CN114479359A

CN114479359A - Fiber and red mud jointly modified epoxy resin composite material and preparation method thereof

Info

Publication number: CN114479359A
Application number: CN202111081244.3A
Authority: CN
Inventors: 裴先强; 张展程; 王彦; 王齐华; 王廷梅; 王泽军
Original assignee: Yantai Zhongke Advanced Materials And Green Chemical Industry Technology Research Institute; Lanzhou Institute of Chemical Physics LICP of CAS
Current assignee: Yantai Zhongke Advanced Materials And Green Chemical Industry Technology Research Institute; Lanzhou Institute of Chemical Physics LICP of CAS
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2022-05-13
Anticipated expiration: 2041-09-15
Also published as: CN114479359B

Abstract

The invention provides an epoxy resin composite material jointly modified by fiber and red mud and a preparation method thereof, belonging to the technical field of composite materials. The red mud surface-modified by the coupling agent is used as the nano-micron composite inorganic filler to modify the epoxy resin matrix, and the crushed fiber is used as the reinforcing material to prepare the epoxy resin composite material, the epoxy resin modified by the red mud has more excellent toughness and strength, and meanwhile, the addition of the red mud surface-modified by the coupling agent also promotes the resin matrix and the fiber reinforcing material to generate a more compact interface effect. Therefore, the epoxy resin composite material prepared by the invention has good mechanical property and tribological property.

Description

Fiber and red mud jointly modified epoxy resin composite material and preparation method thereof

Technical Field

The invention relates to the technical field of composite materials, in particular to an epoxy resin composite material jointly modified by fibers and red mud and a preparation method thereof.

Background

Epoxy resins (EP) are a class of commonly used thermosetting plastics, which have excellent chemical stability, good mechanical properties, high thermal stability, extremely high adhesion and extremely low curing shrinkage, and by virtue of the excellent properties, epoxy resins are often applied in the fields of adhesives, coatings, molding compounds for electronic devices, engineering plastics, composite material substrates, and the like. However, the higher degree of crosslinking also causes the problems of poor toughness and wear resistance, lower material hardness and the like of the epoxy resin.

In order to solve the above problems, methods such as inorganic nanoparticle modification, liquid rubber modification, polyurethane modification, flexible curing agent regulation and control, and directional design of epoxy resin molecular structure are often adopted to improve the toughness of epoxy resin materials. Among them, the inorganic nanoparticle toughening method is a kind of modification method with outstanding advantages. The particle size at the nanometer level, the huge specific surface area and the extremely high modulus endow the inorganic nanoparticles with special properties. Specifically, in the field of epoxy resin/inorganic nano-particle composite materials, the inorganic nano-particles can effectively prevent the extension of cracks in the epoxy resin and effectively disperse stress concentration, thereby achieving the effects of increasing the impact strength of the material and enhancing the toughness of the material. Meanwhile, the high modulus of the nano particles can also effectively increase the hardness of the composite material. For example, patent CN 201410822326.2 discloses an epoxy resin-silica hollow tube composite material and a preparation method thereof, wherein the mechanical property of the epoxy resin is enhanced by the silica hollow tube. More importantly, in the field of tribology, when the epoxy resin/inorganic nano particle composite material is subjected to opposite grinding with metal, the inorganic nano particles can participate in the physical and chemical reaction generated on the interface, so that the effect of reducing the abrasion of the composite material is achieved.

However, the inorganic nanoparticles have a great structural difference from the epoxy resin matrix, and the surface active groups of the inorganic nanoparticles are fewer. The above problems result in poor dispersibility of the inorganic nanoparticles in the epoxy resin, serious agglomeration of the nanoparticles, and weak interfacial interaction force between the inorganic nanoparticles and the epoxy resin. The application of the material in the field of epoxy resin composite materials is seriously influenced by the problems. Meanwhile, due to the limitation of a synthesis method, compared with micron-sized inorganic filler, the inorganic nano particles are expensive, so that the popularization and application of the material as an industrial raw material are limited to a certain extent.

Meanwhile, although epoxy resin materials have better mechanical properties in the field of thermosetting plastics. But is far from the metallic material. In order to solve the above problems, high modulus fiber materials such as glass fiber, carbon fiber, aramid fiber, steel fiber, etc. are often used as a support skeleton to construct an epoxy resin/fiber composite material, thereby achieving the purpose of enhancing the strength and hardness of the material. However, the surface of the fiber-based material is generally smooth and has fewer reactive groups. The inert surface and the vastly different structure result in a weak force between the fiber-like material and the epoxy resin matrix. This phenomenon seriously affects the reliability and application potential of the epoxy/fiber material. In order to solve the above problems, methods such as chemical modification of fiber surface, structural fiber surface roughness, modification of epoxy resin matrix, and the like are often used. For example, patent CN201710465362.1 discloses a method for preparing a dopamine-modified glass fiber/epoxy resin composite material. According to the preparation method, the surface of the glass fiber is modified by dopamine, active functional groups are constructed, the interface acting force of the glass fiber and an epoxy resin matrix is enhanced to a great extent, and the mechanical property of the material is effectively improved. However, the high price of dopamine also limits the potential of this modification method.

Disclosure of Invention

The invention aims to provide an epoxy resin composite material jointly modified by fibers and red mud and a preparation method thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides an epoxy resin composite material jointly modified by fiber and red mud, which comprises the following preparation raw materials in parts by mass: 5-50 parts of crushed fibers, 10-100 parts of coupling agent surface modified red mud material, 50-300 parts of epoxy resin, 0.1-1 part of defoaming agent and 10-45 parts of curing agent.

Preferably, the pulverized fiber comprises pulverized carbon fiber, pulverized aramid fiber or coupling modified pulverized glass fiber; the average length of the pulverized fibers is 50-80 mu m, and the monofilament diameter is 0.1-8 mu m.

Preferably, the preparation method of the coupling modified crushed glass fiber comprises the following steps: mixing a silane coupling agent, ethanol and water to obtain a modified solution; and mixing the modified solution with the crushed glass fiber, and carrying out modification reaction to obtain the coupling modified crushed glass fiber.

Preferably, the preparation method of the coupling agent surface modified red mud material comprises the following steps:

mixing red mud, organic acid and water, and sequentially carrying out dealkalization treatment and sedimentation separation treatment to obtain dealkalized red mud;

mixing the dealkalized red mud, the first coupling agent, the second coupling agent and an organic solvent, and carrying out modification treatment to obtain a coupling agent surface modified red mud material; the first coupling agent is at least one of silane coupling agents, aluminate coupling agents and titanate coupling agents, and the second coupling agent is an amino coupling agent.

