High-temperature-resistant creep-resistant polyphenylene sulfide composite material and preparation method thereof

Abstract

The invention relates to the technical field of polyphenylene sulfide materials, and discloses a high-temperature-resistant creep-resistant polyphenylene sulfide composite material and a preparation method thereof, the composite material comprises the following raw materials by mass: 60-70 parts of polyphenylene sulfide, 30-40 parts of composite glass fiber, 2-4 parts of a flexibilizer, 0.2-0.6 part of an antioxidant, and 0.5-1 part of a processing aid. The polyphenylene sulfide composite material prepared by taking polyphenylene sulfide as a matrix and adding the composite glass fiber, the flexibilizer, the antioxidant and the processing aid has relatively high high temperature resistance, creep resistance and mechanical strength, and the compatibility of the composite glass fiber and polyphenylene sulfide is relatively good, so that the high temperature resistance, creep resistance and mechanical strength of the composite glass fiber are remarkably enhanced.

Description

Technical Field

[0001] This invention relates to the field of polyphenylene sulfide materials technology, specifically to a high-temperature resistant and creep-resistant polyphenylene sulfide composite material and its preparation method. Background Technology

[0002] Polyphenylene sulfide (PPS) is a semi-crystalline, novel, high-performance thermoplastic resin composed of alternating benzene rings and sulfur atoms. It possesses properties such as high mechanical strength, high temperature resistance, chemical resistance, flame retardancy, good thermal stability, and excellent electrical properties, and is widely used in electronics, automotive, aerospace, environmental protection, chemical, and 5G communication fields. However, PPS is prone to creep deformation under prolonged exposure to high temperatures and continuous stress, which can affect dimensional accuracy and component lifespan.

[0003] Polyphenylene sulfide (PPS) composites prepared by adding fiber fillers, toughening agents, antioxidants, and processing aids as the matrix exhibit high high-temperature resistance, mechanical strength, and creep resistance. However, the presence of numerous benzene rings in the PPS backbone increases the rigidity of the material, resulting in brittleness and poor toughness, which greatly limits the application of PPS. Furthermore, the compatibility between fiber fillers and PPS is poor, and single fiber fillers have limited effect on improving the performance of PPS composites, thus restricting the scope of application of PPS composites. Summary of the Invention

[0004] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a high-temperature resistant and creep-resistant polyphenylene sulfide composite material and its preparation method, which solves the problems of high brittleness, poor toughness, and poor compatibility between fiber fillers and polyphenylene sulfide.

[0005] Technical solution To achieve the above objectives, the present invention provides the following technical solution: A high-temperature resistant and creep-resistant polyphenylene sulfide composite material comprises the following raw materials in parts by weight: 60-70 parts polyphenylene sulfide, 30-40 parts composite glass fiber, 2-4 parts toughening agent, 0.2-0.6 parts antioxidant, and 0.5-1 parts processing aid; The composite glass fiber is obtained by mixing and reacting modified glass fiber, silane coupling agent, and glycidyl methacrylate. The modified glass fiber is obtained by synthesizing porous carbon on the surface of glass fiber, and then reacting it with sulfonated lignin and silicon carbide whiskers.

[0006] Furthermore, the composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder and citric acid are added to ethanol and stirred evenly. Hydrochloric acid is added and stirred until the reaction is complete. After filtration, washing and drying, the mixture is placed in a tube furnace and activated with potassium hydroxide solution. Nitrogen gas is then introduced and the mixture is carbonized at high temperature. After cooling to room temperature, the mixture is removed, washed and dried to obtain glass fiber loaded with porous carbon. A2. Sulfonated lignin and glass fiber loaded with porous carbon were added to deionized water and stirred evenly. After adjusting the pH with hydrochloric acid, the mixture was stirred and reacted. Silicon carbide whiskers were added and the mixture was stirred and reacted again. The mixture was then cooled to room temperature, filtered, washed, and dried to obtain modified glass fiber. A3. Add the silane coupling agent to ethanol and deionized water, stir evenly, add the modified glass fiber, stir to react, cool to room temperature, filter, wash and dry to obtain silanized modified glass fiber. A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 75-85℃ for 2-3 hours, cool to room temperature, filter, wash and dry to obtain composite glass fiber.

