Preparation method of degradable directional reed fiber light-transmitting material

Abstract

The invention belongs to the field of reed fiber materials, and provides a preparation method of a degradable directional reed fiber light-transmitting material, which comprises the following steps: sequentially carrying out alkali treatment and bleaching treatment on reed stalks, and carrying out matrix removal on original ecological reed stalks to increase the cellulose exposure rate so as to obtain a reed stalk bleached product; the plasticity of reed stem fibers is improved by utilizing a functional group modification reagent, so that the plasticized reed stems are recombined and shaped in a manner of directional stacking in the fiber direction, integrated pre-pressing forming by a cold pressing process and low-temperature hot pressing under the condition of not adding any gluing medium; and the degradable light-transmitting material with directional structural strength can be prepared. The preparation method can solve the problems of low plasticity and poor self-adhesive property of reed stem fibers, and overcomes the problem that the mechanical property of the prepared product is relatively low due to the fact that the original structural characteristics of the material are damaged by a traditional process, and the prepared light-transmitting material has the advantages of being green, environmentally friendly, degradable and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of reed fiber materials, and relates to the preparation of functionalized reed fiber materials. Specifically, it refers to a preparation method of a degradable and directional reed fiber light-transmitting material. Background Art

[0002] Due to their unique light, heat, and mechanical properties, light-transmitting materials are widely used in fields such as architecture, home furnishing, automobiles, and electronic components. However, traditional light-transmitting materials are mainly made of non-degradable materials such as resins, plastics, and inorganic substances. These products have technical problems such as raw material crises, harmful gas emissions, and waste accumulation, which do not conform to the current environmental protection and sustainable development strategy. It is urgent to seek a green, environmentally friendly, renewable, and degradable low-value biomass material as a substitute, which has important practical significance for the sustainable application and development of transparent materials and the implementation of the "dual carbon" development strategy.

[0003] Reeds have performance advantages such as being renewable, degradable, and highly tough. Their stalks are rich in a directional fiber structure, and by removing some of the matrix, their light transmittance can be increased. They are a potential substitute for light-transmitting materials. However, the plasticity and self-bonding properties of reed fibers are significantly lower than those of traditional light-transmitting materials. Usually, a bottom-up recombination strategy is adopted, and fine fibers are transformed into thermoplastic or thermosetting light-transmitting materials through technical means such as matrix extraction and purification, addition of other gluing media, and chemical cross-linking. This method faces huge obstacles, including the use of cumbersome processing steps, reduction of the natural degradation rate of fiber materials, and destruction of the original fiber tissue structure and its good mechanical properties.

[0004] In response to this, the present invention adopts a top-down method. First, the matrix of the original ecological reed stalks is removed to increase the exposure rate of cellulose, and then the plasticity of the reed stalk fiber is improved through functional group modification. Without adding any gluing medium, it is reshaped by directional stacking of fiber directions and low-temperature hot pressing, so as to directly convert the reed stalk fiber into a light-transmitting material with degradability and directional structural strength. This preparation method not only broadens the application scenarios of reed materials in fields such as architecture, home furnishing, automobiles, and electronic components, but also provides a scientific basis for the development and application of reed-based functional materials and the high-value utilization of reed resources. Summary of the Invention

[0005] The aim of the present invention is to provide a preparation method of a degradable oriented reed fiber light-transmitting material. Without adding any gluing medium, through functional group modification and a top-down oriented stacking and recombination strategy, the raw ecological reed stalk fibers are directly integrally recombined and shaped into a light-transmitting material with degradability and oriented structural strength, thereby solving the technical problems of the traditional process being cumbersome, the natural degradation rate of the prepared fiber material being reduced, and the poor mechanical properties caused by the destruction of the original fiber tissue structure.

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

[0007] A preparation method of a degradable oriented reed fiber light-transmitting material, characterized by comprising the following steps:

[0008] S1. Pretreatment: Remove the reed leaves, reed flowers and impurities such as soil and gravel on the reed stalks, cut them and dry them to obtain a reed pretreatment product with a water content of not more than 20%.

[0009] S2. Alkali treatment: Immerse the reed pretreatment product in step S1 in a sodium hydroxide solution and heat it in a constant temperature water bath for 2.5 - 3 h to obtain reed stalk cellulose.

