Hydrophobic antibacterial finishing liquid and its application in modification method of bamboo hydrophobization

Abstract

The application belongs to the technical field of bamboo materials, and particularly relates to a hydrophobic antibacterial finishing liquid and a modification method for bamboo material hydrophobization by using the same. The bamboo material hydrophobization modification method is used for enhancing the antibacterial and mildew-proof performance of the bamboo material by sequentially immersing the bamboo material in a hydrophobic antibacterial finishing liquid, and the bamboo material immersed in the hydrophobic antibacterial finishing liquid is sequentially immersed in a silicon dioxide sol and a silane coupling agent solution, so that a two-dimensional ordered hydrophobic film layer is formed on the bamboo material, and the hydrophobicity of the bamboo material is significantly enhanced. The bamboo material after the immersion modification has good hydrophobic performance and mildew-proof effect, and thus the problems of deformation, cracking, mildew and decay of the bamboo material due to easy water absorption in a humid environment are reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bamboo materials, and particularly relates to a hydrophobic antibacterial finishing liquid and a modification method for bamboo material hydrophobization. BACKGROUND

[0002] Bamboo is a renewable natural material, has the advantages of short growth cycle, high yield, wide application range, etc., is an important non-wood forest resource, and has great development potential in the development of green low-carbon products. As a kind of natural fiber, bamboo fiber has a large number of hydroxyl groups on the surface, high sugar content, high starch content, easy water absorption, and low compatibility with non-polar resins. The entry of water can easily cause deformation, cracking, mold and decay of bamboo, which seriously affects the use range and use cycle of bamboo products. Therefore, many studies are widely carried out around bamboo modification, such as adding preservatives, filling with resin substances, oil medium heat treatment, and plant essential oil treatment. However, the addition of preservatives may have adverse effects on the environment, and many researchers use substances such as rosin resin and epoxy resin to treat bamboo as a solution. However, the degradation of epoxy resin may also have adverse effects on the environment, and the ammonolysis reaction of rosin under high temperature conditions can lead to unsatisfactory mold prevention effect. SUMMARY

[0003] In order to better solve the problem of easy moisture absorption and mold decay of bamboo, the application provides a hydrophobic antibacterial finishing liquid and a modification method for bamboo material hydrophobization.

[0004] In a first aspect, the application provides a hydrophobic antibacterial finishing liquid:

[0005] A hydrophobic antibacterial finishing liquid, the raw materials of which include 1-2wt% of a synthetic antibacterial agent, according to the weight of the organic solvent; the synthetic antibacterial agent is prepared from polyethylene glycol, organosilicon quaternary ammonium salt containing silicon-oxygen bond and water in a molar ratio of 1:2-3:3-6 under the catalysis of alkylbenzenesulfonic acid.

[0006] By adopting the above technical solution, the good adhesion and penetration properties of low molecular weight polyethylene glycol are combined with the good antibacterial and hydrophobic properties of organosilicon quaternary ammonium salt, so that the prepared synthetic antibacterial agent has good adhesion, antibacterial, penetration and hydrophobic properties.

[0007] Preferably, the antibacterial combination liquid further includes 1-2wt% of n-butyl titanate and 0.15-2wt% of water; and the polyethylene glycol is a low molecular weight polyethylene glycol.

[0008] Low molecular weight polyethylene glycol refers to polyethylene glycol with a molecular weight (Mw) generally between 200 and 20,000.

[0009] By adopting the technical scheme, in the antibacterial combination liquid, n-butyl titanate and water are adopted, n-butyl titanate can be completely hydrolyzed or partially hydrolyzed under the catalysis of the silicone quaternary ammonium salt, and titanium sol with good hydrophobic property and antibacterial and mildew-proof effect is formed, so as to further improve the adhesion and antibacterial properties of the antibacterial combination liquid.

[0010] Preferably, the content of water in the antibacterial combination liquid is 0.4-1.2wt%; the organic solvent is a mixture of alcohol and ester organic solvents or an alcohol organic solvent.

[0011] By adopting the technical scheme, the amount of water in the antibacterial combination liquid is preferably selected, so that the n-butyl titanate is partially hydrolyzed, so that the antibacterial combination liquid not only has antibacterial effect, but also has certain water removal effect, thereby further improving the antibacterial and mildew-proof effect.

