Wear-resistant and aging-resistant composite PC material and preparation method thereof

Abstract

The invention discloses a wear-resistant and aging-resistant composite PC material and a preparation method thereof, belongs to the technical field of polycarbonate materials, and aims to solve the technical problem that the wear resistance, aging resistance and toughness of a polycarbonate material in the prior art need to be further improved. The anti-aging PC material comprises the following components in parts by weight: 105-120 parts of PC, 3-5 parts of an anti-aging auxiliary agent, 7-9 parts of modified carbon nanotubes, 1 part of modified graphene, 0.5-2 parts of epoxy resin, 5-6 parts of a toughening agent and 3-5 parts of an auxiliary additive, and polycarbonate is reinforced and modified through the modified carbon nanotubes, the modified graphene, the modified toughening agent and the anti-aging auxiliary agent. The wear resistance and the tensile strength of the polycarbonate are effectively improved, and the damp-heat aging resistance and the UV aging resistance of the polycarbonate are also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of PC materials, and particularly relates to a wear-resistant and aging-resistant composite PC material and a preparation method thereof. Background Art

[0002] As a high-performance engineering plastic, polycarbonate (PC) is widely used in the fields of aerospace, automotive manufacturing, electronic equipment, and construction due to its excellent impact resistance and dimensional stability. However, the high degree of freedom of the PC molecular chain and the weak intermolecular force result in low surface hardness and susceptibility to external force scratches. Especially in high-load friction scenarios, it is prone to wear. The weak ester bonds and residual impurities in the PC molecular chain are prone to hydrolysis under ultraviolet light and mechanical stress, leading to yellowing and cracking of its surface.

[0003] In the existing PC materials, in order to improve their wear resistance and mechanical strength, nano materials such as nano-aluminum oxide, nano-ceramic powder, and carbon nanotubes are usually selected for filling. Although the mechanical strength and wear resistance can be improved to a certain extent, there is a large polarity difference between the nano-particles and the PC material, resulting in poor dispersion of the nano-particles in the PC material, and the wear resistance and mechanical strength of the PC composite material still need to be further improved. Moreover, traditional PC materials usually use a single antioxidant additive to enhance the anti-aging performance of PC, resulting in the need to further improve the anti-aging performance of the PC composite material. Summary of the Invention

[0004] The purpose of the present invention is to provide a wear-resistant and aging-resistant composite PC material and a preparation method thereof, which modifies the PC material to solve the technical problems that its wear resistance, aging resistance, and mechanical properties need to be further improved.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A wear-resistant and aging-resistant composite PC material, comprising the following components by weight: 105-120 parts of PC, 3-5 parts of aging-resistant additive, 7-9 parts of modified carbon nanotubes, 1 part of modified graphene, 0.5-2 parts of epoxy resin, 5-6 parts of toughening agent, and 3-5 parts of auxiliary additive.

[0006] Further, the aging-resistant additive is composed of antioxidant 1010, UV-328, and hindered amine 292 in a weight ratio of 1:2:1.

[0007] Further, the modified carbon nanotubes are processed by the following steps:

[0008] A1. Add carbon nanotubes and mixed acid into a three-necked flask and stir. React at 60-70 °C for 4-6 h, and perform post-treatment to obtain purified carbon nanotubes;

[0009] A2. Add 3-aminopropyltriethoxysilane and absolute ethanol into a three-necked flask and stir. Add purified carbon nanotubes into the three-necked flask, ultrasonically disperse for 30 - 50 min, then add a catalyst into it. Raise the temperature of the three-necked flask to 55 - 65 °C, keep the temperature for reaction for 3 - 5 h, and perform post-treatment to obtain modified carbon nanotubes.

[0010] The synthesis mechanism of the modified carbon nanotubes is as follows:

[0011] During the reaction process, the strong oxidizing properties of concentrated nitric acid and concentrated sulfuric acid in the mixed acid are used to oxidize the surface of the carbon nanotubes, remove impurities and generate oxygen-containing functional groups on the surface; under the action of ultrasonic waves, it promotes the uniform dispersion of purified carbon nanotubes and 3-aminopropyltriethoxysilane in absolute ethanol. Then, 3-aminopropyltriethoxysilane hydrolyzes under the action of the catalyst to generate reactive silanol groups, and the silanol condenses with the oxygen-containing functional groups on the surface of the purified carbon nanotubes to form amino modification on its surface, and the modified carbon nanotubes are prepared.

