An electrically and thermally responsive hydrogen-bonded adhesive, method of making and use

Abstract

The present application relates to a kind of electric and thermal response hydrogen bond binder, preparation method and application, belong to binder material technical field.The structure formula of the adhesive is the polymer of six-arm initiator, diaminopyridine monomer, thymine monomer, methyl imidazole type ionic liquid.This hydrogen bond binder has multiple hydrogen bond action group, can give binder strong cohesive force, with electrostatic interaction group simultaneously, can controllably release hydrogen bond to improve adhesion, by active controllable free radical polymerization (ATRP) preparation binder, can accurately control and balance the adhesion / cohesion energy of polymer.The binder has electric / thermal response performance, to realize the application in different science and technology fields.

Description

Technical Field

[0001] This invention belongs to the field of adhesive materials technology, and more specifically, relates to an electrically and thermally responsive hydrogen-bonded adhesive, its preparation method and application, which can be applied to structural adhesives, waterproof adhesives, conductive adhesives and other applications. Background Technology

[0002] Adhesives are natural or synthetic materials that can bond similar or dissimilar substances together, and have become indispensable in modern life and industry. After decades of fundamental research, adhesives and their corresponding encapsulation technologies have made revolutionary progress, and high-performance interfacial bonding materials play a crucial role in wearable devices, smart coatings, biochips, medical devices, and aerospace.

[0003] Inspired by the interfacial adhesion properties of naturally adhesive organisms (such as geckos, mussels, and barnacles), artificially constructed supramolecular interfacial adhesive materials, as an emerging branch of polymer science, have aroused great interest in the academic community. At present, a series of molecular units with programmable adhesive forces are available. These units are mainly realized through supramolecular elements, such as host-guest interactions, metal-ligand coordination interactions, electrostatic interactions, van der Waals forces, π-π stacking, and hydrogen bonding interactions.

[0004] Among them, self-assembly mediated by multiple hydrogen bonds is one of the important means of creating new substances and generating new functions from the bottom up. In recent years, many supramolecular polymer interface bonding materials with special structures and excellent performance have been developed, and the responsiveness of such materials to external environments such as temperature, light, pressure, and chemical stimuli has been explored. Application exploration has been carried out in scientific and technological fields such as sensors, conductive materials, information storage, and clinical surgery. Summary of the Invention

[0005] To address the technical problems of existing adhesives, such as the difficulty in balancing cohesive and adhesive forces, lack of functionalization, and limited applicability to various substrates (glass, wood, steel, aluminum, copper, PTFE, etc.), this invention utilizes Active-Controlled Radical Polymerization (ATRP) to copolymerize diaminopyridine / thymine base pairs. Ionic liquid functional units are linked through a six-arm initiator to prepare a novel electro / thermal responsive hydrogen-bonded adhesive. This adhesive aims to precisely control intermolecular forces and interfacial interactions, providing electrothermal responsiveness and underwater adhesion properties.

[0006] To achieve the above objectives, according to one aspect of the present invention, an electrically and thermally responsive hydrogen-bonded adhesive is provided, the adhesive having the structural formula shown in Formula I;

[0007] ;

[0008] Formula I

[0009] The ratio of x, y and z is (1-2):(1-2):(11-13).

[0010] According to another aspect of the present invention, a method for preparing the aforementioned electro- and thermally responsive hydrogen-bonded binder is provided, comprising dissolving a diaminopyridine monomer, a thymine monomer, a methylimidazolium-type ionic liquid, an oxidizing agent, and a complexing agent in an organic solvent to obtain a first mixture; and dissolving a reducing agent and a six-armed initiator in an organic solvent to obtain a second mixture; wherein the structural formulas of the six-armed initiator, thymine monomer, diaminopyridine monomer, and methylimidazolium-type ionic liquid are shown in Formulas II, III, IV, and V;

[0011] , ,

[0012] Formula II Formula III

[0013] , ;

[0014] Type IV Type V

[0015] The first mixture and the second mixture are mixed, reacted in an oil bath, and then the reaction is terminated by immersion in liquid nitrogen. The electrically and thermally responsive hydrogen-bonded binder is obtained by solvent precipitation.

