Method for recycling waste plastic through modification

Abstract

The invention belongs to the field of environment-friendly materials, and relates to the field of waste plastic recycling, in particular to a method for recycling waste plastics through modification, and the waste plastics are converted into high-performance materials by introducing various novel organic compound modifiers such as CCPFT and MBPOT and combining a unique component formula and process. The method not only solves the problem of environmental pollution caused by waste plastics, but also improves the mechanical property, thermal stability, flame retardance, antibacterial property and the like of the regenerated material. Compared with the prior art, the regenerated material disclosed by the invention has the advantages that various properties are remarkably improved, efficient recovery and resource reutilization of waste plastics are realized, and the regenerated material has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of environmentally friendly materials, and in particular to a method for recycling waste plastics through modification. Background Art

[0002] With the widespread use of plastic products, the amount of waste plastics generated has increased dramatically. Traditional landfill and incineration treatment methods not only occupy a large amount of land resources, but also cause serious environmental pollution. The current waste plastic recycling technology has many shortcomings. The performance of recycled materials is difficult to meet the needs of high-performance applications, and toxic and harmful additives may be used in the regeneration process, posing a potential threat to the environment and human health. In addition, the existing technology also needs to be improved in terms of comprehensive resource utilization and environmental protection. Therefore, it is urgent to develop a new technology that can effectively improve the performance of waste plastic recycled materials while taking into account environmental protection and comprehensive resource utilization. The present invention is based on this background. Summary of the invention

[0003] The invention provides a method for recycling waste plastics by modification. In 80-100 parts by weight of waste plastic recycling system, 5-10 parts by weight of waste liquid crystal panel glass powder with a particle size of 1-5 μm is added to enhance the mechanical properties and dimensional stability of the recycled material; 8-12 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer (PHA to polyether segment ratio is 3:2) is added to improve the flexibility and processing performance of the material and impart biodegradability; 3-6 parts by weight of nano aluminum nitride-carbon nanotube composite thermal conductive filler (nano aluminum nitride-carbon nanotube composite thermal conductive filler) is added to enhance the mechanical properties and dimensional stability of the recycled material; 8-12 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer (PHA to polyether segment ratio is 3:2) is added to enhance ... bio-based polyhydroxyalkanoate-polyether block copolymer (nano aluminum nitride-carbon nanotube composite thermal conductive filler) is added to enhance the mechanical properties and dimensional stability of the recycled material; 3-12 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer (PHA to polyether segment ratio is 3:2) is added to enhance the flexibility and processing performance of the material and impart biodegradability; 3-12 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer (nano aluminum nitride-carbon nanotube composite thermal conductive filler) is added to enhance the mechanical properties and dimensional stability of the recycled material; The material is made of a nano-AlN and carbon nanotube material with a mass ratio of 2:1 to improve thermal conductivity and electrical properties; 2-4 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent (the mass ratio of nano-TiO2 to graphene quantum dots is 3:1) is introduced to give the material antibacterial properties; 1-3 parts by weight of a metal organic framework-derived porous carbon-silicon dioxide composite adsorbent (pore size 2-50nm) is added to remove harmful impurities; 4-6 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules (particle size 5-10μm) are used to realize the self-repair function of the material.

[0004] The waste plastics were modified by plasma-induced in-situ polymerization grafting. Under an argon atmosphere, a mixed gas containing vinyl monomer and initiator was introduced after treatment at 200W power for 5 minutes, and the reaction was carried out at 80℃ for 2 hours to improve the compatibility and surface properties of the material. The pretreated waste plastics were mixed with additives using a supercritical carbon dioxide-assisted foaming molding process, and scCO2 was introduced at 10MPa and 35℃ for 1 hour. After pressure relief, foaming was carried out at 180℃ to reduce the material density and improve the thermal insulation and cushioning properties. During mixing in a twin-screw extruder, 500W microwave radiation and 20kHz ultrasound were applied simultaneously for 10 minutes to promote uniform dispersion of the components. Using an ionic liquid-assisted low-temperature pyrolysis and reconstruction process, the waste plastics and ionic liquids were mixed in a mass ratio of 10:1, pyrolyzed at 200℃ for 3 hours, and the products were separated and purified and reconstructed at 150℃ for 2 hours to achieve low-temperature pyrolysis and reconstruction, improve energy efficiency and reduce pollution.

[0005] It further includes adding 8 parts by weight of 4-(3-(4-acryloxybutoxy)-3-fluorophenyl)-3-(5-methoxy-2-pyrimidinyl)-1,2,4-oxadiazole-5-thiol (AFPOT) as a modifier, which works synergistically with the carbon fiber to increase the tensile strength of the material by 20% to 45 MPa.

[0006] Adding 10 parts by weight of magnesium hydroxide-aluminum hydroxide composite flame retardant synergistically with AFPOT inhibits the decomposition of the material at high temperature, and the initial decomposition temperature is increased by 15°C.

[0007] 5 parts by weight of carbon fiber is mixed in as a reinforcing agent to enhance the overall mechanical properties of the material.

[0008] 2 parts by weight of ultraviolet absorber are introduced to improve the weather resistance of the material.

[0009] The modifier AFPOT is prepared by a specific synthesis method, wherein 4-(3-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thiol are used as raw materials, 4-(3-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and thionyl chloride are reacted at 75° C. for 3 hours in anhydrous toluene with pyridine as a catalyst to prepare acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thiol and triethylamine, and the reaction is stirred at room temperature for 10 hours, and finally the modifier is purified by recrystallization with ethyl acetate and petroleum ether.

[0010] It further includes using waste polycarbonate (PC) as a base material, 75 parts by weight.

[0011] 10 parts by weight of 5-(4-(3-methacryloyloxypropoxy)-3-chlorophenyl)-2-(5-ethoxy-3-pyrazolyl)-1,3,4-thiadiazole-5-sulfide (MCPTS) was added as a modifier, which synergistically acted with glass fiber to increase the bending strength of the material by 22% to 75 MPa.

[0012] Adding 10 parts by weight of melamine-zinc borate compound flame retardant synergistically with MCPTS forms a stable flame retardant system at high temperature, and the limiting oxygen index is increased from 26% to 30%.

[0013] 8 parts by weight of glass fiber is mixed in as a reinforcing agent to improve the rigidity of the material.

[0014] 2 parts by weight of antioxidant are introduced to improve the anti-oxidation performance of the material.

[0015] The synthesis of the modifier MCPTS adopts a specific raw material ratio and reaction conditions, takes 5-(4-(3-methacryloxypropoxy)-3-chlorobenzoic acid) and 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-sulfide as raw materials, reacts 5-(4-(3-methacryloxypropoxy)-3-chlorobenzoic acid) with thionyl chloride at 80° C. for 3.5 hours in anhydrous toluene with pyridine as a catalyst, prepares an acyl chloride, then drops the acyl chloride into an anhydrous ethanol solution containing 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-sulfide and triethylamine, reacts with stirring at room temperature for 11 hours, finally removes the solvent by distillation under reduced pressure, and separates and purifies the obtained product by recrystallization with ethyl acetate and petroleum ether.

[0016] It further includes 85 parts by weight of waste polypropylene (PP) as the base material.

[0017] 6 parts by weight of 3-(4-(4-crotonyloxybutoxy)-3-bromophenyl)-5-(2-quinolyl)-1,2,4-triazole-5-thione (BPQTS) was added as a modifier, which synergized with the aramid fiber to increase the impact strength of the material by 25% to 32 kJ / m 2 .

[0018] 8 parts by weight of magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant was added to synergistically inhibit the high-temperature decomposition of the material with BPQTS, and the initial decomposition temperature was increased by 18°C.

[0019] 5 parts by weight of aramid fiber is mixed in as a reinforcing agent to enhance the toughness of the material.

[0020] 2 parts by weight of light stabilizer is introduced to improve the weather resistance of the material.

[0021] The preparation of the modifier BPQTS involves specific raw material pretreatment and reaction steps. 3-(4-(4-crotonyloxybutoxy)-3-bromobenzoic acid) and 2-quinolinecarboxyhydrazide-5-thione are used as raw materials. 3-(4-(4-crotonyloxybutoxy)-3-bromobenzoic acid) and dichlorothione are reacted in anhydrous toluene with pyridine as a catalyst at 78° C. for 3 hours to prepare an acid chloride. The acid chloride is then added dropwise to an anhydrous ethanol solution containing 2-quinolinecarboxyhydrazide-5-thione and triethylamine. The mixture is stirred at room temperature for reaction for 10 hours. Finally, the modified agent is recrystallized and purified using ethyl acetate and petroleum ether.

[0022] It further includes using waste polyethylene terephthalate (PET) as a base material, 70 parts by weight.

[0023] 10 parts by weight of 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodophenyl)-3-(5-methoxy-2-pyrazinyl)-1,2,4-oxadiazole-5-thione (MIPOT) was added as a modifier, which synergistically worked with carbon fiber to increase the tensile strength of the material by 28% to 68 MPa.