[0012] Further, in step A1, the dosage ratio of carbon nanotubes to the mixed acid is 1 g:30 mL. The mixed acid is composed of 98 wt% concentrated sulfuric acid and 68 wt% concentrated nitric acid in a volume ratio of 3:2. The post-treatment includes: after the reaction is completed, lower the temperature of the three-necked flask to room temperature, perform suction filtration, wash the filter cake with purified water until it is neutral, transfer the filter cake to a drying oven at 60 - 70 °C, and dry to constant weight to obtain purified carbon nanotubes; in step A2, the dosage ratio of 3-aminopropyltriethoxysilane, absolute ethanol, purified carbon nanotubes and the catalyst is 1 g:10 mL:3 g:2 mL. The catalyst is 0.5 - 2 mol / L hydrochloric acid solution. The post-treatment includes: after the reaction is completed, lower the temperature of the three-necked flask to room temperature, perform suction filtration, wash the filter cake with purified water until it is neutral, transfer the filter cake to a drying oven at 60 - 70 °C, and dry to constant weight to obtain modified carbon nanotubes.

[0013] Further, the modified graphene is processed by the following steps:

[0014] B1. Add concentrated nitric acid and natural flake graphite into a three-necked flask and stir. Raise the temperature of the three-necked flask to 80 - 90 °C, and perform post-treatment to obtain pre-oxidized graphite;

[0015] B2. Add pre-oxidized graphite, concentrated sulfuric acid and potassium permanganate into a three-necked flask and stir. Lower the temperature of the three-necked flask to 5 - 20 °C, stir for 1 - 2 h, gradually raise the temperature of the three-necked flask to 35 - 40 °C, react for 2 - 3 h, and perform post-treatment to obtain modified graphene.

[0016] The synthesis mechanism of the modified graphene is as follows:

[0017] During the reaction process, concentrated nitric acid oxidizes graphite at high temperature, introducing oxygen-containing groups onto the graphite surface, producing an expansion effect, and promoting the separation of graphite layers; through the dual oxidation of concentrated sulfuric acid and potassium permanganate, the oxidation degree of graphite is further increased, and the interlayer peeling is enhanced, thereby preparing modified graphene.

[0018] Further, in step B1, the dosage ratio of concentrated nitric acid to natural flake graphite is 4 mL:1 g, the concentration of the concentrated nitric acid is 98 wt%, and the post-treatment includes: after the reaction is completed, the temperature of the three-necked flask is reduced to room temperature, suction filtration is carried out, and the filter cake is washed with purified water until neutral to obtain pre-oxidized graphite; in step B2, the dosage ratio of pre-oxidized graphite, concentrated sulfuric acid and potassium permanganate is 1 g:40 mL:3 mL, and the post-treatment includes: after the reaction is completed, the temperature of the three-necked flask is reduced to room temperature, and then the reaction mixture is slowly poured into a beaker containing 100 mL of deionized water and 5 mL of 30% hydrogen peroxide, suction filtration is carried out, the filter cake is washed 3-5 times with 10% hydrochloric acid solution, and then washed with deionized water until neutral. The washed filter cake is transferred to an oven at 60-80 °C and dried to constant weight to obtain graphene oxide powder.

[0019] Further, the toughening agent is processed by the following steps:

[0020] C1. Add polysulfone and carboxyl-terminated nitrile rubber to a high-speed mixer and stir and mix at 150-200 °C for 10-15 min to obtain a premix;

[0021] C2. Add the premix, chain extender and catalyst to a twin-screw extruder, carry out melt blending at a temperature of 280-320 °C for 5-15 min and then extrude and pelletize to obtain a toughening agent.

[0022] The reaction mechanism of the toughening agent is as follows:

[0023] During the reaction process, polysulfone and carboxyl-terminated nitrile rubber are added to a high-speed mixer and melted under high-temperature conditions. The end groups of the carboxyl-terminated nitrile rubber form hydrogen bonds with the polar molecules of polysulfone, enhancing the adhesion and compatibility between the two, making the two polymers mix better; in the extruder, the amino group in 4,4'-diaminodiphenyl sulfone undergoes a condensation reaction with the ester group in polysulfone. Triethylamine, as a catalyst, can accelerate the reaction, enabling the reaction to proceed smoothly in a short time. At the same time, it also enhances the crosslinking degree of the material by promoting the interaction between molecular chains, further enhancing the mechanical properties and wear resistance of the material. The condensation reaction between 4,4'-diaminodiphenyl sulfone and polysulfone leads to the elongation of the molecular chain, thereby increasing the molecular weight of the polymer, improving its mechanical properties, and enhancing toughness, thereby preparing the toughening agent.

