A quaternary ammonium salt modified lignin-based epoxy resin emulsion and its preparation method

Abstract

This invention discloses a quaternary ammonium salt-modified lignin-based epoxy resin emulsion and its preparation and application methods. It is prepared by reacting quaternary ammonium salt, epoxidized lignin, polyamine compounds, reactive diluents, organic solvents, and water. The quaternary ammonium salt and polyamines are uniformly mixed and reacted in an organic solvent under stirring. Then, epoxidized lignin is added to continue the reaction, yielding the quaternary ammonium salt-modified lignin-based epoxy resin. Water is added to reduce the viscosity, resulting in the quaternary ammonium salt-modified lignin-based epoxy resin emulsion. After adding a curing agent and stirring evenly, it can be used to treat wood and bamboo materials by surface coating, immersion, vacuum impregnation, or pressure impregnation. The quaternary ammonium salt-modified lignin-based epoxy resin emulsion prepared by this invention exhibits good antibacterial, antifungal, and UV-resistant effects after curing, and its application to wood and bamboo materials can effectively improve their dimensional stability and durability.

Description

Technical Field

[0001] This invention belongs to the field of epoxy resin functionalization and wood and bamboo material modification and protection technology, specifically relating to a quaternary ammonium salt modified lignin-based epoxy resin emulsion and its preparation and application methods. Background Technology

[0002] Epoxy resins are an important class of thermosetting resins. Due to the high reactivity of their epoxy groups, they can react with a variety of curing agents, allowing for flexible and diverse formulations that can be designed to meet different application needs. They are widely used in aerospace, chemical, construction, and electronics industries as adhesives, coatings, and resin matrices. Currently, bisphenol A (BPA) type epoxy resins are widely used. However, BPA, its main raw material, is considered an endocrine disruptor and is detrimental to human health.

[0003] In recent years, with rising oil prices and increased public awareness of environmental protection and health, the use of bio-based renewable resources to replace bisphenol A in the synthesis of epoxy resins has become a research hotspot. Lignin, as a widely available, renewable, and biodegradable biomass resource, possesses aromatic structures in its molecular chains that impart good rigidity, solvent resistance, and heat resistance to materials. Its various functional groups, such as methoxy, alcoholic hydroxyl, and phenolic hydroxyl groups, give it certain reactivity. However, due to its complex molecular structure and inactive physicochemical properties, it has not yet been fully utilized. Using lignin to replace petroleum-based bisphenol A in the synthesis of epoxy resins is an important development direction for the high-value utilization of lignin. However, lignin's high hydrophobicity makes it difficult to dissolve in water, and lignin-based epoxy resins are mostly in a solid state, exhibiting drawbacks such as difficulty in processing and brittleness. Grafting hydrophilic groups or segments onto the lignin molecular chain can prepare hydrophilic and hydrophobic surfactants, which have been widely used in adsorption, dispersion, and other fields.

[0004] However, it remains challenging to regulate the structure and ratio of hydrophilic and hydrophobic segments to balance the particle size and curing performance of lignin-based epoxy resin systems and achieve effective penetration and full cross-linking of wood and bamboo. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a quaternary ammonium salt modified lignin-based epoxy resin emulsion and its preparation and use method. The purpose is to use lignin to replace bisphenol A to synthesize quaternary ammonium functionalized lignin-based epoxy resin, which can effectively penetrate wood and bamboo materials and react and fix them therein, while improving their dimensional stability and resistance to mildew and decay, thereby achieving long-term modification and protection of wood and bamboo materials.

[0006] The quaternary ammonium salt modified lignin-based epoxy resin emulsion prepared by this invention has good antibacterial, anti-mildew and anti-ultraviolet effects after curing, and can effectively improve the dimensional stability and durability of wood and bamboo materials.

[0007] The technical solution adopted in this invention is as follows:

[0008] I. A quaternary ammonium salt modified lignin-based epoxy resin emulsion:

[0009] It is mainly prepared from quaternary ammonium salts, epoxidized lignin, polyamine compounds, reactive diluents, organic solvents and water. The component ratio by weight is as follows:

[0010]

[0011] The preferred quaternary ammonium salt is 2,3-epoxypropyltrimethylammonium chloride;

[0012] The polyamine compounds include polyetheramines, diethylenetriamines, triethylenetetramines, etc., with polyetheramines D230 or D400 being preferred.

