Vegetable protein adhesive for artificial board and preparation method of vegetable protein adhesive

Abstract

The invention discloses a vegetable protein adhesive for an artificial board and a preparation method of the vegetable protein adhesive, and relates to the technical field of wood adhesives. The vegetable protein adhesive for the artificial board is prepared from vegetable protein, vegetable colloid powder, a pH regulator and deionized water, wherein the vegetable colloid powder is prepared by reacting white latex in jackfruit with trifluoroacetic acid. Under the condition that a chemical modifier, a cross-linking agent and a reinforcing agent are not added, the plant protein molecules and the plant latex powder act synergistically to prepare the adhesive meeting the use requirements of the artificial board, and protease in the plant latex powder is utilized to unfasten the space structure of protein, so that more groups such as hydroxyl are exposed. According to the preparation method, the adhesive which is good in comprehensive performance and capable of meeting use requirements is prepared on the premise that no petroleum derived chemicals are added as modifiers, the low cost is maintained and the process complexity is not increased, and the preparation process is really green and environmentally friendly.

Description

Technical Field

[0001] The invention relates to the technical field of wood adhesives, in particular to a plant protein adhesive for artificial boards and a preparation method thereof. Background Art

[0002] my country's wood-based panel industry has developed rapidly, with production reaching 287 million cubic meters in 2022 and consumption of about 279 million cubic meters. The formaldehyde-based thermosetting adhesives (urea-formaldehyde and modified urea-formaldehyde resins, phenolic resins, melamine formaldehyde resins, etc.) used in the manufacture of wood-based panels are the main cause of formaldehyde release from panels. In recent years, GB / T 39600-2021 "Classification of Formaldehyde Emissions from Wood-Based Panels and Their Products", GB / T 39598-2021 "Guidelines for Indoor Load Limits of Wood-Based Panels Based on Limit Formaldehyde Emissions", T / CNFPIA 1001-2019 "Limits of Formaldehyde Emission from Wood-Based Panels", T / CNFPIA 3002-2018 "Formaldehyde-Free Wood-Based Panels and Their Products" and other standards have been issued and implemented, which have put forward stricter requirements on the formaldehyde release of wood-based panels, and low-formaldehyde and formaldehyde-free adhesives have become an inevitable development direction.

[0003] Formaldehyde-free adhesives represented by polyurethane (isocyanate), soybean protein adhesive, and modified starch adhesive have begun to be applied in the market. Among them, soybean protein adhesive is one of the most studied formaldehyde-free adhesives. Soybean protein adhesive is a plant protein adhesive. Due to the characteristics of natural protein, protein adhesives generally have problems such as poor water resistance, high viscosity, and low bonding strength. Generally, various properties need to be improved by modification. Proteins are often modified by adding various modifiers, or protein adhesives are used after blending with thermosetting resins. These methods often have the problem of complex processes, and the modified substances used are also mostly high-cost, non-renewable petrochemical byproducts, which not only increase costs and process complexity, but also bring new pollution. In the prior art, CN113563841A discloses a modified plant protein adhesive and a preparation method thereof, wherein the modified plant protein adhesive is prepared from plant protein powder, deionized water, silkworm cocoons, alkaline regulators, and protein denaturants, and the protein denaturants are urea, sodium dodecylbenzene sulfonate, etc. However, the use of chemical substances such as urea and sodium dodecyl sulfate during the preparation process increases the burden on the environment.

