High-strength toughened nylon 6 as well as preparation method and application thereof

Abstract

The invention relates to the technical field of nylon 6, in particular to high-strength toughened nylon 6 as well as a preparation method and application thereof. The high-strength toughened nylon 6 is prepared from the following raw materials in parts by mass: 70 to 120 parts of nylon 6, 5 to 15 parts of acrylonitrile-styrene copolymer, 2 to 6 parts of SEBS-g-MAH, 1 to 2 parts of amino-terminated polydimethylsiloxane, 0.1 to 0.2 part of PP-G-MAH, 0.01 to 0.05 part of catalyst, 5 to 10 parts of multiwalled carbon nanotube, 1 to 2 parts of tetraethoxysilane, 1 to 4 parts of boron nitride precursor, 1 to 2 parts of antioxidant and 1 to 2 parts of lubricant. According to the invention, the contradiction between toughening and heat resistance is effectively solved, the toughness of the material is improved, the influence on the heat deformation temperature of the material is smaller, the influence on the heat deformation temperature of the material is reduced, the problem of insufficient heat resistance of the existing toughened nylon material is effectively solved, and the dimensional precision of the product is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of nylon 6 technology, and in particular to a high-strength toughened nylon 6, its preparation method, and its applications. Background Technology

[0002] Nylon 6, as an important polyamide fiber material, is widely used in petrochemical, defense, machinery manufacturing, and textile industries due to its low melting point, wide processing temperature range, and excellent solvent resistance. However, some key performance limitations still exist in practical applications of nylon 6, restricting its expansion in high-end engineering fields.

[0003] Although Nylon 6 exhibits high rigidity and toughness over a wide temperature range, it is prone to cracking under impact, which is one of the main factors limiting its application in harsh environments. Especially in applications requiring dynamic loads or sudden impacts, this performance defect can lead to material failure, affecting the reliability and durability of the overall structure.

[0004] To address the insufficient impact resistance of Nylon 6, current common elastomer toughening methods involve adding elastomers such as POE and SEBS, or their grafts, which can effectively improve the material's toughness and impact resistance. However, because these elastomer materials themselves have low strength and heat resistance, while toughening Nylon 6, they lead to a significant decrease in the material's rigidity and heat distortion temperature, resulting in a marked reduction in heat resistance. This reduction in heat resistance makes the toughened Nylon 6 composite material prone to deformation or performance degradation under high temperature or high load conditions, failing to meet the requirements of certain high-end applications.

[0005] Therefore, how to provide a composite material that can effectively improve the notched impact strength of nylon 6 and enhance its crack resistance, while avoiding a significant decrease in heat resistance during the toughening process, has become a pressing technical problem in the field of materials science. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-strength toughened nylon 6, its preparation method, and its applications.

[0007] A high-strength and toughened nylon 6, the raw materials of which include, by weight: 70-120 parts nylon 6, 5-15 parts acrylonitrile-styrene copolymer, 2-6 parts SEBS-g-MAH, 1-2 parts amino-terminated polydimethylsiloxane, 0.1-0.2 parts PP-G-MAH, 0.01-0.05 parts catalyst, 5-10 parts multi-walled carbon nanotubes, 1-2 parts tetraethyl orthosilicate, 1-4 parts boron nitride precursor, 1-2 parts antioxidant, and 1-2 parts lubricant.

[0008] Preferably, the catalyst is organotin.

[0009] More preferably, the organotin is dibutyltin dilaurate.

[0010] Preferably, the boron nitride precursor is ammoniaborane.

[0011] Preferably, the lubricant is a modified high molecular weight organosilicon lubricant.

[0012] Preferably, the antioxidant includes at least one of antioxidant 1098 and antioxidant 1010.

[0013] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add catalyst, stir at 180-200℃ for 1-2 hours, add PP-G-MAH and continue stirring for 1-2 hours, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant and lubricant and mix evenly to obtain premix. S2. Heat multi-walled carbon nanotubes to 900-950℃ under nitrogen protection, introduce boron nitride precursor vapor and react for 1-2 hours, cool to room temperature, add to ethanol aqueous solution, add tetraethyl orthosilicate, adjust the pH of the system to 8-9, reflux at 60-70℃ for 10-20 hours, centrifuge, wash, vacuum dry, heat treat at 150-200℃ for 1-2 hours under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material and boron nitride / silica modified carbon nanotubes are melt-extruded and granulated.

