Flame-retardant polyamide composite material, and preparation method and application thereof

Abstract

The application discloses a kind of flame-retardant polyamide composite material and its preparation method and application, belong to polymer material technical field, the flame-retardant polyamide composite material, including the following weight parts of component: 48~82 parts nylon resin, 3~9 parts carboxylated polyarylether nitrile, 24~40 parts bromine class flame retardant, 54~72 parts glass fiber.The carboxylated polyarylether nitrile of the present application is added to nylon resin, carboxylated polyarylether nitrile and resin and flame retardant have better compatibility, not easy to be decomposed when material is heated and burns, the carboxyl group of the carboxylated polyarylether nitrile and the end amino group of nylon molecular chain react, form stable chemical bond, to effectively improve the thermal stability of composite material, protect material in a certain range from the influence of external temperature, can significantly improve the mechanical strength and thermal stability of polyamide composite material at high temperature, improve the high-temperature aging strength retention rate of composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a flame-retardant polyamide composite material and a preparation method and application thereof. BACKGROUND

[0002] Polyamide (PA) has excellent mechanical properties, processability, self-lubricity, thermal stability and chemical stability, and is widely used in the fields of automobiles, electronics and electrical appliances, power tools, etc. It is one of the engineering plastics with the largest output and the widest application range in the world. With the development of modern high technology, higher requirements are put forward for the comprehensive performance of materials. When polyamide is applied to the fields of electronics and electrical appliances, new energy, etc. which have high requirements on high temperature, the material needs to meet the requirements of flame retardation under high temperature conditions while maintaining good comprehensive performance. Nylon is one of the representatives of high-strength and high-heat-resistant materials, but due to the heat resistance of the flame retardant itself, the thermal stability of the material also has limitations, and the performance decreases significantly after high-temperature aging.

[0003] Bromine-based flame retardants, as a kind of efficient flame retardant, have been widely used in high molecular materials such as nylon. However, there are also some problems in the use of bromine-based flame retardants, for example, bromine-based flame retardants are prone to decomposition to produce acidic and corrosive gases such as hydrogen bromide during processing or high-temperature aging, and it is difficult to have long-term effect in high-temperature environment, resulting in a significant decrease in performance after high-temperature aging.

[0004] In the prior art, when bromine-based flame retardants are applied to nylon, they usually need to be combined with other synergists, for example, in order to obtain a flame-retardant nylon with excellent flame-retardant performance, CN114031935A adds bromine-based flame retardants and antimony trioxide to nylon, and a large amount of compatibilizer; CN111592754A adds a large amount of bromine-based flame retardant to nylon, and uses a combination of stannate and polyphosphate metal salt instead of antimony compound as a flame-retardant synergist; in order to achieve ideal flame-retardant effect, bromine-based flame retardants need to be combined with flame-retardant synergists in existing bromine-based flame-retardant nylon, although excellent flame-retardant nylon materials are obtained, the problem of significant decrease in performance after high-temperature aging cannot be improved, making it difficult to be applied to the fields of electronics and electrical appliances, new energy, etc. which have high requirements on high temperature.

[0005] Therefore, how to avoid using flame-retardant synergists in bromine-based flame-retardant nylon while meeting the requirements of flame-retardant nylon composite materials under high-temperature conditions has become a technical problem to be solved by those skilled in the art. SUMMARY

[0006] The present application aims at overcoming the shortcomings of the prior art and provides a flame-retardant polyamide composite material, a preparation method and application thereof, which has excellent flame-retardant performance and high-temperature aging strength retention rate and is suitable for the field of electronics and electrical appliances, new energy and other fields with high requirements for high temperature.

[0007] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0008] A polyamide composite material comprises the following components in parts by weight: 48-82 parts of nylon resin, 3-9 parts of carboxylated polyarylene ether nitrile, 24-40 parts of bromine-based flame retardant, and 54-72 parts of glass fiber.

