Lightweight high-thermal-conductivity flame-retardant composite material for air conditioning system and preparation method thereof

Abstract

The invention belongs to the technical field of polymer composite materials, and relates to a light-weight, high-heat-conductivity and flame-retardant composite material for a new energy automobile air conditioning system and a preparation method of the light-weight, high-heat-conductivity and flame-retardant composite material. 10 to 25 parts of multifunctional compound filler; the multifunctional compound filler is formed by compounding two-dimensional titanium carbide nanosheets and hexagonal boron nitride microsheets according to the mass ratio of (1: 4)-(1: 1). 2 to 5 parts of compatilizer; 0.1 to 0.5 part of an antioxidant; and 0.5 to 1.5 parts of a lubricant. Through precise compounding of MXene and h-BN, a new triple synergistic mechanism of heat conduction, electromagnetic shielding and flame retardance is created, hexagonal boron nitride serves as a main heat conduction phase, and a phonon conduction path is built in a matrix through a sheet structure of the hexagonal boron nitride; the two-dimensional titanium carbide nanosheets play a bridging role among the h-BN micron sheets by virtue of high conductivity and huge specific surface area, so that the interface thermal resistance is remarkably reduced, a heat-conducting network is optimized, and meanwhile, the metal conductivity of MXene endows the material with excellent electromagnetic shielding effectiveness.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials technology, and relates to a lightweight, high thermal conductivity, and flame-retardant composite material for air conditioning systems in new energy vehicles and its preparation method. Background Technology

[0002] The air conditioning (HVAC) systems of new energy vehicles are developing towards higher voltage, higher integration, and greater intelligence. The power density of internal components such as the electronic control unit (ECU), PTC heating module, and blower motor has increased significantly, generating a large amount of concentrated heat during operation. Effective thermal management through the materials themselves is crucial to prevent overheating failure. Simultaneously, the high-voltage electrical environment places higher demands on the flame retardancy (e.g., requiring UL94 V-0 rating) and electromagnetic compatibility (EMI shielding) of materials.

[0003] Currently, these components are mostly made of die-cast aluminum alloys or ordinary engineering plastics. While metal materials have good thermal conductivity, they suffer from drawbacks such as heavy weight, high cost, and low processing flexibility. Ordinary plastics (such as PP and PE) have extremely poor thermal conductivity (~0.2 W / m·K) and insufficient flame retardancy, requiring the addition of large amounts of flame retardants, which further deteriorates their mechanical properties and processing flowability, and may release harmful substances. Existing technologies use fillers such as aluminum nitride (AlN) and alumina (Al2O3) to improve the thermal conductivity of plastics, or magnesium hydroxide (MH) and aluminum hydroxide (Al(OH)3) to improve flame retardancy, but it is often difficult to achieve both simultaneously. High filler content easily leads to material embrittlement and a significant increase in density, and cannot solve the electromagnetic interference problems faced by high-voltage systems.

[0004] Therefore, developing a new composite material that integrates high thermal conductivity, high flame retardancy, lightweight, and electromagnetic shielding is of great significance for improving the reliability, safety, and lightweighting of air conditioning systems in new energy vehicles. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a lightweight, high thermal conductivity and flame retardant composite material for air conditioning systems of new energy vehicles and its preparation method. This material achieves synergy and balance of multiple functions such as thermal conductivity, flame retardancy, and electromagnetic shielding through an innovative filler compounding system, thereby overcoming the shortcomings of the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A lightweight, high thermal conductivity, and flame-retardant composite material for air conditioning systems, comprising the following parts by weight of raw materials: Polymer matrix: 75-90 parts; Multifunctional composite filler: 10-25 parts; the multifunctional composite filler is composed of two-dimensional titanium carbide nanosheets and hexagonal boron nitride microsheets in a mass ratio of 1:4 to 1:1; Compatibilizer: 2-5 parts; Antioxidant: 0.1-0.5 parts; Lubricant: 0.5-1.5 parts.

