Organic-inorganic hybrid material, preparation method and application thereof, self-lubricating fabric composite material and preparation method thereof
By chemically bonding long-chain organic lubricating molecules to the surface of the inorganic reinforcing phase, an organic-inorganic hybrid material is formed, which solves the wear problem of the resin matrix and realizes the long-term wear resistance and low friction properties of high-performance fiber fabric composite materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LANZHOU INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2026-03-20
- Publication Date
- 2026-05-15
AI Technical Summary
Existing high-performance fiber fabric composites are prone to resin matrix wear during long-term service, leading to the shedding of reinforcing fibers. Furthermore, commonly used lubricating fillers have poor dispersibility and weak interfacial bonding, making it difficult to provide long-term anti-wear protection.
Long-chain organic lubricating molecules are anchored to the surface of an inorganic reinforcing phase through chemical bonding to form organic-inorganic hybrid materials, including sheet-like hydrotalcite materials and long-chain fatty acids, which enhance interfacial bonding and dispersibility.
It improves the interfacial bonding ability between organic and inorganic materials, enhances the dispersibility of lubricant in resin matrix, provides long-lasting anti-wear protection, reduces the coefficient of friction, and extends the wear life of materials.
Smart Images
Figure CN122039419A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lubricating materials technology, specifically relating to an organic-inorganic hybrid material and its preparation method and application, and a self-lubricating fabric composite material and its preparation method. Background Technology
[0002] Self-lubricating composite materials with high-performance fiber fabrics as reinforcement and resin as the matrix have become ideal materials for key friction components such as aerospace spherical bearings and high-speed precision bearing gaskets due to their excellent load-bearing capacity, corrosion resistance, and maintenance-free characteristics. Among them, basalt fiber (BF) and polytetrafluoroethylene (PTFE) fiber blends can synergistically leverage the low friction characteristics of PTFE fiber and the high strength, heat resistance, and cost advantages of basalt fiber, making them of significant application value under high temperature, high speed, and heavy load conditions.
[0003] However, during long-term service, the resin matrix of such composite materials is prone to wear due to frictional shearing, leading to the exposure and shedding of reinforcing fibers, ultimately causing material failure. Introducing nano-lubricating fillers is an effective modification method to improve the wear resistance of the resin matrix. Currently, commonly used lubricating fillers mainly include two-dimensional layered solid lubricants (such as hexagonal boron nitride) and organic lubricants. Hexagonal boron nitride (BN) has a layered structure similar to graphene and high thermal conductivity, while also possessing excellent electrical insulation, making it an ideal high-performance solid lubricant. However, BN nanosheets have high surface chemical inertness, poor dispersion in the resin matrix, weak interfacial bonding, and stress concentration may occur at the edges of their sheets during friction, affecting the durability of the lubrication effect. On the other hand, long-chain fatty acids such as stearic acid, as classic organic lubricants, can effectively reduce the coefficient of friction, but they have low mechanical strength and poor thermal stability. When used alone, they are prone to thermal decomposition or loss during friction, making it difficult to provide long-term anti-wear protection. Furthermore, simple physical blending with inorganic fillers presents compatibility problems.
[0004] In existing technologies, constructing organic-inorganic hybrid fillers to achieve synergistic effects has become a research trend. However, achieving a stable and robust composite between organic lubricating components and inorganic materials remains a challenge. Conventional physical adsorption or blending methods cannot prevent the organic phase from detaching under high temperature or shear stress. Summary of the Invention
[0005] In view of this, the present invention provides an organic-inorganic hybrid material and its preparation method and application, and a self-lubricating fabric composite material and its preparation method. The organic-inorganic hybrid material provided by the present invention anchors long-chain organic lubricating molecules (long-chain fatty acids) on the surface of the inorganic reinforcing phase through chemical bonding, thereby possessing excellent dispersibility, strong interfacial bonding force and long-lasting lubrication / anti-wear function.
[0006] To address the aforementioned technical problems, this invention provides an organic-inorganic hybrid material comprising a matrix, a sheet-like hydrotalcite material coated on the surface of the matrix, and long-chain fatty acids grafted onto the surface of the sheet-like hydrotalcite material; the matrix is a hydroxylated ceramic or a hydroxylated two-dimensional layered material.
[0007] Preferably, the organic-inorganic hybrid material contains 30-50% by mass of platy hydrotalcite; and the grafting amount of the long-chain fatty acid is 6-10%. The hydroxylated two-dimensional layered material includes hydroxylated boron nitride, hydroxylated graphene, hydroxylated MoS2, or hydroxylated MXene. The flaky hydrotalcite-like material includes magnesium-aluminum layered double hydroxide; The long-chain fatty acids include stearic acid, oleic acid, lauric acid, or palmitic acid.
[0008] This invention also provides a method for preparing the organic-inorganic hybrid material described in the above technical solution, comprising the following steps: The matrix raw material is hydroxylated to obtain the matrix; A hydrothermal method was used to grow lamellar hydrotalcite-like materials in situ on the surface of the matrix to obtain a hydrotalcite-coated matrix composite material. The organic-inorganic hybrid material is obtained by grafting a mixture of the hydrotalcite-coated matrix composite material, long-chain fatty acids, and nonpolar organic solvents.