[0016] Preferably, the preparation of the diaminopyridine monomer specifically involves: adding 6-diaminopyridine and triethylamine to an organic solvent in an ice bath, adding butyryl chloride dropwise, and then sequentially performing vacuum concentration and column chromatography separation to obtain a diaminopyridine precursor; adding the diaminopyridine precursor and triethylamine to an organic solvent in an ice bath, adding methacryloyl chloride dropwise, and then sequentially performing vacuum concentration and column chromatography separation to obtain the diaminopyridine monomer.

[0017] Preferably, the preparation of the thymine monomer specifically involves: adding thymine and a base to water for an oil bath, then adding an aqueous solution of bromoacetic acid, and reacting to obtain a thymine precursor; adding the thymine precursor, 2-hydroxyethyl methacrylate, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, and 4-dimethylaminopyridine to an organic solvent, reacting, and then sequentially performing vacuum concentration and column chromatography separation to obtain the thymine monomer.

[0018] Preferably, the reaction temperature of the thymine precursor, 2-hydroxyethyl methacrylate, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, and 4-dimethylaminopyridine is 70-80°C.

[0019] Preferably, the preparation of the methylimidazolium-type ionic liquid is as follows: 3-bromo-1-propanol and triethylamine are added to an organic solvent for an ice bath, and methacryloyl chloride is added dropwise. Then, vacuum concentration and alkaline alumina column separation are performed sequentially to obtain 3-bromopropyl methacrylate. The 3-bromopropyl methacrylate and 1-methylimidazolium are added to acetonitrile for an oil bath. After the reaction, vacuum concentration and washing are performed sequentially to obtain an aqueous precursor solution of the methylimidazolium-type ionic liquid. The aqueous precursor solution of the methylimidazolium-type ionic liquid is mixed with bis(trifluoromethanesulfonyl)aminolithium salt, and after the reaction, extraction is performed to obtain the methylimidazolium-type ionic liquid.

[0020] Preferably, the reaction time of the 3-bromopropyl methacrylate and 1-methylimidazole is 6-16 h.

[0021] Preferably, the molar ratio of the six-armed initiator, diaminopyridine monomer, thymine monomer, and methylimidazole ionic liquid is 1:80:80:(480-1280).

[0022] Preferably, the oxidant is cuprous bromide, the complexing agent is N,N,N',N'',N''-pentamethyldiethylenetriamine, and the reducing agent is stannous octoate.

[0023] According to another aspect of the invention, the application of the aforementioned electro- and thermally responsive hydrogen-bonded adhesive as a structural adhesive, waterproof adhesive, or conductive adhesive is provided.

[0024] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0025] (1) The hydrogen-bonded adhesive of the present invention introduces multiple hydrogen-bonding groups (diaminopyridine / thymine base pairs), which endows the adhesive with strong cohesive force. In addition, the polymer introduces electrostatic interaction groups (ionic liquid), which can controllably release hydrogen bonds to improve adhesion.

[0026] (2) This invention prepares adhesives through active controlled radical polymerization (ATRP), precisely controlling and balancing the adhesion / cohesive energy of the polymer. The hydrogen-bonded adhesive preparation method designed and developed in this invention prepares different polymer units through organic synthesis, and precisely controls the adhesive strength through controlled active polymerization, making it closer to the application scenario, laying the foundation for the industrial production of novel polymer adhesives.

[0027] (3) The adhesive of the present invention has thermal responsive properties, thereby achieving controllable adhesion and deadhesion. Fifth, the adhesive has electrical responsive properties, thereby enabling its application in the field of conductive adhesives. The adhesive of the present invention can achieve different adhesion at different temperatures, and the anion concentration gradient changes after the polymer is energized, realizing electron transfer and changes in structural strength.

[0028] (4) The hydrogen bonded adhesive designed and developed in this invention has high adhesion strength, temperature / electricity response performance, and underwater adhesion performance, thus broadening the application scenarios of the adhesive. Attached Figure Description

[0029] Figure 1 For P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 )6 1H NMR spectrum and its assignment.

