Wear-resistant anti-fatigue polycarbonate composite material and preparation method thereof

Abstract

The invention relates to the technical field of polycarbonate-based composite materials, and particularly discloses a wear-resistant and anti-fatigue polycarbonate composite material and a preparation method thereof.According to the wear-resistant and anti-fatigue polycarbonate composite material and the preparation method thereof, an ABA type triblock copolymer good in compatibility with the polycarbonate composite material is synthesized, and the toughness, impact strength and fatigue resistance of the composite material are improved; titanium dioxide is used for coating the carbon fibers, so that the strength, rigidity and weather resistance of the composite material are improved; polytetrafluoroethylene-polycarbonate particles are introduced as a lubricating auxiliary agent, so that the friction coefficient and the wear rate are remarkably reduced, and the wear resistance of the composite material is improved.

Description

Technical Field

[0001] This invention relates to the field of polycarbonate-based composite materials technology, specifically to a wear-resistant and fatigue-resistant polycarbonate composite material and its preparation method. Background Technology

[0002] Polycarbonate (PC) is a thermoplastic engineering plastic containing carbonate bonds in its molecular chain. It possesses excellent heat resistance, impact toughness, and transparency, and is widely used in building materials, automotive interiors, electronic product casings, and medical devices. However, pure PC also has some inherent drawbacks, such as poor abrasion resistance, low surface hardness, and susceptibility to scratches; insufficient resistance to ultraviolet aging, leading to molecular chain degradation and defects like yellowing and fogging under prolonged outdoor or sunlight exposure, affecting product appearance and precision; furthermore, PC has insufficient fatigue resistance, making it prone to microcracks that can propagate under long-term stress. Simultaneously, ultraviolet radiation accelerates the PC molecular degradation process, causing molecular chain breakage and ultimately product failure.

[0003] To overcome the limitations of pure PC materials, composite materials are commonly used as an effective approach. Using PC resin as the matrix, functional fillers or reinforcements such as glass fibers, carbon fibers, and carbon nanotubes are introduced to improve the performance of pure PC materials. However, conventional PC composites still face challenges, including poor compatibility between fillers and resin, and weak interfacial bonding. This not only makes it difficult to effectively transfer stress and provide reinforcement, but can also become a source of microcracks, deteriorating the material's fatigue resistance. Furthermore, the addition of fillers often leads to poor melt flowability and processability of the composite material, affecting product quality. Therefore, developing a high-performance polycarbonate composite material with excellent wear resistance and fatigue resistance is crucial. Summary of the Invention

[0004] The purpose of this invention is to provide a wear-resistant and fatigue-resistant polycarbonate composite material and its preparation method, thereby solving the problems of insufficient wear resistance and fatigue resistance of polycarbonate composite materials.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material, specifically comprising: Step 1: Using isophthaloyl chloride, bisphenol A, tetramethylbisphenol F and diamino-terminated polydimethylsiloxane as raw materials, a polyarylate-polymethylsiloxane block copolymer was synthesized. Step 2: Using tetrabutyl titanate and carbon fiber as raw materials, titanium dioxide-carbon fiber is synthesized, and then after plasma activation and grafting with polycarbonate, polycarbonate-titanium dioxide-carbon fiber is obtained. Step 3: Synthesize polytetrafluoroethylene-polycarbonate microparticles using polytetrafluoroethylene and polycarbonate as raw materials; Step 4: Add UV absorber UV-329, light stabilizer 770 and antioxidant 1010 to polycarbonate, mix evenly, and then granulate by twin-screw extrusion to obtain UV-resistant polycarbonate masterbatch. Step 5: Add polyarylate-polymethylsiloxane block copolymer, polytetrafluoroethylene-polycarbonate microparticles, UV-resistant polycarbonate masterbatch and polycarbonate-titanium dioxide-carbon fiber to polycarbonate, mix evenly, and then extrude by twin screw to obtain wear-resistant and fatigue-resistant polycarbonate composite material.

[0006] As a limitation of the present invention, the preparation method of the polyarylate-polymethylsiloxane block copolymer is as follows: Isophthaloyl chloride was added to dichloromethane and magnetically stirred at 200-300 rpm for 10-20 min to obtain an isophthaloyl chloride organic solution. Bisphenol A and tetramethylbisphenol F were added to an aqueous sodium hydroxide solution and magnetically stirred at 200-300 rpm for 20-30 min. Benzyltriethylammonium chloride catalyst was added and magnetically stirred at 200-300 rpm for 10-20 min to obtain a bisphenol salt solution. The isophthaloyl chloride organic solution was then added dropwise to the bisphenol salt solution, and the mixture was stirred at 400-500 rpm under a water bath at 0-5℃. Stir the reaction at 400-500 rpm for 1-2 hours. After the reaction is complete, raise the temperature to 25-30℃ and add a diamino-terminated polydimethylsiloxane organic solution (diamino-terminated polydimethylsiloxane dissolved in dichloromethane). Stir the reaction at 25-30℃ for 1-2 hours. After the reaction is complete, add deionized water to the eluent. Wash the organic phase with deionized water until the pH of the eluent is neutral. Then, precipitate the eluent by adding it dropwise to methanol. After filtration and separation, wash with methanol and dry under vacuum at 60-70℃ for 8-12 hours to obtain the polyarylate-polymethylsiloxane block copolymer.

[0007] As a limitation of the present invention, the isophthaloyl chloride organic solution contains 90-100 g / L isophthaloyl chloride; the bisphenol salt solution contains 55-70 g / L bisphenol A, 75-85 g / L tetramethylbisphenol F, 50-60 g / L sodium hydroxide and 0.9-1.9 g / L catalyst benzyltriethylammonium chloride; the mass ratio of isophthaloyl chloride, bisphenol A and diamino-terminated polydimethylsiloxane is (18-20):(11-14):(20-22).