[0004] Therefore, it is necessary to select natural renewable biomass as a modifier to prepare a plant protein adhesive for artificial panels with good comprehensive performance and that can meet the use requirements, and to ensure the green and environmental protection of the preparation process. Summary of the invention

[0005] In view of the above-mentioned prior art, the purpose of the present invention is to provide a plant protein adhesive for artificial panels and a preparation method thereof. The plant protein adhesive for artificial panels is prepared from plant protein, plant colloid powder, pH regulator and deionized water, and the plant colloid powder is prepared by reacting white latex in jackfruit with trifluoroacetic acid. In the present invention, without adding chemical modifiers, cross-linking agents and reinforcing agents, plant protein molecules and plant latex powder synergistically prepare an adhesive that meets the use requirements of artificial panels, and utilizes the protease in the plant latex powder to unlock the spatial structure of the protein, so that more hydroxyl groups are exposed. The present invention prepares an adhesive with good comprehensive performance that meets the use requirements without adding any petroleum-derived chemicals as modifiers, maintaining a low cost and not increasing the complexity of the process, and the preparation process is truly green and environmentally friendly.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect of the present invention, a plant protein adhesive for artificial panels is provided, wherein the plant protein adhesive is prepared from the following raw materials in parts by weight:

[0008] 150-250 parts of plant protein powder, 500-800 parts of deionized water, 50-80 parts of plant colloid powder, 4-8 parts of pH regulator;

[0009] The plant colloid is prepared by the following method:

[0010] The white latex in the jackfruit is washed, dried, ground and sieved to obtain latex powder; trifluoroacetic acid is added to the latex powder for reaction to obtain a reaction product, and the reaction product is subjected to reduced pressure distillation, dried, ground and sieved to obtain plant colloid powder.

[0011] Preferably, the plant protein powder is one or more of bean protein, cereal protein, nut protein, and cotton protein.

[0012] Preferably, the pH regulator is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, and ammonia water.

[0013] Preferably, the reaction temperature is 70-90° C. and the reaction time is 1.5-2.5 h.

[0014] Preferably, the mass ratio of trifluoroacetic acid to latex powder is 80:20.

[0015] Preferably, the concentration of trifluoroacetic acid is 0.5-1.0 mol / L.

[0016] Preferably, the temperature of the reduced pressure distillation is 60-70°C, and the time of the reduced pressure distillation is 1-1.5h.

[0017] The second aspect of the present invention provides a method for preparing a plant protein adhesive for artificial panels, comprising the following steps:

[0018] (1) mixing plant protein powder and deionized water, and stirring to obtain a plant protein solution;

[0019] (2) adding a pH adjuster to the vegetable protein solution, heating and stirring to obtain a mixture;

[0020] (3) Adding the plant colloid powder to the mixture, keeping it warm and stirring it, and after the reaction is completed, cooling it to obtain the plant protein adhesive for artificial boards.

[0021] Preferably, in step (1), the stirring temperature is 45-55° C., the stirring time is 0.5-1 h, and the stirring speed is 800-1000 r / min.

[0022] Preferably, in step (2), the temperature is raised to 60-70° C., the stirring speed is 800-1000 r / min, and the stirring time is 0.5-1 h.

[0023] Preferably, in step (3), the stirring time is 1-1.5 h, and the stirring speed is 800-1000 r / min.

[0024] Preferably, in step (3), the temperature is lowered to room temperature.

[0025] Preferably, in step (3), the insulation temperature is 50-55°C.

[0026] The third aspect of the present invention provides the use of the plant protein adhesive for artificial panels in the manufacture of artificial panels.

[0027] Beneficial effects of the present invention:

[0028] The present invention uses plant protein, plant colloid and the like as main raw materials to prepare the plant protein adhesive for artificial panels. The main raw materials all come from natural renewable biomass, the preparation process is simple, no harmful components such as formaldehyde are added or released, and the product is green and environmentally friendly.

[0029] The present invention utilizes the white latex in jackfruit after pretreatment, and reacts with trifluoroacetic acid to obtain plant colloid powder as raw material to prepare plant protein adhesive for artificial board. Wherein, the white latex in jackfruit is a white liquid secreted from the fruit core of jackfruit, which will immediately become a sticky latex after contacting the air. This latex has good bonding performance and film-forming property, as well as high flexibility and tensile strength. It is used as a raw material to prepare plant protein adhesive, which can significantly improve the molecular structure and film-forming property of the plant protein adhesive, make the glue layer formed after curing more uniform and dense, thereby hindering water molecules from entering the glue layer, and achieving the purpose of improving water resistance. The present invention, without adding chemical modifiers, cross-linking agents and reinforcing agents, makes the plant protein molecules and the modified jackfruit latex synergistically prepare an adhesive that meets the use requirements of artificial boards, makes full use of natural substances, effectively reduces costs, and complies with the principles of circular economy and sustainable development.

