtain the FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double-network conductive elastomer. The application significantly improves the mechanical properties and durability of the obtained ionic gel on the basis of maintaining the excellent ionic conductivity and biocompatibility of the DES system.

[0005] To achieve the above purpose, the technical solution adopted by the application is as follows: The application protects a preparation method of a FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double-network conductive elastomer, which comprises the following steps: An aliphatic polycarbonate is obtained by copolymerization of 5-methyl-5-benzyloxycarbonyltrimethylene carbonate and 5-methyl-5-carboxyltrimethylene carbonate under vacuum using polyethylene glycol monomethyl ether as a macromolecular initiator and flexible hydrophilic segment, stannous octoate as a catalyst.

[0006] A deep eutectic solvent is obtained by mixing choline chloride and acrylic acid, and a polydeep eutectic solvent gel is obtained by mixing the deep eutectic solvent with a photoinitiator and then performing a photopolymerization reaction.

[0007] A double-network conductive elastomer is obtained by mixing the aliphatic polycarbonate, the polydeep eutectic solvent gel and ferric chloride in an organic solvent, stirring and vacuum drying.

[0008] The present application relates to a double-network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate. First, polyethylene glycol monomethyl ether (mPEG 113 ) is used to initiate monomers 5-methyl-5-benzyloxycarbonyltrimethylene carbonate (MBC) and 5-methyl-5-carboxyltrimethylene carbonate (MCC) to synthesize aliphatic polycarbonate (APC) by copolymerization. The preparation method of MBC and MCC is described in the reference (Du Qingwei. Synthesis and liquid crystal properties of cholesterol-based biomedical polymer materials [D], Shenyang: Northeastern University, 2011) of the research team of the present inventors. Second, a deep eutectic solvent is polymerized by photopolymerization to obtain a polydeep eutectic solvent gel (PDES). Finally, FeCl3 is dissolved in an N,N-dimethylformamide (DMF) solution of APC and PDES, and vacuum dried in a mold to obtain a double-network conductive elastomer. The elastomer has good mechanical properties, sensing properties, biocompatibility, antibacterial and self-repairing properties, and is suitable for motion monitoring, intelligent health care and human-computer interaction fields.

[0009] The monomers MBC and MCC used in the present application can be obtained by laboratory self-preparation, and the synthesis route is consistent with the method disclosed in the previous work of the present inventors, which is described as follows: (1) Synthesis of precursor 2-methyl-2-benzyloxycarbonyl-1,3-propanediol (HBM): The 2,2-dihydroxymethyl propionic acid and potassium hydroxide were added into a three-necked flask in stoichiometric ratio, dissolved in DMF, heated to 100°C under mechanical stirring for 1h to obtain a corresponding potassium salt solution; then, benzyl chloride was slowly added into the system under the control of a constant pressure dropping funnel, and the stirring reaction was continued at 100°C for 16h to make the potassium carboxylate and benzyl chloride undergo esterification reaction to generate the benzyloxycarbonyl-protected diol HBM. After the reaction was completed, the solvent was removed by evaporation under reduced pressure, the residue was dissolved in dichloromethane, inorganic salts were removed by extraction with deionized water for 3 times, the combined organic phase was dried over anhydrous magnesium sulfate, the drying agent was removed by filtration, dichloromethane was removed by rotary evaporation, the crude product was recrystallized with ethyl acetate to obtain white powder solid HBM with a yield of 57%, and the obtained product was dried under vacuum at room temperature and stored in a sealed state.

[0010] (2) Synthesis of monomer 5-methyl-5-benzyloxycarbonyl trimethylene carbonate (MBC): HBM was added into a three-necked flask, ethyl chloroformate and tetrahydrofuran were added, and the pre-reaction was carried out under mechanical stirring in an ice bath, then triethylamine was slowly added as an acid capturing agent to make the hydroxyl group of HBM undergo acyl chloride reaction with ethyl chloroformate to generate an intermediate carbonate; after the addition was completed, the ice bath was removed, the temperature was increased to room temperature, and the stirring was continued to ensure the completion of the reaction. After the reaction was completed, the triethylamine salt was removed by filtration under reduced pressure, the filtrate was rotary evaporated to remove tetrahydrofuran, and the crude product was obtained, which was recrystallized with a volume ratio of 2:1 of ethyl ether / tetrahydrofuran mixed solvent, filtered under reduced pressure, and dried under vacuum at room temperature to obtain white needle-shaped crystal MBC with a yield of 75%.

[0011] (3) Synthesis of monomer 5-methyl-5-carboxyl trimethylene carbonate (MCC): MBC was dissolved in tetrahydrofuran, palladium on carbon and palladium hydroxide were added as catalysts, the system was replaced with hydrogen gas after being vacuumed for several times to make the system in a hydrogen atmosphere, and the stirring reaction was carried out at room temperature for 24h to make the benzyloxycarbonyl protecting group deprotected under catalytic hydrogenolysis conditions to obtain the carbonate MCC with free carboxyl group. After the reaction was completed, the catalyst was removed by filtration under reduced pressure, the solvent was removed by rotary evaporation from the filtrate to obtain white powder crude product, which was recrystallized with ethyl acetate, filtered under reduced pressure, and dried under vacuum at room temperature to obtain white needle-shaped crystal MCC with a yield of 58%.

[0012] Further, the molar ratio of polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyl trimethylene carbonate, 5-methyl-5-carboxyl trimethylene carbonate, and stannous octoate is 1:50:25~50:0.3.

[0013] Further, the temperature of the copolymerization reaction is 100°C~130°C, and the time is 10h~15h.

[0014] Further, the molar ratio of choline chloride and acrylic acid is 1:1~2.

[0015] Further, the amount of the photoinitiator is 0.1wt%-0.5wt% of the total weight of the choline chloride and the acrylic acid.

[0016] Further, the photoinitiator is photoinitiator 2959.

[0017] Further, the polymerization reaction is initiated by ultraviolet light irradiation, the power of the light irradiation is 550W, and the time is 2min-5min.