[0014] Preferably, in S2, the mass fraction of the ethanol aqueous solution is 50-60%.

[0015] Preferably, in S2, the pH value of the system is adjusted to 8-9 using ammonia water with a mass fraction of 20%.

[0016] Preferably, in S3, during the melt extrusion process, the melt extrusion temperature is 280-295℃, the length-to-diameter ratio of the screw of the twin-screw extruder is 35-40:1, and the screw speed is 300-400 rpm.

[0017] The aforementioned high-strength toughened nylon 6 is used as a heat-resistant toughening material for high-temperature or high-load conditions.

[0018] Preferably, the high temperature or high load condition refers to the casing of electronic or electrical appliances.

[0019] Beneficial effects: This invention grows boron nitride nanosheets on the surface of carbon nanotubes. These nanosheets can absorb a large amount of energy through the slippage and rearrangement of the sheets when subjected to impact. In addition, the outermost layer of deposited silica significantly improves the interfacial compatibility with the substrate. At the same time, the carbon nanotubes, boron nitride nanosheets and silica deposited layer synergistically enhance the thermal conductivity of the substrate, effectively enhancing the high thermal stability of the system.

[0020] This invention uses SEBS-g-MAH and amino-terminated polydimethylsiloxane as a compound, which, through the action of PP-G-MAH, can effectively maintain the toughness and thermal stability in high-temperature environments. Combined with boron nitride / silica-modified carbon nanotubes, it can effectively conduct heat and reduce local temperature rise, enabling the composite material to maintain excellent mechanical properties and dimensional stability over a wide temperature range. It effectively restricts the movement of nylon 6 molecular chain segments, thereby helping to maintain the rigidity and heat distortion temperature of the material at high temperatures.

[0021] This invention effectively resolves the contradiction between toughening and heat resistance, improving material toughness while minimizing its impact on the material's heat distortion temperature. This effectively addresses the current problem of insufficient heat resistance in toughened nylon materials, significantly improving the dimensional accuracy of the products. Its preparation method is simple, providing a high-performance composite material solution for high-end engineering applications, and is suitable for large-scale promotion and application. Attached Figure Description

[0022] Figure 1 The image shows a comparison of the tensile strength and flexural strength of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2.

[0023] Figure 2 The notched impact strength comparison diagram shows the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2.

[0024] Figure 3 The graph shows a comparison of the heat distortion temperature and molding shrinkage of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2. Detailed Implementation

[0025] The present invention will be further explained below with reference to specific embodiments.

[0026] The nylon 6 used below is sourced from Sinopec Baling, grade PA6 BL1340H. The acrylonitrile-styrene copolymer used below is sourced from BASF Germany, grade 368R. The polyether silicone oil used below is sourced from Dow Corning, grade SF-8427. The SEBS-g-MAH used below is purchased from Guangdong Chuanheng New Material Technology Co., Ltd., model CH-909E, with a grafting rate of 1.0-2.0%. The amino-terminated polydimethylsiloxane used below is purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd., product number xyh001.

[0027] Example 1 A high-strength and toughened nylon 6, the raw materials of which include: 70g nylon 6, 5g acrylonitrile-styrene copolymer, 2g SEBS-g-MAH, 1g amino-terminated polydimethylsiloxane, 0.1g PP-G-MAH, 0.01g dibutyltin dilaurate, 5g multi-walled carbon nanotubes, 1g tetraethyl orthosilicate, 1g ammonia borane, 1g antioxidant 1010, and 1g polyether silicone oil.

[0028] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add dibutyltin dilaurate, stir at 180℃ for 1 hour, add PP-G-MAH and continue stirring for 1 hour, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1010 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were heated to 900℃ under nitrogen protection, and ammonia borane was introduced to react for 1 hour. After cooling to room temperature, the nanotubes were added to 40g of 50% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 using 20% ​​ammonia water. The mixture was refluxed at 60℃ for 10 hours, centrifuged, washed, vacuum dried, and heat-treated at 150℃ for 1 hour under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 280℃, the screw length-to-diameter ratio of the twin-screw extruder is 35:1, and the screw speed is 300rpm), it is cooled.