[0030] Conventional plant protein adhesives require the use of urea, sodium dodecyl sulfate and other substances to treat the protein, destroying the hydrogen bonding of the protein, causing the spatial structure of the protein to be untied, exposing more hydroxyl groups and the like. The protease contained in the jackfruit latex used in the present invention can also achieve the above purpose, without the need to use chemical substances such as urea and sodium dodecyl sulfate, further improving the environmental performance.

[0031] The plant protein adhesive for artificial boards prepared by the present invention has suitable viscosity and storage period, and the water-resistant bonding strength of the prepared plywood meets the requirements of Class II plywood (≥0.7MPa) in the national standard GB17657-2013 "Test methods for physical and chemical properties of artificial boards and veneer artificial boards". DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0033] As introduced in the background technology section, protein adhesives currently have common problems such as poor water resistance, high viscosity, and low bonding strength. Generally, they need to be modified to improve various properties. Proteins are often modified by adding various modifiers, or protein adhesives are blended with thermosetting resins before use. These methods often have complex processes, and the modified substances used are mostly high-cost, non-renewable petrochemical by-products, which not only increase costs and process complexity, but also bring new pollution.

[0034] Based on this, the purpose of the present invention is to provide a plant protein adhesive for artificial boards and a preparation method thereof, using plant latex powder obtained by reacting natural plant colloid jackfruit latex as a modifier, and without adding chemical modifiers, crosslinking agents and reinforcing agents, making plant protein molecules and jackfruit latex synergistically prepare adhesives that meet the use requirements of artificial boards, effectively reducing the cost of adhesives and simplifying the production process. The plant protein adhesive for artificial boards prepared by the present invention has suitable viscosity and storage period, and the water-resistant bonding strength of the prepared plywood meets the requirements of Class II plywood in the national standard GB17657-2013 "Experimental methods for physical and chemical properties of artificial boards and veneer artificial boards".

[0035] Wherein, the white latex in the jackfruit that the present invention adopts is mainly composed of a kind of material called " pectin ", and this material is a kind of macromolecular compound, and its main structure is a polysaccharide polymer, and molecular weight is higher, and structure is complicated, but film-forming property is good.Because molecular weight is too large, directly and protein effect is limited, after reacting with low concentration trifluoroacetic acid solution, this polysaccharide polymer is hydrolyzed into suitable small and medium molecules of molecular weight, can be interspersed in the gap of protein glue molecular chain to form a network structure, contribute to improve the cross-linking density of protein glue after solidification, reduce glue layer space, thereby improve film-forming property and water resistance of glue.In addition, the protease contained in the white latex can play the effect of processing protein.Meanwhile, in the white latex in the jackfruit, also contain protease and protein, in the jackfruit white latex after low concentration trifluoroacetic acid treatment, still retain protease, protease can replace chemical substances such as urea, sodium dodecyl sulfate to process protein, and better effect.

[0036] The white latex in the jackfruit of the present invention is separated and prepared by the following method:

[0037] (1) Peel and remove the ripe Hainan jackfruit, and cut the remaining part into small pieces to obtain a sample for later use;

[0038] (2) After mixing the sample and pure water in a mass ratio of 1:8, add 0.5 mol / L hydrochloric acid solution to adjust the pH value to 2.5-3.5, perform acid hydrolysis extraction at 65°C for 1 h, and filter to obtain an extract and a residue;

[0039] (3) The extract is distilled under reduced pressure and then dried in a vacuum drying oven at 55°C to obtain the white latex in the jackfruit.

[0040] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0041] The experimental materials used in the embodiments of the present invention are all conventional experimental materials in the art and can be purchased through commercial channels.

