Self-degradable bio-based buoy material for navigation channel and preparation method of self-degradable bio-based buoy material

Abstract

The invention relates to the field of bio-based buoy materials, in particular to a self-degradable bio-based buoy material for a navigation channel and a preparation method of the self-degradable bio-based buoy material. The invention discloses a self-degradable bio-based buoy material for a navigation channel. The self-degradable bio-based buoy material comprises the following substances in parts by weight: 60-70 parts of a polylactic acid monomer; 20 to 40 parts of a polyhydroxyalkanoate monomer; 1 to 5 parts of an anti-ultraviolet degradable bio-based monomer; 0.1 to 1.0 part of a functional auxiliary agent; the anti-ultraviolet degradable bio-based monomer is an esterified derivative of ferulic acid and ethylene glycol diglycidyl ether. A composite component system of the polylactic acid monomer, the polyhydroxyalkanoate monomer and the anti-ultraviolet degradation type bio-based monomer is constructed, and the anti-ultraviolet degradation type bio-based monomer is an esterification derivative of ferulic acid and ethylene glycol diglycidyl ether, so that the core pain point of weak anti-ultraviolet degradation capability of a traditional bio-based material is solved; and meanwhile, the base body is stable in structure, can adapt to the outdoor use environment of the channel buoy, and gives consideration to both practicability and environmental friendliness.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bio-based buoy materials, in particular to a self-degradable bio-based buoy material for waterway and a preparation method thereof. BACKGROUND

[0002] As the core guarantee facility for the safety of ship navigation, waterway buoy plays an indispensable role in the water transportation system. Traditional waterway buoy materials mostly rely on steel and petrochemical-based plastics. However, these materials have many drawbacks in long-term use. Steel is easily eroded by water, which not only leads to the decrease of buoy structure strength and the shortening of service life, but also pollutes the surrounding water environment. Although petrochemical-based plastics have certain corrosion resistance, they are difficult to degrade in the natural environment and long-term stay in water after being discarded, which easily forms microplastic pollution and destroys the water ecological balance. At the same time, the production of traditional materials relies on non-renewable fossil resources and has high energy consumption, which does not meet the current environmental protection concept of sustainable development.

[0003] With the improvement of environmental awareness and the promotion of green development policy, bio-based materials have gradually become a research hotspot to replace traditional buoy materials due to their renewability and biodegradability. Bio-based materials are mostly derived from plant extracts or microbial fermentation products, which can be decomposed into harmless substances in the natural environment, fundamentally solving the environmental pollution problem of traditional materials.

[0004] In view of the above prior art, the inventors found that the existing bio-based buoy material has insufficient ultraviolet degradation resistance. Strong ultraviolet radiation in the water environment can accelerate the molecular chain breakage of bio-based materials, leading to material embrittlement and cracking, and a significant decrease in mechanical properties, which is difficult to meet the stability requirements of long-term outdoor use of the buoy. In addition, a single ultraviolet resistance modification method often cannot balance the anti-aging performance, mechanical properties and self-degradation characteristics of the material, limiting the large-scale application of bio-based buoy materials. SUMMARY

[0005] Based on the technical problems existing in the prior art, the present application provides a self-degradable bio-based buoy material for waterway and a preparation method thereof.

[0006] A self-degradable bio-based buoy material for waterway and a preparation method thereof adopt the following technical solutions: In a first aspect, the present application discloses a self-degradable bio-based buoy material for waterway adopting the following technical solutions: A self-degradable bio-based buoy material for waterway comprises the following substances by weight: 60-70 parts of polylactic acid monomer; 20-40 parts of polyhydroxyalkanoate monomer; 1-5 parts of ultraviolet degradation resistant bio-based monomer; and 0.1-1.0 parts of functional additives. The ultraviolet degradation resistant bio-based monomer is an esterified derivative of ferulic acid and ethylene glycol diglycidyl ether.

[0007] By the technical scheme, the application constructs a composite component system of polylactic acid monomers, polyhydroxyalkanoate monomers and anti-ultraviolet degradation type bio-based monomers, wherein the anti-ultraviolet degradation type bio-based monomers are selected from esterification derivatives of ferulic acid and ethylene glycol diglycidyl ether. The synergistic effect of polylactic acid and polyhydroxyalkanoate provides the basis rigidity, toughness and self-degradation characteristics of the buoy material, and the complementary molecular structures of the two can improve the performance defects of single bio-based materials. The anti-ultraviolet active groups are introduced into the anti-ultraviolet degradation type bio-based monomers through molecular design, and the active groups are in-situ connected to the main chain of the matrix during the copolymerization process, so that the material is endowed with anti-ultraviolet ability from the molecular source, avoiding the problems of easy migration and unstable effect of traditional additive anti-ultraviolet agents. The scheme realizes the organic unification of anti-ultraviolet performance and self-degradation performance, solves the core pain point of weak anti-ultraviolet degradation ability of traditional bio-based materials, retains the environmental protection advantage of bio-based materials, and at the same time, the matrix structure is stable, which can adapt to the outdoor use environment of the channel buoy, and takes into account the practicability and environmental protection.

