A method for producing a polyphenylene sulfide modified composite pellet

Abstract

The application belongs to the technical field of polymer material modification, and discloses a manufacturing method of polyphenylene sulfide modified composite granules, wherein 50-70 parts of polyphenylene sulfide resin, 8-15 parts of nickel intercalated nanometer molybdenum disulfide, 5-10 parts of hollow boron nitride microspheres, 5-8 parts of fluororesin compatibilizer, 3-5 parts of graphene oxide and 15-25 parts of supercritical fluid pretreated glass fibers are combined as raw materials in terms of weight parts; the application aims to provide a manufacturing method of polyphenylene sulfide modified composite granules, and through a special filler compound system and an innovative process, the heat conduction, dielectric, mechanical and corrosion resistance of PPS material are significantly improved, so as to meet the demand of high-end fields for high-performance engineering plastics.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high polymer material modification, and particularly relates to a manufacturing method of polyphenylene sulfide modified composite granules. BACKGROUND

[0002] Polyphenylene sulfide (PPS) is widely used in the fields of electronic appliances, automobiles, aerospace, etc. due to its excellent high-temperature resistance, chemical corrosion resistance, flame resistance, etc. However, the inherent properties of PPS still have certain limitations, such as low thermal conductivity (about 0.2-0.3 W / m·K), insufficient toughness, and unsatisfactory dielectric properties, which are difficult to meet the requirements of high-end application scenarios such as 5G communication and heat dissipation of high-power electronic devices.

[0003] At present, the existing technology mainly modifies PPS by adding conventional fillers (such as glass fibers and talc powder).

[0004] For example, Chinese patent CN119286252A discloses a high-conductive and high-thermal-conductive enhanced polyphenylene sulfide composite based on black talc powder filling and a preparation method thereof, which can improve the material properties to a certain extent, but still cannot meet the requirements of high-end applications in terms of thermal conductivity, dielectric constant, corrosion resistance and other key indicators. In addition, the dispersibility of conventional fillers and the interfacial bonding force with the PPS matrix are limited, which leads to insignificant improvement in the comprehensive performance of the composite material. Therefore, a manufacturing method of polyphenylene sulfide modified composite granules is proposed to solve the problems in the prior art. SUMMARY

[0005] The application aims to provide a manufacturing method of polyphenylene sulfide modified composite granules, which significantly improves the thermal conductivity, dielectric property, mechanical property and corrosion resistance of PPS materials through a special filler compound system and an innovative process, and meets the requirements of high-end fields for high-performance engineering plastics.

[0006] In order to achieve the above-mentioned purpose, the application provides the following technical scheme:

[0007] The application provides a manufacturing method of polyphenylene sulfide modified composite granules, which comprises the following steps:

[0008] S1: raw materials are combined according to the following proportions by weight: 50-70 parts of polyphenylene sulfide resin, 8-15 parts of nickel intercalated nanometer molybdenum disulfide, 5-10 parts of hollow boron nitride microspheres, 5-8 parts of fluororesin compatibilizer, 3-5 parts of graphene oxide, and 15-25 parts of supercritical fluid pretreated glass fibers;

[0009] S2: using supercritical CO2 fluid, pressure is 15-20 MPa, temperature is 40-60℃, glass fiber is treated for 1-2 hours, micro-nano level rough interface is constructed, surface roughness Ra is 0.8-1.6 μm, and then modified by silane coupling agent KH-560;

[0010] S3: nickel intercalated nanometer molybdenum disulfide and graphene oxide are dispersed by an ultrasonic device with power of 800-1200 W and frequency of 20-25 kHz for 30-60 minutes, and 0.5-1% titanate coupling agent is introduced synchronously;

[0011] S4: the pretreated material is put into a double screw extruder with length-diameter ratio of 40:1, and is blended at 280-320℃ and rotation speed of 300-400 r / min, and then composite granules are prepared by water cooling and pelletizing.

[0012] Further, the nickel intercalated nanometer molybdenum disulfide is prepared by a photoreduction method, the photoreduction method uses a nickel nitrate solution as a nickel source, the nickel particle insertion rate is 5-10%, the interlayer spacing is expanded to 0.8-1.2 nm, the photoreduction method uses ultraviolet light with wavelength of 365 nm for irradiation, the concentration of the nickel nitrate solution in the reaction system is 0.05-0.1 mol / L, and the reaction time is 2-3 hours.