[0042] Example 1: Plant protein adhesive for artificial board

[0043] 1. Raw material composition:

[0044] 150 parts of plant protein powder, 500 parts of deionized water, 50 parts of plant colloid powder, 4 parts of pH regulator;

[0045] The plant protein powder is soybean protein powder, and the pH regulator is sodium hydroxide;

[0046] The plant colloid is prepared by the following method:

[0047] The white latex in the jackfruit is washed, dried, ground, and passed through a 200-mesh sieve to obtain latex powder; 1 mol / L trifluoroacetic acid is added to the latex powder, and the reaction is carried out at 80°C for 2 hours to obtain a reaction product, wherein the mass ratio of trifluoroacetic acid to latex powder is 4:1; the reaction product is then subjected to reduced pressure distillation at 65°C for 1.5 hours to remove moisture, and then dried, ground, and passed through a 200-mesh sieve to obtain plant colloid powder.

[0048] 2. Preparation method:

[0049] (1) adding soybean protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0050] (2) adding sodium hydroxide to the vegetable protein solution, heating to 65° C. and stirring for 0.5 h at a stirring speed of 800 r / min to obtain a mixture;

[0051] (3) Add the plant colloid powder to the mixture, keep it warm at 55° C. and stir it for 1 h at a stirring speed of 800 r / min. After the reaction is completed, cool it to room temperature to obtain a plant protein adhesive for artificial boards.

[0052] Example 2: Plant protein adhesive for artificial board

[0053] 1. Raw material composition:

[0054] 200 parts of plant protein powder, 700 parts of deionized water, 60 parts of plant colloid powder, 5 parts of pH regulator;

[0055] The plant protein powder is wheat gluten powder, and the pH regulator is sodium hydroxide;

[0056] The plant colloid is prepared by the following method:

[0057] The white latex in the jackfruit is washed, dried, ground, and passed through a 200-mesh sieve to obtain latex powder; 0.5 mol / L trifluoroacetic acid is added to the latex powder, and the reaction is carried out at 80°C for 2 hours to obtain a reaction product, wherein the mass ratio of trifluoroacetic acid to latex powder is 5:1; the reaction product is then subjected to reduced pressure distillation at 65°C for 1 hour to remove moisture, and then dried, ground, and passed through a 200-mesh sieve to obtain plant colloid powder.

[0058] 2. Preparation method:

[0059] (1) adding wheat gluten flour and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0060] (2) adding sodium hydroxide to the vegetable protein solution, heating to 65° C. and stirring for 1 h at a stirring speed of 1000 r / min to obtain a mixture;

[0061] (3) Add the plant colloid powder to the mixture, keep it warm at 50° C. and stir it for 1 h at a stirring speed of 800 r / min. After the reaction is completed, cool it to room temperature to obtain a plant protein adhesive for artificial boards.

[0062] Example 3: Plant protein adhesive for artificial board

[0063] 1. Raw material composition:

[0064] 250 parts of plant protein powder, 800 parts of deionized water, 80 parts of plant colloid powder, 8 parts of pH regulator;

[0065] The plant protein powder is cotton protein powder, and the pH regulator is potassium hydroxide;

[0066] The plant colloid is prepared by the following method:

[0067] The white latex in the jackfruit is washed, dried, ground, and passed through a 200-mesh sieve to obtain latex powder; 0.8 mol / L trifluoroacetic acid is added to the latex powder, and the reaction is carried out at 80°C for 2 hours to obtain a reaction product, wherein the mass ratio of trifluoroacetic acid to latex powder is 3:1; the reaction product is then evaporated under reduced pressure at 65°C for 1.2 hours to remove moisture, and then dried, ground, and passed through a 200-mesh sieve to obtain plant colloid powder.