[0008] In an alkaline aqueous phase (sodium hydroxide aqueous solution), bisphenol A (BPA) and tetramethylbisphenol F (TMBPF) lose protons to become bisphenol salt anions (BPA). - and TMBPF -At the interface between the aqueous and organic phases, bisphenol A anion undergoes a nucleophilic substitution reaction with isophthaloyl chloride (IPC) dissolved in the organic phase, forming an ester bond (R-COO-R) to obtain a polyarylate hard segment. The amino groups at both ends of the diamino-terminated polydimethylsiloxane (PDMS) replace the acyl chlorides at both ends of the polyarylate hard segment, forming an amide bond (R-CONH-R), thus connecting the two ends of the PDMS soft segment to the polyarylate hard segment via amide bonds. By controlling the amount of diamino-terminated polydimethylsiloxane and other raw materials, an ABA-type (polyarylate-polysiloxane-polyarylate) triblock copolymer was synthesized. The polyarylate segments have different polarities from PDMS, and spontaneously form [the following structure / form] within the composite matrix. The composite material exhibits a nanoscale microphase separation structure. The two polyarylate hard segments are highly compatible with the PC matrix. The aromatic ring structure in the polyarylate hard segments improves the heat resistance, rigidity, and strength of the composite material. The addition of tetramethylbisphenol F, with its four methyl groups, disrupts the regularity of the molecular chain, inhibits crystallization, and improves the processing fluidity of the polymer and the composite material. When the composite material is subjected to stress impact, the PDMS soft segments act as stress concentration points, undergoing plastic deformation, absorbing and dissipating a large amount of energy, thus improving the toughness, impact strength, and fatigue resistance of the composite material. The ABA-type triblock structure provides dual anchoring for the PDMS soft segments, maintaining the rigidity and strength of the composite material while toughening it.

[0009] As a limitation of the present invention, the preparation method of the polycarbonate-titanium dioxide-carbon fiber is as follows: Add tetrabutyl titanate to a mixed solution of anhydrous ethanol and deionized water, and stir magnetically at 200-300 rpm for 10-20 min to obtain a tetrabutyl titanate ethanol solution. Place carbon fibers in anhydrous ethanol for ultrasonic cleaning for 5-10 min, and then vacuum dry at 70-80℃ for 2-4 h. Subsequently, add the carbon fibers to the tetrabutyl titanate ethanol solution, and stir at 25-30℃ and 200-300 rpm for 2-3 h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 70-80℃ for 2-4 h to obtain titanium dioxide-carbon fiber. Titanium dioxide-carbon fiber was placed in a plasma activation device and evacuated to a vacuum of 1×10⁻⁶. -3 -5×10 -3 Pa, a mixture of oxygen and argon is introduced to activate the surface of the carbon fiber through plasma. After the treatment is completed, activated titanium dioxide-carbon fiber is obtained. Amino-terminated polycarbonate oligomers were added to dichloromethane and magnetically stirred at 200-300 rpm for 20-30 min. Then, activated titanium dioxide-carbon fibers and carbonyl diimidazole catalyst were added. Under nitrogen protection, the reaction was carried out at 50-60 °C and 300-400 rpm for 10-12 h. After the reaction was completed, the mixture was washed with anhydrous ethanol and vacuum dried at 60-70 °C for 8-12 h to obtain polycarbonate-titanium dioxide-carbon fibers.

[0010] As a limitation of the present invention, the tetrabutyl titanate ethanol solution contains 50-60 g / L tetrabutyl titanate, and the volume ratio of ethanol to deionized water is (90-110):1; the mass ratio of tetrabutyl titanate, carbon fiber, amino-terminated polycarbonate oligomer and catalyst carbonyl diimidazole is (10-12):(10-15):(5-7):(0.5-0.7); during plasma activation, the process parameters include: oxygen flow rate of 50-70 sccm, argon flow rate of 20-30 sccm, plasma power of 180-200 W, and processing time of 5-10 min.

[0011] Butyl titanate undergoes a hydrolysis-condensation reaction on the surface of carbon fibers, resulting in the in-situ growth of nanoscale titanium dioxide, which coats the carbon fibers. After plasma activation, highly reactive oxygen-containing groups (hydroxyl and carboxyl groups) form on the surface of the titanium dioxide. Under the action of a catalyst, these oxygen-containing groups undergo a condensation reaction with terminal amino groups to form chemical bonds, and polycarbonate is grafted onto the fiber surface. The carbon fibers, as the main reinforcement, significantly improve the strength, rigidity, and creep resistance of the composite material due to their high strength and modulus. Nanoscale titanium dioxide also enhances the surface hardness and wear resistance of the composite material and acts as a stress concentration point within it. The passive properties of the composite material include: passivating crack tips and promoting crack deflection; the pinning effect synergistically enhances the fracture toughness and fatigue resistance of the composite material; absorbing ultraviolet light through valence band electron transitions and nanoscale scattering effects improve the ultraviolet resistance of the composite material; the grafted polycarbonate increases the compatibility with the composite matrix, and its electron-rich aromatic ring structure preferentially reacts with and consumes holes excited by titanium dioxide under ultraviolet light, inhibiting the photocatalytic degradation of titanium dioxide, avoiding damage to the composite matrix, improving the weather resistance of the composite material, and dissipating energy through plastic deformation, thereby improving the impact resistance and fatigue resistance of the composite material.

