Polyetherimide composite material and preparation method thereof

Abstract

The present application relates to the technical field of polymer materials, and provides a polyetherimide composite material and a preparation method thereof, comprising the following components in parts by weight: 50 to 75 parts of a first polyetherimide, 50 to 60 parts of microspheres of a second polyetherimide coated with carbon nanotubes, and 10 to 30 parts of an inorganic filler. The polyetherimide composite material provided by the present application is compounded and used by using a specific content of the first polyetherimide, microspheres of the second polyetherimide coated with carbon nanotubes, and an inorganic filler. The carbon nanotubes in the microspheres can effectively improve the conductivity of the polyetherimide and improve the antistatic effect. On the other hand, the carbon nanotubes in the microspheres are coated and bonded to the surface of the second polyetherimide, which can prevent the carbon nanotubes from agglomerating, so that the carbon nanotubes can be evenly dispersed in the polyetherimide. Therefore, the polyetherimide composite material of the present application not only has good dispersibility and conductivity, but also has beautiful appearance, and can be used in the field of antistatic packaging materials.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a polyetherimide composite material and a preparation method thereof. Background Art

[0002] Polyetherimide (PEI for short) is a thermoplastic special engineering plastic with the best high temperature resistance and dimensional stability, as well as comprehensive properties such as chemical resistance, electrical properties, flame retardancy, high strength, and high rigidity. It is not only widely used in high temperature resistant terminals, IC bases, lighting equipment, FPCB (flexible circuit boards), liquid delivery equipment, aircraft internal parts, medical equipment, and household appliances, but also has an increasingly wide application in antistatic materials. However, polyetherimide has very high insulation properties, which makes it easy to cause material damage during use because static charges cannot be released. Carbon nanotubes are conductive additives for antistatic materials. Although adding them to polyetherimide can effectively improve the conductivity of polyetherimide, carbon nanotubes and polyetherimide have poor compatibility. In the actual processing process, carbon nanotubes are difficult to be evenly dispersed in polyetherimide materials, resulting in poor antistatic effect, and particles exist on the surface of the product, affecting the appearance and performance.

[0003] Therefore, it is necessary to develop a polyetherimide composite material with good dispersibility and conductivity. Summary of the invention

[0004] The purpose of the present application is to provide a polyetherimide composite material and a preparation method thereof, aiming to solve the problems of poor compatibility and poor conductivity of carbon nanotubes and polyetherimide in existing polyetherimide composite materials.

[0005] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0006] In a first aspect, the present application provides a polyetherimide composite material, comprising the following components in parts by weight:

[0007] 50 to 75 parts of the first polyetherimide,

[0008] 50 to 60 parts of carbon nanotube-coated microspheres of the second polyetherimide,

[0009] 10 to 30 parts of inorganic filler.

[0010] In a second aspect, the present application provides a method for preparing a polyetherimide composite material, comprising the following steps:

[0011] Providing raw materials of various components of the polyetherimide composite material of the present application;

[0012] The first polyetherimide, microspheres of the second polyetherimide coated with carbon nanotubes and an inorganic filler are mixed and then extruded to obtain a polyetherimide composite material.

[0013] Compared with the prior art, this application has the following beneficial effects:

[0014] The polyetherimide composite material provided in the first aspect of the present application is prepared by compounding a first polyetherimide having a specific content, microspheres of a second polyetherimide coated with carbon nanotubes, and an inorganic filler. On the one hand, the carbon nanotubes in the microspheres of the second polyetherimide coated with carbon nanotubes can effectively improve the conductivity of the first polyetherimide substrate and improve the antistatic effect of the polyetherimide. On the other hand, the carbon nanotubes in the microspheres of the second polyetherimide coated with carbon nanotubes are coated and bonded to the surface of the second polyetherimide, which can prevent the carbon nanotubes from agglomerating on the surface of the polyetherimide composite material to form particles, so that the carbon nanotubes can be evenly dispersed in the polyetherimide composite material, and the problem of poor compatibility between the carbon nanotubes and the polyetherimide can be overcome. Therefore, the polyetherimide composite material of the present application not only has good dispersibility and good conductivity, but also has an aesthetic appearance, and can be used in the field of antistatic packaging materials.

