High performance ionic gel adhesive and preparation method thereof

Abstract

The application provides a high-performance ionic gel adhesive and a preparation method thereof. The high-performance ionic gel adhesive comprises the following components in parts by weight: 20-40 parts of polymerizable monomers, 30-60 parts of ionic liquids, 0.1-2 parts of a dynamic crosslinking agent, 0.2-1.5 parts of a photoinitiator and 0-5 parts of a functional additive. The double dynamic crosslinking structure formed by the application makes the adhesive have excellent mechanical properties and dynamic reversible characteristics, and simultaneously realizes high strength, high toughness, strong interfacial adhesion, high ionic conductivity, room-temperature self-healing and excellent wide-temperature-range stability.

Description

Technical Field

[0001] This invention relates to a high-performance ion gel adhesive and its preparation method. Background Technology

[0002] In fields such as flexible electronics and wearable devices, extremely high demands are placed on the reliability of connection materials, requiring them to possess excellent conductivity, flexibility, low-temperature stability, interfacial adhesion, and self-healing capabilities. However, traditional adhesives, such as hydrogels, are prone to dehydration and failure, and have poor low-temperature performance; while organic adhesives have poor conductivity and insufficient interfacial compatibility; neither can meet the high-reliability connection requirements of these emerging fields.

[0003] While existing ionic liquid-based materials possess high conductivity, they generally suffer from insufficient adhesion. Their gel structures also exhibit poor structural stability, their performance is easily affected by environmental humidity and temperature, self-healing processes are time-consuming, and their preparation processes are often complex and costly. Therefore, developing a novel adhesive with superior overall performance, strong adaptability, and simple preparation has urgent market demand and technological value. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a high-performance ionic gel adhesive, comprising the following components by weight: 20-40 parts polymerizable monomer, 30-60 parts ionic liquid, 0.1-2 parts dynamic crosslinking agent, 0.2-1.5 parts photoinitiator, and 0-5 parts functional additives.

[0005] The polymerizable monomer is one or more of acrylic acid, hydroxyethyl methacrylate, and acrylamide.

[0006] Polymerizable monomers are used to construct adhesive polymer backbones.

[0007] The ionic liquid is one of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and choline chloride-lactic acid eutectic solvent.

[0008] Ionic liquids act as solvents and conductive media, and participate in the construction of gel networks, thus affecting the mechanical properties of ionogel adhesives.

[0009] The dynamic crosslinking agent is one of ZnCl2, FeCl3, or borate.

[0010] Dynamic crosslinking agents are used to provide metal coordination dynamic bonds for ionic liquids to form a dynamic crosslinking network, giving ionic gel adhesives a basic self-healing ability.

[0011] The functional additive is one or more of fumed silica and precipitated silica.

[0012] The addition of the functional additive silica improves the mechanical properties and self-healing effect of the adhesive.

[0013] The photoinitiator is one of photoinitiator 1173, photoinitiator 184, and photoinitiator 2959.

[0014] Another objective of this invention is to provide a method for preparing the aforementioned high-performance ionogel adhesive, comprising the following steps: S1. Mix the polymerizable monomer, ionic liquid and functional additives according to the formula ratio, and stir at room temperature until homogeneous and transparent; S2. Add dynamic crosslinking agent and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator, stir evenly in the dark, and degas; S4. Pour the precursor liquid into the mold and cure it with ultraviolet light to obtain a high-performance ion gel adhesive.

[0015] The ultraviolet light used for curing has a wavelength of 100nm-400nm and a curing time of 5-30min.

[0016] The high-performance ionogel adhesive of this invention, through the compounding of specific polymerizable monomers, ionic liquids, dynamic crosslinking agents, and functional additives, possesses a dual dynamic crosslinking structure. Specifically, the ionogel adhesive of this invention forms a first-level crosslinking network dominated by chemical covalent bonds through ultraviolet light curing, while simultaneously introducing a reversible second-level dynamic crosslinking network such as metal coordination bonds and hydrogen bonds through the dynamic crosslinking agent, thereby forming a dual dynamic crosslinking structure. This structure enables the adhesive to possess both excellent mechanical properties and dynamic reversible characteristics; it simultaneously achieves high strength, high toughness, strong interfacial adhesion, high ionic conductivity, room temperature self-healing, and excellent wide-temperature stability.

