Modified bamboo cellulose and preparation method thereof

Abstract

The invention provides modified bamboo cellulose and a preparation method thereof, and belongs to the technical field of biomass material modification. The preparation method of the modified bamboo-source cellulose comprises the following steps: extracting cellulose in bamboo wood by adopting a first sodium hydroxide solution and a sodium chlorite solution in sequence to obtain bamboo-source cellulose; dispersing the bamboo source cellulose into a second sodium hydroxide solution, and adding ethanol to inhibit gel formation, so as to obtain a mixture; and carrying out etherification reaction on the mixture and sodium chloroacetate to obtain the modified bamboo cellulose.

Description

Technical Field

[0001] The present application relates to the technical field of biomass material modification, and in particular, to a modified bamboo-derived cellulose and a preparation method thereof. Background Art

[0002] Traditional carboxymethyl cellulose is mostly made from wood pulp or cotton linters, which presents challenges such as high raw material costs and low substitution rates. Bamboo offers significant advantages in sustainable development and the green economy, and its advantages in extracting cellulose from bamboo are significant. Bamboo grows rapidly, reaching maturity in 3-5 years, much faster than trees. It is also widely distributed and a renewable resource. Its cellulose content typically reaches 40%-60%, higher than that of crop straw, resulting in a high yield per unit of raw material. Its loose structure facilitates reagent penetration, reducing extraction complexity.

[0003] Bamboo fiber, a natural, renewable resource, possesses numerous excellent properties, including a high specific surface area, a porous structure, and abundant hydroxyl groups. These properties lend it potential for application in numerous fields. Existing bamboo fiber modification processes typically involve alkaline treatment to remove hemicellulose, acidification to delignify, and bleaching. These complex procedures are prone to cellulose loss during these multiple steps. Furthermore, these conventional processes require the use of large amounts of organic solvents, posing environmental risks.

[0004] Furthermore, unmodified bamboo fiber has significant limitations in practical applications. These include poor dispersibility, making it difficult to disperse evenly when mixed with other substances, which affects the overall performance of the material. Furthermore, it exhibits weak binding properties and inflexible interactions with other components, resulting in insufficient stability and durability in composite materials. These issues severely restrict the efficient application of bamboo fiber in a wider range of applications. Summary of the Invention

[0005] In light of this, the present application provides a modified bamboo-derived cellulose and a method for its preparation. This method utilizes the synergistic effect of NaOH and NaClO₂ to reduce the number of times solid product separation and collection is required, simplifying the process. Carboxyl groups are modified on the surface of the bamboo-derived cellulose to enhance its mechanical strength, water resistance, dispersibility, and binding properties with other components. The modified bamboo-derived cellulose provided herein can be widely used in tobacco, pharmaceutical excipients, and environmentally friendly materials.

[0006] According to an embodiment of the first aspect of the present application, a method for preparing modified bamboo-derived cellulose is provided, comprising: extracting cellulose from bamboo material using a first sodium hydroxide solution and a sodium chlorite solution in sequence to obtain bamboo-derived cellulose; dispersing the bamboo-derived cellulose in a second sodium hydroxide solution, adding ethanol to inhibit gel formation, and obtaining a mixture; and subjecting the mixture to an etherification reaction with sodium chloroacetate to obtain modified bamboo-derived cellulose.

[0007] According to an embodiment of the present application, the above mixture also includes chlorophyll.

[0008] According to an embodiment of the present application, the above-mentioned dispersing the above-mentioned bamboo-derived cellulose in a second sodium hydroxide solution and adding ethanol to inhibit gel formation to obtain a mixture includes: dispersing the above-mentioned bamboo-derived cellulose in a second sodium hydroxide solution, adding ethanol to inhibit gel formation, and then adding chlorophyll to obtain a mixture.

[0009] According to an embodiment of the present application, the ratio of the volume of the chlorophyll to the mass of the bamboo-derived cellulose is (1-3) mL:5 g.

[0010] According to an embodiment of the present application, the ratio of the mass of the bamboo-derived cellulose to the volume of the second sodium hydroxide solution is (3-7) g: (30-70) mL.

[0011] According to an embodiment of the present application, the concentration of the second sodium hydroxide solution is 10wt%~20wt%.