[0009] Preferably, when the matrix raw material is boron nitride, the hydroxylation includes the following steps: Boron nitride was dispersed in a mixed strong alkali solution and subjected to a hydrothermal reaction to obtain hydroxylated boron nitride; The preparation steps of the mixed strong alkali solution include: dissolving sodium hydroxide and potassium hydroxide in an aqueous ethanol solution to obtain the mixed strong alkali solution; The molar ratio of sodium hydroxide to potassium hydroxide is 1:1~2; the total molar concentration of sodium hydroxide and potassium hydroxide in the mixed strong alkali solution is 1~4 mol / L; the volume ratio of water to ethanol in the ethanol aqueous solution is 1:1~2; the mass ratio of the matrix raw material to the volume ratio of the mixed strong alkali solution is 0.5~2g:50~200mL; The hydrothermal reaction is carried out at a temperature of 150~200℃ for 4~8 hours.
[0010] Preferably, the hydrothermal reaction temperature of the hydrothermal method is 80~120℃, and the time is 12~36h; The grafting reaction is carried out at a temperature of 50-80°C for 6-24 hours.
[0011] The present invention also provides the application of the organic-inorganic hybrid material described in the above technical solution or the organic-inorganic hybrid material prepared by the preparation method described in the above technical solution as a lubricant.
[0012] The present invention also provides a self-lubricating fabric composite material, comprising a fabric, a phenolic resin coating the surface of the fabric fibers and filling the gaps between the fabric fibers, and a lubricant dispersed in the phenolic resin; the fabric is obtained by blending a first fiber and a second fiber, wherein the first fiber is polytetrafluoroethylene fiber; and the second fiber includes basalt fiber, glass fiber, carbon fiber or aramid fiber. The lubricant is the organic-inorganic hybrid material described in the above technical solution or the organic-inorganic hybrid material prepared by the preparation method described in the above technical solution.
[0013] Preferably, the fabric has a mass percentage of 65-75%, and the mass ratio of the lubricant to the phenolic resin is 1-5:100. The first fiber has a specification of 11.11 tex to 66.67 tex, and the second fiber has a specification of 11.11 tex to 66.67 tex; The first fiber is a warp yarn, and the second fiber is a weft yarn; the warp density of the fibers in the fabric is 250~350 threads / 10cm, and the weft density is 240~320 threads / 10cm.
[0014] The present invention also provides a method for preparing the self-lubricating fabric composite material described in the above technical solution, comprising the following steps: A lubricant and a phenolic resin solution are mixed to obtain an impregnation solution; the lubricant is the organic-inorganic hybrid material described in the above technical solution or the organic-inorganic hybrid material prepared by the preparation method described in the above technical solution; The fabric is immersed in the impregnation solution and then dried. The immersion and drying steps are repeated to obtain a prepreg. The prepreg is cured to obtain the self-lubricating fabric composite material.
[0015] Preferably, the solvent of the phenolic resin solution is a mixture of ethanol, acetone and ethyl acetate, and the mass concentration of phenolic resin in the phenolic resin solution is 0.1~0.2 g / mL; The mass ratio of lubricant to phenolic resin in the impregnation solution is 1~5:100; The soaking time is 10~30s, and the drying temperature is 30~60℃; The total mass percentage of the phenolic resin and lubricant in the prepreg is 28-32%. The curing temperature is 180~185℃ and the time is 120~150min.
[0016] This invention provides an organic-inorganic hybrid material, comprising a matrix, a lamellar hydrotalcite-like material coated on the surface of the matrix, and long-chain fatty acids grafted onto the surface of the lamellar hydrotalcite-like material; the matrix is a hydroxylated ceramic or a hydroxylated two-dimensional layered material. In this invention, the matrix provides high thermal conductivity and high load-bearing capacity, the lamellar hydrotalcite-like material enhances interfacial bonding and interlayer slip properties, and the surface-grafted long-chain fatty acids significantly improve the dispersibility of the hybrid material in the resin matrix and impart excellent surface lubrication properties. This invention anchors long-chain organic lubricating molecules (long-chain fatty acids) to the surface of the inorganic reinforcing phase through chemical bonding, thereby improving the interfacial bonding ability between the organic and inorganic phases.
[0017] This invention also provides a method for preparing an organic-inorganic hybrid material, comprising the following steps: hydroxylating a matrix raw material to obtain a matrix; growing a lamellar hydrotalcite-like material in situ on the surface of the matrix using a hydrothermal method to obtain a hydrotalcite-coated matrix composite material; and performing a grafting reaction by mixing the hydrotalcite-coated matrix composite material, a long-chain fatty acid, and a nonpolar organic solvent to obtain the organic-inorganic hybrid material. This invention involves heterogeneous nucleation on the hydroxylated matrix surface and epitaxial growth along the matrix surface and edges, ultimately forming a lamellar hydrotalcite-like material coating the matrix. The hydroxyl groups on the matrix surface primarily provide nucleation sites and lower the nucleation energy barrier. Furthermore, the hydroxyl groups can form chemical bonds (such as BO-Al bonds) with trivalent metals in the precursor solution of the lamellar hydrotalcite-like material, thus anchoring the chemical bonds between the hydroxyl groups and the matrix substrate. Meanwhile, this invention grafts long-chain fatty acids onto the surface of sheet-like hydrotalcite materials through dehydroxylation-coordination, thereby anchoring long-chain organic lubricating molecules (long-chain fatty acids) onto the surface of the inorganic reinforcing phase through chemical bonding, which improves the interfacial bonding ability between organic and inorganic components in the hybrid material. Attached Figure Description
[0018] Figure 1 The image shows a SEM image of SA-BN@LDH prepared in Example 1. Figure 2 TEM image of SA-BN@LDH prepared in Example 1; Figure 3 The bar chart shows the friction coefficient and volumetric wear rate of the fabric composite materials prepared in Example 2 and Comparative Examples 1-4 under low-speed heavy load conditions. Figure 4 The bar chart shows the friction coefficient and volumetric wear rate of the fabric composite materials prepared in Example 2 and Comparative Examples 1-4 under high-speed and light-load conditions. Figure 5The images are SEM images of the friction performance of Example 2 and Comparative Example 1 under different conditions. (a) is the SEM image of the surface of Comparative Example 1 (FC-0) after friction under low speed and heavy load conditions, (b) is the SEM image of the surface of Comparative Example 1 (FC-0) after friction under high speed and light load conditions, (c) is the SEM image of the surface of Example 2 (FC-4) after friction under low speed and heavy load conditions, and (d) is the SEM image of the surface of Example 2 (FC-4) after friction under high speed and light load conditions. Figure 6 XPS fine peak fitting analysis of (a)O1s and (b)C1s elements of SA-BN@LDH prepared in Example 1. Detailed Implementation
[0019] This invention provides an organic-inorganic hybrid material, comprising a matrix, a sheet-like hydrotalcite material coated on the surface of the matrix, and long-chain fatty acids grafted onto the surface of the sheet-like hydrotalcite material; the matrix is a hydroxylated ceramic or a hydroxylated two-dimensional layered material.