[0010] S3. Bleaching treatment: Immerse the reed stalk cellulose obtained in step S2 in a bleaching reagent and heat it in a constant temperature water bath until the color of the reed stalks becomes completely white, and then dry it to obtain a reed stalk bleached product, and the water content of the reed stalk bleached product is 2% - 8%.

[0011] S4. Functional group modification treatment: Immerse the reed stalk bleached product obtained in step S3 in a functional group modification reagent, heat it in a water bath in a dark environment to fully react, and then dry it to obtain a plasticized reed stalk, and the water content of the plasticized reed stalk is 25% - 40%.

[0012] S5. Compression molding: Stack and lay the plasticized reed stalks obtained in step S4 layer by layer in the direction of the fiber grain, first use a cold pressing process for integral pre-pressing and molding, and then perform low-temperature hot pressing to recombine and shape to obtain a light-transmitting material with degradability and oriented structural strength.

[0013] Preferably, the concentration of the sodium hydroxide solution is 0.5 - 1.0 wt.%. The mass ratio of the reed pretreatment product to the sodium hydroxide solution is 2 - 3:10 - 16.

[0014] Preferably, the mass ratio of the reed pretreatment product to the bleaching reagent is 2 - 3:11 - 17.

[0015] Preferably, the preparation of the bleaching reagent is specifically as follows: Weigh glacial acetic acid, sodium acetate trihydrate, and sodium chlorite, and place them in deionized water, and stir well until evenly mixed. Among them, the mass ratios of glacial acetic acid, sodium acetate trihydrate, sodium chlorite, and deionized water are 12-30:20-35:12-35:1000-1600, respectively.

[0016] Preferably, in steps S2 and S3, the temperature of the constant temperature water bath is 80-85 °C.

[0017] Preferably, in step S4, the reaction conditions are water bath heating at 50-70 °C for 4-8 h; the mass ratio of the reed pretreatment and the functional group modifier is 2-3:11-17.

[0018] Preferably, the preparation of the functional group modifier is specifically as follows: Weigh sodium periodate and isopropanol, place them in water, and stir well until evenly mixed. Among them, the mass ratios of sodium periodate, isopropanol, and water are 6-8:2-3:100-160.

[0019] Preferably, in steps S3 and S4, the drying method is a closed low-temperature static circulation drying method. Among them, the drying temperature in step S3 is 60-80 °C, and the drying temperature in step S4 is 30±5 °C.

[0020] Preferably, the conditions for cold pressing are a cold pressing pressure of 30-40 MPa and a cold pressing time of 7-15 min. The conditions for low-temperature hot pressing are a hot pressing temperature of 90-120 °C, a hot pressing pressure of 5±1 MPa, and a hot pressing time of 10-15 min.

[0021] The present invention also provides a light-transmitting material prepared from reed stalks with degradability and directional structural strength. The light-transmitting material is prepared according to the above preparation method, and the thickness of the light-transmitting material is 3.0-12 mm, and the density is 0.95-1.3 g / cm 3 .

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. Traditional light-transmitting materials have good plasticity and self-bonding properties themselves, or other light-transmitting gluing media will be introduced, and light-transmitting products can be shaped. The present invention uses a functional group modifier to convert the hydroxyl groups in reed stalk fibers into active functional groups such as aldehyde groups and ketone groups, thereby improving the problems of low plasticity and poor self-bonding properties of reed stalk fibers, and providing a good chemical reaction platform for them.

[0024] 2. Traditional light-transmitting materials usually use materials such as petroleum-based resins, plastics, and inorganic substances as raw materials. These materials have defects such as raw material crisis, harmful gas emissions, and non-degradability. The present invention only uses reed materials with fast growth rate and strong reproductive ability as raw materials, and the prepared light-transmitting materials have advantages such as environmental friendliness and degradability.

[0025] 3. Existing preparation methods of biomass-based light-transmitting materials are basically produced by a bottom-up reorganization strategy, which destroys the original structural characteristics of the materials, and the mechanical properties of the prepared products are relatively low. The present invention utilizes the original fiber structure of reed stalks and prepares them into light-transmitting materials with directional structural strength through a top-down directional stacking and reorganization strategy.