[0008] Further, the anti-ultraviolet degradation type bio-based monomer is made by the following technical scheme: Take ferulic acid and ethylene glycol diglycidyl ether, dissolve in anhydrous ethanol, add p-toluenesulfonic acid, and then pass nitrogen protection. The reaction system is heated to 70-80℃, reflux stirring reaction for 4-6h. After the reaction is completed, it is cooled to room temperature, and the ethanol solvent is removed by reduced pressure distillation to obtain the crude product. After washing and drying, the anti-ultraviolet degradation type bio-based monomer is prepared.

[0009] By the technical scheme, the esterification reaction is used to realize the chemical bonding of ferulic acid and ethylene glycol diglycidyl ether, forming a derivative with anti-ultraviolet activity and copolymerization compatibility. The preparation process is simple and controllable, and does not require complex equipment, so that the target monomer can be efficiently synthesized. The product molecule retains the anti-ultraviolet active groups of ferulic acid and the reactive sites of ethylene glycol diglycidyl ether, which has excellent ultraviolet absorption ability and can be efficiently copolymerized with polylactic acid and polyhydroxyalkanoate monomers, laying a solid foundation for the anti-ultraviolet performance of the subsequent buoy material matrix. At the same time, the preparation process is environmentally friendly, which meets the green development concept of bio-based materials.

[0010] Further, the self-degradation bio-based buoy material for waterway further comprises 0.1-0.5 parts by weight of a bio-based ultraviolet absorber, and the bio-based ultraviolet absorber comprises tea polyphenol grafted cellulose nanocrystal particles.

[0011] By the technical scheme, the application adds a biological-based ultraviolet absorber on the basis of the core component system, and clearly comprises tea polyphenol grafted cellulose nanocrystal particles, to construct a double protection system of self anti-ultraviolet material and external ultraviolet absorber enhancement. Tea polyphenol itself has natural ultraviolet absorption performance, and after being combined with cellulose nanocrystal through graft modification, it not only retains strong ultraviolet absorption capacity, but also can be uniformly dispersed in the matrix by means of the nanoscale effect of cellulose nanocrystal, to avoid the failure of the protection effect caused by the aggregation of tea polyphenol. The biological-based ultraviolet absorber and the matrix component are both of biological-based origin, and have good compatibility, which will not affect the self-degradation performance of the material. The anti-ultraviolet degradation capacity of the buoy material is further strengthened, the double protection system can more comprehensively block the erosion of ultraviolet rays on the material matrix, delay the molecular chain breakage rate, and significantly improve the outdoor service life of the material; at the same time, the introduction of the biological-based ultraviolet absorber does not sacrifice the environmental protection characteristics of the material, and the cellulose nanocrystal can also enhance the mechanical properties of the material to some extent, realizing the synergistic improvement of the anti-ultraviolet performance and the mechanical properties Further, the biological-based ultraviolet absorber further comprises organically modified nanometer montmorillonite and epoxy soybean oil-based epoxy propyl ester, and the mixing ratio of the tea polyphenol grafted cellulose nanocrystal particles, the organically modified nanometer montmorillonite and the epoxy soybean oil-based epoxy propyl ester is 3-5:2-3:1-2.

[0012] By the technical scheme, the application optimizes the mixing ratio range of the three components in the biological-based ultraviolet absorber, to maximize the synergistic protection effect. The tea polyphenol grafted cellulose nanocrystal particles, as the core ultraviolet absorber, need to occupy a dominant proportion to ensure the ultraviolet absorption efficiency; the organically modified nanometer montmorillonite forms a physical barrier through the lamellar structure to assist in blocking the ultraviolet rays that are not absorbed, and the proportion needs to be adapted to the core absorber to avoid excessive amount leading to the decrease of the toughness of the material; the epoxy soybean oil-based epoxy propyl ester has the functions of anti-hydrolysis and auxiliary stabilization, and a low proportion can inhibit the hydrolytic aging caused by ultraviolet irradiation, and an excessive amount may affect the degradation performance of the material. The effect of the scheme lies in that through scientific proportioning, the three components form a synergistic protection network of absorption, blocking and stabilization, which not only ensures the anti-ultraviolet degradation effect, but also avoids the performance imbalance problem caused by excessive amount of a single component, and at the same time, the proportion range has flexibility, which can be adjusted according to the ultraviolet radiation intensity, use environment and other requirements of different navigation channels, to adapt to diversified application scenarios, and give consideration to the protection effect and practicality.

[0013] Further, the tea polyphenol grafted cellulose nanocrystal particles are prepared by the following technical scheme: The cellulose nanocrystal is placed in a silane coupling agent ethanol solution, stirred and mixed, and a tea polyphenol solution is added, heated and reacted, then centrifuged and separated, and the lower precipitate is collected, washed and dried, to prepare the tea polyphenol grafted cellulose nanocrystal particles.

