A method for preparing antibacterial and mildew-resistant wood and bamboo boards made from natural plant extracts

Abstract

This invention belongs to the field of functional engineered wood products, specifically a method for preparing antibacterial and mildew-resistant wood and bamboo boards made from natural plant extracts. The preparation method includes surface treatment of the boards, preparation of antibacterial and mildew-resistant agents, preparation of antibacterial and waterproof agents, coating, and post-treatment. This invention first treats the wood and bamboo boards with a eutectic solution to improve the surface permeability. Then, an antibacterial and waterproof agent is coated onto the surface of the boards. After UV photopolymerization curing, vacuum placement at room temperature, and cleaning, the antibacterial and mildew-resistant wood and bamboo boards are obtained. The antibacterial and mildew-resistant wood and bamboo boards prepared by this invention exhibit antibacterial rates of over 97% against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae, meeting the Class I antibacterial standard; a mildew resistance rate against Aspergillus niger is greater than 97%; high strength, with an internal bond strength of 1.92–2.17 MPa and a static bending strength of 49.8–51.3 MPa; and good waterproofing, with a 24-hour thickness swelling rate of less than 3% after water absorption.

Description

Technical Field

[0001] This invention belongs to the field of functional engineered wood panels, specifically relating to a method for preparing antibacterial and mildew-resistant wood and bamboo panels made from natural plant extracts. Background Technology

[0002] Timber and bamboo are my country's main forest resources and primary raw materials for engineered wood products. They are ubiquitous in daily life, from cutting boards in every household to interior furniture and even wood-based buildings. However, due to their multi-scale hierarchical structure and the highly hygroscopic hydroxyl groups on the surface of cellulose, a major component of timber and bamboo, it is difficult for humid air to escape once it enters the timber. Furthermore, the natural polysaccharides and other small molecules in timber and bamboo provide favorable conditions for bacteria and mold growth. Therefore, timber and bamboo products are prone to deformation and mold growth over prolonged use, posing a serious threat to human health.

[0003] Traditional anti-mold and antibacterial layers typically contain materials such as chlorine, phenol, silver ions, and potassium permanganate. These are chemical-based anti-mold and antibacterial agents, which have short-lasting and poor effectiveness. Some even exhibit volatility, releasing pungent gases and causing environmental pollution. Furthermore, even when preservatives are coated onto wood or bamboo boards, this method cannot prevent moisture from penetrating the board's interior, nor can it effectively isolate oxygen. While this may achieve surface anti-mold and antibacterial properties, mold can still develop inside, causing the board to rot and shortening its lifespan.

[0004] Therefore, there is an urgent need for an antibacterial and antifungal agent with non-toxic, harmless, safe, hygienic, and food-grade natural plant extracts as the main ingredient. This agent should be able to penetrate well into the interior of wood and bamboo boards, and the coating should have the function of isolating water vapor, in order to solve the problem that existing wood and bamboo boards are prone to mold growth due to moisture erosion. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for preparing antibacterial and mildew-resistant wood and bamboo boards made from natural plant extracts, thus solving the problems of wood and bamboo boards being prone to moisture absorption and bacterial growth and mold.

[0006] To solve the above technical problems, the present invention adopts the following technical solution:

[0007] A method for preparing antibacterial and mildew-resistant wood and bamboo boards made from natural plant extracts includes the following steps:

[0008] S1. Surface treatment of the board: Spray the eutectic system solution evenly onto the surface of the wood and bamboo board and let it stand for 24-36 hours.

[0009] S2. Preparation of antibacterial and antifungal agent: Natural plant extracts, emulsifiers, penetrants, silane coupling agents, auxiliaries and deionized water are stirred and mixed to obtain an antibacterial and antifungal agent;

[0010] S3. Preparation of antibacterial and waterproofing agent: Add antibacterial and mildew-preventive agent and photoinitiator to plant waterproofing agent and stir at high speed to obtain antibacterial and waterproofing agent;

[0011] S4. Coating: Apply the antibacterial and waterproof agent to the surface of the wood and bamboo board treated in S1. After the surface is evenly coated, use UV light to polymerize and cure for 60-90 seconds. Then place it in a vacuum oven and leave it under vacuum conditions at room temperature for 18-24 hours to obtain the pretreated wood and bamboo board.

[0012] S5. Post-processing: Remove the pre-treated wood and bamboo boards, clean the surface of the boards, and obtain antibacterial and mildew-resistant wood and bamboo boards.

[0013] Preferably, the method for preparing the eutectic system solution in S1 is as follows: adding hydrogen bond acceptor and hydrogen bond donor to deionized water and stirring evenly to obtain the eutectic system solution.

