Quaternary ammonium salt modified nano antibacterial waterborne epoxy wood and bamboo modifier and preparation method thereof

Abstract

The invention discloses a quaternary ammonium salt modified nano antibacterial waterborne epoxy wood and bamboo modifier and a preparation method thereof. An epoxy prepolymer, an active quaternary ammonium salt compound, an amine curing agent, an organic solvent and water are used as main raw materials, and are mixed according to the weight ratio of 100: 38.7: 44: 30.6: 137.4-641.4 to react to prepare the epoxy curing agent. The preparation method comprises the following steps: mixing an active quaternary ammonium salt compound and an amine curing agent in an organic solvent, reacting to obtain a quaternary ammonium salt modified amine compound, adding an epoxy prepolymer, continuously reacting to synthesize quaternary ammonium salt modified epoxy resin, and adding water to dilute to the required solid content, thereby obtaining the quaternary ammonium salt modified epoxy resin. The waterborne epoxy system with small size, high stability and high reaction activity is prepared. According to the invention, the wood and bamboo can be easily treated by adopting various modes such as spraying, brushing, soaking, vacuum or pressurized dipping and the like, the permeability is good, the wood and bamboo can be firmly fixed in the wood and bamboo after curing reaction, the dimensional stability of the wood and bamboo is improved, and meanwhile, the wood and bamboo anti-mildew agent has better antibacterial and anti-mildew functions.

Description

Technical Field

[0001] The invention belongs to the field of wood and bamboo material processing and modification, and particularly relates to a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier and a preparation method and use method thereof. Background Art

[0002] Epoxy resin is an important class of thermosetting resins, which contain two or more epoxy groups in its molecules. These epoxy groups play a key role in the high performance and multifunctional properties of the resin. Epoxy resin can undergo cross-linking reaction under the conditions of heating or adding curing agent, and has excellent adhesion, mechanical properties and chemical stability. However, epoxy resin usually has a high viscosity, and penetrating wood and bamboo materials requires dilution with organic solvents or high-pressure impregnation, which limits its expanded application.

[0003] At present, waterborne epoxy resins are widely used in industrial flooring, concrete adhesives, anti-corrosion coatings, textile processing and other fields, while their application in wood and bamboo materials is still basically limited to surface modification. How to balance the particle size and curing performance of the waterborne epoxy system so that it can effectively penetrate wood and bamboo materials and fully react is a key problem. Regulating the structure and ratio of the hydrophilic and hydrophobic segments of epoxy resins to prepare a waterborne epoxy system with controllable particle size and reaction activity, so that it can effectively penetrate wood and bamboo materials and cure and cross-link in situ, while improving the mechanical strength, dimensional stability and mildew resistance of wood and bamboo materials, is an important way to meet the green modification of wood and improve its durability. Summary of the invention

[0004] In order to overcome the above-mentioned problems of the prior art, the present invention has developed a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo modifier based on the structure and chemical composition characteristics of wood and bamboo materials themselves, which is used for modification and protection of wood and bamboo materials to improve their durability.

[0005] The quaternary ammonium salt-modified nano waterborne epoxy resin of the present invention has a small particle size and high reaction activity, and is cured and cross-linked inside the wood and bamboo material, which can not only resist the entry of moisture, but also prevent the erosion of mildew and rot fungi, thereby improving the dimensional stability of the wood and bamboo material and achieving long-term antibacterial and mildew and rot resistance.

[0006] The technical solution of the present invention is as follows:

[0007] 1. A quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier:

[0008] It is mainly prepared from epoxy prepolymer, amine curing agent, active quaternary ammonium salt compound, organic solvent and water, wherein the weight ratio of each component is:

[0009] Epoxy prepolymer 100

[0010] Active quaternary ammonium salt compound 38.7

[0011] Amine curing agent 44

[0012] Organic solvents 30.6

[0013] Water 137.4~641.4.

