Thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material and preparation method thereof

Abstract

The invention relates to a thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material and a preparation method thereof. The PA56 and PA66 composite material is at least prepared from the following raw materials in percentage by mass: 10-70% of bio-based PA56, 10-70% of PA66 and 5-20% of MCA, and can also comprise the following raw materials in percentage by mass: 2-15% of a compatilizer, 1-10% of a flame-retardant synergist and 0.1-5% of other processing aids. The composite material disclosed by the invention can be directly used for injection molding, and has the characteristics of excellent comprehensive mechanical property, flame retardant property, processability, low flame retardant dosage and the like. Meanwhile, one of the selected raw materials has a bio-based source and has obvious advantages in low carbon and environmental protection, and the product competitiveness can be improved.

Description

[0001] This application is a divisional application. The application number of the parent application is 2017113446423, the application date is December 14, 2017, and the name of the invention is “A thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composite material and its preparation method”. Technical Field

[0002] The present invention belongs to the technical field of engineering plastics, and relates to a thermoplastic halogen-free flame-retardant PA56 and PA66 composite material and a preparation method thereof, and in particular to a thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material and a preparation method thereof. PA56 has a bio-based source. The composite material product has good flame retardant effect, excellent mechanical properties and processability, and has environmental advantages, and can be used for injection molding of various electronic and electrical equipment and household appliances whose raw materials have bio-source requirements. Background Art

[0003] Polyamide, commonly known as nylon, is a type of polymer material with good mechanical properties, electrical properties, heat resistance, toughness, oil resistance, wear resistance, chemical resistance and self-lubricating properties, and is widely used in various fields of life and production. At the same time, polyamide is a self-extinguishing polymer material, that is, it has a certain flame retardancy, but its flame retardant performance is relatively poor. Its vertical combustion can only reach UL94 V-2 level, and dripping occurs during the combustion process, resulting in a potential risk of fire during use, especially in the field of electronic products. Therefore, the flame retardant modification of polyamide has become a topic of common concern in academia and industry today.

[0004] There are three main ways to make polyamide flame-retardant: (1) adding flame retardants during the modification process, that is, adding flame retardants to the polyamide matrix through physical and mechanical mixing to make it flame-retardant. Its advantages are easy use and wide application, but it has a great impact on the performance of polyamide; (2) grafting or bonding flame retardant groups on the polymer chain or the surface of the product, that is, the flame retardant participates in the reaction as a reactive monomer and is combined with the main chain or side chain of the polyamide, so that the polyamide itself contains flame retardant components. Its characteristics are good stability, low toxicity, little impact on the performance of the material, and long-lasting flame retardancy. It is a more ideal solution, but the operation and processing technology are complicated, and it is not as widely used as additive flame retardants in practical applications; (3) copolymerization with flame retardant monomers to prepare intrinsic flame retardant polyamide. In comparison, the currently widely used method for polyamide flame retardancy is mainly to add flame retardants during the modification process.

[0005] Flame retardants are a type of functional additives that give polymers flame retardancy, and are mainly designed for the flame retardancy of polymer materials. There are many types of flame retardants, which can be divided into additive flame retardants and reactive flame retardants according to the method of use. Additive flame retardants are added to polymers through mechanical mixing methods to make the polymers flame retardant. Currently, additive flame retardants are mainly divided into two categories: organic flame retardants and inorganic flame retardants. Among them, organic flame retardants include halogen (organic chlorides and organic bromides) and non-halogen (nitrogen, phosphorus, nitrogen-phosphorus, silicon, sulfur, boron, etc.)

[0006] With the increasing awareness of safety and environmental protection, people have higher and higher requirements for fire safety and flame retardancy of products, and low-smoke, low-toxic environmentally friendly flame retardants are receiving more and more attention. At present, halogen flame retardants will generate a large amount of smoke and corrosive gases during thermal decomposition and combustion, and may release toxic carcinogens, such as polybrominated benzooxins and polybrominated benzofurans; and in recent years, it has been found that some brominated flame retardants (such as polybrominated diphenyl ethers) themselves have potential hazards to the environment and human health, which is obviously contrary to today's environmental protection requirements.

[0007] Compared with halogen flame retardants, nitrogen flame retardants have the advantages of low toxicity, high flame retardant efficiency, low corrosiveness, no conflict with light stabilizers in materials, high thermal decomposition temperature and environmental friendliness. Nitrogen flame retardants mainly include nitrogen-containing organic compounds such as melamine, dicyanamide, guanidine and their derivatives, among which melamine cyanurate (MCA) is the most widely used.