Preferably, the organic acid comprises acetic acid, oxalic acid, maleic acid or stearic acid; the mass ratio of the red mud to the organic acid is (50-300): 20.

preferably, the temperature of the dealkalization treatment is 50-130 ℃, and the time is 120 min; the temperature of the modification treatment is 90-150 ℃, and the time is 2 h.

Preferably, the silane coupling agent comprises n-octyl triethoxysilane, the aluminate coupling agent comprises isopropoxy distearoyl aluminate or diisopropoxy acetoacetate oleate, and the titanate coupling agent comprises isopropoxy tristearoyl acyloxy titanate or isopropoxy tri (dioctyl phosphate acyloxy) titanate; the amino coupling agent comprises 3-aminopropyltriethoxysilane, 3-urea propyl trimethoxysilane or isopropoxy tri (ethylenediamine N-ethoxy) titanate;

the mass ratio of the dealkalized red mud to the first coupling agent to the second coupling agent is (50-300): (0.2-2): (0.2-2).

Preferably, the curing agent comprises divinyl triamine, diamino diphenyl sulfone, diamino diphenyl methane or tung oil anhydride.

The invention provides a preparation method of the epoxy resin composite material, which comprises the following steps:

mixing the crushed fibers, the coupling agent surface modified red mud material epoxy resin, the defoaming agent and the curing agent, and curing the obtained mixed solution to obtain the epoxy resin composite material jointly modified by the fibers and the red mud. Preferably, the curing treatment includes a first curing treatment and a second curing treatment which are sequentially performed; the temperature of the first curing treatment is 90-150 ℃, and the time is 1-5 h; the temperature of the second curing treatment is 140-200 ℃, and the time is 1-5 h.

The red mud surface-modified by the coupling agent is used as the nano-micron composite inorganic filler to modify the epoxy resin matrix, and the crushed fiber is used as the reinforcing material to prepare the epoxy resin composite material, the epoxy resin modified by the red mud has more excellent toughness and strength, and meanwhile, the addition of the red mud surface-modified by the coupling agent also promotes the resin matrix and the fiber reinforcing material to generate a more compact interface effect. Therefore, the epoxy resin composite material prepared by the invention has good mechanical property and tribological property.

Drawings

FIG. 1 is an SEM image of an impact cross-section of an epoxy resin composite prepared in example 1;

FIG. 2 is a graph of coefficient of friction versus time for the dry friction test of an epoxy resin composite block prepared in example 1;

FIG. 3 is a three-dimensional contour diagram of the surface of a bearing steel pair after a ring block friction test of the epoxy resin composite material pair prepared in example 1 and the bearing steel pair;

FIG. 4 is a graph showing the linear height data of the surface of a bearing steel pair after a ring block friction test of the epoxy resin composite material pair prepared in example 1 and the bearing steel pair.

Detailed Description

In the present invention, the starting materials used are all commercially available products well known in the art, unless otherwise specified.

The coupling agent surface-modified red mud material will be explained first.

In the invention, the preparation method of the coupling agent surface modified red mud material preferably comprises the following steps:

The invention mixes red mud, organic acid and water, and sequentially carries out dealkalization treatment and sedimentation separation treatment to obtain the dealkalized red mud. The source of the Red Mud (RM) is not particularly limited, and red mud from sources well known to those skilled in the art may be used, and in the embodiment of the present invention, the red mud may be specifically red mud generated in a combined process for smelting aluminum. In the invention, the red mud generated in the combined process for smelting aluminum is mostly brown red mud formed by mixing yellow red mud and black red mud, wherein S in the yellow red mud^2-In a low content of (<0.1 wt%), smaller particle size, stronger hydrophilicity and better dispersion performance in water; s in black red mud^2-Higher content of (>0.25wt％)，S^2-The existence of the compound promotes the crystallization and crystal growth of FeO and FeS to a great extent, so that the red mud has larger particles, less surface hydrophilic groups, more electroneutrality and poor dispersibility in water; when S is contained in red mud²⁺When the content is within the range of 0.1-0.25 wt%, the red mud is mostly a mixture of yellow red mud and black red mud, and the color of the red mud is brown, namely brown red mud. The invention firstly dealkalizes the brown red mud and separates the grain diameter by an organic acid dealkalization and sedimentation separation method to obtain dealkalized red mud (namely dealkalized yellow red mud). Then, the high-dispersity red mud with an amino structure, namely, the aminated dealkalized red mud material (RM-NH) is prepared on the basis of the dealkalized red mud by a covalent bond surface modification method₂) The modified red mud is added into an epoxy resin/powder fiber composite material as a modifier, and the gelation time, viscosity and thermal expansion performance of an epoxy resin matrix are effectively changed by the modified red mud. The above changes greatly improve the dispersibility and interfacial compatibility of the powder fiber in the epoxy resin/red mud matrix. The mechanical property of the epoxy resin matrix is improved, and the interface acting force between the epoxy resin matrix and the powder fiber is effectively enhanced. Under the synergistic action of the red mud and the powder fiber, the mechanical properties of the epoxy resin/fiber/red mud (EP/SF/RM) are obviously changed, and the tribological properties are also obviously changedThe improvement is remarkable.

In the invention, the red mud is preferably crushed before use, and then passes through a 100-mesh screen to perform dealkalization treatment on the red mud obtained under the screen; the specific operation method of the crushing treatment is not particularly limited, and the red mud with the required granularity can be obtained, and in the embodiment of the invention, the red mud is added into a solid crusher and is crushed at 23000 rpm.

In the present invention, the organic acid preferably includes acetic acid, oxalic acid, maleic acid, or stearic acid; the mass ratio of the red mud to the organic acid is preferably (50-300): 20, more preferably (100 to 250): 20, more preferably (130-230): 20, more preferably (150 to 200): 20. in the invention, the water is preferably distilled water, and the dosage ratio of the red mud to the water is preferably (50-300) g: (200-800) mL, more preferably (100-250) g: (300-700) mL, more preferably (130-230) g: (400-600) mL, more preferably (150-200) g: (450-550) mL. The method for mixing the red mud, the organic acid and the water is not particularly limited, and all the components can be uniformly mixed.

In the invention, the temperature of the dealkalization treatment is preferably 50-130 ℃, more preferably 60-120 ℃, and further preferably 70-100 ℃; the temperature of the dealkalization treatment is preferably provided by an oil bath pan in the present invention. In the present invention, the time of the dealkalization treatment is preferably 120 min. In the present invention, the dealkalization treatment is preferably performed under a mechanical stirring condition, and the stirring rate is preferably 100 to 1000rpm, more preferably 200 to 600rpm, and further preferably 300 to 500 rpm. In the invention, Na in the red mud is removed during the dealkalization treatment₂Reaction of O with water: na (Na)₂O+H₂O ═ 2NaOH, which is the main cause of alkali contamination of red mud; meanwhile, the concentration of NaOH further influences the reaction process, and Na is inhibited₂Dissolution of O in water, which results in pure H₂Na is difficult to remove by O washing₂And O. The invention carries out dealkalization treatment under the action of organic acid, taking oxalic acid as an example, oxalic acid and Na₂Reaction of NaOH generated by O: HOOC-COOH +2NaOH ═ NaOOC-COONa+2H₂O, can promote Na₂O reacts with water, further increasing Na₂O solubility to remove Na₂The effect of O.