[0017] Compared with the prior art, the significant performance advantages of the present invention are specifically reflected as follows: 1. Excellent mechanical properties: Due to the synergistic effect of chemical crosslinking and dynamic physical crosslinking (metal coordination / hydrogen bonding), the resulting ionogel adhesive has high strength and high toughness, with tensile strength ≥1.2 MPa and elongation at break ≥800%.

[0018] 2. Strong interfacial adhesion; exhibits excellent adhesion performance to a variety of substrates (such as metals, glass, plastics, etc.), with a peel strength ≥900 N / m and a metal shear strength ≥0.6 MPa.

[0019] 3. High ionic conductivity; conductivity ≥1×10⁻³ S / cm, which can meet the requirements for internal circuit conduction of flexible electronic devices.

[0020] 4. Room temperature self-healing ability: Thanks to the reversibility of the dynamic physical cross-linking network and the use of functional additives, after the material is damaged and broken, it only needs to be reconnected at room temperature for 10 minutes. The recovery rate of its mechanical properties and electrical properties can reach more than 85%, which significantly improves the reliability and service life of the device.

[0021] 5. Excellent wide temperature range stability; the mechanical and electrical properties of the adhesive do not significantly decrease within a wide temperature range of -40℃ to 80℃. Especially at the extreme low temperature of -40℃, its mechanical properties are still retained at more than 85%, demonstrating strong environmental adaptability.

[0022] Furthermore, the preparation method of the high-performance ion gel adhesive of the present invention has the advantages of simple process, easy implementation, and low cost. Detailed Implementation

[0023] The solution of this application will be further described below with reference to specific embodiments: Example

[0024] A high-performance ion gel adhesive, by weight, comprises the following components: 25 parts acrylic acid, 45 parts 1-ethyl-3-methylimidazolium tetrafluoroborate, 0.5 parts ZnCl2, 0.8 parts photoinitiator 1173, and 0.5 parts fumed silica.

[0025] The preparation method of the above-mentioned high-performance ionogel adhesive includes the following steps: S1. Mix acrylic acid, 1-ethyl-3-methylimidazolium tetrafluoroborate and fumed silica according to the formula, and stir at room temperature for 30 minutes until homogeneous and transparent; S2. Add ZnCl2 and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator 1173, stir evenly in the dark, and degas under vacuum. S4. Pour the precursor liquid into the mold and cure it with 365nm ultraviolet light for 15 minutes to obtain a high-performance ion gel adhesive. Example

[0026] A high-performance ionic gel adhesive, by weight, comprises the following components: 30 parts hydroxyethyl methacrylate, 50 parts choline chloride-lactic acid eutectic solvent, 0.6 parts borax, 1.0 part photoinitiator 2959, and 0.5 parts fumed silica.

[0027] The preparation method of the above-mentioned high-performance ionogel adhesive includes the following steps: S1. Mix hydroxyethyl methacrylate, choline chloride-lactic acid eutectic solvent, and fumed silica according to the specified ratio, and stir at room temperature for 30 minutes until homogeneous and transparent. S2. Add borax and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator 2959, stir evenly in the dark, and degas under vacuum. S4. Pour the precursor liquid into the mold and cure it with 365nm ultraviolet light for 15 minutes to obtain a high-performance ion gel adhesive. Example

[0028] A high-performance ion gel adhesive, by weight, comprises the following components: 15 parts acrylamide, 15 parts acrylic acid, 40 parts 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 0.4 parts FeCl3, 0.7 parts photoinitiator 184, and 0.5 parts fumed silica.

[0029] The preparation method of the above-mentioned high-performance ionogel adhesive includes the following steps: S1. Mix acrylamide, acrylic acid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and fumed silica according to the specified ratio, and stir at room temperature for 30 minutes until homogeneous and transparent; S2. Add FeCl3 and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator 184, stir evenly in the dark, and degas under vacuum. S4. Pour the precursor liquid into the mold and cure it with 365nm ultraviolet light for 15 minutes to obtain a high-performance ion gel adhesive. Example

[0030] A high-performance ion gel adhesive, by weight, comprises the following components: 10 parts acrylamide, 10 parts acrylic acid, 30 parts 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 0.1 parts FeCl3, 0.2 parts photoinitiator 184, and 0.5 parts fumed silica.