[0013] Further, the hollow boron nitride microspheres are prepared by a chemical vapor deposition method, the particle size is 50-200 nm, the wall thickness is 5-10 nm, and the internal hollow rate is ≥60%.

[0014] Further, the fluororesin compatibility agent is tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, the melt index is 10-15 g / 10 min, the test condition is 372℃, 5 kg, and the interfacial tension with PPS is ≤20 mN / m.

[0015] Further, in the supercritical fluid pretreatment step, 50-100 μm 2 level pits are formed on the surface of the glass fiber, and the interfacial shear strength with PPS resin is ≥18 MPa.

[0016] Further, the ultrasonic dispersion device adopts a three-stage energy superposition cavity, and the fluid flow rate in the tube is controlled at 5-10 m / s, so that the size of the nanometer material agglomerates is ≤100 nm.

[0017] Further, the double screw extruder is provided with a gradient temperature zone, the temperature of the feeding section is 260-280℃, the temperature of the melting section is 290-310℃, the temperature of the homogenizing section is 310-320℃, and the screw combination contains 60% shear thread elements.

[0018] Further, the prepared composite granules have thermal conductivity coefficient ≥1.8 W / m·K, dielectric constant ≤2.6, and notched impact strength ≥25 kJ / m 2And the mass loss is less than or equal to 0.5% after being soaked in concentrated sulfuric acid at 150 DEG C for 1000 hours.

[0019] Further, the reaction temperature of the chemical vapor deposition method is 1200-1400 DEG C, the carrier gas is a mixed gas of argon and ammonia with a volume ratio of 3:1, and the deposition time is 30-60 minutes.

[0020] The beneficial effects of the technical solution are:

[0021] (1) The complex system of nickel intercalated nanometer molybdenum disulfide, hollow boron nitride microspheres, graphene oxide and fluororesin compatibilizer is adopted, the nickel intercalated nanometer molybdenum disulfide and graphene oxide construct a three-dimensional heat conduction network, the thermal conductivity of the composite material is increased from 0.25 W / m·K of pure PPS to 1.8-2.2 W / m·K, which meets the heat dissipation requirement of 5G base station; the hollow boron nitride microspheres reduce the material density by 15-20% and the dielectric constant to 2.4-2.6 at the same time, which is suitable for high-frequency communication; the PFA compatibilizer reduces the interfacial tension and improves the dispersibility of the filler, so that the mass loss of the composite material is less than or equal to 0.5% after being soaked in concentrated sulfuric acid at 150 DEG C for 1000 hours, and the corrosion resistance is more than 3 times higher than that of the traditional system.

[0022] (2) The glass fiber is pretreated by supercritical CO2 fluid, and micro-nano level pits are formed on the surface of the glass fiber, so that the specific surface area is increased by 25%; the subsequent silane coupling agent treatment increases the interfacial shear strength of the fiber and the matrix from 12 MPa to 18-20 MPa, and the tensile strength reaches 150-180 MPa; the three-stage energy superposition ultrasonic device cooperates with the titanate coupling agent to peel off the graphene oxide layer to 1-2 nm, and the nickel intercalated nanometer molybdenum disulfide agglomerates are broken to 50-100 nm, so that the dispersion uniformity is increased by 40%, and the performance fluctuation caused by the agglomeration of the filler is avoided.

[0023] (3) The gradient temperature zone of the double screw extruder is combined with the special screw, so that the PFA compatibilizer forms a gradient distribution, the surface friction coefficient of the material is reduced to 0.12-0.15, and the notched impact strength is increased to 25-28 kJ / m 2 , which solves the problem of "rigid and brittle" of PPS material, and the synergistic effect of the composite antioxidant and the hollow boron nitride microspheres makes the tensile strength retention rate of the material after 1000 hours of heat aging at 260 DEG C exceed 90%, which can serve at high temperature of 220 DEG C for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The process flow chart of the manufacturing method of the polyphenylene sulfide modified composite granules is provided in the present application;

[0025] Figure 2 The data table of the first embodiment of the manufacturing method of the polyphenylene sulfide modified composite granules is provided in the present application;

[0026] Figure 3 Example 2 data table for the manufacturing method of the polyphenylene sulfide modified composite granules proposed in the present application;

