Polyphenylene sulfide composite material and preparation method thereof

Abstract

The invention relates to the field of engineering plastic preparation, in particular to a polyphenylene sulfide composite material and a preparation method thereof.The polyphenylene sulfide composite material is prepared from, by weight, 1-5 parts of modified CNT, 2-30 parts of CF, 1-5 parts of a binder, 1-5 parts of an anti-warping agent, 1-5 parts of an auxiliary and 50-80 parts of PPS, the modified CNT is prepared by mixing HBPPS and CNT, the excellent compatibility between the HBPPS and the PPS is utilized, and the anti-warping performance of the composite material is improved; the mixing uniformity of a reinforcing material CNT in PPS is improved, the agglomeration probability is reduced, and the mechanical property, the processing fluidity and the dimensional stability of the composite material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engineering plastic preparation, and in particular to a polyphenylene sulfide composite material and a preparation method thereof. BACKGROUND

[0002] Fused deposition modeling (FDM) is a widely used 3D printing technology. Unlike traditional subtractive manufacturing, due to its special layer-by-layer working principle, FDM technology has the ability to produce complex geometries, can significantly reduce manufacturing costs, and is widely used in the mechanical, electronic, medical and other industries.

[0003] The typical 3D printing materials of thermoplastic polymers are acrylonitrile-butadiene-styrene (ABS), polylactic acid (PLA), high-density polyethylene (HDPE), nylon (PA), etc. The research on the 3D printing performance of these materials has been relatively mature. In order to improve the mechanical properties of 3D printed products, the 3D printing of thermoplastic polymer consumables is developing towards high-performance special engineering plastics, and the typical materials are polyphenylene sulfide (PPS), polyetherimide (PEI) and polyether ether ketone (PEEK). However, current research mainly focuses on controlling the printing forming process to alleviate the warping deformation of the product and optimize the mechanical properties. Moreover, the mechanical properties of pure resin 3D printed products are poor, and they cannot be used as main load-bearing or structural components.

[0004] Therefore, resin will be mixed with reinforcing materials to overcome these shortcomings. Common reinforcing materials include glass fibers, carbon fibers (CF), carbon nanotubes (CNT), talc, mica, etc. Blending of reinforcing materials and resin matrix can significantly improve the mechanical properties, toughness, heat resistance and dimensional stability of the material, but the large addition of reinforcing materials will lead to their difficult uniform dispersion in the organic matrix, and aggregation will occur, which will affect the mechanical properties and processing fluidity of the polymer composite. SUMMARY

[0005] In order to better improve the dispersion of reinforcing materials and improve the mechanical properties and processing fluidity of polymer composites, the present application provides a polyphenylene sulfide composite material and a preparation method thereof.

[0006] In a first aspect, the polyphenylene sulfide composite material provided by the present application adopts the following technical solution.

[0007] A polyphenylene sulfide composite material, by weight, comprises: 1-5 parts of modified CNT, 2-30 parts of CF, 1-5 parts of a bonding agent, 1-5 parts of an anti-warping agent, 1-5 parts of an auxiliary agent, and 50-80 parts of PPS, wherein the modified CNT is prepared by mixing HBPPS and CNT.

[0008] By employing the above technical solutions, hyperbranched polymers exhibit a highly branched three-dimensional quasi-spherical molecular structure, numerous terminal functional groups, and no chain entanglement, thus displaying unique physicochemical properties such as good solubility and low solution or melt viscosity. Utilizing hyperbranched polyphenylene sulfide (HBPPS) adhered to the CNT surface allows for better dispersion of the reinforcing material within the resin matrix, reducing the porosity of the composite material, improving its overall density and mechanical strength, and ultimately enhancing the polymer's 3D printing performance. CF and modified CNTs work synergistically to provide multi-scale reinforcement, significantly improving flexural modulus and impact toughness; anti-warping agents can suppress deformation caused by thermal stress and improve the dimensional stability of printed parts; the introduction of binders and additives can reduce melt viscosity and improve the processing fluidity of composite materials. The uniformly dispersed modified CNTs form a conductive network, giving the composite material certain thermal conductivity and electromagnetic shielding capabilities. In addition, the flexible branches of HBPPS introduce a microscopic self-healing mechanism, which can repair micro-cracks under thermal cycling and extend the service life of the composite material.

[0009] Optionally, the mass ratio of HBPPS to CNT is 1:10-80.