[0020] In this invention, the hydroxylated two-dimensional layered material may include hydroxylated boron nitride, hydroxylated graphene, hydroxylated MoS2, or hydroxylated MXene; the hydroxylated boron nitride may be hydroxylated hexagonal boron nitride. In this invention, the hydroxyl groups in the matrix primarily provide nucleation sites and lower the nucleation energy barrier. Furthermore, the hydroxyl groups can form chemical bonds with trivalent metals in the precursor solution of the sheet-like hydrotalcite material (e.g., when the sheet-like hydrotalcite material is a magnesium-aluminum layered double hydroxide, a BO-Al bond can be formed), thus anchoring the chemical bonds between the hydroxyl groups and the substrate layers.
[0021] In this invention, the sheet-like hydrotalcite material may include magnesium-aluminum layered double hydroxides; the long-chain fatty acid may include stearic acid, oleic acid, lauric acid, or palmitic acid; the long-chain fatty acid has good thermal stability, which can prevent damage to the long-chain structure during subsequent curing. In this invention, the carboxyl groups at the ends of the long-chain fatty acids can react with the hydroxyl groups on the surface of the sheet-like hydrotalcite material to form bonds, while the long-chain alkyl groups can exert a molecular brush-like effect to prevent the agglomeration of lubricating fillers in the resin matrix.
[0022] In this invention, the mass percentage of the lamellar hydrotalcite material in the organic-inorganic hybrid material can be 30-50%, specifically 35%, 40%, or 45%; the grafting amount of the long-chain fatty acid can be 6-10%, specifically 7%, 8%, or 9%. In this invention, the grafting amount of the long-chain fatty acid refers to the mass percentage of the long-chain fatty acid in the organic-inorganic hybrid material. In this invention, if the mass percentage of the lamellar hydrotalcite material is low, it cannot effectively coat the matrix to form a core-shell structure; if the mass percentage of the lamellar hydrotalcite material is high, it will nucleate independently during the hydrothermal reaction to form large, independent hydrotalcite sheets, rather than nucleating and growing on the surface of the matrix to coat it. In this invention, excessive grafting of long-chain fatty acids will reduce the thermal stability of the organic-inorganic hybrid material.
[0023] This invention also provides a method for preparing the organic-inorganic hybrid material described in the above technical solution, comprising the following steps: The matrix raw material is hydroxylated to obtain the matrix; A hydrothermal method was used to grow lamellar hydrotalcite-like materials in situ on the surface of the matrix to obtain a hydrotalcite-coated matrix composite material. The organic-inorganic hybrid material is obtained by grafting a mixture of the hydrotalcite-coated matrix composite material, long-chain fatty acids, and nonpolar organic solvents.
[0024] This invention involves hydroxylating a matrix material to obtain a matrix. In this invention, the matrix material may include ceramics, boron nitride, graphene, MoS2, or MXene; the boron nitride may be hexagonal boron nitride; the flake diameter of the matrix material may be 0.1~0.4 μm, or 0.2~0.3 μm.
[0025] This invention does not impose any special requirements on the hydroxylation method; conventional hydroxylation methods in the art can be used for different matrix raw materials. In this invention, when the matrix raw material is boron nitride, the hydroxylation may include the following steps: dispersing boron nitride in a mixed strong alkali solution and performing a hydrothermal reaction to obtain hydroxylated boron nitride; the preparation step of the mixed strong alkali solution may include: dissolving sodium hydroxide and potassium hydroxide in an aqueous ethanol solution to obtain the mixed strong alkali solution; the molar ratio of sodium hydroxide to potassium hydroxide may be 1:1~2, specifically 1:1, 1:1.1, or 1:1.5; the total molar concentration of sodium hydroxide and potassium hydroxide in the mixed strong alkali solution may be 1~4 mol / L, specifically 2 mol / L, 2.5 mol / L, or 3 mol / L. L; the volume ratio of water to ethanol in the ethanol-water solution can be 1:1~2, specifically 1:1, 1:1.2 or 1:1.5; the mass ratio of the matrix raw material to the volume ratio of the mixed strong alkali solution can be 0.5~2g:50~200mL, or 1~1.5g:80~150mL, specifically 2g:100mL; the present invention does not have a special limitation on the dispersion method, as long as it can be evenly dispersed; the temperature of the hydrothermal reaction can be 150~200℃, specifically 160℃, 180℃ or 190℃; the time of the hydrothermal reaction can be 4~8h, specifically 5h, 6h or 7h.