[0014] Through the above technical solution, this application addresses the preparation process of tea polyphenol-grafted cellulose nanocrystal particles. By using a silane coupling agent to surface-activate the cellulose nanocrystals, active groups are introduced, providing binding sites for the grafting of tea polyphenols. This allows the tea polyphenols and cellulose nanocrystals to form a stable structure through chemical bonding. This process retains the strong UV absorption capacity of tea polyphenols while leveraging the structural characteristics of cellulose nanocrystals to improve dispersion stability. It avoids the problems of easy aggregation and migration of traditional UV absorbers, enabling uniform distribution within the matrix and continuous protective effects. Simultaneously, the particles have a fully bio-based structure, exhibiting excellent compatibility with the matrix and not affecting the self-degradation performance of the buoy material. Furthermore, the nano-reinforcement effect enhances the material's mechanical strength and weather resistance.

[0015] Secondly, this application provides a method for preparing a self-degradable bio-based buoy material for navigation channels, employing the following technical solution: A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following preparation steps: Polylactic acid monomer, polyhydroxy fatty acid ester monomer and UV-resistant bio-based monomer were stirred and mixed, and a catalyst was added. The solution was polymerized at 120-140℃ for 8-10 hours. After the reaction, epoxidized soybean oil-based glycidyl ester was added and stirred for 30 minutes to obtain a pre-crosslinked copolymer matrix solution. Add tea polyphenol-grafted cellulose nanocrystals and organically modified nano-montmorillonite to the above solution, stir at a constant temperature of 80-90℃ for 1-2 hours, ultrasonically disperse for 30-45 minutes, and dry to obtain composite powder. The composite powder is mixed with citric acid crosslinking agent, added to a twin-screw extruder and extruded at a set temperature gradient. The extruded material is then molded to obtain a preform, thus preparing the UV-resistant bio-based buoy material.

[0016] Through the above technical solution, this application adopts a gradient process design to achieve efficient fusion and synergistic effects of each component. The first step involves solution polymerization to copolymerize the ternary monomers, introducing epoxidized soybean oil-based glycidyl ester for pre-crosslinking, which enhances the stability of the matrix structure. The second step involves adding a bio-based UV absorber to the copolymer matrix solution, using a combination of constant-temperature stirring and ultrasonic dispersion to ensure uniform dispersion of the absorber, preventing agglomeration, and promoting interfacial bonding among the components. The third step, melt blending and molding, further strengthens the matrix network structure through a crosslinking agent, improving the material's density and mechanical properties. The preparation process is logically coherent and progressively advanced, fully leveraging the synergistic effects of each component. It effectively solves the problems of uneven dispersion and poor interfacial compatibility in bio-based materials, resulting in a buoy material with a dense structure, stable performance, and resistance to UV degradation and mechanical properties that meet the requirements for waterway use. Furthermore, the process is simple and controllable, facilitating industrial production and providing a feasible path for the large-scale application of the material.

[0017] Furthermore, the temperature gradient of the twin-screw extruder is set to 160°C, 180°C and 170°C for the feeding section, melting section and extrusion section respectively, and the compression molding conditions are 165-175°C, 8-12MPa and 15-20min.

[0018] Through the above technical solution, this application optimizes the temperature gradient and compression molding conditions of a twin-screw extruder based on the thermal properties and reaction characteristics of the material components. The temperature gradient is designed to match the melting temperature and copolymerization reaction requirements of each component. The feeding section temperature ensures the initial melting of the material, the melting section temperature promotes thorough mixing and cross-linking reaction of the components, and the extrusion section temperature ensures smooth extrusion of the material without thermal degradation. The temperature, pressure, and holding time of the compression molding are adjusted to control the molding density of the material, thereby improving structural compactness and enhancing mechanical properties and UV resistance.

[0019] Furthermore, the catalyst includes at least one of p-toluenesulfonic acid, stannous octanoate, and 4-dimethylaminopyridine.

[0020] Through the above technical solutions, this application provides a variety of catalyst options, selecting suitable catalyst types based on the characteristics of the copolymerization reaction and monomer preparation reaction. This broadens the flexibility and adaptability of the production process, meeting the needs of different production scenarios. Furthermore, the selected catalysts exhibit good compatibility with the bio-based system, do not introduce harmful impurities, and do not affect the material's self-degradation performance or UV resistance. The high efficiency of the catalysts ensures the reaction proceeds fully, improving product yield and material performance stability, thus guaranteeing the mass production of buoy materials.

[0021] In summary, this application has the following beneficial effects: First, this application addresses the core pain point of insufficient UV resistance in bio-based materials through a dual design of molecular-level modification and multi-component synergistic protection. UV-resistant bio-based monomers are copolymerized in situ into the main chain of the material matrix, endowing the matrix with inherent UV resistance. Combined with a stable protective network formed by bio-based UV absorbers, this network comprehensively resists UV erosion of the molecular chains, effectively delaying aging phenomena such as embrittlement and cracking. This comprehensive protection system avoids the limitations of traditional single UV-resistant methods, enabling buoy materials to maintain stable mechanical properties and structural integrity in long-term outdoor water environments, eliminating the need for frequent replacement and maintenance, significantly extending the service life of buoy products, and meeting the long-term reliable operation requirements of waterway facilities. Simultaneously, the UV-resistant modification does not damage the material's matrix structure, ensuring long-lasting and stable protection, and overcoming the drawbacks of traditional additive UV absorbers, such as easy migration and rapid failure.