[0030] Figure 2 The process of preparing samples for shear testing.

[0031] Figure 3 For P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 )6 It can easily lift dumbbell plates weighing 74 kg.

[0032] Figure 4 For P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 6. Thermal response test. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0034] The present invention provides an electro / thermal responsive hydrogen-bonded adhesive, wherein the hydrogen-bonded polymer has a general structural formula as shown in Formula I.

[0035] ;

[0036] Formula I

[0037] The ratio of x, y, and z is in the range of (1-2):(1-2):(11-13), and x, y, and z are all positive integers.

[0038] The composition includes: a six-arm initiator, diaminopyridine (DAP), thymine (Thy), and a methylimidazolium-type ionic liquid (MBA).

[0039] The six-armed initiator has a well-defined chemical structure, as shown in Formula II.

[0040] ;

[0041] Formula II

[0042] The thymine described is a methyl vinyl thymine monomer with a clearly defined chemical structure, as shown in Formula III.

[0043] ;

[0044] Formula III

[0045] The diaminopyridine described herein is an ester-type methyl vinyl diaminopyridine monomer with a clearly defined chemical structure, as shown in Formula IV.

[0046] ;

[0047] Formula IV

[0048] The methylimidazolium-type ionic liquid monomers described herein are ester-type methyl vinyl methyl imidazolium-type ionic liquids with well-defined chemical structures, as shown in Formula V.

[0049] ;

[0050] Formula V

[0051] The present invention discloses a method for preparing an electro / thermal responsive hydrogen-bonded binder, comprising the following steps:

[0052] Step 1: Preparation of diaminopyridine

[0053] (1) 6-Diaminopyridine, triethylamine and organic solvent were mixed and added into an eggplant-shaped flask of appropriate size, immersed in an ice bath, and butyryl chloride was slowly added dropwise to the mixture. The mixture was stirred for 24 h, and then vacuum concentration and column chromatography were performed to remove impurities and obtain pure diaminopyridine precursor.

[0054] (2) The precursor, triethylamine and organic solvent were mixed and added into an eggplant-shaped flask of appropriate size, immersed in an ice bath, and methacryloyl chloride was slowly added dropwise to the mixture. The mixture was stirred for 24 h, and then vacuum concentration and column chromatography were performed to remove impurities and obtain pure diaminopyridine monomer.

[0055] Step 2: Preparation of thymine monomers

[0056] (1) Thymine, potassium hydroxide, and water were mixed and added to a flask of appropriate size. The flask was immersed in a constant temperature oil bath at 100°C and stirred for 30 min. Then, an aqueous solution of bromoacetic acid was added and the mixture was stirred for 1 h. After the reaction was completed, the pH of the solution was adjusted to alkaline. The flask was then placed in an environment at -20°C for 60 min. The pH was then adjusted to acidic. The mixture was filtered to obtain the precursor of thymine monomer.

[0057] (2) The precursor, 2-hydroxyethyl methacrylate, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, 4-dimethylaminopyridine, and dichloromethane solvent were mixed and added into an eggplant-shaped flask of appropriate size. The mixture was stirred for 16 h and then vacuum concentrated and separated by column chromatography to remove impurities and obtain pure monomer.

[0058] Step 3: Preparation of methylimidazolium-type ionic liquids

[0059] (1) 3-bromo-1-propanol, triethylamine, and dichloromethane were mixed and added to a suitable-sized eggplant-shaped flask, immersed in an ice bath, and methacryloyl chloride was slowly added dropwise to the mixture. The mixture was stirred for 24 h, and then vacuum concentrated and passed through a short alkaline alumina column to obtain 3-bromopropyl methacrylate.

[0060] (2) 3-bromopropyl methacrylate, 1-methylimidazole, and acetonitrile were mixed and added into an appropriate-sized eggplant-shaped flask, immersed in an oil bath at a fixed temperature and stirred for 16 h, and then vacuum concentrated. The mixture was dissolved in water and washed with dichloromethane to obtain an aqueous solution of the precursor of the methylimidazole ionic liquid.

