Low-smoke halogen-free flame-retardant high-temperature nylon composite material and preparation method thereof

Abstract

The invention discloses a low-smoke halogen-free flame-retardant high-temperature nylon composite material, which is prepared from the following components in parts by weight: 58.4 to 98.4 parts of high-temperature nylon, 20 to 30 parts of glass fiber, 13 to 15.5 parts of aluminum diethylhypophosphite, 1 to 3 parts of Ti3C2Tx (MXene) flame-retardant synergist, 0.5 to 1 part of silane coupling agent, 0.1 to 0.5 part of internal lubrication heat stabilizer, 0.2 to 0.5 part of compound antioxidant and 0.4 to 1.2 parts of lubricating agent. The low-smoke halogen-free flame-retardant high-temperature nylon composite material is prepared by modifying the Ti3C2Tx with the silane coupling agent and compounding the modified Ti3C2Tx with the ADP, the ADP enables the flame retardant grade to be increased to V1 grade from UL94 V-2, the oxygen index is remarkably increased, and the total heat release amount is reduced; after the modified Ti3C2Tx is added, the flame retardance reaches V0 level when 13 parts of ADP are added, the oxygen index is continuously increased, and the total smoke generation amount is remarkably reduced. The two-dimensional lamellar carbon layer obstructs oxygen, adsorbs volatile matters and cooperates with ADP for flame retardance, meanwhile, heat resistance and mechanical properties are kept, the problems of flammability, dripping ignition and dense smoke are solved, and the requirements for safety and environmental protection are met.

Description

Technical Field

[0001] This invention relates to the field of nylon composite material technology, specifically to a low-smoke, halogen-free, flame-retardant high-temperature nylon composite material and its preparation method. Background Technology

[0002] The increasing demand for high-performance and lightweight products in the electronics and automotive industries is accelerating the replacement of metal components with plastics. Against this backdrop, heat-resistant polyamide materials, with their unique molecular structure advantages—forming PA6T copolymers, PA9T, PA10T, and other varieties by introducing aromatic groups—exhibit excellent heat resistance, hydrolysis resistance, chemical corrosion resistance, and good flowability and molding stability. They not only meet the stringent high-temperature requirements of SMT connectors and engine peripheral components, but also continue to expand their application areas, leading to rapid market growth and making them one of the key engineering plastics for replacing metals.

[0003] However, the carbon-chain-dominated molecular structure of high-temperature nylon results in inherently insufficient flame retardancy, a low limiting oxygen index (LOI), and a vertical burning rating that only reaches UL94 V2. This poses significant safety hazards in practical applications (it easily melts and drips after ignition, causing secondary fires), and releases large amounts of dense smoke during combustion. While traditional halogenated flame retardants can achieve highly efficient flame retardancy with minimal damage to the material's mechanical properties, they still produce large amounts of dense smoke during combustion, facing increasingly stringent regulatory restrictions and market obsolescence. Therefore, it is urgent to overcome the technological bottlenecks in halogen-free flame retardant and smoke-suppressing modification of high-temperature nylon. This requires simultaneously addressing the issues of flammability, drip ignition, and dense smoke release while maintaining the material's original core properties such as heat resistance and mechanical properties, to meet the dual demands of safety and environmental protection in high-end manufacturing. Summary of the Invention

[0004] The purpose of this invention is to provide a low-smoke, halogen-free, flame-retardant high-temperature nylon composite material and its preparation method, aiming to solve the problems in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material is composed of the following components in parts by weight: high-temperature nylon: 58.4-98.4 parts, glass fiber: 20-30 parts, aluminum diethyl phosphite: 13-15.5 parts, Ti3C2T x (MXene) Flame retardant synergist: 1-3 parts, silane coupling agent: 0.5-1 part, internal lubricating heat stabilizer: 0.1-0.5 parts, compound antioxidant: 0.2-0.5 parts, lubricant: 0.4-1.2 parts; The Ti3C2T x(MXene) flame retardant synergist is prepared through an etching reaction step and a product treatment and dispersion preparation step.