[0026] In this invention, the hydrothermal reaction may further include: performing solid-liquid separation on the hydrothermal reaction system, washing and drying the obtained solid to obtain the matrix; the solid-liquid separation can be centrifugation, and this invention has no special requirements for the centrifugation, as long as solid-liquid separation can be achieved; the water used for washing can be deionized water; the washing is performed until the pH value of the washing solution is neutral. This invention has no special requirements for the drying, and conventional methods in the art can be used.
[0027] After obtaining the matrix, the present invention grows lamellar hydrotalcite-like materials in situ on the matrix surface using a hydrothermal method to obtain a hydrotalcite-coated matrix composite material. The present invention does not have special requirements for the method of growing lamellar hydrotalcite-like materials in situ on the matrix surface using a hydrothermal method; conventional methods in the art are acceptable.
[0028] In this invention, when the matrix is hydroxylated boron nitride and the lamellar hydrotalcite material is a magnesium-aluminum layered double hydroxide, the method for in-situ growth of the lamellar hydrotalcite material on the matrix surface using a hydrothermal method may include the following steps: dispersing hydroxylated boron nitride in water to obtain a dispersion; mixing a water-soluble aluminum salt, a water-soluble magnesium salt, and the dispersion, and then performing a hydrothermal reaction to obtain a magnesium-aluminum layered double hydroxide coating hydroxylated boron nitride. In this invention, the water can be deionized water, and the mass concentration of hydroxylated boron nitride in the dispersion can be 0.5~2 mg / mL, specifically 1 mg / mL or 1.5 mg / mL; the water-soluble aluminum salt can be Al(NO3)3·9H2O; the water-soluble magnesium salt can be Mg(NO3)2·6H2O; the molar ratio of magnesium in the water-soluble magnesium salt to aluminum in the water-soluble aluminum salt can be 1.5~3:1, specifically 2:1 or 2. The ratio of aluminum to magnesium in the hydrothermal reaction system is 5:1; the total molar concentration of aluminum and magnesium in the system can be 0.5-4 mmol / 100 mL, specifically 1 mmol / 100 mL, 1.5 mmol / 100 mL, or 3 mmol / 100 mL; the temperature of the hydrothermal reaction can be 80-120℃, specifically 90℃, 100℃, or 110℃; the reaction time can be 12-36 h, specifically 15 h, 20 h, 24 h, or 30 h. In this invention, the hydrothermal reaction may further include: centrifuging the reacted material, and then sequentially washing the centrifuged solid with water, alcohol, and drying to obtain the magnesium-aluminum layered double hydroxide coated with hydroxylated boron nitride. This invention does not have special requirements for the centrifugation, washing, alcohol washing, and drying processes; conventional methods in the art can be used.
[0029] After obtaining the hydrotalcite-coated matrix composite material, the present invention performs a grafting reaction by mixing the hydrotalcite-coated matrix composite material, long-chain fatty acids, and a nonpolar organic solvent to obtain the organic-inorganic hybrid material. In this invention, the nonpolar organic solvent may include cyclohexane or n-hexane; the mass ratio of the hydrotalcite-coated matrix composite material to the long-chain fatty acid may be 0.2~1:0.5~3, specifically 1:2; the mass ratio of the hydrotalcite-coated matrix composite material to the volume ratio of the nonpolar organic solvent may be 0.2~1g:50~200mL, specifically 0.3g:50mL. In this invention, the mixing may include the following steps: first dispersing the hydrotalcite-coated matrix composite material in a portion of the nonpolar organic solvent to obtain a hydrotalcite-coated matrix composite material dispersion; dissolving the long-chain fatty acid in the remaining portion of the nonpolar organic solvent to obtain a long-chain fatty acid solution; and adding the hydrotalcite-coated matrix composite material dispersion to the long-chain fatty acid solution. In this invention, the volume content of the non-polar organic solvent can be 55-65%, specifically 60%, of all non-polar organic solvents. In this invention, the first dispersion can be carried out under ultrasonic conditions for 8-12 minutes, specifically 10 minutes. In this invention, the dissolution can be carried out under stirring conditions; the stirring is not particularly limited, as long as complete dissolution is achieved.
[0030] In this invention, the grafting reaction temperature can be 50~80℃, specifically 60℃ or 70℃; the grafting reaction time can be 6~24h, specifically 10h, 12h, 15h or 20h; the grafting reaction can be accompanied by stirring, and this invention does not have a special limitation on the stirring, as long as the reaction can proceed fully. In this invention, the grafting reaction may further include: solid-liquid separation of the post-grafting system, washing the obtained solid, and vacuum drying to obtain the organic-inorganic hybrid material. In this invention, the solid-liquid separation can be centrifugation; the washing solvent can be cyclohexane or anhydrous ethanol, and the washing can be performed 2 to 4 times, specifically 3 times; the washing process can remove residual long-chain fatty acids from the solid surface; the vacuum drying temperature can be 40 to 80°C, specifically 50°C, 60°C, or 70°C; this invention does not have a special limitation on the vacuum degree of the vacuum drying, as long as a vacuum state can be maintained; this invention does not have a special requirement for the vacuum drying time, as long as the solvent on the solid surface can be removed.