[0008] Melamine cyanurate (MCA) is an additive flame retardant that is non-toxic, odorless, has a high decomposition temperature, has good flame retardant effect, produces little smoke during processing, has good compatibility with polymer matrix, and has no surface migration. It is mainly used for flame retardant of polymer materials such as polyamide, PBT, PP, epoxy resin, silicone, polyurethane, and rubber. MCA has a good flame retardant effect and can be used in combination with other additives. It has a good synergistic effect when used in combination with phosphorus, bromine, antimony and other combustion aids. It is worth mentioning that the effect of MCA is more obvious when it is used in polyamide flame retardant.

[0009] Blending is relatively simple in process, with a wide range of component selection, and can be easily made into new materials with special properties. It is an important field of materials science, so it has developed rapidly. The so-called polymer blending refers to a physical mixture of two or more homopolymers, copolymers, or homopolymers and copolymers with different molecular structures. Generally, there is no covalent bond between the macromolecules of the two components. The mixing of polymers is an endothermic process, which is a heterogeneous system in which one polymer is dispersed in another polymer. The purpose of blending is to prepare polymer materials with improved or unique properties in certain properties. Blended polymers are the earliest multiphase polymers.

[0010] Polymer blending is closely related to the overall development of materials science research. The research on polymer blending has a history of one hundred years. As early as the beginning of the 20th century, there were patent reports on the production of impact-resistant polystyrene by blending. To this day, basic research and applied basic research on polymer blending are still hot topics in the field of polymer materials, and progress is constantly being made in the research of new blending systems and mechanisms; and the method of polymer blending modification is still an important industrial technology in polymer material processing, and its application is widespread in various plastics and rubber products. The development of many successful products in the polymer materials industry is closely based on polymer blending technology. The continuous innovation of blending theory and application technology has promoted the research and industrial application of polymer materials.

[0011] Polymer materials are increasingly used in production and play an increasingly prominent role. At the same time, the performance requirements for polymer materials are also getting higher and higher. The performance of a single polymer is difficult to meet the actual needs of production. The blending modification technology can improve the mechanical properties and processing properties of polymer materials, reduce costs, and expand the scope of use. Blending modification technology is the simplest, most commonly used, and most effective means of polymer material processing and new product development.

[0012] PA56 is made by polycondensation of 1,5-pentanediamine and adipic acid. PA56 is a polyamide with an odd-even structure. Compared with PA66, PA56 and PA66 have certain structural similarities in chemical structure. The main difference is that one of the monomers of PA56, pentamethylenediamine, is a five-carbon diamine, while one of the monomers of PA66, hexamethylenediamine, is a six-carbon diamine. The difference in chemical structure makes the physical and chemical properties of PA56 and PA66 different. For example, the structural symmetry of the repeating unit of PA56 is lower than that of PA66, and the ability to form hydrogen bonds is weaker, so that the hydrogen bond density in the PA56 body is not as high as that of PA66; on the other hand, the amide group density of PA56 is higher than that of PA66, and the electrostatic interaction between molecular chain segments is stronger; combining these two factors, PA56 and PA66 have certain similarities in mechanical properties.

[0013] The difference in chemical structure also gives PA56 different characteristics from PA66. For example, the nitrogen content of PA56 is higher than that of PA66, and it has a higher oxygen index, which has certain advantages in flame retardant modification. For example, the hydrogen bond density in the PA56 body is lower than that in PA66, and the hydrogen bonds between molecules are also low. Under the action of shear force, the chain segments have a higher degree of freedom, thus giving PA56 higher fluidity than PA66.

[0014] PA56 not only has its own advantages, but also has the advantages of nylon products. For example, PA56 is a crystalline polymer with certain reactivity, excellent mechanical properties, wear resistance, self-lubrication, oil resistance, corrosion resistance and good processing and molding properties.

[0015] Based on the above technical foundation, the present invention prepares a halogen-free flame-retardant PA56 / PA66 composite material with excellent comprehensive performance and environmental protection characteristics. Summary of the invention

[0016] The object of the present invention is to provide a thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material with excellent comprehensive mechanical properties and a preparation method thereof. The PA56 and PA66 composite material is a new type of environmentally friendly polymer material that can meet the requirements of electronic and electrical equipment and household appliances, wherein at least part of the raw materials of PA56 are obtained by biological fermentation.