[0012] Preferably, the antibacterial combination liquid further comprises 1-4wt% of a polylactic acid-glycolic acid copolymer solution; the polylactic acid-glycolic acid copolymer solution contains 8-15wt% of polylactic acid-glycolic acid copolymer solution.

[0013] The polylactic acid-glycolic acid copolymer is randomly polymerized from two monomers, lactic acid and glycolic acid, and is a degradable non-structured functional high-molecular organic compound, and the glass transition temperature is between 40-60℃.

[0014] Preferably, the average molecular weight of the polylactic acid-glycolic acid copolymer is 6000-10000, and the solute of the polylactic acid-glycolic acid copolymer solution is ethyl acetate.

[0015] Preferably, the polylactic acid-glycolic acid copolymer contains 40-75wt% of lactic acid structure.

[0016] By adopting the technical scheme, the polylactic acid-glycolic acid copolymer with good hydrophobic property in the antibacterial combination liquid can not only combine water during degradation, but also lactic acid and glycolic acid formed after hydrolysis have good sterilization and mildew-proof effect, thereby further improving the hydrophobic and mildew-proof effect of the antibacterial combination liquid.

[0017] The type of the polylactic acid-glycolic acid copolymer is preferably selected, so that the polylactic acid-glycolic acid copolymer can be better dissolved in the antibacterial combination liquid and infiltrated into the bamboo, and has better permeability and easy degradation performance.

[0018] In a second aspect, the application provides a bamboo hydrophobic modification method.

[0019] A bamboo hydrophobic modification method comprises the following preparation steps:

[0020] Hydrophobic antibacterial finishing liquid treatment: the bamboo is immersed and treated with the hydrophobic antibacterial finishing liquid for 1-6h;

[0021] Silica sol treatment: then the bamboo material treated by the hydrophobic antibacterial finishing liquid is immersed in the silica sol with the content of 10-40wt% of silica, and immersed for 1-5h, and then washed and dried;

[0022] Silane coupling agent solution treatment: the bamboo material treated by the silica sol is immersed in the silane coupling agent solution with the content of 1-10wt% of silane coupling agent, and immersed for 1-5h, and then dried to prepare the modified bamboo material.

[0023] By using the above technical scheme, after the bamboo material is immersed in the hydrophobic antibacterial finishing liquid, the synthesized antibacterial agent has good penetration performance, adhesion performance, antibacterial property and hydrophobic property, the synthesized antibacterial agent can be immersed into the fiber structure of the bamboo material, and thus the antibacterial and mildew-resistant properties and the hydrophobic property are improved.

[0024] Further, the hydrolyzed titanium n-butyrate and / or the polylactic acid-glycolic acid copolymer are used in the hydrophobic antibacterial finishing liquid, the hydrolyzed titanium n-butyrate and the polylactic acid-glycolic acid copolymer in the bamboo material are hydrolyzed and degraded, meet water molecules and are hydrolyzed or degraded, and thus the water content in the bamboo material is reduced; further, the products after the hydrolysis of the titanium n-butyrate and / or the degradation of the polylactic acid-glycolic acid copolymer enhance the antibacterial property of the bamboo material.

[0025] Further, the bamboo material is immersed in the silica sol, the silica sol particles with a three-dimensional network structure containing a large number of hydroxyl groups can be loaded on the surface of the bamboo material to form a micro-nano structure film; then after the cleaned bamboo material is immersed in the silane coupling agent solution, the silane coupling agent is hydrolyzed to generate silanol, and at the same time, the silica sol and the silanol after the alcoholysis of the silane coupling agent can continue to undergo dehydration condensation to form a low-surface-energy siloxane, and thus a two-dimensional ordered hydrophobic film layer is formed on the bamboo material, and the hydrophobicity of the surface of the bamboo material is significantly enhanced.

[0026] In summary, the bamboo material is immersed in the hydrophobic antibacterial finishing liquid to enhance the hydrophobic and mildew-resistant properties of the bamboo material, the bamboo material after being immersed in the hydrophobic antibacterial finishing liquid is sequentially immersed in the silica sol and the silane coupling agent solution, a two-dimensional ordered hydrophobic film layer is formed on the bamboo material, and the hydrophobicity of the bamboo material is significantly enhanced; the modified bamboo material has good hydrophobic property and mildew-resistant effect, and thus the problems of deformation, cracking, mildew and decay of the bamboo material due to easy water absorption in a humid environment are reduced.

