A preparation method of high-strength modified PA6 composite material

Abstract

The present invention relates to the technical field of nylon composite material preparation, and in particular to a method for preparing a high-strength modified PA6 composite material. The method for preparing the high-strength modified PA6 composite material comprises the following steps: step one, preparation of a filler composition, and simultaneous drying of PA6 resin and PA10T resin; step two, uniformly mixing accurately measured PA6 resin, PA10T resin, filler composition, antioxidant, anti-ultraviolet aging additive, lubricant, and coupling agent to obtain a mixture; step three, placing the mixture obtained in step two in a twin-screw extruder for melt extrusion, wire drawing, cooling, and granulation to obtain a high-strength modified PA6 composite masterbatch, and injection molding and heat treatment to obtain a finished high-strength modified PA6 composite material. The modified PA6 composite material prepared in the present invention has good mechanical strength, dimensional stability, and good impact toughness, which expands the application range of nylon 6 products.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon composite material preparation, and in particular to a method for preparing a high-strength modified PA6 composite material. Background Art

[0002] Polyamide, commonly known as nylon, is a general term for thermoplastic resins containing repeating amide groups -[NHCO]- on the main chain of the molecule. Nylon 6 is the earliest developed variety of engineering plastics and is also one of the varieties with the largest output of polyamide plastics. Nylon has the advantages of thermoplasticity, light weight, good toughness, good chemical resistance and durability, wear resistance, and heat resistance. It is widely used in the automotive industry, electronic and electrical industry, mechanical parts, automobiles, aviation and other fields. However, nylon 6 also has the following defects: during use, due to the strong polarity of the amide group in the polyamide molecular chain, it is easy to form hydrogen bonds with water molecules in the environment, resulting in a large water absorption rate of nylon 6, affecting the dimensional stability and mechanical properties of nylon 6 products, and limiting the application and development of nylon 6 products. In order to broaden the application scope of nylon 6, the inventor provides a method for preparing a high-strength modified PA6 composite material. Summary of the Invention

[0003] In order to solve the problems of mechanical property deviation and poor dimensional stability of nylon 6 products in the prior art, the present invention provides a method for preparing a high-strength modified PA6 composite material.

[0004] The present invention provides a method for preparing a high-strength modified PA6 composite material, which is achieved through the following technical solutions:

[0005] A method for preparing a high-strength modified PA6 composite material, wherein the high-strength modified PA6 composite material is prepared from 40-65 parts by weight of PA6 resin, 15-25 parts by weight of PA10T resin, 15-35 parts by weight of a filler composition, 0.5-2 parts by weight of an antioxidant, 0.5-2 parts by weight of an anti-ultraviolet aging additive, 0.5-3 parts by weight of a lubricant, and 0.5-2 parts by weight of a coupling agent;

[0006] The filler composition is composed of chopped glass fibers with nano-carbon grafted on the surface and inorganic whiskers with nano-carbon grafted on the surface; the mass ratio of the chopped glass fibers with nano-carbon grafted on the surface to the inorganic whiskers with nano-carbon grafted on the surface is (80-95):(5-20);

[0007] The preparation method of the high-strength modified PA6 composite material comprises the following steps:

[0008] Step 1: Preparation of filler composition, while drying PA6 resin and PA10T resin separately;

[0009] Step 2: uniformly mix the accurately measured PA6 resin, PA10T resin, filler composition, antioxidant, anti-ultraviolet aging additive, lubricant, and coupling agent to obtain a mixture;

[0010] Step 3: The mixture obtained in step 2 is placed in a twin-screw extruder for melt extrusion at a processing temperature of 260-290° C. and a twin-screw speed of 100-160 rpm. The molten extrudate is drawn and cooled and then fed into a pelletizer for pelletizing. The pelletizer has a cutting speed of 350-400 rpm to obtain a high-strength modified PA6 composite masterbatch.

[0011] Step 4: After vacuum drying, the high-strength modified PA6 composite masterbatch in step 3 is input into an injection molding machine at an injection temperature of 260-285°C, a twin-screw speed of 160-200rpm, and an injection pressure of 75-100MPa. The molten extrudate is injected into a molding mold at a mold temperature of 75-80°C, and the pressure is maintained for 15-30s. The semi-finished high-strength modified PA6 composite material of a predetermined shape is obtained by cooling.

[0012] Step 5: heat-treating the semi-finished high-strength modified PA6 composite material. The heat treatment parameters are as follows: heat-treating at 110-135° C. for 20-35 minutes, and cooling to room temperature to obtain a finished high-strength modified PA6 composite material.

[0013] The modified PA6 composite material prepared in the present invention has excellent mechanical strength, dimensional stability, and good impact toughness, expanding the application range of nylon 6 products. Furthermore, the preparation method of the present invention is relatively simple and easy to operate, facilitating industrial production and reducing the production cost of nylon 6 products.

[0014] Preferably, the high-strength modified PA6 composite material is made of 48-50 parts by weight of PA6 resin, 22-25 parts by weight of PA10T resin, 24-26 parts by weight of filler composition, 0.8-1.2 parts by weight of antioxidant, 0.5-1.2 parts by weight of anti-ultraviolet aging additive, 0.8-1.6 parts by weight of lubricant, and 1.0-1.5 parts by weight of coupling agent.

