A degradable environment-friendly carbon-based composite material packaging box and a preparation method thereof

Abstract

The application discloses a degradable environment-friendly carbon-based composite material packaging box and a preparation method thereof, and relates to the field of preparation of packaging boxes.The packaging box comprises modified shape memory polymer particles, modified carbon-based materials, lignin and degradable plasticizers.The degradable environment-friendly carbon-based composite material packaging box and the preparation method thereof have the advantages that the shape memory polymer particles are cross-linked and modified and degradability is regulated, the mechanical strength and shape memory recovery rate of the polymer are improved, the degradation rate can be flexibly regulated, the prepared packaging box has excellent degradability, mechanical strength and shape memory function, the pain points of existing degradable packaging boxes, such as easy breakage and lack of repair function, are solved, the packaging box can restore to the original state through heating after extrusion deformation, the repeated utilization rate of the packaging is improved, and environmental pollution is reduced.

Description

Technical Field

[0001] This invention relates to the field of packaging box manufacturing, and particularly to a biodegradable and environmentally friendly carbon-based composite material packaging box and its manufacturing method. Background Technology

[0002] With the popularization of environmental protection concepts and the advancement of relevant policies, biodegradable composite material packaging boxes are gradually replacing traditional non-biodegradable packaging and becoming the mainstream of industry development.

[0003] Currently, existing biodegradable packaging boxes are mainly made of polymer materials such as pure polylactic acid (PLA) or ordinary carbon-based composite polymer materials, which have significant technical defects: pure PLA packaging boxes lack mechanical strength, are easily damaged, and have poor impact resistance, failing to meet the needs of heavy-duty packaging; while ordinary carbon-based composite biodegradable packaging boxes offer some improvement in mechanical properties, the poor compatibility between carbon-based materials and the polymer matrix leads to agglomeration, resulting in unstable material performance. Furthermore, neither of these types of packaging boxes possesses shape memory functionality; if deformation occurs during use, it cannot be repaired and must be discarded, reducing the reusability of packaging and increasing environmental pressure. Simultaneously, the current manufacturing process uses a simple combination of carbon-based materials and polymer materials without specific modification treatments, failing to achieve synergistic performance improvements and making it difficult to balance biodegradability, mechanical strength, and ease of use, thus failing to meet the packaging needs of different scenarios.

[0004] Therefore, it is necessary to propose a biodegradable and environmentally friendly carbon-based composite material packaging box and its preparation method to solve the above problems. Summary of the Invention

[0005] The main objective of this invention is to provide a biodegradable and environmentally friendly carbon-based composite material packaging box and its preparation method, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A biodegradable and environmentally friendly carbon-based composite packaging box includes modified shape memory polymer particles, modified carbon-based materials, lignin, and biodegradable plasticizer, comprising, by weight: 55-65 parts of modified shape memory polymer particles, 25-35 parts of modified carbon-based materials, 4-6 parts of lignin, and 4-6 parts of biodegradable plasticizer.

[0007] Preferably, the mass fractions include: 60 parts of modified shape memory polymer particles, 30 parts of modified carbon-based material, 5 parts of lignin, and 5 parts of biodegradable plasticizer.

[0008] Preferably, the components by weight are: 55 parts modified shape memory polymer particles, 35 parts modified carbon-based material, 6 parts lignin, and 4 parts biodegradable plasticizer.

[0009] Preferably, the components by weight are: 65 parts modified shape memory polymer particles, 25 parts modified carbon-based material, 4 parts lignin, and 6 parts biodegradable plasticizer.

[0010] A method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box includes the following steps: S1: Raw material pretreatment, specifically including the following steps: S101: Pretreatment of carbon-based raw materials. Corn straw biomass carbon powder with a particle size of 500 mesh is selected as the carbon-based raw material. It is placed in a vacuum drying oven and dried at 80°C for 4 hours. After drying, it is pulverized again by a high-speed pulverizer and then screened through a 1000-mesh sieve to obtain pure biomass carbon powder for use. S102: Shape memory polymer pretreatment. Biodegradable polycaprolactone was selected as the shape memory polymer. It was cut into particles with a particle size of 5 mm and soaked in anhydrous ethanol for 20 minutes to remove surface oil and impurities. After soaking, the particles were taken out and placed in a vacuum drying oven and dried at 60°C for 2 hours to completely remove ethanol and water, and polycaprolactone particles were obtained for later use. S103: Pretreatment of auxiliary raw materials: Biodegradable polylactic acid is selected as an auxiliary binder, which is crushed into powder with a particle size controlled at 800 mesh, and dried in a drying oven at 65°C for 3 hours; lignin is selected as a reinforcing agent, which is crushed and passed through an 800-mesh sieve to remove impurities, and is then ready for use; After pretreatment of all auxiliary raw materials, they are stored separately in sealed containers to avoid moisture absorption. S2: Carbon-based material modification, used to improve the compatibility of carbon-based materials with shape memory polymers through a dedicated modification process, while also enhancing their dispersibility; S3: Shape memory polymer modification, used to optimize the shape memory and biodegradability of polycaprolactone; S4: Composite melt blending, used to fully fuse carbon-based materials with modified shape memory polymers; S5: Molding process, used to process composite melt into a preset shape of packaging box; S6: Post-processing, used to optimize the performance of packaging boxes, improving their mechanical strength, shape memory properties and biodegradability.