[0007] Furthermore, the polymer matrix is ​​one of the polymer matrices with a melt index of 15-50 g / 10 min.

[0008] Furthermore, the polymer matrix is ​​one of the polymer matrices with a melt index of 15-50 g / 10 min.

[0009] Furthermore, the matrix is ​​PA66 or PA6.

[0010] Furthermore, the antioxidant is a composite system comprising a primary antioxidant and a secondary antioxidant; the primary antioxidant is a hindered phenolic antioxidant, the secondary antioxidant is a phosphite antioxidant, and the weight ratio of the primary antioxidant to the secondary antioxidant is 1:1 to 1:2.

[0011] Furthermore, the lubricant is one of ethylene bis-stearamide, pentaerythritol stearate, or silicone masterbatch.

[0012] Furthermore, the compatibilizer is one or more of maleic anhydride-grafted polyolefin elastomer, ethylene-acrylic acid copolymer, and epoxy-functionalized polyolefin.

[0013] Furthermore, the two-dimensional titanium carbide nanosheets have a sheet size of 1-5 mm and a thickness of 1-5 nm.

[0014] Furthermore, the average particle size of the hexagonal boron nitride microsheets is 10-50 mm.

[0015] On the other hand, the present invention also provides a method for preparing a lightweight, high thermal conductivity, and flame-retardant composite material for air conditioning systems, comprising the following steps: a) Dry-mix two-dimensional titanium carbide nanosheets with hexagonal boron nitride microsheets to obtain a multifunctional composite filler; b) Mix the multifunctional compound filler obtained in step a) with the polymer matrix, compatibilizer, antioxidant, and lubricant to obtain a premix; c) The premix obtained in step b) is melt-blended and extruded into granules to obtain the composite material.

[0016] Furthermore, the dry mixing time described in step a) is 30-60 minutes.

[0017] Furthermore, the mixing described in step b) is carried out in a high-speed mixer for 5-10 minutes at a speed of 700-900 rpm.

[0018] Further, the melt blending described in step c) is carried out in a twin-screw extruder, wherein the processing temperature of the twin-screw extruder is 250-275°C.

[0019] On the other hand, the present invention also provides the application of a lightweight, high thermal conductivity, and flame-retardant composite material for air conditioning systems in the preparation of air conditioning system components for new energy vehicles.

[0020] Furthermore, the components of the new energy vehicle air conditioning system are an electronic control unit housing, a PTC heater bracket, or a cooling fan.

[0021] The beneficial effects of this invention are as follows: 1. This invention creates a novel triple synergistic mechanism of "thermal conductivity, electromagnetic shielding, and flame retardancy" through the precise blending of MXene and h-BN. h-BN: As the dominant thermal filler, its sheet-like structure establishes an efficient phonon conduction path within the matrix, significantly enhancing thermal conductivity. Simultaneously, it possesses high-temperature stability and insulation properties. MXene: As a key functional filler, it plays three major roles: its metallic conductivity significantly improves the electromagnetic shielding effectiveness of the composite material, solving EMI problems in high-voltage systems; its large specific surface area and layered structure, synergistically with h-BN, can more effectively form a dense, continuous carbonaceous protective layer during combustion, greatly enhancing flame retardancy; its nanosheets can fill between h-BN microsheets, optimizing the thermal conductivity network and further improving thermal efficiency. The blending of the two produces a synergistic effect of "1+1+1>3," simultaneously solving three key technical challenges with a single filler system.

[0022] In summary, hexagonal boron nitride (h-BN) serves as the dominant thermal phase in this invention, utilizing its sheet-like structure to construct phonon conduction pathways within the matrix. Two-dimensional titanium carbide (MXene) nanosheets, with their high conductivity and large specific surface area, act as a "bridge" between the h-BN microsheets, significantly reducing interfacial thermal resistance and optimizing the thermal conductivity network, resulting in a maximum thermal conductivity of 1.58 W / (m·K). Simultaneously, the metallic conductivity of MXene endows the material with excellent electromagnetic shielding effectiveness (up to 32 dB), effectively suppressing electromagnetic interference generated by high-voltage air conditioning systems. During combustion, the dense carbonaceous protective layer formed by both components efficiently isolates heat and oxygen, enabling the material to achieve a UL94 V-0 flame retardant rating without the addition of traditional flame retardants, thus balancing insulation stability and fire safety.

