Carboxylated sucrose compound modified wood and preparation method thereof

Abstract

The invention relates to the technical field of wood modification treatment, in particular to carboxylated sucrose compound modified wood and a preparation method thereof. The carboxylated sucrose compound modified wood is obtained by injecting a carboxylated sucrose compound solution into the wood through a vacuum-pressure dipping treatment technology; the carboxylated sucrose compound solution is obtained by dissolving a carboxylated sucrose compound in deionized water. The carboxylated sucrose compound modified wood disclosed by the invention has excellent dimensional stability, mechanical property, ultraviolet degradation resistance and decay resistance, and provides reference significance for developing a green and environment-friendly wood modification technology.

Description

Technical Field

[0001] The present invention relates to the technical field of wood modification treatment, and particularly relates to a carboxylated sucrose complex modified wood and a preparation method thereof. Background Art

[0002] Wood is a natural and environmentally friendly material, with many advantages such as natural color, beautiful texture, high strength-to-weight ratio, convenient processing, adjustable temperature and humidity, etc., and is widely used in fields such as house construction, furniture manufacturing, food packaging, transportation, and even aerospace. In recent years, the rapid development of the Chinese economy has greatly accelerated the urbanization process, and the demand for wood in fields such as construction, furniture, papermaking, and gardening has increased sharply. However, the limited natural forest resources available for exploitation in China have led to an increasingly prominent contradiction between the supply and demand of wood. As a kind of plantation tree species, fast-growing forests have the advantages of fast growth rate, high wood yield, short life cycle, etc. Therefore, vigorously developing fast-growing forests can increase the supply of wood and effectively alleviate the contradiction between the supply and demand of wood.

[0003] However, due to the relatively fast growth rate, artificial fast-growing forests have many defects, such as low density, poor physical and mechanical strength, easy cracking and deformation, easy decay, etc., which seriously restrict the application scope of artificial fast-growing forests. In order to be able to develop and utilize artificial fast-growing forest resources with high quality and efficiency, the fast-growing wood can be modified to endow it with excellent properties, thereby improving its application scope and market competitiveness.

[0004] Patent technical literature CN116396256A discloses a preparation method and application of a carboxylated sucrose wood modifier, which is prepared by three steps of oxidizing sucrose, deprotonating, and carboxylating. The prepared carboxylated sucrose solid powder can be dissolved in water to prepare wood modifier solutions with different concentrations. Using the carboxylated sucrose modifier provided by this invention for wood modification treatment, carboxylated sucrose can effectively fix in wood cells and has good anti-leaching properties; the carboxylated sucrose modified wood has good dimensional stability, greatly improves the comprehensive properties of wood, and extends the service life of wood. However, its mechanical strength, decay resistance, and ultraviolet resistance still need to be further improved. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose a carboxylated sucrose complex modified wood and a preparation method thereof, so as to provide a modified wood with high mechanical strength, high ultraviolet resistance, and high decay resistance.

[0006] Based on the above purpose, the present invention provides a carboxylated sucrose complex modified wood, and the carboxylated sucrose complex modified wood is obtained by injecting a carboxylated sucrose complex solution into the interior of the wood through a vacuum-pressure impregnation treatment technology; The preparation steps of the carboxylated sucrose complex solution are as follows: S1: dissolving sucrose in deionized water, adding hydrogen peroxide, carrying out oxidation reaction at 50-60°C for 10-12h, cooling to obtain an oxidized sucrose solution; then adding sodium hypophosphite to the oxidized sucrose solution, heating to 70°C, reacting for 1h, adding malic acid, reacting at 100-110°C for 20-30min, obtaining a carboxylated sucrose solution, and freeze-drying to obtain a carboxylated sucrose powder; S2: dispersing graphene oxide in deionized water, ultrasonically treating until uniformly dispersed, adding citric acid, reacting at 80-90° C. for 6-7 h, centrifuging, filtering, washing, and drying to obtain carboxylated graphene oxide; S3: Disperse carboxylated graphene oxide and graphene oxide in deionized water, add PVP, stir magnetically for 10 minutes, then add carboxylated sucrose powder, stir evenly and adjust the pH to 5.5, then add EDC, react at room temperature for 24-30 hours, dialyze, and freeze-dry to obtain carboxylated sucrose complex powder.

[0007] Preferably, the usage ratio of sucrose, deionized water, hydrogen peroxide, sodium hypophosphite and malic acid in step S1 is 200-300 g: 1-2 L: 1.8-2 g: 1-2 g: 25-30 g.

