Supramolecular adhesive based on alcohol-based solvent as well as preparation method and use method of supramolecular adhesive

Abstract

The invention provides a supramolecular adhesive based on an alcohol-based solvent as well as a preparation method and a use method of the supramolecular adhesive, and relates to the technical field of high polymer materials. The supramolecular adhesive based on the alcohol-based solvent provided by the invention comprises a polymer containing carboxylic acid groups, a polyvinylpyrrolidone-based polymer and the alcohol-based solvent. According to the invention, the polymer containing carboxylic acid groups and the polyvinylpyrrolidone-based polymer are optimally combined, so that the adhesive shows more excellent bonding capacity when being used for bonding substrates such as glass, ceramics and wood materials. And meanwhile, the adhesive body of the adhesive is transparent, so that the glued product is kept attractive, and the structural stability is ensured. In addition, the adhesive is endowed with a more environment-friendly application advantage due to the recoverable characteristic of the adhesive, and also meets the strict requirements of the current society on sustainable development.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a supramolecular adhesive based on an alcohol-based solvent and a preparation and use method thereof. Background Art

[0002] With the continuous development of modern production and life and science and technology, bonding technology plays an increasingly important role in various industries. Adhesives mostly use polymers as the main component. However, the existing adhesive products on the market have varying degrees of deficiencies in terms of bonding performance, transparency, environmental protection and recyclability. For example, phenolic resin or polyurethane glue, although it has strong bonding performance, is often accompanied by low environmental friendliness and stability problems under high temperature operation; water-soluble adhesives such as polyacrylic acid and polyvinyl alcohol can provide better transparency and recyclability, but in terms of consistency and bonding strength, it is difficult to compete with high-performance adhesives on the market. Especially in the bonding applications of glass, ceramics and wood materials, these adhesives often cannot meet the dual requirements of high strength and aesthetics, causing users to face troubles when choosing bonding materials. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a supramolecular adhesive based on an alcohol-based solvent and a preparation and use method thereof. The supramolecular adhesive provided by the present invention has excellent adhesion and is both beautiful, environmentally friendly and recyclable.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a supramolecular adhesive based on an alcohol-based solvent, comprising a polymer containing a carboxylic acid group, a polyvinyl pyrrolidone-based polymer and an alcohol-based solvent;

[0006] The polymer containing carboxylic acid groups includes at least one of the compounds shown in Formula I to Formula IV:

[0007]

[0008] In Formula I, R 1 is H or Na, R in Formula II 2 is H or alkyl, R 3 is an alkyl group; in formulas Ⅰ to Ⅳ, n / (m+n)=20 to 100%;

[0009] The polyvinyl pyrrolidone-based polymer comprises at least one of the compounds represented by formula V:

[0010]

[0011] In Formula V, R 4 for Wherein ~~ represents the connection site; in formula V, x / (x+y)=20~100%;

[0012] The mass of the polymer containing carboxylic acid groups is 30-70% of the total mass of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer.

[0013] Preferably, the mass of the polymer containing carboxylic acid groups is 40-55% of the total mass of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer.

[0014] Preferably, the alcohol-based solvent is an alcohol solvent or a mixed solvent of an alcohol solvent and water.

[0015] Preferably, the total concentration of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer in the supramolecular adhesive is 45 to 120 mg / mL.

[0016] Preferably, the supramolecular adhesive further comprises a filler.

[0017] Preferably, the filler comprises one or more of tannic acid, carbon dots, chitosan, cellulose, lignin and lignin sulfonic acid.

[0018] Preferably, the carbon dots include one or more of metronidazole carbon dots, ethylenediamine citrate carbon dots, polyacrylic acid carbon dots and polyvinyl alcohol carbon dots.

[0019] Preferably, the mass of the filler is 0 to 30% of the total mass of the polymer containing carboxylic acid groups, the polyvinyl pyrrolidone-based polymer and the filler, and is not 0.

[0020] The present invention provides a method for preparing the supramolecular adhesive described in the above technical solution, comprising the following steps:

[0021] The polymer containing carboxylic acid groups, polyvinyl pyrrolidone-based polymer and alcohol-based solvent are mixed to obtain the supramolecular adhesive.