[0012] As a limitation of the present invention, the method for preparing the polytetrafluoroethylene-polycarbonate microparticles is as follows: Add 55-60wt% polytetrafluoroethylene dispersion and emulsifier Triton X-100 to deionized water, stir evenly, and then stir at high speed of 10000-12000 rpm for 10-15 min to obtain polytetrafluoroethylene emulsion. Add polycarbonate to dichloromethane and stir magnetically at 30-40℃ and 200-300 rpm for 20-30 min. Add polytetrafluoroethylene emulsion dropwise and react at 40-50℃ and 500-600 rpm for 3-4 h. After the reaction is complete, filter, wash with anhydrous ethanol, and vacuum dry at 70-80℃ for 2-4 h to obtain polytetrafluoroethylene-polycarbonate microparticles.

[0013] As a limitation of the present invention, the polytetrafluoroethylene dispersion contains 55-60 wt% polytetrafluoroethylene; the mass ratio of polytetrafluoroethylene dispersion, emulsifier Triton X-100 and polycarbonate is (20-30):(1-1.2):(12-22).

[0014] Polytetrafluoroethylene-polycarbonate microparticles are formed by emulsion-solvent evaporation. The outer PC resin has good compatibility with the matrix of the composite material, and the microparticles can be uniformly dispersed in the matrix of the composite material. During the friction process, after the PC shell wears down, the internal PTFE is exposed. The PTFE forms a solid lubricating layer between the friction surfaces, which changes the friction from the high shear strength of the composite material to the friction between the low shear strength PTFE lubricating layers. This significantly reduces the coefficient of friction and wear rate, and improves the wear resistance of the composite material.

[0015] As a limitation of the present invention, the UV-resistant polycarbonate masterbatch, by weight, comprises: 2-3 parts of UV absorber UV-329, 1-2 parts of light stabilizer 770, 0.5-1.5 parts of antioxidant 1010, and 93.5-96.5 parts of polycarbonate; the process parameters for twin-screw extrusion granulation include: melt temperature of 250-260℃, extrusion temperature of 240-250℃, and screw speed of 200-300 rpm.

[0016] As a limitation of the present invention, the wear-resistant and fatigue-resistant polycarbonate composite material, by weight, comprises: 10-12 parts of polyarylate-polymethylsiloxane block copolymer, 5-7 parts of polytetrafluoroethylene-polycarbonate microparticles, 5-7 parts of UV-resistant polycarbonate masterbatch, 10-12 parts of polycarbonate-titanium dioxide-carbon fiber, and 62-70 parts of polycarbonate; during feeding, the polycarbonate-titanium dioxide-carbon fiber is directly added to the melt system through the side feed port; during twin-screw extrusion molding, the process parameters include: melt temperature of 250-260℃, extrusion temperature of 240-250℃, and screw speed of 200-300 rpm.

[0017] A wear-resistant and fatigue-resistant polycarbonate composite material is prepared by any of the preparation methods described above.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention synthesizes an ABA-type (polyaryl ester-PDMS-polyaryl ester) triblock copolymer with good compatibility with polycarbonate composites. The PDMS soft segments improve the toughness, impact strength, and fatigue resistance of the composite, while maintaining its rigidity and strength. Carbon fibers are modified through polycarbonate oligomer grafting and nano-titanium dioxide coating to enhance the composite's strength, rigidity, and creep resistance. Furthermore, the synergistic effect of nano-titanium dioxide and functional additives such as UV absorber UV-329 improves the weather resistance of the polycarbonate composite. The introduction of polytetrafluoroethylene (PTFE)-polycarbonate microparticles as a lubricant allows PTFE to form a solid lubricating layer between the friction surfaces during friction, significantly reducing the coefficient of friction and wear rate, and improving the wear resistance of the composite. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The terminology used in the embodiments is for describing specific implementation schemes, not for limiting the scope of protection of the present invention. The dosages in the embodiments are laboratory-scale tests and can be scaled up proportionally. 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.

[0020] Diamino-terminated polydimethylsiloxane (Mn=2500), carbon fiber (short-cut carbon fiber, diameter: 3μm, length: 3mm), amino-terminated polycarbonate oligomer (Mn=5000), polytetrafluoroethylene dispersion (solid content: 60wt%, PTFE particle size: 0.3μm), polycarbonate (Mn=30000).

[0021] The preparation method of polytetrafluoroethylene-polycarbonate microparticles is as follows: 20g of 60wt% polytetrafluoroethylene dispersion and 1g of emulsifier Triton X-100 were added to 200mL of deionized water and stirred evenly. The mixture was then stirred at 10000rpm for 10min to obtain a polytetrafluoroethylene emulsion. 12g of polycarbonate was added to 200mL of dichloromethane and magnetically stirred at 200rpm for 20min at 40℃. The polytetrafluoroethylene emulsion was then added dropwise and reacted at 500rpm for 4h at 40℃. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and vacuum dried at 70℃ for 3h to obtain polytetrafluoroethylene-polycarbonate microparticles.

[0022] The preparation method of UV-resistant polycarbonate masterbatch is as follows: Mix 96.5g of polycarbonate, 2g of UV absorber UV-329, 1g of light stabilizer 770 and 0.5g of antioxidant 1010 evenly, and then add them to a twin-screw extruder. Set the melt temperature to 250℃, the extrusion temperature to 240℃ and the screw speed to 300rpm, and extrude and granulate to obtain UV-resistant polycarbonate masterbatch.

