Preparation method and application of high-performance plant protein adhesive with bicontinuous network structure

Abstract

This invention discloses a method for preparing a high-performance plant protein adhesive with a covalent-coordination bicontinuous network structure and its application. The adhesive is prepared from the following raw materials in parts by weight: 20-35 parts plant protein meal, 65-75 parts dispersion medium, 1.5-6 parts chemical covalent crosslinking agent, 1-5 parts flame retardant component, and 0.1-3 parts dynamic coordination reinforcing component. The chemical covalent crosslinking agent is used to construct a stable covalent network framework, while the dynamic coordination reinforcing component forms a coordination network through reversible coordination between metal ions and ligands. This network interpenetrates with the covalent network to form a stable covalent-coordination bicontinuous network structure, enabling stress dissipation and imparting high strength and toughness to the adhesive. The flame retardant component effectively inhibits heat release and smoke generation, providing flame retardant properties, while the phenolic substances in the dynamic coordination component synergistically exert an anti-mildew effect. The preparation method of this invention is simple, environmentally friendly, and the resulting adhesive can be widely used in the preparation of plywood, showing promising prospects for industrial application.

Description

Technical Field

[0001] This invention relates to the field of bio-based adhesives and engineered wood products manufacturing technology, specifically to a high-performance plant protein adhesive with a covalent-coordination dual network structure and its preparation method. Background Technology

[0002] With the rapid development of green and environmentally friendly building materials, bio-based plant protein adhesives have received widespread attention in the wood-based panel industry due to their advantages such as renewable sources, no formaldehyde release, and environmental friendliness. Plant protein molecules contain abundant active groups such as amino, hydroxyl, and carboxyl groups, which can undergo cross-linking reactions to form a three-dimensional network structure, thereby achieving bonding between wood particles and showing the potential to replace traditional urea-formaldehyde resin adhesives.

[0003] However, plant protein adhesives are hydrophilic polymer systems, with molecular chains maintaining structural stability primarily through hydrogen bonds and physical entanglement. They easily absorb water and swell in humid and hot environments, leading to decreased adhesive strength, weakened interfacial bonding, and insufficient wet strength and water resistance. While single covalent crosslinking can improve adhesive strength, excessively high crosslinking density restricts molecular chain movement, increasing system brittleness and making the system prone to crack propagation under impact or long-term stress, resulting in insufficient toughness.

[0004] In existing technologies, improving the performance of plant protein adhesives often involves introducing epoxy crosslinking agents, aldehyde curing agents, or inorganic flame-retardant additives. However, these methods primarily focus on improving single properties (such as wet strength or flame retardancy) and fail to construct a multi-network structure system with synergistic reinforcing effects at the molecular level. Therefore, how to comprehensively improve the strength, toughness, flame retardancy, and mildew resistance of plant protein adhesives by constructing a synergistic structure of covalent crosslinking networks and dynamic coordination networks, while maintaining the green, environmentally friendly, and formaldehyde-free characteristics of plant protein adhesives, and enhancing the interfacial bonding stability between the adhesive layer and the wood substrate, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] This section briefly describes the embodiments and preferred solutions of the present invention. Simplifications or omissions may be included, but such simplifications or omissions do not constitute a limitation on the scope of the present invention.

[0006] To address the problems of insufficient wet strength, low toughness, and limited functional performance in existing technologies, the present invention aims to provide a high-performance plant protein adhesive with a covalent-coordination dual-network structure. By constructing a covalent cross-linked network and a dynamic coordination network to synergistically enhance the structure, functional components with flame retardant, antibacterial, and antifungal properties are introduced, significantly improving the mechanical strength, water resistance, flame retardant properties, and antifungal stability of the plant protein adhesive, thus expanding its application scope in the fields of engineered wood products manufacturing, wood processing, and green and environmentally friendly building materials.

[0007] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: A high-performance plant protein adhesive with a covalent-coordination dual network structure and its preparation thereof, comprising the following components by weight: 20-35 parts of plant protein meal, 65-75 parts of dispersion medium, 1.5-6 parts of chemical covalent crosslinking agent, 1-5 parts of flame retardant component, and 0.1-3 parts of dynamic coordination reinforcing component.