[0022] The present invention provides a method for using the supramolecular adhesive described in the above technical solution, comprising the following steps:

[0023] Directly bonding the supramolecular adhesive to the substrate to be bonded;

[0024] Alternatively, the solvent of the supramolecular adhesive is evaporated to obtain a solid adhesive film; the solid adhesive film is wetted with water and then bonded to the substrate to be bonded.

[0025] The present invention provides a supramolecular adhesive based on an alcohol-based solvent, comprising a polymer containing a carboxylic acid group, a polyvinyl pyrrolidone-based polymer and an alcohol-based solvent, wherein the mass of the polymer containing a carboxylic acid group is 30 to 70% of the total mass of the polymer containing a carboxylic acid group and the polyvinyl pyrrolidone-based polymer. The supramolecular adhesive provided by the present invention has a large number of hydrogen bonds with a high density inside, and reinforced particles are formed in situ inside the material (the conformational difference between the polymer containing a carboxylic acid group and the polyvinyl pyrrolidone-based polymer in the solvent, wherein the more curled particles can form particles, i.e., microphase separation), and the two work together to make the adhesive glue liquid have a high strength, and have a high adhesion to substrates such as glass, ceramics and wood materials; and due to the presence of a large number of hydrogen bonds, when the solvent evaporates, the solid adhesive film formed is activated by water, and there are many hydrogen bonding sites, and it still has a high adhesion to the substrate. In addition, the supramolecular adhesive has a transparent colloid state, which will not affect the appearance of the bonded object, and the effect after bonding is beautiful and the structure is stable. The supramolecular adhesive provided by the present invention has excellent bonding ability and can be used both wet and dry. Its bonding ability on glass materials is significantly better than other adhesive products currently available on the market. It also has excellent bonding ability on ceramics and wood. It also has the characteristics of being beautiful, environmentally friendly and recyclable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The bonding effect of the adhesive of Example 1 on different substrates;

[0027] Figure 2 The bonding effect of the adhesive of Example 2 on different substrates;

[0028] Figure 3 The bonding effect of the adhesive of Example 3 on different substrates;

[0029] Figure 4 The bonding effect of the adhesive of Example 4 on different substrates;

[0030] Figure 5 The bonding effect of the adhesive of Example 5 on different substrates;

[0031] Figure 6 is a transmission electron microscope image of the solid film in Example 1;

[0032] Figure 7 The bonding effect of the adhesive of Example 6 on different substrates;

[0033] Figure 8 This is the thermogravimetric analysis (TGA) curve of the solid film in Example 1. DETAILED DESCRIPTION

[0034] The present invention provides a supramolecular adhesive based on an alcohol-based solvent, comprising a polymer containing a carboxylic acid group, a polyvinyl pyrrolidone-based polymer and an alcohol-based solvent;

[0035] The polymer containing carboxylic acid groups includes at least one of the compounds shown in Formula I to Formula IV:

[0036]

[0037]

[0038] In Formula I, R 1 is H or Na, R in Formula II 2 is H or alkyl, R 3 is an alkyl group; in formulas Ⅰ to Ⅳ, n / (m+n)=20 to 100%;

[0039] The polyvinyl pyrrolidone-based polymer comprises at least one of the compounds represented by formula V:

[0040]

[0041] In Formula V, R 4 for Wherein ~~ represents the connection site; in formula V, x / (x+y)=20~100%;

[0042] The mass of the polymer containing carboxylic acid groups is 30-70% of the total mass of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer.