[0015] By adopting the above technical solutions, the modified PA6 composite material can be given good mechanical strength, dimensional stability, and good impact toughness, while optimizing production costs and improving core production competitiveness.

[0016] Preferably, the chopped glass fiber with surface grafted nanocarbon includes chopped glass fiber as a carrier, the length of the chopped glass fiber is 0.5-3 mm, and the surface of the chopped glass fiber is grafted with at least one of multi-walled carbon nanotubes, single-walled carbon nanotubes, graphene, and nanocarbon fibers by in-situ sintering of nanometals.

[0017] Preferably, the inorganic whiskers with surface grafted nanocarbon include inorganic whiskers as carriers, the length of the inorganic whiskers is 0.5-30 μm, and the surfaces of the inorganic whiskers are grafted with at least one of multi-walled carbon nanotubes, single-walled carbon nanotubes, graphene, and nanocarbon fibers by in-situ sintering of nanometals.

[0018] Preferably, the inorganic whiskers are at least one of zinc oxide whiskers, zirconium oxide whiskers and aluminum oxide whiskers.

[0019] Preferably, the chopped glass fibers with nano-carbon grafted on the surface are compounded by chopped glass fibers with multi-walled carbon nanotube grafted on the surface and chopped glass fibers with graphene grafted on the surface in a mass ratio of 100:(50-200).

[0020] Preferably, the inorganic whiskers with nano-carbon grafted on the surface are prepared by compounding inorganic whiskers with multi-walled carbon nanotube grafted on the surface and inorganic whiskers with graphene grafted on the surface in a mass ratio of 100:(50-200).

[0021] Preferably, the filler composition is made of the following raw materials in the following mass percentages: 30-45wt% of chopped glass fibers with multi-walled carbon nanotubes grafted on the surface, 50-60wt% of chopped glass fibers with graphene grafted on the surface, 3-6wt% of inorganic whiskers with multi-walled carbon nanotubes grafted on the surface, and 2-4wt% of inorganic whiskers with graphene grafted on the surface.

[0022] By adopting the above technical solutions, the overall mechanical strength, impact toughness and dimensional stability of the high-strength modified PA6 composite material can be improved.

[0023] Preferably, the antioxidant is composed of nano silicon nitride, antioxidant 1010, and antioxidant 168; the anti-ultraviolet aging additive is at least one of UV-234, UV-622, UV-1130, UV-292, and UV-123; and the lubricant is at least one of polytetrafluoroethylene powder, molybdenum disulfide, and flake graphite.

[0024] By adopting the above technical solutions, the overall weather resistance and processing performance can be improved.

[0025] Preferably, the coupling agent is at least one of isocyanate silane, epoxy silane, and titanate coupling agent.

[0026] Preferably, the coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and tris(dioctylpyrophosphate) isopropyl titanate in a mass ratio of 100:(10-25).

[0027] By adopting the above technical solution, the filler composition can be dispersed more evenly inside the matrix resin, thereby improving the overall mechanical strength, impact toughness and dimensional stability.

[0028] In summary, the present invention has the following advantages:

[0029] 1. The modified PA6 composite material prepared in the present invention has good mechanical strength, dimensional stability and good impact toughness, which expands the application range of nylon 6 products.

[0030] 2. The equipment used in the preparation method provided by the present invention is relatively conventional, the equipment investment cost is relatively low, and the operating technology of the required equipment is mature, which reduces the overall processing difficulty and facilitates the realization of the purpose of industrialized manufacturing.

[0031] 3. The present invention optimizes the design of the coupling agent and combines it with an optimized ratio of filler composition, so that the filler composition can be more evenly dispersed in the nylon resin system. The nano-carbon grafted on the chopped glass fiber and the nano-carbon grafted on the inorganic whisker overcome the problem of low compatibility with the nylon resin matrix and uneven dispersion, and can make the nano-carbon evenly dispersed in the nylon resin system, greatly enhancing the tensile strength, yield strength, impact toughness of the modified PA6 composite material, and improving the heat resistance and dimensional stability. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, preferred embodiments of the present invention are described below with reference to examples and comparative examples.

[0033] Example

[0034] A high-strength modified PA6 composite material is prepared from 40-65 parts by weight of PA6 resin (Toray CM1007, Japan), 18-25 parts by weight of PA10T resin (polydecane terephthalamide, semi-aromatic nylon, Kingfa Technology Co., Ltd.), 15-35 parts by weight of a filler composition, 0.5-2 parts by weight of an antioxidant, 0.5-2 parts by weight of an anti-ultraviolet aging additive, 0.5-3 parts by weight of a lubricant, and 0.5-2 parts by weight of a coupling agent.

[0035] Preferably, the high-strength modified PA6 composite material is made of 48-50 parts by weight of PA6 resin, 22-25 parts by weight of PA10T resin, 24-26 parts by weight of filler composition, 0.8-1.2 parts by weight of antioxidant, 0.5-1.2 parts by weight of anti-ultraviolet aging additive, 0.8-1.6 parts by weight of lubricant, and 1.0-1.5 parts by weight of coupling agent.