[0024] Adding 12 parts by weight of aluminum hydroxide-magnesium hydroxide composite flame retardant, synergistically with MIPOT, improves the grade from V-2 to V-0 in the UL-94 vertical burning test.

[0025] 8 parts by weight of carbon fiber is mixed in as a reinforcing agent to enhance the mechanical properties of the material.

[0026] 5 parts by weight of nano-silicon dioxide is introduced to improve the wear resistance and hardness of the material.

[0027] The synthetic route of the modifier MIPOT comprises a specific reaction sequence and condition control, wherein 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodobenzoic acid) and 5-methoxy-2-pyrazinecarboxylic acid hydrazide-5-thione are used as raw materials, 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodobenzoic acid) and thionyl chloride are reacted at 82° C. for 3.5 hours in anhydrous toluene with pyridine as a catalyst to prepare acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrazinecarboxylic acid hydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 11 hours, and finally the solvent is removed by distillation under reduced pressure, and the product is purified by post-treatment with ethyl acetate and petroleum ether for recrystallization.

[0028] Further including,

[0029] Waste polystyrene (PS) is used as the base material, 75 parts by weight.

[0030] 10 parts by weight of 5-(4-(4-cinnamoyloxybutoxy)-3-chlorophenyl)-2-(5-fluoro-3-pyridyl)-1,3,4-thiadiazole-5-thiol (CCPFT) was added as a modifier, which synergistically acted with glass fiber to increase the tensile strength of the material by 25% to 55 MPa.

[0031] Adding 10 parts by weight of magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant synergistically with CCPFT inhibits the high-temperature decomposition of the material, and the initial decomposition temperature is increased by 20°C.

[0032] 8 parts by weight of glass fiber is mixed in as a reinforcing agent to enhance the structural strength of the material.

[0033] 2 parts by weight of antioxidant are introduced to improve the anti-oxidation performance of the material.

[0034] The synthesis process of the modifier CCPFT includes the following steps: using 5-(4-(4-cinnamoyloxybutoxy)-3-chlorobenzoic acid) and 5-fluoro-3-pyridinecarboxylic acid hydrazide-5-thiol as raw materials, reacting 5-(4-(4-cinnamoyloxybutoxy)-3-chlorobenzoic acid) with thionyl chloride at 80° C. for 3.5 hours in anhydrous toluene with pyridine as a catalyst to prepare acyl chloride, then dropping the acyl chloride into an anhydrous ethanol solution containing 5-fluoro-3-pyridinecarboxylic acid hydrazide-5-thiol and triethylamine, stirring the reaction at room temperature for 11 hours, and realizing the synthesis of the target product by controlling the temperature and time of different reaction stages, finally removing the solvent by distillation under reduced pressure, and separating and purifying by recrystallization with ethyl acetate and petroleum ether to obtain high-purity CCPFT.

[0035] It further includes: using waste polycarbonate (PC) and polyethylene terephthalate (PET) mixed in a mass ratio of 3:2 as a base material, 70 parts by weight.

[0036] 10 parts by weight of 4-(3-(3-maleimidopropoxy)-4-bromophenyl)-3-(5-methoxy-2-pyrimidinyl)-1,2,4-oxadiazole-5-sulfide (MBPOT) was added as a modifier, which synergistically worked with carbon fiber to increase the bending strength of the material by 28% to 80 MPa.

[0037] By adding 12 parts by weight of aluminum hydroxide-magnesium hydroxide composite flame retardant, which works synergistically with MBPOT, the limiting oxygen index is increased from 27% to 32%.

[0038] 8 parts by weight of carbon fiber is mixed in as a reinforcing agent to improve the rigidity and strength of the material.

[0039] 2 parts by weight of ultraviolet absorber are introduced to improve the weather resistance of the material.

[0040] The preparation method of the modifier MBPOT comprises specific raw material activation and reaction termination conditions, wherein 4-(3-(3-maleimidopropoxy)-4-bromobenzoic acid) and 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thioether are used as raw materials, 4-(3-(3-maleimidopropoxy)-4-bromobenzoic acid) and thionyl chloride are reacted at 75° C. for 3 hours in anhydrous toluene with pyridine as a catalyst to prepare acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thioether and triethylamine, and the reaction is stirred at room temperature for 10 hours, and the purity and structural stability of the product are ensured by controlling the reaction termination conditions, and finally the solvent is removed by reduced pressure distillation, and the target modifier MBPOT is obtained by recrystallization, separation and purification with ethyl acetate and petroleum ether.

[0041] It further includes using waste polypropylene (PP) and polyethylene (PE) mixed in a mass ratio of 2:3 as a base material, 80 parts by weight.

[0042] 8 parts by weight of 5-(4-(4-crotonyloxybutoxy)-3-iodophenyl)-2-(5-ethoxy-3-pyrazolyl)-1,3,4-triazole-5-thiol (BIPTS) was added as a modifier, which synergized with the aramid fiber to increase the impact strength of the material by 30% to 35 kJ / m 2 .

[0043] Adding 10 parts by weight of melamine-zinc borate composite flame retardant synergistically with BIPTS inhibits the high-temperature decomposition of the material, and the initial decomposition temperature is increased by 22°C.

[0044] 5 parts by weight of aramid fiber is mixed in as a reinforcing agent to enhance the toughness of the material.

[0045] 2 parts by weight of light stabilizer is introduced to improve the weather resistance of the material.

[0046] The synthesis of the modifier BIPTS involves specific catalyst selection and reaction process monitoring. 5-(4-(4-crotonyloxybutoxy)-3-iodobenzoic acid) and 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-thiol are used as raw materials. In anhydrous toluene, pyridine is used as a catalyst. 5-(4-(4-crotonyloxybutoxy)-3-iodobenzoic acid) and dichlorothionyl are reacted at 85° C. for 4 hours to prepare an acyl chloride. Then, the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-thiol and triethylamine. The reaction is stirred at room temperature for 12 hours. By real-time monitoring of parameters such as temperature, pressure, and reactant concentration during the reaction, the reaction conditions are adjusted in time to ensure that the reaction proceeds in the direction of generating the target product BIPTS. Finally, the solvent is removed by reduced pressure distillation, and the high-purity BIPTS is obtained by recrystallization and post-treatment with ethyl acetate and petroleum ether.

[0047] It further includes using waste polyvinyl chloride (PVC) as a base material, 75 parts by weight.

[0048] 10 parts by weight of 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorophenyl)-3-(5-methoxy-2-quinolyl)-1,2,4-oxadiazole-5-thione (MCPQT) was added as a modifier, which synergistically worked with carbon fiber to increase the tensile strength of the material by 32% to 50 MPa.

[0049] Adding 10 parts by weight of magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant synergistically with MCPQT improves the grade from V-2 to V-0 in the UL-94 vertical burning test.

[0050] 8 parts by weight of carbon fiber is mixed in as a reinforcing agent to enhance the mechanical properties of the material.

[0051] 2 parts by weight of ultraviolet absorber are introduced to improve the weather resistance of the material.

[0052] The synthesis method of the modifier MCPQT comprises a specific reaction device and an operation process. 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorobenzoic acid) and 5-methoxy-2-quinolinecarboxylic acid hydrazide-5-thione are used as raw materials. In a reaction device equipped with a stirrer, a thermometer and a reflux condenser, in anhydrous toluene, pyridine is used as a catalyst, 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorobenzoic acid) and dichlorothione are reacted at 80° C. for 3.5 hours to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-quinolinecarboxylic acid hydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 11 hours. By strictly controlling the addition order of the raw materials, the reaction temperature and time, the stirring speed during the reaction process and other factors, it is ensured that a high-purity and high-quality MCPQT modifier is synthesized.

[0053] Beneficial effects:

[0054] Waste liquid crystal panel glass powder enhances mechanical properties and dimensional stability; bio-based polyhydroxyalkanoate-polyether block copolymer improves flexibility and processing performance; carbon fiber, glass fiber, aramid fiber and other reinforcing materials, respectively, work with corresponding modifiers to greatly improve tensile, bending, impact and other strengths. Improved functionality: Nano-aluminum nitride-carbon nanotube composite thermal conductive filler improves thermal conductivity and electrical properties; photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent imparts antibacterial properties; ultraviolet absorbers, light stabilizers, and antioxidants respectively improve the weather resistance and antioxidant properties of materials; nano-silicon dioxide improves wear resistance and hardness. Shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules achieve self-repairing function; porous carbon-silicon dioxide composite adsorbents derived from metal organic frameworks remove harmful impurities. Various types of compound flame retardants, such as magnesium hydroxide-aluminum hydroxide compound flame retardants, work with corresponding modifiers to inhibit high-temperature decomposition of materials, increase the initial decomposition temperature, and increase the limiting oxygen index, thereby improving the UL-94 vertical combustion rating. After plasma treatment under argon atmosphere, a mixed gas containing vinyl monomer and initiator is introduced for reaction to improve the compatibility and surface properties of the material. Supercritical carbon dioxide assisted foaming molding process reduces material density and improves thermal insulation and cushioning properties. Microwave and ultrasonic synergistic treatment, microwave radiation and ultrasonic waves are applied during mixing in a twin-screw extruder to promote uniform dispersion of each component. The ionic liquid-assisted low-temperature pyrolysis and reconstruction process achieves low-temperature pyrolysis and reconstruction of waste plastics, improves energy efficiency and reduces pollution. Modifiers obtained by specific complex synthesis methods, such as AFPOT, MCPTS, etc., have a unique molecular structure that can synergize with reinforcing materials and other additives. They can form more stable chemical bonds or enhance intermolecular forces inside the material, optimize the material microstructure, and thus play a key role in improving mechanical properties, flame retardant properties, and thermal stability, thereby achieving a comprehensive upgrade of waste plastic performance. DETAILED DESCRIPTION

[0055] Example 1

[0056] Recipe Implementation

[0057] Use waste polycarbonate (PC) as the base material, 70 parts by weight.

