Bi-crosslinking autonomous self-repairing in-situ polymerization conductive elastomer and preparation method thereof
Through the regulation of the molecular structure of polyacrylic acid and the dual driving of hydrogen bonds and coordination bonds, in-situ polymerization and efficient self-repair of self-healing conductive elastomers are achieved, solving the problems of poor transparency, slow repair efficiency and complex process in the prior art, significantly extending the service life and improving performance.
Patent Information
- Application Number
- CN202510198821.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-05-30
AI Technical Summary
The existing self-healing conductive elastomers have poor transparency, slow conductivity repair efficiency and complex synthesis process.
By regulating the molecular structure of polyacrylic acid, the in-situ polymerization of self-healing conductive elastomers is achieved, and the autonomous self-healing process is accelerated by the dual driving of hydrogen bonds and coordination bonds, and the conductivity is improved through the ionic conductivity mechanism.
It realizes efficient self-repair characteristics, significantly extends the service life of the conductive elastomer, and has excellent conductivity, transparency and flexibility.
Smart Images
Figure CN120059007A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the application field of intelligent materials with flexible, conductive and self-healing functions. Specifically, it relates to a double-crosslinked autonomous self-healing in-situ polymerization conductive elastomer and a preparation method thereof. Background Art
[0002] Self-healing materials are a class of materials that can automatically restore their structure and function through a certain mechanism after being damaged. The repair mechanism can be physical or chemical, such as through external heat sources, light sources or other excitation factors. Physical repair (such as temperature-triggered, light-triggered), chemical repair (chemical bond recombination). The hydrogen bond in chemical repair is reversible and can break and re-bind when stimulated by the outside world. However, due to the weak hydrogen bond, the self-healing speed is usually slow, and the stability is poor, and it is easily affected by environmental factors, resulting in an unpersistent repair effect; the coordination bond is an interaction force between metal ions and ligands, which has strong stability and repair effect in self-healing materials, but the formation of coordination bonds requires precise ligand design.
[0003] Conductive elastomers have attracted great attention due to their remarkable flexibility, elastic recovery and intelligent response characteristics. However, adding conductive fillers will cause the opacity of the elastomer; most synthetic networks involve long heating steps (or ultraviolet radiation) and the addition of toxic crosslinking agents, and the manufacturing process is complex and time-consuming; due to the difficulty of locating dynamic bonds in the polymer network, the development of autonomous self-healing conductive elastomers still requires great efforts. In recent years, although significant progress has been made in the synthesis of self-healing polymers, designing suitable dynamic bonds in stretchable and conductive elastomer structures remains a challenge. Summary of the Invention
[0004] The research focus of self-healing conductive elastomers is to improve the autonomy and stability of elastomer self-healing and the conductivity of elastomers while ensuring the transparency and stretchability of elastomers. This is not only crucial for the research of conductive elastomers themselves, but also will profoundly affect the future development of the field of intelligent materials. Therefore, the mechanism of elastomer conductivity and self-healing is explored through structural design, and an all-round performance balance is achieved. Self-healing technologies based on nanotechnology, biomaterials and multifunctional composite materials will also be further developed, opening up broad prospects for applications in emerging fields such as intelligent materials, wearable devices, energy storage and conversion, sensors and actuators.
[0005] The present invention aims to solve the problems of poor transparency, slow conductivity repair efficiency and complex synthesis process of existing self-healing conductive elastomers. In order to improve the application possibility of self-healing conductive elastomers in the fields of smart materials, wearable devices, energy storage and conversion, sensors and actuators, the present invention obtains a double-crosslinked autonomous self-healing in-situ polymerized conductive elastomer and its preparation method through molecular structure design.
[0006] The present invention achieves in-situ polymerization of the self-healing conductive elastomer by regulating the molecular structure of polyacrylic acid, while hydrogen bonds and coordination bonds drive the autonomous self-healing process at room temperature. In addition, the ionic conduction mechanism not only maintains transparency and stretchability, but also effectively improves conductivity.
[0007] The implementation of the present invention enables the conductive elastomer to obtain efficient self-repairing properties and significantly prolong its service life. The advantages of the elastomer are: strong self-repairing ability, long service life, and excellent electrical conductivity, transparency and flexibility, which makes it have broad application prospects in multiple application scenarios.
[0008] The present invention uses polyacrylic acid as the conductive elastomer matrix, introduces multiple hydrogen bonds through phytic acid and choline chloride, controls the internal coordination number through gallium-indium eutectic, and constructs a dual-drive, giving the elastomer excellent self-healing properties and conductive properties. At the same time, the addition of gallium-indium eutectic simplifies the preparation process of the conductive elastomer and promotes its spontaneous cross-linking and polymerization. The present invention provides a new way for the in-situ polymerization and self-healing regulation of conductive elastomers.