In the present invention, the settling separation treatment preferably comprises: and (3) dispersing and standing the system obtained after dealkalization treatment in sequence, and carrying out solid-liquid separation on the upper layer dispersion liquid obtained after standing to obtain the solid material dealkalized red mud. In the invention, the dispersing temperature is preferably 50-90 ℃, more preferably 60-80 ℃, and further preferably 65-75 ℃; in the invention, the dispersing temperature is preferably lower than the dealkalization temperature, and specifically, the difference between the dealkalization temperature and the dispersing temperature is preferably 5-30 ℃, and more preferably 10-20 ℃; the dispersing time is preferably 2-5 min; the dispersion is preferably carried out under stirring with a glass rod. In the invention, the dispersing is preferably carried out by cooling the system obtained after dealkalization treatment by 5-30 ℃ and dispersing for 2-5 min under the stirring condition of a glass rod. The invention preferably performs dispersion under the conditions, can regulate and control the viscosity of a system obtained after dealkalization treatment, is favorable for controlling the settling rate of large-particle red mud and small-particle red mud, and further selects proper settling time to separate the two types of red mud. In the invention, the standing time is preferably 1-10 min, more preferably 2-5 min, and more preferably 3 min; the invention leads the system to be layered by standing, wherein the upper layer dispersion liquid is yellow, namely yellow red mud with dispersed small particles; the solid-liquid mixture at the lower layer contains large-particle red mud.

In the present invention, the number of times of the settling separation treatment is preferably 1 to 10 times, more preferably 3 to 7 times, and further preferably 5 to 6 times. When the number of times of the sedimentation separation treatment is more than or equal to 2 times, the invention preferably disperses and stands the system obtained after the dealkalization treatment in the above way, adds water to dilute the solid-liquid mixture at the lower layer, disperses and stands the system in the above way, and realizes the multiple sedimentation separation treatment by circulation.

After the final standing, the solid-liquid separation is carried out on the obtained upper-layer dispersion liquid, and the obtained solid material is dealkalized red mud. In the present invention, the upper layer dispersion obtained after each standing may be subjected to solid-liquid separation, or the upper layer dispersion obtained after each standing may be combined and subjected to solid-liquid separation, which is not particularly limited in the present invention. The solid-liquid separation method is not particularly limited, and may be filtration.

According to the invention, preferably, solid materials obtained after solid-liquid separation are sequentially dried and crushed to obtain the dealkalized red mud. In the invention, the drying temperature is preferably 100-200 ℃, and more preferably 120-150 ℃; the time is preferably 10-15 h, and more preferably 12 h.

In the invention, the dealkalized red mud mainly comprises lamellar micron sheets and granular nano microspheres, the material has better monodispersity, and the grain diameter has gradient distribution; specifically, the particle size of the nano-microspheres is preferably 20-100 nm, and the size of the micro-sheet is preferably 10-20 μm.

After dealkalized red mud is obtained, mixing the dealkalized red mud, a first coupling agent, a second coupling agent and an organic solvent, and carrying out modification treatment to obtain a coupling agent surface modified red mud material; the first coupling agent is at least one of silane coupling agents, aluminate coupling agents and titanate coupling agents, and the second coupling agent is an amino coupling agent. In the present invention, the silane-based coupling agent preferably includes n-octyltriethoxysilane (SCA-K08E), the aluminate-based coupling agent preferably includes isopropoxy distearoyloxyaluminate (ACA-K30), and the titanate-based coupling agent preferably includes isopropoxy tristearoyloxytitanate titanate (TCA-KTTT); the amino coupling agent comprises 3-aminopropyltriethoxysilane (SCA-A10E), 3-urea propyl trimethoxysilane (SCA-U60M) or isopropoxy tris (ethylenediamine N-ethoxy) titanate (TCA-K44); the mass ratio of the dealkalized red mud to the first coupling agent to the second coupling agent is preferably (50-300): (0.2-2): (0.2-2). In the present invention, the organic solvent preferably includes ethanol, isopropanol, tetrahydrofuran or N, N-dimethylformamide. In the present invention, the mass ratio of the sum of the first coupling agent and the second coupling agent to the organic solvent is preferably 1: (1-4). In the invention, the dealkalized red mud, the first coupling agent, the second coupling agent and the organic solvent are preferably mixed in a manner that the first coupling agent is mixed with part of the organic solvent to obtain a first coupling agent solution; mixing the second coupling agent with the residual organic solvent to obtain a second coupling agent solution; respectively spraying the first coupling agent solution and the second coupling agent solution on the dealkalized red mud, and stirring and mixing; the stirring speed during stirring and mixing is preferably 20000-30000 rpm, more preferably 25000rpm, and the stirring time is preferably 1-20 min, more preferably 10-15 min.

In the invention, the temperature of the modification treatment is preferably 90-150 ℃, and more preferably 100-130 ℃; the time is preferably 2 h. In the invention, in the modification treatment process, the first coupling agent and the second coupling agent are uniformly dispersed on the surface of the dealkalized red mud under the action of an organic solvent, and are coupled with the dealkalized red mud to finally obtain an aminated dealkalized red mud material, namely a coupling agent surface modified red mud material; in particular, silane coupling agents are more favorable for coupling on SiO₂On the surface, the titanate coupling agent and the aluminate coupling agent are more favorable for coupling at Fe₂O₃、TiO₂ZnO and Al₂O₃A surface.

The epoxy resin composite material modified with both the fiber and the red mud of the present invention will be explained below.

The epoxy resin composite material jointly modified by the fibers and the red mud comprises, by mass, 5-50 parts of pulverized fibers, preferably 10-45 parts, and more preferably 10-30 parts. In the present invention, the pulverized fiber preferably includes a pulverized carbon fiber, a pulverized aramid fiber, or a coupling modified pulverized glass fiber; the average length of the pulverized fibers is preferably 50-80 μm, and the monofilament diameter is preferably 0.1-8 μm. In the examples of the present invention, the pulverized carbon fiber was purchased from SGL group, and the pulverized carbon fiber was CM80-3.0/200-UN milled carbon fiber, and had a fiber density of 1.8g/CM3, an average filament length of 80 μm, a filament diameter of 7 μm, a tensile strength of 3.0GPa, a tensile modulus of 200GPa, and an elongation at break of 1.5%. The crushed aramid fiber is purchased from Nanjing Teng-Yi New Material science and technology Limited company, the mark is KF-300F, the average length of the fiber is 60 mu m, the diameter of a monofilament is 0.5 mu m, and the decomposition temperature is 500 ℃. In the present invention, the pulverized fiber is used as a reinforcing material.