[0013] The epoxidized lignin is prepared by extracting organic solvent lignin or enzymatically hydrolyzed lignin with ethanol, and then reacting it with epichlorohydrin at a temperature range of 80℃ to 100℃ under the action of a catalyst, with an epoxy value of 0.15 to 0.35.

[0014] The organic solvent lignin is ethanol-extracted lignin, and the enzymatically hydrolyzed lignin is extracted from the residue after preparing functional sugars from corn cobs. Compared with traditional alkali lignin and sulfate lignin, it has better compatibility and reactivity. The catalyst is tetramethylammonium chloride and sodium hydroxide.

[0015] The active diluent is a glycidyl ether epoxy prepolymer, mainly a mixture of one or more of ethylene glycol glycidyl ether, propylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, bisphenol A type epoxy prepolymer E51 or E44, with polyethylene glycol diglycidyl ether and E51 (epoxy value 0.41-0.54) being preferred.

[0016] The organic solvent is ethanol, ethylene glycol, polyethylene glycol, or propylene glycol methyl ether, with propylene glycol methyl ether being preferred. It can not only reduce the viscosity of the reaction system as a solvent, but also defoam and toughen the system.

[0017] II. A method for preparing a quaternary ammonium salt modified lignin-based epoxy resin emulsion: The method includes stirring and mixing a polyamine compound and a quaternary ammonium salt in an organic solvent, then cooling and stirring before adding epoxidized lignin to continue the reaction, and finally adding an active diluent and deionized water to continue the reaction and emulsify, thereby preparing a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

[0018] The molar number of epoxy groups in the polyamine compounds, quaternary ammonium salts and epoxidized lignin is controlled according to the ratio of amine-epoxy ring-opening reaction, and the controlled ratio is 1:2-3:2-4.

[0019] The method is as follows: First, polyamine compounds and quaternary ammonium salts are stirred and mixed evenly in an organic solvent, and reacted at 80℃~100℃ for 2h~3h; then, after cooling to 60℃~80℃, epoxidized lignin is added and mixed evenly under stirring, and reacted at 60℃~80℃ for 15min~30min.

[0020] Finally, add reactive diluent and deionized water, continue the reaction and emulsify for 15-30 minutes to prepare a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

[0021] III. A method for treating wood and bamboo with a lignin-based epoxy resin emulsion, the method comprising the following steps: mixing a quaternary ammonium salt modified lignin-based epoxy resin emulsion and a curing agent evenly, adding the mixture to a mold, or treating the wood and bamboo by surface brushing, soaking, vacuum or pressure impregnation, curing at 60℃, 80℃ and 120℃ for 1h to 2h in sequence, and cooling to room temperature to obtain a cured sample, or the treated wood and bamboo.

[0022] Specifically, after obtaining the cured sample, the UV resistance of the cured sample was tested using a UV-Vis-NIR spectrophotometer. After obtaining the treated wood and bamboo, the dimensional stability and UV resistance of the treated wood and bamboo were tested, and the anti-mold performance was tested according to the "Test Method for the Control Efficacy of Anti-mold Agents against Wood Molds and Discoloration Fungi" (GB T18261-2013), and the anti-corrosion performance was tested according to the "Standard test method for wood preservatives by laboratory soil-block cultures" (ASTM D1413-05b).

[0023] The curing agent is a polyetheramine curing agent, preferably D230 or D400.

[0024] The weight ratio of the quaternary ammonium salt modified lignin-based epoxy resin emulsion to the curing agent is adjusted within the range of 100–90:35–25.

[0025] This invention utilizes lignin, a biomass resource, to replace bisphenol A in the synthesis of epoxy resin. Furthermore, through an epoxy ring-opening reaction, quaternary ammonium salts and polyether segments are simultaneously introduced, enhancing both hydrophilicity and flexibility while imparting antibacterial properties. The quaternary ammonium salt-modified lignin-based epoxy resin prepared by this method exhibits good hydrophilicity and can be uniformly dispersed in water to obtain an aqueous emulsion with a certain solid content. Using water as a solvent reduces emulsion viscosity, avoiding the use of organic solvents and making it safer and more environmentally friendly. The lignin-based epoxy resin aqueous emulsion is easy to process wood and bamboo materials, has good permeability, and after curing, it can improve the dimensional stability, antibacterial, antifungal, and UV resistance of wood and bamboo materials, thus enhancing their durability.