[0024] Furthermore, the mass ratio of polyethersulfone to carboxyl-terminated nitrile rubber is 1:2, and the rotation speed of the high-speed stirrer is 800 - 1000 r / min; in step C2, the temperatures of the 6 temperature zones of the twin-screw extruder from the feed end to the discharge end are 200 °C, 250 °C, 250 °C, 260 °C, 280 °C, and 320 °C in sequence, the volume ratio of the premix, chain extender, and catalyst is 50:2:1, the chain extender is 4,4'-diaminodiphenyl sulfone, and the catalyst is triethylamine.

[0025] The present invention also provides a method for preparing a wear-resistant and aging-resistant composite PC material. PC, anti-aging additives, modified carbon nanotubes, modified graphene, epoxy resin, toughening agents, and auxiliary additives are added to a twin-screw extruder, melted and extruded into a mold, and cooled and formed to obtain the composite PC material.

[0026] Furthermore, the temperatures of the 6 temperature zones of the twin-screw extruder from the feed end to the discharge end are 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, and 280 °C in sequence, and the rotation speed of the twin-screw extruder is 250 - 300 r / min.

[0027] The present invention has the following beneficial effects:

[0028] 1. In the present invention, after the surface of carbon nanotubes is oxidized by a mixed acid, amorphous impurities on the surface of the carbon nanotubes are removed, oxygen-containing functional groups are generated on the surface of the carbon nanotubes, and at the same time, the carbon nanotubes are broken by the acid, improving the dispersibility of the carbon nanotubes and providing more active sites for subsequent modification; 3-aminopropyltriethoxysilane undergoes hydrolysis and condensation with the oxygen-containing groups on the surface of the carbon nanotubes, increasing the functional groups on the surface of the carbon nanotubes, improving the dispersibility of the modified carbon nanotubes in the composite PC material, thereby enhancing the interfacial bonding force between the carbon nanotubes and the polymer matrix and improving the tensile strength and toughness of the composite material; by modifying graphene, oxygen-containing groups are introduced on the surface of graphene, changing the surface properties of graphene, breaking the chemical bonds between graphite layers, changing from hydrophobic to hydrophilic, greatly improving its solubility and dispersibility in water. At the same time, the introduction of oxygen-containing groups provides more active sites for graphene. When graphene is compounded with composite PC, the functional groups on the surface of the modified graphene can undergo chemical bonding or physical adsorption with the composite PC, enhancing the interfacial bonding force between graphene and the matrix, thereby improving the mechanical properties, thermal properties, and toughness of the composite material.

[0029] 2. After the toughening agent is modified, polyethersulfone is a heat-resistant plastic with strong heat resistance and processing performance. By combining the rigidity of polyethersulfone and the toughness of carboxyl-terminated nitrile rubber, the toughness of the toughening agent is significantly improved, the impact resistance is enhanced, and it can effectively resist external force impacts, reducing phenomena such as cracking and breaking during the use of the material. Polyethersulfone itself has high heat resistance, and carboxyl-terminated nitrile rubber can also withstand relatively high temperatures to a certain extent. After melt blending and modification, the toughening agent can still maintain good heat resistance and can be used in a high-temperature environment without significant performance degradation. 4,4'-Diaminodiphenyl sulfone enhances the compatibility and intermolecular synergistic effect between polyethersulfone and carboxyl-terminated nitrile rubber through cross-linking, thereby effectively improving the toughening effect and the impact toughness of the composite material. The catalyst triethylamine can promote the chemical reaction between polyethersulfone and carboxyl-terminated nitrile rubber, helping to form a uniform and stable blend system and improving the performance of the toughening agent.

