A functional plastic fiber master batch material and a preparation method thereof

Abstract

The application discloses a functional plastic fiber master batch material and a preparation method thereof, and relates to the technical field of plastic master batches; the functional plastic fiber master batch material is composed of layered nanometer silicate loaded nitrogen-doped carbon nanofibers, a multi-layer composite functional material, polypropylene, an antioxidant and calcium stearate; the combination of the layered nanometer silicate loaded nitrogen-doped carbon nanofibers and the multi-layer composite functional material not only enhances the interface compatibility and combination of the polypropylene matrix, but also synergistically enhances the mechanical properties, the flame-retardant properties and the conductive properties of the plastic through the formed interpenetrating network structure, thereby widening the use range.

Description

Technical Field

[0001] This invention belongs to the field of plastic masterbatch technology, specifically referring to a functional plastic fiber masterbatch material and its preparation method. Background Technology

[0002] Traditional petroleum-based plastics refer to plastic materials made from petroleum through various synthetic processes. These plastics are widely used globally due to their excellent physicochemical properties, low production costs, and wide applicability. The most common petroleum-based plastics include polyethylene, polypropylene, polyvinyl chloride, and polystyrene. Petroleum-based plastics typically possess good chemical stability and corrosion resistance, enabling them to withstand long-term use in various environments. They also exhibit high strength and toughness, meeting the needs of diverse industrial and everyday applications. Furthermore, petroleum-based plastics have excellent processing properties, allowing them to be molded through injection molding, extrusion, blow molding, and other methods to produce products of various shapes and uses. They demonstrate broad application needs in the automotive, electrical, electronics, packaging, and construction industries.

[0003] The existing technology currently suffers from the following main problems:

[0004] The flame retardancy and mechanical properties of materials such as polypropylene are relatively weak, which restricts their application in many ways. Summary of the Invention

[0005] In view of the above situation and to overcome the defects of the prior art, the present invention proposes a functional plastic fiber masterbatch material, comprising the following components in parts by weight: 5-10 parts of layered nano-silicate-supported nitrogen-doped carbon nanofibers, 10-20 parts of multi-level composite functional material, 70-90 parts of polypropylene, 1-3 parts of antioxidant, and 3-5 parts of calcium stearate.

[0006] The layered nanosilicate-supported nitrogen-doped carbon nanofibers are made from the following components in parts by weight: 1-2 parts modified layered nanosilicate, 6-10 parts polyacrylonitrile, 1-5 parts polymethyl methacrylate, 1-2 parts urea, and 1-2 parts melamine.

[0007] The preparation method of the layered nanosilicate-supported nitrogen-doped carbon nanofibers specifically includes the following steps:

[0008] (1) Disperse layered nano silicates in 50 mL of deionized water and sonicate for 30-50 min to obtain a suspension for later use. Then dissolve 0.04-0.1 g of hexadecyltrimethylammonium bromide in 20 mL of 40-50 °C water and stir until completely dissolved. Then, while stirring, add the hexadecyltrimethylammonium bromide solution dropwise to the suspension over 20-30 min. Stir at 60-70 °C for 24 h, centrifuge at 12000-16000 rpm for 10-15 min, and wash the precipitate three times alternately with deionized water and ethanol solution. Dry and grind the precipitate. Hexadecyltrimethylammonium bromide inserts into the silicate interlayer through cation exchange, expanding the interlayer spacing and facilitating the embedding of polymer molecular chains. At the same time, the long alkyl chain of hexadecyltrimethylammonium bromide covers the silicate surface, changing it from hydrophilic to hydrophobic, improving its compatibility with the plastic matrix and enhancing its toughening and flame-retardant properties. Modified layered nano silicates are obtained.

[0009] (2) The modified layered nano silicate described in step (1) is dispersed in a mixed solvent of 10 mL of N,N-dimethylformamide and acetone, wherein the volume ratio of N,N-dimethylformamide and acetone is 7:3. The mixture is stirred for 1-2 h, then 0.1-0.2 g of urea and 0.1-0.2 g of melamine are added and stirred for 10-20 min. Then polymethyl methacrylate is added, and finally 0.6-1.0 g of polyacrylonitrile is added. The mixture is stirred at 40-45 °C for 8-12 h. In this process, the modified layered nano silicate is dispersed in the polymer matrix to form a structure similar to nanobrick-gravel. Polyacrylonitrile provides a rigid skeleton, polymethyl methacrylate fills the pores, and the molecular level of urea and melamine is uniformly distributed between the polymer chains, which is beneficial for subsequent heat treatment to generate porous or flame-retardant active sites. A nanocomposite system with excellent dispersion stability, flame retardancy and spinning fluidity is prepared, and a spinning precursor solution is obtained.

[0010] (3) After filtering the spinning pretreatment solution described in step (2) through a 0.45 μm filter membrane, transfer it to a 10 mL syringe equipped with a No. 25 stainless steel needle. Connect the syringe and the pump through a syringe pump, set the flow rate to 0.8-1.0 mL / h, the voltage to 12-18 kV, and the distance to 12-15 cm. Place the collected spinning fibers in a muffle furnace, first heat it to 130-150℃ at a rate of 2℃ / min and hold it for 30 min, then oxidize it in an air atmosphere at 240-250℃ for 70-80 min. After stabilization, place the fibers in a tube furnace and heat them to 700-800℃ at a rate of 5℃ / min. Mix ammonia gas into the nitrogen atmosphere, with the ammonia flow rate accounting for 10-20% of the total gas flow rate, and carbonize for 70-90 min. Cool it. Through electrospinning and high-temperature carbonization, a fiber structure with porous flame-retardant sites on the surface is obtained. After pre-oxidation and carbonization, polyacrylonitrile forms a carbon fiber skeleton and By retaining nitrogen-doped active sites, modified layered nanosilicates are embedded in the fiber in the form of exfoliated nanosheets, which improves the stability of the structure after carbonization and prevents pore collapse. During the carbonization stage, the infiltration of ammonia and the action of residual polyacrylonitrile molecules form a nitrogen-doped carbon network structure, forming a three-dimensional network in the plastic matrix. This not only inhibits the slippage of plastic molecular chains but also improves the tensile strength and impact resistance of the material through stress transfer. At the same time, the carbon fiber forms a char layer during combustion, which isolates oxygen and heat and delays combustion. The nitrogen-doped sites promote the catalytic carbonization of polymers, forming a dense char layer that enhances flame retardant properties. The physical barrier of the modified layered nanosilicates also helps to block gas diffusion and heat conduction. Furthermore, the modified layered nanosilicates promote fiber dispersion, avoid agglomeration, and optimize the conductive pathway. The carbon fiber provides a conductive network, and nitrogen doping provides additional free electrons, reducing resistivity and improving conductivity, resulting in nitrogen-doped carbon nanofibers supported on layered nanosilicates.

[0011] Preferably, in step (1), the amount of layered nano-silicate added is 0.5-1.0g. When layered nano-silicate is used as a nanofiller for plastics, it can improve the flame retardancy of plastics through physical barrier and catalytic carbonization mechanism, and also improve the tensile strength, impact toughness and other mechanical properties of plastics.

[0012] Preferably, in step (2), the amount of polymethyl methacrylate added is 0.1-0.5g. Polymethyl methacrylate can reduce the viscosity of the spinning solution and improve spinnability. At the same time, as a pore-forming aid, it can further optimize and adjust the porous structure of the fiber.

[0013] This invention also provides a method for preparing functional plastic fiber masterbatch material, specifically including the following steps:

[0014] S1. Disperse 4.0-5.0 g of ammonium polyphosphate in 50 mL of anhydrous methanol and sonicate for 0.5-1 h to form dispersion I. Mix 600.0-650.0 mg of γ-cyclodextrin with 200.0-300.0 mg of potassium hydroxide in 30 mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30 mL of anhydrous methanol and sonicate for 20-30 min to form solution III. Then, add solutions II and III dropwise to dispersion I sequentially, stir at 25 °C for 2-3 h, centrifuge, collect the particles, wash 3-5 times with anhydrous ethanol and anhydrous methanol respectively, and vacuum dry. Ammonium polyphosphate provides expansion flame retardant function, γ- Cyclodextrin encapsulates ammonium polyphosphate through hydrogen bonding or physical adsorption. One end of the amphiphilic block of Pluronic F127 is bound to γ-cyclodextrin, and the other end is connected to carboxylated carbon nanotubes, forming a multilayer stable coating. This improves the compatibility with the plastic matrix, avoids migration and precipitation during melt processing, and enhances interfacial stability. Among them, carboxylated carbon nanotubes not only provide nano-reinforcing effect, which is beneficial to the improvement of mechanical properties, but also promote the formation of dense carbon layers. They also synergistically enhance the maze effect with γ-cyclodextrin, stabilize the carbon layer structure, and reduce the propagation of carbon layer cracks. The hydrophobic cavity of γ-cyclodextrin and the hydrophilic outer wall also form a barrier region, which delays the escape of combustible gases. At the same time, the uniformly dispersed carboxylated carbon nanotubes can build a conductive network on the surface of the composite, reduce resistivity, and obtain γ-cyclodextrin modified composite particles.

