Polysiloxane with self-repairing capability as well as preparation method and application thereof
By introducing transition metal coordinating ions between polymer chains to construct supramolecular interactions, the prepared polysiloxane achieves efficient self-healing at room temperature, solving the self-healing problem of flexible sensors and possessing excellent mechanical properties and thermal stability.
Patent Information
- Application Number
- CN202511359836.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-23
- Publication Date
- 2025-12-19
AI Technical Summary
Existing flexible sensors struggle to achieve effective self-healing under frequent use and scratching. Externally induced self-healing is limited, and intrinsic self-healing materials face challenges in chain diffusion and dynamic bond design.
By introducing transition metal coordination ions such as Fe3+, supramolecular non-covalent interactions are constructed between polymer chains, and metal coordination bonds are designed to achieve self-repair, thus preparing polysiloxanes with self-repairing capabilities.
The prepared polysiloxane can achieve a self-healing efficiency of 90.3% at room temperature, and has excellent mechanical properties, flexibility and thermal stability, making it suitable for the recyclability of flexible sensors.
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Figure CN121159809A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite materials, specifically relating to a self-healing polysiloxane, its preparation method, and its application. Background Technology
[0002] As electronic devices evolve towards flexibility, integration, and intelligence, flexible sensors are widely used in fields such as electronic skin, health monitoring, human-computer interaction, and intelligent machinery, and are expected to become the next generation of revolutionary electronic components. Polysiloxanes are popular in flexible sensor applications due to their advantages such as low glass transition temperature, resistance to high and low temperatures, low surface tension, and biocompatibility. However, due to frequent use and accidental scratches, designing a sensor with good mechanical properties, stability, and self-healing capabilities is of great significance. Self-healing materials can be classified into intrinsic self-healing and exogenous self-healing according to their repair mechanisms. Exogenous self-healing is limited in application due to its need for external stimulation and its limited repair capabilities. Intrinsic self-healing is influenced by both the diffusion and entanglement of polymer chains and the design and selection of dynamic bonds in the polymer chains (supramolecular bonds and dynamic covalent bonds). Compared with covalent bonds, supramolecular covalent bonds have relatively weaker binding energies, and the resulting physical cross-linked networks can be reversibly remodeled. Therefore, supramolecular interactions are widely used in the design of self-healing materials. Therefore, this invention introduces a rational molecular structure design to construct a supramolecular interaction of metal coordination. By selecting metal ions or different ligands to adjust the mechanical strength of the polymer, the polymer can undergo a self-healing process by recombinating the coordination bonds at room temperature after rupture. This self-healing property endows the flexible sensor with recyclability, which is of great significance. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art. The primary objective of this invention is to provide a polysiloxane with self-healing capabilities.
[0004] Another object of the present invention is to provide a method for preparing a polysiloxane with self-healing ability.
[0005] Another object of the present invention is to provide a polysiloxane composite material with self-healing ability.
[0006] Another object of the present invention is to provide the application of the above-mentioned self-healing polysiloxane or composite material.
[0007] The objective of this invention is achieved through the following technical solution:
[0008] A self-healing polysiloxane has the following structural formula:
[0009]
[0010] Among them, M 3+ It is a transition metal coordination ion. It means
[0011] In the formula, n≥2.
[0012] Preferably, the M 3+ Selected from Fe 3+ Al 3+ or Co 3+ .
[0013] Preferably, the structural formula of the self-healing polysiloxane is shown below:
[0014]
[0015] A method for preparing a self-healing polysiloxane includes the following steps:
[0016] A nucleophilic addition reaction was carried out by mixing dihydroxyalkyl-terminated polydimethylsiloxane with isophorone diisocyanate and adding a catalyst and heating. Then, 1,4-butanediol, trimethylolpropane, dopamine hydrochloride and trivalent metal chloride were added sequentially for further reaction. After drying, a polysiloxane with self-healing ability was obtained.