[0027] Figure 4 Example 3 data table for the manufacturing method of the polyphenylene sulfide modified composite granules proposed in the present application;

[0028] Figure 5 Example 4 data table for the manufacturing method of the polyphenylene sulfide modified composite granules proposed in the present application;

[0029] Figure 6 Example 5 data table for the manufacturing method of the polyphenylene sulfide modified composite granules proposed in the present application;

[0030] Figure 7 Example 6 data table for the manufacturing method of the polyphenylene sulfide modified composite granules proposed in the present application;

[0031] Figure 8 Example data comparison table for the manufacturing method of the polyphenylene sulfide modified composite granules proposed in the present application. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0033] The specific implementation process is as follows:

[0034] Example 1:

[0035] Please refer to Figures 1-8 The present application provides a technical solution: a manufacturing method of polyphenylene sulfide modified composite granules, 60 parts by weight of polyphenylene sulfide resin with a specific viscosity of 0.45 dL / g are weighed and dried at 80°C under vacuum for 4 hours to remove moisture; 10 parts of nickel intercalated nanometer molybdenum disulfide with an intercalation rate of 8%, an interlayer spacing of 1.0 nm, and a particle size of 50-80 nm are inserted; 8 parts of hollow boron nitride microspheres with a particle size of 100 nm, a wall thickness of 8 nm, and a hollow rate of 65%; 6 parts of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) with a melt index of 12 g / 10 min, and a test condition of 372°C, 5 kg; 4 parts of graphene oxide with a layer thickness of 1-2 nm, dried at 50°C under vacuum for 2 hours; 20 parts of graphene with a surface roughness Ra=1.2 μm, a surface pit density of 80 pieces / mm 2Supercritical fluid pretreatment of glass fiber; 3 parts of a composite antioxidant compounded by 2:1 of hindered phenol and thioester;

[0036] The glass fiber bundle is loaded into a supercritical CO2 treatment kettle, CO2 gas is introduced to a pressure of 18 MPa, and the temperature is raised to 50℃. After 1.5 hours of heat preservation treatment, the pressure is reduced at a rate of 5 MPa / min to form micron-sized pits on the surface of the fiber; then immersed in a 5% (mass concentration) silane coupling agent KH-560 ethanol solution, stirred at room temperature for 10 minutes, and then taken out and dried in a 100℃ oven for 2 hours;

[0037] The nickel intercalated nanometer molybdenum disulfide and graphene oxide are added to deionized water, and dispersed in an ultrasonic cleaner at a power of 1000W and a frequency of 25kHz for 45 minutes at room temperature. Simultaneously, 0.8% of a titanate coupling agent based on the total mass of the nanometer material is added dropwise, and the temperature of the dispersion is controlled to be ≤40℃, to obtain a stable dispersion with a solid content of 5%;

[0038] All raw materials are fed into a double-screw extruder with a length-diameter ratio of 40:1, the temperature of the feeding section (1-2 zone) is set to 270℃, the temperature of the melting section (3-4 zone) is set to 300℃, the temperature of the homogenization section (5-6 zone) is set to 315℃, the screw rotation speed is set to 350r / min, and the feeding rate is set to 20kg / h; the extrudate is cooled and shaped in a 5℃ circulating water cooling tank, then drawn by an automatic traction machine, cut into 3mm long particles by a granulator, and then sieved to obtain the composite granules.

[0039] Example Two:

[0040] Please refer to Figures 1-8 The application provides a kind of technical scheme: a kind of polyphenyl sulfide modified composite granule manufacturing method, by weight parts, 55 parts of polyphenyl sulfide resin with characteristic viscosity 0.5dL / g are weighed, and the drying condition is same as in example 1;12 parts of nickel intercalated nanometer molybdenum disulfide with nickel intercalation rate 7%, interlayer spacing 0.9nm, particle size 30-60nm;7 parts of hollow boron nitride microspheres with particle size 150nm, wall thickness 6nm, hollow rate 70%;7 parts of PFA with melt index 13g / 10min;3 parts of graphene oxide;22 parts of glass fiber with surface roughness Ra=1.0μm, pit density 70 / mm 2 2.5 parts of a composite antioxidant;