[0043] The supramolecular adhesive provided by the present invention comprises a polymer containing a carboxylic acid group. In the present invention, the polymer containing a carboxylic acid group comprises at least one of the compounds represented by formula I to formula IV; in the present invention, when R 2 When R in Formula II is 3When it is an alkyl group, the alkyl group is preferably a saturated straight-chain alkyl group, more preferably a methyl group or an ethyl group. In the present invention, in Formulas I to IV, n / (m+n)=20-100%, that is, the molar fraction of the acrylic acid unit is 20-100%; when in Formulas I to IV, n / (m+n)=100%, the polymer containing a carboxylic acid group is polyacrylic acid; when n / (m+n) is not 100%, the polymer containing a carboxylic acid group having the structure shown in Formula I is called poly(acrylic acid-co-acrylamide), the polymer containing a carboxylic acid group having the structure shown in Formula II is called poly(acrylic acid-co-acrylate), the polymer containing a carboxylic acid group having the structure shown in Formula III is called poly(acrylic acid-co-ethylene oxide), and the polymer containing a carboxylic acid group having the structure shown in Formula IV is called poly(acrylic acid-co-vinyl alcohol). In the present invention, the weight average molecular weight of the polymer containing a carboxylic acid group is preferably 100,000 to 1,000,000. The present invention has no particular requirements on the source of the polymer containing carboxylic acid groups, and it can be prepared using commercial products well known in the art or using preparation methods well known to those skilled in the art, for example, poly(acrylic acid-co-acrylate) can be prepared by free radical polymerization of acrylic acid and acrylate monomers.

[0044] The supramolecular adhesive provided by the present invention includes a polyvinyl pyrrolidone-based polymer. In the present invention, the polyvinyl pyrrolidone-based polymer includes at least one of the compounds shown in formula V. In the present invention, in formula V, x / (x+y)=20-100%, that is, the molar fraction of the vinyl pyrrolidone unit is 20-100%; when x / (x+y)=100% in formula V, the polyvinyl pyrrolidone-based polymer is polyvinyl pyrrolidone, and the structure is shown in formula V-1; when x / (x+y) is not 100%, the structure of the polyvinyl pyrrolidone-based polymer is specifically shown in formulas V-2 to V-4, and the chemical names are poly(vinyl pyrrolidone-co-vinyl acetate), poly(vinyl pyrrolidone-co-styrene), poly[(2-methylaminoethyl methacrylate diethyl sulfate)] -co(1-vinyl-2-pyrrolidone)]. In the present invention, the weight average molecular weight of the polyvinyl pyrrolidone-based polymer is preferably 40,000 to 1,000,000. The present invention has no particular requirements on the source of the polyvinyl pyrrolidone-based polymer, and it can be prepared by using commercial products well known in the art or by a preparation method well known to those skilled in the art, such as poly(vinyl pyrrolidone-co-vinyl acetate) can be prepared by free radical polymerization of vinyl pyrrolidone and vinyl acetate monomers, and poly(vinyl pyrrolidone-co-styrene) can be prepared by free radical polymerization of vinyl pyrrolidone and styrene monomers.

[0045]

[0046] The supramolecular adhesive provided by the present invention comprises an alcohol-based solvent. In the present invention, the alcohol-based solvent is preferably an alcohol solvent or a mixed solvent of an alcohol solvent and water, the alcohol solvent is preferably ethanol, and the present invention has no special requirements on the ratio of the alcohol solvent to water in the mixed solvent.

[0047] In the present invention, the mass of the polymer containing carboxylic acid groups is 30-70% of the total mass of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer, and can be 30%, 40%, 45%, 50%, 54%, 54.5%, 55%, 60% or 70%; when the proportion of the polymer containing carboxylic acid groups is too high, the amount of hydrogen bonds formed inside the adhesive is small, and the microphase separation structure cannot have the best formation state (when there are too many polymers containing carboxylic acid groups, the microphase separation structures formed are uneven in size and small in number), resulting in a decrease in the strength of the adhesive and inability to perform effective bonding. In the present invention, the total concentration of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer in the supramolecular adhesive is preferably 45-120 mg / mL, and can be 45, 50, 60, 70, 80, 90, 100, 120 mg / mL.

[0048] In the present invention, a large number of hydrogen bonds exist between the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer, and the difference in their conformations in the solvent results in an in-situ formed microphase separation structure inside, which makes the material itself have high strength.

[0049] The supramolecular adhesive provided by the present invention also preferably includes a filler. In the present invention, the filler preferably includes one or more of tannic acid, carbon dots, chitosan, cellulose, lignin and lignin sulfonic acid; the carbon dots preferably include one or more of metronidazole carbon dots, ethylenediamine citrate carbon dots, polyacrylic acid carbon dots and polyvinyl alcohol carbon dots. The present invention has no special requirements on the source of the carbon dots, and the carbon dots can be prepared using commercially available products or by a preparation method well known to those skilled in the art.