[0015] The preparation method of the polyetherimide composite material provided in the second aspect of the present application is to obtain the polyetherimide composite material by mixing the first polyetherimide, the microspheres of the carbon nanotube-coated second polyetherimide and the inorganic filler and then extruding and molding. Since the carbon nanotubes in the microspheres of the carbon nanotube-coated second polyetherimide are coated and bonded to the surface of the second polyetherimide, it is beneficial for the carbon nanotubes to be uniformly dispersed in the polyetherimide during the mixing process, so that they will not agglomerate on the surface of the polyetherimide composite material to form particles, so the obtained polyetherimide composite material has good dispersibility and conductivity, and is beautiful. In addition, the preparation method of the present application has a simple process, is easy to operate, has high efficiency, and is conducive to wide use. DETAILED DESCRIPTION

[0016] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0018] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0019] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0020] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0021] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0022] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0023] In a first aspect, an embodiment of the present application provides a polyetherimide composite material, comprising the following components in parts by weight:

[0024] 50 to 75 parts of the first polyetherimide,

[0025] 50 to 60 parts of carbon nanotube-coated microspheres of the second polyetherimide,

[0026] 10 to 30 parts of inorganic filler.

[0027] The polyetherimide composite material provided in the embodiment of the present application is compounded and used by using a specific content of a first polyetherimide, microspheres of carbon nanotubes coated with a second polyetherimide, and an inorganic filler. On the one hand, the carbon nanotubes in the microspheres of carbon nanotubes coated with the second polyetherimide can effectively improve the conductivity of the first polyetherimide substrate and improve the antistatic effect of the polyetherimide. On the other hand, the carbon nanotubes in the microspheres of carbon nanotubes coated with the second polyetherimide are coated and bonded to the surface of the second polyetherimide, which can prevent the carbon nanotubes from agglomerating on the surface of the polyetherimide composite material to form particles, so that they can be evenly dispersed in the polyetherimide, which can overcome the problem of poor compatibility between carbon nanotubes and polyetherimide. Therefore, the polyetherimide composite material of the present application not only has good dispersibility and good conductivity, but also has beautiful appearance, and can be used in the field of antistatic packaging materials.

[0028] In an embodiment, the polyetherimide composite material includes 50 to 75 parts by weight of the first polyetherimide. In a specific embodiment, the weight of the first polyetherimide can be 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, 72 parts, 75 parts, etc.

[0029] In an embodiment, the polyetherimide composite material includes 50 to 60 parts by weight of microspheres of the second polyetherimide coated with carbon nanotubes. In a specific embodiment, the weight of the microspheres of the second polyetherimide coated with carbon nanotubes can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, etc.

[0030] In an embodiment, the mass ratio of carbon nanotubes to the second polyetherimide in the microspheres of carbon nanotubes coated with the second polyetherimide is (10-50): (85-90), such as 10:90, 11:89, 12:88, 13:87, 14:86, 15:85, 50:88, etc. Within the mass ratio range, the carbon nanotubes can be uniformly adhered to the second polyetherimide particles, which is conducive to uniform dispersion of the carbon nanotubes in the polyetherimide to form a polyetherimide composite material with good dispersibility and good conductivity.

[0031] In an embodiment, the particle size of the microspheres of the carbon nanotubes coated with the second polyetherimide is 0.5 to 2 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc. Within this particle size range, it is beneficial for the microspheres of the carbon nanotubes coated with the second polyetherimide to be uniformly blended with the first polyetherimide, so that the carbon nanotubes can be uniformly dispersed in the polyetherimide to form a polyetherimide composite material with good dispersibility and good conductivity.

[0032] In an embodiment, the carbon nanotubes in the microspheres of carbon nanotube-coated second polyetherimide are multi-walled carbon nanotubes.

[0033] In some embodiments, the aspect ratio of the multi-walled carbon nanotubes is (5000-10000):1, and the specific surface area is 200-350 m 2 / g.