[0041] The glass fiber is treated in supercritical CO2 fluid at a pressure of 17MPa and a temperature of 45℃ for 1.8 hours, and the pressure is released at a rate of 3MPa / min;Then immerse in 6% KH-560 aqueous solution (water: ethanol = 8:2) for 15 minutes, and dry at 110℃ for 1.5 hours;

[0042] The nanometer molybdenum disulfide and graphene oxide are dispersed for 50 minutes by using an ultrasonic device with a power of 900 W and a frequency of 22 kHz, 0.7% titanate coupling agent is added, and a dispersion liquid with a solid content of 6% is prepared, wherein the size of the agglomerates is less than or equal to 80 nm;

[0043] The temperature of the double-screw extruder is set to 265 DEG C for a feeding section, 295 DEG C for a melting section, and 310 DEG C for a homogenizing section, the screw rotation speed is 330 r / min, the feeding rate is 18 kg / h, and the proportion of shearing thread elements is 55%; the extrudate is cooled and shaped in a 6 DEG C circulating water cooling tank, is drawn by an automatic traction machine, is cut into 3 mm long particles by a cutting machine, and the composite granules are obtained after screening.

[0044] Example Three:

[0045] Please refer to Figures 1-8 The application provides a manufacturing method of polyphenylene sulfide modified composite granules, and the method comprises the following steps: 65 parts of polyphenylene sulfide resin with a specific viscosity of 0.35 dL / g are weighed; 9 parts of nickel intercalation nanometer molybdenum disulfide with a nickel intercalation rate of 9% and an interlayer spacing of 1.1 nm are weighed; 9 parts of hollow boron nitride microspheres with a particle size of 80 nm, a wall thickness of 10 nm and a hollow rate of 60% are weighed; 5.5 parts of PFA with a melt index of 11 g / 10 min are weighed; 4.5 parts of graphene oxide are weighed; 18 parts of glass fibers with a surface roughness Ra=1.5 μm and a pit density of 90 pieces / mm 2 are weighed.

[0046] The glass fibers are treated in supercritical CO2 fluid at a pressure of 19 MPa and a temperature of 55 DEG C for 1.2 hours, are immersed in a 7% KH-560 ethanol solution, and are dried at 120 DEG C for 1 hour.

[0047] The nanometer molybdenum disulfide and graphene oxide are dispersed for 50 minutes by using an ultrasonic device with a power of 900 W and a frequency of 22 kHz, 0.7% titanate coupling agent is added, and a dispersion liquid with a solid content of 6% is prepared, wherein the size of the agglomerates is less than or equal to 80 nm;

[0048] The temperature of the double-screw extruder is set to 265 DEG C for a feeding section, 295 DEG C for a melting section, and 310 DEG C for a homogenizing section, the screw rotation speed is 330 r / min, the feeding rate is 18 kg / h, and the proportion of shearing thread elements is 55%; the extrudate is cooled and shaped in a 6 DEG C circulating water cooling tank, is drawn by an automatic traction machine, is cut into 3 mm long particles by a cutting machine, and the composite granules are obtained after screening.

[0049] Example Four:

[0050] Please refer to Figures 1-3 and Figure 5The application provides a kind of technical scheme: a kind of polyphenyl sulfide modified composite granule manufacturing method, by weight parts, 70 parts of polyphenyl sulfide resin with intrinsic viscosity 0.3dL / g are weighed;8 parts of nickel intercalation rate 6%, interlayer spacing 0.8nm nickel intercalation nanometer molybdenum disulfide;10 parts of hollow boron nitride microspheres with particle size 200nm, wall thickness 5nm, hollow rate 75%;8 parts of PFA with melt index 15g / 10min;3.5 parts of graphene oxide;15 parts of glass fiber with surface roughness Ra=0.9μm;

[0051] The glass fiber is treated in supercritical CO2 fluid at a pressure of 20 MPa and a temperature of 60 DEG C for 1 hour, and is modified by being immersed in a 4% KH-560 ethanol solution.

[0052] An ultrasonic device with an opening power of 1200 W and a frequency of 20 kHz is started, and dispersion is performed for 60 minutes, and 1% titanate coupling agent is synchronously added to ensure complete exfoliation of the graphene.