[0007] Furthermore, in the A1 reaction process described above, citric acid acts as a linker, which can chemically bond with the hydroxyl groups on the surface of the glass fiber and the oxygen-containing functional groups in the rice husk powder, so that the rice husk powder is coated on the surface of the glass fiber. Potassium hydroxide acts as an activator, and after high-temperature carbonization, the rice husk powder decomposes to form a dense carbon layer. The activator potassium hydroxide molecules decompose and form pores on the surface of the dense carbon layer, thereby achieving the synthesis of porous carbon on the surface of the glass fiber and obtaining glass fiber loaded with porous carbon.

[0008] Furthermore, during the A2 reaction described above, the porous carbon on the surface of the glass fiber loaded with porous carbon carries a large number of hydroxyl groups, which can chemically bond with the hydroxyl and sulfonic acid groups of sulfonated lignin, allowing sulfonated lignin to be grafted onto the surface of the glass fiber loaded with porous carbon. In addition, sulfonated lignin can also chemically bond with the hydroxyl groups contained on the surface of silicon carbide whiskers, allowing sulfonated lignin and silicon carbide whiskers to form a network structure through chemical cross-linking, which coats the surface of the glass fiber loaded with porous carbon, thus obtaining modified glass fiber.

[0009] Furthermore, during the A3 reaction process described above, the silanol groups generated by the hydrolysis of the silane coupling agent can chemically bond with the oxygen-containing functional groups on the surface of the modified glass fiber, thereby grafting the silane coupling agent onto the modified glass fiber and obtaining silanized modified glass fiber.

[0010] Furthermore, in the A4 reaction process described above, toluene is used as the reaction solvent and azobisisobutyronitrile (AIBN) is used as the initiator, which enables the double bonds on the surface of the silanized modified glass fiber to undergo a copolymerization reaction with glycidyl methacrylate, thereby forming a glycidyl methacrylate copolymer on the surface of the modified glass fiber and obtaining composite glass fiber.

[0011] Further, in step A1, the mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid and potassium hydroxide solution is (2-3):(1-1.5):(0.5-0.7):(100-120):(1-1.2):(1.5-1.8).

[0012] Further, in step A2, the mass ratio of sulfonated lignin, glass fiber loaded with porous carbon, deionized water and silicon carbide whiskers is (1-1.2):(2.3-2.5):(80-100):(1.2-1.4).

[0013] Further, in step A3, the mass ratio of the silane coupling agent, ethanol, deionized water and modified glass fiber is (0.8-1):(80-90):(30-35):(3-3.5).

[0014] Further, in step A4, the mass ratio of the silanized modified glass fiber, glycidyl methacrylate, toluene, and azobisisobutyronitrile is (2-2.5):(1-1.2):(60-80):(0.2-0.5).

[0015] Furthermore, the polyphenylene sulfide has a weight-average molecular weight of 3-5 × 10⁻⁶. 5 .

[0016] Furthermore, the toughening agent is selected from any one of butyl rubber, ethylene propylene rubber, and styrene-butadiene rubber.

[0017] Furthermore, the antioxidant is selected from any one of antioxidant 1010, antioxidant 1098, and antioxidant 168.

[0018] Furthermore, the processing aid is selected from pentaerythritol stearate or silicone powder.

[0019] Furthermore, a method for preparing a high-temperature resistant and creep-resistant polyphenylene sulfide composite material includes the following steps: S1. After pre-drying the polyphenylene sulfide, mix it with toughening agent, antioxidant and processing aid, and stir to obtain a mixture; S2. The mixture is added from the feed hopper of the extruder, and the composite glass fiber is added from the fiber inlet. After melt extrusion and granulation, a polyphenylene sulfide composite material is obtained.

[0020] Furthermore, in step S1, the pre-drying temperature is 100-120℃, and the pre-drying time is 2-4h.

