A low-anisotropy thermally conductive polyphenylene sulfide composite material and a preparation method thereof
By forming a three-dimensional interpenetrating network structure through a mercapto-olefin click chemical reaction, the thermally conductive assembly filler has solved the problem of thermal anisotropy in polyphenylene sulfide composites, achieving high thermal conductivity and uniformity of thermal conductivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGXI JUZHEN TECH DEV CO LTD
- Filing Date
- 2026-04-14
- Publication Date
- 2026-06-30
AI Technical Summary
Existing polyphenylene sulfide composite materials have anisotropic thermal conductivity, which cannot meet the requirements for uniform heat conduction in high-frequency operating environments.
The alkenyl graphene and thiolized carbon nanotubes are covalently bonded through a thiol-alkene click chemistry reaction to form a three-dimensional interpenetrating network structure of thermally conductive assembly filler. This eliminates the directional alignment characteristics of single graphene and carbon nanotubes, ensuring that they maintain a random orientation state after melt shearing processing.
It achieves high thermal conductivity and low thermal anisotropy of composite materials, and improves the uniformity of heat conduction in all directions.
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Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of polyphenylene sulfide composite materials, specifically relating to a low anisotropic thermal conductivity polyphenylene sulfide composite material and its preparation method. Background Technology
[0002] Polyphenylene sulfide (PPS), a semi-crystalline high-performance thermoplastic resin, possesses excellent comprehensive properties, including high crystallinity (up to 70%), a relative density of approximately 1.30, a melting point of 280-290℃, a glass transition temperature of approximately 90℃, and chemical stability, being insoluble in any organic solvent at 200℃. Due to its outstanding mechanical strength, heat resistance, flame retardancy, electrical insulation, and dimensional stability, PPS has been widely used in the electrical and electronic fields, such as as insulating components, connectors, and encapsulation materials. However, with the rapid development of electronic information technology, especially the widespread adoption of high-frequency, high-power applications such as new energy vehicle power battery systems and 5G communication equipment, electronic devices are evolving towards miniaturization, integration, and high frequency, leading to a sharp increase in the heat generated during device operation and placing higher demands on the heat dissipation performance of materials.
[0003] Compared to traditional metal or ceramic materials, PPS, as a typical polymer material, has a low thermal conductivity and poor inherent thermal conductivity, making it unsuitable for the high-efficiency heat dissipation requirements of high-frequency operating environments such as new energy vehicle power batteries and 5G communication equipment. Currently, modification methods mainly involve filling with thermally conductive materials. Carbon materials have a high intrinsic thermal conductivity, and even a low filling amount can significantly improve the thermal conductivity of PPS. Furthermore, carbon materials are low in density and lightweight, which can simultaneously enhance the mechanical properties of PPS. Their thermal and chemical stability are well-suited to PPS, meeting the requirements for high-temperature processing and service. For example, patent CN110240805B discloses a graphene-modified polyphenylene sulfide material and its preparation method, as well as a thermally conductive plastic tube. This modified polyphenylene sulfide material includes 100g of PPS, 15g of PA, 10g of PTFE, 10g of graphene, 1g of carbon nanotubes, 2g of carbon fiber, 10g of silicon carbide powder, and 2g of additives. Patent CN102558862B discloses a polyphenylene sulfide composite material and its preparation method. The polyphenylene sulfide composite material disclosed in this invention comprises the following components and parts by weight: 20-35 parts polyphenylene sulfide resin, 25-50 parts thermally conductive filler, 10-35 parts reinforcing fiber, 2-17 parts elastomer, 0.2-1 part antioxidant, 0.3-0.8 parts coupling agent, 1-2 parts lubricant, 0.5-1 part dispersant and 0.2-0.5 parts nucleating agent.