[0015] S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of a 60% (w / w) methanol solution, and sonicate for 30-40 min to obtain dispersion A. Dissolve 80.0-90.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol, and then add zinc nitrate hexahydrate to obtain solution B. Dissolve 0.2-0.3 g of 3,5-diamino-1,2,4-triazole in 50 mL of anhydrous methanol to obtain solution C. Then, add solutions B and C dropwise to dispersion A, heat to 40-50℃, stir for 2-3 h, centrifuge, wash the precipitate three times with anhydrous methanol, and finally soak it in a 0.5-1.0% (w / w) oleic acid-methanol solution for 20-30 min. Supercritical drying was used to develop a multi-layered composite material with γ-cyclodextrin-modified composite particles as the core layer, a Co / Zn bimetallic organic framework as the middle layer, and oleic acid molecules as the outer shell. This improved the compatibility with the plastic matrix and resulted in a porous, interconnected structure. The hierarchical channel effect allowed the nanofillers to function better, restricting the movement of plastic molecular chains and absorbing impact energy through pore wall deformation, thus significantly enhancing mechanical properties. At the same time, the Co / Zn bimetallic organic framework decomposed into metal oxides at high temperatures, catalyzing the formation of a dense carbon layer in the polymer. This layer isolated heat and oxygen, and the tortuous porous channels prolonged the conduction and diffusion of heat. The difference in atomic radii between Co and Zn bimetals increased lattice stress and dislocation density, promoting electron transition and conduction, which also improved flame retardancy and conductivity.

[0016] S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 130-150℃. The annealing pretreatment can eliminate surface adsorbed water, stabilize nitrogen-containing functional groups, and avoid the generation of gas by subsequent high-temperature extrusion decomposition. Then, it is mixed with the multi-level composite functional material described in step S2, and then polypropylene, antioxidant, and calcium stearate are added and mixed evenly. The antioxidant is composed of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The temperature of the feeding section is controlled at 160-170℃, and the melt extrusion temperature is controlled at 180-200℃. During the melt extrusion process, the layered nano-silicate-loaded nitrogen-doped carbon nanofibers can be wound around the surface of the multi-level composite functional material to form an interpenetrating network. The polar groups introduced by nitrogen doping can form hydrogen bonds or coordination with the metal nodes of the multi-level composite functional material, enhance the interfacial bonding with the polypropylene matrix, and improve the mechanical properties, flame retardancy, and conductivity of plastics. This broadens the application of plastics and yields functional plastic fiber masterbatch material.

[0017] Preferably, in step S1, the amounts of Pluronic F127 and carboxylated carbon nanotubes added are 150.0-200.0 mg and 10.0-15.0 mg, respectively. The carboxylated carbon nanotubes have carboxyl groups on their surface, which can interact with the hydrophilic PEO segments of Pluronic F127 through hydrogen bonds to form a more stable dispersion system. Meanwhile, the hydrophobic PPO segments encapsulate the non-polar regions of the carbon nanotubes, forming a "micelle-nanotube" composite structure, which further inhibits aggregation.

[0018] Preferably, in step S2, the amount of zinc nitrate hexahydrate added is 20.0-30.0 mg. The mild coordination effect of zinc ions reduces the brittleness caused by excessive cross-linking and makes the metal-organic framework material more flexible, making it less prone to breakage during injection molding shearing. During combustion, zinc ions are converted into nano-ZnO, filling the pores of the carbon layer and making it more compact. Furthermore, the introduction of zinc ions narrows the band gap of the metal-organic framework material, and its tetrahedral coordination configuration promotes interfacial contact with carboxylated carbon nanotubes, optimizing the percolation network, thereby enhancing mechanical properties, flame retardancy, and electrical conductivity.

[0019] The beneficial effects achieved by this invention are as follows:

[0020] This invention combines layered nanosilicate-loaded nitrogen-doped carbon nanofibers with multi-level composite functional materials. This not only enhances the interfacial compatibility and bonding with the polypropylene matrix but also synergistically strengthens the mechanical, flame-retardant, and electrical properties of the plastic through the formed interpenetrating network structure, thus broadening its application range. In the layered nanosilicate-loaded nitrogen-doped carbon nanofibers, polyacrylonitrile is pre-oxidized and carbonized to form a carbon fiber skeleton. The modified layered nanosilicate is embedded within the fiber in the form of exfoliated nanosheets, improving the stability of the structure after carbonization and preventing pore collapse. During the carbonization stage, the infiltration of ammonia and the action of residual polyacrylonitrile molecules form a nitrogen-doped carbon network structure, thus enabling electrospinning. The process of fiber fabrication and high-temperature carbonization ultimately yields a carbon fiber structure with porous flame-retardant sites on its surface. This structure can form a three-dimensional network within the plastic matrix, not only inhibiting chain slippage in the plastic molecules but also enhancing the tensile strength and impact resistance of the material through stress transfer. Simultaneously, the carbon fibers form a char layer during combustion, isolating oxygen and heat, thus delaying combustion. Nitrogen-doped sites promote polymer catalytic carbonization, forming a dense char layer that enhances flame-retardant properties. Furthermore, the carbon fibers provide a conductive network, while nitrogen doping provides additional free electrons, reducing resistivity and improving conductivity. The physical barrier provided by the modified layered nanosilicates also helps to block gas diffusion and heat conduction. The modified layered nanosilicates also promote fiber dispersion, prevent agglomeration, and optimize conductive pathways. In this high-performance composite material, γ-cyclodextrin-modified composite particles form the core layer, a Co / Zn bimetallic organic framework forms the intermediate layer, and oleic acid forms the modified outer shell, creating a porous, interconnected composite structure. This structure leverages the hierarchical channel effect to better utilize the nanofiller, effectively restricting the movement of plastic molecular chains. Furthermore, the deformation of the porous walls fully absorbs impact energy, significantly enhancing mechanical properties. Simultaneously, the Co / Zn bimetallic organic framework decomposes into metal oxides at high temperatures, catalyzing the formation of a dense carbon layer that isolates heat and oxygen. The tortuous porous channels extend heat conduction and diffusion. The difference in atomic radii between the Co / Zn bimetals increases lattice stress and dislocation density, promoting electron transition and conduction, which also contributes to improved flame retardancy and electrical conductivity. In this invention, γ-cyclodextrin encapsulates ammonium polyphosphate through hydrogen bonding or physical adsorption. One end of the amphiphilic block of Pluronic F127 is bound to γ-cyclodextrin, and the other end is connected to carboxylated carbon nanotubes, which enhances the labyrinth effect, helps stabilize the carbon layer structure, and reduces the propagation of carbon layer cracks. The hydrophobic cavity and hydrophilic outer wall of γ-cyclodextrin construct a barrier region, delaying the escape of flammable gases. At the same time, the uniformly dispersed carboxylated carbon nanotubes can build a conductive network on the surface of the composite, reducing resistivity. This invention uses layered nanosilicates loaded with nitrogen-doped carbon nanofibers, multi-level composite functional materials, polypropylene, antioxidants, and calcium stearate to prepare a functional plastic fiber masterbatch material, which enhances mechanical properties, flame retardant properties, and electrical conductivity. Attached Figure Description

[0021] Figure 1This is a scanning electron microscope image of the multi-level composite functional material prepared in Example 1 of the present invention;

[0022] Figure 2 The figures show the mechanical properties of Examples 1-4 and Comparative Examples 1-3 of the present invention.

[0023] Figure 3 The limiting oxygen index results are shown in the figures for Examples 1-4 and Comparative Examples 1-3 of the present invention.

[0024] Figure 4 The figures show the volume resistivity results of Examples 1-4 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0027] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; unless otherwise specified, the experimental materials used in the following embodiments are all purchased from commercial channels.

[0028] Example 1

[0029] This embodiment proposes a functional plastic fiber masterbatch material, comprising the following components in parts by weight: 10 parts of layered nano-silicate-supported nitrogen-doped carbon nanofibers, 20 parts of multi-level composite functional material, 90 parts of polypropylene, 3 parts of antioxidant, and 5 parts of calcium stearate.

[0030] Nitrogen-doped carbon nanofibers supported on layered nanosilicates are made from the following components in parts by weight: 2 parts modified layered nanosilicates, 10 parts polyacrylonitrile, 5 parts polymethyl methacrylate, 2 parts urea, and 2 parts melamine.

[0031] The preparation method of nitrogen-doped carbon nanofibers supported on layered nanosilicates specifically includes the following steps:

[0032] (1) Disperse layered nano-silicate in 50 mL of deionized water. The amount of layered nano-silicate added is 1.0 g. When layered nano-silicate is used as a nanofiller for plastics, it can improve the flame retardancy of plastics through physical barrier and catalytic carbonization mechanism, and also improve the tensile strength, impact toughness and other mechanical properties of plastics. After ultrasonic treatment for 50 min, a suspension is obtained for later use. Then, 0.1 g of hexadecyltrimethylammonium bromide is dissolved in 20 mL of 50 °C water and stirred until completely dissolved. Then, while stirring, the hexadecyltrimethylammonium bromide solution is added dropwise to the suspension over 30 min. In the flotation solution, the mixture was stirred at 70℃ for 24 hours, centrifuged at 16000 rpm for 15 minutes, and the precipitate was washed three times alternately with deionized water and ethanol solution. After drying and grinding, hexadecyltrimethylammonium bromide was inserted into the silicate interlayer through cation exchange, which expanded the interlayer spacing and facilitated the embedding of polymer molecular chains. At the same time, the long alkyl chains of hexadecyltrimethylammonium bromide covered the silicate surface, changing it from hydrophilic to hydrophobic, which improved the compatibility with the plastic matrix and facilitated the reinforcing, toughening and flame retardant effects, thus obtaining modified layered nano silicate.