[0018] Further, the mass ratio of the aliphatic polycarbonate and the polydeep eutectic solvent gel is 1:1-3.

[0019] Further, the amount of FeCl3 is 5wt%-20wt% of the total weight of the aliphatic polycarbonate and the polydeep eutectic solvent gel.

[0020] The present application constructs ionic gel with good mechanical properties by using polymerizable DES and reasonably designing hydrogen bond network. PDES is a functional polymer material obtained by polymerization of deep eutectic solvent. PDES has rich functional groups and designability. By selecting different hydrogen bond donors and acceptors and controlling the polymerization process, PDES with different structures and properties can be prepared. In addition, PDES also has good processability, which enables it to be compounded with other materials to prepare composite materials with special properties.

[0021] APC is an important environmentally friendly and medical polymer material. It has good biocompatibility, degradability and controllable mechanical properties, and has attracted much attention. Aliphatic polycarbonates are usually prepared by ring-opening polymerization of cyclic carbonate monomers. This polymerization method has the advantages of mild reaction conditions and controllable product structure. By selecting cyclic carbonate monomers with different structures, the molecular structure and properties of aliphatic polycarbonates can be adjusted. For example, using cyclic carbonate monomers containing different substituents can change the flexibility, crystallinity and biodegradability of polycarbonate chains. Due to the many excellent properties of aliphatic polycarbonates, they have important application prospects in the field of functional materials.

[0022] Metal-ligand coordination is an effective reversible interaction, and metal ions are usually introduced into polymer systems as physical cross-linkers to form metal coordination networks. Compared with hydrogen bonds, metal coordination interactions have higher bond strength, and the metal coordination bonds they form are more difficult to break, so elastomers with metal coordination networks often have higher mechanical strength than elastomers that rely solely on hydrogen bonding. Iron is abundant in nature, and iron salts and other compounds are simple to prepare and relatively inexpensive. Iron is also an essential trace element for living organisms and has good biocompatibility. Trivalent iron ions (Fe 3+ ) have a high valence and a high charge density, which allows them to accept multiple lone pair electrons from ligands through empty orbitals and form multi-dentate coordination structures, thereby constructing more stable and compact metal coordination cross-linking networks.

[0023] The conductive elastomer formed by the complexation of APC and PDES is generally relatively weak in mechanical strength, and the introduction of metal ions using coordination interactions can significantly improve its mechanical properties. There are a large number of carboxyl groups in the APC-PDES conductive elastomer system, which can act as metal coordination ligands, making Fe 3+ an ideal metal coordination ion for APC-PDES conductive elastomer. The present application develops a FeCl3 cross-linked double network conductive elastomer based on polydeep eutectic solvent and polycarbonate, and a large number of multiple hydrogen bonds and metal coordination bonds are formed between APC, PDES and Fe 3+ , which construct a more stable double network structure, significantly improving the mechanical properties and sensing performance of the double network conductive elastomer, and providing a basis for the development of new flexible sensors.

[0024] The present application also protects the application of FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double network conductive elastomer in the preparation of flexible wearable devices, such as sensors.

[0025] Compared with the prior art, the present application has the following beneficial effects: 1. The preparation process is simple, and the entire preparation process does not require complicated procedures, which not only reduces production costs, but also facilitates operation.

[0026] 2. The comprehensive performance of the elastomer is optimized, and the relationship between the mechanical properties, self-repairing ability and sensing performance of the elastomer is optimized through the synergistic effect of the multiple hydrogen bonds and metal coordination bonds formed between APC, PDES and Fe 3+ , solving the problem that the three properties are difficult to be considered together.

[0027] 3. The elastomer is multifunctional, not only having good biocompatibility and degradability, but also having self-repairing, antibacterial, good ionic conductivity and chemical stability.

[0028] 4, wide application range, due to the close skin fit, strain sensitivity, portability characteristics, overcome the shortcomings of traditional rigid sensor, such as wearing discomfort, signal attenuation and invasive complications, in the field of intelligent electronic skin, human motion monitoring and health diagnosis, human-computer interaction has great development prospect. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Figure 1 Synthesis route map of the present application based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double network conductive elastomer.

[0031] Figure 2 Infrared spectrum of the double network conductive elastomer prepared in Example 1~Example 4.

[0032] Figure 3 X-ray photoelectron spectrogram of the double network conductive elastomer prepared in Example 3, wherein a is the high-resolution XPS spectrogram of DPF3, b is the XPS spectrogram of C1s, c is the XPS spectrogram of O1s, and d is the XPS spectrogram of Fe2p.

[0033] Figure 4 Stress-strain curve of the double network conductive elastomer prepared in Example 1~Example 4.

[0034] Figure 5 Norm factor comparison chart and relative resistance-time response chart of the DPF3 sample prepared in Example 3 under different strain ranges, wherein a is the norm factor comparison chart under different strain ranges, and b is the relative resistance-time response chart.

[0035] Figure 6 Electromyographic signal chart of the DPF3 sample prepared in Example 3, wherein a is the electromyographic signal chart of clenching and relaxing muscles at the wrist, and b is the electromyographic signal chart of bending and relaxing arms at the arm.

[0036] Figure 7 Self-repairing performance chart of the DPF3 sample prepared in Example 3, wherein a is the mechanical property chart after self-repairing, and b is the electrical property chart after self-repairing. DETAILED DESCRIPTION

[0037] The specific embodiments of the present application are described in detail below, but it should be understood that the scope of protection of the present application is not limited by the specific embodiments. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application. The experimental methods described in the embodiments of the present application are conventional methods, and the chemical reagents used in the embodiments of the present application are provided by the National Pharmaceutical Group Chemical Reagent Co., Ltd. The materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0038] The present application relates to a preparation method of a double network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, which is carried out according to the following steps: (1) Synthesis of aliphatic polycarbonate (APC): Take mPEG 113 , 5-methyl-5-benzyloxycarbonyl trimethylene carbonate and 5-methyl-5-carboxyl trimethylene carbonate, and place them in a polymerization tube together with stannous octoate toluene solution (0.2 mol / L). After vacuumizing and recharging with argon for 3 times, heat and seal the polymerization tube. Place the polymerization tube in an oil bath at 100℃~130℃, and after the contents in the tube are completely melted, repeatedly shake the polymerization tube to mix the system uniformly. After constant temperature reaction for 10h~15h, take out the polymerization tube, naturally cool to room temperature, dissolve the product with tetrahydrofuran, precipitate with methanol, and vacuum dry to obtain a colorless transparent product.