[0023] 2. This solution achieves a deep balance between high performance and lightweighting, breaking through the technical bottleneck of traditional thermally conductive plastics relying on high filler content. Utilizing the high-efficiency functional properties of MXene at extremely low content, this invention controls the total filler content to a low level of 10-25 parts, far lower than the 30%-50% filler ratio often found in traditional thermally conductive materials. This low-filler strategy not only effectively controls material density and achieves lightweight parts, but also maximizes the preservation of the original mechanical toughness and processing flowability of the polymer matrix (such as PA66). Combined with specific compatibilizers and melt flow index control (20-40 g / 10min), it solves the defects of high-filler materials such as embrittlement, high processing pressure, and poor surface quality, greatly improving the molding freedom of complex thin-walled structural parts.

[0024] 3. This invention directly addresses the core pain points of new energy vehicle air conditioning systems, possessing extremely high industrial application value and technological added value. By optimizing the "filler pre-compounding" and "precision extrusion" processes in the preparation, it ensures the uniform dispersion of nano-sized MXene in the matrix, providing efficient thermal management and electromagnetic protection solutions for highly integrated components such as electronic control unit housings and PTC heater brackets. Compared to traditional aluminum alloy die-castings or highly filled engineering plastics, this material exhibits significant advantages in reducing system weight, lowering production costs, and improving the operational reliability of electronic components under high-voltage environments, providing key material support for the intelligent and integrated development of new energy vehicle HVAC systems.

[0025] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 The table shows the composite material formulations and performance characterizations for Examples 1-3 and Comparative Examples 1-3. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0029] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0030] A lightweight, high thermal conductivity, and flame-retardant composite material for use in air conditioning systems of new energy vehicles, comprising the following raw materials in parts by weight: Polymer matrix: 75-90 parts; the polymer matrix is ​​one or more of all matrices with a melt index of 15-50 g / 10min under the condition of 275℃ / 2.16kg, specifically Nylon 6 (PA6) or Nylon 66 (PA66). Multifunctional composite filler: 10-25 parts; the multifunctional composite filler is composed of two-dimensional titanium carbide (Ti3C2T). X MXene nanosheets and hexagonal boron nitride (h-BN) microsheets are compounded at a mass ratio of (1:4) to (1:1); Compatibilizer: 2-5 parts; the compatibilizer is one or more of maleic anhydride grafted polyolefin elastomer (POE-g-MAH), ethylene-acrylic acid copolymer (EAA), and epoxy functionalized polyolefin. Antioxidant: 0.1-0.5 parts; the antioxidant is a composite system including a primary antioxidant and a secondary antioxidant; the primary antioxidant is a hindered phenolic antioxidant, such as Irganox®1098, the secondary antioxidant is a phosphite antioxidant, such as Irgafos®168, and the weight ratio of the primary antioxidant to the secondary antioxidant is 1:1 to 1:2; Lubricant: 0.5-1.5 parts, wherein the lubricant is ethylene bis-stearamide (EBS), pentaerythritol stearate (PETS) or silicone masterbatch.

[0031] Furthermore, the two-dimensional titanium carbide (Ti3C2T) X The MXene nanosheets have a sheet size of 1-5 μm and a thickness of 1-5 nm.

[0032] Furthermore, the average particle size of the hexagonal boron nitride (h-BN) microsheets is 10-50 μm.