[0017] Preferably, the reaction conditions for the dihydroxyalkyl-terminated polydimethylsiloxane and isophorone diisocyanate are: 80-100°C for 2-6 hours; calculated based on the functional groups participating in the reaction, the molar ratio of hydroxyl groups (-OH) in the dihydroxyalkyl-terminated polydimethylsiloxane to isocyanate groups (-NCO) in the isophorone diisocyanate is 1:1-5, more preferably 1:2.05;
[0018] The reaction conditions for adding 1,4-butanediol are: temperature reduced to 70-90℃, reaction time 0.5-3h;
[0019] The reaction conditions for adding trimethylolpropane are: 70-90℃ for 0.5-3 hours.
[0020] Preferably, the reaction conditions for adding dopamine hydrochloride are: 50-70°C for 0.5-2 hours, and the reaction is carried out under a protective atmosphere, namely nitrogen atmosphere.
[0021] The reaction conditions for adding anhydrous trivalent metal chloride are: pH = 7-8, reaction temperature 30-50℃ for 12-36 h, the reaction is carried out under a protective atmosphere, namely nitrogen atmosphere; the molar ratio of dopamine hydrochloride to trivalent metal chloride is 3:0.2-1.2.
[0022] Preferably, the trivalent metal chloride is FeCl3, AlCl3, or CoCl3;
[0023] The reaction involving the sequential addition of 1,4-butanediol, trimethylolpropane, dopamine hydrochloride, and trivalent metal chloride is carried out by dissolving 1,4-butanediol, trimethylolpropane, dopamine hydrochloride, and trivalent metal chloride in an organic solvent, and then adding them to the reaction system.
[0024] The reaction system uses N,N-dimethylformamide as the organic solvent.
[0025] The total mass of the reaction system is the sum of the masses of the dihydroxyalkyl-terminated polydimethylsiloxane monomer, isoflurane diisocyanate, 1,4-butanediol, trimethylolpropane, dopamine hydrochloride, and anhydrous trivalent metal chloride.
[0026] Preferably, the catalyst is dibutyltin dilaurate;
[0027] The mass of the catalyst is 0.1% to 0.3% of the total mass of the reaction system, more preferably 0.2%.
[0028] A self-healing polysiloxane composite material includes the aforementioned self-healing polysiloxane, a conductive layer, and a copper foil electrode.
[0029] The polysiloxane sample film is adhered to the conductive layer, and the copper foil electrodes are fixed to both ends of the polysiloxane sample film.
[0030] Preferably, the conductive layer is a silver nanowire film, a graphene film, a carbon nanotube film, or a carbon black conductive layer.
[0031] The above-mentioned self-healing polysiloxanes or composite materials are used in flexible sensors.
[0032] The present invention has the following advantages and beneficial effects compared with the prior art:
[0033] (1) The polysiloxane with self-healing ability prepared by the present invention has a tensile strength of up to 400 kPa and an elongation at break of up to 120%. After the prepared film sample is scratched with a utility knife, a self-healing efficiency of 90.3% can be achieved after 8 hours of repair at room temperature.
[0034] (2) In the self-healing polysiloxane prepared in this invention, transition metal coordination ions Fe are introduced into the system. 3+ By constructing supramolecular non-covalent interactions between polymer molecular chains, the molecular chains on the damaged surface can accelerate to approach and reform into effective interaction units, thus endowing the flexible membrane with excellent self-healing properties.
[0035] (3) By adjusting the amount of ligands and ligand metals introduced, the balance between intermolecular forces and chain motion is controlled, so as to prepare polysiloxane sample films with excellent mechanical properties, flexibility, repairability and thermal stability.
[0036] (4) The self-healing polysiloxane sensing composite material prepared in this invention has a polysiloxane matrix that is a thermoplastic polymer, which is easy to mold, and the preparation process of the composite material is simple. After simple drying in a blower oven, the matrix can be directly bonded to the conductive layer, giving the matrix excellent conductivity and sensing signal. Attached Figure Description
[0037] Figure 1 The image shows the infrared spectrum of the polymer synthesized in Example 1.
