Modified PPS with low dielectric loss and high thermal conductivity, and preparation method and application thereof

Abstract

The application discloses a modified PPS with low dielectric loss and high thermal conductivity, and a preparation method and application thereof, wherein the modified PPS comprises 2500-4000 parts by mass of PPS, 500-1000 parts by mass of a composite thermal conductor, 750-1500 parts by mass of PPO, 500-1000 parts by mass of glass beads, 10-50 parts by mass of a surface modifier and 100-200 parts by mass of a compatilizer; the composite thermal conductor is composed of one-dimensional nanotube material and two-dimensional graphene material. The modified PPS has good thermal conductivity and low dielectric loss, is suitable for preparing high-frequency low-loss thermal conductive insulating products, and the preparation method of the modified PPS is simple, adapts to conventional processes of polymer material processing, and is convenient for industrial large-scale production.

Description

Technical Field

[0001] This invention relates to the field of special engineering plastic modification technology, and in particular to a modified PPS with low dielectric loss and high thermal conductivity, its preparation method, and its applications. Background Technology

[0002] With the rapid development of high-frequency electronic technologies such as next-generation high-frequency radio electronics / communication (5G / 6G, millimeter wave), aerospace, and new energy vehicles, the integration and operating frequency of electronic components are constantly increasing, leading to a sharp increase in the internal heat density of equipment. This places more stringent requirements on the integrity of signal transmission (i.e., dielectric properties), and the demand for materials with both excellent dielectric properties (low dielectric constant and low dielectric loss) and thermal insulation is becoming increasingly urgent.

[0003] 6G (sixth-generation mobile communication) uses terahertz signal transmission, offering high speeds, wide applicability, and deeper applications (linking the real physical world with the virtual digital world). It is a converged information network integrating communication, computing, sensing, artificial intelligence (AI), and security. Faster transmission efficiency places higher demands on the stability and reliability of signal transmission. Therefore, developing technologies with low dielectric constants and low dielectric losses, capable of effectively dissipating heat generated during signal exchange to ensure signal integrity while extending the lifespan of internal high-frequency precision electronic components, and achieving stable transmission and effective heat management, is of profound significance.

[0004] Polyphenylene sulfide (PPS), also known as polyphenylene sulfide, is widely used in the communications and electronics industry due to its excellent high-temperature resistance, chemical stability, flame retardancy, superior UV absorption resistance, and good thermal stability. Philips in the United States first synthesized PPS in 1968 using p-dichlorobenzene and sodium sulfide as raw materials through solution condensation polymerization in the polar organic solvent N-methylpyrrolidone (NMP). It was named RYTON in 1973 and began commercialization. In 1984, Macallum first synthesized PPS in the laboratory using the melt reaction of p-dichlorobenzene, sodium carbonate, and sulfur. In 1986, Kureha Chemical Co., Ltd. in Japan developed linear PPS—the second-generation linear high molecular weight PPS resin—and subsequently, Toray Industries, Dai Nippon Oil & Chemical Co., Ltd., Tosoh Corporation, and Idemitsu Corporation established their own polymerization production lines. During the same period, China imported both raw materials for PPS resin and functionalized modified PPS, resulting in high prices for imported modified PPS products. Modification was still in its developmental stage, with relatively low R&D levels and capabilities. With the establishment and commissioning of PPS polymerization production lines by companies such as NHU, Chongqing Jushi, Infinity (formerly Shandong Binhua), Shandong Mingquan Group, and Anhui Tongcheng Ruijia New Materials, as well as the continuous deepening of research on modification principles, favorable conditions have been provided for the development of modification of special engineering plastics in my country.

[0005] However, although PPS has been widely used as an excellent special engineering plastic, it does not meet the requirements of effective heat dissipation in high-frequency environments while ensuring signal transmission integrity. Therefore, it is difficult to apply it directly to the above-mentioned fields. Thus, modifying PPS to have low dielectric loss and good thermal conductivity has become a technical problem that needs to be solved in this field. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a modified PPS with low dielectric loss and high thermal conductivity, its preparation method and application. The modified PPS has good thermal conductivity and low dielectric loss, making it suitable for the preparation of high-frequency, low-loss thermally conductive and insulating products. The preparation method of the modified PPS is simple, compatible with conventional processes for polymer material processing, and facilitates large-scale industrial production.