[0031] The present invention also provides the application of the organic-inorganic hybrid material described in the above technical solution or the organic-inorganic hybrid material prepared by the preparation method described in the above technical solution as a lubricant.
[0032] The present invention also provides a self-lubricating fabric composite material, comprising a fabric, a phenolic resin coating the surface of the fabric fibers and filling the gaps between the fabric fibers, and a lubricant dispersed in the phenolic resin; the fabric is obtained by blending a first fiber and a second fiber, wherein the first fiber is polytetrafluoroethylene fiber (PTFE); and the second fiber includes basalt fiber (BF), glass fiber, carbon fiber or aramid fiber. The lubricant is the organic-inorganic hybrid material described in the above technical solution or the organic-inorganic hybrid material prepared by the preparation method described in the above technical solution.
[0033] In this invention, the diameter of the first fiber can be 15-30 μm, specifically 17 μm, 20 μm, 23 μm, or 25 μm; the first fiber can be a warp yarn; the diameter of the second fiber can be 5-20 μm, specifically 8 μm, 10 μm, 12 μm, 15 μm, or 18 μm; the second fiber can be a weft yarn; the fabric structure can be one or more of ripped twill, 3 / 1 twill, 2 / 2 twill, or plain weave, specifically ripped twill, 3 / 1 twill, 2 / 2 twill, or plain weave. In this invention, the specification of the first fiber can be 11.11 tex to 66.67 tex, or 40-45 tex; the specification of the second fiber can be 11.11 tex to 66.67 tex, or 25-35 tex. In this invention, the warp density of the fibers in the fabric can be 250-350 fibers / 10cm, or 315-335 fibers / 10cm, specifically 280 fibers / 10cm, 300 fibers / 10cm, or 326 fibers / 10cm; the weft density can be 240-320 fibers / 10cm, or 275-315 fibers / 10cm, specifically 250 fibers / 10cm, 280 fibers / 10cm, 290 fibers / 10cm, or 300 fibers / 10cm.
[0034] In this invention, the mass percentage of the fabric can be 65-75%, specifically 70%; the mass ratio of the lubricant to the phenolic resin can be 1-5:100, specifically 2:100, 3:100 or 4:100.
[0035] In this invention, the phenolic resin is the continuous phase, the fibers constituting the fabric are the reinforcing phase, and the lubricant is the lubricating phase.
[0036] In this invention, the self-lubricating composite material has a low coefficient of friction under dry friction conditions, which can extend the wear life.
[0037] The present invention also provides a method for preparing the self-lubricating fabric composite material described in the above technical solution, comprising the following steps: A lubricant and a phenolic resin solution are mixed to obtain an impregnation solution; the lubricant is the organic-inorganic hybrid material described in the above technical solution or the organic-inorganic hybrid material prepared by the preparation method described in the above technical solution; The fabric is immersed in the impregnation solution and then dried. The immersion and drying steps are repeated to obtain a prepreg. The prepreg is cured to obtain the self-lubricating fabric composite material.
[0038] This invention involves mixing a lubricant and a phenolic resin solution to obtain an impregnation solution. In this invention, the solvent for the phenolic resin solution can be a mixture of ethanol, acetone, and ethyl acetate, wherein the volume ratio of ethanol, acetone, and ethyl acetate can be 1:0.8~1.2:0.8~1.2, specifically 1:1:1; the mass concentration of phenolic resin in the phenolic resin solution is 0.1~0.2 g / mL, specifically 0.143 g / mL; and the mass ratio of lubricant to phenolic resin in the impregnation solution can be 1~5:100, specifically 2:100, 3:100, or 4:100.
[0039] In this invention, the mixing can be carried out under ultrasonic conditions. This invention has no special requirements for the ultrasonic treatment, as long as it can achieve uniform mixing.
[0040] After obtaining the impregnation solution, the present invention places the fabric in the impregnation solution for impregnation and then dries it, repeating the impregnation and drying steps to obtain a prepreg. In the present invention, the impregnation process may further include: soaking the fabric in an alkaline cleaning solution, then washing and drying it; the pH value of the alkaline cleaning solution can be 9-11, specifically 10; the soaking temperature can be 90-100℃, specifically 95℃; the soaking time can be 15-25 minutes, specifically 20 minutes; the washing solvent can be deionized water; the present invention has no special limitations on the washing process, as long as the washing solution is neutral after washing. The present invention has no special requirements for the drying process, as long as constant weight is achieved.
[0041] This invention does not have special requirements on the amount of the impregnation solution used, as long as it is sufficient to submerge the fabric. In this invention, the impregnation time can be 10-30 seconds, specifically 15 seconds, 20 seconds, or 25 seconds; the drying temperature can be 30-60°C, specifically 40°C or 50°C; and the drying time can be 20-60 seconds, specifically 30 seconds, 40 seconds, or 50 seconds. This invention does not have special requirements on the number of repeated impregnations and drying cycles, as long as the fabric mass percentage in the prepreg is 65-75% (specifically 70%).
[0042] After obtaining the prepreg, the present invention cures the prepreg to obtain the self-lubricating fabric composite material. In the present invention, before curing, the process may further include: bonding the prepreg to the surface of a carrier; the carrier may include metal, such as Q235 steel, AMS6430 tool steel, 9Cr18 stainless steel, PH13-8Mo stainless steel, or A100 steel. The present invention may use an adhesive for bonding, such as a phenolic resin adhesive.