[0058] 6 parts by weight of discarded liquid crystal panel glass powder were added.

[0059] 10 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer was added.

[0060] 4 parts by weight of nano-aluminum nitride-carbon nanotube composite thermal conductive filler was mixed in.

[0061] 3 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent was introduced.

[0062] 2 parts by weight of a metal organic framework derived porous carbon-silicon dioxide composite adsorbent was added.

[0063] 5 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules were mixed in.

[0064] Process Implementation

[0065] After the waste PC is crushed, it is treated by plasma-induced in-situ polymerization grafting modification process.

[0066] Premix with other formulation components in a high-speed mixer for 30 minutes.

[0067] The mixture enters into a twin-screw extruder and is subjected to a microwave radiation and ultrasonic synergistically enhanced mixing process at 240-260°C.

[0068] During the mixing process, supercritical carbon dioxide is introduced to assist the foaming molding process.

[0069] The compression molding process was adopted and the pressure was maintained at 220℃ and 12MPa for 20 minutes to make a recycled material sample.

[0070] Performance Testing

[0071] The tensile strength reaches 80MPa, which is 30% higher than that of the material without adding the above components and without adopting the new process.

[0072] The thermal conductivity has been increased by 50% to 0.3W / (m·K), effectively improving thermal management performance.

[0073] The antibacterial rate against Escherichia coli and Staphylococcus aureus is over 98%.

[0074] After being damaged, the material was heated to 60°C and the crack repair rate reached 85%.

[0075] Example 2

[0076] Recipe Implementation

[0077] The base material is 75 parts by weight of waste polypropylene (PP) and polyethylene (PE) mixed in a mass ratio of 3:2.

[0078] 8 parts by weight of waste liquid crystal panel glass powder was added.

[0079] 10 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer was added.

[0080] 5 parts by weight of nano-aluminum nitride-carbon nanotube composite thermal conductive filler was mixed in.

[0081] 2 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent was introduced.

[0082] 1 part by weight of a metal organic framework derived porous carbon-silicon dioxide composite adsorbent was added.

[0083] 4 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules were mixed in.

[0084] Process Implementation

[0085] After the waste plastics are mixed and crushed, they are treated with a plasma-induced in-situ polymerization grafting modification process.

[0086] Premix with other formulation components in a high-speed mixer for 25 minutes.

[0087] Entering the twin-screw extruder, microwave radiation and ultrasonic synergistic intensified mixing process is carried out at 180-200°C. During the mixing process, supercritical carbon dioxide is introduced to assist the foaming molding process.

[0088] The recycled material prototype was made using the injection molding process.

[0089] Performance Testing

[0090] The bending strength reaches 60MPa, which is 25% higher than that of the material without the above-mentioned component formula and the new process. The density of the material is reduced by 20%, while the thermal insulation performance is improved by 30%.

[0091] In a simulated natural environment, after 3 months of exposure, the amount of microbial growth on the material surface was significantly reduced.

[0092] When the material is subjected to bending deformation and then heated at 50°C for 10 minutes, the shape recovery rate reaches 80%.

[0093] Example 3

[0094] The formula is implemented with waste polyvinyl chloride (PVC) as the base material, 70 parts by weight.

[0095] 5 parts by weight of waste liquid crystal panel glass powder was added.

[0096] 12 parts by weight of a bio-based polyhydroxyalkanoate-polyether block copolymer was added.

[0097] 3 parts by weight of nano aluminum nitride-carbon nanotube composite thermal conductive filler was mixed in.

[0098] 4 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent was introduced.

[0099] 3 parts by weight of a metal organic framework derived porous carbon-silicon dioxide composite adsorbent was added.

[0100] 6 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules were mixed in.

[0101] Process Implementation

[0102] After the waste PVC is crushed, it is treated by plasma-induced in-situ polymerization grafting modification process.

[0103] Premix with other formulation components in a high-speed mixer for 35 minutes.

[0104] Entering the twin-screw extruder, microwave radiation and ultrasonic synergistic intensified mixing process is carried out at 160-180°C. During the mixing process, supercritical carbon dioxide is introduced to assist the foaming molding process.

[0105] The recycled material sample is made using extrusion molding technology.

[0106] Performance Testing

[0107] Impact strength reaches 40kJ / m 2 , which is 40% higher than that of materials without the above-mentioned components and new processes. The material's adsorption rate for harmful gases such as formaldehyde is over 80%.

[0108] In the antibacterial test, the antibacterial rate against Candida albicans reached 95%.

[0109] After multiple cycles of damage and repair, the material can still maintain good mechanical properties, with a mechanical property retention rate of 80%.

[0110] Comparative Example 1

[0111] The formulation is implemented with waste polycarbonate (PC) as the base material, 70 parts by weight.

[0112] 10 parts by weight of traditional calcium carbonate filler (replacing waste liquid crystal panel glass powder) was added.

[0113] 10 parts by weight of common plasticizer (instead of bio-based polyhydroxyalkanoate-polyether block copolymer) was added. 4 parts by weight of single nano aluminum nitride thermal conductive filler (instead of composite thermal conductive filler) was mixed in.

[0114] No antimicrobial agents added.

[0115] 2 parts by weight of activated carbon (replacing the porous carbon-silicon dioxide composite adsorbent derived from a metal organic framework) was added. No smart repair microcapsules were added.

[0116] Process Implementation

[0117] After the waste PC is crushed, it is premixed with other formulation components in a high-speed mixer for 30 minutes.

[0118] Enter the twin-screw extruder and mix conventionally at 240-260℃.

[0119] The compression molding process was adopted and the pressure was maintained at 220℃ and 12MPa for 20 minutes to make a recycled material sample.

[0120] Performance Testing

[0121] The tensile strength is only 50 MPa, which is significantly lower than that of Example 1.

[0122] The thermal conductivity is 0.2W / (m·K), and the improvement in thermal management performance is not obvious.

[0123] The antibacterial rate against Escherichia coli and Staphylococcus aureus is less than 30%.

[0124] Unable to repair itself after being damaged.

[0125] Example 4

[0126] The formulation is implemented with waste polystyrene (PS) as the base material, 80 parts by weight.

[0127] 8 parts by weight of waste liquid crystal panel glass powder was added.

[0128] 8 parts by weight of a bio-based polyhydroxyalkanoate-polyether block copolymer was added.

[0129] 5 parts by weight of nano-aluminum nitride-carbon nanotube composite thermal conductive filler was mixed in.

[0130] 3 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent was introduced.

[0131] 2 parts by weight of a metal organic framework derived porous carbon-silicon dioxide composite adsorbent was added.

[0132] 4 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules were mixed in.

[0133] Process Implementation

[0134] After the waste PS is crushed, it is treated by plasma-induced in-situ polymerization grafting modification process.

[0135] Premix with other formulation components in a high-speed mixer for 30 minutes.

[0136] The mixture enters the twin-screw extruder and is subjected to microwave radiation and ultrasonic synergistically enhanced mixing process at 170-190°C.

[0137] During the mixing process, supercritical carbon dioxide is introduced to assist the foaming molding process.

[0138] The recycled material prototype was made using the injection molding process.

[0139] Performance Testing

[0140] The tensile strength reaches 65MPa, which is about 40% higher than that of PS recycled materials using only traditional recycling processes.

[0141] The thermal conductivity of the material is increased to 0.25W / (m·K), which effectively improves the thermal conductivity performance. This value is about 56% higher than that of traditional recycled PS materials.

[0142] In the antibacterial test, the antibacterial rates against Escherichia coli and Staphylococcus aureus were both over 97%.

[0143] When the material is scratched, the crack repair rate can reach 82% under heating conditions at 65°C.

[0144] Example 5

[0145] Recipe Implementation

[0146] The base material is 70 parts by weight of waste polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) mixed in a mass ratio of 2:3.

[0147] 10 parts by weight of waste liquid crystal panel glass powder was added.

[0148] 10 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer was added.

[0149] 4 parts by weight of nano-aluminum nitride-carbon nanotube composite thermal conductive filler was mixed in.

[0150] 2 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent was introduced.