[0026] 4. During the raw material preparation process, in order to prevent it from shrinking, agglomerating, and the functional groups being consumed in advance, the raw materials are dried by a closed low-temperature static circulation drying method at 30-80°C, which has the advantages of energy saving and improved drying efficiency. Brief Description of the Drawings

[0027] Figure 1 It is a diagram showing the change trend of functional groups before and after reed fiber treatment;

[0028] Figure 2 It is a comparative schematic diagram of the influence of the functional group modification treatment time on the transparency of the prepared reed fiber light-transmitting material (a is the functional group modification treatment for 4h, b is the functional group modification treatment for 12h). Detailed Embodiment

[0029] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0030] The preparation method of the degradable directional reed fiber light-transmitting material in the embodiment of the present invention will be specifically described below.

[0031] A preparation method of a degradable directional reed fiber light-transmitting material includes the following steps:

[0032] S1. Pretreatment: Remove impurities such as reed leaves, reed flowers, and the soil and gravel on its surface from the reed stalks, and then cut them into specifications with a length of 90-120 mm, and dry to obtain a reed pretreatment product with a moisture content of no more than 20%.

[0033] S2. Alkali treatment: Immerse the reed pre-treatment product in step S1 in a sodium hydroxide solution with a concentration of 0.5 - 1.0 wt.%, and heat it in a constant temperature water bath at 80 - 85 °C for 2.5 - 3 h to remove the surface silica layer of the reed stalk and part of the matrix such as hemicellulose, lignin, and extractives on the fibers, and improve the exposure rate of cellulose. Then wash the reed stalks with removed part of the matrix with deionized water until neutral to obtain reed stalk cellulose. The mass ratio of the reed pre-treatment product to the sodium hydroxide solution is 2 - 3:10 - 16.

[0034] S3. Bleaching treatment: First, prepare the bleaching reagent. Specifically, weigh glacial acetic acid, sodium acetate trihydrate, and sodium chlorite and place them in deionized water, and stir at room temperature until fully mixed evenly. Among them, the mass ratios of glacial acetic acid, sodium acetate trihydrate, sodium chlorite, and deionized water are 12 - 30:20 - 35:12 - 35:1000 - 1600 respectively. Then immerse the reed stalk cellulose obtained in step S2 in the prepared bleaching reagent and heat it in a constant temperature water bath at 80 - 85 °C. The mass ratio of the reed pre-treatment product to the bleaching reagent is 2 - 3:11 - 17. During this period, replace the bleaching reagent every 6 h until the color of the reed stalks becomes completely white to increase its light transmittance. Finally, wash the bleached reed stalks with deionized water until neutral and dry them to a moisture content of 2% - 8% to obtain bleached reed stalks, and seal them for standby. Among them, to prevent shrinkage during the drying process of the raw materials and improve the drying efficiency, a closed low-temperature static circulation drying method is used here, and the drying temperature is 60 - 80 °C.

[0035] S4. Functional group modification treatment: First, prepare the functional group modification reagent. Specifically, weigh sodium periodate and isopropanol and place them in deionized water, and stir at room temperature until fully mixed evenly. Among them, the mass ratios of sodium periodate, isopropanol, and deionized water are 6 - 8:2 - 3:100 - 160. Then immerse the bleached reed stalks obtained in step S3 in the functional group modification reagent. The mass ratio of the reed pre-treatment product to the functional group modification reagent is 2 - 3:11 - 17. Heat it in a water bath at 50 - 70 °C for 4 - 8 h in a dark environment. During this period, the functional group modification reagent can convert the hydroxyl groups in the reed stalk fibers into active functional groups such as aldehyde groups and ketone groups to improve the plasticity of the reed stalk fibers. Finally, wash the plasticized reed stalk fibers with deionized water and dry them to a moisture content of 25% - 40% to obtain plasticized reed stalks, and seal them for standby. Among them, to prevent the raw materials from agglomerating or the functional groups from being consumed in advance due to the influence of temperature during the drying process, a closed low-temperature static circulation drying method is used here, and the drying temperature is 30 ± 5 °C.

[0036] S5. Stack and lay the plasticized reed stalks obtained in step S4 layer by layer along the fiber grain direction, and perform integrated pre-pressing and forming under the conditions of a cold pressing pressure of 30 - 40 MPa and a cold pressing time of 7 - 15 min. Subsequently, perform low-temperature hot pressing under the conditions of a hot pressing temperature of 90 - 120 °C, a hot pressing pressure of 5 ± 1 MPa, and a hot pressing time of 10 - 15 min. During this period, active functional groups such as hydroxyl, aldehyde, and ketone groups in the reed stalk fibers can be directly recombined and shaped through acetalization reaction and esterification reaction into a light-transmitting material with degradable and directional structural strength. The thickness of the light-transmitting material is 3.0 - 12 mm, and the density is 0.95 - 1.3 g / cm 3 .