[0039] (2) Synthesis of polydeep eutectic solvent (PDES): Take dry choline chloride and acrylic acid, add them to a flask, and heat to form a uniform transparent deep eutectic solvent (DES); add 0.1wt%~0.5wt% of photoinitiator 2959 to the DES, and under ultraviolet light irradiation, initiate free radical polymerization of the acrylic acid groups to obtain a PDES gel.

[0040] (3) Preparation of a double network conductive elastomer: Place APC and PDES gel in DMF according to a mass ratio of 1:1~3, and then take 5wt%~20wt% of FeCl3 and add it to the mixed system, heat and stir to dissolve the two components; pour the mixed solution into a polytetrafluoroethylene mold, vacuum dry, and obtain a series of double network conductive elastomers (DPF).

[0041] The instruments and characterization methods used are as follows: (1) Infrared spectroscopy (FT-IR): tested by Spectrumho Fourier transform infrared spectrometer of American PerkinElmerg Company, the wave number range of absorption spectrum scanning is 500cm -1-4000 cm -1 .

[0042] (2) X-ray photoelectron spectroscopy (XPS): The elemental composition and electronic state distribution of the double network conductive elastomer were analyzed by using the Escalab 250Xi model X-ray photoelectron spectrometer of the United States ThermoFisher Scientific Company, using AlKα (hv = 1486.6 eV) as the excitation source, and the power was 150 W. All spectra were corrected using the binding energy of C1s (284.8 eV).

[0043] (3) Mechanical property test: CMT6103 electronic universal testing machine of Metzler industrial system was used, the sample was prepared by a dumbbell-shaped polytetrafluoroethylene mold with a size of national standard I, and the tensile rate was 50 mm·min -1 , taking stress as the Y axis and strain as the X axis to obtain the stress-strain curve of the double network conductive elastomer.

[0044] (4) Sensing performance test: CHI760E electrochemical workstation of Shanghai Chenhua Instrument Co., Ltd. was used for testing. When detecting the conductive performance and sensing performance of the double network conductive elastomer sample, the double network conductive elastomer was prepared into a size of 30 mm 15 mm 3 mm by a polytetrafluoroethylene mold, and the two ends were fixed by double-headed alligator clip electrodes, and the other end of the alligator clip electrode was connected to the electrochemical workstation. The i-t mode was selected to record the strain current change of the double network conductive elastomer, and the strain sensing signal was represented by the relative resistance change (ΔR / R0). The resistance (R, Ω) was calculated by the following formula:

[0045] In the formula, is the voltage (V) applied by the electrochemical workstation, is the current (A) of the double network conductive elastomer.

[0046] The relative resistance change was calculated by the following formula: In the formula, R is the resistance value of the double network conductive elastomer under strain, and R0 is the initial resistance value of the double network conductive elastomer.

[0047] The sensitivity of the flexible sensor assembled by the double network conductive elastomer is usually measured by the specification factor (GF), which is calculated by the following formula.

[0048] In the formula for the relative resistance change, for the strain applied to the dual-network conductive elastomer, including the applied force.

[0049] The technical solutions of the present application are further studied by using the following examples, and the specific research methods and results are shown as follows: Example 1 A preparation method of a dual-network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, the steps are as follows: S1, synthesis of aliphatic polycarbonate APC: In this example, polyethylene glycol monomethyl ether mPEG 113 (number average molecular weight M n ≈5000g·mol⁻¹, purity ≥99%, purchased from Aladdin Reagent Co., Ltd.) (0.95g, 0.5mmol), 5-methyl-5-benzyloxy carbonyl trimethylene carbonate (MBC, 6.25g, 25mmol) and 5-methyl-5-carboxyl trimethylene carbonate (MCC, 2.0g, 12.5mmol) were placed in a polymerization tube, 350μL of stannous octoate toluene solution (concentration of 0.2062mol·L⁻¹, purity ≥95%, purchased from Sigma Reagent Co., Ltd.) was added, vacuumed and then filled with nitrogen, repeated 3 times, finally vacuumed to 12 mmHg pressure in the polymerization tube, the polymerization tube was heated and sealed, and the polymerization tube was placed in a 130℃ oil bath. After the contents in the tube were completely melted, the system was mixed uniformly by repeatedly shaking the polymerization tube. After constant temperature reaction for 12h, the polymerization tube was taken out, naturally cooled to room temperature, the product was dissolved with tetrahydrofuran, precipitated with methanol, and vacuum dried to obtain aliphatic polycarbonate, denoted as APC.

[0050] The purpose of this step is to prepare a flexible polycarbonate containing carboxyl side chains, which provides a covalent main chain and coordination sites for subsequent construction of a "covalent-hydrogen bond-coordination" multi-level network. Among them, mPEG 113 As a macromolecular initiator and flexible hydrophilic segment, it can improve the flexibility and hydrophilicity of the obtained dual-network conductive elastomer, and provide a continuous phase for subsequent ion conduction; MBC is a hydrophobic carbonate monomer, and its benzyl side group is beneficial to improve the mechanical strength and anti-creep performance of aliphatic polycarbonate; MCC contains carboxyl side chains, which is a key monomer for forming hydrogen bond network and Fe 3+ coordination cross-linking sites; stannous octoate as a ring-opening polymerization catalyst, activates the carbonyl group of carbonate monomers (5-methyl-5-benzyloxy carbonyl trimethylene carbonate and 5-methyl-5-carboxyl trimethylene carbonate), promotes the polymerization of mPEG 113Nucleophilic ring-opening of the terminal hydroxyl group of the cyclic carbonate monomer to achieve controllable copolymerization. The molar ratio of MBC to MCC is preferably set within a certain range (50:25 in the examples), and when the content of MCC is moderate, the number of carboxyl groups in the system is sufficient to form a dense hydrogen bonding and metal coordination network; if the content of MCC is too high, the aliphatic polycarbonate is too hydrophilic, the glass transition temperature increases, and the mechanical strength decreases in a humid environment; if the content of MCC is too low, the coordination sites are insufficient, the crosslinking density is low, and it is difficult to form an effective double network, which affects self-repairing and mechanical properties. 3+ Coordination sites are insufficient, crosslinking density is low, and it is difficult to form an effective double network, which affects self-repairing and mechanical properties.

