A fluorinated elastomer capable of underwater self-repairing, and its preparation method and use

Abstract

The present invention provides a fluorine-containing elastomer that can self-repair underwater, and its preparation method and use, which belong to the field of polymer materials. The fluorine-containing elastomer of the present invention is obtained by grafting pyridine groups on the main chain of fluororubber. The present invention realizes the self-repair of commercial fluorine-containing elastomers in a simple way. Based on the dipole-dipole interaction of CF3-CF3 and CF3-pyridine N, the prepared fluorine-containing elastomer has excellent self-repairing performance (in air and water environments) and good mechanical strength; at the same time, due to the introduction of pyridine polar groups, the dielectric constant of the material is greatly improved, showing excellent piezoelectric properties. The preparation process of the present invention is simple, the obtained material has multiple functionalities and excellent comprehensive performance, and provides a new idea for the design and development of self-repairing elastomers for electronic and energy devices.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and in particular relates to an underwater self-repairing fluorine-containing elastomer, a preparation method thereof, and uses thereof. Background Art

[0002] Polymers are widely used in various flexible electronic and energy devices, including energy harvesting and storage devices, wearable electronic devices, electronic skin, flexible sensors, flexible robots, and flexible electronic circuits, due to their excellent mechanical properties. Although polymers used in flexible devices have the ability to adapt to large strains / stresses or geometric deformations, they are often subject to mechanical damage such as wear, tear, scratches, and accidental cutting, as well as electrical damage under long-term strong electric fields during actual application, which destroys the structural and functional integrity of the polymer part of the device, resulting in device performance degradation or even catastrophic failure. Therefore, giving polymer materials in flexible electronic and energy devices damage resistance, wear resistance, and repair capabilities is of great significance to improving the long-term stability and reliability of polymers in flexible devices. Inspired by the powerful self-healing ability of biological systems, the concept of self-healing has been introduced into polymers to achieve self-repair of mechanical and electrical damage, thereby significantly improving the service life and reliability of flexible electronic and energy devices.

[0003] To achieve the "self-healing" ability of polymers, it is often necessary to introduce dynamic covalent bonds or supramolecular interactions into the polymers to generate strong interactions between polymer chains, so that the broken surfaces can be reconnected. However, the self-healing polymers based on reversible dynamic covalent bonds or dynamic non-covalent bonds reported so far are usually unstable under humid conditions. In a humid environment, water molecules can play a variety of roles: donors and acceptors of hydrogen bonds, ligands, polar solvents, etc. This means that the dynamic bonds will be disturbed in many ways: water molecules will saturate hydrogen bonds, bind to metal cations, and solvate ions, thereby greatly reducing the bonding constants of these bonds. As a result, the self-healing material will gradually swell and lose its self-healing ability.

[0004] Ion-dipole and dipole-dipole interactions are supramolecular interactions. Although their strength is far less than that of chemical bonds such as covalent bonds, they are ubiquitous between polymer chains. Some researchers have rationally exploited this supramolecular interaction to successfully design self-healing materials that can function in complex environments. These materials are widely used in wearable devices and human-computer interfaces. While these methods, utilizing dipole-dipole and ion-dipole interactions, achieve self-healing properties in various aquatic conditions, the plasticizing effect of plasticizers or ionic liquids increases the distance between chains, resulting in generally weaker mechanical properties.

[0005] Fluorine atoms in fluoroelastomers have a small atomic radius and the strongest electronegativity. The C-F bond is a very poor hydrogen donor and hydrogen acceptor. The water environment makes fluoropolymers have a very weak acceptance of water molecules, ensuring the stability of the material underwater. Therefore, this characteristic of fluoroelastomers can be used to develop water-resistant self-healing elastomers. Although there are reports on self-healing materials of fluoromonomers, the polymer structures in most of these works are carefully designed, and their self-healing systems are "tailor-made". There are very few studies on the intrinsic self-healing of commercial fluoroelastomers. How to achieve underwater self-healing of commercial fluoroelastomers in a simple way and keep the fluoroelastomers with good mechanical properties requires further research. Summary of the Invention

[0006] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a fluorine-containing elastomer capable of underwater self-repairing, and a preparation method and use thereof.