[0017] To achieve the above objectives, the technical solution of the present invention is to provide an environmentally friendly thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material, wherein the composite material is prepared from at least the following raw materials in the following mass percentages.

[0018] Bio-based PA56: 10-75%;

[0019] PA66: 10-75%;

[0020] Flame retardant: 5-20%, preferably 6-9%, the particle size of the flame retardant is 0.1-0.2 microns.

[0021] Among them, 1,5-pentanediamine, one of the polymer monomers of bio-based PA56, is obtained through bio-fermentation technology, and the source of diadipic acid, one of the polymer monomers, can be obtained through bio-fermentation technology or through petrochemical manufacturing, but it is necessary to ensure that the mass of the polymer monomer obtained by bio-fermentation accounts for 47.17-100wt% of the total mass of bio-based PA56. Bio-based PA56 contains organic carbon from renewable sources that meets the ASTM D6866 standard. In the present invention, PA56 is bio-based PA56 chips, PA66 is PA66 chips, and the 98wt% sulfuric acid relative viscosity of PA56 and PA66 is 2.2-3.8. The specific viscosity range selected depends on the downstream application. For products requiring high fluidity, low-viscosity polyamide is selected as the raw material.

[0022] PA56 and PA66 have certain similarities in chemical structure, but the differences in molecular structure lead to some differences between the two polyamides. On the one hand, the presence of hydrogen bonds makes the two have certain compatibility; on the other hand, the structural differences and different molecular symmetries lead to a decrease in hydrogen bond density, thereby reducing the compatibility between the two polyamides. Therefore, PA56 and PA66 have partial compatibility, and the addition of a compatibilizer can further improve the compatibility between the two polymers. In the present invention, the raw material of the composite material may also include a compatibilizer, which accounts for 2 to 15% by mass of the raw material. The compatibilizer includes or is one or more of methyl methacrylate-butadiene-styrene copolymer, methyl methacrylate-ethyl acrylate, random ethylene-butyl acrylate copolymer, random ethylene-methyl acrylate-maleic anhydride copolymer, ethylene-butyl acrylate-glycidyl methacrylate copolymer, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted polyolefin elastomer, maleic anhydride grafted ethylene propylene diene rubber, maleic anhydride grafted ethylene-vinyl acetate, maleic anhydride grafted hydrogenated butadiene-styrene block copolymer and maleic anhydride grafted ethylene-butadiene-styrene copolymer.

[0023] There are many additive flame retardants that can be used for nylon flame retardancy, mainly including halogen flame retardants, nitrogen flame retardants, phosphorus flame retardants, inorganic flame retardants and other types of flame retardants. For polyamide products, nitrogen flame retardants such as melamine cyanurate (MCA) are ideal flame retardants. MCA has more advantages than other flame retardants, such as high whiteness, excellent dispersibility, low toxicity, high temperature resistance, and strong compatibility with other flame retardant systems. Modified polyamides with added MCA flame retardants are particularly suitable for the production of computers, fax machines, telephones, copiers, home appliances and other products.

[0024] The present invention applies MCA flame retardant to bio-based PA56 and PA66 composite materials. The present invention prepares bio-based PA56 and PA66 composite materials with flame retardant characteristics for the first time through blending and modification technology. This new material has its unique advantages. The product can be used for injection molding of various electronic and electrical equipment and household appliances that require raw materials with biological sources.

[0025] Although MCA has excellent flame retardant properties, the amount of addition is relatively large, the cost is high, and the negative effect on the physical properties of the material is obvious. In order to reduce the amount of addition, optimize the physical properties and improve the flame retardant effect, the raw materials of the composite material of the present invention also include a flame retardant synergist, which accounts for 1 to 10% by mass of the raw materials; the flame retardant synergist includes or is one or more of zinc borate, zinc oxide, montmorillonite, antimony trioxide, silicone flame retardant SFR-100, potassium carbonate, and calcium stearate.

[0026] In the present invention, the raw materials of the composite material also include other processing aids, the mass percentage of which is 0.1 to 5%, preferably 0.1 to 1%;

[0027] Preferably, the other processing aids include or are one or more of an anti-drip agent, an antioxidant and a lubricant;

[0028] The anti-dripping agent includes or is polytetrafluoroethylene powder (PTFE powder). Before making the bio-based PA56 and PA66 composite materials, the flame retardant, the flame retardant synergist and the anti-dripping agent are premixed and ultra-finely processed in a ball mill to make the average particle size of the flame retardant, the flame retardant synergist and the anti-dripping agent 0.1 to 0.2 microns.