[0008] As a preferred embodiment of a high-performance plant protein adhesive with a covalent-coordination dual network structure belonging to this invention, the plant protein meal contains 46% crude protein, ≤10% moisture, 7% crude fat, 3%~8% ash, 3%~10% crude fiber, and the particle size of the plant protein is 100~200 mesh.

[0009] As a preferred embodiment of a high-performance plant protein adhesive with a covalent-coordination dual network structure belonging to this invention, the chemical covalent crosslinking agent is one or more of epoxidized lignin, bisphenol A type epoxy resin (industrial type), and bio-based glycidyl ethers.

[0010] In a preferred embodiment of a high-performance plant protein adhesive with a covalent-coordination dual network structure, the dispersion medium is deionized water.

[0011] A method for preparing a high-performance plant protein adhesive with a covalent-coordination dual network structure, the specific steps of which are as follows: S1. Add 28g of plant protein meal to 72g of deionized water and stir evenly at room temperature until a stable plant protein suspension is formed. The solid content can be adjusted appropriately according to the needs of subsequent reactions to ensure sufficient contact and uniform dispersion of the cross-linking agent, providing a good foundation for subsequent covalent cross-linking reactions.

[0012] S2. Add 3.5g of chemical covalent crosslinking agent to the plant protein suspension prepared in step S1, and stir continuously for 10-30 minutes to ensure that the plant protein and crosslinking agent are fully mixed and homogeneous. The crosslinking agent can be one or more of epoxidized lignin, bisphenol A type epoxy resin, or bio-based glycidyl ethers to ensure efficient reaction with the active groups of plant protein under subsequent heating conditions.

[0013] S3. Heat the mixture obtained in step S2 to 60°C and maintain the reaction for 120 minutes to allow the chemical covalent crosslinking agent to covalently crosslink with the active groups in the plant protein, forming a stable three-dimensional network structure. After the reaction is complete, allow the system to cool naturally to room temperature to obtain a uniform and viscous plant protein covalently crosslinked adhesive, which provides a stable basis for the subsequent addition of flame retardant components and dynamic coordination reinforcing components.

[0014] As a preferred embodiment of the method for preparing a high-performance plant protein adhesive with a covalent-coordination dual network structure according to the present invention, the specific steps of the method for preparing the high-performance plant protein adhesive are as follows: S1. Weigh 2.5g of the flame retardant component and add it to the prepared covalent crosslinking base adhesive solution. Stir at 500rpm for 20 minutes at 50℃ to ensure that the flame retardant component is evenly dispersed in the system and fully contacts the protein molecular chains to form a preliminary synergistic structure.

[0015] S2. Weigh 0.8g of the dynamic coordination enhancement component and dissolve it in 8g of deionized water to form a homogeneous solution. Then, slowly add it dropwise to the mixed system obtained in step S1 at room temperature (25℃) for 10 minutes. At the same time, stir continuously at 400~600rpm for 20 minutes to allow the metal ions to form coordination bonds with the active groups in the system and construct a reversible dynamic coordination network structure.

[0016] S3. Allow the resulting mixture to stand at room temperature for 30 minutes to allow the covalent and coordination networks to further stabilize. If necessary, add an appropriate amount of deionized water to adjust the viscosity or solid content of the system to obtain a high-performance plant protein adhesive with a covalent-coordination dual network structure. The final colloid mass is 115-120g.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The adhesive of this invention uses plant protein meal as the main raw material. By constructing a covalent cross-linked network and a dynamic coordination network to synergistically enhance the structure, the mechanical properties and interfacial bonding strength of the plant protein adhesive are significantly improved. The covalent cross-linked structure improves the cohesive strength of the adhesive layer, while the dynamic coordination network endows the system with a certain degree of flexibility and stress relief capability, enabling the adhesive layer to maintain structural stability under stress or humid and hot environments. Experiments have shown that plywood prepared using the adhesive of this invention can achieve a wet bonding strength of over 0.94 MPa, meeting the requirements of Class II indoor plywood standards, and a dry bonding strength of over 1.95 MPa, which is significantly improved compared to unmodified plant protein adhesives, exhibiting excellent comprehensive mechanical properties.