[0021] Furthermore, in step S1, the stirring rate is 300-400 r / min, and the stirring time is 30-40 min.

[0022] Furthermore, in step S2, the extruder is a twin-screw extruder with zone 1 temperature of 260-290℃, zone 2 temperature of 290-300℃, zone 3 temperature of 290-300℃, zone 4 temperature of 290-300℃, zone 5 temperature of 290-300℃, zone 6 temperature of 290-300℃, and die head temperature of 290-300℃; the screw speed is 150-250 r / min.

[0023] Beneficial technical effects (1) In the technical solution of the present invention, porous carbon is synthesized on the surface of glass fiber. On the one hand, porous carbon has abundant micropores and mesopores, which allows molten polyphenylene sulfide to penetrate into these pores. Through the riveting effect, the glass fiber and polyphenylene sulfide form a mechanical interlock, which improves the bonding force between the glass fiber and the polyphenylene sulfide composite material and avoids the glass fiber from easily agglomerating, migrating and precipitating in the polyphenylene sulfide composite material, thus affecting the high temperature resistance, creep resistance and mechanical properties of the polyphenylene sulfide composite material. On the other hand, the porous carbon contains a nano-hybrid structure, which can absorb and weaken the external force, thereby improving the mechanical properties of the polyphenylene sulfide composite material.

[0024] (2) In the technical solution of this invention, sulfonated lignin and silicon carbide whiskers form a network structure through chemical cross-linking, which coats the surface of glass fiber loaded with porous carbon. On the one hand, silicon carbide whiskers maintain extremely high rigidity at high temperatures, preventing the polyphenylene sulfide composite material from creeping and deforming under continuous stress in a high-temperature environment for a long time. Moreover, the cross-linked network structure formed by sulfonated lignin and silicon carbide whiskers can absorb and weaken the stress generated by external forces, thereby improving the mechanical strength of the polyphenylene sulfide composite material. On the other hand, molten polyphenylene sulfide can also penetrate into the cross-linked network structure formed by sulfonated lignin and silicon carbide whiskers, further improving the bonding force between glass fiber and polyphenylene sulfide through the riveting effect, thereby improving the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material.

[0025] (3) In the technical solution of this invention, a silane coupling agent is grafted onto the modified glass fiber to introduce reactive double bonds on the surface of the modified glass fiber, which is beneficial for grafting glycidyl methacrylate onto the surface of the modified glass fiber and improving the toughness of the polyphenylene sulfide composite material. The silanized modified glass fiber undergoes a copolymerization reaction with glycidyl methacrylate to form a glycidyl methacrylate copolymer on the surface of the modified glass fiber, thus obtaining a composite glass fiber. On the one hand, glycidyl methacrylate can continuously penetrate the network formed by the molecular chain segments of polyphenylene sulfide to form a semi-interpenetrating network polymer, thereby effectively improving the toughness of the polyphenylene sulfide composite material and facilitating the uniform dispersion of the composite glass fiber in the polyphenylene sulfide composite material, thereby improving the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material. On the other hand, the whiskers in the composite glass fiber can effectively fill the resin matrix and form a fiber-whisker multi-scale hybrid reinforcement network with the glass fiber, which greatly restricts molecular chain slippage and improves the creep resistance of the polyphenylene sulfide composite material.

[0026] (4) In the technical solution of the present invention, polyphenylene sulfide is used as the matrix, and composite glass fiber, toughening agent, antioxidant and processing aid are added. The prepared polyphenylene sulfide composite material has high high temperature creep resistance and mechanical strength. Moreover, the composite glass fiber and polyphenylene sulfide have good compatibility, which significantly enhances the high temperature creep resistance and mechanical strength of the composite glass fiber. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The raw materials used in the embodiments of this invention are shown below, and all reagents used are analytical grade.

[0029] The weight-average molecular weight of polyphenylene sulfide is 4 × 10⁻⁶. 5 .

[0030] The toughening agent is butyl rubber, the antioxidant is antioxidant 1010, and the processing aid is pentaerythritol stearate.