[0034] In some embodiments, the multi-walled carbon nanotubes include first multi-walled carbon nanotubes, second multi-walled carbon nanotubes, third multi-walled carbon nanotubes and fourth multi-walled carbon nanotubes, and the mass ratio of the first multi-walled carbon nanotubes, the second multi-walled carbon nanotubes, the third multi-walled carbon nanotubes and the fourth multi-walled carbon nanotubes is (20-30): (20-30): (20-30): (10-40), specifically, the first multi-walled carbon nanotubes account for 20-30wt%, the second multi-walled carbon nanotubes account for 20-30wt%, the third multi-walled carbon nanotubes account for 20-30wt%, and the fourth multi-walled carbon nanotubes account for 10-40wt%. The present invention sets the specifications and mass ratio ranges of the first multi-walled carbon nanotubes, the second multi-walled carbon nanotubes, the third multi-walled carbon nanotubes and the fourth multi-walled carbon nanotubes, which can be beneficial for the multi-walled carbon nanotubes to form a good gradient dispersion in the process of preparing the carbon nanotube slurry, improve the dispersion performance of the carbon nanotubes, and form a uniform coating when sprayed on the surface of the second polyetherimide particles, so that the carbon nanotubes can be evenly dispersed in the polyetherimide to form a polyetherimide composite material with good dispersibility and good conductivity.

[0035] In the embodiment, the diameter of the first multi-walled carbon nanotube is 16-20nm, and the length is 51-79μm; the diameter of the second multi-walled carbon nanotube is 11-15nm, and the length is 20-40μm; the diameter of the third multi-walled carbon nanotube is 6-10nm, and the length is 80-100μm; the diameter of the fourth multi-walled carbon nanotube is 6-10nm, and the length is 40-60μm. Through the specific combination of different diameters and lengths of the first multi-walled carbon nanotube, the second multi-walled carbon nanotube, the third multi-walled carbon nanotube, and the fourth multi-walled carbon nanotube in this embodiment, that is, by selecting multi-walled carbon nanotubes of different specifications for compounding, a gradient dispersion is formed to obtain uniformly and stably dispersed multi-walled carbon nanotubes, which can improve the dispersion performance of carbon nanotubes, so that the multi-walled carbon nanotubes can be uniformly coated with the second polyetherimide, so that the carbon nanotubes can be uniformly dispersed in the polyetherimide to form a polyetherimide composite material with good dispersibility and good conductivity.

[0036] In an embodiment, the inorganic filler is selected from at least one or more of silicon dioxide, magnesium oxide, talc, calcium carbonate, asbestos, and kaolin. The particle size of the inorganic filler is 3 to 5 μm, such as 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc. Within this particle size range, it is beneficial for the inorganic filler to be uniformly dispersed in the polyetherimide, thereby improving the wear resistance and stability of the polyetherimide composite material.

[0037] In an embodiment, the polyetherimide composite material further comprises 3 to 5 parts of an antioxidant. In a specific embodiment, the weight percentage of the antioxidant may be 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc.

[0038] In some embodiments, the antioxidant can be selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (1010), tris(2,4-di-tert-butylphenyl) phosphite (168), β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (1076), 2,4,6-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl) mesitylene (1330), 2 , at least one or more of 2-thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)ethyl propionate (1035), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid (3144), N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine (1024), and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (126) are mixed.

[0039] A second aspect of the embodiment of the present application provides a method for preparing a polyetherimide composite material, comprising the following steps:

[0040] S01: providing raw materials of various components of the polyetherimide composite material of the embodiment of the present application;

[0041] S02: mixing the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes, and the inorganic filler, and then extruding and molding the mixture to obtain a polyetherimide composite material.

[0042] The preparation method of the polyetherimide composite material provided in the embodiment of the present application is to obtain the polyetherimide composite material by mixing the first polyetherimide, the microspheres of the carbon nanotube-coated second polyetherimide and the inorganic filler and then extruding and molding. Since the carbon nanotubes in the microspheres of the carbon nanotube-coated second polyetherimide are coated and bonded to the surface of the second polyetherimide, it is beneficial for the carbon nanotubes to be uniformly dispersed in the polyetherimide during the mixing process, so that they will not agglomerate on the surface of the polyetherimide composite material to form particles, so the obtained polyetherimide composite material has good dispersibility and conductivity, and is beautiful. In addition, the preparation method of the present application has a simple process, is easy to operate, has high efficiency, and is conducive to wide use.

[0043] Among them, the polyetherimide composite material in step S01 is the polyetherimide composite material of the above-mentioned embodiment of the present application. Therefore, the specific types and contents of the various component raw materials of the polyetherimide composite material of the embodiment of the present application provided in step S01 are as shown above, and will not be repeated here to save space.