[0018] 2. This invention, by introducing flame-retardant components and dynamically coordinated reinforcing components, endows the system with excellent flame-retardant and anti-mildew properties while improving structural strength. Under heating conditions, the flame-retardant components promote char formation and form a dense protective layer, improving the material's heat resistance and flame-retardant rating. The metal ions in the dynamically coordinated reinforcing components can interact with protein molecules and microbial cell membrane structures, thereby inhibiting mold growth and reducing the risk of microbial erosion of the adhesive layer during storage and use. Compared to simply adding chemical preservatives, this invention's system achieves stable embedding of flame-retardant and anti-mildew functions through a synergistic network structure, preventing migration and loss. The adhesive maintains good anti-mildew stability and long-term service performance even in high-humidity environments. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 The dry bonding strength comparison bar chart of the adhesives prepared in Comparative Examples 1-3 and Examples 1-4 provided for this invention; Figure 2 The wet bonding strength comparison bar chart of the adhesives prepared in Comparative Examples 1-3 and Examples 1-4 provided for this invention; Figure 3 The bar chart shows the limiting oxygen index (LOI) test results of the adhesives prepared in Comparative Examples 1-3 and Examples 1-4 after curing, provided by the present invention. Figure 4 The bar chart shows the anti-mildew test results of the adhesives prepared in Comparative Examples 1-3 and Examples 1-4 provided by the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments of the present invention are given for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from its spirit and intent, and all such modifications and substitutions fall within the scope of the present invention.

[0021] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0022] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional operating methods. Unless otherwise specified, the materials and reagents used in the embodiments of this invention can be purchased commercially.

[0023] Unless otherwise specified, the term "parts" in this invention refers to parts by weight.

[0024] This invention provides a covalent-based This high-strength, flame-retardant, and mildew-resistant plant protein adhesive features a dual-network coordination structure. By constructing a covalently cross-linked network and a dynamic coordination network to synergistically enhance the structure, and by introducing flame-retardant and mildew-resistant functional components, it significantly improves the mechanical properties, flame-retardant properties, and mildew resistance of the plant protein adhesive, expanding its application range in areas such as engineered wood products manufacturing, wood processing, and green building materials. It comprises the following components in parts by weight: By weight, the composition includes 20-35 parts plant protein meal, 65-75 parts dispersion medium, 1.5-6 parts chemical covalent crosslinking agent, 1-5 parts flame retardant component, and 0.1-3 parts dynamic coordination enhancement component. The plant protein meal contains 46% crude protein, ≤10% moisture, 7% crude fat, 3%-8% ash, and 3%-10% crude fiber, with a plant protein particle size of 100-200 mesh. The chemical covalent crosslinking agent is one or more of epoxidized lignin, bisphenol A type epoxy resin (industrial type), and bio-based glycidyl ethers. The dispersion medium is deionized water.

[0025] To verify the performance of the high-strength antibacterial plant protein adhesive based on the biomimetic functional enhancement structure of the present invention, the following comparative example 1 is provided first. 3 and Example 1 4. Comparison and verification.

[0026] Comparative Example 1 (Pure Plant Protein Adhesive) S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. Stirring can be done using a magnetic or mechanical stirrer at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed, exhibiting a fine and uniform gel-like state. The solid content can be adjusted appropriately according to subsequent process requirements to ensure good flowability and workability of the gel, while ensuring sufficient dispersion of flame-retardant and dynamically coordinated reinforcing components, facilitating full contact with protein molecular chains, forming a stable basic gel layer structure, and providing a reliable initial system for the construction of the dual-network structure.

[0027] Comparative Example 2 (Covalent crosslinking only) S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. A magnetic or mechanical stirrer can be used for stirring. Continue stirring at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed, exhibiting a fine and uniform gel-like consistency.

[0028] S2. Add 3.5g of covalent crosslinking agent to the plant protein dispersion from step S1, stir well, and heat to 80℃ for 60 minutes to allow the crosslinking agent to covalently crosslink with the active groups of the protein molecules, forming a three-dimensional network structure. After the reaction is complete, allow it to cool naturally to room temperature to obtain a covalently crosslinked plant protein adhesive.

[0029] Comparative Example 3 (covalent crosslinking + flame retardant, no coordination) S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. A magnetic stirrer or mechanical stirrer can be used for stirring; continue stirring at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed.