[0030] 3. After adding anti-aging additives to the present invention, antioxidant 1010 is a hindered phenol antioxidant that can provide active hydrogen atoms to combine with free radicals generated during the processing and use of PC materials, thereby terminating the free radical chain reaction and preventing the oxidation process, improving the thermal stability and processing stability of PC materials and extending their service life. UV-328 belongs to benzotriazole ultraviolet absorbers, which can strongly absorb ultraviolet light and convert the absorbed ultraviolet light energy into harmless heat energy and release it, thereby improving the light aging resistance of PC materials. Hindered amine 292 is a highly efficient light stabilizer that exerts its light stabilizing effect through various ways such as capturing free radicals in PC materials, decomposing peroxides, and quenching excited state molecules. Hindered amine 292 will undergo a reversible conversion of nitroxide free radicals under light irradiation, thereby continuously capturing free radicals and inhibiting the progress of photooxidation reactions, further improving the light aging resistance of PC materials. Antioxidant 1010, UV-328, and hindered amine 292 build a synergistic anti-aging system for ultraviolet light aging resistance in the composite PC material, thereby more comprehensively protecting the PC material from damage by ultraviolet light and photooxidation, extending the service life of the PC material in outdoor and light environments, and at the same time improving the weather resistance and mechanical properties of the PC material. Detailed implementation mode

[0031] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention.

[0032] In this application, the carbon nanotubes are multi-walled carbon nanotubes, selected from Jiangsu Pioneer Nano Materials Technology Co., Ltd., with a CAS number of 1333-86-4, a length of 10-30 um, a diameter of 10-30 nm, and a purity of 95%;

[0033] In this application, the polyethersulfone is selected from Dongguan Yingxiang Plastic Raw Materials Co., Ltd., with a grade of JF1006, a specification of 25 mm, and an active ingredient content of 100%;

[0034] In this application, the carboxyl-terminated nitrile rubber is selected from Hubei Langbo Wanwu Medicine Co., Ltd., with an active ingredient content of 98%;

[0035] In this application, 3-aminopropyltriethoxysilane is selected from Shandong Jueneng Chemical Co., Ltd., with a CAS number of 919-30-2 and an active ingredient content of 100%;

[0036] In this application, 4,4'-diaminodiphenyl sulfone is selected from Dongguan Hongzan Composite Materials Technology Co., Ltd., with a CAS number of 80-08-003, a particle size of 5-40 um, and an active ingredient content of 99.5%;

[0037] Example 1

[0038] This example provides a method for preparing a wear-resistant and aging-resistant composite PC material, which includes the following steps:

[0039] S1. Prepare modified carbon nanotubes

[0040] Mix 98 wt% concentrated sulfuric acid and 68 wt% concentrated nitric acid in a volume ratio of 3:2 and set aside after mixing evenly;

[0041] Weigh: Add 5 g of carbon nanotubes and 150 mL of the mixed acid to a three-necked flask and stir. Raise the temperature of the three-necked flask to 60 °C, keep the temperature for 4 h, lower the temperature of the three-necked flask to room temperature, filter by suction, wash the filter cake with purified water until neutral, transfer the filter cake to a drying oven at 60 °C, and dry to constant weight to obtain purified carbon nanotubes;

[0042] Weigh: Add 10 g of 3-aminopropyltriethoxysilane and 100 mL of absolute ethanol to a three-necked flask, add 30 g of purified carbon nanotubes to the three-necked flask, ultrasonically disperse for 30 min, then add 20 mL of 0.5 mol / L hydrochloric acid solution thereto, raise the temperature of the three-necked flask to 55 °C, keep the temperature for 3 h, lower the temperature of the three-necked flask to room temperature, filter by suction, wash the filter cake with purified water until neutral, transfer the filter cake to a drying oven at 60 °C, and dry to constant weight to obtain modified carbon nanotubes.

[0043] S2. Prepare modified graphene

[0044] Weigh: 20 mL of 98 wt% concentrated nitric acid and 5 g of natural flake graphite are added to a three-necked flask and stirred. The temperature of the three-necked flask is raised to 80 °C, then lowered to room temperature. Filter by suction, and the filter cake is washed with purified water until neutral to obtain pre-oxidized graphite;

[0045] Weigh: 5 g of pre-oxidized graphite, 200 mL of 68 wt% concentrated sulfuric acid, and 15 mL of potassium permanganate are added to a three-necked flask and stirred. The temperature of the three-necked flask is lowered to 5 °C and stirred for 1 h. Then the temperature of the three-necked flask is gradually raised to 35 °C and reacted for 2 h. The temperature of the three-necked flask is lowered to room temperature. Then the reaction mixture is slowly poured into a beaker containing 100 mL of deionized water and 5 mL of 30% hydrogen peroxide. Filter by suction, and the filter cake is washed 3 times with 10% hydrochloric acid solution, and then washed with deionized water until neutral. The washed filter cake is transferred to an oven at 60 °C and dried to constant weight to obtain graphene oxide powder.

