A kind of all-biomass high-strength waterproof composite material and its preparation method and application

Abstract

The present invention discloses an all-biomass high-strength waterproof composite material and its preparation method and application, which relate to the field of papermaking technology. The preparation method of the all-biomass high-strength waterproof composite material provided by the present invention is to prepare a mixed slurry of a fiber suspension containing natural cellulose and pollen microgel, apply it on the surface of a substrate, dry and peel it to obtain a mixed film, then soak it in a chitosan solution, and obtain the final product after drying. The all-biomass high-strength waterproof composite material provided by the present invention has a simple preparation process and does not require complicated heat treatment or mechanical pressing processes; it fully utilizes the synergistic effect of natural cellulose, pollen gel and chitosan to achieve a combination of high mechanical strength and long-term water resistance. The all-biomass high-strength waterproof composite material provided by the present invention can be welded and bonded only by chitosan, without the need to add additional adhesives, which simplifies the production process and reduces costs; it can be widely used in high-performance waterproof products such as straws, packaging bags, patches, etc., and has important environmental value and application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of papermaking, and in particular to an all-biomass high-strength waterproof composite material and a preparation method and application thereof. Background Art

[0002] Papermaking technology uses raw materials such as wood, reeds, bagasse, rice straw, wheat straw, cotton straw, hemp stalks, and cotton to produce pulp through mechanical, chemical, or a combination of both methods, ultimately producing finished paper. The modern papermaking industry, in addition to producing various paper types, also includes complex processing steps such as coating, glazing, gluing, and laminating to meet the diverse needs of paper and board for various applications. As a traditional industrial sector, the papermaking industry primarily faces environmental pollution issues related to water, air, solid waste, and noise pollution. Papermaking wastewater contains persistent substances such as lignin, sugars, and heavy metals, leading to oxygen depletion in water bodies, the death of aquatic plants and animals, and long-term siltation, resulting in black and odorous water bodies. Sulfur dioxide, nitrogen oxides, and volatile organic compounds (VOCs) emitted during papermaking produce a pungent odor and impact the health of nearby residents. Solid wastes such as pulp residue, rotten pulp, and bark generated by papermaking can encroach on land and contaminate groundwater, contributing to soil pollution and the accumulation of toxic and hazardous substances in agricultural and sideline products.

[0003] As the most abundant renewable resource on Earth, lignocellulose, with its biodegradability, sustainability, and recyclability, is an ideal candidate to replace biodegradable materials. However, traditional paper-based materials often suffer from insufficient strength and poor functionality, limiting their application. To overcome these shortcomings, paper is often modified with plastic coatings or synthetic chemical additives. However, the introduction of plastics can create new environmental issues, such as increasing the difficulty of paper recycling and biodegradation.

[0004] Therefore, developing new paper-based materials based on natural biomass, without the addition of any synthetic chemicals, is of great scientific significance and application value. Researchers both domestically and internationally have conducted extensive research on the preparation and functionalization of all-biomass materials, and have achieved a series of advances. For example, natural polymers such as nanocellulose, lignin, and chitosan are used to enhance paper strength; and hydrophobic modification and surface coatings are used to improve paper's water resistance. However, existing technologies still suffer from high costs, complex processes, and unstable performance, which limit their large-scale application. Summary of the Invention

[0005] To address the challenges of existing all-biomass high-strength waterproof composite materials, such as high preparation costs, complex processes, insufficient mechanical properties, and poor waterproofing, the present invention provides an all-biomass high-strength waterproof composite material, its preparation method, and its application. This invention utilizes the synergistic effects of three biomass materials: natural fiber, pollen, and chitosan. Through a simple, integrated mixing-drying-soaking-and-re-drying process, the present invention produces a renewable, biodegradable, and high-strength all-biomass waterproof composite material with excellent mechanical and waterproof properties. In practical applications, this all-biomass high-strength waterproof composite material can also be welded using materials such as chitosan (solution), eliminating the need for other adhesives. It can be widely used in any technical field requiring biodegradable, waterproof, and high-strength materials, including but not limited to straws, bags, and patches. This is achieved through the following technologies.