[0033] (2) The modified layered nano-silicate described in step (1) is dispersed in a mixed solvent of 10 mL of N,N-dimethylformamide and acetone, wherein the volume ratio of N,N-dimethylformamide to acetone is 7:3. The mixture is stirred continuously for 2 h, then 0.2 g of urea and 0.2 g of melamine are added and stirred for 20 min. Then, 0.5 g of polymethyl methacrylate is added. Polymethyl methacrylate can reduce the viscosity of the spinning solution and improve spinnability. At the same time, it can also act as a pore-forming aid to further optimize the spinning process. The porous structure of the fiber was adjusted, and finally 1.0 g of polyacrylonitrile was added. The mixture was stirred at 45 °C for 12 h. In this process, the modified layered nano-silicate was dispersed in the polymer matrix to form a nano-brick-gravel structure. Polyacrylonitrile provided a rigid skeleton, polymethyl methacrylate filled the pores, and urea and melamine were uniformly distributed at the molecular level between the polymer chains, which is beneficial for the subsequent heat treatment to generate porous or flame-retardant active sites. A nanocomposite system with excellent dispersion stability, flame retardancy and spinning flowability was prepared, and a spinning precursor solution was obtained.

[0034] (3) The spinning precursor solution described in step (2) was filtered through a 0.45 μm filter membrane and transferred to a 10 mL syringe. The syringe was equipped with a No. 25 stainless steel needle. The syringe and the pump were connected by a syringe pump. The flow rate was set to 1.0 mL / h, the voltage to 18 kV, and the distance to 15 cm. The collected spinning fibers were placed in a muffle furnace and heated to 150 °C at a rate of 2 °C / min and held for 30 min. Then, the fibers were oxidized in an air atmosphere at 250 °C for 80 min. The stabilized fibers were then placed in a tube furnace and heated to 800 °C at a rate of 5 °C / min. Ammonia was mixed in a nitrogen atmosphere, with the ammonia flow rate accounting for 20% of the total gas flow rate. The fibers were carbonized for 90 min and cooled. Through electrospinning and high-temperature carbonization, a fiber structure with porous flame-retardant sites on the surface was obtained. After pre-oxidation and carbonization, polyacrylonitrile formed a carbon fiber skeleton and retained nitrogen-doped active sites. The modified layered nanofibers were then processed. Silicates are embedded within fibers in the form of exfoliated nanosheets, improving the stability of the structure after carbonization and preventing pore collapse. During the carbonization stage, the infiltration of ammonia and the action of residual polyacrylonitrile molecules form a nitrogen-doped carbon network structure, creating a three-dimensional network in the plastic matrix. This not only inhibits the slippage of plastic molecular chains but also enhances the tensile strength and impact resistance of the material through stress transfer. Simultaneously, the carbon fibers form a char layer during combustion, isolating oxygen and heat and delaying combustion. Nitrogen-doped sites promote polymer catalysis to form char, creating a dense char layer that enhances flame retardant properties. The physical barrier of the modified layered nanosilicates also helps to block gas diffusion and heat conduction. Furthermore, the modified layered nanosilicates promote fiber dispersion, prevent agglomeration, and optimize conductive pathways. Carbon fibers provide a conductive network, while nitrogen doping provides additional free electrons, reducing resistivity and improving conductivity, resulting in nitrogen-doped carbon nanofibers supported on layered nanosilicates.

[0035] This embodiment provides a method for preparing functional plastic fiber masterbatch material, specifically including the following steps:

[0036] S1. Disperse 5.0 g of ammonium polyphosphate in 50 mL of anhydrous methanol and sonicate for 1 h to form dispersion I. Mix 650.0 mg of γ-cyclodextrin and 300.0 mg of potassium hydroxide in 30 mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30 mL of anhydrous methanol. The amounts of Pluronic F127 and carboxylated carbon nanotubes added are 200.0 mg and 15.0 mg, respectively. The carboxylated carbon nanotubes have carboxyl groups on their surface, which can interact with the hydrophilic PEO segments of Pluronic F127 through hydrogen bonds to form a more stable dispersion system. The hydrophobic PPO segments encapsulate the nonpolar regions of the carbon nanotubes, forming a "micelle-nanotube" composite structure, further inhibiting aggregation. Sonicate for 30 min to form solution III. Then, add solutions II and III dropwise to dispersion I sequentially and incubate at 25°C. After stirring for 3 hours, the mixture was centrifuged, the particles were collected, washed five times with anhydrous ethanol and anhydrous methanol respectively, and vacuum dried. Ammonium polyphosphate was used as the core to provide expansion and flame retardant function. γ-cyclodextrin coated the ammonium polyphosphate through hydrogen bonding or physical adsorption. One end of the amphiphilic block of Pluronic F127 was combined with γ-cyclodextrin, and the other end was connected to carboxylated carbon nanotubes to form a multilayer stable coating, which improved the compatibility with the plastic matrix, prevented migration and precipitation during melt processing, and enhanced the interfacial stability. Among them, carboxylated carbon nanotubes not only provided nano-reinforcement effect, which is beneficial to the improvement of mechanical properties, but also promoted the formation of dense carbon layers. They also synergistically enhanced the maze effect with γ-cyclodextrin, stabilized the carbon layer structure, and reduced the propagation of carbon layer cracks. The hydrophobic cavity of γ-cyclodextrin and the hydrophilic outer wall also formed a barrier region to delay the escape of combustible gases. At the same time, the uniformly dispersed carboxylated carbon nanotubes can build a conductive network on the surface of the composite to reduce resistivity, thus obtaining γ-cyclodextrin modified composite particles.

[0037] S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of a 60% (w / w) methanol solution and sonicate for 40 min. This is prepared as dispersion A. Dissolve 90.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol, and then add 30.0 mg of zinc nitrate hexahydrate. The mild coordination effect of zinc ions reduces the brittleness caused by excessive cross-linking and also makes the metal-organic framework material more flexible, preventing it from becoming brittle during injection molding shearing. It is easily broken; during combustion, zinc ions are converted into nano-ZnO, filling the pores of the carbon layer and making it denser. Furthermore, the introduction of zinc ions narrows the band gap of the metal-organic framework material, and its tetrahedral coordination configuration promotes interfacial contact with carboxylated carbon nanotubes, optimizing the percolation network and thus enhancing mechanical properties, flame retardancy, and conductivity. Solution B is prepared for later use. 0.3 g of 3,5-diamino-1,2,4-triazole is dissolved in 50 mL of anhydrous methanol to prepare solution C. Then, solutions B and C are prepared according to... The mixture was added dropwise to dispersion A, heated to 50°C, stirred for 3 hours, centrifuged, and the precipitate was washed three times with anhydrous methanol. Finally, it was soaked in a 1.0% oleic acid methanol solution for 30 minutes, removed, and supercritically dried. The composite particles modified with γ-cyclodextrin served as the core layer, with a Co / Zn bimetallic organic framework in the middle layer and an outer shell coating oleic acid molecules, improving compatibility with the plastic matrix and exhibiting a porous and interconnected structure. Through the hierarchical channel effect, the nanofiller function was better utilized, restricting the movement of plastic molecular chains and absorbing impact energy through pore wall deformation, significantly enhancing mechanical properties. At the same time, the Co / Zn bimetallic organic framework decomposed into metal oxides at high temperatures, catalyzing the polymer to form a dense carbon layer, isolating heat and oxygen. Through tortuous porous channels, the conduction and diffusion of heat were prolonged. The difference in atomic radii of Co / Zn bimetals led to an increase in lattice stress and dislocation density, promoting electron transition and conduction, which also helped improve flame retardancy and conductivity, resulting in a multi-level composite functional material.

[0038] S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 150°C. This annealing pretreatment eliminates surface adsorbed water, stabilizes nitrogen-containing functional groups, and prevents gas generation during subsequent high-temperature extrusion decomposition. Then, the mixture is first mixed with the multi-level composite functional material described in step S2, followed by the addition of polypropylene, antioxidants, and calcium stearate. The mixture is thoroughly mixed, with the antioxidants consisting of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The feeding section temperature is controlled at 170°C, and the melt extrusion temperature at 200°C. During melt extrusion, the layered nano-silicate-loaded nitrogen-doped carbon nanofibers can entangle on the surface of the multi-level composite functional material, forming an interpenetrating network. The polar groups introduced by nitrogen doping can form hydrogen bonds or coordination interactions with the metal nodes of the multi-level composite functional material, enhancing the interfacial bonding with the polypropylene matrix. This improves the mechanical properties, flame retardancy, and conductivity of the plastic, broadening the application of the plastic and yielding a functional plastic fiber masterbatch material.

[0039] In this embodiment, the microstructure of the prepared multi-level composite functional material was observed using scanning electron microscopy. Figure 1 This is a 1000x magnified SEM image of the multi-level composite functional material prepared in Example 1, such as... Figure 1 The multi-level composite functional material prepared in this embodiment exhibits a porous, interconnected structure.