[0007] To address the aforementioned technical problems, a first aspect of the present invention provides a modified PPS with low dielectric loss and high thermal conductivity, comprising the following components in parts by mass: PPS: 2500-4000 parts by weight; Composite thermal conductive agent: 500-1000 parts by weight; PPO: 700-1500 parts by weight; Glass microspheres: 200-500 parts by weight; Surface modifier: 10-50 parts by weight; Compatibilizer: 100-200 parts by weight; The composite thermal conductive agent is composed of one-dimensional nanotube materials and two-dimensional graphene materials.

[0008] In this invention, through the synergistic effect of each component, the modified PPS material has good thermal conductivity and low dielectric loss. Specifically, its thermal conductivity is not less than 1.8 W / m•K, its dielectric constant is not more than 2.8ε@1MHz, and its dielectric loss is not more than 0.0028 tanδ@1GHz.

[0009] In this invention, PPS serves as the matrix resin, providing the material with basic heat resistance, mechanical strength, and insulation properties. The composite thermally conductive agent constructs a continuous and efficient thermally conductive network, significantly improving the material's thermal conductivity while maintaining its low dielectric properties without increasing the system's dielectric loss. PPO, as a low-dielectric, heat-resistant auxiliary resin, has a molecular chain composed of benzene rings and ether bonds, resulting in a uniform electron cloud distribution, low polarizability, and high molecular chain rigidity, making dipole movement difficult. Using PPO as the low-dielectric phase dilutes the continuous phase structure of PPS, increasing the free volume of the amorphous region of the system. By reducing the number of polarization units per unit volume, the overall polarization capability of the composite material is reduced, significantly lowering its dielectric properties. Glass microspheres assist in optimizing the material's dielectric properties. Surface modifiers are mainly used to activate the glass microspheres, increasing their interfacial compatibility with other components, inhibiting interfacial polarization, and reducing the aggregation of glass microspheres. Compatibilizers are mainly used to improve the interfacial compatibility between PPS and PPE, thereby reducing the migration of defects and impurity ions at the interface, thus reducing the material's conductive loss and interfacial polarization loss.

[0010] In one specific embodiment, the composite thermal conductive agent is prepared as follows: S11. Disperse the two-dimensional graphene material in the first solvent and add a dispersant; S12. Disperse the one-dimensional nanotube material in a second solvent; S13. After mixing the system of S11 and S12, filter it through a filter membrane with a pore size of 0.1 to 0.45 μm and discard the supernatant. S14. The system retained in S13 is ultrasonically dispersed and then filtered. The filter cake is dried to obtain a composite thermal conductive agent.

[0011] Preferably, the two-dimensional graphene material in S11 is a 1-3 layer graphene oxide material, the first solvent is a mixed solvent formed by ethanol and water in a ratio of 1:1 to 3 (e.g., 1:1, 1:2, 1:3), and the dispersant is one or more combinations of sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, polyvinylpyrrolidone, sodium lignin sulfonate, and sodium polystyrene sulfonate. The one-dimensional nanotubes in S12 are boron nitride nanotubes, and the second solvent is a mixed solvent formed by ethanol and water in a ratio of 1:1 to 3 (e.g., 1:1, 1:2, 1:3). In S13, the filter is filtered through the filter membrane under vacuum conditions; In S14, ultrasonic dispersion is performed using a probe ultrasonic instrument under ice-water bath conditions.

[0012] More preferably, the mass-to-volume ratio of the two-dimensional graphene material to the first solvent is 1 kg: 5 to 20 L; The mass ratio of two-dimensional graphene materials to one-dimensional nanotubes is 1 to 5:1; The mass of the dispersant added is 0.001% to 0.01% of the mass of the two-dimensional graphene material.

