High-performance vegetable protein adhesive and preparation method thereof

Abstract

The invention discloses a high-performance vegetable protein adhesive and a preparation method thereof.The high-performance vegetable protein adhesive is characterized by being prepared from, by weight, 30 parts of soybean meal, 70 parts of water, 0-0.4 part of urease, 0-0.5 M of urea and 0-0.5 M. The preparation method comprises the steps that the urea and the calcium chloride are dissolved in the water, and the mixture is stirred to be uniform; uniformly stirring to form a urea-calcium chloride aqueous solution; s2, adding the soybean meal into the urea-calcium chloride aqueous solution obtained in the step S1, stirring to form uniformly mixed slurry, and standing for later use; s2, adding the urease into the mixed slurry obtained in the step S2, and stirring until the urease is uniformly dissolved to form protein adhesive slurry; s3, the protein adhesive slurry obtained in the step S3 is subjected to a reaction at the room temperature, the high-performance plant protein adhesive is obtained, the adhesive generated through the method can balance cohesion of a bonding interface and the adhesive, and therefore high bonding strength is achieved.

Description

Technical Field

[0001] This invention relates to the field of biomass adhesives, specifically to a high-performance plant protein adhesive and its preparation method. Background Technology

[0002] Adhesives play a vital role in materials engineering and manufacturing, including in construction, aircraft, automobiles, furniture, footwear, and packaging. While traditional synthetic adhesives offer advantages such as high performance and low cost, they also pose significant environmental problems. The petroleum-based raw materials used in traditional adhesives are non-renewable, and some synthetic resin adhesives release toxic gases during use; for example, formaldehyde-based adhesives used in engineered wood products release formaldehyde and other carcinogens.

[0003] Plant proteins offer significant advantages for sustainable development and show great potential in replacing existing petroleum-based polymers. The preparation of protein adhesives involves altering material properties, such as covalent chemical crosslinking and multiple covalent interactions. However, this often makes it difficult to balance the contradiction between the adhesive interface and the adhesive's cohesive strength, resulting in lower mechanical properties (interfacial strength). Performance and cost are perennial concerns when developing novel adhesive products for sustainable development. Therefore, developing high-performance, low-cost, sustainable bio-based adhesives is a major challenge. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] Therefore, the purpose of this invention is to provide a high-performance plant protein adhesive and its preparation method, wherein the resulting adhesive can balance the bonding interface and the cohesive force of the adhesive, thereby achieving high bonding strength.

[0006] 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 is composed of the following components in parts by weight: 30 parts soybean meal, 70 parts water, 0-0.4 parts urea-degrading enzyme, 0-0.5M urea, and 0-0.5M calcium chloride.

[0007] In a preferred embodiment of the high-performance plant protein adhesive of the present invention, the urea-degrading enzyme has a weight of 0-0.2 parts, the urea concentration is 0-0.3M, and the calcium chloride concentration is 0-0.3M.

[0008] In a preferred embodiment of the high-performance plant protein adhesive described in this invention, the water is one or more of tap water, softened water, and deionized water.

[0009] In a preferred embodiment of the high-performance plant protein adhesive described in this invention, the soybean meal contains 53% protein and 33% carbohydrates.

[0010] In a preferred embodiment of the high-performance plant protein adhesive described in this invention, the concentration of urea is 0.02-0.3M and the concentration of calcium chloride is 0.02-0.3M.

[0011] A method for preparing a high-performance plant protein adhesive, comprising the following steps: S1. Dissolve urea and calcium chloride in the water and stir until homogeneous to form a urea-calcium chloride aqueous solution; S2. Add the soybean meal to the urea-calcium chloride aqueous solution obtained in step S1, stir to form a uniform slurry, and let it stand for later use. S3. Add the urea-decomposing enzyme to the mixed slurry obtained in step S2, and stir until it is uniformly dissolved to form a protein adhesive slurry. S4. React the protein adhesive slurry obtained in step S3 at room temperature to obtain the high-performance plant protein adhesive.

[0012] In a preferred embodiment of the preparation method of the high-performance plant protein adhesive of the present invention, in step S1, stirring is carried out at room temperature; in step S2, the stirring time is 5 minutes and the standing time is 1 hour.

[0013] In a preferred embodiment of the preparation method of the high-performance plant protein adhesive described in this invention, the stirring time in step S3 is 5 minutes.