[0008] Preferably, the usage ratio of graphene oxide, deionized water and citric acid in step S2 is 3-5g:100ml:25-50ml.

[0009] Preferably, in step S3, the usage ratio of carboxylated graphene oxide, graphene oxide, deionized water, PVP, carboxylated sucrose powder and EDC is 1.5-2g:0.25-0.5g:500-800ml:0.1-0.2g:80-100g:0.5-1g.

[0010] Preferably, the particle size of the graphene oxide is 0.8-1.2 nm.

[0011] More preferably, the graphene oxide is purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0012] Furthermore, the present invention also provides a method for preparing a carboxylated sucrose complex modified wood, the specific steps of which are as follows: (1) dissolving carboxylated sucrose complex powder in deionized water to obtain a carboxylated sucrose complex solution with a concentration of 10%-15%; (2) Vacuum-treat the wood under a vacuum of -0.06 to -0.1 MPa for 4 - 8 h, introduce the carboxylated sucrose complex solution, perform pressure treatment at a pressure of 0.5 - 2.0 MPa for 12 - 24 h, then leave it at room temperature for 1 - 2 d, and then dry it at 40 - 60 °C and 70 - 90 °C for 12 - 24 h respectively, and then dry it at 100 - 140 °C for 12 - 24 h to obtain carboxylated sucrose complex-modified wood.

[0013] Advantages of the present invention: For the carboxylated sucrose complex-modified wood of the present invention, through the efficient fixation of the carboxylated sucrose modified complex in the wood structure, the dimensional stability, mechanical properties, ultraviolet light degradation resistance and decay resistance of the modified wood are all improved, thereby improving the utilization rate of wood resources and providing a reference for the development of green and environmentally friendly wood modification technologies.

[0014] In the present invention, carboxylated sucrose is compounded with graphene oxide by physical cross-linking. Under the influence of hydrogen bonds and π-π interactions, graphene oxide can better exist inside the wood, and then better exert its antibacterial and ultraviolet resistance abilities.

[0015] In the present invention, carboxylated sucrose is grafted with graphene oxide by chemical cross-linking. The two are tightly combined through ether bonds and ester bonds, so that graphene oxide can better combine with the wood, and then better exert its antibacterial and ultraviolet resistance abilities.

[0016] In the present invention, carboxylated sucrose and graphene oxide are combined together by physical and chemical actions, and the formed complex solution enters the wood interior, so that the mechanical properties, ultraviolet light degradation resistance and decay resistance of the wood are all significantly improved. Specific embodiments

[0017] To make the purpose, technical solutions and advantages of the present invention clearer, the following further elaborates on the present invention in conjunction with specific embodiments.

[0018] Example 1: A preparation method of carboxylated sucrose complex-modified wood, the specific steps are as follows: (1) Dissolve 200 g of sucrose in 1 L of deionized water, add 1.8 g of hydrogen peroxide, perform an oxidation reaction at 50 °C for 10 h, cool to obtain an oxidized sucrose solution; then add 1 g of sodium hypophosphite to the oxidized sucrose solution, heat up to 70 °C, react for 1 h, add 25 g of malic acid, and react at 100 °C for 20 min to obtain a carboxylated sucrose solution, and freeze-dry to obtain carboxylated sucrose powder; (2) Dispersing 3 g of graphene oxide in 100 ml of deionized water, ultrasonically treating until uniformly dispersed, adding 25 ml of citric acid, reacting at 80 ° C for 6 h, centrifuging, filtering, washing, and drying to obtain carboxylated graphene oxide; (3) Disperse 1.5 g of carboxylated graphene oxide and 0.25 g of graphene oxide in 500 ml of deionized water, add 0.1 g of PVP, stir magnetically for 10 min, then add 80 g of carboxylated sucrose powder, stir evenly and adjust the pH to 5.5, then add 0.5 g of EDC, react at room temperature for 24 h, dialyze, and freeze-dry to obtain carboxylated sucrose complex powder; (4) The carboxylated sucrose complex powder was dissolved in deionized water to obtain a carboxylated sucrose complex solution with a concentration of 10%. The wood was subjected to vacuum treatment at a vacuum degree of -0.06 MPa for 4 h, the carboxylated sucrose complex solution was introduced, and the wood was subjected to pressure treatment at a pressure of 0.5 MPa for 12 h. Subsequently, the wood was placed at room temperature for 1 day, dried at 40°C and 70°C for 12 h, respectively, and then dried at 100°C for 12 h to obtain carboxylated sucrose complex modified wood.