[0022] Secondly, this application constructs a component system with bio-based raw materials as the core, and all key components are derived from renewable resources, thus eliminating dependence on fossil resources and conforming to the concept of green development. The material can be completely degraded into harmless substances in the natural environment, fundamentally solving the ecological problems such as water pollution and microplastic residues caused by the disposal of traditional steel and petrochemical-based plastic buoys, effectively protecting the aquatic ecological balance. Furthermore, environmentally friendly solvents and biocompatible catalysts are used in the preparation process, avoiding the introduction and emission of harmful chemicals and reducing the environmental burden of the production process. From the perspective of the entire life cycle from raw material acquisition and product production to waste degradation, this material achieves a comprehensive balance of environmental performance, responding to environmental policy requirements and providing a feasible path for the green upgrading of waterway facilities, demonstrating significant ecological benefits and social value.

[0023] Third, this application achieves a unified balance of UV resistance, mechanical properties, self-degradation properties, and processing performance through scientific component ratios and a gradient preparation process. The synergistic effect of polylactic acid and polyhydroxyalkanoates provides the material with balanced rigidity and toughness. The bio-based UV absorber enhances UV resistance while also improving the material's mechanical strength. The optimization of functional additives and process parameters ensures good processing flowability and molding effects. The synergistic design of each component and process avoids imbalances in other properties caused by optimizing a single performance, enabling the buoy material to meet the structural strength and stability requirements for waterway use while also possessing convenient processing and molding characteristics. Simultaneously, the preparation process is simple and controllable, compatible with conventional production equipment, and requires no complex or special devices, lowering the technical threshold and cost of industrial production, facilitating large-scale promotion and application, and laying a solid foundation for the industrialization of bio-based buoy materials. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the embodiments.

[0025] Preparation Example 1 UV-resistant bio-based monomer 1 100g ferulic acid and 110g ethylene glycol diglycidyl ether were dissolved in 1000mL of anhydrous ethanol. After adding 3g p-toluenesulfonic acid, nitrogen gas was introduced at a flow rate of 0.5L / min for 30min for protection. The reaction system was then heated to 70℃ and stirred under reflux at 200r / min for 4h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The ethanol solvent was removed by vacuum distillation at 0.08MPa and 40℃ to obtain the crude product. The mixture was stirred for 10min each time and allowed to stand for separation. The supernatant was discarded. The washed product was placed in a vacuum drying oven and dried at 50℃ and 0.07MPa for 3h to prepare the UV-resistant bio-based monomer 1.

[0026] Preparation Example 2 UV-resistant bio-based monomer 2 125g ferulic acid and 145g ethylene glycol diglycidyl ether were dissolved in 2000mL of anhydrous ethanol. After adding 5g p-toluenesulfonic acid, nitrogen gas was introduced at a flow rate of 0.7L / min for 30min for protection. The reaction system was then heated to 75℃ and stirred under reflux at 250r / min for 5h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The ethanol solvent was removed by vacuum distillation at 0.08MPa and 45℃ to obtain the crude product. The mixture was stirred for 12min each time and allowed to stand for separation. The supernatant was discarded. The washed product was placed in a vacuum drying oven and dried at 60℃ and 0.07MPa for 4h to prepare the UV-resistant bio-based monomer 2.

[0027] Preparation Example 3 UV-resistant bio-based monomer 3 150g ferulic acid and 180g ethylene glycol diglycidyl ether were dissolved in 3000mL of anhydrous ethanol. After adding 8g p-toluenesulfonic acid, nitrogen gas was introduced at a flow rate of 1.0L / min for 30min for protection. The reaction system was then heated to 80℃ and stirred under reflux at 300r / min for 6h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The ethanol solvent was removed by vacuum distillation at 0.09MPa and 50℃ to obtain the crude product. The mixture was stirred for 15min each time and allowed to stand for separation. The supernatant was discarded. The washed product was placed in a vacuum drying oven and dried at 70℃ and 0.08MPa for 3-6h to prepare the UV-resistant bio-based monomer 3.

[0028] Preparation Example 4 Tea polyphenol grafted cellulose nanocrystal particles 1 Five kilograms of cellulose nanocrystals were placed in an ethanol solution containing 0.05 kg of 2% (w / w) silane coupling agent KH-550 and stirred at 200 rpm for 30 min. One kilogram of tea polyphenols was dissolved in 10 L of a 50% (w / w) ethanol-water mixed solvent, and the mixture was stirred for another 10 min until homogeneous. The reaction system was heated to 60°C and kept at this temperature for 4 h, with stirring at 200 rpm to promote the grafting reaction. After the reaction, the mixture was centrifuged at 8000 rpm for 10 min and the lower precipitate was collected. The precipitate was washed twice with a 50% (w / w) ethanol-water mixed solvent, stirring for 10 min after each wash before centrifugation. Finally, the precipitate was placed in a vacuum drying oven and dried at 50°C and 0.07 MPa for 4-8 h to obtain tea polyphenol-grafted cellulose nanocrystal particles.