[0014] The epoxy prepolymer is mainly made of glycidyl ether epoxy resin, preferably E51 or E44;

[0015] The active quaternary ammonium salt compound is 2,3-epoxypropyltrimethylammonium chloride, epoxy hexadecyltrimethylammonium chloride, epoxy tetramethylammonium salt, etc., and 2,3-epoxypropyltrimethylammonium chloride is preferred.

[0016] The amine curing agent is preferably a polyetheramine curing agent;

[0017] The organic solvent is propylene glycol methyl ether, N,N-dimethylformamide, propylene glycol monomethyl ether, etc., and propylene glycol methyl ether is preferred.

[0018] 2. A method for preparing a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier, the preparation method comprising the following steps:

[0019] (1) Add a certain amount of quaternary ammonium salt, a portion of amine curing agent and organic solvent into a three-necked flask, stir and mix evenly, and react at 100° C. for 1 h to 2 h;

[0020] (2) adding epoxy prepolymer to the solution after the reaction in step (1), stirring and mixing, and continuing the reaction for 1 hour;

[0021] (3) After cooling, water is added to the solution after the reaction in step (2) under stirring to adjust the solid content;

[0022] (4) Continue to add another portion of the amine curing agent and stir evenly to obtain a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier.

[0023] The weight ratio of the quaternary ammonium salt and the amine curing agent added in step (1) is 38.7:29.3, and the weight ratio of the amine curing agent added in step (4) to the quaternary ammonium salt added in step (1) is 14.7:38.7.

[0024] The weight ratio of the epoxy prepolymer added in step (2) to the quaternary ammonium salt added in step (1) is 100:38.7.

[0025] In the step (3), water is added to adjust the solid content within the range of 20% to 50%.

[0026] 3. A method for treating wood or bamboo with a nano-antibacterial water-based epoxy wood or bamboo modifier, wherein the nano-antibacterial water-based epoxy wood or bamboo modifier is used to treat wood or bamboo in a variety of ways such as spraying, brushing, soaking or pressurizing, vacuum impregnation, etc.

[0027] The invention uses epoxy prepolymer, active quaternary ammonium salt compound, amine curing agent, organic solvent and water as raw materials, and is prepared by mixed reaction according to the weight ratio of 100:38.7:44:30.6:137.4-641.4. Firstly, the active quaternary ammonium salt compound and the amine curing agent are mixed and reacted in an organic solvent to obtain an amine compound modified by a quaternary ammonium salt; then, the epoxy prepolymer is added to continue the reaction to synthesize a quaternary ammonium salt modified epoxy resin; water is added to dilute to the required solid content to prepare a small-scale, high-stability and reactive water-based epoxy system; and the wood and bamboo materials can be easily treated by various methods such as spraying, brushing, soaking, vacuum or pressure impregnation.

[0028] Beneficial effects of the present invention:

[0029] Quaternary ammonium salts have hydrophilicity and antibacterial functions. Directly chemically bonding them to the epoxy resin molecular chain can not only resist the loss of small molecule quaternary ammonium salts, but also give the epoxy resin better hydrophilicity and disperse it in water to form a nano-scale, highly stable and reactive epoxy system. The synthesis conditions are mild and the process is simple, which is suitable for large-scale production. According to application requirements, wood and bamboo materials can be treated by spraying, brushing, soaking or pressurizing, vacuum impregnation and other means to anchor the hydroxyl groups of wood and bamboo materials to form a cross-linked network and fix them therein, which can effectively improve the dimensional stability of wood and bamboo materials, inhibit their deformation and cracking, and at the same time resist erosion by mildew and fungi, thereby extending their service life.

[0030] The modifier of the invention has good permeability and is firmly fixed in the wood and bamboo materials after the curing reaction, thereby improving the dimensional stability of the wood and bamboo materials and having good anti-bacteria and anti-mildew and rot functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The waterborne epoxy resin emulsion and its particle size distribution (a) and the cured sample (b);

[0032] Figure 2 The results of the anti-swelling rate of untreated wood and treated wood according to different embodiments are shown in the figure;

[0033] Figure 3 The figures are the infection status and mass loss rate results of untreated wood and the groups treated with different embodiments by white rot fungi (a) and brown rot fungi (b);

[0034] Figure 4The infection status diagram of the untreated bamboo specimens (A1, B1, C1) and the treated specimens (A2, B2, C2) of Example 3 after being cultured in an environment of Penicillium citrinum, Trichoderma viride and Aspergillus niger for 7 days. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with embodiments.