[0012] According to an embodiment of the present application, the volume of the ethanol is 20% to 40% of the volume of the second sodium hydroxide solution.

[0013] According to an embodiment of the present application, the above-mentioned extraction of cellulose from bamboo using a first sodium hydroxide solution and a sodium chlorite solution in sequence to obtain bamboo-derived cellulose includes: adding bamboo to a first sodium hydroxide solution, heating to 60°C~100°C, reacting for 8h~14h, separating and washing after the reaction to obtain crude cellulose; mixing the above-mentioned crude cellulose with a sodium chlorite solution, adjusting the pH to 1~2, and then heating to 40°C~60°C, reacting for 5h~10h, separating, washing, and drying after the reaction to obtain bamboo-derived cellulose.

[0014] According to an embodiment of the present application, the concentration of the first sodium hydroxide solution is 6 wt % to 10 wt %.

[0015] According to an embodiment of the present application, the ratio of the mass of the bamboo material to the volume of the first sodium hydroxide solution is (1-2) g: (40-60) mL.

[0016] According to an embodiment of the present application, the concentration of the sodium chlorite solution is 3wt%~8wt%.

[0017] According to an embodiment of the present application, the ratio of the mass of the bamboo material to the volume of the sodium chlorite solution is (4-6) g: (40-60) mL.

[0018] According to the embodiment of the present application, the etherification reaction of the mixture with sodium chloroacetate to obtain the modified bamboo-derived cellulose includes: adding sodium chloroacetate after the mixture is cooled to 10℃ or below, heating to 55℃-60℃, controlling the pH of the mixture to 8-9, reacting for 3-6h, after the reaction is completed, adjusting the pH of the mixture to 6.5-7.5, and then separating, washing and drying to obtain the modified bamboo-derived cellulose.

[0019] According to the embodiment of the present application, the mass ratio of sodium chloroacetate to the bamboo-derived cellulose is (1-3):1.

[0020] According to the embodiment of the second aspect of the present application, the modified bamboo-derived cellulose is prepared by the preparation method of the modified bamboo-derived cellulose.

[0021] According to the embodiment of the present application, the alkali treatment for removing hemicellulose, acidification for removing lignin and bleaching are integrated into a single step reaction in the traditional process, the synergistic effect of NaOH and NaClO2 is used to reduce the number of times of separating and collecting the solid product, and the operation is simple; the carboxyl groups are modified on the surface of the bamboo-derived cellulose, and the introduction of negative groups helps to improve the hydrophilicity and adsorption performance of the bamboo-derived cellulose, and increase the active sites of the bamboo-derived cellulose, so that the stable chemical bonds are formed on the surface of the cellulose, the mechanical strength, water resistance, dispersibility and the binding force with other components are enhanced, and the bamboo-derived cellulose can be widely applied in the fields of tobacco, pharmaceutical auxiliary materials and environmental protection materials. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and other objects, features and advantages of the present application will become more apparent from the following description of the embodiments of the present application taken with reference to the accompanying drawings, in which:

[0023] Figure 1 A scanning electron microscope image of the bamboo-derived cellulose provided in Example 1 is shown;

[0024] Figure 2 A thermogravimetric analysis graph of the bamboo-derived cellulose provided in Example 1 is shown;

[0025] Figure 3 A Fourier transform infrared spectrogram of the bamboo-derived cellulose before and after modification provided in Example 1 is shown;

[0026] Figure 4 A Zeta potential distribution graph of the modified bamboo-derived cellulose provided in Example 1 is shown;

[0027] Figure 5 An image of the modified bamboo-derived cellulose provided in Example 1 is shown;

[0028] Figure 6 A solid ultraviolet-visible absorption spectrogram of the bamboo-derived cellulose before and after modification provided in Example 4 is shown;

[0029] Figure 7 Fig. 4 shows the infrared spectrum of the bamboo cellulose before and after modification prepared in Example 4.