[0031] The glass fiber has a diameter of 80 nm and a length of 10 µm.

[0032] The silicon carbide whiskers have a diameter of 50 nm and a length of 1.5 µm.

[0033] The sulfonated lignin, model MDH, was purchased from Hubei Maidehao Biotechnology Co., Ltd.

[0034] The silane coupling agent is KH570 (γ-methacryloyloxypropyltrimethoxysilane).

[0035] Example 1 A high-temperature resistant and creep-resistant polyphenylene sulfide composite material comprises the following raw materials in parts by weight: 60 parts polyphenylene sulfide, 30 parts composite glass fiber, 2-4 parts butyl rubber, 0.2 parts antioxidant 1010, and 0.5 parts pentaerythritol stearate; A method for preparing a high-temperature resistant and creep-resistant polyphenylene sulfide composite material includes the following steps: S1. After pre-drying polyphenylene sulfide, it is mixed with butyl rubber, antioxidant 1010 and pentaerythritol stearate, and stirred to obtain a mixture; the pre-drying temperature is 100-120℃, the pre-drying time is 2h; the stirring rate is 300r / min, and the stirring time is 30min. S2. The mixture is added from the feed hopper of the extruder, and the composite glass fiber is added from the fiber inlet. After melt extrusion and granulation, a polyphenylene sulfide composite material is obtained. The extruder is a twin-screw extruder with zone 1 temperature of 260℃, zone 2 temperature of 290℃, zone 3 temperature of 290℃, zone 4 temperature of 290℃, zone 5 temperature of 290℃, zone 6 temperature of 290℃, and die head temperature of 290℃. The screw speed is 150 r / min.

[0036] Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. It was then placed in a tube furnace, activated with 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, washed with deionized water until the washing solution was neutral, and dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 2:1:0.5:100:1:1.5. A2. Sulfonated lignin and glass fibers loaded with porous carbon were added to deionized water and stirred until homogeneous. Hydrochloric acid (36% by mass) was added to adjust the pH to 4.5. The mixture was stirred at 55°C for 1.5 hours. Silicon carbide whiskers were added, and the reaction was continued for another 1.5 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain modified glass fibers. The mass ratio of sulfonated lignin, glass fibers loaded with porous carbon, deionized water, and silicon carbide whiskers was 1:2.3:80:1.2. A3. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 0.8:80:30:3; A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 75℃ for 2h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, glycidyl methacrylate, toluene and azobisisobutyronitrile is 2:1:60:0.2.

[0037] Example 2 A high-temperature resistant and creep-resistant polyphenylene sulfide composite material comprises the following raw materials in parts by weight: 65 parts polyphenylene sulfide, 35 parts composite glass fiber, 3 parts butyl rubber, 0.4 parts antioxidant 1010, and 0.8 parts pentaerythritol stearate; A method for preparing a high-temperature resistant and creep-resistant polyphenylene sulfide composite material includes the following steps: S1. After pre-drying polyphenylene sulfide, it is mixed with butyl rubber, antioxidant 1010 and pentaerythritol stearate, and stirred to obtain a mixture; the pre-drying temperature is 110℃, the pre-drying time is 3h; the stirring rate is 350r / min, and the stirring time is 35min. S2. The mixture is added from the feed hopper of the extruder, and the composite glass fiber is added from the fiber inlet. After melt extrusion and granulation, a polyphenylene sulfide composite material is obtained. The extruder is a twin-screw extruder with zone 1 temperature of 270℃, zone 2 temperature of 295℃, zone 3 temperature of 295℃, zone 4 temperature of 295℃, zone 5 temperature of 295℃, zone 6 temperature of 295℃, and die head temperature of 295℃. The screw speed is 200r / min.

