Carbon sequestration thermal insulation material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of heat insulation, and particularly discloses a carbon sequestration heat insulation material and a preparation method and application thereof. The carbon-sequestration thermal insulation material is prepared from the following raw materials in parts by weight: 12 to 16 parts of ethylene-vinyl acetate copolymer emulsion, 20 to 30 parts of cellulose acetate fiber, 5 to 8 parts of thermal insulation filler, 40 to 50 parts of modified biochar and 70 to 80 parts of polylactic acid, and the modified biochar is obtained by hydrophobic modification. The composition can be used in the technical field of paper cup manufacturing and the like, and has the advantages of good heat insulation performance and good mechanical performance.

Description

Technical Field

[0001] The present application relates to the field of thermal insulation materials, and more specifically, to a carbon-fixing thermal insulation material and a preparation method and application thereof. Background Art

[0002] As the global climate change problem becomes increasingly serious, reducing carbon emissions has become a common focus of global concern. Among the many solutions, carbon sequestration technology has received widespread attention because it can fix carbon dioxide in the atmosphere and thus reduce greenhouse gas emissions. At the same time, the demand for thermal insulation materials in the fields of construction and industry is also increasing. Good thermal insulation materials can effectively reduce energy consumption and reduce the operating costs of buildings and industrial equipment. However, existing thermal insulation materials often have some problems. On the one hand, the thermal insulation performance of traditional thermal insulation materials is limited, and it is difficult to meet the increasing demand for thermal insulation. On the other hand, many thermal insulation materials have poor mechanical properties and are prone to damage during use, affecting their service life and thermal insulation effect. Therefore, the development of a carbon-fixing thermal insulation material that has both good thermal insulation properties and high mechanical properties has become a problem that needs to be solved urgently. Summary of the invention

[0003] In order to improve the mechanical strength and thermal insulation capacity of a carbon-fixing thermal insulation material, the present application provides a carbon-fixing thermal insulation material and a preparation method and application thereof.

[0004] The present application provides a carbon-fixing thermal insulation material, which adopts the following technical solution: In a first aspect, a carbon-fixing heat-insulating material comprises the following raw materials in parts by weight: 12-16 parts of ethylene-vinyl acetate copolymer emulsion, 20-30 parts of cellulose acetate, 5-8 parts of thermal insulation filler, 40-50 parts of modified biochar, and 70-80 parts of polylactic acid, wherein the modified biochar is obtained through hydrophobic modification.

[0005] By adopting the above technical scheme, ethylene-vinyl acetate copolymer emulsion and acetate fiber as the base material provide good flexibility and processing performance, ensuring the molding and durability of the carbon-fixing insulation material; the insulating filler and modified biochar form an effective insulation barrier, reducing heat transfer and improving the insulation effect of the material; polylactic acid as the main bio-based plastic not only increases the strength and toughness of the paper cup, but also further improves its biodegradability, achieving a perfect combination of environmental protection and practicality.

[0006] This scheme combines the flexibility of ethylene-vinyl acetate copolymer emulsion, the heat resistance of acetate fiber, the thermal insulation performance of thermal insulation fillers, the carbon fixation and reinforcement effects of modified biochar, and the biodegradability and high strength of polylactic acid to prepare a new carbon-fixing thermal insulation material with excellent thermal insulation performance and good carbon fixation effect. This material not only helps to reduce carbon emissions, but also plays an excellent role in thermal insulation and reinforcement in the fields of construction, automobiles, aerospace, etc., and has broad application prospects.

[0007] Optionally, the modified biochar comprises the following steps: (1) Selecting agricultural waste or forestry residue as reactants, washing, drying, and crushing the reactants, placing them in an oxygen-deficient environment, reacting at 300-700°C and naturally cooling to room temperature to obtain biochar; (2) The obtained biochar is immersed in a modifier solution at 60-80° C. for 1-2 hours, taken out, dried, further crushed, dispersed in water to form a modified biochar suspension, polyacrylamide is added for mixed reaction, and dried using a supercritical fluid as a drying medium to obtain the modified biochar.

[0008] By adopting the above technical solution, through the pyrolysis and activation steps, the porosity and specific surface area of ​​biochar are greatly improved, which not only significantly enhances its adsorption capacity for gases such as carbon dioxide, but also improves its catalytic activity, which helps to further improve the carbon fixation effect of the material. Secondly, the impregnation treatment of the modifier solution effectively changes the surface properties of the biochar, giving it better chemical stability and thermal stability, allowing the modified biochar to maintain excellent performance in high temperature environments. Furthermore, the addition of polyacrylamide promotes the formation of a more stable gel network structure, significantly improves the mechanical strength and overall stability of the biochar, and provides a solid structural support for carbon fixation insulation materials.