[0036] Embodiments of the present invention are as follows:

[0037] Embodiment 1:

[0038] Epoxy prepolymer (E51) 100

[0039] 2,3-Epoxypropyltrimethylammonium chloride 38.7

[0040] Polyetheramine (D230) 44

[0041] Propylene glycol methyl ether 30.6

[0042] Water 641.4

[0043] (1) Take 38.7 parts by weight of 2,3-epoxypropyltrimethylammonium chloride, 29.3 parts by weight of polyetheramine D230 and 30.6 parts by weight of propylene glycol methyl ether and put them into a three-necked flask, and react at 100°C for 2 hours; put in 100 parts by weight of epoxy prepolymer E51, and continue to react at 100°C for 1 hour; after cooling, add 641.4 parts by weight of water to adjust the solid content of the water-based system to 20%; add 14.7 parts by weight of curing agent, stir evenly, and obtain a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier. After dilution with water, test its particle size and distribution. The results show that the water-based epoxy resin system is nano-scale, with an average particle size of 10.2nm ( Figure 1 a). The effective particle size of waterborne epoxy wood and bamboo modifier reaches nanometer level, and there are a large number of particles below 10nm. According to the curing procedures of 60℃ / 2h, 80℃ / 4h, 105℃ / 2h and 120℃ / 1h, a dense solid film is formed after the curing reaction. The cured sample is as follows Figure 1 As shown in b.

[0044] (2) The quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo modifier was impregnated into poplar specimens (dimensional stability size: 20*20*20mm, anti-corrosion size: 20*20*10mm) by the vacuum-pressure impregnation method, and cured according to the curing procedures of 60℃ / 2h, 80℃ / 4h, 105℃ / 2h and 120℃ / 1h. The dimensional stability of the wood specimens was tested according to the national standard GB / T 1934.2-2009 "Determination of Wood Swelling". The dried specimens were soaked in water at room temperature for 72h, and the size was measured immediately after being taken out. After that, they were dried and soaked in water again. This cycle was repeated 3 times. The changes in the size of the specimens before and after soaking and drying were recorded, and the swelling and anti-swelling rates of the specimens were calculated to evaluate the ability of the treated materials to resist deformation. Figure 2 As shown, the anti-swelling rate of the wood treated in Example 1 is 15%.

[0045] (3) The antiseptic properties of untreated and treated wood were tested according to ASTM D1413 "Standard Test Method for Wood Preservatives by Laboratory Soil-Block Cultures". Two species of fungi, brown rot and white rot, were selected and cultured for 90 days at 28±2°C and 75±5% relative humidity. The surface mycelium was removed and the mixture was dried. The mass loss rate was calculated after weighing, and the corrosion resistance grade was evaluated according to ASTM D1413. Figure 3 As shown, the mass loss rates of the wood treated in Example 1 after infection by white rot fungi and brown rot fungi were 3.4% and 3.9% respectively, both reaching the strong corrosion resistance level I.

[0046] Embodiment 2:

[0047] Epoxy prepolymer (E51) 100

[0048] 2,3-Epoxypropyltrimethylammonium chloride 38.7

[0049] Polyetheramine (D230) 44

[0050] Propylene glycol methyl ether 30.6

[0051] Water 361.4

[0052] (1) 38.7 parts by weight of 2,3-epoxypropyltrimethylammonium chloride, 29.3 parts by weight of polyetheramine D230 and 30.6 parts by weight of propylene glycol methyl ether were placed in a three-necked flask and reacted at 100° C. for 2 h; 100 parts by weight of epoxy prepolymer E51 were added and the reaction continued at 100° C. for 1 h; after cooling, 361.4 parts by weight of water were added to adjust the solid content of the aqueous system to 30%; 14.7 parts by weight of a curing agent was added and stirred evenly to obtain a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier.