[0038] Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. The mixture was then placed in a tube furnace, activated with 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, and washed with deionized water until the washing solution was neutral. It was then dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 2.5:1.3:0.6:110:1.1:1.6. A2. Sulfonated lignin and glass fibers loaded with porous carbon were added to deionized water and stirred evenly. The pH was adjusted to 4.5 with 36% hydrochloric acid by mass. The mixture was stirred at 55°C for 1.5 hours. Silicon carbide whiskers were added, and the reaction was continued for another 1.5 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain modified glass fibers. The mass ratio of sulfonated lignin, glass fibers loaded with porous carbon, deionized water, and silicon carbide whiskers was 1.1:2.3:90:1.3. A3. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 0.9:85:33:3.2. A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 80℃ for 2.5h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, glycidyl methacrylate, toluene and azobisisobutyronitrile is 2.3:1.1:70:0.3.

[0039] Example 3 A high-temperature resistant and creep-resistant polyphenylene sulfide composite material comprises the following raw materials in parts by weight: 70 parts polyphenylene sulfide, 40 parts composite glass fiber, 4 parts butyl rubber, 0.6 parts antioxidant 1010, and 1 part pentaerythritol stearate; A method for preparing a high-temperature resistant and creep-resistant polyphenylene sulfide composite material includes the following steps: S1. After pre-drying polyphenylene sulfide, it is mixed with butyl rubber, antioxidant 1010 and pentaerythritol stearate, and stirred to obtain a mixture; the pre-drying temperature is 120℃, the pre-drying time is 4h; the stirring rate is 400r / min, and the stirring time is 40min. S2. The mixture is added from the feed hopper of the extruder, and the composite glass fiber is added from the fiber inlet. After melt extrusion and granulation, a polyphenylene sulfide composite material is obtained. The extruder is a twin-screw extruder with zone 1 temperature of 290℃, zone 2 temperature of 300℃, zone 3 temperature of 300℃, zone 4 temperature of 300℃, zone 5 temperature of 300℃, zone 6 temperature of 300℃, and die head temperature of 300℃. The screw speed is 250r / min.

[0040] Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. The mixture was then placed in a tube furnace, activated with a 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, and washed with deionized water until the washing solution was neutral. It was then dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 3:1.5:0.7:120:1.2:1.8. A2. Sulfonated lignin and glass fibers loaded with porous carbon were added to deionized water and stirred evenly. The pH was adjusted to 4.5 with 36% hydrochloric acid by mass. The mixture was stirred at 55°C for 1.5 hours. Silicon carbide whiskers were added, and the reaction was continued for another 1.5 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain modified glass fibers. The mass ratio of sulfonated lignin, glass fibers loaded with porous carbon, deionized water, and silicon carbide whiskers was 1.2:2.5:100:1.4. A3. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 1:90:35:3.5. A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 85℃ for 3h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, glycidyl methacrylate, toluene and azobisisobutyronitrile is 2.5:1.2:80:0.5.

[0041] Comparative Example 1 The only difference between this comparative example and Example 3 is the preparation of the composite glass fiber, as detailed below: Composite glass fiber is specifically prepared by the following steps: A1. Sulfonated lignin and glass fiber were added to deionized water and stirred evenly. Hydrochloric acid with a mass fraction of 36% was added to adjust the pH to 4.5. The mixture was stirred at 55℃ for 1.5 hours. Silicon carbide whiskers were added, and the reaction was continued to be stirred for 1.5 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in an oven at 70℃ for 10 minutes to obtain modified glass fiber. The mass ratio of sulfonated lignin, glass fiber, deionized water, and silicon carbide whiskers was 1.2:2.5:100:1.4. A2. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 1:90:35:3.5. A3. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 85℃ for 3h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, glycidyl methacrylate, toluene and azobisisobutyronitrile is 2.5:1.2:80:0.5.

[0042] Comparative Example 2 The only difference between this comparative example and Example 3 is the preparation of the composite glass fiber, as detailed below: Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. The mixture was then placed in a tube furnace, activated with a 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, and washed with deionized water until the washing solution was neutral. It was then dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 3:1.5:0.7:120:1.2:1.8. A2. Add porous carbon-loaded glass fibers to deionized water, stir evenly, add 36% hydrochloric acid to adjust the pH to 4.5, stir at 55℃ for 1.5h, add silicon carbide whiskers, continue stirring for 1.5h, cool to room temperature, filter, wash three times with deionized water, and dry in a 70℃ oven for 10min to obtain modified glass fibers; the mass ratio of porous carbon-loaded glass fibers, deionized water and silicon carbide whiskers is 2.5:100:2.6. A3. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 1:90:35:3.5. A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 85℃ for 3h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, glycidyl methacrylate, toluene and azobisisobutyronitrile is 2.5:1.2:80:0.5.

