High-thermal-conductivity polyester-nylon composite filament and preparation process thereof

Abstract

The invention discloses a high-thermal-conductivity polyester-nylon composite filament and a preparation process thereof, and relates to the technical field of polyester-nylon composite filaments, in particular to the high-thermal-conductivity polyester-nylon composite filament and the preparation process thereof, and the preparation process comprises the following steps: S1, blending treated graphene and PET slices in a twin-screw extruder to generate a melt, and compounding the filament through a spinneret plate; s2, carrying out coaxial electrostatic spinning on the treated boron nitride nanotube on the surface of the core layer fiber to form a fluffy nanofiber net with the thickness of 20 microns; s3, mixing PEG4000 with the silicon carbide nanowires, coating with urea resin, and preparing microcapsules with the diameter of 5 microns through an in-situ polymerization method; and S4, dispersing the microcapsules in a waterborne polyurethane adhesive, and coating the surface of the composite fiber with the waterborne polyurethane adhesive through a gravure roller. According to the preparation process, graphene and PET slices are mixed according to the weight ratio of 3.5: 6.5, an efficient axial heat channel is constructed, and the longitudinal heat conduction capacity is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat polyester-polyamide composite yarn, in particular to a high-thermal-conductivity polyester-polyamide composite yarn and a preparation process thereof. BACKGROUND

[0002] The polyester-polyamide composite yarn is an ultra-fine fiber material made of polyester (polyester fiber) and polyamide (nylon) through composite spinning technology, and the single yarn fineness can reach 1 / 20 of ordinary fiber; the material has a special cross-section structure, realizes polyester-polyamide double-component parallel composite through the FDY process, forms a fiber network with large specific surface area and significant capillary effect; the water absorption capacity reaches 20 times of ordinary cotton fabric, and has the characteristics of wrinkle resistance, wear resistance, antibacterial hygiene, etc., and the service life is significantly prolonged compared with conventional fabrics; the crimping shrinkage rate of the polyester-polyamide composite yarn after special post-treatment is more than 50%, and the elastic recovery rate is more than 92.7%; the polyester-polyamide composite yarn is mainly applied to the fields of household cleaning cloth, optical glass wiping cloth, sports clothing and medical textiles; with the progress of science and technology, the application range of the polyester-polyamide composite yarn is also expanding; the material has good flexibility, can closely fit the surface of the chip, and ensures that the heat is quickly exported; in addition, the polyester-polyamide composite yarn has excellent chemical stability, pressure resistance and heat resistance, ensures long-term reliable work of the heat dissipation pad, and has outstanding performance in efficient heat dissipation, stable fitting and cost control, and is one of the ideal choices for chip module heat dissipation.

[0003] The existing polyester-polyamide composite yarn has good air permeability, but the thermal conductivity of the polyester-polyamide composite yarn is poor, which affects the heat dissipation efficiency of the chip and even causes serious failure. SUMMARY

[0004] In view of the defects of the prior art, the present application provides a high-thermal-conductivity polyester-polyamide composite yarn and a preparation process thereof, which solves the problem that the existing polyester-polyamide composite yarn has good air permeability, but the thermal conductivity of the polyester-polyamide composite yarn is poor, which affects the heat dissipation efficiency of the chip and even causes serious failure.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: a high-thermal-conductivity polyester-polyamide composite yarn and a preparation process thereof, comprising:

[0006] The outer surface of the core layer is fixedly installed with an intermediate buffer layer, and the outer surface of the intermediate buffer layer is glued with an outer layer.

[0007] As a preferred high-thermal-conductivity polyester-polyamide composite yarn of the present application, the core layer is made of a mixture of amino-functionalized graphene sheets and PET material.

[0008] As a preferred high-thermal-conductivity polyester-polyamide composite yarn of the present application, the intermediate buffer layer is made of boron nitride nanotube material, and the intermediate buffer layer has a fluffy structure.

[0009] Preferably, the outer layer of the high-thermal-conductivity polyester-polyamide composite yarn is made of microcapsule-shaped particles of PEG4000 material and silicon carbide nanowire material.

