Low-temperature-freezing-resistant polycarbonate abrasive material and preparation method thereof

Abstract

The invention relates to the technical field of polycarbonate composite materials, and discloses a low temperature freezing resistant polycarbonate abrasive material and a preparation method thereof, the low temperature freezing resistant polycarbonate abrasive material comprises the following raw materials by mass: 80-90 parts of polycarbonate, 25-30 parts of an organosilicon-polycarbonate copolymer, 10-15 parts of a wear resistant filler, 12-14 parts of a low temperature resistant modifier, 5-7 parts of a flexibilizer, 0.5-0.7 part of a compatilizer, and 0.4-0.6 part of an antioxidant. Silicon carbide nanowires in the wear-resistant filler are wound on the surfaces of the composite modified glass fibers, so that a sandwich structure on the surfaces of the composite modified glass fibers can be stabilized, and the situation that graphene oxide on the surfaces of the composite modified glass fibers falls off and the wear resistance is influenced under long-term friction of the polycarbonate abrasive material is avoided; the porous structure of the low-temperature-resistant modifier can effectively prevent external cold air from invading, and the situation that movement of a polycarbonate molecular chain segment is limited at low temperature, and the low-temperature-resistant toughness is reduced is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of polycarbonate composite materials, and specifically to a low-temperature resistant polycarbonate abrasive and a preparation method thereof. Background Art

[0002] In the processing of injection-molded and compression-molded parts, there are often some flashings at the edges and corners of many parts. Processing them manually not only has low efficiency, but also the appearance of the processed parts cannot be guaranteed, affecting the appearance of the parts; using conventional abrasives for processing can meet general flashings, but for some relatively precise and high-requirement parts or for some parts with relatively high hardness and rigidity, the processing effect is relatively poor and needs to be carried out at low temperature. General abrasives are prone to breakage at low temperature and cannot achieve the effect of processing flashings.

[0003] Polycarbonate (PC) has the advantages of high low-temperature impact resistance and good hardness, so it is widely used in the process of processing flashings that require low-temperature freezing treatment, with obvious effects and relatively small wear. However, the existing polycarbonate abrasives have poor low-temperature toughness. When processing the flashings of parts, they are prone to crack and break, and the abrasion resistance of polycarbonate abrasives is insufficient, resulting in easy wear under long-term friction and reducing the service life of polycarbonate. Summary of the Invention

[0004] The present invention provides a low-temperature resistant polycarbonate abrasive and a preparation method thereof, which solve the problems of poor low-temperature toughness and insufficient abrasion resistance of polycarbonate abrasives.

[0005] The technical solution of the present invention: A low-temperature resistant polycarbonate abrasive, comprising the following raw materials in parts by mass: 80-90 parts of polycarbonate, 25-30 parts of organosilicon-polycarbonate copolymer, 10-15 parts of wear-resistant filler, 12-14 parts of low-temperature modifier, 5-7 parts of toughening agent, 0.5-0.7 parts of compatibilizer, and 0.4-0.6 parts of antioxidant; The wear-resistant filler is obtained by mixing and reacting oxidized glass fiber, zirconium oxychloride octahydrate and ammonia water, then mixing with pretreated graphene oxide, and adding silica sol and glucose to continue the reaction; The low-temperature modifier is obtained by surface-modifying epoxidized styrene-butadiene rubber with amino silane and then mixing and reacting with chitosan, glutaraldehyde and hydroxypropyl cellulose.

[0006] A preparation method of a low-temperature resistant polycarbonate abrasive, comprising the following preparation steps: S1. Place polycarbonate, organosilicon-polycarbonate copolymer, wear-resistant filler, low-temperature modifier, toughening agent, compatibilizer and antioxidant in a mixer, and stir and mix at 400-500 r / min for 30-40 min to obtain a mixed material; S2. Place the mixture in a twin-screw extruder for melt mixing, melt extrude and draw it through a die, and wind it to obtain the as-wound virgin fiber. Cut the as-wound virgin fiber into pellets to obtain polycarbonate abrasives.

[0007] Further, the polycarbonate is selected from aliphatic polycarbonate, aromatic polycarbonate or aliphatic-aromatic polycarbonate.

[0008] Further, the weight-average molecular weight of the polycarbonate-silicone block copolymer is 17,000 - 25,000, and the effective silicon content is 6 - 9%.

[0009] Further, the toughening agent has a core-shell structure. The shell is a methyl methacrylate-butadiene copolymer with a molecular weight of 20,000 - 25,000; the core is silicone rubber with an effective silicon content of 20 - 30%.

[0010] Further, the compatibilizer is an ethylene-methyl acrylate copolymer.

[0011] Further, the antioxidant is selected from antioxidant 168 and antioxidant 1010.

[0012] Further, the length-diameter ratio of the twin-screw extruder is (36 - 40):1. The processing temperatures of each section of the twin-screw extruder are as follows: the first section is 230 - 240 °C, the second section is 235 - 245 °C, the third section is 240 - 250 °C, the fourth section is 250 - 260 °C, the fifth section is 260 - 270 °C, the sixth section is 250 - 260 °C, the seventh section is 240 - 250 °C, and the head is 220 - 240 °C.

[0013] Further, for the extrusion and melt drawing process: the water temperature of the extrusion cooling water is 25 - 50 °C, the first drawing speed is 10 - 20 m / min; the temperature of the hot water tank for drawing is 80 - 98 °C; the second drawing speed is 30 - 90 m / min; the temperature of the heat treatment oven is 140 - 190 °C; the third drawing speed is 25 - 80 m / min.

[0014] Further, the wear-resistant filler is specifically prepared by the following steps: A1. Place the glass fiber in hydrogen peroxide, stir evenly, heat up to 105 - 115 °C, stir and react for 3 - 4 h, cool to room temperature, filter, wash, and dry to obtain oxidized glass fiber; A2. Add zirconium oxychloride octahydrate and oxidized glass fiber to deionized water, stir evenly, add ammonia water, glycine and potassium chloride, stir and mix, then place it in a reaction kettle, carry out hydrothermal reaction at 170 - 190 °C for 20 - 22 h, cool to room temperature, filter, wash, and dry to obtain glass fiber loaded with nano-zirconia oxide. A3. Graphene oxide is added to Tris-HCl buffer solution in water. After ultrasonic dispersion, dopamine is added, and ultrasonic dispersion is continued. Then, after filtration, washing, and drying, polydopamine-modified graphene oxide is obtained. A4. The polydopamine-modified graphene oxide is added to deionized water and stirred evenly. Glass fiber loaded with nano-zirconia is added, and stirring and mixing are carried out at 800 - 1000 r / min for 1 - 2 h. After filtration, washing, and drying, the composite modified glass fiber is obtained. A5. Tetraethyl orthosilicate, deionized water, and sodium hydroxide are mixed and stirred evenly to form silica sol. Nitric acid is added to the silica sol and stirred evenly to obtain a mixed solution. Glucose is added to deionized water and stirred at 40 - 50 °C for 25 - 35 min. The mixed solution and the composite modified glass fiber are added and stirred evenly, and then pyrolyzed at high temperature at 1250 - 1350 °C for 2 - 4 h, and cooled to room temperature to obtain the wear-resistant filler.

[0015] Furthermore, in the above A1 reaction process, hydrogen peroxide is used as an oxidant, which breaks the silicon-oxygen-silicon bonds on the surface of the glass fiber, exposing a large number of silanol group structures, and oxidized glass fiber is obtained.

