In-situ spontaneous polymerization adhesive as well as preparation method and application thereof

Abstract

The invention relates to an in-situ spontaneous polymerization adhesive as well as a preparation method and application thereof. The in-situ spontaneous polymerization adhesive is prepared from the following raw materials: glycidol and a polyphenol compound. The in-situ spontaneous polymerization adhesive provided by the invention is high in bonding strength, excellent in reusability, good in spectrum bonding effect, wide in application range, simple in preparation method, free of additional solvent and green and environment-friendly.

Description

An in-situ spontaneously polymerizing adhesive, its preparation method and application Technical Field

[0001] This invention relates to the field of adhesive materials technology, and in particular to an in-situ spontaneously polymerizing adhesive, its preparation method, and its application. Background Technology

[0002] Adhesives, as indispensable chemical products in modern life and industry, are widely used in food packaging, furniture manufacturing, electronics and information technology, biomedicine, and aerospace. Traditional adhesives are typically composed mainly of polymers, such as epoxy resins, polyurethanes, and polyacrylates. Their adhesion mechanism relies on chemical bonding, physical adsorption, or mechanical interlocking between the prepolymer and the curing agent, achieving high-strength adhesion through chemical crosslinking and physical entanglement. However, these adhesives suffer from drawbacks such as high energy consumption during curing processes, irreversible adhesion, poor interfacial compatibility, and significant environmental harm.

[0003] Supramolecular adhesives, as an emerging type of adhesive material, are assembled from functional small molecule monomers through non-covalent interactions (such as hydrogen bonds, metal coordination bonds, electrostatic interactions, and π-π stacking interactions), and belong to the category of low molecular weight adhesives. Based on the unique properties of non-covalent interactions, low molecular weight adhesives exhibit many properties different from traditional polymer adhesives, such as reusability, irritation responsiveness, and recyclability, showing practical application potential in areas such as removable encapsulation of electronic devices, non-invasive peelable biomedical dressings, and recyclable lithium battery adhesives. The emergence of low molecular weight adhesives provides new development opportunities and broad prospects for the development of low-carbon, green, high-adhesion-strength, and reusable adhesive materials.

[0004] Most supramolecular adhesive systems are currently hot melt adhesives, requiring heating to a molten state to achieve sufficient fluidity for easy coating. During the heating and melting process, some molecular chains of low molecular weight adhesives still maintain non-covalent interactions, resulting in high intermolecular cohesive energy. This significantly restricts the movement of molecular chains during adhesion, reducing the adhesive's wetting and interfacial adhesion to the substrate surface, leading to decreased adhesion strength. Furthermore, hot melt curing low molecular weight adhesives often form excessively thick adhesive layers, resulting in resource waste and hindering their application in electronic packaging devices.

[0005] Therefore, developing an adhesive that can be prepared through in-situ spontaneous polymerization and possesses both high cohesive strength and high adhesive strength has become an urgent problem to be solved. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides an in-situ spontaneously polymerizing adhesive, its preparation method, and its applications. The in-situ spontaneously polymerizing adhesive exhibits high bonding strength, excellent reusability, good spectral bonding performance, and a wide range of applications. Furthermore, its preparation method is simple, requires no additional solvents, and is environmentally friendly.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an in-situ spontaneous polymerization adhesive, wherein the raw materials for preparing the in-situ spontaneous polymerization adhesive include glycidyl ether and polyphenolic compounds.

[0008] The in-situ spontaneous polymerization adhesive provided by this invention uses glycidyl ether and polyphenolic compounds as raw materials, which enables it to achieve excellent bonding performance and repeatability, as well as to bond a variety of materials well. In other words, it has good spectral bonding effect and a wide range of applications.

[0009] In this invention, "in-situ spontaneous polymerization" refers to the bonding process where glycidyl glycerol undergoes spontaneous ring-opening polymerization induced by acidic polyphenols without the need for additional catalysts, and is cured in situ on the surface of the substrate to be bonded.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0011] As a preferred embodiment of the present invention, the mass ratio of the polyphenolic compound to glycidol is 1:(0.5-2.2), wherein (0.5-2.2) can be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.5, 1.8, 2.0 or 2.2, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and is further preferably 1:(0.6-1.8).