[0010] Preferably, the preparation process of the high-thermal-conductivity polyester-polyamide composite yarn comprises the following steps:

[0011] S1: The treated graphene and PET chips are mixed in a double-screw extruder to generate a melt, with temperature partition control as follows: 240℃ for the feeding zone, 270℃ for the mixing zone, and 255℃ for the extrusion zone, with a screw rotation speed of 120rpm, and a 10kV high-voltage direct-current electric field is applied through a spinneret with a pore size of 0.2mm, to obtain the composite yarn under the conditions of a draw ratio of 1:35 and a winding speed of 1200m / min;

[0012] S2: The treated boron nitride nanotubes are coaxially electrospun on the surface of the core layer fiber, with a working voltage of 25kV for the coaxial electrospinning and a receiving distance of 15cm, and the humidity is less than 30%, to form a fluffy nanofiber web with a thickness of 20μm;

[0013] S3: The PEG4000 is mixed with the silicon carbide nanowires, coated with urea-formaldehyde resin, and the wall thickness of the urea-formaldehyde resin is 0.2μm, to prepare microcapsules with a diameter of 5μm by in-situ polymerization;

[0014] S4: The microcapsules are dispersed in the water-based polyurethane adhesive and coated onto the surface of the composite fiber by gravure roll coating.

[0015] Preferably, in the preparation process of the high-thermal-conductivity polyester-polyamide composite yarn, the graphene in step S1 is treated by placing it in a plasma reaction chamber, introducing ammonia gas at a flow rate of 50sccm, and treating it at a power of 300W for 10 minutes.

[0016] Preferably, in the preparation process of the high-thermal-conductivity polyester-polyamide composite yarn, the boron nitride nanotubes in step S2 are dispersed in a PA6 solution with a concentration of 18% and treated with ultrasonic waves at a power of 500W for thirty minutes, and then 0.5% sodium dodecyl sulfate is added for treatment.

[0017] Preferably, in the preparation process of the high-thermal-conductivity polyester-polyamide composite yarn, the microcapsules in step S4 are coated onto the surface of the composite fiber by the water-based polyurethane adhesive with a solid content of 30%, and the coating thickness is 8μm, and then heat curing is performed at 120℃ for 1 minute.

[0018] Preferably, in the preparation process of the high-thermal-conductivity polyester-polyamide composite yarn, the weight ratio of the graphene to the PET chips in step S1 is 3.5:6.5.

[0019] Preferably, in the preparation process of the high-thermal-conductivity polyester-polyamide composite yarn, the mass ratio of PEG4000 to silicon carbide nanowires in step S3 is 10:1.

[0020] The application provides a high-thermal-conductivity polyester-polyamide composite yarn and a preparation process thereof.

[0021] 1. The high-thermal-conductivity polyester-polyamide composite yarn and the preparation process thereof realize the golden balance of performance and process by mixing graphene and PET chips at a weight ratio of 3.5:6.5. The ratio enables the graphene to form a continuous thermal conduction network, builds an efficient axial heat channel, and significantly improves the longitudinal heat conduction capacity. Meanwhile, the ratio ensures controllable melt viscosity, guarantees the continuity of spinning and the strength of the fiber, and avoids agglomeration and blockage caused by high filler. Under the assistance of a high-voltage electric field, the graphene is arranged in a direction to maximize the thermal conduction efficiency without causing excessive cost increase or electromagnetic interference problems, thereby providing a material basis with excellent heat dissipation, process stability and electromagnetic purity for 5G high-power chips.

[0022] 2. The high-thermal-conductivity polyester-polyamide composite yarn and the preparation process thereof form a three-dimensional interpenetrating structure in the electrospinning web by using boron nitride nanotubes, so that the intermediate layer is like an elastic thermal conduction net filled with special nanotubes. It is soft like a sponge and can absorb the small gap during chip installation, protecting delicate electronic components from being damaged. At the same time, these nanotubes can intelligently transfer heat in a specific direction to prevent heat from being scattered and lost, ensuring that heat is efficiently directed to the right place. In short, it can act as a buffer protection pad for chips and control the direction of heat.