[0036] The antioxidant is composed of nano silicon nitride, antioxidant 1010, and antioxidant 168, and the mass ratio of nano silicon nitride, antioxidant 1010, and antioxidant 168 is 20:75:5.

[0037] The anti-ultraviolet aging additive is at least one of UV-234, UV-622, UV-1130, UV-292, and UV-123. Preferably, the anti-ultraviolet aging additive is UV-622, UV-1130, and UV-292. The UV-622 and anti-ultraviolet aging additives are composed of UV-622, UV-1130, and UV-292 in a mass ratio of 30:60:10.

[0038] The lubricant is at least one of polytetrafluoroethylene powder, molybdenum disulfide, and flake graphite. Preferably, the lubricant is molybdenum disulfide, which can play a lubricating role and improve wear resistance and flame retardancy.

[0039] The coupling agent is at least one of isocyanate silane, epoxy silane, and titanate coupling agent. Preferably, the coupling agent is composed of γ-glycidyloxypropyltrimethoxysilane and tris(dioctylpyrophosphate) isopropyl titanate in a mass ratio of 100:(10-25).

[0040] The filler composition is composed of short glass fibers with nano-carbon grafted on the surface and inorganic whiskers with nano-carbon grafted on the surface in a mass ratio of (80-95):(5-20).

[0041] The chopped glass fiber with surface grafted nanocarbon includes chopped glass fiber as a carrier, the length of the chopped glass fiber is 0.5-3mm, and at least one of multi-walled carbon nanotubes, single-walled carbon nanotubes, graphene, and nanocarbon fibers is grafted on the surface of the chopped glass fiber by in-situ sintering of nanometal.

[0042] Preferably, the chopped glass fibers with nano-carbon grafted on the surface are prepared by compounding the chopped glass fibers with multi-walled carbon nanotube grafted on the surface and the chopped glass fibers with graphene grafted on the surface in a mass ratio of 100:(50-200).

[0043] The surface-grafted inorganic whiskers with nanocarbons include inorganic whiskers as carriers, the inorganic whiskers having a length of 0.5-30 μm and being at least one of zinc oxide whiskers, zirconium oxide whiskers, and aluminum oxide whiskers. At least one of multi-walled carbon nanotubes, single-walled carbon nanotubes, graphene, and nanocarbon fibers is grafted onto the surface of the inorganic whiskers by in-situ sintering of nanometals.

[0044] Preferably, the inorganic whiskers with nanocarbon grafted on the surface are prepared by compounding the inorganic whiskers with multi-walled carbon nanotube grafted on the surface and the inorganic whiskers with graphene grafted on the surface in a mass ratio of 100:(50-200).

[0045] Further preferably, the filler composition is made of the following raw materials in the following mass percentages: 30-45wt% of chopped glass fibers with multi-walled carbon nanotubes grafted on the surface, 50-60wt% of chopped glass fibers with graphene grafted on the surface, 3-6wt% of inorganic whiskers with multi-walled carbon nanotubes grafted on the surface, and 2-4wt% of inorganic whiskers with graphene grafted on the surface.

[0046] A method for preparing a high-strength modified PA6 composite material comprises the following steps:

[0047] Step 1, preparing a filler composition, namely preparing chopped glass fibers with multi-walled carbon nanotubes grafted on the surface, chopped glass fibers with graphene grafted on the surface, inorganic whiskers with multi-walled carbon nanotubes grafted on the surface, and inorganic whiskers with graphene grafted on the surface respectively, mixing the prepared chopped glass fibers with multi-walled carbon nanotubes grafted on the surface, chopped glass fibers with graphene grafted on the surface, inorganic whiskers with multi-walled carbon nanotubes grafted on the surface, and inorganic whiskers with graphene grafted on the surface uniformly according to a ratio, and then dry-kneading the mixture with a coupling agent to obtain a finished filler composition;

[0048] At the same time, PA6 resin and PA10T resin were dried separately, with the specific drying parameters being drying at 110°C for 12 hours;

[0049] Step 2: Accurately weigh the PA6 resin and PA10T resin dried in step 1, the finished filler composition in step 1, the antioxidant, the anti-ultraviolet aging additive, and the lubricant according to the formula, place them in a high-speed dispersion kettle, perform high-speed dispersion treatment for 2-4 hours under nitrogen protection, and fully mix to obtain a mixture;

[0050] Step 3: The mixture obtained in step 2 is placed in a twin-screw extruder for melt extrusion at a processing temperature of 260-290° C. and a twin-screw speed of 100-160 rpm. The molten extrudate is drawn and cooled and then input into a pelletizer for pelletizing. The pelletizer has a cutting speed of 350-400 rpm to obtain a high-strength modified PA6 composite masterbatch. The obtained high-strength modified PA6 composite masterbatch has a particle size of 2.0-3.0 mm.