[0010] Optionally, the mass ratio of HBPPS to CNT is 1:20.

[0011] Optionally, the adhesive includes at least one of ethylene-acrylic acid copolymer (EAA), bisphenol A type epoxy resin, and ethylene-methacrylate copolymer (EMA), and the anti-warping agent includes at least one of nano-barium sulfate, nano-silica, and nano-glass microspheres.

[0012] Optionally, the additive is a coupling agent and a lubricant, wherein the coupling agent is a silane coupling agent, and the lubricant is one or a mixture of two of lithium stearate and silicone.

[0013] By adopting the above technical solution, the mass ratio of HBPPS to CNT can ensure that HBPPS covers the CNT surface in an appropriate amount, and avoid excessive HBPPS leading to increased viscosity or insufficient HBPPS leading to poor dispersion. The choice of binder can enhance the interfacial adhesion between PPS and the reinforcing material, reduce phase separation, and improve interlaminar shear strength; Silane coupling agents promote chemical bonding and enhance corrosion resistance, while lubricants reduce friction, decrease processing torque, and improve extrusion efficiency.

[0014] Secondly, the method for preparing a polyphenylene sulfide composite material provided in this application adopts the following technical solution.

[0015] A method for preparing a polyphenylene sulfide composite material, comprising the following steps.

[0016] S1. Preparation of modified CNTs; S2. Mix PPS, modified CNT, binder, anti-warping agent and additives evenly to obtain the main material; S3. Feed the main material from the main feed port of the extruder and feed the CF from the side feed port of the extruder for extrusion granulation.

[0017] By adopting the above technical solution, side-feeding CF can reduce the possibility of early shear damage to CF, control fiber orientation, reduce the porosity of composite materials, increase modulus, and reduce thermal degradation.

[0018] Optionally, the preparation of modified CNTs by S1 specifically includes the following steps: S11. Mix HBPPS and CNT evenly in an organic solvent to obtain a slurry mixture; S12. The mixture slurry is baked to remove the solvent and obtain a blocky solid. S13. Grind the blocky solid into powder, bake it again, and grind it again to obtain modified CNTs.

[0019] By adopting the above technical solution, the solvent is completely removed by two-step baking and fine powder is produced by two grinding processes to facilitate subsequent mixing and reduce viscosity. Compared with acid modification, it can also reduce CNT damage. Furthermore, the HBPPS branches rearrange during baking to form a network, which improves the fatigue resistance of the composite material.

[0020] Optionally, in step S3, the CF is first sizing before feeding, and the sizing agent accounts for 0.2-0.7% of the weight of the CF.

[0021] Optionally, the sizing agent includes polyamide elastomer, thermoplastic polyurethane elastomer, and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer in a ratio of (1-2):(1-3):(1-5).

[0022] By adopting the above technical solution, it is ensured that the sizing agent covers the CF surface appropriately, avoiding excessive thickness leading to brittleness or excessive thinness leading to weak adhesion, which helps to improve the interfacial shear strength and reduce fiber pull-out failure. The formulation of the sizing agent provides flexibility and reactivity, enhances the compatibility of CF and PPS, and promotes stress transfer.

[0023] Optionally, the preparation of HBPPS required for CNT modification in step S1 specifically includes the following steps: S111. Potassium 2,4-dichlorobenzylthiophenol salt and potassium hydroxide are prepolymerized in hexamethylphosphoramide solvent for 4-6 hours at room temperature to obtain oligomers; S112. Heat the oligomer to 200-220℃ and react for 8-10 hours. During the reaction, introduce 0.5-2wt% of a multifunctional monomer to obtain the reactant. S113. Pour the reactants into hydrochloric acid solution to precipitate, filter and wash to remove monomers and solvents, and obtain crude product; S114. The crude product is purified by dissolving in tetrahydrofuran and / or precipitating in cyclohexane to obtain a product with a high molecular weight. S115. Filter and dry the high molecular weight product to obtain light brown HBPPS powder.

[0024] By adopting the above technical solutions, S111 and S112 can obtain HBPPS products with narrow molecular weight distribution, improve the solubility and low viscosity of HBPPS, so that HBPPS can be more effectively attached to the CNT surface in CNT modification. The introduction of multifunctional monomers to obtain highly branched HBPPS helps to reduce CNT agglomeration and can also improve the thermal stability of composite materials. S113-115 removes as many impurities as possible to improve HBPPS stability.