[0016] Furthermore, in the above A2 reaction process, a large number of hydroxyl groups are carried on the surface of the oxidized glass fiber, which can combine with zirconium ions in zirconium oxychloride octahydrate, enabling the zirconium source zirconium oxychloride octahydrate to be adsorbed on the surface of the oxidized glass fiber. Ammonia water is used as a precipitating agent, and glycine and potassium chloride are used as assistants, which can react with zirconium oxychloride octahydrate to form zirconium hydroxide deposited on the surface of the oxidized glass fiber. Continuing the reaction, zirconium hydroxide decomposes by heating, realizing the synthesis of 30 - 40 nm nano-zirconia on the surface of the oxidized glass fiber, and the glass fiber loaded with nano-zirconia is obtained.

[0017] Furthermore, in the above A3 reaction process, in Tris-HCl buffer solution, dopamine can self-polymerize on the surface of graphene oxide to form polydopamine, and polydopamine-modified graphene oxide is formed.

[0018] Furthermore, in the above A4 reaction process, a large number of phenolic hydroxyl groups are contained on the surface of the polydopamine-modified graphene oxide, which has excellent adhesion performance and can adhere to the surface of the glass fiber loaded with nano-zirconia, and the composite modified glass fiber is obtained.

[0019] Further, in the above A5 reaction process, using the composite modified glass fiber as a template, silica sol as the silicon source, and glucose as the carbon source, through high-temperature pyrolysis, the silica sol pyrolyzes to form silicon monoxide gas, which can react with the carbon element on the surface of the composite modified glass fiber to form silicon carbide crystal nuclei. Continuing the pyrolysis, glucose pyrolyzes to provide a large amount of carbon monoxide gas, which continues to react with the silicon monoxide, realizing the formation of silicon carbide nanowires with a diameter of 80 - 100 nm and a length of 5 - 10 μm on the surface of the composite modified glass fiber, and obtaining wear-resistant fillers.

[0020] Further, in step A1, the dosage ratio of glass fiber to hydrogen peroxide is (8 - 12) g : (45 - 55) mL.

[0021] Further, in step A2, the dosage ratio of zirconium oxychloride octahydrate, oxidized glass fiber, deionized water, ammonia water, glycine, and potassium chloride is (1.6 - 2) g : (4 - 5) g : (35 - 45) mL : (4 - 6) mL : (0.1 - 0.3) g : (0.3 - 0.5) g.

[0022] Further, in step A3, the dosage ratio of graphene oxide, Tris-HCl buffer solution, and dopamine is (1.4 - 1.6) g : (90 - 110) mL : (0.6 - 0.8) g.

[0023] Further, in step A4, the dosage ratio of graphene oxide modified with polydopamine, deionized water, and glass fiber loaded with nano-zirconium oxide is (1.1 - 1.3) g : (90 - 110) mL : (3.1 - 3.3) g.

[0024] Further, in step A5, the mass ratio of tetraethyl orthosilicate, deionized water, and sodium hydroxide is (0.8 - 1.2) : (50 - 60) : (6 - 7) g.

[0025] Further, in step A5, the dosage ratio of glucose, deionized water, the mixed solution, and the composite modified glass fiber is (3 - 4) g : (35 - 45) mL : (9 - 11) mL : (6 - 7) g.

[0026] Further, the length of the glass fiber is 10 - 15 μm, and the diameter is 0.3 - 0.5 μm.

[0027] Further, the particle size of graphene oxide is 0.5 - 1 μm.

[0028] Further, the low-temperature resistant modifier is specifically prepared by the following steps: B1. Add epoxidized styrene-butadiene rubber to ethanol and deionized water, stir evenly, add amino silane and hydrochloric acid, stir and react at 65 - 75 °C for 1 - 2 h, cool to room temperature, filter, wash, and dry to obtain modified styrene-butadiene rubber; B2. Add the modified styrene-butadiene rubber into deionized water, stir evenly, add chitosan, acetic acid solution and hydroxypropyl cellulose, after ultrasonic treatment, add aqueous glutaraldehyde solution, stir until it becomes gel-like, and the gel is freeze-dried to obtain the low-temperature resistant modifier.

[0029] Further, during the above B1 reaction process, the hydroxyl groups generated by the hydrolysis of amino silane can undergo ring-opening reaction with the epoxy groups in epoxidized styrene-butadiene rubber, enabling the amino silane to graft onto the epoxidized styrene-butadiene rubber to obtain the modified styrene-butadiene rubber.

[0030] Further, during the above B2 reaction process, chitosan and hydroxypropyl cellulose act as the gel skeleton, and glutaraldehyde acts as the cross-linking agent, which can react with the active functional groups in chitosan and hydroxypropyl cellulose to form a porous aerogel with a cross-linked network structure. Moreover, glutaraldehyde can also react with the amino and hydroxyl groups in the modified styrene-butadiene rubber, enabling the modified styrene-butadiene rubber to be embedded into the porous aerogel to obtain the low-temperature resistant modifier.

[0031] Further, in step B1, the dosage ratio of epoxidized styrene-butadiene rubber, ethanol, deionized water, amino silane and hydrochloric acid is (5.2 - 5.4) g : (55 - 65) mL : (15 - 25) mL : (1 - 2) g : (0.2 - 0.4) mL.

[0032] Further, in step B2, the dosage ratio of modified styrene-butadiene rubber, deionized water, chitosan, acetic acid solution, hydroxypropyl cellulose and aqueous glutaraldehyde solution is (0.5 - 0.7) g : (25 - 35) mL : (0.2 - 0.4) g : (0.2 - 0.4) mL : (18 - 22) g : (25 - 35) mL.

[0033] Further, the amino silane is γ-aminopropyltriethoxysilane.

[0034] The present invention has the following beneficial effects: (1) In the technical solution of the present invention, hydrogen peroxide is used as the oxidant, which breaks the silicon-oxygen-silicon bonds on the surface of the glass fiber, exposing a large number of silicon hydroxyl structures, increasing the surface activity of the glass fiber, and being conducive to forming a concave-convex wear-resistant layer on the surface of the glass fiber; synthesizing nano-zirconia on the surface of the oxidized glass fiber. On the one hand, at low temperatures, the formed nano-zirconia can absorb external stress, prevent the glass fiber from cracking at low temperatures and causing a decrease in the wear resistance of the polycarbonate abrasive, and the nano-zirconia and glass fiber increase the wear resistance and mechanical properties of the polycarbonate abrasive. On the other hand, the nano-zirconia forms a concave-convex wear-resistant layer on the surface of the glass fiber, plugs the pore structure of the glass fiber, reduces the moisture absorption performance of the glass fiber, and when added to the polycarbonate abrasive, increases the wear resistance and mechanical properties of the abrasive.

[0035] (2) In the technical solution of the present invention, polydopamine-modified graphene oxide endows graphene oxide with excellent adhesion performance, enabling it to adhere to the surface of glass fibers loaded with nano-zirconia. On the one hand, graphene oxide adheres to the surface of glass fibers loaded with nano-zirconia. Nano-zirconia serves as a lubricating component in the interlayer between graphene oxide and glass fibers. During the friction process of polycarbonate, nano-zirconia moves back and forth in the interlayer, generating a micro-ball bearing effect, increasing the buffering distance of graphene oxide on the surface of glass fibers, reducing friction, achieving a wear-resistant effect, and thus increasing the wear resistance of the polycarbonate abrasive. On the other hand, the lamellar structure of graphene oxide increases the roughness of the glass fibers, improves the contact area between the glass fibers and polycarbonate, enables the glass fibers to be filled into the polycarbonate abrasive, and the excellent aspect ratio of the composite modified glass fibers is randomly distributed in the polycarbonate abrasive, serving as stress concentration points. At low temperatures, when the abrasive is impacted, the composite modified glass fibers absorb a large amount of impact energy, thereby enhancing the low-temperature strength of the polycarbonate abrasive.