[0009] In addition, the rich pore structure of the modified biochar forms an effective air layer in the material. This structural characteristic greatly hinders the transfer of heat, thereby significantly improving the thermal insulation performance of the material. At the same time, after modification and the addition of polyacrylamide, the hydrophobicity of the biochar is significantly improved, effectively preventing the leakage of water molecules and further enhancing the waterproof performance of the carbon-fixing insulation material.

[0010] Optionally, the modified solution is obtained by mixing methyltrimethoxysilane and polyionic liquid in a weight ratio of 2.8-3:0.2-1.

[0011] By adopting the above technical scheme, when methyltrimethoxysilane contacts and reacts with biochar, it can form a dense protective film on the surface of biochar. This protective film can effectively block the transfer of heat, reduce heat convection and radiation, and thus significantly improve the thermal insulation performance of the material. Polyionic liquids can interact with the functional groups on the surface of biochar to form a tight bond. This combination not only enhances the interfacial bonding force between biochar and the modifier, but also enables the modified biochar to be better dispersed and combined in the carbon-fixing insulation material. In addition, the viscoelastic behavior of polyionic liquids helps to form a denser structure, further hindering the transfer of heat and enhancing the thermal insulation effect. At the same time, polyionic liquids and methyltrimethoxysilane act synergistically during the modification process, jointly enhancing the structural stability of biochar, making it less likely to deform or crack in a high temperature environment, and improving the mechanical strength of the material.

[0012] Optionally, the weight ratio of the biochar, modifier solution and polyacrylamide added is 1:2-3:0.1-0.2.

[0013] Optionally, natural vegetable oil is also added during the modification process, and the weight ratio of the natural vegetable oil to the polyacrylamide is 0.2-0.3:1.

[0014] By adopting the above technical solution, the vegetable oil can produce evenly distributed small bubbles under heating conditions. During the modification process, the natural vegetable oil can penetrate into the pores of the biochar, thereby constructing a lightweight porous structure with extremely low thermal conductivity in the material, enhancing the thermal insulation performance of the material. It can also work with methyltrimethoxysilane and polyionic liquid to form a hydrophobic layer, which can effectively block the penetration and erosion of water molecules on the one hand, and on the other hand, can make the modified biochar more stable in the carbon-fixing thermal insulation material.

[0015] Optionally, the thermal insulation filler is hollow alumina balls.

[0016] Optionally, 8-10 parts of microalgae calcium carbonate are also added to the raw materials.

[0017] By adopting the above technical solution, microalgae calcium carbonate has a unique pore structure and low thermal conductivity, which can effectively block the transfer of heat. The microalgae calcium carbonate particles are fine and well dispersed, easy to mix evenly with the raw materials, better embedded in the molding process, forming a more compact structure, further improving the mechanical properties of the material, more durable, not easy to deform, and better able to maintain its shape and structural stability when subjected to external forces.

[0018] In a second aspect, the present application provides a method for preparing a carbon-fixing thermal insulation material, using the following technical solution: A method for preparing a carbon-fixing thermal insulation material comprises the following steps: After heating to 70-80° C. to fully mix the modified biochar and acetate fiber, polylactic acid, thermal insulation filler and ethylene-vinyl acetate copolymer emulsion are added in sequence, heated to 150-180° C., blended and melted, and extruded to obtain the carbon-fixing thermal insulation material.

[0019] By adopting the above technical scheme, the addition of acetate fiber can improve the heat resistance and heat insulation performance of the material, but its hydrophilicity easily absorbs water and allows liquid to pass through. Therefore, the modified biochar is pre-mixed with the acetate fiber and then added to other raw materials for melt blending. This can better wrap the acetate fiber, so that it can have a heat-resistant and heat-insulating effect without affecting the waterproof performance of the material.

[0020] In a third aspect, the present application provides an application of a carbon-fixing thermal insulation material in the manufacture of paper cups.

[0021] By adopting the above technical solution, the prepared paper cup has good heat insulation ability and can well prevent scalding when hot water is poured into it. In addition, the paper cup body made of this material is stronger and is not easy to deform or leak at high temperatures.