[0046] S3. Prepare the modified toughening agent

[0047] Weigh: 5 g of polyethersulfone and 10 g of carboxyl-terminated nitrile rubber are added to a high-speed mixer, and the rotation speed is 800 r / min. Stir and mix at 150 °C for 10 min to make the two preliminarily mixed evenly. The pre-mixed material is added to a twin-screw extruder and melt-blended at 280 °C for 5 min. Through a metering device, 15 mL of 4,4'-diaminodiphenyl sulfone and 5 mL of catalyst triethylamine are added to the twin-screw extruder. The material is extruded from the head of the twin-screw extruder and cooled and shaped through a water-cooling system, and then pelletized with a pelletizer to obtain the toughening agent.

[0048] S4. Prepare the composite PC material

[0049] Mix antioxidant 1010, UV-328, and hindered amine 292 evenly according to the weight ratio of 1:2:1 to obtain the anti-aging aid;

[0050] Weigh: 105 g of PC, 3 mL of anti-aging aid, 7 g of modified carbon nanotubes, 1 g of modified graphene, 0.2 g of epoxy resin, 5 mL of toughening agent, and 3 mL of auxiliary additive are added to a twin-screw extruder. Control the temperatures of the 6 temperature zones of the twin-screw extruder from the feeding end to the discharging end to be 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, and 280 °C in sequence. The rotation speed of the twin-screw extruder is 250 r / min, heat for 15 min, melt and extrude into a mold, and cool and form to obtain the composite PC material.

[0051] Example 2

[0052] This example provides a preparation method of a wear-resistant and anti-aging composite PC material, including the following steps:

[0053] S1. Prepare the modified carbon nanotubes

[0054] Mix 98 wt% concentrated sulfuric acid and 68 wt% concentrated nitric acid in a volume ratio of 3:2 and keep it evenly mixed for standby;

[0055] Weigh: 5 g of carbon nanotubes and 150 mL of the mixed acid, add them to a three-necked flask and stir. Heat the temperature of the three-necked flask to 65 °C, keep the temperature for reaction for 5 h, then lower the temperature of the three-necked flask to room temperature, carry out suction filtration, wash the filter cake with purified water until it is neutral, transfer the filter cake to a drying oven at 65 °C, and dry it to constant weight to obtain purified carbon nanotubes;

[0056] Weigh: 10 g of 3-aminopropyltriethoxysilane and 100 mL of absolute ethanol, add them to a three-necked flask, add 30 g of purified carbon nanotubes to the three-necked flask, disperse them ultrasonically for 40 min, then add 20 mL of 1.2 mol / L hydrochloric acid solution to it, heat the temperature of the three-necked flask to 60 °C, keep the temperature for reaction for 4 h, lower the temperature of the three-necked flask to room temperature, carry out suction filtration, wash the filter cake with purified water until it is neutral, transfer the filter cake to a drying oven at 65 °C, and dry it to constant weight to obtain modified carbon nanotubes.

[0057] S2. Preparation of modified graphene

[0058] Weigh: 20 mL of 98 wt% concentrated nitric acid and 5 g of natural flake graphite, add them to a three-necked flask and stir. Heat the temperature of the three-necked flask to 85 °C, then lower the temperature of the three-necked flask to room temperature, carry out suction filtration, wash the filter cake with purified water until it is neutral to obtain pre-oxidized graphite;

[0059] Weigh: 5 g of pre-oxidized graphite, 200 mL of 68 wt% concentrated sulfuric acid, and 15 mL of potassium permanganate, add them to a three-necked flask and stir. Lower the temperature of the three-necked flask to 12 °C, stir for 1.5 h, gradually heat the three-necked flask to 37 °C, react for 2.5 h, lower the temperature of the three-necked flask to room temperature, then slowly pour the reaction mixture into a beaker containing 100 mL of deionized water and 5 mL of 30% hydrogen peroxide, carry out suction filtration, wash the filter cake 4 times with 10% hydrochloric acid solution, and then wash it with deionized water until it is neutral. Transfer the washed filter cake to a drying oven at 70 °C and dry it to constant weight to obtain graphene oxide powder.

