Graphite glutinous rice biomimetic glue and preparation method and application thereof

Abstract

The application relates to the field of biomimetic glue, and particularly discloses a graphite glutinous rice biomimetic glue as well as a preparation method and application thereof. The graphite glutinous rice biomimetic glue is prepared from the following raw materials in percentage by weight: glutinous rice extract 64.5-65%, plant fiber 10-20%, mineral compound 15-25%, and graphite substance 0.1-0.5%; the mineral compound is composed of nanoscale silicate and calcium-based minerals in a weight ratio of (2-4):1, and the plant fiber is bamboo fiber and / or flax fiber. The preparation method comprises the following steps: S1, ultrasonic blending and dispersion of the mineral compound and the graphite substance to obtain a mixture; and S2, adding the plant fiber and the mixture into the glutinous rice extract and uniformly stirring. The prepared graphite glutinous rice biomimetic glue is used for building boards, has good temperature resistance, humidity resistance and environmental protection, and has good bonding stability; the building boards are not prone to interlayer expansion cracking and separation under long-term complex humid and hot environment, and are suitable for high-end home decoration.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biomimetic glue, more particularly, it relates to a graphite glutinous rice biomimetic glue and a preparation method thereof. BACKGROUND

[0002] In the production process of building board materials such as plywood, particle board, fiber board, etc., adhesives play a crucial role. With the increasing demand for functionality and environmental protection of building board materials in the construction industry, adhesives not only affect the bonding strength and durability of the board, but also relate to the environmental performance and production cost of the board.

[0003] At present, the commonly used adhesives in building board materials are generally synthetic resin adhesives and biomimetic adhesives. Synthetic resin adhesives such as urea-formaldehyde resin glue, phenol-formaldehyde resin glue, polyurethane glue, epoxy resin glue, etc. These adhesives have good bonding strength, but they release harmful substances such as formaldehyde during long-term use in complex hot and humid environments, causing harm to the environment and human health. Biomimetic adhesives include cellulose glue, lignin glue, starch glue, soybean protein glue, etc. Through biomimetic modification, the adhesion performance is improved, and the adhesives have the advantages of green environmental protection, biodegradability, etc. However, these biomimetic adhesives have problems such as interlayer expansion, cracking and separation when used in long-term complex hot and humid environments, especially when used in high-end home decoration, their performance cannot meet the needs of consumers. Therefore, further research is needed on the adhesives currently used in building board materials. SUMMARY

[0004] In order to solve the problem that the existing adhesives for building board materials cannot better combine temperature resistance, humidity resistance and environmental protection when used in long-term complex hot and humid environments, the present application provides a graphite glutinous rice biomimetic glue and a preparation method and application thereof.

[0005] In a first aspect, the present application provides a graphite glutinous rice biomimetic glue, which adopts the following technical solution:

[0006] A graphite glutinous rice biomimetic glue is prepared from the following raw materials by weight percentage:

[0007] Glutinous rice extract 64.5-65%

[0008] Plant fiber 10-20%

[0009] Mineral compound 15-25%

[0010] Graphite substance 0.1-0.5%;

[0011] The mineral complex is composed of nanosilicate and calcium-based minerals in a weight ratio of (2-4):1; the nanoscale silicate is nanosilicate lithium magnesium and / or nanosilicate magnesium aluminum, and the calcium-based mineral is wollastonite and / or calcite; the plant fiber is bamboo fiber and / or flax fiber.

[0012] By adopting the above technical scheme, the bionic glue of the present application takes waxy rice extract as a dispersion system, and the waxy rice extract contains a large amount of amylopectin, which gives the bionic glue excellent bonding performance and environmental friendliness. However, the waxy rice extract is insufficient in heat resistance and moisture resistance, so plant fiber, mineral complex and graphite compound are added to the waxy rice extract. By controlling the proportion of the three, a good synergistic effect can be achieved, and they are uniformly dispersed in the waxy rice extract to form a uniform and stable adhesive system, giving the bionic glue excellent temperature resistance and moisture resistance. The plant fiber is bamboo fiber and / or flax fiber, which has good bionic performance and low cost, and can also give the bionic glue excellent mechanical strength, thereby improving the adhesion of the bionic glue. The nanoscale silicate and calcium-based mineral are used as the mineral complex in an optimal weight ratio, and the nanosilicate lithium magnesium and / or nanosilicate magnesium aluminum are used as the nanoscale silicate, and the wollastonite and / or calcite are used as the calcium-based substance, which can further disperse and combine with the waxy rice extract. Under the synergistic effect of the plant fiber and the graphite substance, the hygroscopicity of the bionic glue system can be reduced, and the temperature resistance and moisture resistance of the bionic glue can be improved.