[0025] In summary, this application includes at least the following beneficial effects: 1. This application utilizes the good thermal conductivity of hyperbranched polyphenylene sulfide-carbon nanotubes (HBPPS-CNT), which helps the composite material to dissipate heat and cool in time during the 3D printing process, so as to fix the material shape. In addition, CNT has the ability to induce the formation of higher-order interphase polymer layers, which can promote mechanical strengthening through the interfacial stress transfer between nanotubes and polymers.

[0026] 2. The use of CF in this application improves the strength and rigidity of the product, and plays a good role in skeleton support during the 3D printing process; 3. By applying a sizing treatment to the CF surface, the bonding strength between PPS and CF is improved, thereby enhancing the interlayer bonding force of the 3D printed parts.

[0027] 4. The addition of binders such as ethylene-acrylic acid copolymer (EAA), bisphenol A type epoxy resin, and ethylene-methacrylate copolymer (EMA) improves the toughness of the material, reduces the crystallinity of PPS during the printing process, reduces the porosity of the 3D printed parts, improves interlayer bonding, and enhances the quality of 3D printing.

[0028] 5. Compared with conventional particle size fillers, nano-sized anti-warping agents can fill PPS resin to the maximum extent, effectively filling the resin space and reducing the warpage of printed parts. Nano-sized anti-warping agents give the material optimal rigidity-toughness balance characteristics and obtain higher interlayer bonding strength. Attached Figure Description

[0029] Figure 1This is a flowchart of a method for preparing polyphenylene sulfide composite materials; Figure 2 This is a flowchart of the preparation of modified CNTs; Figure 3 This is a flowchart of the preparation process for HBPPS. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the accompanying drawings.

[0031] This application discloses a polyphenylene sulfide composite material, which, by weight, comprises: 1-5 parts of modified CNTs, 2-30 parts of CF, 1-5 parts of binder, 1-5 parts of anti-warping agent, 1-5 parts of additives, and 50-80 parts of PPS, wherein the modified CNTs are prepared by mixing HBPPS and CNTs, and the mass ratio of HBPPS to CNTs is 1:10-80.

[0032] CNTs can be multi-walled carbon nanotubes with a purity of ≥98%, an average diameter of 12 nm, an average length of 10 μm, and a moisture content of <1%. CF can have a diameter of 7 μm and a length of 3 mm. CF can also be a mixture of chopped carbon fibers and carbon fiber powder, where the chopped carbon fibers have a diameter of 6-8 μm and a length of 3-6 mm, and the carbon fiber powder has a diameter of 6-8 μm and a length of 50-100 μm.

[0033] The binder includes at least one of ethylene-acrylic acid copolymer (EAA), bisphenol A type epoxy resin, and ethylene-methacrylate copolymer (EMA). The anti-warping agent includes at least one of nano-barium sulfate, nano-silica, and nano-glass microspheres. The additives are coupling agents and lubricants; the coupling agent is a silane coupling agent, and the lubricant is one or a mixture of two of lithium stearate and silicone.

[0034] This application also discloses a method for preparing polyphenylene sulfide composite materials, referring to... Figure 1 Specifically, it includes the following steps.

[0035] S1. Preparation of modified CNTs. (Refer to...) Figure 2 Specifically, it includes the following steps.

[0036] S11. Mix HBPPS and CNT evenly in an organic solvent to obtain a slurry mixture.

[0037] Mixing is performed by stirring followed by sonication to ensure uniform dispersion of CNTs in the mixture slurry. Organic solvents have good solubility for hyperbranched polyphenylene sulfide, such as at least one of pyridine, chloroform, dichloromethane, and tetrahydrofuran.

[0038] S12. The mixture slurry is baked at 80°C for 12 hours to remove the solvent and obtain a blocky solid.

[0039] S13. Grind the blocky solid into powder and bake it again at 80°C for 15 hours and grind it again to obtain modified CNT in the form of black powder.

[0040] Reference Figure 3 The preparation of HBPPS specifically includes the following steps.

[0041] S111. Potassium 2,4-dichlorobenzylthiophenol salt and potassium hydroxide are prepolymerized in hexamethylphosphoramide solvent for 4-6 hours at room temperature to obtain oligomers.

[0042] Potassium 2,4-dichlorothiophenol can be obtained by reacting 2,4-dichlorothiophenol with potassium hydroxide in an aqueous solution at room temperature for 4 hours.

