Softened wood preparation method, prepared softened wood and application of softened wood

Abstract

The invention provides a preparation method of softened wood, the prepared softened wood and application of the softened wood. The preparation method comprises the steps of ethanol soaking, vacuum treatment, drying, reaction with a deep eutectic solvent, forming and drying. Conventional wood is used as a raw material, and the softened wood is prepared through the method. The prepared softened wood has high softening deformation capacity, and the bending performance of the wood is more excellent.

Description

Technical Field

[0001] The present invention relates to the field of new wood technology development and modification, and particularly relates to a preparation method of softened wood and its application. Background Art

[0002] During the production of wooden furniture, the production of bent components often requires direct sawing of large pieces of materials or splicing of small pieces of materials. However, direct sawing of large pieces of materials results in serious waste and low material utilization rate; splicing of small pieces of materials requires mortise and tenon joints or adhesive bonding. The mortise and tenon manufacturing process is complex and increases the working hours, and adhesive bonding needs to consider the problem of formaldehyde release. Therefore, the wood softening and bending technology has always been a research hotspot in the industry. By using the wood softening technology, hard wood can be softened and bent into the shape required by product design, reducing material waste and saving working hours and labor costs. After the wood is softened, its plasticity is improved, the processing difficulty is effectively reduced, and the application range is wider. This is of great significance for improving the wood utilization rate and enabling wood to obtain higher added value in the fields of furniture, interior decoration, architecture, etc. Summary of the Invention

[0003] The main object of the present invention is to overcome the deficiencies in the prior art and provide a preparation method of softened wood. This method uses anhydrous ferric chloride-assisted deep eutectic solvent heating and air drying processes, which have the advantages of shorter reaction time, higher efficiency, and being green, environmentally friendly, economical and energy-saving.

[0004] Another object of the present invention is to provide a softened wood product prepared by the above method and its application. The prepared softened wood has a high bending deformation ability. Although its hardness decreases, the amount of decrease is not much (7HSA). Therefore, the softened wood can have good bending performance and strong mechanical properties at the same time. The process of this method is relatively simple, and the deep eutectic solvent used is green, environmentally friendly, recyclable and reusable.

[0005] The present invention provides a preparation method of softened wood, the obtained softened wood and its application, including the following steps: (1): Select wood without wormholes and dry it at 100 - 110 °C for 10 - 15 h for later use; (2): Immerse the dried wood prepared in step (1) in an ethanol solution at an immersion temperature of 20 - 30 °C for 10 - 12 h. Perform vacuum treatment for 1 - 2 h during the ethanol immersion time. After the immersion ends, take out the wood and impregnate it with deionized water for 1 - 2 h, then take out the wood for later use; (3): Prepare a deep eutectic solvent, place the wood obtained in step (2) in the deep eutectic solvent for reaction, set the reaction temperature and reaction time, and take out the wood for later use after the reaction ends; (4): Place the wood obtained in step (3) in a mold for shaping, and take out the wood for standby; (5): After rinsing the wood obtained in step (4) with deionized water, perform blowing drying, set the drying time, drying temperature and drying pressure, and obtain the softened wood after drying.

[0006] Preferably, the wood in step (1) is beech wood, and the density of the wood is 0.75 g / cm 3 .

[0007] Preferably, the preparation method of the deep eutectic solvent in step (3) is to mix a hydrogen bond donor (HBD), a hydrogen bond acceptor (HBA) and anhydrous ferric chloride in a certain molar ratio, and stir at a set temperature to obtain the deep eutectic solvent.

[0008] Preferably, the molar ratio of the hydrogen bond donor (HBD) to the hydrogen bond acceptor (HBA) is 10:1, and the set temperature is 90 °C.

[0009] Preferably, the hydrogen bond acceptor (HBA) is choline chloride, and the hydrogen bond donor (HBD) is lactic acid.

[0010] Preferably, the reaction temperature in step (3) is 105 °C, and the reaction time is 1 - 5 h.