[0053] The temperature of the double-screw extruder is set to 280 DEG C for a feeding section, 310 DEG C for a melting section, and 325 DEG C for a homogenizing section, the screw rotation speed is 400 r / min, the feeding rate is 22 kg / h, a low-shear screw combination with a shear element ratio of 50% is used, the extrudate is cooled and shaped in a 5 DEG C circulating water cooling tank, is drawn by an automatic traction machine, and is cut into 3mm-long particles, and the composite granules are obtained after screening.

[0054] Example Five

[0055] Please refer to Figures 1-8 The application provides a kind of technical scheme: a kind of polyphenyl sulfide modified composite granule manufacturing method, by weight parts, 50 parts of polyphenyl sulfide resin with intrinsic viscosity 0.55dL / g are weighed, and are dried at 80 DEG C for 4 hours;8 parts of nickel intercalation rate 5%, interlayer spacing 0.8nm nickel intercalation nanometer molybdenum disulfide;10 parts of hollow boron nitride microspheres (maximize dielectric optimization) with particle size 200nm, wall thickness 5nm, hollow rate 75%;8 parts of PFA with melt index 15g / 10min;3 parts of graphene oxide;25 parts of supercritical fluid pretreated glass fiber with surface roughness Ra=0.8μm, pit density 50 / mm 2

[0056] The glass fiber is treated in supercritical CO2 fluid at a pressure of 15 MPa and a temperature of 40 DEG C for 2 hours to form low-density micro-nano pits;Then, the glass fiber is immersed in a 3% silane coupling agent KH-560 ethanol solution for 10 minutes and is dried at 100 DEG C for 2 hours.

[0057] An ultrasonic device with a power of 800 W and a frequency of 20 kHz is used to disperse the nanomaterials for 60 minutes, and 0.5% titanate coupling agent is added to ensure that the hollow boron nitride microspheres are uniformly distributed and are not damaged.​

[0058] The twin-screw extruder is set to a feeding section of 260℃, a melting section of 290℃, and a homogenizing section of 310℃, a screw rotation speed of 300r / min, and a shear thread element proportion of 50% (low shear protection hollow structure); the extrudate is cooled in a 6℃ water tank, and granulated to obtain composite granules with a particle size of 3mm.

[0059] Example six:

[0060] Please refer to Figures 1-8 The application provides a manufacturing method of polyphenylene sulfide modified composite granules, which comprises the following steps: 60 parts of polyphenylene sulfide resin with a specific viscosity of 0.4dL / g are weighed; 15 parts of nickel intercalated nanometer molybdenum disulfide with a nickel intercalation rate of 10% and an interlayer spacing of 1.2nm (maximum filler amount) are weighed; 5 parts of hollow boron nitride microspheres with a particle size of 50nm and a wall thickness of 10nm are weighed; 5 parts of PFA with a melt index of 10g / 10min are weighed; 5 parts of graphene oxide are weighed; 20 parts of supercritical fluid pretreated glass fibers with a surface roughness Ra=1.6μm and a pit density of 100 / mm 2 2 parts of composite antioxidant are weighed.

[0061] The glass fibers are treated in a supercritical CO2 fluid at a pressure of 20MPa and a temperature of 60℃ for 1 hour, and the surface pit depth is 5-8μm; the glass fibers are modified by being immersed in a 10% silane coupling agent KH-560 ethanol solution and dried at 120℃ for 1 hour;

[0062] The nickel intercalated molybdenum disulfide and the graphene oxide are dispersed by an ultrasonic device with a power of 1200W and a frequency of 25kHz for 30 minutes, and 1% titanate coupling agent is added to form a close heat conduction network.

[0063] The temperature of the twin-screw extruder is set to a feeding section of 280℃, a melting section of 320℃, and a homogenizing section of 325℃, a screw rotation speed of 400r / min, and a shear thread element proportion of 70% (strengthened dispersion); after extrusion, the extrudate is rapidly cooled in a 4℃ ice water bath, and granulated to obtain ultrahigh heat conduction composite granules with a particle size of 2.5mm.