[0060] S3. Preparation of modified toughening agent

[0061] Weigh: 5 g of polyethersulfone and 10 g of carboxyl-terminated nitrile rubber are added to a high-speed mixer. The rotation speed is 900 r / min, and the mixture is stirred at 180 °C for 10 - 12 min to make a preliminary uniform mixture of the two. The pre-mixed material is added to a twin-screw extruder and melt-blended at a temperature of 300 °C for 10 min. 15 mL of 4,4'-diaminodiphenyl sulfone and 5 mL of catalyst triethylamine are added to the twin-screw extruder through a metering device. The material is extruded from the head of the twin-screw extruder, cooled and shaped by a water-cooling system, and then pelletized by a pelletizer to obtain a toughening agent.

[0062] S4. Prepare the composite PC material

[0063] Mix antioxidant 1010, UV-328 and hindered amine 292 evenly according to the weight ratio of 1:2:1 to obtain an anti-aging aid;

[0064] Weigh: 113 g of PC, 4 mL of anti-aging aid, 8 g of modified carbon nanotubes, 1 g of modified graphene, 1.5 g of epoxy resin, 5.5 mL of toughening agent, and 4 mL of auxiliary additive are added to a twin-screw extruder. Control the temperatures of the 6 temperature zones of the twin-screw extruder from the feed end to the discharge end to be 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, and 280 °C in sequence. The rotation speed of the twin-screw extruder is 275 r / min. Heat for 15 min, melt and extrude into a mold, and cool and form to obtain a composite PC material.

[0065] Example 3

[0066] This example provides a method for preparing a wear-resistant and anti-aging composite PC material, including the following steps:

[0067] S1. Prepare modified carbon nanotubes

[0068] Mix 98 wt% concentrated sulfuric acid and 68 wt% concentrated nitric acid evenly according to the volume ratio of 3:2 for standby;

[0069] Weigh: 5 g of carbon nanotubes and 150 mL of mixed acid are added to a three-necked flask and stirred. The temperature of the three-necked flask is raised to 70 °C, and the reaction is carried out for 6 h while maintaining the temperature. The temperature of the three-necked flask is lowered to room temperature, and suction filtration is carried out. The filter cake is washed with purified water until neutral. The filter cake is transferred to a drying oven at 70 °C and dried to constant weight to obtain purified carbon nanotubes;

[0070] Weigh: 10 g of 3-aminopropyltriethoxysilane and 100 mL of absolute ethanol and add them to a three-necked flask. Then add 30 g of purified carbon nanotubes to the three-necked flask, ultrasonically disperse for 50 min, and then add 20 mL of 2 mol / L hydrochloric acid solution. Raise the temperature of the three-necked flask to 65 °C, keep the temperature for reaction for 5 h, lower the temperature of the three-necked flask to room temperature, carry out suction filtration, wash the filter cake with purified water until neutral, transfer the filter cake to a drying oven at 70 °C, and dry to constant weight to obtain modified carbon nanotubes.

[0071] S2. Prepare modified graphene

[0072] Weigh: 20 mL of 98 wt% concentrated nitric acid and 5 g of natural flake graphite and add them to a three-necked flask for stirring. Raise the temperature of the three-necked flask to 90 °C, then lower the temperature of the three-necked flask to room temperature, carry out suction filtration, wash the filter cake with purified water until neutral to obtain pre-oxidized graphite.

[0073] Weigh: 5 g of pre-oxidized graphite, 200 mL of 68 wt% concentrated sulfuric acid, and 15 mL of potassium permanganate and add them to a three-necked flask for stirring. Lower the temperature of the three-necked flask to 20 °C, stir for 2 h, gradually raise the temperature of the three-necked flask to 40 °C, react for 3 h, lower the temperature of the three-necked flask to room temperature, and then slowly pour the reaction mixture into a beaker containing 100 mL of deionized water and 5 mL of 30% hydrogen peroxide. Carry out suction filtration, wash the filter cake 5 times with 10% hydrochloric acid solution, and then wash with deionized water until neutral. Transfer the washed filter cake to a drying oven at 80 °C and dry to constant weight to obtain graphene oxide powder.

