Recyclable mussel-imitating bio-based epoxy resin adhesive and preparation method thereof

Abstract

The invention discloses a recoverable mussel-imitating bio-based epoxy resin adhesive and a preparation method thereof, and is characterized in that the recoverable mussel-imitating bio-based epoxy resin adhesive is prepared according to the following steps: (1) reacting a bio-based epoxy monomer with an aldehyde compound containing a phenolic hydroxyl group under the action of a catalyst to obtain bio-based epoxy polyaldehyde; and (2) reacting the prepared bio-based epoxy polyaldehyde, diamine and a mussel-imitating aldehyde compound to obtain the mussel-imitating bio-based epoxy resin adhesive. The cross-linking density and the network rigidity are greatly improved, and the mussel-imitated aldehyde group compound contains a catechol structure, can form non-covalent acting forces such as hydrogen bonds, metal coordination, cations-pi and the like with various surfaces, and can be tightly adhered to the surfaces of different objects. The catechol structure is introduced into the dynamic covalent bond cross-linked bio-based epoxy resin, and the high-performance bio-based epoxy resin adhesive which is high in adhesion strength and can be plasticized and recycled is obtained.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, in particular to a recyclable mussel-like bio-based epoxy resin adhesive and a preparation method thereof. Background Art

[0002] The permanent cross-linking structure gives thermosetting epoxy resin excellent heat resistance, solvent resistance and mechanical properties. It can be used as coatings, adhesives, elastomers and composite materials and is widely used in construction materials, automobile manufacturing, electronics and electrical appliances, aerospace and other fields. However, thermosetting epoxy resin is facing challenges such as resource crisis and environmental pollution. On the one hand, traditional thermosetting epoxy resin relies on non-renewable fossil resources, and its widespread use will face resource shortage problems; on the other hand, due to its permanent cross-linking structure, thermosetting epoxy resin cannot be processed repeatedly, and it is difficult to degrade and recycle after use, which will cause serious waste of resources and environmental pollution. These problems have seriously hindered the sustainable development of thermosetting epoxy resin.

[0003] Using renewable resources such as vegetable oils, furan derivatives, lignin and its derivatives as raw materials instead of fossil resources to prepare bio-based epoxy resins can to some extent solve the dependence of thermosetting epoxy resins on fossil resources and improve the sustainability of thermosetting epoxy resins. However, bio-based thermosetting epoxy resins usually have a permanent cross-linked structure similar to that of traditional thermosetting epoxy resins, and are still difficult to degrade and recycle after use and disposal, which still leads to problems such as resource waste and environmental pollution. Introducing dynamic covalent bonds such as disulfide bonds, imine bonds, acetal bonds or borate bonds into thermosetting epoxy resins to prepare dynamic covalent cross-linked epoxy resins can solve the problems of non-reproducibility and difficulty in degradation and recycling. Dynamic covalent cross-linked polymers are also called covalent adaptive networks, which exhibit similar physical and chemical properties to traditional thermosetting polymers at room temperature. At high temperatures, dynamic covalent bonds can undergo exchange reactions to change the topological structure of the cross-linked network, thereby giving the covalent adaptive network stress relaxation and fluidity, which can be molded and processed like thermoplastic polymers. In addition, dynamic covalent bonds can be used to exchange small molecule compounds with appropriate functional groups, causing the cross-linked network to degrade and dissolve in the solvent. At the same time, the cross-linked network can be reconstructed by removing the solvent and small molecule compounds, thereby achieving the degradation and recycling of thermosetting epoxy resins. Therefore, introducing dynamic covalent bonds into bio-based epoxy resins to prepare bio-based epoxy covalent adaptive networks provides an effective method for the sustainable development of thermosetting epoxy resins.

[0004] The plasticity and degradability of bio-based epoxy covalent adaptive networks make them very suitable for use as easily processed recyclable bio-based adhesives. Taking advantage of its plasticity, it can be hot-pressed into adhesives of different shapes (films or sheets), which can be directly placed between the objects to be bonded, and can be bonded under heating and pressure. After the adhesive is discarded, it is placed in a small molecule solution that can react with the dynamic covalent bonds in the adhesive, and the adhesive can be degraded and recycled through exchange reactions. Therefore, using bio-based epoxy covalent adaptive networks as adhesives can greatly promote the sustainable development of adhesives. However, since the bio-based epoxy covalent adaptive network is a cross-linked polymer, during the bonding process with the object, the contact with the surface of the object is not as tight as the liquid precursor of the traditional thermosetting resin, resulting in a lower bonding strength of the bio-based epoxy covalent adaptive network. Summary of the invention

[0005] In view of the above technical problems, the purpose of the present invention is to provide a recyclable mussel-like bio-based epoxy resin adhesive and a preparation method thereof, so as to obtain a high-performance bio-based epoxy resin adhesive with high adhesion strength, plasticization and recyclability.