[0012] This invention improves the adhesive properties of the resulting in-situ spontaneously polymerized adhesive by optimizing the mass ratio of polyphenolic compounds to glycidyl ether. Within a certain range, the adhesive strength of the in-situ spontaneously polymerized adhesive decreases as the mass proportion of glycidyl ether increases; similarly, the adhesive strength also decreases when the mass proportion of polyphenolic compounds is high. This is because the polyglycidyl ether formed after the polymerization of glycidyl ether is a soft segment, while the polyphenolic compounds are hard segments. Only by adjusting the optimal ratio of the two can a balance be achieved between "adhesion" and "cohesive strength" in the adhesive.

[0013] Preferably, the structural formula of the polyphenolic compound is shown in Formula I: R1-R5 are each independently selected from hydrogen or hydroxyl groups, and R1-R5 include at least two hydroxyl groups; R6 is selected from any one of hydrogen, halogen, amino, hydroxyl, and C1-C70 organic groups.

[0014] Wherein, C1-C70 can be C1, C5, C10, C20, C30, C40, C50, C60 or C70, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0015] Preferably, R6 is selected from hydrogen, halogen, amino, -COOR A -CH2=CH2-COOR B Any one of them.

[0016] Preferably, R A Selected from hydrogen or groups having any of the following structures: , Wherein, R7, R8, and R9 are each independently selected from hydroxyl groups; s represents an integer from 1 to 4 (e.g., 1, 2, 3, or 4), more preferably 2 or 3, and even more preferably 2; m represents an integer from 1 to 4 (e.g., 1, 2, 3, or 4), more preferably 2 or 3, and even more preferably 2; n represents an integer from 1 to 5 (e.g., 1, 2, 3, 4, or 5), more preferably 2 or 3, and even more preferably 3; M is selected from C1-C5 alkylene groups; R'1, R'2, R'3, and R'4 may be the same or different, and each is independently selected from hydrogen or groups having the following structures: ;R 10 Selected from hydroxyl groups; t represents an integer from 1 to 4 (e.g., it can be 1, 2, 3 or 4), more preferably 2 or 3, and even more preferably 2.

[0017] Preferably, R B The substituted group is selected from hydrogen, substituted or unsubstituted C3-C7 cycloalkyl groups, more preferably hydrogen, substituted or unsubstituted cyclohexane; the substituted group is selected from hydroxyl or carboxyl groups.

[0018] C1-C5 can be, for example, C1, C2, C3, C4 or C5, and C3-C7 can be, for example, C3, C4, C5, C6 or C7.

[0019] In the structure of this invention, the dashed lines (---) represent connection sites.

[0020] Preferably, the polyphenolic compound includes any one or a combination of at least two of the following: tannic acid, epigallocatechin gallate, gallic acid, chlorogenic acid, caffeic acid, or pyrogallic acid.

[0021] Preferably, the number average molecular weight of the in-situ spontaneously polymerizing adhesive is 1500-3000 g / mol, for example, it can be 1500 g / mol, 1800 g / mol, 2000 g / mol, 2200 g / mol, 2400 g / mol, 2600 g / mol, 2800 g / mol or 3000 g / mol, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0022] In a second aspect, the present invention provides a method for preparing an in-situ spontaneously polymerizing adhesive as described in the first aspect, the method comprising the following steps: mixing glycidyl ether and a polyphenolic compound and reacting them to obtain the in-situ spontaneously polymerizing adhesive.

[0023] Preferably, the mixing is carried out under stirring.

[0024] It should be noted that the present invention does not impose any special limitation on the stirring rate, and stirring rates commonly used in the art are applicable.

[0025] Preferably, the stirring time is 5-60 min, for example, it can be 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0026] It should be noted that the stirring time limit in this invention is only used to fully mix glycidyl ether and polyphenolic compounds to form a uniform binder precursor solution. Therefore, the specific stirring time includes, but is not limited to, the 5-60 min mentioned above, and can be adjusted adaptively according to actual experimental conditions or production needs.

[0027] Preferably, the reaction temperature is 60-120℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃ or 120℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0028] Preferably, the reaction time is 2-10 h, for example, it can be 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the range.

[0029] This invention optimizes the temperature and time of the reaction, thereby further improving the bonding performance of the resulting in-situ spontaneous polymerization adhesive. Once a certain range is exceeded, even if the temperature or time is further increased, the bonding strength will no longer be significantly improved.

[0030] Preferably, the reaction is followed by a cooling step.

[0031] It should be noted that the present invention does not have a special limitation on the cooling temperature, which may include, but is not limited to, room temperature (20-30°C).