[0009] The present application creatively adds carboxylated polyarylene ether nitrile and bromine-based flame retardant to the flame-retardant nylon resin, and the carboxylated polyarylene ether nitrile has better compatibility with the resin and the bromine-based flame retardant and is not easy to be decomposed when the material is heated and burned. The carboxyl group of the carboxylated polyarylene ether nitrile reacts with the terminal amino group of the nylon molecular chain to form a stable chemical bond, thereby effectively improving the thermal stability of the composite material, protecting the material from the influence of the external temperature within a certain range, and the carboxylated polyarylene ether nitrile itself contains benzene rings and has excellent carbon formation capability. In combination with the above-mentioned bromine-based flame retardant, the carboxylated polyarylene ether nitrile and the bromine-based flame retardant work together to synergistically promote carbon formation, which can improve the carbon formation effect of the material during burning, form a stable carbon layer, prevent the entry of oxygen, and thus achieve the effect of flame retardation. The polyamide composite material can significantly improve the mechanical strength and thermal stability of the polyamide composite material at high temperature, improve the high-temperature aging strength retention rate of the composite material, and is suitable for the field of electronics and electrical appliances, new energy and other fields with high requirements for high temperature.

[0010] In the polyamide composite material of the present application, only the bromine-based flame retardant needs to be added to achieve excellent flame-retardant effect. Compared with the prior art, no flame-retardant synergist and compatibilizer is needed. The carboxylated polyarylene ether nitrile can work together with other ingredients in the nylon system to form a stable crosslinked structure and has excellent high-temperature stability. Meanwhile, the benzene rings in the molecular structure of the carboxylated polyarylene ether nitrile can play a good protective and heat-insulating role, and can delay or inhibit the oxidation and decomposition of the bromine-based flame retardant at high temperature.

[0011] The nylon resin is used in an amount of 48-82 parts, for example, 48 parts, 50 parts, 60 parts, 70 parts, 80 parts, 82 parts or a range formed by any two of the above values.

[0012] The carboxylated polyarylene ether nitrile is used in an amount of 3-9 parts, for example, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or a range formed by any two of the above values.

[0013] The bromine-based flame retardant is used in an amount of 24-40 parts, for example, 24 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, or a range defined by any two of the above values.

[0014] The glass fiber is used in an amount of 54-72 parts, for example, 54 parts, 55 parts, 58 parts, 60 parts, 62 parts, 65 parts, 68 parts, 70 parts, 72 parts, or a range defined by any two of the above values.

[0015] In the flame-retardant polyamide composite of the present application, the weight percentage of the nylon resin is not less than 28%.

[0016] In the flame-retardant polyamide composite of the present application, the weight percentage of the glass fiber is not less than 30%, thereby giving the system good basic strength and heat resistance.

[0017] It should be noted that the carboxylated polyarylene ether nitrile is obtained by treating the polyarylene ether nitrile with a conventional chemical reagent, and the present application is not limited to the specific chemical reagent and treatment method, as long as the carboxyl content of the polyarylene ether nitrile meets the corresponding requirements.

[0018] For example, the chemical reagent includes, but is not limited to, phosphoric acid, sulfuric acid, formic acid, acetic acid, benzoic acid, oxalic acid, citric acid, malic acid, and tartaric acid.

[0019] For example, the preparation method of the carboxylated polyarylene ether nitrile is as follows: 100 parts of polyarylene ether nitrile is added to 200-5000 parts of a chemical reagent, reacted, washed, and dried to obtain the carboxylated polyarylene ether nitrile.

[0020] Preferably, the chemical reagent is used in an amount of 325-1123 parts.

[0021] The reaction is carried out at a temperature of 100-120°C, and the reaction time can be 0.1-72 h.

[0022] Preferably, the chemical reagent includes a phosphoric acid solution and a sulfuric acid solution.

[0023] For example, the volume ratio of the phosphoric acid solution to the sulfuric acid solution is (1-10):1, for example, 1:1, 3:1, 5:1, 8:1, 10:1, or a range defined by any two of the above values.

[0024] For example, the mass fraction of the phosphoric acid solution is 2-20%, for example, 2%, 5%, 10%, 12%, 15%, 20%, or a range defined by any two of the above values.

[0025] For example, the mass fraction of the sulfuric acid solution is 2-20%, for example, it can be 2%, 5%, 10%, 12%, 15%, 20% or a range formed by any two of the above values.