[0044] In step S02, the preparation steps of the microspheres of carbon nanotubes coated with the second polyetherimide include: adding the acidified carbon nanotubes to a solvent for dispersion treatment, then adding silicone resin for mixing treatment to obtain carbon nanotube slurry; melt spraying and granulating the second polyetherimide powder to form second polyetherimide particles, and then spraying the carbon nanotube slurry on the surface of the second polyetherimide particles to obtain microspheres of carbon nanotubes coated with the second polyetherimide. By adding the acidified carbon nanotubes to the solvent for centrifugal dispersion treatment, the carbon nanotubes can be dispersed in layers and gradients, and the addition of silicone resin can prevent the carbon nanotubes from sinking or floating, thereby obtaining a stably dispersed carbon nanotube slurry, which is conducive to the carbon nanotube slurry being smoothly sprayed on the surface of the second polyetherimide particles to form a uniform carbon nanotube coating layer. The second polyetherimide powder is melt-sprayed and granulated, and during the spray granulation of the second polyetherimide powder, carbon nanotube slurry is sprayed on the surface of the second polyetherimide particles, so that the carbon nanotube slurry wraps the second polyetherimide particles, thereby obtaining carbon nanotube-coated microspheres of the second polyetherimide with uniform particle size distribution and good fluidity. Furthermore, during the mixing treatment and extrusion molding of the carbon nanotube-coated microspheres of the second polyetherimide with the first polyetherimide and an inorganic filler, the carbon nanotubes will not agglomerate, so that the obtained polyetherimide composite material has good conductivity, no fine particles on the surface, and is beautiful.

[0045] In the embodiment, the acidified carbon nanotubes can be prepared by conventional preparation methods in the art or directly purchased and used. The carbon nanotube slurry can be sprayed onto the surface of the second polyetherimide particles by conventional spraying process, which will not be described here, and dried after spraying.

[0046] In the embodiment, the mass ratio of the acidified carbon nanotubes, the silicone resin and the solvent is (0.1-0.2): (0.2-0.3): 1. Within this mass ratio range, it is beneficial to form a stably dispersed carbon nanotube slurry, and it is beneficial to spray the carbon nanotube slurry onto the surface of the second polyetherimide particles to form a uniform carbon nanotube coating layer.

[0047] In an embodiment, the preparation step of acidified carbon nanotubes includes: subjecting the carbon nanotubes to ultrasonic treatment and then placing them in mixed acid for acidification treatment. The ultrasonic treatment may be performed by placing the carbon nanotubes in an ultrasonic device, the frequency of the ultrasonic treatment being 20 to 40 kHz, the power being 80 to 200 W, and the time being 30 to 60 min. The time of the acidification treatment is 2 to 4 h. The mixed acid solution includes concentrated nitric acid and concentrated sulfuric acid in a volume ratio of (1 to 3): (3 to 1), for example, the mixed acid solution may include concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 1:3. The carbon nanotubes may increase the number of functional groups by ultrasonic treatment, and then after acidification treatment, a large number of carboxyl groups and hydroxyl groups may be generated on the surface of the carbon nanotubes, thereby improving the dispersion performance of the carbon nanotubes.

[0048] In the embodiment, the mixing process can be a conventional mixing process, as long as the raw material components such as the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes and the inorganic filler can be mixed uniformly. For example, the mixing can be carried out by stirring.

[0049] In an embodiment, a screw extruder can be used to extrude the mixed material, wherein the screw extruder can be a twin-screw extruder. Under the action of the screw of the twin-screw extruder, the mixed material is first heated and melted at high temperature to form a melt, and then extruded by the screw. The main barrel of the extrusion-molded twin-screw extruder is divided into 360℃~370℃, 360℃~370℃, 370℃~380℃, 370℃~380℃, 370℃~380℃, 390℃~400℃, 390℃~400℃, 400℃~410℃, 400℃~410℃, 390℃~410℃ ten-stage control, by segmentally controlling the temperature in the main barrel of the twin-screw extruder, so that each raw material component is evenly heated in each part and stage in the barrel, so that each raw material component is mixed more evenly, and the dispersion and conductivity of the prepared polyetherimide composite material are improved.

[0050] In an embodiment, after the melt-plastication treatment in step S02, the polyetherimide composite material obtained by the melt-plastication treatment may also be subjected to granulation treatment, for example, the polyetherimide composite material melt subjected to the melt-extrusion treatment is pulled out through a shaping die at a constant moving speed, and then cooled in a water tank, air-dried and pelletized to obtain polyetherimide composite material pellets.

[0051] The following describes the invention in conjunction with specific embodiments.

[0052] Example 1

[0053] This embodiment provides a polyetherimide composite material and a preparation method thereof.