[0038] Figure 2 This is an optical microscopic diagram showing the repair of the polymer synthesized in Example 1 after fracture damage at room temperature for a certain period of time. Detailed Implementation
[0039] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the following embodiments are generally performed under conventional test conditions or according to the test conditions recommended by the reagent company. Unless otherwise specified, all materials and reagents used are commercially available.
[0040] Mechanical property testing: The tensile properties of the sample films were tested at room temperature using a KJ-10653B electronic universal testing machine. At least three sets of valid data were collected for each sample, and the average value was taken. The film sample dimensions were dumbbell type, 70 mm long, 5 mm wide, and 1 mm thick, with a tensile rate set to 200 mm / min.
[0041] Self-healing performance test: Self-healing performance is mainly evaluated by assessing the mechanical strength and scratch recovery of the sample within a set time. First, the sample mold is cut into two sections and reassembled. Then, the sample is allowed to self-heal under certain time and room temperature conditions, and the degree of mechanical property recovery is evaluated. Scratch repair performance is assessed by creating scratches of a certain depth on the film surface using a surgical scalpel. The scratch repair is observed using an optical microscope equipped with a THMS600E Linkam constant-temperature heating stage. The scratch depth is approximately 100% of the film thickness, or 1 mm.
[0042] Example 1
[0043] This embodiment provides a method for preparing a self-healing polysiloxane as follows:
[0044] 4.90 g of dihydroxyalkyl-terminated polydimethylsiloxane (Mw = 2000) and 1.77 g of isoflurane diisocyanate (a mixture of isomers) (IPDI, 99%) were dissolved in 5 g of N,N-dimethylformamide (DMF) and placed in a 150 ml three-necked flask equipped with a mechanical stirrer. 0.02 g of dibutyltin dilaurate (DBTDL) was added, and the reaction was carried out at 90 °C for 4 h. Immediately afterwards, the temperature was lowered to 80 °C, and 0.24 g of 1,4-butanediol (BDO) dissolved in 0.5 g of DMF was added to the reaction system. The reaction was carried out at 80 °C for 1.5 h. Subsequently, the temperature was maintained at 80℃. 0.24g of trimethylolpropane (TMP) dissolved in 0.6g of DMF was added to the above reaction system. After reacting for 1 hour, the temperature of the oil bath was lowered to 60℃, nitrogen gas was introduced, and 0.064g of dopamine hydrochloride (DOPA) dissolved in 0.2g of DMF was added to the above reaction system. After reacting for 1 hour, 0.02g of triethylamine (TEA) was added dropwise to adjust the pH to 7-8. Then, the temperature was cooled to 40℃, and 0.011g of FeCl3 dissolved in 0.3g of DMF was added to the above reaction system. The molar ratio of dopamine hydrochloride to anhydrous ferric chloride was 3:0.6. The reaction was carried out under nitrogen protection for 24 hours. The reaction was stopped, the product was removed and placed in a mold, and dried in a forced-air oven at 90℃ for 14 hours to obtain a self-healing polysiloxane sample film with a thickness of approximately 1mm, denoted as Si-DOPA3-Fe. 0.6 Its structural formula and reaction process are shown in Formula I.
[0045]
[0046] The structural formula is as follows, where n≥2.
[0047]
[0048] The prepared polysiloxane material was characterized by infrared spectroscopy, and the infrared results are as follows: Figure 1 As shown. Among them, at 2270cm -1 No characteristic absorption peak of -NCO was observed nearby, indicating that -NCO has been completely reacted. (1721 cm⁻¹) -1 A characteristic absorption peak for the stretching vibration of -C=O appears at 1243 cm⁻¹. -1 The peak value at 1533.73 cm⁻¹ is the stretching vibration peak of -COC. -1 The characteristic peaks are generated by the s-bending vibration of the NH group in urethane or urea groups. These results indicate that the urethane group structure in the polysiloxane chain has been successfully constructed.
[0049] Example 2
[0050] Polysiloxanes complexed with dopamine hydrochloride and anhydrous ferric chloride in different proportions were prepared using the same method.