[0006] Further, the etching reaction step involves dissolving 16 g of lithium fluoride (LiF) in 320 mL of 9 M hydrochloric acid (HCl) and stirring for 30 min until completely dissolved. Then, 50 g of Ti3AlC2 is slowly added to the mixture over 10 min, and the mixture is stirred at room temperature for 20 min. The mixture is then transferred to a 40 °C oil bath and stirred continuously for 24 h, allowing LiF to react with HCl to generate HF. This HF is then selectively etched to remove the Al layer, yielding a product containing the surface functional group -T. x Multilayer Ti3C2T x After the reaction was complete, a large amount of deionized water / ethanol mixture was added and allowed to stand for 12 h. After the product settled, the supernatant was removed. The supernatant was neutralized with excess Ca(OH)2 solution. The process of "adding water / ethanol-standing-settling-removing supernatant" was repeated three times to remove soluble impurities, and finally, multilayer Ti3C2T was obtained. x (MXene) aggregated precipitate product; The product processing and dispersion preparation steps include: further treating the collected Ti3C2T with a large amount of deionized water. x The (MXene) aggregate precipitate was repeatedly centrifuged and washed until the pH of the supernatant was close to 6. Ethanol at four times the product's mass was added, and the mixture was subjected to pulsed sonication for 1 hour using an ultrasonic cell disruptor at a frequency of 20 kHz and a power of 320 W to remove the aggregates. The supernatant was then collected by centrifugation (1500 rpm, 5 min) to obtain Ti3C2T. x (MXene) flame retardant synergist was finally formulated into a 15 mg / ml Ti3C2T solution. x (MXene) flame retardant synergist solution and refrigerate for later use.

[0007] Furthermore, the high-temperature nylon is PA6T-66 or PA10T.

[0008] Furthermore, the lubricant is one of polyethylene wax, montan wax, ester wax, or silicone.

[0009] Furthermore, the silane coupling agent is one of KH-550, KH-560, and KH-570.

[0010] Furthermore, the compound antioxidant is two or more of the following: 626, 9228, GA-80, 1098, 1010, and 1790.

[0011] Furthermore, the compound antioxidant is composed of 9228 and 1098 in a mass ratio of 1:1.

[0012] Furthermore, the glass fiber is 10-micron Taishan chopped glass fiber 301-HP.

[0013] The present invention also provides a method for preparing the above-mentioned low-smoke halogen-free flame-retardant high-temperature nylon composite material, comprising the following steps: 1) Mixture preparation: Add aluminum diethylphosphite (ADP) to Ti3C2T x Add Ti3C2T to the (MXene) flame retardant synergist solution. x The flame retardant synergist solution and 1 wt% of diethylaluminum hypophosphite silane coupling agent KH-560 were ultrasonically dispersed (320 W, 30 min), and then Ti3C2T was removed by rotary evaporation. x The ethanol solvent in the (MXene) flame retardant synergist solution was then dried in a vacuum oven at 60°C for 24 h to obtain silane-modified ADP / Ti3C2T. x mixture; 2) Material mixing: After drying the high-temperature nylon resin at 130℃ for 4 h, it is mixed with the above-mentioned silane-modified ADP / Ti3C2T x The mixture, internal lubricating heat stabilizer, compound antioxidant, and lubricant are mixed in a high-speed mixer at room temperature at a speed of 600-800 rpm for 5-10 minutes until uniformly dispersed. 3) Melt extrusion molding: The mixed materials are added to a twin-screw extruder with a length-to-diameter ratio of 48:1 for melt extrusion. Glass fibers are added from the side feed port. The melt temperature is controlled at 290℃~320℃ and the screw speed is 200-500 rpm. The extrudate is cooled, air-dried, pelletized, and sieved to obtain the halogen-free flame-retardant high-temperature nylon composite material.

[0014] Furthermore, the cooling is water-cooled at a temperature of 20-30°C for 1-3 minutes; the air-drying process removes surface moisture by airflow at a speed of 2-5 m / s; the pelletizing process uses a rotary pelletizer with a pellet length of 2-4 mm; and the sieving process uses a 20-40 mesh screen to remove excessively long or short particles.