[0006] The present invention provides a method for preparing an all-biomass high-strength waterproof composite material, comprising the following steps:

[0007] The natural fibers are removed from impurities and crushed to prepare a fiber suspension with a solid-liquid mass volume ratio of (0.01-0.02) g / mL;

[0008] Remove impurities and lipids from the surface of natural pollen, add alkali solution and stir, wash until the mixed system is neutral, remove excess water to obtain pollen microgel with a solid content of 0.5-3%;

[0009] The fiber suspension and the pollen microgel are uniformly mixed to obtain a mixed slurry, which is then applied on the surface of the substrate by scraping, and then peeled off after drying to obtain a mixed film;

[0010] The mixed film is placed in a chitosan solution for treatment, washed, and dried to obtain the all-biomass high-strength waterproof composite material.

[0011] Furthermore, in the mixed slurry, the mass of the natural fibers accounts for 1%-90% of the total mass of the natural fibers and pollen.

[0012] Furthermore, the mass fraction of the chitosan solution is 1-4%, the molecular weight of chitosan is 50-150 kDa, and the soaking time is 0.1-24 h.

[0013] Furthermore, the alkali solution is a NaOH solution or a KOH solution with a volume fraction of 1-20%, and the mass volume ratio of the natural pollen to the alkali solution is (0.05-0.1) g / mL.

[0014] Furthermore, the alkali solution stirring treatment is carried out at 50-100° C. for 0.1-24 h.

[0015] Furthermore, the method for removing impurities and lipids on the surface of natural pollen is: washing the natural pollen with a washing solvent, wherein the mass volume ratio of the natural pollen to the washing solvent is (0.2-10) g / mL; the washing solvent is water, and one or more of ethanol, acetone or ether.

[0016] Furthermore, the natural fiber is a fiber of plant origin.

[0017] Furthermore, the plant source includes but is not limited to any one or more of cotton, bamboo, straw, and wood. For example, the natural fiber can be lignocellulose fiber extracted from trees such as coniferous forests or broad-leaved forests.

[0018] Optionally, the raw material natural pollen for preparing the all-biomass high-strength waterproof composite material provided by the present invention can be selected from natural pollen of any common source, including but not limited to any one or a mixture of sunflower, rose, lotus, rapeseed and pine pollen.

[0019] Optionally, the substrate used for scraping the mixed slurry is generally made of plastic, metal and wood, and the substrate can be a flat plate or a plate of any other shape.

[0020] Optionally, the drying condition for the scraping mixed slurry is to dry it naturally until it can be peeled off smoothly, or it can be air-dried or heated to dry.

[0021] The present invention also provides an all-biomass high-strength waterproof composite material, which is prepared by any of the above-mentioned preparation methods.

[0022] The present invention also provides an application of the above-mentioned all-biomass high-strength waterproof composite material, which utilizes the excellent mechanical properties and waterproof properties of the all-biomass high-strength waterproof composite material, as well as the ability to be welded through chitosan solution. It can be mainly used to prepare various high-performance waterproof materials, showing significant environmental friendliness and practical value, and has broad application prospects.

[0023] Preferably, the waterproof material can be used to prepare straws, packaging bags, patches, etc.

[0024] Compared with the prior art, the present invention is beneficial in that:

[0025] 1. This invention utilizes the synergistic effects of natural fibers, pollen, and chitosan to create an all-biomass, high-strength, waterproof composite material with excellent mechanical and waterproof properties. The all-biomass, high-strength, waterproof composite material produced by this invention exhibits excellent mechanical and waterproof properties, with a tensile strength of 5-80 MPa and an elongation at break of 0.1-10%. Chitosan also enables welding, and it can be used to make products such as straws, bags, and patches, further expanding its application range. This invention provides new ideas and methods for developing new, green, biodegradable paper materials, is of great significance for promoting the green and sustainable development of the papermaking industry, and has significant economic and social benefits.

[0026] 2. The raw materials used in the present invention are all renewable and biodegradable biomass materials. No plastic coating or synthetic chemical additives are required during the preparation process, which solves the problems of high resource consumption and severe environmental pollution in the traditional papermaking industry from the source; it provides new ideas and methods for the development of green, environmentally friendly and degradable new paper materials, which is of great significance to promoting the green and sustainable development of the papermaking industry and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the integrated preparation of mixing-drying-immersing-drying of all-biomass high-strength waterproof composite materials.