[0013] In this specific scheme, two-dimensional graphene itself possesses good intralayer thermal conductivity, but its interlayer thermal conductivity needs improvement. Therefore, by combining it with one-dimensional nanotubes, the one-dimensional nanotubes enhance interlayer thermal conductivity. Specifically, the one-dimensional nanotubes may be inserted between the two-dimensional graphene layers through ultrasonic vibration, forming a "nanorhinus" structure, thereby creating vertical thermal conduction pathways between the two-dimensional graphene layers. Overall, this constitutes a three-dimensional, continuously conductive thermal network with reduced anisotropy. In particular, when the one-dimensional nanotubes are boron nitride nanotubes and the two-dimensional graphene is graphene oxide, the two have similar atomic arrangements, resulting in similar lattice constants and phonon vibration modes. This effectively reduces phonon scattering at the interface, which is more conducive to efficient heat transfer between the two, further improving the thermal conductivity of the modified PPS material. It should be noted that when dispersing two-dimensional graphene materials, a dispersant is preferably added. Its main function is to prevent interlayer stacking or agglomeration of the two-dimensional graphene. For example, when the two-dimensional graphene is graphene oxide and the dispersant is sodium dodecylbenzenesulfonate, there is a strong π-π bond interaction between the benzene rings of sodium dodecylbenzenesulfonate and the unoxidized hydrophobic regions (aromatic structures) on the surface of the graphene oxide sheets. Due to the increased negative charge density on the surface of the graphene oxide sheets (increasing the absolute value of the Zeta sites), a strong electrostatic repulsion is generated. This repulsion is sufficient to overcome the van der Waals forces between the sheets, thereby effectively preventing the graphene oxide sheets from approaching each other and stacking or agglomerating.

[0014] In one specific embodiment, the glass microspheres are 2000–4000 mesh vacuum glass microspheres. Understandably, the dielectric constant of vacuum glass microspheres is approximately 1, which is much lower than that of the polymer matrix. The uniformly dispersed vacuum glass microspheres are equivalent to introducing countless uniformly dispersed "low-dielectric bubbles" into the composite material, which, according to the composite medium theory (Lichtenecker mixing rule), can effectively reduce the overall dielectric constant of the material.

[0015] In one specific embodiment, the surface modifier is selected from aqueous solutions of KH-560, KH-550, KH-590, or KH-540, with a mass concentration of 93%–98%. Understandably, due to the significant differences in dielectric properties and conductivity between the surface of the vacuum glass microspheres and the polymer matrix, charge easily accumulates at the interface under an alternating electric field, resulting in significant interfacial polarization and affecting the dielectric loss of the material. Therefore, it is preferable to use surfactants to introduce abundant hydroxyl and carboxyl groups onto the surface of the vacuum glass microspheres, facilitating the formation of stable chemical bonds with the polymer matrix, increasing the interfacial compatibility between the vacuum glass microspheres and the matrix, thereby suppressing interfacial polarization. Furthermore, surfactants can effectively inhibit the aggregation of vacuum glass microspheres, ensuring uniform dispersion during processing. This results in a uniform micro-"vacuum" structure throughout the material, achieving low dielectric properties.

[0016] In one specific embodiment, the compatibilizer includes one or more of SEBS-g-MAH, SEBS-g-GMA, SBS-g-MAH, and SBS-g-GMA. Understandably, by using a compatibilizer, the interfacial compatibility between PPS and PPO can be improved, reducing the migration of defects and impurity ions at the interface, thereby reducing the material's conductive loss and interfacial polarization loss; the grafting rate of the compatibilizer in this invention can be, for example, 0.5%-1.2%, preferably 0.8%.

[0017] To address the aforementioned technical problems, a second aspect of the present invention is to provide the application of the aforementioned modified PPS with low dielectric loss and high thermal conductivity in the preparation of high-frequency, low-loss, thermally conductive insulating products.

[0018] Since the modified PPS provided by this invention has both low dielectric damage and high thermal conductivity, it is particularly suitable for application in the field of high-frequency, low-loss thermally conductive insulating products, such as next-generation high-frequency high-electromagnetic electronics / communications (5G / 6G, millimeter wave), aerospace and new energy vehicles.

[0019] To address the aforementioned technical problems, a third aspect of the present invention provides a method for preparing the aforementioned modified PPS with low dielectric loss and high thermal conductivity, comprising: S1. Preparation of composite thermal conductive agent; S2, Material Premixing: PPS, the composite thermal conductive agent obtained in step S1, PPO, glass microspheres, surface modifier and compatibilizer are premixed at high speed. S3. The premixed system in S2 is extruded and granulated using a twin-screw extrusion process to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0020] Preferably, the rotation speed of the high-speed premixing in S2 is 800-1000 rpm, and the premixing time is 10-30 min; The extrusion temperature in S3 is 270℃~320℃, and the screw speed is 300~400rpm.

[0021] In this invention, the composite thermal conductive agent is prepared, for example, by the following method: S11. Disperse the two-dimensional graphene material in the first solvent and add a dispersant; S12. Disperse the one-dimensional nanotube material in a second solvent; S13. After mixing the system of S11 and S12, filter it through a filter membrane with a pore size of 0.1 to 0.45 μm and discard the supernatant. S14. The system retained in S13 is ultrasonically dispersed and then filtered. The filter cake is dried to obtain a composite thermal conductive agent.