[0013] In summary, the graphite waxy rice bionic glue prepared by the present application can effectively reduce the interlayer expansion, cracking and separation of building boards when used in long-term complex hot and humid environments, and also has good flame retardance and environmental friendliness, no formaldehyde and TVOC release, and is suitable for high-end home decoration.

[0014] Preferably, the particle size of the nanoscale silicate is 20-50 nm, and the particle size of the calcium-based substance is 0.5-2 μm.

[0015] By adopting the above technical scheme, the nanoscale silicate and calcium-based substance with an optimal particle size are compounded as the mineral complex. The nanoscale silicate with a small particle size can be interwoven and dispersed in the gap of the calcium-based substance with a large particle size, reducing the dispersion distance of the mineral complex in the waxy rice extract, improving the stability of the "skeleton" of the bionic glue, and thus improving the cohesion of the bionic glue, so as to improve the moisture resistance and heat resistance of the bionic glue, and also improve the flame retardance of the bionic glue.

[0016] Preferably, the plant fiber is a modified plant fiber, and the modified plant fiber is prepared by the following steps: adding chitosan quaternary ammonium salt and 1-butyl-3-methyl imidazole acetate into 5-15 wt% aqueous solution of alkaline hydroxide, stirring uniformly, then adding plant fiber, heating to 60-80℃, stirring and soaking for 20-40 min, washing with water and drying to obtain the modified plant fiber.

[0017] By adopting the above technical solution, although the plant fiber has good adsorption performance, it is found in use that the dispersion performance of the plant fiber in the biomimetic glue with other components is low, which makes the biomimetic glue prone to moisture absorption in a humid and hot environment, reducing the temperature resistance and moisture resistance of the biomimetic glue. Therefore, by adding chitosan quaternary ammonium salt and 1-butyl-3-methyl imidazole acetate into the aqueous solution of alkaline hydroxide and treating the plant fiber under the optimal temperature and time conditions, the plant fiber can be fluffed, the molecular chain segments of the plant fiber are more soft and loose, and the chitosan quaternary ammonium salt and 1-butyl-3-methyl imidazole acetate can produce good synergistic effect to form a uniform adsorption film on the surface of the loose molecular chain segments, which can improve the adsorption uniformity and stability of the mineral compound and graphite material, significantly improve the compatibility and binding force between the plant fiber and the mineral compound and the graphite material, and further reduce the problem of easy moisture absorption of the plant fiber, further improve the cohesion of the biomimetic glue as the "supporting skeleton", improve the durability and bonding stability of the biomimetic glue in a complex humid and hot environment, and reduce the interlayer expansion, cracking and separation problems of the building board in use.

[0018] Preferably, the modified plant fiber is prepared from the following raw materials by weight:

[0019] Plant fiber 4-6 parts

[0020] 5-15 wt% aqueous solution of alkaline hydroxide 8-10 parts

[0021] Chitosan quaternary ammonium salt 0.2-0.4 parts

[0022] 1-butyl-3-methyl imidazole acetate 0.3-0.5 parts

[0023] The aqueous solution of alkaline hydroxide is any one of aqueous solution of sodium hydroxide and aqueous solution of potassium hydroxide.

[0024] By adopting the above technical solution, the amount of each component in the modified plant fiber is optimized, which can improve the modification efficiency of the plant fiber while reducing the problem of corrosion of the plant fiber due to excessive aqueous solution of hydroxide, thereby affecting the mechanical strength.

[0025] Preferably, the plant fiber has a size of 1.1-1.5 dtex and a length of 5-10 um.

[0026] By adopting the above technical solution, the plant fiber with the optimal size has good supportability and dispersibility, which can further improve the overall bonding strength and durability of the biomimetic glue.