[0011] Preferably, in step S2, the specific modification process includes the following steps: S201: Surface activation treatment. The biomass carbon powder pretreated by S1 is placed in a plasma treatment instrument, the plasma power is adjusted to 300W, and the treatment time is 15 minutes. The surface of the carbon powder is generated by plasma bombardment. After the treatment is completed, it is quickly taken out and placed in a sealed container to cool to room temperature. S202: Coupling modification treatment: Prepare a 5% (w / w) silane coupling agent solution, add the activated biomass carbon powder to the solution, and stir at 300 r / min for 60 minutes at room temperature to ensure that the coupling agent is uniformly coated on the carbon powder surface. After stirring, use a centrifuge to centrifuge at 8000 r / min for 15 minutes to separate the modified carbon powder, and place it in a vacuum drying oven at 70℃ for 3 hours to obtain the coupling modified carbon-based material for later use. S203: Dispersion optimization treatment. The dried coupling modified carbon-based material is placed in a high-speed disperser, a small amount of pretreated lignin is added, the dispersion speed is 5000 r / min, and the dispersion time is 20 minutes, so that the lignin is uniformly attached to the surface of the carbon-based material.

[0012] Preferably, step S3 specifically includes the following steps: S301: Crosslinking modification treatment. The polycaprolactone particles pretreated with S1 are placed in a reactor, and a crosslinking agent with a mass fraction of 3% is added. The reactor temperature is adjusted to 120℃, the stirring speed is 200r / min, and the reaction is carried out at a constant temperature for 40 minutes. S302: Degradability control treatment. Pretreated polylactic acid powder is added to the reaction vessel and stirred for 30 minutes to ensure that the polylactic acid and the cross-linked polycaprolactone are fully mixed. After the reaction is completed, the mixture is taken out, cooled to room temperature, and crushed into particles with a particle size of 3 mm to obtain modified shape memory polymer particles for later use.

[0013] Preferably, step S4 specifically includes the following steps: S401: Raw material mixing ratio: According to the mass parts, take the modified shape memory polymer particles, modified carbon-based materials, lignin, and biodegradable plasticizer, put them into a high-speed mixer, stir at a stirring speed of 4000 r / min, stir at room temperature for 30 minutes to make all raw materials uniformly mixed to obtain mixed raw materials; S402: Melt blending. The mixed raw materials are added to a twin-screw extruder. The temperatures of each section of the extruder are adjusted: the feed section temperature is 110℃, the melt section temperature is 130℃, and the discharge section temperature is 120℃. The screw speed is 250r / min, and the melt blending time is 25 minutes to form a uniform composite melt. S403: Melt filtration. The composite melt is passed through a 1200-mesh filter screen to remove impurities and incompletely melted particles. The filtered composite melt is then placed in an insulated container and kept at 125°C for later use.

[0014] Preferably, step S5 specifically includes the following steps: S501: Mold pretreatment. Select a special mold for packaging boxes, wipe the mold surface clean, apply a layer of biodegradable release agent, and then put the mold into a constant temperature oven and preheat it at 80℃ for 30 minutes. S502: Injection molding, the heat-insulated composite melt is injected into the preheated mold, the injection pressure is controlled at 15MPa, the injection speed is 50mm / s, after injection, the pressure inside the mold is kept constant, and the temperature is kept constant for 20 minutes to allow the composite melt to fully solidify and form the initial blank of the packaging box. S503: Demolding process. After cooling, open the mold, take out the initial blank of the packaging box, wipe the surface of the initial blank with a clean cloth to remove residual mold release agent and impurities, and obtain the semi-finished packaging box.

[0015] Preferably, step S6 specifically includes the following steps: S601: Shape memory shaping process: Place the semi-finished packaging box in a constant temperature chamber, adjust the temperature to 70℃, keep it at a constant temperature for 15 minutes, and then slowly cool it to room temperature; S602: Surface strengthening treatment. Place the shaped packaging box semi-finished product into the plasma treatment instrument, adjust the power to 250W, and the treatment time to 10 minutes. After the treatment is completed, take it out and cool it to room temperature. For constant temperature curing, place the post-treated packaging box in a vacuum drying oven, adjust the temperature to 60℃, the vacuum degree to 0.08MPa, and cure at a constant temperature for 8 hours.

[0016] Compared with the prior art, the present invention provides a biodegradable and environmentally friendly carbon-based composite material packaging box and its preparation method, which has the following beneficial effects: The biodegradable and environmentally friendly carbon-based composite packaging box and its preparation method effectively improve the compatibility and dispersibility of carbon-based materials with shape memory polymers by performing plasma surface activation, coupling modification and dispersibility optimization on carbon-based materials, avoiding agglomeration and making the composite material performance more stable.

[0017] This biodegradable and environmentally friendly carbon-based composite packaging box and its preparation method improve the mechanical strength and shape memory recovery rate of the polymer by crosslinking modification and degradability control, and achieve flexible control of the degradation rate to adapt to different usage scenarios.

[0018] This invention relates to a biodegradable and environmentally friendly carbon-based composite material packaging box and its preparation method. The resulting packaging box possesses excellent biodegradability, mechanical strength, and shape memory function. It addresses the shortcomings of existing biodegradable packaging boxes, such as easy breakage and lack of repair capabilities. After being deformed by compression, the box can be restored to its original shape by heating, thereby improving the reusability of the packaging and reducing environmental pollution.