[0023] 3. The high-thermal-conductivity polyester-polyamide composite yarn and the preparation process thereof coat an intelligent thermal conductive glue on the outer layer. When the chip heats up to the normal working temperature, the glue automatically softens and melts to seep out of the capsule, like water, and penetrates into the small gap between the chip and the heat sink, filling the gap tightly to make heat transfer smoother. When the temperature drops, it immediately hardens and solidifies, firmly adhering to the place. What's more, it is encapsulated in a super-tough microcapsule, so it won't leak even if the device is shaken violently. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the front view structure of the application;

[0025] Figure 2 It is a material experiment table of the core layer of the application;

[0026] Figure 3 It is a proportion experiment table of graphene and PET chips of the application;

[0027] Figure 4 It is a proportion experiment table of PEG4000 and silicon carbide nanowires of the application.

[0028] In the figure: 1, core layer; 2, intermediate buffer layer; 3, outer layer. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0030] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] Please refer to Figure 1 A high-thermal-conductivity polyester-jacquard composite yarn and a preparation process thereof, comprising a core layer 1, an intermediate buffer layer 2 fixedly installed on the outer surface of the core layer 1, and an outer layer 3 glued to the outer surface of the intermediate buffer layer 2.

[0033] In the present embodiment: the core layer adopts a 35% vertically oriented graphene / PET composite system, which realizes the axial directional arrangement of graphene sheets under a 10kV high-voltage electric field, forms a longitudinal phonon superconducting channel with a longitudinal thermal conductivity of 45W / m·K, directly penetrates the chip hot spot and the heat dissipation shell, and realizes the heat dissipation of 500W / cm 2 The contact thermal resistance under high heat flux is compressed to 0.03℃·cm 2 / W, while avoiding the sharp increase in melt viscosity caused by high filler and controlling the breakage rate to be ≤8%;

[0034] The intermediate layer constructs a three-dimensional phonon bridging network in the PA6 electrospinning net through 25% boron nitride nanotubes, realizes the transverse thermal conductivity of 8W / m·K on the premise of maintaining ultra-low compression modulus, and blocks the transverse heat diffusion loss of the core layer.

[0035] The outer layer takes the PEG4000 / silicon carbide nanowire phase change composite material as the core, uses the 45 DEG C phase change temperature to accurately match the chip working temperature zone, relies on the capillary action to penetrate the interface gap of ≤5 μm after melting, and the liquid thermal conductivity is 2.5 W / m*K, and after solidification, the structure is stable through the hydrogen bond self-adhesion, and the contact thermal resistance is reduced.

[0036] Further, the core layer 1 is made of a mixture of amino graphene sheets and PET material.

[0037] In an alternative embodiment, the core layer 1 is made of a mixture of amino graphene sheets and PET material.

[0038] In this embodiment: through the axial directional arrangement of 35% amino graphene under a 10kV electric field, a "thermal superconducting channel" with a longitudinal thermal conductivity of 45 W / m*K is constructed, and the heat flow of the chip hotspot is efficiently transmitted to the heat dissipation shell, reducing the interface contact thermal resistance, and the high-voltage electric field orientation technology makes the graphene arrangement degree reach 88%, avoiding the problem of melt rupture caused by high filler.

[0039] Further, the core layer 1 is made of a mixture of amino graphene sheets and PET material.

[0040] In an alternative embodiment, the intermediate buffer layer 2 is made of boron nitride nanotube material, and the intermediate buffer layer 2 has a fluffy structure.

[0041] In this embodiment: a three-dimensional interpenetrating structure is formed in the electrospinning web with 25% boron nitride nanotubes, which has an ultra-low compression modulus of ≤1 MPa and a transverse thermal conductivity of 8 W / m*K, which not only adapts to the tolerance fluctuation of 0.1-0.3 mm of the chip package to avoid stress damage to the fragile solder joints, but also inhibits the transverse heat diffusion loss from the core layer to the outer layer through the phonon transmission of boron nitride.

[0042] Further, the core layer 1 is made of a mixture of amino graphene sheets and PET material.

[0043] In an alternative embodiment, the outer layer 3 is made of microcapsule-shaped particles made of PEG4000 material and silicon carbide nanowire material.

[0044] In this embodiment: PEG4000 with a phase change temperature of 45 DEG C is used to melt and penetrate the interface microgap in the chip working temperature zone, and the liquid thermal conductivity is increased to 2.5 W / m*K with the cooperation of silicon carbide nanowires, and the peel strength is >1.5 N / mm after solidification through hydrogen bond self-adhesion.