[0029] Preparation Example 5 Tea polyphenol grafted cellulose nanocrystal particles 2 7.5 kg of cellulose nanocrystals were placed in an ethanol solution containing 0.15 kg of 2% (w / w) silane coupling agent KH-550 and stirred at 250 rpm for 37 min. 2.1 kg of tea polyphenols were dissolved in 30 L of a 50% (w / w) ethanol-water mixed solvent and stirred for another 12 min until homogeneous. The reaction system was heated to 65℃ and maintained at this temperature for 5 h, with stirring at 250 rpm to promote a complete grafting reaction. After the reaction, the mixture was centrifuged at 9000 rpm for 12 min and the lower precipitate was collected. The precipitate was washed twice with a 50% (w / w) ethanol-water mixed solvent, stirring for 12 min after each wash before centrifugation. Finally, the precipitate was placed in a vacuum drying oven and dried at 60℃ and 0.075 MPa for 4-8 h to obtain tea polyphenol-grafted cellulose nanocrystal particles.

[0030] Preparation Example 6 Tea polyphenol grafted cellulose nanocrystal particles 3 10 kg of cellulose nanocrystals were placed in an ethanol solution containing 0.3 kg of 2% (w / w) silane coupling agent KH-550 and stirred at 300 rpm for 45 min. 3.3 kg of tea polyphenols were dissolved in 66 L of a 50% (w / w) ethanol-water mixed solvent and stirred for another 15 min until homogeneous. The reaction system was heated to 70℃ and maintained at this temperature for 6 h, with stirring at 300 rpm to promote a complete grafting reaction. After the reaction, the mixture was centrifuged at 10000 rpm for 15 min, and the lower precipitate was collected. The precipitate was washed three times with a 50% (w / w) ethanol-water mixed solvent, stirring for 15 min after each wash before centrifugation. Finally, the precipitate was placed in a vacuum drying oven and dried at 70℃ and 0.08 MPa for 4-8 h to obtain tea polyphenol-grafted cellulose nanocrystal particles.

[0031] Preparation Example 7 Functional additives Take 0.3 kg of acetylated monoglyceride, 0.15 kg of calcium stearate and 0.05 kg of natural vitamin E and add them to a high-speed mixer. Stir at 200-300 r / min for 30-40 min at 60-70℃ to make the components evenly dispersed, and the functional additive is prepared. Example 1

[0032] A self-degradable bio-based buoy material for navigation, comprising the following substances: 60kg polylactic acid monomer, 20kg polyhydroxyalkanoate monomer, 1kg UV-resistant bio-based monomer, 0.1kg functional additives.

[0033] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 1 were added to a reactor and stirred at 200 rpm for 30 min until homogeneous. Then, 0.4 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 120 °C. Solution polymerization was carried out at 0.1 MPa for 8 h, maintaining a stirring speed of 150 rpm during the reaction. After the reaction was completed, the temperature was lowered to 90 °C to obtain a pre-crosslinked copolymer matrix solution. The mixture was transferred to a vacuum drying oven and dried at 60 °C and 0.07 MPa for 6 h to remove the solvent, yielding the composite powder.

[0034] Take 85 kg of the above composite powder, add 0.4 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 5 kg / h, the screw speed to 150 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 165℃ and 8 MPa pressure. After holding the pressure for 15 min, cool them to below 50℃ at a rate of 5℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 2

[0035] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxyalkanoate monomer, 3kg UV-resistant bio-based monomer, 0.5kg functional additives.

[0036] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 1 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, and nitrogen gas was introduced for protection. The temperature was raised to 130 °C, and solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction was completed, the temperature was lowered to 95 °C to obtain a pre-crosslinked copolymer matrix solution. The mixture was transferred to a vacuum drying oven and dried at 70 °C and 0.08 MPa for 7 h to remove the solvent, yielding the composite powder.

[0037] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 3

[0038] A self-degradable bio-based buoy material for navigation, comprising the following substances: 70kg polylactic acid monomer, 40kg polyhydroxyalkanoate monomer, 5kg UV-resistant bio-based monomer, 1.0kg functional additives.

[0039] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 1 were added to a reactor and stirred at 300 rpm for 45 min until homogeneous. Then, 1.7 kg of stannous octoate catalyst was added, and nitrogen gas was introduced for protection. The temperature was raised to 140 °C, and solution polymerization was carried out at 0.15 MPa for 10 h, maintaining a stirring speed of 200 rpm throughout the reaction. After the reaction was completed, the temperature was lowered to 100 °C to obtain a pre-crosslinked copolymer matrix solution. The mixture was transferred to a vacuum drying oven and dried at 80 °C and 0.09 MPa for 6-8 h to remove the solvent, yielding the composite powder.