[0014] Preferably, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1 to 1:2.

[0015] Preferably, the hydrogen bond donor includes one or more of lactic acid, citric acid, malic acid, xylitol, tartaric acid, sorbitol, glucose, and sucrose; and the hydrogen bond acceptor is betaine.

[0016] Preferably, the mass fraction of the eutectic system solution in S1 is 10-30%, and the spraying rate is 100-150 g / m³. 2 .

[0017] Betaine, as a natural hydrogen bond acceptor, can form a eutectic system with a variety of natural and non-toxic hydrogen bond donors. When sprayed on the surface of the board and left for 24-36 hours, it can effectively degrade some of the lignin and hemicellulose macromolecules on the surface of the board. Furthermore, some water molecules in the eutectic system solution enter the cell wall and break the hydrogen bonds between cellulose molecules, producing free hydroxyl groups, increasing the molecular chain spacing, increasing the microfibril gaps, and enhancing the permeability of the wood and bamboo cell walls.

[0018] Preferably, the wood-bamboo board in S1 is one of solid wood-bamboo board, MDF, core board, or spliced ​​board.

[0019] Preferably, by mass percentage, the antibacterial and antifungal agent in S2 comprises 5-15% natural plant extracts, 1-3% emulsifiers, 2-5% penetrants, 0.5-2% silane coupling agents, 10-20% additives, and the remainder is deionized water.

[0020] Furthermore, the natural plant extracts include allicin, curcumin, bamboo leaf extract, and citrus peel extract. Allicin can destroy the sulfhydryl enzymes of molds and inhibit their metabolism; curcumin has broad-spectrum antibacterial activity and can block the detection and spread of molds; bamboo leaf extract is rich in flavonoids, plant polysaccharides, and benzoquinone active substances, which have a strong inhibitory effect on viruses, bacteria, fungi, and molds; hesperidin in citrus peel extract has a good inhibitory effect on Rhizopus nigricans, Aspergillus niger, Paecilomyces cerevisiae, and Aspergillus oryzae. The active ingredients of various natural plant extracts are different, and their combined use can play a synergistic role. It has a very broad-spectrum inactivation activity against various bacteria and molds. Compared with traditional antibacterial and antifungal agents, it has the characteristics of broad spectrum, high efficiency, long-lasting effect, and no biological resistance. Compared with inorganic metal nanoparticles, it has the characteristics of safety, environmental friendliness, and harmlessness to the human body.

[0021] Preferably, the mass ratio of allicin, curcumin, bamboo leaf extract, and citrus peel extract is 2-3:3-5:1-2:1-2, more preferably 2.5:4:1.5:1.5.

[0022] Preferably, the emulsifier is one or more of polyethylene glycol, sodium carboxymethyl cellulose, sodium acrylate polymer, and polysorbate, all of which are food-grade emulsifiers and harmless to the human body.

[0023] Preferably, the penetrant is sulfated castor oil, more preferably sodium ricinoleate sulfate.

[0024] Preferably, the silane coupling agent is 3-aminopropyltriethoxysilane.

[0025] Preferably, the additive is anhydrous ethanol.

[0026] Preferably, the stirring rate in step S2 is 200–400 r / min, and the stirring time is 10–20 min.

[0027] Preferably, the amount of antibacterial and antifungal agent added in S3 is 0.5 to 3% of the mass of the plant waterproofing agent.

[0028] Preferably, the plant-based waterproofing agent in S3 is modified corn oil.

[0029] Preferably, the modified corn oil is prepared by:

[0030] S31. Add corn oil, formic acid, disodium ethylenediaminetetraacetate solution and aluminum sulfate catalyst to the reaction vessel, stir evenly and heat to 50-60℃, then add hydrogen peroxide dropwise, react for 5-6 hours and filter to obtain the reaction solution, adjust the pH of the reaction solution to neutral, separate the oil phase using a separatory funnel, wash the oil phase and rotary evaporate to obtain epoxidized corn oil.

[0031] S32. Add epoxidized corn oil, triethylamine catalyst, and hydroquinone polymerization inhibitor to a reaction vessel, then add acrylic acid dropwise, heat to 110-120℃ and react for 3-4 hours, cool to 30-40℃ and dissolve in methyl ethyl ketone, then precipitate in petroleum ether to remove unreacted acrylic acid, and obtain an intermediate system.

[0032] S33. Add maleic anhydride, tetrabutyl titanate catalyst and hydroquinone polymerization inhibitor to the intermediate system, heat to 70-85℃ and react for 2-3 hours. After the reaction is completed, cool to 30-40℃, wash and separate with saturated sodium chloride solution, and obtain modified corn oil containing unsaturated double bonds and carboxyl groups by rotary evaporation.