[0026] The beneficial effects of this invention are:

[0027] The lignin-based epoxy resin modified with quaternary ammonium salt of this invention has a certain degree of hydrophilicity. When it is uniformly dispersed in water, an aqueous emulsion is obtained, which is convenient for processing wood and bamboo materials. After curing, it can effectively improve the dimensional stability of wood and bamboo materials, inhibit their cracking and deformation, and at the same time endow wood and bamboo materials with good antibacterial, anti-mildew and anti-rot and anti-ultraviolet functions, thereby solving the problem that wood and bamboo materials are prone to cracking, deformation and mildew, which hinders their high-quality development.

[0028] The technical content disclosed in this invention is of great significance for promoting the high-value utilization of lignin and the high-quality development of wood and bamboo materials. Attached Figure Description

[0029] Figure 1 Image (A) shows the lignin-based epoxy resin emulsion of Example 1, and image (B) shows the cured sample.

[0030] Figure 2 Image (A) and UV spectrum (B) of the sample cured after UV irradiation in Example 1;

[0031] Figure 3 The swelling rate and swelling resistance of untreated wood and the treated wood of Example 5;

[0032] Figure 4 The diagram shows the fungal infection status of untreated bamboo and bamboo treated in Example 5;

[0033] Figure 5 Images showing the condition of untreated wood and treated wood from Example 5 after a 90-day indoor preservative test.

[0034] Figure 6 Images of untreated wood and treated wood from Example 5 after UV irradiation. Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] The embodiments of the present invention are as follows:

[0037] Example 1 (compare with the raw material and weight ratio values ​​corresponding to Example 1 in Table 1): The molar number of epoxy groups in polyamine compounds, quaternary ammonium salts and epoxidized lignin is 1:2:4.

[0038] Six parts of 2,3-epoxypropyltrimethylammonium chloride, 4.5 parts of polyetheramine D-230, and 39.4 parts of propylene glycol methyl ether were placed in a three-necked flask and stirred until homogeneous. The mixture was reacted at 100°C for 3 hours. After cooling to 80°C, 26.4 parts of epoxidized lignin were added with stirring and mixed evenly. The mixture was reacted for 15 minutes. Subsequently, 23.7 parts of deionized water were added, and the reaction was continued and emulsified for 15 minutes to obtain a quaternary ammonium salt-modified lignin-based epoxy resin emulsion. Figure 1 A).

[0039] Then, polyetheramine was added for curing. The curing agent was calculated based on a weight ratio of 100:25 between the lignin-based epoxy resin emulsion and the curing agent. After mixing evenly, the mixture was successively cured at 60℃, 80℃, and 120℃ for 2 hours, and then cooled to room temperature to obtain the cured sample. Figure 1 B).

[0040] The UV resistance of the cured samples was tested using a UV-Vis-NIR spectrophotometer, with bisphenol A epoxy resin (EP) serving as the control sample. Figure 2 After two days of UV irradiation, the bisphenol A type epoxy resin cured film (EP) showed obvious yellowing, while the lignin-based epoxy resin cured film did not show any significant changes. Figure 2 A). This is mainly because the conjugated groups in lignin, such as carbon-carbon double bonds, carbonyl groups, and benzene rings, can effectively absorb ultraviolet light, thus giving lignin-based epoxy resins significant UV resistance. Compared with bisphenol A type epoxy resins, lignin-based epoxy resin cured films exhibit significant ultraviolet absorption capabilities in the UV-C (200–280 nm), UV-B (280–320 nm), and UV-A (320–400 nm) regions, demonstrating a significant UV resistance effect. Figure 2 B).

[0041] Example 2 (compare with the raw material and weight ratio values ​​corresponding to Example 2 in Table 1): The molar number of epoxy groups in polyamine compounds, quaternary ammonium salts and epoxidized lignin is 1:2:3.