[0022] Preferably, the two-dimensional graphene material in S11 is a 1-3 layer graphene oxide material, the first solvent is a mixed solvent formed by ethanol and water in a ratio of 1:1-3, and the dispersant is one or more combinations of sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, polyvinylpyrrolidone, sodium lignin sulfonate, and sodium polystyrene sulfonate. The one-dimensional nanotubes in S12 are boron nitride nanotubes, and the second solvent is a mixed solvent of ethanol and water in a ratio of 1:1 to 3. In S13, the filter is filtered through the filter membrane under vacuum conditions; In S14, ultrasonic dispersion is performed using a probe ultrasonic instrument under ice-water bath conditions.

[0023] More preferably, the mass-to-volume ratio of the two-dimensional graphene material to the first solvent is 1 kg: 5 to 20 L; The mass ratio of two-dimensional graphene materials to one-dimensional nanotubes is 1 to 5:1; The mass of the dispersant added is 0.001% to 0.01% of the mass of the two-dimensional graphene material.

[0024] The method for preparing modified PPS with low dielectric loss and high thermal conductivity in this invention is compatible with conventional processes for polymer material processing and is convenient for large-scale industrial production. The resulting modified PPS has low dielectric constant, low dielectric loss, high thermal conductivity and stable mechanical properties, which meets the application requirements of high-frequency electronics, 5G communication and other fields. Attached Figure Description

[0025] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is the preparation process of the composite thermal conductive agent in this invention. Detailed Implementation

[0027] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] The material information in this embodiment of the invention is as follows: Ethanol-Deionized Water: Composed of 100L of 98% ethanol (chemically pure) and 200L of deionized water; Graphene oxide (two-dimensional graphene): 5000-8000 mesh, 1-3 layers, Macklin reagent; Sodium dodecylbenzenesulfonate: Macklin reagent; Boron nitride nanotubes (one-dimensional nanotubes): length 10–100 nm, Macklin reagent; Polyphenylene ether (PPO): Asahi Kasei of Japan, molecular weight 30000~80000; Vacuum glass microspheres: 3000 mesh, Porter, USA; KH-560 (95% aqueous solution): Organosilicon from Wuhan University; Polyphenylene sulfide (PPS): Zhejiang Xinhecheng; Compatibilizer: SEBS-g-MAH (0.8% grafting rate); It should be noted that all raw materials described in this invention can be purchased through commercial channels, and are not limited to the manufacturers and brands listed in this embodiment. Any similar products whose performance, specifications, and technical parameters meet the requirements of this invention can be used as equivalent substitutes. Example 1:

[0029] S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to the mixer, start stirring at 100rpm for 30min, then add 0.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixtures obtained in S11 and S12 are simultaneously placed in a vacuum filter press for vacuum filtration and intercalation. The filter membrane pore size is 0.1 μm, the vacuum degree is -1 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe at a power of 500 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain the boron nitride nanotube / graphene oxide intercalated thermal conductive agent (see details). Figure 1 ), namely composite thermal conductive agent; S2, Material Premixing: Take 500g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution, mass about 15g) and 3350g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0030] Example 2: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.0g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The pore size of the filter membrane is 0.1 μm, the vacuum degree is -1 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 500 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2, Material Premixing: Take 500g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3350g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0031] Example 3: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The pore size of the filter membrane is 0.1 μm, the vacuum degree is -1 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 500 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2, Material Premixing: Take 500g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3350g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0032] Example 4: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The filter membrane pore size is 0.1 μm, the vacuum degree is -3 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 500 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2, Material Premixing: Take 500g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3350g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0033] Example 5: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The filter membrane pore size is 0.1 μm, the vacuum degree is -5 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 500 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2. Material premixing: Take 500g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3500g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0034] Example 6: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The pore size of the filter membrane is 0.3 μm, the vacuum degree is -5 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 1000 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2. Material premixing: Take 500g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3500g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0035] Example 7: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 20kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The filter membrane pore size is 0.3 μm, the vacuum degree is -3 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 1000 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2, Material Premixing: Take 1000g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 2850g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0036] Example 8: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 50kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The filter membrane pore size is 0.3 μm, the vacuum degree is -3 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 1000 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2, Material Premixing: Take 1000g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 2850g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0037] Example 9: S1. Preparation of composite thermal conductive agent: S11. Add 200L of ethanol-deionized water and 10kg of graphene oxide to a mixer, start stirring at 100rpm for 30min, then add 1.5g of sodium dodecylbenzenesulfonate and continue mixing at the same speed for 10min. S12. Add 200L of ethanol-deionized water and 10kg of boron nitride nanotubes to another mixer, turn on the mixer, and set the speed to 100rpm for 60min. S13. The mixture obtained in S11 and the mixture obtained in S12 are placed in a vacuum filter for vacuum filtration and intercalation. The filter membrane pore size is 0.3 μm, the vacuum degree is -3 MPa, and the filtration time is 30 min. After filtration, the supernatant is removed, and the bottom liquid is placed in an ice-water bath and ultrasonically dispersed using an ultrasonic probe with a power of 1000 W. The ultrasonic cycle is 2 seconds on and 4 seconds off for 10 min. Afterward, the mixture is vacuum dried to obtain boron nitride nanotube / graphene oxide intercalated thermal conductive agent, i.e., composite thermal conductive agent. S2, Material Premixing: Take 1000g of the composite thermal conductive agent obtained in S1, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 2850g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S3. The premixed material obtained in S2 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain modified PPS with low dielectric loss and high thermal conductivity.