[0040] Example 2

[0041] This embodiment proposes a functional plastic fiber masterbatch material, comprising the following components in parts by weight: 5 parts of layered nano-silicate-supported nitrogen-doped carbon nanofibers, 10 parts of multi-level composite functional material, 70 parts of polypropylene, 1 part of antioxidant, and 3 parts of calcium stearate.

[0042] Nitrogen-doped carbon nanofibers supported on layered nanosilicates are made from the following components in parts by weight: 1 part modified layered nanosilicate, 6 parts polyacrylonitrile, 1 part polymethyl methacrylate, 1 part urea, and 1 part melamine.

[0043] The preparation method of nitrogen-doped carbon nanofibers supported on layered nanosilicates specifically includes the following steps:

[0044] (1) Disperse layered nano-silicate in 50 mL of deionized water. The amount of layered nano-silicate added is 0.5 g. When layered nano-silicate is used as a nanofiller for plastics, it can improve the flame retardancy of plastics through physical barrier and catalytic carbonization mechanism, and also improve the tensile strength, impact toughness and other mechanical properties of plastics. After ultrasonic treatment for 30 min, a suspension is obtained for later use. Then, 0.04 g of hexadecyltrimethylammonium bromide is dissolved in 20 mL of 40 °C water and stirred until completely dissolved. Then, while stirring, the hexadecyltrimethylammonium bromide solution is added dropwise to the suspension over 20 min. In the flotation solution, the mixture was stirred at 60℃ for 24 hours, centrifuged at 12000 rpm for 10 minutes, and the precipitate was washed three times alternately with deionized water and ethanol solution. After drying and grinding, hexadecyltrimethylammonium bromide was inserted into the silicate interlayer through cation exchange, which expanded the interlayer spacing and facilitated the embedding of polymer molecular chains. At the same time, the long alkyl chains of hexadecyltrimethylammonium bromide covered the silicate surface, changing it from hydrophilic to hydrophobic, which improved the compatibility with the plastic matrix and facilitated the reinforcing, toughening and flame retardant effects, thus obtaining modified layered nano silicate.

[0045] (2) The modified layered nano-silicate described in step (1) is dispersed in a mixed solvent of 10 mL of N,N-dimethylformamide and acetone, wherein the volume ratio of N,N-dimethylformamide to acetone is 7:3. The mixture is stirred continuously for 1 h, then 0.1 g of urea and 0.1 g of melamine are added and stirred for 10 min. Then, 0.1 g of polymethyl methacrylate is added. Polymethyl methacrylate can reduce the viscosity of the spinning solution and improve spinnability. At the same time, it can also act as a pore-forming aid to further optimize the spinning process. The porous structure of the fiber was adjusted, and finally 0.6 g of polyacrylonitrile was added. The mixture was stirred at 40 °C for 8 h. In this process, the modified layered nano-silicate was dispersed in the polymer matrix to form a nano-brick-gravel structure. Polyacrylonitrile provided a rigid skeleton, polymethyl methacrylate filled the pores, and urea and melamine were uniformly distributed at the molecular level between the polymer chains, which is beneficial for the subsequent heat treatment to generate porous or flame-retardant active sites. A nanocomposite system with excellent dispersion stability, flame retardancy and spinning flowability was prepared, and a spinning precursor solution was obtained.

[0046] (3) The spinning precursor solution described in step (2) was filtered through a 0.45 μm filter membrane and transferred to a 10 mL syringe. The syringe was equipped with a No. 25 stainless steel needle. The syringe and the pump were connected by a syringe pump. The flow rate was set to 0.8 mL / h, the voltage to 12 kV, and the distance to 12 cm. The collected spinning fibers were placed in a muffle furnace and heated to 130 °C at a rate of 2 °C / min and held for 30 min. Then, the fibers were oxidized in an air atmosphere at 240 °C for 70 min. The stabilized fibers were then placed in a tube furnace and heated to 700 °C at a rate of 5 °C / min. Ammonia was mixed in a nitrogen atmosphere, with the ammonia flow rate accounting for 10% of the total gas flow rate. The fibers were carbonized for 70 min and cooled. Through electrospinning and high-temperature carbonization, a fiber structure with porous flame-retardant sites on the surface was obtained. After pre-oxidation and carbonization, polyacrylonitrile formed a carbon fiber skeleton and retained nitrogen-doped active sites. The modified layered nanofibers were then processed. Silicates are embedded within fibers in the form of exfoliated nanosheets, improving the stability of the structure after carbonization and preventing pore collapse. During the carbonization stage, the infiltration of ammonia and the action of residual polyacrylonitrile molecules form a nitrogen-doped carbon network structure, creating a three-dimensional network in the plastic matrix. This not only inhibits the slippage of plastic molecular chains but also enhances the tensile strength and impact resistance of the material through stress transfer. Simultaneously, the carbon fibers form a char layer during combustion, isolating oxygen and heat and delaying combustion. Nitrogen-doped sites promote polymer catalysis to form char, creating a dense char layer that enhances flame retardant properties. The physical barrier of the modified layered nanosilicates also helps to block gas diffusion and heat conduction. Furthermore, the modified layered nanosilicates promote fiber dispersion, prevent agglomeration, and optimize conductive pathways. Carbon fibers provide a conductive network, while nitrogen doping provides additional free electrons, reducing resistivity and improving conductivity, resulting in nitrogen-doped carbon nanofibers supported on layered nanosilicates.

[0047] This embodiment provides a method for preparing functional plastic fiber masterbatch material, specifically including the following steps:

[0048] S1. Disperse 4.0 g of ammonium polyphosphate in 50 mL of anhydrous methanol and sonicate for 0.5 h to form dispersion I. Mix 600.0 mg of γ-cyclodextrin and 200.0 mg of potassium hydroxide in 30 mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30 mL of anhydrous methanol. The amounts of Pluronic F127 and carboxylated carbon nanotubes added are 150.0 mg and 10.0 mg, respectively. The carboxylated carbon nanotubes have carboxyl groups on their surface, which can interact with the hydrophilic PEO segments of Pluronic F127 through hydrogen bonds to form a more stable dispersion system. The hydrophobic PPO segments encapsulate the nonpolar regions of the carbon nanotubes, forming a "micelle-nanotube" composite structure, further inhibiting aggregation. Sonicate for 20 min to form solution III. Then, add solutions II and III dropwise to dispersion I sequentially. Stirred at ℃ for 2 h, centrifuged, collected the particles, washed three times with anhydrous ethanol and anhydrous methanol respectively, and vacuum dried. Ammonium polyphosphate is used as the core to provide expansion flame retardant function. γ-cyclodextrin encapsulates ammonium polyphosphate through hydrogen bonding or physical adsorption. One end of the amphiphilic block of Pluronic F127 is combined with γ-cyclodextrin, and the other end is connected to carboxylated carbon nanotubes to form a multilayer stable coating, which improves the compatibility with the plastic matrix, avoids migration and precipitation during melt processing, and enhances the interfacial stability. Among them, carboxylated carbon nanotubes not only provide nano-reinforcement effect, which is beneficial to the improvement of mechanical properties, but also promote the formation of dense carbon layer, and synergistically enhance the maze effect with γ-cyclodextrin, stabilize the carbon layer structure, and reduce the propagation of carbon layer cracks. The hydrophobic cavity of γ-cyclodextrin and the hydrophilic outer wall also form a barrier region to delay the escape of combustible gases. At the same time, the uniformly dispersed carboxylated carbon nanotubes can build a conductive network on the surface of the composite, reduce resistivity, and obtain γ-cyclodextrin modified composite particles.

[0049] S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of a 60% (w / w) methanol solution and sonicate for 30 min. This is prepared as dispersion A. Dissolve 80.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol, and then add 20.0 mg of zinc nitrate hexahydrate. The mild coordination effect of zinc ions reduces the brittleness caused by excessive cross-linking and also makes the metal-organic framework material more flexible, preventing it from becoming brittle during injection molding shearing. It is easily broken; during combustion, zinc ions are converted into nano-ZnO, filling the pores of the carbon layer and making it denser. Furthermore, the introduction of zinc ions narrows the band gap of the metal-organic framework material, and its tetrahedral coordination configuration promotes interfacial contact with carboxylated carbon nanotubes, optimizing the percolation network and thus enhancing mechanical properties, flame retardancy, and conductivity. Solution B is prepared for later use. 0.2 g of 3,5-diamino-1,2,4-triazole is dissolved in 50 mL of anhydrous methanol to prepare solution C. Then, solutions B and C are prepared according to... The mixture was added dropwise to dispersion A, heated to 40°C, stirred for 2 hours, centrifuged, and the precipitate was washed three times with anhydrous methanol. Finally, it was soaked in a 0.5% oleic acid methanol solution for 20 minutes, removed, and supercritically dried. The composite particles modified with γ-cyclodextrin served as the core layer, with a Co / Zn bimetallic organic framework in the middle layer and an outer shell coating oleic acid molecules, improving compatibility with the plastic matrix and exhibiting a porous and interconnected structure. Through the hierarchical channel effect, the nanofiller function was better utilized, restricting the movement of plastic molecular chains and absorbing impact energy through pore wall deformation, significantly enhancing mechanical properties. At the same time, the Co / Zn bimetallic organic framework decomposed into metal oxides at high temperatures, catalyzing the formation of a dense carbon layer in the polymer, isolating heat and oxygen. Through tortuous porous channels, the conduction and diffusion of heat were prolonged. The difference in atomic radii of Co / Zn bimetals led to an increase in lattice stress and dislocation density, promoting electron transition and conduction, which also helped improve flame retardancy and conductivity, resulting in a multi-level composite functional material.