In the present invention, the method for preparing the coupling modified milled glass fiber preferably comprises the steps of: mixing a silane coupling agent, ethanol and water to obtain a modified solution; and mixing the modified solution with the crushed glass fiber, and carrying out modification reaction to obtain the coupling modified crushed glass fiber.

According to the invention, a silane coupling agent, ethanol and water are mixed to obtain a modified solution. The present invention does not require any particular kind of silane coupling agent, and silane coupling agents known in the art may be used. In an embodiment of the present invention, the silane coupling agent is KH-550. In the invention, the mass ratio of the silane coupling agent to the ethanol to the water is preferably 1: 2-6: 0.2-1. In the present invention, the mixing is preferably performed under stirring conditions, and the stirring time is preferably 30 min. The present invention does not require any particular speed of agitation, and can employ agitation speeds well known in the art. In the mixing process, the silane coupling agent is hydrolyzed.

After the modified liquid is obtained, the modified liquid and the crushed glass fiber are mixed for modification reaction to obtain the coupling modified crushed glass fiber. In the embodiment of the invention, the crushed glass fiber is purchased from Nanjing glass fiber research and design institute, the product number is EMG-250, the fiber length is 50-80 μm, and the monofilament diameter is 5 μm. In the present invention, the mass ratio of the modifying solution to the pulverized glass fibers is preferably 1: 50 to 300, and more preferably 1:100 to 250. In the present invention, mixing the modifying solution with the pulverized glass fibers preferably includes: and (3) placing the crushed glass fiber into a crusher, keeping the crusher rotating, uniformly spraying the modified liquid into the crusher, sealing the cavity of the crusher, and stirring. In the present invention, the pulverizer is preferably a high-speed pulverizer; the rotational speed of the pulverizer is preferably 10 rpm. The invention preferably adopts a spray gun to spray the modifying liquid into the pulverizer. In the present invention, the rotation speed of the stirring is preferably 23000rpm, and the stirring time is preferably 3 min.

In the invention, the modification temperature is preferably 100-180 ℃, more preferably 120-150 ℃, and the modification time is preferably 1-5 h, more preferably 2-3 h.

Based on the mass parts of the crushed fibers, the raw materials for preparing the epoxy resin composite material jointly modified by the fibers and the red mud comprise 10-100 parts, preferably 20-90 parts, and more preferably 30-80 parts of the coupling agent surface modified red mud material. The coupling agent surface modified red mud material is added into the composite material of epoxy resin/powder fiber as a modifying agent, so that the gelation time, viscosity and thermal expansion performance of the epoxy resin matrix are effectively changed. The above changes greatly improve the dispersibility and interfacial compatibility of the powder fiber in the epoxy resin/red mud matrix. The mechanical property of the epoxy resin matrix is improved, and the interface acting force between the epoxy resin matrix and the powder fiber is effectively enhanced. Under the synergistic effect of the red mud and the powder fiber, the mechanical property of the epoxy resin/fiber/red mud (EP/SF/RM) is obviously changed, and the tribological property is also obviously improved.

On the basis of the mass parts of the crushed fibers, the raw materials for preparing the epoxy resin composite material jointly modified by the fibers and the red mud comprise 50-300 parts of epoxy resin, preferably 80-270 parts of epoxy resin, more preferably 100-250 parts of epoxy resin, and further preferably 120-200 parts of epoxy resin. In the present invention, the epoxy resin is preferably a bisphenol A type epoxy resin, more preferably E-51, E-54, E-31 or E-10.

The raw materials for preparing the epoxy resin composite material jointly modified by the fibers and the red mud comprise 0.1-1 part of defoaming agent, preferably 0.2-0.5 part, and more preferably 0.2 part by weight based on the mass parts of the crushed fibers. The invention has no special requirement on the specific type of the defoaming agent, and the defoaming agent well known in the field can be adopted, and the specific type of the defoaming agent can be silicone oil.

The preparation raw materials of the epoxy resin composite material jointly modified by the fibers and the red mud comprise 10-45 parts of curing agent, preferably 20-35 parts of curing agent, and more preferably 22-25 parts of curing agent by mass. In the present invention, the curing agent preferably includes Divinyltriamine (DETA), diaminodiphenyl sulfone (DDS), diaminodiphenylmethane (DDM), Tung Oil Anhydride (TOA).

mixing the crushed fibers, the coupling agent surface modified red mud material, the epoxy resin antifoaming agent and the curing agent, and curing the obtained mixed system to obtain the epoxy resin composite material modified by the fibers and the red mud.

In the invention, the mixing of the crushed fibers, the coupling agent surface modified red mud material, the epoxy resin antifoaming agent and the curing agent preferably comprises: mixing the crushed fibers, the coupling agent surface modified red mud material and the epoxy resin, and performing dispersion treatment to obtain a dispersion treatment system; the dispersion treatment system, the defoaming agent and the curing agent were mixed (first mixing means). Or mixing the crushed fibers, the coupling agent surface modified red mud material, the epoxy resin and the defoaming agent, and performing dispersion treatment to obtain a dispersion treatment system; the dispersion treatment system and the curing agent are mixed (second mixing means).

According to the invention, the proper adding time of the defoaming agent is preferably selected according to the viscosity of the system, and when the viscosity of the mixture of the crushed fibers, the coupling agent surface modified red mud material and the epoxy resin is higher, the defoaming agent is preferably added after the epoxy resin is added; when the viscosity of the mixture of the crushed fibers, the coupling agent surface modified red mud material and the epoxy resin is low, the defoaming agent and the curing agent are preferably added together. This is common knowledge in the art and will not be described further herein.

The first mixing method will be explained below.

The invention mixes the crushed fiber, the coupling agent surface modified red mud material and the epoxy resin, and carries out dispersion treatment to obtain a dispersion treatment system. In the present invention, mixing the pulverized fibers, the coupling agent surface-modified red mud material, and the epoxy resin preferably includes: pre-mixing the crushed fibers and the coupling agent surface modified red mud to obtain fiber/RM powder; and adding the fiber/RM powder into epoxy resin for dispersion treatment. In the present invention, the premixing is preferably carried out in a high-speed pulverizer.

In the invention, the temperature of the dispersion treatment is preferably 50-100 ℃, more preferably 60-90 ℃, and further preferably 70-80 ℃; the time is preferably 5 to 15min, more preferably 7 to 13min, and still more preferably 9 to 11 min. In the invention, the dispersion treatment is preferably carried out in a high-speed stirring tank, and in the invention, the polytetrafluoroethylene ball-milling stirring head is preferably adopted for high-speed stirring, and the stirring speed is preferably 1000-9000 rpm.