[0019] Example 2: A method for preparing a carboxylated sucrose complex modified wood, the specific steps are as follows: (1) Dissolve 250 g of sucrose in 1.5 L of deionized water, add 1.9 g of hydrogen peroxide, carry out oxidation reaction at 55 ° C for 11 hours, cool to obtain an oxidized sucrose solution; then add 1.5 g of sodium hypophosphite to the oxidized sucrose solution, heat to 70 ° C, react for 1 hour, add 27 g of malic acid, react at 105 ° C for 25 minutes to obtain a carboxylated sucrose solution, freeze-dry to obtain a carboxylated sucrose powder; (2) Dispersing 4 g of graphene oxide in 100 ml of deionized water, ultrasonically treating until uniformly dispersed, adding 27 ml of citric acid, reacting at 85 °C for 6 h, centrifuging, filtering, washing, and drying to obtain carboxylated graphene oxide; (3) 1.8 g of carboxylated graphene oxide and 0.4 g of graphene oxide were dispersed in 700 ml of deionized water, 0.15 g of PVP was added, and magnetic stirring was performed for 10 min. Then, 90 g of carboxylated sucrose powder was added, stirred evenly, and the pH was adjusted to 5.5. Then, 0.7 g of EDC was added, and the mixture was reacted at room temperature for 26 h. The mixture was dialyzed and freeze-dried to obtain carboxylated sucrose complex powder. (4) Dissolve the carboxylated sucrose complex powder in deionized water to obtain a 13% carboxylated sucrose complex solution; subject the wood to vacuum treatment at a vacuum degree of -0.08 MPa for 6 h, introduce the carboxylated sucrose complex solution, carry out pressure treatment at a pressure of 1 MPa for 20 h, then place it at room temperature for 2 d, and then dry it at 50 °C and 80 °C for 20 h respectively, and then dry it at 120 °C for 20 h to obtain the carboxylated sucrose complex modified wood.

[0020] Example 3: A method for preparing carboxylated sucrose complex modified wood, the specific steps are as follows: (1) Dissolve 300 g of sucrose in 2 L of deionized water, add 2 g of hydrogen peroxide, carry out an oxidation reaction at 60 °C for 12 h, cool to obtain an oxidized sucrose solution; then add 2 g of sodium hypophosphite to the oxidized sucrose solution, heat up to 70 °C, react for 1 h, add 30 g of malic acid, and react at 110 °C for 30 min to obtain a carboxylated sucrose solution, and freeze-dry to obtain carboxylated sucrose powder; (2) Disperse 5 g of graphene oxide in 100 ml of deionized water, ultrasonically treat until evenly dispersed, add 50 ml of citric acid, react at 90 °C for 7 h, centrifuge, filter, wash, and dry to obtain carboxylated graphene oxide; (3) Disperse 2 g of carboxylated graphene oxide and 0.5 g of graphene oxide in 800 ml of deionized water, add 0.2 g of PVP, stir magnetically for 10 min, then add 100 g of carboxylated sucrose powder, stir evenly and adjust the pH to 5.5, then add 1 g of EDC, react at room temperature for 30 h, dialyze, and freeze-dry to obtain carboxylated sucrose complex powder; (4) Dissolve the carboxylated sucrose complex powder in deionized water to obtain a 15% carboxylated sucrose complex solution; subject the wood to vacuum treatment at a vacuum degree of -0.1 MPa for 8 h, introduce the carboxylated sucrose complex solution, carry out pressure treatment at a pressure of 2.0 MPa for 24 h, then place it at room temperature for 2 d, and then dry it at 60 °C and 90 °C for 24 h respectively, and then dry it at 140 °C for 24 h to obtain the carboxylated sucrose complex modified wood.