[0027] Preferably, the waxy rice extract is prepared by the following steps:

[0028] The waxy rice powder and water are mixed in a weight ratio of 1:(10-12), 0.1-0.3wt% of amylase based on the weight of the waxy rice powder is added for enzymatic hydrolysis, the enzymatic hydrolysis temperature is 40-50℃, the enzymatic hydrolysis time is 1-2h, then 1-2wt% of polyaspartic acid based on the weight of the waxy rice powder is added and mixed uniformly to prepare the waxy rice extract.

[0029] By adopting the above technical solution, since the waxy rice contains a large amount of amylopectin, although it has good bonding performance, it will affect the fluidity and cohesion of the glue when used in biomimetic glue. Therefore, the application uses amylase and polyaspartic acid to prepare waxy rice extract, uses amylase to enzymatically hydrolyze the waxy rice powder under optimal temperature and time conditions, optimizes the ratio of amylose and amylopectin in the waxy rice extract, and further gelatinizes with polyaspartic acid to improve the fluidity and cohesion of the biomimetic glue. At the same time, polyaspartic acid can further improve the bonding performance of the waxy rice extract with plant fiber, mineral compound and graphite material. Through the process of enzymatic hydrolysis combined with polyaspartic acid, the waxy rice extract prepared in this way is applied to biomimetic glue, which can maintain good stability and bonding strength performance in complex humid and hot environments.

[0030] Preferably, the amylase is composed of alpha-amylase and isoamylase in a weight ratio of 1:(0.1-0.25).

[0031] By adopting the above technical solution, alpha-amylase and isoamylase with an optimal weight ratio are used as amylase, which can better optimize the ratio of amylose and amylopectin in the waxy rice extract, and synergistically improve the bonding stability of the waxy rice extract, thereby improving the moisture and heat bonding stability of the biomimetic glue.

[0032] Preferably, the graphite material includes graphite and / or graphene.

[0033] By adopting the above technical solution, the graphite material has excellent heat conduction performance and flame retardant properties, and also has good thermal expansion performance, which can effectively repair the tiny cracks generated by the building board in complex humid and hot environments. This self-repairing ability significantly reduces the risk of interlayer separation and cracking of the building board, thereby improving the overall stability and service life of the board, and is particularly suitable for high-end home decoration scenes with high environmental protection and durability requirements.

[0034] In a second aspect, the application provides a preparation method of a graphite glutinous rice biomimetic glue, which adopts the following technical scheme:

[0035] A preparation method of a graphite glutinous rice biomimetic glue, comprising the following steps:

[0036] S1, ultrasonic blending and dispersing mineral compound and graphite substance to obtain a mixture;

[0037] S2, adding plant fiber and the mixture into glutinous rice extract, stirring uniformly to obtain the graphite glutinous rice biomimetic glue.

[0038] By adopting the above technical scheme, the mineral compound and the graphite substance are first subjected to ultrasonic blending and dispersing treatment, so that the mineral compound and the graphite substance are fully mixed and dispersed, and then the plant fiber and the mixture are added into the glutinous rice extract and stirred uniformly, so that the mixture and the plant fiber are uniformly dispersed by using the bonding and dispersing properties of the glutinous rice extract, thereby obtaining the biomimetic glue with good fluidity, uniformity and cohesion.

[0039] In a third aspect, the application provides an application of a graphite glutinous rice biomimetic glue, which adopts the following technical scheme:

[0040] An application of a graphite glutinous rice biomimetic glue, which is applied to building boards.

[0041] By adopting the above technical scheme, the application of the graphite glutinous rice biomimetic glue in building boards can significantly improve the bonding strength and durability of the boards, and is particularly suitable for high-end home decoration with high performance requirements.

[0042] In summary, the application has at least one of the following beneficial technical effects:

[0043] 1. The graphite glutinous rice biomimetic glue of the application is compounded by glutinous rice extract, plant fiber, mineral compound and graphite substance, uses bamboo fiber and / or flax fiber as plant fiber, uses nanometer lithium magnesium silicate and / or nanometer magnesium aluminum silicate as nanometer silicate, and uses wollastonite and / or calcite as calcium-based substance as mineral compound, and each component synergizes with each other, is used in building boards, has good temperature resistance, humidity resistance and environmental protection, has good bonding stability, and is suitable for high-end home decoration.