[0027] Preferably, the silane coupling agent has two or more siloxane groups and a long-chain alkane in its structure; the temperature of the hydrophobic antibacterial finishing liquid is 30-40℃; the drying is first low-temperature drying at 50-70℃, and then rapid drying at 110℃.

[0028] Through the technical scheme, the small structure inside the bamboo is opened by the high temperature, and the components in the antibacterial combination liquid can be better immersed into the bamboo fiber structure; and the temperature of the hydrophobic antibacterial finishing liquid has no obvious effect on the impregnation effect of the bamboo after the temperature exceeds 45 DEG C.

[0029] Preferably, the average particle size of the silica sol is 2-50 nm.

[0030] Preferably, the silica sol is compounded by small particle size, medium particle size and large particle size silica sols in a mass ratio of 1: (2-3) : (4-8), the average particle size of the small particle size silica sol is 2-9 nm, the average particle size of the medium particle size silica sol is 10-20 nm, and the average particle size of the large particle size silica sol is 21-50 nm.

[0031] Through the technical scheme, the particle size of the silica sol is preferably selected, and the silica sols of small particle size, medium particle size and large particle size are compounded, the large particle size silica sol can enter the cell cavity inside the bamboo, but it is difficult to enter the nanometer space such as the gap of the cell wall and the microfibril of the bamboo, while the small particle size and medium particle size silica sols can easily be immersed in the gap of the cell wall and the microfibril of the bamboo; the silica sols of small particle size, medium particle size and large particle size are compounded, thereby further improving the binding force between the silica sol film and the bamboo and improving the hydrophobic properties of the internal structure and the surface of the bamboo.

[0032] Preferably, the bamboo is subjected to cleaning treatment before being treated by the hydrophobic antibacterial finishing liquid; the cleaning treatment is 360 DEG spraying treatment on the surface of the bamboo, the sprayed bamboo is shaken to remove the large water droplets on the surface, and then the bamboo is dried by circulating hot air, the temperature of the hot air is 60-80 DEG C, and the air speed is 25-40 m / s.

[0033] The bamboo is treated by the hydrophobic antibacterial finishing liquid, and then the surface of the bamboo is subjected to plasma pretreatment, and then the bamboo is immersed in the silica sol and the silane coupling agent solution.

[0034] Through the technical scheme, the antibacterial components in the hydrophobic antibacterial finishing liquid can be more easily combined with the bamboo after the bamboo is cleaned; the surface of the bamboo is roughened by the plasma pretreatment, and the active groups on the surface of the bamboo are increased, thereby improving the interaction force between the bamboo and the hydrophobic film layer formed by the silica sol and the silane coupling agent solution, and further improving the hydrophobic properties of the bamboo after the modification by the immersion.

[0035] In summary, the present application has the following beneficial effects:

[0036] 1. A hydrophobic antibacterial finishing liquid, comprising 1-2 wt% of a synthetic antibacterial agent based on the amount of solute water; the synthetic antibacterial agent is prepared from polyethylene glycol, organosilicon quaternary ammonium salt containing siloxane bond and water in a molar ratio of 1:2-3:3-6 under the catalysis of alkyl benzene sulfonic acid; the low molecular weight polyethylene glycol has good adhesion and penetration properties, and is compatible with the organosilicon quaternary ammonium salt which has good antibacterial and hydrophobic properties, and the prepared synthetic antibacterial agent has good adhesion, antibacterial, penetration and hydrophobic properties.

[0037] 2. A method for modifying the hydrophobicity of bamboo, the bamboo is dipped in a hydrophobic antibacterial finishing liquid to enhance the antibacterial and mildew-proof properties of the bamboo, and the bamboo after being dipped in the hydrophobic antibacterial finishing liquid is sequentially dipped in a silica sol and a silane coupling agent solution to form a two-dimensional ordered hydrophobic film layer on the bamboo, thereby significantly enhancing the hydrophobicity of the bamboo; the modified bamboo has good hydrophobicity and mildew-proof effect, thereby reducing the deformation, cracking, mildew and decay of the bamboo due to easy water absorption in a humid environment.