[0053] (2) The quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo modifier was impregnated into poplar specimens (dimensional stability size: 20*20*20mm, anti-corrosion size: 20*20*10mm) by the vacuum-pressure impregnation method, and cured according to the curing procedures of 60℃ / 2h, 80℃ / 4h, 105℃ / 2h and 120℃ / 1h. The dimensional stability of the wood specimens was tested according to the national standard GB / T 1934.2-2009 "Determination of Wood Swelling". The dried specimens were soaked in water at room temperature for 72h, and the size was measured immediately after being taken out. After that, they were dried and soaked in water again. This cycle was repeated 3 times. The changes in the size of the specimens before and after soaking and drying were recorded, and the swelling and anti-swelling rates of the specimens were calculated to evaluate the ability of the treated materials to resist deformation. Figure 2 As shown, the anti-swelling rate of the wood treated in Example 2 is 29.1%.

[0054] (3) The antiseptic properties of untreated and treated wood were tested according to ASTM D1413 "Standard Test Method for Wood Preservatives by Laboratory Soil-Block Cultures". Two species of fungi, brown rot and white rot, were selected and cultured for 90 days at 28±2°C and 75±5% relative humidity. The surface mycelium was removed and the mixture was dried. The mass loss rate was calculated after weighing, and the corrosion resistance grade was evaluated according to ASTM D1413. Figure 3 As shown, the mass loss rates of the wood treated in Example 1 after infection by white rot fungi and brown rot fungi were 3.2% and 3.1% respectively, both reaching the strong corrosion resistance level I.

[0055] Embodiment 3:

[0056] Epoxy prepolymer (E51) 100

[0057] 2,3-Epoxypropyltrimethylammonium chloride 38.7

[0058] Polyetheramine (D230) 44

[0059] Propylene glycol methyl ether 30.6

[0060] Water 221.4

[0061] (1) 38.7 parts by weight of 2,3-epoxypropyltrimethylammonium chloride, 29.3 parts by weight of polyetheramine D230 and 30.6 parts by weight of propylene glycol methyl ether were placed in a three-necked flask and reacted at 100° C. for 2 h; 100 parts by weight of epoxy prepolymer E51 were added and the reaction continued at 100° C. for 1 h; after cooling, 221.4 parts by weight of water were added to adjust the solid content of the aqueous system to 40%; 14.7 parts by weight of a curing agent was added and stirred evenly to obtain a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier.

[0062] (2) The quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo modifier was impregnated into poplar specimens (dimensional stability size: 20*20*20mm, anti-corrosion size: 20*20*10mm) by the vacuum-pressure impregnation method, and cured according to the curing procedures of 60℃ / 2h, 80℃ / 4h, 105℃ / 2h and 120℃ / 1h. The dimensional stability of the wood specimens was tested according to the national standard GB / T 1934.2-2009 "Determination of Wood Swelling". The dried specimens were soaked in water at room temperature for 72h, and the size was measured immediately after being taken out. After that, they were dried and soaked in water again. This cycle was repeated 3 times. The changes in the size of the specimens before and after soaking and drying were recorded, and the swelling and anti-swelling rates of the specimens were calculated to evaluate the ability of the treated materials to resist deformation. Figure 2 As shown, the anti-swelling rate of the wood treated in Example 3 is 38.1%. The results show that the water-based epoxy wood and bamboo material modifier can fill the cell cavity and prevent the entry of water, enter and deposit in the cell cavity, cell wall and other structures, and the cross-linked network formed inside the wood reduces the moisture absorption rate, thereby improving the dimensional stability of the wood.