[0044] 2. By using alkaline hydroxide aqueous solution, chitosan quaternary ammonium salt and 1-butyl-3-methyl imidazole acetate plant fiber to modify the plant fiber, the bulkiness and adsorbability of the plant fiber can be improved, the bonding performance of the plant fiber with the mineral compound and the graphite substance can be improved, and the temperature resistance and humidity resistance of the biomimetic glue can be further improved.

[0045] 3. The waxy rice extract is prepared by using waxy rice powder, water, amylase consisting of alpha-amylase and isoamylase, and polyaspartic acid, the process of enzymolysis and cooperation of polyaspartic acid is used to improve the problem of low flowability and cohesion of biomimetic glue caused by high content of amylopectin in waxy rice powder, the cohesion of biomimetic glue is improved, and the adhesive stability of biomimetic glue in long-term humid heat environment is improved.

[0046] 4. The preparation method of the biomimetic glue of the application, the mineral compound and the graphite substance are blended and ultrasonically dispersed, and then mixed with the plant fiber and the waxy rice extract, so that the uniform dispersion and sufficient reaction of the components are ensured, the process flow is simplified, the production efficiency is improved, the method is suitable for industrial production, and the viscosity stability of the prepared biomimetic glue is good. DETAILED DESCRIPTION

[0047] 1. Plant fiber: bamboo fiber 1.1-1.5 dtex, length 5-10 μm

[0048] Flax fiber 1.1-1.5 dtex, length 5-10 μm;

[0049] 2. Nanoscale silicate: nanoscale lithium magnesium silicate: particle size 20-50 nm

[0050] Nanoscale magnesium aluminum silicate; particle size 20-50 nm;

[0051] 3. Calcium-based minerals: wollastonite: particle size 0.5-2 μm

[0052] Calcite: particle size 0.5-2 μm;

[0053] 4. Chitosan quaternary ammonium salt: Ping polybiotic, content 99%;

[0054] 5. 1-Butyl-3-methylimidazole acetate: CAS number 284049-75-8, content 99%;

[0055] 6. Alpha-amylase: enzyme activity 100,000 u / g;

[0056] 7. Isoamylase: enzyme activity 100,000 u / g;

[0057] 8. Polyaspartic acid: CAS number 25608-40-6, Langboman, content 98%;

[0058] 9. Graphite substance: graphite 8000 mesh

[0059] Graphene 8000 mesh.

[0060] Preparation example of modified plant fiber

[0061] Preparation example 1

[0062] Preparation Example 1 discloses a modified plant fiber prepared by the following steps:

[0063] 0.2 kg of chitosan quaternary ammonium salt and 0.5 kg of 1-butyl-3-methyl imidazole acetate were added to 8 kg of 5 wt% sodium hydroxide aqueous solution, after stirring uniformly, 4 kg of bamboo fiber with specification of 1.1 dtex, 5 μm was added as plant fiber, the temperature was raised to 80℃, and stirring soaking was performed for 20 min, and then water washing and drying were performed to prepare the modified plant fiber.

[0064] Preparation Examples 2-3

[0065] Preparation Examples 2-3 are different from Preparation Example 1 in that the raw material usage amount and preparation conditions are different, and specific reference can be made to Table 1 below.

[0066] Table 1 Parameter table of Preparation Examples 1-3

[0067]

[0068]

[0069] Preparation Example 4

[0070] Preparation Example 4 is different from Preparation Example 1 in that 1-butyl-3-methyl imidazole acetate is replaced by chitosan quaternary ammonium salt in equal amount, and the others are the same as Preparation Example 1.

[0071] Preparation Example 5

[0072] Preparation Example 5 is different from Preparation Example 1 in that chitosan quaternary ammonium salt is replaced by chitosan in equal amount, and the others are the same as Preparation Example 1.

[0073] Preparation Example 6

[0074] Preparation Example 6 is different from Preparation Example 1 in that 1-butyl-3-methyl imidazole acetate is replaced by γ-aminopropyl triethoxysilane in equal amount, and the others are the same as Preparation Example 1.

[0075] Preparation Example of waxy rice extract

[0076] Preparation Example 7

[0077] 1 kg of waxy rice powder and 10 kg of water were mixed uniformly, 1 g of amylase (α-amylase and pullulanase = 1:0.2) was added for enzymolysis, the enzymolysis temperature was 40℃, the enzymolysis time was 2 h, then 20 g of polyaspartic acid was added and mixed uniformly to prepare the waxy rice extract.