[0038] Comparative Example 1: S1. Put 5000g of PPS directly into a high-speed premixer and stir for 10 minutes at 800rpm. S2. The material that has been stirred at high speed in S1 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain PPS of Comparative Example 1.

[0039] That is, the PPS in this comparative example was not modified.

[0040] Comparative Example 2: S1. Add 665g of graphene oxide, 335g of boron nitride nanotubes, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 2850g of PPS into a high-speed mixer and mix at 800rpm for 10min to obtain a premixed material. S2. The premixed material obtained in S1 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain the modified PPS of Comparative Example 2.

[0041] That is, in this comparative example, graphene oxide and boron nitride nanotubes were not combined, but added directly.

[0042] Comparative Example 3: S1. Take 1000g of the composite thermal conductive agent prepared in Example 7, 250g of vacuum glass microspheres, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3600g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S2. The premixed material obtained in S1 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain the comparative example of three-modified PPS.

[0043] That is, no PPO was added to this comparative example.

[0044] Comparative Example 4: S1. Take 1000g of the composite thermal conductive agent prepared in Example 7, 750g of polyphenylene ether, 150g of compatibilizer, 15mL of KH-560 (95% concentration aqueous solution) and 3100g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S2. The premixed material obtained in S1 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain the modified PPS of Comparative Example 4.

[0045] That is, no vacuum glass microspheres were added in this comparative example.

[0046] Comparative Example 5: S1. Take 1000g of the composite thermal conductive agent prepared in Example 7, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 150g of compatibilizer, and 2850g of PPS and put them into a high-speed mixer. Mix them at 800rpm for 10min to obtain the premixed material. S2. The premixed material obtained in S1 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain the modified PPS of Comparative Example 5.

[0047] That is, KH-560 was not added to this comparative example.

[0048] Comparative Example 6: S1. Take 1000g of the composite thermal conductive agent prepared in Example 7, 750g of polyphenylene ether, 250g of vacuum glass microspheres, 15mL of KH-560 (95% concentration aqueous solution) and 3000g of PPS and put them into a high-speed mixer. Mix at 800rpm for 10min to obtain the premixed material. S2. The premixed material obtained in S1 is fed into a twin-screw extruder for blending and granulation. The extrusion temperature in each temperature zone is 270 / 290 / 320 / 320 / 320 / 320 / 290 / 290 / 290 / 290 / 300 / 320℃, and the screw speed is 300rpm, to obtain the modified PPS of Comparative Example 6.

[0049] That is, no compatibilizer was added in this comparative example.

[0050] Test example: In the test examples of this invention, thermal conductivity, dielectric constant, and dielectric loss were tested for Examples 1 to 9 and Comparative Examples 1 to 6. The test standards and test conditions for each test item are as follows: Thermal conductivity: ISO 22007-2; room temperature 23±2℃; probe power 0.5W; test time 10S Dielectric constant: IEC 61189-2-271; Frequency: 10GHz; Test temperature: 23℃; Single test time: 30s Dielectric loss: IEC 61189-2-271; Frequency: 10GHz; Test temperature: 23℃; Weak coupling (coupling coefficient = 0.05) The test results are shown in Table 1: Table 1: Test results of thermal conductivity, dielectric constant and dielectric loss for Examples 1 to 9 and Comparative Examples 1 to 6