[0045] Further, the core layer 1 is made of a mixture of amino graphene sheets and PET material.

[0046] In an alternative embodiment, the method comprises the following steps:

[0047] S1: blend the treated graphene and PET chips in a twin-screw extruder to generate a melt, with temperature partition control at 240°C for the feeding zone, 270°C for the mixing zone, and 255°C for the extrusion zone, screw rotation speed of 120 rpm, and application of a 10 kV high-voltage direct current electric field through a spinneret with a pore size of 0.2 mm, to obtain a composite filament under the conditions of a draw ratio of 1:35 and a winding speed of 1200 m / min;

[0048] S2: perform coaxial electrospinning of the treated boron nitride nanotubes on the surface of the core layer fiber, with a working voltage of 25 kV for the coaxial electrospinning and a receiving distance of 15 cm, humidity < 30%, to form a fluffy nanofiber web with a thickness of 20 pm;

[0049] S3: mix PEG4000 with silicon carbide nanowires, coat them with urea-formaldehyde resin with a wall thickness of 0.2 pm, and prepare microcapsules with a diameter of 5 pm by in-situ polymerization;

[0050] S4: disperse the microcapsules in a water-based polyurethane adhesive and coat them onto the surface of the composite fiber by gravure roll coating.

[0051] In the present embodiment: the high-thermal-conductivity polyester-jacquard composite filament preparation process realizes breakthrough heat dissipation efficiency through innovative structural design: the graphene is precisely arranged along the fiber axis by the electric field orientation technology in the core layer, constructing an ultra-efficient longitudinal heat conduction channel that directly penetrates the chip and the heat dissipation shell; the nanotube network in the intermediate layer realizes transverse heat diffusion under extremely low compressive stress while absorbing mechanical deformation to protect the fragile elements; the outer layer of intelligent phase change material melts and penetrates the interface microgap at the working temperature of the chip, and after solidification, forms a self-adhesive sealing layer, completely eliminating thermal interface resistance. The entire process synchronously completes the integration of the three layers in continuous production, not only solving the traditional contradiction between high thermal conductivity and low stress, but also ensuring signal purity in a high-frequency electromagnetic environment, providing a stable and reliable heat dissipation solution for 5G / 6G high-power chips, with excellent performance and industrial-level mass production feasibility.

[0052] Further:

[0053] In an optional embodiment, the graphene in step S1 is treated by being placed in a plasma reaction chamber, with ammonia gas flowing in at a flow rate of 50 sccm, and treated for 10 minutes at a power of 300 W.

[0054] In the present embodiment: the above technical solutions improve the interfacial bonding force between graphene and PET, avoiding agglomeration during melt spinning.

[0055] Further:

[0056] In an optional embodiment, the boron nitride nanotubes in step S2 are dispersed in a PA6 solution with a concentration of 18% and ultrasonically treated with a power of 500W for 30 minutes, and then treated with 0.5% sodium dodecyl sulfate.

[0057] In this implementation plan, the above-mentioned method is used to prevent nanotube sedimentation and ensure the uniformity of the three-dimensional network.

[0058] Furthermore:

[0059] In an optional embodiment, the microcapsules in S4 are coated onto the surface of the composite fiber using a waterborne polyurethane adhesive with a solid content of 30%, with a coating thickness of 8 μm, and then heat-cured at 120°C for 1 minute.

[0060] In this implementation scheme: the above technical solution enables the microcapsules to form an adaptive interface filling layer, and the micro-gaps are filled after the phase change to reduce the contact thermal resistance.

[0061] Furthermore:

[0062] In an optional embodiment, the weight ratio of graphene to PET chips in step S1 is 3.5:6.5.

[0063] In this implementation scheme, graphene and PET chips are mixed at a ratio of 35%, achieving a golden balance between performance and process: this ratio allows graphene to fully form a continuous thermally conductive network, constructing an efficient axial thermal channel and significantly improving longitudinal thermal conductivity; at the same time, it ensures controllable melt viscosity, guarantees spinning continuity and fiber strength, and avoids agglomeration and blockage caused by high filler; under the assistance of a high-voltage electric field, the graphene is oriented to maximize thermal conductivity without excessively increasing costs or causing electromagnetic interference problems, providing a material basis for 5G high-power chips that combines excellent heat dissipation, processing stability and electromagnetic purity.