[0028] Figure 2 This is a diagram of the large-scale preparation of the all-biomass high-strength waterproof composite material of Example 1. In particular, a: natural fiber and pollen slurry; b: coating process; c: macroscopic photo of the all-biomass high-strength waterproof composite material.

[0029] Figure 3 The mechanical properties of the materials prepared in Example 1, Comparative Example 1 and Comparative Example 2. Wherein, a: stress-strain curve; b: tensile strength test result; c: Young's modulus test result.

[0030] Figure 4 These are the stress-strain curves of the all-biomass paper prepared in Examples 2-9 and Comparative Examples 3 and 4. Here, a: the mass ratio of natural fiber to pollen was changed; b: the conditions for soaking in the chitosan solution were changed.

[0031] Figure 5 The waterproof properties of the materials prepared in Comparative Example 1 and Comparative Example 2. Wherein, a: Photograph of water contact angle; b: Water contact angle-time curve; c: Water absorption rate-time curve.

[0032] Figure 6Chitosan weldability of the materials prepared in Example 1, Comparative Example 1, and Comparative Example 2. a: Photograph of chitosan welding; b: Water stability of chitosan after welding; c: Stress-strain curves of chitosan before and after welding.

[0033] Figure 7 This is an application of the all-biomass high-strength waterproof composite straw prepared in Example 1. In particular, a: straw preparation process; b: mechanical stability; c: potato insertability; d: water absorption performance; e: compatibility with different beverages.

[0034] Figure 8 This is the application of the biomass paper bag prepared in Example 1. In particular, a: the preparation process and waterproof effect of the all-biomass high-strength waterproof composite bag; b: the all-biomass high-strength waterproof composite bag can hold more water and fish.

[0035] Figure 9 This is the application of the all-biomass high-strength waterproof composite patch prepared in Example 1. In particular, a: the container is damaged and leaking; b: the biomass paper patch repairs the container; c: the repaired container can continue to hold water. DETAILED DESCRIPTION

[0036] The technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] In some embodiments of the present invention, the preparation method of the all-biomass high-strength waterproof composite material is as follows Figure 1 As shown, an integrated process of mixing-drying-immersing-drying is adopted, specifically:

[0038] The natural fibers are removed from impurities and crushed to prepare a fiber suspension with a solid-liquid mass volume ratio of (0.01-0.02) g / mL;

[0039] Remove impurities and lipids from the surface of natural pollen, add alkali solution and stir, wash until the mixed system is neutral, remove excess water to obtain pollen microgel with a solid content of 0.5-3%;

[0040] The fiber suspension and the pollen microgel are uniformly mixed to obtain a mixed slurry, which is then applied on the surface of the substrate by scraping, and then peeled off after drying to obtain a mixed film;

[0041] The mixed film is placed in a chitosan solution for treatment, washed, and dried to obtain the all-biomass high-strength waterproof composite material.

[0042] The all-biomass high-strength waterproof composite material prepared by the above method has excellent mechanical properties and waterproof properties, and can be welded through chitosan solution.

[0043] Unless otherwise specified, the materials used in the present invention can be commercially available products.

[0044] In the following examples, the pollen particles used were natural sunflower pollen, provided by Shaanxi Guanlin Biochemical Co., Ltd. in China, and the natural fibers were broadleaf pulp fibers, provided by Aomei Medical Products Co., Ltd. Acetone, ether, ethanol, KOH, NaOH, chitosan, and acetic acid were provided by Sinopharm Group with a purity of ≥85%. All aqueous solutions were prepared using deionized water.

[0045] Chitosan was commercial chitosan of corresponding molecular weight. A 1% acetic acid aqueous solution was prepared, and then chitosan was added and stirred until completely dissolved to prepare a chitosan solution of corresponding mass fraction.

[0046] Optionally, in the mixed slurry, the mass of the natural fibers accounts for 1%-90% of the total mass of the natural fibers and pollen.

[0047] Optionally, the mass fraction of the chitosan solution is 1-4%, the molecular weight of chitosan is 50-150 kDa, and the soaking time is 0.1-24 h.

[0048] Optionally, the alkali solution is a NaOH solution or a KOH solution with a volume fraction of 1-20%, and the mass volume ratio of the natural pollen to the alkali solution is (0.05-0.1) g / mL.

[0049] Further optionally, the alkali solution stirring treatment is carried out at 50-100° C. for 0.1-24 h.