[0030] S2. Add 3.5g of covalent crosslinking agent to the plant protein dispersion from step S1, stir well, and heat to 80℃ for 60 minutes to allow the crosslinking agent to covalently crosslink with the active groups of the protein molecules, forming a three-dimensional network structure. After the reaction is complete, allow it to cool naturally to room temperature to obtain a covalently crosslinked plant protein adhesive.

[0031] S3. Subsequently, 2.5g of flame retardant component was added to the S2 system and stirred at 50℃ for 20min to obtain covalently flame-retardant modified plant protein adhesive without adding dynamic coordination reinforcing component.

[0032] Implementation Case 1 S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. A magnetic stirrer or mechanical stirrer can be used for stirring; continue stirring at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed.

[0033] S2. Add 3.5g of covalent crosslinking agent to the plant protein dispersion from step S1, stir well, and heat to 80℃ for 60 minutes to allow the crosslinking agent to covalently crosslink with the active groups of the protein molecules, forming a three-dimensional network structure. After the reaction is complete, allow it to cool naturally to room temperature to obtain a covalently crosslinked plant protein adhesive.

[0034] S3. Subsequently, 2.5g of flame retardant component was added to the system of S2, and the mixture was stirred at 50℃ for 20min to obtain covalent-flame retardant modified plant protein adhesive.

[0035] S4. Take 0.8g of the dynamic coordination enhancement component, dissolve it in an appropriate amount of deionized water, slowly add it dropwise to the above system, stir at room temperature for 20min, let it stand and mature for 30min to obtain a covalent-coordination dual network plant protein adhesive.

[0036] Implementation Case 2 S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. A magnetic stirrer or mechanical stirrer can be used for stirring; continue stirring at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed.

[0037] S2. Add 3.5g of covalent crosslinking agent to the plant protein dispersion from step S1, stir well, and heat to 80℃ for 60 minutes to allow the crosslinking agent to covalently crosslink with the active groups of the protein molecules, forming a three-dimensional network structure. After the reaction is complete, allow it to cool naturally to room temperature to obtain a covalently crosslinked plant protein adhesive.

[0038] S3. Subsequently, 2.5g of flame retardant component was added to the system of S2, and the mixture was stirred at 50℃ for 20min to obtain covalent-flame retardant modified plant protein adhesive.

[0039] S4. Take 0.3g of the dynamic coordination enhancement component, dissolve it in an appropriate amount of deionized water, slowly add it dropwise to the above system, stir at room temperature for 20min, let it stand and mature for 30min to obtain a covalent-coordination dual network plant protein adhesive.

[0040] Implementation Case 3 S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. A magnetic stirrer or mechanical stirrer can be used for stirring; continue stirring at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed.

[0041] S2. Add 3.5g of covalent crosslinking agent to the plant protein dispersion from step S1, stir well, and heat to 80℃ for 60 minutes to allow the crosslinking agent to covalently crosslink with the active groups of the protein molecules, forming a three-dimensional network structure. After the reaction is complete, allow it to cool naturally to room temperature to obtain a covalently crosslinked plant protein adhesive.

[0042] S3. Subsequently, 4g of flame retardant component was added to the system of S2, and the mixture was stirred at 50°C for 20min to obtain covalently flame-retardant modified plant protein adhesive.

[0043] S4. Take 0.8g of the dynamic coordination enhancement component, dissolve it in an appropriate amount of deionized water, slowly add it dropwise to the above system, stir at room temperature for 20min, let it stand and mature for 30min to obtain a covalent-coordination dual network plant protein adhesive.

[0044] Implementation Case 4 S1. Add 28g of plant protein meal to 72g of deionized water slowly while stirring to prevent clumping or uneven aggregation. A magnetic stirrer or mechanical stirrer can be used for stirring; continue stirring at room temperature for 20-30 minutes until a uniform and stable plant protein suspension is formed.

[0045] S2. Add 3.5g of covalent crosslinking agent to the plant protein dispersion from step S1, stir well, and heat to 80℃ for 60 minutes to allow the crosslinking agent to covalently crosslink with the active groups of the protein molecules, forming a three-dimensional network structure. After the reaction is complete, allow it to cool naturally to room temperature to obtain a covalently crosslinked plant protein adhesive.

[0046] S3. Subsequently, 2.5g of flame retardant component was added to the system of S2, and the mixture was stirred at 50℃ for 20min to obtain covalent-flame retardant modified plant protein adhesive.