[0050] In an embodiment of the present invention, the metronidazole carbon dots are preferably prepared by the following method: subjecting a metronidazole aqueous solution to a hydrothermal reaction, filtering the resulting reaction solution to obtain a filtrate; subjecting the filtrate to a freeze-drying treatment to obtain a metronidazole carbon dot. In the present invention, the concentration of the metronidazole aqueous solution is preferably 0.1 mmol / mL; the temperature of the hydrothermal reaction is preferably 200°C, and the time is preferably 8 hours. In the present invention, the reaction solution is preferably cooled and then filtered. The present invention has no special requirements for the conditions of the freeze-drying treatment, and the freeze-drying conditions familiar to those skilled in the art can be used. In the present invention, the metronidazole carbon dots can be configured as an aqueous solution of the desired concentration for use.

[0051] In an embodiment of the present invention, the citric acid ethylenediamine carbon dots are preferably prepared by the following method: citric acid, ethylenediamine and water are mixed for hydrothermal reaction, the resulting reaction solution is filtered to obtain a filtrate; the filtrate is freeze-dried to obtain the citric acid ethylenediamine carbon dots. In the present invention, the water is preferably deionized water, the dosage ratio of the citric acid, ethylenediamine and water is preferably 1g:300μL:10mL; the temperature of the hydrothermal reaction is preferably 200°C, and the time is preferably 5 to 8h.

[0052] In an embodiment of the present invention, the polyacrylic acid carbon dots are preferably prepared by the following method: mixing polyacrylic acid (PAA), ethylenediamine and water for hydrothermal reaction, filtering the resulting reaction solution to obtain a filtrate; and freeze-drying the filtrate to obtain the polyacrylic acid carbon dots. In the present invention, the water is preferably deionized water, and the amount ratio of the polyacrylic acid, ethylenediamine and water is preferably 70 mg: 170 μL: 10 mL; the temperature of the hydrothermal reaction is preferably 200 ° C, and the time is preferably 5 to 8 hours.

[0053] In an embodiment of the present invention, the polyvinyl alcohol carbon dots are preferably prepared by the following method: subjecting a polyvinyl alcohol aqueous solution to a hydrothermal reaction, filtering the resulting reaction solution to obtain a filtrate; and freeze-drying the filtrate to obtain the polyvinyl alcohol carbon dots. In the present invention, the concentration of the polyvinyl alcohol aqueous solution is preferably 0.4 to 50 mg / mL, the temperature of the hydrothermal reaction is preferably 160 to 340°C, and the time is preferably 0.1 to 10 hours.

[0054] In the present invention, the mass of the filler is preferably 0-30% of the total mass of the polymer containing carboxylic acid groups, the polyvinyl pyrrolidone-based polymer and the filler, and is not 0, preferably 3-20%, and more preferably 5-15%.

[0055] The supramolecular adhesive provided by the present invention is a high-strength recyclable polymer composite adhesive with excellent bonding strength, durability and adaptability. It has good adaptability and durability in various substrates (such as glass, ceramics, wood materials, iron, stainless steel, PMMA) and temperature resistance, moisture resistance (such as when the humidity is very high in summer, it does not affect the use of adhesives). In addition, the supramolecular adhesive provided by the present invention is not only significantly superior to other adhesive products in the existing market in terms of adhesion, but also can show unique advantages in terms of beauty (its colloid is transparent and does not affect the appearance of the bonded object) and environmental protection. In addition, the supramolecular adhesive has good recyclability, such as soaking in water or weak alkaline water, the adhesive film formed by the adhesive can be recycled after falling off from the substrate (the composition of the solution after dissolution does not change), and the recyclable characteristics of the adhesive not only give it a more environmentally friendly application advantage, but also meet the strict requirements of today's society for sustainable development. The adhesive provided by the present invention has excellent comprehensive performance and a wide range of application prospects.

[0056] The present invention provides a method for preparing the supramolecular adhesive described in the above technical solution, comprising the following steps:

[0057] The polymer containing carboxylic acid groups, polyvinyl pyrrolidone-based polymer and alcohol-based solvent are mixed to obtain the supramolecular adhesive.