[0050] Optionally, the method for removing impurities and lipids on the surface of natural pollen is: washing the natural pollen with a washing solvent, wherein the mass volume ratio of the natural pollen to the washing solvent is (0.2-10) g / mL; the washing solvent is water, and one or more of ethanol, acetone or ether.

[0051] Alternatively, the natural fiber may be any plant-derived fiber, such as cotton, bamboo, straw, wood, and the like.

[0052] Example 1

[0053] The preparation method of the all-biomass high-strength waterproof composite material provided in this embodiment is:

[0054] (1) 1 g of impurity-removed broadleaf pulp fiber was added to 100 mL of water and ground to obtain a uniformly dispersed fiber suspension of 0.01 g / mL.

[0055] (2) 100 g of natural sunflower pollen was washed with 200 mL of water and defatted with 200 mL of ethanol;

[0056] 200 mL of 10% KOH solution was added and the pollen was treated with alkali at 80°C for 12 h to remove the pollen cytoplasm and soften the shell. After washing with water until neutral and filtering, a pollen microgel with a solid content of 2% and high viscosity was obtained.

[0057] (3) The fiber suspension and the pollen microgel are uniformly mixed to prepare a mixed slurry; the amount of the fiber suspension and the pollen microgel is such that the mass of the natural fiber accounts for 40% of the total mass of the natural fiber and the pollen.

[0058] (4) The mixed slurry is evenly scraped onto the surface of a flat substrate, and peeled off after the water evaporates naturally, thereby obtaining the mixed film.

[0059] (5) The mixed membrane was immersed in a chitosan solution with a mass fraction of 3% and a molecular weight of 150 kDa for 12 h, and then fully rinsed with water to remove surface residues and then dried to obtain an all-biomass high-strength waterproof composite material.

[0060] The preparation process is as follows Figure 1 and 2 shown. Figure 2 Figure a shows the natural fiber and pollen slurry; Figure b shows the coating process; and Figure c shows a photo of the all-biomass high-strength waterproof composite material.

[0061] Comparative Example 1

[0062] Compared with Example 1, the material provided in this comparative example is a pure paper fiber sample that does not contain any pollen material and has not been treated with chitosan solution. The preparation method is: 100 g of fiber suspension is directly spread on the surface of the substrate, and after the water evaporates naturally, it is peeled off to obtain the pure fiber paper of Comparative Example 1.

[0063] Comparative Example 2

[0064] The material provided in this comparative example is different from that in Example 1 in that it has not been soaked in chitosan solution, i.e., it corresponds to the mixed membrane material prepared in step (4) of Example 1, and is called fiber-pollen paper.

[0065] Examples 2-4 and Comparative Examples 3-4

[0066] The preparation methods of the all-biomass high-strength waterproof composite materials provided in Examples 2-4 are basically the same as those in Example 1, except that the amounts of the fiber suspension and pollen microgel are changed, as shown in Table 1 below, based on the percentage of natural fiber to the total mass of natural fiber and pollen.

[0067] The material provided in Comparative Example 3 does not contain any fiber, that is, the pollen microgel prepared in step (2) of Example 1 is directly scraped onto a flat substrate according to step (4) to form a membrane material, and then immersed in a chitosan solution according to step (5).

[0068] The material provided in Comparative Example 4 does not contain any pollen, that is, the fiber suspension prepared in step (1) of Example 1 is directly scraped onto a flat substrate according to step (4) to prepare a pure paper fiber sample, which is then immersed in a chitosan solution according to step (5).

[0069] Table 1

[0070]

[0071] Examples 5-9

[0072] The preparation methods of the materials of Examples 5-9 are basically the same as those of Example 1, except that the conditions for immersing in the chitosan solution are changed, as shown in Table 2 below.

[0073] Table 2

[0074]

[0075] Test Example: Performance Test of Materials Prepared in Examples and Comparative Examples

[0076] 1. Mechanical properties

[0077] Mechanical properties are one of the key indicators for evaluating a material's suitability for replacing traditional plastics in practical applications. To investigate the mechanical strength of the finished materials prepared in the aforementioned examples and comparative examples, the present invention cut samples from each of the examples and comparative examples into 1 cm × 10 cm strips and subjected them to tensile strength tests at room temperature using a universal materials testing machine in accordance with GB / T 1040-2006. The test conditions were as follows: a tensile speed of 10 mm / min, a clamp spacing of 50 mm, and at least five tests per sample group, with the average result taken as the final result.