[0011] Preferably, the curvature radii of the beakers in step (4) are 1 / 15, 1 / 30, 1 / 40, 1 / 50, 1 / 60, 1 / 75, 1 / 90 respectively.

[0012] Preferably, the drying time in step (5) is 48 h, the drying temperature is 60 °C, and the drying pressure is 8.5 MPa.

[0013] The present invention also provides the softened wood prepared by the above-mentioned method for preparing softened wood.

[0014] The present invention also provides the application of the above-mentioned softened wood in the preparation of furniture and the construction industry.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. Using conventional wood, the obtained softened wood has a high bending deformation ability, and the softening performance of the wood is more excellent than before.

[0016] 2. The process of this method is relatively simple, and the anhydrous ferric chloride-assisted deep eutectic solvent used is green and environmentally friendly, and has recyclability and reusability.

[0017] The above content is only an overview of the technical solution of the present invention. To understand the technical means of the present invention more clearly, the present invention will be further described below in conjunction with the accompanying drawings. Brief Description of the Drawings

[0018] Figure 1 It is a process flow chart for the preparation of the present invention. Detailed Embodiments

[0019] To understand the present invention, the present invention will be further described below in conjunction with embodiments.

[0020] The present invention uses wood as a raw material, and softwood is prepared through steps such as drying, soaking in ethanol and vacuum treatment, reacting with a deep eutectic solvent, shaping treatment, and air drying.

[0021] The specific embodiments are as follows. Embodiment

[0022] The present invention provides a method for preparing softwood, the obtained softwood and its application, including the following steps: (1): Select beech wood without insect holes, with a thickness of 1 mm and a density of 0.75 g / cm 3 , and dry it at 60 °C for 12 h for later use; (2): Immerse the dried wood prepared in step (1) in an ethanol solution, with an immersion temperature of 27 °C and an immersion time of 12 h. Perform vacuum treatment for 1 h during the ethanol immersion time. After the immersion ends, take out the wood and impregnate the wood with deionized water for 1 h, and then take out the wood for later use; (3): Prepare a deep eutectic solvent. Select lactic acid, choline chloride and anhydrous ferric chloride and mix them in a molar ratio of 10:1:0.28, and stir evenly at a temperature of 60 °C to obtain a deep eutectic solvent. Place the wood prepared in step (2) in the deep eutectic solvent for reaction, with a reaction temperature of 105 °C and a reaction time of 1 h. After the reaction ends, take out the wood for later use; (4): Bend the wood prepared in step (3). After the treatment ends, take out the wood for later use; (5): After rinsing the wood prepared in step (4) with deionized water, dry it with a blower dryer for 24 h, with a drying temperature of 60 °C and a drying pressure of 7.38 MPa. After drying, softwood is obtained.

[0023] After testing, the softwood prepared in this embodiment can reach a minimum bending radius of 15 mm and a hardness of 63 HSA. Embodiment

[0024] The present invention provides a method for preparing softwood, the obtained softwood and its application, including the following steps: (1): Select beech wood without insect holes, with a thickness of 2.5 mm and a density of 0.75 g / cm 3 , dry it at 60 °C for 12 h and set aside; (2): Immerse the dry wood prepared in step (1) in an ethanol solution at an immersion temperature of 27 °C for 12 h. Perform vacuum treatment for 1 h during the ethanol immersion time. After the immersion, take out the wood and impregnate it with deionized water for 1 h, then take out the wood and set it aside; (3): Prepare a deep eutectic solvent by mixing lactic acid, choline chloride, and anhydrous ferric chloride in a molar ratio of 10:1:0.28, and stir evenly at a temperature of 90 °C to obtain the deep eutectic solvent. Place the wood prepared in step (2) in the deep eutectic solvent for reaction at a reaction temperature of 105 °C for 2 h. After the reaction, take out the wood and set it aside; (4): Bend the wood prepared in step (3). After the treatment, take out the wood and set it aside; (5): After rinsing the wood prepared in step (4) with deionized water, dry it with a blast dryer for 24 h at a drying temperature of 70 °C and a drying pressure of 7.45 MPa. After drying, obtain the softened wood.