[0078] Preparation Examples 8-9

[0079] Preparation Examples 8-9 are different from Preparation Example 1 in that the raw material usage amount and preparation conditions are different, and specific reference can be made to Table 2 below.

[0080] Table 2 parameters of preparation examples 7-9

[0081]

[0082]

[0083] Preparation example 10

[0084] Preparation example 10 is different from preparation example 7 in that the amylase is composed of alpha-amylase and isoamylase with a weight ratio of 1:0.1, and the rest is the same as preparation example 7.

[0085] Preparation example 11

[0086] Preparation example 11 is different from preparation example 7 in that the amylase is composed of alpha-amylase and isoamylase with a weight ratio of 1:0.25, and the rest is the same as preparation example 7.

[0087] Preparation example 12

[0088] Preparation example 12 is different from preparation example 7 in that 1 kg of waxy rice powder and 10 kg of water are mixed evenly, 10 g of citric acid and 5 g of hydrogen peroxide are added for hydrolysis, the hydrolysis temperature is 40℃, the hydrolysis time is 1 h, then 20 g of polyaspartic acid is added and mixed evenly to prepare waxy rice extract.

[0089] Example

[0090] Example 1

[0091] Example 1 discloses a graphite waxy rice biomimetic glue, which is prepared by the following steps:

[0092] S1, 1.5 kg of mineral compound (composed of nano-magnesium aluminum silicate and wollastonite with a weight ratio of 2:1) and 0.01 kg of graphene as graphite material are ultrasonically blended and dispersed, the ultrasonic frequency is controlled at 40 kHz, and the dispersion time is 30 min to prepare a mixture;

[0093] S2, 2 kg of bamboo fiber with a specification of 1.1 dtex, 5 μm is added to 6.49 kg of commercially available waxy rice extract solution as plant fiber and the mixture prepared in step S1, stirring for 40 min, stirring evenly, to prepare a graphite waxy rice biomimetic glue;

[0094] The waxy rice extract solution is prepared by waxy rice extract and water with a weight ratio of 10:1, and the waxy rice extract is from Waterless Bio, with a mesh size of 80-100 mesh.

[0095] Examples 2-3

[0096] Examples 2-3 are different from example 1 in that the raw material dosage and preparation conditions are different, see table 3 below.

[0097] Table 3. Parameters of Examples 1-3

[0098]

[0099] Example 4

[0100] Example 4 differs from Example 1 in that the particle size of the nano-magnesium aluminum silicate is 20 nm, the particle size of the wollastonite is 0.5 μm, and the rest is the same as Example 1.

[0101] Example 5

[0102] Example 5 differs from Example 1 in that the particle size of the nano-magnesium aluminum silicate is 50 nm, the particle size of the wollastonite is 2 μm, and the rest is the same as Example 1.

[0103] Examples 6-8

[0104] Examples 6-8 differ from Example 5 in that the sources of the plant fiber and the glutinous rice extract are different, as shown in Table 4 below.

[0105] Table 4. Sources of plant fiber and glutinous rice extract of Examples 6-8

[0106] Examples Sources of plant fibers Sources of waxy rice extract Example 6 Preparation Example 1 Preparation Example 7 Example 7 Preparation Example 2 Preparation Example 8 Example 8 Preparation Example 3 Preparation Example 9

[0107] Example 9

[0108] Example 9 differs from Example 6 in that the plant fiber is derived from Preparation Example 4, and the rest is the same as Example 6.

[0109] Example 10

[0110] Example 10 differs from Example 6 in that the plant fiber is derived from Preparation Example 5, and the rest is the same as Example 6.

[0111] Example 11

[0112] Example 11 differs from Example 6 in that the plant fiber is derived from Preparation Example 6, and the rest is the same as Example 6.

[0113] Example 12

[0114] Example 12 differs from Example 6 in that the glutinous rice extract is derived from Preparation Example 10, and the rest is the same as Example 6.

[0115] Example 13

[0116] Example 13 differs from Example 6 in that the glutinous rice extract is derived from Preparation Example 11, and the rest is the same as Example 6.

[0117] Example 14

[0118] Example 14 differs from Example 6 in that the waxy rice extract is derived from Preparation Example 12, and the rest is the same as Example 6.