[0043] S112. Heat the oligomer to 200-220℃ and react for 8-10 hours. During the reaction, introduce 0.5-2wt% of a multifunctional monomer, such as 1,3,5-trichlorobenzene, to obtain the reactants.

[0044] S113. Pour the reactants into a 10% hydrochloric acid solution to precipitate, filter and wash to remove monomers and solvents, and obtain crude product.

[0045] S114. The crude product is purified by dissolving in tetrahydrofuran and / or precipitating in cyclohexane to obtain a product with a high molecular weight.

[0046] S115. The high molecular weight product was filtered and dried to obtain light brown HBPPS powder. The relative molecular mass of the obtained HBPPS was 3400 g / mol.

[0047] S2. Place PPS, modified CNT, binder, anti-warping agent, and additives in a high-speed mixer and mix them evenly to obtain the main material.

[0048] Before S3, the CF is sized. The sizing agent accounts for 0.2-0.7% of the weight of the CF. The CF can be a polyamide elastomer, thermoplastic polyurethane elastomer, or ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer with a ratio of (1-2):(1-3):(1-5).

[0049] S3. Feed the main material from the main feed port of the extruder and feed the CF from the side feed port of the extruder. The screw speed is 200-400 rpm / min and the temperature of the processing zone is 260-330℃ for extrusion granulation.

[0050] The following description is based on specific embodiments and comparative examples.

[0051] Example 1:

[0052] A polyphenylene sulfide composite material, by weight, comprises: 2 parts modified CNT, 30 parts CF, 5 parts binder, 5 parts anti-warping agent, 1 part additive, and 50 parts PPS, wherein the modified CNT is prepared by mixing HBPPS and CNT, wherein the mass ratio of HBPPS to CNT is 1:80.

[0053] A method for preparing a polyphenylene sulfide composite material includes the following steps.

[0054] S1. Preparation of modified CNTs.

[0055] The preparation of HBPPS specifically includes the following steps.

[0056] S111. Potassium 2,4-dichlorobenzylthiophenol salt and potassium hydroxide were prepolymerized in hexamethylphosphoramide solvent for 4 hours at room temperature to obtain oligomers.

[0057] Potassium 2,4-dichlorothiophenol can be obtained by reacting 2,4-dichlorothiophenol with potassium hydroxide in an aqueous solution at room temperature for 4 hours.

[0058] S112. The oligomer is heated to 200℃ and reacted for 8 hours. During the reaction, 0.5wt% of 1,3,5-trichlorobenzene is introduced to obtain the reactants.

[0059] S113. Pour the reactants into a 10% hydrochloric acid solution to precipitate, filter and wash to remove monomers and solvents, and obtain crude product.

[0060] S114. The crude product is purified by dissolving in tetrahydrofuran and / or precipitating in cyclohexane to obtain a product with a high molecular weight.

[0061] S115. Filter and dry the high molecular weight product to obtain light brown HBPPS powder.

[0062] S2. Place PPS, modified CNT, binder, anti-warping agent, and additives in a high-speed mixer and mix them evenly to obtain the main material.

[0063] Before S3, the CF is sized. The sizing agent accounts for 0.2% of the weight of the CF. The CF can be a polyamide elastomer, thermoplastic polyurethane elastomer, and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer in a ratio of 1:1:1.

[0064] S3. Feed the main material from the main feed port of the extruder and feed the CF from the side feed port of the extruder. The screw speed is 300 rpm / min and the temperature of the processing zone is 300℃ for extrusion granulation.

[0065] Example 2:

[0066] The difference from Example 1 is that the mass ratio of HBPPS to CNT is 1:40.

[0067] Example 3:

[0068] The difference from Example 1 is that the mass ratio of HBPPS to CNT is 1:20.

[0069] Example 4:

[0070] The difference from Example 1 is that the mass ratio of HBPPS to CNT is 1:10.

[0071] Example 5:

[0072] The difference from Example 3 is that the amount of CF is 20 parts and the amount of modified CNT is 5 parts.

[0073] Example 6:

[0074] The difference from Example 5 is that CF is 10 parts.

[0075] Example 7:

[0076] The difference from Example 3 is that the modified CNT is 1 part.

[0077] Example 8:

[0078] The difference from Example 3 is that the modified CNT is 3 parts.

[0079] Example 9:

[0080] The difference from Example 3 is that the modified CNT is 5 parts and the binder is 3 parts.

