A high-insulation polyetheretherketone composite material and preparation method thereof

Abstract

A high-insulation polyetheretherketone composite material and a preparation method thereof belong to the technical field of composite material preparation process, and specifically relate to a high-insulation polyetheretherketone composite material and a preparation method thereof. The purpose of the present invention is to provide a high-insulation PEEK composite material, which can achieve the improvement of the comprehensive performance of the material by optimizing the formula ratio, processing the filler interface and selecting a suitable granulation process, so as to better meet the requirements of high-tech equipment for high heat resistance, high flame retardancy, high insulation, high strength and other aspects of the material. The material includes the following components: 60-80% PEEK resin, 20-40% insulating filler, 0.1-0.5% fluorine-containing lubricant, and 0.1-0.2% antioxidant; after fully mixing the above components, the product plastic particles are obtained by twin-screw extrusion granulation.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material preparation technology, and particularly relates to a high-insulation polyetheretherketone composite material and a preparation method thereof. Background Art

[0002] With the development of the electronic and electrical industry, the demand for flame-retardant engineering plastics with high electrical insulation performance is growing in industrial appliances, household appliances, and automotive appliances. For example, high-voltage electrical switches, transformer coil skeletons, high-temperature resistant relays, delicate thin-walled electronic and electrical components, low-voltage vacuum contactors, circuit breakers, etc. all require thermoplastic engineering plastics with high heat resistance, high flame retardancy, and high insulation. The development of high-insulation and high-flame retardant plasticizers is one of the important directions for engineering plastic modification at present. In power systems, such as high-voltage capacitors and cables, the breakdown strength of the material is a key parameter because it is directly related to the insulation performance and safe operation of the equipment; in the aerospace field, in addition to high strength and light weight, composite materials also need to have good breakdown strength and flame retardancy to ensure reliability and safety in extreme environments; in the military field, composite materials are used in armor and protective equipment. These application scenarios require materials with high breakdown strength and heat resistance to resist high-speed impact and fire.

[0003] As a special engineering plastic, polyetheretherketone (PEEK) has the following significant advantages among many insulating materials:

[0004] 1) PEEK has an extremely high melting point (343°C) and glass transition temperature (143°C), and can maintain its performance in long-term high-temperature environments; 2) PEEK has high strength, rigidity and fatigue resistance, which makes it perform well in applications subject to mechanical stress; 3) PEEK has good resistance to most chemicals, including hydrolysis, acid and alkali, and organic solvents; 4) PEEK can maintain high electrical insulation properties over a wide range of temperature and frequency, making it suitable for use in electronic and electrical insulation materials; 5) PEEK has a low coefficient of friction, which can reduce friction and wear without the need for additional lubrication; 6) PEEK can be processed using traditional plastic processing techniques such as injection molding, extrusion molding, etc.; 7) PEEK is inherently flame retardant and can meet strict safety standards without the addition of additional flame retardants.

[0005] Chinese patent "An insulating coating for overhead high-voltage wires and its preparation method" CN118325399A discloses an insulating coating with fluorocarbon resin and polysiloxane resin as the main resin, and nano-insulating materials such as nano-ceramics, nano-composite materials, polyimide, and PEEK are added. Chinese patent "An insulating material and high-temperature resistant thin-walled wire for automobiles" CN116874978A discloses an insulating composite material with PEEK as the main resin and aluminum hydroxide and phlogopite powder as fillers. In many studies, fillers such as modified magnesium hydroxide, fluoroplastic powder, mica or calcined kaolin have been proven to help improve the insulation of plastics. However, simply combining PEEK with insulating fillers will result in many defects in the microscopic interface and structure of the material, affecting the comprehensive performance of the material. Summary of the invention

[0006] The purpose of the present invention is to provide a high-insulation polyetheretherketone composite material, which can achieve improved comprehensive performance by optimizing the formula ratio and processing the filler interface, so as to better meet the requirements of high-tech equipment for materials with high heat resistance, high flame retardancy, high insulation, high strength, etc.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A high-insulation polyetheretherketone composite material comprises the following components: 60-80% of PEEK resin, 20-40% of insulating filler, 0.1-0.5% of fluorine-containing lubricant, and 0.1-0.2% of phosphite antioxidant; the above components are fully mixed and then subjected to twin-screw extrusion granulation to obtain product plastic particles, and in the twin-screw extrusion process, the selected screw structure does not contain a kneading block; wherein the insulating material is composed of fluoroplastics and mica in a certain proportion; the mica is surface treated before use, and the treatment process is as follows: 5%-10% of the mass of the mica is taken, the anhydride is fully mixed with the mica after grinding, and the mixture is placed in a blast oven and baked at 200°C for 1-2 hours, and then the temperature is raised to 220°C and the baking is continued for 1 hour.