[0058] In the present invention, the mixing method is preferably:

[0059] dissolving the polymer containing carboxylic acid groups in a portion of an alcohol-based solvent to obtain a polymer solution containing carboxylic acid groups;

[0060] dissolving the polyvinyl pyrrolidone-based polymer in the remaining alcohol-based solvent to obtain a polyvinyl pyrrolidone-based polymer solution;

[0061] The carboxylic acid group-containing polymer solution is mixed with a polyvinyl pyrrolidone-based polymer solution to obtain the supramolecular adhesive.

[0062] The present invention has no particular requirement on the ratio of the partial alcohol-based solvent to the remaining alcohol-based solvent. In the present invention, the supramolecular adhesive is in a viscous state.

[0063] In the present invention, when the supramolecular adhesive includes a filler, the filler can be added to the polymer solution containing a carboxylic acid group or to the polyvinyl pyrrolidone-based polymer solution.

[0064] The preparation method provided by the invention has simple steps, is easy to operate, and has good environmental protection and economic benefits.

[0065] The present invention provides a method for using the supramolecular adhesive described in the above technical solution, comprising the following steps:

[0066] Directly bonding the supramolecular adhesive to the substrate to be bonded;

[0067] Alternatively, the solvent of the supramolecular adhesive is evaporated to obtain a solid adhesive film; the solid adhesive film is wetted with water and then bonded to the substrate to be bonded.

[0068] In the present invention, the total concentration of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer in the supramolecular adhesive used to obtain the solid adhesive film is further preferably 45 to 55 mg / mL.

[0069] The supramolecular adhesive provided by the present invention can be used directly in the form of glue liquid, and has excellent bonding strength to substrates such as glass, ceramics, wood materials, iron, stainless steel, PMMA, etc.; and after the solvent evaporates, the solid adhesive film formed is excited by water, and its hydrogen bonds are opened, and it will also produce high adhesion with the substrate. The supramolecular adhesive provided by the present invention can be used both dry and wet, and has strong adaptability. In an embodiment of the present invention, the supramolecular adhesive is poured into a mold, and the solvent is naturally evaporated at room temperature to form a solid adhesive film. The present invention has no special requirements for the method of wetting the solid adhesive film with water.

[0070] In order to further illustrate the present invention, the supramolecular adhesive based on alcohol-based solvents and the preparation and use methods thereof provided by the present invention are described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0071] Example 1

[0072] A supramolecular adhesive, the preparation method is as follows:

[0073] (1) Solution preparation

[0074] Prepare polyacrylic acid (PAA, weight average molecular weight 450,000) and polyvinylpyrrolidone (PVPON, weight average molecular weight 360,000) into 45 mg / mL ethanol solutions respectively. Ensure that the polymers used are high-purity finished products and are purchased directly from reputable suppliers (such as Sigma).

[0075] (2) Mixing

[0076] The PAA solution prepared in (1) and the PVPON solution are uniformly mixed in a container in a certain ratio to form a viscous glue solution, wherein the mass ratio of polyacrylic acid to polyvinyl pyrrolidone is 1.2:1.

[0077] Film formation and softening:

[0078] (a) Film formation

[0079] Pour the above glue solution into a mold of appropriate shape to form a film, and let the solvent evaporate naturally at room temperature to form a solid glue film.

[0080] Figure 6 is a transmission electron microscope (TEM) image of the formed solid film, such as Figure 6 As shown, there is a microphase separation structure inside the adhesive, the size of the microphase structure is 45 to 60 nm, and the microphase structure is relatively uniform.

[0081] The prepared solid glue material has good plasticity (can be softened by water and arbitrarily shaped) and is suitable for large-scale production. Figure 8This is the thermogravimetric analysis (TGA) curve of the solid film, from which it can be seen that the product has good temperature resistance.

[0082] (b) Softening and application

[0083] Soak the solid adhesive film in water and wait for it to soften before using it for bonding. This adhesive is particularly suitable for bonding glass materials and has excellent bonding properties. The following is an evaluation of its bonding properties.