[0032] Specifically, the preparation method of the in-situ spontaneously polymerizing adhesive provided by the present invention includes the following steps: stirring glycidyl ether and polyphenolic compounds for 5-60 min to obtain an adhesive precursor solution, reacting at 60-120℃ for 2-10 h, cooling, and obtaining the in-situ spontaneously polymerizing adhesive.

[0033] Thirdly, the present invention provides a bonding method for an in-situ spontaneously polymerizing adhesive as described in the first aspect, the bonding method comprising the following steps: mixing glycidyl ether and a polyphenolic compound and coating the mixture onto the surface of the substrate to be adhered, followed by curing to achieve bonding of the substrate.

[0034] Preferably, the curing temperature is 60-120℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃ or 120℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0035] Preferably, the curing time is 2-10 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0036] The bonding method provided by this invention obtains an adhesive precursor solution by mixing glycidyl ether and polyphenolic compounds. This solution can be directly coated onto the surface of the substrate to be bonded without adding any additional solvent. The substrate can be bonded by hot-pressing and curing under specific conditions (60-120℃, 2-10 h). The entire process is simple, green and environmentally friendly, and the resulting adhesive layer is thin. It has excellent bonding strength and repeatability for a variety of materials.

[0037] Fourthly, the present invention provides an adhesive material comprising at least one of the in-situ spontaneously polymerizing adhesives as described in the first aspect and in-situ spontaneously polymerizing adhesives prepared by the preparation method of the in-situ spontaneously polymerizing adhesives as described in the second aspect.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects: The in-situ spontaneous polymerization adhesive provided by the present invention uses glycidyl ether and polyphenolic compounds as raw materials, and has excellent bonding performance (bonding strength of 1.43-7.62 MPa) and reusability (bonding strength does not decrease significantly after 10 reuses). It can also have good bonding effects on a variety of substrates such as epoxy resin (EP), acrylonitrile-butadiene-styrene copolymer (ABS), polyether ether ketone (PEEK), polycarbonate (PC), polyethylene (PE), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polypropylene (PP), polyurethane (PU), ceramics, wood, glass, copper, iron, aluminum and titanium. That is, it has good spectral bonding effect and wide application range, especially excellent bonding performance (bonding strength ≥5.9 MPa) on epoxy resin, ceramics, wood, glass, copper, iron, aluminum and titanium. Attached Figure Description

[0039] Figure 1 shows the FTIR spectrum of the in-situ spontaneously polymerized adhesive provided in Example 1; where G represents glycidyl ether, TA represents tannic acid, and P(TA-G) represents the in-situ spontaneously polymerized adhesive; Figure 2 shows the in-situ spontaneously polymerized adhesive provided in Example 1. 1 ¹H NMR spectrum; Figure 3 shows the test results of the in-situ self-polymerizing adhesive provided in Example 1 on different substrates; where EP represents epoxy resin, ABS represents acrylonitrile-butadiene-styrene copolymer, PEEK represents polyetheretherketone, PC represents polycarbonate, PE represents polyethylene, PMMA represents polymethyl methacrylate, PET represents polyethylene terephthalate, PVC represents polyvinyl chloride, PTFE represents polytetrafluoroethylene, PP represents polypropylene, PU represents polyurethane, Ceramic represents ceramic, Wood represents wood board, and Glass represents glass; Figure 4 shows the test results of the in-situ self-polymerizing adhesive provided in Example 1 on the reusability of epoxy resin boards. Detailed Implementation

[0040] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0041] Unless otherwise specified, the materials and equipment involved in the following detailed embodiments are all conventional materials and equipment in the art and will not affect the technical effects of the present invention.

[0042] Unless otherwise specified, all reagents and raw materials used in the following examples and comparative examples are commercially available products. Some raw material information is as follows: Tannic acid: CAS No. 1401-55-4, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Epigallocatechin gallate: CAS No. 989-51-5, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Gallic acid: CAS No. 149-91-7, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Pyrogallic acid: CAS No. 87-66-1, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Chlorogenic acid: CAS No. 206-325-6, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Caffeic acid: CAS No. 331-39-5, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; Glycidol: CAS No. 556-52-5, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0043] Example 1 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The preparation method includes the following steps: 0.74 g of glycidyl ether and 0.85 g of tannic acid are mixed and stirred for 30 min to form a uniform adhesive precursor solution. The solution is reacted at 80°C for 8 h and then cooled to 25°C to obtain the in-situ spontaneously polymerizing adhesive.