[0033] Preferably, the mass ratio of corn oil, hydrogen peroxide, formic acid, and aluminum sulfate in S31 is 1-1.1:1.1-1.2:0.16-0.18:0.14-0.16.

[0034] Preferably, the concentration of the disodium ethylenediaminetetraacetate solution in S31 is 1-2 wt%, and the amount added is 0.01-0.05% of the mass of corn oil.

[0035] Preferably, the hydrogen peroxide dripping rate in S31 is 1-3 ml / min.

[0036] Preferably, the mass ratio of epoxy corn oil to acrylic acid in S32 is 11-12:10.

[0037] Preferably, the amount of triethylamine added in S32 is 1.5 to 2% of the mass of epoxidized corn oil, and the amount of hydroquinone added is 0.2 to 0.3% of the mass of epoxidized corn oil.

[0038] Preferably, the amount of maleic anhydride added in S33 is 15-20% of the mass of the intermediate system.

[0039] Preferably, the amount of tetrabutyl titanate added in S33 is 1 to 1.5% of the mass of the intermediate system, and the amount of hydroquinone added is 0.1 to 0.2% of the mass of the intermediate system.

[0040] Preferably, the photoinitiator in S3 is photoinitiator 1173, and the amount added is 3-5% of the mass of the plant waterproofing agent.

[0041] Preferably, the high-speed stirring rate in S3 is 800-1000 r / min, and the time is 10-20 min.

[0042] Preferably, the amount of antibacterial and waterproofing agent applied in step S4 is 2-5% of the mass of the wood or bamboo board.

[0043] Preferably, the energy density of the UV light in S4 is 1000–1500 mW / cm². 2.

[0044] Preferably, the vacuum degree of the room temperature vacuum in S4 is 100 Pa.

[0045] Because modified corn oil is modified with carboxyl groups and unsaturated double bonds, and natural plant extracts are surface-modified with amino groups under the action of silane coupling agents, antibacterial and antifungal agents and photoinitiators are added to the plant waterproofing agent and stirred at high speed to produce an antibacterial and waterproofing agent. Under the action of UV light irradiation, the carboxyl groups of modified corn oil and the amino groups in natural plant extracts condense, and the unsaturated double bonds in modified corn oil also copolymerize and crosslink, further improving the density of the antibacterial and waterproofing agent after curing on the board surface, resulting in better waterproof and antifungal effects, and also enhancing the strength of the board.

[0046] By adopting the above technical solution, the technical effect achieved by the present invention is as follows:

[0047] 1. The antibacterial and mildew-resistant wood and bamboo boards prepared by this invention have an antibacterial rate of over 97% against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae (as determined according to LY / T 1926-2020), meeting the antibacterial grade I standard; and a mildew resistance rate of over 97% against Aspergillus niger (as determined according to GB / T 18261-2000).

[0048] 2. The antibacterial and mildew-resistant wood and bamboo boards prepared by this invention are made from natural and environmentally friendly raw materials. They belong to food-grade antibacterial and mildew-resistant boards and can be widely used in hospitals, schools, offices, homes, restaurants, shopping malls and other places.

[0049] 3. The antibacterial and mildew-resistant wood and bamboo boards prepared by this invention have high strength, with an internal bond strength of 1.92–2.17 MPa and a static bending strength of 49.8–51.3 MPa; they also have good waterproof performance, with a thickness swelling rate of less than 3% after 24 hours of water absorption (measured according to GB / T11718.6-1989). Detailed Implementation

[0050] The present invention will be further illustrated below with reference to specific embodiments.

[0051] Example 1

[0052] S1. Surface treatment of the board: Spray the eutectic system solution evenly onto the surface of the wood and bamboo board and let it stand for 30 hours.

[0053] S2. Preparation of antibacterial and antifungal agent: Natural plant extracts, emulsifiers, penetrants, silane coupling agents, auxiliaries and deionized water are stirred and mixed to obtain an antibacterial and antifungal agent;

[0054] S3. Preparation of antibacterial and waterproofing agent: Add antibacterial and mildew-preventive agent and photoinitiator to plant waterproofing agent and stir at high speed to obtain antibacterial and waterproofing agent;

[0055] S4. Coating: Apply the antibacterial and waterproof agent to the surface of the wood and bamboo board treated in S1. After the surface is evenly coated, use UV light to polymerize and cure for 80 seconds. Then place it in a vacuum oven and place it under vacuum conditions at room temperature for 20 hours to obtain the pretreated wood and bamboo board.