[0054] The polyetherimide composite material comprises the following components in parts by weight:

[0055] 60 parts of the first polyetherimide,

[0056] 50 parts of carbon nanotube-coated microspheres of the second polyetherimide,

[0057] 15 parts of silicon dioxide;

[0058] Among them, the mass ratio of carbon nanotubes and the second polyetherimide in the carbon nanotube-coated microspheres is 10:90, the carbon nanotubes are multi-walled carbon nanotubes, and the multi-walled carbon nanotubes are composed of first multi-walled carbon nanotubes, second multi-walled carbon nanotubes, third multi-walled carbon nanotubes and fourth multi-walled carbon nanotubes in a mass ratio of 20:30:25:25, and the first multi-walled carbon nanotubes have a diameter of 16 to 20 nm and a length of 51 to 79 μm, the second multi-walled carbon nanotubes have a diameter of 11 to 15 nm and a length of 20 to 40 μm, the third multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 80 to 100 μm, the fourth multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 40 to 60 μm, and the particle size of the carbon nanotube-coated microspheres of the second polyetherimide is 1 mm.

[0059] The preparation method of the polyetherimide composite material comprises the following steps:

[0060] S11: Preparation of carbon nanotube-coated microspheres of the second polyetherimide:

[0061] The carbon nanotubes were placed in an ultrasonic device with a frequency of 20 kHz and a power of 80 W for 30 minutes for ultrasonic treatment, and then acidified in a mixed acid solution (concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3) for 3 hours to obtain acidified carbon nanotubes;

[0062] The acidified carbon nanotubes were added to water and centrifuged for dispersion, and then a 300×10 -6 m 2 / s of silicone resin to obtain a carbon nanotube slurry, wherein the carbon nanotubes account for 10wt% of the solvent and the silicone resin accounts for 30wt% of the solvent;

[0063] The second polyetherimide powder is melt-spray granulated to form second polyetherimide particles, and then the carbon nanotube slurry is sprayed on the surface of the second polyetherimide particles during the spray granulation process to obtain carbon nanotube-coated second polyetherimide microspheres;

[0064] S12: According to the raw materials and contents of the components of the polyetherimide composite material of Example 1, weigh the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes, and silicon dioxide;

[0065] S13: placing the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes and silicon dioxide in a mixer at a rotation speed of 200 r / min for mixing for 30 minutes, and then extruding and molding to obtain a polyetherimide composite material.

[0066] Example 2

[0067] This embodiment provides a polyetherimide composite material and a preparation method thereof.

[0068] The polyetherimide composite material comprises the following components in parts by weight:

[0069] 65 parts of the first polyetherimide,

[0070] 60 parts of carbon nanotube-coated microspheres of the second polyetherimide,

[0071] 20 parts of talc;

[0072] Among them, the mass ratio of carbon nanotubes and the second polyetherimide in the carbon nanotube-coated microspheres of the second polyetherimide is 13:87, the carbon nanotubes are multi-walled carbon nanotubes, and the multi-walled carbon nanotubes are composed of first multi-walled carbon nanotubes, second multi-walled carbon nanotubes, third multi-walled carbon nanotubes and fourth multi-walled carbon nanotubes in a mass ratio of 20:30:25:25, and the first multi-walled carbon nanotubes have a diameter of 16 to 20 nm and a length of 51 to 79 μm, the second multi-walled carbon nanotubes have a diameter of 11 to 15 nm and a length of 20 to 40 μm, the third multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 80 to 100 μm, the fourth multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 40 to 60 μm, and the particle size of the carbon nanotube-coated microspheres of the second polyetherimide is 1 mm.

[0073] The preparation method of the polyetherimide composite material comprises the following steps:

[0074] S11: Preparation of carbon nanotube-coated microspheres of the second polyetherimide:

[0075] The carbon nanotubes were placed in an ultrasonic device with a frequency of 30 kHz and a power of 150 W for 45 min, and then acidified in a mixed acid solution (concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3) for 3 h to obtain acidified carbon nanotubes;

[0076] The acidified carbon nanotubes were added to water and centrifuged for dispersion, and then a 500×10 -6 m2 / s of silicone resin to obtain a carbon nanotube slurry, wherein the carbon nanotubes account for 20wt% of the solvent and the silicone resin accounts for 20wt% of the solvent;

[0077] The second polyetherimide powder is melt-spray granulated to form second polyetherimide particles, and then the carbon nanotube slurry is sprayed on the surface of the second polyetherimide particles during the spray granulation process to obtain carbon nanotube-coated second polyetherimide microspheres;

[0078] S12: according to the raw materials and contents of the components of the polyetherimide composite material of Example 1, weigh the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes, and talc;

[0079] S13: placing the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes and talc in a mixer at a rotation speed of 200 r / min for mixing for 30 minutes, and then extruding to obtain a polyetherimide composite material.