[0026] Preferably, the components include the following parts by weight: 40-90 parts of a nylon resin, 3-9 parts of a carboxylated polyarylether nitrile, 25-38 parts of a bromine-based flame retardant, and 55-70 parts of glass fiber. In particular, when the amount of each raw material is within this range, the flame retardant performance and high-temperature aging strength retention are more optimal.

[0027] Preferably, the end amino group content of the nylon resin is 25-90 mmol / kg, for example, it can be 25 mmol / kg, 30 mmol / kg, 32 mmol / kg, 35 mmol / kg, 38 mmol / kg, 40 mmol / kg, 42 mmol / kg, 45 mmol / kg, 50 mmol / kg, 60 mmol / kg, 70 mmol / kg, 80 mmol / kg, 85 mmol / kg, 90 mmol / kg or a range formed by any two of the above values.

[0028] Preferably, the end amino group content of the nylon resin is 30-85 mmol / kg.

[0029] The inventors of the present application found in a large number of studies that the nylon resin of the present application mainly affects the performance of the composite material through the end amino group content. When the end amino group content of the nylon resin is controlled within this range, it can fully react with the carboxyl group of the carboxylated polyarylether nitrile to form a stable chemical structure, thereby improving the high-temperature aging strength retention and flame retardant performance of the polyamide composite material.

[0030] Preferably, the end amino group content of the nylon resin is 32-45 mmol / kg.

[0031] Preferably, the relative viscosity of the nylon resin is 2.0-3.5 dl / g, for example, it can be 2.0 dl / g, 2.2 dl / g, 2.5 dl / g, 2.8 dl / g, 3.0 dl / g, 3.2 dl / g, 3.5 dl / g or a range formed by any two of the above values.

[0032] Preferably, the nylon resin is at least one of PA66, PA610 and PA1010.

[0033] Preferably, the carboxyl content of the carboxylated polyarylene ether nitrile is 0.8-12 wt%, for example, it can be 0.8, 1%, 2%, 3%, 5%, 6%, 8%, 9%, 11%, 12% or a range between any two of them. By controlling the carboxyl content of the polyarylene ether nitrile, the carboxylated polyarylene ether nitrile has better compatibility with the resin and the flame retardant, and is not easy to be decomposed when the material is burned under heat, further improving the flame retardant performance and high-temperature aging strength retention rate of the material.

[0034] Preferably, the carboxyl content of the carboxylated polyarylene ether nitrile is 1-11 wt%.

[0035] Preferably, the carboxyl content of the carboxylated polyarylene ether nitrile is 2-9 wt%.

[0036] Preferably, the glass fiber is an alkali-free glass fiber.

[0037] Preferably, the diameter of the glass fiber is ≤12 μm, for example, it can be 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm or a range between any two of them. Preferably, the diameter of the glass fiber is 9-12 μm. Preferably, the bromine-based flame retardant is at least one of brominated polystyrene, brominated epoxy resin, decabromodiphenyl ethane.

[0038] Preferably, it further comprises 0.1-10 parts of an auxiliary agent, for example, it can be 0.1 parts, 0.5 parts, 1 parts, 2 parts, 4 parts, 5 parts, 6 parts, 8 parts, 10 parts or a range between any two of them.

[0039] Preferably, the auxiliary agent comprises at least one of a lubricant, a nucleating agent, an antioxidant, an antistatic agent.

[0040] The polyamide composite material described in the present application can comprise a lubricant, and suitable lubricants include but are not limited to polyethylene wax, fatty acid ester, hyperbranched amide and combinations thereof.

[0041] The polyamide composite material described in the present application can comprise a nucleating agent, and suitable nucleating agents include but are not limited to sodium phenylphosphinate, silicon dioxide, talc powder and combinations thereof.

[0042] The polyamide composite material described in the present application can comprise an antioxidant, and suitable antioxidants include but are not limited to antioxidant 1098, antioxidant 1010, antioxidant 1076, antioxidant 168 and combinations thereof.

[0043] The polyamide composite material described in the present application can comprise an antistatic agent, and suitable antistatic agents include but are not limited to zinc oxide, manganese dioxide, chromium trioxide and combinations thereof.

