A method for regulating the dynamic performance of hot-pressing molding epoxy vitrimer composites by the content of oriented filler V-shaped

Abstract

The application discloses a method for regulating the dynamic performance of hot-pressing molding epoxy vitrimer composites by the V-shaped content of oriented fillers, uses flake graphite as the lamellar oriented filler, and uses the dynamically chemically cross-linked epoxy vitrimer as the resin matrix, so that the content of the lamellar oriented filler is changed by changing the single-layer thickness and the number of layers while keeping the total thickness unchanged, and the V-shaped regulation method of the dynamic performance of the hot-pressing molding anisotropic epoxy vitrimer composites is realized. The dynamic performance of the epoxy vitrimer composite presents a V-shaped change trend with the content of the lamellar oriented filler, which is completely different from the linear inhibition behavior of conventional fillers, and the application can be used for regulating the dynamic performance of the epoxy vitrimer by the V-shaped content of the oriented filler.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional polymers and their composites, and specifically relates to a method for regulating the dynamic properties of hot-pressed epoxy vitrimer composites through the content of oriented fillers and V-shaped patterns. BACKGROUND

[0002] With the rapid development of science and technology, organic polymer materials have become one of the indispensable materials for the development of human society. According to the difference of crosslinking structure and forming method, polymer materials can be generally divided into two categories: thermosetting polymers and thermoplastic polymers. Among them, thermosetting polymers have the advantages of stable structure, solvent resistance and excellent performance after curing and forming. At the same time, due to its three-dimensional crosslinking network structure, it cannot be reprocessed and recycled. At the same time, linear non-crosslinked thermoplastic polymers can be processed and formed by hot pressing, injection molding and other methods, but they are not resistant to solvent and have some shortcomings in structural stability. In 2011, the emergence of epoxy glass polymers (vitrimer) broke the inherent boundaries between traditional thermosetting polymers and thermoplastic polymers. With the help of reversible exchange reactions of dynamic crosslinking points, epoxy vitrimers can have three-dimensional crosslinking network structure, solvent resistance and structural stability, while also showing stress release, reworkability and other dynamic properties. How to regulate the stress release behavior and reworkability of epoxy vitrimers and composites and their typical dynamic performance characteristic parameters such as stress relaxation time (τ) has important significance for improving the dynamic performance of epoxy vitrimers. At present, in addition to the methods of catalyst, ester bond content, nanoparticles and other methods for regulating the dynamic performance and characteristic parameters of epoxy vitrimers, more methods for regulating the dynamic performance of epoxy vitrimers and composites are still lacking.

[0003] Here, we take advantage of the hot-press reworkability of epoxy vitrimer, by introducing the lamellar oriented filler (flake graphite), and using the content of the lamellar oriented filler to achieve the V-shaped regulation of the dynamic performance of the hot-press molded epoxy vitrimer composite. With the gradual increase of the content of the lamellar oriented filler from 0, the dynamic performance of the anisotropic epoxy vitrimer in both horizontal and vertical directions is first gradually improved with the addition of the lamellar oriented filler, the stress relaxation behavior is accelerated, and the time required to release stress and the characteristic stress relaxation time (τ) are gradually shortened, but when the content of the lamellar oriented filler exceeds a certain threshold, the dynamic performance of the anisotropic epoxy vitrimer is instead deteriorated with the increase of the content of the lamellar oriented filler, the stress relaxation behavior is slowed down, and the stress relaxation time (τ) is gradually extended. The V-shaped change trend is completely different from the linear inhibition behavior of conventional fillers. The present application can be used to regulate the dynamic performance of epoxy vitrimer by the V-shaped regulation of the content of the oriented filler, and to realize the design and preparation of epoxy vitrimer materials with the same horizontal dynamic performance under different filler contents. SUMMARY

[0004] The present application overcomes the shortcomings of the prior art and provides an embodiment of a method for regulating the dynamic performance of hot-press molded epoxy vitrimer composite by the V-shaped regulation of the content of the oriented filler, in order to generate more methods for regulating the dynamic performance of epoxy vitrimer and composite, and to realize the regulation of the stress release behavior and reworkability of the regulated epoxy vitrimer and composite, as well as the regulation of the stress relaxation time (τ) and other typical dynamic performance characteristic parameters.