[0056] S5. Post-processing: Remove the pre-treated wood and bamboo boards, clean the surface of the boards, and obtain antibacterial and mildew-resistant wood and bamboo boards.

[0057] The method for preparing the eutectic system solution in S1 is as follows: adding hydrogen bond acceptor and hydrogen bond donor into deionized water and stirring evenly to obtain the eutectic system solution.

[0058] The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1.5.

[0059] The hydrogen bond donor is lactic acid, and the hydrogen bond acceptor is betaine.

[0060] The mass fraction of the eutectic system solution in S1 is 20%, and the spraying rate is 120 g / m³. 2 .

[0061] The wood and bamboo board in S1 is a solid wood and bamboo board.

[0062] By mass percentage, the antibacterial and antifungal agent in S2 comprises 10% natural plant extracts, 2% emulsifiers, 3% penetrants, 1.5% silane coupling agents, 15% additives, and the remainder is deionized water.

[0063] The natural plant extracts include allicin, curcumin, bamboo leaf extract, and citrus peel extract, with the mass ratio of allicin, curcumin, bamboo leaf extract, and citrus peel extract being 2.5:4:1.5:1.5.

[0064] The emulsifier is polyethylene glycol, the penetrant is sodium ricinoleate sulfate, the silane coupling agent is 3-aminopropyltriethoxysilane, and the additive is anhydrous ethanol.

[0065] The stirring rate in S2 is 300 r / min, and the stirring time is 15 min.

[0066] The amount of antibacterial and antifungal agent added in S3 is 2% of the mass of the plant waterproofing agent.

[0067] The plant-based waterproofing agent in S3 is modified corn oil.

[0068] The method for preparing the modified corn oil is as follows:

[0069] S31. Add corn oil, formic acid, disodium ethylenediaminetetraacetate solution and aluminum sulfate catalyst to the reaction vessel, stir evenly and heat to 55°C, then add hydrogen peroxide dropwise, react for 5.5 hours and filter to obtain the reaction solution. Adjust the pH of the reaction solution to neutral, separate the oil phase using a separatory funnel, wash the oil phase and rotary evaporate to obtain epoxidized corn oil.

[0070] S32. Epoxy corn oil, triethylamine catalyst, and hydroquinone polymerization inhibitor are added to the reactor, followed by the dropwise addition of acrylic acid. The mixture is heated to 116°C and reacted for 3.5 hours. After cooling to 35°C, it is dissolved in methyl ethyl ketone and then precipitated in petroleum ether to remove unreacted acrylic acid, thus obtaining an intermediate system.

[0071] S33. Maleic anhydride, tetrabutyl titanate catalyst, and hydroquinone polymerization inhibitor were added to the intermediate system. The mixture was heated to 80°C and reacted for 2.5 h. After the reaction was completed, the mixture was cooled to 35°C, washed and separated with saturated sodium chloride solution, and then rotary evaporated to obtain modified corn oil containing unsaturated double bonds and carboxyl groups.

[0072] The mass ratio of corn oil, hydrogen peroxide, formic acid, and aluminum sulfate in S31 is 1.05:1.15:0.17:0.15.

[0073] The concentration of the disodium ethylenediaminetetraacetate solution in S31 is 1.5 wt%, and the amount added is 0.03% of the mass of corn oil.

[0074] The drop rate of hydrogen peroxide in S31 is 2 ml / min.

[0075] The mass ratio of epoxy corn oil to acrylic acid in S32 is 11.5:10.

[0076] The amount of triethylamine added in S32 is 1.7% of the mass of epoxidized corn oil, and the amount of hydroquinone added is 0.25% of the mass of epoxidized corn oil.

[0077] The amount of maleic anhydride added in S33 is 18% of the mass of the intermediate system.

[0078] The amount of tetrabutyl titanate added in S33 is 1.2% of the mass of the intermediate system, and the amount of hydroquinone added is 0.15% of the mass of the intermediate system.

[0079] The photoinitiator in S3 is photoinitiator 1173, and the amount added is 4% of the mass of the plant waterproofing agent.

[0080] The high-speed stirring rate in S3 is 900 r / min, and the time is 15 min.

[0081] The amount of antibacterial and waterproofing agent applied in S4 is 4% of the mass of the wood or bamboo board.

[0082] The energy density of the UV light in S4 is 1200 mW / cm². 2 .

[0083] The vacuum degree of the room temperature vacuum in S4 is 100 Pa.

[0084] Example 2

[0085] S1. Surface treatment of the board: Spray the eutectic system solution evenly onto the surface of the wood and bamboo board and let it stand for 24 hours.