[0029] In the present invention, the antioxidant includes or is one or more of N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)propionate]pentaerythritol diphosphite, 2,2-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4-butylene-bis-(6-tert-butyl-m-cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

[0030] In the present invention, the lubricant includes or is one or more of N, N'-ethylene bis stearamide, oxidized polyethylene wax, polyethylene-vinyl acetate wax, partially saponified polyethylene wax, oleamide, erucic acid amide, pentaerythritol stearate, montanic acid ester, calcium stearate, zinc stearate, sodium stearate, barium stearate, polymer organic silicon (such as silicone powder) and amino silicone oil. The role of the lubricant is multifaceted, such as the main role of the lubricant is to reduce the friction between the resin molecular segments during the extrusion process, the friction between the melt and the processing equipment, prevent the resin degradation caused by frictional heat generation, and ensure that the performance of the composite material will not deteriorate due to thermal degradation. The lubricant can also reduce the apparent viscosity of the resin, increase the fluidity of the resin, improve the processability of the blend, and improve processing efficiency. Furthermore, the lubricant can also prevent the resin from adhering to the mold and increase the demoulding property during the molding process.

[0031] In the present invention, the preparation method of the thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composite material comprises the following steps:

[0032] 1) 5-20% of the flame retardant in the raw material is homogenized and ultra-finely ground in a ball mill to a particle size of 0.1-0.2 microns, and then added to the side feed hopper of the extruder;

[0033] 2) 10-75% of bio-based PA56 and 10-75% of PA66 are mixed uniformly in a high-speed mixer by mass percentage, and then added to the main feeding hopper of the extruder; preferably, the mixing is uniformly carried out in the high-speed mixer at a speed of 500-700 rpm for 3-5 minutes;

[0034] 3) Adjust the aspect ratio of the screw of the extruder to 1:40-52, the screw speed to 300-600 rpm, the temperature settings of each zone of the extruder from the main feeding port to the die are 80±10℃, 220±10℃, 250±10℃, 270±10℃, 280±10℃, 280±10℃, 275±10℃, and the die temperature is 270±10℃.

[0035] Preferably, in step 1), the raw material further comprises a flame retardant synergist accounting for 1 to 10% by mass of the raw material and a modifier accounting for 0.1 to 2% by mass of the total mass of the flame retardant and the flame retardant synergist; and / or

[0036] In the step 2), the raw material further comprises a compatibilizer accounting for 2 to 15% by mass of the raw material; preferably, the modifier comprises or is any one of sodium caprolactam and silane coupling agent KH-550.

[0037] The raw materials of the composite material also include other processing aids, which account for 0.1-5% by mass of the raw materials, preferably 0.1-1%; the other processing aids include or are one or more of anti-dripping agents, antioxidants and lubricants; the anti-dripping agent accounts for 0.1-1% by mass of the raw materials; the anti-dripping agent is used in step 1), and the antioxidant and lubricant are used in step 2).

[0038] In the present invention, the thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite materials are injection molded into test specimens after being dried at 80°C for 6 hours, and the injection molding temperature is 260-275°C.

[0039] In the present invention, the performance test of thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composite materials refers to the following standards:

[0040] Table 1 Test Standards

[0041]

[0042] The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite materials prepared by the present invention can be used for injection molding of various parts or structural materials of electronic, electrical appliances, furniture and other products. The present invention controls the particle size of the flame retardant, flame retardant synergist and even anti-dripping agent, which can not only reduce the amount of flame retardant, but also further improve the impact resistance of the composite material. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with examples, but the present invention is not limited to these examples.

[0044] The raw material information selected by the present invention is as follows:

[0045] Bio-based PA56: Cathay (Jinxiang) Biomaterials Co., Ltd. The mass of the polymerized monomers produced by biofermentation accounts for 100% of the total mass of the bio-based PA56, 96wt% sulfuric acid relative viscosity 2.7

[0046] PA66 (PA66): Pingdingshan Shenma Engineering Plastics Co., Ltd., 96wt% sulfuric acid relative viscosity 2.7

[0047] Melamine cyanurate (MCA, as flame retardant): Jinan Taixing Fine Chemical Co., Ltd. Zinc borate (ZnB4O7, as flame retardant synergist): Shandong Bio Industrial Co., Ltd.

[0048] Zinc oxide (ZnO, as flame retardant synergist): Lianda Fine Chemical Co., Ltd.