[0007] The invention provides a fluorine-containing elastomer capable of underwater self-repairing. The fluorine-containing elastomer is obtained by grafting pyridine groups onto the main chain of fluorine rubber.

[0008] Furthermore, the fluorine-containing elastomer is obtained by subjecting fluororubber to a dehydrogenation and defluorination reaction with an organic amine, followed by a Michael addition reaction with hydroxypyridine.

[0009] Furthermore,

[0010] The mass volume ratio of the fluororubber to the organic amine is 10 g: (1-5) mL;

[0011] And / or, the temperature of the dehydrogenation and defluorination reaction is 10 to 40° C., and the reaction time is 10 to 20 hours;

[0012] and / or, the mass ratio of the fluororubber to hydroxypyridine is 10:(1-5);

[0013] And / or, the temperature of the Michael addition reaction is 10-40° C., and the reaction time is 10-20 h.

[0014] Furthermore,

[0015] The mass volume ratio of the fluororubber to the organic amine is 10 g:1.6 mL;

[0016] And / or, the mass ratio of the fluororubber to hydroxypyridine is 10:1.6.

[0017] Furthermore,

[0018] The organic amine is triethylamine;

[0019] And / or, the hydroxypyridine is 3-hydroxypyridine.

[0020] The present invention also provides a method for preparing the aforementioned fluorine-containing elastomer, which comprises the following steps:

[0021] (1) In the solvent, fluororubber and organic amine undergo dehydrogenation and defluorination reactions;

[0022] (2) After the reaction in step (1) is completed, hydroxypyridine solution is added to cause Michael addition reaction to obtain the product.

[0023] Furthermore,

[0024] In step (1), the solvent is a ketone or ester solvent;

[0025] And / or, in step (1), the mass volume ratio of the fluororubber to the organic amine is 10 g: (1 to 5) mL;

[0026] And / or, in step (1), the temperature of the dehydrogenation and defluorination reaction is 10 to 40° C., and the reaction time is 10 to 20 hours;

[0027] And / or, in step (2), the mass ratio of the fluororubber to the hydroxypyridine is 10:(1-5);

[0028] and / or, in step (2), the solvent of the hydroxypyridine solution is a mixed solution of ethanol and ketones or esters;

[0029] And / or, in step (2), the temperature of the Michael addition reaction is 10-40° C., and the reaction time is 10-20 h.

[0030] Furthermore,

[0031] In step (1), the solvent is acetone;

[0032] And / or, in step (1), the mass volume ratio of the fluororubber to the organic amine is 10 g:1.6 mL;

[0033] And / or, in step (2), the mass ratio of the fluororubber to the hydroxypyridine is 10:1.6;

[0034] And / or, in step (2), the solvent of the hydroxypyridine solution is a mixed solution of ethanol and acetone; preferably, the volume ratio of the ethanol to acetone is 2:1;

[0035] And / or, in step (2), the product is washed and then dried after the reaction.

[0036] Furthermore,

[0037] The organic amine is triethylamine;

[0038] And / or, the hydroxypyridine is 3-hydroxypyridine.

[0039] The present invention also provides the use of the aforementioned fluorinated elastomer in self-healing elastomers for electronic and energy devices;

[0040] Preferably, the fluorinated elastomer is used in the preparation of self-healing flexible electronic devices.

[0041] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0042] Starting from the ionic cross-linking mechanism of fluororubber, the present invention completes the chemical modification of commercial fluororubber through a simple method. First, triethylamine is used to treat fluororubber (FKM) to generate a -CF=CH- double bond on the main chain. Then the hydroxyl group of 3-hydroxypyridine attacks this double bond, and the pyridine group is introduced into the fluororubber main chain, successfully preparing a fluoroelastomer containing pyridine groups. Based on the dipole-dipole interaction of CF3-CF3 and CF3-pyridine N, the prepared fluoroelastomer is not affected by water molecules and has excellent self-healing properties in both air and water environments; at the same time, the fluoroelastomer has good mechanical strength. And due to the introduction of the pyridine polar group, the dielectric constant of the fluoroelastomer is greatly improved, showing excellent dielectric and piezoelectric properties. The preparation process of the present invention is simple, and the obtained fluoroelastomer has multiple functionalities and excellent comprehensive performance. It has broad application prospects as a dielectric material in many flexible electronic and energy devices that require high stability, high reliability and good safety. The present invention provides a reference for using dipole forces to achieve self-healing of commercial materials.