[0086] S2. Preparation of antibacterial and antifungal agent: Natural plant extracts, emulsifiers, penetrants, silane coupling agents, auxiliaries and deionized water are stirred and mixed to obtain an antibacterial and antifungal agent;

[0087] S3. Preparation of antibacterial and waterproofing agent: Add antibacterial and mildew-preventive agent and photoinitiator to plant waterproofing agent and stir at high speed to obtain antibacterial and waterproofing agent;

[0088] S4. Coating: Apply the antibacterial and waterproof agent to the surface of the wood and bamboo board treated in S1. After the surface is evenly coated, use UV light to polymerize and cure for 90 seconds. Then place it in a vacuum oven and place it under vacuum conditions at room temperature for 18 hours to obtain the pretreated wood and bamboo board.

[0089] S5. Post-processing: Remove the pre-treated wood and bamboo boards, clean the surface of the boards, and obtain antibacterial and mildew-resistant wood and bamboo boards.

[0090] The method for preparing the eutectic system solution in S1 is as follows: adding hydrogen bond acceptor and hydrogen bond donor into deionized water and stirring evenly to obtain the eutectic system solution.

[0091] The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1.

[0092] The hydrogen bond donor is citric acid, and the hydrogen bond acceptor is betaine.

[0093] The mass fraction of the eutectic system solution in S1 is 10%, and the spraying rate is 150 g / m³. 2 .

[0094] The wood and bamboo board in S1 is a solid wood and bamboo board.

[0095] By mass percentage, the antibacterial and antifungal agent in S2 comprises 5% natural plant extracts, 1% emulsifier, 2% penetrant, 0.5% silane coupling agent, 20% additives, and the remainder is deionized water.

[0096] The natural plant extracts include allicin, curcumin, bamboo leaf extract, and citrus peel extract, with the mass ratio of allicin, curcumin, bamboo leaf extract, and citrus peel extract being 2:3:1:1.

[0097] The emulsifier is polyethylene glycol, the penetrant is sodium ricinoleate sulfate, the silane coupling agent is 3-aminopropyltriethoxysilane, and the additive is anhydrous ethanol.

[0098] The stirring rate in S2 is 200 r / min, and the stirring time is 20 min.

[0099] The amount of antibacterial and antifungal agent added in S3 is 0.5% of the mass of the plant waterproofing agent.

[0100] The plant-based waterproofing agent in S3 is modified corn oil.

[0101] The method for preparing the modified corn oil is as follows:

[0102] S31. Add corn oil, formic acid, disodium ethylenediaminetetraacetate solution and aluminum sulfate catalyst to the reaction vessel, stir evenly and heat to 50°C, then add hydrogen peroxide dropwise, react for 5 hours and filter to obtain the reaction solution, adjust the pH of the reaction solution to neutral, separate the oil phase using a separatory funnel, wash the oil phase and rotary evaporate to obtain epoxidized corn oil.

[0103] S32. Epoxy corn oil, triethylamine catalyst, and hydroquinone inhibitor are added to the reactor, followed by the dropwise addition of acrylic acid. The mixture is heated to 110°C and reacted for 4 hours. After cooling to 30°C, it is dissolved in methyl ethyl ketone and then precipitated in petroleum ether to remove unreacted acrylic acid, thus obtaining an intermediate system.

[0104] S33. Add maleic anhydride, tetrabutyl titanate catalyst and hydroquinone polymerization inhibitor to the intermediate system, heat to 70℃ and react for 2 hours. After the reaction is completed, cool to 30℃, wash and separate with saturated sodium chloride solution, and obtain modified corn oil containing unsaturated double bonds and carboxyl groups by rotary evaporation.

[0105] The mass ratio of corn oil, hydrogen peroxide, formic acid, and aluminum sulfate in S31 is 1:1.1:0.16:0.14.

[0106] The concentration of the disodium ethylenediaminetetraacetate solution in S31 is 1 wt%, and the amount added is 0.01% of the mass of corn oil.

[0107] The drop rate of hydrogen peroxide in S31 is 1 ml / min.

[0108] The mass ratio of epoxy corn oil to acrylic acid in S32 is 11:10.

[0109] The amount of triethylamine added in S32 is 1.5% of the mass of epoxidized corn oil, and the amount of hydroquinone added is 0.2% of the mass of epoxidized corn oil.

[0110] The amount of maleic anhydride added in S33 is 15% of the mass of the intermediate system.

[0111] In S33, the amount of tetrabutyl titanate added is 1% of the mass of the intermediate system, and the amount of hydroquinone added is 0.1% of the mass of the intermediate system.

[0112] The photoinitiator in S3 is photoinitiator 1173, and the amount added is 3% of the mass of the plant waterproofing agent.