[0042] 7.5 parts of 2,3-epoxypropyltrimethylammonium chloride, 5.6 parts of polyetheramine D-230, and 37.3 parts of propylene glycol methyl ether were placed in a three-necked flask and stirred until homogeneous. The mixture was reacted at 100°C for 3 hours. After cooling to 80°C, 24.9 parts of epoxidized lignin were added under stirring and mixed evenly. The mixture was reacted for 15 minutes. Then, 24.7 parts of deionized water were added and the reaction was continued and emulsified for 15 minutes to obtain a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

[0043] Then polyetheramine was added for curing. The curing agent was calculated based on a weight ratio of 100:25 between the lignin-based epoxy resin emulsion and the curing agent. After mixing evenly, the mixture was successively cured at 60℃, 80℃ and 120℃ for 2 hours, and then cooled to room temperature to obtain the cured sample.

[0044] Example 3 (compare with the raw material and weight ratio values ​​corresponding to Example 3 in Table 1): The molar number of epoxy groups in polyamine compounds, quaternary ammonium salts and epoxidized lignin is 1:3:2.

[0045] Ten parts of 2,3-epoxypropyltrimethylammonium chloride, 5.1 parts of polyetheramine D-230, and 15 parts of propylene glycol methyl ether were placed in a three-necked flask and stirred until homogeneous. The mixture was reacted at 100°C for 3 hours. After cooling to 80°C, 15 parts of epoxidized lignin were added and stirred until homogeneous. The mixture was reacted for 15 minutes. Then, 55 parts of deionized water were added and the reaction was continued and emulsified for 15 minutes to obtain a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

[0046] Then polyetheramine was added for curing. The curing agent was calculated based on a weight ratio of 100:25 between the lignin-based epoxy resin emulsion and the curing agent. After mixing evenly, the mixture was successively cured at 60℃, 80℃ and 120℃ for 2 hours, and then cooled to room temperature to obtain the cured sample.

[0047] Example 4 (compare with the raw material and weight ratio values ​​corresponding to Example 4 in Table 1): The molar ratio of epoxy groups in polyamine compounds, quaternary ammonium salts, and epoxidized lignin is 1:2:4. Compared with Example 1, E51 was added to reduce the viscosity of the reaction system and further improve the solubility and compatibility of lignin in the reaction system.

[0048] 6.5 parts of 2,3-epoxypropyltrimethylammonium chloride, 4.9 parts of polyetheramine D-230, and 34.3 parts of propylene glycol methyl ether were placed in a three-necked flask and stirred until homogeneous. The mixture was reacted at 100°C for 3 hours. After cooling to 80°C, 23 parts of epoxidized lignin and 3.4 parts of E51 were added under stirring and mixed evenly. The mixture was reacted for 15 minutes. Subsequently, 1.9 parts of polyethylene glycol diglycidyl ether and 25.8 parts of deionized water were added and the reaction was continued and emulsified for 15 minutes to obtain a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

[0049] Then polyetheramine was added for curing. The curing agent was calculated based on a weight ratio of 100:25 between the lignin-based epoxy resin emulsion and the curing agent. After mixing evenly, the mixture was successively cured at 60℃, 80℃ and 120℃ for 2 hours, and then cooled to room temperature to obtain the cured sample.

[0050] Example 5 (compare with the raw material and weight ratio values ​​corresponding to Example 5 in Table 1): The molar ratio of epoxy groups in the polyamine compound, quaternary ammonium salt, and epoxidized lignin is 1:2:4. Compared to Example 4, the content of polyethylene glycol diglycidyl ether is increased to further reduce the emulsion viscosity.

[0051] 6.4 parts of 2,3-epoxypropyltrimethylammonium chloride, 4.8 parts of polyetheramine D-230, and 33.8 parts of propylene glycol methyl ether were placed in a three-necked flask and stirred until homogeneous. The mixture was reacted at 100°C for 3 hours. After cooling to 80°C, 22.6 parts of epoxidized lignin and 3.3 parts of E51 were added under stirring and mixed evenly. The mixture was reacted for 15 minutes. Subsequently, 3.8 parts of polyethylene glycol diglycidyl ether and 25.3 parts of deionized water were added and the reaction was continued and emulsified for 15 minutes to obtain a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

[0052] Then, polyetheramine is added for curing. The curing agent is calculated according to the weight ratio of lignin-based epoxy resin emulsion to curing agent of 100:25. After mixing evenly, the wood test blocks (test block size: 20*20*20mm) are treated by vacuum pressure impregnation. They are then heated and cured at 60℃, 80℃ and 120℃ for 2 hours each to obtain the treated material.