[0078] The experimental results are as follows Figure 3 show, Figure 3In the figure, Figure a is a stress-strain curve, Figure b is the tensile strength test results of the materials of Example 1, Comparative Example 1 and Comparative Example 2, and Figure c is the Young's modulus test results of the materials of Example 1, Comparative Example 1 and Comparative Example 2. It can be seen that in the tensile test, the tensile strength of the pure paper fiber sample prepared in Comparative Example 1 is 5.44 MPa, which shows that the single paper fiber material has obvious deficiencies in mechanical strength and is difficult to meet the requirements of high-strength applications; the mechanical strength of the fiber-pollen paper prepared in Comparative Example 2 is 48.49 MPa, which is about 9 times higher than that of the pure paper fiber sample in Comparative Example 1; after soaking in chitosan solution, the tensile strength of the fiber-pollen-chitosan paper prepared in Example 1 is further increased to 80.32 MPa, which is about 15 times higher than that of the pure paper fiber sample in Comparative Example 1, and the Young's modulus is also significantly increased to 2.52 GPa.

[0079] like Figure 4 As shown in the figure, by adjusting the mass ratio of natural fiber and pollen in the material, and changing the conditions of soaking chitosan solution (such as soaking time, solution concentration and molecular weight), composite materials with different tensile strengths can be obtained.

[0080] With the introduction of pollen microgels, the tensile strength of the composite material gradually increased; however, when the pollen microgel content was too high, the continuous link structure of the fibers inside the material was destroyed, resulting in a decrease in tensile strength.

[0081] Shortening the immersion time of chitosan solution, lowering the concentration of chitosan solution, or reducing the molecular weight of chitosan may lead to insufficient infiltration of chitosan on the surface of natural fibers and pollen, and failure to form effective interfacial interaction with the two, thereby weakening the tensile strength of the composite material.

[0082] This significant improvement in mechanical properties is attributed to the synergistic effect of natural fibers, pollen and chitosan. The pollen particles are evenly dispersed in the natural fiber network, improving the overall mechanical properties of the material. After soaking in chitosan solution, the mechanical strength is further significantly enhanced, indicating that the addition of chitosan not only enhances the interfacial bonding between natural fibers and pollen, but also forms a continuous network structure through its own characteristics, further improving the overall rigidity and strength of the material.

[0083] 2. Water stability

[0084] In the practical application of paper-based alternative materials, excellent water resistance is one of the key indicators to ensure their functionality and durability. In order to evaluate the water stability of the materials in the above examples and comparative examples, contact angle tests and water absorption tests were performed on these materials.

[0085] (1) Contact angle test

[0086] Contact angles were measured using a static contact angle meter according to GB / T 30447-2013. The initial contact angle and the rate of decrease of the water contact angle over time were measured. The test conditions were as follows: a 5 μL droplet volume, a temperature of 25°C, and a relative humidity of 50%.

[0087] The results are as follows Figure 5 As shown in Figures a and b, the results show that the pure paper fiber sample of Comparative Example 1 absorbs water droplets quickly at the moment of contact with water, and the water contact angle is almost 0; the fiber-pollen paper sample of Comparative Example 2 after adding pollen has an initial contact angle of 95°, which is 13° after 5 minutes; the fiber-partitioned-chitosan paper of Example 1, after being soaked in chitosan solution, has an initial water contact angle increased to 99°, which is 59° after 5 minutes. It can be seen that the rate of decrease of the water contact angle with time is significantly lower than that of Comparative Example 2. This shows that the pure paper fiber sample of Comparative Example 1 has ultra-fast water absorption capacity, and after being soaked in chitosan solution, it effectively delays the water penetration process, significantly improving the water resistance of the material.

[0088] (2) Water absorption test

[0089] Water absorption is another important indicator for evaluating a material's water resistance. According to GB / T 461.1-2002, samples were cut into 2 cm x 2 cm squares and immersed in water before measuring their water absorption. The calculation formula is: Water absorption = [(W - W0) / W0] × 100%; where W is the weight of the sample after water absorption, and W0 is the weight of the dry sample.