[0113] The high-speed stirring rate in S3 is 800 r / min, and the time is 10 min.

[0114] The amount of antibacterial and waterproofing agent applied in S4 is 2% of the mass of the wood or bamboo board.

[0115] The energy density of the UV light in S4 is 1000 mW / cm². 2 .

[0116] The vacuum degree of the room temperature vacuum in S4 is 100 Pa.

[0117] Example 3

[0118] S1. Surface treatment of the board: Spray the eutectic system solution evenly onto the surface of the wood and bamboo board and let it stand for 36 hours.

[0119] S2. Preparation of antibacterial and antifungal agent: Natural plant extracts, emulsifiers, penetrants, silane coupling agents, auxiliaries and deionized water are stirred and mixed to obtain an antibacterial and antifungal agent;

[0120] S3. Preparation of antibacterial and waterproofing agent: Add antibacterial and mildew-preventive agent and photoinitiator to plant waterproofing agent and stir at high speed to obtain antibacterial and waterproofing agent;

[0121] S4. Coating: Apply the antibacterial and waterproof agent to the surface of the wood and bamboo board treated in S1. After the surface is evenly coated, use UV light to polymerize and cure for 60 seconds. Then place it in a vacuum oven and place it under vacuum conditions at room temperature for 24 hours to obtain the pretreated wood and bamboo board.

[0122] S5. Post-processing: Remove the pre-treated wood and bamboo boards, clean the surface of the boards, and obtain antibacterial and mildew-resistant wood and bamboo boards.

[0123] The method for preparing the eutectic system solution in S1 is as follows: adding hydrogen bond acceptor and hydrogen bond donor into deionized water and stirring evenly to obtain the eutectic system solution.

[0124] The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:2.

[0125] The hydrogen bond donor is malic acid, and the hydrogen bond acceptor is betaine.

[0126] The mass fraction of the eutectic system solution in S1 is 30%, and the spraying rate is 100 g / m³. 2 .

[0127] The wood and bamboo board in S1 is a solid wood and bamboo board.

[0128] By mass percentage, the antibacterial and antifungal agent in S2 comprises 15% natural plant extracts, 3% emulsifiers, 5% penetrants, 2% silane coupling agents, 10% additives, and the remainder is deionized water.

[0129] The natural plant extracts include allicin, curcumin, bamboo leaf extract, and citrus peel extract, with the mass ratio of allicin, curcumin, bamboo leaf extract, and citrus peel extract being 3:5:2:2.

[0130] The emulsifier is polyethylene glycol, the penetrant is sodium ricinoleate sulfate, the silane coupling agent is 3-aminopropyltriethoxysilane, and the additive is anhydrous ethanol.

[0131] The stirring rate in S2 is 400 r / min, and the stirring time is 10 min.

[0132] The amount of antibacterial and antifungal agent added in S3 is 3% of the mass of the plant waterproofing agent.

[0133] The plant-based waterproofing agent in S3 is modified corn oil.

[0134] The method for preparing the modified corn oil is as follows:

[0135] S31. Add corn oil, formic acid, disodium ethylenediaminetetraacetate solution and aluminum sulfate catalyst to the reaction vessel, stir evenly and heat to 60°C, then add hydrogen peroxide dropwise. After reacting for 6 hours, filter to obtain the reaction solution, adjust the pH of the reaction solution to neutral, separate the oil phase using a separatory funnel, wash the oil phase and rotary evaporate to obtain epoxidized corn oil.

[0136] S32. Epoxy corn oil, triethylamine catalyst, and hydroquinone polymerization inhibitor are added to a reaction vessel, followed by the addition of acrylic acid. The mixture is heated to 120°C and reacted for 3 hours. After cooling to 40°C, it is dissolved in methyl ethyl ketone and then precipitated in petroleum ether to remove unreacted acrylic acid, thus obtaining an intermediate system.

[0137] S33. Add maleic anhydride, tetrabutyl titanate catalyst and hydroquinone polymerization inhibitor to the intermediate system, heat to 85℃ and react for 3 hours. After the reaction is completed, cool to 40℃, wash and separate with saturated sodium chloride solution, and obtain modified corn oil containing unsaturated double bonds and carboxyl groups by rotary evaporation.

[0138] The mass ratio of corn oil, hydrogen peroxide, formic acid, and aluminum sulfate in S31 is 1.1:1.2:0.18:0.16.

[0139] The concentration of the disodium ethylenediaminetetraacetate solution in S31 is 2 wt%, and the amount added is 0.05% of the mass of corn oil.

[0140] The drop rate of hydrogen peroxide in S31 is 3 ml / min.