[0084] Adhesion performance:

[0085] For glass adhesion, the strength can be evaluated by standard tensile test. The film thickness is about 200nm. The results show that the bonding strength exceeds 23MPa, and no damage is found in the bonding area, indicating excellent performance under the strength requirements. Figure 1 The specific bonding strength data are as follows:

[0086] Glass: 24.4MPa;

[0087] Ceramic: 12.8MPa;

[0088] Wood: 12.3MPa;

[0089] Iron: 5.5MPa;

[0090] Stainless steel: 6.4MPa;

[0091] PMMA: 4.08MPa.

[0092] Display Features:

[0093] The glue part after bonding is transparent and colorless, and the bonding thickness is only 200nm, ensuring the beauty and optical properties of the final product.

[0094] Example 2

[0095] A supramolecular adhesive, the preparation method is as follows:

[0096] Poly(acrylic acid-co-acrylamide) (sigma, weight average molecular weight 520,000, product number 511471) and polyvinyl pyrrolidone (PVPON, weight average molecular weight 360,000) were prepared into 50 mg / mL ethanol solutions respectively; the two solutions were mixed to obtain a glue solution in a viscous state; the mass ratio of poly(acrylic acid-co-acrylamide) to polyvinyl pyrrolidone was 1:1.

[0097] The adhesive solution obtained above was used to bond substrates. The test results of its adhesive performance on different substrates are as follows: Figure 2The specific data are as follows:

[0098] Glass: 12.8MPa;

[0099] Ceramics: 9.7MPa;

[0100] Wood: 11.5MPa;

[0101] Iron: 6.3MPa;

[0102] Stainless steel: 6.9MPa;

[0103] PMMA: 1.2MPa.

[0104] Example 3

[0105] Poly(acrylic acid-co-acrylamide) (sigma, weight average molecular weight 520,000, product number 511471) and poly(vinyl pyrrolidone-co-styrene) (Sigma, product number 434450) were prepared into 45 mg / mL ethanol solutions. Tannic acid was added to the ethanol solution of poly(acrylic acid-co-acrylamide) with a mass fraction of 5% (relative to the total mass of poly(acrylic acid-co-acrylamide), poly(vinyl pyrrolidone-co-styrene) and tannic acid). Subsequently, the mixed solution with tannic acid added was mixed with the ethanol solution of poly(vinyl pyrrolidone-co-styrene) to form a viscous glue; wherein the mass ratio of poly(acrylic acid-co-acrylamide) to poly(vinyl pyrrolidone-co-styrene) was 1:1.5.

[0106] The glue obtained above was cast to prepare solid glue, and the solid glue film was soaked in water. After it softened, it was bonded to the substrate. The results of its adhesion on different substrates are as follows. Figure 3 The specific data are as follows:

[0107] Glass: 18.5MPa;

[0108] Ceramics: 8.7MPa;

[0109] Wood: 16.8MPa;

[0110] Iron: 4.3MPa;

[0111] Stainless steel: 5.2MPa;

[0112] PMMA: 4.2MPa.

[0113] Example 4

[0114] Poly(acrylic acid-co-methyl acrylate) (cas number: 25302-81-2) and poly(1-vinylpyrrolidone-co-styrene) (purchased from Sigma, product number 434450) were prepared into 45 mg / mL ethanol solutions respectively; the two were mixed to obtain a viscous glue solution, in which the mass ratio of poly(acrylic acid-co-acrylate) to poly(1-vinylpyrrolidone-co-styrene) was 1:1.2.

[0115] The glue solution obtained above was cast to obtain solid glue, and the solid glue film was soaked in water. After it softened, it was bonded to the substrate. The adhesion on different substrates was tested. The results are as follows Figure 4 The specific data are as follows:

[0116] Glass: 16.4MPa;

[0117] Ceramics: 9.4MPa;

[0118] Wood: 16.6MPa;

[0119] Iron: 3.2MPa;

[0120] Stainless steel: 2.2MPa;

[0121] PMMA: 1.5MPa.