[0004] The above describes techniques for improving the thermal conductivity of polyphenylene sulfide (PPS) by adding carbon materials, but these techniques face the problem of thermal anisotropy. One-dimensional fillers such as carbon fibers and carbon nanotubes exhibit significant differences in thermal conductivity along the axial and radial directions; two-dimensional fillers such as graphite and graphene show significant differences in in-plane and out-of-plane thermal conductivity. During melt processing, the shear flow field causes one-dimensional fillers to align axially, while two-dimensional fillers align in the in-plane direction. This intrinsic anisotropy of the fillers, combined with the processing-induced orientation effect, results in significant overall thermal anisotropy in the composite material. Since PPS, as a thermal interface material or structural heat dissipation component, often requires efficient and uniform heat conduction in all directions in practical applications, it is necessary to address this problem to prepare a PPS composite material with low thermal anisotropy and excellent thermal conductivity. Summary of the Invention
[0005] To address the aforementioned technical problems, this invention provides a low anisotropic thermally conductive polyphenylene sulfide composite material and its preparation method. This invention utilizes a mercapto-olefin click chemistry reaction to covalently bond alkenyl graphene with mercapto-carbon nanotubes, forming a thermally conductive assembly filler with a three-dimensional interpenetrating network structure. This eliminates the intrinsic directional alignment characteristics of single graphene and carbon nanotubes. The mercapto-olefin click reaction involves random site covalent bonding, resulting in a random arrangement of network crosslinking nodes in three-dimensional space. There is no obvious mechanical / fluid field orientation preference, and under shear force, there are no directional stress points, preventing the nanospheres from turning. After melt shear processing, the thermally conductive assembly filler maintains its random orientation state, and the shear flow field has a minimal directional induction effect on it, achieving high thermal conductivity and low thermal anisotropy in the composite material.
[0006] To achieve the above objectives, the following technical solution is adopted:
[0007] A low anisotropic thermally conductive polyphenylene sulfide composite material comprises the following raw materials in parts by weight: 40-60 parts polyphenylene sulfide, 25-35 parts thermally conductive assembly filler, 3-5 parts compatibilizer, 1-3 parts antioxidant, and 1-2 parts lubricant. The thermally conductive assembly filler is prepared by the following steps: 1) reacting an unsaturated acyl chloride compound with amino graphene to obtain alkenyl-modified graphene; 2) reacting a mercaptosilane coupling agent with carbon nanotubes to obtain mercapto-modified carbon nanotubes; and 3) reacting alkenyl-modified graphene with mercapto-modified carbon nanotubes to obtain the thermally conductive assembly filler.
[0008] In step 1), the mass ratio of the amino-graphene to the unsaturated acyl chloride compound is 1-3:1.8-2.4, preferably 3:1.8-2.4.
[0009] The aminated graphene has a diameter of 1-8 μm, a thickness of 0.8-4 nm, and an ammoniation rate of 3.8-4.2 wt%. The unsaturated acyl chloride compound is selected from one or more combinations of 3-maleiminobenzoic acid chloride, 4-maleiminobenzoyl chloride, acryloyl chloride, methacryloyl chloride, and 4-vinylbenzoyl chloride.
[0010] Specifically, step 1) is as follows: dispersing amino-modified graphene in an organic solvent, adding an acid-binding agent, and reacting with an unsaturated acyl chloride compound solution to obtain alkenyl-modified graphene;
[0011] The mass ratio of the aminated graphene, organic solvent, and acid-binding agent is 1-3:100-150:0.8-1.0, preferably 3:100:0.8-1.0. The organic solvent is selected from one or more combinations of dichloromethane, tetrahydrofuran, ethyl acetate, chloroform, and toluene. The acid-binding agent is selected from one or more combinations of triethylamine, pyridine, and N,N-diisopropylethylamine. The concentration of the unsaturated acyl chloride compound solution is 5-10 wt%. The solvent for the unsaturated acyl chloride compound solution is selected from one or more combinations of dichloromethane, tetrahydrofuran, ethyl acetate, chloroform, and toluene. The reaction is carried out under an inert atmosphere at a temperature of -5°C to 0°C for 10-16 hours. After the reaction, centrifugation, washing, and drying are also performed.
[0012] In step 2), the carbon nanotubes have an outer diameter of 8-15 nm and a length of 0.5-2 μm. The mercaptosilane coupling agent is selected from one or more combinations of mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and mercaptomethylmethyldiethoxysilane.
[0013] Specifically, step 2) is as follows: prepare a carbon nanotube dispersion, add a mercaptosilane coupling agent, heat to reflux and react to obtain mercapto-modified carbon nanotubes;
[0014] The mass ratio of carbon nanotubes, organic solvent, and mercaptosilane coupling agent is 1-1.5:100:1-3. The solvent for the carbon nanotube dispersion is selected from one or more combinations of benzene, toluene, and xylene. The reaction time is 12-24 hours. After the reaction, centrifugation, washing, and drying are also performed.