[0061] (3) Mix the aqueous solution of methylimidazolium-type ionic liquid precursor and bis(trifluoromethanesulfonyl)amino lithium salt into an appropriate-sized eggplant-shaped flask, stir at room temperature for 24 h, and then extract to obtain pure monomer.

[0062] Step 4: Atom Transfer Radical Polymerization

[0063] The monomers prepared in steps one to three, the six-armed initiator, cuprous bromide, N,N,N',N'',N''-pentamethyldiethylenetriamine, and organic solvent were placed in a Schlenk flask. Stannous octoate, the six-armed ATRP initiator, and organic solvent were placed in another Schlenk flask. The mixture was bubbled for 30 min to remove air. The above solutions were then mixed under vacuum and immersed in a constant temperature oil bath at 75°C for several hours. The polymerization was then terminated by immersion in liquid nitrogen, and the pure polymer binder was obtained by solvent precipitation.

[0064] Preferably, in steps (1) and (2), the organic solvent is a polar organic solvent, preferably one or more of dichloromethane, ethyl acetate, and methanol.

[0065] Preferably, in step two (1), the alkalinity and acidity are preferably at pH values ​​of 5.0-6.0 and 1.5-2.5, respectively.

[0066] Preferably, in step three (2), the fixed temperature is a reaction temperature of 70-80℃, preferably 75℃.

[0067] Preferably, in step four, the organic solvent is a strongly polar solvent, preferably one or more of dimethyl sulfoxide and N,N-dimethylformamide.

[0068] Preferably, in step four, the number of hours is 6-16 hours, preferably 9 hours.

[0069] The following are specific embodiments.

[0070] Example

[0071] P(DAP 0.8 - co -Thy 0.9 - co -MBA 13.3 6. P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 6. Preparation method of hydrogen-bonded binder

[0072] The preparation method mainly includes the following steps:

[0073] Step 1: Preparation of diaminopyridine

[0074] (1) Mix 6-diaminopyridine, triethylamine and dichloromethane into an eggplant-shaped flask of appropriate size, immerse in an ice bath, and slowly add butyryl chloride to the mixture. Stir for 24 h, then perform vacuum concentration and column chromatography separation (eluent: petroleum ether: ethyl acetate = 1:1) to remove impurities and obtain pure diaminopyridine precursor. The specific molar ratio of the additives is shown in the table below.

[0075]

[0076] (2) The precursor, triethylamine and dichloromethane were mixed and added into an eggplant-shaped flask of appropriate size, immersed in an ice bath, and methacryloyl chloride was slowly added dropwise to the mixture. The mixture was stirred for 24 h, and then vacuum concentration and column chromatography were performed sequentially (the eluent was dichloromethane:methanol = 100:3) to remove impurities and obtain pure diaminopyridine monomer. The specific molar ratio of the additives is shown in the table below.

[0077]

[0078] Step 2: Preparation of thymine monomers

[0079] (1) Thymine, potassium hydroxide, and water were mixed and added to a flask of appropriate size. The flask was then immersed in a constant temperature oil bath at 100°C and stirred for 30 min. Then, an aqueous solution of bromoacetic acid was added and the mixture was stirred for 1 h. After the reaction was completed, the pH of the solution was adjusted to 5.5. The flask was then placed in a -20°C environment for 60 min. The pH was then adjusted to 2.0 and filtered to obtain the precursor of thymine monomer. The specific molar ratio of the added materials is shown in the table below.

[0080]

[0081] (2) The precursor, 2-hydroxyethyl methacrylate, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, 4-dimethylaminopyridine, and dichloromethane solvent were mixed and added into an eggplant-shaped flask of appropriate size. The mixture was stirred for 16 h and then vacuum concentrated and separated by column chromatography to remove impurities and obtain pure monomers. The specific molar ratios of the additives are shown in the table below.