[0043] Simply put, this invention achieves the self-healing of commercial fluoroelastomers through a simple method. Based on the dipole-dipole interactions of CF3-CF3 and CF3-pyridinium N, the resulting fluoroelastomer exhibits excellent self-healing properties (in both air and water environments) and good mechanical strength. Furthermore, the introduction of pyridinium polar groups significantly enhances the dielectric constant of the material, demonstrating excellent piezoelectric properties. The invention offers a simple preparation process, and the resulting material possesses diverse functionality and excellent overall performance, providing new insights into the design and development of self-healing elastomers for electronic and energy devices.

[0044] Obviously, based on the above contents of the present invention, according to common technical knowledge and customary means in this field, without departing from the above basic technical ideas of the present invention, other various forms of modifications, replacements or changes can be made.

[0045] The following is a further detailed description of the present invention through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-mentioned content of the present invention fall within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The figure is a flow chart for preparing the underwater self-repairable fluoroelastomer (FKM-HPY) of the present invention.

[0047] Figure 2 These are the infrared characterization spectra of different fluororubber samples: a is the infrared spectra of FKM and samples treated with triethylamine for different times; b is the infrared spectra of B-FKM-12H and FKM-HPY-2.

[0048] Figure 3 F1s spectra of B-FKM-12H and FKM-HPY-2.

[0049] Figure 4 A small molecule model for dipole-dipole interactions calculated using density functional theory (DFT).

[0050] Figure 5 The dipole-dipole interactions were calculated using all-atom molecular dynamics (MD) simulations of the polymer repeating units.

[0051] Figure 6 Stress-strain curves of B-FKM-12H and FKM-HPY-2.

[0052] Figure 7 These are the self-healing test results of FKM-HPY-2 in air: a is the stress-strain curve of 5 min repair at different repair temperatures in air, where Pristine is the initial sample; b is the stress-strain curve of different repair times at 40°C in air; c is the stress-strain curve of 60 min self-healing at different temperatures in air.

[0053] Figure 8 Optical microscope image of a scratched FKM-HPY-2 film after healing at 60°C.

[0054] Figure 9 These are the self-healing test results of FKM-HPY-2 in water: a is the stress-strain curve of the original sample and the repair time in 20℃ water; b is the stress-strain curve of self-healing in 60℃ water for 60 minutes.

[0055] Figure 10The dielectric properties and conductivity results of various fluororubbers: a is the relationship between the dielectric constant and frequency of FKM, B-FKM-12H, FKM-HPY-1, and FKM-HPY-2 at 20°C; b is the conductivity of FKM at different temperatures (-40°C, -20°C, 0°C, 20°C, 40°C, and 60°C) as a function of frequency; c is the conductivity of B-FKM-12H at different temperatures as a function of frequency; d is the conductivity of FKM-HPY-2 at different temperatures as a function of frequency.

[0056] Figure 11 The output voltage and current results of FKM-HPY-2 under different conditions of applying 2n periodic external force: a is voltage; b is current. DETAILED DESCRIPTION

[0057] The raw materials and equipment used in the specific embodiments of the present invention are all known products and are obtained by purchasing commercial products.

[0058] Commercial bisphenol-cured difluororubber (brand DH-7630) was purchased from Sichuan Daohong New Materials Co., Ltd. 3-Hydroxypyridine (Py, 98.0%) was purchased from Adamas. Triethylamine, acetone, ethanol, and petroleum ether were purchased from Tansoole (China).

[0059] In the specific embodiment of the present invention, the room temperature ranges from 20 to 30°C.