[0050] S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 130°C. Annealing pretreatment can eliminate surface adsorbed water, stabilize nitrogen-containing functional groups, and avoid gas generation during subsequent high-temperature extrusion decomposition. Then, it is mixed with the multi-level composite functional material described in step S2, followed by the addition of polypropylene, antioxidant, and calcium stearate. The mixture is homogeneous, with the antioxidant consisting of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The feeding section temperature is controlled at 160°C, and the melt extrusion temperature is controlled at 180°C. During the melt extrusion process, the layered nano-silicate-loaded nitrogen-doped carbon nanofibers can wrap around the surface of the multi-level composite functional material to form an interpenetrating network. The polar groups introduced by nitrogen doping can form hydrogen bonds or coordination with the metal nodes of the multi-level composite functional material, enhancing the interfacial bonding with the polypropylene matrix. This is beneficial for the filler to improve the mechanical properties, flame retardancy, and conductivity of plastics, broadening the application of plastics and obtaining functional plastic fiber masterbatch material.

[0051] Example 3

[0052] This embodiment proposes a functional plastic fiber masterbatch material, comprising the following components in parts by weight: 7.5 parts of layered nano-silicate-supported nitrogen-doped carbon nanofibers, 15 parts of multi-level composite functional material, 80 parts of polypropylene, 2 parts of antioxidant, and 4 parts of calcium stearate.

[0053] Nitrogen-doped carbon nanofibers supported on layered nanosilicates are made from the following components in parts by weight: 1.5 parts modified layered nanosilicates, 8 parts polyacrylonitrile, 3 parts polymethyl methacrylate, 1.5 parts urea, and 1.5 parts melamine.

[0054] The preparation method of nitrogen-doped carbon nanofibers supported on layered nanosilicates specifically includes the following steps:

[0055] (1) Disperse layered nano-silicate in 50 mL of deionized water. The amount of layered nano-silicate added is 0.75 g. When layered nano-silicate is used as a nanofiller for plastics, it can improve the flame retardancy of plastics through physical barrier and catalytic carbonization mechanism, and also improve the tensile strength, impact toughness and other mechanical properties of plastics. After ultrasonic treatment for 40 min, a suspension is obtained for later use. Then, 0.07 g of hexadecyltrimethylammonium bromide is dissolved in 20 mL of 45 °C water and stirred until completely dissolved. Then, while stirring, the hexadecyltrimethylammonium bromide solution is added dropwise to the suspension over 25 min. In the flotation solution, the mixture was stirred at 65℃ for 24 hours, centrifuged at 14000 rpm for 12.5 min, and the precipitate was washed three times alternately with deionized water and ethanol solution, dried, and ground. Hexadecyltrimethylammonium bromide was inserted into the silicate interlayer through cation exchange, which expanded the interlayer spacing and facilitated the embedding of polymer molecular chains. At the same time, the long alkyl chains of hexadecyltrimethylammonium bromide covered the silicate surface, changing it from hydrophilic to hydrophobic, which improved the compatibility with the plastic matrix and helped to exert the functions of reinforcement, toughening, and flame retardancy, thus obtaining modified layered nano silicate.

[0056] (2) The modified layered nano-silicate described in step (1) is dispersed in a mixed solvent of 10 mL of N,N-dimethylformamide and acetone, wherein the volume ratio of N,N-dimethylformamide to acetone is 7:3. The mixture is stirred continuously for 1.5 h, then 0.15 g of urea and 0.15 g of melamine are added and stirred for 15 min. Then, 0.3 g of polymethyl methacrylate is added. Polymethyl methacrylate can reduce the viscosity of the spinning solution and improve spinnability. At the same time, as a pore-forming aid, it further optimizes the spinning process. The porous structure of the fiber was adjusted by adding 0.8 g of polyacrylonitrile and stirring at 42.5 °C for 10 h. In this process, the modified layered nano-silicate is dispersed in the polymer matrix to form a nano-brick-gravel structure. Polyacrylonitrile provides a rigid skeleton, polymethyl methacrylate fills the pores, and urea and melamine are uniformly distributed at the molecular level between polymer chains, which is beneficial for the subsequent heat treatment to generate porous or flame-retardant active sites. A nanocomposite system with excellent dispersion stability, flame retardancy and spinning flowability was prepared, and a spinning precursor solution was obtained.

[0057] (3) The spinning precursor solution described in step (2) was filtered through a 0.45 μm filter membrane and transferred to a 10 mL syringe. The syringe was equipped with a No. 25 stainless steel needle. The syringe and the pump were connected by a syringe pump. The flow rate was set to 0.9 mL / h, the voltage to 15 kV, and the distance to 13.5 cm. The collected spinning fibers were placed in a muffle furnace and heated to 140 °C at a rate of 2 °C / min and held for 30 min. Then, the fibers were oxidized in an air atmosphere at 245 °C for 75 min. The stabilized fibers were then placed in a tube furnace and heated to 750 °C at a rate of 5 °C / min. Ammonia was mixed in a nitrogen atmosphere, with the ammonia flow rate accounting for 15% of the total gas flow rate. The fibers were carbonized for 80 min and cooled. Through electrospinning and high-temperature carbonization, a fiber structure with porous flame-retardant sites on the surface was obtained. After pre-oxidation and carbonization, polyacrylonitrile formed a carbon fiber skeleton and retained nitrogen-doped active sites. The modified layered nanofibers were then processed. The layered silicate nanofibers are embedded in the fibers in the form of exfoliated nanosheets, which improves the stability of the structure after carbonization and prevents pore collapse. During the carbonization stage, the infiltration of ammonia and the action of residual polyacrylonitrile molecules form a nitrogen-doped carbon network structure, forming a three-dimensional network in the plastic matrix. This not only inhibits the slippage of plastic molecular chains, but also improves the tensile strength and impact resistance of the material through stress transfer. At the same time, the carbon fibers form a char layer during combustion, which isolates oxygen and heat and delays combustion. The nitrogen doping sites promote the catalytic carbonization of polymers, forming a dense char layer and enhancing flame retardant properties. The physical barrier of the modified layered silicate nanofibers also helps to block gas diffusion and heat conduction. Furthermore, the modified layered silicate nanofibers promote fiber dispersion, avoid agglomeration, and optimize the conductive pathway. The carbon fibers provide a conductive network, and nitrogen doping provides additional free electrons, reducing resistivity and improving conductivity, resulting in nitrogen-doped carbon nanofibers supported on layered silicate nanofibers.

[0058] This embodiment provides a method for preparing functional plastic fiber masterbatch material, specifically including the following steps:

[0059] S1. Disperse 4.5g of ammonium polyphosphate in 50mL of anhydrous methanol and sonicate for 0.75h to form dispersion I. Mix 625.0mg of γ-cyclodextrin and 250.0mg of potassium hydroxide in 30mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30mL of anhydrous methanol. The amounts of Pluronic F127 and carboxylated carbon nanotubes added are 175.0mg and 12.5mg, respectively. The carboxylated carbon nanotubes have carboxyl groups on their surface, which can interact with the hydrophilic PEO segments of Pluronic F127 through hydrogen bonds to form a more stable dispersion system. The hydrophobic PPO segments encapsulate the nonpolar regions of the carbon nanotubes, forming a "micelle-nanotube" composite structure, further inhibiting aggregation. Sonicate for 25min to form solution III. Then, add solutions II and III dropwise to dispersion I sequentially. Stirred at ℃ for 2.5 h, centrifuged, collected the particles, washed 4 times with anhydrous ethanol and anhydrous methanol respectively, and vacuum dried. Ammonium polyphosphate is used as the core to provide expansion flame retardant function. γ-cyclodextrin encapsulates ammonium polyphosphate through hydrogen bonding or physical adsorption. One end of the amphiphilic block of Pluronic F127 is combined with γ-cyclodextrin, and the other end is connected to carboxylated carbon nanotubes to form a multilayer stable coating, which improves the compatibility with the plastic matrix, avoids migration and precipitation during melt processing, and enhances the interfacial stability. Among them, carboxylated carbon nanotubes not only provide nano-reinforcement effect, which is beneficial to the improvement of mechanical properties, but also promote the formation of dense carbon layer, and synergistically enhance the maze effect with γ-cyclodextrin, stabilize the carbon layer structure, and reduce the propagation of carbon layer cracks. The hydrophobic cavity of γ-cyclodextrin and the hydrophilic outer wall also form a barrier region to delay the escape of combustible gases. At the same time, the uniformly dispersed carboxylated carbon nanotubes can build a conductive network on the surface of the composite, reduce resistivity, and obtain γ-cyclodextrin modified composite particles.