[0082]

[0083] Step 3: Preparation of methylimidazolium-type ionic liquids

[0084] (1) 3-bromo-1-propanol, triethylamine, and dichloromethane were mixed and added to an appropriate-sized eggplant-shaped flask, immersed in an ice bath, and methacryloyl chloride was slowly added dropwise to the mixture. The mixture was stirred for 24 h, and then vacuum concentrated and passed through a short alkaline alumina column to obtain 3-bromopropyl methacrylate. The specific molar ratio of the added materials is shown in the table below.

[0085]

[0086] (2) 3-bromopropyl methacrylate and 1-methylimidazole (molar ratio of 1.2:1), acetonitrile, are mixed and added to an appropriate-sized eggplant-shaped flask. The mixture is then immersed in an oil bath at 75°C and stirred for 16 h. Vacuum concentration is carried out sequentially, and the mixture is dissolved in water and washed with dichloromethane to obtain an aqueous solution of the precursor of the methylimidazole ionic liquid.

[0087] (3) Mix the aqueous solution of the methylimidazolium ionic liquid precursor with lithium bis(trifluoromethanesulfonyl)amino (molar ratio of 1:3) and add it to a suitable-sized eggplant-shaped flask. Stir at room temperature for 24 h, and then extract to obtain pure monomer.

[0088] Step 4: Atom Transfer Radical Polymerization

[0089] The monomers prepared in steps one to three, cuprous bromide, and N,N,N',N'',N''-pentamethyldiethylenetriamine, in DMF solvent, were placed in Schlenk flask 1. Stannous octoate and a six-arm ATRP initiator, also in DMF solvent, were placed in another Schlenk flask 2. The two Schlenk flasks were bubbled for 30 min to remove air. The solutions were then mixed under vacuum and stirred in a 75°C constant-temperature oil bath for 9 h. Polymerization was then terminated by immersion in liquid nitrogen, and the purified polymer binder was obtained through solvent precipitation to prepare P(DAP). 0.8 - co -Thy 0.9 - co -MBA 13.3 6. P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The molar ratios of 6 are shown in the table below.

[0090] P(DAP 0.8 - co -Thy 0.9 - co -MBA 13.3 6:

[0091]

[0092] P(DAP 1.7 - co -Thy 2.0 - co -MBT 11.4 6:

[0093]

[0094] For example P(DAP) 0.8 - co -Thy 0.9 - co -MBA 13.3 6. P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 6. Conduct the experiment.

[0095] 1. Test P(DAP) 0.8 - co -Thy 0.9 - co -MBA 13.3 6. P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 )6 Structure and adhesive properties.

[0096] With P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 Taking 6 as an example, it was determined by nuclear magnetic resonance testing and assigned to characteristic hydrogen (as shown in the attached diagram of the instruction manual). Figure 1 As shown in the figure, characteristic hydrogens 1-3 can be assigned to MBA, characteristic hydrogens 4-5 can be assigned to Thy, characteristic hydrogens 6-20 can be assigned to DAP, and characteristic hydrogen 11 can be assigned to the characteristic hydrogen on the initiator, which can clearly characterize the success of polymer synthesis.

[0097] P(DAP 0.8 - co -Thy 0.9 - co -MBA 13.3 6. P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 Adhesion properties characterization of 6.

[0098] (1) Sample preparation

[0099] Before characterizing the adhesion properties, sample preparation is performed. First, the polymer sample is heated to 130°C. After the polymer softens, it is coated onto the surfaces of different substrates. Another substrate plate is then pressed onto the bonding surface, and a pressure of 5 kg is applied for 30 min. Finally, the sample is cooled to 30°C, indicating successful preparation (as shown in the attached diagram in the instruction manual). Figure 2 (As shown).

[0100] (2) Shear strength

[0101] The shear test was conducted continuously in a constant temperature and humidity environment using a universal testing machine. The tensile rate was 10 mm / min. Each test parameter had to be measured repeatedly at least 5 times and the average value was taken.