[0009] Preferably, the high-insulation polyetheretherketone composite material comprises the following components: 65-70% PEEK resin, 5-10% fluoroplastic, 20-30% mica, 0.1-0.3% fluorine-containing lubricant, and 0.1-0.2% antioxidant.

[0010] Preferably, the fluoroplastic is polytetrafluoroethylene (PTFE) or perfluoroalkyl (PFA) or a combination of PTFE and PFA.

[0011] Preferably, the mica is one or both of phlogopite and synthetic mica.

[0012] Preferably, the acid anhydride is one or more of maleic anhydride, succinic acid glycoside, and adipic anhydride.

[0013] Preferably, the fluorine-containing lubricant is perfluoropolyether oil (PFPE).

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention provides a high-insulation polyetheretherketone composite material and a preparation method thereof, selects PEEK with excellent insulation and fluoroplastics as base resins, and achieves all-round improvement in the mechanical properties, insulation properties and flame retardant properties of the material by adding lamellar mica fillers.

[0016] Maleic anhydride is used to treat the surface of mica, and the blast oven is set to program the temperature to ensure that the mica surface fully absorbs maleic anhydride without introducing excess anhydride into the composite material system. The current conventional treatment method is to directly mix maleic anhydride with other raw materials, but since the processing temperature of PEEK material is 360~400℃, which is much higher than the boiling point of maleic anhydride, excess maleic anhydride will vaporize during the basic granulation process and seriously affect the product quality.

[0017] In the twin-screw extrusion process, the selected screw structure does not contain kneading blocks, which avoids excessive damage to the mica sheet structure. The higher diameter-to-thickness ratio can ensure the mechanical strength and breakdown strength of the product. However, the absence of kneading blocks will lead to a decrease in the dispersion effect of the filler. It must be used in conjunction with filler surface modification and fluorine-containing lubricants to ensure that the dispersion of the filler is not affected. DETAILED DESCRIPTION

[0018] In order to clearly and completely describe the technical solution and technical effects of the present application, the present application is further described in detail below in conjunction with the embodiments. The specific embodiments described here are part of the embodiments of the present application, rather than all of the embodiments, and are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention.

[0019] Example 1

[0020] PEEK resin 60%, PTFE 9.5%, phlogopite 30%, PFPE 0.4%, tris(2,4-di-tert-butylphenyl) phosphite 0.1%, after fully mixing the above components, they are extruded and granulated by twin screws to obtain product plastic particles, and the selected screw structure does not contain kneading blocks; the phlogopite is surface treated before use, and the treatment process is as follows: 8% of the mass of phlogopite succinic anhydride is taken, and after grinding, it is fully mixed with the phlogopite, placed in a blast oven at 200°C for 2 hours, and the temperature is raised to 220°C and continued to be baked for 1 hour.

[0021] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0022] Example 2

[0023] PEEK resin 69.7%, PTFE 5%, phlogopite 25%, PFPE 0.1%, tris(2,4-di-tert-butylphenyl) phosphite 0.2%, after fully mixing the above components, extruding and granulating by twin-screw, the product plastic particles are obtained, and the selected screw structure does not contain a kneading block; the phlogopite is surface treated before use, and the treatment process is as follows: take 8% of maleic anhydride by weight of the phlogopite, grind it and mix it with the phlogopite, place it in a blast oven at 200°C for 2 hours, heat it to 220°C and continue to bake for 1 hour.

[0024] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0025] Example 3

[0026] PEEK resin 74.7%, PTFE 5%, phlogopite 20%, PFPE 0.1%, tris(2,4-di-tert-butylphenyl) phosphite 0.2%, after fully mixing the above components, extruding and granulating through a twin-screw, the selected screw structure does not contain a kneading block; the phlogopite is surface treated before use, and the treatment process is as follows: maleic anhydride 8% by weight of the phlogopite is taken, ground and fully mixed with the phlogopite, placed in a blast oven at 200°C for 2 hours, and then heated to 220°C and continued to be baked for 1 hour.

[0027] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0028] Example 4

[0029] PEEK resin 79.7%, PTFE 5%, phlogopite 15%, PFPE 0.1%, tris(2,4-di-tert-butylphenyl) phosphite 0.2%, after fully mixing the above components, extruding and granulating by twin-screw, the selected screw structure does not contain kneading blocks; the phlogopite is surface treated before use, and the treatment process is as follows: take maleic anhydride 8% by weight of the phlogopite, grind it and mix it with the phlogopite, place it in a blast oven at 200°C for 2 hours, heat it to 220°C and continue to bake for 1 hour.