[0044] The application further provides a preparation method of the flame-retardant polyamide composite material, comprising the following steps: uniformly mixing the components except the glass fiber according to the proportion, feeding into a double-screw extruder for melt mixing, feeding the glass fiber, extruding and granulating to obtain the flame-retardant polyamide composite material.

[0045] Preferably, the length-diameter ratio of the screw of the double-screw extruder is (40-48):1, for example, 40:1, 42:1, 45:1, 48:1 or a range formed by any two of the above values.

[0046] Preferably, the barrel temperature during the melt mixing in the double-screw extruder is 240-270 DEG C, for example, 240 DEG C, 250 DEG C, 260 DEG C, 270 DEG C or a range formed by any two of the above values.

[0047] Preferably, the screw rotation speed during the melt mixing in the double-screw extruder is 200-550 rpm, for example, 200 rpm, 300 rpm, 400 rpm, 500 rpm, 550 rpm or a range formed by any two of the above values.

[0048] The application further provides an application of the flame-retardant polyamide composite material in the electronic and electrical field or the new energy field.

[0049] The application has the advantages that: the carboxylated polyarylene ether nitrile and the bromine-based flame retardant are added to the flame-retardant nylon resin, the carboxylated polyarylene ether nitrile has better compatibility with the resin and the bromine-based flame retardant and is not easy to be decomposed when the material is heated and burned, the carboxyl group of the carboxylated polyarylene ether nitrile reacts with the terminal amino group of the nylon molecular chain to form a stable chemical bond, thereby effectively improving the thermal stability of the composite material, protecting the material from the influence of the external temperature within a certain range, and the carboxylated polyarylene ether nitrile itself contains a benzene ring and has excellent carbon formation capacity, the combination of the carboxylated polyarylene ether nitrile and the bromine-based flame retardant and the synergistic promotion of carbon formation can improve the carbon formation effect of the material during burning, form a stable carbon layer, prevent the entry of oxygen and thus achieve the flame-retardant effect, significantly improve the mechanical strength and the thermal stability of the polyamide composite material at high temperature, improve the high-temperature aging strength retention rate of the composite material, and be suitable for the electronic and electrical field and the new energy field which have high requirements on high temperature. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0051] In the present application, the technical features described in an open way include both a closed technical solution consisting of listed features and an open technical solution containing the listed features.

[0052] In the present application, if no special description is made, the numerical interval is regarded as continuous and includes the minimum value and the maximum value of the range and each value between the minimum value and the maximum value. Further, when the range refers to an integer, each integer between the minimum value and the maximum value of the range is included. In addition, when multiple ranges are provided to describe a feature or a characteristic, the ranges can be combined. In other words, unless otherwise specified, all the ranges disclosed herein should be understood as including any and all sub-ranges falling within the range.

[0053] The raw materials used in the examples and comparative examples are described as follows:

[0054] PA66-1: PA66, EP1106, end amino group content is 39 mmol / kg, Huifeng Group Co.

[0055] PA66-2: PA66, EP1107, end amino group content is 32 mmol / kg, Huifeng Group Co.

[0056] PA66-3: PA66, FYR26K, end amino group content is 45 mmol / kg, Henan Shenma Group.

[0057] PA66-4: PA66, EP122, end amino group content is 30 mmol / kg, Huifeng Group.

[0058] PA66-5: PA66, EP158NH, end amino group content is 85 mmol / kg, Huifeng Group.

[0059] PA610: PA610, LC1624, end amino group content is 35 mmol / kg, Celanese.

[0060] Glass fiber: ECS10-3.0-T435N, Taishan Group, diameter is 10 μm.

[0061] Auxiliary agent: antioxidant 1098, BASF Co.

[0062] Brominated polystyrene, SAYTEX HP-5010PST, industrial grade, Albemarle.

[0063] Brominated epoxy resin: CXB-2000, industrial grade, Albemarle.

[0064] Decabromodiphenyl ethane: industrial grade, Albemarle.

[0065] Carboxylated polyarylether nitrile-1: carboxyl content is 5wt%.

[0066] Carboxylated polyarylether nitrile-2: carboxyl content is 9wt%.