[0080] Example 3

[0081] This embodiment provides a polyetherimide composite material and a preparation method thereof.

[0082] The polyetherimide composite material comprises the following components in parts by weight:

[0083] 70 parts of the first polyetherimide,

[0084] 55 parts of carbon nanotube-coated microspheres of the second polyetherimide,

[0085] Calcium carbonate 20 parts;

[0086] Among them, the mass ratio of carbon nanotubes and the second polyetherimide in the carbon nanotube-coated microspheres is 10:90, the carbon nanotubes are multi-walled carbon nanotubes, and the multi-walled carbon nanotubes are composed of first multi-walled carbon nanotubes, second multi-walled carbon nanotubes, third multi-walled carbon nanotubes and fourth multi-walled carbon nanotubes in a mass ratio of 20:30:25:25, and the first multi-walled carbon nanotubes have a diameter of 16 to 20 nm and a length of 51 to 79 μm, the second multi-walled carbon nanotubes have a diameter of 11 to 15 nm and a length of 20 to 40 μm, the third multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 80 to 100 μm, the fourth multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 40 to 60 μm, and the particle size of the carbon nanotube-coated microspheres of the second polyetherimide is 1 mm.

[0087] The preparation method of the polyetherimide composite material comprises the following steps:

[0088] S11: Preparation of carbon nanotube-coated microspheres of the second polyetherimide:

[0089] The carbon nanotubes were placed in an ultrasonic device with a frequency of 40 kHz and a power of 200 W for 60 min, and then acidified in a mixed acid solution (concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3) for 3 h to obtain acidified carbon nanotubes;

[0090] The acidified carbon nanotubes were added to water and centrifuged for dispersion, and then a 200×10 -6 m 2 / s of silicone resin to obtain a carbon nanotube slurry, wherein the carbon nanotubes account for 15wt% of the solvent and the silicone resin accounts for 25wt% of the solvent;

[0091] The second polyetherimide powder is melt-spray granulated to form second polyetherimide particles, and then the carbon nanotube slurry is sprayed on the surface of the second polyetherimide particles during the spray granulation process to obtain carbon nanotube-coated second polyetherimide microspheres;

[0092] S12: according to the raw materials and contents of the components of the polyetherimide composite material of Example 1, weigh the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes, and calcium carbonate;

[0093] S13: placing the second polyetherimide, the microspheres coated with the second polyetherimide by carbon nanotubes and calcium carbonate in a mixer at a rotation speed of 200 r / min for mixing for 30 minutes, and then extruding and molding to obtain a polyetherimide composite material.

[0094] Example 4

[0095] This comparative example provides a polyetherimide composite material and a preparation method thereof.

[0096] The polyetherimide composite material comprises the following components in parts by weight:

[0097] 70 parts of the first polyetherimide,

[0098] 55 parts of carbon nanotube-coated microspheres of the second polyetherimide,

[0099] Calcium carbonate 20 parts;

[0100] The mass ratio of carbon nanotubes to the second polyetherimide in the carbon nanotube-coated microspheres is 10:90, the particle size of the carbon nanotube-coated microspheres is 1 mm, and the carbon nanotubes are multi-walled carbon nanotubes with a diameter of 16-20 nm and a length of 51-79 μm.