[0064] Heat conduction performance analysis (Examples 3 and 6): Example 3 (9 parts of nickel intercalation + 9 parts of hollow boron nitride) realizes heat conduction (2.1W / m·K) and mechanical properties (impact strength 28kJ / m 2) and the interlayer spacing (1.1 nm) of nickel intercalated nanometer molybdenum disulfide is expanded to facilitate phonon transmission, and the graphene oxide (4.5 parts) fills the gap between fillers to form a continuous network; Example 6 (nickel intercalation 15 parts + graphene oxide 5 parts) improves the thermal conductivity to 2.2 W / m·K by using the maximum amount of filler, which is the highest value in the whole series, but the hollow boron nitride microspheres are only 5 parts, which leads to a slight increase in the dielectric constant (2.7), indicating that too high a conductive filler will have a negative impact on the dielectric properties;

[0065] Dielectric performance analysis (Examples 2 and 5): Example 2 (hollow boron nitride 7 parts + glass fiber 22 parts) has a dielectric constant as low as 2.4, thanks to the high aspect ratio (150 nm particle size / 6 nm wall thickness) and uniform dispersion of the hollow boron nitride microspheres. The 70% hollow rate creates a large number of low dielectric nanocavities inside the material, effectively suppressing electromagnetic wave loss. Example 5 (hollow boron nitride 10 parts + glass fiber 25 parts) further reduces the dielectric constant to 2.3, which is the only example below 2.4, but its thermal conductivity (1.75 W / m·K) decreases slightly, reflecting the negative correlation between dielectric and thermal properties, making it suitable for high-frequency communication equipment insulation components.

[0066] Mechanical performance analysis (Examples 3 and 6): The notched impact strength (28 kJ / m 2 ) and interfacial shear strength (19 MPa) of Example 3 are both at a medium level. The glass fiber surface roughness Ra=1.5 μm, and the pit density is 90 pits / mm 2 , forming a "mechanical engagement + chemical grafting" dual interface effect that effectively transfers the load. Example 6 has the highest interfacial shear strength of 20 MPa with the highest roughness Ra=1.6 μm and 20 parts of glass fiber, which is the highest in the whole series. This shows that fine-tuning the micro-nano structure of the fiber surface is the key to improving the interfacial bonding force, especially at high filler content, avoiding the "stress concentration" defect.

[0067] Effect of process parameters on filler dispersion and interfacial bonding: The supercritical treatment pressure of Examples 1-4 is 15-20 MPa at 40-60°C. As the pressure increases, the glass fiber surface pit density increases from 50 pits / mm 2 (Example 5) to 100 pits / mm 2 (Example 6), and the roughness Ra increases from 0.8 μm (Example 5) to 1.6 μm (Example 6). Experimental data shows that when Ra=1.2-1.5 μm (Examples 1-3), the interfacial shear strength is stable at 18-19 MPa, and when Ra>1.5 μm (Example 6), the mechanical engagement area between the fiber and the resin increases by 20%, and the strength breaks through 20 MPa, but too high a roughness may lead to uneven distribution of the fiber surface coupling agent (such as the slight decrease in corrosion resistance of Example 6);

[0068] Ultrasonic power and dispersion time directly affect the agglomeration state of nanomaterials: the breakage rate of hollow boron nitride microspheres in Example 5 (800 W / 60 min) is <5%, maintaining the integrity of the hollow structure, and the dielectric performance is optimal; while in Example 6 (1200 W / 30 min), due to high power and short time dispersion, nickel intercalated molybdenum disulfide is more fully exfoliated (agglomerates ≤50 nm), but part of the graphene sheets are fractured, resulting in a surface resistivity of 8.0×10 7 Ω·cm, and the antistatic property is improved; this shows that the dispersion parameters need to be selected according to the characteristics of the filler: brittle hollow fillers (boron nitride) are suitable for low-power long-time dispersion, while layered conductive fillers (molybdenum disulfide, graphene) are suitable for high-power short-time exfoliation;

[0069] Extrusion temperature and screw speed affect the distribution morphology of fillers: in Example 2 (265-310℃ / 330r / min), the PFA compatibilizer forms a "sea-island structure" of 10-15μm, with an interfacial tension of 18mN / m with the PPS matrix, and the notched impact strength is improved by 26%; in Example 6 (280-325℃ / 400r / min), high shear makes PFA disperse into 5-8μm microzones, and the interfacial reaction is more complete, but the breakage rate of hollow boron nitride microspheres increases to 8%, resulting in a slight decrease in corrosion resistance (0.4% mass loss); it can be seen that low shear (≤300r / min) protects the hollow structure, and high shear (≥350r / min) strengthens the interfacial bonding, and the process window is selected according to the target performance;