After the dispersion treatment, the first vacuum degassing is preferably carried out on the obtained system to obtain a dispersion treatment system; the first vacuum degassing is preferably performed at 50-100 ℃, more preferably at 60-90 ℃ for 10 min; the first vacuum degassing is preferably carried out in a vacuum oven.

After a dispersion treatment system is obtained, the dispersion treatment system, the defoaming agent and the curing agent are mixed and cured to obtain the epoxy resin composite material modified by the fibers and the red mud.

In the present invention, mixing the dispersion treatment system, the defoaming agent, and the curing agent preferably includes: and adding a defoaming agent and a curing agent into the dispersion system, and stirring for 5-15 min at 50-100 ℃. In the present invention, the rotation speed of the stirring is preferably 1000 to 9000rpm, and more preferably 2000 to 8000 rpm. The invention can ensure the curing agent to be fully dissolved by mixing under the conditions.

After mixing the dispersion treatment system, the defoaming agent and the curing agent, the present invention preferably subjects the obtained system to second vacuum defoaming and then subjects the obtained system to curing treatment. In the invention, the second vacuum degassing temperature is preferably 50-100 ℃, and more preferably 60-90 ℃; the second vacuum degassing time is preferably 5-15 min, and more preferably 8-12 min; the second vacuum degassing is preferably carried out in a vacuum oven.

The second mixing mode will be explained below.

The method comprises the steps of mixing crushed fibers, a coupling agent surface modified red mud material, epoxy resin and a defoaming agent, and performing dispersion treatment to obtain a dispersion treatment system; subjecting the dispersion-treated body to dispersion treatment

Mixing with a curing agent.

The method mixes the crushed fibers, the coupling agent surface modified red mud material, the epoxy resin and the defoaming agent, and carries out dispersion treatment to obtain a dispersion treatment system. In the present invention, mixing the pulverized fiber, the coupling agent surface-modified red mud material, the epoxy resin, and the antifoaming agent preferably includes: pre-mixing the crushed fibers and the coupling agent surface modified red mud to obtain fiber/RM powder; adding the fiber/RM powder into epoxy resin, and then adding a defoaming agent for dispersion treatment. In the present invention, the premixing is preferably carried out in a high-speed pulverizer. The conditions of the dispersion processing are the same as those of the first mixing mode, and are not described again here.

After the dispersion treatment system is obtained, the present invention mixes the dispersion treatment system with a curing agent.

In the present invention, mixing the dispersion treatment system and the curing agent preferably includes: and adding a curing agent into the dispersion system, and stirring for 5-15 min at 50-100 ℃. In the present invention, the rotation speed of the stirring is preferably 1000 to 9000rpm, and more preferably 2000 to 8000 rpm. The invention can ensure the curing agent to be fully dissolved by mixing under the conditions.

After mixing the dispersion treatment system and the curing agent, it is preferable in the present invention to subject the obtained system to the second vacuum defoaming and then subject the obtained system to the curing treatment. In the present invention, the conditions of the second vacuum degassing are the same as those of the second vacuum degassing in the first mixing method, and thus the details thereof are not repeated.

In the present invention, the curing treatment preferably includes a first curing treatment and a second curing treatment which are performed in this order; the temperature of the first curing treatment is preferably 90-150 ℃, more preferably 100-140 ℃, and further preferably 100-130 ℃; the first curing treatment time is preferably 1-5 hours, and more preferably 2-4 hours; the temperature of the second curing treatment is preferably 140-200 ℃, more preferably 150-190 ℃, and further preferably 150-170 ℃; the time of the second curing treatment is preferably 1 to 5 hours, and more preferably 2 to 4 hours. In the present invention, the temperature of the second curing treatment is preferably higher than that of the first curing treatment. In the invention, the system obtained after the second vacuum degassing is preferably placed in a mold for curing treatment.

After the curing treatment, the obtained material is preferably naturally cooled to room temperature, so that the epoxy resin composite material modified by the fiber and the red mud is obtained. The curing treatment is carried out in an oven, after the curing treatment is finished, the oven is preferably powered off, and the obtained material is naturally cooled to room temperature in the oven.

The present invention will be described in detail with reference to the following examples, but the scope of the present invention should not be construed as being limited thereto.

Example 1

1. Preparation of dealkalized red mud

Adding 160g of Red Mud (RM) into a solid grinder, grinding at a high speed of 23000rpm, sieving the ground RM with a 100-mesh sieve, transferring the sieved RM into a round-bottom flask, adding 600mL of distilled water and 20g of oxalic acid, and reacting for 120min under the condition of mechanical stirring at 1000rpm by controlling the reaction temperature of an oil bath to be 80 ℃ to obtain a first RM dispersion liquid; cooling the temperature of the first RM dispersion liquid to 60 ℃, and dispersing the red mud again through stirring by a glass rod to obtain a second RM dispersion liquid; standing the second RM dispersion liquid for 3min, taking the upper layer yellow dispersion liquid, and performing suction filtration to obtain an RM filter cake, thereby completing 1-time settling separation; diluting the lower-layer solid-liquid mixture obtained after standing by adding water, then repeating the settling separation treatment step, carrying out the settling separation treatment step for 6 times in total, combining the upper-layer yellow dispersion liquid collected after each settling separation treatment, carrying out suction filtration to obtain an RM filter cake, drying the RM filter cake in a 120 ℃ oven for 12 hours, and crushing by using a solid crusher at the rotating speed of 23000rpm to obtain the dealkalized red mud.

2. Preparation of coupling agent surface modified RM

Dissolving 0.38g of titanate coupling agent isopropoxy tri (ethylenediamine-N-ethoxy) titanate (ACA-K44) in isopropanol (in a mass ratio, ACA-K44: isopropanol-1: 4) to obtain an ACA-K44 solution; dissolving 0.76g of aluminate coupling agent isopropoxy distearoyloxyaluminate (ACA-K30) in isopropanol (in a mass ratio, ACA-K30: isopropanol-1: 4) to obtain an ACA-K30 solution; putting 100g dealkalized red mud into a crusher, spraying 1.9g of ACA-K44 solution and 3.8g of ACA-K30 solution into the crusher through a spraying pot, stirring for 15min at 25000rpm to ensure that the coupling agent is fully dispersed on the surface of RM, and then putting the uniformly mixed system into an oven to react for 2h at 120 ℃ to obtain the coupling agent surface modified RM.