[0102] Through testing, P(DAP) 0.8 - co -Thy 0.9 - co -MBA 13.3 ), P(DAP 1.7 - co -Thy 2.0 - co -MBT 11.4 )6 exhibits good mechanical properties under different substrates, and its shear strength is shown in the table below. It can be seen that P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The adhesive exhibited excellent adhesion to both hydrophilic and hydrophobic substrates. Materials tested for adhesion included polyoxymethylene (POM), polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), copper, stainless steel, glass, and ceramics. (P(DAP)) 1.7 - co -Thy 2.0 - co -MBT 11.4 The maximum viscous shear strength of P(DAP) reached 11.8 MPa on ceramic substrates, 10.4 MPa on glass substrates, 7.2 MPa on stainless steel substrates, and 1.4 MPa on polytetrafluoroethylene substrates, demonstrating excellent adhesive properties. It is worth noting that P(DAP) exhibits... 1.7 - co -Thy 2.0 - co -MBT 11.4 The shear strength of 6 is higher than that of P(DAP). 0.8 - co -Thy 0.9 -co -MBA 13.3 This can be attributed to the increased number of hydrogen bonds inside the polymer, which allows the ionic liquid to release hydrogen bonds to a greater extent, thereby increasing interfacial adhesion.

[0103] P(DAP 1.7 - co -Thy 2.0 - co -MBT 11.4 6:

[0104]

[0105] P(DAP 0.8 - co -Thy 0.9 - co -MBA 13.3 6:

[0106]

[0107] (3) Application scenarios

[0108] Through P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The two bonded ceramic plates can withstand a weight of 74 kg, with a bonding area of ​​195 mm². 2 This indicates that the polymer has high adhesion to different surfaces. Meanwhile, through P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The prepared sample can also easily lift the dumbbell plate (as shown in the attached diagram in the instruction manual). Figure 3 As shown in the figure, its high adhesive strength and stability make it applicable in various fields.

[0109] 2. Test P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 Temperature response performance of 6.

[0110] Shear tests at different temperatures were conducted continuously in a constant temperature and humidity environment using a universal testing machine. The tensile rate was 10 mm / min. Each test parameter had to be measured repeatedly at least 5 times and the average value was taken.

[0111] Taking a glass substrate as an example, P(DAP)1.7 - co -Thy 2.0 - co -MBT 11.4 The shear strength of 6 at 30℃, 50℃, and 70℃ is shown in the table below. The adhesive performance decreases with increasing temperature, which is attributed to the dynamic non-covalent bonds within the polymer, thus achieving temperature-responsive performance and making it easier to achieve adhesion and deadhesion; through P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The bonded sample could withstand a weight of 11.8 kg for 30 days without bonding failure. Heating it for 11 seconds could detach the adhesive (as shown in the attached diagram in the instruction manual). Figure 4 (As shown).

[0112]

[0113] 3. Test P(DAP) 0.8 - co -Thy 0.9 - co -MBA 13.3 6. P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The electrical response performance of 6.

[0114] Shear tests under different voltages and energizing times were conducted continuously in a constant temperature and humidity environment using a universal testing machine. The tensile rate was 10 mm / min, and the substrate was ITO conductive glass. Each test parameter had to be measured continuously for at least 5 times and the average value was taken.

[0115] At room temperature, for P(DAP) 0.8 - co -Thy 0.9 - co -MBA 13.3 )6 Tests were conducted under different voltages and energizing times. The shear strength under the ITO conductive glass substrate increased with increasing voltage and energizing time, attributed to the migration of anions on the polymer backbone, leading to enhanced electrostatic interaction, reaching a maximum of 10.2 MPa. Meanwhile, for P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4)6. Tests were conducted at different voltages and with different energizing times, and the shear strength showed no significant change. To achieve an electrical response, the test temperature was increased to 50℃ for P(DAP). 0.8 - co -Thy 0.9 - co -MBA 13.3 Its shear strength increased from 3.1 MPa to 4.8 MPa, for P(DAP) 1.7 - co -Thy 2.0 - co -MBT 11.4 The shear strength increased from 5.3 MPa to 6.8 MPa, thanks to the temperature being raised above the polymer's glass transition temperature, which allowed anions more room to move.