[0090] The results are as follows Figure 5 As shown in Figure c, the water absorption of the fiber-pollen-chitosan paper (approximately 50%) is significantly lower than that of the pure fiber paper (approximately 700%) and the fiber-pollen paper (approximately 300%). This indicates that the all-biomass high-strength waterproof composite material soaked in chitosan solution in Example 1 not only hinders water penetration but also significantly reduces the paper's overall affinity for water, thereby reducing water damage to the mixed biomass network structure in the all-biomass high-strength waterproof composite material.

[0091] 3. Chitosan weldability

[0092] like Figure 6 As shown in Figure a, the present invention provides a green chitosan-based bonding method to verify the chitosan weldability of the all-biomass high-strength waterproof composite material prepared in Example 1. The specific method involves first evenly coating the surface of the all-biomass high-strength waterproof composite material with a 3% by mass chitosan solution. The two layers of the all-biomass high-strength waterproof composite material to be bonded are then aligned and pressed together. The bonding process is completed after drying. The bonded samples were then tested for water stability and mechanical properties.

[0093] like Figure 6 As shown in Figure b, the sample of the all-biomass high-strength waterproof composite material prepared in Example 1 after being bonded with chitosan solution can be placed in water to maintain a stable state and has good mechanical properties. Figure 6 The tensile force shown in Figure c) will not separate easily.

[0094] like Figure 6 As shown in Figure c, mechanical tests found that the mechanical strength of the bonded samples remained consistent with the original, both approximately 80 MPa, indicating that chitosan adhesive can meet the bonding requirements of most paper-based materials.

[0095] Application example: Product application of the all-biomass high-strength waterproof composite material prepared in Example 1

[0096] To verify the practical application performance of the all-biomass high-strength waterproof composite material described in this invention, we used it as raw material and combined it with chitosan solution as a green adhesive to prepare products such as straws, bags, and patches, and conducted systematic testing and evaluation of their waterproof performance and usage.

[0097] 1. Preparation and performance testing of straws

[0098] like Figure 7 As shown in Figure a, the preparation method of the straw is as follows: the all-biomass high-strength waterproof composite material prepared in Example 1 is cut into strips of appropriate size; the cut high-strength waterproof composite material strips are wound on a metal mold to form a tubular structure; chitosan solution is applied to the joints, slight pressure is applied and the straw is dried to form a strong bonding interface; the chitosan on the surface is washed off and the straw is naturally dried, and the formed straw is removed from the mold to obtain the all-biomass high-strength waterproof composite material straw.

[0099] like Figure 7 As shown in Figure b, the prepared all-biomass high-strength waterproof composite straw has good mechanical strength and can support a weight of 1,000 g without deformation.

[0100] like Figure 7 As shown in Figure c, the prepared all-biomass high-strength waterproof composite material straw can be smoothly inserted into the potato, indicating that it can be used as a straw to easily insert beverages.

[0101] like Figure 7 As shown in Figure d, when the straws are soaked in water, the pure paper fiber straws of Comparative Example 1 (ordinary commercially available paper straws) and the fiber-pollen paper straws of Comparative Example 2 (made by gluing the fiber-pollen paper of Comparative Example 2 with water) will deform at the tube ends as the soaking time increases, while the all-biomass paper straws of Example 1 still maintain a complete and firm round shape after soaking, without obvious expansion or deformation, indicating that they have excellent waterproof properties.

[0102] like Figure 7 As shown in Figure e, the straws did not soften or crack after being soaked in various beverages for one day, indicating that they can be used for daily use.

[0103] 2. Bag preparation and performance testing

[0104] like Figure 8 As shown in Figure a, the all-biomass high-strength waterproof composite material prepared in Example 1 is cut into sheets and strips of appropriate sizes, folded and bonded with chitosan solution to form a bag structure, and the formed bag is dried to obtain an all-biomass high-strength waterproof composite material bag.

[0105] like Figure 8 As shown in Figure b, when water was added to the all-biomass high-strength waterproof composite bag of Example 1, the bag's shape remained stable, with no swelling, deformation, or damage. This demonstrates its excellent mechanical strength and structural stability. After seven days, there was still no leakage, and the bag's surface was dry with no signs of moisture, indicating good waterproof properties. Furthermore, large all-biomass high-strength waterproof composite bags can hold more water and fish, exhibiting good stability and waterproof properties, demonstrating their feasibility and superiority in practical applications.