[0122] Example 5

[0123] Poly(acrylic acid-co-methyl acrylate) (cas number: 25302-81-2) and poly(vinyl pyrrolidone-co-vinyl acetate) (sigma, weight average molecular weight 50,000, product number 190845) were prepared into 55 mg / mL ethanol solutions. Chitosan was added to the ethanol solution of poly(acrylic acid-co-acrylate) at a mass fraction of 7% (relative to the total mass of poly(acrylic acid-co-acrylate), poly(vinyl pyrrolidone-co-vinyl acetate) and chitosan), and the obtained mixed solution of poly(acrylic acid-co-acrylate) and chitosan was mixed with the ethanol solution of poly(vinyl pyrrolidone-co-vinyl acetate) to form a viscous glue solution, wherein the mass ratio of poly(acrylic acid-co-acrylate) to poly(vinyl pyrrolidone-co-vinyl acetate) was 1:1.

[0124] The glue solution obtained above was cast to prepare solid glue, and the solid glue film was soaked in water and bonded to the substrate after it softened. The adhesion test results are as follows: Figure 5 The specific data are as follows:

[0125] Glass: 17.9MPa;

[0126] Ceramics: 10.4MPa;

[0127] Wood: 10.8MPa;

[0128] Iron: 2.1MPa;

[0129] Stainless steel: 1.8MPa;

[0130] PMMA: 0.9MPa.

[0131] The adhesive composed of polyacrylic acid and polyvinyl alcohol is widely used in the prior art. According to experimental data, when the concentration of the adhesive is 20mg / mL, it shows good bonding performance. However, when its concentration is reduced to 10mg / mL, the viscosity of the adhesive is significantly reduced, thereby causing its bonding ability to significantly decrease. In addition, when the concentration is 15mg / mL, the viscosity and bonding ability of the adhesive are both between 10mg / mL and 20mg / mL, reflecting the correlation between concentration and bonding performance. The present invention improves the performance of the adhesive by adjusting the formula, optimizing the combination of polymers, and especially in terms of bonding force and operational stability. The adhesive has good bonding performance at high concentration or low concentration, overcoming the limitations of the prior art.

[0132] Example 6

[0133] A supramolecular adhesive, the preparation method is as follows:

[0134] Preparation of metronidazole carbon dots: 20 mL of a 0.1 mmol / mL metronidazole aqueous solution was prepared and placed in a reactor. The temperature was set to 200° C. and the reaction time was 8 hours. After the reaction was completed, the reaction vessel was taken out and cooled. The obtained solution was filtered and freeze-dried to obtain metronidazole carbon dots.

[0135] Preparation of adhesive: Poly(acrylic acid-co-acrylamide) (purchased from Sigma, weight average molecular weight 520,000, product number 511471) and polyvinyl pyrrolidone (PVPON, weight average molecular weight 360,000) were prepared into 50 mg / mL ethanol solutions respectively; metronidazole carbon dots were added to the ethanol solution of poly(acrylic acid-co-acrylamide) at a mass fraction of 15% (relative to the total mass of poly(acrylic acid-co-acrylamide), polyvinyl pyrrolidone and metronidazole carbon dots), and the two solutions were mixed to obtain a glue solution in a viscous state; the mass ratio of poly(acrylic acid-co-acrylamide) to polyvinyl pyrrolidone was 1:1.

[0136] The glue solution obtained above is cast to form a solid glue, and the solid glue film is soaked in water. After it softens, it is bonded to the substrate. The bonding performance test results of the solid glue on different substrates are as follows: Figure 7The specific data are as follows:

[0137] Glass: 21.8MPa;

[0138] Ceramics: 10.3MPa;

[0139] Wood: 9.5MPa;

[0140] Iron: 6.5MPa;

[0141] Stainless steel: 7.9MPa;

[0142] PMMA: 2.3MPa.

[0143] Carbon dots were introduced as fillers to improve the performance of the adhesive. Experiments show that the amount of carbon dots introduced has a significant effect on the performance of the adhesive: when the mass fraction of carbon dots is less than 3%, there is no significant change in the adhesion and concentration of the adhesive, indicating that the addition of low-concentration fillers failed to effectively improve the adhesive performance. When the amount of carbon dots introduced increased to 5%, the viscosity of the adhesive increased significantly, and the bonding ability also improved, indicating that at an appropriate filler addition, the filler can promote the overall performance of the adhesive. However, when the concentration of the adhesive is too high, the viscosity of the adhesive solution will decrease again, and the bonding ability will also decrease. This shows that in the formulation design of the adhesive, maintaining an appropriate concentration and filler ratio is one of the key factors to improve the bonding performance.