[0030] Figure 8 Fig. 5 shows the image of the modified bamboo cellulose prepared in Example 4. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It is to be understood, however, that the description is merely exemplary and is not intended to limit the scope of the present application. In the following detailed description of the embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present application. However, it would be apparent to those skilled in the art that the embodiments of the present application can be practiced without these specific details. In other instances, well-known structures and techniques have not been described in detail in order to avoid obscuring aspects of the present application.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "includes" indicates the presence of the features, steps, operations, but does not preclude the presence or addition of one or more other features.

[0033] In the case where expressions such as "at least one of A, B, and C, etc." are used, it generally should be interpreted to include any of one, all, etc. of the items enumerated (e.g., "a system having at least one of A, B, and C" should be interpreted to include a system having A alone, a system having B alone, a system having C alone, a system having both A and B together, a system having both A and C together, a system having both B and C together, and / or a system having all of A, B, and C together, etc.). In the case where an expression such as "at least one of A, B, or C, etc." is used, it generally should be interpreted to include any of one, all, etc. of the items enumerated (e.g., "a system having at least one of A, B, or C" should be interpreted to include a system having A alone, a system having B alone, a system having C alone, a system having both A and B together, a system having both A and C together, a system having both B and C together, and / or a system having all of A, B, and C together, etc.).

[0034] It is found in the process of implementing the present application that the cooperation of NaOH and NaClO2 can reduce the number of times of separating and collecting the solid product, and make the preparation method of cellulose more simple; and the carboxyl group can be modified on the surface of the bamboo cellulose to improve the performance of the cellulose.

[0035] In view of this, according to the first aspect of the embodiments of the present application, a preparation method of modified bamboo cellulose is provided, including steps S10-S30.

[0036] In step S10, the cellulose in the bamboo is extracted by using a first sodium hydroxide solution and a sodium chlorite solution in sequence to obtain the bamboo cellulose.

[0037] In step S20, bamboo-derived cellulose is dispersed in a second sodium hydroxide solution, and ethanol is added to inhibit gel formation to obtain a mixture.

[0038] In step S30, the mixture is subjected to an etherification reaction with sodium chloroacetate to obtain modified bamboo-derived cellulose.

[0039] According to the embodiments of the present application, the alkali treatment for hemicellulose removal, acid delignification, and bleaching carried out step by step in the traditional process are integrated into a single-step reaction. The synergistic effect of NaOH and NaClO2 is used to reduce the number of times the solid product is separated and collected, and the operation is simple. The carboxyl groups on the surface of the bamboo cellulose are modified, and the introduction of negatively charged groups helps to improve the hydrophilicity and adsorption properties of the bamboo cellulose and increase the active sites of the bamboo cellulose, so that stable chemical bonds are formed on the surface of the cellulose, thereby enhancing its mechanical strength, water resistance, dispersibility, and binding force with other components. The invention can be widely used in tobacco, pharmaceutical excipients, environmentally friendly materials and other fields.

[0040] The present application does not particularly limit the type and form of bamboo, as long as the purpose of the present application can be achieved. For example, the type of bamboo can include moso bamboo, arrow bamboo, yellow stem bamboo, etc., and the form of bamboo can include bamboo powder, bamboo silk, etc.

[0041] In some embodiments of the present application, step S10, sequentially extracting cellulose from bamboo using a first sodium hydroxide solution and a sodium chlorite solution to obtain bamboo-derived cellulose may include steps S14 and S18.

[0042] In step S14, bamboo materials can be added to the first sodium hydroxide solution, heated to 60° C. to 100° C., reacted for 8 h to 14 h, and separated and washed after the reaction to obtain crude cellulose.

[0043] Illustratively, in step S14, bamboo can be added to a first sodium hydroxide solution, heated to a temperature range of 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C or any two of the above temperatures, and reacted for 8h, 9h, 10h, 11h, 12h, 13h, 14h or any two of the above time periods. After the reaction is completed, the bamboo can be separated and washed to obtain crude cellulose.

[0044] In step S18, the crude cellulose can be mixed with a sodium chlorite solution, the pH value is adjusted to 1-2, and then heated to 40°C-60°C for reaction for 5h-10h. After the reaction is completed, the bamboo-derived cellulose can be obtained by separation, washing, and drying.