[0047] S4. Take 1.5g of the dynamic coordination enhancement component, dissolve it in an appropriate amount of deionized water, slowly add it dropwise to the above system, stir at room temperature for 20min, let it stand and mature for 30min to obtain a covalent-coordination dual network plant protein adhesive.

[0048] Adhesive performance evaluation experiment: Poplar veneer was selected and sawn according to GB / T9846.7-2004 standard, with a sample size of 100mm × 25mm. The plywood preparation process parameters are as follows: glue application rate of 300-400g / m² (double-sided glue application), followed by assembly and placement in a hot press at a unit pressure of 1.0-1.2MPa and a temperature of 120℃ for 360s. The plywood was then cooled to room temperature after pressing.

[0049] The wet-dry bonding strength test method involves immersing the sample in warm water (60±3℃) for 3 hours, removing it, cooling it at room temperature for 10 minutes, and then performing the shear strength test. The average value of 6 samples per group is taken. The test results are as follows: Figure 1 and Figure 2 As shown. To evaluate flame retardant performance, the limiting oxygen index (LOI) of the plywood was tested according to relevant standards. Each sample was tested three times, and the average value was taken. The results are shown below. Figure 3 As shown. To evaluate the anti-mold performance of the adhesive, the prepared plywood samples were placed in a constant temperature and humidity chamber (temperature 28±2℃, relative humidity above 85%) and cultured for 28 days. The surface mold growth was observed and graded. The results are shown below. Figure 4 As shown.

[0050]

[0051] Table 1. Plate Performance Testing The specific experimental results are shown in Table 1. The covalent-coordination dual-network structure constructed in this invention significantly improves the overall performance of plant protein adhesives. Figure 1 and Figure 2 As shown, Comparative Example 1 (unmodified plant protein adhesive) had a dry bonding strength of 1.10 MPa and a wet bonding strength of only 0.38 MPa, exhibiting poor water resistance. Comparative Example 2 (covalent crosslinking only) showed an improved wet strength of 0.72 MPa, but still exhibited performance degradation. Examples 1-4, after constructing a covalent-coordination dual-network structure, all achieved wet bonding strengths exceeding 0.90 MPa, with Example 4 reaching a maximum of 1.00 MPa, significantly superior to the comparative examples and meeting the requirements for Class II indoor plywood (≥0.7 MPa). Figure 3 As shown, the limiting oxygen index (LOI) of the comparative system is approximately 21-22%, indicating weak flame retardant performance. After adding the flame retardant component, the LOI of the example systems increases to over 30%, with Example 3 reaching 32%. Figure 4As shown, the diameter of the inhibition zone in the comparative samples was relatively small, with Comparative Example 1 being only 0-1 mm, and Comparative Examples 2 and 3 being 1 mm and 2 mm respectively, indicating limited anti-mold effects. However, after introducing the dynamic coordination enhancement component, the diameter of the inhibition zone in Examples 1-3 increased to 2-4 mm, and the high-coordination type Example 4 further reached 5 mm, demonstrating the best anti-mold performance. This indicates that the coordination structure formed by metal ions and protein active groups not only enhances network stability but also effectively inhibits mold growth, improving the long-term service performance of the material in humid and hot environments.

[0052] In summary, this invention achieves a synergistic improvement in mechanical properties, flame retardant properties, and mildew-resistant properties by constructing a synergistic structure of covalent cross-linked network and dynamic coordination network, and by introducing flame-retardant and mildew-resistant functional components, which is significantly superior to existing plant protein adhesive systems.

[0053] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A high-performance plant protein adhesive with a covalent-coordination dual network structure, characterized in that... include: Plant protein meal, chemical covalent crosslinking agent, dispersion medium, flame retardant component, dynamic coordination enhancement component; By weight, the composition is: 20-35 parts plant protein meal, 65-75 parts dispersion medium, 1.5-6 parts chemical covalent crosslinking agent, 1-5 parts flame retardant component, and 0.1-3 parts dynamic coordination enhancement component.

2. The high-performance plant protein adhesive with a covalent-coordination dual network structure according to claim 1, characterized in that, The plant protein meal is one of soybean protein meal, cottonseed meal or rapeseed meal, wherein the crude protein content is 46%, the moisture content is ≤10%, the crude fat content is 7%, the ash content is 3%~8%, the crude fiber content is 3%~10%, and the particle size of the plant protein is 100~200 mesh.