[0051] Step 4: The high-strength modified PA6 composite masterbatch in step 3 is placed in a vacuum drying oven, evacuated to 10 Pa and vacuum dried at 105 ° C for 6 hours. The high-strength modified PA6 composite masterbatch after vacuum drying is input into an injection molding machine for injection molding. The injection temperature is 260-285 ° C, the twin-screw speed is 160-200 rpm, and the molten extrudate discharged from the injection molding machine die head is injected into a molding mold with a mold temperature of 75-80 ° C at an injection pressure of 75-100 MPa. The pressure is maintained at 30-50 MPa for 15-30 seconds and cooled to below 60 ° C at a cooling pressure of 10-25 MPa to obtain a semi-finished high-strength modified PA6 composite material of a predetermined shape;

[0052] Step 5: heat-treating the semi-finished high-strength modified PA6 composite material. The heat treatment parameters are as follows: heat-treating at 110-135° C. for 20-35 minutes, and cooling to room temperature to obtain a finished high-strength modified PA6 composite material.

[0053] Preparation Example 1: Chopped glass fibers with multi-walled carbon nanotubes grafted onto their surfaces are prepared as follows:

[0054] Step 1: At room temperature, add 0.04 mol of 2-ethyl-4-methylimidazole 2E4MI and 0.02 mol of silver acetate AgAc to 1000 mL of dichloromethane and stir magnetically at 240 r / min until the AgAc particles disappear completely to obtain a clear and transparent Ag(2E4MI)2Ac complex solution;

[0055] Step 2: Add 1g of CNTs (Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Industrial-grade multi-walled carbon nanotubes IMWCNTs, model TNIMH8) and 1g of PVP (polyvinyl pyrrolidone, K30, Shanghai MacLean Biochemical Technology Co., Ltd.) to the Ag(2E4MI)2Ac complex solution, and use ultrasonic dispersion (ultrasonic generator power 1200W, frequency 20kHz) for 3 hours, add 100g of chopped glass fiber (fiber diameter: 6-9μm, refractive index: 1.54, product hardness: 7H, fiber density: 2.2T / cubic, product shape: fibrous, tensile strength: 1950mpa, length 3mm, customized by Shijiazhuang Super Micro New Material Technology Co., Ltd.), and continue ultrasonic dispersion for 30min to obtain a dispersion;

[0056] Step 3: The dispersion obtained in step 2 is subjected to vacuum distillation to remove dichloromethane from the dispersion, and the solid is subjected to high-temperature sintering. The high-temperature sintering temperature is controlled at 210°C and the high-temperature sintering time is 4 hours. The obtained solid is placed in a three-roll mill and ground three times. The roller spacing of the three-roll mill is 80 μm. The obtained powder is added to 500 mL of ethanol and stirred evenly. It is then poured into a basket grinder for grinding at a speed of 2000 r / min for 30 minutes, and then filtered and dried to obtain the finished product.

[0057] Preparation Example 2: Preparation Example 2 is to prepare chopped glass fibers with surface grafted graphene. The steps are basically the same as the preparation method of chopped glass fibers with surface grafted multi-walled carbon nanotubes in Preparation 1, except that: Step 2: 1 g of graphene (Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Industrial Grade Graphene TNIRGO) and 1 g of PVP (polyvinyl pyrrolidone, K30, Shanghai McLean Biochemical Technology Co., Ltd.) were added to the Ag(2E4MI)2Ac complex solution, and ultrasonic dispersion (ultrasonic generator power 1200 W, frequency 20 kHz) was used for 3 hours. 100 g of chopped glass fibers (fiber diameter: 6-9 μm, refractive index: 1.54, product hardness: 7H, fiber density: 2.2 T / cubic, product shape: fibrous, tensile strength: 1950 MPa, length 3 mm, customized by Shijiazhuang Superfine New Materials Technology Co., Ltd.) were added and ultrasonic dispersion was continued for 30 min to obtain a dispersion. The remaining steps are the same as Preparation Example 1.

[0058] Preparation Example 3: Preparation Example 3 is to prepare inorganic whiskers with multi-walled carbon nanotubes grafted on the surface. Its preparation method is basically the same as the preparation method of chopped glass fibers with multi-walled carbon nanotubes grafted on the surface. The difference is: Step 2: 1g of CNTs (industrial-grade multi-walled carbon nanotubes IMWCNTs, model TNIMH8, from Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences) and 1g of PVP (polyvinyl pyrrolidone, K30, Shanghai MacLean Biochemical Technology Co., Ltd.) were added to the Ag(2E4MI)2Ac complex solution, and ultrasonic dispersion (ultrasonic generator power 1200W, frequency 20kHz) was used for 3 hours. 100g of alumina whiskers (diameter: 0.5-1um, length: 10um, aspect ratio: 15, purity: 99.9%, customized by Hubei Xinyuhong Biomedical Technology Co., Ltd.) was added and ultrasonic dispersion was continued for 30 minutes to obtain a dispersion. The remaining steps were the same as those in Preparation Example 1.

[0059] Preparation Example 4: Preparation Example 4 is to prepare inorganic whiskers with surface grafted graphene. Its preparation method is basically the same as the preparation method of short glass fibers with surface grafted graphene. The difference is: Step 2: 1g of graphene (industrial grade graphene TNIRGO, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences) and 1g of PVP (polyvinyl pyrrolidone, K30, Shanghai McLean Biochemical Technology Co., Ltd.) are added to the Ag(2E4MI)2Ac complex solution, and ultrasonic dispersion (ultrasonic generator power 1200W, frequency 20kHz) is used for 3 hours. 100g of alumina whiskers (diameter: 0.5-1um, length: 10um, aspect ratio: 15, purity: 99.9%, customized by Hubei Xinyuhong Biomedical Technology Co., Ltd.) are added and ultrasonic dispersion is continued for 30min to obtain a dispersion. The remaining steps are the same as those of Preparation Example 1.