[0043] In this invention, the curing temperature can be 180~185℃, specifically 184℃; the curing holding time can be 120~150min, specifically 130min or 140min.
[0044] In this invention, the curing process may further include: cooling the cured product to room temperature, where the room temperature can be 20~35℃, specifically 25~30℃; this invention does not have a specific limitation on the cooling method, and in the embodiments of this invention, the cooling is air cooling.
[0045] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0046] Example 1 Two g of hexagonal boron nitride powder with a particle size of 0.1-0.4 μm was dispersed in 100 mL of a mixed alkaline solution with a total hydroxide molar concentration of 3 mol / L, and then hydrothermally reacted at 180 °C for 4 h. The solute in the mixed alkaline solution was a mixture of sodium hydroxide and potassium hydroxide in a molar ratio of 1:1.06, and the solvent was a mixture of water and ethanol in a volume ratio of 1:1.2. After hydrothermal reaction, the system was centrifuged, and the solid obtained by centrifugation was washed with deionized water until neutral and then vacuum dried to obtain hydroxylated boron nitride.
[0047] Hydroxylated boron nitride was dispersed in deionized water to obtain an aqueous dispersion of hydroxylated boron nitride with a mass concentration of 1 mg / mL; water-soluble magnesium salt Mg(NO3)2·6H2O and aluminum salt Al(NO3)3·9H2O were added according to the Mg... 2+ With Al 3+ Add Mg to the dispersion at a molar ratio of 2:1 and stir for 1 hour to allow Mg to be released. 2+ With Al 3+ The total molar concentration was 1.5 mmol / 100 mL. The stirred mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 100 °C for 24 h. The system after hydrothermal reaction was centrifuged, and the solid after centrifugation was washed with water, alcohol and dried in sequence to obtain magnesium aluminum layered double hydroxide coated with hydroxylated boron nitride, denoted as BN@LDH.
[0048] 0.3 g of BN@LDH was dispersed (ultrasonicated for 10 min) in 30 mL of cyclohexane to obtain a BN@LDH dispersion; 0.6 g of stearic acid was dissolved (stirred) in 20 mL of cyclohexane to obtain a stearic acid solution; the BN@LDH dispersion was added to the stearic acid solution and refluxed and stirred at 60 °C for 12 h (grafting reaction); the grafted system was centrifuged, and the solid obtained by centrifugation was washed three times with anhydrous ethanol and then vacuum dried at 60 °C for 12 h to obtain an organic-inorganic hybrid material, denoted as SA-BN@LDH.
[0049] The prepared SA-BN@LDH was examined by scanning electron microscopy and transmission electron microscopy, respectively. The SEM images are shown below. Figure 1 As shown, the obtained TEM image is as follows Figure 2 As shown. From Figures 1-2 It can be observed that magnesium-aluminum layered double hydroxide nanosheets successfully grew and adhered on the surface and edges of a large hexagonal boron nitride sheet, forming a clear core-shell heterostructure.
[0050] Example 2 A fabric with a twill weave structure is constructed by blending basalt fiber filaments of 25~35tex as weft yarns and polytetrafluoroethylene fiber filaments of 40~45tex as warp yarns. The warp density is controlled within the range of 326 threads / 10cm, and the weft density is controlled within the range / deviation of 290 threads / 10cm. The fabric is immersed in an alkaline cleaning solution with a pH of approximately 10 at 95℃ for 20 minutes. The immersed fabric is then rinsed with deionized water until the rinsing solution is neutral. Finally, the fabric is thoroughly dried at room temperature (30℃) to obtain the pretreated fabric.
[0051] 10g of phenolic resin was dissolved in 70mL of a mixed solvent of ethanol, acetone and ethyl acetate in a volume ratio of 1:1:1 to obtain a phenolic resin solution with a mass concentration of 0.143g / mL. SA-BN@LDH prepared in Example 1 was added to the phenolic resin solution and ultrasonically treated to disperse it evenly to obtain an impregnation solution. The mass ratio of SA-BN@LDH to phenolic resin was 3:100.
[0052] The pretreated fabric is immersed in the impregnation solution (completely submerging the fabric) for 20 seconds and then dried at 40°C for 45 seconds. The immersion and drying steps are repeated 14 times (to control the mass ratio of the fabric in the prepreg to about 70%) to obtain the prepreg.
[0053] The prepreg was bonded to the surface of a metal carrier (Q235 steel) using phenolic resin adhesive and cured at a constant temperature of 184℃ for 140 min, then air-cooled to room temperature (25℃) to obtain a self-lubricating fabric composite material, denoted as FC-4.
[0054] Comparative Example 1 The pretreated fabric was prepared according to the method of Example 2; The fabric composite material was impregnated and cured according to the method of Example 2, and the result was labeled FC-0 (as a blank control sample). The difference was that the phenolic resin solution in Example 1 was used directly as the impregnation solution.
[0055] Comparative Example 2 The pretreated fabric was prepared according to the method of Example 2; Phenolic resin was dissolved in a mixed solvent of ethanol, acetone and ethyl acetate in a volume ratio of 1:1:1 to obtain a phenolic resin solution with a mass concentration of 0.143 g / mL. Hexagonal boron nitride powder (BN) was added to the phenolic resin solution and ultrasonically treated to disperse it evenly to obtain an impregnation solution. The mass ratio of hexagonal boron nitride powder to phenolic resin was 3:100.
