Bamboo mould-proof green-keeping agent, preparation method and application

Abstract

The invention discloses a mildew-proof green-keeping agent for bamboo wood, a preparation method and application. The preparation method of the bamboo wood mildew-proof green-keeping agent comprises the following steps: S1, adding chitosan into an acetic acid aqueous solution, and stirring until the chitosan is dissolved to obtain a mixed solution A; s2, adding copper salt into deionized water, and stirring until the copper salt is dissolved to obtain a mixed solution B; s3, adding cinnamyl aldehyde into an ethanol water solution, and stirring until cinnamyl aldehyde is dissolved to obtain a mixed solution C; and S4, the mixed solution A, the mixed solution B and the mixed solution C are mixed at the same time, stirring is conducted again under the water bath condition till the cinnamyl aldehyde chitosan copper is obtained through a reaction, and the cinnamyl aldehyde chitosan copper serves as the mildew-proof and green-keeping agent for the bamboo wood. Bamboo obtained through the treatment method is better in green-keeping and mildew-proof effects, bamboo green of the bamboo treated through the mildew-proof green-keeping agent is dark green, the bamboo can be kept green indoors and outdoors for a long time, the efficient mildew-proof performance is achieved, the treatment method is simple, and the mildew-proof green-keeping agent is non-toxic and harmless.

Description

Technical Field

[0001] The invention relates to the technical field of bamboo anti-mildew and green-keeping, and in particular to a method for preparing a bamboo anti-mildew and green-keeping agent. Background Art

[0002] As a natural biomass material that grows rapidly, has excellent mechanical properties and is rich in resources, bamboo has gradually received attention in recent years in the context of sustainable development. Bamboo buildings, handicrafts and decorations made of bamboo have natural colors and rich cultural connotations, and also have a wide range of applications and use value. However, due to the biological properties of bamboo, these products are easily affected by the environment and faded and infected by mold during indoor and outdoor applications. Therefore, it is necessary to use certain technical treatments to give bamboo the ability to resist mold and maintain its natural greenness, so as to extend the service life of various bamboo products.

[0003] Chitosan is a non-toxic and renewable polymer material. It is a natural polysaccharide obtained by deacetylation of chitin and is widely used in the pharmaceutical and food industries. Cinnamaldehyde, as a natural plant-derived essential oil compound, is one of the main components of cinnamon essential oil. In recent years, it has been widely used in combination with chitosan in the fields of fruit and vegetable preservation, food packaging and corrosion inhibitors.

[0004] The green preservation treatment of bamboo is mainly achieved by replacing magnesium ions in bamboo green chlorophyll with copper ions to make chlorophyll more stable. However, the materials treated with complexes such as copper sulfate, copper naphthenate and copper acetate have the disadvantages of easy fading, strong odor, high toxicity and poor light resistance. At present, there are green preservation treatments with natural substances such as chitosan copper salt and sodium copper chlorophyll. Although the green color of bamboo is greatly preserved, it is impossible to achieve long-term mildew prevention. In addition, compared with the bamboo green preservation measures of chitosan copper salt, this method has better green preservation and mildew prevention effects. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a bamboo anti-mildew and greening agent, a preparation method and application, which aims to keep the bamboo green for a long time and have the ability to resist mold infection to extend the service life of bamboo products and prevent the bamboo from fading and mildewing due to the influence of light, biological effects, etc.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] 1. A method for preparing a bamboo anti-mildew and greening agent, the steps of the method are as follows:

[0008] S1, adding chitosan into acetic acid aqueous solution and stirring until it is completely dissolved to obtain a mixed solution A;

[0009] S2, adding copper salt into deionized water and stirring until it is completely dissolved to obtain a mixed solution B;

[0010] S3, adding cinnamaldehyde into ethanol aqueous solution and stirring until completely dissolved to obtain a mixed solution C;

[0011] S4, mixing the mixed solution A, the mixed solution B and the mixed solution C at the same time, and stirring again in a water bath until the reaction is complete to obtain cinnamaldehyde chitosan copper as a bamboo anti-mildew and greening agent.

[0012] The bamboo anti-mildew and greening agent can be mixed according to usage requirements.

[0013] The chitosan in S1 has a molecular weight of 30,000 and a deacetylation degree of more than 85%.

[0014] The copper salt in S2 is copper chloride.

[0015] The mass ratio of chitosan in S1, copper salt in S2 and cinnamaldehyde in S3 is (1-1.7):(3.2-5.1):(1.8-2.1).

[0016] The volume fraction of the acetic acid aqueous solution in S1 is 8% to 12%, and the volume fraction of the ethanol aqueous solution in S3 is 90% to 100%.

[0017] The water bath temperature in S4 is 75-85°C.

[0018] 2. A bamboo anti-mildew and greening agent is prepared by any preparation method described in steps S1-S5 above.