[0060] Example 1: A high-strength modified PA6 composite material consists of 55 parts of PA6 resin, 25 parts of PA10T resin, 8 parts of chopped glass fibers surface-grafted with multi-walled carbon nanotubes, 7.2 parts of chopped glass fibers surface-grafted with graphene, 0.48 parts of inorganic whiskers surface-grafted with multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers surface-grafted with graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0061] A method for preparing a high-strength modified PA6 composite material comprises the following steps:

[0062] Step 1, preparation of the filler composition, namely, preparing chopped glass fibers with multi-walled carbon nanotubes grafted on the surface (see Preparation Example 1), chopped glass fibers with graphene grafted on the surface (see Preparation Example 2), inorganic whiskers with multi-walled carbon nanotubes grafted on the surface (see Preparation Example 3), and inorganic whiskers with graphene grafted on the surface (see Preparation Example 4);

[0063] 240 g of the prepared chopped glass fibers with multi-walled carbon nanotubes grafted on the surface, 216 g of the chopped glass fibers with graphene grafted on the surface, 14.4 g of the inorganic whiskers with multi-walled carbon nanotubes grafted on the surface, and 9.6 g of the inorganic whiskers with graphene grafted on the surface were placed in a high-speed stirring kettle and mixed at 400 rpm for 15 min. After uniform mixing, 30 g of γ-glycidyloxypropyltrimethoxysilane and 6 g of tris(dioctylpyrophosphate)isopropyl titanate were dry-kneaded for 30 min to obtain a finished filler composition;

[0064] At the same time, PA6 resin and PA10T resin were dried separately, with the specific drying parameters being drying at 110°C for 12 hours;

[0065] Step 2: According to the formula, 1650 g of the PA6 resin dried in step 1, 750 g of the PA10T resin, 516 g of the finished filler composition in step 1, 7.2 g of nano-silicon nitride, 27 g of antioxidant 1010, 1.8 g of antioxidant 168, 24 g of molybdenum disulfide, 7.2 g of UV-622, 14.4 g of UV-11302, and 2.4 g of UV-292 were accurately weighed and placed in a high-speed dispersing kettle. The mixture was mixed at 400 rpm for 2.0 h under nitrogen protection and thoroughly mixed to obtain a mixture;

[0066] Step three, the mixture obtained in step two is placed in a twin-screw extruder for melt extrusion, the machining temperature is 260-290°C, the extrusion processing temperature is divided into five sections, the first extrusion processing temperature zone is set at 260°C, the second extrusion processing temperature zone is set at 275°C, the third extrusion processing temperature zone is set at 285°C, the fourth extrusion processing temperature zone is set at 290°C, and the fifth extrusion processing temperature zone is set at 290°C. The twin-screw speed is 124rpm, and the molten extrudate is drawn and cooled and then input into a granulator for pelletizing. The cutting speed of the granulator is 360rpm to obtain a high-strength modified PA6 composite masterbatch, and the particle size of the obtained high-strength modified PA6 composite masterbatch is between 2.0-2.4mm;

[0067] Step 4: The high-strength modified PA6 composite masterbatch in step 3 is placed in a vacuum drying oven, evacuated to 10Pa and vacuum dried at 105°C for 6 hours. The high-strength modified PA6 composite masterbatch after vacuum drying is input into the injection molding machine for injection molding. The injection molding temperature is 260-285°C. The extrusion processing temperature of the injection molding machine is divided into seven sections. The first extrusion processing temperature zone is set at 260°C, the second extrusion processing temperature zone is set at 270°C, the third extrusion processing temperature zone is set at 275°C, and the fourth extrusion processing temperature zone is set at 285°C. The temperature of each temperature zone is set at 280°C, the temperature of the fifth extrusion processing temperature zone is set at 285°C, the temperature of the sixth extrusion processing temperature zone is set at 285°C, and the temperature of the seventh extrusion processing temperature zone is set at 285°C. The speed of the twin-screw is 165 rpm. The molten extrudate discharged from the die head of the injection molding machine is injected into a molding mold with a mold temperature of 80°C at an injection pressure of 80 MPa. The pressure is maintained at a holding pressure of 40 MPa for 30 seconds, and the mixture is cooled to below 60°C at a cooling pressure of 20 MPa to obtain a semi-finished high-strength modified PA6 composite material of a predetermined shape.

[0068] Step 5: heat-treating the semi-finished high-strength modified PA6 composite material. The heat treatment parameters are as follows: heat-treating at 125° C. for 30 minutes, and cooling to room temperature to obtain a finished high-strength modified PA6 composite material.