[0056] The impregnation and curing were carried out according to the method of Example 2, except that the impregnation solution was the impregnation solution prepared in Comparative Example 2, and the resulting fabric composite material was denoted as FC-1.
[0057] Comparative Example 3 The pretreated fabric was prepared according to the method of Example 2; 2.5 mmol Mg(NO3)2·6H2O (0.641 g), 1.25 mmol Al(NO3)3·9H2O (0.469 g) and 0.751 g urea were dissolved in 100 mL of deionized water, stirred evenly, and then transferred to a reaction vessel for hydrothermal reaction at 120 °C for 15 h. After the hydrothermal reaction, the solid was centrifuged and washed with water and alcohol, respectively. The washed product was then vacuum dried at 60 °C to obtain magnesium-aluminum layered double hydroxide, denoted as MgAl-LDH. Phenolic resin was dissolved in a mixed solvent of ethanol, acetone and ethyl acetate in a volume ratio of 1:1:1 to obtain a phenolic resin solution with a mass concentration of 0.143 g / mL. The obtained MgAl-LDH was added to the phenolic resin solution and ultrasonically treated to make it uniformly dispersed to obtain an impregnation solution. The mass ratio of MgAl-LDH to phenolic resin was 3:100.
[0058] The impregnation and curing were carried out according to the method of Example 2, except that the impregnation solution was the impregnation solution prepared in Comparative Example 3, and the resulting fabric composite material was denoted as FC-2.
[0059] Comparative Example 4 The pretreated fabric was prepared according to the method of Example 2; Phenolic resin was dissolved in a mixed solvent of ethanol, acetone and ethyl acetate in a volume ratio of 1:1:1 to obtain a phenolic resin solution with a mass concentration of 0.143 g / mL. BN@LDH prepared in Example 1 was added to the phenolic resin solution and ultrasonically treated to disperse it evenly to obtain an impregnation solution. The mass ratio of BN@LDH to phenolic resin was 3:100.
[0060] The impregnation and curing were carried out according to the method of Example 2, except that the impregnation solution was the impregnation solution prepared in Comparative Example 4, and the resulting fabric composite material was denoted as FC-3.
[0061] The frictional properties of the fabric composite materials prepared in Examples 2 and Comparative Examples 1-4 were tested under low-speed heavy load and high-speed light load conditions using a Xuanwu No. 3 pin-disc friction and wear testing machine at room temperature. The results of the friction coefficient and volumetric wear rate are listed in Table 1. The test conditions for low-speed heavy load were: rotation speed 240 r / min, load 70 MPa, mating surface GCr15 steel, and test time 2 h; the test conditions for high-speed light load were: rotation speed 600 r / min, load 40 MPa, mating surface GCr15 steel, and test time 2 h.
[0062] Table 1. Friction properties of the fabric composites prepared in Example 2 and Comparative Examples 1-4 under different conditions.
[0063] Based on Table 1, a bar chart comparing the friction coefficient and volumetric wear rate under low-speed, heavy-load conditions was plotted. Figure 3 As shown in Table 1, a bar chart comparing the friction coefficient and volumetric wear rate under high-speed, light-load conditions was plotted. Figure 4 As shown. (Combined with Table 1 and...) Figures 3-4 As can be seen, the pure BF / PTFE fabric composite without filler has a higher wear rate. In contrast, the composite with SA-BN@LDH hybrid filler exhibits the lowest wear rate and a lower coefficient of friction.
[0064] The self-lubricating fabric composites of Example 2 and Comparative Example 1 were subjected to tribological performance testing under different conditions, and SEM images were obtained, as shown below. Figure 5 As shown, (a) is a SEM image of the surface of Comparative Example 1 (FC-0) after friction under low-speed heavy-load conditions, (b) is a SEM image of the surface of Comparative Example 1 (FC-0) after friction under high-speed light-load conditions, (c) is a SEM image of the surface of Example 2 (FC-4) after friction under low-speed heavy-load conditions, and (d) is a SEM image of the surface of Example 2 (FC-4) after friction under high-speed light-load conditions. Figure 5It can be seen that under the conditions of 240 r / min rotation speed and 70 MPa load, the pure BF / PTFE material (Comparative Example 1) exhibits severe resin peeling and fiber pull-out on its surface; for the composite material with added SA-BN@LDH (Example 2), no phase separation phenomenon is observed on its wear surface, with only partial resin peeling. Under the conditions of 600 r / min rotation speed and 40 MPa load, the composite material with added SA-BN@LDH (Example 2) has a smoother and more even wear surface compared to the pure BF / PTFE material (Comparative Example 1), showing only slight plastic deformation of the material and forming a continuous and dense lubricating film, proving that the SA-BN@LDH hybrid filler has excellent synergistic friction reduction and wear resistance.
[0065] X-ray photoelectron spectroscopy (XPS) was performed on the SA-BN@LDH prepared in Example 1 to obtain the XPS spectrum, as shown below. Figure 6 As shown. According to Figure 6 In the O 1s spectrum of SA-BN@LDH, a new O=CO peak appears at 532.8 eV, attributed to the carboxylate oxygen of the grafted stearic acid. The MO peak position remains almost unchanged, confirming that the LDH skeleton is not damaged and the dehydroxylation-coordination mechanism is dominant. In the C 1s spectrum of SA-BN@LDH, the area at 284.8 eV is significantly enhanced (segment CC / CH), and a shoulder peak appears at 285.5 eV, belonging to the COM environment, indicating that the carboxylate group forms a covalent bond with the surface Al. Stearic acid is covalently anchored through the Al-OC bond, which improves the interfacial binding ability between organic and inorganic components.