[0116]

[0117]

[0118] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electrically and thermally responsive hydrogen-bonded adhesive, characterized in that, The structural formula of the adhesive is shown in Formula I; ； Formula I The ratio of x, y, and z is (1-2):(1-2):(11-13), and x, y, and z are all positive integers.

2. The method for preparing the electro- and thermally responsive hydrogen-bonded binder as described in claim 1, characterized in that, A first mixture is obtained by dissolving a diaminopyridine monomer, a thymine monomer, a methylimidazolium-type ionic liquid, an oxidizing agent, and a complexing agent in an organic solvent; a second mixture is obtained by dissolving a reducing agent and a six-armed initiator in an organic solvent; the structural formulas of the six-armed initiator, thymine monomer, diaminopyridine monomer, and methylimidazolium-type ionic liquid are shown in Formulas II, III, IV, and V. 、 、 Formula II Formula III 、 ； Type IV Type V The first mixture and the second mixture are mixed, reacted in an oil bath, and then the reaction is terminated by immersion in liquid nitrogen. The electrically and thermally responsive hydrogen-bonded binder is obtained by solvent precipitation.

3. The preparation method according to claim 2, characterized in that, The preparation of the diaminopyridine monomer is specifically as follows: 6-diaminopyridine and triethylamine are added to an organic solvent and placed in an ice bath, and butyryl chloride is added dropwise. Then, vacuum concentration and column chromatography separation are performed sequentially to obtain the diaminopyridine precursor. The diaminopyridine precursor and triethylamine are added to an organic solvent and placed in an ice bath, and methacryloyl chloride is added dropwise. Then, vacuum concentration and column chromatography separation are performed sequentially to obtain the diaminopyridine monomer.

4. The preparation method according to claim 2, characterized in that, The preparation of the thymine monomer is specifically as follows: thymine and a base are added to water for an oil bath, followed by the addition of an aqueous solution of bromoacetic acid. After the reaction, a thymine precursor is obtained. The thymine precursor, 2-hydroxyethyl methacrylate, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, and 4-dimethylaminopyridine are added to an organic solvent. After the reaction, vacuum concentration and column chromatography are performed sequentially to obtain the thymine monomer.

5. The preparation method according to claim 4, characterized in that, The reaction temperature of the thymine precursor, 2-hydroxyethyl methacrylate, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride, and 4-dimethylaminopyridine is 70-80℃.

6. The preparation method according to claim 2, characterized in that, The preparation of the methylimidazolium-type ionic liquid is as follows: 3-bromo-1-propanol and triethylamine are added to an organic solvent in an ice bath, and methacryloyl chloride is added dropwise. Then, vacuum concentration and alkaline alumina column separation are performed sequentially to obtain 3-bromopropyl methacrylate. The 3-bromopropyl methacrylate and 1-methylimidazolium are added to acetonitrile in an oil bath. After the reaction, vacuum concentration and washing are performed sequentially to obtain an aqueous precursor solution of the methylimidazolium-type ionic liquid. The aqueous precursor solution of the methylimidazolium-type ionic liquid is mixed with bis(trifluoromethanesulfonyl)aminolithium salt, and after the reaction, extraction is performed to obtain the methylimidazolium-type ionic liquid.

7. The preparation method according to claim 6, characterized in that, The reaction time of 3-bromopropyl methacrylate and 1-methylimidazole is 6-16 h.

8. The preparation method according to any one of claims 2-7, characterized in that, The molar ratio of the six-armed initiator, diaminopyridine monomer, thymine monomer, and methylimidazolium-type ionic liquid is 1:80:80:(480-1280).

9. The preparation method according to any one of claims 2-7, characterized in that, The oxidant is cuprous bromide, the complexing agent is N,N,N',N'',N''-pentamethyldiethylenetriamine, and the reducing agent is stannous octoate.

10. The application of the electro- and thermally responsive hydrogen-bonded adhesive as described in claim 1 as a structural adhesive, waterproof adhesive, or conductive adhesive.

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