[0023] Example 1: A method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material, specifically as follows: Step 1: Add 18g of isophthaloyl chloride to 200mL of dichloromethane and stir magnetically at 200rpm for 15min to obtain an organic solution of isophthaloyl chloride. Add 11.5g of bisphenol A and 15g of tetramethylbisphenol F to 200mL of dichloromethane. In a 5wt% sodium hydroxide aqueous solution, the mixture was magnetically stirred at 200 rpm for 30 min. 0.18 g of benzyltriethylammonium chloride catalyst was added, and the mixture was magnetically stirred at 200 rpm for 10 min to obtain a bisphenol salt solution. Isophthalyl chloride organic solution was added dropwise to the bisphenol salt solution. The mixture was stirred at 500 rpm for 1 h in a 5℃ water bath. After the reaction was complete, the temperature was raised to 25℃, and a diamino-terminated polydimethylsiloxane organic solution (20 g of diamino-terminated polydimethylsiloxane dissolved in 50 mL of dichloromethane) was added. The mixture was stirred at 25℃ at 500 rpm for 1 h. After the reaction was complete, deionized water was added to liquefy the mixture. The organic phase was washed with deionized water until the pH of the eluent was neutral. The precipitate was then added dropwise to 500 mL of methanol. After filtration and separation, the precipitate was washed with methanol and dried under vacuum at 60℃ for 12 h to obtain a polyarylate-polymethylsiloxane block copolymer. Step 2: Add 11g of tetrabutyl titanate to a mixed solution of 200mL anhydrous ethanol and 2mL deionized water, and stir magnetically at 200rpm for 15min to obtain a tetrabutyl titanate ethanol solution. Place 10g of carbon fiber in anhydrous ethanol and ultrasonically clean for 5min, then vacuum dry at 80℃ for 2h. Subsequently, add it to the tetrabutyl titanate ethanol solution and stir at 25℃ and 200rpm for 2h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 80℃ for 2h to obtain titanium dioxide-carbon fiber. Step 3: Place the titanium dioxide-carbon fiber into the plasma activation device and evacuate to a vacuum of 5×10⁻⁶. -3 Pa, a mixture of oxygen and argon was introduced to activate the surface of the plasma. The oxygen flow rate was set to 50 sccm, the argon flow rate to 20 sccm, the plasma power to 200 W, and the treatment time to 10 min. After the treatment was completed, activated titanium dioxide-carbon fiber was obtained. Step 4: Add 5g of amino-terminated polycarbonate oligomer to 150mL of dichloromethane, stir magnetically at 200rpm for 20min, then add activated titanium dioxide-carbon fiber and 0.5g of carbonyl diimidazole catalyst. Under nitrogen protection, react at 50℃ and 300rpm for 12h. After the reaction is complete, wash with anhydrous ethanol and vacuum dry at 60℃ for 12h to obtain polycarbonate-titanium dioxide-carbon fiber. Step 5: Mix 70g of polycarbonate, 10g of polyarylate-polymethylsiloxane block copolymer, 5g of polytetrafluoroethylene-polycarbonate microparticles, and 5g of UV-resistant polycarbonate masterbatch, and then add them to a twin-screw extruder for extrusion. Set the melt temperature to 250℃, the extrusion temperature to 240℃, and the screw speed to 200rpm. Add 10g of polycarbonate-titanium dioxide-carbon fiber directly to the melt system in the extruder through the side feed port. Extrusion molding is performed to obtain a wear-resistant and fatigue-resistant polycarbonate composite material.

[0024] Example 2: A method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material, specifically as follows: Step 1: Add 19g of isophthaloyl chloride to 200mL of dichloromethane and stir magnetically at 200rpm for 15min to obtain an organic solution of isophthaloyl chloride. Add 13g of bisphenol A and 16g of tetramethylbisphenol F to 200mL of dichloromethane. In a 5wt% sodium hydroxide aqueous solution, the mixture was magnetically stirred at 200 rpm for 30 min. 0.18 g of benzyltriethylammonium chloride catalyst was added, and the mixture was magnetically stirred at 200 rpm for 10 min to obtain a bisphenol salt solution. Isophthalyl chloride organic solution was added dropwise to the bisphenol salt solution. The mixture was stirred at 500 rpm for 1 h in a 5℃ water bath. After the reaction was complete, the temperature was raised to 25℃, and a diamino-terminated polydimethylsiloxane organic solution (20 g of diamino-terminated polydimethylsiloxane dissolved in 50 mL of dichloromethane) was added. The mixture was stirred at 25℃ at 500 rpm for 1 h. After the reaction was complete, deionized water was added to liquefy the mixture. The organic phase was washed with deionized water until the pH of the eluent was neutral. The precipitate was then added dropwise to 500 mL of methanol. After filtration and separation, the precipitate was washed with methanol and dried under vacuum at 60℃ for 12 h to obtain a polyarylate-polymethylsiloxane block copolymer. Step 2: Add 10g of tetrabutyl titanate to a mixed solution of 200mL anhydrous ethanol and 2mL deionized water, and stir magnetically at 200rpm for 15min to obtain a tetrabutyl titanate ethanol solution. Place 10g of carbon fiber in anhydrous ethanol and ultrasonically clean for 5min, then vacuum dry at 80℃ for 2h. Subsequently, add it to the tetrabutyl titanate ethanol solution and stir at 25℃ and 200rpm for 2h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 80℃ for 2h to obtain titanium dioxide-carbon fiber. Step 3: Place the titanium dioxide-carbon fiber into the plasma activation device and evacuate to a vacuum of 5×10⁻⁶. -3Pa, a mixture of oxygen and argon was introduced to activate the surface of the plasma. The oxygen flow rate was set to 60 sccm, the argon flow rate to 30 sccm, the plasma power to 200W, and the treatment time to 10 min. After the treatment was completed, activated titanium dioxide-carbon fiber was obtained. Step 4: Add 6g of amino-terminated polycarbonate oligomer to 150mL of dichloromethane, stir magnetically at 200rpm for 20min, then add activated titanium dioxide-carbon fiber and 0.5g of carbonyl diimidazole catalyst. Under nitrogen protection, react at 50℃ and 300rpm for 12h. After the reaction is complete, wash with anhydrous ethanol and vacuum dry at 60℃ for 12h to obtain polycarbonate-titanium dioxide-carbon fiber. Step 5: Mix 66g of polycarbonate, 11g of polyarylate-polymethylsiloxane block copolymer, 6g of polytetrafluoroethylene-polycarbonate microparticles, and 6g of UV-resistant polycarbonate masterbatch, and then add the mixture to a twin-screw extruder for extrusion. Set the melt temperature to 250℃, the extrusion temperature to 240℃, and the screw speed to 200rpm. Add 11g of polycarbonate-titanium dioxide-carbon fiber directly to the melt system inside the extruder through the side feed port. Extrusion molding is performed to obtain a wear-resistant and fatigue-resistant polycarbonate composite material.