[0060] Example 1: Preparation of the underwater self-repairable fluoroelastomer (FKM-HPY) of the present invention

[0061] Preparation of polymer FKM-HPY (using FKM-HPY-2 as an example): First, dissolve 10g of fluororubber in 50ml of acetone in a 250ml beaker. Then, add 1.6ml of triethylamine dropwise. After reacting at room temperature for 12 hours, add 1.6g of 3-hydroxypyridine in an ethanol-acetone solution (10ml of ethanol and 5ml of acetone). Continue the reaction for another 12 hours before terminating. The resulting product is precipitated and washed three times in petroleum ether, then washed three times with deionized water to remove unreacted monomers. Dry in a vacuum oven at 60°C to constant weight to obtain a brown solid.

[0062] According to the preparation method of Example 1, FKM-HPY-1 was prepared by changing the amount of 3-hydroxypyridine from 1.6 g to 1 g.

[0063] Figure 1 The preparation process of the underwater self-healing fluoroelastomer (FKM-HPY) of the present invention is as follows: first, triethylamine is used to treat fluororubber (FKM) to generate a -CF=CH- double bond on the main chain, and then the hydroxyl group of 3-hydroxypyridine attacks the double bond to introduce the pyridine group into the fluororubber main chain.

[0064] Comparative Example 1: Preparation of other fluorinated elastomers (B-FKM)

[0065] Preparation of polymer B-FKM (using B-FKM-12H as an example): First, dissolve 10g of fluororubber in 50ml of acetone in a 100ml beaker. Then, add 1.6ml of triethylamine dropwise. After the addition is complete, continue the reaction at room temperature for 12 hours. The resulting product is precipitated and washed three times in petroleum ether, then washed three times with deionized water to remove unreacted monomer. Dry in a vacuum oven at 60°C to constant weight to obtain a yellow-brown solid. The "12H" in B-FKM-12H refers to the reaction time of 12 hours.

[0066] According to the preparation method of Comparative Example 1, the reaction time was changed to 1 h, 2 h and 3 h to prepare B-FKM-1H, B-FKM-2H and B-FKM-3H.

[0067] The beneficial effects of the present invention are demonstrated below through specific test examples.

[0068] Test Example 1: Structural Characterization of the Underwater Self-Healing Fluoroelastomer of the Present Invention

[0069] 1. Infrared spectroscopy characterization

[0070] The raw material fluororubber (FKM), FKM-HPY-2 prepared in Example 1, B-FKM-1H, B-FKM-2H, B-FKM-3H and B-FKM-12H prepared in Comparative Example 1 were characterized by infrared spectroscopy. The results are as follows: Figure 2 As shown. Figure 2 The infrared spectrum of a shows that the FTIR spectra of fluororubber treated with triethylamine for different times are compared with those of untreated fluororubber. -1 A stretching vibration peak corresponding to a non-conjugated double bond appears at , and the peak gradually increases with the extension of the reaction time, which preliminarily proves that the fluororubber undergoes a dehydrofluoric acid reaction in an alkaline environment and generates a double bond on the main chain. Figure 2 The infrared spectrum of b shows that at 1578cm -1 The vibration absorption peak corresponding to the ring deformation in the pyridine molecule plane appears at 1480 cm -1 A vibration absorption peak corresponding to the CH deformation on the pyridine molecular skeleton appeared, proving that 3-hydroxypyridine was successfully connected to the fluororubber main chain.

[0071] 2. X-ray photoelectron spectroscopy (XPS) characterization

[0072] Sample B-FKM-12H prepared in Comparative Example 1 and sample FKM-HPY-2 prepared in Example 1 were analyzed using a Kratos XSAM800 X-ray photoelectron spectrometer. The X-ray radiation source was Mg Ka (hv = 253 eV), and the test conditions were 12 kV and 15 mA, with point acquisition mode. Narrow spectrum scans were performed for C1s, N1s, O1s, and F1s.

[0073] In order to prove the existence of the dipole effect between CF3 dipole and pyridine N in 3-hydroxypyridine modified fluororubber, the present invention uses X-ray photoelectron spectroscopy (XPS) to study the position of the 1s orbital binding energy peak of F before and after modification ( Figure 3 ).from Figure 3 It can be seen from the graph that the 1s binding energy peak of the modified (FKM-HPY-2)F shifted by 0.25 eV from 689 eV to 688.75 eV, indicating that there is an interaction between the electronegative CF3 group of the fluororubber side chain and the N cation on the pyridine ring.