[0060] S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of a 60% (w / w) methanol solution and sonicate for 35 min. This is prepared as dispersion A. Dissolve 85.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol, and then add 25.0 mg of zinc nitrate hexahydrate. The mild coordination effect of zinc ions reduces the brittleness caused by excessive cross-linking and also makes the metal-organic framework material more flexible, making it less prone to breakage during injection molding shearing. During crushing and combustion, zinc ions are converted into nano-ZnO, filling the pores of the carbon layer and making it denser. Furthermore, the introduction of zinc ions narrows the band gap of the metal-organic framework material, and its tetrahedral coordination configuration promotes interfacial contact with carboxylated carbon nanotubes, optimizing the percolation network and thus enhancing mechanical properties, flame retardancy, and conductivity. This is prepared as solution B. 0.25 g of 3,5-diamino-1,2,4-triazole is dissolved in 50 mL of anhydrous methanol, prepared as solution C. Then, solutions B and C are sequentially... The mixture was added dropwise to dispersion A, heated to 45℃, stirred for 2.5 h, centrifuged, and the precipitate was washed three times with anhydrous methanol. Finally, it was soaked in a 0.75% oleic acid methanol solution for 25 min, removed, and supercritical dried. The composite particles modified with γ-cyclodextrin served as the core layer, with a Co / Zn bimetallic organic framework in the middle layer and an outer shell coating oleic acid molecules, improving compatibility with the plastic matrix and exhibiting a porous and interconnected structure. Through the hierarchical channel effect, the nanofiller function was better utilized, restricting the movement of plastic molecular chains and absorbing impact energy through pore wall deformation, significantly enhancing mechanical properties. At the same time, the Co / Zn bimetallic organic framework decomposed into metal oxides at high temperatures, catalyzing the polymer to form a dense carbon layer, isolating heat and oxygen. Through tortuous porous channels, the conduction and diffusion of heat were prolonged. The difference in atomic radii of Co / Zn bimetals led to an increase in lattice stress and dislocation density, promoting electron transition and conduction, which also helped improve flame retardancy and conductivity, resulting in a multi-level composite functional material.

[0061] S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 140°C. This annealing pretreatment eliminates surface adsorbed water, stabilizes nitrogen-containing functional groups, and prevents gas generation during subsequent high-temperature extrusion decomposition. The mixture is then first mixed with the multi-level composite functional material described in step S2, followed by the addition of polypropylene, antioxidants, and calcium stearate. The mixture is thoroughly mixed, with the antioxidants consisting of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The feeding section temperature is controlled at 165°C, and the melt extrusion temperature at 190°C. During melt extrusion, the layered nano-silicate-loaded nitrogen-doped carbon nanofibers can entangle on the surface of the multi-level composite functional material, forming an interpenetrating network. The polar groups introduced by nitrogen doping can form hydrogen bonds or coordination interactions with the metal nodes of the multi-level composite functional material, enhancing the interfacial bonding with the polypropylene matrix. This improves the mechanical properties, flame retardancy, and conductivity of the plastic, broadening the application of the plastic and yielding a functional plastic fiber masterbatch material.

[0062] Example 4

[0063] This embodiment proposes a functional plastic fiber masterbatch material, comprising the following components in parts by weight: 10 parts of layered nano-silicate-supported nitrogen-doped carbon nanofibers, 10 parts of multi-level composite functional material, 90 parts of polypropylene, 3 parts of antioxidant, and 5 parts of calcium stearate.

[0064] Nitrogen-doped carbon nanofibers supported on layered nanosilicates are made from the following components in parts by weight: 2 parts modified layered nanosilicates, 6 parts polyacrylonitrile, 1 part polymethyl methacrylate, 2 parts urea, and 2 parts melamine.

[0065] The preparation method of nitrogen-doped carbon nanofibers supported on layered nanosilicates specifically includes the following steps:

[0066] (1) Disperse layered nano-silicate in 50 mL of deionized water. The amount of layered nano-silicate added is 1.0 g. When layered nano-silicate is used as a nanofiller for plastics, it can improve the flame retardancy of plastics through physical barrier and catalytic carbonization mechanism, and also improve the tensile strength, impact toughness and other mechanical properties of plastics. After ultrasonic treatment for 30 min, a suspension is obtained for later use. Then, 0.04 g of hexadecyltrimethylammonium bromide is dissolved in 20 mL of 50 °C water and stirred until completely dissolved. Then, while stirring, the hexadecyltrimethylammonium bromide solution is added dropwise to the suspension over 30 min. In the flotation solution, the mixture was stirred at 70℃ for 24 hours, centrifuged at 16000 rpm for 10 minutes, and the precipitate was washed three times alternately with deionized water and ethanol solution, dried, and ground. Hexadecyltrimethylammonium bromide was inserted into the silicate interlayer through cation exchange, which expanded the interlayer spacing and facilitated the embedding of polymer molecular chains. At the same time, the long alkyl chains of hexadecyltrimethylammonium bromide covered the silicate surface, changing it from hydrophilic to hydrophobic, which improved the compatibility with the plastic matrix and facilitated the reinforcing, toughening, and flame-retardant effects, resulting in modified layered nano silicate.

[0067] (2) The modified layered nano-silicate described in step (1) is dispersed in a mixed solvent of 10 mL of N,N-dimethylformamide and acetone, wherein the volume ratio of N,N-dimethylformamide to acetone is 7:3. The mixture is stirred continuously for 1 h, then 0.2 g of urea and 0.2 g of melamine are added and stirred for 10 min. Then, 0.1 g of polymethyl methacrylate is added. Polymethyl methacrylate can reduce the viscosity of the spinning solution and improve spinnability. At the same time, it can also act as a pore-forming aid to further optimize the spinning process. The porous structure of the fiber was adjusted, and finally 0.6 g of polyacrylonitrile was added. The mixture was stirred at 45 °C for 8 h. In this process, the modified layered nano-silicate was dispersed in the polymer matrix to form a nano-brick-gravel structure. Polyacrylonitrile provided a rigid skeleton, polymethyl methacrylate filled the pores, and urea and melamine were uniformly distributed at the molecular level between the polymer chains, which is beneficial for the subsequent heat treatment to generate porous or flame-retardant active sites. A nanocomposite system with excellent dispersion stability, flame retardancy and spinning flowability was prepared, and a spinning precursor solution was obtained.

[0068] (3) The spinning precursor solution described in step (2) was filtered through a 0.45 μm filter membrane and transferred to a 10 mL syringe. The syringe was equipped with a No. 25 stainless steel needle. The syringe and the pump were connected by a syringe pump. The flow rate was set to 1.0 mL / h, the voltage to 18 kV, and the distance to 15 cm. The collected spinning fibers were placed in a muffle furnace and heated to 150 °C at a rate of 2 °C / min and held for 30 min. Then, the fibers were oxidized in an air atmosphere at 250 °C for 70 min. The stabilized fibers were then placed in a tube furnace and heated to 800 °C at a rate of 5 °C / min. Ammonia was mixed in a nitrogen atmosphere, with the ammonia flow rate accounting for 10% of the total gas flow rate. The fibers were carbonized for 90 min and cooled. Through electrospinning and high-temperature carbonization, a fiber structure with porous flame-retardant sites on the surface was obtained. After pre-oxidation and carbonization, polyacrylonitrile formed a carbon fiber skeleton and retained nitrogen-doped active sites. The modified layered nanofibers were then processed. Silicates are embedded within fibers in the form of exfoliated nanosheets, improving the stability of the structure after carbonization and preventing pore collapse. During the carbonization stage, the infiltration of ammonia and the action of residual polyacrylonitrile molecules form a nitrogen-doped carbon network structure, creating a three-dimensional network in the plastic matrix. This not only inhibits the slippage of plastic molecular chains but also enhances the tensile strength and impact resistance of the material through stress transfer. Simultaneously, the carbon fibers form a char layer during combustion, isolating oxygen and heat and delaying combustion. Nitrogen-doped sites promote polymer catalysis to form char, creating a dense char layer that enhances flame retardant properties. The physical barrier of the modified layered nanosilicates also helps to block gas diffusion and heat conduction. Furthermore, the modified layered nanosilicates promote fiber dispersion, prevent agglomeration, and optimize conductive pathways. Carbon fibers provide a conductive network, while nitrogen doping provides additional free electrons, reducing resistivity and improving conductivity, resulting in nitrogen-doped carbon nanofibers supported on layered nanosilicates.

[0069] This embodiment provides a method for preparing functional plastic fiber masterbatch material, specifically including the following steps:

[0070] S1. Disperse 5.0 g of ammonium polyphosphate in 50 mL of anhydrous methanol and sonicate for 0.5 h to form dispersion I. Mix 600.0 mg of γ-cyclodextrin and 300.0 mg of potassium hydroxide in 30 mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30 mL of anhydrous methanol. The amounts of Pluronic F127 and carboxylated carbon nanotubes added are 150.0 mg and 15.0 mg, respectively. The carboxylated carbon nanotubes have carboxyl groups on their surface, which can interact with the hydrophilic PEO segments of Pluronic F127 through hydrogen bonds to form a more stable dispersion system. The hydrophobic PPO segments encapsulate the nonpolar regions of the carbon nanotubes, forming a "micelle-nanotube" composite structure, further inhibiting aggregation. Sonicate for 20 min to form solution III. Then, add solutions II and III dropwise to dispersion I sequentially. Stirred at ℃ for 2 h, centrifuged, and the particles were collected. They were washed five times with anhydrous ethanol and anhydrous methanol, respectively, and then vacuum dried. Ammonium polyphosphate was used as the core to provide expansion and flame retardant function. γ-cyclodextrin coated the ammonium polyphosphate through hydrogen bonding or physical adsorption. One end of the amphiphilic block of Pluronic F127 was combined with γ-cyclodextrin, and the other end was connected to carboxylated carbon nanotubes to form a multilayer stable coating, which improved the compatibility with the plastic matrix, prevented migration and precipitation during melt processing, and enhanced the interfacial stability. Among them, carboxylated carbon nanotubes not only provided nano-reinforcement effect, which is beneficial to the improvement of mechanical properties, but also promoted the formation of dense carbon layers. They also synergistically enhanced the maze effect with γ-cyclodextrin, stabilized the carbon layer structure, and reduced the propagation of carbon layer cracks. The hydrophobic cavity of γ-cyclodextrin and the hydrophilic outer wall also formed a barrier region to delay the escape of flammable gases. At the same time, the uniformly dispersed carboxylated carbon nanotubes can build a conductive network on the surface of the composite to reduce resistivity, thus obtaining γ-cyclodextrin modified composite particles.