[0036] (3) In the technical solution of the present invention, silicon carbide nanowires are formed on the surface of the composite modified glass fibers. On the one hand, the formed silicon carbide nanowires wind around the surface of the composite modified glass fibers, which can stabilize the interlayer structure on the surface of the composite modified glass fibers, prevent the graphene oxide on the surface of the composite modified glass fibers from falling off under long-term friction, affecting the wear resistance, and thus increasing the service life of the abrasive. On the other hand, the silicon carbide nanowires wind around the surface of the composite modified glass fibers, further increasing the contact area between the wear-resistant filler and the polycarbonate abrasive, enabling the wear-resistant filler to be evenly distributed in the polycarbonate abrasive, and the silicon carbide nanowires can also improve the low-temperature strength of the abrasive.

[0037] (4) In the technical solution of the present invention, styrene-butadiene rubber has a relatively low glass transition temperature and is not easily frozen into a rigid structure at low temperatures. When added to the polycarbonate abrasive, it significantly enhances the low-temperature resistance of the polycarbonate abrasive; amino silane is grafted onto epoxidized styrene-butadiene rubber, which is beneficial for the epoxidized styrene-butadiene rubber to be embedded into the aerogel structure. Chitosan and hydroxypropyl cellulose serve as the gel skeletons, and glutaraldehyde serves as the cross-linking agent to form a porous aerogel with a cross-linked network structure. Moreover, the modified styrene-butadiene rubber is embedded into the porous aerogel. On the one hand, the formed porous aerogel can effectively prevent the intrusion of external cold air, avoid the movement of polycarbonate molecular segments being restricted at low temperatures, and the low-temperature toughness decreasing, resulting in cracks and breakage easily occurring when the polycarbonate abrasive processes the burrs of the workpiece. On the other hand, the modified styrene-butadiene rubber is embedded into the porous aerogel, increasing the cross-linking density of the porous aerogel, improving the mechanical strength and porosity, and further enhancing the low-temperature strength of the polycarbonate abrasive. Specific embodiments

[0038] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] The raw materials used in the embodiments of the present invention are as follows, and all the reagents used are of analytical grade.

[0040] Among them, the polycarbonate is an aromatic polycarbonate with a viscosity-average molecular weight of 17,000 and a melt index of 3 g / 10 min at 300 °C and 1.2 kg.

[0041] The polycarbonate-silicone block copolymer has a weight-average molecular weight of 20,000 and an effective silicon content of 7.3%. It is purchased from Fujian Sanyou Chemical Co., Ltd. and the product number is ST6-3022PJ.

[0042] The toughening agent is a core-shell structure toughening agent. Its shell is a methyl methacrylate-butadiene copolymer with a molecular weight of 23,000, and its core is silicone rubber with a glass transition temperature of -80 °C and an effective silicon content of 25%. It is purchased from Mitsubishi Rayon Polymer Materials (Nantong) Co., Ltd. and the product number is S-2030.

[0043] The compatibilizer is an ethylene-methyl acrylate copolymer, purchased from Arkema (China) Investment Co., Ltd., and the product number is AX8900.

[0044] The antioxidant is antioxidant 168.

[0045] The coupling agent is γ-aminopropyltriethoxysilane.

[0046] The styrene-butadiene rubber has a product number of 1712 and is of industrial grade. It is purchased from Yueyang Xingchang Petrochemical Co., Ltd.

[0047] The epoxidized styrene-butadiene rubber is specifically prepared by the following steps: Add 10 g of styrene-butadiene rubber to 100 mL of cyclohexane, stir evenly at 70 °C, add 1.1 g of formic acid, 0.3 g of polyethylene glycol-400 and 2.4 g of hydrogen peroxide, stir at 200 r / min for 2 h, place it in 100 mL of deionized water, heat up to 100 °C to form a precipitate, and dry the precipitate at 120 °C for 24 h to remove the organic solvent to obtain epoxidized styrene-butadiene rubber.

[0048] Example 1 A low-temperature resistant polycarbonate abrasive, comprising the following raw materials in parts by mass: 80 parts of aromatic polycarbonate, 25 parts of silicone-polycarbonate copolymer, 10 parts of wear-resistant filler, 12 parts of low-temperature resistant modifier, 5 parts of core-shell structure toughening agent, 0.5 part of ethylene-methyl acrylate copolymer, and 0.4 part of antioxidant 168; A preparation method of a low-temperature resistant polycarbonate abrasive, comprising the following preparation steps: S1. Place the aromatic polycarbonate, silicone-polycarbonate copolymer, wear-resistant filler, low-temperature resistant modifier, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, and stir and mix at 400 r / min for 30 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, wind it up to obtain a wound primary filament, and pelletize the wound primary filament to obtain a polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 36:1, and the processing temperatures of each section of the twin-screw extruder are: the first section is 230 °C, the second section is 235 °C, the third section is 240 °C, the fourth section is 250 °C, the fifth section is 260 °C, the sixth section is 250 °C, the seventh section is 240 °C, and the head is 220 °C; The extrusion and melt drawing process: the water temperature of the extrusion cooling water is 25 °C, the first drawing speed is 10 m / min; the temperature of the stretching hot water tank is 80 °C; the second drawing speed is 30 m / min; the temperature of the heat treatment oven is 140 °C; the third drawing speed is 25 m / min.

[0049] The wear-resistant filler is specifically prepared by the following steps: A1. Place 8 g of glass fiber in 45 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 105 °C, stir and react for 3 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 1.6 g of zirconium oxychloride octahydrate and 4 g of oxidized glass fiber to 35 mL of deionized water, stir evenly, add 4 mL of ammonia water, 0.1 g of glycine, and 0.3 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, and carry out hydrothermal reaction at 170 °C for 20 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano-zirconium oxide; A3. Add 1.4 g of graphene oxide to 90 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse it at 25 °C and 2000 r / min for 20 min, add 0.6 g of dopamine, ultrasonically disperse it at 30 °C and 2000 r / min for 2 h, filter, wash it with deionized water three times, and dry it in an oven at 70 °C for 10 min to obtain polydopamine-modified graphene oxide; A4. Add 1.1 g of polydopamine-modified graphene oxide to 90 mL of deionized water, stir evenly, add 3.1 g of glass fiber loaded with nano-zirconia, stir and mix at 800 r / min for 1 h, filter, wash it with deionized water three times, and dry it in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A5. Mix 0.8 g of tetraethyl orthosilicate, 50 g of deionized water and 6 g of sodium hydroxide, stir evenly to form silica sol, adjust the pH to 3.5 by adding nitric acid with a mass fraction of 68% to the silica sol to obtain a mixed solution, add 3 g of glucose to 35 mL of deionized water, stir at 40 °C for 25 min, add 9 mL of the mixed solution and 6 g of composite modified glass fiber, continue to stir for 2 h, place it in a closed reaction kettle, introduce argon, pyrolyze at 1250 °C for 2 h, and cool to room temperature to obtain wear-resistant filler.

[0050] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.2 g of epoxidized styrene-butadiene rubber to 55 mL of ethanol and 15 mL of deionized water, stir evenly, add 1 g of γ-aminopropyltriethoxysilane and 0.2 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 65 °C for 1 h, cool to room temperature, filter, wash it with ethanol three times and deionized water three times, and dry it in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber; B2. Add 0.5 g of modified styrene-butadiene rubber to 25 mL of deionized water, stir evenly, add 0.2 g of chitosan, 0.2 mL of acetic acid solution and 18 g of hydroxypropyl cellulose, ultrasonically treat it at 40 KHz for 30 min, add 35 mL of aqueous glutaraldehyde solution with a mass fraction of 2%, stir until it becomes gel-like, and freeze-dry it at -30 °C for 24 h to obtain the low-temperature resistant modifier.