[0021] Comparative Example 1: A method for preparing carboxylated sucrose complex modified wood, which is different from Example 2 in that there is no graphene oxide, and the specific steps are as follows: (1) Dissolve 250 g of sucrose in 1.5 L of deionized water, add 1.9 g of hydrogen peroxide, carry out an oxidation reaction at 55 °C for 11 h, cool to obtain an oxidized sucrose solution; then add 1.5 g of sodium hypophosphite to the oxidized sucrose solution, heat up to 70 °C, react for 1 h, add 27 g of malic acid, react at 105 °C for 25 min to obtain a carboxylated sucrose solution, and freeze-dry to obtain carboxylated sucrose powder; (2) Disperse 4 g of graphene oxide in 100 ml of deionized water, ultrasonically treat until uniformly dispersed, add 27 ml of citric acid, react at 85 °C for 6 h, centrifuge, filter, wash, and dry to obtain carboxylated graphene oxide; (3) Disperse 2.2 g of carboxylated graphene oxide in 700 ml of deionized water, add 0.15 g of PVP, stir magnetically for 10 min, then add 90 g of carboxylated sucrose powder, stir evenly and adjust the pH to 5.5, add 0.7 g of EDC, react at room temperature for 26 h, dialyze, and freeze-dry to obtain carboxylated sucrose composite powder; (4) Dissolve the carboxylated sucrose composite powder in deionized water to obtain a 13% carboxylated sucrose composite solution; subject the wood to vacuum treatment at a vacuum degree of -0.08 MPa for 6 h, introduce the carboxylated sucrose composite solution, carry out pressure treatment at a pressure of 1 MPa for 20 h, then place it at room temperature for 2 d, dry at 50 °C and 80 °C for 20 h respectively, and then dry at 120 °C for 20 h to obtain carboxylated sucrose composite modified wood.

[0022] Comparative Example 2: A method for preparing carboxylated sucrose composite modified wood, which is different from Example 2 in that there is no graphene oxide. The specific steps are as follows: (1) Dissolve 250 g of sucrose in 1.5 L of deionized water, add 1.9 g of hydrogen peroxide, carry out an oxidation reaction at 55 °C for 11 h, cool to obtain an oxidized sucrose solution; then add 1.5 g of sodium hypophosphite to the oxidized sucrose solution, heat up to 70 °C, react for 1 h, add 27 g of malic acid, react at 105 °C for 25 min to obtain a carboxylated sucrose solution, and freeze-dry to obtain carboxylated sucrose powder; (2) Disperse 2.2 g of graphene oxide in 700 ml of deionized water, add 0.15 g of PVP, stir magnetically for 10 min, then add 90 g of carboxylated sucrose powder, stir evenly and adjust the pH to 5.5, add 0.7 g of EDC, react at room temperature for 26 h, dialyze, and freeze-dry to obtain carboxylated sucrose composite powder; (3) Dissolve the carboxylated sucrose complex powder in deionized water to obtain a 13% carboxylated sucrose complex solution; subject the wood to vacuum treatment at a vacuum degree of -0.08 MPa for 6 h, introduce the carboxylated sucrose complex solution, perform pressure treatment at a pressure of 1 MPa for 20 h, then leave it at room temperature for 2 d, dry it at 50 °C and 80 °C for 20 h respectively, and then dry it at 120 °C for 20 h to obtain the carboxylated sucrose complex modified wood.

[0023] Comparative Example 3: A method for preparing carboxylated sucrose complex modified wood, which is different from Example 2 in that there is no graphene oxide. The specific steps are as follows: (1) Dissolve 250 g of sucrose in 1.5 L of deionized water, add 1.9 g of hydrogen peroxide, perform an oxidation reaction at 55 °C for 11 h, cool to obtain an oxidized sucrose solution; then add 1.5 g of sodium hypophosphite to the oxidized sucrose solution, raise the temperature to 70 °C, react for 1 h, add 27 g of malic acid, and react at 105 °C for 25 min to obtain a carboxylated sucrose solution, and freeze-dry to obtain carboxylated sucrose powder; (2) Dissolve the carboxylated sucrose powder in deionized water to obtain a 13% carboxylated sucrose complex solution; subject the wood to vacuum treatment at a vacuum degree of -0.08 MPa for 6 h, introduce the carboxylated sucrose complex solution, perform pressure treatment at a pressure of 1 MPa for 20 h, then leave it at room temperature for 2 d, dry it at 50 °C and 80 °C for 20 h respectively, and then dry it at 120 °C for 20 h to obtain the carboxylated sucrose complex modified wood.

[0024] Performance Test Bending strength: Refer to GB / T1936.1-2009 "Test Method for Bending Strength of Wood" to measure the bending strength of wood. The test results are shown in Table 1; UV resistance: Use the QUV accelerated aging experiment (ASTM G154, UVA-340 lamp, 60 °C / 4 h light + 50 °C / 4 h condensation, cycle for 7 days) to test its bending strength. The test results are shown in Table 1; Decay resistance: Place the wood obtained in the present invention in a soft rot fungus environment at the same time to receive the anti-corrosion performance test (the test standard is European standard EN807). After 30 d, weigh the oven-dry mass of the sample and calculate the mass loss rate. The test results are shown in Table 1.