[0106] 3. Preparation and performance testing of patches

[0107] like Figure 9 As shown in Figure a, the all-biomass high-strength waterproof composite material prepared in Example 1 is cut into round or square sheets of appropriate size. The size is selected according to the size of the defect of the damaged container to ensure that the patch can completely cover the damaged part; then the all-biomass high-strength waterproof composite material patch is tightly attached to the defective part of the damaged container using a chitosan solution with a mass fraction of 3%, ensuring that the patch is tightly combined with the surface of the container; after drying, the patch is firmly bonded to the container, and the damaged container can be repaired; after the repair is completed, an appropriate amount of water is added to the repaired container, and the leakage of the container is observed after standing for a period of time.

[0108] The test results are as follows Figure 9 As shown in Figures b and c, the container repaired with the all-biomass high-strength waterproof composite patch remained stable and leak-free after 12 hours and 24 hours, indicating that the patch has good repair performance and sealing properties.

[0109] In summary, the present invention provides a kind of all-biomass high-strength waterproof composite material based on the synergistic effect of natural fiber, pollen and chitosan. It uses natural biomass as raw material and prepares an all-biomass high-strength waterproof composite material with excellent mechanical properties and waterproof properties through a simple, green and efficient integrated process of mixing-drying-soaking-and-drying. At the same time, welding can also be achieved through chitosan, and it can be used to prepare products such as straws, packaging bags and patches, which fully proves its feasibility and superiority in practical applications. The successful implementation of the present invention will provide a practical solution to solve the limitations of plastic pollution and the development of paper-based materials. It can be widely used in food packaging, medical supplies, daily consumer goods and other fields, and promote the development of society in a green and sustainable direction.

[0110] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details of the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a biomass high-strength waterproof composite material, characterized in that: Prepared by the following steps: The natural fibers are removed from impurities and crushed to prepare a fiber suspension with a solid-liquid mass volume ratio of (0.01-0.02) g / mL; Impurities and lipids on the surface of natural pollen are removed, and an alkali solution is added and stirred, washed until the mixed system is neutral, and excess water is removed to obtain a pollen microgel with a solid content of 0.5-3%. The alkali solution is a NaOH solution or KOH solution with a volume fraction of 1-20%, and the mass volume ratio of the natural pollen to the alkali solution is (0.05-0.1) g / mL. The alkali solution stirring treatment is carried out at 50-100°C for 0.1-24 hours. The fiber suspension and the pollen microgel are uniformly mixed to obtain a mixed slurry, which is then applied to the surface of a substrate by scraping, and then peeled off after drying to obtain a mixed film; in the mixed slurry, the mass of the natural fiber accounts for 1% to 90% of the total mass of the natural fiber and the pollen; The mixed film is immersed in a chitosan solution, washed, and dried to obtain the all-biomass high-strength waterproof composite material; the mass fraction of the chitosan solution is 1-4%, the molecular weight of chitosan is 50-150 kDa, and the immersion time is 0.1-24 hours.

2. The method for preparing the all-biomass high-strength waterproof composite material according to claim 1, characterized in that: The method for removing impurities and lipids on the surface of natural pollen is as follows: washing the natural pollen with a washing solvent, wherein the mass volume ratio of the natural pollen to the washing solvent is (0.2-10) g / mL; the washing solvent is water, and one or more of ethanol, acetone or ether.

3. The method for preparing the all-biomass high-strength waterproof composite material according to claim 1, characterized in that: The natural fibers are fibers of plant origin.

4. The method for preparing the all-biomass high-strength waterproof composite material according to claim 3, characterized in that: The plant source includes any one or more of cotton, bamboo, straw, and wood.

5. A high-strength waterproof composite material made of biomass, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 4.

6. An application of an all-biomass high-strength waterproof composite material, characterized in that: The all-biomass high-strength waterproof composite material is prepared by the preparation method according to any one of claims 1 to 4, or is the all-biomass high-strength waterproof composite material according to claim 5; Used to prepare waterproof materials.

7. The use of the all-biomass high-strength waterproof composite material according to claim 6, characterized in that: The waterproof material is used for preparing straws, packaging bags and patches.

Images