[0049] Montmorillonite (MMT, as a flame retardant synergist): Jiangxi Gukang New Materials Co., Ltd.

[0050] Antimony trioxide (Sb2O3, as a flame retardant synergist): Zijiang Chemical Co., Ltd.

[0051] Silicone flame retardant (RM4-7081, as a flame retardant synergist): Dow Corning (Shanghai) Co., Ltd. Potassium carbonate (K2CO3, as a flame retardant synergist): Zhengzhou Yuteng Chemical Products Co., Ltd.

[0052] Calcium stearate (CaSt2, as a flame retardant synergist): Shanghai Huayi Chemical Additives Co., Ltd.

[0053] Coupling agent KH-550: Shanghai Jiuying New Materials Co., Ltd.

[0054] Maleic anhydride grafted polyolefin elastomer (POE-g-MA, as compatibilizer): DuPont China Group Co., Ltd.

[0055] N,N'-ethylenebisstearamide (EBS, as lubricant): Suzhou Liansheng Chemical Company

[0056] N,N-Bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (Antioxidant 1098): Ciba Specialty Chemicals (China) Co., Ltd.

[0057] PTFE (anti-dripping agent): Hubei Xinmao High-tech Materials Co., Ltd.

[0058] Embodiment 1:

[0059] (1) The flame retardant, flame retardant synergist, anti-dripping agent and modifier are placed in a ball mill for mixing and ultra-fine grinding. The ball milling temperature is 25° C., the ball milling speed is 200 rpm, and the ball milling time is 24 hours, until the particle size is 0.1 to 0.2 μm, and then added to the side feed hopper of the extruder;

[0060] (2) Bio-based PA56, PA66, compatibilizer, lubricant and antioxidant were mixed uniformly in a high-speed mixer at a mixing temperature of 25° C. and a speed of 600 rpm for 3 minutes, and then added into the main feeding hopper of the extruder;

[0061] (3) The aspect ratio of the screw used for melt extrusion was 1:40, the screw speed was 300 rpm, and the temperature settings of each zone of the extruder from feeding to die were 80°C, 220°C, 250°C, 270°C, 280°C, 280°C, and 275°C, respectively. The die temperature was 270°C to obtain thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composites.

[0062] The formulas of the composite materials of Examples 1 to 7 are shown in Table 2, and the formulas of Examples 8 to 12 and Comparative Examples 1 to 2 are shown in Table 3, wherein the flame retardant, flame retardant synergist, and anti-drip agent selected in the comparative example have not been subjected to ball milling treatment, and the experimental steps of the examples and comparative examples refer to Example 1, and the corresponding test results are listed in Table 4:

[0063] Table 2: Formula of the composite materials of Examples 1 to 7 (unit: g)

[0064]

[0065]

[0066] Table 3: Formula of the composite materials of Examples 8 and 9 and the comparative example (unit: g)

[0067]

[0068] Table 4: Comparison of the performance of the composite materials of the embodiments and comparative examples

[0069]

[0070]

[0071] The experimental results show that controlling the flame retardant, flame retardant synergist and anti-dripping agent through the ball milling process can not only reduce the amount of flame retardant used, but also further improve the impact resistance of the composite material.

[0072] The above description of the embodiments is to facilitate the understanding and use of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material, characterized by: The composite material is prepared from at least the following raw materials in percentage by mass: Bio-based PA56: 10-70%; PA66: 10-70%; Flame retardant: 5-20%, the particle size of the flame retardant is 0.1-0.2 microns; The flame retardant includes a nitrogen-based flame retardant; The raw materials of the composite material also include a flame retardant synergist, and the particle size of the flame retardant synergist is 0.1 to 0.2 microns; The raw materials of the composite material also include an anti-dripping agent, and the particle size of the anti-dripping agent is 0.1 to 0.2 microns.

2. The thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composite material according to claim 1, wherein: The bio-based PA56 contains organic carbon from a renewable source that meets the ASTM D6866 standard; and / or, at least one polymerization monomer of the bio-based PA56 is produced by a bio-fermentation method, and the mass of the polymerization monomer produced by the bio-fermentation method accounts for 47.17 to 100% of the total mass of the bio-based PA56.

3. The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to claim 1 or 2, wherein: The bio-based PA56 is a bio-based PA56 slice, and the PA66 is a PA66 slice. The 96wt% sulfuric acid relative viscosity of the bio-based PA56 slice and the PA66 slice is 2.2-3.

8.