[0015] The mass ratio of alkenyl-modified graphene to thiol-modified carbon nanotubes is 1-5:1, preferably 1-3:1.
[0016] Specifically, step 3) is as follows: prepare an alkenyl-modified graphene dispersion; prepare a thiol-modified carbon nanotube dispersion; under ultrasonic stirring, mix the thiol-modified carbon nanotube dispersion and the alkenyl-modified graphene dispersion, and then heat to react to obtain a thermally conductive assembled filler.
[0017] The alkenyl-modified graphene dispersion has a solid content of 3-5 wt%. The solvent for the alkenyl-modified graphene dispersion is selected from one or more combinations of DMF, toluene, benzene, and xylene. The thiol-modified carbon nanotube dispersion has a solid content of 3-5 wt%. The solvent for the thiol-modified carbon nanotube dispersion is selected from one or more combinations of DMF, toluene, benzene, and xylene. The thiol-modified carbon nanotube dispersion is added dropwise to the alkenyl-modified graphene dispersion and mixed thoroughly over 1-2 hours. The ultrasonic stirring conditions are: ultrasonic power of 200-300 W, ultrasonic frequency of 25-35 kHz, and stirring speed of 500-800 rpm. The heating reaction is carried out under an inert atmosphere, continuing the ultrasonic stirring conditions to 65-70℃ for 3-5 hours. After the reaction, centrifugation, washing, drying, grinding, and sieving are performed. The washing is done by alternating between alcohol and water 1-3 times. The drying is carried out at 60-80℃ to constant weight. The grinding and sieving process retains sieve residue with a particle size of 1-5 μm.
[0018] The compatibilizer is selected from one or more of the following: styrene-maleic anhydride copolymer, maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, maleic anhydride-grafted styrene-ethylene-butadiene-styrene copolymer, maleic anhydride-grafted ethylene-octene copolymer, and maleic anhydride-grafted ethylene propylene diene monomer (EPDM) rubber. Preferably, it is a styrene-maleic anhydride copolymer with a weight-average molecular weight of 500-8000 and an acid value of 330-500 mg KOH / g.
[0019] The polyphenylene sulfide has a weight-average molecular weight of 20,000 to 60,000
[0020] The antioxidant is selected from one or more of antioxidants 1010, antioxidant 168, antioxidant B215, antioxidant 1098, antioxidant 264, antioxidant 1076, antioxidant 2246, antioxidant 300, and antioxidant 330.
[0021] The lubricant is selected from one or more of calcium stearate, magnesium stearate, paraffin wax, and erucamide.
[0022] The present invention also provides a method for preparing the above-mentioned low anisotropic thermal conductivity polyphenylene sulfide composite material, comprising the following steps:
[0023] Polyphenylene sulfide, thermally conductive assembly filler, compatibilizer, antioxidant, and lubricant are mixed and extruded into granules to obtain a low anisotropic thermally conductive polyphenylene sulfide composite material.
[0024] The extrusion granulation temperature is 260-320℃, and the screw speed is 200-400rpm.
[0025] Compared with the prior art, the beneficial effects of the present invention are:
[0026] This invention utilizes a mercapto-alkene click chemistry reaction to covalently bond alkenyl graphene with mercapto-carbon nanotubes, forming a thermally conductive assembly filler with a three-dimensional interpenetrating network structure. This eliminates the intrinsic directional alignment characteristics of single graphene and carbon nanotubes. The mercapto-alkene click reaction involves random site covalent bonding, with network cross-linking nodes randomly arranged in three-dimensional space. There is no obvious mechanical / fluid field orientation preference, and there are no directional stress points under shear force, thus not inducing the nanospheres to turn. After melt shear processing, the thermally conductive assembly filler still maintains a random orientation state, and the shear flow field has little directional induction effect on it, achieving high thermal conductivity and low thermal anisotropy in the composite material. Detailed Implementation
[0027] The present invention will be further described below with reference to specific embodiments, but is not limited to the contents of the specification. Unless otherwise specified, all "parts" mentioned in the embodiments of the present invention are parts by weight. All reagents used are commercially available in the art.