[0119] Comparative Example

[0120] Comparative Example 1

[0121] Comparative Example 1 differs from Example 1 in that the mineral complex is composed of aluminum silicate and wollastonite in a weight ratio of 2:1, the particle size of the aluminum silicate is 100 nm, the particle size of the wollastonite is 200 nm, and the rest is the same as Example 1.

[0122] Comparative Example 2

[0123] Comparative Example 2 differs from Example 1 in that the mineral complex is diatomite, the particle size of the diatomite is 200 nm, and the rest is the same as Example 1.

[0124] Comparative Example 3

[0125] Comparative Example 3 differs from Example 1 in that the amount of plant fiber is 3 kg, the amount of mineral complex is 0.5 kg, and the rest is the same as Example 1.

[0126] Comparative Example 4

[0127] Comparative Example 4 differs from Example 1 in that graphene is replaced with an equal amount of mineral complex, and the rest is the same as Example 1.

[0128] Performance Test

[0129] The following tests the performance of the graphite waxy rice glue prepared in Examples 1-14 and Comparative Examples 1-4:

[0130] 1. Initial glue strength test

[0131] The graphite waxy rice biomimetic glue is coated on the wood board at a coating amount of 100 g / m 2 , two layers of wood boards are laminated, and the laminated board with a thickness of 5 mm is prepared by curing at a temperature of 60℃ for 2h. Referring to the test method in GB / T 17657-2022 "Test Methods for Physicochemical Properties of Wood-based Panels and Veneered Wood-based Panels", the bonding strength of the laminated board (unit: MPa) is tested, and the test results are recorded;

[0132] 2. Temperature-resistant bonding strength test

[0133] The graphite waxy rice biomimetic glue is coated on the wood board at a coating amount of 100 g / m 2The graphite glutinous rice biomimetic glue was coated on the wood board at a coating amount of 100 g / m2, two layers of wood boards were laminated, and a plywood with a thickness of 5 mm was prepared by curing at a temperature of 60 °C for 2 h. The plywood was placed at a temperature of 120 °C for 7 days, the bonding strength (unit: MPa) of the plywood was tested according to the test method in GB / T 17657-2022 “Test methods of physical and chemical properties of wood-based panels and veneered wood-based panels”, and the test results were recorded;

[0134] 3. Hot and humid bonding strength test

[0135] The graphite glutinous rice biomimetic glue was coated on the wood board at a coating amount of 100 g / m 2 The plywood with a thickness of 5 mm was prepared by laminating two layers of wood boards, and curing at a temperature of 60 °C for 2 h. The plywood was placed in a constant temperature and humidity chamber at a temperature of 85 °C and a humidity of 85%, and tested for 7 days. The bonding strength (unit: MPa) of the plywood was tested according to the test method in GB / T 17657-2022 “Test methods of physical and chemical properties of wood-based panels and veneered wood-based panels”, and the test results were recorded;

[0136] The following are the performance test data of the graphite glutinous rice biomimetic glue prepared in Examples 1-14 and Comparative Examples 1-4. See Table 5 below for details.

[0137] Table 5 Performance test data of Examples 1-14 and Comparative Examples 1-4

[0138]

[0139]

[0140] It can be concluded from Examples 1-3 and Examples 4-5, Comparative Examples 1-3 and Table 5 that, compared with Example 1, Examples 4-5 further optimize the particle size of the nanoscale silicate and calcium-based substance, the initial bonding strength of the prepared graphite glutinous rice biomimetic glue is improved, and the decline rate of the bonding strength after the temperature resistance and moisture resistance tests is reduced. This may be because the nanoscale silicate and calcium-based substance with an optimal particle size can produce a better synergistic effect, can improve the cohesion of the graphite glutinous rice glue, and thus can improve the temperature resistance and moisture resistance bonding properties of the graphite glutinous rice glue. In Comparative Example 1, nanoscale silicate is replaced by aluminum silicate, and in Comparative Example 2, the mineral compound is replaced by diatomite, and the initial bonding strength of the prepared graphite glutinous rice biomimetic glue is significantly reduced, and the decline rate of the bonding strength after the temperature resistance and moisture resistance tests is significantly increased. In Comparative Example 3, the amount of plant fiber is increased, and the amount of mineral compound is significantly reduced, and the decline rate of the bonding strength of the prepared graphite glutinous rice biomimetic glue after the temperature resistance and moisture resistance tests is significantly increased, and the glue board is obviously cracked. This may be because the amount of mineral compound is reduced, the synergistic dispersibility of plant fiber and graphite substance in the glutinous rice extract is reduced, and thus the temperature resistance and moisture resistance of the graphite glutinous rice biomimetic glue are significantly reduced.