[0031] The preparation method of the above-mentioned high-performance ionogel adhesive includes the following steps: S1. Mix acrylamide, acrylic acid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and fumed silica according to the specified ratio, and stir at room temperature for 30 minutes until homogeneous and transparent; S2. Add FeCl3 and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator 184, stir evenly in the dark, and degas under vacuum. S4. Pour the precursor liquid into the mold and cure it with 365nm ultraviolet light for 15 minutes to obtain a high-performance ion gel adhesive. Example

[0032] A high-performance ion gel adhesive, by weight, comprises the following components: 20 parts acrylamide, 20 parts acrylic acid, 60 parts 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 32 parts FeCl3, 0.2 parts photoinitiator 184, and 0.5 parts fumed silica.

[0033] The preparation method of the above-mentioned high-performance ionogel adhesive includes the following steps: S1. Mix acrylamide, acrylic acid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and fumed silica according to the specified ratio, and stir at room temperature for 30 minutes until homogeneous and transparent; S2. Add FeCl3 and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator 184, stir evenly in the dark, and degas under vacuum. S4. Pour the precursor liquid into the mold and cure it with 365nm ultraviolet light for 15 minutes to obtain a high-performance ion gel adhesive. Example

[0034] A high-performance ion gel adhesive, by weight, comprises the following components: 25 parts acrylic acid, 45 parts 1-ethyl-3-methylimidazolium tetrafluoroborate, 0.5 parts ZnCl2, 0.8 parts photoinitiator 1173, and 0.5 parts precipitated silica.

[0035] The preparation method of the above-mentioned high-performance ionogel adhesive includes the following steps: S1. Mix acrylic acid, 1-ethyl-3-methylimidazolium tetrafluoroborate and fumed silica according to the formula, and stir at room temperature for 30 minutes until homogeneous and transparent; S2. Add ZnCl2 and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator 1173, stir evenly in the dark, and degas under vacuum. S4. Pour the precursor liquid into the mold and cure it with 365nm ultraviolet light for 15 minutes to obtain a high-performance ion gel adhesive.

[0036] An ionomer gel adhesive, by weight, comprises the following components: 25 parts acrylic acid, 20 parts 1-ethyl-3-methylimidazolium tetrafluoroborate, 0.5 parts ZnCl2, 0.8 parts photoinitiator 1173, and 0.5 parts fumed silica.

[0037] The difference between this iontophoretic adhesive and Example 1 lies in the amount of 1-ethyl-3-methylimidazolium tetrafluoroborate used, while its preparation method is the same as in Example 1.

[0038] An ionomer gel adhesive, by weight, comprises the following components: 30 parts hydroxyethyl methacrylate, 70 parts choline chloride-lactic acid eutectic solvent, 0.6 parts borax, 1.0 part photoinitiator 2959, and 0.5 parts fumed silica.

[0039] The difference between this ionogel adhesive and Example 2 lies in the amount of choline chloride-lactic acid eutectic solvent used, while its preparation method is the same as that of Example 2.

[0040] A high-performance ion gel adhesive, by weight, comprises the following components: 15 parts acrylamide, 15 parts acrylic acid, 20 parts 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 0.4 parts FeCl3, 0.7 parts photoinitiator 184, and 0.5 parts fumed silica.

[0041] The difference between this iontophoretic adhesive and that of Example 3 is the amount of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt used, while the preparation method is the same as that of Example 3.

[0042] A high-performance ion gel adhesive, by weight, comprises the following components: 10 parts acrylamide, 10 parts acrylic acid, 20 parts 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 0.1 parts FeCl3, 0.2 parts photoinitiator 184, and 0.5 parts fumed silica.

[0043] The difference between this iontophoretic adhesive and that of Example 4 is the amount of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt used, while the preparation method is the same as that of Example 4.

[0044] A high-performance ion gel adhesive, by weight, comprises the following components: 10 parts acrylamide, 10 parts acrylic acid, 70 parts 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 0.1 parts FeCl3, 0.2 parts photoinitiator 184, and 0.5 parts fumed silica.

[0045] The difference between this iontophoretic adhesive and that of Example 5 is the amount of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt used, while the preparation method is the same as that of Example 5.