[0101] The preparation method of the polyetherimide composite material comprises the following steps:

[0102] S1: Preparation of carbon nanotube-coated microspheres of the second polyetherimide:

[0103] The carbon nanotubes were placed in an ultrasonic device with a frequency of 40 kHz and a power of 200 W for 60 min, and then acidified in a mixed acid solution (concentrated nitric acid and concentrated sulfuric acid with a volume ratio of 1:3) for 3 h to obtain acidified carbon nanotubes;

[0104] The acidified carbon nanotubes were added to water and centrifuged for dispersion, and then a 200×10 -6 m 2 / s of silicone resin to obtain a carbon nanotube slurry, wherein the carbon nanotubes account for 15wt% of the solvent and the silicone resin accounts for 25wt% of the solvent;

[0105] The second polyetherimide powder is melt-spray granulated to form second polyetherimide particles, and then the carbon nanotube slurry is sprayed on the surface of the second polyetherimide particles during the spray granulation process to obtain carbon nanotube-coated second polyetherimide microspheres;

[0106] S2: According to the raw materials and contents of each component of the polyetherimide composite material of Comparative Example 2, weigh the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes, and calcium carbonate;

[0107] S3: placing the first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes and calcium carbonate in a mixer at a rotation speed of 200 r / min for mixing for 30 minutes, and then extruding to obtain a polyetherimide composite material.

[0108] Comparative Example 1

[0109] This comparative example provides a polyetherimide composite material and a preparation method thereof.

[0110] The polyetherimide composite material comprises the following components in parts by weight:

[0111] Polyetherimide 119.5 parts,

[0112] 5.5 parts of carbon nanotubes,

[0113] Calcium carbonate 20 parts;

[0114] Among them, the carbon nanotubes are multi-walled carbon nanotubes, which are composed of first multi-walled carbon nanotubes, second multi-walled carbon nanotubes, third multi-walled carbon nanotubes and fourth multi-walled carbon nanotubes in a mass ratio of 20:30:25:25, and the first multi-walled carbon nanotubes have a diameter of 16 to 20 nm and a length of 51 to 79 μm, the second multi-walled carbon nanotubes have a diameter of 11 to 15 nm and a length of 20 to 40 μm, the third multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 80 to 100 μm, and the fourth multi-walled carbon nanotubes have a diameter of 6 to 10 nm and a length of 40 to 60 μm.

[0115] The preparation method of the polyetherimide composite material comprises the following steps:

[0116] S1: According to the raw materials and contents of each component of the polyetherimide composite material of Comparative Example 1, weigh polyetherimide, carbon nanotubes and calcium carbonate;

[0117] S2: placing polyetherimide, carbon nanotubes and calcium carbonate in a mixer at a rotation speed of 200 r / min for mixing for 30 minutes, and then extruding to obtain a polyetherimide composite material.

[0118] Related performance test analysis:

[0119] 1. The tensile strength of the polyetherimide composite materials provided in Examples 1 to 4 and Comparative Example 1 was tested according to GB / T1040 standard. The specimen type was Type II specimen, the specimen size (mm) was: 115 (length) × (6 ± 0.04) (width of the middle parallel part) × 2 (thickness), and the tensile speed was 200 mm / min.

[0120] 2. The polyetherimide composite materials provided in Examples 1 to 4 and Comparative Example 1 were subjected to bending strength tests according to GB9341 / T standard, wherein the sample type was a sample size (mm): (80±0.4)×(10±0.1)×(4±0.02), and the bending speed was 20 mm / min.

[0121] 3. According to GB / T 1843-2008 standard, the polyetherimide composite materials provided in Examples 1 to 4 and Comparative Example 1 were subjected to a notched cantilever beam impact strength test, wherein the pendulum energy was 2.75 J.

[0122] 4. The surface resistivity of the polyetherimide composite materials provided in Examples 1 to 4 and Comparative Example 1 was tested using a surface resistivity meter.

[0123] The test results are shown in Table 1 below:

[0124] Table 1

[0125] Test items Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Tensile strength MPa 98 96 105 101 103 Bending strength MPa 140 136 150 143 148 Izod impact strength J / m 72 76 73 72 71 Surface resistivity Ω / Sq <![CDATA[10 5.2 ]]> <![CDATA[10 4.1 ]]> <![CDATA[10 6.0 ]]> <![CDATA[10 7.1 ]]> <![CDATA[10 9.8 ]]>