3. Preparation of epoxy resin composite material

Pre-mixing 11.8g of crushed carbon fibers (SCF) and 50.8g of coupling agent surface modified RM by a high-speed crusher to obtain SCF/RM powder; weighing 100g of epoxy resin E-51 in a high-speed stirring tank, adding the SCF/RM powder, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 70 ℃, adjusting the stirring speed to be 5000rpm, stirring at a high speed for 10min, and carrying out vacuum degassing on the obtained system in a vacuum oven at 70 ℃ for 10min to obtain a dispersion treatment system; adding 25g of curing agent DDM and 0.2g of silicone oil into the dispersion treatment system as defoaming agents, keeping the reaction temperature of 70 ℃, adjusting the stirring speed to 5000rpm, reacting for 10min, vacuum degassing the obtained system in a vacuum oven at 70 ℃ for 10min, pouring the vacuum degassed system into a mold, curing for 2h at 120 ℃, curing for 2h at 160 ℃, and naturally cooling in the oven to obtain the epoxy resin composite material jointly modified by fibers and red mud.

The sample sizes of the impact strength, the bending strength and the compression strength and the test method are cut in a dust-free saw according to national standards of GBT 1843-. A Jinan Yihua high-speed ring block friction tester (MRH-3) is used for carrying out a ring block dry friction test on a 12 x 4 sample under the positive pressure of 32N at the linear speed of 1m/s, and the abrasion resistance of the material is evaluated.

The properties of the epoxy resin composite material prepared in example 1 are shown in table 1.

TABLE 1 Properties of epoxy resin composites prepared in example 1

Example 2

1. Preparation of dealkalized red mud

The same as in example 1.

2. Preparation of coupling agent surface modified RM

The same as in example 1.

3. Preparation of epoxy resin composite material

Premixing 21.7g of crushed aramid fiber (SKF) and 36.6g of coupling agent surface modified RM by adopting a high-speed crusher to obtain SKF/RM powder; weighing 96g of epoxy resin E-51 in a high-speed stirring tank, adding the SKF/RM powder, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 70 ℃, adjusting the stirring speed to be 5000rpm, stirring at a high speed for 10min, and carrying out vacuum degassing on the obtained system in a vacuum oven at 70 ℃ for 10min to obtain a dispersion treatment system; adding 24.1g of curing agent DDM and 0.2g of silicone oil into the dispersion treatment system as defoaming agents, keeping the reaction temperature of 70 ℃, adjusting the stirring speed to 5000rpm, reacting for 10min, vacuum degassing the obtained system in a vacuum oven at 70 ℃ for 10min, pouring the vacuum degassed system into a mold, curing for 2h at 120 ℃, curing for 2h at 160 ℃, and naturally cooling in the oven to obtain the epoxy resin composite material modified by the fibers and the red mud.

The epoxy resin composite material prepared in example 2 was subjected to the performance test with reference to the method of example 1, and the results are shown in table 2.

TABLE 2 Properties of epoxy resin composites prepared in example 2

Example 3

1. Preparation of dealkalized red mud

The same as in example 1.

2. Preparation of coupling agent surface modified RM

The same as in example 1.

3. SGF surface modification

Firstly, weighing 1.5000g of silane coupling agent KH-550, 5.4000g of ethanol and 0.6000g of water by an analytical balance, mixing the three, and carrying out magnetic stirring reaction for 30min to obtain a modified solution; loading into a liquid spray gun for later use; meanwhile, 150g of SGF is weighed in a high-speed pulverizer, the high-speed pulverizer is kept to rotate at a low speed of 10rpm, the solution is uniformly sprayed into the high-speed pulverizer through a liquid spray gun, then, the cavity of the pulverizer is sealed, the mixture is stirred for 3min at a speed of 23000rpm to ensure uniform dispersion of the modified solution in the SGF, and finally, the stirred mixture is reacted for 2h at 120 ℃ to obtain the coupling agent surface modified SGF.

4. Preparation of epoxy resin composite material

Pre-mixing 30g of silane coupling agent modified ground glass fiber (SGF) and 40g of coupling agent surface modified RM by adopting a high-speed grinder to obtain SGF/RM powder; weighing 90g of epoxy resin E-31 in a high-speed stirring tank, adding the SGF/RM powder, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 70 ℃, adjusting the stirring speed to be 5000rpm, stirring at a high speed for 10min, and carrying out vacuum degassing on the obtained system in a vacuum oven at 70 ℃ for 10min to obtain a dispersion treatment system; adding 22.5g of curing agent DDM and 0.2g of silicone oil into the dispersion treatment system as defoaming agents, keeping the reaction temperature of 70 ℃, adjusting the stirring speed to 5000rpm, reacting for 10min, vacuum degassing the obtained system in a vacuum oven at 70 ℃ for 10min, pouring the vacuum degassed system into a mold, curing for 2h at 120 ℃, curing for 2h at 160 ℃, and naturally cooling in the oven to obtain the epoxy resin composite material modified by the fibers and the red mud.

The epoxy resin composite material prepared in example 3 was subjected to the performance test with reference to the method of example 1, and the results are shown in table 3.

TABLE 3 Properties of epoxy resin composites prepared in example 3

Example 4

1. Preparation of dealkalized red mud

The same as in example 1.

2. Preparation of coupling agent surface modified RM

The same as in example 1.

3. Preparation of epoxy resin composite material

Premixing 30.2g of crushed carbon fibers (SCF) and 26.7g of coupling agent surface modified RM by a high-speed crusher to obtain SCF/RM powder; weighing 105g of epoxy resin E-10 in a high-speed stirring tank, adding the SCF/RM powder and 0.2g of silicone oil as defoaming agents, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 50 ℃, adjusting the stirring speed to be 4000rpm, stirring at a high speed for 8min, and carrying out vacuum degassing on the obtained system in a vacuum oven at 50 ℃ for 8min to obtain a dispersion treatment system; adding 35g of curing agent DDM into the dispersion treatment system, keeping the reaction temperature of 50 ℃, adjusting the stirring speed to 4000rpm, reacting for 80min, vacuum degassing the obtained system in a vacuum oven at 50 ℃ for 5min, pouring the vacuum degassed system into a mold, curing for 2h at 100 ℃, curing for 2h at 150 ℃, and naturally cooling in the oven to obtain the epoxy resin composite material jointly modified by the fibers and the red mud.

The epoxy resin composite material prepared in example 4 was subjected to a performance test with reference to the method of example 1, and the results are shown in table 3.

Table 4 properties of epoxy resin composites prepared in example 4

Example 5

1. Preparation of dealkalized red mud

The same as in example 1.

2. Preparation of coupling agent surface modified RM

The same as in example 1.