[0025] After testing, the softened wood prepared in this example can reach a minimum bending radius of 40 mm and a hardness of 63 HSA. Example

[0026] The present invention provides a method for preparing softened wood, the obtained softened wood and its application, including the following steps: (1): Select beech wood without insect holes, with a thickness of 3.5 mm and a density of 0.75 g / cm 3 , dry it at 60 °C for 12 h and set aside; (2): Immerse the dry wood prepared in step (1) in an ethanol solution at an immersion temperature of 27 °C for 12 h. Perform vacuum treatment for 1 h during the ethanol immersion time. After the immersion, take out the wood and impregnate it with deionized water for 1 h, then take out the wood and set it aside; (3): Prepare a deep eutectic solvent by mixing lactic acid, choline chloride, and anhydrous ferric chloride in a molar ratio of 10:1:0.28, and stir evenly at a temperature of 90 °C to obtain the deep eutectic solvent. Place the wood prepared in step (2) in the deep eutectic solvent for reaction at a reaction temperature of 105 °C for 3 h. After the reaction, take out the wood and set it aside; (4): Bend the wood prepared in step (3). After the treatment, take out the wood and set it aside; (5): After rinsing the wood obtained in step (4) with deionized water, it is dried with a blast dryer for 36 h at a drying temperature of 75 °C and a drying pressure of 8.25 MPa. After drying, softened wood is obtained.

[0027] After testing, the softened wood prepared in this example can achieve a minimum bending radius of 50 mm and a hardness of 63 HSA. Example

[0028] The present invention provides a method for preparing softened wood, the obtained softened wood and its application, including the following steps: (1): Select beech wood without wormholes, with a thickness of 5 mm and a density of 0.75 g / cm 3 , and dry it at 60 °C for 12 h for later use; (2): Immerse the dried wood prepared in step (1) in an ethanol solution at an immersion temperature of 27 °C for 12 h. During the ethanol immersion time, perform vacuum treatment for 1 h. After the immersion, take out the wood and impregnate the wood with deionized water for 1 h, and then take out the wood for later use; (3): Prepare a deep eutectic solvent by mixing lactic acid, choline chloride and anhydrous ferric chloride in a molar ratio of 10:1:0.28, and stir evenly at a temperature of 60 °C to obtain a deep eutectic solvent. Place the wood prepared in step (2) in the deep eutectic solvent for reaction at a reaction temperature of 105 °C for 5 h. After the reaction, take out the wood for later use; (4): Bend the wood prepared in step (3), and after the treatment, take out the wood for later use; (5): After rinsing the wood obtained in step (4) with deionized water, dry it with a blast dryer for 48 h at a drying temperature of 80 °C and a drying pressure of 8.5 MPa. After drying, softened wood is obtained.

[0029] After testing, the softened wood prepared in this example can achieve a minimum bending radius of 60 mm and a hardness of 63 HSA.

[0030] When the beech wood is treated with the deep eutectic solvent, the minimum bending radii are different at different thicknesses and different times. The maximum bending radii and Shore hardness of different examples are shown in Table 1.

[0031] Table 1 Maximum bending radii and Shore hardness of different examples Example 1 Example 2 Example 3 Example 4 Wood type Beech Beech Beech Beech <![CDATA[Wood density g / cm 3 > 0.75 0.75 0.75 0.75 Hydrogen bond donor HBD Lactic acid Lactic acid Lactic acid Lactic acid Hydrogen bond acceptor HBA Choline chloride Choline chloride Choline chloride Choline chloride Molar ratio of HBD and HBA 10:1 10:1 10:1 10:1 Minimum bending radius mm 15 40 50 60 Shore hardness HSA 63 63 63 63 In the present invention, the wood is subjected to conventional drying treatment. After drying, the wood is immersed in absolute ethanol, and then vacuum treatment is carried out on the wood, followed by rinsing with deionized water. Subsequently, the wood sample is reacted in a mixed solution of a deep eutectic solvent and ferric chloride anhydrous, and then bending and shaping treatment is carried out on the wood. It is required that the wood be in a wet and hot state during the shaping treatment. Finally, the obtained wood is rinsed with deionized water and then dried in a blast dryer to obtain softened wood.