[0037] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0038] Example 1

[0039] S1. Pretreatment: Remove impurities such as reed leaves, reed flowers, and soil and gravel on the surface of the reed stalks, and then cut them into a specification of 90 - 120 mm in length and dry them to a bone-dry state to obtain reed pretreatment products.

[0040] S2. Alkali treatment: Immerse 300 parts by weight of the reed pretreatment products in 1600 parts by weight of a sodium hydroxide solution (concentration: 0.5 wt.%) and heat them at a constant temperature of 80 °C in a water bath for 2.5 h. Subsequently, wash them with deionized water until neutral and drain the water to obtain reed stalk cellulose for standby.

[0041] S3. Bleaching treatment:

[0042] Prepare a bleaching reagent at room temperature: Weigh 12 parts by weight of glacial acetic acid, 20 parts by weight of sodium acetate trihydrate, and 12 parts by weight of sodium chlorite and place them in 1600 parts by weight of deionized water, and stir evenly at room temperature.

[0043] Immerse the reed stalk cellulose obtained in step S2 in the bleaching reagent and heat it at a constant temperature of 80 °C in a water bath. During this period, replace the solution every 6 h until the color of the reed stalks becomes completely white. Then, wash them with deionized water until neutral and control the moisture content to 2% - 8% by using a 60 °C closed low-temperature static circulation drying method to obtain bleached reed stalk products, which are sealed for standby.

[0044] S4. Functional group modification treatment:

[0045] Prepare a functional group modification reagent at room temperature: Weigh 60 parts by weight of sodium periodate and 20 parts by weight of isopropanol and place them in 1600 parts by weight of deionized water and stir evenly at room temperature.

[0046] Subsequently, the bleached reed stalks obtained in step S3 are immersed in a functional group modification reagent, and after constant temperature heating in a water bath at 50°C for 4 h in a dark environment, they are washed with deionized water and dried by a closed low-temperature static circulation drying method at 30°C to control the moisture content to 25% - 30%, obtaining plasticized reed stalks, which are sealed and reserved for use.

[0047] S5. Compression molding: The plasticized reed stalks obtained in step S4 are stacked layer by layer along the fiber longitudinal direction, and integrally pre-pressed and formed under the conditions of a cold pressing pressure of 30 MPa and a cold pressing time of 7 min. Subsequently, low-temperature hot pressing is carried out under the conditions of a hot pressing temperature of 95°C, a hot pressing pressure of 5 MPa, and a hot pressing time of 10 min, obtaining a degradable oriented reed fiber light-transmitting material with a thickness of 3 mm and a density of 0.95 g / cm 3 ³.

[0048] Example 2

[0049] S1. Pretreatment: Remove impurities such as reed leaves, reed flowers, soil, and gravel on the surface of the reed stalks, and then cut them into a specification of 280 - 320 mm in length and dry them to a bone-dry state, obtaining reed pre-treated materials.

[0050] S2. Alkali treatment: Immerse 250 parts by weight of the reed pre-treated materials in 1300 parts by weight of a sodium hydroxide solution (concentration: 0.8 wt.%) and carry out constant temperature heating in a water bath at 85°C for 2.5 h. Subsequently, wash them with deionized water until neutral and drain the water to obtain reed stalk cellulose for standby.

[0051] S3. Bleaching treatment:

[0052] Prepare a bleaching reagent at room temperature: Weigh 20 parts by weight of glacial acetic acid, 28 parts by weight of sodium acetate trihydrate, and 23 parts by weight of sodium chlorite, place them in 1400 parts by weight of deionized water, and stir evenly at room temperature.

[0053] Immerse the reed stalk cellulose obtained in step 2 in the bleaching reagent and carry out constant temperature heating in a water bath at 80°C. During this period, replace the solution every 6 h until the color of the reed stalks becomes completely white. Then, wash them with deionized water until neutral and control the moisture content to 2% - 8% by a closed low-temperature static circulation drying method at 70°C, obtaining bleached reed stalks, which are sealed and reserved for use.

[0054] S4. Functional group modification treatment:

[0055] Prepare a functional group modification reagent at room temperature: Weigh 70 parts by weight of sodium periodate and 25 parts by weight of isopropyl alcohol, place them in 1300 parts by weight of deionized water, and stir evenly at room temperature.