[0066] The self-lubricating fabric composite material provided by this invention exhibits a low coefficient of friction, excellent wear resistance, and stable operation under both high-speed light-load and low-speed heavy-load dry friction conditions. It is particularly suitable for mechanical transmission components such as self-lubricating bearing pads that have strict requirements for friction reduction, wear resistance, and lightweighting.
[0067] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. An organic-inorganic hybrid material, characterized in that, It includes a matrix, a sheet-like hydrotalcite material coated on the surface of the matrix, and long-chain fatty acids grafted onto the surface of the sheet-like hydrotalcite material; the matrix is a hydroxylated ceramic or a hydroxylated two-dimensional layered material.
2. The organic-inorganic hybrid material according to claim 1, characterized in that, The organic-inorganic hybrid material contains 30-50% by mass of platy hydrotalcite; the grafting amount of the long-chain fatty acid is 6-10%. The hydroxylated two-dimensional layered material includes hydroxylated boron nitride, hydroxylated graphene, hydroxylated MoS2, or hydroxylated MXene. The flaky hydrotalcite-like material includes magnesium-aluminum layered double hydroxide; The long-chain fatty acids include stearic acid, oleic acid, lauric acid, or palmitic acid.
3. The method for preparing the organic-inorganic hybrid material according to claim 1 or 2, characterized in that, Includes the following steps: The matrix raw material is hydroxylated to obtain the matrix; A hydrothermal method was used to grow lamellar hydrotalcite-like materials in situ on the surface of the matrix to obtain a hydrotalcite-coated matrix composite material. The organic-inorganic hybrid material is obtained by grafting a mixture of the hydrotalcite-coated matrix composite material, long-chain fatty acids, and nonpolar organic solvents.
4. The preparation method according to claim 3, characterized in that, When the matrix raw material is boron nitride, the hydroxylation includes the following steps: Boron nitride was dispersed in a mixed strong alkali solution and subjected to a hydrothermal reaction to obtain hydroxylated boron nitride; The preparation steps of the mixed strong alkali solution include: dissolving sodium hydroxide and potassium hydroxide in an aqueous ethanol solution to obtain the mixed strong alkali solution; The molar ratio of sodium hydroxide to potassium hydroxide is 1:1~2; the total molar concentration of sodium hydroxide and potassium hydroxide in the mixed strong alkali solution is 1~4 mol / L; the volume ratio of water to ethanol in the ethanol aqueous solution is 1:1~2; the mass ratio of the matrix raw material to the volume ratio of the mixed strong alkali solution is 0.5~2g:50~200mL; The hydrothermal reaction is carried out at a temperature of 150~200℃ for 4~8 hours.
5. The preparation method according to claim 3, characterized in that, The hydrothermal reaction temperature of the hydrothermal method is 80~120℃, and the time is 12~36h; The grafting reaction is carried out at a temperature of 50-80°C for 6-24 hours.
6. The application of the organic-inorganic hybrid material according to claim 1 or 2, or the organic-inorganic hybrid material prepared by the preparation method according to any one of claims 3 to 5, as a lubricant.
7. A self-lubricating fabric composite material, characterized in that, The fabric includes a phenolic resin coating the surface of the fabric fibers and filling the gaps between the fabric fibers, and a lubricant dispersed in the phenolic resin; the fabric is obtained by blending a first fiber and a second fiber, wherein the first fiber is polytetrafluoroethylene fiber; and the second fiber includes basalt fiber, glass fiber, carbon fiber or aramid fiber. The lubricant is the organic-inorganic hybrid material according to any one of claims 1 to 3 or the organic-inorganic hybrid material prepared by the preparation method according to any one of claims 4 to 5.
8. The self-lubricating fabric composite material according to claim 7, characterized in that, The fabric has a mass percentage content of 65-75%, and the mass ratio of the lubricant to the phenolic resin is 1-5:
100. The first fiber has a specification of 11.11 tex to 66.67 tex, and the second fiber has a specification of 11.11 tex to 66.67 tex; The first fiber is a warp yarn, and the second fiber is a weft yarn; the warp density of the fibers in the fabric is 250~350 threads / 10cm, and the weft density is 240~320 threads / 10cm.
9. The method for preparing the self-lubricating fabric composite material according to claim 7 or 8, characterized in that, Includes the following steps: A lubricant and a phenolic resin solution are mixed to obtain an impregnation solution; the lubricant is the organic-inorganic hybrid material according to any one of claims 1 to 3 or the organic-inorganic hybrid material prepared by the preparation method according to any one of claims 4 to 5; The fabric is immersed in the impregnation solution and then dried. The immersion and drying steps are repeated to obtain a prepreg. The prepreg is cured to obtain the self-lubricating fabric composite material.
10. The preparation method according to claim 9, characterized in that, The solvent of the phenolic resin solution is a mixture of ethanol, acetone and ethyl acetate, and the mass concentration of phenolic resin in the phenolic resin solution is 0.1~0.2 g / mL; The mass ratio of lubricant to phenolic resin in the impregnation solution is 1~5:100; The soaking time is 10~30s, and the drying temperature is 30~60℃; The total mass percentage of the phenolic resin and lubricant in the prepreg is 28-32%. The curing temperature is 180~185℃ and the time is 120~150min.