[0022] In summary, this application has the following beneficial effects: 1. The introduction of modified biochar in this application not only enhances the carbon fixation capacity of the material, but also effectively hinders the transfer of heat through its rich pore structure, thereby improving the thermal insulation performance. At the same time, the synergistic effect of ethylene-vinyl acetate copolymer emulsion, acetate fiber and polylactic acid ensures the durability of the material, so that the material can still maintain a stable thermal insulation effect and good mechanical properties in a high temperature environment.

[0023] 2. The materials prepared in this application use a large amount of bio-based and renewable raw materials, which significantly reduces carbon emissions and improves the sustainability of the materials. In addition, the biodegradability of the materials is also in line with the current environmental protection trend, which helps to reduce environmental pollution and ecological damage. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with embodiments.

[0025] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0026] Natural vegetable oil was purchased from Jining Fangde Chemical Co., Ltd., natural pine oil product number: HJSJY-5; polyvinyl imidazole was purchased from Wuhan Shuer Biotechnology Co., Ltd., CAS number: 25232-42-2; polyacrylamide was purchased from Gongyi Bibo Water Supply Material Co., Ltd., PAM ion degree 20-70%, model: BIBO-CPAM; Preparation examples of raw materials and / or intermediates Preparation Example 1 A modified biochar, the preparation of which comprises the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) 75 kg of methyltrimethoxysilane and 25 kg of polyvinyl imidazole (polyionic liquid) were mixed to obtain a modifier solution. 50 kg of biochar was soaked and washed in deionized water, then immersed in the modifier solution at 70 °C for reaction for 2 h. After being taken out and dried, the mixture was further crushed and dispersed in water to form a modified biochar suspension. 5 kg of polyacrylamide was added for mixed reaction, and the mixture was dried using supercritical carbon dioxide fluid to obtain modified biochar.

[0027] Preparation Example 2 A modified biochar, the preparation of which comprises the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) 140 kg of methyltrimethoxysilane and 10 kg of polyvinyl imidazole (polyionic liquid) were mixed to obtain a modifier solution. 50 kg of biochar was soaked and washed in deionized water, then immersed in the modifier solution at 60 °C for 2 h. After being taken out and dried, the mixture was further crushed and dispersed in water to form a modified biochar suspension. 10 kg of polyacrylamide was added to the mixture for mixed reaction, and the mixture was dried using supercritical carbon dioxide fluid to obtain modified biochar.

[0028] Preparation Example 3 A modified biochar, the preparation of which comprises the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) 105.5 kg of methyltrimethoxysilane and 21.5 kg of polyvinyl imidazole (polyionic liquid) were mixed to obtain a modifier solution. 50 kg of biochar was soaked and washed in deionized water, then immersed in the modifier solution at 80 °C for reaction for 1 hour. After being taken out and dried, the mixture was further crushed and dispersed in water to form a modified biochar suspension. 8 kg of polyacrylamide was added for mixed reaction, and the mixture was dried using supercritical carbon dioxide fluid to obtain modified biochar.

[0029] Preparation Example 4 A modified biochar, which is different from Preparation Example 1 in that 1 kg of natural vegetable oil is added after adding polyacrylamide in this Preparation Example, specifically comprising the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) 75 kg of methyltrimethoxysilane and 25 kg of polyvinyl imidazole (polyionic liquid) were mixed to obtain a modifier solution. 50 kg of biochar was soaked and cleaned in deionized water, then immersed in the modifier solution at 70 °C for reaction for 2 h. After being taken out and dried, it was further crushed and dispersed in water to form a modified biochar suspension. 5 kg of polyacrylamide and 1 kg of natural vegetable oil were added to the mixture for reaction, and the mixture was dried using supercritical carbon dioxide fluid to obtain modified biochar.

[0030] Preparation Example 5 A modified biochar, which is different from Preparation Example 4 in that 1.5 kg of natural vegetable oil is added after adding polyacrylamide in this Preparation Example.

[0031] Preparation Example 6 A modified biochar, which is different from Preparation Example 1 in that no polyionic liquid is added during the modification process of this Preparation Example, and the preparation comprises the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) Take 100 kg of methyltrimethoxysilane as the modifier solution, take 50 kg of biochar, soak it in deionized water and wash it, immerse it in the modifier solution at 70 ° C for reaction and immersion for 2 hours, take it out and dry it, further crush it, disperse it in water to form a modified biochar suspension, add 5 kg of polyacrylamide to mix and react, and use supercritical carbon dioxide fluid to dry it to obtain modified biochar.