[0043] Comparative Example 3 The only difference between this comparative example and Example 3 is the preparation of the composite glass fiber, as detailed below: Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. The mixture was then placed in a tube furnace, activated with a 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, and washed with deionized water until the washing solution was neutral. It was then dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 3:1.5:0.7:120:1.2:1.8. A2. Sulfonated lignin and glass fibers loaded with porous carbon were added to deionized water and stirred evenly. The pH was adjusted to 4.5 by adding 36% hydrochloric acid. The mixture was stirred at 55°C for 1.5 hours, cooled to room temperature, filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 minutes to obtain modified glass fibers. The mass ratio of sulfonated lignin, glass fibers loaded with porous carbon, and deionized water was 2.6:2.5:100. A3. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 1:90:35:3.5. A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 85℃ for 3h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, glycidyl methacrylate, toluene and azobisisobutyronitrile is 2.5:1.2:80:0.5.

[0044] Comparative Example 4 The only difference between this comparative example and Example 3 is the preparation of the composite glass fiber, as detailed below: Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. The mixture was then placed in a tube furnace, activated with a 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, and washed with deionized water until the washing solution was neutral. It was then dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 3:1.5:0.7:120:1.2:1.8. A2. Sulfonated lignin and glass fibers loaded with porous carbon were added to deionized water and stirred evenly. The pH was adjusted to 4.5 with 36% hydrochloric acid by mass. The mixture was stirred at 55°C for 1.5 hours. Silicon carbide whiskers were added, and the reaction was continued for another 1.5 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain modified glass fibers. The mass ratio of sulfonated lignin, glass fibers loaded with porous carbon, deionized water, and silicon carbide whiskers was 1.2:2.5:100:1.4. A3. Modified glass fiber and glycidyl methacrylate were added to toluene and stirred until homogeneous. Azobisisobutyronitrile was then added and stirred at 85°C for 3 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in an oven at 70°C for 10 minutes to obtain composite glass fiber. The mass ratio of modified glass fiber, glycidyl methacrylate, toluene, and azobisisobutyronitrile was 2.5:1.2:80:0.5.

[0045] Comparative Example 5 The only difference between this comparative example and Example 3 is the preparation of the composite glass fiber, as detailed below: Composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder, and citric acid were added to ethanol and stirred until homogeneous. 36% hydrochloric acid was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in a 70°C oven for 10 minutes. The mixture was then placed in a tube furnace, activated with a 25% potassium hydroxide solution, and carbonized at 850°C for 4 hours after nitrogen gas was introduced. The mixture was cooled to room temperature, removed, and washed with deionized water until the washing solution was neutral. It was then dried in a 70°C oven for 10 minutes to obtain glass fiber loaded with porous carbon. The mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid, and potassium hydroxide solution was 3:1.5:0.7:120:1.2:1.8. A2. Sulfonated lignin and glass fibers loaded with porous carbon were added to deionized water and stirred evenly. The pH was adjusted to 4.5 with 36% hydrochloric acid by mass. The mixture was stirred at 55°C for 1.5 hours. Silicon carbide whiskers were added, and the reaction was continued for another 1.5 hours. The mixture was cooled to room temperature, filtered, washed three times with deionized water, and dried in a 70°C oven for 10 minutes to obtain modified glass fibers. The mass ratio of sulfonated lignin, glass fibers loaded with porous carbon, deionized water, and silicon carbide whiskers was 1.2:2.5:100:1.4. A3. Add KH570 to ethanol and deionized water, stir well, add modified glass fiber, stir and react at 70℃ for 30 min, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain silanized modified glass fiber; the mass ratio of KH570, ethanol, deionized water and modified glass fiber is 1:90:35:3.5. A4. Add silanized modified glass fiber to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 85℃ for 3h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain composite glass fiber; the mass ratio of silanized modified glass fiber, toluene and azobisisobutyronitrile is 3.7:80:0.5.