[0051] Example 2 A low-temperature resistant and freeze-resistant polycarbonate abrasive, comprising the following raw materials in parts by mass: 85 parts of aromatic polycarbonate, 28 parts of organosilicon-polycarbonate copolymer, 13 parts of wear-resistant filler, 13 parts of low-temperature resistant modifier, 6 parts of core-shell structure toughening agent, 0.6 part of ethylene-methyl acrylate copolymer, 0.5 part of antioxidant 168; A preparation method of a low-temperature resistant and freeze-resistant polycarbonate abrasive, comprising the following preparation steps: S1. Mix the aromatic polycarbonate, silicone-polycarbonate copolymer, wear-resistant filler, low-temperature resistance modifier, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 at 450 r / min for 35 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw it through a die, and wind it to obtain a wound primary filament. Cut the wound primary filament into pellets to obtain polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 38:1, and the processing temperatures of each section of the twin-screw extruder are: the first section is 235 °C, the second section is 240 °C, the third section is 245 °C, the fourth section is 255 °C, the fifth section is 265 °C, the sixth section is 255 °C, the seventh section is 245 °C, and the head is 230 °C; Extrusion and melt drawing process: The water temperature of the extrusion cooling water is 38 °C, and the first drawing speed is 15 m / min; the temperature of the stretching hot water tank is 90 °C; the second drawing speed is 60 m / min; the temperature of the heat treatment oven is 165 °C; the third drawing speed is 55 m / min.

[0052] The wear-resistant filler is specifically prepared by the following steps: A1. Place 10 g of glass fiber in 50 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 108 °C, stir and react for 3.5 h, cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 1.8 g of zirconium oxychloride octahydrate and 4.5 g of oxidized glass fiber to 40 mL of deionized water, stir evenly, add 5 mL of ammonia water, 0.2 g of glycine, and 0.4 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, and carry out hydrothermal reaction at 180 °C for 21 h. Cool to room temperature, filter, wash 3 times with deionized water, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano-zirconium oxide; A3. Add 1.5 g of graphene oxide to 100 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse it at 25 °C and 2000 r / min for 20 min, add 0.7 g of dopamine, ultrasonically disperse it at 30 °C and 2000 r / min for 2 h, filter, wash 3 times with deionized water, and dry in an oven at 70 °C for 10 min to obtain poly-dopamine-modified graphene oxide; A4. Add 1.2 g of poly-dopamine-modified graphene oxide to 100 mL of deionized water, stir evenly, add 3.2 g of glass fiber loaded with nano-zirconium oxide, stir and mix at 900 r / min for 1.5 h, filter, wash 3 times with deionized water, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A5. Mix 1 g of tetraethyl orthosilicate, 55 g of deionized water and 6.5 g of sodium hydroxide, stir evenly to form silica sol, add nitric acid with a mass fraction of 68% to the silica sol to adjust the pH to 3.5 to obtain a mixed solution. Add 3.5 g of glucose to 40 mL of deionized water, stir at 45 °C for 30 min, add 10 mL of the mixed solution and 6.5 g of composite modified glass fiber, continue to stir for 2 h, place it in a closed reaction kettle, introduce argon, pyrolyze at high temperature at 1300 °C for 3 h, and cool to room temperature to obtain wear-resistant filler.

[0053] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.3 g of epoxidized styrene-butadiene rubber to 60 mL of ethanol and 20 mL of deionized water, stir evenly, add 1.5 g of γ-aminopropyltriethoxysilane and 0.3 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 70 °C for 1.5 h, cool to room temperature, filter, wash with ethanol 3 times, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber; B2. Add 0.6 g of modified styrene-butadiene rubber to 30 mL of deionized water, stir evenly, add 0.3 g of chitosan, 0.3 mL of acetic acid solution and 20 g of hydroxypropyl cellulose, ultrasonically treat at 40 KHz for 30 min, add 30 mL of an aqueous solution of glutaraldehyde with a mass fraction of 2%, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain the low-temperature resistant modifier.

[0054] Example 3 A low-temperature resistant and freeze-resistant polycarbonate abrasive, comprising the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of organosilicon-polycarbonate copolymer, 15 parts of wear-resistant filler, 14 parts of low-temperature resistant modifier, 7 parts of core-shell structure toughener, 0.7 part of ethylene-methyl acrylate copolymer, 0.6 part of antioxidant 168; A preparation method of a low-temperature resistant and freeze-resistant polycarbonate abrasive, comprising the following preparation steps: S1. Place the aromatic polycarbonate, organosilicon-polycarbonate copolymer, wear-resistant filler, low-temperature resistant modifier, core-shell structure toughener, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, stir and mix at 500 r / min for 40 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, wind up to obtain a wound primary filament, and pelletize the wound primary filament to obtain polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are as follows: the first section is 240 °C, the second section is 245 °C, the third section is 250 °C, the fourth section is 260 °C, the fifth section is 270 °C, the sixth section is 260 °C, the seventh section is 250 °C, and the head is 240 °C; Extrusion and melting drawing process: the water temperature of the extrusion cooling water is 50 °C, and the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0055] The wear-resistant filler is specifically prepared by the following steps: A1. Place 12 g of glass fiber in 55 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 2 g of zirconium oxychloride octahydrate and 5 g of oxidized glass fiber to 45 mL of deionized water, stir evenly, add 6 mL of ammonia water, 0.3 g of glycine and 0.5 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, carry out hydrothermal reaction at 190 °C for 22 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano zirconia; A3. Add 1.6 g of graphene oxide to 110 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse at 25 °C and 2000 r / min for 20 min, add 0.8 g of dopamine, ultrasonically disperse at 30 °C and 2000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain polydopamine-modified graphene oxide; A4. Add 1.3 g of polydopamine-modified graphene oxide to 110 mL of deionized water, stir evenly, add 3.3 g of glass fiber loaded with nano zirconia, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A5. Mix 1.2 g of tetraethyl orthosilicate, 60 g of deionized water and 7 g of sodium hydroxide, stir evenly to form silica sol, add nitric acid with a mass fraction of 68% to the silica sol to adjust the pH to 3.5 to obtain a mixed solution, add 4 g of glucose to 45 mL of deionized water, stir at 50 °C for 35 min, add 11 mL of the mixed solution and 7 g of composite modified glass fiber, continue to stir for 2 h, place in a closed reaction kettle, introduce argon, carry out high-temperature pyrolysis at 1350 °C for 4 h, and cool to room temperature to obtain the wear-resistant filler.

[0056] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.4 g of epoxidized styrene-butadiene rubber to 65 mL of ethanol and 25 mL of deionized water, stir evenly, add 2 g of γ-aminopropyltriethoxysilane and 0.4 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 75 °C for 2 h, cool to room temperature, filter, wash 3 times with ethanol and 3 times with deionized water, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber; B2. Add 0.7 g of modified styrene-butadiene rubber to 35 mL of deionized water, stir evenly, add 0.4 g of chitosan, 0.4 mL of acetic acid solution and 22 g of hydroxypropyl cellulose, perform ultrasonic treatment at 40 KHz for 30 min, add 35 mL of an aqueous solution of glutaraldehyde with a mass fraction of 2%, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain the low-temperature resistant modifier.