[0019] The biodegradable and environmentally friendly carbon-based composite material packaging box and its preparation method have specific and highly operable steps in the entire preparation process. The raw materials are readily available and environmentally friendly, enabling large-scale production. The prepared packaging boxes are suitable for various packaging scenarios such as general use, heavy objects, short-term use, and lightweight packaging, making them highly practical. Attached Figure Description

[0020] Figure 1 This is a flowchart of the preparation process of the present invention. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0022] A biodegradable and environmentally friendly carbon-based composite packaging box includes modified shape memory polymer particles, modified carbon-based materials, lignin, and biodegradable plasticizer, comprising, by weight: 55-65 parts of modified shape memory polymer particles, 25-35 parts of modified carbon-based materials, 4-6 parts of lignin, and 4-6 parts of biodegradable plasticizer.

[0023] The mass fractions include: 60 parts modified shape memory polymer particles, 30 parts modified carbon-based material, 5 parts lignin, and 5 parts biodegradable plasticizer.

[0024] The composition by weight is as follows: 55 parts modified shape memory polymer particles, 35 parts modified carbon-based material, 6 parts lignin, and 4 parts biodegradable plasticizer.

[0025] The mixture contains 65 parts of modified shape memory polymer particles, 25 parts of modified carbon-based materials, 4 parts of lignin, and 6 parts of biodegradable plasticizer.

[0026] Example 1: like Figure 1 As shown, a method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box includes the following steps: S1: Raw material pretreatment, specifically including the following steps: S101: Pretreatment of carbon-based raw materials. Corn straw biomass carbon powder with a particle size of 500 mesh is selected as the carbon-based raw material. It is placed in a vacuum drying oven and dried at 80°C for 4 hours. After drying, it is pulverized again by a high-speed pulverizer and then screened through a 1000-mesh sieve to obtain pure biomass carbon powder for use. S102: Shape memory polymer pretreatment. Biodegradable polycaprolactone was selected as the shape memory polymer. It was cut into particles with a particle size of 5 mm and soaked in anhydrous ethanol for 20 minutes to remove surface oil and impurities. After soaking, the particles were taken out and placed in a vacuum drying oven and dried at 60°C for 2 hours to completely remove ethanol and water, and polycaprolactone particles were obtained for later use. S103: Pretreatment of auxiliary raw materials: Biodegradable polylactic acid is selected as an auxiliary binder, which is crushed into powder with a particle size controlled at 800 mesh, and dried in a drying oven at 65°C for 3 hours; lignin is selected as a reinforcing agent, which is crushed and passed through an 800-mesh sieve to remove impurities, and is then ready for use; After pretreatment of all auxiliary raw materials, they are stored separately in sealed containers to avoid moisture absorption. S2: Carbon-based material modification, used to improve the compatibility of carbon-based materials with shape memory polymers and enhance their dispersibility through a dedicated modification process. The dedicated modification process specifically includes the following steps: S201: Surface activation treatment. The biomass carbon powder pretreated by S1 is placed in a plasma treatment instrument. The plasma power is adjusted to 300W and the treatment time is 15 minutes. The plasma bombardment causes active groups such as hydroxyl and carboxyl groups to be generated on the surface of the carbon powder, which enhances its binding ability with the polymer. After the treatment is completed, it is quickly taken out and placed in a sealed container to cool to room temperature to avoid loss of active groups. S202: Coupling modification treatment: Prepare a 5% (w / w) silane coupling agent solution, add the activated biomass carbon powder to the solution, and stir at 300 r / min for 60 minutes at room temperature to ensure that the coupling agent is uniformly coated on the carbon powder surface. After stirring, use a centrifuge to centrifuge at 8000 r / min for 15 minutes to separate the modified carbon powder, and place it in a vacuum drying oven at 70℃ for 3 hours to obtain the coupling modified carbon-based material for later use. S203: Dispersion optimization treatment. The dried coupling modified carbon-based material is placed in a high-speed disperser, and a small amount of pretreated lignin is added. The dispersion speed is 5000 r / min and the dispersion time is 20 minutes. This allows the lignin to be uniformly attached to the surface of the carbon-based material, further improving its dispersibility in the subsequent melt blending process and avoiding agglomeration. S3: Shape memory polymer modification, used to optimize the shape memory and biodegradability of polycaprolactone, specifically including the following steps: S301: Crosslinking modification treatment. The pretreated polycaprolactone particles of S1 are placed in a reactor, and a crosslinking agent with a mass fraction of 3% is added. The reactor temperature is adjusted to 120℃, the stirring speed is 200r / min, and the reaction is carried out at a constant temperature for 40 minutes. The mechanical strength and shape memory recovery rate of polycaprolactone are improved through the crosslinking reaction, ensuring that it is not easily deformed during subsequent processing and use. S302: Degradability control treatment. Pretreated polylactic acid powder is added to the reactor and stirred for 30 minutes to fully mix the polylactic acid with the cross-linked polycaprolactone. The high degradability of polylactic acid is used to control the degradation rate of the overall polymer and improve the adhesion performance of the polymer, laying the foundation for subsequent composite with carbon-based materials. After the reaction is completed, the mixture is taken out, cooled to room temperature, and crushed into particles with a particle size of 3 mm to obtain modified shape memory polymer particles for later use. S4: Composite melt blending, used to fully fuse carbon-based materials with modified shape memory polymers, specifically including the following steps: S401: Mix the raw materials according to the following proportions: Take 60 parts by mass of modified shape memory polymer particles, 30 parts by mass of modified carbon-based material, 5 parts by mass of lignin, and 5 parts by mass of biodegradable plasticizer. Take the modified shape memory polymer particles, modified carbon-based material, lignin, and biodegradable plasticizer, put them into a high-speed mixer, stir at a stirring speed of 4000 r / min, and stir at room temperature for 30 minutes to make all raw materials uniformly mixed to obtain the mixed raw materials. S402: Melt blending. The mixed raw materials are added to a twin-screw extruder. The temperatures of each section of the extruder are adjusted: the feed section temperature is 110℃, the melt section temperature is 130℃, and the discharge section temperature is 120℃. The screw speed is 250 r / min, and the melt blending time is 25 minutes. Through the shearing action of the screw, the modified carbon-based material is uniformly dispersed in the modified shape memory polymer matrix to form a uniform composite melt. S403: Melt filtration. The composite melt is passed through a 1200-mesh filter screen to remove impurities and incompletely melted particles. The filtered composite melt is then placed in an insulated container and kept at 125°C for later use. S5: Forming process, used to process the composite melt into a preset shape of a packaging box, specifically including the following steps: S501: Mold pretreatment. Use a special mold for packaging boxes. Wipe the mold surface clean and apply a layer of biodegradable release agent. Then put the mold into a constant temperature oven and preheat it at 80℃ for 30 minutes to prevent the composite melt from sticking to the mold and to ensure that the surface of the packaged box after molding is smooth. S502: Injection molding, the heat-insulated composite melt is injected into the preheated mold, the injection pressure is controlled at 15MPa, the injection speed is 50mm / s, after injection, the pressure inside the mold is kept constant, and the temperature is kept constant for 20 minutes to allow the composite melt to fully solidify and form the initial blank of the packaging box. S503: Demolding process. After cooling, open the mold, take out the packaging box blank, wipe the surface of the blank with a clean cloth to remove residual mold release agent and impurities, and obtain the packaging box semi-finished product. S6: Post-processing, used to optimize the performance of the packaging box, improving its mechanical strength, shape memory properties, and biodegradability, specifically including the following steps: S601: Shape memory shaping process. The semi-finished packaging box is placed in a constant temperature chamber, the temperature is adjusted to 70℃, and it is kept at a constant temperature for 15 minutes. Then it is slowly cooled to room temperature. Through this process, the shape of the packaging box is fixed, its shape memory recovery rate is improved, and it is ensured that the packaging box can be restored to its original shape by heating after being squeezed and deformed. S602: Surface strengthening treatment. The shaped packaging box semi-finished product is placed in a plasma treatment instrument, the power is adjusted to 250W, and the treatment time is 10 minutes. This further improves the density and wear resistance of the packaging box surface, while enhancing its surface hydrophilicity, making it easier to clean during subsequent use. After the treatment is completed, it is taken out and cooled to room temperature. Constant temperature curing involves placing the post-treated packaging box into a vacuum drying oven, adjusting the temperature to 60℃, the vacuum degree to 0.08MPa, and curing at a constant temperature for 8 hours. This allows the molecules in the composite system to fully cross-link, further enhancing the mechanical strength and shape memory stability of the packaging box, while also accelerating the evaporation of residual moisture inside the material.