[0014] In a preferred embodiment of the preparation method of the high-performance plant protein adhesive described in this invention, the reaction time in step S4 is 6 hours.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The adhesive formulation in this invention follows the principles of environmental protection and sustainable development. The preparation method is simple, the raw materials are widely available and renewable, and the resulting protein adhesive has high performance and is easy to apply industrially. The method of modifying soybean meal with urea decomposition enzyme in this invention helps to achieve uniform dispersion of soybean meal, promotes the formation of mechanical interlock between the adhesive and the substrate, and thus increases the interfacial bonding strength.

[0016] 2. This invention differs from other modification methods in that it achieves in-situ mineralization of calcium carbonate while improving interfacial bonding strength. It forms an interlocking structure with soybean meal through coordination bonds, increasing cohesion and improving mechanical properties. As a novel biomass adhesive, this invention does not contain formaldehyde or other volatile organic compounds, thus solving the problems of petroleum resource consumption and indoor air pollution caused by traditional synthetic adhesives. Attached Figure Description

[0017] 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 detailed 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 bonding strength test diagrams of plywood prepared using soybean meal adhesive in Examples 1-5 and Comparative Examples 1-2 provided for this invention; Figure 2 Wood breakage rate test charts of plywood prepared with soybean meal adhesives prepared in Example 4 and Comparative Examples 1-2 provided by the present invention; Figure 3 Mirror images of the bonding interface of plywood prepared with soybean meal adhesive in Example 4 and Comparative Examples 1-2 provided by the present invention; Figure 4 Thermal stability test diagrams of soybean meal adhesives prepared in Example 4 and Comparative Examples 1-2 provided by the present invention. Detailed Implementation

[0018] 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. Example

[0019] S1. Dissolve 0-0.02M urea and 0-0.02M calcium chloride in 70 parts of water and stir evenly at room temperature to form a urea-calcium chloride aqueous solution; S2. Add 30 parts of soybean meal to the urea-calcium chloride aqueous solution in step S1 and stir for 5 minutes to form a uniform slurry. Let it stand for 1 hour for later use. S3. Add 0-0.2 parts of urea decomposing enzyme to the mixed slurry in step S2 and stir for 5 minutes to dissolve evenly, forming a protein adhesive slurry; S4. After reacting the protein adhesive slurry from step S3 at room temperature for 6 hours, this urea-degrading enzyme-modified high-performance soybean meal adhesive is obtained. Example

[0020] S1. Dissolve 0.03-0.05M urea and 0.03-0.05M calcium chloride in 70 parts of water and stir evenly at room temperature to form a urea-calcium chloride aqueous solution; S2. Add 30 parts of soybean meal to the urea-calcium chloride aqueous solution in step S1 and stir for 5 minutes to form a uniform slurry. Let it stand for 1 hour for later use. S3. Add 0-0.2 parts of urea decomposing enzyme to the mixed slurry in step S2 and stir for 5 minutes to dissolve evenly, forming a protein adhesive slurry; S4. After reacting the protein adhesive slurry from step S3 at room temperature for 6 hours, this urea-degrading enzyme-modified high-performance soybean meal adhesive is obtained. Example

[0021] S1. Dissolve 0.06-0.09M urea and 0.06-0.09M calcium chloride in 70 parts of water, and stir evenly at room temperature to form a urea-calcium chloride aqueous solution; S2. Add 30 parts of soybean meal to the urea-calcium chloride aqueous solution in step S1 and stir for 5 minutes to form a uniform slurry. Let it stand for 1 hour for later use. S3. Add 0-0.2 parts of urea decomposing enzyme to the mixed slurry in step S2 and stir for 5 minutes to dissolve evenly, forming a protein adhesive slurry; S4. After reacting the protein adhesive slurry from step S3 at room temperature for 6 hours, this urea-degrading enzyme-modified high-performance soybean meal adhesive is obtained. Example

[0022] S1. Dissolve 0.1-0.15M urea and 0.1-0.15M calcium chloride in 70 parts of water, and stir evenly at room temperature to form a urea-calcium chloride aqueous solution; S2. Add 30 parts of soybean meal to the urea-calcium chloride aqueous solution in step S1 and stir for 5 minutes to form a uniform slurry. Let it stand for 1 hour for later use. S3. Add 0-0.2 parts of urea decomposing enzyme to the mixed slurry in step S2 and stir for 5 minutes to dissolve evenly, forming a protein adhesive slurry; S4. After reacting the protein adhesive slurry from step S3 at room temperature for 6 hours, this urea-degrading enzyme-modified high-performance soybean meal adhesive is obtained. Example

[0023] S1. Dissolve 0.2-0.3M urea and 0.2-0.3M calcium chloride in 70 parts of water, and stir evenly at room temperature to form a urea-calcium chloride aqueous solution; S2. Add 30 parts of soybean meal to the urea-calcium chloride aqueous solution in step S1 and stir for 5 minutes to form a uniform slurry. Let it stand for 1 hour for later use. S3. Add 0-0.2 parts of urea decomposing enzyme to the mixed slurry in step S2 and stir for 5 minutes to dissolve evenly, forming a protein adhesive slurry; S4. After reacting the protein adhesive slurry from step S3 at room temperature for 6 hours, this urea-degrading enzyme-modified high-performance soybean meal adhesive is obtained.