[0057] Comparative Example 1 A low-temperature resistant and freeze-resistant polycarbonate abrasive includes the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of organosilicon-polycarbonate copolymer, 15 parts of wear-resistant filler, 14 parts of low-temperature resistant modifier, 7 parts of core-shell structure toughening agent, 0.7 part of ethylene-methyl acrylate copolymer, and 0.6 part of antioxidant 168; A preparation method of a low-temperature resistant and freeze-resistant polycarbonate abrasive includes the following preparation steps: S1. Place the aromatic polycarbonate, organosilicon-polycarbonate copolymer, wear-resistant filler, low-temperature resistant modifier, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, stir and mix at 500 r / min for 40 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, perform melt extrusion and drawing through a die, wind, obtain the wound primary filament, and pelletize the wound primary filament to obtain the polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are respectively: 240 °C for the first section, 245 °C for the second section, 250 °C for the third section, 260 °C for the fourth section, 270 °C for the fifth section, 260 °C for the sixth section, 250 °C for the seventh section, and 240 °C for the head; Extrusion and melt drawing process: The water temperature of the extrusion cooling water is 50 °C, the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0058] The wear-resistant filler is specifically prepared by the following steps: A1. Place 12 g of glass fiber into 55 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 1.6 g of graphene oxide to 110 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse at 25 °C and 2000 r / min for 20 min, add 0.8 g of dopamine, ultrasonically disperse at 30 °C and 2000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain polydopamine-modified graphene oxide; A3. Add 1.3 g of polydopamine-modified graphene oxide to 110 mL of deionized water, stir evenly, add 3.3 g of oxidized glass fiber, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A4. Mix 1.2 g of tetraethyl orthosilicate, 60 g of deionized water and 7 g of sodium hydroxide, stir evenly to form silica sol, add nitric acid with a mass fraction of 68% to the silica sol to adjust the pH to 3.5 to obtain a mixed solution, add 4 g of glucose to 45 mL of deionized water, stir at 50 °C for 35 min, add 11 mL of the mixed solution and 7 g of composite modified glass fiber, continue to stir for 2 h, place in a closed reaction kettle, introduce argon, pyrolyze at high temperature of 1350 °C for 4 h, cool to room temperature to obtain wear-resistant filler.

[0059] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.4 g of epoxidized styrene-butadiene rubber to 65 mL of ethanol and 25 mL of deionized water, stir evenly, add 2 g of γ-aminopropyltriethoxysilane and 0.4 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 75 °C for 2 h, cool to room temperature, filter, wash with ethanol 3 times, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber; B2. Add 0.7 g of modified styrene-butadiene rubber to 35 mL of deionized water, stir evenly, add 0.4 g of chitosan, 0.4 mL of acetic acid solution and 22 g of hydroxypropyl cellulose, ultrasonically treat at 40 KHz for 30 min, add 35 mL of aqueous solution of glutaraldehyde with a mass fraction of 2%, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain the low-temperature resistant modifier.

[0060] Comparative Example 2 A low-temperature-resistant frozen polycarbonate abrasive, comprising the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of silicone-polycarbonate copolymer, 15 parts of wear-resistant filler, 14 parts of low-temperature modifier, 7 parts of core-shell toughening agent, 0.7 part of ethylene-methyl acrylate copolymer, and 0.6 part of antioxidant 168; A preparation method of a low-temperature-resistant frozen polycarbonate abrasive, comprising the following preparation steps: S1. Place the aromatic polycarbonate, silicone-polycarbonate copolymer, wear-resistant filler, low-temperature modifier, core-shell toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, and stir and mix at 500 r / min for 40 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, and wind it to obtain a wound primary filament. Cut the wound primary filament to obtain polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are: 240 °C for the first section, 245 °C for the second section, 250 °C for the third section, 260 °C for the fourth section, 270 °C for the fifth section, 260 °C for the sixth section, 250 °C for the seventh section, and 240 °C for the head; Extrusion melt drawing process: The water temperature of the extrusion cooling water is 50 °C, and the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0061] The wear-resistant filler is specifically prepared by the following steps: A1. Place 12 g of glass fiber in 55 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 2 g of zirconium oxychloride octahydrate and 5 g of oxidized glass fiber to 45 mL of deionized water, stir evenly, add 6 mL of ammonia water, 0.3 g of glycine, and 0.5 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, and carry out hydrothermal reaction at 190 °C for 22 h. Cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano-zirconium oxide; A3. Add 1.3 g of graphene oxide to 110 mL of deionized water, stir evenly, add 3.3 g of glass fiber loaded with nano-zirconium oxide, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A4. Mix 1.2 g of tetraethyl orthosilicate, 60 g of deionized water and 7 g of sodium hydroxide, stir evenly to form silica sol, add nitric acid with a mass fraction of 68% to the silica sol to adjust the pH to 3.5 to obtain a mixed solution. Add 4 g of glucose to 45 mL of deionized water, stir at 50 °C for 35 min, add 11 mL of the mixed solution and 7 g of composite modified glass fiber, continue to stir for 2 h, place it in a closed reaction kettle, introduce argon, pyrolyze at high temperature of 1350 °C for 4 h, and cool to room temperature to obtain wear-resistant filler.

[0062] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.4 g of epoxidized styrene-butadiene rubber to 65 mL of ethanol and 25 mL of deionized water, stir evenly, add 2 g of γ-aminopropyltriethoxysilane and 0.4 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 75 °C for 2 h, cool to room temperature, filter, wash with ethanol 3 times, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber. B2. Add 0.7 g of modified styrene-butadiene rubber to 35 mL of deionized water, stir evenly, add 0.4 g of chitosan, 0.4 mL of acetic acid solution and 22 g of hydroxypropyl cellulose, ultrasonically treat at 40 KHz for 30 min, add 35 mL of aqueous glutaraldehyde solution with a mass fraction of 2%, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain the low-temperature resistant modifier.

[0063] Comparative Example 3 A low-temperature resistant and freeze-resistant polycarbonate abrasive includes the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of organosilicon-polycarbonate copolymer, 15 parts of composite modified glass fiber, 14 parts of low-temperature resistant modifier, 7 parts of core-shell structure toughening agent, 0.7 part of ethylene-methyl acrylate copolymer, and 0.6 part of antioxidant 168. A preparation method of a low-temperature resistant and freeze-resistant polycarbonate abrasive includes the following preparation steps: S1. Place the aromatic polycarbonate, organosilicon-polycarbonate copolymer, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, composite modified glass fiber, low-temperature resistant modifier, and antioxidant 168 in a mixer, stir and mix at 500 r / min for 40 min to obtain a mixed material. S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, wind up to obtain a wound primary filament, and pelletize the wound primary filament to obtain polycarbonate abrasive. Among them, the length-diameter ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are as follows: the first section is 240 °C, the second section is 245 °C, the third section is 250 °C, the fourth section is 260 °C, the fifth section is 270 °C, the sixth section is 260 °C, the seventh section is 250 °C, and the head is 240 °C; Extrusion and melting drawing process: the water temperature of the extrusion cooling water is 50 °C, and the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0064] The composite modified glass fiber is specifically prepared by the following steps: A1. Place 12 g of glass fiber in 55 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 2 g of zirconium oxychloride octahydrate and 5 g of oxidized glass fiber to 45 mL of deionized water, stir evenly, add 6 mL of ammonia water, 0.3 g of glycine, and 0.5 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, carry out hydrothermal reaction at 190 °C for 22 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano zirconium oxide; A3. Add 1.6 g of graphene oxide to 110 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse at 25 °C and 2000 r / min for 20 min, add 0.8 g of dopamine, ultrasonically disperse at 30 °C and 2000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain polydopamine-modified graphene oxide; A4. Add 1.3 g of polydopamine-modified graphene oxide to 110 mL of deionized water, stir evenly, add 3.3 g of glass fiber loaded with nano zirconium oxide, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber.