[0051] The polymerization temperature is controlled at 100℃~130℃, and the time is 10h~15h, which not only ensures that the carbonate monomer is completely melted and has sufficient reactivity, but also avoids thermal degradation of the monomer or polymer caused by excessively high temperature. If the temperature or time is too low, the conversion rate of the carbonate monomer will be insufficient, and the molecular weight will be low, which will further result in insufficient strength of the obtained double network conductive elastomer and increased creep caused by residual small molecule plasticization; if the temperature is too high or the time is too long, chain transfer and crosslinking side reactions are easy to occur, resulting in a wide molecular weight distribution, and even partial gelation, which reduces the processability and elasticity of the aliphatic polycarbonate.

[0052] Through the above raw material selection and process parameter control, APC containing both hydrophilic soft segments and sufficient carboxyl functional groups is obtained, which lays a foundation for constructing a double network structure with high strength and high repairability.

[0053] S2, synthesis of polydeep eutectic solvent PDES: In this embodiment, choline chloride (13.96g, 0.1mol) is mixed with acrylic acid (12.96g, 0.18mol), the reaction system is heated and stirred in a 60℃ constant temperature oil bath for 4h, until the system becomes a uniform transparent liquid, a deep eutectic solvent DES is obtained; 15mL of DES is taken, then 0.5wt% of photoinitiator 2959 is added, and the mold is placed under a 365nm ultraviolet lamp with a power of 550W, 10cm away from the light source, the light irradiation time is 2min, and a polydeep eutectic solvent gel PDES is obtained.

[0054] The purpose of this step is to introduce a covalent crosslinking network while maintaining the high ionic conductivity and designability of DES, to obtain an ionic conductive skeleton with shape stability and mechanical strength.

[0055] ChCl:Acrylic acid molar ratio is preferably 1:1~2, 1:1.8 is used in this embodiment. When the proportion of acrylic acid is too low, the covalent network is sparse, and the mechanical strength of the deep eutectic solvent gel is insufficient, which is easy to break under large strain; when the proportion of acrylic acid is too high, the original DES hydrogen bond network is destroyed, which leads to a significant decrease in ionic conductivity.

[0056] ChCl:Acrylic acid molar ratio is preferably 1:1~2, 1:1.8 is used in this embodiment. When the proportion of acrylic acid is too low, the covalent network is sparse, and the mechanical strength of the deep eutectic solvent gel is insufficient, which is easy to break under large strain; when the proportion of acrylic acid is too high, the original DES hydrogen bond network is destroyed, which leads to a significant decrease in ionic conductivity.

[0057] The amount of photoinitiator is controlled at 0.1wt%~0.5wt% of the total mass of DES, and 0.5wt% is used in this embodiment. When the content is too low, the ultraviolet curing is not complete, and the residual unreacted acrylic acid is not conducive to environmental safety and the stability of the deep eutectic solvent gel; when the content is too high, the residual excess free radicals and by-products in the system can cause the deep eutectic solvent gel to be colored and aged, and can hinder the ion conduction channel. The power and irradiation time of the ultraviolet lamp (such as 550W, 2min~5min) are used to ensure that the deep eutectic solvent gel is fully cured inside: insufficient power or time will lead to uneven internal and external curing and inconsistent performance, and excessive or long time may cause excessive crosslinking and local thermal damage.

[0058] Through the above design, PDES retains the ion conduction advantage of DES while introducing a stable covalent network, becoming the main ion conduction phase and flexible support skeleton in the dual-network conductive elastomer.

[0059] S3, preparation of APC / PDES and FeCl3 to form a dual-network conductive elastomer: In this embodiment, the pre-prepared APC and PDES are mixed in a mass ratio of 1:2, and are dissolved in 10mL of N,N-dimethylformamide (DMF) together, after obtaining a uniform solution, 5wt% of FeCl3 is added, and Fe 3+ is dispersed uniformly and coordinates with the carboxyl groups in APC and the anions in PDES, then the solution is poured into a mold, and vacuum drying is carried out at 60°C for 20h to remove the solvent and complete the crosslinking, obtaining a dual-network conductive elastomer based on FeCl3 crosslinked deep eutectic solvent and polycarbonate, named DPF1.

[0060] The purpose of this step is to crosslink the APC and PDES through Fe 3+Carboxyl / Anion Coordination Crosslinking, on the basis of APC / PDES covalent-hydrogen bond network, introduces a dynamic metal coordination network, thus constructing a double network structure with high strength, high elongation and excellent self-healing performance.

[0061] DMF is a polar organic solvent that can dissolve APC, PDES and FeCl3 simultaneously, ensuring uniform mixing of the three at the molecular scale and providing conditions for the subsequent formation of a continuous and uniform double network structure. If the solvent has insufficient solubility or volatilizes too quickly, it is easy to cause phase separation or the formation of a large number of pores during film formation, resulting in significant deterioration of mechanical and conductive properties.

[0062] The mass ratio of APC to PDES is preferably 1:1 to 3, and in this embodiment it is 1:2, in order to strike a balance between rigid carbonate segments and flexible DES gel networks: when the PDES content is too low, the system lacks ion channels, and the conductivity and strain response sensitivity decrease; when the PDES content is too high, the covalent carbonate network is relatively sparse, and the overall strength and fatigue resistance decrease.