[0005] The present application is a method for regulating the dynamic performance of hot-press molded epoxy vitrimer composite by the V-shaped regulation of the content of the oriented filler, using flake graphite as the lamellar oriented filler and dynamically chemically cross-linked epoxy vitrimer as the resin matrix. By changing the single-layer thickness, the number of layers while keeping the total thickness consistent, and the content of the lamellar oriented filler, hot-press molded anisotropic epoxy vitrimer composites with different oriented filler contents are obtained, to realize the V-shaped regulation method of the dynamic performance of the epoxy vitrimer composite. With the gradual increase of the content of the lamellar oriented filler from 0, the dynamic performance of the anisotropic epoxy vitrimer in both horizontal and vertical directions is first gradually improved with the addition of the lamellar oriented filler, the stress relaxation behavior is accelerated, and the time required to release stress (τ) is gradually shortened, but when the content of the lamellar oriented filler exceeds a certain threshold, the dynamic performance of the anisotropic epoxy vitrimer is instead deteriorated with the increase of the content of the lamellar oriented filler, the stress relaxation behavior is slowed down, and the stress relaxation time (τ) is gradually extended.

[0006] The sheet layer filler content is regulated by changing the single layer thickness, the number of layers and keeping the total thickness consistent, and the hot-pressed anisotropic epoxy vitrimer composite material with different orientation filler content is prepared according to weight fractions of 70-100 parts of epoxy resin (including any one of bisphenol A diglycidyl ether, bisphenol A diglycidyl ester, bisphenol S diglycidyl ether, bisphenol S diglycidyl ester, bisphenol F diglycidyl ether, bisphenol F diglycidyl ester, 1,4-butanediol glycidyl ether, hydrogenated bisphenol A diglycidyl ether, trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80 or pentaerythritol tetraglycidyl ether, or a mixture of two or more thereof) and 20-100 parts of epoxy curing agent (including any one or a mixture of two or more of glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, pentane tricarboxylic acid, butane tetracarboxylic acid, dithiodiphenylamine, dithiodibutyric acid, dithiodipropionic acid, dithiodiacetic acid) and 0-10 parts of catalyst (including any one or a mixture of two or more of triazabicyclo, zinc acetylacetone, triphenyl phosphine, etc. ester bond catalysts) to obtain an epoxy vitrimer matrix. Then, the obtained epoxy vitrimer is hot-pressed into a sheet of different thickness, and a layer of flake graphite (including any one of 50 mesh, 100 mesh, 200 mesh, 325 mesh flake graphite) is covered on the vitrimer sheet, which is then hot-pressed on the surface of the epoxy vitrimer matrix to make the flake graphite orient and arrange, thereby obtaining a single-layer epoxy vitrimer composite material. Then, the epoxy vitrimer composite material with different thickness is hot-pressed to composite and form the single-layer epoxy vitrimer composite material with different number of layers, and the flake graphite is further highly oriented and arranged in the matrix, thereby obtaining the hot-pressed anisotropic epoxy vitrimer composite material with different orientation filler content under the condition of keeping the total thickness consistent.