[0074] 3. Small molecule model of dipole-dipole interaction

[0075] In order to further understand the dipole-dipole interaction between -CF3 and pyridine N, density functional theory calculations (DFT) and all-atom molecular dynamics simulations (MD simulations) were performed at the theoretical level. The results are shown in Figure 2. Figure 4 and Figure 5 As shown. Using a small molecule model, density functional theory (DFT) calculations showed that the CF3-CF3 interaction energy is lower than the CF3-pyridine N interaction energy, proving the existence of a dipole-dipole interaction between CF3 and pyridine N. The existence of a dipole-dipole interaction in the polymer was further confirmed by all-atom molecular dynamics (MD) simulations. In order to save computing resources, 5 molecular chains with 12 repeating units were selected as the polymer model for simulation calculations. The specific calculations were performed using the open source software Materials studio developed by Accelrys Corporation in the United States. First, the amorphous polymer molecular chain was constructed using the Amphorous module; then molecular dynamics calculations were performed using the Forcite module. The weak interaction energy of the entire polymer system was calculated by molecular dynamics, and the pyridine ring was compared with the benzene ring to further verify the dipole-dipole interaction between the polymers. During the simulation process, the pyridine ring was replaced with the benzene ring, and the interaction energy was calculated. The energy was -363.053 kcal / mol, which was lower than that of the pyridine ring, indicating the existence of a dipole-dipole interaction between CF3 and pyridine N.

[0076] Test Example 2: Mechanical Properties Test of the Underwater Self-Repairable Fluoroelastomer of the Present Invention

[0077] Tensile testing was conducted on an Instron 5967 tensile tester. The test specimens (sample B-FKM-12H prepared in Comparative Example 1 and sample FKM-HPY-2 prepared in Example 1) were dumbbell-shaped, with an inner gauge length of 20 mm, a width of 2 mm, and a thickness of 1 mm. The test rate was 100 mm / min.

[0078] The dipole-dipole interaction between -CF3 and pyridine N and its effect on the mechanical properties of fluorinated elastomers were studied by uniaxial tensile tests. Figure 6 It can be seen that the dipole interaction between -CF3 and pyridine N has a certain contribution to the tensile strength. The tensile strength of FKM-HPY-2 reaches about 1 MPa, which is significantly better than that of fluoroelastomers without pyridine.

[0079] Test Example 3: Self-repairing performance test of the underwater self-repairing fluoroelastomer of the present invention

[0080] The sample self-healing efficiency is defined as the ratio of the tensile strength of the repaired sample to the tensile strength of the original sample, as shown in the following formula (1):

[0081]

[0082] where σ cut represents the tensile strength of the repaired specimen after cutting, σ uncut Represents the tensile strength of the original sample. The tensile rate is 100 mm / min.

[0083] The present invention used FKM-HPY-2 prepared in Example 1 to study the self-healing properties of a pyridine-grafted fluoroelastomer. Uniaxial tensile tests were conducted on both the original and repaired specimens. The intact specimens were first cut in half and then gently spliced together. Without applying external force, the specimens were allowed to heal under different conditions, temperatures, and time periods.

[0084] Figure 7 a shows the self-healing ability of FKM-HPY-2 in air at different temperatures. It can be seen that the self-healing speed of fluoroelastomer in air is very fast. At 20℃, it can recover 97.6% of its original tensile strength in 5 minutes. However, the strain repair efficiency is relatively low. After 5 minutes of repair at 20℃, the strain is only 3.8% of the original strain. Figure 7Figures 7b and 7c show that increasing the repair temperature or extending the repair time has a positive effect on the strain repair efficiency of the polymer. For example, when the repair temperature is raised to 40°C, the strain reaches 1300% after 60 minutes of repair and 2000% after 120 minutes of repair (the original strain is 1940%). On the one hand, increasing the temperature can improve the mobility of polymer segments, thereby promoting the dynamics of dipole-dipole interactions. On the other hand, extending the repair time provides favorable conditions for the migration and diffusion of polymer segments in the damaged interface area. These two factors synergistically promote the self-repair process.