[0069] The difference between Example 2 and Example 1 is that: a high-strength modified PA6 composite material consists of 60 parts of PA6 resin, 20 parts of PA10T resin, 8 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 7.2 parts of chopped glass fibers with surface grafted graphene, 0.48 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0070] The difference between Example 3 and Example 1 is that a high-strength modified PA6 composite material is composed of 65 parts of PA6 resin, 15 parts of PA10T resin, 8 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 7.2 parts of chopped glass fibers with surface grafted graphene, 0.48 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0071] The difference between Example 4 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 12 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 10.8 parts of chopped glass fibers with surface grafted graphene, 0.72 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.48 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0072] The difference between Example 5 and Example 1 is that a high-strength modified PA6 composite material is composed of 52.8 parts of PA6 resin, 13.2 parts of PA10T resin, 15 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 13.5 parts of chopped glass fibers with surface grafted graphene, 0.9 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.60 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0073] The difference between Example 6 and Example 1 is that a high-strength modified PA6 composite material is composed of 48.8 parts of PA6 resin, 17.5 parts of PA10T resin, 15.75 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 1.05 parts of chopped glass fibers with surface grafted graphene, 0.70 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0074] The difference between Example 7 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 22.8 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 0 parts of chopped glass fibers with surface grafted graphene, 1.2 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0075] The difference between Example 8 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 22.8 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 0 parts of chopped glass fibers with surface grafted graphene, 0 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 1.2 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0076] The difference between Example 9 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 0 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 22.8 parts of chopped glass fibers with surface grafted graphene, 1.2 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0077] The difference between Example 10 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 0 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 22.8 parts of chopped glass fibers with surface grafted graphene, 0 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 1.2 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0078] The difference between Example 11 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 21.6 parts of chopped glass fibers surface-grafted with multi-walled carbon nanotubes, 2.4 parts of inorganic whiskers surface-grafted with multi-walled carbon nanotubes, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0079] The difference between Example 12 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 19.2 parts of chopped glass fibers surface-grafted with multi-walled carbon nanotubes, 4.8 parts of inorganic whiskers surface-grafted with multi-walled carbon nanotubes, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0080] The difference between Example 13 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 12 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 10.8 parts of chopped glass fibers with surface grafted graphene, 0.72 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.48 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, and 1.2 parts of γ-glycidyloxypropyltrimethoxysilane.

[0081] The difference between Example 14 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 12 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 10.8 parts of chopped glass fibers with surface grafted graphene, 0.72 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.48 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, and 1.2 parts of 3-isocyanatepropyltriethoxysilane.

[0082] The difference between Comparative Example 1 and Example 1 is that the high-strength modified PA6 composite material consists of 80 parts of PA6 resin, 8 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 7.2 parts of chopped glass fibers with surface grafted graphene, 0.48 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0083] The difference between Comparative Example 2 and Example 1 is that the high-strength modified PA6 composite material is composed of 70 parts of PA6 resin, 10 parts of PA10T resin, 8 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 7.2 parts of chopped glass fibers with surface grafted graphene, 0.48 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctyl pyrophosphate) isopropyl titanate.

[0084] The difference between Comparative Example 3 and Example 1 is that the high-strength modified PA6 composite material consists of 50 parts of PA6 resin, 30 parts of PA10T resin, 8 parts of chopped glass fibers surface-grafted with multi-walled carbon nanotubes, 7.2 parts of chopped glass fibers surface-grafted with graphene, 0.48 parts of inorganic whiskers surface-grafted with multi-walled carbon nanotubes, 0.32 parts of inorganic whiskers surface-grafted with graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0085] The difference between Comparative Example 4 and Example 1 is that a high-strength modified PA6 composite material is composed of 68.8 parts of PA6 resin, 17.2 parts of PA10T resin, 5.25 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 4.725 parts of chopped glass fibers with surface grafted graphene, 0.315 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.21 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0086] The difference between Comparative Example 5 and Example 1 is that a high-strength modified PA6 composite material is composed of 44.8 parts of PA6 resin, 11.2 parts of PA10T resin, 6.125 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 5.5125 parts of chopped glass fibers with surface grafted graphene, 0.3675 parts of inorganic whiskers with surface grafted multi-walled carbon nanotubes, 0.245 parts of inorganic whiskers with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0087] The difference between Comparative Example 6 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 24 parts of chopped glass fiber (fiber diameter: 6-9 μm, refractive index: 1.54, product hardness: 7H, fiber density: 2.2T / cubic, product shape: fibrous, tensile strength: 1950 MPa, length 3 mm, customized by Shijiazhuang Super Micro New Material Technology Co., Ltd.), 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctyl pyrophosphate) isopropyl titanate.

[0088] The difference between Comparative Example 7 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 24 parts of chopped glass fibers with surface grafted multi-walled carbon nanotubes, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctyl pyrophosphate) isopropyl titanate.

[0089] The difference between Comparative Example 8 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 24 parts of chopped glass fiber with surface grafted graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0090] The difference between Comparative Example 9 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 23.52 parts of chopped glass fibers surface-grafted with multi-walled carbon nanotubes, 0.48 parts of inorganic whiskers surface-grafted with multi-walled carbon nanotubes, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0091] The difference between Comparative Example 10 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 18 parts of chopped glass fibers surface-grafted with multi-walled carbon nanotubes, 6 parts of inorganic whiskers surface-grafted with multi-walled carbon nanotubes, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0092] The difference between Comparative Example 11 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 22.8 parts of chopped glass fiber, 1.2 parts of inorganic whiskers, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctylpyrophosphate) isopropyl titanate.