[0141] In combination with Example 5 and Examples 6-14 and in combination with Table 5, it can be concluded that using the modified plant fiber and waxy rice extract of the present application can produce a better synergistic effect, and the stone-ground waxy rice biomimetic glue prepared has a higher bonding strength, and the bonding strength can remain good stability after the temperature resistance and moisture resistance tests. Compared with Example 6, Examples 9-11 change the preparation components of the modified plant fiber, and the initial bonding strength of the stone-ground waxy rice biomimetic glue prepared is reduced, and the decline rate of the bonding strength after the temperature resistance and moisture resistance tests is also increased. Compared with Example 6, Examples 12-13 further optimize the type of amylase, and the initial bonding strength of the stone-ground waxy rice biomimetic glue prepared is increased, and the bonding strength after the temperature resistance test appears a slight rise, and the decline rate of the bonding strength after the moisture resistance test is also lower, which may be because the excessive decomposition of pullulan in waxy rice powder by the pullulanase in Example 6 reduces the bonding strength of the stone-ground waxy rice glue prepared, while the optimal ratio of α-amylase and isoamylase in Examples 12-13 can better optimize the ratio of amylopectin and amylose in the waxy rice extract, thereby improving the bonding stability of the stone-ground waxy rice biomimetic glue. Compared with Example 6, Example 14 changes the enzymatic hydrolysis process in the preparation process of the waxy rice extract, and then gelatinizes with polyaspartic acid, and the initial bonding strength of the stone-ground waxy rice biomimetic glue prepared is reduced, and the decline rate of the bonding strength after the temperature resistance and moisture resistance tests is also increased, which may be that the preparation process of hydrolyzing first and then combining with polyaspartic acid reduces the bonding performance of the waxy rice extract, thereby reducing the bonding stability, which further indicates that the waxy rice extract prepared by the preparation process of the present application of waxy rice powder enzymolysis combined with polyaspartic acid can significantly improve the bonding stability of the biomimetic glue.

[0142] Further, in combination with Example 1 and Comparative Example 4 and in combination with Table 5, it can be concluded that using the stone-ground substance and mineral complex of the present application for compounding can improve the bonding stability of the stone-ground waxy rice glue prepared. Compared with Example 1, the bonding stability of Comparative Example 4 is reduced, and the cracking condition changes from slight cracking to cracking, which may be because the absence of the stone-ground substance reduces the expansion self-repairing performance of the stone-ground waxy rice biomimetic glue in a high-temperature environment, thereby making the cracking condition more serious.

[0143] 4. Application test

[0144] 1) The stone-ground waxy rice glue prepared in Example 1, Example 6 and Comparative Example 2 was subjected to application test: the stone-ground waxy rice biomimetic glue was coated on the wood board at a coating amount of 100 g / m 2 , two layers of wood boards were laminated, and the wood board was cured at a temperature of 60°C for 2h to prepare a plywood with a thickness of 5mm.

[0145] According to the test method in GB / T 9846-2015 "Back-through plywood", 6 test pieces are taken, the cumulative peeling length of each test piece on the same glue layer is not more than 25mm, the immersion peeling performance of the plywood is tested, and the number of test pieces meeting the standard is greater than or equal to 90% of the total number of test pieces; according to the test method in GB / T 39600-2021 "Classification of formaldehyde emission of wood-based panels and their products", the formaldehyde emission (unit: mg / m 3 , 52h) is tested.

[0146] 2) The following application tests are carried out on the graphite glutinous rice glue prepared in Example 1, Example 6 and Comparative Example 2: the graphite glutinous rice glue is coated on the glass magnesium plate at a coating amount of 100g / m 2 , and two layers of glass magnesium plates are laminated, and a fire-retardant composite board with a thickness of 5mm is prepared by curing at a temperature of 60℃ for 2h.

[0147] According to the test methods in GB 8624-2012 "Classification of combustion performance of building materials and products" and GB 20286-2006 "Combustion performance requirements and identification of flame-retardant products and components in public places", the combustion performance grade of the fire-retardant composite board is tested.