[0068] 2. Preparation method:

[0069] (1) adding cotton protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0070] (2) adding sodium hydroxide to the vegetable protein solution, heating to 65° C. and stirring for 0.5 h at a stirring speed of 900 r / min to obtain a mixture;

[0071] (3) Add the plant colloid powder to the mixture, keep it warm at 53° C. and stir it for 1 h at a stirring speed of 800 r / min. After the reaction is completed, cool it to room temperature to obtain a plant protein adhesive for artificial boards.

[0072] Example 4: Plant protein adhesive for artificial board

[0073] 1. Raw material composition:

[0074] 150 parts of plant protein powder, 500 parts of deionized water, 50 parts of plant colloid powder, 4 parts of pH regulator;

[0075] The plant protein powder is soybean protein powder, and the pH regulator is sodium hydroxide;

[0076] The plant colloid is prepared by the following method:

[0077] The white latex in the jackfruit is washed, dried, ground, and passed through a 200-mesh sieve to obtain latex powder; 0.5 mol / L trifluoroacetic acid is added to the latex powder, and the reaction is carried out at 70°C for 1.5 hours to obtain a reaction product, wherein the mass ratio of trifluoroacetic acid to latex powder is 4:1; the reaction product is then subjected to reduced pressure distillation at 60°C for 1.5 hours to remove moisture, and then dried, ground, and passed through a 200-mesh sieve to obtain plant colloid powder.

[0078] 2. Preparation method:

[0079] (1) adding soybean protein powder and deionized water into a reactor, stirring at a temperature of 45° C. and a speed of 900 r / min for 0.5 h to obtain a plant protein solution;

[0080] (2) adding sodium hydroxide to the vegetable protein solution, heating to 60° C. and stirring for 0.5 h at a stirring speed of 800 r / min to obtain a mixture;

[0081] (3) Add the plant colloid powder to the mixture, keep it warm at 55° C. and stir it for 1.25 h at a stirring speed of 900 r / min. After the reaction is completed, cool it to room temperature to obtain a plant protein adhesive for artificial boards.

[0082] Example 5: Plant protein adhesive for artificial board

[0083] 1. Raw material composition:

[0084] 150 parts of plant protein powder, 500 parts of deionized water, 50 parts of plant colloid powder, 4 parts of pH regulator;

[0085] The plant protein powder is soybean protein powder, and the pH regulator is sodium hydroxide;

[0086] The plant colloid is prepared by the following method:

[0087] The white latex in the jackfruit is washed, dried, ground, and passed through a 200-mesh sieve to obtain latex powder; 1 mol / L trifluoroacetic acid is added to the latex powder, and the reaction is carried out at 90°C for 2.5 hours to obtain a reaction product, wherein the mass ratio of trifluoroacetic acid to latex powder is 4:1; the reaction product is then subjected to reduced pressure distillation at 70°C for 1.5 hours to remove moisture, and then dried, ground, and passed through a 200-mesh sieve to obtain plant colloid powder.

[0088] 2. Preparation method:

[0089] (1) adding soybean protein powder and deionized water into a reactor, stirring at a temperature of 55° C. and a speed of 1000 r / min for 0.75 h to obtain a plant protein solution;

[0090] (2) adding sodium hydroxide to the vegetable protein solution, heating to 70° C. and stirring for 0.5 h at a stirring speed of 800 r / min to obtain a mixture;

[0091] (3) Add the plant colloid powder to the mixture, keep it warm at 55° C. and stir it for 1.5 h at a stirring speed of 1000 r / min. After the reaction is completed, cool it to room temperature to obtain a plant protein adhesive for artificial boards.

[0092] Comparative Example 1: Plant protein adhesive for artificial boards

[0093] The difference between this comparative example and Example 3 is that no plant colloid powder is added. The specific preparation method is:

[0094] (1) adding soybean protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0095] (2) adding sodium hydroxide to the plant protein solution, heating to 65° C. and stirring for 0.5 h at a stirring speed of 800 r / min to obtain a mixture; after the reaction is completed, cooling to room temperature to obtain a plant protein adhesive for artificial panels.