[0030] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0031] Example 5

[0032] PEEK resin 79.7%, PFA 5%, phlogopite 15%, PFPE 0.1%, bis(2,4-di-tert-butylphenyl)pentaerythritol bis(diphosphite) 0.2%, after fully mixing the above components, extruding and granulating through a twin-screw, the product plastic particles are obtained, and the selected screw structure does not contain a kneading block; the phlogopite is surface treated before use, and the treatment process is as follows: 4% succinic anhydride and 4% adipic anhydride of the phlogopite mass are taken, and after grinding, they are fully mixed with the phlogopite, placed in a blast oven at 200°C for 2 hours, and then the temperature is raised to 220°C and continued to be baked for 1 hour.

[0033] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0034] Comparative Example 1

[0035] PEEK resin 99.7%, PFPE 0.1%, tris(2,4-di-tert-butylphenyl) phosphite 0.2%, after fully mixing the above components, extruding and granulating through a twin-screw extruder to obtain product plastic granules, the selected screw structure does not contain a kneading block;

[0036] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0037] Comparative Example 2

[0038] PEEK resin 69.7%, PTFE 5%, phlogopite 25%, PFPE 0.1%, tris(2,4-di-tert-butylphenyl) phosphite 0.2%, after fully mixing the above components, they are extruded and granulated by twin screws to obtain product plastic particles, and the selected screw structure is a triple kneading block; the phlogopite is surface treated before use, and the treatment process is as follows: maleic anhydride 8% by weight of the phlogopite is taken, and after grinding, it is fully mixed with the phlogopite, placed in a blast oven at 200°C for 2 hours, and the temperature is raised to 220°C and continued to be baked for 1 hour.

[0039] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0040] Comparative Example 3

[0041] PEEK resin 69.7%, PTFE 5%, phlogopite 25%, PFPE 0.1%, tris(2,4-di-tert-butylphenyl) phosphite 0.2%, after fully and evenly mixing the above components, extruding and granulating through a twin-screw extruder to obtain product plastic granules, the selected screw structure does not contain a kneading block; the phlogopite is not surface treated before use.

[0042] The obtained product plastic particles were used to prepare standard specimens using an injection molding machine to test the tensile strength, bending strength and breakdown strength. The experimental results are shown in Table 1.

[0043] Table 1 Parameters of tensile strength, flexural strength and breakdown strength of different ratios

[0044]

[0045] By comparing Examples 2 to 4, it can be found that as the mica content increases, the breakdown strength and mechanical properties of the material gradually improve, but the mechanical properties of the material in Example 1 are lower than those of the material in Example 2. This is because the increase in filler content leads to an increase in the melt viscosity of the material, which increases the difficulty of granulation and injection molding, resulting in injection molding defects, thereby causing a decrease in the mechanical strength value.

[0046] Comparative Example 1 is pure PEEK resin without any additives. By comparing the parameters with those of other examples, it can be determined that the addition of fillers significantly improves the mechanical and insulation properties of the composite material.

[0047] Comparative Example 2 is a material obtained by granulation under high shear conditions. Compared with Example 2, the materials prepared by the two processes have basically the same breakdown strength, but the tensile strength is significantly reduced, the bending strength is slightly improved, and the overall performance is reduced. This is because the shearing during the twin-screw extrusion process destroys the flaky structure of the mica.

[0048] Comparative Example 3 is a material obtained by directly granulating filler mica without surface treatment. Compared with Example 2, its various mechanical properties are significantly reduced. This is because the mica itself without surface treatment has poor dispersibility, and there is no strong mixing shear kneading section in the granulation process, which directly leads to uneven dispersion of the filler, thereby causing a decrease in mechanical properties.

Claims

1. A high-insulation polyetheretherketone composite material, comprising the following components: 65-70% PEEK resin, 5-10% fluoroplastic, 20-30% mica, 0.1-0.3% fluorine-containing lubricant, and 0.1-0.2% phosphite antioxidant; the above components are fully mixed and then granulated by twin-screw extrusion to obtain product plastic particles, and the selected screw structure does not contain a kneading block during the twin-screw extrusion process; the mica is surface treated before use, and the treatment process is as follows: 5%-10% of the mass of mica is taken, the anhydride is fully mixed with the mica after grinding, and the mixture is placed in a blast oven at 200°C for 1-2 hours, and the temperature is raised to 220°C and continued to be baked for 1 hour.

2. A high insulation polyetheretherketone composite material according to claim 1, characterized in that The fluoroplastic is polytetrafluoroethylene, or perfluoroalkyl compound, or a combination of polytetrafluoroethylene and perfluoroalkyl compound.

3. A high insulation polyetheretherketone composite material according to claim 1, characterized in that The mica is one or both of phlogopite and synthetic mica.

4. A high insulation polyetheretherketone composite material according to claim 1, characterized in that The acid anhydride is one or more of maleic anhydride, succinic anhydride and adipic anhydride.

5. The high insulation polyetheretherketone composite material according to claim 1, characterized in that The fluorine-containing lubricant is perfluoropolyether oil.

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