[0019] 3. Application of a bamboo anti-mildew and greening agent:

[0020] The bamboo anti-mildew and green-keeping agent obtained by the method is used for bamboo anti-mildew and green-keeping.

[0021] 4. A method of using a bamboo anti-mildew and greening agent:

[0022] The newly cut wood is immersed in the bamboo anti-mildew and green-keeping agent, heated at 80°C for 2 hours, taken out after heating, and the unreacted agent is rinsed with deionized water, and finally air-dried or kiln-dried to obtain the anti-mildew and green-keeping bamboo product. The newly cut wood refers to the newly cut bamboo, and the unreacted agent refers to the part of the bamboo anti-mildew and green-keeping agent that has not reacted with the bamboo.

[0023] The present invention has the following beneficial effects:

[0024] The present application combines cinnamaldehyde, chitosan and copper salt. Due to the Schiff base structure formed between chitosan and cinnamaldehyde, bamboo can obtain excellent antibacterial properties. In addition, the adsorption of metal ions by the Schiff base structure makes copper ions more stable than single chitosan fixation. Therefore, the bamboo obtained by the treatment method has better green preservation and mildew resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the preparation of green and mildew-proof raw bamboo;

[0026] Figure 2 This is a comparison of raw bamboo that is untreated, treated only with chitosan copper, and treated with cinnamaldehyde chitosan copper proposed in this patent after being placed naturally indoors and outdoors for 90 days;

[0027] Figure 3 The 30-day mildew prevention test results of raw bamboo are shown in FIG. 1 , which are untreated bamboo, bamboo treated with chitosan copper only, and bamboo treated with cinnamaldehyde chitosan copper proposed in this patent; DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with embodiments, but the embodiments of the present invention are not limited thereto.

[0029] The present invention can be implemented by the following embodiments, but is not limited to the following embodiments.

[0030] 1. Preparation and treatment process of bamboo anti-mildew and greening agent

[0031] Embodiment 1:

[0032] Reagent preparation: Weigh 3g of chitosan and dissolve it in 100ml of 12% acetic acid aqueous solution; then weigh 9g of copper chloride and dissolve it in 100ml of deionized water; then prepare 100ml of 90% ethanol aqueous solution and add 6ml of cinnamaldehyde. Stir the three solutions evenly and mix them at the same time, stir again under 80℃ water bath until the reaction is complete, and obtain cinnamaldehyde chitosan copper treatment agent. The chitosan has a molecular weight of 30,000 and a deacetylation degree of more than 85%.

[0033] Use of bamboo anti-mildew and greening agent: immerse the newly cut bamboo in the treatment agent, heat it at 80℃ for 2h, take it out, rinse the unreacted agent and surface floating color with deionized water, and air-dry or kiln-dry to obtain the anti-mildew and greening bamboo product.

[0034] like Figure 1 and Figure 2As shown in the figure, the surface color of the raw bamboo treated with the agent of the present invention becomes brighter. In the process of natural placement indoors or outdoors, the raw bamboo treated with the agent of the present invention still maintains green within 90 days. The raw bamboo that has not been treated has faded seriously. The raw bamboo treated with only chitosan copper has a little green left in the indoor part, and the outdoor part has completely faded. Figure 3 As shown, after a 30-day long-term mildew-proof experiment, it can be found that the mildew-proof property of the original bamboo treated with the agent of the present invention is as high as 100% during the experiment.

[0035] 2. The anti-mildew and greening effect of bamboo

[0036] The surface color values ​​of untreated bamboo, bamboo treated with chitosan copper and bamboo treated with the agent of the present invention were read using a DC-P3 automatic colorimeter. The color value changes of the three samples within 90 days indoors and outdoors are shown in Table 1 and Table 2, respectively. According to the color judgment system defined by the International Commission on Illumination (CIE) in 1976, L * is the lightness of the bamboo, ranging from 100 (white) to 0 (black), a * represents the red to green axis, positive represents red, negative represents green, b * Represents the yellow to blue axis, positive for yellow, negative for blue, a * The lower the value, the greener the sample. After 15 days of storage, the a value of untreated raw bamboo placed indoors and outdoors was * have reached 0.42 and 4.85 respectively, both of which are positive values, indicating that the original bamboo has lost its green color. * are -4.81 and -1.31 respectively, which are still negative values, proving that the original bamboo retains a good green color. * After 90 days, the a values ​​of untreated bamboo, chitosan copper treated bamboo and cinnamaldehyde chitosan copper treated bamboo were * The values ​​were 1.08, -0.03 and -1.45 respectively. The bamboo treated with the agent of the present invention can keep green for a long time. The outdoor environment is harsh. The a of untreated bamboo, chitosan copper treated bamboo and cinnamaldehyde chitosan copper treated bamboo * The values ​​vary greatly, being 5.9, 2.33 and 0.38 respectively. The agent of the present invention can still provide long-term green protection for bamboo even in outdoor environment.