[0141] The mass ratio of epoxy corn oil to acrylic acid in S32 is 12:10.

[0142] The amount of triethylamine added in S32 is 2% of the mass of epoxidized corn oil, and the amount of hydroquinone added is 0.3% of the mass of epoxidized corn oil.

[0143] The amount of maleic anhydride added in S33 is 20% of the mass of the intermediate system.

[0144] The amount of tetrabutyl titanate added in S33 is 1.5% of the mass of the intermediate system, and the amount of hydroquinone added is 0.2% of the mass of the intermediate system.

[0145] The photoinitiator in S3 is photoinitiator 1173, and the amount added is 5% of the mass of the plant waterproofing agent.

[0146] The high-speed stirring rate in S3 is 1000 r / min, and the time is 20 min.

[0147] The amount of antibacterial and waterproofing agent applied in S4 is 5% of the mass of the wood or bamboo board.

[0148] The energy density of the UV light in S4 is 1500 mW / cm². 2 .

[0149] The vacuum degree of the room temperature vacuum in S4 is 100 Pa.

[0150] Comparative Example 1

[0151] Select a representative Example 1, remove S1, and keep the rest the same as Example 1, as Comparative Example 1.

[0152] Comparative Example 2

[0153] Example 1, a representative example, was selected. S32 and S33 were removed, and epoxy corn oil was used as the plant waterproofing agent. All other aspects were the same as in Example 1. This example served as Comparative Example 2.

[0154] Comparative Example 3

[0155] Example 1, a representative example, was selected. The silane coupling agent in the antibacterial and antifungal agent in S2 was removed, and the rest was the same as in Example 1. This was used as Comparative Example 3.

[0156] The antibacterial and mildew-resistant wood and bamboo boards prepared in Examples 1-3 were tested for their antibacterial, mildew-resistant, strength, and waterproof properties. The specific test results are shown in Table 1.

[0157] Table 1

[0158]

[0159] The antibacterial and mildew-resistant wood and bamboo boards prepared in Comparative Examples 1-3 were tested for strength, water resistance, and other properties. The specific test results are shown in Table 2.

[0160] Table 2

[0161]

[0162] As shown in Table 2, removing step S1 in Comparative Example 1 resulted in a decrease in both the strength and waterproofing effect of the board. This is because the eutectic system solution improved the permeability of the board, allowing the antibacterial and waterproofing agent to penetrate deep into the inner layer of the board, forming cross-linked polymerization and condensation structures inside, thus improving the strength and waterproofing performance of the board. Comparative Example 2 shows that the modified corn oil has more carboxyl groups and unsaturated double bonds compared to epoxidized corn oil, forming more condensation and cross-linking structures under UV light conditions. Therefore, the strength and waterproofing effect of Example 1 are better than those of Comparative Example 2. In Comparative Example 3, the silane coupling agent in the antibacterial and antifungal agent in step S2 was removed. The surface of the natural plant extract was not modified with amino groups, so it could not condense with the carboxyl groups of the modified corn oil. Therefore, the performance of Comparative Example 3 also showed a downward trend.

[0163] Unless otherwise specified, all proportions and percentages mentioned in this invention are mass proportions and mass percentages; all raw materials are commercially available.