[0044] The infrared spectrum of the in-situ spontaneously polymerized adhesive is shown in Figure 1. The characteristic absorption peak of the cyclic ether of glycidyl ether in P(TA-G) is at 904 cm⁻¹. -1 and 1040 cm -1 The disappearance indicates that glycidol underwent a ring-opening polymerization reaction, generating an in-situ spontaneously polymerized adhesive.

[0045] The 1H NMR spectrum of the in-situ spontaneously polymerized adhesive is shown in Figure 2. A signal peak of glycidyl ring-opening polymerization appeared at 3.0-4.0 ppm, which also indicates the formation of the in-situ spontaneously polymerized adhesive.

[0046] Example 2 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction temperature in Example 1 is adjusted from 80°C to 120°C. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0047] Example 3 This example provides an in-situ spontaneous polymerization adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction temperature in Example 1 is adjusted from 80°C to 60°C. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0048] Example 4 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction temperature in Example 1 is adjusted from 80°C to 100°C. All other raw materials, amounts added, and preparation methods are the same as in Example 1.

[0049] Example 5 This example provides an in-situ spontaneous polymerization adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction time in Example 1 is adjusted from 8 h to 2 h. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0050] Example 6 This example provides an in-situ spontaneous polymerization adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction time in Example 1 is adjusted from 8 h to 4 h. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0051] Example 7 This example provides an in-situ spontaneous polymerization adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction time in Example 1 is adjusted from 8 h to 6 h. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0052] Example 8 This example provides an in-situ spontaneous polymerization adhesive and its preparation method. The only difference between this example and Example 1 is that the reaction time in Example 1 is adjusted from 8 h to 10 h. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0053] Example 9 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the amount of glycidol added in Example 1 is adjusted from 0.74 g to 0.56 g. The other raw materials, amounts added and preparation methods are the same as in Example 1.

[0054] Example 10 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the amount of glycidol added in Example 1 is adjusted from 0.74 g to 1.11 g. The other raw materials, amounts added and preparation methods are the same as in Example 1.

[0055] Example 11 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the amount of glycidol added in Example 1 is adjusted from 0.74 g to 1.48 g. The other raw materials, amounts added and preparation methods are the same as in Example 1.

[0056] Example 12 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the amount of glycidol added in Example 1 is adjusted from 0.74 g to 1.85 g. The other raw materials, amounts added and preparation methods are the same as in Example 1.

[0057] Example 13 This example provides an in-situ spontaneously polymerized adhesive and its preparation method. The only difference between this example and Example 1 is that the tannic acid in Example 1 is replaced with an equal mass of epigallocatechin gallate. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0058] Example 14 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the tannic acid in Example 1 is replaced with an equal mass of gallic acid. The other raw materials, amounts added, and preparation methods are the same as in Example 1.

[0059] Example 15 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the tannic acid in Example 1 is replaced with an equal mass of chlorogenic acid. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0060] Example 16 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the tannic acid in Example 1 is replaced with an equal mass of caffeic acid. The other raw materials, amounts added, and preparation methods are the same as in Example 1.

[0061] Example 17 This example provides an in-situ spontaneously polymerizing adhesive and its preparation method. The only difference between this example and Example 1 is that the tannic acid in Example 1 is replaced with an equal mass of pyrogallic acid. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0062] Comparative Example 1 This comparative example provides a hot melt adhesive and its preparation method. The preparation method includes the following steps: 0.74 g of polyglycidyl ether (number average molecular weight of 1800 g / mol, prepared according to the preparation method of hyperbranched polyether copolymer in Example 1 of CN116836669A) and 0.85 g of pyrogallol are mixed and heated at 80°C for 1 h to obtain the hot melt adhesive.

[0063] Performance Test 1: The adhesive performance of the adhesives provided in Examples 1-17 and Comparative Example 1 was tested using the following method: Two epoxy resin sheets with dimensions of 100 mm × 25 mm were taken as samples. 100 mg of the adhesive precursor solution from Examples 1-17 was applied between the two sample strips, with a bonding area of ​​25 mm × 12.5 mm. A pressure of 1000 Pa was applied, and the samples were hot-pressed and cured according to the corresponding reaction conditions of Examples 1-17. After cooling to room temperature, the adhesive strength was tested using a universal tensile testing machine. During the tensile test, the tensile rate was 5 mm / min. A complete test was performed when the two materials were completely separated. A total of 3 tests were conducted, and the average value was taken.