[0056] Subsequently, the bleached reed stalks obtained in step S3 are immersed in a functional group modification reagent, and after being heated in a water bath at 60°C for 6 hours in a dark environment, they are washed with deionized water, and the moisture content is controlled to 30% - 35% by a closed low-temperature static circulation drying method at 30°C to obtain plasticized reed stalks, which are sealed for standby.

[0057] S5. Compression molding: Stack the plasticized reed stalks obtained in step S4 layer by layer in the direction of the fiber grain, and perform integrated pre-compression molding under the conditions of a cold pressing pressure of 35 MPa and a cold pressing time of 10 minutes. Subsequently, perform low-temperature hot pressing under the conditions of a hot pressing temperature of 105°C, a hot pressing pressure of 5 MPa, and a hot pressing time of 12 minutes to obtain a degradable oriented reed fiber light-transmitting material with a thickness of 8 mm and a density of 1.1 g / cm 3 .

[0058] Example 3

[0059] S1. Pretreatment: Remove impurities such as reed leaves, reed flowers, and the soil and gravel on their surfaces from the reed stalks, and then cut them into specifications with a length of 680 - 720 mm and dry them to a bone-dry state to obtain reed pretreated materials.

[0060] S2. Alkali treatment:

[0061] Immerse 200 parts by weight of the reed pretreated materials in 1000 parts by weight of a sodium hydroxide solution (concentration: 0.8 wt.%) and heat them in a water bath at 85°C for 3 hours. Subsequently, wash them with deionized water until neutral, and drain the water to obtain reed stalk cellulose for standby.

[0062] S3. Bleaching treatment:

[0063] Prepare a bleaching reagent at room temperature: Weigh 30 parts by weight of glacial acetic acid, 35 parts by weight of sodium acetate trihydrate, and 35 parts by weight of sodium chlorite and place them in 1000 parts by weight of deionized water, and stir evenly.

[0064] Immerse the reed stalk cellulose obtained in step 2 in the bleaching reagent and heat it in a water bath at 85°C. During this period, replace the solution every 6 hours until the color of the reed stalks completely turns white, then wash them with deionized water until neutral, and use a closed low-temperature static circulation drying method at 80°C to make the moisture content 2% - 8% to obtain bleached reed stalks, which are sealed for standby.

[0065] S4. Functional group modification treatment: Prepare a functional group modification reagent at room temperature: Weigh 80 parts by weight of sodium periodate and 30 parts by weight of isopropyl alcohol and place them in 1000 parts by weight of deionized water, and stir evenly at room temperature.

[0066] Subsequently, the bleached reed stalks obtained in step S3 are immersed in a functional group modification reagent, and after being kept at a constant temperature of 70 °C in a water bath for 8 h in a dark environment, they are washed with deionized water and dried by a closed low-temperature static circulation drying method at 30 °C to a moisture content of 35% - 40% to obtain plasticized reed stalks, which are sealed for standby.

[0067] S5. Compression molding: The plasticized reed stalks obtained in step S4 are stacked layer by layer in the direction of the fiber longitudinal grain, and are integrally pre-pressed and formed under the conditions of a cold pressing pressure of 40 MPa and a cold pressing time of 15 min. Subsequently, low-temperature hot pressing is carried out under the conditions of a hot pressing temperature of 115 °C, a hot pressing pressure of 5 MPa, and a hot pressing time of 15 min, to obtain a degradable oriented reed fiber light-transmitting material with a thickness of 12 mm and a density of 1.3 g / cm 3 ³.

[0068] Comparative example 1:

[0069] Steps S1 - S3 in this comparative example are exactly the same as steps S1 - S3 in Example 1. The bleached reed stalks are not subjected to functional group modification, but are directly compression molded.

[0070] S4. Direct compression molding: The bleached reed stalks obtained in step S3 are stacked layer by layer in the direction of the fiber longitudinal grain, and are integrally pre-pressed and formed under the conditions of a cold pressing pressure of 30 MPa and a cold pressing time of 7 min. Subsequently, low-temperature hot pressing is carried out under the conditions of a hot pressing temperature of 95 °C, a hot pressing pressure of 5 MPa, and a hot pressing time of 10 min, to obtain a degradable oriented reed fiber material with a thickness of 3 mm and a density of 0.91 g / cm 3 ³.

[0071] Comparative example 2:

[0072] Steps S1 - S3 in this comparative example are exactly the same as steps S1 - S3 in Example 1.