[0074] S3. Prepare modified toughening agent

[0075] Weigh: 5 g of polyethersulfone and 10 g of carboxyl-terminated nitrile rubber and add them to a high-speed mixer. The rotation speed is 1000 r / min, and stir and mix at 200 °C for 15 min to make the two preliminarily mixed evenly. Add the pre-mixed material to a twin-screw extruder, carry out melt blending at a temperature of 320 °C for 15 min, add 15 mL of 4,4'-diaminodiphenyl sulfone and 5 mL of catalyst triethylamine to the twin-screw extruder through a metering device. The material is extruded from the head of the twin-screw extruder, cooled and shaped through a water cooling system, and then pelletized with a pelletizer to obtain a toughening agent.

[0076] S4. Prepare composite PC material

[0077] Mix antioxidant 1010, UV-328, and hindered amine 292 evenly according to a weight ratio of 1:2:1 to obtain an anti-aging aid.

[0078] Weigh: 120 g of PC, 5 mL of anti-aging agent, 9 g of modified carbon nanotubes, 1 g of modified graphene, 2 g of epoxy resin, 6 mL of toughening agent, and 5 mL of auxiliary additive, and add them to a twin-screw extruder. Control the temperatures of the 6 temperature zones of the twin-screw extruder from the feeding end to the discharging end to be 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, and 280 °C in sequence. The rotation speed of the twin-screw extruder is 300 r / min. Heat for 15 min, melt and extrude into a mold, and cool and form to obtain a composite PC material.

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 3 is that step S1 is cancelled, and the carbon nanotubes in step S1 are used to replace the modified carbon nanotubes in step S4.

[0081] Comparative Example 2

[0082] The difference between this comparative example and Example 3 is that step S2 is cancelled, and the natural flake graphite in step S2 is used to replace the modified graphene in step S4.

[0083] Comparative Example 3

[0084] The difference between this comparative example and Example 3 is that step S3 is cancelled, and the carboxylated acrylonitrile-butadiene rubber in step S3 is used to replace the modified toughening agent in step S4.

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 3 is that UV-328 is not added to the anti-aging agent in step S4.

[0087] Performance test:

[0088] Refer to the standard GB / T 1843-2008 "Determination of Izod impact strength of plastics" to determine the Izod notched impact strength of the composite PC materials prepared in Examples 1-3 and Comparative Examples 1-4;

[0089] Refer to the standard GB / T 35513.2-2017 "Plastics - Polycarbonate (PC) moulding and extrusion materials - Part 2: Preparation of test specimens and determination of properties" to determine the tensile strength and wear resistance of the composite PC materials prepared in Examples 1-3 and Comparative Examples 1-4;

[0090] Place the composite PC prepared in Examples 1-3 and Comparative Examples 1-4 in a xenon lamp aging test chamber to simulate the ultraviolet, visible, and infrared radiation in natural sunlight, and set the light intensity to 60 - 100 W / m 2, the blackboard temperature is 50 °C, the relative humidity is 50%, the cycle period adopts 100 minutes of light + 20 minutes of water spraying, and the aging is 1000 h. The UV aging resistance of the composite PC is measured. The specific test results are shown in Table 1 below.

[0091] Table 1 - Performance test data table of the specimens

[0092]

[0093] Data analysis:

[0094] Comparative analysis is carried out on the data in Table 1 above. The notched Izod impact strength of the composite PC material prepared by the present invention reaches 79 kJ / m 2 , the tensile strength reaches 70 MPa, and the abrasion loss is 3.2 mg. After UV aging, the notched Izod impact strength is 68 kJ / m 2 , the tensile strength is 65 MPa, and the abrasion loss is 3.8 mg. The test data of each example are better than those of the comparative example. Therefore, after modifying carbon nanotubes, graphene and toughening agents and adding antioxidant UV-328, the present invention not only effectively improves the wear resistance and aging resistance of the composite PC material, but also improves the toughness and mechanical strength.

[0095] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific implementation manners. Obviously, according to the content of this specification, many modifications and changes can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A wear-resistant and aging-resistant composite PC material, characterized in that: The invention comprises the following components in parts by weight: 105-120 parts of PC, 3-5 parts of anti-aging additive, 7-9 parts of modified carbon nanotubes, 1 part of modified graphene, 0.5-2 parts of epoxy resin, 5-6 parts of toughening agent and 3-5 parts of auxiliary additives.