[0065] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.4 g of epoxidized styrene-butadiene rubber to 65 mL of ethanol and 25 mL of deionized water, stir evenly, add 2 g of γ-aminopropyltriethoxysilane and 0.4 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 75 °C for 2 h, cool to room temperature, filter, wash with ethanol 3 times, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber; B2. Add 0.7 g of modified styrene-butadiene rubber to 35 mL of deionized water, stir evenly, add 0.4 g of chitosan, 0.4 mL of acetic acid solution and 22 g of hydroxypropyl cellulose, ultrasonically treat for 30 min at 40 KHz, add 35 mL of 2% glutaraldehyde aqueous solution, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain a low-temperature resistant modifier.

[0066] Comparative Example 4 A low-temperature resistant frozen polycarbonate abrasive, comprising the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of organosilicon-polycarbonate copolymer, 15 parts of wear-resistant filler, 14 parts of low-temperature resistant modifier, 7 parts of core-shell structure toughening agent, 0.7 part of ethylene-methyl acrylate copolymer, 0.6 part of antioxidant 168; A preparation method of a low-temperature resistant frozen polycarbonate abrasive, comprising the following preparation steps: S1. Place the aromatic polycarbonate, organosilicon-polycarbonate copolymer, wear-resistant filler, low-temperature resistant modifier, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, and stir and mix at 500 r / min for 40 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, wind up to obtain a wound primary filament, and pelletize the wound primary filament to obtain polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are: 240 °C for the first section, 245 °C for the second section, 250 °C for the third section, 260 °C for the fourth section, 270 °C for the fifth section, 260 °C for the sixth section, 250 °C for the seventh section, and 240 °C for the head; Extrusion and melt drawing process: The water temperature of the extrusion cooling water is 50 °C, and the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0067] The wear-resistant filler is specifically prepared by the following steps: A1. Place 12 g of glass fiber in 55 mL of 25% hydrogen peroxide solution, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 2 g of zirconium oxychloride octahydrate and 5 g of oxidized glass fiber into 45 mL of deionized water, stir evenly, add 6 mL of ammonia water, 0.3 g of glycine and 0.5 g of potassium chloride, stir and mix at 85 °C for 10 min, place it in a reaction kettle, carry out hydrothermal reaction at 190 °C for 22 h, cool to room temperature, filter, wash with deionized water for 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano zirconium oxide; A3. Add 1.6 g of graphene oxide into 110 mL of Tris-HCl buffer solution with pH of 8.5, ultrasonically disperse it at 25 °C and 2000 r / min for 20 min, add 0.8 g of dopamine, ultrasonically disperse it at 30 °C and 2000 r / min for 2 h, filter, wash with deionized water for 3 times, and dry in an oven at 70 °C for 10 min to obtain graphene oxide modified with polydopamine; A4. Add 1.3 g of graphene oxide modified with polydopamine into 110 mL of deionized water, stir evenly, add 3.3 g of glass fiber loaded with nano zirconium oxide, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water for 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A5. Mix 1.2 g of tetraethyl orthosilicate, 60 g of deionized water and 7 g of sodium hydroxide, stir evenly to form silica sol, add nitric acid with a mass fraction of 68% to the silica sol to adjust the pH to 3.5 to obtain a mixed solution, add 4 g of glucose into 45 mL of deionized water, stir at 50 °C for 35 min, add 11 mL of the mixed solution and 7 g of composite modified glass fiber, continue to stir for 2 h, place it in a closed reaction kettle, introduce argon, carry out high-temperature pyrolysis at 1350 °C for 4 h, cool to room temperature to obtain wear-resistant filler.

[0068] The low-temperature resistant modifier is specifically prepared by the following steps: Add 0.7 g of epoxidized styrene-butadiene rubber into 35 mL of deionized water, stir evenly, add 0.4 g of chitosan, 0.4 mL of acetic acid solution and 22 g of hydroxypropyl cellulose, ultrasonically treat it at 40 KHz for 30 min, add 35 mL of 2% glutaraldehyde aqueous solution, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain the low-temperature resistant modifier.

[0069] Comparative Example 5 A low-temperature resistant and freeze-resistant polycarbonate abrasive includes the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of organosilicon-polycarbonate copolymer, 15 parts of wear-resistant filler, 14 parts of modified styrene-butadiene rubber, 7 parts of core-shell structure toughening agent, 0.7 part of ethylene-methyl acrylate copolymer, and 0.6 part of antioxidant 168; A preparation method of a low-temperature resistant and freeze-resistant polycarbonate abrasive includes the following preparation steps: S1. Place the aromatic polycarbonate, silicone-polycarbonate copolymer, wear-resistant filler, modified styrene-butadiene rubber, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, and stir and mix at 500 r / min for 40 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, and wind it to obtain the wound primary filament. Cut the wound primary filament into pellets to obtain polycarbonate abrasive; Among them, the length-diameter ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are: the first section is 240 °C, the second section is 245 °C, the third section is 250 °C, the fourth section is 260 °C, the fifth section is 270 °C, the sixth section is 260 °C, the seventh section is 250 °C, and the head is 240 °C; Extrusion and melt drawing process: the water temperature of the extrusion cooling water is 50 °C, and the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0070] The wear-resistant filler is specifically prepared by the following steps: A1. Place 12 g of glass fiber in 55 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 2 g of zirconium oxychloride octahydrate and 5 g of oxidized glass fiber to 45 mL of deionized water, stir evenly, add 6 mL of ammonia water, 0.3 g of glycine, and 0.5 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, and carry out hydrothermal reaction at 190 °C for 22 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano-zirconium oxide; A3. Add 1.6 g of graphene oxide to 110 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse at 25 °C and 2000 r / min for 20 min, add 0.8 g of dopamine, ultrasonically disperse at 30 °C and 2000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain poly-dopamine modified graphene oxide; A4. Add 1.3 g of poly-dopamine modified graphene oxide to 110 mL of deionized water, stir evenly, add 3.3 g of glass fiber loaded with nano-zirconium oxide, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A5. Mix 1.2 g of tetraethyl orthosilicate, 60 g of deionized water and 7 g of sodium hydroxide, stir evenly to form silica sol, add nitric acid with a mass fraction of 68% to the silica sol to adjust the pH to 3.5 to obtain a mixed solution. Add 4 g of glucose to 45 mL of deionized water, stir at 50 °C for 35 min, add 11 mL of the mixed solution and 7 g of composite modified glass fiber, continue to stir for 2 h, place it in a closed reaction kettle, introduce argon, pyrolyze at 1350 °C for 4 h, and cool to room temperature to obtain wear-resistant filler.

[0071] The modified styrene-butadiene rubber is specifically prepared by the following steps: Add 5.4 g of epoxidized styrene-butadiene rubber to 65 mL of ethanol and 25 mL of deionized water, stir evenly, add 2 g of γ-aminopropyltriethoxysilane and 0.4 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 75 °C for 2 h, cool to room temperature, filter, wash 3 times with ethanol, wash 3 times with deionized water, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber.