[0070] Nickel intercalated nanometer molybdenum disulfide (conductive filler) and hollow boron nitride microspheres (insulating filler) exhibit a typical antagonistic effect: Example 6 (high conductive filler) has the highest thermal conductivity (2.2W / m·K), but the highest dielectric constant (2.7); Example 5 (high insulating filler) has the lowest dielectric constant (2.3), but the thermal conductivity decreases to 1.75W / m·K; by optimizing the ratio of the two (such as 10:8 in Example 1), a balance between thermal conductivity (2.0W / m·K) and dielectric property (2.5) can be achieved, meeting the needs of most engineering scenarios;

[0071] The content of glass fiber is positively correlated with the amount of PFA compatibilizer: in Example 2 (22 parts of glass fiber + 7 parts of PFA), the notched impact strength (26kJ / m 2 ) and corrosion resistance (0.25% mass loss) are excellent, because PFA forms a 0.5-1μm thick corrosion-resistant coating on the surface of the fiber, and at the same time enhances the interfacial compatibility of the fiber and the resin; while in Example 6 (20 parts of glass fiber + 5 parts of PFA), the corrosion resistance decreases slightly (0.4% mass loss) due to the reduction of PFA content, indicating that the compatibilizer needs to be matched with the fiber content to form a complete interfacial protective layer;

[0072] Increasing the content of nickel intercalated molybdenum disulfide (such as 15 parts in Example 6) reduces the surface resistivity to 8.0×107 Ω·cm, meet the antistatic requirements, but too high conductive filler may lead to melt viscosity drop (15% increase in extrusion pressure of Example 6), which needs to be adjusted by screw combination (such as increasing shear elements) to maintain processing stability; the surface resistivity of Example 4 (8 parts of nickel intercalation + 8 parts of PFA) is 2.0 x 10 8 Ω·cm, in the balance interval of antistatic and processability, suitable for processing of electronic components sensitive to static electricity;

[0073] Example 1 (60 parts of PPS + 20 parts of glass fiber) is suitable for general engineering scenarios, with high thermal conductivity (2.0 W / m·K), dielectricity (2.5), impact strength (27 kJ / m 2 ) without obvious shortcoming, which can be used for automobile engine parts and industrial pump bodies; Example 4 (70 parts of PPS + 15 parts of glass fiber) reduces the content of fiber to improve the continuity of resin matrix, with dielectric constant 2.5 and surface resistivity 2.0 x 10 8 Ω·cm, suitable for small electronic accessories with high requirements for insulation and processing fluidity;

[0074] High-performance oriented (Examples 3 and 6): the comprehensive performance of Example 3 is the best (thermal conductivity 2.1 + impact 28 + dielectricity 2.6), which can be used as a material for core components of high-end equipment; the ultra-high thermal conductivity (2.2 W / m·K) of Example 6 is suitable for 5G base station heat dissipation modules and new energy vehicle battery thermal management systems, and its surface resistivity 8.0 x 10 7 Ω·cm meets the electromagnetic shielding requirement;

[0075] Special function type (Examples 2 and 5): the ultra-low dielectric constant (2.4) of Example 2 is suitable for high-frequency circuit board substrates, and the dielectric constant 2.3 of Example 5 reaches the microwave device level standard (such as satellite communication antenna insulating layer), and the corrosion resistance (mass loss ≤0.25%) of both makes them irreplaceable in chemical and corrosive environments.

[0076] Compared with the prior art, the present application realizes performance breakthrough through "three core innovations":

[0077] Abandoning traditional single filling of talcum powder / glass fiber, a multi-scale synergistic system of "nickel intercalated nanometer molybdenum disulfide (thermal conductivity) + hollow boron nitride microspheres (dielectricity) + fluororesin compatibilizer (interface)" is constructed, which fills the gap of the prior art in the difficulty of achieving thermal conductivity-dielectricity-corrosion resistance performance;

[0078] Supercritical fluid treatment makes the surface roughness of the fiber increase by 3 times, combined with the activation of the nanometer material dispersed by ultrasonic waves, the interfacial shear strength is increased from 12 MPa (conventional coupling agent) to 18-20 MPa, solving the long-standing interfacial debonding problem of PPS composite materials;