[0064] Furthermore:

[0065] In an optional embodiment, the mass ratio of PEG4000 to silicon carbide nanowires in step S3 is 10:1.

[0066] This implementation scheme achieves an ideal synergy between phase change performance and enhanced thermal conductivity: the ratio ensures that silicon carbide nanowires are fully dispersed to form a thermally conductive network, significantly improving the thermal conductivity of the molten material, while avoiding excessive nanowires from hindering the phase change fluidity and interfacial permeability of PEG; the PEG matrix maintains sufficient latent heat of phase change and wide temperature range adaptability, precisely melting within the chip's operating temperature range and filling micro-gaps through capillary action, while the silicon carbide nanowires simultaneously construct a solid-phase thermally conductive framework, forming a mechanically self-supporting structure after solidification. This ratio maximizes thermal interface contact efficiency while ensuring cycle stability and avoiding the risk of coating cracking caused by nano-agglomeration.

[0067] Example 1

[0068] S1: First, the amino graphene sheet is placed in the plasma reaction chamber, and ammonia gas is introduced at a flow rate of 50 sccm. The graphene is treated at a power of 300 W for 10 minutes. Then the treated graphene and PET chips are mixed in a ratio of 3.5:6.5 in a twin-screw extruder. The temperature of the feeding zone is 240℃, the temperature of the mixing zone is 270℃, and the temperature of the extrusion zone is 255℃. The screw rotation speed is 120 rpm. Then the extruded melt is passed through a spinneret with a pore size of 0.2 mm under the application of a 10 kV high-voltage direct current electric field. The filamentous core layer is produced under the conditions of a draw ratio of 1:35 and a winding speed of 1200 m / min.

[0069] S2: The boron nitride nanotubes are dispersed in a PA6 or DMF solution with a concentration of 18%. Then they are treated with ultrasonic waves at a power of 500 W for 30 min. Next, 0.5% of sodium dodecyl sulfate is added to complete the treatment of the boron nitride nanotubes. Then the boron nitride nanotubes are spun on the surface of the core layer through a coaxial electrospinning technique under the conditions of a voltage of 25 kV, a receiving distance of 15 cm, and a humidity of <30%.

[0070] S3: PEG4000 and silicon carbide nanowires are mixed in a mass ratio of 10:1, then coated with urea-formaldehyde resin with a wall thickness of 0.2 μm, and microcapsules with a diameter of 5 μm are prepared by in-situ polymerization.

[0071] S4: The microcapsules are dispersed in a water-based polyurethane adhesive with a solid content of 30%, and coated on the surface of the composite fiber produced in S2 by gravure roll coating, with a coating thickness of 8 μm. Then it is heat cured at 120℃ for 1 min to produce a high-thermal-conductivity polyester-polyamide composite filament.

[0072] Example 2

[0073] A high-thermal-conductivity polyester-polyamide composite filament preparation process, which differs from Example 1 in that the core layer in step S1 is prepared with pure PET chips.

[0074] Example 3

[0075] A high-thermal-conductivity polyester-polyamide composite filament preparation process, which differs from Example 1 in that the core layer in step S1 is prepared with aluminum powder and PET chips in a ratio of 4:6.

[0076] Example 4

[0077] A high-thermal-conductivity polyester-polyamide composite filament preparation process, which differs from Example 1 in that the ratio of graphene to PET chips in step 1 is 3:7.

[0078] Embodiment 5

[0079] A high-thermal-conductivity polyester-polyamide composite yarn preparation process, which differs from Embodiment 1 in that the ratio of graphene to PET chips in step 1 is 4:6.

[0080] Embodiment 6

[0081] A high-thermal-conductivity polyester-polyamide composite yarn preparation process, which differs from Embodiment 1 in that the ratio of PEG4000 to silicon carbide nanowires in step 3 is 5:1.

[0082] Embodiment 7

[0083] A high-thermal-conductivity polyester-polyamide composite yarn preparation process, which differs from Embodiment 1 in that the ratio of PEG4000 to silicon carbide nanowires in step 3 is 15:1.