[0028] Aminated graphene, catalog number XF005, with a diameter of 4μm, a thickness of 1.2nm, and an aminated content of 4.2wt%, is from XFNANO.
[0029] Aminated graphene, catalog number G196559, with a diameter of 1.3 μm, a thickness of 3.8 nm, and an aminated content of 3.8 wt%, is from Aladdin.
[0030] Carbon nanotubes, catalog number C419574, with an outer diameter of 8-15 nm and a length of 0.5-2 μm, are from Aladdin.
[0031] The polyphenylene sulfides with weight average molecular weights of 20,000 and 60,000 were both sourced from Jiangxi Juzhen Technology Development Co., Ltd.
[0032] Styrene-maleic anhydride copolymer, part number 4119848DE, Mw 7500, acid value 375 mg KOH / g, from Adamas.
[0033] Maleic anhydride-grafted polypropylene, part number P478291, Mw 9100, maleic anhydride grafting amount 10wt%, sourced from Aladdin.
[0034] Example 1
[0035] 1) 3g of amino-modified graphene G196559 was dispersed in 100g of dichloromethane by ultrasonication at 60kHz for 1h, 1g of triethylamine was added, and 24g of 10wt% 3-maleimide benzoyl chloride solution (the solvent was a mixed solvent of dichloromethane and ethyl acetate in a volume ratio of 3:1) was added dropwise. The reaction was carried out at 0℃ for 10h under a nitrogen atmosphere. After the reaction was completed, the precipitate was centrifuged and washed three times with ethanol and water, respectively. It was pre-cooled at -35℃ for 6h and freeze-dried at -40℃ for 24h under a vacuum of 10Pa to obtain alkenyl-modified graphene.
[0036] 2) 1.5g of carbon nanotubes C419574 were dispersed in 100g of toluene by sonication at 60kHz for 1h to obtain a dispersion of carbon nanotubes C419574. 3g of mercaptopropyltrimethoxysilane was added, and the mixture was heated to reflux and reacted for 12h. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed twice with ethanol and water, respectively. The precipitate was dried at 60℃ to constant weight to obtain mercapto-modified carbon nanotubes.
[0037] 3) Alkenyl-modified graphene was dispersed in DMF by ultrasonication at 60 kHz for 1 h to prepare an alkenyl-modified graphene dispersion with a solid content of 5 wt%; thiol-modified carbon nanotubes were dispersed in DMF by ultrasonication at 80 kHz for 1 h to obtain a thiol-modified carbon nanotube dispersion with a solid content of 5 wt%; under ultrasonic stirring conditions of 300 W ultrasonic power, 35 kHz ultrasonic frequency, and 500 rpm, the thiol-modified carbon nanotube dispersion was added dropwise to the alkenyl-modified graphene dispersion at a mass ratio of 3:1. After 2 h of addition, nitrogen gas was introduced, and the mixture was continued to react under the above ultrasonic stirring conditions at 70 °C for 3 h. After the reaction was completed, the mixture was centrifuged, washed twice with alternating ethanol and water, dried at 80 °C to constant weight, ground and sieved, and the residue with a particle size of 1-5 μm was retained to obtain the thermally conductive assembly filler.
[0038] 4) Mix 40 kg of polyphenylene sulfide with a weight average molecular weight of 60,000, 35 kg of thermally conductive assembly filler prepared by the above method, 5 kg of compatibilizer styrene-maleic anhydride copolymer 4119848DE, 1 kg of antioxidant 1010, and 2 kg of calcium stearate, and extrude and granulate to obtain a low anisotropic thermally conductive polyphenylene sulfide composite material.
[0039] The extrusion granulation parameters are as follows: twin-screw extruder extrusion temperatures of 280℃, 285℃, 295℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, die head temperature of 310℃, screw diameter of 65mm, length-to-diameter ratio of 40:1, and screw speed of 400rpm.
[0040] Example 2
[0041] The rest is the same as in Example 1, except that in step 1), the aminated graphene G196559 is replaced with an equal mass of aminated graphene XF005.
[0042] Example 3
[0043] The rest is the same as in Example 1, except that in step 1), the amount of 10wt% 3-maleimide benzoyl chloride solution used is 18g.
[0044] Example 4
[0045] The rest is the same as in Example 1, except that in step 1), the 10wt% methacryloyl chloride solution is replaced with an equal mass of 10wt% methacryloyl chloride.