[0085] The self-healing process of the sample (FKM-HPY-2) was visually observed using a polarizing microscope. First, a scratch of about 30 to 50 μm was pre-made on the sample film using a single-sided blade, and then the sample was placed on a polarizing microscope hot stage (preset temperature 60°C) to observe the scratch repair process. Figure 8 It can be seen that the scratch gradually began to close within 30 seconds and almost completely disappeared within 90 seconds.

[0086] The results of the sample (FKM-HPY-2) repaired at 20℃ water temperature for different times are as follows Figure 9 As shown in Figure a, after 30 minutes of underwater repair, the tensile strength of the sample can reach 96% of the original tensile strength. As the time is extended to 60 minutes, the strain reaches 115%, which means that the material of the present invention can indeed self-repair underwater. On this basis, the present invention tested the self-repair performance of the sample in 60℃ water, and the results are as follows Figure 9 As shown in Figure b, after 60 minutes of self-healing, the tensile strength of the sample recovered to about 95% of the original strength, while the strain was almost completely recovered. These results indicate that the hydrophobic nature of the fluororubber backbone eliminates the interference of water molecules, ensuring that the dipole-dipole interaction between the polymer interior and the contact surface remains effective underwater.

[0087] Test Example 4: Electrical Performance Test of the Underwater Self-Healing Fluoroelastomer of the Present Invention

[0088] The raw material fluororubber (FKM), FKM-HPY-1 and FKM-HPY-2 prepared in Example 1, and B-FKM-12H samples prepared in Comparative Example 1 were tested.

[0089] Broadband dielectric testing of the samples was performed on a Nococontrol Concept 50 system equipped with an Alpha impedance analyzer and a Quatro Cryosystem temperature controller. The test method involved placing a disc-shaped sample approximately 1 mm thick and 20 mm in diameter between two parallel copper electrodes, clamping them, and placing them in the test instrument. The frequency range of the temperature-sweep mode was 10 -1 ~10 7Hz, temperature range is -60℃~60℃, and temperature gradient is 10℃.

[0090] Piezoelectric performance test: Aluminum foil was pasted on both sides of the sample and corona polarization was performed for 60 minutes using a piezoelectric material composite polarization machine (Shaanxi Huiyan New Material Technology Co., Ltd., HYJH-F) at a temperature of 100°C and a voltage of 20 kV / mm. The polarized sample was then coated with aluminum tape as an electrode and wire and wrapped with a polyimide film. A linear motor (NTIAG, USA, HS01-37166), an electrometer (Keithley Instruments, USA, 6514) and a current preamplifier (SRS, USA, SR570) were used to test the piezoelectric output performance of the sample. The impact force was approximately 2N.

[0091] The introduction of pyridine groups increases the dielectric constant of fluororubber. For example, at room temperature of 20°C and frequency of 100 Hz, the dielectric constant of FKM-HPY-2 reaches 22.5, which is more than twice the dielectric constant of conventional fluororubber. Figure 10 a) The conductivity results of FKM, B-FKM-12H, and FKM-HPY-2 are as follows Figure 10 As shown in Figures 10b, 10c, and 10d, it can be seen that the presence of carbon-carbon double bonds on the main chains of both triethylamine-treated fluororubber and pyridine-grafted fluoroelastomer enhances electron delocalization, making the charge migration and accumulation process more obvious, thereby increasing the conductivity.

[0092] The piezoelectric response of FKM-HPY-2 was further investigated. Figure 11 The output open circuit voltage and short circuit current of FKM-HPY-2 under different conditions (freshly prepared original sample, sample stored in air for 7 days, self-repaired sample after 60 minutes of self-repair at 40℃, and sample stored in air for 7 days after self-repair) are shown. Figure 11 As can be seen from the images, both the repaired and unrepaired FKM-HPY-2 samples exhibited a stable and continuous piezoelectric response to cyclic loading. The intact FKM-HPY-2 sample exhibited a much better piezoelectric response, with a stable output voltage of approximately 32V and a short-circuit current of 0.9μA. The repaired sample's output voltage and short-circuit current decreased slightly, but the voltage remained around 29V and the short-circuit current remained at 0.5μA, indicating that the damaged piezoelectric network structure had fully recovered.