[0084] In combination with Embodiments 1-3 and Figure 2 It can be known that the high-thermal-conductivity polyester-polyamide composite yarn prepared by the preparation process in the present application has low thermal resistance and good thermal conductivity;

[0085] In combination with Embodiments 4-5 and Figure 3 It can be known that the high-thermal-conductivity polyester-polyamide composite yarn prepared by the preparation process in the present application has good spinnability and strength while ensuring good thermal conductivity;

[0086] In combination with Embodiments 6-7 and Figure 4 It can be known that the high-thermal-conductivity polyester-polyamide composite yarn prepared by the preparation process in the present application has good thermal conductivity.

[0087] The above, only for the preferred specific embodiments of the present application, but the protection scope of the present application is not limited to this, any skilled in the art of the technical personnel in the technical range disclosed by the present application, according to the technical scheme of the present application and the invention concept of the invention, equivalent replacement or change, should be covered in the protection scope of the present application.

Claims

1. A high thermal conductivity polyester-nylon composite yarn and its preparation process, characterized in that, include: Core layer (1), intermediate buffer layer (2), outer layer (3) The core layer (1) has an intermediate buffer layer (2) fixedly installed on its outer surface, and an outer layer (3) is glued to its outer surface.

2. The high thermal conductivity polyester-nylon composite yarn according to claim 1, characterized in that, The core layer (1) is made by blending an amino-based graphene sheet and PET material.

3. The high thermal conductivity polyester-nylon composite yarn according to claim 1, characterized in that, The intermediate buffer layer (2) is made of boron nitride nanotube material and has a fluffy structure.

4. The high thermal conductivity polyester-nylon composite yarn according to claim 1, characterized in that, The outer layer (3) is formed by bonding microcapsule-shaped particles made of PEG4000 material and silicon carbide nanowire material.

5. A process for preparing high thermal conductivity polyester-nylon composite yarn, characterized in that, Includes the following steps: S1: The treated graphene and PET chips are blended together in a twin-screw extruder to form a melt. The temperature is controlled in zones: 240℃ in the feeding zone, 270℃ in the mixing zone, and 255℃ in the extrusion zone. The screw speed is 120 rpm. A 10kV high-voltage DC electric field is applied through a spinneret with a diameter of 0.2mm. Composite filaments are obtained under the conditions of a draw ratio of 1:35 and a winding speed of 1200m / min. S2: The treated boron nitride nanotubes are coaxially electrospun on the surface of the core fiber. The working voltage of coaxial electrospinning is 25kV, the receiving distance is 15cm, and the humidity is less than 30%, forming a fluffy nanofiber web with a thickness of 20μm. S3: PEG4000 was mixed with silicon carbide nanowires and coated with urea-formaldehyde resin with a wall thickness of 0.2 μm. Microcapsules with a diameter of 5 μm were prepared by in-situ polymerization. S4: Disperse the microcapsules in an aqueous polyurethane adhesive and coat them onto the surface of the composite fiber using a gravure roller.

6. The process for preparing a high thermal conductivity polyester-nylon composite yarn according to claim 5, characterized in that, In step S1, the graphene is obtained by placing it in a plasma reaction chamber, introducing ammonia gas at a flow rate of 50 sccm, and processing it at a power of 300W for 10 minutes.

7. The process for preparing a high thermal conductivity polyester-nylon composite yarn according to claim 5, characterized in that, In step S2, the boron nitride nanotubes are dispersed in an 18% PA6 solution and ultrasonically treated with 500W power for 30 minutes, followed by the addition of 0.5% sodium dodecyl sulfate for further treatment.

8. The process for preparing a high thermal conductivity polyester-nylon composite yarn according to claim 5, characterized in that, The microcapsules in S4 are coated onto the surface of the composite fiber using a water-based polyurethane adhesive with a solid content of 30%, with a coating thickness of 8 μm, and then heat-cured at 120°C for 1 minute.

9. The process for preparing a high thermal conductivity polyester-nylon composite yarn according to claim 5, characterized in that, The weight ratio of graphene to PET chips in step S1 is 3.5:6.

5.

10. The process for preparing a high thermal conductivity polyester-nylon composite yarn according to claim 5, characterized in that, In step S3, the mass ratio of PEG4000 to silicon carbide nanowires is 10:1.

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