[0029] Example 2 A high-strength and toughened nylon 6, the raw materials of which include: 120g nylon 6, 15g acrylonitrile-styrene copolymer, 6g SEBS-g-MAH, 2g amino-terminated polydimethylsiloxane, 0.2g PP-G-MAH, 0.05g dibutyltin dilaurate, 10g multi-walled carbon nanotubes, 2g tetraethyl orthosilicate, 4g ammonia borane, 2g antioxidant 1098, and 2g polyether silicone oil.

[0030] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add dibutyltin dilaurate, stir at 200℃ for 2 hours, add PP-G-MAH and continue stirring for 2 hours, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1098 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were heated to 1000℃ under nitrogen protection, and ammonia borane was introduced for 2 hours. After cooling to room temperature, the nanotubes were added to 60g of 60% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 using 20% ​​ammonia water. The mixture was refluxed at 70℃ for 20 hours, centrifuged, washed, vacuum dried, and heat-treated at 200℃ for 2 hours under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 295℃, the screw length-to-diameter ratio of the twin-screw extruder is 40:1, and the screw speed is 400rpm), it is cooled.

[0031] Example 3 A high-strength and toughened nylon 6, the raw materials of which include: 90g nylon 6, 12g acrylonitrile-styrene copolymer, 3g SEBS-g-MAH, 1.8g amino-terminated polydimethylsiloxane, 0.12g PP-G-MAH, 0.04g dibutyltin dilaurate, 7g multi-walled carbon nanotubes, 1.8g tetraethyl orthosilicate, 2g ammonia borane, 1.8g antioxidant 1010, and 1.2g polyether silicone oil.

[0032] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add dibutyltin dilaurate, stir at 195℃ for 80 min, add PP-G-MAH and continue stirring for 100 min, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1010 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were heated to 920℃ under nitrogen protection, and ammonia borane was introduced for 100 min. After cooling to room temperature, they were added to 45 g of 58% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 with 20% ammonia water. The reaction was carried out under reflux at 62℃ for 18 h, centrifuged, washed, vacuum dried, and heat-treated at 160℃ for 100 min under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 285℃, the screw length-to-diameter ratio of the twin-screw extruder is 39:1, and the screw speed is 330rpm), it is cooled.

[0033] Example 4 A high-strength and toughened nylon 6, the raw materials of which include: 110g nylon 6, 8g acrylonitrile-styrene copolymer, 5g SEBS-g-MAH, 1.2g amino-terminated polydimethylsiloxane, 0.18g PP-G-MAH, 0.02g dibutyltin dilaurate, 9g multi-walled carbon nanotubes, 1.2g tetraethyl orthosilicate, 3g ammonia borane, 1.2g antioxidant 1098, and 1.8g polyether silicone oil.

[0034] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add dibutyltin dilaurate, stir at 185℃ for 100 min, add PP-G-MAH and continue stirring for 80 min, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1098 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were heated to 940℃ under nitrogen protection, and ammonia borane was introduced for 80 min. After cooling to room temperature, the nanotubes were added to 55 g of 52% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 with 20% ammonia water. The mixture was refluxed at 68℃ for 12 h, centrifuged, washed, vacuum dried, and heat-treated at 180℃ for 80 min under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 290℃, the screw length-to-diameter ratio of the twin-screw extruder is 37:1, and the screw speed is 370rpm), it is cooled.

[0035] Example 5 A high-strength and toughened nylon 6, the raw materials of which include: 100g nylon 6, 10g acrylonitrile-styrene copolymer, 4g SEBS-g-MAH, 1.5g amino-terminated polydimethylsiloxane, 0.15g PP-G-MAH, 0.03g dibutyltin dilaurate, 8g multi-walled carbon nanotubes, 1.5g tetraethyl orthosilicate, 2.5g ammonia borane, 1.5g antioxidant 1010, and 1.5g polyether silicone oil.