[0025] Example 3: A method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material, specifically as follows: Step 1: Add 20g of isophthaloyl chloride to 200mL of dichloromethane and stir magnetically at 200rpm for 15min to obtain an organic solution of isophthaloyl chloride. Add 14g of bisphenol A and 17g of tetramethylbisphenol F to 200mL of dichloromethane. In a 5wt% sodium hydroxide aqueous solution, the mixture was magnetically stirred at 200 rpm for 30 min. 0.18 g of benzyltriethylammonium chloride catalyst was added, and the mixture was magnetically stirred at 200 rpm for 10 min to obtain a bisphenol salt solution. Isophthalyl chloride organic solution was added dropwise to the bisphenol salt solution. The mixture was stirred at 500 rpm for 1 h in a 5℃ water bath. After the reaction was complete, the temperature was raised to 25℃, and a diamino-terminated polydimethylsiloxane organic solution (20 g of diamino-terminated polydimethylsiloxane dissolved in 50 mL of dichloromethane) was added. The mixture was stirred at 25℃ at 500 rpm for 1 h. After the reaction was complete, deionized water was added to liquefy the mixture. The organic phase was washed with deionized water until the pH of the eluent was neutral. The precipitate was then added dropwise to 500 mL of methanol. After filtration and separation, the precipitate was washed with methanol and dried under vacuum at 60℃ for 12 h to obtain a polyarylate-polymethylsiloxane block copolymer. Step 2: Add 12g of tetrabutyl titanate to a mixed solution of 200mL anhydrous ethanol and 2mL deionized water, and stir magnetically at 200rpm for 15min to obtain a tetrabutyl titanate ethanol solution. Place 10g of carbon fiber in anhydrous ethanol and ultrasonically clean for 5min, then vacuum dry at 80℃ for 2h. Subsequently, add it to the tetrabutyl titanate ethanol solution and stir at 25℃ and 200rpm for 2h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 80℃ for 2h to obtain titanium dioxide-carbon fiber. Step 3: Place the titanium dioxide-carbon fiber into the plasma activation device and evacuate to a vacuum of 5×10⁻⁶. -3 Pa, a mixture of oxygen and argon was introduced to activate the surface of the plasma. The oxygen flow rate was set to 60 sccm, the argon flow rate to 20 sccm, the plasma power to 200W, and the treatment time to 10 min. After the treatment was completed, activated titanium dioxide-carbon fiber was obtained. Step 4: Add 7g of amino-terminated polycarbonate oligomer to 150mL of dichloromethane, stir magnetically at 200rpm for 20min, then add activated titanium dioxide-carbon fiber and 0.5g of carbonyl diimidazole catalyst. Under nitrogen protection, react at 50℃ and 300rpm for 12h. After the reaction is complete, wash with anhydrous ethanol and vacuum dry at 60℃ for 12h to obtain polycarbonate-titanium dioxide-carbon fiber. Step 5: Mix 62g of polycarbonate, 12g of polyarylate-polymethylsiloxane block copolymer, 7g of polytetrafluoroethylene-polycarbonate microparticles, and 7g of UV-resistant polycarbonate masterbatch, and then add the mixture to a twin-screw extruder for extrusion. Set the melt temperature to 250℃, the extrusion temperature to 240℃, and the screw speed to 200rpm. Add 12g of polycarbonate-titanium dioxide-carbon fiber directly to the melt system in the extruder through the side feed port. Extrusion molding is performed to obtain a wear-resistant and fatigue-resistant polycarbonate composite material.