[0051] 4.90 g of dihydroxyalkyl-terminated polydimethylsiloxane (Mw = 2000) and 1.77 g of isoflurane diisocyanate (a mixture of isomers) (IPDI, 99%) were dissolved in 5 g of N,N-dimethylformamide (DMF) and placed in a 150 ml three-necked flask equipped with a mechanical stirrer. 0.02 g of dibutyltin dilaurate (DBTDL) was added, and the reaction was carried out at 90 °C for 4 h. Immediately afterwards, the temperature was lowered to 80 °C, and 0.24 g of 1,4-butanediol (BDO) dissolved in 0.5 g of DMF was added to the reaction system. The reaction was carried out at 80 °C for 1.5 h. Subsequently, the temperature was maintained at 80℃. 0.24g of trimethylolpropane (TMP) dissolved in 0.6g of DMF was added to the above reaction system. After reacting for 1 hour, the temperature of the oil bath was lowered to 60℃, nitrogen gas was introduced, and 0.064g of dopamine hydrochloride (DOPA) dissolved in 0.2g of DMF was added to the above reaction system. After reacting for 1 hour, 0.02g of triethylamine (TEA) was added dropwise to adjust the pH to 7-8. Then, the temperature was cooled to 40℃, and 0.004g, 0.007g, 0.011g, 0.015g, 0.018g, and 0.022g of FeCl3 were dissolved in 0.3g of DMF. The above reaction system was added to DMF and reacted under nitrogen protection for 24 hours to obtain polysiloxanes with molar ratios of dopamine hydrochloride to anhydrous ferric chloride of 3:0.2, 3:0.4, 3:0.8, 3:1.0, and 3:1.2, respectively.
[0052] Comparative Example 1
[0053] Polysiloxane materials without FeCl3 were prepared using the same method, and the resulting products are shown in Formula II, where n≥2.
[0054]
[0055] 4.90 g of poly(dimethylsiloxane), dihydroxyalkyl-terminated (Mw = 2000), and 1.77 g of isoflurane diisocyanate (a mixture of isomers) (IPDI, 99%) were dissolved in 5 g of N,N-dimethylformamide (DMF) and placed in a 150 ml three-necked flask equipped with a mechanical stirrer. 0.02 g of dibutyltin dilaurate (DBTDL) was added, and the reaction was carried out at 90 °C for 4 h. Immediately afterwards, the temperature was lowered to 80 °C, and 0.24 g of 1,4-butanediol (BDO) dissolved in 0.5 g of DMF was added to the reaction system. The reaction was carried out at 80 °C for 1.5 h. Subsequently, the temperature was maintained at 80℃. 0.24g of trimethylolpropane (TMP) dissolved in 0.6g of DMF was added to the above reaction system. After reacting for 1 hour, the temperature of the oil bath was lowered to 60℃, nitrogen gas was introduced, and 0.064g of dopamine hydrochloride (DOPA) dissolved in 0.2g of DMF was added to the above reaction system. After reacting for 1 hour, 0.02g of triethylamine (TEA) was added dropwise to adjust the pH of the solution to 7-8. After reacting for a period of time, the system was cooled to room temperature to obtain a polysiloxane material without metal complexation.
[0056] Mechanical properties of polysiloxane films with different ratios of dopamine hydrochloride complexed with anhydrous ferric chloride were tested. The experimental data are shown in Table 1. The tensile strength can reach up to 400 kPa and the elongation at break can reach 120%.
[0057] Table 1
[0058]
[0059]
[0060] The self-healing properties of polysiloxane films with different ratios of dopamine hydrochloride and anhydrous ferric chloride were tested. The films self-healed for 8 hours at room temperature. The experimental data are shown in Table 2. The self-healing effect is as follows: Figure 2 As shown.
[0061] Table 2
[0062]
[0063] The polysiloxane prepared by this invention possesses certain self-healing capabilities and good mechanical properties. When the ratio of dopamine hydrochloride to anhydrous ferric chloride is 3:0.6, the polysiloxane composite material exhibits the best self-healing performance. (The last sentence appears to be incomplete and possibly refers to a different topic.) 0.6 A self-healing efficiency of 90.3% can be achieved after 8 hours of repair at room temperature.