[0007] Compared with the prior art, the present application has the following beneficial effects:

[0008] By introducing different amounts of lamellar-oriented fillers (such as flake graphite) into epoxy vitrimer and hot-pressing epoxy vitrimers of different thicknesses with the lamellar-oriented fillers, the dynamic properties of hot-pressed epoxy vitrimer composites were controlled in a V-shape by utilizing the filler content. As the lamellar-oriented filler content gradually increases from 0, the dynamic properties of the anisotropic epoxy vitrimer, whether in the horizontal or vertical direction, initially improve with the addition of lamellar-oriented fillers, with accelerated stress relaxation behavior and a gradual decrease in the time required to release stress and the characteristic stress relaxation time (τ). However, as the lamellar-oriented filler content exceeds a certain threshold, the dynamic properties deteriorate with further increases in lamellar-oriented filler content, stress relaxation behavior slows down, and the characteristic stress relaxation time (τ) gradually lengthens. Attached Figure Description

[0009] Figure 1 Hot pressing of epoxy Vitrimer composites with different orientation filler contents and V-shaped control of dynamic properties by orientation filler content.

[0010] Figure 2 The V-shaped regulation of the horizontal dynamic properties of hot-pressed epoxy Vitrimer composites by the content of orientation filler.

[0011] Figure 3 The V-shaped regulation of the vertical dynamic properties of hot-pressed epoxy Vitrimer composites by the content of orientation filler.

[0012] Figure 4 The V-shaped regulation of the characteristic stress relaxation time (τ) in the horizontal / vertical directions of hot-pressed epoxy Vitrimer composites by the content of orientation filler. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0014] Example 1

[0015] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 5 / 13mm, 5 / 11mm, 5 / 9mm, 5 / 6mm, 5mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material was composite-molded using a multi-layer hot-pressing method. While maintaining the total thickness (e.g., 5 mm) (e.g., number of epoxy vitrimer layers: 5 / 13 mm × 13 layers, 5 / 11 mm × 11 layers, 5 / 9 mm × 9 layers, 5 / 6 mm × 6 layers, 5 mm × 1 layer), further hot-pressing was used to highly oriented the flake graphite within the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., number of lamellar oriented filler layers: 12, 10, 8, 5, 0) and different filler contents (e.g., lamellar oriented filler contents are shown in Table 1). Figure 1 (Table 1).

[0016] Table 1. Single-layer thickness, number of layers, total thickness, and orientation filler content of hot-pressed epoxy Vitrimer composite materials.

[0017]

[0018] The epoxy resin is a diglycidyl ether such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether, as well as diglycidyl esters such as bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, and bisphenol F diglycidyl ester, and polyglycidyl ethers such as trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether, any one of which The epoxy curing agent is any one or a mixture of two or more dicarboxylic acid compounds such as glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, etc., and any one or a mixture of two or more polycarboxylic acid compounds such as pentanetricarboxylic acid, butanetetracarboxylic acid, etc.; the catalyst is any one or a mixture of two or more ester bond catalysts such as triazabicyclohexane, zinc acetylacetonate, triphenylphosphine, etc.; and the flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0019] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler. Figure 2 ).

[0020] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction vary in a V-shape with the content of orientation filler. Figure 3 ).

[0021] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal / vertical directions varies in a V-shape with the content of orientation filler. Figure 4 ).

[0022] Example 2

[0023] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 4 / 13mm, 4 / 11mm, 4 / 9mm, 4 / 6mm, 4mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material is composite-molded using a multi-layer hot pressing method. While maintaining the total thickness (e.g., 4 mm), the epoxy vitrimer layer number is further hot-pressed to make the flake graphite highly oriented in the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., lamellar oriented filler layer numbers: 12, 10, 8, 5, 0) and different orientation filler contents.

[0024] The epoxy resin is a diglycidyl ether such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether, as well as diglycidyl esters such as bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, and bisphenol F diglycidyl ester, and polyglycidyl ethers such as trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether, any one of which The epoxy curing agent is any one or a mixture of two or more dicarboxylic acid compounds such as glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, etc., and any one or a mixture of two or more polycarboxylic acid compounds such as pentanetricarboxylic acid, butanetetracarboxylic acid, etc.; the catalyst is any one or a mixture of two or more ester bond catalysts such as triazabicyclohexane, zinc acetylacetonate, triphenylphosphine, etc.; and the flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0025] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler.

[0026] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction change in a V-shape with the content of orientation filler.