[0151] 3 parts by weight of a metal organic framework derived porous carbon-silicon dioxide composite adsorbent was added.

[0152] 5 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules were mixed in.

[0153] Process Implementation

[0154] After the waste plastics are mixed and crushed, they are treated with a plasma-induced in-situ polymerization grafting modification process.

[0155] Premix with other formulation components in a high-speed mixer for 35 minutes.

[0156] The mixture enters into a twin-screw extruder and is subjected to a microwave radiation and ultrasonic synergistically enhanced mixing process at 230-250°C.

[0157] During the mixing process, supercritical carbon dioxide is introduced to assist the foaming molding process.

[0158] The compression molding process was adopted and the pressure was maintained at 210℃ and 10MPa for 25 minutes to make a recycled material sample.

[0159] Performance Testing

[0160] The bending modulus reaches 4.5 GPa, which is about 38% higher than that of similar recycled materials that do not adopt the technology of the present invention.

[0161] The material density is reduced by 18%, while the thermal insulation performance is increased by 28%, performing excellently in terms of energy saving and heat preservation.

[0162] After being placed in a simulated natural environment for 4 months, the amount of microbial growth on the material surface was much lower than that of ordinary recycled materials.

[0163] When the material is bent and deformed, the shape recovery rate can reach 83% under 55°C and a certain pressure environment.

[0164] Example 6

[0165] Recipe Implementation

[0166] Use waste polymethyl methacrylate (PMMA) as the base material, 75 parts by weight.

[0167] 6 parts by weight of discarded liquid crystal panel glass powder were added.

[0168] 12 parts by weight of a bio-based polyhydroxyalkanoate-polyether block copolymer was added.

[0169] 3 parts by weight of nano aluminum nitride-carbon nanotube composite thermal conductive filler was mixed in.

[0170] 4 parts by weight of a photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent was introduced.

[0171] 1 part by weight of a metal organic framework derived porous carbon-silicon dioxide composite adsorbent was added.

[0172] 5 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules were mixed in.

[0173] Process Implementation

[0174] After the waste PMMA is crushed, it is treated by plasma-induced in-situ polymerization grafting modification process.

[0175] Premix with other formulation components in a high-speed mixer for 28 minutes.

[0176] The mixture enters the twin-screw extruder and is subjected to microwave radiation and ultrasonic synergistically enhanced mixing process at 160-180°C.

[0177] During the mixing process, supercritical carbon dioxide is introduced to assist the foaming molding process.

[0178] The recycled material sample is made using extrusion molding technology.

[0179] Performance Testing

[0180] Impact strength reaches 35kJ / m 2 , which is about 52% higher than PMMA materials recycled by traditional processes.

[0181] The adsorption and purification rate of common harmful gases in the air such as formaldehyde and benzene reaches over 75%.

[0182] In the antibacterial test against Candida albicans, Escherichia coli and other bacteria, the antibacterial rate was above 93%.

[0183] After multiple damage repair cycles, the material can still maintain more than 78% of its initial mechanical properties.

[0184] Example 7

[0185] Design of new organic compound modifiers:

[0186] An organic compound named 4-(3-(4-acryloyloxybutoxy)-3-fluorophenyl)-3-(5-methoxy-2-pyrimidinyl)-1,2,4-oxadiazole-5-thiol (AFPOT) was designed. In the waste plastic system, in the 4-(3-(4-acryloyloxybutoxy)-3-fluorophenyl) part, the double bond in the acryloxybutoxy group can undergo an addition reaction with the unsaturated bonds in the waste plastic, thereby enhancing the binding with the base material. The fluorine atom changes the electron cloud density of the phenyl group and optimizes the interaction with other groups, while the butoxy group plays a role in connecting and regulating steric hindrance. In the 3-(5-methoxy-2-pyrimidinyl) part, the methoxy group enhances the stability of the pyrimidinyl group, and the pyrimidinyl group combines with other components through π-π stacking and hydrogen bonds, thereby improving the compatibility of the material. In the structure of 1,2,4-oxadiazole-5-thiol, the thiol group can form strong chemical bonds with metal nanoparticles to enhance the cross-linking degree of the material. The conjugated structure of the oxadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0187] Synthesis method:

[0188] 4-(3-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thiol are used as raw materials. 4-(3-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 75°C for 3 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thiol and triethylamine, and the reaction is stirred at room temperature for 10 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product AFPOT. This synthesis method refers to the preparation literature of oxadiazole thiol and pyrimidine compounds.

[0189] Recipe Implementation:

[0190] The base material is waste polyvinyl chloride (PVC), 80 parts by weight.

[0191] 8 parts by weight of AFPOT was added as a modifier.

[0192] Add 10 parts by weight of magnesium hydroxide-aluminum hydroxide composite flame retardant.

[0193] 5 parts by weight of carbon fiber was mixed as a reinforcing agent.

[0194] 2 parts by weight of ultraviolet absorber were introduced.

[0195] Process implementation:

[0196] After the waste PVC is crushed, it is premixed with other formulation components in a high-speed mixer for 30 minutes.

[0197] Enter into the twin-screw extruder, melt blend at 160-180°C, and the screw speed is 150rpm.

[0198] During the blending process, ultrasonic treatment was used for 30 minutes to promote uniform dispersion of the components.

[0199] The recycled material sample is made using extrusion molding technology.

[0200] Synergistic test:

[0201] Compared with the same formula material without AFPOT, the tensile strength of the material with AFPOT increased by 20% to 45MPa. AFPOT and carbon fiber synergistically strengthen the internal structure of the material.

[0202] In the thermal stability test, the initial decomposition temperature increased by 15°C. The oxadiazole ring and thiol group synergize with the magnesium hydroxide-aluminum hydroxide composite flame retardant to effectively inhibit the decomposition of the material at high temperature.

[0203] Compared with the materials modified with common acryloxy and thiol compounds in the prior art, the tensile strength of the material of this embodiment is increased by 8%-12%, and the initial decomposition temperature is increased by 10-13° C. In the weather resistance test, after 1000 hours of artificial accelerated aging, the mechanical property retention rate of the material is 10%-15% higher than that of similar modified materials in the prior art.

[0204] Example 8

[0205] Design of new organic compound modifiers:

[0206] The design name is 5-(4-(3-methacryloyloxypropoxy)-3-chlorophenyl)-2-(5-ethoxy-3-pyrazolyl)

[0207] -1,3,4-thiadiazole-5-sulfide (MCPTS) is an organic compound. In the waste plastic system, in the 5-(4-(3-methacryloxypropoxy)-3-chlorophenyl) part, the double bond in the methacryloxypropoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The chlorine atom optimizes the interaction between the phenyl group and other groups, and the propoxy group adjusts the steric hindrance and electron cloud density. In the 2-(5-ethoxy-3-pyrazolyl) part, the ethoxy group enhances the stability of the pyrazolyl group, and the pyrazolyl group combines with other components through π-π stacking and hydrogen bonds to improve the compatibility of the material. In the 1,3,4-thiadiazole-5-sulfide structure, the sulfide group can form a strong chemical bond with the metal oxide, enhance the cross-linking degree of the material, and the conjugated structure of the thiadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0208] Synthesis method:

[0209] 5-(4-(3-methacryloyloxypropoxy)-3-chlorobenzoic acid) and 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-sulfide are used as raw materials. 5-(4-(3-methacryloyloxypropoxy)-3-chlorobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 80°C for 3.5 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-sulfide and triethylamine, and the reaction is stirred at room temperature for 11 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product MCPTS. This synthesis method refers to the preparation literature of thiadiazole sulfide and pyrazole compounds.

[0210] Recipe Implementation:

[0211] Use waste polycarbonate (PC) as base material, 75 parts by weight.

[0212] 10 parts by weight of MCPTS was added as a modifier.

[0213] 10 parts by weight of melamine-zinc borate composite flame retardant was added.

[0214] 8 parts by weight of glass fiber was mixed as a reinforcing agent.

[0215] 2 parts by weight of an antioxidant were introduced.

[0216] Process implementation:

[0217] After the waste PC was crushed, it was premixed with other formulation components in a high-speed mixer for 35 minutes.

[0218] Enter into the twin-screw extruder, melt blend at 220-240°C, and the screw speed is 160rpm.

[0219] During the blending process, microwave radiation treatment was used for 15 minutes to promote uniform dispersion and chemical reaction of each component.

[0220] The compression molding process was adopted and the pressure was maintained at 200°C and 10MPa for 20 minutes to make a recycled material sample.

[0221] Synergistic test:

[0222] Compared with the same formula material without MCPTS, the bending strength of the material with MCPTS increased by 22% to 75MPa. MCPTS works synergistically with glass fiber to enhance the rigidity of the material.

[0223] In the flame retardant performance test, the limiting oxygen index increased from 26% to 30%. The thiadiazole ring and thioether group of MCPTS synergistically with the melamine-zinc borate compound flame retardant formed a more stable flame retardant system at high temperatures.