[0033] The present invention also provides a method for preparing the composite material, specifically including the following steps: A1 Packing Pretreatment and Compounding: Two-dimensional titanium carbide (MXene) nanosheets and hexagonal boron nitride (h-BN) microsheets are dry-mixed in a low-speed mixer for 30-60 minutes in a certain proportion to obtain a uniform multifunctional compounded packing.

[0034] A2 Premix: The polymer matrix, the multifunctional compound filler obtained in step 1, compatibilizer, antioxidant, and lubricant are put into a high-speed mixer and mixed for 5-10 minutes to obtain a premix.

[0035] A3 Melt Blending Granulation: The premixed material is fed into a twin-screw extruder, and after melt blending, extrusion, cooling, and pelletizing, composite material particles are obtained. The extruder temperature is set according to the selected polymer matrix (e.g., PA66: 250-280℃).

[0036] Examples 1 to 3 Preparation of a lightweight, high thermal conductivity, and flame-retardant composite material for air conditioning systems in new energy vehicles: according to Figure 1 The raw materials were weighed according to the indicated proportions to prepare the three quantitative high thermal conductivity flame retardant composite materials in Examples 1 to 3 respectively: Polymer matrix: PA66 (DuPont, Zytel 101L) MXene: Two-dimensional titanium carbide nanosheets (sheet size ~2μm, thickness ~3nm, provided by Ningbo Institute of Materials Technology and Engineering) h-BN: Hexagonal boron nitride microsheets (average particle size ~25μm); Compatibilizer: Maleic anhydride grafted polyolefin (POE-g-MAH); Antioxidant: Irganox 1098 Lubricant: Vinyl bis-stearamide (EBS) The specific preparation process is as follows: Mix MXene and h-BN Figure 1 The proportions are dry-mixed in a low-speed mixer for 45 minutes.

[0037] Add all ingredients to a high-speed mixer and mix at 800 rpm for 8 minutes.

[0038] Melt blending and granulation were performed using a co-rotating twin-screw extruder (L / D=40). The extrusion temperatures of the co-rotating twin-screw extruder were set to: 250℃, 255℃, 260℃, 265℃, 265℃, 260℃ (die head).

[0039] The granules extruded by the co-rotating twin-screw extruder were vacuum dried at 100°C for 4 hours, and then injection molded into standard test strips as samples.

[0040] Comparative Example 1 Pure PA66.

[0041] Comparative Example 2 The formulation is similar to that of Example 2, but all the compound fillers are replaced with an equal amount of h-BN (i.e., the total addition amount is 15 parts, all of which are h-BN).

[0042] Comparative Example 3 The formulation is similar to that of Example 2, but all the compound fillers are replaced with an equal amount of MXene (i.e., the total amount added is 15 parts, all of which are MXene).

[0043] Performance Tests and Results The samples prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested, and the results are shown in the figure. Figure 1 .

[0044] The testing method is as follows: To comprehensively evaluate the overall performance of the prepared composite material, its thermal conductivity, electrical properties, flame retardancy, mechanical properties, and basic physical properties were systematically tested. All tests were conducted under standard environmental conditions of (23±2)℃ and (50±5)% relative humidity, and the samples were conditioned in this environment for at least 24 hours before testing.

[0045] 1. Thermal Conductivity: Tested according to ASTM E1461 standard using a Netzsch LFA 467 HyperFlash® laser thermal conductivity meter. Before testing, the sample was processed into a circular disc with a diameter of 12.7 mm and a thickness of 3.0 mm. The surface was polished and coated with a thin layer of graphite to enhance infrared signal absorption. The test was conducted at room temperature. The thermal diffusivity (α) of the material was calculated by measuring the temperature change curve of the sample's back side after the laser pulse over time. The thermal conductivity (λ) was then calculated using the formula λ=α*ρ*Cp, where ρ is the material density and Cp is the specific heat capacity (calibrated using Pyroceram® standard strips).

