Environment-friendly shaving board and preparation method thereof

Abstract

The present application relates to the technical field of furniture board, and discloses an environment-friendly shaving board and a preparation method thereof, wherein pentaerythritol glycidyl ether, hexadecyl dimethyl tertiary amine and epichlorohydrin are used as raw materials, a multi-epoxy quaternary ammonium salt crosslinking agent is obtained, and the multi-epoxy quaternary ammonium salt crosslinking agent, soybean protein and polyhydroxy phytic acid, and graphene oxide produce multiple key cooperation, an environment-friendly flame-retardant and mildew-proof adhesive is obtained, and the environment-friendly flame-retardant and mildew-proof adhesive is mixed with bamboo wood shavings, and then hot-pressed to form the environment-friendly shaving board; the polyhydroxy phytic acid is rich in phosphorus elements and has a flame-retardant effect; the quaternary ammonium salt group has a good prevention and control effect on mold and discoloration bacteria; the multi-epoxy quaternary ammonium salt crosslinking agent is equivalent to a physical crosslinking point in the shaving board, and the bamboo wood shavings are anchored together with the adhesive, so that the further expansion of micro-cracks into large cracks is limited, the board blank is more compact, and the effect of strengthening and toughening is achieved; the raw materials are widely sourced, non-toxic, harmless and free of formaldehyde release, and green and environment-friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of furniture board, in particular to an environment-friendly shaving board and a preparation method thereof. BACKGROUND

[0002] The shaving board belongs to one kind of artificial board, which is made of wood chips or other wood fiber materials and adhesive under certain temperature and pressure, and can be used to manufacture furniture, desks, floors, walls and office supplies. In the preparation process of the shaving board, the adhesive plays a key role in bonding the shaving particles together to form a stable structure, so the performance and environmental protection of the adhesive directly affect the overall quality and environmental protection level of the shaving board. In the preparation of traditional shaving board, the commonly used adhesive such as urea-formaldehyde resin adhesive may release harmful substances such as free formaldehyde, which will cause harm to the environment and human health, and has poor environmental protection performance. If this kind of environmental protection problem cannot be properly handled, it will affect the overall development of the shaving board.

[0003] The main raw materials of the shaving board are wood chips and adhesive. The natural adhesive such as soybean protein adhesive can significantly reduce the formaldehyde emission, even reaching the standard of no formaldehyde emission. However, it has low strength and poor water resistance. In addition, the existing shaving board has high hygroscopicity, poor corrosion and mildew resistance, and is easy to breed bacteria in humid environment, so the service life is short. Moreover, the raw materials of the shaving board are mainly composed of cellulose, hemicellulose and lignin, which are flammable and easy to burn at high temperature, releasing flammable gas and heat, which may cause fire. Patent No. CN106863528B discloses a preparation method of antibacterial and mildew-proof environment-friendly shaving board. Modified defatted soybean paste, leveling agent, organic bentonite and additives are fully stirred and uniformly obtained as A agent. Bee glue powder, antioxidant and emulsifier are mixed and uniformly obtained as B agent. A agent and B agent are mixed in a mass ratio of 4-5:1 to obtain adhesive. The antibacterial and mildew-proof effect is realized by using the natural broad-spectrum antibacterial and bactericidal property of bee glue, but the use is complex, the double-component adhesive needs to be prepared, the antibacterial and mildew-proof effect is limited, and the flame retardant property of the shaving board is not improved, which is not suitable for industrial production.

[0004] In the prior art, inorganic flame retardants or mildew-proof agents are generally added for flame retardation and mildew-proofing, but the shaving board prepared has certain odor, which affects the indoor environmental quality of people's life, is not environmentally friendly, and too much inorganic filler will reduce the mechanical properties of the shaving board. The present application aims to prepare a quaternary ammonium salt type epoxy antibacterial agent, which tightly combines phytic acid, graphene and soybean protein through various bonding effects, so as to enhance and toughen the shaving board, realize green environmental protection, mildew-proofing and flame retardation, and broaden the application range of the shaving board. SUMMARY

[0005] The present application aims to solve the problems of the prior art, such as large moisture absorption, poor mildew resistance, easy release of formaldehyde gas, poor environmental protection, easy burning at high temperature, and poor flame retardancy, and provides an environmentally friendly particle board and a preparation method thereof.