[0053] Dry test blocks were immersed in water at room temperature for 72 hours. Immediately after removal, their dimensions were measured. The blocks were then dried again, followed by immersion, and this cycle was repeated three times. The dimensional changes of the test blocks before and after immersion and drying were recorded. Based on the obtained data, the swelling rate and swelling resistance of the test blocks were calculated, and the dimensional stability of the treated material was analyzed. Figure 3 It can be seen that the untreated wood had a moisture swelling rate of 13.2%, while after treatment with lignin-based epoxy resin emulsion, the moisture swelling rate decreased to 7.3%, and the swelling resistance reached 43.5%. This shows that the construction of the lignin-based epoxy resin crosslinking network in wood can improve the dimensional stability of wood and enhance its resistance to deformation.

[0054] The anti-mold performance of treated wood was tested according to the standard "Test Method for the Control Efficacy of Antifungal Agents against Wood Molds and Discoloration Fungi" (GB T18261-2013). Untreated bamboo specimens and treated wood were incubated for one week in environments containing *Trichoderma viride*, *Penicillium citrinum*, and *Aspergillus niger*. The condition of the specimens is shown in the following image. Figure 4 As shown in the figure, untreated wood is easily infected by Trichoderma viride, Penicillium citrinum, and Aspergillus niger, while treated wood shows almost no signs of mold infection, demonstrating a better anti-mold effect.

[0055] The preservative properties of wood were tested according to the standard "Standard test method for wood preservatives by laboratory soil-block cultures" (ASTM D1413-05b). Untreated and treated wood underwent a 90-day laboratory preservative test. The samples after the test are as follows: Figure 5As shown, it is evident that brown rot fungi grow more easily on the surface of untreated material, with the entire surface of the specimen covered in hyphae. However, growth on treated material is severely inhibited, with almost no hyphae covering the surface. Observation of samples after surface hyphae removal revealed that untreated material infected with brown rot fungi exhibited severe deformation, while treated material showed no deformation after infection.

[0056] The UV resistance of untreated and treated materials was tested using a UV-Vis-NIR spectrophotometer. Figure 6 After 5 days of UV irradiation, the untreated wood showed obvious yellowing, while the treated wood did not show any significant changes. This demonstrates that the cross-linking and fixation of lignin-based epoxy resin in wood can give it excellent UV resistance.

[0057] All the embodiments described above can achieve the above technical effects, among which embodiments 1 and 5 are preferred embodiments.

[0058] The raw materials and their weight proportions in the above embodiments are shown in the table below.

[0059] Table 1

[0060]

[0061] In all the above embodiments, epoxidized lignin was prepared by the following process: 10g of ethanol was used to extract lignin, 59.7g of epichlorohydrin, 0.1g of water and 0.1g of tetramethylammonium chloride were added to a three-necked flask and refluxed at 100℃ for 4h. Then, 4.3g of sodium hydroxide solution was added and refluxed at 100℃ for 1h. After the reaction was completed, the mixture was poured into a 3L beaker and deionized water was added to precipitate the solid. The solid was then vacuum filtered, and the upper solid was collected and dried in a 60℃ oven to obtain epoxidized lignin.

[0062] This experiment directly synthesized a new system, with the control group consisting of pure epoxy resin (EP) and untreated wood.

[0063] As demonstrated by the above experiments, the quaternary ammonium salt-modified lignin-based epoxy resin emulsion disclosed in this invention exhibits superior UV resistance compared to bisphenol A type epoxy resin. Treatment of wood and bamboo can impart dimensional stability and anti-mildew properties. Furthermore, the prepared lignin-based epoxy resin emulsion can also be applied to the preparation of coatings, adhesives, and wood-bamboo based composite materials.