[0046] Example 5
[0047] The rest is the same as in Example 1, except that in step 3), the mercapto-modified carbon nanotube dispersion is dropped into the alkenyl-modified graphene dispersion at a mass ratio of 1:1.
[0048] Example 6
[0049] The rest is the same as in Example 1, except that in step 3), the mercapto-modified carbon nanotube dispersion is added dropwise to the alkenyl-modified graphene dispersion at a mass ratio of 5:1.
[0050] Example 7
[0051] The rest is the same as in Example 1, except that in step 4), the amount of polyphenylene sulfide with a weight average molecular weight of 60,000 is 60 kg, and the amount of styrene-maleic anhydride copolymer is 3 kg.
[0052] Example 8
[0053] The rest is the same as in Example 1, except that in step 4), the amount of thermally conductive assembly filler used is 25 kg.
[0054] Example 9
[0055] The rest is the same as in Example 1, except that in step 4), an equal mass of maleic anhydride-grafted polypropylene P478291 compatibilizer is used instead of styrene-maleic anhydride copolymer 4119848DE.
[0056] Example 10
[0057] 1) 1g of amino-modified graphene XF005 was dispersed in 100g of dichloromethane by ultrasonication at 60kHz for 1h, 0.8g of triethylamine was added, and 18g of 10wt% 4-maleimide benzoyl chloride solution (the solvent was a mixture of dichloromethane and ethyl acetate in a volume ratio of 3:1) was added dropwise. The reaction was carried out at 0℃ for 10h under a nitrogen atmosphere. After the reaction was completed, the precipitate was centrifuged and washed three times with ethanol and water, respectively. It was pre-cooled at -35℃ for 6h and freeze-dried at -40℃ for 24h under a vacuum of 10Pa to obtain alkenyl-modified graphene.
[0058] 2) 1.5g of carbon nanotubes C419574 were dispersed in 100g of toluene by sonication at 60kHz for 1h to obtain a dispersion of carbon nanotubes C419574. 1g of 3-mercaptopropyltriethoxysilane was added, and the mixture was heated to reflux and reacted for 12h. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed twice with ethanol and water, respectively. The precipitate was dried at 60℃ to constant weight to obtain mercapto-modified carbon nanotubes.
[0059] 3) Alkenyl-modified graphene was dispersed in DMF by ultrasonication at 60 kHz for 1 h to prepare an alkenyl-modified graphene dispersion with a solid content of 5 wt%; thiol-modified carbon nanotubes were dispersed in DMF by ultrasonication at 80 kHz for 1 h to obtain a thiol-modified carbon nanotube dispersion with a solid content of 5 wt%; under ultrasonic stirring conditions of 300 W ultrasonic power, 35 kHz ultrasonic frequency, and 500 rpm, the thiol-modified carbon nanotube dispersion was added dropwise to the alkenyl-modified graphene dispersion at a mass ratio of 3:1. After 1 h of addition, nitrogen gas was introduced, and the mixture was continued to react under the above ultrasonic stirring conditions at 70 °C for 3 h. After the reaction was completed, the mixture was centrifuged, washed twice with alternating ethanol and water, dried at 80 °C to constant weight, ground and sieved, and the residue with a particle size of 1-5 μm was retained to obtain the thermally conductive assembly filler.
[0060] 4) Mix 40 kg of polyphenylene sulfide with a weight average molecular weight of 20,000, 35 kg of thermally conductive assembly filler prepared by the above method, 5 kg of compatibilizer styrene-maleic anhydride copolymer 4119848DE, 1 kg of antioxidant 1010, and 2 kg of calcium stearate, and extrude and granulate to obtain a low anisotropic thermally conductive polyphenylene sulfide composite material.
[0061] The extrusion granulation parameters are as follows: twin-screw extruder extrusion temperatures of 280℃, 285℃, 295℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, die head temperature of 310℃, screw diameter of 65mm, length-to-diameter ratio of 40:1, and screw speed of 400rpm.