[0015] Existing high-temperature nylon technologies suffer from insufficient inherent flame retardancy due to its predominantly carbon-chain molecular structure. Specifically, it exhibits a low limiting oxygen index (LOI), achieving only a UL94 V2 vertical burning rating. This presents significant safety hazards in practical applications (it easily melts and drips after ignition, potentially causing secondary fires), and releases large amounts of dense smoke during combustion. While traditional halogenated flame retardants achieve highly efficient flame retardancy with minimal damage to the material's mechanical properties, they still produce substantial amounts of dense smoke during combustion, facing increasingly stringent regulatory restrictions and market obsolescence. Therefore, there is an urgent need to overcome the technological bottlenecks in halogen-free flame retardant and smoke-suppressing modifications for high-temperature nylon. This requires addressing the issues of flammability, drip ignition, and dense smoke release while maintaining the material's original core properties such as heat resistance and mechanical strength, to meet the dual demands of safety and environmental protection in high-end manufacturing.

[0016] The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material and its preparation method provided by this invention have the following advantages compared to the prior art: This invention relates to a low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material with high mechanical properties, high heat resistance, and low-smoke, halogen-free, and environmentally friendly characteristics. This is achieved through surface modification of Ti3C2T using a silane coupling agent. x The use of MXene flame retardant synergist, combined with aluminum diethylphosphite (ADP), successfully prepared a low-smoke, halogen-free flame-retardant high-temperature nylon composite material, achieving multiple technical benefits: compared to the unmodified system, the addition of ADP improved the material's flame retardancy rating from UL94 V2 to V1, significantly increased the limiting oxygen index, and substantially reduced the total heat release (solving the flammability and heat release issues); further, the introduction of modified Ti3C2T... x Subsequently, with an ADP addition of 13 parts, the flame retardant rating jumped to V0, and the oxygen index increased with Ti3C2T. x The content increases and continues to improve, while the total smoke production is significantly reduced compared to the single ADP system (solving the problem of dense smoke release); its mechanism lies in the modification of Ti3C2T. x The two-dimensional layered structure forms a dense and continuous carbon layer at high temperatures, which not only blocks oxygen from contacting the resin and inhibits the spread of combustion, but also adsorbs flammable volatiles and reduces smoke generation. At the same time, it works synergistically with ADP to exert the phosphorus-based flame retardant effect. While significantly improving the halogen-free flame retardant performance (reaching V0 level) and low smoke characteristics of the material, it maintains the original heat resistance, mechanical strength and other core properties of high-temperature nylon. It effectively solves the safety hazards of high-temperature resistant nylon such as flammability, ignition by molten dripping and release of dense smoke during combustion, and meets the dual requirements of safety and environmental protection in the high-end manufacturing field. Detailed Implementation

[0017] The present invention will be described in detail below with reference to specific embodiments.

[0018] Example 1 A low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material is composed of the following components in parts by weight: high-temperature nylon: 98.4 parts, glass fiber: 25 parts, aluminum diethyl phosphite: 13 parts, Ti3C2T x (MXene) Flame retardant synergist: 1 part, silane coupling agent: 1 part, internal lubricating heat stabilizer: 0.5 parts, compound antioxidant: 0.4 parts, lubricant: 0.7 parts.

[0019] The diethylaluminum hypophosphite (ADP) is Oprui ADP-30, the internal lubricating heat stabilizer is Clariant TFB117, and the glass fiber is 10-micron Taishan short-cut glass fiber 301-HP.

[0020] In this embodiment, the high-temperature nylon is PA6T-66; in other embodiments, the high-temperature nylon can be PA10T.

[0021] In this embodiment, the silane coupling agent is KH-550. In other embodiments, the carbon fiber substrate can be KH-560 or KH-570.

[0022] In this embodiment, the silane coupling agent is KH560. In other embodiments, the silane coupling agent can be one of KH-550, KH-560, and KH-570.

[0023] In this embodiment, the lubricant is an ester wax (specifically Honeywell Specialty Ester Wax 6901). In other embodiments, the lubricant may be one of polyethylene wax, montan wax, ester wax, or silicone.

[0024] In this embodiment, the compound antioxidant is composed of 9228 and 1098 in a mass ratio of 1:1. In other embodiments, the compound antioxidant is two or more of 626, 9228, GA-80, 1098, 1010, and 1790.