[0026] Based on Example 1, the following comparative experiments were conducted, specifically Comparative Example 1, Comparative Example 2, and Comparative Example 3, as described below: Comparative Example 1: This comparative example relates to a method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material. The difference from Example 1 is that polytetrafluoroethylene-polycarbonate microparticles were not added. Specifically: Step 1: Add 18g of isophthaloyl chloride to 200mL of dichloromethane and stir magnetically at 200rpm for 15min to obtain an organic solution of isophthaloyl chloride. Add 11.5g of bisphenol A and 15g of tetramethylbisphenol F to 200mL of dichloromethane. In a 5wt% sodium hydroxide aqueous solution, the mixture was magnetically stirred at 200 rpm for 30 min. 0.18 g of benzyltriethylammonium chloride catalyst was added, and the mixture was magnetically stirred at 200 rpm for 10 min to obtain a bisphenol salt solution. Isophthalyl chloride organic solution was added dropwise to the bisphenol salt solution. The mixture was stirred at 500 rpm for 1 h in a 5℃ water bath. After the reaction was complete, the temperature was raised to 25℃, and a diamino-terminated polydimethylsiloxane organic solution (20 g of diamino-terminated polydimethylsiloxane dissolved in 50 mL of dichloromethane) was added. The mixture was stirred at 25℃ at 500 rpm for 1 h. After the reaction was complete, deionized water was added to liquefy the mixture. The organic phase was washed with deionized water until the pH of the eluent was neutral. The precipitate was then added dropwise to 500 mL of methanol. After filtration and separation, the precipitate was washed with methanol and dried under vacuum at 60℃ for 12 h to obtain a polyarylate-polymethylsiloxane block copolymer. Step 2: Add 10g of tetrabutyl titanate to a mixed solution of 200mL anhydrous ethanol and 2mL deionized water, and stir magnetically at 200rpm for 15min to obtain a tetrabutyl titanate ethanol solution. Place 10g of carbon fiber in anhydrous ethanol and ultrasonically clean for 5min, then vacuum dry at 80℃ for 2h. Subsequently, add it to the tetrabutyl titanate ethanol solution and stir at 25℃ and 200rpm for 2h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 80℃ for 2h to obtain titanium dioxide-carbon fiber. Step 3: Place the titanium dioxide-carbon fiber into the plasma activation device and evacuate to a vacuum of 5×10⁻⁶. -3 Pa, a mixture of oxygen and argon was introduced to activate the surface of the plasma. The oxygen flow rate was set to 50 sccm, the argon flow rate to 20 sccm, the plasma power to 200 W, and the treatment time to 10 min. After the treatment was completed, activated titanium dioxide-carbon fiber was obtained. Step 4: Add 5g of amino-terminated polycarbonate oligomer to 150mL of dichloromethane, stir magnetically at 200rpm for 20min, then add activated titanium dioxide-carbon fiber and 0.5g of carbonyl diimidazole catalyst. Under nitrogen protection, react at 50℃ and 300rpm for 12h. After the reaction is complete, wash with anhydrous ethanol and vacuum dry at 60℃ for 12h to obtain polycarbonate-titanium dioxide-carbon fiber. Step 5: Mix 70g of polycarbonate, 10g of polyarylate-polymethylsiloxane block copolymer, and 5g of UV-resistant polycarbonate masterbatch, and then add them to a twin-screw extruder for extrusion. Set the melt temperature to 250℃, the extrusion temperature to 240℃, and the screw speed to 200rpm. Add 10g of polycarbonate-titanium dioxide-carbon fiber directly to the melt system in the extruder through the side feed port. Extrusion molding is performed to obtain a wear-resistant and fatigue-resistant polycarbonate composite material.

[0027] Comparative Example 2: This comparative example relates to a method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material. The difference from Example 1 is that the carbon fibers are only subjected to plasma activation treatment, specifically: Step 1: Add 18g of isophthaloyl chloride to 200mL of dichloromethane and stir magnetically at 200rpm for 15min to obtain an organic solution of isophthaloyl chloride. Add 11.5g of bisphenol A and 15g of tetramethylbisphenol F to 200mL of dichloromethane. In a 5wt% sodium hydroxide aqueous solution, the mixture was magnetically stirred at 200 rpm for 30 min. 0.18 g of benzyltriethylammonium chloride catalyst was added, and the mixture was magnetically stirred at 200 rpm for 10 min to obtain a bisphenol salt solution. Isophthalyl chloride organic solution was added dropwise to the bisphenol salt solution. The mixture was stirred at 500 rpm for 1 h in a 5℃ water bath. After the reaction was complete, the temperature was raised to 25℃, and a diamino-terminated polydimethylsiloxane organic solution (20 g of diamino-terminated polydimethylsiloxane dissolved in 50 mL of dichloromethane) was added. The mixture was stirred at 25℃ at 500 rpm for 1 h. After the reaction was complete, deionized water was added to liquefy the mixture. The organic phase was washed with deionized water until the pH of the eluent was neutral. The precipitate was then added dropwise to 500 mL of methanol. After filtration and separation, the precipitate was washed with methanol and dried under vacuum at 60℃ for 12 h to obtain a polyarylate-polymethylsiloxane block copolymer. Step 2: Place the carbon fiber into the plasma activation device and evacuate to a vacuum of 5×10⁻⁶. -3 Pa, a mixture of oxygen and argon was introduced to activate the surface of the carbon fiber using plasma. The oxygen flow rate was set to 50 sccm, the argon flow rate to 20 sccm, the plasma power to 200 W, and the treatment time to 10 min. Once the treatment was completed, activated carbon fiber was obtained. Step 3: Mix 70g of polycarbonate, 10g of polyarylate-polymethylsiloxane block copolymer, 5g of polytetrafluoroethylene-polycarbonate microparticles, and 5g of UV-resistant polycarbonate masterbatch, and then add the mixture to a twin-screw extruder for extrusion. Set the melt temperature to 250℃, the extrusion temperature to 240℃, and the screw speed to 200rpm. Add 10g of activated carbon fiber directly to the melt system in the extruder through the side feed port. Extrusion molding is performed to obtain a wear-resistant and fatigue-resistant polycarbonate composite material.