[0093] In summary, the present invention successfully prepared a fluoroelastomer containing pyridine groups, realizing the self-repair of commercial fluoroelastomers. Based on the dipole-dipole interaction of CF3-CF3 and CF3-pyridine N, the prepared fluoroelastomer has excellent self-repairing properties in both air and water environments; at the same time, the fluoroelastomer has good mechanical strength. And due to the introduction of pyridine polar groups, the dielectric constant of the fluoroelastomer is greatly improved, showing excellent dielectric and piezoelectric properties. The preparation process of the present invention is simple, and the obtained fluoroelastomer has multiple functionalities and excellent comprehensive performance. It has broad application prospects as a dielectric material in many flexible electronic and energy devices that require high stability, high reliability and good safety. The present invention provides a reference for the use of dipole forces to achieve self-repair of commercial materials.

Claims

1. A fluoroelastomer capable of underwater self-repairing, characterized by: The fluorine-containing elastomer is obtained by reacting fluororubber with organic amine through dehydrogenation and defluorination, and then reacting with hydroxypyridine through Michael addition reaction; The fluororubber is bisphenol-sulfurized binary fluororubber; The organic amine is triethylamine; The temperature of the dehydrogenation and defluorination reaction is 10 to 40° C., and the reaction time is 10 to 20 hours; The temperature of the Michael addition reaction is 10-40° C., and the reaction time is 10-20 hours.

2. The fluorine-containing elastomer according to claim 1, characterized in that: The mass volume ratio of the fluororubber to the organic amine is 10 g: (1-5) mL; And / or, the mass ratio of the fluororubber to hydroxypyridine is 10:(1-5).

3. The fluorine-containing elastomer according to claim 2, characterized in that: The mass volume ratio of the fluororubber to the organic amine is 10 g:1.6 mL; And / or, the mass ratio of the fluororubber to hydroxypyridine is 10:1.

6.

4. The fluorinated elastomer according to any one of claims 1 to 3, characterized in that: The hydroxypyridine is 3-hydroxypyridine.

5. The method for preparing a fluorinated elastomer according to any one of claims 1 to 4, characterized in that: It includes the following steps: (1) In the solvent, fluororubber and organic amine undergo dehydrogenation and defluorination reactions; (2) After the reaction of step (1) is completed, hydroxypyridine solution is added to cause Michael addition reaction to obtain; In step (1), the fluororubber is bisphenol-sulfurized binary fluororubber; In step (1), the organic amine is triethylamine; In step (1), the temperature of the dehydrogenation and defluorination reaction is 10 to 40° C., and the reaction time is 10 to 20 hours; In step (2), the temperature of the Michael addition reaction is 10 to 40° C., and the reaction time is 10 to 20 hours.

6. The preparation method according to claim 5, characterized in that: In step (1), the solvent is a ketone or ester solvent; And / or, in step (1), the mass volume ratio of the fluororubber to the organic amine is 10 g: (1 to 5) mL; And / or, in step (2), the mass ratio of the fluororubber to the hydroxypyridine is 10:(1-5); And / or, in step (2), the solvent of the hydroxypyridine solution is a mixed solution of ethanol and ketones or esters.

7. The preparation method according to claim 6, characterized in that: In step (1), the solvent is acetone; And / or, in step (1), the mass volume ratio of the fluororubber to the organic amine is 10 g:1.6 mL; And / or, in step (2), the mass ratio of the fluororubber to the hydroxypyridine is 10:1.6; And / or, in step (2), the solvent of the hydroxypyridine solution is a mixed solution of ethanol and acetone; And / or, in step (2), the product is washed and then dried after the reaction.

8. The preparation method according to claim 7, characterized in that: In step (2), the volume ratio of ethanol to acetone is 2:

1.

9. The preparation method according to claim 8, characterized in that: The hydroxypyridine is 3-hydroxypyridine.

10. Use of the fluorinated elastomer according to any one of claims 1 to 4 in self-healing elastomers for electronic and energy devices.

11. The use according to claim 10, characterized in that: Use of the fluorine-containing elastomer in preparing self-healing flexible electronic devices.

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