[0096] Comparative Example 2: Plant protein adhesive for artificial boards

[0097] The difference between this comparative example and Example 3 is that the plant colloid powder is prepared from only the white latex in jackfruit. The specific preparation method is:

[0098] (1) washing and drying the white latex in jackfruit, grinding it, and passing it through a 200-mesh sieve to obtain latex powder as plant colloid powder;

[0099] (2) adding soybean protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0100] (3) adding sodium hydroxide to the vegetable protein solution, heating to 65° C. and stirring for 0.5 h at a stirring speed of 800 r / min to obtain a mixture;

[0101] (4) Add the plant colloid powder to the mixture, keep warm and stir for 1 hour at a stirring speed of 800 r / min. After the reaction is completed, cool to room temperature to obtain a plant protein adhesive for artificial boards.

[0102] Comparative Example 3: Plant protein adhesive for artificial boards

[0103] The difference between this comparative example and Example 3 is that no pH regulator is added. The specific preparation method is:

[0104] (1) adding soybean protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0105] (2) The plant protein solution is heated to 65° C., and the plant colloid powder is added to the mixture. The mixture is kept warm and stirred for 1 hour at a stirring speed of 800 r / min. After the reaction is completed, the mixture is cooled to room temperature to obtain a plant protein adhesive for artificial boards.

[0106] Comparative Example 4: Plant protein adhesive for artificial boards

[0107] The difference between this comparative example and Example 3 is that polyamide epichlorohydrin is used to replace the plant colloid powder. The specific preparation method is:

[0108] (1) adding soybean protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0109] (2) adding sodium hydroxide to the vegetable protein solution, heating to 65° C. and stirring for 0.5 h at a stirring speed of 800 / min to obtain a mixture;

[0110] (3) Add amide epichlorohydrin to the mixture, keep warm and stir for 1 hour at a stirring speed of 800 r / min. After the reaction is completed, cool to room temperature to obtain a plant protein adhesive for artificial panels.

[0111] Comparative Example 5: Plant protein adhesive for artificial boards

[0112] The difference between this comparative example and Example 3 is that no plant colloid powder and alkaline regulator are added. The specific preparation method is:

[0113] (1) adding soybean protein powder and deionized water into a reactor, stirring at 50° C. and 800 r / min for 1 h to obtain a plant protein solution;

[0114] (2) The plant protein solution was heated to 65° C. and stirred for 0.5 h at a stirring speed of 800 r / min, and then cooled to room temperature to obtain a plant protein adhesive for artificial panels.

[0115] Test Example 1:

[0116] According to the test method in GB / T 14074-2017 “Test methods for adhesives and resins for wood industry”, the performance of the plant protein adhesives for wood-based panels prepared in Examples 1-3 and Comparative Examples 1-4 was tested, and the results are shown in Table 1.

[0117] Table 1 Adhesive performance indicators

[0118]

[0119]

[0120] Reference standard: National standard GB / T 14074-2017 "Test methods for adhesives and resins for wood industry".

[0121] It can be seen from Table 1 that the storage period of the plant protein adhesive for artificial boards (Examples 1-3) prepared by the present invention is longer than that of the plant protein adhesive for artificial boards prepared by Comparative Examples 1-4, and the viscosity of the plant protein adhesive for artificial boards prepared by the present invention is within an appropriate range, and the storage period and applicable period both meet the requirements for the use of artificial boards, and there is no free formaldehyde in the adhesive.

[0122] Test Example 2:

[0123] The adhesives prepared in the above examples 1-3 and comparative examples 1-4 were respectively used to laminate three-layer plywood of 400×400 mm. The eucalyptus veneer used had a moisture content of 10-12% and a thickness of 1.7 mm. The amount of glue applied on both sides of the plywood core board was: 320 g / m 2 The hot pressing time is 5 minutes, the hot pressing temperature is 135°C, and the hot pressing pressure is 1.0-1.1MPa.