[0028] Comparative Example 3: This comparative example relates to a method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material. The difference from Example 1 is that a polyarylate-polymethylsiloxane block copolymer is not added. Specifically: Step 1: Add 10g of tetrabutyl titanate to a mixed solution of 200mL anhydrous ethanol and 2mL deionized water, and stir magnetically at 200rpm for 15min to obtain a tetrabutyl titanate ethanol solution. Place 10g of carbon fiber in anhydrous ethanol and ultrasonically clean for 5min, then vacuum dry at 80℃ for 2h. Subsequently, add it to the tetrabutyl titanate ethanol solution and stir at 25℃ and 200rpm for 2h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 80℃ for 2h to obtain titanium dioxide-carbon fiber. Step 2: Place the titanium dioxide-carbon fiber into the plasma activation device and evacuate to a vacuum of 5×10⁻⁶. -3 Pa, a mixture of oxygen and argon was introduced to activate the surface of the plasma. The oxygen flow rate was set to 50 sccm, the argon flow rate to 20 sccm, the plasma power to 200 W, and the treatment time to 10 min. After the treatment was completed, activated titanium dioxide-carbon fiber was obtained. Step 3: Add 5g of amino-terminated polycarbonate oligomer to 150mL of dichloromethane, stir magnetically at 200rpm for 20min, then add activated titanium dioxide-carbon fiber and 0.5g of carbonyl diimidazole catalyst. Under nitrogen protection, react at 50℃ and 300rpm for 12h. After the reaction is complete, wash with anhydrous ethanol and vacuum dry at 60℃ for 12h to obtain polycarbonate-titanium dioxide-carbon fiber. Step 4: Mix 70g of polycarbonate, 5g of polytetrafluoroethylene-polycarbonate microparticles, and 5g of UV-resistant polycarbonate masterbatch, and then add them to a twin-screw extruder for extrusion. Set the melt temperature to 250℃, the extrusion temperature to 240℃, and the screw speed to 200rpm. Add 10g of polycarbonate-titanium dioxide-carbon fiber directly to the melt system inside the extruder through the side feed port. Extrusion molding is performed to obtain a wear-resistant and fatigue-resistant polycarbonate composite material.

[0029] Testing experiment: Polycarbonate composite material test samples were prepared according to the preparation methods in the examples and comparative examples, and abrasion resistance, scratch resistance, fatigue resistance and UV aging resistance tests were conducted.

[0030] The abrasion resistance test was conducted in accordance with the "Test Method for Rolling Abrasion of Plastics" (GB / T 5478-2008). The grinding wheel selected was the CS-10 grinding wheel that conforms to the standard. The load was 1 kg and the friction speed was 5000 r. The volume loss of the composite material test sample was tested. Each sample was tested 3 times and the average value was taken.

[0031] The scratch resistance test was conducted in accordance with the "Determination of Scratch Performance of Plastics" (GB / T 41878-2022). A standard diamond scratch needle (120° cone angle, 200μm tip radius) was selected. The scratching speed was 100mm / min and the scratch length was 100mm. The critical normal load of the composite material test sample was tested. Each sample was tested 3 times and the average value was taken.

[0032] The fatigue resistance test was conducted according to "Test Methods for Fatigue Properties of Polymer-Based Composite Materials Part 3: Tensile Fatigue Test" (GB / T 35465.3-2017), with a stress ratio of 0.1, a frequency of 10 Hz, and a preset number of cycles of 10. 7 Each sample was tested three times, and the average value of the results was taken.

[0033] The UV aging resistance test was conducted in accordance with "Laboratory Light Source Exposure Test Methods for Plastics - Part 3: Fluorescent UV Lamp" (GB / T 16422.3-2022). The light source was a UVA-340 UV lamp, and the cycle was 8 hours of illumination (60℃) + 4 hours of condensation (50℃), for a total duration of 1000 hours. The tensile strength retention rate of the composite material test samples was tested, and each sample was tested 5 times. The average value of the results was taken.

[0034] Conclusion: The test data shows that, compared with the test results of the comparative example, the critical normal load, fatigue strength, and tensile strength retention rate of the polycarbonate composite material prepared in the example are all higher than those of the comparative example, while the volume loss after friction is lower than that of the comparative example. The wear-resistant and fatigue-resistant polycarbonate composite material provided by the present invention has good wear resistance, friction resistance, fatigue resistance, and UV aging resistance, and can solve the problems of insufficient wear resistance and fatigue resistance of polycarbonate composite materials.

[0035] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material, characterized in that: Specifically: Step 1: Using isophthaloyl chloride, bisphenol A, tetramethylbisphenol F and diamino-terminated polydimethylsiloxane as raw materials, a polyarylate-polymethylsiloxane block copolymer was synthesized. Step 2: Using tetrabutyl titanate and carbon fiber as raw materials, titanium dioxide-carbon fiber is synthesized, and then after plasma activation and grafting with polycarbonate, polycarbonate-titanium dioxide-carbon fiber is obtained. Step 3: Synthesize polytetrafluoroethylene-polycarbonate microparticles using polytetrafluoroethylene and polycarbonate as raw materials; Step 4: Add UV absorber UV-329, light stabilizer 770 and antioxidant 1010 to polycarbonate, mix evenly, and then granulate by twin-screw extrusion to obtain UV-resistant polycarbonate masterbatch. Step 5: Add polyarylate-polymethylsiloxane block copolymer, polytetrafluoroethylene-polycarbonate microparticles, UV-resistant polycarbonate masterbatch and polycarbonate-titanium dioxide-carbon fiber to polycarbonate, mix evenly, and then extrude by twin screw to obtain wear-resistant and fatigue-resistant polycarbonate composite material.

2. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 1, characterized in that: The preparation method of polyarylate-polymethylsiloxane block copolymer is as follows: Isophthaloyl chloride was added to dichloromethane and magnetically stirred at 200-300 rpm for 10-20 min to obtain an isophthaloyl chloride organic solution. Bisphenol A and tetramethylbisphenol F were added to an aqueous sodium hydroxide solution and magnetically stirred at 200-300 rpm for 20-30 min. Benzyltriethylammonium chloride catalyst was added and magnetically stirred at 200-300 rpm for 10-20 min to obtain a bisphenol salt solution. The isophthaloyl chloride organic solution was then added dropwise to the bisphenol salt solution, and the mixture was stirred at 400-500 rpm under a water bath at 0-5℃. Stir the reaction at 400-500 rpm for 1-2 hours. After the reaction is complete, raise the temperature to 25-30℃ and add a diamino-terminated polydimethylsiloxane organic solution (diamino-terminated polydimethylsiloxane dissolved in dichloromethane). Stir the reaction at 25-30℃ for 1-2 hours. After the reaction is complete, add deionized water to the eluent. Wash the organic phase with deionized water until the pH of the eluent is neutral. Then, precipitate the eluent by adding it dropwise to methanol. After filtration and separation, wash with methanol and dry under vacuum at 60-70℃ for 8-12 hours to obtain the polyarylate-polymethylsiloxane block copolymer.

3. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 2, characterized in that: The isophthaloyl chloride organic solution contains 90-100 g / L isophthaloyl chloride; the bisphenol salt solution contains 55-70 g / L bisphenol A, 75-85 g / L tetramethylbisphenol F, 50-60 g / L sodium hydroxide and 0.9-1.9 g / L catalyst benzyltriethylammonium chloride; the mass ratio of isophthaloyl chloride, bisphenol A and diamino-terminated polydimethylsiloxane is (18-20):(11-14):(20-22).

4. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 1, characterized in that: The preparation method of polycarbonate-titanium dioxide-carbon fiber is as follows: Add tetrabutyl titanate to a mixed solution of anhydrous ethanol and deionized water, and stir magnetically at 200-300 rpm for 10-20 min to obtain a tetrabutyl titanate ethanol solution. Place carbon fibers in anhydrous ethanol for ultrasonic cleaning for 5-10 min, and then vacuum dry at 70-80℃ for 2-4 h. Subsequently, add the carbon fibers to the tetrabutyl titanate ethanol solution, and stir at 25-30℃ and 200-300 rpm for 2-3 h. After the reaction is complete, filter, wash with deionized water, and vacuum dry at 70-80℃ for 2-4 h to obtain titanium dioxide-carbon fiber. Titanium dioxide-carbon fiber was placed in a plasma activation device, and the vacuum was evacuated to 1×10⁻⁶. -3 -5×10 -3 Pa, a mixture of oxygen and argon is introduced to activate the surface of the carbon fiber through plasma. After the treatment is completed, activated titanium dioxide-carbon fiber is obtained. Amino-terminated polycarbonate oligomers were added to dichloromethane and magnetically stirred at 200-300 rpm for 20-30 min. Then, activated titanium dioxide-carbon fibers and carbonyl diimidazole catalyst were added. Under nitrogen protection, the reaction was carried out at 50-60 °C and 300-400 rpm for 10-12 h. After the reaction was completed, the mixture was washed with anhydrous ethanol and vacuum dried at 60-70 °C for 8-12 h to obtain polycarbonate-titanium dioxide-carbon fibers.

5. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 4, characterized in that: The butyl titanate ethanol solution contains 50-60 g / L butyl titanate, and the volume ratio of ethanol to deionized water is (90-110):1; the mass ratio of butyl titanate, carbon fiber, amino-terminated polycarbonate oligomer and catalyst carbonyl diimidazole is (10-12):(10-15):(5-7):(0.5-0.7); the process parameters for plasma activation include: oxygen flow rate of 50-70 sccm, argon flow rate of 20-30 sccm, plasma power of 180-200 W, and processing time of 5-10 min.

6. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 1 is characterized in that: The preparation method of polytetrafluoroethylene-polycarbonate microparticles is as follows: Add 55-60wt% polytetrafluoroethylene dispersion and emulsifier Triton X-100 to deionized water, stir evenly, and then stir at high speed of 10000-12000 rpm for 10-15 min to obtain polytetrafluoroethylene emulsion. Add polycarbonate to dichloromethane and stir magnetically at 30-40℃ and 200-300 rpm for 20-30 min. Add polytetrafluoroethylene emulsion dropwise and react at 40-50℃ and 500-600 rpm for 3-4 h. After the reaction is complete, filter, wash with anhydrous ethanol, and vacuum dry at 70-80℃ for 2-4 h to obtain polytetrafluoroethylene-polycarbonate microparticles.

7. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 6, characterized in that: The polytetrafluoroethylene dispersion contains 55-60 wt% polytetrafluoroethylene; the mass ratio of polytetrafluoroethylene dispersion, emulsifier Triton X-100 and polycarbonate is (20-30):(1-1.2):(12-22).

8. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 1, characterized in that: By weight, the UV-resistant polycarbonate masterbatch comprises: 2-3 parts UV absorber UV-329, 1-2 parts light stabilizer 770, 0.5-1.5 parts antioxidant 1010, and 93.5-96.5 parts polycarbonate; the process parameters for twin-screw extrusion granulation include: melt temperature of 250-260℃, extrusion temperature of 240-250℃, and screw speed of 200-300 rpm.

9. The method for preparing a wear-resistant and fatigue-resistant polycarbonate composite material according to claim 1, characterized in that: By weight, the wear-resistant and fatigue-resistant polycarbonate composite material comprises: 10-12 parts of polyarylate-polymethylsiloxane block copolymer, 5-7 parts of polytetrafluoroethylene-polycarbonate microparticles, 5-7 parts of UV-resistant polycarbonate masterbatch, 10-12 parts of polycarbonate-titanium dioxide-carbon fiber, and 62-70 parts of polycarbonate; during feeding, the polycarbonate-titanium dioxide-carbon fiber is directly added to the melt system through the side feed port; during twin-screw extrusion molding, the process parameters include: melt temperature of 250-260℃, extrusion temperature of 240-250℃, and screw speed of 200-300 rpm.

10. A wear-resistant and fatigue-resistant polycarbonate composite material, characterized in that: It is prepared by any one of the preparation methods according to claims 1-9.

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