[0067] Carboxylated polyarylether nitrile-3: carboxyl content is 2wt%.

[0068] Carboxylated polyarylether nitrile-4: carboxyl content is 1wt%.

[0069] Carboxylated polyarylether nitrile-5: carboxyl content is 11wt%.

[0070] The preparation method of the carboxylated polyarylether nitrile-1 to the carboxylated polyarylether nitrile-5 is as follows:

[0071] 100 parts by weight of polyarylether nitrile is placed in a reaction kettle, and 325-1123 parts of chemical reagents (a volume ratio of 3:1 of a 10wt% phosphoric acid solution and a 10wt% dilute sulfuric acid) are added, the reaction kettle is heated to 110℃, vacuum is extracted, the vacuum degree is 0.06Mpa, and after 0.2-48h of reaction, filtration is performed, pure water is used for washing, filtration is performed, and the product is placed in a dehumidifying dryer for drying at 130 degrees for 0.6h to obtain the carboxylated polyarylether nitrile resin for standby use.

[0072] Polyarylether nitrile: brand: PEN ID300, source: Japan Idemitsu.

[0073] The carboxylated polyarylether nitrile-1 to the carboxylated polyarylether nitrile-5 are obtained by adjusting the chemical reagents and / or the reaction time, so that carboxylated polyarylether nitriles with different carboxyl contents are obtained.

[0074] The component raw materials used in the embodiments and the comparative examples of the present application are all commercially available raw materials unless otherwise specified, and the component raw materials used in each parallel experiment are all the same.

[0075] The test standards of the raw material parameters are as follows:

[0076] In the present application, the testing method of the end amino group content of the nylon resin is as follows: the end amino group content of the sample is titrated by using a full-automatic potentiometric titrator, 0.5 g of the nylon resin sample to be measured is added into a mixed solution of phenol (45 mL) and anhydrous methanol (3 mL), heated to reflux, after the sample is completely dissolved, cooled to room temperature, and the end amino group content is titrated by using a calibrated hydrochloric acid standard solution, and the standard of the full-automatic potentiometric titrator is that the pH is 7.0.

[0077] In the present application, the testing method of the relative viscosity of the nylon resin is as follows: the relative viscosity of the nylon resin with a concentration of 0.01 g / dL is measured in 98% concentrated sulfuric acid at 25±0.01℃.

[0078] In the present application, the carboxyl content of the carboxylated polyarylether nitrile is tested by using ultraviolet absorption spectroscopy (determination wavelength 240 nm, and the carboxyl content is calculated according to Lambert-Beer law).

[0079] In the present application, the testing method of the diameter of the glass fiber is as follows: 100 glass fiber samples are placed under a microscope for observation, the diameters of all the glass fibers in the sample are calculated, and thus the diameter of the glass fiber is obtained.

[0080] Examples and comparative examples:

[0081] The components and weight parts of the flame-retardant polyamide composite material of the examples and comparative examples are shown in Tables 1-3 (all in parts by weight).

[0082] The preparation method of the flame-retardant polyamide material of the examples and comparative examples both includes the following steps:

[0083] According to the ratio, the components except the glass fiber are uniformly mixed, put into a double screw extruder for melt mixing, the glass fiber is side fed, extruded and granulated to obtain the flame-retardant polyamide composite material, wherein the length-diameter ratio of the screw of the double screw extruder is 44:1, when melt mixing is carried out in the double screw extruder, the barrel temperature is 240-270℃, and the screw rotation speed is 200-550 rpm.

[0084]

[0085]

[0086] Table 2

[0087]

[0088] Table 3

[0089]

[0090] Performance test

[0091] High temperature aging strength retention test: the prepared material was injected into a 275℃ injection molding machine at a speed of 55% of the rated speed of a 280T injection molding machine and a pressure of 50bar to produce a tensile sample. The prepared sample was aged at 160℃ for 1000 hours, and then tensile strength test was performed to compare the strength of the material before and after aging, and the retention rate of the material strength was tested.