[0046] The performance of the polyphenylene sulfide composite materials prepared in Examples 1-3 and Comparative Examples 1-5 was then tested. The specific test methods are as follows: The heat distortion temperature was tested according to ISO 75-1:2020; the tensile strength test was performed according to ISO 527-1:2019; and the flexural modulus test was performed according to ISO 178:2019.

[0047] The notched impact strength test of the cantilever beam was performed in accordance with the standard GB / T1843-2008.

[0048] The specific results of the stability test are shown in Table 1.

[0049] Table 1 Performance testing of polyphenylene sulfide composite materials prepared in Examples 1-3 and Comparative Examples 1-5

[0050] As shown in Table 1, the polyphenylene sulfide composite materials of all embodiments outperform the reference material, and the prepared polyphenylene sulfide composite materials exhibit high high-temperature creep resistance and mechanical strength. This fully demonstrates the performance of the polyphenylene sulfide composite materials provided by this invention.

[0051] Comparative Example 1 showed that when glass fibers loaded with porous carbon were replaced with composite glass fibers, the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material decreased. This demonstrates that the synthesis of porous carbon on the surface of glass fibers, with its abundant micropores and mesopores, allows molten polyphenylene sulfide to penetrate into these pores. Through the riveting effect, the glass fibers and polyphenylene sulfide form a mechanical interlock, improving the bonding force between the glass fibers and the polyphenylene sulfide composite material. This prevents the glass fibers from easily agglomerating, migrating, and precipitating in the polyphenylene sulfide composite material, thus affecting its high-temperature creep resistance and mechanical properties.

[0052] Comparative Example 2, in which sulfonated lignin was replaced by silicon carbide whiskers, and Comparative Example 3, in which silicon carbide whiskers were replaced by sulfonated lignin, were added to polyphenylene sulfide composite materials. The high-temperature creep resistance and mechanical properties of these composites decreased, demonstrating that the network structure formed by the chemical cross-linking of sulfonated lignin and silicon carbide whiskers can absorb and weaken the stress generated by external forces, improving the mechanical strength of the polyphenylene sulfide composite material. Furthermore, the silicon carbide whiskers maintain extremely high rigidity at high temperatures, preventing creep deformation of the polyphenylene sulfide composite material under continuous stress in a high-temperature environment. In addition, molten polyphenylene sulfide can also penetrate into the cross-linked network structure formed by sulfonated lignin and silicon carbide whiskers, further enhancing the bonding force between the glass fiber and polyphenylene sulfide through a riveting effect, thus improving the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material.

[0053] Comparative Example 4 showed that when the silanized modified glass fiber was replaced with a composite glass fiber prepared by adding modified glass fiber to the polyphenylene sulfide composite material, its high-temperature creep resistance and mechanical properties decreased. This demonstrates that grafting the silane coupling agent onto the modified glass fiber introduces reactive double bonds on the surface of the modified glass fiber, which is beneficial for grafting glycidyl methacrylate onto the surface of the modified glass fiber and improving the toughness of the polyphenylene sulfide composite material. Glycidyl methacrylate can continuously penetrate the network formed by the molecular chain segments of polyphenylene sulfide, forming a semi-interpenetrating network polymer, thereby effectively improving the toughness of the polyphenylene sulfide composite material and facilitating the uniform dispersion of the composite glass fiber in the polyphenylene sulfide composite material, thus improving the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material.

[0054] Comparative Example 5 showed that when glycidyl methacrylate was replaced with silanized modified glass fiber to prepare composite glass fiber, the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material decreased. This demonstrates that glycidyl methacrylate can continuously penetrate the network formed by the molecular chain segments of polyphenylene sulfide, forming a semi-interpenetrating network polymer. This effectively improves the toughness of the polyphenylene sulfide composite material and facilitates the uniform dispersion of composite glass fiber in the polyphenylene sulfide composite material, thereby improving the high-temperature creep resistance and mechanical properties of the polyphenylene sulfide composite material.