[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:
[0010] The object of the present invention is to provide a method for preparing a double-crosslinked autonomous self-repairing in-situ polymerized conductive elastomer, comprising the following steps:
[0011] Step 1, adding choline chloride to acrylic acid, stirring evenly at a certain temperature, then adding phytic acid, stirring evenly, to obtain a mixed solution A;
[0012] Step 2, adding gallium-indium eutectic to acrylic acid, and ultrasonically dispersing the mixture until uniform, to obtain a mixed solution B;
[0013] Step 3: Add the mixed solution B to the mixed solution A, stir evenly, then pour into a polytetrafluoroethylene mold and let stand for a while to obtain a double-cross-linked, autonomous, self-repairing in-situ polymerized conductive elastomer.
[0014] It is further defined that in step 1, the molar ratio of choline chloride to acrylic acid is (0.4-0.8):1.
[0015] It is further defined that in step 1, stirring is performed at 60°C to 120°C.
[0016] Further limit that in step 1, stirring is carried out at a speed of 1000 rpm - 1500 rpm.
[0017] Further limit that in step 1, the mass ratio of phytic acid to acrylic acid is (0.01 - 0.2)∶1.
[0018] Further limit that in step 2, the mass ratio of gallium - indium eutectic to acrylic acid solution is (0.01 - 0.2)∶1.
[0019] Further limit that in step 2, the frequency of the ultrasonic wave is 20 kHz.
[0020] Further limit that in step 2, the ultrasonic time is 30 min - 120 min.
[0021] Further limit that in step 3, the volume ratio of mixed solution B added to mixed solution A is (0.01 - 0.05):1.
[0022] Further limit that in step 3, the standing time is 10 min - 15 min.
[0023] Further limit that in step 3, stirring is carried out at a speed of 1000 rpm - 1500 rpm.
[0024] Another object of the present invention is the double - crosslinked self - healing in - situ polymerization conductive elastomer prepared by any of the above methods.
[0025] Compared with the prior art, the present invention has the following beneficial effects:
[0026] The present invention prepares a double - crosslinked self - healing in - situ polymerization conductive elastomer, which is used in smart materials, wearable devices, energy storage and conversion, sensors and actuators. The efficient self - healing property extends the service life; the gallium - indium eutectic controls the internal coordination number, endows the elastomer with excellent self - healing properties and conductive properties, simplifies the preparation process of the conductive elastomer, and promotes its spontaneous crosslinking and polymerization.
[0027] The present invention realizes the in - situ polymerization of the self - healing conductive elastomer by regulating the molecular structure of polyacrylic acid. At the same time, the dual driving of hydrogen bonds and coordination bonds accelerates the process of self - healing at room temperature. In addition, the ionic conduction mechanism not only maintains transparency and stretchability, but also effectively improves the conductivity. It can be used in smart materials such as wearable devices, energy storage and conversion, sensors and actuators.
[0028] The present invention uses gallium - indium eutectic to initiate the free - radical polymerization of polyacrylic acid to prepare a conductive elastomer, and the polymerization can be completed in only 8 minutes. Without any additional initiator and cross - linker, the preparation process of the conductive elastomer is simplified.
[0029] The present invention uses highly cross-linked points inside the free-radical polymerized conductive elastomer, making it have excellent electrical conductivity (0.0124 S / m) and transparency (93%). The eutectic gallium-indium can form coordination bonds inside to make the conductive elastomer have excellent self-healing efficiency (98.5%).
[0030] In order to further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the attached drawings are only for reference and illustration purposes and are not used to limit the present invention. Description of the Drawings
[0031] Figure 1 Digital photos and thermal infrared images of the polymerization process of the double-crosslinked self-autonomous self-healing in-situ polymerization conductive elastomer prepared;
[0032] Figure 2 In-situ infrared images of the polymerization process of the double-crosslinked self-autonomous self-healing in-situ polymerization conductive elastomer prepared;
[0033] Figure 3 Optical properties of the double-crosslinked self-autonomous self-healing in-situ polymerization conductive elastomer prepared in Examples 1, 2, 3, and 4, Figure 3 where a) is the optical transmittance curve; b) is the optical transmittance
[0034] Figure 4 Demonstration of the self-healing process of the double-crosslinked self-autonomous self-healing in-situ polymerization conductive elastomer prepared, Figure 4 where a) is the self-healing process of the conductive elastomer; b) is the conductive elastomer lifting a 200 g weight after 1 min of repair;
[0035] Figure 5 SEM images of the double-crosslinked self-autonomous self-healing in-situ polymerization conductive elastomer at different self-healing times prepared, Figure 5 where a) is the SEM image of the ACPM conductive elastomer after 0.5 hours of repair; b) is the SEM image of the ACPM conductive elastomer after 24 hours of repair. Detailed Embodiments
[0036] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, and at the same time do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the inventive concept of the present invention, several deformations and improvements can be made. These all belong to the protection scope of the present invention.