[0032] Preparation Example 7 A modified biochar, which is different from Preparation Example 1 in that no methyltrimethoxysilane is added during the modification process in this Preparation Example, and the preparation comprises the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) Take 100 kg of polyvinyl imidazole (polyionic liquid) as the modifier solution, take 50 kg of biochar, soak it in deionized water and wash it, immerse it in the modifier solution at 70 ° C for reaction and immersion for 2 hours, take it out and dry it, further crush it, disperse it in water to form a modified biochar suspension, add 5 kg of polyacrylamide to mix and react, and use supercritical carbon dioxide fluid to dry it to obtain modified biochar.

[0033] Preparation Example 8 A modified biochar, which is different from Preparation Example 1 in that no polyacrylamide is added during the modification process in this Preparation Example, and the preparation comprises the following steps: (1) Rice husk is selected as a reactant, the reactant is washed, dried at 70°C for 24 hours to remove moisture, crushed, placed in a muffle furnace, filled with nitrogen to ensure sintering under anoxic conditions, the temperature is raised to 500°C at a heating rate of 10°C / min for 2 hours, and naturally cooled to room temperature to obtain biochar; (2) 75 kg of methyltrimethoxysilane and 25 kg of polyvinyl imidazole (polyionic liquid) were mixed to obtain a modifier solution. 50 kg of biochar was soaked and washed with deionized water, then immersed in the modifier solution at 70 °C for 2 h. After being taken out, dried, and further crushed, modified biochar was obtained. Example

[0034] Example 1 A carbon-fixing heat-insulating material, the preparation of which comprises the following steps: After heating to 75°C and thoroughly mixing 45 kg of the modified biochar obtained in Preparation Example 1 with 25 kg of acetate fiber, 80 kg of polylactic acid, 6.5 kg of alumina hollow spheres and 14 kg of ethylene-vinyl acetate copolymer emulsion were added in sequence, and then heated to 180°C in a twin-screw extruder to blend and melt, and extruded to obtain the carbon-fixing insulation material.

[0035] An application of a carbon-fixing heat-insulating material in a heat-insulating paper cup specifically comprises the following steps: Add the carbon-fixed insulation material into the barrel of the laminating machine, heat it to 180°C and melt it, then coat the base paper with a coating amount of 12g / m 2The base paper thickness is 0.4mm. The prepared carbon-fixed insulation material is coated on the surface of the base paper to form an outer cup coated paper. The outer cup coated paper is cut into fan-shaped cup pieces by a die-cutting machine and then rolled into shape. The cup bottom and the rolled mouth are bonded to obtain an insulating paper cup.

[0036] Example 2 A carbon-fixing heat-insulating material, the preparation of which comprises the following steps: After heating to 70°C and thoroughly mixing 40 kg of the modified biochar obtained in Preparation Example 2 with 30 kg of acetate fiber, 75 kg of polylactic acid, 8 kg of hollow alumina balls and 16 kg of ethylene-vinyl acetate copolymer emulsion were added in sequence, and then heated to 150°C in a twin-screw extruder to blend and melt, and extrude to obtain the carbon-fixing insulation material.

[0037] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0038] Example 3 A carbon-fixing heat-insulating material, the preparation of which comprises the following steps: After heating to 80°C and thoroughly mixing 50 kg of the modified biochar obtained in Preparation Example 3 with 20 kg of acetate fiber, 70 kg of polylactic acid, 5 kg of hollow alumina balls and 12 kg of ethylene-vinyl acetate copolymer emulsion were added in sequence, and then heated to 160°C in a twin-screw extruder to blend and melt, and extruded to obtain the carbon-fixing insulation material.

[0039] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0040] Example 4 A carbon-fixing thermal insulation material, which is different from Example 1 in that the modified biochar prepared in Preparation Example 4 is used in this example.

[0041] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0042] Example 5 A carbon-fixing thermal insulation material, which is different from Example 1 in that the modified biochar prepared in Preparation Example 5 is used in this example.

[0043] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0044] Example 6 A carbon-fixing thermal insulation material, which is different from Example 1 in that the modified biochar prepared in Preparation Example 6 is used in this example.

[0045] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0046] Example 7 A carbon-fixing thermal insulation material, which is different from Example 1 in that the modified biochar prepared in Preparation Example 7 is used in this example.