[0027] Example 2: like Figure 1 As shown, a method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box includes the following steps: S1: Raw material pretreatment, specifically including the following steps: S101: Pretreatment of carbon-based raw materials. Corn straw biomass carbon powder with a particle size of 500 mesh is selected as the carbon-based raw material. It is placed in a vacuum drying oven and dried at 80°C for 4 hours. After drying, it is pulverized again by a high-speed pulverizer and then screened through a 1000-mesh sieve to obtain pure biomass carbon powder for use. S102: Shape memory polymer pretreatment. Biodegradable polycaprolactone was selected as the shape memory polymer. It was cut into particles with a particle size of 5 mm and soaked in anhydrous ethanol for 20 minutes to remove surface oil and impurities. After soaking, the particles were taken out and placed in a vacuum drying oven and dried at 60°C for 2 hours to completely remove ethanol and water, and polycaprolactone particles were obtained for later use. S103: Pretreatment of auxiliary raw materials: Biodegradable polylactic acid is selected as an auxiliary binder, which is crushed into powder with a particle size controlled at 800 mesh, and dried in a drying oven at 65°C for 3 hours; lignin is selected as a reinforcing agent, which is crushed and passed through an 800-mesh sieve to remove impurities, and is then ready for use; After pretreatment of all auxiliary raw materials, they are stored separately in sealed containers to avoid moisture absorption. S2: Carbon-based material modification, used to improve the compatibility of carbon-based materials with shape memory polymers and enhance their dispersibility through a dedicated modification process. The dedicated modification process specifically includes the following steps: S201: Surface activation treatment. The biomass carbon powder pretreated by S1 is placed in a plasma treatment instrument. The plasma power is adjusted to 300W and the treatment time is 15 minutes. The plasma bombardment causes active groups such as hydroxyl and carboxyl groups to be generated on the surface of the carbon powder, which enhances its binding ability with the polymer. After the treatment is completed, it is quickly taken out and placed in a sealed container to cool to room temperature to avoid loss of active groups. S202: Coupling modification treatment: Prepare a 5% (w / w) silane coupling agent solution, add the activated biomass carbon powder to the solution, and stir at 300 r / min for 60 minutes at room temperature to ensure that the coupling agent is uniformly coated on the carbon powder surface. After stirring, use a centrifuge to centrifuge at 8000 r / min for 15 minutes to separate the modified carbon powder, and place it in a vacuum drying oven at 70℃ for 3 hours to obtain the coupling modified carbon-based material for later use. S203: Dispersion optimization treatment. The dried coupling modified carbon-based material is placed in a high-speed disperser, and a small amount of pretreated lignin is added. The dispersion speed is 5000 r / min and the dispersion time is 20 minutes. This allows the lignin to be uniformly attached to the surface of the carbon-based material, further improving its dispersibility in the subsequent melt blending process and avoiding agglomeration. S3: Shape memory polymer modification, used to optimize the shape memory and biodegradability of polycaprolactone, specifically including the following steps: S301: Crosslinking modification treatment. The pretreated polycaprolactone particles of S1 are placed in a reactor, and a crosslinking agent with a mass fraction of 3% is added. The reactor temperature is adjusted to 120℃, the stirring speed is 200r / min, and the reaction is carried out at a constant temperature for 40 minutes. The mechanical strength and shape memory recovery rate of polycaprolactone are improved through the crosslinking reaction, ensuring that it is not easily deformed during subsequent processing and use. S302: Degradability control treatment. Pretreated polylactic acid powder is added to the reactor and stirred for 30 minutes to fully mix the polylactic acid with the cross-linked polycaprolactone. The high degradability of polylactic acid is used to control the degradation rate of the overall polymer and improve the adhesion performance of the polymer, laying the foundation for subsequent composite with carbon-based materials. After the reaction is completed, the mixture is taken out, cooled to room temperature, and crushed into particles with a particle size of 3 mm to obtain modified shape memory polymer particles for later use. S4: Composite melt blending, used to fully fuse carbon-based materials with modified shape memory polymers, specifically including the following steps: S401: Mix the raw materials according to the following proportions: Take 55 parts of modified shape memory polymer particles, 35 parts of modified carbon-based material, 6 parts of lignin, and 4 parts of biodegradable plasticizer by mass. Take the modified shape memory polymer particles, modified carbon-based material, lignin, and biodegradable plasticizer, put them into a high-speed mixer, stir at a stirring speed of 4000 r / min, and stir at room temperature for 30 minutes to make all raw materials uniformly mixed to obtain the mixed raw materials. S402: Melt blending. The mixed raw materials are added to a twin-screw extruder. The temperatures of each section of the extruder are adjusted: the feed section temperature is 110℃, the melt section temperature is 130℃, and the discharge section temperature is 120℃. The screw speed is 250 r / min, and the melt blending time is 25 minutes. Through the shearing action of the screw, the modified carbon-based material is uniformly dispersed in the modified shape memory polymer matrix to form a uniform composite melt. S403: Melt filtration. The composite melt is passed through a 1200-mesh filter screen to remove impurities and incompletely melted particles. The filtered composite melt is then placed in an insulated container and kept at 125°C for later use. S5: Forming process, used to process the composite melt into a preset shape of a packaging box, specifically including the following steps: S501: Mold pretreatment. Use a special mold for packaging boxes. Wipe the mold surface clean and apply a layer of biodegradable release agent. Then put the mold into a constant temperature oven and preheat it at 80℃ for 30 minutes to prevent the composite melt from sticking to the mold and to ensure that the surface of the packaged box after molding is smooth. S502: Injection molding, the heat-insulated composite melt is injected into the preheated mold, the injection pressure is controlled at 15MPa, the injection speed is 50mm / s, after injection, the pressure inside the mold is kept constant, and the temperature is kept constant for 20 minutes to allow the composite melt to fully solidify and form the initial blank of the packaging box. S503: Demolding process. After cooling, open the mold, take out the packaging box blank, wipe the surface of the blank with a clean cloth to remove residual mold release agent and impurities, and obtain the packaging box semi-finished product. S6: Post-processing, used to optimize the performance of the packaging box, improving its mechanical strength, shape memory properties, and biodegradability, specifically including the following steps: S601: Shape memory shaping process. The semi-finished packaging box is placed in a constant temperature chamber, the temperature is adjusted to 70℃, and it is kept at a constant temperature for 15 minutes. Then it is slowly cooled to room temperature. Through this process, the shape of the packaging box is fixed, its shape memory recovery rate is improved, and it is ensured that the packaging box can be restored to its original shape by heating after being squeezed and deformed. S602: Surface strengthening treatment. The shaped packaging box semi-finished product is placed in a plasma treatment instrument, the power is adjusted to 250W, and the treatment time is 10 minutes. This further improves the density and wear resistance of the packaging box surface, while enhancing its surface hydrophilicity, making it easier to clean during subsequent use. After the treatment is completed, it is taken out and cooled to room temperature. Constant temperature curing involves placing the post-treated packaging box into a vacuum drying oven, adjusting the temperature to 60℃, the vacuum degree to 0.08MPa, and curing at a constant temperature for 8 hours. This allows the molecules in the composite system to fully cross-link, further enhancing the mechanical strength and shape memory stability of the packaging box, while also accelerating the evaporation of residual moisture inside the material.