[0036] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add dibutyltin dilaurate, stir at 190℃ for 90 min, add PP-G-MAH and continue stirring for 90 min, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1010 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were heated to 920℃ under nitrogen protection, and ammonia borane was introduced for 90 min. After cooling to room temperature, the nanotubes were added to 50 g of 55% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 with 20% ammonia water. The mixture was refluxed at 65℃ for 15 h, centrifuged, washed, vacuum dried, and heat-treated at 170℃ for 90 min under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 288℃, the screw length-to-diameter ratio of the twin-screw extruder is 38:1, and the screw speed is 350rpm), it is cooled.

[0037] Comparative Example 1 A high-strength and toughened nylon 6, the raw materials of which include: 100g nylon 6, 10g acrylonitrile-styrene copolymer, 4g SEBS-g-MAH, 1.5g amino-terminated polydimethylsiloxane, 8g multi-walled carbon nanotubes, 1.5g tetraethyl orthosilicate, 2.5g ammonia borane, 1.5g antioxidant 1010, and 1.5g polyether silicone oil.

[0038] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, then add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1010 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were heated to 920℃ under nitrogen protection, and ammonia borane was introduced for 90 min. After cooling to room temperature, the nanotubes were added to 50 g of 55% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 with 20% ammonia water. The mixture was refluxed at 65℃ for 15 h, centrifuged, washed, vacuum dried, and heat-treated at 170℃ for 90 min under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 288℃, the screw length-to-diameter ratio of the twin-screw extruder is 38:1, and the screw speed is 350rpm), it is cooled.

[0039] Comparative Example 2 A high-strength and toughened nylon 6, the raw materials of which include: 100g nylon 6, 10g acrylonitrile-styrene copolymer, 4g SEBS-g-MAH, 1.5g amino-terminated polydimethylsiloxane, 0.15g PP-G-MAH, 0.03g dibutyltin dilaurate, 10.5g multi-walled carbon nanotubes, 1.5g tetraethyl orthosilicate, 1.5g antioxidant 1010, and 1.5g polyether silicone oil.

[0040] The preparation method of the above-mentioned high-strength toughened nylon 6 includes the following steps: S1. Mix SEBS-g-MAH and amino-terminated polydimethylsiloxane evenly, add dibutyltin dilaurate, stir at 190℃ for 90 min, add PP-G-MAH and continue stirring for 90 min, cool to room temperature, add nylon 6, acrylonitrile-styrene copolymer, antioxidant 1010 and polyether silicone oil and mix evenly to obtain a premix. S2. Multi-walled carbon nanotubes were added to 50g of 55% ethanol aqueous solution, tetraethyl orthosilicate was added, and the pH of the system was adjusted to 8-9 with 20% ammonia water. The reaction was carried out under reflux at 65℃ for 15h, centrifuged, washed, vacuum dried, and heat-treated at 170℃ for 90min under nitrogen protection to obtain boron nitride / silica modified carbon nanotubes. S3. The premixed material is fed into the twin-screw extruder via the main feeder, and the boron nitride / silica modified carbon nanotubes are fed into the twin-screw extruder via the side feeder. After melt extrusion granulation (during melt extrusion, the melt extrusion temperature is 288℃, the screw length-to-diameter ratio of the twin-screw extruder is 38:1, and the screw speed is 350rpm), it is cooled.

[0041] The tensile strength of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2 was determined in accordance with GB / T 1040.1-2025 "Determination of tensile properties of plastics - Part 1: General".

[0042] The flexural strength of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2 was determined in accordance with GB / T 9341-2008 "Determination of Flexural Properties of Plastics".

[0043] like Figure 1 As shown, the high-strength toughened nylon 6 obtained in Example 5 has the highest tensile strength and flexural strength, which are significantly better than those of Comparative Examples 1-2.

[0044] The notched impact strength of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2 was determined in accordance with GB / T 1843-2008 "Determination of impact strength of plastic cantilever beam".

[0045] like Figure 2As shown, the notched impact strength of the high-strength toughened nylon 6 obtained in Example 5 is the highest, which is significantly better than that of Comparative Examples 1-2.

[0046] The heat distortion temperature of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2 was determined with reference to GB / T 1634.1-2025 "Determination of Deformation Temperature of Plastics under Load - Part 1: General Test Methods", where the load was 1.8 MPa.

[0047] The molding shrinkage of the high-strength toughened nylon 6 obtained in Example 5 and Comparative Examples 1-2 was determined in accordance with GB / T 17037.4-2003 "Preparation of injection molded specimens of thermoplastic materials - Part 4: Determination of molding shrinkage".