[0063] The amount of FeCl3 added is controlled at 5wt% to 20wt% relative to the total mass of APC and PDES. When the Fe 3+ content is moderate, it can form multi-coordination crosslinking with the carboxyl groups on the APC chain and the anions in the DES system, constructing a dense and reversible metal coordination network; when the content is too low, the coordination crosslinking density is insufficient, and the self-healing efficiency and anti-creep ability are poor; when the content is too high, the network is too dense, the double network conductive elastomer becomes brittle and the elongation at break decreases, and too much inorganic salt can shield the ion channels, reducing the conductivity.

[0064] The drying temperature is controlled at about 60°C, taking into account the complete volatilization of the solvent and the stability of the polymer / coordination structure. If the temperature or time is insufficient, residual DMF acts as a plasticizer, resulting in a low modulus and poor dimensional stability of the double network conductive elastomer; if the temperature is too high, it can destroy the DES hydrogen bond network and the Fe 3+ coordination structure, causing phase separation or performance degradation.

[0065] Mechanism and relationship between structure and performance improvement: Through the above steps, the double network conductive elastomer obtained in this embodiment simultaneously contains structures with the following types of synergistic effects: (1) the covalent main chain network formed by APC and PDES, which provides basic mechanical support and shape retention ability; (2) the hydrogen bond network between the carboxyl groups on the MCC and the DES components, which achieves efficient stress dissipation and gives the double network conductive elastomer certain self-healing ability; (3) the dynamic metal coordination network formed between Fe 3+ and carboxyl groups / anions, which can undergo reversible dissociation-recombination under external force, achieving energy absorption and rapid self-healing while maintaining continuous conductive pathways.

[0066] Compared with the existing DES gel mainly relying on single hydrogen bond or physical entanglement, the embodiment introduces polymerizable DES and carboxyl-containing polycarbonate, and constructs a multi-level double network structure by using FeCl3. On the one hand, the tensile strength and elongation at break of the double network conductive elastomer are significantly improved, and the stability under cyclic tension is improved. On the other hand, the synergistic effect of dynamic coordination and hydrogen bond enables the double network conductive elastomer to spontaneously reconstruct the network at room temperature after damage, and quickly recover the conductive path, thereby realizing high-sensitivity strain sensing and excellent self-repairing performance. The synergistic design of the above key steps and process parameters is the fundamental reason why the present application is different from the prior art and realizes significant improvement in comprehensive performance.

[0067] Embodiment 2 A preparation method of a double network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, which is the same as steps S1 and S2 of embodiment 1, and the only difference is that: S3, preparation of the double network conductive elastomer: The APC and PDES gel are mixed in a mass ratio of 1:2, and are dispersed in 10 mL of DMF. Then, 10wt% of FeCl3 is weighed and added to the above mixed system, and is dissolved by heating and stirring. The obtained mixed solution is poured into a polytetrafluoroethylene mold, and is vacuum dried at 60°C for 20h to obtain a double network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, which is named as DPF2.

[0068] Embodiment 3 A preparation method of a double network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, which is the same as steps S1 and S2 of embodiment 1, and the only difference is that: S3, preparation of the double network conductive elastomer: The APC and PDES gel are mixed in a mass ratio of 1:2, and are dispersed in 10 mL of DMF. Then, 15wt% of FeCl3 is weighed and added to the above mixed system, and is dissolved by heating and stirring. The obtained mixed solution is poured into a polytetrafluoroethylene mold, and is vacuum dried at 60°C for 20h to obtain a double network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, which is named as DPF3.

[0069] Embodiment 4 A preparation method of a double network conductive elastomer based on FeCl3 cross-linked polydeep eutectic solvent and polycarbonate, which is the same as steps S1 and S2 of embodiment 1, and the only difference is that: S3, preparation of the double network conductive elastomer: The APC and PDES gel were mixed in a mass ratio of 1:2, and were dispersed in 10 mL of DMF, then 20 wt% of FeCl3 was weighed and added to the above mixed system, and was dissolved by heating and stirring. The obtained mixed solution was poured into a polytetrafluoroethylene mold, and was vacuum dried at 60°C for 20 h to obtain a FeCl3-crosslinked polydeep eutectic solvent and polycarbonate double network conductive elastomer, named as DPF4.

[0070] Example 5 A preparation method of a FeCl3-crosslinked polydeep eutectic solvent and polycarbonate double network conductive elastomer, comprising the following steps: S1, synthesis of aliphatic polycarbonate APC: In this example, polyethylene glycol monomethyl ether mPEG 113 (number average molecular weight M n ≈5000 g·mol⁻¹, purity ≥99%, purchased from Aladdin Reagent Co., Ltd.) (0.95 g, 0.5 mmol), 5-methyl-5-benzyloxycarbonyl trimethylene carbonate (MBC, 6.25 g, 25 mmol), and 5-methyl-5-carboxyl trimethylene carbonate (MCC, 4.0 g, 25 mmol) were placed in a polymerization tube, 350 μL of stannous octoate toluene solution (concentration of 0.2062 mol·L⁻¹, purity ≥95%, purchased from Sigma Reagent Co., Ltd.) was added, vacuum was applied and then nitrogen was filled, the above operation was repeated for 3 times, finally the pressure in the polymerization tube was vacuumed to 12 mmHg, the polymerization tube was heated and sealed, and the polymerization tube was placed in a 130°C oil bath. After the contents in the tube were completely melted, the polymerization tube was repeatedly shaken to mix the system uniformly. After constant temperature reaction for 10 h, the polymerization tube was taken out, naturally cooled to room temperature, the product was dissolved with tetrahydrofuran, precipitated with methanol, and vacuum dried to obtain an aliphatic polycarbonate, denoted as APC.