[0047] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0048] Example 8 A carbon-fixing thermal insulation material, which is different from Example 1 in that the modified biochar prepared in Preparation Example 8 is used in this example.

[0049] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0050] Example 9 A carbon-fixing heat-insulating material, which is different from Example 1 in that 8 kg of microalgae calcium carbonate is also added in this example.

[0051] Example 10 A carbon-fixing heat-insulating material, which is different from Example 1 in that 9 kg of microalgae calcium carbonate is also added in this example.

[0052] Embodiment 11 A carbon-fixing heat-insulating material, which is different from Example 1 in that 10 kg of microalgae calcium carbonate is also added in this example.

[0053] Comparative Example Comparative Example 1 A carbon-fixing thermal insulation material, which is different from Example 1 in that an equal amount of unmodified biochar is used to replace the modified biochar in this comparative example.

[0054] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0055] Comparative Example 2 A carbon-fixing thermal insulation material, which is different from Example 1 in that acetate fiber is not added in this comparative example.

[0056] The application of a carbon-fixed insulation material in an insulating paper cup is shown in Example 1.

[0057] Comparative Example 3 A paper cup is not coated with the heat-insulating material prepared in the present application, but is coated with commercially available degradable PLA coated paper for paper cups.

[0058] Performance testing Detection method / test method Referring to the relevant capacity standards in GB / T 27590-2022 "Paper Cup", a paper cup with a capacity of 250 ml was prepared according to the application of Example 1 and tested; Paper cup leakage performance test: Select a suitable test solution according to the requirements of GB / T 27590-2022 "Paper Cup", add the test solution to about 6mm from the cup mouth plane or the capacity mark, and then place the paper cup containing the test solution on a dry glass plate. To prevent the water vapor generated in the contact area between the bottom of the cup and the dry glass plate from affecting the inspection results, place the paper cup above two parallel bars on the surface of the dry glass plate or flat plate, so that there is a certain distance between the bottom of the paper cup and the surface of the dry glass plate or flat plate. Let it stand for 24 hours and observe whether there is any watermark on the glass plate or flat plate; Mechanical strength: Refer to the method in Appendix A of GB / T 27590-2022 "Paper Cups" to test the body stiffness of paper cups. Place the paper cup to be tested on the movable sample stand of the cup body stiffness tester. Adjust the height of the movable sample stand so that the probe is close to the side wall of the paper cup. The vertical distance between the probe and the bottom of the cup is about 2 / 3 of the cup height. The cup body seam of the paper cup to be tested should face the tester. Start the instrument and measure the body stiffness. Measure 5 paper cups for each sample and take the average value to represent the test result, accurate to 0.01N; Thermal insulation performance test: refer to the method described in Appendix A of GB / T 31480-2015 to test the thermal conductivity of the paper cup; place the material on a heat source at a certain temperature, measure the temperature change record on the other side of the material, and evaluate the thermal insulation performance of the material.

[0059] Table 1 Test data Cup body stiffness / N <![CDATA[Thermal conductivity 10 -2 W / m·k]]> Temperature change / ℃ Leakage performance Example 1 125.43 0.21 65.23 pass Example 2 123.56 0.23 64.87 pass Example 3 124.76 0.22 65.12 pass Example 4 128.14 0.19 66.34 pass Example 5 128.89 0.18 66.78 pass Example 6 115.32 0.28 61.45 pass Example 7 110.67 0.31 60.98 pass Example 8 108.9 0.33 62.12 pass Example 9 138.23 0.17 67.12 pass Example 10 140.56 0.16 67.45 pass Embodiment 11 142.89 0.15 67.78 pass Comparative Example 1 101.43 0.75 55.12 Failed Comparative Example 2 107.23 0.42 58.34 pass Comparative Example 3 85.67 1.45 50.45 Failed Combining Examples 1-3 and Comparative Example 1 and Table 1, it can be seen that the test results of Examples 1-3 are better than those of Comparative Example 1, indicating that when the biochar is not modified, its thermal insulation ability is significantly reduced and its waterproof property is poor. The present application not only improves the porosity inside the biochar through the modification of the biochar, forming a good insulating air layer, greatly hindering heat transfer and improving the thermal insulation effect, but also improves the hydrophobic and waterproof ability of the biochar through modification, thereby enhancing the waterproof effect of the material.