[0027] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal and vertical directions varies in a V-shape with the content of orientation filler.

[0028] Example 3

[0029] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 3 / 13mm, 3 / 11mm, 3 / 9mm, 3 / 6mm, 3mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material is composite-molded using a multi-layer hot pressing method. While maintaining the total thickness (e.g., 3 mm) (e.g., number of epoxy vitrimer layers: 3 / 13 mm × 13 layers, 3 / 11 mm × 11 layers, 3 / 9 mm × 9 layers, 3 / 6 mm × 6 layers, 3 mm × 1 layer), further hot pressing is used to make the flake graphite highly oriented in the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., number of lamellar oriented filler layers: 12, 10, 8, 5, 0) and different orientation filler contents.

[0030] The epoxy resin is a diglycidyl ether such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether, as well as diglycidyl esters such as bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, and bisphenol F diglycidyl ester, and polyglycidyl ethers such as trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether, any one of which The epoxy curing agent is any one or a mixture of two or more dicarboxylic acid compounds such as glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, etc., and any one or a mixture of two or more polycarboxylic acid compounds such as pentanetricarboxylic acid, butanetetracarboxylic acid, etc.; the catalyst is any one or a mixture of two or more ester bond catalysts such as triazabicyclohexane, zinc acetylacetonate, triphenylphosphine, etc.; and the flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0031] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler.

[0032] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction change in a V-shape with the content of orientation filler.

[0033] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal and vertical directions varies in a V-shape with the content of orientation filler.

[0034] Example 4

[0035] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 6 / 13mm, 6 / 11mm, 6 / 9mm, 6 / 6mm, 6mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material is composite-molded using a multi-layer hot pressing method. While maintaining the total thickness (e.g., 6 mm), the epoxy vitrimer layer number is further hot-pressed to make the flake graphite highly oriented in the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., lamellar oriented filler layer numbers: 12, 10, 8, 5, 0) and different orientation filler contents.

[0036] The epoxy resin is a diglycidyl ether such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether, as well as diglycidyl esters such as bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, and bisphenol F diglycidyl ester, and polyglycidyl ethers such as trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether, any one of which The epoxy curing agent is any one or a mixture of two or more dicarboxylic acid compounds such as glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, etc., and any one or a mixture of two or more polycarboxylic acid compounds such as pentanetricarboxylic acid, butanetetracarboxylic acid, etc.; the catalyst is any one or a mixture of two or more ester bond catalysts such as triazabicyclohexane, zinc acetylacetonate, triphenylphosphine, etc.; and the flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0037] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler.

[0038] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction change in a V-shape with the content of orientation filler.

[0039] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal and vertical directions varies in a V-shape with the content of orientation filler.

[0040] Example 5

[0041] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 8 / 13mm, 8 / 11mm, 8 / 9mm, 8 / 6mm, 8mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material is composite-molded using a multi-layer hot pressing method. While maintaining the total thickness (e.g., 8 mm) (e.g., number of epoxy vitrimer layers: 8 / 13 mm × 13 layers, 8 / 11 mm × 11 layers, 8 / 9 mm × 9 layers, 8 / 6 mm × 6 layers, 8 mm × 1 layer), further hot pressing is used to make the flake graphite highly oriented in the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., number of lamellar oriented filler layers: 12, 10, 8, 5, 0) and different orientation filler contents.

[0042] The epoxy resin is a diglycidyl ether such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether, as well as diglycidyl esters such as bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, and bisphenol F diglycidyl ester, and polyglycidyl ethers such as trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether, any one of which The epoxy curing agent is any one or a mixture of two or more dicarboxylic acid compounds such as glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, etc., and any one or a mixture of two or more polycarboxylic acid compounds such as pentanetricarboxylic acid, butanetetracarboxylic acid, etc.; the catalyst is any one or a mixture of two or more ester bond catalysts such as triazabicyclohexane, zinc acetylacetonate, triphenylphosphine, etc.; and the flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0043] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler.