[0224] Compared with the materials modified by ordinary methacryloyloxy and thioether compounds in the prior art, the bending strength of the material of this embodiment is increased by 10%-15%, and the limiting oxygen index is increased by 2-3 percentage points. In the oxidation resistance test, the oxidation induction time of the material under accelerated oxidation conditions is extended by 15-20 minutes compared with similar modified materials in the prior art.

[0225] Example 9

[0226] Design of new organic compound modifiers:

[0227] An organic compound named 3-(4-(4-crotonoyloxybutoxy)-3-bromophenyl)-5-(2-quinolyl)-1,2,4-triazole-5-thione (BPQTS) was designed. In the waste plastic system, in the 3-(4-(4-crotonoyloxybutoxy)-3-bromophenyl) part, the double bond in the crotonoyloxybutoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The bromine atom optimizes the interaction between the phenyl group and other groups, and the butoxy group regulates the steric hindrance and electron cloud density. In the 5-(2-quinolyl) part, the quinolyl group has a larger conjugated system, which is tightly combined with other components through π-π stacking and hydrogen bonding, thereby improving the compatibility of the material. In the 1,2,4-triazole-5-thione structure, the thione group can form a coordination bond with metal ions to enhance the cross-linking degree of the material. The conjugated structure of the triazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0228] Synthesis method:

[0229] 3-(4-(4-crotonyloxybutoxy)-3-bromobenzoic acid) and 2-quinolinecarboxylic acid hydrazide-5-thione are used as raw materials. 3-(4-(4-crotonyloxybutoxy)-3-bromobenzoic acid) and dichlorothione are reacted in anhydrous toluene with pyridine as a catalyst at 78°C for 3 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 2-quinolinecarboxylic acid hydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 10 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is performed with ethyl acetate and petroleum ether to obtain the target product BPQTS. This synthesis method refers to the preparation literature of triazolethione and quinoline compounds.

[0230] Recipe Implementation:

[0231] The base material is waste polypropylene (PP), 85 parts by weight.

[0232] 6 parts by weight of BPQTS were added as a modifier.

[0233] 8 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant was added.

[0234] 5 parts by weight of aramid fiber was mixed as a reinforcing agent.

[0235] 2 parts by weight of light stabilizer were introduced.

[0236] Process implementation:

[0237] The waste PP was crushed and premixed with other formulation components in a high-speed mixer for 28 minutes.

[0238] Enter into the twin-screw extruder, melt blend at 170-190°C, and the screw speed is 140rpm.

[0239] During the blending process, high-voltage pulse electric field treatment was used with an electric field strength of 2.5 kV / cm and a pulse frequency of 18 Hz for 20 minutes to promote the orientation arrangement and interface bonding of each component.

[0240] The recycled material prototype was made using the injection molding process.

[0241] Synergistic test:

[0242] Compared with the same formula material without BPQTS, the impact strength of the material with BPQTS increased by 25% to 32kJ / m 2 BPQTS works synergistically with aramid fibers to enhance the toughness of the material.

[0243] In the thermal stability test, the initial decomposition temperature increased by 18°C. The triazole ring and thioketone group of BPQTS synergistically with the magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant effectively inhibited the decomposition of the material at high temperature.

[0244] Compared with the materials modified with common crotonyloxy and thioketone compounds in the prior art, the impact strength of the material of this embodiment is increased by 12%-18%, and the initial decomposition temperature is increased by 10-15° C. In the weather resistance test, after 1500 hours of artificial accelerated aging, the mechanical property retention rate of the material is 12%-18% higher than that of similar modified materials in the prior art.

[0245] Example 10

[0246] Design of new organic compound modifiers:

[0247] An organic compound named 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodophenyl)-3-(5-methoxy-2-pyrazinyl)-1,2,4-oxadiazole-5-thione (MIPOT) was designed. In the waste plastic system, in the 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodophenyl) part, the double bond in the 2-methyl-3-butenoyloxypropoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The iodine atom optimizes the interaction between the phenyl group and other groups, and the propoxy group regulates the steric hindrance and electron cloud density. In the 3-(5-methoxy-2-pyrazinyl) part, the methoxy group enhances the stability of the pyrazinyl group, and the pyrazinyl group combines with other components through π-π stacking and hydrogen bonds to improve the compatibility of the material. In the structure of 1,2,4-oxadiazole-5-thione, the thione group can form a coordination bond with metal ions to enhance the cross-linking degree of the material, and the conjugated structure of the oxadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0248] Synthesis method:

[0249] 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodobenzoic acid) and 5-methoxy-2-pyrazinecarboxylic acid hydrazide-5-thione are used as raw materials. 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 82°C for 3.5 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrazinecarboxylic acid hydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 11 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product MIPOT. This synthesis method refers to the preparation literature of oxadiazolethione and pyrazine compounds.

[0250] Recipe Implementation:

[0251] The base material is 70 parts by weight of waste polyethylene terephthalate (PET).

[0252] 10 parts by weight of MIPOT was added as a modifier.

[0253] Add 12 parts by weight of aluminum hydroxide-magnesium hydroxide composite flame retardant.

[0254] 8 parts by weight of carbon fiber was mixed as a reinforcing agent.

[0255] 5 parts by weight of nano-silicon dioxide is introduced to improve the wear resistance and hardness of the material.

[0256] Process implementation:

[0257] The waste PET was crushed and premixed with other formulation components in a high-speed mixer for 32 minutes.

[0258] Enter into the twin-screw extruder, melt blend at 240-260°C, and the screw speed is 170rpm.

[0259] During the blending process, ultrasonic and microwave treatments were used alternately, with an ultrasonic power of 200 W and a microwave power of 500 W. Each treatment lasted 5 minutes and was performed alternately 3 times to promote uniform dispersion and chemical reaction of the components.

[0260] The compression molding process was adopted and the pressure was maintained at 220℃ and 12MPa for 22 minutes to make a recycled material sample.

[0261] Synergistic test:

[0262] Compared with the same formula material without MIPOT, the tensile strength of the material with MIPOT increased by 28% to 68MPa. MIPOT and carbon fiber synergistically strengthen the internal structure of the material.

[0263] In the flame retardant performance test, the UL-94 vertical burning test was upgraded from V-2 to V-0. The oxadiazole ring and thioketone group of MIPOT synergistically work with the aluminum hydroxide-magnesium hydroxide compound flame retardant to form a more effective flame retardant barrier at high temperatures.

[0264] Compared with the conventional modified materials containing crotonyloxy and thioketone compounds in the prior art, the tensile strength of the material of this embodiment is increased by 15%-20%, and in the UL-94 vertical burning test, it is improved from V-2 to V-0. In the wear resistance test, the wear amount of the material is reduced by 15%-20% compared with the similar modified materials in the prior art.

[0265] Embodiment 11

[0266] Design of new organic compound modifiers:

[0267] An organic compound named 5-(4-(4-cinnamoyloxybutoxy)-3-chlorophenyl)-2-(5-fluoro-3-pyridyl)-1,3,4-thiadiazole-5-thiol (CCPFT) was designed. In the waste plastic system, in the 5-(4-(4-cinnamoyloxybutoxy)-3-chlorophenyl) part, the cinnamoyl group of the cinnamoyloxybutoxy group can interact with the aromatic structure in the waste plastic through π-π stacking, thereby enhancing the intermolecular binding force. The chlorine atom optimizes the interaction between the phenyl group and other groups, and the butoxy group plays a role in connecting and regulating the electron cloud density. In the 2-(5-fluoro-3-pyridyl) part, the fluorine atom enhances the electron-withdrawing ability of the pyridyl group, and the pyridyl group combines with other components through π-π stacking and hydrogen bonds, thereby improving the compatibility of the material. In the structure of 1,3,4-thiadiazole-5-thiol, the thiol group can form strong chemical bonds with metal nanoparticles to enhance the cross-linking degree of the material. The conjugated structure of the thiadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0268] Synthesis method:

[0269] 5-(4-(4-cinnamoyloxybutoxy)-3-chlorobenzoic acid) and 5-fluoro-3-pyridinecarboxylic acid hydrazide-5-thiol are used as raw materials. 5-(4-(4-cinnamoyloxybutoxy)-3-chlorobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 80°C for 3.5 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-fluoro-3-pyridinecarboxylic acid hydrazide-5-thiol and triethylamine, and the reaction is stirred at room temperature for 11 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product CCPFT. This synthesis method refers to the preparation literature of thiadiazole mercaptan and pyridine compounds.

[0270] Recipe Implementation:

[0271] Waste polystyrene (PS) is used as the base material, 75 parts by weight.

[0272] 10 parts by weight of CCPFT was added as a modifier.

[0273] 10 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant was added.

[0274] 8 parts by weight of glass fiber was mixed as a reinforcing agent.

[0275] 2 parts by weight of an antioxidant were introduced.

[0276] Process implementation:

[0277] After the waste PS was crushed, it was premixed with other formulation components in a high-speed mixer for 35 minutes.

[0278] Enter into the twin-screw extruder, melt blend at 180-200°C, and the screw speed is 160rpm.

[0279] During the blending process, ultrasonic treatment was used for 20 minutes to promote uniform dispersion of the components.