[0124] According to the test performance requirements of Class II plywood in GB / T 17657-2013 "Test methods for physical and chemical properties of wood-based panels and veneer wood-based panels": the test piece was immersed in 63°C hot water for 3 hours and then cooled at room temperature for 10 minutes. The shear strength of the test piece was tested using a universal mechanical testing machine. The test results of the plywood performance of Examples 1-3 and Comparative Examples 1-4 are shown in Table 2.

[0125] Table 2 Plywood bonding strength test results

[0126]

[0127] Reference standard: National standard GB / T 17657-2013 "Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels".

[0128] As can be seen from Table 2, the wet bonding strength of the plant protein adhesive prepared by the present invention is 0.85-0.92MPa, while in Comparative Example 1, no plant colloid powder is added, and the wet bonding strength of the prepared plant protein adhesive is only 0.48MPa, and in Comparative Example 2, unmodified jackfruit white latex is added as plant colloid powder, and the wet bonding strength of the prepared plant protein adhesive is only 0.37MPa, and in Comparative Example 3, no alkaline regulator is used, and the wet bonding strength of the prepared plant protein adhesive is only 0.46MPa. It can be seen that the combination of the modified white latex in jackfruit and the pH regulator in the present invention has a synergistic effect in improving the wet bonding strength of the plant protein adhesive. At the same time, the plywood prepared by the plant protein adhesive for artificial boards prepared by the present invention can meet the national standard requirements for Class II boards, while the plywood prepared by the adhesives of Comparative Examples 1-3 and 5 does not meet the national standard requirements. The adhesive of Comparative Example 4 can also meet the national standard requirements, but a chemical modifier is used.

[0129] The raw materials and preparation method of the plant protein adhesive for artificial panels prepared by the present invention are an organic whole. Reducing or changing the raw material composition or reducing a certain step in the preparation method will significantly reduce the performance of the prepared adhesive.

[0130] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A plant protein adhesive for artificial boards, characterized in that: It is prepared from the following raw materials in parts by weight: 150-250 parts of plant protein powder, 500-800 parts of deionized water, 50-80 parts of plant colloid powder, 4-8 parts of pH regulator; The plant colloid is prepared by the following method: The white latex in the jackfruit is washed, dried, ground and sieved to obtain latex powder; trifluoroacetic acid is added to the latex powder for reaction to obtain a reaction product, and the reaction product is subjected to reduced pressure distillation, dried, ground and sieved to obtain plant colloid powder.

2. The plant protein adhesive for artificial panels according to claim 1, characterized in that: The plant protein powder is one or more of bean protein, cereal protein, nut protein and cotton protein.

3. The plant protein adhesive for artificial panels according to claim 1, characterized in that: The pH regulator is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide and ammonia water.

4. The plant protein adhesive for artificial panels according to claim 1, characterized in that: The reaction temperature is 70-90°C, the reaction time is 1.5-2.5h, and the mass ratio of trifluoroacetic acid to latex powder is 80:

20.

5. The method for preparing the plant protein adhesive for artificial panels according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) mixing plant protein powder and deionized water, and stirring to obtain a plant protein solution; (2) adding a pH adjuster to the vegetable protein solution, heating and stirring to obtain a mixture; (3) Adding the plant colloid powder to the mixture, keeping it warm and stirring it, and after the reaction is completed, cooling it to obtain the plant protein adhesive for artificial boards.

6. The method for preparing the plant protein adhesive for artificial panels according to claim 5, characterized in that: In step (1), the stirring temperature is 45-55° C., the stirring time is 0.5-1 h, and the stirring speed is 800-1000 r / min.

7. The method for preparing the plant protein adhesive for artificial panels according to claim 5, characterized in that: In step (2), the temperature is raised to 60-70° C., the stirring speed is 800-1000 r / min, and the stirring time is 0.5-1 h.

8. The method for preparing the plant protein adhesive for artificial panels according to claim 5, characterized in that: In step (3), the stirring time is 1-1.5h, and the stirring speed is 800-1000r / min.

9. Use of the plant protein adhesive for artificial panels according to any one of claims 1 to 4 in the manufacture of artificial panels.

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