[0063] (3) The antiseptic properties of untreated and treated wood were tested according to ASTM D1413 "Standard Test Method for Wood Preservatives by Laboratory Soil-Block Cultures". Two species of fungi, brown rot and white rot, were selected and cultured for 90 days at 28±2°C and 75±5% relative humidity. The surface mycelium was removed and the mixture was dried. The mass loss rate was calculated after weighing, and the corrosion resistance grade was evaluated according to ASTM D1413. Figure 3 As shown, the mass loss rates of the untreated materials after infection by white rot fungi and brown rot fungi were 41.5% and 58.2%, respectively, while those after treatment in Example 3 were 3.2% and 3.3%, respectively, both reaching the strong corrosion resistance level I.

[0064] (4) The quaternary ammonium salt-modified nano water-based epoxy resin was impregnated into bamboo pieces (20*20 mm) and cured at 60℃ / 2h, 80℃ / 4h, 105℃ / 2h, and 120℃ / 1h. The treated wood was then cultured in the environment of Penicillium citrinum, Trichoderma viride, and Aspergillus niger for one week to evaluate the anti-mildew performance of the treated wood. Figure 4 As shown in the figure, it can be seen that the untreated material is easily infected by Penicillium citrinum, Trichoderma virens and Aspergillus niger, while there is no sign of mold infection on the surface of the treated material, indicating that it has a good anti-mildew effect.

[0065] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily modify these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the embodiments described herein, and 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 present invention should be within the scope of protection of the present invention.

Claims

1. A quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier, characterized in that: It is mainly prepared from epoxy prepolymer, amine curing agent, active quaternary ammonium salt compound, organic solvent and water, wherein the weight ratio of each component is: Epoxy prepolymer 100 Active quaternary ammonium salt compound 38.7 Amine curing agent 44 Organic solvents 30.6 Water 137.4~641.

4.

2. The quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier according to claim 1, characterized in that: The epoxy prepolymer mainly adopts glycidyl ether epoxy resin; The active quaternary ammonium salt compound is 2,3-epoxypropyltrimethylammonium chloride, epoxy hexadecyltrimethylammonium chloride, epoxy tetramethylammonium salt and the like.

3. The quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier according to claim 1, characterized in that: The amine curing agent is a polyetheramine curing agent; The organic solvent is propylene glycol methyl ether, N,N-dimethylformamide, propylene glycol monomethyl ether and the like.

4. A method for preparing a nano antibacterial waterborne epoxy wood and bamboo material modifier modified by a quaternary ammonium salt as claimed in any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: (1) Add the quaternary ammonium salt, a portion of the amine curing agent and the organic solvent into a container, stir and mix them evenly, and then react at 100° C. for 1 h to 2 h; (2) adding epoxy prepolymer to the solution after the reaction in step (1), stirring and mixing, and continuing the reaction for 1 hour; (3) After cooling, water is added to the solution after the reaction in step (2) under stirring to adjust the solid content; (4) Continue to add another portion of the amine curing agent and stir evenly to obtain a quaternary ammonium salt-modified nano antibacterial water-based epoxy wood and bamboo material modifier.

5. A preparation method according to claim 4, characterized in that: The weight ratio of the quaternary ammonium salt and the amine curing agent added in the step (1) is 38.7:29.3, and the weight ratio of the amine curing agent added in the step (4) to the quaternary ammonium salt added in the step (1) is 14.7:38.

7.

6. A preparation method according to claim 4, characterized in that: The weight ratio of the epoxy prepolymer added in the step (2) to the quaternary ammonium salt added in the step (1) is 100:38.

7.

7. A preparation method according to claim 4, characterized in that: In the step (3), water is added to adjust the solid content within the range of 20% to 50%.

8. A method for treating wood and bamboo materials using the nano antibacterial waterborne epoxy wood and bamboo material modifier according to any one of claims 1 to 3 or the nano antibacterial waterborne epoxy wood and bamboo material modifier prepared by the preparation method according to any one of claims 4 to 7, characterized in that: The method comprises the following steps: using the nano antibacterial water-based epoxy wood and bamboo material modifier to treat wood or bamboo material in a variety of ways, such as spraying, brushing, soaking, pressurizing, vacuum impregnation, etc.

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