[0046] 2. Heat Deflection Temperature (HDT): Tested using a Ceast HDT 3 VICAT instrument according to ISO 75-2:2013 standard (Method A). The specimen size was 80 mm × 10 mm × 4 mm, and the bending stress was set to 1.80 MPa. The specimen was placed in a silicone oil bath and heated at a uniform rate of 120 °C / h. The temperature at which the specimen deflection reached 0.34 mm was recorded as the heat deflection temperature of the material. 3. Vertical Burning Rating (UL-94): The specimens are rated according to ANSI / UL 94-2013 standard using an FTT vertical burning tester. The specimen size is 125mm × 13mm × 1.6mm (or 3.2mm). Five specimens are tested per group. A Bunsen burner (flame height 20mm) is applied to the lower end of the vertically clamped specimen twice for 10 seconds. The flaming burning time (t1, t2) and flameless burning time after each application of flame are recorded, as well as whether molten droplets ignite the absorbent cotton. Based on this, the material is determined to be V-0, V-1, V-2, or unrated (Burning).

[0047] 4. Electrical and electromagnetic shielding performance testing Volume Resistivity: Tested according to ASTM D257-14 standard using a Keithley 6517B high-resistivity meter with an 8009 resistance test fixture. A 500V DC voltage was applied to the composite material sample (≥100 mm × 100 mm × 2 mm), and the current value was read after stabilizing for 60 seconds. The volume resistivity was then calculated.

[0048] Electromagnetic Interference Shielding Effectiveness (EMI SE): Tested at 1 GHz according to ASTM D4935-18 using an Agilent PNA series vector network analyzer (VNA) with a coaxial flange test fixture. The material was machined into a concentric ring-shaped specimen with an inner diameter of 3.04 mm and an outer diameter of 7.00 mm. By measuring the reflection and attenuation of incident electromagnetic waves (S-parameters: S11, S21) by the specimen, the total shielding effectiveness (SET), reflection loss (SER), and absorption loss (SEA) of the material were calculated, all in decibels (dB). SET = SER + SEA.

[0049] 5. Bending performance: Three-point bending tests were conducted using an Instron 5967 universal testing machine according to ISO 178:2019 standard. The specimen size was 80mm × 10mm × 4mm, the support span was 64mm, and the test speed was 2mm / min. The load-displacement curves were recorded, and the bending strength (σf) and bending modulus (Ef) were calculated.

[0050] Density: Tested according to ISO 1183-1:2019 (Method A: Impregnation method). The mass of the sample in air and distilled water was determined at room temperature using an analytical balance with an accuracy of 0.1 mg, and the density was calculated.

[0051] In summary, the above-described embodiments successfully prepared a series of PA66 composites filled with hexagonal-Boron Nitride (h-BN) and MXene through systematic formulation design, and characterized their key properties such as thermal conductivity, electrical properties, flame retardancy, and mechanical properties. The results show that the introduction of fillers significantly modulates and improves the overall performance of the matrix resin, and h-BN and MXene exhibit a significant synergistic effect at specific compounding ratios. The performance improvement of the composites is mainly attributed to the introduction of functional fillers and their interaction network formed in the PA66 matrix. The significant enhancement of thermal conductivity, especially in Example 3 (8% h-BN, 7% MXene), exhibited the highest thermal conductivity (1.58 W / (m·K)), far exceeding that of pure PA66 (approximately 0.25-0.28 W / (m·K)). This is attributed to the possible efficient heat conduction pathways formed by h-BN and MXene in the matrix, and the MXene sheets potentially acting as a "bridging" mechanism between h-BN particles, collectively reducing interfacial thermal resistance. In terms of electrical performance, the transformation of the material from an insulator to a conductor / electromagnetic shielding material is closely related to the MXene content, which plays a dominant role in the formation of the conductive network. When the MXene content reaches a certain threshold (as in Example 3), the material achieves a shielding effectiveness of 32 dB at a frequency of 1 GHz, indicating that it has commercial-grade electromagnetic interference protection capabilities. The shielding mechanism is mainly based on loss absorption. The improved flame retardant properties, particularly the high MXene content examples achieving a UL94 V-0 rating, are likely related to MXene's role in promoting the formation of a dense char layer in the condensed phase, effectively isolating heat and oxygen. Mechanical property analysis shows that h-BN significantly contributes to maintaining the material's flexural strength and modulus. While mechanical properties decrease with increasing MXene content, they remain superior to pure resin, reflecting a balance between filler synergistic reinforcement and interfacial interactions. The significant increase in heat distortion temperature, especially in Comparative Example 2 (with only 15% h-BN), reaching 195°C, is significantly higher than pure PA66 (approximately 75°C), primarily due to the rigid filler's restriction of polymer chain thermal movement.