[0046] A high-performance ion gel adhesive, by weight, comprises the following components: 25 parts acrylic acid, 45 parts 1-ethyl-3-methylimidazolium tetrafluoroborate, 0.5 parts ZnCl2, 0.8 parts photoinitiator 1173, and 0 parts precipitated silica.

[0047] The difference between this iontophoretic adhesive and Example 1 lies in the amount of fumed silica used, while its preparation method is the same as that of Example 1.

[0048] The ion gel adhesives prepared in the above examples and comparative examples were tested.

[0049] I. The testing method is as follows: 1. Tensile Testing at Fracture: The ionomer gel adhesive was die-cut into dumbbell-shaped specimens with a length of 20 mm, a width of 4.0 mm, and a thickness of 0.2 mm. These specimens were then clamped onto an electronic universal tensile testing machine with a 100 N sensor. The testing environment was 23 ± 2℃ and a relative humidity of 50 ± 5%. The specimens were stretched longitudinally at a speed of 100 mm / min until fracture. The stress and strain at fracture were calculated. Three sets of tests were performed, and the average value was taken.

[0050] 2. Peel strength: The iontophoresis adhesive was applied to a 50μm PET backing material, and the sample was cut into pieces 120mm long, 25mm wide, and 0.2mm thick. These samples were then applied to SUS-B, glass, PC+20%GF, and other materials. The samples were rolled back and forth three times with a 2kg roller and placed in an environment of 23±2℃ and 50±5% relative humidity for 20 minutes. Then, the samples were clamped on an electronic universal tensile testing machine with a 100N sensor. The samples were stretched longitudinally at a speed of 300mm / min, and the average peel force in the 20mm-80mm range was recorded. Three sets of tests were performed, and the average value was taken.

[0051] 3. Shear Strength: Ionomer gel adhesive samples were die-cut to a length of 25 mm, a width of 25 mm, and a thickness of 0.2 mm. These samples were then bonded between two SUS-B plates and compressed with a force of 625 N for 30 seconds. The samples were then placed in an environment of 23±2℃ and 50±5% relative humidity for 2 hours. Next, the samples were clamped onto an electronic universal tensile testing machine with a 2000 N sensor. The testing environment was 23±2℃ and 50±5% relative humidity. The samples were stretched longitudinally at a speed of 10 mm / min until the maximum force was reached. The maximum force was recorded, and the shear strength was calculated. Three sets of tests were performed, and the average value was taken.

[0052] 4. Conductivity: The ionogel adhesive was die-cut into ionogel discs with a diameter of 8 mm and a thickness of 0.2 mm. Then, using an 8 mm diameter stainless steel battery casing as the working electrode, the ionogel discs were integrated into a button cell device (CR2032). The electrochemical performance of the ionogel was tested using an electrochemical workstation (CHI 760). At room temperature, the Nyquist plot of the ionogel was obtained by EIS. The test parameters were as follows: frequency sweep range of 1 Hz-105 Hz at open circuit voltage, AC amplitude of 0.01 V, three sets of tests were performed, and the average value was taken.

[0053] 5. Self-healing performance test: (1) The ionogel adhesive was die-cut into dumbbell-shaped samples with a length of 20 mm, a width of 4.0 mm, and a thickness of 0.2 mm. The samples were cut in the middle with a blade (keeping the cross-section flat), and the cross-sections were immediately brought into contact. A certain pressure was applied to ensure that the broken molecular chains were in full contact. The samples were then placed in a constant temperature and humidity chamber and incubated for 10 min under certain conditions (23±2℃, relative humidity of 50±5%). The stress-strain curves of the ionogel adhesive were tested using an electronic universal testing machine to detect the recovery of the mechanical properties of the ionogel adhesive at room temperature (test environment 23±2℃, relative humidity of 50±5%). Three groups were tested, and the average value was taken.