[0071] S2, synthesis of polydeep eutectic solvent PDES: In this example, choline chloride (13.96 g, 0.1 mol) and acrylic acid (14.4 g, 0.2 mol) were mixed, the reaction system was heated and stirred in a 60°C constant temperature oil bath for 4 h until the system became a uniform transparent liquid to obtain a deep eutectic solvent DES; 15 mL of the DES was taken, then 0.3 wt% of a photoinitiator 2959 was added, and the mixture was placed in a polytetrafluoroethylene mold. The mold was placed under a 365 nm ultraviolet lamp with a power of 550 W, and the polymerization was initiated by irradiation at a distance of 10 cm. The irradiation time was 5 min to obtain a polydeep eutectic solvent gel PDES.

[0072] S3, preparation of APC / PDES and FeCl3 double network conductive elastomer: In this embodiment, the pre-prepared APC and PDES were mixed in a mass ratio of 1:3 and dissolved in 10 mL of DMF to obtain a homogeneous solution. Then 15 wt% of FeCl3 was added and stirred thoroughly to make Fe 3+ uniformly dispersed and coordinated with the carboxyl groups in APC and the anions in PDES. Subsequently, the solution was poured into a mold and dried at 60°C under vacuum for 20 h to remove the solvent and complete the crosslinking, obtaining a FeCl3-based polydeep eutectic solvent and polycarbonate double network conductive elastomer.

[0073] Example 6 A method for preparing a FeCl3-based polydeep eutectic solvent and polycarbonate double network conductive elastomer, the steps are as follows: S1. Synthesis of aliphatic polycarbonate APC: In this embodiment, polyethylene glycol monomethyl ether mPEG 113 (number average molecular weight M n ≈5000 g·mol⁻¹, purity ≥99%, purchased from Aladdin Reagent Co., Ltd.) (0.95 g, 0.5 mmol), 5-methyl-5-benzyloxycarbonyl trimethylene carbonate (MBC, 6.25 g, 25 mmol), and 5-methyl-5-carboxyl trimethylene carbonate (MCC, 3.2 g, 20 mmol) were placed in a polymerization tube. 350 μL of stannous octoate toluene solution (concentration of 0.2062 mol·L⁻¹, purity ≥95%, purchased from Sigma Reagent Co., Ltd.) was added. After vacuuming and refilling with nitrogen, the process was repeated three times. Finally, the pressure in the polymerization tube was vacuumed to 12 mmHg. The polymerization tube was heated and sealed, and placed in a 100°C oil bath. After the contents in the tube were completely melted, the tube was shaken repeatedly to mix the system uniformly. After 15 h of constant temperature reaction, the polymerization tube was removed and naturally cooled to room temperature. The product was dissolved in tetrahydrofuran and precipitated in methanol, and vacuum dried to obtain the aliphatic polycarbonate, denoted as APC.

[0074] S2. Synthesis of polydeep eutectic solvent PDES: In this embodiment, choline chloride (13.96 g, 0.1 mol) and acrylic acid (7.2 g, 0.1 mol) were mixed. The reaction system was heated and stirred in a 60°C constant temperature oil bath for 4 h until the system became a homogeneous transparent liquid, obtaining a deep eutectic solvent DES. 15 mL of DES was taken, followed by the addition of 0.1 wt% of photoinitiator 2959. The mold was placed under a 365 nm ultraviolet lamp with a power of 550 W, 10 cm away from the light source. The light irradiation time was 4 min, obtaining a polydeep eutectic solvent gel PDES.

[0075] S3. Preparation of APC / PDES and FeCl3 double network conductive elastomer: In this embodiment, pre-prepared APC and PDES were mixed at a mass ratio of 1:1 and dissolved together in 10 mL of DMF to obtain a homogeneous solution. Then, 10 wt% FeCl3 was added and stirred thoroughly to allow the Fe to dissolve. 3+ The solution is uniformly dispersed and coordinates with the carboxyl groups in APC and the anions in PDES. Then, the solution is poured into a mold and vacuum dried at 60°C for 20 h to remove the solvent and complete the crosslinking, resulting in a dual-network conductive elastomer based on FeCl3 crosslinking of polydeterminate solvent and polycarbonate.

[0076] Examples 1-6 of this invention all yielded high-strength, highly repairable dual-network conductive elastomers based on FeCl3 crosslinked deep eutectic solvent and polycarbonate. The dual-network conductive elastomers obtained in Examples 1-4 are used as examples for further research. Specific research methods and results are shown below: like Figure 1 As shown, the synthesis of the double-network conductive elastomer based on FeCl3-crosslinked deep eutectic solvent and polycarbonate in this invention is divided into three stages: ring-opening polymerization of aliphatic polycarbonate (APC), construction of polymerizable deep eutectic solvent PDES, and photopolymerization and FeCl3 crosslinking. 3+ Induced dual-network crosslinking to form a gel.

[0077] First, polyethylene glycol monomethyl ether (mPEG) is used. 113 This process initiates a ring-opening copolymerization reaction between 5-methyl-5-benzyloxycarbonyltrimethylene carbonate (MBC) and 5-methyl-5-carboxytrimethylene carbonate (MCC) to generate APC. Stannous octoate (Sn(Oct)₂) acts as a Lewis acid catalyst, coordinating with the carbonyl group of the cyclic carbonate monomer to lower the C–O bond energy, thus enabling mPEG... 113 The terminal hydroxyl groups are more likely to engage in nucleophilic attacks on cyclic carbonates, facilitating the transfer of the active site between monomers. As the reaction proceeds, MBC and MCC are sequentially ring-opened and grafted onto mPEG. 113 At the chain ends, a linear polycarbonate backbone containing benzyl and carboxyl side groups is formed. The benzyl groups provide some hydrophobicity and a rigid framework, while the carboxyl groups facilitate subsequent hydrogen bonding and Fe2+ bonding. 3+ Coordination crosslinking provides reaction sites.