[0055] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0057] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. A high-temperature resistant and creep-resistant polyphenylene sulfide composite material, characterized in that, The raw materials include the following parts by weight: 60-70 parts polyphenylene sulfide, 30-40 parts composite glass fiber, 2-4 parts toughening agent, 0.2-0.6 parts antioxidant, and 0.5-1 parts processing aid; The composite glass fiber is obtained by mixing and reacting modified glass fiber, silane coupling agent, and glycidyl methacrylate. The modified glass fiber is obtained by synthesizing porous carbon on the surface of glass fiber, and then reacting it with sulfonated lignin and silicon carbide whiskers.

2. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 1, characterized in that, The composite glass fiber is specifically prepared by the following steps: A1. Glass fiber, rice husk powder and citric acid are added to ethanol and stirred evenly. Hydrochloric acid is added and stirred until the reaction is complete. After filtration, washing and drying, the mixture is placed in a tube furnace and activated with potassium hydroxide solution. Nitrogen gas is then introduced and the mixture is carbonized at high temperature. After cooling to room temperature, the mixture is removed, washed and dried to obtain glass fiber loaded with porous carbon. A2. Sulfonated lignin and glass fiber loaded with porous carbon were added to deionized water and stirred evenly. After adjusting the pH with hydrochloric acid, the mixture was stirred and reacted. Silicon carbide whiskers were added and the mixture was stirred and reacted again. The mixture was then cooled to room temperature, filtered, washed, and dried to obtain modified glass fiber. A3. Add the silane coupling agent to ethanol and deionized water, stir evenly, add the modified glass fiber, stir to react, cool to room temperature, filter, wash and dry to obtain silanized modified glass fiber. A4. Add silanized modified glass fiber and glycidyl methacrylate to toluene, stir evenly, add azobisisobutyronitrile, stir and react at 75-85℃ for 2-3 hours, cool to room temperature, filter, wash and dry to obtain composite glass fiber.

3. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 2, characterized in that, In step A1, the mass ratio of glass fiber, rice husk powder, citric acid, ethanol, hydrochloric acid and potassium hydroxide solution is (2-3):(1-1.5):(0.5-0.7):(100-120):(1-1.2):(1.5-1.8).

4. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 2, characterized in that, In step A2, the mass ratio of sulfonated lignin, glass fiber loaded with porous carbon, deionized water and silicon carbide whiskers is (1-1.2):(2.3-2.5):(80-100):(1.2-1.4).

5. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 2, characterized in that, In step A3, the mass ratio of the silane coupling agent, ethanol, deionized water and modified glass fiber is (0.8-1):(80-90):(30-35):(3-3.5).

6. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 2, characterized in that, In step A4, the mass ratio of the silanized modified glass fiber, glycidyl methacrylate, toluene, and azobisisobutyronitrile is (2-2.5):(1-1.2):(60-80):(0.2-0.5).

7. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 1, characterized in that, The polyphenylene sulfide has a weight-average molecular weight of 3-5 × 10⁻⁵. 5 .

8. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 1, characterized in that, The toughening agent is selected from any one of butyl rubber, ethylene propylene rubber, and styrene-butadiene rubber.

9. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 1, characterized in that, The antioxidant is selected from any one of antioxidant 1010, antioxidant 1098 and antioxidant 168; The processing aid is selected from pentaerythritol stearate or silicone powder.

10. The high-temperature resistant and creep-resistant polyphenylene sulfide composite material according to claim 1, characterized in that, The preparation method of the polyphenylene sulfide composite material includes the following steps: S1. After pre-drying the polyphenylene sulfide, mix it with toughening agent, antioxidant and processing aid, and stir to obtain a mixture; S2. The mixture is added from the feed hopper of the extruder, and the composite glass fiber is added from the fiber inlet. After melt extrusion and granulation, a polyphenylene sulfide composite material is obtained.

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