[0093] The difference between Comparative Example 12 and Example 1 is that a high-strength modified PA6 composite material is composed of 57.6 parts of PA6 resin, 14.4 parts of PA10T resin, 22.8 parts of chopped glass fiber, 1.2 parts of inorganic whiskers, 0.24 parts of multi-walled carbon nanotubes, 0.24 parts of graphene, 0.24 parts of nano-silicon nitride, 0.9 parts of antioxidant 1010, 0.06 parts of antioxidant 168, 0.8 parts of molybdenum disulfide, 0.24 parts of UV-622, 0.48 parts of UV-11302, 0.08 parts of UV-292, 1 part of γ-glycidyloxypropyltrimethoxysilane, and 0.2 parts of tris(dioctyl pyrophosphate) isopropyl titanate.

[0094] The control group was a commercially available 30wt% glass fiber modified nylon 6 resin material, an injection molding grade glass fiber reinforced nylon PA6 material from Suzhou New District Huashida Engineering Plastics Co., Ltd.

[0095] Performance testing

[0096] 1. Tensile strength: According to GB / T 1040-2018 "Test method for tensile properties of plastics", the tensile strength of nylon composite materials was measured at a temperature of 23°C and a tensile rate of 20 mm / min.

[0097] 2. Flexural properties: According to GB / T 9341-2008 “Determination of flexural properties of plastics”, the tensile strength of nylon composite materials was measured at a temperature of 23°C and a rate of 2 mm / min.

[0098] 3. Impact toughness: According to GB / T 1043-2008, V-notch specimens were used to measure the simply supported beam notched impact strength of nylon composite materials at a temperature of 23°C and a pendulum of 5.5J.

[0099] 4. Absorption performance determination method: first place the high-strength modified PA6 composite masterbatch in a vacuum drying oven, evacuate to 10Pa and vacuum dry at 105°C for 6 hours, weigh and record it as m1, soak the vacuum-dried high-strength modified PA6 composite masterbatch in deionized water at 23°C for 24 hours, wipe the surface moisture with cotton cloth, and weigh and record it as m2. The water absorption rate is calculated as follows: ω = (m2-m1)*100 / m1.

[0100] Data Analysis

[0101] Table 1: Test parameters of high-strength modified PA6 composite materials in Examples 1-14 and Comparative Examples 1-12

[0102]

[0103]

[0104] Combining Examples 1-3 and Comparative Examples 1-3 with Table 1, it can be seen that when PA10T resin and PA6 resin are blended and compounded and the mass ratio of PA10T resin to PA6 resin is controlled to be (55-65):(15-25), the mechanical properties, dimensional stability and impact resistance of the prepared PA6 composite material are relatively excellent.

[0105] From Examples 2, 4-6, and Comparative Examples 4-5 and Table 1, it can be seen that the addition amount of the filler composition is preferably 15-35 wt%. When the filler exceeds about 25 wt%, although the tensile strength and flexural strength are improved, the impact toughness is on a downward trend. Taking into account the mechanical properties and impact toughness, the addition amount of the filler composition is preferably 24-26 wt%.

[0106] From Examples 2, 4-6, and Comparative Examples 4-5 and Table 1, it can be seen that the filler composition composed of the surface-grafted nano-carbon chopped glass fibers and the surface-grafted nano-carbon inorganic whiskers prepared in the present invention can effectively improve the mechanical properties and impact toughness of the modified PA6 composite material.

[0107] In combination with Examples 4, 7-12 and Comparative Examples 6-12 and Table 1, it can be seen that the filler composition composed of the mass ratio of the surface-grafted nano-carbon chopped glass fibers to the surface-grafted nano-carbon inorganic whiskers is (80-95): (5-20) and can effectively improve the mechanical properties and impact toughness of the modified PA6 composite material. Preferably, the filler composition composed of 30-45wt% of the surface-grafted multi-walled carbon nanotube chopped glass fibers, 50-60wt% of the surface-grafted graphene chopped glass fibers, 3-6wt% of the surface-grafted multi-walled carbon nanotube inorganic whiskers, and 2-4wt% of the surface-grafted graphene inorganic whiskers can effectively ensure the mechanical properties and impact toughness of the modified PA6 composite material, while reducing the overall production cost and facilitating the lightweighting of the PA6 nylon material.

[0108] From Example 1 and Examples 13-14 and Table 1, it can be seen that the use of a coupling agent consisting of γ-glycidyloxypropyltrimethoxysilane and tris(dioctylpyrophosphate) isopropyl titanate in a mass ratio of 100:(10-25) can improve the uniform dispersion of the filler composition, thereby improving the mechanical properties and impact toughness of the modified PA6 composite material, thereby expanding the application range of nylon 6 products.

[0109] In summary, the modified PA6 composite material prepared in the present invention has good mechanical strength, dimensional stability and good impact toughness, which expands the application range of nylon 6 products.