[0044] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction change in a V-shape with the content of orientation filler.

[0045] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal and vertical directions varies in a V-shape with the content of orientation filler.

[0046] Example 6

[0047] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 10 / 13 mm, 10 / 11 mm, 10 / 9 mm, 10 / 6 mm, 10 mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material is composite-molded using a multi-layer hot pressing method. While maintaining the total thickness (e.g., 10 mm) (e.g., number of epoxy vitrimer layers: 10 / 13 mm × 13 layers, 10 / 11 mm × 11 layers, 10 / 9 mm × 9 layers, 10 / 6 mm × 6 layers, 10 mm × 1 layer), further hot pressing is used to make the flake graphite highly oriented in the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., number of lamellar oriented filler layers: 12, 10, 8, 5, 0) and different orientation filler contents.

[0048] The epoxy resin is a diglycidyl ether such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, and hydrogenated bisphenol A diglycidyl ether, as well as diglycidyl esters such as bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, and bisphenol F diglycidyl ester, and polyglycidyl ethers such as trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether, any one of which The epoxy curing agent is any one or a mixture of two or more dicarboxylic acid compounds such as glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, etc., and any one or a mixture of two or more polycarboxylic acid compounds such as pentanetricarboxylic acid, butanetetracarboxylic acid, etc.; the catalyst is any one or a mixture of two or more ester bond catalysts such as triazabicyclohexane, zinc acetylacetonate, triphenylphosphine, etc.; and the flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0049] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler.

[0050] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction change in a V-shape with the content of orientation filler.

[0051] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal and vertical directions varies in a V-shape with the content of orientation filler.

[0052] Example 7

[0053] This invention discloses a method for controlling the dynamic properties of hot-pressed epoxy vitrimer composites by V-shaped adjustment of the content of oriented filler. The method is as follows: First, an epoxy vitrimer matrix is ​​obtained by curing 70-100 parts by weight of epoxy resin, 20-100 parts by weight of epoxy curing agent, and 1-10 parts by weight of catalyst. Then, the obtained epoxy vitrimer is hot-pressed into sheets of different thicknesses (e.g., epoxy vitrimer layer thicknesses: 4 / 13mm, 4 / 11mm, 4 / 9mm, 4 / 6mm, 4mm, etc.). Next, a layer of flake graphite is coated onto the sheet, and then hot-pressed onto the surface of the epoxy vitrimer matrix. This causes the flake graphite to be distributed flatly on the epoxy vitrimer surface under a certain pressure, thereby obtaining a single-layer epoxy vitrimer composite material. Finally, the single-layer epoxy vitrimer composite material is composite-molded using a multi-layer hot pressing method. While maintaining the total thickness (e.g., 4 mm), the epoxy vitrimer layer number is further hot-pressed to make the flake graphite highly oriented in the matrix, thereby obtaining epoxy vitrimer composite materials with different filler layer numbers (e.g., lamellar oriented filler layer numbers: 12, 10, 8, 5, 0) and different orientation filler contents.

[0054] The epoxy resin is any one or a mixture of two or more of the following: bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, etc.; bisphenol A diglycidyl ester, bisphenol S diglycidyl ester, bisphenol F diglycidyl ester, etc.; and trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80 or pentaerythritol tetraglycidyl ether, etc. The epoxy curing agent is any one or a mixture of two or more of the following: dithiodiphenylamine, dithiodibutyric acid, dithiodipropionic acid, dithiodiacetic acid, etc. The flake graphite is any one of flake graphite with a size of 50 mesh, 100 mesh, 200 mesh, or 325 mesh.

[0055] The dynamic properties of hot-pressed epoxy Vitrimer composites in the horizontal direction vary in a V-shape with the content of oriented filler.

[0056] The dynamic properties of hot-pressed epoxy Vitrimer composites in the vertical direction change in a V-shape with the content of orientation filler.