[0006] The present application is realized by the following technical solutions:

[0007] A preparation method of an environmentally friendly particle board comprises the following steps:

[0008] Step (1), preparing shavings: the bamboo and wood waste is peeled, screened, and impurities are removed, and then added to a pulverizer to process shavings with a length of 100-120 mm, a width of 20-50 mm, and a thickness of 0.3-0.5 mm, to obtain shavings raw materials.

[0009] Step (2), preparing the shavings mixed with glue: the shavings raw materials are dried and placed in a drum glue mixer, and an environmentally friendly flame-retardant mildew-resistant adhesive and paraffin are added, and stirred at 500-800 r / min for 1-3 h, and dried to a water content of 3-5 wt%, to obtain shavings mixed with glue.

[0010] Step (3), preparing the environmentally friendly particle board: the shavings mixed with glue are manually laid into a single-layer board blank, and then loaded into a steel membrane frame to lay into a three-layer structure of upper and lower surface layers and a core layer, and then placed in a hot press for hot pressing, demolding and curing, to obtain the environmentally friendly particle board.

[0011] Preferably, in step (2), the mass ratio of the shavings raw materials, the environmentally friendly flame-retardant mildew-resistant adhesive, and the paraffin is 100:3-15:2-4.

[0012] Preferably, in step (3), the hot pressing pressure is 3-6 MPa, the hot pressing time is 8-15 min, and the hot pressing temperature is 130-150 DEG C.

[0013] Preferably, the preparation method of the environmentally friendly flame-retardant mildew-resistant adhesive in step (2) comprises the following steps:

[0014] Step S1, under a nitrogen atmosphere, a reaction flask is added with pentaerythritol glycidyl ether and ethanol, stirred uniformly, and then added with hexadecyl dimethyl tertiary amine and hydrochloric acid, stirred and reacted, after the reaction is completed, distilled under reduced pressure, and recrystallized with a mixed solvent of acetone and ethyl acetate, to obtain a long-chain quaternary ammonium salt intermediate.

[0015] Step S2, under a nitrogen atmosphere, a reaction flask is added with the long-chain quaternary ammonium salt intermediate and acetonitrile, stirred uniformly, and then added with epichlorohydrin and sodium hydroxide, stirred and reacted, after the reaction is completed, distilled under reduced pressure, to obtain a polycyclic quaternary ammonium salt crosslinking agent.

[0016] Step S3: Mix soybean protein, polyhydroxy phytic acid, and graphene oxide dispersion evenly, sonicate for 15-25 minutes, then add polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and vigorously homogenize at room temperature for 20-40 minutes to obtain an environmentally friendly flame-retardant and mildew-proof adhesive.

[0017] Preferably, in step S1, the mass ratio of pentaerythritol glycidyl ether, hexadecyl dimethyl tertiary amine, and hydrochloric acid is 100:305-330:15-25.

[0018] Preferably, the reaction temperature in step S1 is 65-80℃ and the reaction time is 24-48h.

[0019] Preferably, in step S2, the mass ratio of the long-chain quaternary ammonium salt intermediate, epichlorohydrin, and sodium hydroxide is 100:28-40:10-15.

[0020] Preferably, the reaction temperature in step S2 is 45-60℃ and the reaction time is 5-12h.

[0021] Preferably, in step S3, the mass ratio of soybean protein, polyhydroxyphytic acid, graphene oxide dispersion, and polyepoxy quaternary ammonium salt crosslinking agent is 100:4-8:20-35:2-10.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention uses pentaerythritol glycidyl ether, hexadecyl dimethyl tertiary amine, and epichlorohydrin as raw materials to obtain a polyepoxy quaternary ammonium salt crosslinking agent through a chemical reaction. Then, soybean protein, polyhydroxy phytic acid, and graphene oxide are tightly linked together through this crosslinking agent to obtain an environmentally friendly flame-retardant and mildew-proof adhesive. Finally, bamboo and wood waste is shaving, mixed with adhesive, and hot-pressed to obtain an environmentally friendly particleboard.