[0110] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method for preparing a high-strength modified PA6 composite material, characterized in that: The high-strength modified PA6 composite material is made of 40-65 parts by weight of PA6 resin, 15-25 parts by weight of PA10T resin, 15-35 parts by weight of a filler composition, 0.5-2 parts by weight of an antioxidant, 0.5-2 parts by weight of an anti-ultraviolet aging additive, 0.5-3 parts by weight of a lubricant, and 0.5-2 parts by weight of a coupling agent; The filler composition is composed of chopped glass fibers with nano-carbon grafted on the surface and inorganic whiskers with nano-carbon grafted on the surface; the mass ratio of the chopped glass fibers with nano-carbon grafted on the surface to the inorganic whiskers with nano-carbon grafted on the surface is (80-95):(5-20); The chopped glass fiber with nano-carbon grafted on the surface comprises chopped glass fiber as a carrier, the length of the chopped glass fiber is 0.5-3 mm, and the surface of the chopped glass fiber is grafted with multi-walled carbon nanotubes or graphene by in-situ sintering of nano-metal; The inorganic whiskers with nano-carbon grafted on the surface include inorganic whiskers as carriers, the length of the inorganic whiskers is 0.5-30 μm, and the surfaces of the inorganic whiskers are grafted with multi-walled carbon nanotubes or graphene by in-situ sintering of nano-metals; The preparation method of the high-strength modified PA6 composite material comprises the following steps: Step 1: Preparation of filler composition, while drying PA6 resin and PA10T resin separately; Step 2: uniformly mix the accurately measured PA6 resin, PA10T resin, filler composition, antioxidant, anti-ultraviolet aging additive, lubricant, and coupling agent to obtain a mixture; Step 3: The mixture obtained in step 2 is placed in a twin-screw extruder for melt extrusion at a temperature of 260-290° C. and a twin-screw speed of 100-160 rpm. The molten extrudate is drawn and cooled and then fed into a pelletizer for pelletizing. The pelletizer has a cutting speed of 350-400 rpm to obtain a high-strength modified PA6 composite masterbatch. Step 4: After vacuum drying, the high-strength modified PA6 composite masterbatch in step 3 is input into an injection molding machine at an injection temperature of 260-285°C, a twin-screw speed of 160-200rpm, and an injection pressure of 75-100MPa. The molten extrudate is injected into a molding mold at a mold temperature of 75-80°C, and the pressure is maintained for 15-30s. The semi-finished high-strength modified PA6 composite material of a predetermined shape is obtained by cooling. Step 5: heat-treating the semi-finished high-strength modified PA6 composite material. The heat treatment parameters are as follows: heat-treating at 110-135° C. for 20-35 minutes, and cooling to room temperature to obtain a finished high-strength modified PA6 composite material.

2. The method for preparing a high-strength modified PA6 composite material according to claim 1, characterized in that: The high-strength modified PA6 composite material is made of 48-50 parts by weight of PA6 resin, 22-25 parts by weight of PA10T resin, 24-26 parts by weight of a filler composition, 0.8-1.2 parts by weight of an antioxidant, 0.5-1.2 parts by weight of an anti-ultraviolet aging additive, 0.8-1.6 parts by weight of a lubricant, and 1.0-1.5 parts by weight of a coupling agent.

3. The method for preparing a high-strength modified PA6 composite material according to claim 1, characterized in that: The inorganic whiskers are at least one of zinc oxide whiskers, zirconium oxide whiskers and aluminum oxide whiskers.

4. The method for preparing a high-strength modified PA6 composite material according to claim 3, characterized in that: The inorganic whiskers with nano-carbon grafted on the surface are composed of aluminum oxide whiskers with multi-walled carbon nanotube grafted on the surface and aluminum oxide whiskers with graphene grafted on the surface.

5. The method for preparing a high-strength modified PA6 composite material according to claim 1, characterized in that: The inorganic whiskers with nano-carbon grafted on the surface are prepared by compounding the inorganic whiskers with multi-walled carbon nanotube grafted on the surface and the inorganic whiskers with graphene grafted on the surface in a mass ratio of 100:(50-200).

6. The method for preparing a high-strength modified PA6 composite material according to claim 5, characterized in that: The filler composition is made of the following raw materials in the following mass percentages: 30-45 wt% of chopped glass fibers with multi-walled carbon nanotubes grafted on the surface, 50-60 wt% of chopped glass fibers with graphene grafted on the surface, 3-6 wt% of inorganic whiskers with multi-walled carbon nanotubes grafted on the surface, and 2-4 wt% of inorganic whiskers with graphene grafted on the surface.

7. The method for preparing a high-strength modified PA6 composite material according to claim 5, characterized in that: The antioxidant is composed of nano silicon nitride, antioxidant 1010, and antioxidant 168; the anti-ultraviolet aging additive is at least one of UV-234, UV-622, UV-1130, UV-292, and UV-123; the lubricant is at least one of polytetrafluoroethylene micropowder, molybdenum disulfide, and flake graphite; and the coupling agent is at least one of isocyanate silane, epoxy silane, and titanate coupling agent.

8. The method for preparing a high-strength modified PA6 composite material according to claim 7, characterized in that: The coupling agent is composed of gamma-glycidyloxypropyltrimethoxysilane and tris(dioctylpyrophosphate) isopropyl titanate in a mass ratio of 100:(10-25).

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