3. The high-performance plant protein adhesive with a covalent-coordination dual network structure according to claim 1, characterized in that, The chemical covalent crosslinking agent is epoxidized lignin.

4. A method for preparing a high-performance plant protein adhesive with a covalent-coordination dual network structure as described in any one of claims 1-3, characterized in that, The specific steps are as follows: S1. Add 28g of plant protein meal to 72g of deionized water and stir evenly at room temperature until a stable plant protein suspension is formed. The solid content can be adjusted appropriately according to the needs of subsequent reactions to ensure sufficient contact and uniform dispersion of the crosslinking agent, thus providing a good foundation for subsequent covalent crosslinking reactions. S2. Add 3.5g of chemical covalent crosslinking agent to the plant protein suspension prepared in step S1, and stir continuously for 10-30 minutes to ensure that the plant protein and the crosslinking agent are fully mixed and homogeneous, so as to ensure that they can react efficiently with the active groups of the plant protein under subsequent heating conditions. S3. Heat the mixture obtained in step S2 to 60°C and maintain the reaction for 120 minutes to allow the chemical covalent crosslinking agent to covalently crosslink with the active groups in the plant protein to form a stable three-dimensional network structure. After the reaction is complete, allow the system to cool naturally to room temperature to obtain a uniform and viscous plant protein covalent crosslinked adhesive, which provides a stable basis for the subsequent addition of flame retardant components and dynamic coordination reinforcing components. S4. Weigh 2.5g of flame retardant component and add it to the prepared covalent crosslinking base adhesive solution. Stir at 500rpm for 20 minutes at 50℃ to ensure that the flame retardant component is evenly dispersed in the system and fully contacts the protein molecular chain to form a preliminary synergistic structure. S5. Weigh 0.8g of the dynamic coordination enhancement component, dissolve it in an appropriate amount of deionized water to form a homogeneous solution, and then slowly add it dropwise to the mixed system obtained in step S4 at room temperature (25℃). The dropwise addition time is controlled within 10 minutes. At the same time, stir continuously at 400~600rpm for 20 minutes to allow the metal ions to form coordination bonds with the active groups in the system and construct a reversible dynamic coordination network structure. S6. Allow the resulting mixture to stand at room temperature for 30 minutes to allow the covalent and coordination networks to further stabilize. If necessary, add an appropriate amount of deionized water to adjust the viscosity or solid content of the system to obtain a high-performance plant protein adhesive with a covalent-coordination dual network structure.

5. A high-performance plant protein adhesive with a covalent-coordination dual network structure according to claim 4, characterized in that... The flame retardant component is one or more of ammonium polyphosphate, zinc borate, guanidine phosphate, nano-hydroxyapatite, and sodium borate; preferably, it is a composite flame retardant made by compounding ammonium polyphosphate and zinc borate in a mass ratio of 2:1 to 4:

1.

6. The high-performance plant protein adhesive with a covalent-coordination dual network structure according to claim 4, characterized in that... The preparation method of the dynamically coordinated enhanced component includes the following specific steps: S1. Weigh 1-5 parts by weight of a metal salt and 0.5-3 parts by weight of an organic ligand; wherein the metal salt is one or more of zinc sulfate, zinc chloride, copper sulfate, silver nitrate, and sodium borate; and the organic ligand is one or more of catechin, gallic acid, epigallocatechin gallate, and citric acid. S2. Dissolve the metal salt in 10-20 parts of deionized water and stir until completely dissolved to obtain a metal salt solution. S3. Dissolve the organic ligand in 5-10 parts of deionized water and stir until completely dissolved to obtain a ligand solution. S4. At room temperature, the ligand solution is slowly added dropwise to the metal salt solution over a period of 10 to 15 minutes, while stirring continuously at 300 to 500 rpm. After the addition is complete, stirring is continued for 20 to 30 minutes to allow the metal ions and organic ligands to fully coordinate and form a stable metal-ligand complex solution, which is the dynamic coordination enhancement component.

7. A high-performance plant protein adhesive as described in claim 5 can be used in novel renewable engineered wood products.

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