[0037] In the examples where specific conditions are not specified, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments where the manufacturers are not specified, they are all conventional products that can be obtained by purchasing in the market.
[0038] Example 1: The preparation method of the double-crosslinked self-healing in-situ polymerization conductive elastomer in this example is achieved through the following steps:
[0039] Step 1: Add 14 g of choline chloride to a beaker containing 20 g of acrylic acid, stir at a speed of 1200 revolutions per minute at 80 °C until uniform, add 2 g of phytic acid, and stir at a speed of 1200 revolutions per minute until uniform to obtain a mixed solution A;
[0040] Step 2: Add 0.05 g of gallium-indium eutectic to 1 g of acrylic acid, and perform ultrasonic dispersion for 30 minutes under ultrasonic parameters at a frequency of 20 kHz, such as under the frequency condition, to obtain a mixed solution B;
[0041] Step 3: Then add the mixed solution B obtained in Step 2 to the mixed solution A in Step 1, stir evenly at a speed of 1200 revolutions per minute, and then pour it into a polytetrafluoroethylene mold and let it stand for 12 min to obtain the double-crosslinked self-healing in-situ polymerization conductive elastomer.
[0042] Example 2: The preparation method of the double-crosslinked self-healing in-situ polymerization conductive elastomer in this example is achieved through the following steps:
[0043] Step 1: Add 14 g of choline chloride to a beaker containing 14 g of acrylic acid, stir at a speed of 1200 revolutions per minute at 90 °C until uniform, add 2.8 g of phytic acid, and stir at a speed of 1200 revolutions per minute until uniform to obtain a mixed solution A;
[0044] Step 2: Add 0.07 g of gallium-indium eutectic to 0.7 g of acrylic acid, and perform ultrasonic dispersion for 60 minutes under the condition of a frequency of 20 kHz to obtain a mixed solution B;
[0045] Step 3: Then add the mixed solution B obtained in Step 2 to the mixed solution A in Step 1, stir evenly at a speed of 1200 revolutions per minute, and then pour it into a polytetrafluoroethylene mold and let it stand for 14 min to obtain the double-crosslinked self-healing in-situ polymerization conductive elastomer.
[0046] Example 3: The preparation method of the double-crosslinked self-healing in-situ polymerization conductive elastomer in this example is achieved through the following steps:
[0047] Step 1: Add 16 g of choline chloride into a beaker containing 24 g of acrylic acid, stir at a speed of 1200 revolutions per minute at 60 °C until uniform, add 3 g of phytic acid, and stir at a speed of 1200 revolutions per minute until uniform to obtain mixed solution A;
[0048] Step 2: Add 0.09 g of gallium-indium eutectic into 0.6 g of acrylic acid, perform ultrasonic dispersion at a frequency of 20 kHz for 45 minutes to obtain mixed solution B;
[0049] Step 3: Then add the mixed solution B obtained in Step 2 into the mixed solution A in Step 1, stir evenly at a speed of 1200 revolutions per minute, then pour it into a polytetrafluoroethylene mold, and let it stand for 13 min to obtain a double-crosslinked self-healing in-situ polymerization conductive elastomer.
[0050] Example 4: The preparation method of the double-crosslinked self-healing in-situ polymerization conductive elastomer in this example is achieved through the following steps:
[0051] Step 1: Add 21 g of choline chloride into a beaker containing 28 g of acrylic acid, stir at a speed of 1200 revolutions per minute at 100 °C until uniform, add 2.8 g of phytic acid, and stir at a speed of 1200 revolutions per minute until uniform to obtain mixed solution A;
[0052] Step 2: Add 0.112 g of gallium-indium eutectic into 0.56 g of acrylic acid, perform ultrasonic dispersion at a frequency of 20 kHz for 120 minutes to obtain mixed solution B;
[0053] Step 3: Then add the mixed solution B obtained in Step 2 into the mixed solution A in Step 1, stir evenly at a speed of 1200 revolutions per minute, then pour it into a polytetrafluoroethylene mold, and let it stand for 12 min to obtain a double-crosslinked self-healing in-situ polymerization conductive elastomer.