[0062] Comparative Example 1
[0063] 1) 3g of amino-modified graphene XF005 was dispersed in 100g of dichloromethane by ultrasonication at 60kHz for 1h, 1g of triethylamine was added, and 24g of 10wt% 3-maleimide benzoyl chloride solution (the solvent was a mixture of dichloromethane and ethyl acetate in a volume ratio of 3:1) was added dropwise. The reaction was carried out at 0℃ for 10h under a nitrogen atmosphere. After the reaction was completed, the precipitate was centrifuged and washed three times with ethanol and water, respectively. It was pre-cooled at -35℃ for 6h and freeze-dried at -40℃ for 24h under a vacuum of 10Pa to obtain alkenyl-modified graphene.
[0064] 2) 1.5g of carbon nanotubes C419574 were dispersed in 100g of toluene by sonication at 60kHz for 1h to obtain a dispersion of carbon nanotubes C419574. 3g of mercaptopropyltrimethoxysilane was added, and the mixture was heated to reflux and reacted for 12h. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed twice with ethanol and water, respectively. The precipitate was dried at 60℃ to constant weight to obtain mercapto-modified carbon nanotubes.
[0065] 3) Mix 40 kg of polyphenylene sulfide with a weight average molecular weight of 60,000, 26.25 kg of alkenyl-modified graphene, 8.75 kg of mercapto-modified carbon nanotubes, 5 kg of compatibilizer styrene-maleic anhydride copolymer 4119848DE, 1 kg of antioxidant 1010, and 2 kg of calcium stearate, and extrude and granulate to obtain a low anisotropic thermally conductive polyphenylene sulfide composite material.
[0066] The extrusion granulation parameters are as follows: twin-screw extruder extrusion temperatures of 280℃, 285℃, 295℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, 300℃, die head temperature of 310℃, screw diameter of 65mm, length-to-diameter ratio of 40:1, and screw speed of 400rpm.
[0067] The difference is that step 3 is not present.
[0068] Application examples
[0069] The low anisotropic thermally conductive polyphenylene sulfide composite materials prepared in the above embodiments and comparative examples were injection molded in a co-rotating parallel twin-screw injection molding machine. The injection process parameters were: nozzle temperature 320°C, first stage temperature 330°C, second stage temperature 310°C, and injection pressure 100MPa.
[0070] The composite materials prepared in the above application examples and comparative application examples were subjected to the following performance tests:
[0071] 1. Thermal conductivity: The thermal diffusivity or thermal conductivity was measured by the flash method according to standard GB / T 22588-2008. The longitudinal (i.e., axial direction, parallel to the injection direction of the injection molding machine) thermal conductivity and the transverse (i.e., radial direction, perpendicular to the injection direction of the injection molding machine, and within the cross-section of the cylinder) thermal conductivity were tested using an LFA476 laser flash spectrometer. The sample with a diameter of 25.4 mm and a thickness of 6 mm was injection molded.
[0072] 2. Tensile strength: Dumbbell-shaped specimens were prepared according to standard GB / T 1040.1-2006 using injection molding and cutting methods. The length direction of the dumbbell-shaped specimens was perpendicular to the injection direction of the injection molding machine. Tensile properties were tested, and the obtained tensile strength was recorded as transverse tensile strength. The tensile rate was 10 mm / min.
[0073] Table 1 Performance Test Results
[0074]
[0075] As can be seen from the performance test results in Table 1, the composite material prepared by this invention possesses excellent mechanical properties, high thermal conductivity, and low thermal anisotropy. The performance test results of Examples 1 and 3 show that reducing the amount of 3-maleimide-benzoyl chloride leads to an increase in longitudinal thermal conductivity and a decrease in transverse thermal conductivity, i.e., increased thermal anisotropy. This may be because the covalent bond connections between the alkenyl-modified graphene and the thiol-modified carbon nanotubes within the formed thermally conductive assembly filler are reduced, and the three-dimensional interpenetrating structure becomes unstable under melt shear, causing deformation and orientation of the thermally conductive assembly filler. The increased tensile strength of the composite material in Example 3 verifies this hypothesis. Examples 1, 4, and 9 show that when graphene is modified with 3-maleimide-benzoic acid chloride and the compatibilizer is a styrene-maleic anhydride copolymer, the composite material achieves even better thermal conductivity and mechanical properties.
[0076] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.