2. The wear-resistant and aging-resistant composite PC material according to claim 1, characterized in that: The anti-aging auxiliary agent is composed of antioxidant 1010, UV-328 and hindered amine 292 in a weight ratio of 1:2:

1.

3. The wear-resistant and aging-resistant composite PC material according to claim 1, characterized in that: The modified carbon nanotubes are obtained by processing the following steps: A1. Add carbon nanotubes and mixed acid into a three-necked flask, stir, react at 60-70° C. for 4-6 hours, and post-treat to obtain purified carbon nanotubes; A2. Add 3-aminopropyltriethoxysilane and anhydrous ethanol into a three-necked flask and stir, add purified carbon nanotubes into the three-necked flask, ultrasonically disperse for 30-50 minutes, and then add a catalyst, increase the temperature of the three-necked flask to 55-65°C, keep the reaction warm for 3-5 hours, and post-treat to obtain modified carbon nanotubes.

4. The wear-resistant and aging-resistant composite PC material according to claim 3, characterized in that: In step A1, the amount ratio of carbon nanotubes and mixed acid is 1g:30mL, and the mixed acid is composed of 98wt% concentrated sulfuric acid and 68wt% concentrated nitric acid in a volume ratio of 3:2; in step A2, the amount ratio of 3-aminopropyltriethoxysilane, anhydrous ethanol, purified carbon nanotubes and catalyst is 1g:10mL:3g:2mL, and the catalyst is 0.5-2mol / L hydrochloric acid solution.

5. The wear-resistant and aging-resistant composite PC material according to claim 1, characterized in that: The modified graphene is processed by the following steps: B1. Add concentrated nitric acid and natural flake graphite into a three-necked flask and stir. The temperature of the three-necked flask is raised to 80-90° C. and post-treated to obtain pre-oxidized graphite. B2. Add pre-oxidized graphite, concentrated sulfuric acid and potassium permanganate into a three-necked flask and stir. Lower the temperature of the three-necked flask to 5-20° C. and stir for 1-2 hours. Gradually heat the three-necked flask to 35-40° C. and react for 2-3 hours. Post-treat to obtain modified graphene.

6. The wear-resistant and aging-resistant composite PC material according to claim 1, characterized in that: In step B1, the ratio of concentrated nitric acid to natural flake graphite is 4 mL: 1 g, and the concentration of concentrated nitric acid is 98 wt %; in step B2, the ratio of pre-oxidized graphite, concentrated sulfuric acid and potassium permanganate is 1 g: 40 mL: 3 mL, and the concentration of concentrated sulfuric acid is 68 wt %.

7. The wear-resistant and aging-resistant composite PC material according to claim 1, characterized in that: The toughening agent is obtained by processing the following steps: C1. Add polyethersulfone and carboxyl-terminated nitrile rubber into a high-speed mixer, and stir and mix at 150-200° C. for 10-15 minutes to obtain a premix; C2. Add the pre-material, chain extender and catalyst into a twin-screw extruder, melt-blend at a temperature of 280-320° C. for 5-15 minutes, and then extrude and granulate to obtain a toughening agent.

8. The wear-resistant and aging-resistant composite PC material according to claim 7, characterized in that: In step C1, the mass ratio of polyether sulfone to terminal carboxyl nitrile rubber is 1:2, and the rotation speed of the high-speed stirrer is 800-1000r / min; in step C2, the temperatures of the six temperature sections of the twin-screw extruder from the feed end to the discharge end are 200°C, 250°C, 250°C, 260°C, 280°C, and 320°C, respectively, and the volume ratio of the premix, the chain extender, and the catalyst is 50:2:1, the chain extender is 4,4'-diaminodiphenyl sulfone, and the catalyst is triethylamine.

9. A method for preparing a wear-resistant and aging-resistant composite PC material according to any one of claims 1 to 8, characterized in that: PC, anti-aging additive, modified carbon nanotube, modified graphene, epoxy resin, toughening agent and auxiliary additives are added into a twin-screw extruder, melt-extruded into a mold, cooled and formed to obtain a composite PC material.

10. The method for preparing a wear-resistant and aging-resistant composite PC material according to claim 9, characterized in that: The temperatures of the six temperature sections of the twin-screw extruder from the feed end to the discharge end are 230° C., 240° C., 250° C., 260° C., 270° C., and 280° C., respectively, and the rotation speed of the twin-screw extruder is 250-300 r / min.

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