[0060] Combining Examples 1-3 and Comparative Example 2 and Table 1, it can be seen that the test results of Examples 1-3 are better than those of Comparative Example 2, indicating that the addition of acetate fiber can improve the heat resistance and mechanical strength of the material, thereby giving the material good thermal insulation performance and mechanical strength.

[0061] It can be seen from Examples 1-5 and Table 1 that the test results of Examples 4-5 are better than those of Examples 1-3, indicating that the addition of natural vegetable oil is conducive to the formation of a porous structure and further optimizes the internal structure of the modified biochar, thereby reducing heat transfer and improving thermal insulation performance. At the same time, the waterproof component in the vegetable oil can further give the material good waterproof properties.

[0062] Combining Example 1 with Example 6 and Table 1, it can be seen that the test results of Example 1 are better than those of Example 6. The addition of polyionic liquid can enhance the interfacial bonding force between biochar and the modifier, help form a material with a tighter structure, and improve the thermal insulation capacity of the material.

[0063] Combining Example 1 with Example 7 and Table 1, it can be seen that the test results of Example 1 are better than those of Example 7. The addition of methyltrimethoxysilane can form a dense protective film on the surface of biochar, thereby effectively blocking the transfer of heat, reducing heat convection and radiation, and improving the thermal insulation performance of the material.

[0064] Combining Example 1 with Example 8 and Table 1, it can be seen that the test results of Example 1 are better than those of Example 8, indicating that the addition of polyacrylamide can help the gelation of biochar, contribute to the formation of internal voids in the modified biochar, form an insulating air layer, block heat convection, inhibit heat conduction and heat radiation, and thus greatly improve the heat resistance and insulation properties of the material.

[0065] Combining Example 1 with Examples 9-11 and Table 1, it can be seen that the test results of Examples 9-11 are better than those of Example 1. The pore structure and low thermal conductivity of the microalgae calcium carbonate help to block the transfer of heat and improve the thermal insulation performance of the material.

[0066] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A carbon-fixing thermal insulation material, characterized in that: The composition comprises the following raw materials in parts by weight: 12-16 parts of ethylene-vinyl acetate copolymer emulsion, 20-30 parts of cellulose acetate, 5-8 parts of thermal insulation filler, 40-50 parts of modified biochar, and 70-80 parts of polylactic acid, wherein the modified biochar is obtained through hydrophobic modification.

2. The carbon-fixing thermal insulation material according to claim 1, characterized in that: The modified biochar comprises the following steps: (1) Select agricultural waste or forestry residue as reactants, wash, dry and crush the reactants, place them in an oxygen-deficient environment, react at 300-700°C and naturally cool to room temperature to obtain biochar; (2) The obtained biochar is immersed in a modifier solution at 60-80°C for 1-2 hours, taken out, dried, further crushed, and dispersed in water to form a modified biochar suspension, polyacrylamide is added to the mixture for reaction, and supercritical fluid is used as a drying medium to dry the biochar to obtain the modified biochar.

3. The carbon-fixing thermal insulation material according to claim 2, characterized in that: The modified solution is obtained by mixing methyltrimethoxysilane and polyionic liquid in a weight ratio of 2.8-3:0.2-1.

4. The carbon-fixing thermal insulation material according to claim 2, characterized in that: The weight ratio of the biochar, the modifier solution and the polyacrylamide added is 1:2-3:0.1-0.

2.

5. The carbon-fixing thermal insulation material according to claim 2, characterized in that: Natural vegetable oil is also added during the modification process, and the weight ratio of the natural vegetable oil to the polyacrylamide is 0.2-0.3:

1.

6. The carbon-fixing thermal insulation material according to claim 1, characterized in that: The heat-insulating filler is hollow alumina balls.

7. The carbon-fixing thermal insulation material according to claim 1, characterized in that: 8-10 parts of microalgae calcium carbonate are also added to the raw materials.

8. A method for preparing a carbon-fixing thermal insulation material according to any one of claims 1 to 7, characterized in that: The steps include: After heating to 70-80° C. to fully mix the modified biochar and acetate fiber, polylactic acid, thermal insulation filler and ethylene-vinyl acetate copolymer emulsion are added in sequence, heated to 150-180° C., blended and melted, and extruded to obtain the carbon-fixing thermal insulation material.

9. The carbon-fixing thermal insulation material according to any one of claims 1 to 7 or the carbon-fixing thermal insulation material obtained by the preparation method according to claim 8 is used for the specific application of manufacturing thermal insulation paper cups.