[0028] Example 3: like Figure 1 As shown, a method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box includes the following steps: S1: Raw material pretreatment, specifically including the following steps: S101: Pretreatment of carbon-based raw materials. Corn straw biomass carbon powder with a particle size of 500 mesh is selected as the carbon-based raw material. It is placed in a vacuum drying oven and dried at 80°C for 4 hours. After drying, it is pulverized again by a high-speed pulverizer and then screened through a 1000-mesh sieve to obtain pure biomass carbon powder for use. S102: Shape memory polymer pretreatment. Biodegradable polycaprolactone was selected as the shape memory polymer. It was cut into particles with a particle size of 5 mm and soaked in anhydrous ethanol for 20 minutes to remove surface oil and impurities. After soaking, the particles were taken out and placed in a vacuum drying oven and dried at 60°C for 2 hours to completely remove ethanol and water, and polycaprolactone particles were obtained for later use. S103: Pretreatment of auxiliary raw materials: Biodegradable polylactic acid is selected as an auxiliary binder, which is crushed into powder with a particle size controlled at 800 mesh, and dried in a drying oven at 65°C for 3 hours; lignin is selected as a reinforcing agent, which is crushed and passed through an 800-mesh sieve to remove impurities, and is then ready for use; After pretreatment of all auxiliary raw materials, they are stored separately in sealed containers to avoid moisture absorption. S2: Carbon-based material modification, used to improve the compatibility of carbon-based materials with shape memory polymers and enhance their dispersibility through a dedicated modification process. The dedicated modification process specifically includes the following steps: S201: Surface activation treatment. The biomass carbon powder pretreated by S1 is placed in a plasma treatment instrument. The plasma power is adjusted to 300W and the treatment time is 15 minutes. The plasma bombardment causes active groups such as hydroxyl and carboxyl groups to be generated on the surface of the carbon powder, which enhances its binding ability with the polymer. After the treatment is completed, it is quickly taken out and placed in a sealed container to cool to room temperature to avoid loss of active groups. S202: Coupling modification treatment: Prepare a 5% (w / w) silane coupling agent solution, add the activated biomass carbon powder to the solution, and stir at 300 r / min for 60 minutes at room temperature to ensure that the coupling agent is uniformly coated on the carbon powder surface. After stirring, use a centrifuge to centrifuge at 8000 r / min for 15 minutes to separate the modified carbon powder, and place it in a vacuum drying oven at 70℃ for 3 hours to obtain the coupling modified carbon-based material for later use. S203: Dispersion optimization treatment. The dried coupling modified carbon-based material is placed in a high-speed disperser, and a small amount of pretreated lignin is added. The dispersion speed is 5000 r / min and the dispersion time is 20 minutes. This allows the lignin to be uniformly attached to the surface of the carbon-based material, further improving its dispersibility in the subsequent melt blending process and avoiding agglomeration. S3: Shape memory polymer modification, used to optimize the shape memory and biodegradability of polycaprolactone, specifically including the following steps: S301: Crosslinking modification treatment. The pretreated polycaprolactone particles of S1 are placed in a reactor, and a crosslinking agent with a mass fraction of 3% is added. The reactor temperature is adjusted to 120℃, the stirring speed is 200r / min, and the reaction is carried out at a constant temperature for 40 minutes. The mechanical strength and shape memory recovery rate of polycaprolactone are improved through the crosslinking reaction, ensuring that it is not easily deformed during subsequent processing and use. S302: Degradability control treatment. Pretreated polylactic acid powder is added to the reactor and stirred for 30 minutes to fully mix the polylactic acid with the cross-linked polycaprolactone. The high degradability of polylactic acid is used to control the degradation rate of the overall polymer and improve the adhesion performance of the polymer, laying the foundation for subsequent composite with carbon-based materials. After the reaction is completed, the mixture is taken out, cooled to room temperature, and crushed into particles with a particle size of 3 mm to obtain modified shape memory polymer particles for later use. S4: Composite melt blending, used to fully fuse carbon-based materials with modified shape memory polymers, specifically including the following steps: S401: Mix the raw materials according to the following proportions: Take 65 parts of modified shape memory polymer particles, 25 parts of modified carbon-based material, 4 parts of lignin, and 6 parts of biodegradable plasticizer by mass. Take the modified shape memory polymer particles, modified carbon-based material, lignin, and biodegradable plasticizer, put them into a high-speed mixer, stir at a stirring speed of 4000 r / min, and stir at room temperature for 30 minutes to make all raw materials uniformly mixed to obtain the mixed raw materials. S402: Melt blending. The mixed raw materials are added to a twin-screw extruder. The temperatures of each section of the extruder are adjusted: the feed section temperature is 110℃, the melt section temperature is 130℃, and the discharge section temperature is 120℃. The screw speed is 250 r / min, and the melt blending time is 25 minutes. Through the shearing action of the screw, the modified carbon-based material is uniformly dispersed in the modified shape memory polymer matrix to form a uniform composite melt. S403: Melt filtration. The composite melt is passed through a 1200-mesh filter screen to remove impurities and incompletely melted particles. The filtered composite melt is then placed in an insulated container and kept at 125°C for later use. S5: Forming process, used to process the composite melt into a preset shape of a packaging box, specifically including the following steps: S501: Mold pretreatment. Use a special mold for packaging boxes. Wipe the mold surface clean and apply a layer of biodegradable release agent. Then put the mold into a constant temperature oven and preheat it at 80℃ for 30 minutes to prevent the composite melt from sticking to the mold and to ensure that the surface of the packaged box after molding is smooth. S502: Injection molding, the heat-insulated composite melt is injected into the preheated mold, the injection pressure is controlled at 15MPa, the injection speed is 50mm / s, after injection, the pressure inside the mold is kept constant, and the temperature is kept constant for 20 minutes to allow the composite melt to fully solidify and form the initial blank of the packaging box. S503: Demolding process. After cooling, open the mold, take out the packaging box blank, wipe the surface of the blank with a clean cloth to remove residual mold release agent and impurities, and obtain the packaging box semi-finished product. S6: Post-processing, used to optimize the performance of the packaging box, improving its mechanical strength, shape memory properties, and biodegradability, specifically including the following steps: S601: Shape memory shaping process. The semi-finished packaging box is placed in a constant temperature chamber, the temperature is adjusted to 70℃, and it is kept at a constant temperature for 15 minutes. Then it is slowly cooled to room temperature. Through this process, the shape of the packaging box is fixed, its shape memory recovery rate is improved, and it is ensured that the packaging box can be restored to its original shape by heating after being squeezed and deformed. S602: Surface strengthening treatment. The shaped packaging box semi-finished product is placed in a plasma treatment instrument, the power is adjusted to 250W, and the treatment time is 10 minutes. This further improves the density and wear resistance of the packaging box surface, while enhancing its surface hydrophilicity, making it easier to clean during subsequent use. After the treatment is completed, it is taken out and cooled to room temperature. Constant temperature curing involves placing the post-treated packaging box into a vacuum drying oven, adjusting the temperature to 60℃, the vacuum degree to 0.08MPa, and curing at a constant temperature for 8 hours. This allows the molecules in the composite system to fully cross-link, further enhancing the mechanical strength and shape memory stability of the packaging box, while also accelerating the evaporation of residual moisture inside the material.