3. Preparation of epoxy resin composite material

Premixing 25.5g of crushed glass fiber and 29.5g of coupling agent surface modified RM by adopting a high-speed crusher to obtain SGF/RM powder; weighing 93.5g of epoxy resin E-44 in a high-speed stirring tank, adding SGF/RM powder and 0.2g of silicone oil as defoaming agents, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 80 ℃, adjusting the stirring speed to be 5000rpm, stirring at a high speed for 5min, and carrying out vacuum degassing on the obtained system in a vacuum oven at 80 ℃ for 5min to obtain a dispersion treatment system; adding 23.4g of curing agent DDM into the dispersion treatment system, keeping the reaction temperature of 80 ℃, adjusting the stirring speed to 5000rpm, reacting for 5min, vacuum degassing the obtained system in a vacuum oven at 80 ℃ for 5min, pouring the vacuum degassed system into a mold, curing for 2h at 150 ℃, curing for 2h at 180 ℃, and naturally cooling in the oven to obtain the epoxy resin composite material jointly modified by the fibers and the red mud.

The epoxy resin composite material prepared in example 5 was subjected to the performance test with reference to the method of example 1, and the results are shown in table 5.

Table 5 properties of the epoxy resin composite prepared in example 5.

Comparative example 1

Preparation of EP

Placing 100g of epoxy resin E-51 and 25g of curing agent DDM in a high-speed stirring tank, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 70 ℃, adjusting the stirring speed to be 4000rpm, reacting for 10min, then passing through a vacuum oven, carrying out vacuum degassing for 5min at the temperature of 70 ℃, then pouring the vacuum degassed system into a mold, curing for 2h at the temperature of 100 ℃, then curing for 2h at the temperature of 160 ℃, and naturally cooling in the oven to obtain the EP material.

The EP material prepared in comparative example 1 was subjected to a performance test with reference to the method of example 1, and the results are shown in table 6.

TABLE 6 Properties of the EP material prepared in comparative example 1

Comparative example 2

EP/RM composites

1. Preparation of dealkalized red mud

The same as in example 1.

2. Preparation of coupling agent surface modified RM

The same as in example 1.

3. Synthesis of EP/RM composites

Weighing 120g of epoxy resin, putting the epoxy resin into a high-speed stirring tank, adding 45g of coupling agent surface modified RM and 0.2g of silicone oil as a defoaming agent, selecting a polytetrafluoroethylene ball milling stirring head, controlling the reaction temperature to be 60 ℃, adjusting the stirring speed to be 5000rpm, stirring at a high speed for 10min, and then carrying out vacuum degassing at 50 ℃ for 10min through a vacuum oven to obtain a dispersion treatment system; adding 40g of curing agent into the dispersion treatment system, keeping the reaction temperature at 60 ℃, adjusting the stirring speed to 5000rpm, and stirring at high speed for 10 min. And then vacuum degassing for 10min at the temperature of 50 ℃ through a vacuum oven, pouring the vacuum degassed system into a mold, curing for 2h at the temperature of 120 ℃, then curing for 2h at the temperature of 160 ℃, and naturally cooling in the oven to obtain the EP/RM composite material.

The EP/RM composites prepared in comparative example 2 were subjected to performance tests with reference to the method of example 1, and the results are shown in Table 7.

TABLE 7 Properties of EP/RM composites prepared in comparative example 2

Comparative example 3

Synthesis of EP/SCF composite:

weighing 112.7g of epoxy resin E-51, adding 23.7g of SCF powder into a high-speed stirring tank, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 50 ℃, adjusting the stirring speed to be 3000rpm, stirring for 5min at a high speed, then passing through a vacuum oven, carrying out vacuum degassing for 5min at 50 ℃, then adding 28.2g of curing agent DDM into the vacuum degassed system, using 0.2g of silicone oil as a defoaming agent, keeping the reaction temperature at 50 ℃, adjusting the stirring speed to be 3000rpm, reacting for 10min, then passing through the vacuum oven, carrying out vacuum degassing for 5min at 50 ℃, pouring the vacuum degassed system into a mold, curing for 1h at 100 ℃, then curing for 3h at 180 ℃, and naturally cooling in the oven to obtain the EP/SCF composite material.

The EP/SCF composite prepared in comparative example 3 was subjected to the performance test with reference to the method of example 1, and the results are shown in Table 8.

TABLE 8 Properties of EP/SCF composites prepared in comparative example 3

Comparative example 4

Synthesis of EP/SKF composite material

Weighing 116.8g of epoxy resin E-51 in a high-speed stirring tank, adding 16.3g of SKF powder, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 50 ℃, adjusting the stirring speed to be 6000rpm, stirring at a high speed for 10min, and then performing vacuum degassing at 50 ℃ for 5min through a vacuum oven; adding 29.2g of curing agent DDM and 0.2g of silicone oil into the system after vacuum deaeration as defoaming agents, keeping the reaction temperature of 50 ℃, adjusting the stirring speed to 6000rpm, reacting for 10min, and then passing through a vacuum oven to perform vacuum deaeration for 5min at the temperature of 50 ℃; and pouring the vacuum degassed system into a mold, curing at 100 ℃ for 1h, then curing at 180 ℃ for 3h, and naturally cooling in an oven to obtain the EP/SKF composite material.

The EP/SKF composite material prepared in comparative example 4 was subjected to the performance test with reference to the method of example 1, and the results are shown in Table 9.

TABLE 9 Properties of the EP/SKF composites prepared in comparative example 4

Comparative example 5

EP/SGF composite material

1. SGF surface modification

Weighing 1.5000g of silane coupling agent KH-550, 5.4000g of ethanol and 0.6000g of water by an analytical balance, mixing the three, reacting for 30min by magnetic stirring to obtain a modified liquid, and filling the modified liquid into a liquid spray gun for later use; meanwhile, 150g of SGF is weighed in a high-speed pulverizer, the high-speed pulverizer is kept to rotate at a low speed of 10rpm, the solution is uniformly sprayed into the high-speed pulverizer through a liquid spray gun, and then the cavity of the pulverizer is sealed and stirred for 3min at a speed of 23000rpm so as to ensure uniform dispersion of the modified solution in the SGF; and finally reacting the stirred mixture for 2 hours at the temperature of 120 ℃ to obtain the coupling agent surface modified SGF.

2. Synthesis of EP/SGF composites

Weighing 103.3g of epoxy resin E-51, putting the epoxy resin E-51 in a high-speed stirring tank, adding 30g of coupling agent surface modified SGF powder, selecting a polytetrafluoroethylene ball-milling stirring head, controlling the reaction temperature to be 60 ℃, adjusting the stirring speed to be 6000rpm, stirring at a high speed for 5min, and then carrying out vacuum degassing at 60 ℃ for 5min through a vacuum oven; adding 25.3g of curing agent DDM and 0.2g of silicone oil into the vacuum degassed system as a defoaming agent, maintaining the reaction temperature of 50 ℃, adjusting the stirring speed to be 6000rpm, reacting for 5min, and then passing through a vacuum oven to carry out vacuum degassing for 5min at the temperature of 50 ℃; the vacuum degassed system was poured into a mold and cured at 100 ℃ for 2h, followed by 180 ℃ for 2 h. And naturally cooling in an oven to obtain the EP/SGF composite material.