[0057] The characteristic stress relaxation time of hot-pressed epoxy Vitrimer composites in the horizontal and vertical directions varies in a V-shape with the content of orientation filler.

[0058] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A method for controlling the dynamic properties of hot-pressed epoxy Vitrimer composites by V-shaped adjustment of the content of oriented fillers, characterized in that, Using flake graphite as a lamellar orientation filler and dynamically chemically cross-linked epoxy vitrimer as a resin matrix, anisotropic epoxy vitrimer composites with different orientation filler contents were obtained by changing the single-layer thickness and number of layers while maintaining a consistent total thickness. This achieved a V-shaped control method for the dynamic properties of epoxy vitrimer composites. As the lamellar orientation filler content gradually increased from 0, the dynamic properties of the anisotropic epoxy vitrimer, whether in the horizontal or vertical direction, initially improved gradually with the addition of lamellar orientation filler, with accelerated stress relaxation behavior and a gradually shortened stress release time (τ). However, as the lamellar orientation filler content exceeded a certain threshold, the dynamic properties deteriorated with the increase of lamellar orientation filler content, with slower stress relaxation behavior and a gradually longer stress relaxation time (τ).

2. The method for controlling the dynamic properties of hot-pressed epoxy Vitrimer composite materials by V-shaped adjustment of the content of oriented filler as described in claim 1, characterized in that, The hot-pressed anisotropic epoxy vitrimer composite material with different orientation filler contents is prepared by curing an epoxy vitrimer matrix by weight of 70-100 parts epoxy resin, 20-100 parts epoxy curing agent, and 0-10 parts catalyst. The resulting epoxy vitrimer is then hot-pressed into sheets of different thicknesses, and a layer of flake graphite is coated onto the vitrimer sheets. This is then hot-pressed onto the surface of the epoxy vitrimer matrix, causing the flake graphite to align, thus obtaining a single-layer epoxy vitrimer composite material. Subsequently, epoxy vitrimer composite materials of different thicknesses are hot-pressed to combine the single-layer epoxy vitrimer composite materials with different numbers of layers, further aligning the flake graphite within the matrix. This process, while maintaining a consistent total thickness, yields hot-pressed anisotropic epoxy vitrimer composite materials with different orientation filler contents.

3. The method for controlling the dynamic properties of hot-pressed epoxy Vitrimer composite materials by V-shaped adjustment of the content of oriented filler as described in claim 2, characterized in that, The epoxy resin is selected from any one or a mixture of two or more of the following: bisphenol A diglycidyl ether, bisphenol A diglycidyl ester, bisphenol S diglycidyl ether, bisphenol S diglycidyl ester, bisphenol F diglycidyl ether, bisphenol F diglycidyl ester, 1,4-butanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, trifunctional glycidyl ether AFG90, tetrafunctional glycidyl ether AG80, or pentaerythritol tetraglycidyl ether.

4. The method for controlling the dynamic properties of hot-pressed epoxy Vitrimer composite materials by V-shaped adjustment of the content of oriented filler as described in claim 2, characterized in that, The epoxy curing agent is selected from any one or a mixture of two or more of the following: glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, pentanetricarboxylic acid, butanetetracarboxylic acid, dithiodiphenylamine, dithiodibutyric acid, dithiodipropionic acid, and dithiodiacetic acid.

5. The method for controlling the dynamic properties of hot-pressed epoxy Vitrimer composite materials by V-shaped adjustment of the content of oriented filler according to claim 2, characterized in that, The catalyst is selected from any one or a mixture of two or more ester-bonded catalysts such as triazabicyclohexane, zinc acetylacetonate, and triphenylphosphine.

6. The method for controlling the dynamic properties of hot-pressed epoxy Vitrimer composite materials by V-shaped adjustment of the content of oriented filler according to claim 3, characterized in that, The flake graphite includes any one of the following sizes: 50 mesh, 100 mesh, 200 mesh, and 325 mesh flake graphite.

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