[0029] The performance of the biodegradable and environmentally friendly carbon-based composite material packaging box prepared by this invention is compared with that of packaging boxes prepared by existing technologies. The comparison table is as follows: Performance indicators Prior Art 1 (Pure Polylactic Acid Packaging Box) Existing technology 2 (ordinary carbon-based composite biodegradable packaging box) Example 1 Example 2 Example 3 Tensile strength (MPa) 18-22 25-28 32-35 38-41 29-32 Impact strength (kJ / m²) 12-15 18-21 25-28 30-33 22-25 Shape memory recovery rate (%) No shape memory function No shape memory function 92-95 90-93 94-96 Degradation period (natural environment, months) 6-8 8-10 7-9 8-10 5-7 Density (g / cm³) 1.25-1.30 1.35-1.40 1.30-1.35 1.38-1.43 1.28-1.33 Surface abrasion resistance (abrasion amount mg / 1000 revolutions) 15-18 10-13 6-9 4-7 7-10 As can be seen from the comparison table above, the packaging boxes prepared by the embodiments of this method are significantly superior to the two existing technologies in terms of tensile strength, impact strength, and surface abrasion resistance. They also have a unique shape memory function, and the degradation cycle can be flexibly adjusted according to needs. This perfectly solves the pain points of poor mechanical properties and lack of repair function in existing technologies, fully demonstrating the creativity and practicality of this preparation method. At the same time, all properties meet the requirements for the use of biodegradable packaging boxes and are suitable for different scenarios.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A biodegradable and environmentally friendly carbon-based composite material packaging box, comprising modified shape memory polymer particles, modified carbon-based materials, lignin, and a biodegradable plasticizer, characterized in that: The composition by weight includes: 55-65 parts modified shape memory polymer particles, 25-35 parts modified carbon-based material, 4-6 parts lignin, and 4-6 parts biodegradable plasticizer.