[0040] Take 135 kg of the above composite powder, add 1.4 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 10 kg / h, the screw speed to 200 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 175℃ and 12 MPa pressure. After holding the pressure for 20 min, cool them to below 50℃ at a rate of 10℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 4

[0041] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxyalkanoate monomer, 3kg UV-resistant bio-based monomer, 0.5kg functional additives.

[0042] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, and nitrogen gas was introduced for protection. The temperature was raised to 130 °C, and solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm throughout the reaction. After the reaction was completed, the temperature was lowered to 95 °C to obtain a pre-crosslinked copolymer matrix solution. The mixture was transferred to a vacuum drying oven and dried at 70 °C and 0.08 MPa for 7 h to remove the solvent, yielding the composite powder.

[0043] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 5

[0044] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxyalkanoate monomer, 3kg UV-resistant bio-based monomer, 0.5kg functional additives.

[0045] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 3 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, and nitrogen gas was introduced for protection. The temperature was raised to 130 °C, and solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm throughout the reaction. After the reaction was completed, the temperature was lowered to 95 °C to obtain a pre-crosslinked copolymer matrix solution. The mixture was transferred to a vacuum drying oven and dried at 70 °C and 0.08 MPa for 7 h to remove the solvent, yielding the composite powder.

[0046] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 6

[0047] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxyalkanoate monomer, 3kg UV-resistant bio-based monomer, 0.1kg tea polyphenol grafted cellulose nanocrystal particles, 0.5kg functional additives.

[0048] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 130 °C. Solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction, the temperature was lowered to 95 °C to obtain a pre-crosslinked copolymer matrix solution. Tea polyphenol-grafted cellulose nanocrystals 1 were added to the above copolymer matrix solution, and the temperature was raised to 90 °C. The mixture was stirred at 250 rpm for 2 h, while simultaneously ultrasonically dispersed at 500 W for 45 min. The mixture was transferred to a vacuum drying oven and dried at 70 °C and 0.08 MPa vacuum for 7 h to remove the solvent, yielding a composite powder.

[0049] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 7

[0050] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxyalkanoate monomer, 3kg UV-resistant bio-based monomer 1, 0.3kg tea polyphenol grafted cellulose nanocrystal particles 2, 0.5kg functional additives.

[0051] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 130°C. Solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction, the temperature was lowered to 95°C to obtain a pre-crosslinked copolymer matrix solution. Tea polyphenol-grafted cellulose nanocrystals 2 were added to the above copolymer matrix solution, and the temperature was raised to 90°C. The mixture was stirred at 250 rpm for 2 h, while simultaneously ultrasonically dispersed at 500 W for 45 min. The mixture was transferred to a vacuum drying oven and dried at 70°C and 0.08 MPa for 7 h to remove the solvent, yielding a composite powder.

[0052] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 8

[0053] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxyalkanoate monomer, 3kg UV-resistant bio-based monomer, 0.5kg tea polyphenol-grafted cellulose nanocrystals, and 0.5kg functional additives.

[0054] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 130°C. Solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction, the temperature was lowered to 95°C to obtain a pre-crosslinked copolymer matrix solution. Tea polyphenol-grafted cellulose nanocrystals 3 were added to the above copolymer matrix solution, and the temperature was raised to 90°C. The mixture was stirred at 250 rpm for 2 h, while simultaneously ultrasonically dispersed at 500 W for 45 min. The mixture was transferred to a vacuum drying oven and dried at 70°C and 0.08 MPa for 7 h to remove the solvent, yielding a composite powder.

[0055] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 9

[0056] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxy fatty acid ester monomer, 3kg UV-resistant bio-based monomer 1, 0.05kg tea polyphenol grafted cellulose nanocrystal particles 2, 0.017kg epoxidized soybean oil-based glycidyl ester, 0.033kg organically modified nano-montmorillonite, and 0.5kg functional additives.

[0057] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 130°C. Solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction, the temperature was lowered to 95°C, and epoxidized soybean oil-based glycidyl oxide was added. Stirring continued for 30 min to obtain a pre-crosslinked copolymer matrix solution. Tea polyphenol-grafted cellulose nanocrystals 2 and organically modified nano-montmorillonite were added to the above copolymer matrix solution. The temperature was raised to 90°C, and the mixture was stirred at 250 rpm for 2 h. Simultaneously, ultrasonic dispersion was performed at 500 W for 45 min. The mixture was transferred to a vacuum drying oven and dried at 70°C and 0.08 MPa vacuum for 7 h to remove the solvent, obtaining the composite powder.

[0058] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 10

[0059] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxy fatty acid ester monomer, 3kg UV-resistant bio-based monomer 1, 0.25kg tea polyphenol grafted cellulose nanocrystal particles 2, 0.1kg epoxidized soybean oil-based glycidyl oxide, 0.15kg organically modified nano-montmorillonite, and 0.5kg functional additives.