[0064] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A lignin-based epoxy resin emulsion modified with quaternary ammonium salt, characterized in that, It is prepared from quaternary ammonium salt, epoxidized lignin, polyamine compounds, reactive diluent, organic solvent and deionized water, and the component ratio by weight is: Quaternary ammonium salts: 6.0~10.3 Epoxidized lignin 15~31.3 Polyamine compounds 4.5~5.6 Reactive diluent 0~12.9 Organic solvents 15~39.4 Deionized water: 19.5~55.3; The quaternary ammonium salt is selected as 2,3-epoxypropyltrimethylammonium chloride; the polyamine compound is a polyether amine. The preparation method includes stirring and mixing polyamine compounds and quaternary ammonium salts in an organic solvent, then cooling and stirring before adding epoxidized lignin to continue the reaction, and finally adding an active diluent and deionized water to continue the reaction and emulsify, thereby preparing a quaternary ammonium salt modified lignin-based epoxy resin emulsion. The molar number of epoxy groups in the polyamine compounds, quaternary ammonium salts and epoxidized lignin is controlled according to the ratio of amine-epoxy ring-opening reaction, and the controlled ratio is 1:2~3:2~4.

2. The quaternary ammonium salt modified lignin-based epoxy resin emulsion according to claim 1, characterized in that: The epoxidized lignin is prepared by extracting organic solvent lignin or enzymatically hydrolyzed lignin with ethanol, and then reacting it with epichlorohydrin at a temperature range of 80℃~100℃ under the action of a catalyst, with an epoxy value of 0.15~0.

35.

3. The quaternary ammonium salt modified lignin-based epoxy resin emulsion according to claim 2, characterized in that: The organic solvent lignin is lignin extracted with ethanol, the enzymatically hydrolyzed lignin is extracted from the residue after preparing functional sugars from corn cobs, and the catalyst is tetramethylammonium chloride and sodium hydroxide.

4. The quaternary ammonium salt modified lignin-based epoxy resin emulsion according to claim 1, characterized in that: The reactive diluent is one or a mixture of more than one of ethylene glycol glycidyl ether, propylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, and bisphenol A type epoxy prepolymer E51 or E44; the organic solvent is ethanol, ethylene glycol, polyethylene glycol, or propylene glycol methyl ether.

5. A method for preparing the lignin-based epoxy resin emulsion modified with quaternary ammonium salt as described in claim 1, characterized in that: The method involves mixing and reacting polyamine compounds and quaternary ammonium salts in an organic solvent, then cooling and stirring before adding epoxidized lignin to continue the reaction, and finally adding an active diluent and deionized water to continue the reaction and emulsify, thereby preparing a quaternary ammonium salt-modified lignin-based epoxy resin emulsion.

6. The method for preparing a quaternary ammonium salt modified lignin-based epoxy resin emulsion according to claim 5, characterized in that: The method is specifically as follows: First, the polyamine compound and quaternary ammonium salt are stirred and mixed evenly in an organic solvent, and then reacted at 80℃~100℃ for 2h~3h. Then, after cooling to 60℃~80℃, add epoxidized lignin while stirring and mix evenly. React at 60℃~80℃ for 15min~30min. Finally, add reactive diluent and deionized water, continue the reaction and emulsify for 15-30 minutes to prepare a quaternary ammonium salt modified lignin-based epoxy resin emulsion.

7. A method for treating wood and bamboo materials using a lignin-based epoxy resin emulsion prepared according to any one of claims 1-4 or any one of claims 5-6, characterized in that, The method includes the following steps: The lignin-based epoxy resin emulsion modified with quaternary ammonium salt and the curing agent are stirred and mixed evenly. The wood and bamboo materials are treated by surface brushing, soaking, vacuum or pressure impregnation. They are cured at 60℃, 80℃ and 120℃ for 1h to 2h in sequence, and then cooled to room temperature to obtain the treated wood and bamboo materials.

8. The method for processing wood and bamboo according to claim 7, characterized in that: The curing agent is a polyetheramine curing agent.

9. The method for processing wood and bamboo according to claim 7, characterized in that: The weight ratio of the quaternary ammonium salt modified lignin-based epoxy resin emulsion to the curing agent is in the range of 100~90:35~25.

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