[0072] Comparative Example 6 A low-temperature resistant polycarbonate abrasive, comprising the following raw materials in parts by mass: 90 parts of aromatic polycarbonate, 30 parts of organosilicon-polycarbonate copolymer, 15 parts of wear-resistant filler, 14 parts of low-temperature resistant modifier, 7 parts of core-shell structure toughening agent, 0.7 part of ethylene-methyl acrylate copolymer, 0.6 part of antioxidant 168; A preparation method of a low-temperature resistant polycarbonate abrasive, comprising the following preparation steps: S1. Place the aromatic polycarbonate, organosilicon-polycarbonate copolymer, wear-resistant filler, low-temperature resistant modifier, core-shell structure toughening agent, ethylene-methyl acrylate copolymer, and antioxidant 168 in a mixer, stir and mix at 500 r / min for 40 min to obtain a mixed material; S2. Place the mixed material in a twin-screw extruder for melt mixing, melt extrude and draw through a die, wind up to obtain a wound primary filament, and pelletize the wound primary filament to obtain polycarbonate abrasive; Among them, the aspect ratio of the twin-screw extruder is 40:1, and the processing temperatures of each section of the twin-screw extruder are: 240 °C for the first section, 245 °C for the second section, 250 °C for the third section, 260 °C for the fourth section, 270 °C for the fifth section, 260 °C for the sixth section, 250 °C for the seventh section, and 240 °C for the die head; Extrusion and melt drawing process: The water temperature of the extrusion cooling water is 50 °C, and the first drawing speed is 20 m / min; the temperature of the stretching hot water tank is 98 °C; the second drawing speed is 90 m / min; the temperature of the heat treatment oven is 190 °C; the third drawing speed is 80 m / min.

[0073] The wear-resistant filler is specifically prepared by the following steps: A1. Place 12 g of glass fiber into 55 mL of hydrogen peroxide with a mass fraction of 25%, stir evenly, heat up to 115 °C, stir and react for 4 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain oxidized glass fiber; A2. Add 2 g of zirconium oxychloride octahydrate and 5 g of oxidized glass fiber to 45 mL of deionized water, stir evenly, add 6 mL of ammonia water, 0.3 g of glycine, and 0.5 g of potassium chloride, stir and mix at 85 °C for 10 min, place in a reaction kettle, carry out hydrothermal reaction at 190 °C for 22 h, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 3 h to obtain glass fiber loaded with nano zirconium oxide; A3. Add 1.6 g of graphene oxide to 110 mL of Tris-HCl buffer solution with a pH of 8.5, ultrasonically disperse at 25 °C and 2000 r / min for 20 min, add 0.8 g of dopamine, ultrasonically disperse at 30 °C and 2000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain polydopamine-modified graphene oxide; A4. Add 1.3 g of polydopamine-modified graphene oxide to 110 mL of deionized water, stir evenly, add 3.3 g of glass fiber loaded with nano zirconium oxide, stir and mix at 1000 r / min for 2 h, filter, wash with deionized water 3 times, and dry in an oven at 80 °C for 15 min to obtain composite modified glass fiber; A5. Mix 1.2 g of tetraethyl orthosilicate, 60 g of deionized water, and 7 g of sodium hydroxide, stir evenly to form silica sol, adjust the pH to 3.5 by adding nitric acid with a mass fraction of 68% to the silica sol to obtain a mixed solution, add 4 g of glucose to 45 mL of deionized water, stir at 50 °C for 35 min, add 11 mL of the mixed solution and 7 g of composite modified glass fiber, continue to stir for 2 h, place in a closed reaction kettle, introduce argon, carry out high-temperature pyrolysis at 1350 °C for 4 h, and cool to room temperature to obtain wear-resistant filler.

[0074] The low-temperature resistant modifier is specifically prepared by the following steps: B1. Add 5.4 g of styrene-butadiene rubber to 65 mL of ethanol and 25 mL of deionized water, stir evenly, add 2 g of γ-aminopropyltriethoxysilane and 0.4 mL of hydrochloric acid with a mass fraction of 36%, stir and react at 75 °C for 2 h, cool to room temperature, filter, wash with ethanol 3 times, wash with deionized water 3 times, and dry in an oven at 70 °C for 10 min to obtain modified styrene-butadiene rubber; B2. Add 0.7 g of modified styrene-butadiene rubber to 35 mL of deionized water, stir evenly, add 0.4 g of chitosan, 0.4 mL of acetic acid solution and 22 g of hydroxypropyl cellulose, ultrasonically treat for 30 min at 40 KHz, add 35 mL of an aqueous glutaraldehyde solution with a mass fraction of 2%, stir until it becomes gel-like, and freeze-dry at -30 °C for 24 h to obtain a low-temperature resistant modifier. Now, perform performance tests on the polycarbonate abrasives prepared in Examples 1-3 and Comparative Examples 1-5.

[0075] Select the above-prepared polycarbonate abrasives, and perform performance tests after injection molding into strips. Among them, the injection pressure is 90 MPa, and the injection temperature is 280 °C. Tensile strength: Test according to the GB / T1040-2006 standard, the tensile rate is 50 mm / min, and the test is carried out at room temperature of 23 °C and at low temperature of -60 °C.

[0076] Notched impact strength: Test according to the GB / T1843-2008 standard.

[0077] Wear resistance: Test with reference to GB / T3960-2016.

[0078] Treatment effect of flash and abrasive wear resistance at low temperature: Use a copper sheet with a diameter of 60 mm and a thickness of 3 mm as the workpiece to be treated. Among them, the copper sheet is a pure copper sheet; put the workpiece to be treated and the polycarbonate abrasive (with a mass of M1) into the flash treatment machine together. The mass ratio of the workpiece to be treated to the polycarbonate abrasive is 1:1. The particle size of the polycarbonate abrasive is 1 mm, the vibration frequency is 30 Hz, the amplitude is 8 mm, liquid nitrogen is used as the freezing treatment medium, and impact the flash of the workpiece at -100 °C for 4 h. Then record the polycarbonate abrasive as M2, and the loss rate of the polycarbonate abrasive = (M1 - M2 / M1) × 100%. Also, check whether the surface of the workpiece to be treated is smooth and free of defects.

[0079] The test results are shown in Table 1 below.

[0080] Table 1 Performance tests of polycarbonate abrasives prepared in Examples 1-3 and Comparative Examples 1-6

[0081] It can be seen from the data in Table 1 that the polycarbonate abrasives prepared in Examples 1-3 have high mechanical properties, wear resistance and low-temperature freezing resistance.

[0082] In Comparative Example 1, the wear-resistant filler prepared by replacing the glass fiber loaded with nano-zirconia oxide with oxidized glass fiber was added to the polycarbonate abrasive, and its mechanical properties and wear resistance decreased. This proved that the nano-zirconia oxide synthesized on the surface of the oxidized glass fiber could absorb external stress at low temperature, prevent the glass fiber from breaking at low temperature, which led to the decrease in the wear resistance of the polycarbonate abrasive, and an uneven wear-resistant layer was formed on the surface, increasing the wear resistance and mechanical properties of the abrasive.

[0083] In Comparative Example 2, the wear-resistant filler prepared by replacing the poly-dopamine modified graphene oxide with graphene oxide was added to the polycarbonate abrasive, and its mechanical properties and wear resistance decreased. This proved that the poly-dopamine modified graphene oxide could adhere to the surface of the glass fiber loaded with nano-zirconia oxide. The nano-zirconia oxide served as a lubricating component between the graphene oxide and the glass fiber, increasing the wear resistance of the polycarbonate abrasive, increasing the roughness of the glass fiber, improving the contact area between the glass fiber and the polycarbonate, and then being randomly distributed in the polycarbonate abrasive, absorbing a large amount of impact energy and improving the low-temperature strength.

[0084] In Comparative Example 3, the wear-resistant filler was replaced with composite modified glass fiber and added to the polycarbonate abrasive, and its wear resistance and mechanical properties decreased. This proved that the silicon carbide nanowires wound around the surface of the composite modified glass fiber could stabilize the sandwich structure on the surface of the composite modified glass fiber, improving the wear resistance. Moreover, the silicon carbide nanowires wound around the surface of the composite modified glass fiber further increased the contact area between the wear-resistant filler and the polycarbonate abrasive, enhancing the low-temperature strength of the abrasive.