[0024] Polyhydroxyphosphoric acid is rich in phosphorus. As combustion proceeds, intermolecular interactions occur between adhesive components. Rapid carbonization is formed through the thermal condensation of phosphorus functional groups in polyhydroxyphytic acid molecules, reducing the flammability of the material. At the same time, the layered structure of graphene oxide provides a stronger physical barrier to protect carbonized residues than traditional inorganic compounds, providing thermal shielding for the carbonized layer. This effectively prevents the volatilization of flue gas particles during combustion and increases the diffusion paths of oxygen and heat sources, thereby improving the flame retardant performance of particleboard. In addition, phytic acid and soybean protein are low-cost and widely available biomass materials that are non-toxic, harmless, formaldehyde-free, green, environmentally friendly, and pollution-free. Their structure contains antibacterial quaternary ammonium salt groups, which have good control effects on molds and discoloration bacteria. They are adsorbed onto the cell surface of molds and discoloration bacteria through electrostatic adsorption. Subsequently, their hydrophobic long-chain alkyl groups insert into the lipid layer of the cell membrane, changing the permeability of the cell membrane, disrupting the cell membrane composition, causing cell membrane structural disorder, affecting the normal physiological function of the cell, and ultimately leading to cell death.

[0025] The environmentally friendly flame-retardant and mildew-resistant adhesive contains polyhydroxy phytic acid with a cyclic structure of multidentate ligands. The abundant hydroxyl groups in its structure have strong hydrogen bonding with graphene oxide, allowing phytic acid to insert into the interlayer spacing of graphene sheets and crosslink with multiple graphene sheets to form a dense crosslinked network structure. The polyepoxy quaternary ammonium salt crosslinking agent has four epoxy groups at the chain ends, which can undergo ring-opening reactions with the hydroxyl groups in phytic acid and the amino groups in soybean protein to form a covalent bond interface. The polyepoxy quaternary ammonium salt crosslinking agent is equivalent to a physical crosslinking point in particleboard. It is "anchored" to bamboo and wood shavings by the adhesive, which limits the further expansion of microcracks into large cracks, making the board more compact and achieving the effect of strengthening and toughening. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments. These embodiments will help those skilled in the art to further understand this invention, but do not limit the invention in any way. Unless otherwise stated, the raw materials and reagents used in this application are commercially available products or can be prepared by known methods.

[0027] Soy protein (46% protein) was purchased from Shandong Xiangchi Grain and Oil Co., Ltd., China.

[0028] Pentaerythritol glycidyl ether, CAS number 3126-63-4.

[0029] Hexadecyl dimethyl tertiary amine, CAS number 112-69-6.

[0030] Preparation of polyhydroxyphytic acid: 4.36 g of pentaerythritol and 27.23 g of phytic acid were added to a 250 mL three-necked flask and mixed thoroughly. The mixture was then heated to 120 °C and reacted for 3 h to obtain the crude product. Finally, the crude product was obtained by vacuum filtration and freeze-drying. The preparation reaction formula is as follows:

[0031]

[0032] Preparation of graphene oxide dispersion: 2.4 g of graphite powder and 8 g of NaNO3 were mixed in 140 mL of concentrated H2SO4, and the resulting mixture was stirred in an ice bath for 2 h. Then, 12 g of KMnO4 was added dropwise to the solution prepared above at a rate of 1 g / min. After the reaction proceeded for 5 h, 500 mL of deionized water was added to the reaction vessel, and the resulting mixture was stirred at 35 °C for 60 min. After stirring was completed, the reaction was terminated with a large amount of water and 10 mL of H2O2. The prepared product was left to stand for 48 h, and then purified by centrifugation with 30% HCl solution and sonicated for 30 min to obtain graphene oxide dispersion.