[0052] As can be seen, this invention successfully prepared a multifunctional composite material with high thermal conductivity, excellent electromagnetic shielding, flame retardancy and good mechanical properties by compounding h-BN and MXene. Its properties can be effectively controlled by the filler ratio, providing a material solution for applications in the fields of thermal management and electromagnetic protection of electronic devices.

[0053] 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 it. 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 spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A lightweight high thermal conductive flame retardant composite material for an air conditioning system, characterized by, consists of the following raw materials in parts by mass: a polymer matrix: 75-90 parts; a multifunctional compounded filler: 10-25 parts; the multifunctional compounded filler is compounded by two-dimensional titanium carbide nanosheets and hexagonal boron nitride microparticles at a mass ratio of 1:4~1:1; a compatibilizer: 2-5 parts; an antioxidant: 0.1-0.5 parts; a lubricant: 0.5-1.5 parts.

2. The composite material of claim 1, wherein, The polymer matrix has a melt index of 15-50 g / 10 min.

3. The composite material of claim 2, wherein, The polymer matrix has a melt index of 15-50 g / 10 min.

4. The composite material of claim 3, wherein, The matrix is PA66 or PA6.

5. The composite material of claim 1, wherein, The antioxidant is a composite system including a primary antioxidant and a secondary antioxidant; the primary antioxidant is a hindered phenolic antioxidant, the secondary antioxidant is a phosphite antioxidant, and the weight ratio of the primary antioxidant to the secondary antioxidant is 1:1~1:

2.

6. The composite material of claim 1, wherein, The lubricant is one of ethylene bis-stearamide, pentaerythritol stearate or silicone granules.

7. The composite material of claim 1, wherein, The compatibilizer is one or more of maleic anhydride grafted polyolefin elastomer, ethylene-acrylic acid copolymer, and epoxy-functionalized polyolefin.

8. The composite material of claim 1, wherein, The two-dimensional titanium carbide nanosheet has a sheet size of 1-5 mm and a thickness of 1-5 nm.

9. The composite material of claim 1, wherein, The average particle size of the hexagonal boron nitride microparticle is 10-50 mm.

10. A method of making a composite material as claimed in any one of claims 1 to 9 characterised in that, The method comprises the following steps: a) dry mixing two-dimensional titanium carbide nanosheets with hexagonal boron nitride microparticles to obtain a multifunctional compounded filler; b) mixing the multifunctional compounded filler obtained in step a) with a polymer matrix, a compatibilizer, an antioxidant, and a lubricant to obtain a premix; c) melt blending and extruding the premix obtained in step b) to obtain the composite material.

11. The method of claim 10, wherein, The dry mixing time in step a) is 30-60 minutes.

12. The method of claim 10, wherein, The mixing in step b) is carried out in a high-speed mixer, and the mixing time is 5-10 minutes at a speed of 700~900 rpm.

13. The method of claim 10, wherein, The melt blending in step c) is carried out in a twin-screw extruder, wherein the processing temperature of the twin-screw extruder is 250-275°C.

14. Use of the composite material as claimed in any one of claims 1-9 in the preparation of a new energy automobile air conditioning system component.

15. Use according to claim 14, characterized in that, The new energy automobile air conditioning system component is an electronic control unit housing, a PTC heater support or a cooling fan.

Images