[0006] In order to achieve the above object, the technical solution of the present invention is: a method for preparing a recyclable mussel-like bio-based epoxy resin adhesive, characterized in that it is prepared according to the following steps:

[0007] (1) reacting a bio-based epoxy monomer with an aldehyde compound containing a phenolic hydroxyl group under the action of a catalyst to obtain a bio-based epoxy polyaldehyde;

[0008] (2) The prepared bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compound are reacted to obtain mussel-like bio-based epoxy resin adhesive.

[0009] In the above scheme: in step (1), the bio-based epoxy monomer and the aldehyde compound containing phenolic hydroxyl group are added according to the molar ratio of phenolic hydroxyl group to epoxy group of 0.5-1:1, and the amount of catalyst used is 0.01-1% of the total mass of the bio-based epoxy monomer and the aldehyde compound containing phenolic hydroxyl group.

[0010] In the above scheme: in step (1), the reaction temperature is 100-180°C.

[0011] In the above scheme: the bio-based epoxy monomer is any one of epoxy soybean oil, epoxy linseed oil and glycerol triglycidyl ether.

[0012] In the above scheme: the phenolic hydroxyl aldehyde compound is any one of vanillin, p-hydroxybenzaldehyde and m-hydroxybenzaldehyde.

[0013] In the above scheme: the catalyst is any one of 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole and 4-dimethylaminopyridine.

[0014] In the above scheme: bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compound are added according to the molar ratio of aldehyde group to amino group of 1:1, wherein the content of mussel-like aldehyde compound is 1%-10% of the mass of bio-based epoxy polyaldehyde, and the reaction temperature is 120-180°C.

[0015] In the above scheme: the diamine is any one of decanediamine, dimeramine, p-phenylenediamine, diphenylmethanediamine, isophoronediamine and dicyclohexylmethanediamine.

[0016] In the above scheme: the mussel-like aldehyde compound is 2,3-dihydroxybenzaldehyde or 3,4-dihydroxybenzaldehyde.

[0017] A recyclable mussel-like bio-based epoxy resin adhesive prepared by the preparation method of the recyclable mussel-like bio-based epoxy resin adhesive.

[0018] Beneficial effects: The present invention uses bio-based epoxy monomers and phenolic hydroxyl aldehyde compounds as raw materials to synthesize bio-based epoxy polyaldehyde precursors, which are then reacted with diamines and mussel-like aldehyde compounds to prepare mussel-like bio-based epoxy resin adhesives, which greatly improves the crosslinking density and network rigidity of the adhesive. Mussel-like aldehyde compounds contain catechol structures, which can form hydrogen bonds, metal coordination, cation-π and other non-covalent forces with a variety of surfaces, and can adhere tightly to the surfaces of different objects. The present invention introduces catechol structures into bio-based epoxy resins with dynamic covalent crosslinking to obtain high-performance bio-based epoxy resin adhesives with high adhesion strength, plasticizability, and recyclability. DETAILED DESCRIPTION

[0019] The present invention will be further described below by way of examples:

[0020] Example 1

[0021] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0022] p-Hydroxybenzaldehyde and epoxy linseed oil are added to a reaction bottle at a phenolic hydroxyl group / epoxy molar ratio of 0.5:1, and then a catalyst 1-methylimidazole is added at a total weight of 0.1% of the p-hydroxybenzaldehyde and epoxy linseed oil, and the reaction is carried out at 120°C for 6 hours to obtain a bio-based epoxy polyaldehyde, and then diphenylmethanediamine and 3,4-dihydroxybenzaldehyde at a weight of 1% of the bio-based epoxy polyaldehyde are added, and the bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compounds are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 180°C for 1 hour to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0023] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on its upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), its lap shear strength was measured to be 8.53MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0024] Example 2

[0025] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0026] Vanillin and epoxy soybean oil are added to a reaction bottle at a phenolic hydroxyl / epoxy molar ratio of 0.7:1, and then a catalyst 2-methylimidazole is added at a total weight of 0.5% of the total weight of the vanillin and the epoxy soybean oil, and the reaction is carried out at 100°C for 10 hours to obtain a bio-based epoxy polyaldehyde, and then decanediamine and 2,3-dihydroxybenzaldehyde at a weight of 3% of the weight of the bio-based epoxy polyaldehyde are added, and the bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compounds are added at a molar ratio of aldehyde to amino group of 1:1, and the reaction is carried out at 160°C for 3 hours to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0027] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 9.47MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0028] Example 3