[0033] Example 1

[0034] (1) Under a nitrogen atmosphere, 35 g of pentaerythritol glycidyl ether and 280 mL of ethanol were added to a reaction flask. After stirring until homogeneous, 112 g of hexadecyl dimethyl tertiary amine and 75 g of 30% hydrochloric acid were added. The mixture was reacted at 75 °C for 32 h, followed by vacuum distillation and recrystallization in a mixed solvent of acetone and ethyl acetate to obtain a long-chain quaternary ammonium salt intermediate. The preparation reaction formula is as follows:

[0035]

[0036] (2) Under a nitrogen atmosphere, 30 g of a long-chain quaternary ammonium salt intermediate and 300 mL of acetonitrile were added to a reaction flask. After stirring evenly, 9.6 g of epichlorohydrin and 3.6 g of sodium hydroxide were added. The reaction was carried out at 55 °C for 10 h, followed by vacuum distillation to obtain a polyepoxy quaternary ammonium salt crosslinking agent. The preparation reaction formula is as follows:

[0037]

[0038] (3) Mix 100g soybean protein, 5g polyhydroxy phytic acid and 25g graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 20min, then add 2g polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 30min to obtain an environmentally friendly flame retardant and mildew-proof adhesive.

[0039] (4) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 110 mm, a width of 30 mm and a thickness of 0.4 mm to obtain wood shaving raw material; dry 100 g of wood shaving raw material, place it in a drum mixer, add 3 g of environmentally friendly flame retardant and mildew-proof adhesive and 3 g of paraffin wax, stir at 650 r / min for 2 h, and dry it to a moisture content of 4 wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single layer board blank, put it in a steel film frame to lay it into a three-layer structure of upper and lower surface layer and core layer, and place it in a hot press for hot pressing molding. The hot pressing pressure is 5 MPa, the hot pressing time is 12 min, and the hot pressing temperature is 140℃. Then demold and cure for 7 days to obtain environmentally friendly particleboard.

[0040] Example 2

[0041] (1) Under a nitrogen atmosphere, 52g pentaerythritol glycidyl ether and 260mL ethanol were added to a reaction flask and stirred until homogeneous. Then, 158.6g hexadecyl dimethyl tertiary amine and 7.8g hydrochloric acid with a mass fraction of 30% were added. The reaction was carried out at 80℃ for 24h. The mixture was then distilled under reduced pressure and recrystallized from a mixed solvent of acetone and ethyl acetate to obtain a long-chain quaternary ammonium salt intermediate.

[0042] (2) Under a nitrogen atmosphere, 45g of long-chain quaternary ammonium salt intermediate and 360mL of acetonitrile were added to a reaction flask. After stirring evenly, 12.6g of epichlorohydrin and 4.5g of sodium hydroxide were added. The reaction was carried out at 60℃ for 5h. The mixture was then distilled under reduced pressure to obtain a polyepoxy quaternary ammonium salt crosslinking agent.

[0043] (3) Mix 100g soybean protein, 4g polyhydroxy phytic acid and 20g graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 25min, then add 4g polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 20min to obtain an environmentally friendly flame retardant and mildew-proof adhesive.

[0044] (4) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 100mm, a width of 20mm and a thickness of 0.3mm to obtain wood shaving raw material; dry 100g of wood shaving raw material, place it in a drum mixer, add 6g of environmentally friendly flame retardant and mildew-proof adhesive and 2g of paraffin wax, stir at 800r / min for 1h, and dry it to a moisture content of 5wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single-layer board blank, install it in a steel film frame to form a three-layer structure of upper and lower surface layer and core layer, place it in a hot press for hot pressing molding, the hot pressing pressure is 6MPa, the hot pressing time is 8min, the hot pressing temperature is 150℃, and then demold and cure for 7 days to obtain environmentally friendly particleboard.

[0045] Example 3

[0046] (1) Under a nitrogen atmosphere, 12g pentaerythritol glycidyl ether and 120mL ethanol were added to a reaction flask and stirred until homogeneous. Then, 39.6g hexadecyl dimethyl tertiary amine and 3g hydrochloric acid with a mass fraction of 30% were added. The reaction was carried out at 65℃ for 48h. The mixture was then distilled under reduced pressure and recrystallized from a mixed solvent of acetone and ethyl acetate to obtain a long-chain quaternary ammonium salt intermediate.