2. The biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 1, characterized in that: The mass fractions include: 60 parts modified shape memory polymer particles, 30 parts modified carbon-based material, 5 parts lignin, and 5 parts biodegradable plasticizer.

3. The biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 2, characterized in that: The components, by weight, include: 55 parts modified shape memory polymer particles, 35 parts modified carbon-based material, 6 parts lignin, and 4 parts biodegradable plasticizer.

4. The biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 1, characterized in that: The components, by weight, include: 65 parts modified shape memory polymer particles, 25 parts modified carbon-based material, 4 parts lignin, and 6 parts biodegradable plasticizer.

5. A method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box, comprising using a biodegradable and environmentally friendly carbon-based composite material packaging box as described in any one of claims 1-4, characterized in that: The following steps are included: S1: Raw material pretreatment, specifically including the following steps: S101: Pretreatment of carbon-based raw materials. Corn straw biomass carbon powder with a particle size of 500 mesh is selected as the carbon-based raw material. It is placed in a vacuum drying oven and dried at 80°C for 4 hours. After drying, it is pulverized again by a high-speed pulverizer and then screened through a 1000-mesh sieve to obtain pure biomass carbon powder for use. S102: Shape memory polymer pretreatment. Biodegradable polycaprolactone was selected as the shape memory polymer. It was cut into particles with a particle size of 5 mm and soaked in anhydrous ethanol for 20 minutes to remove surface oil and impurities. After soaking, the particles were taken out and placed in a vacuum drying oven and dried at 60°C for 2 hours to completely remove ethanol and water, and polycaprolactone particles were obtained for later use. S103: Pretreatment of auxiliary raw materials: Biodegradable polylactic acid is selected as an auxiliary binder, which is crushed into powder with a particle size controlled at 800 mesh, and dried in a drying oven at 65°C for 3 hours; lignin is selected as a reinforcing agent, which is crushed and passed through an 800-mesh sieve to remove impurities, and is then ready for use; After pretreatment of all auxiliary raw materials, they are stored separately in sealed containers to avoid moisture absorption. S2: Carbon-based material modification, used to improve the compatibility of carbon-based materials with shape memory polymers through a dedicated modification process, while also enhancing their dispersibility; S3: Shape memory polymer modification, used to optimize the shape memory and biodegradability of polycaprolactone; S4: Composite melt blending, used to fully fuse carbon-based materials with modified shape memory polymers; S5: Molding process, used to process composite melt into a preset shape of packaging box; S6: Post-processing, used to optimize the performance of packaging boxes, improving their mechanical strength, shape memory properties and biodegradability.