[0029] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0030] m-Hydroxybenzaldehyde and glycerol triglycidyl ether are added to a reaction bottle in a phenolic hydroxyl group / epoxy molar ratio of 1:1, and then a catalyst 1,2-methylimidazole is added at a total weight of 0.01% of the total weight of m-hydroxybenzaldehyde and glycerol triglycidyl ether, and the reaction is carried out at 140°C for 4 hours to obtain a bio-based epoxy polyaldehyde, and then a dimeramine and 3,4-dihydroxybenzaldehyde at a weight of 10% of the weight of the bio-based epoxy polyaldehyde are added, and the bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compounds are added in a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 140°C for 6 hours to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0031] The adhesive was hot pressed at 160°C and 10MPa pressure for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 11.35MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0032] Example 4

[0033] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0034] p-Hydroxybenzaldehyde and epoxy soybean oil are added to a reaction bottle at a phenolic hydroxyl group / epoxy molar ratio of 0.7:1, and then a catalyst 4-methylaminopyridine is added at a total weight of 1% of p-hydroxybenzaldehyde and epoxy soybean oil, and the reaction is carried out at 160°C for 3 hours to obtain a bio-based epoxy polyaldehyde, and then dicyclohexylmethanediamine and 3,4-dihydroxybenzaldehyde at a weight of 5% of the bio-based epoxy polyaldehyde are added, and the bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compounds are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 120°C for 10 hours to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0035] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on its upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), its lap shear strength was measured to be 12.73MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0036] Example 5

[0037] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0038] m-Hydroxybenzaldehyde and epoxy linseed oil are added to a reaction bottle at a phenolic hydroxyl group / epoxy group molar ratio of 0.8:1, and then a catalyst 1,2-dimethylimidazole is added at a total weight of 0.8% of the m-hydroxybenzaldehyde and epoxy linseed oil, and the reaction is carried out at 180°C for 2 hours to obtain a bio-based epoxy polyaldehyde, and then isophorone diamine and 2,3-dihydroxybenzaldehyde at a weight of 7% of the bio-based epoxy polyaldehyde are added, and the bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compounds are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 150°C for 5 hours to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0039] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 9.85MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0040] Example 6

[0041] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0042] Vanillin and epoxy soybean oil are added to a reaction bottle at a phenolic hydroxyl group / epoxy group molar ratio of 0.6:1, and then a catalyst 1-dimethylimidazole is added at a total weight of 0.3% of the vanillin and epoxy soybean oil, and the reaction is carried out at 130°C for 6 hours to obtain a bio-based epoxy polyaldehyde. Then, p-phenylenediamine and 3,4-dihydroxybenzaldehyde at a weight of 5% of the bio-based epoxy polyaldehyde are added. The bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compound are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 160°C for 3 hours to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0043] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 9.96MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0044] Example 7

[0045] Preparation of recyclable mussel-like bio-based epoxy resin adhesive:

[0046] Vanillin and glycerol triglycidyl ether are added to a reaction bottle in a phenolic hydroxyl / epoxy molar ratio of 1:1, and then a catalyst 1,2-methylimidazole with a total mass of 0.05% of m-hydroxybenzaldehyde and glycerol triglycidyl ether is added, and the reaction is carried out at 120°C for 8 hours to obtain a bio-based epoxy polyaldehyde, and then dicyclohexylmethanediamine and 3,4-dihydroxybenzaldehyde with a mass of 5% of the bio-based epoxy polyaldehyde are added. The bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compounds are added in a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 160°C for 3 hours to obtain a recyclable mussel-like bio-based epoxy resin adhesive.

[0047] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 10.55MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0048] In addition, we prepared three types of recyclable bio-based epoxy resins without mussel-like structures as control samples and tested their adhesive properties.

[0049] Comparative Example 1

[0050] p-Hydroxybenzaldehyde and epoxy soybean oil are added to a reaction bottle at a phenolic hydroxyl group / epoxy molar ratio of 0.7:1, and then a catalyst 4-methylaminopyridine is added at a total weight of 1% of p-hydroxybenzaldehyde and epoxy soybean oil, and the reaction is carried out at 160°C for 3 hours to obtain a bio-based epoxy polyaldehyde, and then dicyclohexylmethanediamine is added, and the bio-based epoxy polyaldehyde and diamine are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 120°C for 10 hours to obtain a recyclable bio-based epoxy resin adhesive.