[0054] (2) The ionogel adhesive was die-cut into ionogel discs with a diameter of 8 mm and a thickness of 0.2 mm. The sample was cut in the middle with a blade (keeping the cut surface flat), and the cut surfaces were immediately brought into contact. A certain pressure was applied to ensure that the broken molecular chains were in full contact. Then, the sample was placed in a constant temperature and humidity chamber and incubated for 10 min under certain conditions (23±2℃, relative humidity of 50±5%). The electrochemical performance of the ionogel adhesive was tested using an electrochemical workstation (CHI 760) to detect the recovery of the conductivity of the ionogel adhesive at room temperature (test environment 23±2℃, relative humidity of 50±5%). Three groups were tested, and the average value was taken.

[0055] 6. Low-temperature mechanical properties: The sample size for low-temperature tensile strength, elongation at break, peel force, and shear strength is the same as that for room temperature. The difference is that before testing, the sample needs to be placed in a low-temperature tensile testing chamber at -40℃ for 2 hours before testing. Three sets of tests are performed, and the average value is taken.

[0056] II. Test Results The test results for each embodiment and comparative example are shown in Tables 1-3 below: Table 1. Room temperature mechanical properties of the examples and comparative examples

[0057] Table 2. Low-temperature mechanical properties of the examples and comparative examples

[0058] Table 3. Conductivity and self-healing efficiency of the examples and comparative examples.

[0059] As can be seen from the test results of Examples 1-6 above, the iontophoresis adhesive of the present invention has the following excellent properties: 1. It has high strength and high toughness; tensile strength ≥1.2 MPa, elongation at break ≥800%.

[0060] 2. Strong interfacial adhesion; exhibits excellent adhesion performance to a variety of substrates (such as metals, glass, plastics, etc.), with a peel strength ≥900 N / m and a metal shear strength ≥0.6 MPa.

[0061] 3. High ionic conductivity; conductivity ≥1×10⁻³ S / cm, which can meet the requirements for internal circuit conduction of flexible electronic devices.

[0062] 4. Room temperature self-healing ability; mechanical and electrical recovery rate ≥85% within 10 minutes after reconnection following fracture.

[0063] 5. Wide temperature range stability: The mechanical and electrical properties do not significantly decrease within a wide temperature range of -40℃ to 80℃. In particular, at the extreme low temperature of -40℃, the mechanical properties are still retained at more than 85%.

[0064] As can be seen from the test results of Examples 1-5 and Comparative Examples 1-5 above, the ion gel adhesive of the present invention can only meet the above-mentioned excellent performance requirements by compounding monomers, ionic liquids and dynamic crosslinking agents within a specific range.

[0065] As can be seen from the test results of Example 1 and Comparative Example 6 above, fumed silica or precipitated silica has an improving effect on the mechanical properties and self-healing effect of the ion gel adhesive of the present invention.

[0066] The above preferred embodiments should be regarded as illustrative examples of the embodiments of the present application. Any technical deductions, substitutions, improvements, etc. that are similar to or based on the present application should be considered within the scope of protection of this patent.

Claims

1. A high performance ionic gel adhesive, characterized by, By weight, it includes the following components: 20-40 parts of polymerizable monomer; 30-60 parts of ionic liquid; 0.1-2 parts of dynamic crosslinking agent; Photoinitiator 0.2-1.5 parts; Functional additives: 0-5 parts; The polymerizable monomer is one or more of acrylic acid, hydroxyethyl methacrylate, and acrylamide; The ionic liquid is one of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and choline chloride-lactic acid eutectic solvent. The dynamic crosslinking agent is one of ZnCl2, FeCl3, or borate.

2. The high-performance ionogel adhesive according to claim 1, characterized in that, The functional additive is one or more of fumed silica and precipitated silica.

3. The high-performance ionogel adhesive according to claim 1, characterized in that, The photoinitiator is one of photoinitiator 1173, photoinitiator 184, and photoinitiator 2959.

4. The process for the preparation of high performance ionogel adhesives according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Mix the polymerizable monomer, ionic liquid and functional additives according to the formula ratio, and stir at room temperature until homogeneous and transparent; S2. Add dynamic crosslinking agent and stir continuously until completely dissolved to form a homogeneous precursor solution; S3. Add photoinitiator, stir evenly in the dark, and degas; S4. Pour the precursor liquid into the mold and cure it with ultraviolet light to obtain a high-performance ion gel adhesive.

5. The method for preparing the high-performance ionogel adhesive according to claim 4, characterized in that, The ultraviolet light used for curing has a wavelength of 100nm-400nm and a curing time of 5-30min.

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