[0025] Among them, Ti3C2T x (MXene) flame retardant synergist is prepared through an etching reaction step and a product treatment and dispersion preparation step: (a) Etching reaction steps: 16 g of lithium fluoride (LiF) was dissolved in 320 mL of 9 M hydrochloric acid (HCl) and stirred for 30 min until completely dissolved; then 50 g of Ti3AlC2 was slowly added to the mixture over 10 min and stirred at room temperature for 20 min, and then transferred to a 40 ℃ oil bath for continuous stirring for 24 h, so that LiF reacts with HCl to generate HF, and the Al layer is selectively etched away to obtain a Ti3AlC2 layer containing surface functional groups. x Multilayer Ti3C2T xAfter the reaction was complete, a large amount of deionized water / ethanol mixture was added and allowed to stand for 12 hours. After the product settled, the supernatant was removed. The supernatant was neutralized with excess Ca(OH)2 solution. The process of "adding water / ethanol-standing-settling-removing supernatant" was repeated three times to remove soluble impurities, finally yielding multilayer Ti3C2T. x (MXene) aggregated precipitate product; (b) Product processing and dispersion preparation steps: The collected Ti3C2T was then treated with a large amount of deionized water. x The (MXene) aggregate precipitate was repeatedly centrifuged and washed until the pH of the supernatant was close to 6. Ethanol (4 times the product's mass, ethanol volume to product mass ratio 4:1) was added to the product, and the mixture was subjected to pulsed sonication for 1 hour using an ultrasonic cell disruptor at a frequency of 20 kHz and a power of 320 W to remove the aggregates. The supernatant was then collected by centrifugation (1500 rpm, 5 min) to obtain Ti3C2T. x (MXene) flame retardant synergist was finally formulated into a 15 mg / ml Ti3C2T solution. x (MXene) flame retardant synergist solution and refrigerate for later use.

[0026] The preparation method of the low-smoke halogen-free flame-retardant high-temperature nylon composite material in Example 1 above includes the following steps: 1) Mixture preparation: Add aluminum diethylphosphite (ADP) to Ti3C2T x Add Ti3C2T to the (MXene) flame retardant synergist solution. x The flame retardant synergist solution and 1 wt% of diethylaluminum hypophosphite silane coupling agent KH-560 were ultrasonically dispersed (320 W, 30 min), and then Ti3C2T was removed by rotary evaporation. x The ethanol solvent in the (MXene) flame retardant synergist solution was then dried in a vacuum oven at 60°C for 24 h to obtain silane-modified ADP / Ti3C2T. x mixture; 2) Material mixing: After drying the high-temperature nylon resin at 130℃ for 4 h, it is mixed with the above-mentioned silane-modified ADP / Ti3C2T x The mixture, internal lubricating heat stabilizer, compound antioxidant, and lubricant are mixed in a high-speed mixer at room temperature at a speed of 600-800 rpm for 5-10 minutes until uniformly dispersed. 3) Melt extrusion molding: The mixed materials are added to a twin-screw extruder with a length-to-diameter ratio of 48:1 for melt extrusion. Glass fibers are added from the side feed port. The melt temperature is controlled at 290℃~320℃ and the screw speed is 200-500 rpm. The extrudate is cooled, air-dried, pelletized, and sieved to obtain the halogen-free flame-retardant high-temperature nylon composite material. Cooling is carried out by water cooling at a water temperature of 20-30℃ for 1-3 minutes. Air drying is achieved by blowing air to remove surface moisture at a speed of 2-5 m / s. Pelletizing is carried out using a rotary pelletizer with a pellet length of 2-4 mm. Sieving is carried out using a 20-40 mesh screen to remove excessively long or short particles.

[0027] Example 2 Unlike Example 1, the following components were used: high-temperature nylon: 88.4 parts, Ti3C2T x (MXene) Flame retardant synergist: 2 parts.

[0028] Example 3 Unlike Example 1, the following components were used: high-temperature nylon: 73.4 parts, Ti3C2T x (MXene) Flame retardant synergist: 3 parts.

[0029] Example 4 The difference from Example 1 is that: high-temperature nylon: 58.4 parts, aluminum diethylphosphite: 15.5 parts.

[0030] Example 5 Unlike Example 1, the high-temperature nylon was 58.4 parts, of which the high-temperature nylon was PA10T.

[0031] Comparative Example 1 Unlike Example 1, the high-temperature nylon content was 58.4 parts, and Ti3C2T was not added in Comparative Example 1. x (MXene) Flame retardant synergist.