[0060] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 130°C. Solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction, the temperature was lowered to 95°C, and epoxidized soybean oil-based glycidyl oxide was added. Stirring continued for 30 min to obtain a pre-crosslinked copolymer matrix solution. Tea polyphenol-grafted cellulose nanocrystals 2 and organically modified nano-montmorillonite were added to the above copolymer matrix solution. The temperature was raised to 90°C, and the mixture was stirred at 250 rpm for 2 h. Simultaneously, ultrasonic dispersion was performed at 500 W for 45 min. The mixture was transferred to a vacuum drying oven and dried at 70°C and 0.08 MPa vacuum for 7 h to remove the solvent, obtaining the composite powder.

[0061] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material. Example 11

[0062] A self-degradable bio-based buoy material for navigation, comprising the following substances: 65kg polylactic acid monomer, 30kg polyhydroxy fatty acid ester monomer, 3kg UV-resistant bio-based monomer 1, 0.15kg tea polyphenol grafted cellulose nanocrystal particles 2, 0.056kg epoxidized soybean oil-based glycidyl oxide, 0.094kg organically modified nano-montmorillonite, and 0.5kg functional additives.

[0063] A method for preparing a self-degradable bio-based buoy material for navigation channels includes the following steps: Polylactic acid monomer, polyhydroxyalkanoate monomer, and UV-resistant bio-based monomer 2 were added to a reactor and stirred at 250 rpm for 38 min until homogeneous. Then, 1 kg of stannous octoate catalyst was added, nitrogen gas was introduced for protection, and the temperature was raised to 130°C. Solution polymerization was carried out at 0.12 MPa for 9 h, maintaining a stirring speed of 175 rpm during the reaction. After the reaction, the temperature was lowered to 95°C, and epoxidized soybean oil-based glycidyl oxide was added. Stirring continued for 30 min to obtain a pre-crosslinked copolymer matrix solution. Tea polyphenol-grafted cellulose nanocrystals 2 and organically modified nano-montmorillonite were added to the above copolymer matrix solution. The temperature was raised to 90°C, and the mixture was stirred at 250 rpm for 2 h. Simultaneously, ultrasonic dispersion was performed at 500 W for 45 min. The mixture was transferred to a vacuum drying oven and dried at 70°C and 0.08 MPa vacuum for 7 h to remove the solvent, obtaining the composite powder.

[0064] Take 108 kg of the above composite powder, add 0.9 kg of citric acid crosslinking agent, mix evenly, and then feed it into a twin-screw extruder. Set the feeding rate to 8 kg / h, the screw speed to 175 r / min, and the temperature gradient to 160℃ in the feeding section, 180℃ in the melting section, and 170℃ in the extrusion section. Extrude and granulate to obtain composite granules. Place the granules in a molding press and mold them at 170℃ and 10 MPa pressure. After holding the pressure for 17 min, cool them to below 50℃ at a rate of 7℃ / min and demold to obtain the blank, which is the UV-resistant bio-based buoy material.

[0065] Mechanical properties before aging: According to GB / T1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets", a universal testing machine was used with a tensile rate of 50 mm / min. The test specimens were type I dumbbell plates. Five specimens were tested in each group, and the average value was taken. Mechanical property retention rate after UV aging: First, aging treatment was carried out according to GB / T16422.2-2014 "Laboratory Light Source Exposure Test Methods for Plastics - Part 2: Xenon Arc Lamp" (irradiance 0.51 W / m², blackboard temperature 60℃, relative humidity 50%, aging time 1000 h); then, tensile strength and elongation at break were tested according to GB / T1040.3-2006 above. Retention rate = (value after aging / value before aging) × 100%; According to GB / T38082-2019 "Test Method for Degradation of Biodegradable Plastics in Seawater Environment", the sample (particle size 2 mm) was placed in artificial seawater (salinity 35‰, temperature 25℃, stirring rate 50 r / min) and cultured for 6 months. The degradation rate was calculated by the weight loss method: (initial mass - residual mass) / initial mass × 100%. The results are shown in Table 1 below: Table 1 Performance Test Table Sample Unaged tensile strength (MPa) Tensile strength retention after 1000h UV aging (%) 6 month seawater degradation rate (%) Example 1 32.6 58.3 35.7 Example 2 36.8 61.5 33.2 Example 3 40.2 63.1 31.8 Example 4 37.5 64.8 32.5 Example 5 38.1 66.2 31.2 Example 6 39.5 78.6 34.6 Example 7 42.3 85.4 33.8 Example 8 43.7 88.7 32.9 Example 9 45.2 90.5 35.1 Example 10 47.8 94.2 34.2 Example 11 46.5 92.8 34.8 By comparing the test results of Examples 1-11 above with those in Table 1, it can be found that: Based on the technical solutions of Examples 1-5, the tensile strength and elongation at break of the material gradually increase with the increase of the amount of UV-resistant bio-based monomers and the introduction of composite additives, reflecting the synergistic effect of matrix copolymerization modification and nano-additive enhancement.