[0144] Example 7

[0145] A supramolecular adhesive, the preparation method is as follows:

[0146] Preparation of adhesive: Polyacrylic acid (purchased from Sigma, weight average molecular weight 450,000) and poly [(2-dimethylaminoethyl methacrylate diethyl sulfate-co (1-vinyl-2-pyrrolidone)] (Sigma, product number 190888) were prepared into 45 mg / mL ethanol solutions respectively; the two were mixed to obtain a viscous adhesive solution, in which the mass ratio of polyacrylic acid to poly [(2-dimethylaminoethyl methacrylate diethyl sulfate-co (1-vinyl-2-pyrrolidone)] was 1:1.

[0147] The adhesive prepared in Example 7 also has good bonding strength to substrates such as glass, ceramics, wood materials, iron, stainless steel, and PMMA.

[0148] Example 8

[0149] Polyacrylic acid (sigma, weight average molecular weight 450,000) and polyvinyl pyrrolidone (PVPON, weight average molecular weight 360,000) were prepared into 100 mg / mL ethanol solutions respectively; the two solutions were mixed to obtain a glue solution in a viscous state; the mass ratio of polyacrylic acid to polyvinyl pyrrolidone was 1:1. The obtained glue solution has good bonding ability to substrates such as glass, wood, iron and stainless steel.

[0150] The present invention solves the problem of insufficient adhesion faced by adhesives in the prior art by optimizing the combination of polyacrylic acid and polyvinyl pyrrolidone and further introducing a reasonably designed filler, thereby showing a more superior performance.

[0151] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A supramolecular adhesive based on an alcohol-based solvent, characterized in that: including a polymer containing a carboxylic acid group, a polyvinyl pyrrolidone-based polymer, and an alcohol-based solvent; The polymer containing a carboxylic acid group comprises at least one of the compounds represented by Formula I to Formula IV: In formula I, R1 is H or Na, in formula II, R2 is H or alkyl, and R3 is alkyl; in formulas I to IV, n / (m+n)=20 to 100%; The polyvinyl pyrrolidone-based polymer comprises at least one of the compounds represented by formula V: In Formula V, R4 is Wherein ~~ represents the connection site; in formula V, x / (x+y)=20~100%; The mass of the polymer containing carboxylic acid groups is 30-70% of the total mass of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer.

2. The supramolecular adhesive according to claim 1, characterized in that The mass of the polymer containing carboxylic acid groups is 40-55% of the total mass of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer.

3. The supramolecular adhesive according to claim 1, characterized in that The alcohol-based solvent is an alcohol solvent or a mixed solvent of an alcohol solvent and water.

4. The supramolecular adhesive according to any one of claims 1 to 3, characterized in that: The total concentration of the polymer containing carboxylic acid groups and the polyvinyl pyrrolidone-based polymer in the supramolecular adhesive is 45-120 mg / mL.

5. The supramolecular adhesive according to claim 1, characterized in that: Also includes fillers.

6. The supramolecular adhesive according to claim 5, characterized in that The filler includes one or more of tannic acid, carbon dots, chitosan, cellulose, lignin and lignin sulfonic acid.

7. The supramolecular adhesive according to claim 6, characterized in that: The carbon dots include one or more of metronidazole carbon dots, ethylenediamine citrate carbon dots, polyacrylic acid carbon dots and polyvinyl alcohol carbon dots.

8. The supramolecular adhesive according to claim 5, 6 or 7, characterized in that: The mass of the filler is 0 to 30% of the total mass of the polymer containing carboxylic acid groups, the polyvinyl pyrrolidone-based polymer and the filler, and is not 0.

9. The method for preparing the supramolecular adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polymer containing carboxylic acid groups, polyvinyl pyrrolidone-based polymer and alcohol-based solvent are mixed to obtain the supramolecular adhesive.

10. The method for using the supramolecular adhesive according to any one of claims 1 to 8, characterized in that: The following steps are involved: Directly bonding the supramolecular adhesive to the substrate to be bonded; Alternatively, the solvent of the supramolecular adhesive is evaporated to obtain a solid adhesive film; the solid adhesive film is wetted with water and then bonded to the substrate to be bonded.

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