[0047] (2) Under a nitrogen atmosphere, 10g of long-chain quaternary ammonium salt intermediate and 80mL of acetonitrile were added to the reaction flask. After stirring evenly, 4g of epichlorohydrin and 1.5g of sodium hydroxide were added. The reaction was carried out at 45℃ for 12h. The mixture was then distilled under reduced pressure to obtain the polyepoxy quaternary ammonium salt crosslinking agent.

[0048] (3) Mix 100g soybean protein, 8g polyhydroxy phytic acid and 35g graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 25min, then add 6g polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 40min to obtain an environmentally friendly flame retardant and mildew-proof adhesive.

[0049] (4) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 120mm, a width of 50mm and a thickness of 0.5mm to obtain wood shaving raw material; dry 100g of wood shaving raw material, place it in a drum mixer, add 9g of environmentally friendly flame retardant and mildew-proof adhesive and 4g of paraffin wax, stir at 500r / min for 3h, and dry to a moisture content of 3wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single-layer board blank, install it in a steel film frame to form a three-layer structure of upper and lower surface layer and core layer, place it in a hot press for hot pressing molding, the hot pressing pressure is 3MPa, the hot pressing time is 15min, the hot pressing temperature is 130℃, and then demold and cure for 7 days to obtain environmentally friendly particleboard.

[0050] Example 4

[0051] (1) Under a nitrogen atmosphere, 25g pentaerythritol glycidyl ether and 150mL ethanol were added to a reaction flask and stirred until homogeneous. Then, 793g hexadecyl dimethyl tertiary amine and 5.5g hydrochloric acid with a mass fraction of 30% were added. The reaction was carried out at 70℃ for 30h. The mixture was then distilled under reduced pressure and recrystallized from a mixed solvent of acetone and ethyl acetate to obtain a long-chain quaternary ammonium salt intermediate.

[0052] (2) Under a nitrogen atmosphere, 18g of long-chain quaternary ammonium salt intermediate and 170mL of acetonitrile were added to the reaction flask. After stirring evenly, 6.3g of epichlorohydrin and 2.45g of sodium hydroxide were added. The reaction was carried out at 50℃ for 9h. The mixture was then distilled under reduced pressure to obtain the polyepoxy quaternary ammonium salt crosslinking agent.

[0053] (3) Mix 100g soybean protein, 7g polyhydroxy phytic acid and 30g graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 18min, then add 8g polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 35min to obtain an environmentally friendly flame retardant and mildew-proof adhesive.

[0054] (4) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 105mm, a width of 25mm and a thickness of 0.35mm to obtain wood shaving raw material; dry 100g of wood shaving raw material, place it in a drum mixer, add 12g of environmentally friendly flame retardant and mildew-proof adhesive and 4g of paraffin wax, stir at 750r / min for 2h, and dry it to a moisture content of 4wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single-layer board blank, install it in a steel film frame to form a three-layer structure of upper and lower surface layer and core layer, place it in a hot press for hot pressing molding, the hot pressing pressure is 5MPa, the hot pressing time is 12min, the hot pressing temperature is 145℃, and then demold and cure for 7 days to obtain environmentally friendly particleboard.

[0055] Example 5

[0056] (1) Under a nitrogen atmosphere, 8g pentaerythritol glycidyl ether and 75mL ethanol were added to the reaction flask. After stirring evenly, 26g hexadecyl dimethyl tertiary amine and 2g hydrochloric acid with a mass fraction of 30% were added. The reaction was carried out at 80℃ for 48h. The mixture was then distilled under reduced pressure and recrystallized from a mixed solvent of acetone and ethyl acetate to obtain a long-chain quaternary ammonium salt intermediate.

[0057] (2) Under a nitrogen atmosphere, 5g of long-chain quaternary ammonium salt intermediate and 50mL of acetonitrile were added to the reaction flask. After stirring evenly, 1.8g of epichlorohydrin and 0.7g of sodium hydroxide were added. The reaction was carried out at 55℃ for 12h. The reaction was carried out by vacuum distillation to obtain polyepoxy quaternary ammonium salt crosslinking agent.

[0058] (3) Mix 100g soybean protein, 6g polyhydroxy phytic acid and 30g graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 25min, then add 10g polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 40min to obtain environmentally friendly flame retardant and mildew-proof adhesive.