[0064] Two epoxy resin sheets measuring 100 mm × 25 mm were used as samples. The hot melt adhesive from Comparative Example 1 was heated to 80°C. Then, 100 mg of the heated hot melt adhesive was applied between the two sample strips, with a bonding area of ​​25 mm × 12.5 mm. A pressure of 1000 Pa was applied, and the bond was cured by hot pressing at 80°C for 10 min. After cooling to room temperature, the bond strength was tested using a universal tensile testing machine. During the tensile test, the tensile rate was 5 mm / min. A complete test was performed when the two materials were completely separated. A total of 3 tests were conducted, and the average value was taken.

[0065] The test results are shown in Table 1.

[0066] II. Adhesion performance test of in-situ spontaneously polymerizing adhesive on different substrates. The test method is as follows: Two 100 mm × 25 mm plates of different materials were taken as samples. 100 mg of the adhesive precursor solution from Example 1 was applied between the two sample strips. The bonding area was 25 mm × 12.5 mm. A pressure of 1000 Pa was applied, and the adhesive was cured by hot pressing at 80℃ for 8 h. The adhesive strength was tested using a universal tensile testing machine. During the tensile test, the tensile rate was 5 mm / min. A complete test was performed when the two materials were completely separated. A total of 3 tests were conducted, and the average value was taken. The test results are shown in Figure 3.

[0067] III. Reusability Test of In-situ Spontaneous Polymerization Adhesive: The test method is as follows: Take two epoxy resin board samples with dimensions of 100 mm × 25 mm. Apply 100 mg of the adhesive precursor solution from Example 1 between the two sample strips, with a bonding area of ​​25 mm × 12.5 mm. Apply a pressure of 1000 Pa and perform hot-press curing at 80℃ for 8 h. Use a universal tensile testing machine to test the bond strength. During the tensile test, the tensile rate is 5 mm / min. Tensile testing is performed until the two materials are completely separated, which constitutes a complete test. A total of 3 tests are conducted, and the average value is taken. Bond the two separated samples together and re-bond them after hot-press curing at 80℃ for 10 min. Use a universal tensile testing machine to test the bond strength. Repeat the above operation process 9 times. The test results are shown in Figure 4.

[0068] Table 1 According to the test results, (1) As can be seen from Examples 1 to 17, by using glycidyl ether and polyphenolic compounds as raw materials, the present invention can make the obtained in-situ spontaneously polymerized adhesive have excellent bonding performance (bonding strength of 1.43-7.62 MPa).

[0069] (2) As can be seen from Examples 1 to 2-8, by further optimizing the reaction temperature and time, the present invention can effectively adjust the bonding effect of the in-situ spontaneous polymerization adhesive, thereby obtaining a better technical effect of bonding strength.

[0070] (3) As can be seen from Examples 1 to 9-12, by adjusting the mass ratio of polyphenolic compounds to glycidol, the present invention can further improve the bonding strength of the obtained in-situ spontaneous polymerization adhesive, making its bonding effect better.

[0071] (4) As can be seen from Examples 1 to 13-17, by optimizing the types of polyphenolic compounds, the present invention can further improve the bonding strength of the obtained in-situ spontaneous polymerization adhesive, making its bonding effect better.

[0072] (5) By comparing Examples 1-17 with Comparative Example 1, it can be seen that Comparative Example 1 uses a conventional hot melt curing adhesive application process with a bonding strength of 1.52 MPa. It also requires additional heating to a molten state to obtain sufficient fluidity for coating, making the process more complex. This shows that the in-situ spontaneous polymerization adhesive provided by the present invention has superior bonding performance, simple application process, and thinner adhesive layer thickness, among other excellent comprehensive effects.

[0073] As shown in Figure 3, the in-situ spontaneously polymerizing adhesive provided in Example 1 has good adhesion to a variety of substrates such as EP, ABS, PEEK, PC, PE, PMMA, PET, PVC, PTFE, PP, PU, ​​ceramics, wood, glass, copper, iron, aluminum and titanium. This indicates that the spontaneously polymerizing adhesive provided by the present invention has spectral adhesion properties, especially excellent adhesion strength (≥5.9 MPa) to epoxy resin, ceramics, wood, glass, copper, iron, aluminum and titanium.