[0071] S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of a 60% (w / w) methanol solution and sonicate for 30 min. This is prepared as dispersion A. Dissolve 90.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol, and then add 20.0 mg of zinc nitrate hexahydrate. The mild coordination effect of zinc ions reduces the brittleness caused by excessive cross-linking and also makes the metal-organic framework material more flexible, preventing it from becoming brittle during injection molding shearing. It is easily broken; during combustion, zinc ions are converted into nano-ZnO, filling the pores of the carbon layer and making it denser. Furthermore, the introduction of zinc ions narrows the band gap of the metal-organic framework material, and its tetrahedral coordination configuration promotes interfacial contact with carboxylated carbon nanotubes, optimizing the percolation network and thus enhancing mechanical properties, flame retardancy, and conductivity. Solution B is prepared for later use. 0.3 g of 3,5-diamino-1,2,4-triazole is dissolved in 50 mL of anhydrous methanol to prepare solution C. Then, solutions B and C are prepared according to... The mixture was added dropwise to dispersion A, heated to 50°C, stirred for 2 hours, centrifuged, and the precipitate was washed three times with anhydrous methanol. Finally, it was soaked in a 1.0% oleic acid methanol solution for 20 minutes, removed, and supercritically dried. The composite particles modified with γ-cyclodextrin served as the core layer, with a Co / Zn bimetallic organic framework in the middle layer and an outer shell coating oleic acid molecules, improving compatibility with the plastic matrix and exhibiting a porous and interconnected structure. Through the hierarchical channel effect, the nanofiller function was better utilized, restricting the movement of plastic molecular chains and absorbing impact energy through pore wall deformation, significantly enhancing mechanical properties. At the same time, the Co / Zn bimetallic organic framework decomposed into metal oxides at high temperatures, catalyzing the formation of a dense carbon layer in the polymer, isolating heat and oxygen. Through tortuous porous channels, the conduction and diffusion of heat were prolonged. The difference in atomic radii between Co / Zn bimetals led to an increase in lattice stress and dislocation density, promoting electron transition and conduction, which also helped improve flame retardancy and conductivity, resulting in a multi-level composite functional material.

[0072] S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 150°C. This annealing pretreatment eliminates surface adsorbed water, stabilizes nitrogen-containing functional groups, and prevents gas generation during subsequent high-temperature extrusion decomposition. The mixture is then first mixed with the multi-level composite functional material described in step S2, followed by the addition of polypropylene, antioxidants, and calcium stearate. The mixture is thoroughly mixed, with the antioxidants consisting of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The feeding section temperature is controlled at 170°C, and the melt extrusion temperature at 180°C. During melt extrusion, the layered nano-silicate-loaded nitrogen-doped carbon nanofibers can entangle on the surface of the multi-level composite functional material, forming an interpenetrating network. The polar groups introduced by nitrogen doping can form hydrogen bonds or coordination interactions with the metal nodes of the multi-level composite functional material, enhancing the interfacial bonding with the polypropylene matrix. This improves the mechanical properties, flame retardancy, and conductivity of the plastic, broadening the application of the plastic and yielding a functional plastic fiber masterbatch material.

[0073] Comparative Example 1

[0074] This comparative example provides a functional plastic fiber masterbatch material, which differs from Example 1 in that the layered nano-silicate-loaded nitrogen-doped carbon nanofibers do not contain polyacrylonitrile and ammonia is not introduced during the carbonization process; in the preparation method of the layered nano-silicate-loaded nitrogen-doped carbon nanofibers, polyacrylonitrile is not added in step (2) and nitrogen is only introduced during the carbonization process in step (3), without ammonia; the preparation method of the functional plastic fiber masterbatch material is the same as that of Example 1.

[0075] Comparative Example 2

[0076] This comparative example provides a functional plastic fiber masterbatch material, which differs from Example 1 in that the multi-layered composite functional material does not contain Pluronic F127; the preparation method of layered nano-silicate-loaded nitrogen-doped carbon nanofibers is the same as in Example 1; and Pluronic F127 is not added in step S1 of the preparation method of the functional plastic fiber masterbatch material.

[0077] Comparative Example 3

[0078] This comparative example provides a functional plastic fiber masterbatch material, which differs from Example 1 in that the multi-layered composite functional material does not contain a Co / Zn bimetallic organic framework; the preparation method of the layered nanosilicate-loaded nitrogen-doped carbon nanofibers is the same as in Example 1; and step S2 of the preparation method of the functional plastic fiber masterbatch material does not include cobalt nitrate hexahydrate, zinc nitrate hexahydrate, and 3,5-diamino-1,2,4-triazole.

[0079] Experimental Example 1

[0080] Mechanical property test

[0081] Test samples: functional plastic fiber masterbatch materials prepared in Examples 1-4 and Comparative Examples 1-3.

[0082] Test method: The test samples are prepared into standard specimens (GB / T17037.1-2019) by injection molding machine, and mechanical properties are tested. Among them, tensile properties are tested according to standard GB / T1040.1-2018, and impact strength is determined according to standard GB / T1843-2008 for cantilever beam notched impact strength.

[0083] Figure 2 The figures show the mechanical property results of Examples 1-4 and Comparative Examples 1-3; as shown, the tensile strength and impact strength of Examples 1-4 are 96-105 MPa and 23.8-25.6 KJ / m, respectively. 2 This indicates strong mechanical properties; the tensile strength and impact strength of comparative examples 1-3 were 71-82 MPa and 14.1-18.7 KJ / m, respectively. 2 The results indicate that the mechanical properties are generally average. Comparative Example 1, with its layered nano-silicate-loaded nitrogen-doped carbon nanofibers, lacks polyacrylonitrile and ammonia is not introduced during carbonization, thus failing to form a porous carbon fiber framework. This hinders the suppression of plastic molecular chain slippage and the improvement of tensile strength and impact resistance through stress transfer, resulting in generally average mechanical properties. Comparative Example 2, with its multi-level composite functional material, lacks Pluronic F127, preventing the connection of γ-cyclopaste and carboxylated carbon nanotubes via amphiphilic block copolymerization. This negatively impacts interfacial stability and the suppression of carboxylated carbon nanotube aggregation, leading to generally average mechanical properties. Comparative Example 3, with its multi-level composite functional material, lacks a Co / Zn bimetallic organic framework, hindering the formation of a porous, interconnected composite structure. This limits the filling effect of hierarchical channels and the suppression of plastic molecular chain movement, resulting in generally average mechanical properties.

[0084] Experiment Example 2

[0085] Flame retardant performance test

[0086] Test samples: functional plastic fiber masterbatch materials prepared in Examples 1-4 and Comparative Examples 1-3.

[0087] Test method: The test sample is prepared into a standard sample strip (100mm×10mm×4mm) by injection molding machine, and then the limiting oxygen index is tested according to the standard GB / T2406.2-2009 "Determination of burning behavior of plastics by oxygen index method". The higher the limiting oxygen index (%), the better the flame retardancy.

[0088] Figure 3The figures show the limiting oxygen index (LOI) results for Examples 1-4 and Comparative Examples 1-3. As shown, the LIOI for Examples 1-4 is 29-33%, indicating good flame retardancy; the LIOI for Comparative Examples 1-3 is 16-25%, indicating moderate flame retardancy. Comparative Example 1's layered nano-silicate-supported nitrogen-doped carbon nanofibers do not contain polyacrylonitrile and ammonia is not introduced during carbonization, thus failing to form a carbon fiber structure with porous flame-retardant sites. Consequently, a dense char layer cannot be formed during combustion, resulting in moderate flame retardancy. The multi-level composite functional material in Comparative Example 2 does not contain Pluronic F127, which cannot inhibit the aggregation of carboxylated carbon nanotubes, thus hindering the formation of a dense carbon layer. This reduces the maze effect between carboxylated carbon nanotubes and γ-cyclodextrin, which is detrimental to stabilizing the carbon layer structure and results in mediocre flame retardancy. The multi-level composite functional material in Comparative Example 3 does not contain a Co / Zn bimetallic organic framework, which cannot decompose into metal oxides at high temperatures. This is detrimental to catalyzing the formation of a dense carbon layer and isolating heat and oxygen, resulting in mediocre flame retardancy.

[0089] Experimental Example 3

[0090] Electrical conductivity experiment

[0091] Test samples: functional plastic fiber masterbatch materials prepared in Examples 1-4 and Comparative Examples 1-3.