[0038] 3. Preferably, the silica sol is prepared by using small particle size, medium particle size and large particle size silica sols; and the adhesion between the silica sol film and the bamboo and the hydrophobicity of the bamboo are further improved. DETAILED DESCRIPTION

[0039] Preparation Example 1-1, a synthetic antibacterial agent, the preparation method is as follows:

[0040] 1 mol of polyethylene glycol (molecular weight 700), 3 mol of water, and 2 mol of dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (CAS: 27668-52-6, molecular weight 496.28) are put into a reaction kettle, stirred uniformly, heated to 60°C, and then 25 g of catalyst (dodecyl benzene sulfonic acid) is added, stirred for 3 h, and dehydrated to obtain the synthetic antibacterial agent.

[0041] Preparation Example 1-2, a synthetic antibacterial agent, the preparation method is as follows:

[0042] 1 mol of polyethylene glycol (molecular weight 1000), 4 mol of water, and 3 mol of dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (molecular weight 496.28) are put into a reaction kettle, stirred uniformly, heated to 65°C, and then 30 g of catalyst (dodecyl benzene sulfonic acid) is added, stirred for 4 h, and dehydrated to obtain the synthetic antibacterial agent.

[0043] Preparation Example 1-3, a synthetic antibacterial agent, the preparation method is as follows:

[0044] Take 1 mol polyethylene glycol (molecular weight 5000), 6 mol water, 2.5 mol 3- (triethoxysilylpropyl) dimethyl octadecyl ammonium chloride, (CAS: 62117-57-1, molecular weight 538.3) into the reaction kettle, stir evenly, heat to 50℃, then add 20g catalyst (dodecyl benzene sulfonic acid), stir for 5h, dehydrate to prepare the synthetic antibacterial agent.

[0045] Preparation Example 2-1, a polylactic acid-glycolic acid copolymer solution, the preparation method is as follows:

[0046] 10g of polylactic acid-glycolic acid copolymer (average number average molecular weight of 7000) is added to 90g of ethyl acetate to form a mixture, the mixture is heated to 50℃, and stirred at 50℃, 200rmp for 8h to prepare a polylactic acid-glycolic acid copolymer solution with a mass fraction of 10wt%.

[0047] Preparation Example 2-2, a polylactic acid-glycolic acid copolymer solution, the preparation method is as follows:

[0048] 8g of polylactic acid-glycolic acid copolymer (average number average molecular weight of 6000) is added to 92g of ethyl acetate to form a mixture, the mixture is heated to 60℃, and stirred at 60℃, 300rmp for 6h to prepare a polylactic acid-glycolic acid copolymer solution with a mass fraction of 8wt%.

[0049] Preparation Example 2-3, a polylactic acid-glycolic acid copolymer solution, the preparation method is as follows:

[0050] 15g of polylactic acid-glycolic acid copolymer (average number average molecular weight of 8000) is added to 85g of ethyl acetate to form a mixture, the mixture is heated to 55℃, and stirred at 55℃, 400rmp for 10h to prepare a polylactic acid-glycolic acid copolymer solution with a mass fraction of 15wt%. Example

[0051] Example 1-1, a hydrophobic antibacterial finishing liquid, the organic solvent is a combination of anhydrous ethanol and anhydrous ethyl acetate with a mass ratio of 4:1, and the raw materials of the hydrophobic antibacterial finishing liquid include 1.5wt% of the synthetic antibacterial agent (using the synthetic antibacterial agent of Preparation Example 1-1), 1.5wt% of n-butyl titanate, 0.4wt% of water, and 2wt% of the polylactic acid-glycolic acid copolymer solution (using the polylactic acid-glycolic acid copolymer solution of Preparation Example 2-1), the raw materials of the hydrophobic antibacterial finishing liquid are stirred and mixed to prepare the hydrophobic antibacterial finishing liquid, which is sealed and refrigerated for later use.