[0045] Illustratively, in step S18, the crude cellulose can be mixed with a sodium chlorite solution, and the pH value can be adjusted to a range between 1, 1.5, 2 or any two of the above values, and then heated to a temperature range between 40°C, 42°C, 45°C, 48°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C or any two of the above temperatures, and reacted for 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h or any two of the above time periods. After the reaction is completed, the crude cellulose is separated, washed, and dried to obtain the bamboo-derived cellulose.

[0046] The synergistic effect of NaOH and NaClO₂ reduces the number of times solid product separation and collection is required, simplifying the process. The resulting bamboo-derived cellulose exhibits excellent air permeability and mechanical properties, and features numerous small pores on the fiber surface, which contribute to enhanced adsorption properties. Retaining these treatment parameters within the aforementioned ranges further enhances the effectiveness of bamboo-derived cellulose treatment.

[0047] In step S14 and / or step S10, the concentration of the first sodium hydroxide solution may be 6 wt % to 10 wt %. For example, the concentration of the first sodium hydroxide solution may be 6 wt %, 7 wt %, 8 wt %, 9 wt %, 10 wt %, or a range between any two of the above values.

[0048] In step S14 and / or step S10, the ratio of the mass of the bamboo material to the volume of the first sodium hydroxide solution may be (1-2) g: (40-60) mL. For example, the ratio of the mass of the bamboo material to the volume of the first sodium hydroxide solution may be 1 g:60 mL, 1 g:55 mL, 1 g:50 mL, 1 g:45 mL, 1 g:40 mL, 1.2 g:40 mL, 1.5 g:40 mL, 1.8 g:40 mL, 2 g:40 mL, or a range between any two of the above ratios.

[0049] In step S18 and / or step S10, the concentration of the sodium chlorite solution may be 3 wt% to 8 wt%. For example, the concentration of the sodium chlorite solution may be 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or a range between any two of the above values.

[0050] In step S18 and / or step S10, the ratio of the mass of the bamboo material to the volume of the sodium chlorite solution may be (4-6) g: (40-60) mL. For example, the ratio of the mass of the bamboo material to the volume of the sodium chlorite solution may be 4 g:60 mL, 4 g:55 mL, 4 g:50 mL, 4 g:45 mL, 4 g:40 mL, 4.5 g:40 mL, 5 g:40 mL, 5.5 g:40 mL, 6 g:40 mL, or a range between any two of the above ratios.

[0051] In some embodiments of the present application, in step S20, the mixture further includes chlorophyll. Dispersing the bamboo-derived cellulose in the second sodium hydroxide solution and adding ethanol to inhibit gel formation to obtain the mixture comprises: dispersing the bamboo-derived cellulose in the second sodium hydroxide solution, adding ethanol to inhibit gel formation, and then adding chlorophyll to obtain the mixture.

[0052] Natural bamboo fiber has weak bonding with other ingredients, resulting in poor stability and durability of the composite material. Modifying the surface of bamboo cellulose with carboxyl groups helps improve its hydrophilicity and adsorption properties. Simultaneously introducing chlorophyll groups into the surface of bamboo cellulose further enhances the interaction between the fiber and other substances, improving the bonding strength and enhancing the modified bamboo cellulose's light responsiveness, antioxidant properties, and biocompatibility.

[0053] In step S20, the ratio of the volume of chlorophyll to the mass of bamboo-derived cellulose may be (1-3) mL:5 g. For example, the ratio of the volume of chlorophyll to the mass of bamboo-derived cellulose may be 1 mL:5 g, 1.5 mL:5 g, 2 mL:5 g, 2.5 mL:5 g, 3 mL:5 g, or a range between any two of the above ratios.

[0054] In step S20, the ratio of the mass of the bamboo-derived cellulose to the volume of the second sodium hydroxide solution may be (3-7) g: (30-70) mL. For example, the ratio of the mass of the bamboo-derived cellulose to the volume of the second sodium hydroxide solution may be 3 g:70 mL, 3 g:60 mL, 3 g:50 mL, 3 g:40 mL, 3 g:30 mL, 4 g:30 mL, 5 g:30 mL, 6 g:30 mL, 7 g:30 mL, or a range between any two of the above ratios.