[0048] like Figure 3 As shown, the high-strength toughened nylon 6 obtained in Example 5 has the highest heat distortion temperature and the lowest molding shrinkage, which is significantly better than Comparative Examples 1-2.

[0049] The reason for the above results is that the present invention grows boron nitride nanosheets on the surface of carbon nanotubes. These nanosheets not only absorb a large amount of energy upon impact through the slippage and rearrangement of the sheets, but also, in conjunction with the formed silica deposition layer, significantly improve the interfacial compatibility with the matrix. Simultaneously, the carbon nanotubes, boron nitride nanosheets, and silica deposition layer synergistically enhance the thermal conductivity of the matrix, effectively improving the high thermal stability of the system. The present invention uses SEBS-g-MAH compounded with amino-terminated polydimethylsiloxane, and after PP-G-MAH treatment, it can effectively maintain the toughness and thermal stability in high-temperature environments. Combined with boron nitride / silica-modified carbon nanotubes, it effectively conducts heat, reduces local temperature rise, and enables the composite material to maintain excellent mechanical properties and dimensional stability over a wide temperature range. It effectively restricts the movement of nylon 6 molecular chain segments, thereby helping to maintain the rigidity and heat distortion temperature of the material at high temperatures.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-strength toughened nylon 6, characterized in that, The raw materials include by mass fraction: nylon 670-120 parts, acrylonitrile-styrene copolymer 5-15 parts, SEBS-g-MAH 2-6 parts, amino-terminated polydimethylsiloxane 1-2 parts, PP-G-MAH 0.1-0.2 parts, catalyst 0.01-0.05 parts, multi-walled carbon nanotubes 5-10 parts, tetraethyl orthosilicate 1-2 parts, boron nitride precursor 1-4 parts, antioxidant 1-2 parts, lubricant 1-2 parts.

2. The high-strength toughened nylon 6 of claim 1, wherein, The catalyst is organic tin.

3. The high-strength toughened nylon 6 of claim 2, wherein, The organic tin is dibutyltin dilaurate.

4. The high-strength toughened nylon 6 of claim 1, wherein, The boron nitride precursor is ammonia borane.

5. The high-strength toughened nylon 6 of claim 1, wherein, The lubricant is a modified high molecular weight silicone lubricant.

6. The high-strength toughened nylon 6 of claim 1, wherein, The antioxidant includes at least one of antioxidant 1098 and antioxidant 1010.

7. A process for the preparation of high-strength toughened nylon 6 according to any one of claims 1 to 6, characterized in that, The method includes the following steps: S1, uniformly mix SEBS-g-MAH and amino-terminated polydimethylsiloxane, add catalyst, stir at 180-200℃ for 1-2h, add PP-G-MAH and continue stirring for 1-2h, cool to room temperature, uniformly mix nylon 6, acrylonitrile-styrene copolymer, antioxidant and lubricant to obtain a premix; S2, heat multi-walled carbon nanotubes to 900-950℃ under nitrogen protection, introduce boron nitride precursor vapor for 1-2h, reduce to room temperature, add to an ethanol aqueous solution, add tetraethyl orthosilicate, adjust the system pH value to 8-9, reflux at 60-70℃ for 10-20h, centrifuge, wash, vacuum dry, heat treat at 150-200℃ for 1-2h under nitrogen protection to obtain boron nitride / silicon dioxide modified carbon nanotubes; S3, melt extrude and granulate the premix and boron nitride / silicon dioxide modified carbon nanotubes.

8. The method for preparing high-strength toughened nylon 6 according to claim 7, characterized in that, In S2, the mass fraction of the ethanol aqueous solution is 50-60%; use 20% ammonia water to adjust the system pH value to 8-9.

9. The method for preparing high-strength toughened nylon 6 according to claim 7, characterized in that, In S3, during melt extrusion, the melt extrusion temperature is 280-295℃, the screw length-diameter ratio of the twin-screw extruder is 35-40:1, and the screw rotation speed is 300-400rpm.

10. The high-strength toughened nylon 6 of any one of claims 1-6 as a heat-resistant toughening material for high-temperature or high-load working conditions.

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