[0052] Example 1-2, a hydrophobic antibacterial finishing liquid, the organic solvent is anhydrous ethanol and anhydrous ethyl acetate with a mass ratio of 5:1, and the raw materials of the hydrophobic antibacterial finishing liquid include 2wt% of the synthetic antibacterial agent (the synthetic antibacterial agent of Preparation Example 1-2), 2wt% of n-butyl titanate, 1wt% of water, and 4wt% of the polylactic acid-glycolic acid copolymer solution (the polylactic acid-glycolic acid copolymer solution of Preparation Example 2-2), the raw materials of the hydrophobic antibacterial finishing liquid are stirred and mixed to prepare the hydrophobic antibacterial finishing liquid, which is sealed and refrigerated for later use.

[0053] Example 1-3, a hydrophobic antibacterial finishing liquid, the organic solvent is anhydrous ethanol, and the raw materials of the hydrophobic antibacterial finishing liquid include 1wt% of the synthetic antibacterial agent (the synthetic antibacterial agent of Preparation Example 1-3), 1wt% of n-butyl titanate, 2wt% of water, and 1wt% of the polylactic acid-glycolic acid copolymer solution (the polylactic acid-glycolic acid copolymer solution of Preparation Example 2-3), the raw materials of the hydrophobic antibacterial finishing liquid are stirred and mixed to prepare the hydrophobic antibacterial finishing liquid, which is sealed and refrigerated for later use.

[0054] Example 1-4, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that the content of water in the antibacterial combination liquid is 0.15wt%.

[0055] Example 1-5, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that the content of water in the antibacterial combination liquid is 1wt%.

[0056] Example 1-6, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that the content of water in the antibacterial combination liquid is 1.2wt%.

[0057] Example 1-7, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that the content of water in the antibacterial combination liquid is 2wt%.

[0058] Example 1-8, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that the polylactic acid-glycolic acid copolymer solution is not used in the antibacterial combination liquid.

[0059] Example 1-9, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that n-butyl titanate and water are not used in the antibacterial combination liquid.

[0060] Example 1-10, a hydrophobic antibacterial finishing liquid, which is different from Example 1-1 in that n-butyl titanate, water, and the polylactic acid-glycolic acid copolymer solution are not used in the antibacterial combination liquid.

[0061] Example 2-1, a method for hydrophobic modification of bamboo, comprising the following preparation steps:

[0062] Cleaning treatment: The surface of the bamboo (Phyllostachys pubescens without bamboo green and bamboo yellow) was treated by 360° spraying, then the bamboo after spraying was shaken to remove the large water droplets on the surface, and then dried by circulating hot air, the hot air temperature was 70±10℃, the wind speed was 30±5m / s, and the time was 10h.

[0063] Hydrophobic antibacterial finishing liquid treatment: the bamboo was immersed in the hydrophobic antibacterial finishing liquid of Example 1-1 (temperature 35℃) for 3h, the mass ratio of hydrophobic antibacterial finishing liquid to bamboo was 10:1, and then the bamboo was placed in an oven after washing the surface with spraying water, the temperature was controlled at 80±10℃, and the time was 10±2h.

[0064] Plasma pretreatment: the bamboo treated by the hydrophobic antibacterial finishing liquid was modified by plasma: open the plasma discharge cavity and put in the bamboo, close the discharge cavity; oxygen and nitrogen gas were introduced, the gas flow rates of oxygen and nitrogen were 0.4±0.1L / min and 2.2±0.3L / min respectively; atmospheric pressure discharge plasma modification was used, the treatment time was 105±75s, a uniform defect layer was formed on the surface of the bamboo, and the hydrophilic groups on the surface of the bamboo were increased.

[0065] Silica sol treatment: then the bamboo treated by the hydrophobic antibacterial finishing liquid was immersed in a silica sol with a silica content of 30wt% (average particle size 20nm) for 3h, the mass ratio of silica sol to bamboo was 10:1, and then the bamboo was washed with spraying water and dried by circulating hot air, the hot air temperature was 70±10℃, the wind speed was 30±3m / s, and the drying time was 8±2h.

[0066] Silane coupling agent solution treatment: the bamboo treated by the silica sol was immersed in a silane coupling agent solution with a mass fraction of 8wt% silane coupling agent for 3h, the mass ratio of silane coupling agent solution to bamboo was 10:1, then low-temperature drying was carried out at 60±10℃ for 4h, and then rapid drying was carried out at 110℃ for 1h.

[0067] Examples 2-2 to 2-3, a method for modifying the hydrophobicity of bamboo, which is different from Example 2-1 in that the types of raw materials, the weights of raw materials and the process parameter settings in the modification method are different, as shown in Table 1.