[0055] In step S20, the concentration of the second sodium hydroxide solution may be 10 wt % to 20 wt %. For example, the concentration of the second sodium hydroxide solution may be 10 wt %, 11 wt %, 12 wt %, 13 wt %, 14 wt %, 15 wt %, 16 wt %, 17 wt %, 18 wt %, 19 wt %, 20 wt %, or a range between any two of the above values.

[0056] In step S20, the volume of ethanol may be 20% to 40% of the volume of the second sodium hydroxide solution. For example, the volume of ethanol may be 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40% of the volume of the second sodium hydroxide solution, or a range between any two of the above values.

[0057] In some embodiments of the present application, in step S30, etherification reaction of the mixture with sodium chloroacetate to obtain modified bamboo-derived cellulose includes: cooling the mixture to below 10°C, adding sodium chloroacetate, heating the mixture to 55°C to 60°C, controlling the pH of the mixture to 8-9, reacting for 3-6 hours, and after completion of the reaction, adjusting the pH of the mixture to 6.5-7.5, separating, washing, and drying to obtain modified bamboo-derived cellulose. Reaction conditions within the above range can further enhance the modification effect of the carboxyl groups and / or chlorophyll of the modified bamboo-derived cellulose.

[0058] Illustratively, in step S30, the mixture can be cooled to below 10°C, for example, in a range between 10°C, 9°C, 8°C, 5°C, 3°C, 1°C or any two of the above temperatures, and then sodium chloroacetate is added, and the temperature is raised to a range between 55°C, 56°C, 57°C, 58°C, 59°C, 60°C or any two of the above temperatures, and the pH of the mixture is controlled to be in a range between 8, 8.5, 9 or any two of the above values, and the reaction is carried out for 3h, 3.5h, 4h, 5h, 5.5h, 6h or any two of the above values. After the reaction is completed, the pH of the mixed product is adjusted to a range between 6.5, 7, 7.5 or any two of the above values, and the product is separated, washed and dried to obtain modified bamboo-derived cellulose.

[0059] In step S30, the mass ratio of sodium chloroacetate to bamboo-derived cellulose may be (1-3): 1. For example, the mass ratio of sodium chloroacetate to bamboo-derived cellulose may be 1:1, 1.5:1, 2:1, 2.5:1, 3:1, or a range between any two of the above ratios.

[0060] According to an embodiment of the second aspect of the present application, there is provided modified bamboo-derived cellulose prepared by the above-mentioned preparation method of modified bamboo-derived cellulose.

[0061] The present application is described in detail below with reference to the examples to facilitate understanding of the present application by persons skilled in the art. It is necessary to point out that the examples are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Non-essential improvements and adjustments made to the present application by relevant technical personnel based on the above invention content should still fall within the scope of protection of the present application. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods that are not mentioned in detail are all process steps or preparation methods known to relevant technical personnel.

[0062] Example 1

[0063] This embodiment provides a modified bamboo-derived cellulose and a preparation method thereof, comprising the following steps:

[0064] Step (1): Weigh 10 g of bamboo powder and place it in a sodium hydroxide solution (concentration of 8%) at a ratio of 50 mL of sodium hydroxide solution per 1 g of bamboo powder. Stir and heat at 85°C in an oil bath for 12 h. After the reaction is completed, wash the sample repeatedly with deionized water until the washing solution is neutral. Subsequently, add a 5% sodium chlorite solution by mass to the sample, and add hydrochloric acid dropwise to adjust the pH of the solution to about 1-2. Place the sample in an oil bath again and stir and heat at 45°C for 6 h. Finally, wash and dry the sample to obtain bamboo-derived cellulose.

[0065] Step (2): Disperse 5 g of bamboo cellulose in 50 mL of 15% NaOH solution and stir at room temperature for 1 hour. Add 20 mL of ethanol to inhibit gel formation to obtain a mixture.

[0066] Step (3): Cool the mixture to 10°C. Add sodium chloroacetate (7.5 g dissolved in 10 mL of water) dropwise, raise the temperature to 55°C, and react for 3 hours, controlling the pH to 8-9. Neutralize with glacial acetic acid to pH = 7, and separate the product by centrifugation. Wash with 70% ethanol three times to remove NaCl and unreacted reagents, and vacuum dry to obtain modified bamboo-derived cellulose.