[0073] S4. Functional group modification treatment:

[0074] Prepare a functional group modification reagent at room temperature: Weigh 150 parts by weight of sodium periodate and 75 parts by weight of isopropanol, place them in 1600 parts by weight of deionized water, and stir evenly at room temperature.

[0075] Subsequently, the bleached reed stalks obtained in step S3 are immersed in the functional group modification reagent, and after being kept at a constant temperature of 50 °C in a water bath for 4 h in a dark environment, they are washed with deionized water and dried by a closed low-temperature static circulation drying method to control the moisture content to 5% - 8% to obtain plasticized reed stalks, which are sealed for standby.

[0076] S5. Compression molding: Stack and lay the plasticized reed stalks obtained in step S4 layer by layer along the fiber grain direction, and perform integrated pre-pressing molding under the conditions of a cold pressing pressure of 30 MPa and a cold pressing time of 7 min. Subsequently, perform low-temperature hot pressing under the conditions of a hot pressing temperature of 95 °C, a hot pressing pressure of 5 MPa, and a hot pressing time of 10 min to obtain a degradable oriented reed fiber light-transmitting material with a thickness of 3 mm and a density of 0.98 g / cm 3 3

[0077] Comparative Example 3:

[0078] Steps S1 - S3 in this comparative example are exactly the same as steps S1 - S3 in Example 1.

[0079] S4. Functional group modification treatment:

[0080] Prepare the functional group modification reagent at room temperature: Weigh 150 parts by weight of sodium periodate and 75 parts by weight of isopropanol, place them in 1600 parts by weight of deionized water, and stir evenly at room temperature.

[0081] Subsequently, immerse the reed stalk bleach obtained in step S3 in the functional group modification reagent, and after constant temperature heating in a 50 °C water bath for 4 h in a dark environment, wash it with deionized water, and control the moisture content to 50% - 56% using a 30 °C closed low-temperature static circulation drying method to obtain plasticized reed stalks, which are sealed and reserved.

[0082] S5. Compression molding: Stack and lay the plasticized reed stalks obtained in step S4 layer by layer along the fiber grain direction, and perform integrated pre-pressing molding under the conditions of a cold pressing pressure of 30 MPa and a cold pressing time of 7 min. Subsequently, perform low-temperature hot pressing under the conditions of a hot pressing temperature of 95 °C, a hot pressing pressure of 5 MPa, and a hot pressing time of 10 min to obtain a degradable oriented reed fiber light-transmitting material with a thickness of 3 mm and a density of 0.93 g / cm 3 3

[0083] Test Example 1

[0084] Perform performance tests such as mechanical strength, light transmittance, and abrasion resistance on the degradable oriented reed fiber light-transmitting materials obtained in Examples 1 - 3 and Comparative Examples 1 - 3. The results are shown in Table 1.

[0085] Table 1. Performance test results table

[0086]

[0087] As can be seen from Table 1, the bending strength, tensile strength, and light transmittance of the degradable oriented reed fiber light-transmitting material prepared in the embodiments of the present invention are significantly better than those of the degradable oriented reed fiber light-transmitting material prepared in the comparative example. It shows that through the modification of functional groups in reeds and the optimization of the parameters for functional group modification, the mechanical properties of the material can be effectively improved on the premise of meeting the light transmittance requirements.

[0088] Test Example 2

[0089] The changing trend diagram of functional groups before and after the treatment of reed fibers was characterized by Fourier transform infrared spectroscopy (FTIR). Among them, the characteristic peaks related to lignin are at 1605 and 1510 cm Figure 1 . For the reed fibers after lignin removal, almost no lignin components exist. In addition, as the aldehyde group modification time of the lignin-removed reed fibers becomes longer, the hemiacetal characteristic peak position at 880 cm -1 first increases and then decreases, indicating that the aldehyde group modification time of reed fibers should not exceed 12 h. -1

[0090] In addition, the present invention investigated the influence of different functional group modification treatment times of reed fibers on the transparency of the prepared reed fiber light-transmitting materials. Figure 2 a is the light-transmitting material prepared after the aldehyde group modification of reed fibers for 4 h, Figure 2 b is the light-transmitting material prepared after the aldehyde group modification of reed fibers for 12 h. It was found that the light transmittance of the reed fiber light-transmitting material with 12 h of aldehyde group modification is significantly lower.