[0081] Example 10:

[0082] The difference from Example 9 is that the adhesive is 5 parts and the anti-warping agent is 3 parts.

[0083] Example 11: The difference from Example 1 is that a polyphenylene sulfide composite material, by weight, comprises: 1 part modified CNT, 2 parts CF, 1 part binder, 1 part anti-warping agent, 5 parts additives, and 80 parts PPS.

[0084] S111. Potassium 2,4-dichlorobenzylthiophenol salt and potassium hydroxide were prepolymerized in hexamethylphosphoramide solvent for 6 hours at room temperature to obtain oligomers.

[0085] S112. The oligomer is heated to 220℃ and reacted for 10 hours. During the reaction, 2 wt% of 1,3,5-trichlorobenzene is introduced to obtain the reactant.

[0086] Before S3, the CF is sized. The sizing agent accounts for 0.7% of the weight of the CF. The CF can be a polyamide elastomer, thermoplastic polyurethane elastomer, and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer in a ratio of 2:3:5.

[0087] Comparative Example 1: The difference from Example 1 is that the modified CNTs are replaced with unmodified CNTs.

[0088] Comparative Example 2: The difference from Example 1 is that the CF was not sized before S3.

[0089] Comparative Example 3: The difference from Example 1 is that S111 and S112 are combined into one step and modified to react 2,4-dichlorothiophenol potassium salt with potassium hydroxide in hexamethylphosphoramide solvent for 12 h at a reaction temperature of 180°C.

[0090] Tensile properties were tested according to standard ISO 527, including tensile strength, elongation at break, and tensile modulus.

[0091] Bending performance testing shall be conducted in accordance with standard ISO 178 to test bending strength and bending modulus.

[0092] Impact performance testing shall be conducted in accordance with standard ISO 179 to test notched impact strength.

[0093] Warping is determined by visual inspection and calipers and is divided into three levels: severe, moderate, and none. Severely warped samples have corners that are raised more than or equal to 5mm and cannot be placed flat; moderately warped samples have corners that are raised 1-5mm and are basically flat; samples without warping have corners that are raised less than 1mm and are completely flat.

[0094] Shrinkage deformation is determined visually and with the aid of calipers and is divided into three levels: severe, moderate, and none. Severely deformed samples have an actual size deviation from the mold size greater than or equal to 2% and irregular edges; moderately deformed samples have a deviation of 0.5-2% and basically regular edges; and samples without deformation have a deviation of less than 0.5% and regular edges.

[0095] The specific results are shown in Table 1 below, where tensile strength is in MPa, elongation at break is in %, tensile modulus is in GPa, flexural strength is in MPa, flexural modulus is in GPa, and notched impact strength is in KJ. cm -2 .

[0096] Table 1:

[0097] As can be seen from Examples 1 to 4, when the ratio of HBPPS to CNTs increases from 1:80 to 1:20, the tensile and flexural strengths continuously improve. This is because the increased HBPPS coverage fully coats the CNT surface, eliminating agglomeration and forming a continuous interfacial bonding layer. However, when the ratio is further increased to 1:10, the performance slightly decreases. This is because excessive HBPPS leads to an increase in melt viscosity, causing minor defects during processing. Therefore, in this application, the material performance is optimal when the ratio of HBPPS to CNTs is 1:20.

[0098] Examples 3, 5, 6, 7, and 8 show that the tensile strength of 30 parts of CF is significantly higher than that of 20 parts of CF. A higher CF content provides skeletal support, effectively improving the material's strength and rigidity. In Example 5, the 5 parts of modified CNTs yielded the highest notched impact strength, indicating that the modified CNTs, acting as a nano-reinforcing phase, form a conductive / thermal conductive network, alleviating stress concentration and improving toughness. Furthermore, the CF and modified CNT ratios in Example 3 were well-matched, resulting in sufficient interfacial bonding. In Example 6, the 10 parts of CF content was relatively low, negatively impacting the overall material performance.

[0099] Examples 3, 9, and 10 show that three parts of adhesive or three parts of warpage agent are insufficient to effectively achieve a balance between rigidity and toughness and dimensional stability.

[0100] As can be seen from Example 11, even with only 2 parts of this low amount of CF, increasing the PPS content can still produce a composite material with basic mechanical properties and processing stability.