[0067] The bamboo-derived cellulose and modified bamboo-derived cellulose prepared in this example were tested.

[0068] Figure 1 The scanning electron microscope images of bamboo-derived cellulose provided in Example 1 are shown, wherein (a) to (d) are scanning electron microscope images at different magnifications. Figure 1The presence of gaps between bamboo cellulose fibers indicates a certain degree of air permeability and permeability. The obvious interlacing and entanglement between the fibers indicates good mechanical properties. Several small pores appear on the fiber surface, which help improve the fiber's adsorption properties.

[0069] Figure 2 The thermogravimetric analysis diagram of bamboo-derived cellulose provided in Example 1 is shown. Figure 2 It can be seen that at a temperature of approximately 300°C, the mass loss of cellulose is relatively slow, and the mass retention rate is high, with a mass retention rate of 95.08% in the initial stage. This shows that within this temperature range, cellulose is relatively stable, with only a small amount of adsorbed water or volatile substances being removed, resulting in a slight decrease in quality, indicating that bamboo cellulose has strong thermal stability.

[0070] Figure 3 The Fourier transform infrared spectra of bamboo cellulose before and after modification provided in Example 1 are shown. Figure 3 It can be seen that the stretching vibration peaks at 1360 and 1735 cm-1 indicate that carboxyl groups are introduced into the surface of the modified bamboo-derived cellulose.

[0071] Figure 4 The Zeta potential distribution diagram of the modified bamboo-derived cellulose provided in Example 1 is shown. Figure 4 It can be seen that the Zeta potential of -23.4 mV indicates that the treated cellulose surface has a moderate negative charge, which helps to improve its hydrophilicity and adsorption properties.

[0072] Figure 5 : shows an image of modified bamboo-derived cellulose provided in Example 1. Figure 5 It can be seen that the modified bamboo-derived cellulose provided in this embodiment has good dispersibility and high whiteness.

[0073] Example 2

[0074] This embodiment provides a modified bamboo-derived cellulose and a preparation method thereof, with reference to Example 1, except that in step (1), the bamboo powder is replaced with bamboo filaments of equal mass.

[0075] Example 3

[0076] This embodiment provides a modified bamboo-derived cellulose and a preparation method thereof, with reference to Example 1, except that in step (1), the moso bamboo powder is replaced with an equal mass of arrowroot bamboo powder.

[0077] Example 4

[0078] This embodiment provides a modified bamboo-derived cellulose and a preparation method thereof, with reference to the embodiment, except that, in step (2), after adding ethanol, 1 mL of chlorophyll is added, and the mixture is stirred and mixed to obtain a mixture.

[0079] Figure 6 The solid UV-visible absorption spectra of bamboo cellulose before and after modification provided in Example 4 are shown, wherein a is the solid UV-visible absorption spectrum of bamboo cellulose before modification, and b is the solid UV-visible absorption spectrum of bamboo cellulose after modification. Chlorophyll molecules have a unique conjugated double bond structure, which enables electrons within the molecule to transition between different energy levels, thereby absorbing light of specific wavelengths. Figure 6 It can be seen that in the chlorophyll-modified bamboo-derived cellulose material, the broad absorption peaks at 410 nm and 640 nm are attributed to the π-π* transitions of electrons in chlorophyll derivatives, indicating that it has good photoresponsivity.

[0080] Figure 7 The infrared spectra of bamboo-derived cellulose prepared in Example 4 before and after modification are shown, wherein a is the infrared spectra of bamboo-derived cellulose before modification, and b is the infrared spectra of bamboo-derived cellulose after modification. Figure 7 The peak at 1572 cm⁻¹ is attributed to the conjugated C=C stretching vibration of the porphyrin ring in the chlorophyll molecule. Cellulose itself lacks aromatic structures, so this peak directly confirms the presence of chlorophyll. The peak at 1407 cm⁻¹ originates from the superposition of the bending vibrations of the methyl / methylene groups in the chlorophyll molecule and the inherent CH bending vibrations of cellulose, indicating an interaction between the two.

[0081] Figure 8 Shown is an image of the modified bamboo-derived cellulose prepared in Example 4. Figure 8 The actual object is light green, proving that the chlorophyll has been successfully modified.