[0079] By gradient design of filler ratio (50-70 parts of PPS) and process parameters (260-325℃ extrusion temperature), the performance of the material can be adjusted from general grade to aviation grade, covering more than 90% of engineering plastic application scenarios, while the existing technology can only realize single performance optimization;

[0080] Embodiments 1-6 build a full series of PPS modified material system through precise combination of filler ratio and process parameters, covering "balanced basic performance-high-end performance breakthrough-special function customization". The synergistic effect of special filler is the core driving force of performance improvement, and innovative processes such as supercritical treatment and ultrasonic dispersion are the key to releasing the potential of fillers. The above is only an embodiment of the present application, and well-known specific technical solutions or characteristics in the scheme are not described in detail. It should be pointed out that for those skilled in the art, without departing from the technical solutions of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the patent. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A method for manufacturing polyphenylene sulfide modified composite granules, characterized in that: Includes the following steps: S1: By weight, 50-70 parts of polyphenylene sulfide resin, 8-15 parts of nickel intercalated molybdenum disulfide nanoparticles, 5-10 parts of hollow boron nitride microspheres, 5-8 parts of fluororesin compatibilizer, 3-5 parts of graphene oxide and 15-25 parts of supercritical fluid pretreated glass fiber are combined into a raw material combination. S2: Supercritical CO2 fluid is used at a pressure of 15-20 MPa and a temperature of 40-60℃ to treat glass fiber for 1-2 hours to construct a micro-nano-level rough interface with a surface roughness Ra of 0.8-1.6 μm. Then, it is modified by impregnation with silane coupling agent KH-560. S3: Nickel-intercalated molybdenum disulfide nanoparticles and graphene oxide are dispersed for 30-60 minutes using an ultrasonic device with a power of 800-1200W and a frequency of 20-25kHz, while 0.5-1% titanate coupling agent is introduced simultaneously. S4: The pretreated material is fed into a twin-screw extruder with a length-to-diameter ratio of 40:1 and blended at 280-320℃ and a speed of 300-400r / min. The mixture is then water-cooled and pelletized to obtain composite pellets.

2. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 1, characterized in that: The nickel-intercalated molybdenum disulfide nanoparticles were prepared by photoreduction, which used nickel nitrate solution as the nickel source. The nickel particle insertion rate was 5-10%, and the interlayer spacing was increased to 0.8-1.2 nm. The photoreduction method used ultraviolet light with a wavelength of 365 nm for irradiation. The concentration of nickel nitrate solution in the reaction system was 0.05-0.1 mol / L, and the reaction time was 2-3 hours.

3. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 2, characterized in that: The hollow boron nitride microspheres are prepared by chemical vapor deposition, with a particle size of 50-200 nm, a wall thickness of 5-10 nm, and an internal hollowness of ≥60%.

4. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 3, characterized in that: The fluororesin compatibilizer is a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer with a melt index of 10-15 g / 10 min and test conditions of 372℃ and 5 kg.

5. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 4, characterized in that: In the supercritical fluid pretreatment step, micron-level pits with a density of 50-100 pits / mm² are formed on the surface of the glass fiber.

6. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 5, characterized in that: The ultrasonic dispersion device adopts a three-stage energy superposition cavity, and the fluid velocity inside the tube is controlled at 5-10m / s, so that the size of the nanomaterial aggregates is ≤100nm.

7. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 6, characterized in that: The twin-screw extruder is equipped with a gradient temperature zone, with a feeding section temperature of 260-280℃, a melting section temperature of 290-310℃, and a homogenization section temperature of 310-320℃. The screw assembly includes 60% shear screw elements.

8. The method for manufacturing polyphenylene sulfide modified composite granules according to any one of claims 1-7, characterized in that: The thermal conductivity of the prepared composite granules is ≥1.8W / m. . K, dielectric constant ≤2.6, notched impact strength ≥25kJ / m², and mass loss ≤0.5% after immersion in concentrated sulfuric acid at 150℃ for 1000 hours.

9. The method for manufacturing polyphenylene sulfide modified composite granules according to claim 3, characterized in that: The reaction temperature of the chemical vapor deposition method is 1200-1400℃, the carrier gas is a mixture of argon and ammonia in a volume ratio of 3:1, and the deposition time is 30-60 minutes.

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