[0051] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 6.45MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0052] Comparative Example 2

[0053] m-Hydroxybenzaldehyde and epoxy linseed oil are added to a reaction bottle at a phenolic hydroxyl group / epoxy group molar ratio of 0.8:1, and then a catalyst 1,2-dimethylimidazole is added at a total weight of 0.8% of the m-hydroxybenzaldehyde and epoxy linseed oil, and the reaction is carried out at 180°C for 2 hours to obtain a bio-based epoxy polyaldehyde, and then isophorone diamine is added, and the bio-based epoxy polyaldehyde and diamine are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 150°C for 5 hours to obtain a recyclable bio-based epoxy resin adhesive.

[0054] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 5.44MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0055] Comparative Example 3

[0056] Vanillin and glycerol triglycidyl ether are added to a reaction bottle at a phenolic hydroxyl / epoxy molar ratio of 1:1, and then 0.05% of the total mass of m-hydroxybenzaldehyde and glycerol triglycidyl ether as a catalyst 1,2-methylimidazole are added, and the reaction is carried out at 120°C for 8 hours to obtain a bio-based epoxy polyaldehyde, and then dimeramine is added, and the bio-based epoxy polyaldehyde and diamine are added at a molar ratio of aldehyde group to amino group of 1:1, and the reaction is carried out at 160°C for 3 hours to obtain a recyclable bio-based epoxy resin adhesive.

[0057] The adhesive was hot-pressed at 160°C and 10MPa for 10 minutes by molding to obtain an adhesive film with a thickness of 0.25mm. The film was cut into a 15mm×10mm rectangular film and placed on one end of a stainless steel sample (50mm×10mm wide×2mm thick). Another stainless steel sample was overlapped on the upper end to form a lap joint. The lap joint was preheated at 160°C for 5 minutes on a hot press and hot-pressed at 1MPa for 5 minutes to complete the bonding. Then, according to the national standard (GB / T 7124-2008), the lap shear strength was measured to be 6.23MPa. The tested sample was placed in a 0.1mol / L ethylenediamine / DMF solution at 80°C for two hours to completely dissolve, achieving degradation and recycling.

[0058] By comparing the lap shear strength of the adhesives prepared in the comparative example and the example, it can be seen that the introduction of the imitation mussel structure greatly improves the adhesion strength of the adhesive.

[0059] The present invention is not limited to the above-mentioned embodiments. Those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a recyclable mussel-like bio-based epoxy resin adhesive, characterized in that: Prepare according to the following steps: (1) reacting a bio-based epoxy monomer with an aldehyde compound containing a phenolic hydroxyl group under the action of a catalyst to obtain a bio-based epoxy polyaldehyde; (2) The prepared bio-based epoxy polyaldehyde, diamine and mussel-like aldehyde compound are reacted to obtain mussel-like bio-based epoxy resin adhesive.

2. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to claim 1, characterized in that: In step (1), the bio-based epoxy monomer and the aldehyde compound containing phenolic hydroxyl groups are added according to a molar ratio of phenolic hydroxyl groups to epoxy groups of 0.5-1:1, and the amount of catalyst used is 0.01-1% of the total mass of the bio-based epoxy monomer and the aldehyde compound containing phenolic hydroxyl groups.

3. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to claim 2, characterized in that: In step (1), the reaction temperature is 100-180°C.

4. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to any one of claims 1 to 3, characterized in that: The bio-based epoxy monomer is any one of epoxidized soybean oil, epoxidized linseed oil and glycerol triglycidyl ether.

5. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to claim 4, characterized in that: The phenolic hydroxyl aldehyde compound is any one of vanillin, p-hydroxybenzaldehyde and m-hydroxybenzaldehyde.

6. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to claim 5, characterized in that: The catalyst is any one of 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole and 4-dimethylaminopyridine.

7. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to any one of claims 1 to 3, characterized in that: Bio-based epoxy polyaldehyde, diamine and imitation mussel aldehyde compound are added according to the molar ratio of aldehyde group to amino group of 1:1, wherein the content of imitation mussel aldehyde compound is 1%-10% of the mass of bio-based epoxy polyaldehyde, and the reaction temperature is 120-180℃.

8. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to claim 7, characterized in that: The diamine is any one of decanediamine, dimeramine, p-phenylenediamine, diphenylmethanediamine, isophoronediamine and dicyclohexylmethanediamine.

9. The method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to claim 8, characterized in that: The mussel-like aldehyde compound is 2,3-dihydroxybenzaldehyde or 3,4-dihydroxybenzaldehyde.

10. A recyclable mussel-like bio-based epoxy resin adhesive prepared by the method for preparing the recyclable mussel-like bio-based epoxy resin adhesive according to any one of claims 1 to 10.