[0101] As can be seen from Example 1 and Comparative Example 1, the modified CNT significantly improves the tensile modulus and fundamentally improves warpage and shrinkage deformation. This is because HBPPS forms a coating layer on the CNT surface, reducing stress concentration caused by CNT agglomeration. At the same time, the flexible branches of HBPPS optimize the interfacial bonding between CNT and PPS matrix, improving dimensional stability.

[0102] As can be seen from Example 1 and Comparative Example 2, sizing treatment improves tensile and flexural strength and eliminates warping. This is because the sizing agent forms a transition layer on the CF surface, which enhances the interfacial adhesion between CF and the PPS matrix and reduces fiber pull-out failure.

[0103] As can be seen from Example 1 and Comparative Example 3, the single-step reaction at 180°C for 12 hours, without the introduction of a multifunctional monomer, resulted in insufficient branching of HBPPS and a wide molecular weight distribution, making it unable to effectively encapsulate CNTs. In contrast, the stepwise process in Example 1 allowed the HBPPS branches to rearrange fully, forming a uniform coating layer. Therefore, the mechanical properties and dimensional stability were significantly better than those in Comparative Example 3.

[0104] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A polyphenylene sulfide composite material, characterized in that: By weight, it comprises: 1-5 parts of modified CNT, 2-30 parts of CF, 1-5 parts of binder, 1-5 parts of anti-warping agent, 1-5 parts of additives, and 50-80 parts of PPS, wherein the modified CNT is prepared by mixing HBPPS and CNT.

2. The polyphenylene sulfide composite material according to claim 1, characterized in that: The mass ratio of HBPPS to CNT is 1:10-80.

3. The polyphenylene sulfide composite material according to claim 2, characterized in that: The mass ratio of HBPPS to CNT is 1:

20.

4. The polyphenylene sulfide composite material according to claim 1, characterized in that: The adhesive includes at least one of ethylene-acrylic acid copolymer (EAA), bisphenol A type epoxy resin, and ethylene-methacrylate copolymer (EMA), and the anti-warping agent includes at least one of nano-barium sulfate, nano-silica, and nano-glass microspheres.

5. The polyphenylene sulfide composite material according to claim 1, characterized in that: The additives are coupling agents and lubricants, wherein the coupling agent is a silane coupling agent, and the lubricant is one or a mixture of two of lithium stearate and silicone.

6. A method for preparing a polyphenylene sulfide composite material, comprising preparing a polyphenylene sulfide composite material according to any one of claims 1-5, characterized in that: Specifically, the steps include the following: S1. Preparation of modified CNTs; S2. Mix PPS, modified CNT, binder, anti-warping agent and additives evenly to obtain the main material; S3. Feed the main material from the main feed port of the extruder and feed the CF from the side feed port of the extruder for extrusion granulation.

7. The method for preparing a polyphenylene sulfide composite material according to claim 6, characterized in that: The preparation of modified CNTs using S1 specifically includes the following steps: S11. Mix HBPPS and CNT evenly in an organic solvent to obtain a slurry mixture; S12. The mixture slurry is baked to remove the solvent and obtain a blocky solid. S13. Grind the blocky solid into powder, bake it again, and grind it again to obtain modified CNTs.

8. The method for preparing a polyphenylene sulfide composite material according to claim 6, characterized in that: Before feeding the CF in S3, a sizing treatment is performed, and the sizing agent accounts for 0.2-0.7% of the weight of the CF.

9. The method for preparing a polyphenylene sulfide composite material according to claim 8, characterized in that: The sizing agent comprises polyamide elastomer, thermoplastic polyurethane elastomer, and ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA) terpolymer in a ratio of (1-2):(1-3):(1-5).

10. A method for preparing a polyphenylene sulfide composite material according to claim 6, characterized in that: The preparation of HBPPS required for CNT modification in S1 specifically includes the following steps: S111. Potassium 2,4-dichlorobenzylthiophenol salt and potassium hydroxide are prepolymerized in hexamethylphosphoramide solvent for 4-6 hours at room temperature to obtain oligomers; S112. Heat the oligomer to 200-220℃ and react for 8-10 hours. During the reaction, introduce 0.5-2wt% of a multifunctional monomer to obtain the reactant. S113. Pour the reactants into hydrochloric acid solution to precipitate, filter and wash to remove monomers and solvents, and obtain crude product; S114. The crude product is purified by dissolving in tetrahydrofuran and / or precipitating in cyclohexane to obtain a product with a high molecular weight. S115. Filter and dry the high molecular weight product to obtain light brown HBPPS powder.

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