4. The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to any one of claims 1 to 3, wherein: The raw materials of the composite material also include a compatibilizer, which accounts for 2 to 15% by mass of the raw materials; preferably, the compatibilizer includes or is one or more of methyl methacrylate-butadiene-styrene copolymer, methyl methacrylate-ethyl acrylate, random ethylene-butyl acrylate copolymer, random ethylene-methyl acrylate-maleic anhydride copolymer, ethylene-butyl acrylate-glycidyl methacrylate copolymer, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted polyolefin elastomer, maleic anhydride grafted ethylene propylene diene rubber, maleic anhydride grafted ethylene-vinyl acetate, maleic anhydride grafted hydrogenated butadiene-styrene block copolymer and maleic anhydride grafted ethylene-butadiene-styrene copolymer.

5. The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to any one of claims 1 to 4, wherein: The flame retardant includes or is melamine cyanurate.

6. The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to any one of claims 1 to 5, wherein: The mass percentage of the flame retardant synergist in the raw material is 1-10%; preferably, the flame retardant synergist includes or is one or more of zinc borate, zinc oxide, montmorillonite, antimony trioxide, organosilicon flame retardant SFR-100, potassium carbonate and calcium stearate.

7. The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to any one of claims 5 or 6, wherein: The surfaces of the flame retardant and the flame retardant synergist are modified by a modifier, and the modifier includes or is any one of sodium caprolactam and silane coupling agent KH-550; preferably, the mass of the modifier is 0.1-2% of the total mass of the flame retardant and the flame retardant synergist.

8. The thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to claim 7, wherein: The raw materials of the composite material also include other processing aids, which account for 0.1-5% by mass of the raw materials, preferably 0.1-1%; preferably, the other processing aids include or are one or more of antioxidants and lubricants; more preferably, the antioxidants include or are N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 2,2-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4-di-tert-butylphenol, One or more of butane-bis-(6-tert-butyl-m-cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; and / or, more preferably, the lubricant includes or is one or more of N,N'-ethylene bisstearamide, oxidized polyethylene wax, polyethylene-vinyl acetate wax, partially saponified polyethylene wax, oleamide, erucamide, pentaerythritol stearate, montanate, calcium stearate, zinc stearate, sodium stearate, barium stearate, polymer silicone and amino silicone oil; more preferably, the polymer silicone is silicone powder.

9. The thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composite material according to claim 8, wherein: The mass percentage of the anti-dripping agent to the raw material is 0.1-1%; and / or, preferably, the anti-dripping agent is polytetrafluoroethylene powder.

10. A method for preparing a thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material, characterized in that: The steps include: 1) 5-20% of the flame retardant in the raw material is homogenized and ultra-finely ground in a ball mill to a particle size of 0.1-0.2 microns, and then the obtained flame retardant system is added to the side feed hopper of the extruder; 2) 10-75% of bio-based PA56 and 10-75% of PA66 are mixed uniformly by mass percentage, and then added to the main feeding hopper of the extruder; preferably, the mixing is uniformly carried out in a high-speed mixer at a speed of 500-700 rpm for 3-5 minutes; 3) adjusting the aspect ratio of the screw of the extruder to 1:40-52, the screw speed to 300-600 rpm, the temperature of each zone of the extruder from the main feeding port to the die to 80±10°C, 220±10°C, 250±10°C, 270±10°C, 280±10°C, 280±10°C, 275±10°C, the die temperature to 270±10°C, and obtaining thermoplastic halogen-free flame retardant bio-based PA56 and PA66 composite materials.

11. The method for preparing the thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to claim 10, wherein: In the step 1), the raw material further comprises a flame retardant synergist accounting for 1 to 10% by weight of the raw material and a modifier accounting for 0.1 to 2 wt% of the total mass of the flame retardant and the flame retardant synergist; and / or in the step 2), the raw material further comprises a compatibilizer accounting for 2 to 15% by weight of the raw material; preferably, the modifier comprises or is any one of sodium caprolactam and silane coupling agent KH-550.

12. The method for preparing the thermoplastic halogen-free flame-retardant bio-based PA56 and PA66 composite material according to claim 11, wherein: The raw materials of the composite material also include other processing aids, which account for 0.1-5% by mass of the raw materials, preferably 0.1-1%; the other processing aids include or are one or more of anti-dripping agents, antioxidants and lubricants; the anti-dripping agent accounts for 0.1-1% by mass of the raw materials; the anti-dripping agent is used in step 1), and the antioxidant and lubricant are used in step 2).

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