[0064] Example 3
[0065] This embodiment provides a polysiloxane composite material with self-healing capabilities, and the preparation method is as follows:
[0066] (1) A silver nanowire solution (3 mg / mL) dissolved in a certain amount of ethanol was filtered using a circulating water vacuum pump to obtain a silver nanowire film as a conductive layer on the filter paper.
[0067] (2) The prepared polysiloxane sample film is used as the substrate and applied to the silver nanowire film. After being treated in a forced-air oven at 90°C for 14 hours, the substrate can be directly bonded to the conductive layer. Then, copper foil electrodes are attached to both ends to obtain a polysiloxane self-healing flexible conductive composite film.
[0068] The polysiloxane self-healing flexible conductive composite film obtained by combining the two can be applied to flexible sensors to achieve real-time and rapid capture and monitoring of daily physiological activities of the human body (such as bending movements of fingers, wrists and knees, neck movements, swallowing and other actions). Moreover, it exhibits excellent stability, which shows great application potential for the preparation of multifunctional flexible polysiloxane sensors in the fields of bionic electronic skin and wearable electronic devices.
[0069] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A polysiloxane with self-healing capabilities, characterized in that, The structural formula is shown below: Among them, M 3+ It is a transition metal coordination ion. It means In the formula, n≥2.
2. The self-healing polysiloxane according to claim 1, characterized in that, The M 3+ Selected from Fe 3+ Al 3+ or Co 3+ .
3. A method for preparing a self-healing polysiloxane as described in claim 1 or 2, characterized in that, Includes the following steps: Dihydroxyalkyl-terminated polydimethylsiloxane was mixed with isophorone diisocyanate and then reacted with a catalyst under heating. Then, 1,4-butanediol, trimethylolpropane, dopamine hydrochloride and trivalent metal chloride were added sequentially and reacted. After drying, a self-healing polysiloxane was obtained.
4. The method for preparing the self-healing polysiloxane according to claim 3, characterized in that, The reaction conditions for the dihydroxyalkyl-terminated polydimethylsiloxane and isophorone diisocyanate are: 80-100℃ for 2-6 hours; the molar ratio of the hydroxyl groups in the dihydroxyalkyl-terminated polydimethylsiloxane to the isocyanate groups in the isophorone diisocyanate is 1:1-5. The reaction conditions for adding 1,4-butanediol are: temperature reduced to 70-90℃, reaction time 0.5-3h; The reaction conditions for adding trimethylolpropane are: 70-90℃ for 0.5-3 hours.
5. The method for preparing the self-healing polysiloxane according to claim 3, characterized in that, The reaction conditions for adding dopamine hydrochloride are: 50-70°C for 0.5-2 hours, and the reaction is carried out under a protective atmosphere; The reaction conditions for adding anhydrous trivalent metal chloride are: pH = 7-8, reaction temperature 30-50℃ for 12-36 h, and the reaction is carried out under a protective atmosphere. The molar ratio of dopamine hydrochloride to trivalent metal chloride is 3:0.2 to 1.
2.
6. The method for preparing the self-healing polysiloxane according to claim 3, characterized in that, The trivalent metal chloride is FeCl3, AlCl3, or CoCl3; The reaction system uses N,N-dimethylformamide as the organic solvent.
7. The method for preparing the self-healing polysiloxane according to claim 3, characterized in that, The catalyst is dibutyltin dilaurate; The mass of the catalyst is 0.1% to 0.3% of the total mass of the reaction system.
8. A self-healing polysiloxane conductive composite material, characterized in that, It includes the polysiloxane as described in claim 1 or 2, a conductive layer, and a copper foil electrode; the polysiloxane film is adhered to the conductive layer, and the copper foil electrode is fixed to both ends of the polysiloxane sample film.
9. The self-healing polysiloxane conductive composite material according to claim 8, characterized in that the conductive layer is a silver nanowire film, a graphene film, a carbon nanotube film, or a carbon black conductive layer.
10. The application of the self-healing polysiloxane of claim 1 or 2 or the polysiloxane conductive composite material of claim 8 or 9 in flexible sensors.