[0024] Comparative Example 1 S1. Add 30 parts soybean meal to 70 parts water and stir for 5 minutes at room temperature to form a uniform slurry; S2. After reacting the mixed slurry from step S1 at room temperature for 6 hours, this protein adhesive is obtained.

[0025] Comparative Example 2 S1. Dissolve 0.2-0.3M calcium carbonate in 70 parts of water and stir evenly at room temperature to form a calcium carbonate aqueous solution; S2. Add 30 parts of soybean meal to step S1 and stir at room temperature for 5 minutes to form a uniform slurry; S3. After reacting the mixed slurry from step S2 at room temperature for 6 hours, this protein adhesive is obtained.

[0026] The modified soybean meal adhesives prepared in Comparative Examples 1-2 and Examples 1-5 of this invention were subjected to performance tests according to the following method. Adhesive performance evaluation experiment: Poplar plywood, sawn according to GB / T9846.7-2004, with sample dimensions of 100mm × 25mm. Plywood preparation process parameters: Apply adhesive 300-400g / m² (double-sided), then place in a hot press and hot-press at 120℃ for 360s under a unit pressure of 1.0-1.2MPa.

[0027] See appendix Figure 1 It can be seen that the bonding strength of the plywood prepared using soybean meal adhesive is higher than that of Comparative Example 1, and the bonding strength of Examples 4-5 is higher than that of Comparative Example 2.

[0028] See appendix Figure 2 The wood breakage rate of the plywood prepared in Example 4 was much higher than that of Comparative Example 1 and Comparative Example 2, reaching 90%.

[0029] See appendix Figure 3 It can be seen that the plywood prepared in Example 4 has dense and continuous adhesive lines and can form more mechanical interactions with the substrate, indicating that the prepared soybean meal adhesive effectively increases the interfacial bonding strength.

[0030] See appendix Figure 4Compared with Comparative Examples 1-2, the urea-degrading enzyme-modified soybean meal adhesive exhibited the highest thermal stability. This indicates that the prepared soybean meal adhesive achieves a balance between improving interfacial bonding strength and internal cross-linking, thereby increasing cohesive stability.

[0031] 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, characterized in that, The soybean meal 30 parts, water 70 parts, urea decomposition enzyme 0-0.4 parts, urea 0-0.5M, calcium chloride 0-0.5M.

2. The high performance plant protein adhesive according to claim 1, characterized in that, The weight of the urea decomposition enzyme is 0-0.2 parts, the concentration of urea is 0-0.3M, and the concentration of calcium chloride is 0-0.3M.

3. The high performance plant protein adhesive according to claim 1, wherein, The water is one or more of tap water, softened water, and deionized water.

4. The high performance plant protein adhesive of claim 1, wherein, The protein content of the soybean meal is 53%, and the carbohydrate content is 33%.

5. The high-performance vegetable protein adhesive according to claim 1 or 2, characterized in that, The concentration of urea is 0.02-0.3M, and the concentration of calcium chloride is 0.02-0.3M.

6. A method for preparing the high performance plant protein adhesive according to any one of claims 1 to 5, characterized in that, The steps are as follows: S1, dissolve urea and calcium chloride in the water, stir evenly to form a urea-calcium chloride aqueous solution; S2, add the soybean meal to the urea-calcium chloride aqueous solution obtained in step S1, stir to form a uniform mixture slurry, and then stand by; S3, add the urea decomposition enzyme to the mixture slurry obtained in step S2, stir until dissolved evenly to form a protein adhesive slurry; S4, react the protein adhesive slurry obtained in step S3 at room temperature to obtain the high-performance plant protein adhesive.

7. The method for preparing a high-performance plant protein adhesive according to claim 1, characterized in that, In step S1, the stirring is carried out at room temperature; in step S2, the stirring time is 5 minutes, and the standing time is 1 hour.

8. The method for preparing a high-performance plant protein adhesive according to claim 1, characterized in that, In step S3, the stirring time is 5 minutes.

9. The method for preparing a high-performance plant protein adhesive according to claim 1, characterized in that, In step S4, the reaction time is 6 hours.

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