[0126] As can be seen from Table 1, the tensile strength, flexural strength and Izod impact strength of the polyetherimide composite materials provided in Examples 1 to 3 are very similar to those of the polyetherimide composite materials provided in Comparative Example 1. However, the surface resistivity of the polyetherimide composite materials provided in Comparative Example 1 is 10 9.8 The surface resistivity of the polyetherimide composite material provided in Examples 1 to 3 is 10 6.0 Ω / Sq or less, which is at least 3.8 orders of magnitude smaller than the surface resistivity of the polyetherimide composite material provided in Comparative Example 1, indicating that the polyetherimide composite materials provided in Examples 1 to 3 of the present application can prevent carbon nanotubes from agglomerating by coating carbon nanotubes on the surface of the second polyetherimide particles to form microspheres of carbon nanotubes coating the second polyetherimide, thereby overcoming the problem of poor compatibility between carbon nanotubes and polyetherimide. Therefore, the polyetherimide composite materials of the present application embodiment have good dispersibility and good conductivity. The surface resistivity of the polyetherimide composite material provided in Example 3 is significantly lower than that of the polyetherimide composite material provided in Example 4, indicating that by selecting multi-walled carbon nanotubes of different specifications for compounding, it is beneficial for multi-walled carbon nanotubes to form a gradient dispersion in the process of preparing carbon nanotube slurry, improving the dispersion performance of carbon nanotubes, and when sprayed on the surface of the second polyetherimide particles, a uniform coating can be formed, so that the carbon nanotubes can be evenly dispersed in the polyetherimide, thereby further improving the conductivity of the polyetherimide composite material.

[0127] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A polyetherimide composite material, It is characterized in that The composition comprises the following components in parts by weight: 50-75 parts of the first polyetherimide, 50-60 parts of carbon nanotube-coated microspheres of the second polyetherimide, 10~30 parts of inorganic filler; The carbon nanotubes in the carbon nanotube-coated microspheres of the second polyetherimide are multi-walled carbon nanotubes; the multi-walled carbon nanotubes include first multi-walled carbon nanotubes, second multi-walled carbon nanotubes, third multi-walled carbon nanotubes and fourth multi-walled carbon nanotubes, and the mass ratio of the first multi-walled carbon nanotubes, the second multi-walled carbon nanotubes, the third multi-walled carbon nanotubes and the fourth multi-walled carbon nanotubes is (20-30): (20-30): (20-30): (10-40); The diameter of the first multi-walled carbon nanotube is 16~20nm, and the length is 51~79μm; the diameter of the second multi-walled carbon nanotube is 11~15nm, and the length is 20~40μm; the diameter of the third multi-walled carbon nanotube is 6~10nm, and the length is 80~100μm; the diameter of the fourth multi-walled carbon nanotube is 6~10nm, and the length is 40~60μm.

2. The polyetherimide composite material according to claim 1, It is characterized in that The mass ratio of the carbon nanotubes in the microspheres coated with the second polyetherimide to the second polyetherimide is (10-50): (85-90); and / or The particle size of the carbon nanotube-coated second polyetherimide microspheres is 0.5-2 mm.

3. The polyetherimide composite material according to claim 2, It is characterized in that The multi-walled carbon nanotubes have an aspect ratio of (5000-10000):1 and a specific surface area of ​​200-350 m 2 / g.

4. The polyetherimide composite material according to any one of claims 1 to 3, It is characterized in that The inorganic filler is selected from at least one of silicon dioxide, magnesium oxide, talc, calcium carbonate, asbestos and kaolin; and / or The particle size of the inorganic filler is 3-5 μm.

5. The polyetherimide composite material according to any one of claims 1 to 3, It is characterized in that The polyetherimide composite material also includes 3 to 5 parts of an antioxidant.

6. A method for preparing a polyetherimide composite material, It is characterized in that The following steps are involved: Providing raw materials of various components of the polyetherimide composite material according to any one of claims 1 to 5; The first polyetherimide, the microspheres of the second polyetherimide coated with carbon nanotubes and the inorganic filler are mixed and then extruded to obtain a polyetherimide composite material.

7. The preparation method according to claim 6, It is characterized in that The steps for preparing the carbon nanotube-coated second polyetherimide microspheres include: The acidified carbon nanotubes are added into a solvent for dispersion treatment, and then silicone resin is added for mixing treatment to obtain a carbon nanotube slurry; The second polyetherimide powder is melt-sprayed to form second polyetherimide particles, and then the carbon nanotube slurry is sprayed on the surface of the second polyetherimide particles to obtain microspheres of the second polyetherimide coated with the carbon nanotubes.

8. The preparation method according to claim 7, It is characterized in that The mass ratio of the acidified carbon nanotubes, the silicone resin and the solvent is (0.1-0.2): (0.2-0.3): 1; and / or The preparation steps of the acidified carbon nanotubes include: subjecting the carbon nanotubes to ultrasonic treatment and then placing them in mixed acid for acidification treatment.