[0082] Example 5

[0083] This embodiment provides a modified bamboo-derived cellulose and a preparation method thereof, with reference to Example 4, except that in step (1), the bamboo powder is replaced with bamboo filaments of equal mass.

[0084] Example 6

[0085] This embodiment provides a modified bamboo-derived cellulose and a preparation method thereof, with reference to Example 4, except that in step (1), the moso bamboo powder is replaced with an equal mass of arrowroot bamboo powder.

[0086] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above is only a specific embodiment of this application and is not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A method for preparing modified bamboo-derived cellulose, comprising: extracting cellulose from bamboo material using a first sodium hydroxide solution and a sodium chlorite solution in sequence to obtain bamboo-derived cellulose; dispersing the bamboo-derived cellulose in a second sodium hydroxide solution, and adding ethanol to inhibit gel formation to obtain a mixture; The mixture is subjected to etherification reaction with sodium chloroacetate to obtain modified bamboo-derived cellulose.

2. The method for preparing modified bamboo-derived cellulose according to claim 1, wherein: The mixture also includes chlorophyll; The bamboo-derived cellulose is dispersed in a second sodium hydroxide solution, and ethanol is added to inhibit gel formation to obtain a mixture comprising: The bamboo-derived cellulose is dispersed in a second sodium hydroxide solution, ethanol is added to inhibit gel formation, and chlorophyll is added to obtain a mixture.

3. The method for preparing modified bamboo-derived cellulose according to claim 2, wherein: The ratio of the volume of the chlorophyll to the mass of the bamboo-derived cellulose is (1-3) mL:5 g.

4. The method for preparing modified bamboo-derived cellulose according to any one of claims 1 to 3, wherein: The ratio of the mass of the bamboo-derived cellulose to the volume of the second sodium hydroxide solution is (3-7) g: (30-70) mL; The concentration of the second sodium hydroxide solution is 10wt%~20wt%; The volume of the ethanol is 20% to 40% of the volume of the second sodium hydroxide solution.

5. The method for preparing modified bamboo-derived cellulose according to claim 1, wherein: The method of extracting cellulose from bamboo material by sequentially using a first sodium hydroxide solution and a sodium chlorite solution to obtain bamboo-derived cellulose comprises: adding bamboo to a first sodium hydroxide solution, heating to 60°C to 100°C, reacting for 8h to 14h, separating and washing after the reaction to obtain crude cellulose; The crude cellulose is mixed with a sodium chlorite solution, the pH is adjusted to 1-2, and then heated to 40° C.-60° C., and reacted for 5 h-10 h. After the reaction is completed, the bamboo-derived cellulose is separated, washed, and dried to obtain the bamboo-derived cellulose.

6. The method for preparing modified bamboo-derived cellulose according to claim 1 or 5, wherein: The concentration of the first sodium hydroxide solution is 6 wt% to 10 wt%; The ratio of the mass of the bamboo material to the volume of the first sodium hydroxide solution is (1-2) g: (40-60) mL.

7. The method for preparing modified bamboo-derived cellulose according to claim 1 or 5, wherein: The concentration of the sodium chlorite solution is 4wt%~6wt%; The ratio of the mass of the bamboo material to the volume of the sodium chlorite solution is (4-6) g: (40-60) mL.

8. The method for preparing modified bamboo-derived cellulose according to claim 1, wherein: The step of subjecting the mixture to an etherification reaction with sodium chloroacetate to obtain the modified bamboo-derived cellulose comprises: The mixture is cooled to below 10° C., sodium chloroacetate is added, and the temperature is raised to 55° C. to 60° C., the pH of the mixture is controlled to be 8 to 9, and the reaction is carried out for 3 h to 6 h. After the reaction is completed, the pH of the mixed product is adjusted to 6.5 to 7.5, and the mixture is separated, washed, and dried to obtain modified bamboo-derived cellulose.

9. The method for preparing modified bamboo-derived cellulose according to claim 1 or 8, wherein: The mass ratio of the sodium chloroacetate to the bamboo-derived cellulose is (1-3):

1.

10. Modified bamboo-derived cellulose obtained by the preparation method of modified bamboo-derived cellulose according to any one of claims 1 to 9.

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