Claims
1. A low anisotropic thermal conductivity polyphenylene sulfide composite material, characterized in that, The raw materials include the following parts by weight: 40-60 parts polyphenylene sulfide, 25-35 parts thermally conductive assembly filler, 3-5 parts compatibilizer, 1-3 parts antioxidant, and 1-2 parts lubricant. The thermally conductive assembly filler is prepared by the following steps: 1) reacting an unsaturated acyl chloride compound with amino graphene to obtain alkenyl-modified graphene; 2) reacting a mercaptosilane coupling agent with carbon nanotubes to obtain mercapto-modified carbon nanotubes; 3) reacting alkenyl-modified graphene with mercapto-modified carbon nanotubes to obtain the thermally conductive assembly filler; the particle size of the thermally conductive assembly filler is 1-5 μm.
2. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 1, characterized in that, In step 1), the mass ratio of the aminated graphene to the unsaturated acyl chloride compound is 1-3:1.8-2.4, preferably 3:1.8-2.4; the aminated graphene has a diameter of 1-8 μm, a thickness of 0.8-4 nm, and an aminated rate of 3.8-4.2 wt%; the unsaturated acyl chloride compound is selected from one or more combinations of 3-maleiminobenzoic acid chloride, 4-maleiminobenzoyl chloride, acryloyl chloride, methacryloyl chloride, and 4-vinylbenzoyl chloride.
3. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 1, characterized in that, Step 1) specifically involves dispersing amino-modified graphene in an organic solvent, adding an acid-binding agent, and then adding an unsaturated acyl chloride compound solution to react and obtain alkenyl-modified graphene.
4. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 3, characterized in that, The mass ratio of the amino-based graphene, organic solvent, and acid-binding agent is 1-3:100-150:0.8-1.0, preferably 3:100:0.8-1.0; the organic solvent is selected from one or more combinations of dichloromethane, tetrahydrofuran, ethyl acetate, chloroform, and toluene; the acid-binding agent is selected from one or more combinations of triethylamine, pyridine, and N,N-diisopropylethylamine; the concentration of the unsaturated acyl chloride compound solution is 5-10 wt%.
5. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 1, characterized in that, In step 2), the carbon nanotube has an outer diameter of 8-15 nm and a length of 0.5-2 μm; the mercaptosilane coupling agent is selected from one or more combinations of mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and mercaptomethylmethyldiethoxysilane.
6. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 1, characterized in that, In step 3), the mass ratio of alkenyl-modified graphene to thiol-modified carbon nanotubes is 1-5:1, preferably 1-3:
1.
7. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 1, characterized in that, Step 3) specifically involves: preparing an alkenyl-modified graphene dispersion; preparing a thiol-modified carbon nanotube dispersion; and mixing the thiol-modified carbon nanotube dispersion and the alkenyl-modified graphene dispersion under ultrasonic stirring conditions, followed by heating and reaction to obtain a thermally conductive assembled filler.
8. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 7, characterized in that, The alkenyl-modified graphene dispersion has a solid content of 3-5 wt%; the solvent of the alkenyl-modified graphene dispersion is selected from one or more combinations of DMF, toluene, benzene, and xylene; the thiol-modified carbon nanotube dispersion has a solid content of 3-5 wt%; the solvent of the thiol-modified carbon nanotube dispersion is selected from one or more combinations of DMF, toluene, benzene, and xylene; the thiol-modified carbon nanotube dispersion is added dropwise to the alkenyl-modified graphene dispersion and mixed thoroughly over 1-2 hours.
9. The low anisotropic thermal conductivity polyphenylene sulfide composite material according to claim 1, characterized in that, The polyphenylene sulfide has a weight-average molecular weight of 20,000-60,000; the compatibilizer is selected from one or more of the following: styrene-maleic anhydride copolymer, maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, maleic anhydride-grafted styrene-ethylene-butadiene-styrene copolymer, maleic anhydride-grafted ethylene-octene copolymer, and maleic anhydride-grafted ethylene propylene diene monomer (EPDM) rubber, preferably a styrene-maleic anhydride copolymer with a weight-average molecular weight of 500-8000 and an acid value of 330-500 mg KOH / g.
10. A method for preparing the low anisotropic thermal conductivity polyphenylene sulfide composite material according to any one of claims 1-9, characterized in that, Includes the following steps: Polyphenylene sulfide, thermally conductive assembly filler, compatibilizer, antioxidant, and lubricant are mixed and extruded into granules to obtain a low anisotropic thermally conductive polyphenylene sulfide composite material.