[0148] The following are the application performance test data of the graphite glutinous rice glue prepared in Example 1, Example 6 and Comparative Example 2, which are shown in Table 6 below.

[0149] Table 6 Application performance data of Example 1, Example 6 and Comparative Example 2

[0150]

[0151] Combining Example 1, Example 6 and Comparative Example 2 and Table 6, it can be concluded that the graphite glutinous rice glue prepared in the present application meets the immersion peeling performance of plywood, and the formaldehyde emission is <0.01 / mg / m 3 , which is much lower than the national standard EN F grade ≤0.025mg / m 3 ; when applied to fire-retardant composite boards, the combustion performance reaches the non-combustible A (A2-s1, d0, t0) level, and is suitable for use in building boards, especially for high-end home decoration. The immersion peeling performance of the plywood in Comparative Example 2 is unqualified, which may be due to the use of diatomite to reduce the temperature resistance and humidity resistance of the graphite glutinous rice biomimetic glue.

[0152] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the present embodiments without creative contribution after reading the present specification, but as long as the scope of the claims of the present application is within the scope of the present application.

Claims

1. A graphite-rice biomimetic glue, characterized in that, It is prepared from the following raw materials in weight percentage: Waxy rice extract 64.5-65% Plant fiber 10-20% Mineral compound 15-25% Graphite substance 0.1-0.5%; The mineral compound is composed of nano-silicate and calcium-based mineral in weight ratio of (2-4):1; the nano-silicate is nano-lithium magnesium silicate and / or nano-magnesium aluminum silicate, the calcium-based mineral is wollastonite and / or calcite, and the plant fiber is bamboo fiber and / or flax fiber; the waxy rice extract is prepared by the following steps: Waxy rice powder and water are mixed in weight ratio of 1:(10-12), 0.1-0.3wt% of amylase is added to the waxy rice powder for enzymatic hydrolysis, the enzymatic hydrolysis temperature is 40-50℃, the enzymatic hydrolysis time is 1-2h, then 1-2wt% of polyaspartic acid is added to the waxy rice powder, and the mixture is uniformly mixed to prepare the waxy rice extract; the amylase is composed of α-amylase and isoamylase in weight ratio of 1:(0.1-0.25).

2. The graphite-rice biomimetic glue according to claim 1, characterized in that, The particle size of the nano-silicate is 20-50nm, and the particle size of the calcium-based mineral is 0.5-2µm.

3. The graphite-rice biomimetic glue according to claim 1, wherein, The plant fiber is modified plant fiber, which is prepared by the following steps: Chitosan quaternary ammonium salt and 1-butyl-3-methyl imidazole acetate are added to 5-15wt% alkaline hydroxide aqueous solution, the mixture is stirred uniformly, then plant fiber is added, the temperature is raised to 60-80℃, and the mixture is stirred and soaked for 20-40min, and then the mixture is washed with water and dried to prepare the modified plant fiber.

4. The graphite-rice biomimetic glue according to claim 3, characterized in that, The modified plant fiber is prepared from the following raw materials in weight percentage: Plant fiber 4-6 parts 5-15wt% alkaline hydroxide aqueous solution 8-10 parts Chitosan quaternary ammonium salt 0.2-0.4 parts 1-butyl-3-methyl imidazole acetate 0.3-0.5 parts; The alkaline hydroxide aqueous solution is any one of sodium hydroxide aqueous solution and potassium hydroxide aqueous solution.

5. The graphite-rice biomimetic glue according to claim 4, characterized in that, The specification of the plant fiber is 1.1-1.5dtex, and the length is 5-10µm.

6. The graphite-rice biomimetic glue according to claim 1, wherein, The graphite substance includes graphite and / or graphene.

7. A method of preparing the graphite-rice biomimetic glue according to any one of claims 1-6, characterized by, The method comprises the following steps: S1, ultrasonic blending and dispersion of the mineral compound and the graphite substance to prepare a mixture; S2, adding the plant fiber and the mixture to the waxy rice extract, stirring uniformly to prepare a graphite waxy rice biomimetic glue.

8. Use of the graphite glutinous rice biomimetic glue according to any one of claims 1-6, characterized in that, It is applied to building boards.

Images