[0068] Table 1: List of raw material types, raw material weights and process parameter settings in the bamboo hydrophobic modification method of Examples 2-1 to 2-3

[0069]

[0070] Embodiment 2-4 to Embodiment 2-10, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the hydrophobic and antibacterial finishing solution is replaced by the hydrophobic and antibacterial finishing solution of Embodiment 1-4 to Embodiment 1-10 in turn.

[0071] Embodiment 2-11, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the silica sol is replaced by silica sols with small particle size (2 nm), medium particle size (10 nm) and large particle size (30 nm) at a mass ratio of 1:2.5:6.

[0072] Embodiment 2-12, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the silica sol is replaced by silica sols with small particle size (9 nm), medium particle size (20 nm) and large particle size (50 nm) at a mass ratio of 1:3:8.

[0073] Embodiment 2-13, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the silica sol is replaced by silica sols with small particle size (5 nm), medium particle size (15 nm) and large particle size (22 nm) at a mass ratio of 1:2:4.

[0074] Embodiment 2-14, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the silica sol is replaced by silica sols with small particle size (2 nm), medium particle size (10 nm) and large particle size (30 nm) at a mass ratio of 1:2.5:2.

[0075] Embodiment 2-15, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the silica sol is replaced by silica sols with small particle size (2 nm) and medium particle size (10 nm) at a mass ratio of 1:2.5.

[0076] Embodiment 2-16, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-1 in that the silica sol is replaced by silica sols with medium particle size (10 nm) and large particle size (30 nm) at a mass ratio of 2.5:6; and the temperature of the hydrophobic and antibacterial finishing solution is 20℃.

[0077] Comparative Example 1, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-10 in that the synthetic antibacterial agent in the hydrophobic and antibacterial finishing solution is replaced by γ-(2,3-epoxypropyl) propyl trimethoxysilane to replace dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride in equal molar.

[0078] Comparative Example 2, a method for modifying bamboo into hydrophobic material, which is different from Embodiment 2-10 in that the synthetic antibacterial agent in the hydrophobic and antibacterial finishing solution is replaced by nonylphenol polyoxyethylene ether NP-10 (molecular weight 660) to replace polyethylene glycol (molecular weight 700) in equal molar.

[0079] Comparative Example 3, a method for hydrophobically modifying bamboo, differs from Examples 2-10 in that the bamboo is not treated with the hydrophobic antibacterial finishing solution.

[0080] Comparative Example 4, a method for hydrophobically modifying bamboo, differs from Examples 2-10 in that the bamboo is not treated with the silica sol.

[0081] Comparative Example 5, a method for hydrophobically modifying bamboo, differs from Examples 2-10 in that 3-aminopropyltrimethoxysilane is used instead of an equimolar amount of dodecyltrimethoxysilane in the silane coupling agent solution.

[0082] Comparative Example 6, a method for hydrophobically modifying bamboo, differs from Examples 2-10 in that the bamboo is not treated with the silane coupling agent solution.

[0083] Test 1: Water contact angle

[0084] The static water contact angle of the surface of the test sample was measured using a video contact angle optical meter (PZ-200SD, WYHOMI). Deionized water was used as the liquid, and the volume of the droplet was 10 uL. For each measurement, three different positions on the surface of the sample were randomly selected, and the average value was taken.

[0085] Test 2: Control efficacy

[0086] According to the test method for mildew resistance performance in GB / T 18261-2013, the test sample was tested for mildew resistance performance using Aspergillus niger (mold) and Colletotrichum cacao (discoloration fungus), and control efficacy E was used as an indicator.

[0087] E = (1 - D1 / D0) * 100%;

[0088] Control efficacy, %; D1 - average infection value of the test sample; D0 - average infection value of the untreated control sample (untreated modified bamboo).

[0089] Test sample: The modified bamboo prepared by the method for hydrophobically modifying bamboo in Examples 2-1 to 2-16 is the example sample; the modified bamboo prepared by the method for hydrophobically modifying bamboo in Comparative Examples 1 to 6 is the comparative example sample.