[0051] As shown in Table 1, Examples 1 to 9 exhibit excellent dielectric and thermal conductivity properties. Comparative Example 1, due to the lack of PPS modification, has the worst thermal conductivity, the highest dielectric constant, and the highest dielectric loss. Comparative Example 2, due to the absence of graphene oxide and boron nitride nanotubes, shows poor thermal conductivity. Comparative Examples 3, 4, 5, and 6, due to the lack of PPO, vacuum glass microspheres, KH-560, and compatibilizer, respectively, have worse dielectric properties than the examples.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A modified PPS with low dielectric loss and high thermal conductivity, characterized in that, Includes the following components in parts by mass: PPS: 2500-4000 parts by weight; Composite thermal conductive agent: 500-1000 parts by weight; PPO: 700-1500 parts by weight; Glass microspheres: 200-500 parts by weight; Surface modifier: 10-50 parts by weight; Compatibilizer: 100-200 parts by weight; The composite thermal conductive agent is composed of one-dimensional nanotube materials and two-dimensional graphene materials.

2. The modified PPS with low dielectric loss and high thermal conductivity as described in claim 1, characterized in that, The preparation method of the composite thermal conductive agent is as follows: S11. Disperse the two-dimensional graphene material in the first solvent and add a dispersant; S12. Disperse the one-dimensional nanotube material in a second solvent; S13. After mixing the system of S11 and S12, filter it through a filter membrane with a pore size of 0.1 to 0.45 μm and discard the supernatant. S14. The system retained in S13 is ultrasonically dispersed and then filtered. The filter cake is dried to obtain a composite thermal conductive agent.

3. The modified PPS with low dielectric loss and high thermal conductivity as described in claim 2, characterized in that, The two-dimensional graphene material in S11 is a 1-3 layer graphene oxide material, the first solvent is a mixed solvent formed by ethanol and water in a ratio of 1:1 to 3, and the dispersant is one or more combinations of sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, polyvinylpyrrolidone, sodium lignin sulfonate, and sodium polystyrene sulfonate. The one-dimensional nanotubes in S12 are boron nitride nanotubes, and the second solvent is a mixed solvent of ethanol and water in a ratio of 1:1 to 3. In S13, the filter is filtered through the filter membrane under vacuum conditions; In S14, ultrasonic dispersion is performed using a probe ultrasonic instrument under ice-water bath conditions.

4. The modified PPS with low dielectric loss and high thermal conductivity as described in claim 2, characterized in that, The mass-to-volume ratio of the two-dimensional graphene material to the first solvent is 1 kg: 5–20 L; The mass ratio of two-dimensional graphene materials to one-dimensional nanotubes is 1 to 5:1; The mass of the dispersant added is 0.001% to 0.01% of the mass of the two-dimensional graphene material.

5. The modified PPS with low dielectric loss and high thermal conductivity as described in claim 1, characterized in that, The glass microspheres are 2000-4000 mesh vacuum glass microspheres.

6. The modified PPS with low dielectric loss and high thermal conductivity as described in claim 1, characterized in that, The surface modifier is selected from aqueous solutions of KH-560, KH-550, KH-590 or KH-540, with a mass concentration of 93% to 98%.

7. The modified PPS with low dielectric loss and high thermal conductivity as described in claim 1, characterized in that, The compatibilizer includes one or more of SEBS-g-MAH, SEBS-g-GMA, SBS-g-MAH, and SBS-g-GMA.

8. The application of a modified PPS with low dielectric loss and high thermal conductivity as described in any one of claims 1-7 in the preparation of high-frequency, low-loss, thermally conductive insulating products.

9. A method for preparing modified PPS with low dielectric loss and high thermal conductivity as described in any one of claims 1-7, characterized in that, include: S1. Preparation of composite thermal conductive agent; S2, Material Premixing: PPS, the composite thermal conductive agent obtained in step S1, PPO, glass microspheres, surface modifier and compatibilizer are premixed at high speed. S3. The premixed system in S2 is extruded and granulated using a twin-screw extrusion process to obtain modified PPS with low dielectric loss and high thermal conductivity.

10. The preparation method according to claim 9, characterized in that, The speed of the S2 medium-high speed premix is ​​800-1000 rpm, and the premixing time is 10-30 min; The extrusion temperature in S3 is 270℃~320℃, and the screw speed is 300~400rpm.

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