[0032] A deep eutectic solvent refers to a deep eutectic mixture composed of a certain molar ratio of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) (such as lactic acid and choline chloride, lactic acid and histidine, malic acid and choline chloride, malic acid and proline, oxalic acid and choline chloride, etc.). The deep eutectic solvent has the ability to selectively cleave ether bonds without affecting the C—C bonds in lignin. The added FeCl3 can act as an active site to provide acidic protons, improving the softening efficiency of the DES. The treated wood has good flexibility and can be bent and deformed under the action of a small force. Most of the vessel pores, cell cavities, and cell gaps in the beech wood after treatment are filled with the DES, reducing the pores of the wood. 86.1% of the lignin and 47.9% of the hemicellulose are removed. The DES selectively removes the lignin between cells without significantly affecting the structural components of the cell wall, thereby obtaining a smaller hardness and a larger bending deformation ability.

[0033] The above is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes. However, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation method of softened wood, the obtained softened wood and its application, characterized in that: It includes the following steps: (1): Select wood without insect holes, dry it at 100 - 110 °C for 10 - 15 h, and set aside for use; (2): Immerse the dried wood reserved in step (1) in an ethanol solution, with the immersion temperature being 20 - 30 °C and the immersion time being 10 - 12 h. Conduct vacuum treatment for 1 - 2 h during the ethanol immersion time. After the immersion ends, take out the wood and impregnate the wood with deionized water for 1 - 2 h, then take out the wood and set aside for use; (3): Prepare a deep eutectic solvent, and place the wood obtained in step (2) in a mixed solution of the deep eutectic solvent and anhydrous ferric chloride to react. Set the reaction temperature and reaction time. After the reaction ends, take out the wood and set aside for use; (4): Put the wood obtained in step (3) into a mold for shaping; (5): After rinsing the wood obtained in steps (3) and (4) with deionized water, dry it in a forced-air drying oven, set the drying time and drying temperature. After drying ends, obtain the shaped wood products made of softened wood.

2. The preparation method of softened wood according to claim 1, the obtained softened wood and its application are characterized in that: The wood described in step (1) is beech, and the density of the wood is 0.75 g / cm 3 .

3. A method for preparing softened wood as claimed in claim 1, the softened wood obtained thereby, and their applications, characterized in that: The preparation method of the deep eutectic solvent described in step (3) is to mix a hydrogen bond donor, a hydrogen bond acceptor, and FeCl₃ with a set molar ratio, and stir at a set temperature to obtain the deep eutectic solvent.

4. A method for preparing softened wood according to claim 3, the softened wood obtained thereby, and its application, characterized in that: The molar ratio of the hydrogen bond donor to the hydrogen bond acceptor is 10:1 - 2:1, and the set temperature is 90 °C.

5. A preparation method of softened wood, the obtained softened wood and its application according to claim 3, characterized in that: The hydrogen bond acceptor is choline chloride, and the hydrogen bond donor is any one of lactic acid. Anhydrous FeCl₃ provides acidic protons as the active site.

6. A method for preparing softwood and the obtained softwood and its application according to claim 1, characterized in that: The reaction temperature described in step (3) is 90 - 120 °C, and the reaction time is 1 - 5 h.

7. A method for preparing softened wood according to claim 1, the obtained softened wood and its application, characterized in that: The curvature radii of the mold described in step (4) are 1 / 15, 1 / 30, 1 / 40, 1 / 50, 1 / 60, 1 / 75, 1 / 90 respectively.

8. A method for preparing softened wood according to claim 1, the obtained softened wood and its application, characterized in that: The drying time described in step (5) is 24 h - 48 h, the drying temperature is 60 - 80 °C, and the drying pressure is 7.38 - 8.5 MPa.

9. A softened wood prepared by the preparation method as described in claim 1.

10. An application of the softened wood as described in claim 9 in the preparation of furniture and the construction industry.

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