[0092] Test method: Prepare a standard circular sample (50 mm in diameter and 3 mm in thickness) and then perform volume resistivity test according to the plastic resistivity test standard GB / T1410-2006 to obtain the volume resistivity (Ω·cm).

[0093] Figure 4 The figures show the volume resistivity results for Examples 1-4 and Comparative Examples 1-3. As shown, the volume resistivity of Examples 1-4 is 12-21 Ω·cm, indicating good conductivity; the volume resistivity of Comparative Examples 1-3 is 43-65 Ω·cm, indicating moderate conductivity. Comparative Example 1's layered nano-silicate-loaded nitrogen-doped carbon nanofibers do not contain polyacrylonitrile, and ammonia is not introduced during carbonization, thus failing to form carbon fibers that can provide a conductive network, and also lacking nitrogen-doped sites that can provide additional free electrons, resulting in moderate conductivity. Comparative Example 2's multi-level composite functional material does not contain PluronicF127, which is detrimental to the uniform dispersion of carboxylated carbon nanotubes and cannot optimize the conductive network, resulting in moderate conductivity. Comparative Example 3's multi-level composite functional material does not contain a Co / Zn bimetallic organic framework, which cannot induce an increase in lattice stress and dislocation density through the difference in bimetallic atomic radii, thus hindering the promotion of electron transition conduction, resulting in moderate conductivity.

[0094] The above experimental results show that the mechanical properties, flame retardant properties, and electrical conductivity of Examples 1-4 of the present invention are significantly better than those of Comparative Examples 1-3. Among them, Example 1, which uses layered nano-silicate loaded nitrogen-doped carbon nanofibers and multi-level composite functional materials, has stronger mechanical properties, better flame retardant properties, and better electrical conductivity. The combination of layered nano-silicate loaded nitrogen-doped carbon nanofibers and multi-level composite functional materials not only enhances the interfacial compatibility and bonding with the polypropylene matrix, but also synergistically enhances the mechanical properties, flame retardant properties, and electrical conductivity of the plastic through the formed interpenetrating network structure.

[0095] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

[0096] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A functional plastic fiber masterbatch material, characterized in that: The functional plastic fiber masterbatch material comprises the following components in parts by weight: 5-10 parts of layered nano-silicate-supported nitrogen-doped carbon nanofibers, 10-20 parts of multi-level composite functional material, 70-90 parts of polypropylene, 1-3 parts of antioxidant, and 3-5 parts of calcium stearate; the layered nano-silicate-supported nitrogen-doped carbon nanofibers are made from the following components in parts by weight: 1-2 parts of modified layered nano-silicate, 6-10 parts of polyacrylonitrile, 1-5 parts of polymethyl methacrylate, 1-2 parts of urea, and 1-2 parts of melamine. The preparation method of the functional plastic fiber masterbatch material specifically includes the following steps: S1. Disperse 4.0-5.0g of ammonium polyphosphate in 50mL of anhydrous methanol and sonicate for 0.5-1h to form dispersion I. Mix 600.0-650.0mg of γ-cyclodextrin with 200.0-300.0mg of potassium hydroxide in 30mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30mL of anhydrous methanol and sonicate for 20-30min to form solution III. Then add solution II and solution III dropwise to dispersion I. Stir at 25℃ for 2-3h, centrifuge, collect particles, wash with anhydrous ethanol and anhydrous methanol 3-5 times respectively, and vacuum dry to obtain γ-cyclodextrin modified composite particles. S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of 60% methanol solution and sonicate for 30-40 min to obtain dispersion A. Dissolve 80.0-90.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol and add zinc nitrate hexahydrate to obtain solution B. Dissolve 0.2-0.3 g of 3,5-diamino-1,2,4-triazole in 50 mL of anhydrous methanol to obtain solution C. Then, add solutions B and C dropwise to dispersion A, heat to 40-50℃, stir for 2-3 h, centrifuge, wash the precipitate three times with anhydrous methanol, and finally soak in 0.5-1.0% oleic acid-methanol solution for 20-30 min. Remove and supercritically dry to obtain multi-level composite functional materials. S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 130-150℃, and then mixed with the multi-level composite functional material described in step S2. Polypropylene, antioxidant, and calcium stearate are then added and mixed evenly. The antioxidant consists of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The feeding section temperature is controlled at 160-170℃ and the melt extrusion temperature is controlled at 180-200℃ to obtain functional plastic fiber masterbatch material. The preparation method of the layered nanosilicate-supported nitrogen-doped carbon nanofibers specifically includes the following steps: (1) Disperse layered nano-silicate in 50 mL of deionized water and sonicate for 30-50 min to obtain a suspension for later use. Then dissolve 0.04-0.1 g of hexadecyltrimethylammonium bromide in 20 mL of 40-50 °C water and stir until completely dissolved. Then, while stirring, add the hexadecyltrimethylammonium bromide solution dropwise to the suspension over 20-30 min. Stir at 60-70 °C for 24 h, centrifuge at 12000-16000 rpm for 10-15 min, wash the precipitate three times alternately with deionized water and ethanol solution, dry, and grind to obtain modified layered nano-silicate. (2) Disperse the modified layered nano silicate described in step (1) in a mixed solvent of 10 mL of N,N-dimethylformamide and acetone, wherein the volume ratio of N,N-dimethylformamide and acetone is 7:3, and stir continuously for 1-2 h. Then add 0.1-0.2 g of urea and 0.1-0.2 g of melamine, stir for 10-20 min, then add polymethyl methacrylate, and finally add 0.6-1.0 g of polyacrylonitrile. Stir at 40-45 °C for 8-12 h to obtain the spinning precursor solution. (3) After filtering the spinning precursor solution described in step (2) through a 0.45μm filter membrane, transfer it to a 10mL syringe equipped with a No. 25 stainless steel needle. Connect the syringe and the pump through a syringe pump, set the flow rate to 0.8-1.0mL / h, the voltage to 12-18kV, and the distance to 12-15cm. Place the collected spinning fibers in a muffle furnace, heat them to 130-150℃ at a rate of 2℃ / min and hold for 30min, then oxidize them in an air atmosphere at 240-250℃ for 70-80min. Place the stabilized fibers in a tube furnace and heat them to 700-800℃ at a rate of 5℃ / min. Mix ammonia into the nitrogen atmosphere, with the ammonia flow rate accounting for 10-20% of the total gas flow rate. Carbonize for 70-90min and cool to obtain layered nano-silicate-loaded nitrogen-doped carbon nanofibers.

2. A method for preparing functional plastic fiber masterbatch material according to claim 1, characterized in that: Specifically, the following steps are included: S1. Disperse 4.0-5.0g of ammonium polyphosphate in 50mL of anhydrous methanol and sonicate for 0.5-1h to form dispersion I. Mix 600.0-650.0mg of γ-cyclodextrin with 200.0-300.0mg of potassium hydroxide in 30mL of 30% methanol solution to form solution II. Dissolve Pluronic F127 and carboxylated carbon nanotubes in 30mL of anhydrous methanol and sonicate for 20-30min to form solution III. Then add solution II and solution III dropwise to dispersion I. Stir at 25℃ for 2-3h, centrifuge, collect particles, wash with anhydrous ethanol and anhydrous methanol 3-5 times respectively, and vacuum dry to obtain γ-cyclodextrin modified composite particles. S2. Disperse the γ-cyclodextrin-modified composite particles described in step S1 in 100 mL of 60% methanol solution and sonicate for 30-40 min to obtain dispersion A. Dissolve 80.0-90.0 mg of cobalt nitrate hexahydrate in 80 mL of anhydrous methanol and add zinc nitrate hexahydrate to obtain solution B. Dissolve 0.2-0.3 g of 3,5-diamino-1,2,4-triazole in 50 mL of anhydrous methanol to obtain solution C. Then, add solutions B and C dropwise to dispersion A, heat to 40-50℃, stir for 2-3 h, centrifuge, wash the precipitate three times with anhydrous methanol, and finally soak in 0.5-1.0% oleic acid-methanol solution for 20-30 min. Remove and supercritically dry to obtain multi-level composite functional materials. S3. The layered nano-silicate-loaded nitrogen-doped carbon nanofibers are annealed at 130-150℃, and then mixed with the multi-level composite functional material described in step S2. Polypropylene, antioxidant, and calcium stearate are then added and mixed evenly. The antioxidant consists of equal weights of antioxidant 1010 and antioxidant 168. The mixture is then added to an extruder for melt extrusion and granulation. The feeding section temperature is controlled at 160-170℃ and the melt extrusion temperature is controlled at 180-200℃ to obtain functional plastic fiber masterbatch material.

3. The method for preparing functional plastic fiber masterbatch material according to claim 2, characterized in that: In step S1, the amounts of Pluronic F127 and carboxylated carbon nanotubes added are 150.0-200.0 mg and 10.0-15.0 mg, respectively.

4. The method for preparing functional plastic fiber masterbatch material according to claim 3, characterized in that: In step S2, the amount of zinc nitrate hexahydrate added is 20.0-30.0 mg.

5. The method for preparing functional plastic fiber masterbatch material according to claim 4, characterized in that: In step (1), the amount of layered nano-silicate added is 0.5-1.0g.

6. The method for preparing functional plastic fiber masterbatch material according to claim 5, characterized in that: In step (2), the amount of polymethyl methacrylate added is 0.1-0.5g.

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