[0037] Table 1

[0038]

[0039] Table 2

[0040]

[0041]

[0042] Figure 1 The picture is composed of the finished product of the preparation of the present invention and the pictures of the surface of untreated bamboo and treated bamboo taken by a digital camera, showing the use process and effect of the preparation of the present invention.

[0043] like Figure 1 As shown in the figure, the surface of the bamboo treated with cinnamaldehyde chitosan copper and chitosan copper reagents is dark in color and has a positive a* value at the beginning because the film-forming surface of chitosan is covered with a rough layer. During the indoor placement process, it gradually turns green and shows the color of natural bamboo. Therefore, why is the a* value of the bamboo treated with the invention reagents in Tables 1 and 2 the same on the first day? * The value is positive.

[0044] Figure 2 The figure shows the surface color states of untreated bamboo, chitosan copper treated bamboo and cinnamaldehyde chitosan copper treated bamboo after being placed indoors and outdoors for 90 days, which were photographed by a digital camera. The surface color can correspond to the color coefficient values ​​in Table 1 and Table 2, which can prove that the agent of the present invention has a long-term greening effect on the original bamboo.

[0045] Figure 3 The mildew resistance experiments of untreated bamboo, chitosan copper treated bamboo and cinnamaldehyde chitosan copper treated bamboo were conducted with reference to the national standard GB / T 18261-2013. It can be seen from the state of bamboo at different times that the original bamboo treated with the agent of the present invention has long-term mildew resistance.

[0046] Anti-mildew effect: Figure 3 As shown in the figure, in the mildew-proof experiment, the untreated bamboo blocks were already infected by mildew at 7 days, while the simple chitosan copper treatment and the cinnamaldehyde chitosan copper treatment showed no changes. At 30 days, the untreated bamboo blocks were seriously infected, and the chitosan copper treatment samples were also infected by mildew, but the cinnamaldehyde chitosan copper treatment samples still maintained a bright green color without any trace of mildew infection, and the mildew-proof effect reached 100%.

[0047] Therefore, compared with the previously proposed chitosan copper greening agent, the cinnamaldehyde chitosan copper treatment agent proposed in the present invention can enable bamboo to have a longer-lasting green protection and antibacterial ability, greatly improving the service life of bamboo.

Claims

1. A method for preparing a bamboo anti-mildew and greening agent, characterized in that: The steps of the method are as follows: S1, adding chitosan into acetic acid aqueous solution and stirring until dissolved to obtain a mixed solution A; S2, adding copper salt into deionized water and stirring until dissolved to obtain a mixed solution B; S3, adding cinnamaldehyde to an ethanol aqueous solution and stirring until dissolved to obtain a mixed solution C; S4, mixing the mixed solution A, the mixed solution B and the mixed solution C at the same time, and stirring again in a water bath until the reaction obtains cinnamaldehyde chitosan copper as a bamboo anti-mildew and greening agent.

2. The method for preparing a bamboo anti-mildew and greening agent according to claim 1, characterized in that: The chitosan in S1 has a molecular weight of 30,000 and a deacetylation degree of more than 85%.

3. The method for preparing a bamboo anti-mildew and greening agent according to claim 1, characterized in that: The copper salt in S2 is copper chloride.

4. The method for preparing a bamboo anti-mildew and greening agent according to claim 1 or 3, characterized in that: The mass ratio of chitosan in S1, copper salt in S2 and cinnamaldehyde in S3 is (1-1.7): (3.2-5.1): (1.8-2.1).

5. The method for preparing a bamboo anti-mildew and greening agent according to claim 1, characterized in that: The volume fraction of the acetic acid aqueous solution in S1 is 8% to 12%, and the volume fraction of the ethanol aqueous solution in S3 is 90% to 100%.

6. The method for preparing a bamboo anti-mildew and greening agent according to claim 1, characterized in that: The water bath temperature in S4 is 75-85°C.

7. A bamboo anti-mildew and greening agent, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 6.

8. A bamboo anti-mildew and greening agent prepared by the preparation method according to any one of claims 1 to 6, or use of the bamboo anti-mildew and greening agent according to claim 7 in bamboo anti-mildew and greening.

9. A bamboo anti-mildew and greening agent prepared by the preparation method according to any one of claims 1 to 6 or a method for using the bamboo anti-mildew and greening agent according to claim 7, characterized in that: Immerse the newly cut timber in the bamboo anti-mildew and greening agent, heat it at 80°C for 2 hours, take it out after heating, rinse the unreacted agent with deionized water, and finally air-dry or kiln-dry to obtain the anti-mildew and greening bamboo product.

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