[0078] Secondly, choline chloride (ChCl) and acrylic acid are mixed in a certain molar ratio, and after heating, a low eutectic system, i.e., a deep eutectic solvent (DES), is formed through multiple hydrogen bonds and electrostatic interactions. Among them, the -OH on the ChCl cation and the -COOH in the acrylic acid molecule interact through hydrogen bonds, and at the same time, there is electrostatic coordination between Cl⁻ and the protonated acrylic acid, which significantly reduces the melting point of the system and makes it liquid. Subsequently, a hydrophilic photoinitiator 2959 is added to the DES, and under ultraviolet light irradiation, 2959 decomposes to release free radicals, which attack the C=C double bond in the acrylic acid molecule, initiating chain radical polymerization, and gradually forming a PDES covalent network with polyacrylic acid chains as the main chain and ChCl partially trapped in between. This process is essentially an ionic gel network constructed by "hydrogen bond self-assembly + radical polymerization" in cooperation: hydrogen bonds and electrostatic interactions maintain the ionic environment of DES.

[0079] Finally, the pre-synthesized APC is dissolved in DMF, and a certain amount of FeCl3 is added to form a uniform dispersion of Fe 3+ In the process of drying into a gel, the carboxyl groups of MCC are gradually partially deprotonated to form -COO⁻, and Fe 3+ forms a multi-coordination complex with -COO⁻, and at the same time, Fe 3+ can also coordinate and electrostatically interact with the carboxylic acid groups in PDES and Cl⁻, thereby introducing a second set of dynamic metal coordination network on the basis of the APC / PDES covalent network. Figure 1 In the right side enlarged schematic, the solid line represents the covalent main chain of APC and PDES, the dashed line represents the hydrogen bond between carboxyl groups and between carboxyl groups and DES components, and the dotted line and node correspond to the coordination crosslinking of Fe 3+ and carboxylic acid / chloride ion.

[0080] Under external force, the APC / PDES covalent chain provides basic bearing capacity, and the hydrogen bond network is preferentially broken to dissipate energy, while Fe 3+ -Carboxylic acid coordination bonds can reversibly dissociate and recombine to achieve stress release and structure reconstruction; when the external force is removed or the crack is closed, the residual carboxyl / Fe 3+ / hydrogen bond interactions reestablish crosslinking points, and the conductive path and mechanical network are restored, thereby endowing the double network conductive elastomer with high strength, high elongation, and room temperature self-healing ability. This synergy of "hydrogen bond network + metal coordination network" is the fundamental mechanism that distinguishes the double network conductive elastomer of the present application from existing single physical or chemical crosslinking DES gels and achieves significant improvement in comprehensive performance.

[0081] Figure 2 Infrared spectra of the double network conductive elastomers prepared in Examples 1-4. The absorption peak at 3400 cm -1 is the stretching vibration peak of O-H, and the absorption peak at 1735 cm-1 the stretching vibration of C=0 at 1737 cm -1 the stretching vibration of COOH and Fe 3+ the anti-symmetrical stretching vibration of COO- after the deprotonation of the metal coordination, at 1409 cm -1 the symmetrical stretching vibration of COO- at 1340 cm -1 the C-N stretching vibration of the quaternary ammonium salt in choline chloride, while the absorption peak at 1120 cm -1 should be attributed to the stretching vibration of C-O-C in polycarbonate. With the increase of the doping content of FeCl3, the stretching vibration of C=0 further shifted from 1737 cm -1 to 1746 cm -1 , which proved the formation of the metal coordination between the carboxyl group and Fe 3+ .

[0082] Figure 3 X-ray photoelectron spectroscopy of the double network conductive elastomer prepared in Example 3. Figure 3 a figure in the figure is the high-resolution XPS spectrum of DPF3, which shows that C, O, Cl and Fe elements exist. Figure 3 b figure in the figure is the XPS spectrum of C1s, from which it can be obtained that C exists in four chemical forms. Figure 3 c figure in the figure is the XPS spectrum of O1s, and in DPF3, O exists in two chemical forms, in which the peak at 532.33 eV is attributed to the binding energy of C=0, and the peak at 533.89 eV is attributed to the binding energy of Fe-O, which shows that the metal coordination is formed between Fe and the carboxyl group. Figure 3 d figure in the figure is the XPS spectrum of Fe2p, in which the peaks at 709.26 eV, 712.06 eV, 716.96 eV and 718.26 eV should be attributed to Fe2p 3 / 2 and its satellite peaks, while the peaks at 723.76 eV, 727.36 eV, 732.26 eV and 733.96 eV should be attributed to Fe2p 1 / 2 and its satellite peaks.

[0083] Figure 4The figures show the stress-strain curves of the dual-network conductive elastomers prepared in Examples 1-4. As the FeCl3 doping content increased from 5 wt% to 15 wt%, the fracture stress increased from 210 kPa to 494 kPa, while the elongation at break also increased from 566% to 883%. This is because the dual-network conductive elastomer contains a non-covalent interaction network composed of hydrogen bond networks and metal coordination networks. During stretching, this non-covalent interaction network undergoes network destruction and regeneration (including the breaking and regeneration of hydrogen bonds between PDES and APC, and the interaction of metal coordination ions FeCl3). 3+ The continuous dissociation and re-dynamic coordination of numerous carboxyl groups in the system provides a reversible energy dissipation mechanism for the dual-network conductive elastomer, thereby improving its tensile strength and elongation at break. As the FeCl3 doping content increases from 15 wt% to 20 wt%, the fracture stress of the dual-network conductive elastomer increases from 494 kPa to 802 kPa, while the elongation at break decreases significantly from 883% to 545%. This is because the excessively high FeCl3 doping content leads to an overly dense physical cross-linking network formed by metal coordination within the dual-network conductive elastomer, while the Fe... 3+ The formation of metal coordination bonds with a large number of carboxyl groups also crowds out the space for hydrogen bond formation, which weakens the synergistic effect of the hydrogen bond network, reduces energy dissipation efficiency, and causes the elasticity of the dual-network conductive elastomer to decrease.