[0092] Combustion performance test: the material sample was dried at 120℃ for 4 hours, and then injected into a 295℃ injection molding machine at a speed of 55% of the rated speed of a 280T injection molding machine and a pressure of 50bar to produce a combustion sample with a thickness of 0.8mm according to the UL-94 standard, and combustion test was performed.

[0093] Table 4

[0094]

[0095]

[0096] As can be seen from Table 4, the polyamide composite material described in the application has excellent high temperature aging strength retention and flame retardant performance.

[0097] The strength retention rate of the polyamide composite material prepared in the application after aging at 160℃ for 1000 hours reaches more than 70%, and the flame retardant grade is V-0.

[0098] As can be seen from Comparative Example 1 and Comparative Examples 1-3, the carboxylated polyarylene ether nitrile and bromine-based flame retardant in the application have a synergistic effect on flame retardation and high temperature aging strength retention, and the combination of the two significantly improves the flame retardant performance and strength retention rate.

[0099] As can be seen from Comparative Example 1 and Comparative Example 4, by using carboxylated polyarylene ether nitrile, the application significantly improves the flame retardant performance and high temperature aging strength retention.

[0100] As can be seen from Comparative Example 1 and Comparative Examples 5-6, by controlling each raw material within the range of the application, the flame retardant performance and high temperature aging strength retention are significantly improved.

[0101] As can be seen from Comparative Example 1 and Comparative Examples 7-8, by controlling the amount of carboxylated polyarylene ether nitrile within the range of the application, the flame retardant performance and high temperature aging strength retention are further improved.

[0102] As can be seen from the comparison between Comparative Example 1 and Examples 12-16, the flame retardant performance and high-temperature aging strength retention rate are further improved by controlling the terminal amino group content of the nylon resin to be 32-45 mmol / kg. If the terminal amino group content is too low, sufficient terminal amino groups cannot be provided, which leads to performance degradation. If the terminal amino group content is too high, the thermal stability of the nylon is poor, which leads to easy decomposition and deterioration, and deformation and cracking are prone to occur during use.

[0103] As can be seen from the comparison between Comparative Example 1 and Examples 17-20, the flame retardant performance and high-temperature aging strength retention rate are further improved by the carboxyl content of the carboxylated polyarylene ether nitrile. If the carboxyl content of the carboxylated polyarylene ether nitrile is too low, sufficient carboxyl groups cannot be provided, which leads to performance degradation. If the carboxyl content is too high, the thermal stability is poor due to the high activity of the carboxyl groups.

[0104] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A polyamide composite material, characterized in that, It includes the following components in parts by weight: 48-82 parts nylon resin, 3-9 parts carboxylated polyarylene ether nitrile, 24-40 parts brominated flame retardant, and 54-72 parts glass fiber; The nylon resin has a terminal amino content of 25~90 mmol / kg; The carboxyl content of the carboxylated polyarylene ether nitrile is 0.8~12wt%.

2. The polyamide composite material according to claim 1, characterized in that, It includes the following components by weight: 50-80 parts nylon resin, 3-9 parts carboxylated polyarylene ether nitrile, 25-38 parts brominated flame retardant, and 55-70 parts glass fiber.

3. The polyamide composite material according to claim 1, characterized in that, The nylon resin is at least one of PA66, PA610, and PA1010.

4. The polyamide composite material according to claim 1, characterized in that, The glass fiber is alkali-free glass fiber, and the diameter of the glass fiber is ≤12μm.

5. The polyamide composite material according to claim 4, characterized in that, The brominated flame retardant is at least one of brominated polystyrene, brominated epoxy resin, and decabromodiphenyl ethane.

6. The polyamide composite material according to claim 1, characterized in that, It also includes 0.1 to 10 parts of additives, which include at least one of lubricant, nucleating agent, antioxidant, and antistatic agent.

7. The method for preparing the polyamide composite material according to any one of claims 1 to 6, characterized in that, The process includes the following steps: according to the formula, the components except glass fiber are mixed evenly, fed into a twin-screw extruder for melt mixing, glass fiber is fed from the side, and extrusion granulation is performed to obtain a polyamide composite material.

8. The application of the polyamide composite material according to any one of claims 1 to 6 in the fields of electronics and electrical engineering or new energy.

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