[0090] Test data: The detection results of the water contact angle and control efficacy of the modified bamboo prepared by the method for hydrophobically modifying bamboo in Examples 2-1 to 2-16 and Comparative Examples 1 to 6 are shown in Table 2.

[0091] Table 2: The water contact angle and control efficiency of modified bamboo prepared by the bamboo hydrophobic modification method of Example 2-1 to Example 2-15 and Comparative Example 1 to Comparative Example 6

[0092]

[0093] It can be seen from Example 2-1 to Example 2-15 and Comparative Example 1 to Comparative Example 6 in combination with Table 2 that:

[0094] The control efficiency of the modified bamboo prepared by the bamboo hydrophobic modification method of Example 2-10 is higher than that of Comparative Example 1 to Comparative Example 6, indicating that the treatment of bamboo with the synthetic antibacterial agent prepared by compounding dimethyl octadecyl [3- (trimethoxysilyl) propyl] ammonium chloride and polyethylene glycol improves the mildew resistance of bamboo; it may be because the prepared synthetic antibacterial agent has good antibacterial and mildew resistance performance and penetration performance, and has certain hydrophobic performance, thereby enhancing the mildew resistance of bamboo; the use of a synthetic antibacterial agent containing a quaternary ammonium salt in combination with silica sol and a silane coupling agent solution makes the prepared modified bamboo have good hydrophobic performance and mildew resistance.

[0095] The water contact angle of the bamboo prepared by the bamboo hydrophobic modification method of Comparative Example 2 is less than that of Example 2-10, which may be because the synthetic antibacterial agent uses nonylphenol polyoxyethylene ether NP-10 to replace polyethylene glycol in equal molar amount, resulting in a decrease in the dispersion performance of the synthetic antibacterial agent, causing the hydrophilic group to aggregate, and causing the water contact angle to decrease.

[0096] The water contact angle of the modified bamboo prepared by the bamboo hydrophobic modification method of Comparative Example 5 is less than that of Example 2-10, which may be because the structure of 3-aminopropyltrimethoxysilane does not contain long-chain alkanes, and contains a hydrophilic amino group, resulting in an increase in the hydrophilic performance of the modified bamboo and a decrease in the hydrophobic performance; while the structure of dodecyltrimethoxysilane contains not only hydrophobic silicon elements but also hydrophobic long-chain alkanes, and forms a better compatibility effect with the hydrophobic film layer formed by the silica sol, thereby improving the hydrophobic performance and mildew resistance of the modified bamboo.

[0097] The water contact angle and control efficiency of the modified bamboo prepared by the bamboo hydrophobic modification method of Example 2-4 to Example 2-7 and Example 2-1 indicate that as the water content in the hydrophobic antibacterial finishing liquid increases (the water content is in the range of 0.15-2wt%), the water contact angle first increases and then remains unchanged, and the control efficiency first increases and then decreases, which may be because the increase in water content causes the hydrolysis of n-butyl titanate, consumes water, and increases the mildew resistance and water contact angle; when the water content increases, the content of titanium sol does not change, and the water contact angle does not change; because the increase in water content may cause mildew, the control efficiency becomes poor.

[0098] Compared with Example 2-8 to Example 2-10, the water contact angle and control efficacy (mildew prevention effect) of the modified bamboo prepared by using the bamboo hydrophobic modification method of Example 2-1 are higher, indicating that the hydrophobic and antibacterial finishing liquid of polylactic acid-glycolic acid copolymer solution, n-butyl titanate and water is used to prepare the modified bamboo, and the hydrophobic property and mildew prevention effect of the modified bamboo are better; it may be because the titanium sol prepared by hydrolysis of n-butyl titanate has good water resistance, and part of the hydrolyzed n-butyl titanate can consume the water in the bamboo when it is hydrolyzed in the bamboo, thereby improving the mildew prevention effect of the bamboo; polylactic acid-glycolic acid copolymer has good water resistance and is easy to hydrolyze, and can reduce the water content in the bamboo when it is hydrolyzed; the titanium sol and polylactic acid-glycolic acid copolymer hydrolyzed in the bamboo are mutually synergistic, further improving the hydrophobic property and mildew prevention effect of the modified bamboo.