[0280] The recycled material prototype was made using the injection molding process.

[0281] Synergistic test:

[0282] Compared with the same formula material without CCPFT, the tensile strength of the material with CCPFT increased by 25% to 55MPa. CCPFT and glass fiber synergistically strengthen the internal structure of the material.

[0283] In the thermal stability test, the initial decomposition temperature increased by 20°C. The thiadiazole ring and thiol group synergize with the magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant to effectively inhibit the decomposition of the material at high temperature.

[0284] Compared with the materials modified with common cinnamoyloxy and thiol compounds in the prior art, the tensile strength of the material of this embodiment is increased by 10%-15%, and the initial decomposition temperature is increased by 12-16° C. In the antioxidant performance test, the oxidation induction time of the material under accelerated oxidation conditions is extended by 12-18 minutes compared with similar modified materials in the prior art.

[0285] Example 12

[0286] Design of new organic compound modifiers:

[0287] An organic compound named 4-(3-(3-maleimidopropoxy)-4-bromophenyl)-3-(5-methoxy-2-pyrimidinyl)-1,2,4-oxadiazole-5-thioether (MBPOT) was designed. In the waste plastic system, in the 4-(3-(3-maleimidopropoxy)-4-bromophenyl) part, the double bond in the maleimidopropoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The bromine atom optimizes the interaction between the phenyl group and other groups, and the propoxy group regulates the steric hindrance and electron cloud density. In the 3-(5-methoxy-2-pyrimidinyl) part, the methoxy group enhances the stability of the pyrimidinyl group, and the pyrimidinyl group combines with other components through π-π stacking and hydrogen bonds to improve the compatibility of the material. In the 1,2,4-oxadiazole-5-sulfide structure, the sulfide group can form a strong chemical bond with the metal oxide to enhance the cross-linking degree of the material. The conjugated structure of the oxadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0288] Synthesis method:

[0289] 4-(3-(3-maleimidopropoxy)-4-bromobenzoic acid) and 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-sulfide are used as raw materials. 4-(3-(3-maleimidopropoxy)-4-bromobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 75°C for 3 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-sulfide and triethylamine, and the reaction is stirred at room temperature for 10 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product MBPOT. This synthesis method refers to the preparation literature of oxadiazole sulfide and pyrimidine compounds.

[0290] Recipe Implementation:

[0291] The base material is 70 parts by weight of waste polycarbonate (PC) and polyethylene terephthalate (PET) mixed in a mass ratio of 3:2.

[0292] 10 parts by weight of MBPOT was added as a modifier.

[0293] Add 12 parts by weight of aluminum hydroxide-magnesium hydroxide composite flame retardant.

[0294] 8 parts by weight of carbon fiber was mixed as a reinforcing agent.

[0295] 2 parts by weight of ultraviolet absorber were introduced.

[0296] Process implementation:

[0297] After the waste plastics are mixed and crushed, they are premixed with other formulation components in a high-speed mixer for 30 minutes.

[0298] Enter into the twin-screw extruder, melt blend at 230-250°C, and the screw speed is 170rpm.

[0299] During the blending process, microwave radiation treatment was used for 15 minutes to promote uniform dispersion and chemical reaction of each component.

[0300] The compression molding process was adopted and the pressure was maintained at 210℃ and 10MPa for 20 minutes to make a recycled material sample.

[0301] Synergistic test:

[0302] Compared with the same formula material without MBPOT, the bending strength of the material with MBPOT increased by 28% to 80MPa. MBPOT works synergistically with carbon fiber to enhance the rigidity of the material.

[0303] In the flame retardant performance test, the limiting oxygen index increased from 27% to 32%. The oxadiazole ring and thioether group of MBPOT synergistically with the aluminum hydroxide-magnesium hydroxide composite flame retardant formed a more stable flame retardant system at high temperatures.

[0304] Compared with the materials modified by common maleimide and thioether compounds in the prior art, the bending strength of the material of this embodiment is increased by 12%-18%, and the limiting oxygen index is increased by 3-4 percentage points. In the weather resistance test, after 1500 hours of artificial accelerated aging, the mechanical property retention rate of the material is 12%-18% higher than that of similar modified materials in the prior art.

[0305] Embodiment 13

[0306] Design of new organic compound modifiers:

[0307] An organic compound named 5-(4-(4-crotonoyloxybutoxy)-3-iodophenyl)-2-(5-ethoxy-3-pyrazolyl)-1,3,4-triazole-5-thiol (BIPTS) was designed. In the waste plastic system, in the 5-(4-(4-crotonoyloxybutoxy)-3-iodophenyl) part, the double bond in the crotonoyloxybutoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The iodine atom optimizes the interaction between the phenyl group and other groups, and the butoxy group regulates the steric hindrance and electron cloud density. In the 2-(5-ethoxy-3-pyrazolyl) part, the ethoxy group enhances the stability of the pyrazolyl group, and the pyrazolyl group combines with other components through π-π stacking and hydrogen bonds to improve the compatibility of the material. In the 1,3,4-triazole-5-thiol structure, the thiol group can form a strong chemical bond with metal nanoparticles to enhance the cross-linking degree of the material, and the conjugated structure of the triazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0308] Synthesis method:

[0309] 5-(4-(4-crotonyloxybutoxy)-3-iodobenzoic acid) and 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-thiol are used as raw materials. 5-(4-(4-crotonyloxybutoxy)-3-iodobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 85°C for 4 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-thiol and triethylamine, and the reaction is stirred at room temperature for 12 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product BIPTS. This synthesis method refers to the preparation literature of triazole thiol and pyrazolyl compounds.

[0310] Recipe Implementation:

[0311] The base material is 80 parts by weight of waste polypropylene (PP) and polyethylene (PE) mixed in a mass ratio of 2:3.

[0312] 8 parts by weight of BIPTS were added as a modifier.

[0313] 10 parts by weight of melamine-zinc borate composite flame retardant was added.

[0314] 5 parts by weight of aramid fiber was mixed as a reinforcing agent.

[0315] 2 parts by weight of light stabilizer were introduced.

[0316] Process implementation:

[0317] After the waste plastics are mixed and crushed, they are premixed with other formulation components in a high-speed mixer for 30 minutes.

[0318] Enter into the twin-screw extruder, melt blend at 170-190°C, and the screw speed is 150rpm.

[0319] During the blending process, high-voltage pulse electric field treatment was used with an electric field strength of 3 kV / cm and a pulse frequency of 20 Hz for 20 minutes to promote the orientation arrangement and interface bonding of each component.

[0320] The recycled material prototype was made using the injection molding process.

[0321] Synergistic test:

[0322] Compared with the same formula material without BIPTS, the impact strength of the material with BIPTS is increased by 30% to 35kJ / m 2 BIPTS works synergistically with aramid fibers to enhance the toughness of the material.

[0323] In the thermal stability test, the initial decomposition temperature increased by 22°C. The triazole ring and thiol group of BIPTS synergize with the melamine-zinc borate composite flame retardant to effectively inhibit the decomposition of the material at high temperatures.

[0324] Compared with the materials modified with common crotonyloxy and thiol compounds in the prior art, the impact strength of the material of this embodiment is increased by 15%-20%, and the initial decomposition temperature is increased by 12-18° C. In the weather resistance test, after 1800 hours of artificial accelerated aging, the mechanical property retention rate of the material is 15%-20% higher than that of similar modified materials in the prior art.

[0325] Embodiment 14

[0326] Design of new organic compound modifiers:

[0327] An organic compound named 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorophenyl)-3-(5-methoxy-2-quinolyl)-1,2,4-oxadiazole-5-thione (MCPQT) was designed. In the waste plastic system, in the 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorophenyl) part, the double bond in the 2-methyl-3-butenoyloxypropoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The chlorine atom optimizes the interaction between the phenyl group and other groups, and the propoxy group regulates the steric hindrance and electron cloud density. In the 3-(5-methoxy-2-quinolyl) part, the methoxy group enhances the stability of the quinolyl group, and the quinolyl group combines with other components through π-π stacking and hydrogen bonds to improve the compatibility of the material. In the structure of 1,2,4-oxadiazole-5-thione, the thione group can form a coordination bond with metal ions to enhance the cross-linking degree of the material, and the conjugated structure of the oxadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0328] Synthesis method:

[0329] 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorobenzoic acid) and 5-methoxy-2-quinolinecarboxylic acid hydrazide-5-thione are used as raw materials. 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 80°C for 3.5 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-quinolinecarboxylic acid hydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 11 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product MCPQT. This synthesis method refers to the preparation literature of oxadiazolethione and quinoline compounds.

[0330] Recipe Implementation:

[0331] Use waste polyvinyl chloride (PVC) as base material, 75 parts by weight.

[0332] 10 parts by weight of MCPQT was added as a modifier.

[0333] 10 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant was added.

[0334] 8 parts by weight of carbon fiber was mixed as a reinforcing agent.

[0335] 2 parts by weight of ultraviolet absorber were introduced.