[0025]

[0026] Data analysis: It can be seen from the data of the examples in Table 1 that for the carboxylated sucrose complex-modified wood of the present invention, through the efficient fixation of the carboxylated sucrose modified complex in the wood structure, the mechanical properties, ultraviolet light degradation resistance and decay resistance of the wood are all improved, thereby improving the utilization rate of wood resources and providing a reference for the development of green and environmentally friendly wood modification technologies.

[0027] It can be seen from the data of Example 2 and Comparative Example 1 in Table 1 that by compounding carboxylated sucrose with graphene oxide by physical cross-linking, under the influence of hydrogen bonds and π-π interactions, the two are more closely combined, and then graphene oxide can better exist inside the wood, and then better play its antibacterial and ultraviolet resistance capabilities.

[0028] It can be seen from the data of Example 2 and Comparative Example 2 in Table 1 that by grafting carboxylated sucrose with graphene oxide by chemical cross-linking, the two are tightly combined through ether bonds and ester bonds, enabling graphene oxide to better combine with the wood, and then better play its antibacterial and ultraviolet resistance capabilities. At the same time, graphene itself can act as a physical strengthening phase to improve the mechanical properties of the wood.

[0029] It can be seen from the data of Example 2 and Comparative Example 3 in Table 1 that in the present invention, carboxylated sucrose and graphene oxide are combined together by physical and chemical actions, and the formed complex solution enters the wood, significantly improving the mechanical properties, ultraviolet light degradation resistance and decay resistance of the wood.

[0030] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A carboxylated sucrose complex-modified wood, characterized in that, The carboxylated sucrose complex modified wood is obtained by injecting a carboxylated sucrose complex solution into the interior of the wood through a vacuum-pressure impregnation treatment technique; The preparation steps of the carboxylated sucrose complex solution are as follows: S1: Dissolve sucrose in deionized water, add hydrogen peroxide, and carry out an oxidation reaction at 50 - 60 °C for 10 - 12 h, then cool to obtain an oxidized sucrose solution; subsequently, add sodium hypophosphite to the oxidized sucrose solution, raise the temperature to 70 °C, react for 1 h, add malic acid, and react at 100 - 110 °C for 20 - 30 min to obtain a carboxylated sucrose solution, and then freeze-dry to obtain carboxylated sucrose powder; S2: Disperse graphene oxide in deionized water, ultrasonically treat until uniformly dispersed, add citric acid, and react at 80 - 90 °C for 6 - 7 h, then centrifuge, filter, wash, and dry to obtain carboxylated graphene oxide; S3: Disperse carboxylated graphene oxide and graphene oxide in deionized water, add PVP, stir magnetically for 10 min, then add carboxylated sucrose powder, stir evenly and adjust the pH to 5.5, then add EDC, react at room temperature for 24 - 30 h, dialyze, and freeze-dry to obtain carboxylated sucrose complex powder.

2. The carboxylated sucrose complex-modified wood according to claim 1, wherein In step S1, the dosage ratio of sucrose, deionized water, hydrogen peroxide, sodium hypophosphite, and malic acid is 200 - 300 g: 1 - 2 L: 1.8 - 2 g: 1 - 2 g: 25 - 30 g.

3. The carboxylated sucrose complex-modified wood according to claim 1, wherein In step S2, the dosage ratio of graphene oxide, deionized water, and citric acid is 3 - 5 g: 100 ml: 25 - 50 ml.

4. The carboxylated sucrose complex-modified wood according to claim 1, wherein In step S3, the dosage ratio of carboxylated graphene oxide, graphene oxide, deionized water, PVP, carboxylated sucrose powder, and EDC is 1.5 - 2 g: 0.25 - 0.5 g: 500 - 800 ml: 0.1 - 0.2 g: 80 - 100 g: 0.5 - 1 g.

5. The carboxylated sucrose complex modified wood according to claim 1, wherein, The particle size of the graphene oxide is 0.8 - 1.2 nm.

6. A preparation method of carboxylated sucrose complex modified wood according to any one of claims 1-5, characterized in that, The specific steps are as follows: (1) Dissolve the carboxylated sucrose complex powder in deionized water to obtain a 10% - 15% carboxylated sucrose complex solution; (2) First, subject the wood to a vacuum treatment at a vacuum degree of -0.06 ~ -0.1 MPa for 4 - 8 h, then introduce the carboxylated sucrose complex solution, carry out a pressure treatment at a pressure of 0.5 - 2.0 MPa for 12 - 24 h, then place it at room temperature for 1 - 2 d, and then dry it at 40 - 60 °C and 70 - 90 °C for 12 - 24 h respectively, and then dry it at 100 - 140 °C for 12 - 24 h to obtain the carboxylated sucrose complex modified wood.

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