6. The method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 5, characterized in that: In step S2, the specific modification process includes the following steps: S201: Surface activation treatment. The biomass carbon powder pretreated by S1 is placed in a plasma treatment instrument, the plasma power is adjusted to 300W, and the treatment time is 15 minutes. The surface of the carbon powder is generated by plasma bombardment. After the treatment is completed, it is quickly taken out and placed in a sealed container to cool to room temperature. S202: Coupling modification treatment: Prepare a 5% (w / w) silane coupling agent solution, add the activated biomass carbon powder to the solution, and stir at 300 r / min for 60 minutes at room temperature to ensure that the coupling agent is uniformly coated on the carbon powder surface. After stirring, use a centrifuge to centrifuge at 8000 r / min for 15 minutes to separate the modified carbon powder, and place it in a vacuum drying oven at 70℃ for 3 hours to obtain the coupling modified carbon-based material for later use. S203: Dispersion optimization treatment. The dried coupling modified carbon-based material is placed in a high-speed disperser, a small amount of pretreated lignin is added, the dispersion speed is 5000 r / min, and the dispersion time is 20 minutes, so that the lignin is uniformly attached to the surface of the carbon-based material.

7. The method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 5, characterized in that: S3 specifically includes the following steps: S301: Crosslinking modification treatment. The polycaprolactone particles pretreated with S1 are placed in a reactor, and a crosslinking agent with a mass fraction of 3% is added. The reactor temperature is adjusted to 120℃, the stirring speed is 200r / min, and the reaction is carried out at a constant temperature for 40 minutes. S302: Degradability control treatment. Pretreated polylactic acid powder is added to the reaction vessel and stirred for 30 minutes to ensure that the polylactic acid and the cross-linked polycaprolactone are fully mixed. After the reaction is completed, the mixture is taken out, cooled to room temperature, and crushed into particles with a particle size of 3 mm to obtain modified shape memory polymer particles for later use.

8. The method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 5, characterized in that: S4 specifically includes the following steps: S401: Raw material mixing ratio: According to the mass parts, take the modified shape memory polymer particles, modified carbon-based materials, lignin, and biodegradable plasticizer, put them into a high-speed mixer, stir at a stirring speed of 4000 r / min, stir at room temperature for 30 minutes to make all raw materials uniformly mixed to obtain mixed raw materials; S402: Melt blending. The mixed raw materials are added to a twin-screw extruder. The temperatures of each section of the extruder are adjusted: the feed section temperature is 110℃, the melt section temperature is 130℃, and the discharge section temperature is 120℃. The screw speed is 250r / min, and the melt blending time is 25 minutes to form a uniform composite melt. S403: Melt filtration. The composite melt is passed through a 1200-mesh filter screen to remove impurities and incompletely melted particles. The filtered composite melt is then placed in an insulated container and kept at 125°C for later use.

9. The method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 5, characterized in that: S5 specifically includes the following steps: S501: Mold pretreatment. Select a special mold for packaging boxes, wipe the mold surface clean, apply a layer of biodegradable release agent, and then put the mold into a constant temperature oven and preheat it at 80℃ for 30 minutes. S502: Injection molding, the heat-insulated composite melt is injected into the preheated mold, the injection pressure is controlled at 15MPa, the injection speed is 50mm / s, after injection, the pressure inside the mold is kept constant, and the temperature is kept constant for 20 minutes to allow the composite melt to fully solidify and form the initial blank of the packaging box. S503: Demolding process. After cooling, open the mold, take out the initial blank of the packaging box, wipe the surface of the initial blank with a clean cloth to remove residual mold release agent and impurities, and obtain the semi-finished packaging box.

10. The method for preparing a biodegradable and environmentally friendly carbon-based composite material packaging box according to claim 5, characterized in that: S6 specifically includes the following steps: S601: Shape memory shaping process: Place the semi-finished packaging box in a constant temperature chamber, adjust the temperature to 70℃, keep it at a constant temperature for 15 minutes, and then slowly cool it to room temperature; S602: Surface strengthening treatment. Place the shaped packaging box semi-finished product into the plasma treatment instrument, adjust the power to 250W, and the treatment time to 10 minutes. After the treatment is completed, take it out and cool it to room temperature. For constant temperature curing, place the post-treated packaging box in a vacuum drying oven, adjust the temperature to 60℃, the vacuum degree to 0.08MPa, and cure at a constant temperature for 8 hours.

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