[0164] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing antibacterial and mildew-resistant wood and bamboo boards made from natural plant extracts, characterized in that, The preparation method includes the following steps: S1. Surface treatment of the board: Spray the eutectic system solution evenly onto the surface of the wood and bamboo board and let it stand for 24-36 hours. S2. Preparation of antibacterial and antifungal agent: Natural plant extracts, emulsifiers, penetrants, silane coupling agents, auxiliaries and deionized water are stirred and mixed to obtain an antibacterial and antifungal agent; S3. Preparation of antibacterial and waterproofing agent: Add antibacterial and mildew-preventive agent and photoinitiator to plant waterproofing agent and stir at high speed to obtain antibacterial and waterproofing agent; S4. Coating: Apply the antibacterial and waterproof agent to the surface of the wood and bamboo board treated in S1. After the surface is evenly coated, use UV light to polymerize and cure for 60-90 seconds. Then place it in a vacuum oven and leave it under vacuum conditions at room temperature for 18-24 hours to obtain the pretreated wood and bamboo board. S5. Post-processing: Remove the pre-treated wood and bamboo boards, clean the surface of the boards, and obtain antibacterial and mildew-resistant wood and bamboo boards. The silane coupling agent is 3-aminopropyltriethoxysilane; The plant-based waterproofing agent in S3 is modified corn oil; The method for preparing the modified corn oil is as follows: S31. Add corn oil, formic acid, disodium ethylenediaminetetraacetate solution and aluminum sulfate catalyst to the reaction vessel, stir evenly and heat to 50-60℃, then add hydrogen peroxide dropwise, react for 5-6 hours and filter to obtain the reaction solution, adjust the pH of the reaction solution to neutral, separate the oil phase using a separatory funnel, wash the oil phase and rotary evaporate to obtain epoxidized corn oil. S32. Add epoxidized corn oil, triethylamine catalyst, and hydroquinone polymerization inhibitor to a reaction vessel, then add acrylic acid dropwise, heat to 110-120℃ and react for 3-4 hours, cool to 30-40℃ and dissolve in methyl ethyl ketone, then precipitate in petroleum ether to remove unreacted acrylic acid, and obtain an intermediate system. S33. Add maleic anhydride, tetrabutyl titanate catalyst and hydroquinone polymerization inhibitor to the intermediate system, heat to 70-85℃ and react for 2-3 hours. After the reaction is completed, cool to 30-40℃, wash and separate with saturated sodium chloride solution, and obtain modified corn oil containing unsaturated double bonds and carboxyl groups by rotary evaporation. The mass ratio of epoxy corn oil to acrylic acid in S32 is 11-12:10; The amount of triethylamine added in S32 is 1.5-2% of the mass of epoxidized corn oil, and the amount of hydroquinone added is 0.2-0.3% of the mass of epoxidized corn oil. The amount of maleic anhydride added in S33 is 15-20% of the mass of the intermediate system; The amount of tetrabutyl titanate added in S33 is 1-1.5% of the mass of the intermediate system, and the amount of hydroquinone added is 0.1-0.2% of the mass of the intermediate system. The amount of antibacterial and waterproof agent applied in S4 is 2-5% of the mass of the wood or bamboo board. The energy density of the UV light in S4 is 1000–1500 mW / cm². 2 ; The vacuum degree of the room temperature vacuum in S4 is 100 Pa.

2. The method for preparing a natural plant extract antibacterial and mildew-resistant wood and bamboo board according to claim 1, characterized in that, The method for preparing the eutectic system solution in S1 is as follows: adding hydrogen bond acceptor and hydrogen bond donor into deionized water and stirring evenly to obtain the eutectic system solution; The molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1 to 1:2; The hydrogen bond donor includes one or more of lactic acid, citric acid, malic acid, xylitol, tartaric acid, sorbitol, glucose, and sucrose; the hydrogen bond acceptor is betaine. The mass fraction of the eutectic system solution in S1 is 10-30%, and the spraying rate is 100-150 g / m³. 2 .

3. The method for preparing a natural plant extract antibacterial and mildew-resistant wood and bamboo board according to claim 1, characterized in that, By mass percentage, the antibacterial and antifungal agent in S2 comprises 5-15% natural plant extracts, 1-3% emulsifiers, 2-5% penetrants, 0.5-2% silane coupling agents, 10-20% additives, and the remainder is deionized water.

4. The method for preparing a natural plant extract antibacterial and mildew-resistant wood and bamboo board according to claim 3, characterized in that, The natural plant extracts include allicin, curcumin, bamboo leaf extract, and citrus peel extract; the mass ratio of allicin, curcumin, bamboo leaf extract, and citrus peel extract is 2-3:3-5:1-2:1-2; The emulsifier is one or more of polyethylene glycol, sodium carboxymethyl cellulose, sodium acrylate polymer, and polysorbate; The penetrant is sulfated castor oil; The additive is anhydrous ethanol.

5. The method for preparing a natural plant extract antibacterial and mildew-resistant wood and bamboo board according to claim 1, characterized in that, The amount of antibacterial and antifungal agent added in S3 is 0.5 to 3% of the mass of the plant waterproofing agent.

6. The method for preparing a natural plant extract antibacterial and mildew-resistant wood and bamboo board according to claim 1, characterized in that, The mass ratio of corn oil, hydrogen peroxide, formic acid, and aluminum sulfate in S31 is 1–1.1:1.1–1.2:0.16–0.18:0.14–0.

16. The concentration of the disodium ethylenediaminetetraacetate solution in S31 is 1-2 wt%, and the amount added is 0.01-0.05% of the mass of corn oil. The drop rate of hydrogen peroxide in S31 is 1-3 ml / min.

7. The method for preparing a natural plant extract antibacterial and mildew-resistant wood and bamboo board according to claim 1, characterized in that, The photoinitiator in S3 is photoinitiator 1173, and the amount added is 3-5% of the mass of the plant waterproofing agent. The high-speed stirring rate in S3 is 800-1000 r / min, and the time is 10-20 min.

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