[0059] (4) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 110 mm, a width of 45 mm and a thickness of 0.45 mm to obtain wood shaving raw material; dry 100 g of wood shaving raw material, place it in a drum mixer, add 15 g of environmentally friendly flame retardant and mildew-proof adhesive and 3 g of paraffin wax, stir at 750 r / min for 3 h, and dry it to a moisture content of 5 wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single layer board blank, install it in a steel film frame to form a three-layer structure of upper and lower surface layer and core layer, place it in a hot press for hot pressing molding, the hot pressing pressure is 5 MPa, the hot pressing time is 15 min, the hot pressing temperature is 150℃, and then demold and cure for 7 days to obtain environmentally friendly particleboard.

[0060] Comparative Example 1

[0061] (1) Mix 100g soybean protein, 5g polyhydroxy phytic acid and 25g graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 20min, then add 2g pentaerythritol glycidyl ether, place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 30min to obtain an environmentally friendly adhesive.

[0062] (2) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 110 mm, a width of 30 mm and a thickness of 0.4 mm to obtain wood shaving raw material; dry 100 g of wood shaving raw material, place it in a drum mixer, add 3 g of environmentally friendly adhesive and 3 g of paraffin wax, stir at 650 r / min for 2 h, and dry it to a moisture content of 4 wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single layer board blank, put it in a steel film frame to form a three-layer structure of upper and lower surface layer and core layer, place it in a hot press for hot pressing molding, the hot pressing pressure is 5 MPa, the hot pressing time is 12 min, the hot pressing temperature is 140℃, and then demold and cure for 7 days to obtain particleboard.

[0063] Comparative Example 2

[0064] (1) Mix 100g of soybean protein and 25g of graphene oxide dispersion with a mass concentration of 2g / mL evenly, sonicate for 20min, then add 2g of polyepoxy quaternary ammonium salt crosslinking agent (prepared from Example 1), place in a high-speed shear dispersion homogenizer, and homogenize vigorously at room temperature for 30min to obtain an environmentally friendly adhesive.

[0065] (2) Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 110 mm, a width of 30 mm and a thickness of 0.4 mm to obtain wood shaving raw material; dry 100 g of wood shaving raw material, place it in a drum mixer, add 3 g of environmentally friendly adhesive and 3 g of paraffin wax, stir at 650 r / min for 2 h, and dry it to a moisture content of 4 wt% to obtain mixed wood shavings; manually lay the mixed wood shavings into a single layer board blank, put it in a steel film frame to form a three-layer structure of upper and lower surface layer and core layer, place it in a hot press for hot pressing molding, the hot pressing pressure is 5 MPa, the hot pressing time is 12 min, the hot pressing temperature is 140℃, and then demold and cure for 7 days to obtain particleboard.

[0066] Comparative Example 3

[0067] Bamboo and wood waste is peeled, sieved, and impurities are removed. It is then added to a pulverizer and processed into wood shavings with a length of 110mm, a width of 30mm, and a thickness of 0.4mm to obtain wood shaving raw material. 100g of wood shaving raw material is dried and placed in a drum mixer. 3g of phenolic resin adhesive (commercially available) and 3g of paraffin wax are added and stirred at 650r / min for 2 hours. The mixture is then dried until the moisture content is 4wt% to obtain glue-mixed wood shavings. The glue-mixed wood shavings are manually laid into a single-layer board blank, which is then placed in a steel mold frame to form a three-layer structure of upper and lower surface layers and a core layer. The board is then placed in a hot press for hot pressing at a pressure of 5MPa, a time of 12min, and a temperature of 140℃. After demolding and curing for 7 days, particleboard is obtained.

[0068] Mildew resistance test: The mildew resistance of the prepared particleboard was tested according to GB / T 18261-2013 standard. Each group was repeated three times and the average value was taken.

[0069] The experimental molds (Aspergillus niger, Trichoderma viride) and discoloration fungi (Diplosporium cocovenenans, Fusarium moniliforme) were all purchased from Ningbo Mingzhou Biotechnology Co., Ltd.