[0032] Comparative Example 2 Unlike Example 1, the following components were used: high-temperature nylon: 58.4 parts, aluminum diethylphosphite: 15.5 parts, and Ti3C2T was not added in Comparative Example 2. x (MXene) Flame retardant synergist.

[0033] Comparative Example 3 Unlike Example 1, the high-temperature nylon content was 88.4 parts, and Comparative Example 3 did not contain diethylaluminum hypophosphite or Ti3C2T. x (MXene) Flame retardant synergist.

[0034] Comparative Example 4 Unlike Example 1, the high-temperature nylon content was 58.4 parts, and Comparative Example 4 did not contain diethylaluminum hypophosphite or Ti3C2T.x (MXene) flame retardant synergist, but with the addition of unmodified diethyl aluminum hypophosphite.

[0035] The composite materials prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to performance tests, and the results are shown in Table 1 below: Table 1

[0036] The test standard for "tensile strength / MPa" is GB / T1040; The test standard for “bending strength / MPa” is GB / T9341; The test standard for “flexural modulus / MPa” is GB / T9341; The test standard for "notched impact strength of cantilever beam / kJ / m2" is GB / T1843; The testing standard for the "oxygen index" is GB / T 2406.2-2009; The testing standard for "vertical burning UL94 rating 0.8mm" is UL 94. The test standard for "Total heat release / MJ·m-2" is ASTM E-1354; The testing standard for "total smoke production·m⁻²" is ASTM E-1354.

[0037] As can be seen from Examples 1-4, the amount of surface-modified carbon fiber added has a significant impact on the mechanical properties of low-smoke halogen-free flame-retardant high-temperature nylon composite materials. The more surface-modified carbon fiber added, the better the overall mechanical properties.

[0038] Comparative Examples 3 and 4 show that the addition of ADP effectively improves the flame retardant properties of high-temperature nylon composite materials. Specifically, its limiting oxygen index (LOI) is significantly improved, the vertical burning rating is improved from UL94 V2 to V1, and the total heat release is also significantly reduced. This indicates that ADP has a positive effect on the flame retardant efficiency and heat suppression effect of the material. However, it should be noted that this single addition system does not improve the amount of smoke generated during the combustion process, and there is still a problem of dense smoke release. As can be seen from Examples 1-5 and Comparative Examples 1-4, further introduction of modified Ti3C2T x Subsequently, with an ADP addition of 13 parts, the flame retardant rating jumped to V0, and the oxygen index increased with Ti3C2T. x The content increases and continues to improve, while the total smoke production is significantly reduced compared to the single ADP system (solving the problem of dense smoke release); its mechanism lies in the modification of Ti3C2T. xThe two-dimensional layered structure forms a dense and continuous carbon layer at high temperatures, which not only blocks oxygen from contacting the resin and inhibits the spread of combustion, but also adsorbs flammable volatiles and reduces smoke generation. At the same time, it works synergistically with ADP to exert the phosphorus-based flame retardant effect. While significantly improving the halogen-free flame retardant performance (reaching V0 level) and low smoke characteristics of the material, it maintains the original heat resistance, mechanical strength and other core properties of high-temperature nylon. It effectively solves the safety hazards of high-temperature resistant nylon such as flammability, ignition by molten dripping and release of dense smoke during combustion, and meets the dual requirements of safety and environmental protection in the high-end manufacturing field.

[0039] Where there is no conflict, the above embodiments and features can be combined with each other.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material, characterized in that, It is composed of the following components in parts by weight: high-temperature nylon: 58.4-98.4 parts, glass fiber: 20-30 parts, aluminum diethylphosphite: 13-15.5 parts, Ti3C2T x (MXene) Flame retardant synergist: 1-3 parts, silane coupling agent: 0.5-1 part, internal lubricating heat stabilizer: 0.1-0.5 parts, compound antioxidant: 0.2-0.5 parts, lubricant: 0.4-1.2 parts; The Ti3C2T x (MXene) flame retardant synergist is prepared through an etching reaction step and a product treatment and dispersion preparation step.