The EP/SGF composite material prepared in comparative example 5 was subjected to the performance test with reference to the method of example 1, and the results are shown in Table 10.

TABLE 10 Properties of EP/SGF composites prepared in comparative example 5

The three comparative examples of the EP material of comparative example 1, the EP/RM composite material of comparative example 2 and the EP/SCF composite material of comparative example 3 are compared with the epoxy resin composite material (EP/SCF/RM composite material) of example 3, and the synergistic effect of SCF and RM is proved to remarkably enhance the tribological property and the mechanical property of the EP/SCF/RM composite material. The EP/SCF/RM composite material has the lowest volumetric wear rate and the lowest friction coefficient while ensuring excellent mechanical properties. The synergistic effect between SK (G) F and RM is also demonstrated by comparing the comparative example 1EP material, the comparative example 4EP/SKF composite material, the comparative example 5EP/SGF composite material, the comparative example 2EP/RM composite material with the EP/SKF/RM composite material of example 2 and the EP/SGF/RM composite material of example 3.

And (4) result characterization:

1. the impact section of the epoxy resin composite material prepared in example 1 was subjected to SEM characterization, and the results are shown in fig. 1. As can be seen from FIG. 1, the rod-shaped fibers and the EP/RM matrix modified by the red mud have a ripple-rich structure. The rich ripple structure demonstrates a significant increase in EP toughness under RM modification. Meanwhile, the epoxy resin matrix tightly wraps the connecting fibers, and no obvious gap or air hole exists between the epoxy resin matrix and the connecting fibers. This indicates that the interaction force between SF and EP/RM matrix is significantly enhanced under the action of RM. This change can significantly enhance the mechanical properties of the material during stretching, bending and impact of the material.

2. FIG. 2 is a graph of coefficient of friction versus time for the dry friction test of the epoxy resin composite ring block prepared in example 1. As shown, the coefficient of friction between the epoxy composite and the steel ring increases and then decreases over time during the run-in phase. Along with the change of time, the friction between the composite material and the steel ring enters a stable state, and the friction coefficient is gradually stabilized and finally stabilized at about 0.4. Compared with the EP material of comparative example 1, the EP/RM composite material of comparative example 2 and the EP/SCF composite material of comparative example 3, the friction coefficient is lowest. The reduction in the coefficient of friction is due to the following reasons: the fiber can be regarded as disordered graphite material, and easily sheared graphite-like substances are released to the interface of the composite material and the bearing steel in the process of material friction and wear, so that the lubrication effect is realized. In addition, the bearing steel has multiple RM distributions on a micro-nano scale, so that gullies and scratches on the surface of the bearing steel are filled. Meanwhile, instantaneous high temperature generated by the contact of the SCF and the bearing steel promotes the reaction of friction chemistry and friction physics, and the RM is more effectively sintered on the surface of the bearing steel to form a more stable transfer film. In the combined promotion of the above three reasons, the EP/SCF/RM composite material of example 1 and the bearing steel have a remarkably reduced friction coefficient when being opposite to each other.

3. FIG. 3 is a three-dimensional contour diagram of the surface of a bearing steel pair after a ring block friction test is performed on the epoxy resin composite material pair prepared in example 1 and the bearing steel pair. Comparing the blank bearing steel surfaces at the left and right ends of the picture, the composite material/bearing steel sliding contact area at the center of the picture is found to have an obvious orientation protruding structure, which is a transfer film formed on the surface of the bearing steel couple at the sliding friction stage of the composite material couple and the bearing steel couple.

4. FIG. 4 is the surface linear height data of the epoxy resin composite material pair prepared in example 1 and the bearing steel pair subjected to a ring block friction test. The data show that the transfer film thickness of the dual surface of the bearing steel is 0.3-0.6 μm.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The epoxy resin composite material jointly modified by fiber and red mud comprises the following preparation raw materials in parts by mass: 5-50 parts of crushed fibers, 10-100 parts of coupling agent surface modified red mud material, 50-300 parts of epoxy resin, 0.1-1 part of defoaming agent and 10-45 parts of curing agent.

2. The epoxy composite of claim 1, wherein the milled fibers comprise milled carbon fibers, milled aramid fibers, or coupled modified milled glass fibers; the average length of the pulverized fibers is 50-80 mu m, and the monofilament diameter is 0.1-8 mu m.

3. The epoxy resin composite material as claimed in claim 2, wherein the preparation method of the coupling modified milled glass fiber comprises the following steps: mixing a silane coupling agent, ethanol and water to obtain a modified solution; and mixing the modified solution with the crushed glass fiber, and carrying out modification reaction to obtain the coupling modified crushed glass fiber.

4. The epoxy resin composite material according to claim 1, wherein the preparation method of the coupling agent surface-modified red mud material comprises the following steps:

5. The epoxy composite of claim 4, wherein the organic acid comprises acetic acid, oxalic acid, maleic acid, or stearic acid; the mass ratio of the red mud to the organic acid is (50-300): 20.

6. the epoxy resin composite material as claimed in claim 4, wherein the dealkalization treatment is carried out at a temperature of 50 to 130 ℃ for 120 min; the temperature of the modification treatment is 90-150 ℃, and the time is 2 h.

7. The epoxy resin composite of claim 4, wherein the silane-based coupling agent comprises n-octyltriethoxysilane, the aluminate-based coupling agent comprises isopropoxy distearoyloxy aluminate or diisopropoxyl acetoacetate oleate, and the titanate-based coupling agent comprises isopropoxy tristearoyloxy titanate or isopropoxy tris (dioctylphosphatoxy) titanate; the amino coupling agent comprises 3-aminopropyltriethoxysilane, 3-urea propyl trimethoxysilane or isopropoxy tri (ethylenediamine N-ethoxy) titanate;

8. The epoxy composite of claim 1, wherein the curing agent comprises divinyl triamine, diamino diphenyl sulfone, diamino diphenyl methane, or tung oil anhydride.

9. A method for preparing the epoxy resin composite material as claimed in any one of claims 1 to 8, characterized by comprising the steps of:

mixing the crushed fibers, the coupling agent surface modified red mud material epoxy resin, the defoaming agent and the curing agent, and curing the obtained mixed solution to obtain the epoxy resin composite material jointly modified by the fibers and the red mud.

10. The production method according to claim 9, wherein the curing treatment includes a first curing treatment and a second curing treatment which are sequentially performed; the temperature of the first curing treatment is 90-150 ℃, and the time is 1-5 h; the temperature of the second curing treatment is 140-200 ℃, and the time is 1-5 h.