[0070] Infection value: 0, no mycelium or mold spots on the sample surface.

[0071] Infection value: 1, the infected area on the sample surface is <1 / 4.

[0072] Infection value: 2, infection area on the sample surface is 1 / 4-1 / 2.

[0073] Infection value: 3, infection area on the sample surface is 1 / 2-3 / 4.

[0074] Infection value: 4, infection area on the sample surface > 3 / 4.

[0075] Table 1 Anti-mildew performance test

[0076] aspergillus niger trichoderma virens macrophomina phaseolina fusarium moniliforme example 1 1 1 1 1 example 2 1 1 1 0 example 3 0 1 1 0 example 4 0 0 0 0 example 5 0 0 0 0 comparative example 1 3 3 4 4 comparative example 2 1 0 1 1 comparative example 3 4 4 4 4

[0077] During sample culture, the growth of mold on the samples was observed regularly. The moldy area was visually measured and the mold grade was assessed. The lower the infection value, the better the anti-mold effect. The test results in the table above show that as the content of environmentally friendly flame-retardant and anti-mold adhesive increases, the anti-mold performance of particleboard gradually improves, exhibiting good control effects against both mold and discoloration fungi. This is because the environmentally friendly flame-retardant and anti-mold adhesive contains antibacterial quaternary ammonium salt groups. These groups first adsorb onto the cell surface of mold and discoloration fungi through electrostatic adsorption. Subsequently, their hydrophobic long-chain alkyl groups insert into the lipid layer of the cell membrane, altering cell membrane permeability, disrupting cell membrane composition, leading to cell membrane structural disorder, affecting normal cell physiological functions, and ultimately causing cell death. Comparative Examples 1 and 3 do not contain quaternary ammonium salt antibacterial groups and therefore do not have anti-mold effects, showing poor control effects against mold and discoloration fungi.

[0078] Table 2 Flame retardancy and environmental performance tests

[0079]

[0080] Particleboard is a flammable material, posing a fire safety hazard when used in public places or densely populated areas. Improving the flame retardancy of adhesives can reduce the fire risk of plywood to some extent. As shown in the test results above, the flame retardant performance of particleboard gradually increases with the increase of the content of environmentally friendly flame-retardant and mildew-resistant adhesives. The limiting oxygen index in Example 4 reached 35.4%, reaching the level of a flame-retardant material. This is because the polyhydroxyphosphoric acid in the environmentally friendly flame-retardant and mildew-resistant adhesive is rich in phosphorus. As combustion proceeds, intermolecular interactions occur between adhesive components, and rapid carbonization is formed through the thermal condensation of phosphorus functional groups in polyhydroxyphytic acid molecules, reducing the flammability of the material. At the same time, the layered structure of graphene oxide has a stronger physical barrier effect than traditional inorganic compounds in protecting carbonized residues, providing a thermal shielding effect for the carbonized layer, effectively preventing the volatilization of smoke particles during combustion, and increasing the diffusion path of oxygen and heat sources, thereby improving the flame retardant performance of particleboard. In addition, phytic acid and soybean protein are low-cost and widely available biomass materials that are non-toxic, harmless, and formaldehyde-free, making them green, environmentally friendly, and pollution-free. Comparative Example 3 uses commercially available phenolic resin adhesives, which have a high formaldehyde release rate and are harmful to human health.

[0081] Mechanical performance testing: Referring to the standard GB / T 17657-2013 "Test methods for physical and chemical properties of wood-based panels and decorative wood-based panels", a microcomputer-controlled electronic mechanical testing machine was used to test the physical and mechanical properties of the prepared particleboard, such as elastic modulus, internal bond strength, and water absorption thickness expansion rate.