2. The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material according to claim 1, characterized in that, The etching reaction steps are as follows: 16 g of lithium fluoride (LiF) is dissolved in 320 mL of 9 M hydrochloric acid (HCl) and stirred for 30 min until completely dissolved; then 50 g of Ti3AlC2 is slowly added to the mixture over 10 min, and stirred at room temperature for 20 min, then transferred to a 40 ℃ oil bath for continuous stirring and reaction for 24 h, so that LiF reacts with HCl to generate HF, selectively etching away the Al layer to obtain a product containing surface functional groups -T x Multilayer Ti3C2T x After the reaction was complete, a large amount of deionized water / ethanol mixture was added and allowed to stand for 12 h. After the product settled, the supernatant was removed. The supernatant was neutralized with excess Ca(OH)2 solution. The process of "adding water / ethanol-standing-settling-removing supernatant" was repeated three times to remove soluble impurities, finally yielding multilayer Ti3C2T. x (MXene) aggregated precipitate product; The product processing and dispersion preparation steps include: further treating the collected Ti3C2T with a large amount of deionized water. x The (MXene) aggregate precipitate was repeatedly centrifuged and washed until the pH of the supernatant was close to 6. Ethanol at four times the product's mass was added, and the mixture was subjected to pulsed sonication for 1 hour using an ultrasonic cell disruptor at a frequency of 20 kHz and a power of 320 W to remove the aggregates. The supernatant was then collected by centrifugation (1500 rpm, 5 min) to obtain Ti3C2T. x (MXene) flame retardant synergist was finally formulated into a 15 mg / ml Ti3C2T solution. x (MXene) flame retardant synergist solution and refrigerate for later use.

3. The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material according to claim 1, characterized in that, The high-temperature nylon is PA6T-66 or PA10T.

4. The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material according to claim 1, characterized in that, The lubricant is one of polyethylene wax, montan wax, ester wax, or silicone.

5. The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material according to claim 1, characterized in that, The silane coupling agent is one of KH-550, KH-560, and KH-570.

6. The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material according to claim 1, characterized in that, The compound antioxidant is two or more of the following: 626, 9228, GA-80, 1098, 1010, and 1790.

7. The low-smoke halogen-free flame-retardant high-temperature nylon composite material according to claim 6, characterized in that, The compound antioxidant is composed of 9228 and 1098 in a mass ratio of 1:

1.

8. The low-smoke halogen-free flame-retardant high-temperature nylon composite material according to claim 1, characterized in that, The glass fiber is 10-micron Taishan short-cut glass fiber 301-HP.

9. A method for preparing a low-smoke, halogen-free, flame-retardant high-temperature nylon composite material as described in any one of claims 1-8, characterized in that, Includes the following steps: 1) Mixture preparation: Add aluminum diethylphosphite (ADP) to Ti3C2T x Add Ti3C2T to the (MXene) flame retardant synergist solution. x The flame retardant synergist solution and 1 wt% of diethylaluminum hypophosphite silane coupling agent KH-560 were ultrasonically dispersed (320 W, 30 min), and then Ti3C2T was removed by rotary evaporation. x The ethanol solvent in the (MXene) flame retardant synergist solution was then dried in a vacuum oven at 60°C for 24 h to obtain silane-modified ADP / Ti3C2T. x mixture; 2) Material mixing: After drying the high-temperature nylon resin at 130℃ for 4 h, it is mixed with the above-mentioned silane-modified ADP / Ti3C2T x The mixture, internal lubricating heat stabilizer, compound antioxidant, and lubricant are mixed in a high-speed mixer at room temperature at a speed of 600-800 rpm for 5-10 minutes until uniformly dispersed. 3) Melt extrusion molding: The mixed materials are added to a twin-screw extruder with a length-to-diameter ratio of 48:1 for melt extrusion. Glass fibers are added from the side feed port. The melt temperature is controlled at 290℃~320℃ and the screw speed is 200-500 rpm. The extrudate is cooled, air-dried, pelletized, and sieved to obtain the halogen-free flame-retardant high-temperature nylon composite material.

10. The low-smoke, halogen-free, flame-retardant, high-temperature nylon composite material according to claim 9, characterized in that, The cooling process uses water cooling at a temperature of 20-30℃ for 1-3 minutes; the air drying process removes surface moisture by blowing air at a speed of 2-5 m / s; the pelletizing process uses a rotary pelletizer with a pellet length of 2-4 mm; and the sieving process uses a 20-40 mesh screen to remove excessively long or short particles.

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