[0054] During the synthesis of the double-crosslinked self-healing in-situ polymerization conductive elastomer, images of the acrylic acid-choline chloride-phytic acid-gallium-indium eutectic mixed solution were taken and thermal infrared imaging was performed. The results are shown in Figure 1 . Figure 1 It shows that the mixed solution was initially uniformly gray. As time passed, the viscosity of the solution gradually increased and the color changed from gray to transparent. After 8 minutes, the solution completed the transformation from liquid to solid, and infrared thermal imaging verified the exothermic phenomenon of the entire reaction process.
[0055] The in-situ infrared spectrum during the polymerization of the double-crosslinked self-healing in-situ polymerization conductive elastomer is as shown in Figure 2 shown. From Figure 2As can be seen, the carbon-carbon double bonds gradually disappear, indicating that the polymerization reaction is in progress. The stretching vibration peak of the carbon-oxygen double bond in polyacrylic acid does not completely disappear and is shifted simultaneously, indicating that a polycondensation reaction has occurred inside polyacrylic acid, and the movement ability of the groups is restricted due to hydrogen bond interaction during the polymerization process. Finally, the new peak at 1470 cm -1 further verifies the coordination between Ga 3+ ions and carboxyl groups.
[0056] The transmittance of the conductive elastomers with different addition amounts of gallium-indium eutectic prepared in Examples 1, 2, 3, and 4 was measured using a UV spectrophotometer. From Figure 3 it can be seen that the transmittance curves of the conductive elastomers with different addition amounts of gallium-indium eutectic almost coincide, indicating that the addition of gallium-indium eutectic increases rather than decreases the transmittance. This is because gallium-indium eutectic not only acts as a conductive particle but also as a crosslinking initiator. More gallium-indium eutectic provides more crosslinking points, thus making the crosslinked network of the polymer denser, resulting in an increase in transmittance.
[0057] The damage-repair experiment was used to explore the self-repair characteristics of the double-crosslinked self-healing in-situ polymerization conductive elastomer. The results are as Figure 4 shown. First, a piece of conductive elastomer was taken and cut in the middle. Then, the cut ends were immediately aligned and connected. After 1 minute of self-repair time, a 200 g weight could be immediately suspended. This proves the rapid self-repair characteristic of the double-crosslinked self-healing in-situ polymerization conductive elastomer at room temperature.
[0058] SEM was used to test the damaged positions of the double-crosslinked self-healing in-situ polymerization conductive elastomer at different self-repair times. The results are as Figure 5 shown. From Figure 5 it can be seen that at the interface of the conductive elastomer that has just experienced 0.5 h, binding has begun, but there are still obvious gaps. The polymers on both sides begin to diffuse and approach. When the repair time reaches 24 h, the scar structure at the interface basically disappears, the interface is flat and smooth, leaving only a faint trace. Such excellent repair effects come from the diffusion movement of hydrogen bonds and the re-crosslinking of coordination bonds.
[0059] The specific embodiments of the present invention have been described above. It should be noted that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which does not affect the essence of the present invention.
Claims
1. A method for preparing a double-crosslinked, self-repairing, in-situ polymerized conductive elastomer, characterized in that: The following steps are involved: Step 1, adding choline chloride to acrylic acid, stirring evenly at a certain temperature, then adding phytic acid, stirring evenly, to obtain a mixed solution A; Step 2, adding gallium-indium eutectic to acrylic acid, and ultrasonically dispersing the mixture until uniform, to obtain a mixed solution B; Step 3: Add the mixed solution B to the mixed solution A, stir evenly, then pour into a polytetrafluoroethylene mold and let stand for a period of time to obtain a double-cross-linked, autonomous and self-repairing in-situ polymerized conductive elastomer.
2. The method according to claim 1, characterized in that: The molar ratio of choline chloride to acrylic acid is (0.4-0.8):
1.
3. The method according to claim 1, characterized in that: Stir at 60℃~120℃.
4. The method according to claim 1, characterized in that: The mass ratio of phytic acid to acrylic acid is (0.01-0.2):
1.
5. The method according to claim 1, characterized in that: The mass ratio of the gallium-indium eutectic to the acrylic acid solution is (0.01-0.2):
1.
6. The method according to claim 1, characterized in that: The frequency of ultrasound was 20 kHz.
7. The method according to claim 1, characterized in that: The ultrasonic time is 30min to 120min.
8. The method according to claim 1, characterized in that: The volume ratio of mixed solution B added to mixed solution A is (0.01-0.05):
1.
9. The method according to claim 1, characterized in that: The standing time is 10min to 15min.
10. A double-crosslinked, autonomous, self-repairing in-situ polymerized conductive elastomer prepared by the method according to any one of claims 1 to 9.