[0082] Table 3 Mechanical property tests

[0083]

[0084] The test results in the table above show that the prepared particleboard is more waterproof, has higher bonding strength, and better mechanical properties. This is because the polyhydroxy phytic acid in the environmentally friendly flame-retardant and mildew-resistant adhesive contains a cyclic structure with multidentate ligands. The abundant hydroxyl groups in its structure have strong hydrogen bonding with graphene oxide, allowing phytic acid to insert into the interlayer spacing of graphene sheets and crosslink with multiple graphene sheets to form a dense crosslinked network structure. The polyepoxy quaternary ammonium salt crosslinking agent molecules have four epoxy groups at the chain ends, which can undergo ring-opening reactions with the hydroxyl groups in phytic acid and the amino groups in soybean protein to form a covalent bond interface. The polyepoxy quaternary ammonium salt crosslinking agent is equivalent to a physical crosslinking point in the particleboard. It is "anchored" to bamboo and wood shavings by the adhesive, which limits the further expansion of microcracks into large cracks, making the board more compact and achieving the effect of strengthening and toughening.

[0085] The above embodiments are used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing environmentally friendly particleboard, characterized in that, The preparation method includes the following steps: Step (1) Preparation of wood shavings: Peel, screen and remove impurities from bamboo and wood waste, add it to a crusher and process it into wood shavings with a length of 100-120mm, a width of 20-50mm and a thickness of 0.3-0.5mm to obtain wood shaving raw materials; Step (2) Preparation of Glue-Mixed Shavings: Dry the shavings raw material, place it in a drum mixer, add environmentally friendly flame-retardant and mildew-proof adhesive and paraffin, stir at 500-800 r / min for 1-3 h, and dry to a moisture content of 3-5 wt% to obtain glue-mixed shavings. Step (3) Preparation of environmentally friendly particleboard: The glue-mixed particleboard is manually laid into a single-layer board blank, which is then placed in a steel film frame to form a three-layer structure of upper and lower surface layers and core layer. The board is then placed in a hot press for hot pressing, demolding and curing to obtain environmentally friendly particleboard. The preparation method of the environmentally friendly flame-retardant and mildew-proof adhesive in step (2) includes the following steps: Step S1: Under a nitrogen atmosphere, pentaerythritol glycidyl ether and ethanol were added to a reaction flask and stirred until homogeneous. Then, hexadecyl dimethyl tertiary amine and hydrochloric acid were added and stirred to react. After the reaction was completed, the mixture was distilled under reduced pressure and recrystallized from a mixed solvent of acetone and ethyl acetate to obtain a long-chain quaternary ammonium salt intermediate. Step S2: Under a nitrogen atmosphere, add the long-chain quaternary ammonium salt intermediate and acetonitrile to the reaction flask, stir evenly, then add epichlorohydrin and sodium hydroxide, stir to react, and after the reaction is completed, distill under reduced pressure to obtain the polyepoxy quaternary ammonium salt crosslinking agent. Step S3: Mix soybean protein, polyhydroxy phytic acid, and graphene oxide dispersion evenly, sonicate for 15-25 minutes, then add polyepoxy quaternary ammonium salt crosslinking agent, place in a high-speed shear dispersion homogenizer, and vigorously homogenize at room temperature for 20-40 minutes to obtain an environmentally friendly flame-retardant and mildew-proof adhesive.

2. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step (2), the mass ratio of wood shavings, environmentally friendly flame-retardant and mildew-proof adhesive, and paraffin wax is 100:3-15:2-4.

3. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step (3), the hot pressing pressure is 3-6 MPa, the hot pressing time is 8-15 min, and the hot pressing temperature is 130-150℃.

4. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step S1, the mass ratio of pentaerythritol glycidyl ether, hexadecyl dimethyl tertiary amine, and hydrochloric acid is 100:305-330:15-25.

5. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step S1, the reaction temperature is 65-80℃ and the reaction time is 24-48h.

6. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step S2, the mass ratio of the long-chain quaternary ammonium salt intermediate, epichlorohydrin, and sodium hydroxide is 100:28-40:10-15.

7. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step S2, the reaction temperature is 45-60℃ and the reaction time is 5-12h.

8. The method for preparing environmentally friendly particleboard according to claim 1, characterized in that, In step S3, the mass ratio of soybean protein, polyhydroxy phytic acid, graphene oxide dispersion, and polyepoxy quaternary ammonium salt crosslinking agent is 100:4-8:20-35:2-10.

9. An environmentally friendly particleboard, characterized in that, It is obtained by the preparation method according to any one of claims 1-8.

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