[0074] As shown in Figure 4, the self-polymerizing adhesive provided in Example 1 was repeatedly bonded 10 times, and its bonding strength remained basically unchanged. This indicates that the self-polymerizing adhesive provided by the present invention has excellent repeatability, and the bonding strength did not decrease significantly after being used 10 times.

[0075] In summary, the in-situ spontaneously polymerizing adhesive prepared by the present invention using glycidyl ether and polyphenolic compounds as raw materials has excellent bonding and reusability properties, and exhibits good bonding effects on a variety of substrates, meaning it has good spectral bonding performance and a wide range of applications.

[0076] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An in-situ spontaneously polymerizing adhesive, characterized in that, The raw materials for preparing the in-situ spontaneously polymerizing adhesive include glycidyl ether and polyphenolic compounds.

2. The in-situ spontaneously polymerizing adhesive according to claim 1, characterized in that, The mass ratio of the polyphenolic compound to glycidol is 1:(0.5-2.2).

3. The in-situ spontaneously polymerizing adhesive according to claim 1 or 2, characterized in that, The structural formula of the polyphenolic compound is shown in Formula I: Wherein, R1-R5 are each independently selected from hydrogen or hydroxyl groups, and R1-R5 include at least two hydroxyl groups; R6 is selected from any one of hydrogen, halogen, amino, hydroxyl, and C1-C70 organic groups; preferably, R6 is selected from hydrogen, halogen, amino, and -COOR. A -CH2=CH2-COOR B Any one of them; preferably, R A Selected from hydrogen or groups having any of the following structures: 、 In this context, R7, R8, and R9 are each independently selected from hydroxyl groups; s represents an integer from 1 to 4; m represents an integer from 1 to 4; n represents an integer from 1 to 5; M is selected from C1-C5 alkylene groups; R'1, R'2, R'3, and R'4 may be the same or different, and are each independently selected from hydrogen or groups having the following structures: ;R 10 Selected from hydroxyl groups; t represents an integer from 1 to 4; preferably, R B It is selected from hydrogen, substituted or unsubstituted C3-C7 cycloalkyl groups; the substituted substituent is selected from hydroxyl or carboxyl groups.

4. The in-situ spontaneously polymerizing adhesive according to any one of claims 1-3, characterized in that, The polyphenolic compounds include any one or a combination of at least two of the following: tannic acid, epigallocatechin gallate, gallic acid, chlorogenic acid, caffeic acid, or pyrogallic acid.

5. The in-situ spontaneously polymerizing adhesive according to any one of claims 1-4, characterized in that, The number-average molecular weight of the in-situ spontaneously polymerized adhesive is 1500-3000 g / mol.

6. A method for preparing an in-situ spontaneously polymerizing adhesive as described in any one of claims 1-5, characterized in that, The preparation method includes the following steps: mixing glycidyl ether and polyphenolic compounds and reacting them to obtain the in-situ spontaneously polymerized adhesive.

7. The method for preparing the in-situ spontaneously polymerizing adhesive according to claim 6, characterized in that, The mixing is carried out under stirring; preferably, the stirring time is 5-60 min; preferably, the reaction temperature is 60-120℃; preferably, the reaction time is 2-10 h; preferably, the reaction is followed by a cooling step.

8. The method for preparing the in-situ spontaneously polymerizing adhesive according to claim 6 or 7, characterized in that, The preparation method includes the following steps: after stirring glycidyl ether and polyphenolic compounds for 5-60 min to obtain an adhesive precursor solution, reacting it at 60-120℃ for 2-10 h, and cooling it to obtain the in-situ spontaneously polymerized adhesive.

9. A bonding method for an in-situ spontaneously polymerizing adhesive as described in any one of claims 1-5, characterized in that, The bonding method includes the following steps: mixing glycidyl ether and polyphenolic compounds and coating the mixture onto the surface of the substrate to be bonded, followed by curing to achieve bonding of the substrate; preferably, the curing temperature is 60-120℃; preferably, the curing time is 2-10 h.

10. An adhesive material, characterized in that, The adhesive material includes at least one of the in-situ spontaneously polymerizing adhesives as described in any one of claims 1-5, and in-situ spontaneously polymerizing adhesives prepared by the preparation method of the in-situ spontaneously polymerizing adhesives as described in any one of claims 6-8.

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