[0085] In Comparative Example 4, the low-temperature resistant modifier prepared by replacing the modified styrene-butadiene rubber with epoxidized styrene-butadiene rubber was added to the polycarbonate abrasive, and its wear resistance and mechanical properties decreased. This proved that the amino silane grafted on the epoxidized styrene-butadiene rubber was beneficial for the epoxidized styrene-butadiene rubber to embed into the aerogel structure, increasing the cross-linking density of the porous aerogel, improving the mechanical strength and porosity, and further enhancing the low-temperature strength of the polycarbonate abrasive.

[0086] In Comparative Example 5, the low-temperature resistant modifier was replaced with modified styrene-butadiene rubber and added to the polycarbonate abrasive, and its wear resistance and mechanical properties decreased. This proved that chitosan and hydroxypropyl cellulose served as the gel skeleton, and glutaraldehyde served as the cross-linking agent to form a cross-linked network structure of porous aerogel, which could effectively prevent the intrusion of external cold air, avoid the limitation of the movement of the polycarbonate molecular chain segments at low temperature and the decrease in low-temperature toughness, resulting in cracks and breakage easily occurring when the polycarbonate abrasive was used to process the burrs of the workpiece.

[0087] Comparative Example 6 The low-temperature resistant modifier prepared by replacing epoxidized styrene-butadiene rubber with styrene-butadiene rubber was added to the polycarbonate abrasive, and its wear resistance and mechanical properties decreased. This proved that the hydroxyl groups generated by the hydrolysis of amino silane could undergo a ring-opening reaction with the epoxy groups in the epoxidized styrene-butadiene rubber, which was beneficial for the embedding of epoxidized styrene-butadiene rubber into the aerogel structure, increasing the crosslinking density of the porous aerogel, improving the mechanical strength and porosity, and further enhancing the low-temperature strength of the polycarbonate abrasive.

[0088] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0089] The above content is only an example and illustration of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. As long as they do not deviate from the scope defined by the invention, they should all fall within the protection scope of the present invention.

Claims

1. A low temperature resistant polycarbonate abrasive, characterized in that: The invention comprises the following raw materials in parts by weight: 80-90 parts of polycarbonate, 25-30 parts of organosilicon-polycarbonate copolymer, 10-15 parts of wear-resistant filler, 12-14 parts of low-temperature resistant modifier, 5-7 parts of toughening agent, 0.5-0.7 parts of compatibilizer and 0.4-0.6 parts of antioxidant; The wear-resistant filler is obtained by mixing oxidized glass fiber, zirconium oxychloride octahydrate and ammonia water, then mixing with pretreated graphene oxide, and adding silica sol and glucose to continue the reaction; The low temperature resistant modifier is obtained by surface-modifying epoxidized styrene-butadiene rubber with aminosilane and then mixing and reacting with chitosan, glutaraldehyde and hydroxypropyl cellulose.

2. The low-temperature resistant polycarbonate abrasive according to claim 1, characterized in that: The wear-resistant filler is specifically prepared by the following steps: A1. Place the glass fiber in hydrogen peroxide, stir evenly, heat to 105-115°C, stir and react for 3-4 hours, cool to room temperature, filter, wash and dry to obtain oxidized glass fiber; A2. Add zirconium oxychloride octahydrate and oxidized glass fiber to deionized water, stir evenly, add ammonia, glycine and potassium chloride, stir and mix, place in a reactor, hydrothermally react at 170-190 ° C for 20-22h, cool to room temperature, filter, wash and dry to obtain glass fiber loaded with nano zirconium oxide; A3. adding graphene oxide to Tris-HCl buffer water, and then adding dopamine after ultrasonic dispersion, and then filtering, washing, and drying to obtain polydopamine-modified graphene oxide; A4. Add the polydopamine-modified graphene oxide to deionized water, stir evenly, add the glass fiber loaded with nano-zirconium oxide, stir and mix at 800-1000r / min for 1-2h, filter, wash and dry to obtain a composite modified glass fiber; A5. Mix tetraethyl silicate, deionized water and sodium hydroxide, stir evenly to form silica sol, add nitric acid to the silica sol, stir evenly to obtain a mixed solution, add glucose to the deionized water, stir at 40-50°C for 25-35 minutes, add the mixed solution and composite modified glass fiber, stir evenly, pyrolyze at 1250-1350°C for 2-4 hours, cool to room temperature, and obtain a wear-resistant filler.

3. The low-temperature resistant polycarbonate abrasive according to claim 2, characterized in that: In step A1, the ratio of glass fiber to hydrogen peroxide is (8-12) g: (45-55) mL; In step A2, the ratio of zirconium oxychloride octahydrate, oxidized glass fiber, deionized water, aqueous ammonia, glycine and potassium chloride is (1.6-2) g: (4-5) g: (35-45) mL: (4-6) mL: (0.1-0.3) g: (0.3-0.5) g.

4. The low-temperature resistant polycarbonate abrasive according to claim 2, characterized in that: In step A3, the ratio of graphene oxide, Tris-HCl buffer and dopamine is (1.5-1.6) g: (90-110) mL: (0.6-0.8) g; In step A4, the amount ratio of the polydopamine-modified graphene oxide, deionized water and glass fiber loaded with nano-zirconium oxide is (1.1-1.3) g: (90-110) mL: (3.1-3.3) g.

5. The low-temperature resistant polycarbonate abrasive according to claim 2, characterized in that: In step A5, the mass ratio of tetraethyl silicate, deionized water and sodium hydroxide is (0.8-1.2):(50-60):(6-7); The dosage ratio of the glucose, deionized water, mixed liquid and composite modified glass fiber is (3-4) g: (35-45) mL: (9-11) mL: (6-7) g.

6. The low-temperature resistant polycarbonate abrasive according to claim 1, characterized in that: The low temperature resistant modifier is specifically prepared by the following steps: B1. Add epoxidized styrene butadiene rubber to ethanol and deionized water, stir evenly, add aminosilane and hydrochloric acid, stir and react at 65-75°C for 1-2h, cool to room temperature, filter, wash and dry to obtain modified styrene butadiene rubber; B2. Add the modified styrene-butadiene rubber to deionized water, stir evenly, add chitosan, acetic acid solution and hydroxypropyl cellulose, ultrasonically treat, add glutaraldehyde aqueous solution, stir until gel-like, freeze-dry the gel to obtain a low-temperature resistant modifier.

7. The low-temperature resistant polycarbonate abrasive according to claim 6, characterized in that: In step B1, the ratio of the epoxidized styrene-butadiene rubber, ethanol, deionized water, aminosilane and hydrochloric acid is (5.2-5.4) g: (55-65) mL: (15-25) mL: (1-2) g: (0.2-0.4) mL.

8. The low-temperature resistant polycarbonate abrasive according to claim 6, characterized in that: In step B2, the amount ratio of the modified styrene-butadiene rubber, deionized water, chitosan, acetic acid solution, hydroxypropyl cellulose and glutaraldehyde aqueous solution is (0.5-0.7) g: (25-35) mL: (0.2-0.4) g: (0.2-0.4) mL: (18-22) g: (25-35) mL.

9. A method for preparing a low-temperature resistant polycarbonate abrasive according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: S1. The polycarbonate, the silicone-polycarbonate copolymer, the wear-resistant filler, the low-temperature modifier, the toughening agent, the compatibilizer, and the antioxidant are placed in a mixer and stirred at 400-500 r / min for 30-40 min to obtain a mixture; S2. placing the mixed material in a twin-screw extruder for melt kneading, extruding the mixed material through a die for melt extrusion and drawing, winding to obtain wound spun yarn, pelletizing the wound spun yarn to obtain a polycarbonate abrasive.

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