[0084] Figure 5 The diagram shows a comparison of the gauge factor (Figure a) and the relative resistance-time response (Figure b) of the DPF3 sample prepared in Example 3 under different strain ranges. As the strain range increased from 0%–100% to 200%–300%, the gauge factor increased from 3.26 to 5.70; as the strain of the dual-network conductive elastomer increased from 100% to 300%, the relative resistance increased from an average of 371% to an average of 1288%. This is because with increasing strain, the dual-network conductive elastomer is stretched, and choline chloride and Fe... 3+ The reduced contact between the two networks leads to an increase in contact resistance. At the same time, the transverse strain causes longitudinal compression of the dual-network conductive elastomer, which hinders or even destroys the channels for ion migration, restricts ion migration, increases tunneling resistance, and makes the resistance change more obvious. The sensitivity of the dual-network conductive elastomer is improved, and the gauge factor is increased.

[0085] Figure 6 Figure a shows the muscle current sensing signal of the DPF3 sample prepared in Example 3 at the wrist during the clenching and relaxing of the fist. Figure 6Figure b in the figure is the DPF3 sample prepared in Example 3 is the muscle current sensing signal of elbow bending-relaxing at the arm, as the muscle forces, the voltage rises rapidly; the muscle force ends, the voltage falls to the baseline, the muscle force process is recorded completely, so the DPF3 film can also be applied in the field of human physiological signal monitoring.

[0086] Figure 7 The self-repairing performance of the DPF3 sample prepared in Example 3 is shown in the table, wherein the self-repairing performance is characterized by the recovery degree of the breaking stress. The initial breaking stress of the DPF3 sample before cutting is 484 kPa; after the DPF3 sample is completely cut, the two fracture surfaces are pasted together, and the tensile test is carried out after being naturally placed at room temperature for 4 h, at this time, the breaking stress is 51 kPa, and the self-repairing efficiency η is calculated according to η = σ / σ0 x 100%, wherein σ0 is the initial breaking stress, and σ is the breaking stress after self-repairing, and the self-repairing efficiency is about 10.5%; after self-repairing at 60 DEG C for 1 h, the breaking stress of the DPF3 is increased to 341 kPa, and the self-repairing efficiency is about 70.5%. In addition, the completely cut DPF3 sample is pasted after the two fracture surfaces are connected with the electrochemical workstation, and the current signal can be recovered and stabilized within 100 ms, indicating that the dual-network conductive elastomer has good self-repairing ability in the aspects of mechanics and electricity.

[0087] In summary, the application develops a FeCl3 cross-linked polydeep eutectic solvent and polycarbonate dual-network conductive elastomer, the preparation process is simple, and the application has very important application prospect in the fields of human motion monitoring, health monitoring, disease diagnosis, rehabilitation treatment and daily health assessment.

[0088] Although the preferred embodiments of the application have been described, those skilled in the art who know the inventive concept of the application can make additional changes and modifications to the embodiments, and these changes and modifications all fall within the scope of the application.

[0089] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. If these modifications and variations of the application fall within the scope of the equivalent technology of the application, the application also intends to include these modifications and variations.

Claims

1. A process for the preparation of a FeCl3 cross-linked based polydeep eutectic solvent and polycarbonate double network conductive elastomer characterized by, The method comprises the following steps: The copolymerization is carried out under vacuum conditions, using polyethylene glycol monomethyl ether as a macromolecular initiator and a flexible hydrophilic segment, using 5-methyl-5-benzyloxy carbonyl trimethylene carbonate and 5-methyl-5-carboxyl trimethylene carbonate as raw materials, and using stannous octoate as a catalyst, mPEG 113 The terminal hydroxyl group of mPEG initiates the nucleophilic ring-opening of 5-methyl-5-benzyloxy carbonyl trimethylene carbonate and 5-methyl-5-carboxyl trimethylene carbonate, and initiates the copolymerization of the two, to obtain an aliphatic polycarbonate; Choline chloride is mixed with acrylic acid to obtain a deep eutectic solvent, the deep eutectic solvent is mixed with a photoinitiator, and the polymerization of the double bond of the acrylic acid is initiated by light to solidify the originally flowing deep eutectic solvent into an ionic gel with a three-dimensional covalent network, thereby obtaining a polydeep eutectic solvent gel; The aliphatic polycarbonate, the polydeep eutectic solvent gel and the ferric chloride are mixed in an organic solvent, stirred, and Fe 3+ is uniformly dispersed and coordinates with the carboxyl groups in the aliphatic polycarbonate and the anions in the polydeep eutectic solvent gel, and vacuum dried to obtain a polydeep eutectic solvent and polycarbonate double network conductive elastomer crosslinked based on FeCl3.

2. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The molar ratio of polyethylene glycol monomethyl ether, 5-methyl-5-benzyloxycarbonyl trimethylene carbonate, 5-methyl-5-carboxyl trimethylene carbonate and stannous octoate is 1:50:25-50:0.

3.

3. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The temperature of the copolymerization reaction is 100-130 DEG C, and the time is 10-15 h.

4. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The molar ratio of choline chloride and acrylic acid is 1:1-2.

5. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The amount of the photoinitiator added accounts for 0.1-0.5 wt% of the total weight of choline chloride and acrylic acid.

6. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The polymerization reaction is carried out under the condition of irradiation of a 550 W ultraviolet lamp for 2-5 min.

7. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The mass ratio of the aliphatic polycarbonate and the polydeep eutectic solvent gel is 1:1-3.

8. The process for the preparation of FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer according to claim 1, characterized in that, The amount of the ferric chloride added accounts for 5-20 wt% of the total weight of the aliphatic polycarbonate and the polydeep eutectic solvent gel.

9. A FeCl3 crosslinking based polydeep eutectic solvent and polycarbonate double network conductive elastomer characterized in that, The polydeep eutectic solvent and the polycarbonate double network conductive elastomer are prepared by the method of any one of claims 1-8.

10. Use of the FeCl3 cross-linked polydeep eutectic solvent and polycarbonate double network conductive elastomer of claim 9 in the preparation of a flexible wearable device.

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