[0066] A comparison of Examples 6-8 and Examples 1-5 reveals that the technical solution of this application adds a bio-based UV absorber, specifically containing tea polyphenol-grafted cellulose nanocrystal particles, constructing a dual protection system enhanced by both the self-resistant UV material and the external UV absorber. This strengthens the buoy material's resistance to UV degradation. The dual protection system more comprehensively blocks UV erosion of the material matrix, slows down the rate of molecular chain breakage, and significantly improves the material's outdoor lifespan. Simultaneously, the introduction of the bio-based UV absorber does not sacrifice the material's environmental friendliness, and the cellulose nanocrystals also enhance the material's mechanical properties, achieving a synergistic improvement in both UV resistance and mechanical properties.

[0067] Finally, by comparing Examples 9-11 and Examples 6-8, it is further illustrated that this application optimizes the mixing ratio range of the three components in the bio-based UV absorber to maximize the synergistic protective effect. Through a scientific ratio, the three components form a synergistic protective network of absorption, blocking, and stability, ensuring both the anti-UV degradation effect and avoiding performance imbalance caused by excessive amounts of a single component. Furthermore, the ratio range is flexible and can be adjusted according to the UV radiation intensity and usage environment requirements of different shipping routes, adapting to diverse application scenarios and balancing protective effectiveness with practicality.

[0068] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0069] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0070] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0071] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

Claims

1. A self-degradable bio-based buoy material for waterways, characterized in that, Includes the following substances in parts by weight: 60-70 parts of polylactic acid monomer; 20-40 parts of polyhydroxyalkanoate monomer; 1-5 parts of UV-resistant bio-based monomers; Functional additives: 0.1-1.0 parts; The UV-resistant bio-based monomer is an esterified derivative of ferulic acid and ethylene glycol diglycidyl ether.

2. The self-degradable bio-based buoy material for navigation channels according to claim 1, characterized in that, The UV-resistant bio-based monomer is manufactured using the following technical solution: Ferulic acid and ethylene glycol diglycidyl ether were dissolved in anhydrous ethanol. After adding p-toluenesulfonic acid, nitrogen gas was introduced for protection. The reaction system was heated to 70-80℃ and stirred under reflux for 4-6 hours. After the reaction was completed, the mixture was cooled to room temperature and the ethanol solvent was removed by vacuum distillation to obtain the crude product. The crude product was washed and dried to prepare the UV-resistant bio-based monomer.

3. The self-degradable bio-based buoy material for navigation channels according to claim 1, characterized in that, The self-degradable bio-based buoy material for navigation also includes 0.1-0.5 parts by weight of a bio-based ultraviolet absorber, which includes tea polyphenol-grafted cellulose nanocrystal particles.

4. The self-degradable bio-based buoy material for navigation channels according to claim 3, characterized in that, The bio-based ultraviolet absorber also includes organically modified nano-montmorillonite and epoxidized soybean oil-based glycidyl ester, and the mixing ratio of the tea polyphenol grafted cellulose nanocrystal particles, organically modified nano-montmorillonite, and epoxidized soybean oil-based glycidyl ester is 3~5:2~3:1~2.

5. The self-degradable bio-based buoy material for navigation channels according to claim 3, characterized in that, The tea polyphenol-grafted cellulose nanocrystal particles are prepared using the following technical solution: Cellulose nanocrystals are placed in an ethanol solution of silane coupling agent, stirred and mixed, and tea polyphenol solution is added. After heating and maintaining the temperature for reaction, the lower precipitate is collected by centrifugation, washed and dried to prepare tea polyphenol-grafted cellulose nanocrystal particles.

6. A method for preparing a self-degradable bio-based buoy material for navigation channels according to any one of claims 1-5, characterized in that, The preparation steps include the following: Polylactic acid monomer, polyhydroxy fatty acid ester monomer and UV-resistant bio-based monomer were stirred and mixed, and a catalyst was added. The solution was polymerized at 120-140℃ for 8-10 hours. After the reaction, epoxidized soybean oil-based glycidyl ester was added and stirred for 30 minutes to obtain a pre-crosslinked copolymer matrix solution. Add tea polyphenol-grafted cellulose nanocrystals and organically modified nano-montmorillonite to the above solution, stir at a constant temperature of 80-90℃ for 1-2 hours, ultrasonically disperse for 30-45 minutes, and dry to obtain composite powder. The composite powder is mixed with citric acid crosslinking agent, added to a twin-screw extruder and extruded at a set temperature gradient. The extruded material is then molded to obtain a preform, thus preparing the UV-resistant bio-based buoy material.

7. The method for preparing a self-degradable bio-based buoy material for navigation channels according to claim 6, characterized in that, The temperature gradient of the twin-screw extruder is set to 160℃, 180℃ and 170℃ for the feeding section, melting section and extrusion section respectively, and the compression molding conditions are 165-175℃, 8-12MPa and 15-20min.

8. The method for preparing a self-degradable bio-based buoy material for navigation channels according to claim 6, characterized in that, The catalyst includes at least one of p-toluenesulfonic acid, stannous octoate, and 4-dimethylaminopyridine.