[0099] Compared with Example 2-14 to Example 2-16 and Example 2-1, the water contact angle and control efficacy (mildew prevention effect) of the modified bamboo prepared by using the bamboo hydrophobic modification method of Example 2-11 and Example 2-13 are higher, indicating that the small particle size, medium particle size and large particle size silica sols in the hydrophobic and antibacterial finishing liquid are matched, and the dosage is optimized, further improving the hydrophobic property and mildew prevention effect of the modified bamboo; it may be because the large particle size silica sol can enter the cell cavity inside the bamboo, and the small particle size and medium particle size silica sols are more easily immersed in the gap of the cell wall and the inter-fibril gap of the bamboo; the matching of the small particle size, medium particle size and large particle size silica sols further improves the bonding force of the silica sol formed film and the bamboo and the hydrophobic property of the internal structure and surface of the bamboo.

[0100] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make non-creative contribution modifications to the embodiments according to the needs after reading the present specification, but as long as the scope of the claims of the present application is within the scope of the patent law.

Claims

1. A hydrophobic antibacterial finishing liquid, characterized in that, The raw materials include 1-2 wt% of a synthetic antibacterial agent by weight of the organic solvent; the synthetic antibacterial agent is prepared by reacting polyethylene glycol, an organosilicon quaternary ammonium salt containing silicon-oxygen bonds, and water in a molar ratio of 1:2 to 3:3 to 6 under the catalysis of alkylbenzene sulfonic acid. The hydrophobic antibacterial finishing solution also includes 1-2 wt% of tetrabutyl titanate and 0.15-2 wt% of water; the polyethylene glycol is a low molecular weight polyethylene glycol. The hydrophobic antibacterial finishing solution also includes 1-4 wt% polylactic acid-glycolic acid copolymer solution; the polylactic acid-glycolic acid copolymer solution contains 8-15 wt% polylactic acid-glycolic acid copolymer solution.

2. The hydrophobic antibacterial finishing solution according to claim 1, characterized in that, The water content in the hydrophobic antibacterial finishing solution is 0.4-1.2 wt%; the organic solvent is a mixture of alcohols and esters or an alcohol-based organic solvent.

3. The hydrophobic antibacterial finishing solution according to claim 1, characterized in that, The average number-average molecular weight of the polylactic acid-glycolic acid copolymer is 6,000-10,000.

4. A method for hydrophobic modification of bamboo, characterized in that, The preparation steps include the following: Hydrophobic antibacterial finishing liquid treatment: Bamboo is immersed in the hydrophobic antibacterial finishing liquid according to any one of claims 1-3 for 1-6 hours; Silica sol treatment: The bamboo treated with hydrophobic antibacterial finishing solution is then immersed in silica sol with a silica content of 10-40wt% for 1-5 hours, followed by cleaning and drying. Silane coupling agent solution treatment: Bamboo treated with silica sol is immersed in a silane coupling agent solution with a silane coupling agent content of 1-10 wt% for 1-5 hours, and then dried to obtain modified bamboo.

5. The method for hydrophobic modification of bamboo according to claim 4, characterized in that, The silane coupling agent contains two or more siloxane groups and long-chain alkanes in its structure; the temperature of the hydrophobic antibacterial finishing solution is 30-40℃; the drying process involves first performing low-temperature drying at 50-70℃, followed by rapid drying at 110℃.

6. The method for hydrophobic modification of bamboo according to claim 4, characterized in that, The average particle size of the silica sol is 2-50 nm.

7. The method for hydrophobic modification of bamboo according to claim 6, characterized in that, The silica sol is formulated with small, medium, and large particle sizes in a mass ratio of 1:(2-3):(4-8); the average particle size range of the small-particle-size silica sol is 2-9 nm; the average particle size range of the medium-particle-size silica sol is 10-20 nm; and the average particle size range of the large-particle-size silica sol is 21-50 nm.

8. The method for hydrophobic modification of bamboo according to claim 4, characterized in that, Before being treated with the hydrophobic antibacterial finishing liquid, the bamboo material is first cleaned. The cleaning process involves spraying the surface of the bamboo material with 360° water, shaking off the large water droplets after spraying, and then drying it with circulating hot air at a temperature of 60-80℃ and a wind speed of 25-40m / s. After being treated with a hydrophobic antibacterial finishing solution, the bamboo surface is pretreated with plasma, and then impregnated with silica sol and silane coupling agent solution in sequence.

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