[0091] To sum up, the present invention uses a functional group modifier to convert the hydroxyl groups in reed stalk fibers into active functional groups such as aldehyde groups and ketone groups, and then utilizes the original fiber structure of reed stalks. Through a top-down directional stacking and recombination strategy, it can be prepared into a light-transmitting material with directional structural strength, improving the problems of low plasticity and poor self-bonding performance of reed stalk fibers. And on the premise of meeting the light transmittance requirements, the mechanical properties of the material are effectively improved. It also solves the problems that traditional light-transmitting materials use materials such as petroleum-based resins, plastics, and inorganic substances as production raw materials, which are prone to raw material crises, harmful gas emissions, and non-degradability.

[0092] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can certainly make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present invention.

Claims

1. A preparation method of a degradable and oriented reed fiber light-transmitting material, characterized in that, It includes the following steps: S1. Pretreatment: Remove the impurities on the reed stalks, cut them and dry them to obtain reed pretreatment products with a moisture content not exceeding 20%; S2. Alkali treatment: Immerse the reed pretreatment products in step S1 in a sodium hydroxide solution, and heat them in a constant temperature water bath for 2.5 - 3 h to obtain reed stalk cellulose; S3. Bleaching treatment: Immerse the reed stalk cellulose obtained in step S2 in a bleaching reagent and heat it in a constant temperature water bath until the color of the reed stalks becomes completely white, and then dry it to obtain reed stalk bleached products, and the moisture content of the reed stalk bleached products is 2% - 8%; S4. Functional group modification treatment: Immerse the reed stalk bleached products obtained in step S3 in a functional group modification reagent, heat it in a water bath in a dark environment for sufficient reaction, and then dry it to obtain plasticized reed stalks, and the moisture content of the plasticized reed stalks is 25% - 40%; S5. Compression molding: Stack and lay the plasticized reed stalks obtained in step S4 layer by layer along the fiber grain direction, first use a cold pressing process for integrated pre-pressing molding, and then perform low-temperature hot pressing to reorganize and shape to obtain a light-transmitting material with degradability and directional structural strength.

2. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 1, wherein The concentration of the sodium hydroxide solution is 0.5 - 1.0 wt.%. The mass ratio of the reed pretreatment products to the sodium hydroxide solution is 2 - 3:10 - 16.

3. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 1, characterized in that, The mass ratio of the reed pretreatment products to the bleaching reagent is 2 - 3:11 - 17.

4. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 3, characterized in that, The specific preparation of the bleaching reagent is: Weigh glacial acetic acid, sodium acetate trihydrate and sodium chlorite and place them in water, stir well until evenly mixed, and among them, the mass ratios of glacial acetic acid, sodium acetate trihydrate, sodium chlorite and water are 12 - 30:20 - 35:12 - 35:1000 - 1600 respectively.

5. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 1, characterized in that, In step S2 and step S3, the temperature of the constant temperature water bath is 80 - 85 °C.

6. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 1, characterized in that, In step S4, the reaction conditions are heating in a water bath at 50 - 70 °C for 4 - 8 h; the mass ratio of the reed pretreatment products to the functional group modification reagent is 2 - 3:11 - 17.

7. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 6, characterized in that, The specific preparation of the functional group modification reagent is: Weigh sodium periodate and isopropanol and place them in water, stir well until evenly mixed, and among them, the mass ratios of sodium periodate, isopropanol and water are 6 - 8:2 - 3:100 - 160.

8. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 1, characterized in that, In step S3 and step S4, the drying method is a closed low-temperature static circulation drying method, and among them, the drying temperature in step S3 is 60 - 80 °C, and the drying temperature in step S4 is 30 ± 5 °C.

9. The preparation method of a degradable and oriented reed fiber light-transmitting material according to claim 1, characterized in that, The conditions of the cold pressing are a cold pressing pressure of 30 - 40 MPa and a cold pressing time of 7 - 15 min, and the conditions of the low-temperature hot pressing are a hot pressing temperature of 90 - 120 °C, a hot pressing pressure of 5 ± 1 MPa, and a hot pressing time of 10 - 15 min.

10. A light-transmitting material prepared from reed stalks, which has degradability and directional structural strength, is characterized in that, The light-transmitting material is prepared by the preparation method according to any one of claims 1 to 9. The thickness of the light-transmitting material is 3.0 to 12 mm, and the density is 0.95 to 1.3 g / cm 3 .

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