[0336] Process implementation:

[0337] After the waste PVC is crushed, it is premixed with other formulation components in a high-speed mixer for 35 minutes.

[0338] Enter into the twin-screw extruder, melt blend at 160-180°C, and the screw speed is 160rpm.

[0339] During the blending process, ultrasonic and microwave treatments were used alternately, with an ultrasonic power of 220 W and a microwave power of 600 W. Each treatment lasted 5 minutes and was performed alternately 3 times to promote uniform dispersion and chemical reaction of the components.

[0340] The recycled material sample is made using extrusion molding technology.

[0341] Synergistic test:

[0342] Compared with the same formula material without MCPQT, the tensile strength of the material with MCPQT increased by 32% to 50MPa. MCPQT and carbon fiber synergistically strengthened the internal structure of the material.

[0343] In the flame retardant performance test, the UL-94 vertical burning test was upgraded from V-2 to V-0. The oxadiazole ring and thioketone group of MCPQT synergistically with the magnesium hydroxide-aluminum hydroxide-phosphate melamine salt compound flame retardant formed a more effective flame retardant barrier at high temperatures.

[0344] Compared with the materials modified with common crotonyloxy and thioketone compounds in the prior art, the tensile strength of the material of this embodiment is increased by 15%-20%, and in the UL-94 vertical burning test, it is improved from V-2 level to V-0 level. In the weather resistance test, after 1200 hours of artificial accelerated aging, the mechanical property retention rate of the material is 15%-20% higher than that of similar modified materials in the prior art.

[0345] Embodiment 15

[0346] Design of new organic compound modifiers:

[0347] An organic compound named 5-(4-(4-acryloyloxybutoxy)-3-fluorophenyl)-2-(5-ethoxy-3-pyridyl)-1,3,4-thiadiazole-5-sulfide (APFTS) was designed. In the waste plastic system, in the 5-(4-(4-acryloyloxybutoxy)-3-fluorophenyl) part, the double bond in the acryloxybutoxy group can undergo an addition reaction with the unsaturated bond in the waste plastic to achieve bonding with the base material. The fluorine atom optimizes the interaction between the phenyl group and other groups, and the butoxy group regulates the steric hindrance and electron cloud density. In the 2-(5-ethoxy-3-pyridyl) part, the ethoxy group enhances the stability of the pyridyl group, and the pyridyl group combines with other components through π-π stacking and hydrogen bonds to improve the compatibility of the material. In the 1,3,4-thiadiazole-5-sulfide structure, the sulfide group can form a strong chemical bond with the metal oxide, enhance the cross-linking degree of the material, and the conjugated structure of the thiadiazole ring helps to improve the thermal stability, chemical stability and flame retardant properties of the material.

[0348] Synthesis method:

[0349] 5-(4-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and 5-ethoxy-3-pyridinecarboxylic acid hydrazide-5-sulfide are used as raw materials. 5-(4-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and dichlorothionyl are reacted in anhydrous toluene with pyridine as a catalyst at 80°C for 3.5 hours to obtain the corresponding acid chloride. Then, the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-ethoxy-3-pyridinecarboxylic acid hydrazide-5-sulfide and triethylamine, and the reaction is stirred at room temperature for 11 hours. After the reaction is completed, the solvent is removed by distillation under reduced pressure, and recrystallization is carried out with ethyl acetate and petroleum ether to obtain the target product APFTS. This synthesis method refers to the preparation literature of thiadiazole sulfide and pyridine compounds.

[0350] Recipe Implementation:

[0351] The base material is waste polybutylene terephthalate (PBT), 80 parts by weight.

[0352] 8 parts by weight of APFTS were added as a modifier.

[0353] 10 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant was added.

[0354] 5 parts by weight of aramid fiber was mixed as a reinforcing agent.

[0355] 2 parts by weight of ultraviolet absorber were introduced.

[0356] Process implementation:

[0357] The waste PBT was crushed and premixed with other formulation components in a high-speed mixer for 30 minutes.

[0358] Enter into the twin-screw extruder, melt blend at 220-240°C, and the screw speed is 150rpm.

[0359] During the blending process, ultrasonic treatment was used for 25 minutes to promote uniform dispersion of the components.

[0360] The recycled material prototype was made using the injection molding process.

[0361] Synergistic test:

[0362] Compared with the same formula material without APFTS, the tensile strength of the material with APFTS increased by 23% to 62MPa. APFTS and aramid fiber synergistically strengthened the internal structure of the material.

[0363] In the thermal stability test, the initial decomposition temperature increased by 18°C. The thiadiazole ring and sulfide group synergize with the magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant to effectively inhibit the decomposition of the material at high temperature.

[0364] Compared with the materials modified with common acryloxy and thioether compounds in the prior art, the tensile strength of the material of this embodiment is increased by 10%-14%, and the initial decomposition temperature is increased by 10-15° C. In the weather resistance test, after 1200 hours of artificial accelerated aging, the mechanical property retention rate of the material is 10%-15% higher than that of similar modified materials in the prior art.

[0365] Example 16

[0366] The structure, composition and properties of the material are confirmed through a variety of analytical techniques. FT-IR spectroscopy can accurately identify characteristic functional groups in compounds. For example, in the examples, the specific absorption peaks of new organic compounds can verify their structural composition. 1 H NMR further determines the environment and quantity of hydrogen atoms in the molecule through chemical shift and peak area, and assists in clarifying the structure of the compound. Elemental analysis gives the proportion of each element in a quantitative form to ensure that the synthetic product meets expectations. These technologies confirm each other and ensure that the newly synthesized modifiers and recycled materials have accurate chemical structures from different angles, as shown in Table 1.

[0367] Table 1 Characterization verification description

[0368]

[0369]

[0370]

[0371]

[0372]

[0373]

[0374]

[0375]

[0376] In terms of mechanical properties, tensile, bending and impact strength are greatly improved. For example, in Example 14, after adding a specific modifier, the tensile strength of PVC recycled materials increased by 32% to 50MPa. This is due to the synergistic effect of the modifier and the reinforcing agent, which enhances the internal structure of the material. In terms of thermal stability, the initial decomposition temperature is significantly improved. In Example 9, the initial decomposition temperature of the waste PP recycled material is increased by 18°C. The special structure of the modifier and the flame retardant synergistically inhibit high-temperature decomposition. The antibacterial and adsorption properties are also very outstanding. The antibacterial rate for a variety of harmful bacteria exceeds 90%, and the adsorption rate for harmful gases is more than 80%, which effectively improves the functionality of the material. In addition, it also performs well in intelligent repair, heat insulation and other properties. In Example 2, the material density is reduced by 20%, while the heat insulation performance is increased by 30%. See Table 2. These synergistic results show that the combination of new modifiers and unique formula processes can significantly improve the comprehensive performance of waste plastic recycled materials.

Claims

1. A method for recycling waste plastics by modification, characterized in that: S1. Material preparation: 80-100 parts by weight of waste plastics, 5-10 parts by weight of waste liquid crystal panel glass powder with a particle size of 1-5 μm, 8-12 parts by weight of bio-based polyhydroxyalkanoate-polyether block copolymer, 3-6 parts by weight of nano-aluminum nitride-carbon nanotube composite thermal conductive filler, 2-4 parts by weight of photocatalytic nano-titanium dioxide-graphene quantum dot composite antibacterial agent, 1-3 parts by weight of metal organic framework-derived porous carbon-silicon dioxide composite adsorbent, 4-6 parts by weight of shape memory polyurethane-carbon nanofiber composite intelligent repair microcapsules; S2. Plasma-induced in-situ polymerization grafting modification is performed on waste plastics. In an argon atmosphere, a mixed gas containing vinyl monomer and initiator is introduced after treatment at 200W for 5 minutes, and the reaction is carried out at 80°C for 2 hours to improve the compatibility and surface properties of the material. The pretreated waste plastics are mixed with other materials using a supercritical carbon dioxide-assisted foaming molding process, and CO2 is introduced at 10MPa and 35°C for 1 hour. After pressure relief, foaming is carried out at 180°C to reduce the material density and improve the thermal insulation and cushioning properties. During mixing in a twin-screw extruder, 500W microwave radiation and 20kHz ultrasound are applied simultaneously for 10 minutes to promote uniform dispersion of the components. Using an ionic liquid-assisted low-temperature pyrolysis and reconstruction process, waste plastics and ionic liquids are mixed in a mass ratio of 10:1, pyrolyzed at 200°C for 3 hours, and the products are separated and purified and reconstructed at 150°C for 2 hours to achieve low-temperature pyrolysis and reconstruction.

2. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 8 parts by weight of 4-(3-(4-acryloyloxybutoxy)-3-fluorophenyl)-3-(5-methoxy-2-pyrimidinyl)-1,2,4-oxadiazole-5-thiol is added as a modifier, which acts synergistically with the carbon fiber; 10 parts by weight of a magnesium hydroxide-aluminum hydroxide composite flame retardant is added to cooperate with the modifier to inhibit the decomposition of the material at high temperature; 5 parts by weight of carbon fiber is mixed as a reinforcing agent; and 2 parts by weight of an ultraviolet absorber is introduced; the modifier uses 4-(3-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thiol as raw materials, and in anhydrous toluene, pyridine is used as a catalyst, 4-(3-(4-acryloyloxybutoxy)-3-fluorobenzoic acid) and dichlorothionyl are reacted at 75° C. for 3 hours to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-thiol and triethylamine, and the reaction is stirred at room temperature for 10 hours, and finally the acyl chloride is purified by recrystallization with ethyl acetate and petroleum ether.

3. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 10 parts by weight of 5-(4-(3-methacryloxypropoxy)-3-chlorophenyl)-2-(5-ethoxy-3-pyrazolyl)-1,3,4-thiadiazole-5-sulfide is added as a modifier to synergize with glass fiber; 10 parts by weight of a melamine-zinc borate composite flame retardant is added to synergize with the modifier; 8 parts by weight of glass fiber is mixed in as a reinforcing agent; 2 parts by weight of an antioxidant is introduced; the synthesis of the modifier is based on 5-(4-(3-methacryloxypropoxy)-3-chlorophenyl)-2-(5-ethoxy-3-pyrazolyl)-1,3,4-thiadiazole-5-sulfide In anhydrous toluene, with pyridine as a catalyst, 5-(4-(3-methacryloyloxypropoxy)-3-chlorobenzoic acid) and dichlorothionyl are reacted at 80° C. for 3.5 hours to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-sulfide and triethylamine, and the reaction is stirred at room temperature for 11 hours. Finally, the solvent is removed by distillation under reduced pressure, and the product is separated and purified by recrystallization with ethyl acetate and petroleum ether.

4. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 6 parts by weight of 3-(4-(4-crotonyloxybutoxy)-3-bromophenyl)-5-(2-quinolyl)-1,2,4-triazole-5-thione are added as a modifier to synergize with the aramid fiber; 8 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant is added to synergize with the modifier to inhibit the high temperature decomposition of the material; 5 parts by weight of aramid fiber are mixed as a reinforcing agent; 2 parts by weight of a light stabilizer are introduced; the modifier is 3-(4-(4- Crotonoyloxybutoxy)-3-bromobenzoic acid) and 2-quinolinecarboxyhydrazide-5-thione are used as raw materials, 3-(4-(4-crotonoyloxybutoxy)-3-bromobenzoic acid) and dichlorothione are first reacted in anhydrous toluene with pyridine as a catalyst at 78°C for 3 hours to prepare acid chloride, and then the acid chloride is added dropwise to an anhydrous ethanol solution containing 2-quinolinecarboxyhydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 10 hours, and finally purified by recrystallization with ethyl acetate and petroleum ether.

5. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 10 parts by weight of 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodophenyl)-3-(5-methoxy-2-pyrazinyl)-1,2,4-oxadiazole-5-thione are added as a modifier to synergize with carbon fiber; 12 parts by weight of aluminum hydroxide-magnesium hydroxide composite flame retardant are added; 8 parts by weight of carbon fiber are mixed in as a reinforcing agent; 5 parts by weight of nano silicon dioxide are introduced; the synthesis route of the modifier is 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodobenzoic acid ) and 5-methoxy-2-pyrazinecarboxylic acid hydrazide-5-thione as raw materials, in anhydrous toluene, with pyridine as catalyst, 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-iodobenzoic acid) and dichlorothionyl are reacted at 82° C. for 3.5 hours to prepare acid chloride, and then the acid chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrazinecarboxylic acid hydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 11 hours, and finally the solvent is removed by distillation under reduced pressure, and the product is purified by post-treatment with recrystallization from ethyl acetate and petroleum ether.

6. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 10 parts by weight of 5-(4-(4-cinnamoyloxybutoxy)-3-chlorophenyl)-2-(5-fluoro-3-pyridyl)-1,3,4-thiadiazole-5-thiol are added as a modifier to synergize with glass fiber; 10 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant is added to synergize with the modifier to inhibit the high-temperature decomposition of the material; 8 parts by weight of glass fiber are mixed as a reinforcing agent; 2 parts by weight of an antioxidant are introduced; the synthesis of the modifier is based on 5-(4-(4-cinnamoyloxybutoxy)-3-chlorobenzoic acid) and 5-fluoro-3- Taking pyridine carboxyhydrazide-5-thiol as a raw material, in anhydrous toluene and with pyridine as a catalyst, 5-(4-(4-cinnamoyloxybutoxy)-3-chlorobenzoic acid) and thionyl chloride are reacted at 80°C for 3.5 hours to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-fluoro-3-pyridine carboxyhydrazide-5-thiol and triethylamine, and the reaction is stirred at room temperature for 11 hours. The synthesis of the target product is achieved by controlling the temperature and time of different reaction stages, and finally the solvent is removed by distillation under reduced pressure, and the high-purity modifier is obtained by recrystallization, separation and purification with ethyl acetate and petroleum ether.

7. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 10 parts by weight of 4-(3-(3-maleimidopropoxy)-4-bromophenyl)-3-(5-methoxy-2-pyrimidinyl)-1,2,4-oxadiazole-5-sulfide is added as a modifier to synergize with the carbon fiber; 12 parts by weight of an aluminum hydroxide-magnesium hydroxide composite flame retardant is added to synergize with the modifier; 8 parts by weight of carbon fiber is mixed as a reinforcing agent; 2 parts by weight of an ultraviolet absorber is introduced; the preparation method of the modifier MBPOT is to use 4-(3-(3-maleimidopropoxy)-4-bromobenzoic acid) and 5-methoxy- 2-pyrimidinecarboxylic acid hydrazide-5-sulfide is used as a raw material, 4-(3-(3-maleimidopropoxy)-4-bromobenzoic acid) and dichlorothionyl are reacted at 75°C for 3 hours in anhydrous toluene with pyridine as a catalyst to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-pyrimidinecarboxylic acid hydrazide-5-sulfide and triethylamine, and the reaction is stirred at room temperature for 10 hours. The purity and structural stability of the product are ensured by controlling the reaction termination conditions, and finally the solvent is removed by reduced pressure distillation, and the target modifier is separated and purified by recrystallization with ethyl acetate and petroleum ether.

8. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 8 parts by weight of 5-(4-(4-crotonyloxybutoxy)-3-iodophenyl)-2-(5-ethoxy-3-pyrazolyl)-1,3,4-triazole-5-thiol is added as a modifier to act synergistically with aramid fiber; 10 parts by weight of melamine-zinc borate composite flame retardant is added; 5 parts by weight of aramid fiber is mixed as a reinforcing agent; 2 parts by weight of light stabilizer is introduced; the synthesis of the modifier is carried out using 5-(4-(4-crotonyloxybutoxy)-3-iodobenzoic acid) and 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-thiol as raw materials, and pyridine is used as a catalyst in anhydrous toluene. The invention relates to a novel polyol-modified polyol, wherein 5-(4-(4-crotonyloxybutoxy)-3-iodobenzoic acid) is reacted with thionyl chloride at 85° C. for 4 hours to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-ethoxy-3-pyrazolecarboxylic acid hydrazide-5-thiol and triethylamine, and the mixture is stirred at room temperature for 12 hours. The reaction conditions are adjusted in time by real-time monitoring of parameters such as temperature, pressure, and reactant concentration during the reaction process to ensure that the reaction proceeds in the direction of generating the target product BIPTS. Finally, the solvent is removed by distillation under reduced pressure, and the mixture is recrystallized with ethyl acetate and petroleum ether to obtain the modifier with high purity.

9. The method for recycling waste plastics according to claim 1, characterized in that: Also includes 10 parts by weight of 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorophenyl)-3-(5-methoxy-2-quinolyl)-1,2,4-oxadiazole-5-thione are added as a modifier to synergize with the carbon fiber; 10 parts by weight of a magnesium hydroxide-aluminum hydroxide-phosphate melamine salt composite flame retardant is added to synergize with the modifier; 8 parts by weight of carbon fiber are mixed as a reinforcing agent; 2 parts by weight of an ultraviolet absorber are introduced; the synthesis method of the modifier is to use 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorobenzoic acid) and 5-methoxy-2-quinolyl)-1,2,4-oxadiazole-5-thione as a modifier. Hydrazide-5-thione is used as a raw material, in a reaction device equipped with a stirrer, a thermometer and a reflux condenser, in anhydrous toluene, with pyridine as a catalyst, 4-(3-(2-methyl-3-butenoyloxypropoxy)-4-chlorobenzoic acid) and dichlorothionyl are reacted at 80° C. for 3.5 hours to prepare an acyl chloride, and then the acyl chloride is added dropwise to an anhydrous ethanol solution containing 5-methoxy-2-quinolinecarboxyhydrazide-5-thione and triethylamine, and the reaction is stirred at room temperature for 11 hours. By strictly controlling the addition sequence of the raw materials, the reaction temperature and time, the stirring speed during the reaction and other factors, it is ensured that a high-purity and high-quality modifier is synthesized.

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