WS2 / MXene / HBPSi synergistically enhanced epoxy resin composite material and preparation method thereof

Abstract

The invention discloses a preparation method of a WS2 / MXene / HBPSi synergistically enhanced epoxy resin composite material. The preparation method specifically comprises the following steps: preparing a WS2 / MXene hybrid from few-layer MXene powder, WCl6 and a sulfur source precursor; the preparation method comprises the following steps: uniformly mixing tetraethoxysilane, neopentyl glycol and triethanolamine, and carrying out gradient heating reaction to obtain HBPSi; epoxy resin EP is used as a resin matrix, DDS is used as a curing agent, a WS2 / MXene hybrid is used as a lubricating additive, HBPSi is used as a toughening agent, and the epoxy resin composite material is prepared by combining a melt blending process with a staged heating curing method. According to the method, the toughness and the interface bonding strength of the material are remarkably improved by introducing HBPSi, the friction coefficient of the material is effectively reduced and the wear resistance is improved through the synergistic effect of WS2 and MXene, and cooperative regulation and control of structural strengthening and friction performance improvement are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material preparation, and specifically relates to a method for preparing a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material, and also relates to the epoxy resin composite material. Background Art

[0002] Epoxy resin (EP) is widely used in automotive, aerospace, and electronic packaging due to its excellent mechanical properties, dimensional stability, superior adhesion, and chemical stability. However, the inherent brittleness, high coefficient of friction, and wear of EP materials limit their application in high-end friction and wear applications. To improve the overall performance of epoxy resin, it is often modified by introducing lubricating or reinforcing fillers to enhance its tribological and mechanical properties.

[0003] MXene is a new type of two-dimensional layered material composed of transition metal carbides or carbonitrides, with large interlayer spacing and excellent mechanical properties. Due to the weak van der Waals force between MXene layers, the material is prone to interlayer slip during friction, showing excellent self-lubricating and friction-reducing properties. Studies have shown that filling MXene into a polymer matrix can significantly enhance the mechanical strength of the resin matrix and reduce its friction coefficient and wear rate. For example, introducing 0.5 wt% Ti3C2T into epoxy resin x -MXene can increase the tensile strength of the composite material by 18%, the fracture toughness by 30%, and reduce the friction coefficient to 0.18, further verifying the excellent potential of MXene in enhancing the mechanical and friction properties of epoxy resin.

[0004] WS2 (tungsten sulfide) is a gray-black, layered material with a hexagonal lattice structure. Its crystal structure resembles a "hamburger," with each layer consisting of a single layer of tungsten atoms sandwiched between two layers of sulfur atoms. This weak interlayer bonding gives it excellent friction reduction and wear resistance, making it widely used as a traditional solid lubricant in demanding tribological environments such as high temperatures and high loads. Particularly at the nanoscale, WS2 can form a dense lubricating film on the material surface, effectively reducing the friction coefficient and improving interfacial slip behavior, thereby significantly enhancing the overall tribological performance of the composite. Compared to single filler additions, composites with a layered (2D / 2D) structure exhibit superior tribological performance. Researchers successfully synthesized WS2 / MoS2 micro-nanomaterials by coating activated micronized WS2 with nano-MoS2. Experimental results show that the addition of this composite to a base oil reduced wear by 65.3% and 46.4% compared to using micronized WS2 or nano-MoS2 alone. This demonstrates the significant synergistic effect of multi-scale layered structures in optimizing lubrication performance. Therefore, Ti3C2T x The hybrid constructed by MXene and WS2 as a lubricating additive is expected to further exert its structural characteristics and synergistic lubrication advantages to achieve more efficient friction reduction and anti-wear effects.

[0005] Hyperbranched polysiloxanes (HBPSi) are a class of polymers exhibiting organic-inorganic hybrid properties. Their backbone consists of Si-OC bonds, enriched with a variety of organic functional groups on the side chains. Compared to traditional hyperbranched polysiloxanes with Si-O-Si bonds as their backbone, Si-OC HBPSi incorporates polar CO bonds in its backbone, significantly improving its interfacial compatibility with polar epoxy resin matrices and thereby enhancing interfacial bonding strength. Furthermore, the carbon element in the Si-OC structure imparts enhanced chemical reactivity to the polysiloxane, facilitating the introduction of a variety of reactive functional groups that synergize with epoxy groups to form a dense cross-linked network. The highly branched structure creates numerous intramolecular cavities within HBPSi, while its abundant terminal functional groups react with the epoxy matrix, further promoting uniform dispersion and structural stability. By introducing HBPSi, not only can the cross-linking density of the system be appropriately reduced and the brittle characteristics of the epoxy resin after curing be alleviated, but the toughness and thermal stability of the composite material can also be significantly improved on the basis of improving the mechanical strength.

[0006] Based on the above material properties, it is particularly important to prepare WS2 / MXene / HBPSi synergistically reinforced epoxy resin composites by synergizing WS2 and MXene as lubricating additives and using HBPSi rich in hydroxyl groups as a toughening agent. Summary of the Invention

[0007] The purpose of the present invention is to provide a preparation method of WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite materials, which solves the problems of high friction coefficient and high wear rate of existing epoxy resin composite materials.

[0008] Another object of the present invention is to provide a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material.

[0009] The technical solution adopted by the present invention is a method for preparing a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material, which is specifically implemented according to the following steps: Step 1, preparing few-layer MXene powder; Step 2: Prepare WS2 / MXene hybrid using few-layer MXene powder, WCl6 and sulfur source precursor; Step 3, uniformly mixing ethyl orthosilicate, neopentyl glycol and triethanolamine, and performing a gradient temperature reaction under nitrogen atmosphere protection and condensation reflux to obtain HBPSi; In step 4, epoxy resin EP is used as the resin matrix, DDS is used as the curing agent, WS2 / MXene hybrid is used as the lubricating additive, and HBPSi is used as the toughening agent. A WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material is prepared by a melt blending process combined with a staged temperature rise curing method.

[0010] The present invention is also characterized in that: In step 2, specifically: The few-layer MXene powder prepared in step 1 is ultrasonically dispersed in DMF to form a MXene / DMF mixture; then WCl6 and a sulfur source precursor are sequentially added to the MXene / DMF mixture for hydrothermal reaction, washed, and freeze-dried to obtain a WS2 / MXene hybrid.

[0011] The mass ratio of few-layer MXene powder, WCl6 and sulfur source precursor is 1~4:0.8~3.5:1.6~7; the sulfur source precursor is any one of thiourea, sodium sulfide or thioacetamide.

[0012] The hydrothermal reaction temperature is 150-190°C, the reaction time is 12-24 hours, the freeze-drying temperature is -60°C~-50°C, and the freeze-drying time is 24-72 hours.

[0013] In step 3, the gradient temperature reaction process is: heating from 70°C to 145°C and keeping the temperature for 4.5-10 hours; specifically: When heating from 70℃ to 95℃, the heating rate is 15-20℃ / h and the holding time is 1-2h; When heating from 95℃ to 120℃, the heating rate is 10-15℃ / h and the holding time is 2-5h; When heating from 120℃ to 135℃, the heating rate is 5-10℃ / h and the holding time is 1-2h; When the temperature rises from 135°C to 145°C, the heating rate is 2-5°C / h and the holding time is 0.5-1h.

[0014] In step 3, the molar ratio of ethyl orthosilicate, neopentyl glycol and triethanolamine is 1:1:1-2.

[0015] In step 4, specifically: The epoxy resin EP is stirred at 130-140°C for 15-30 min to obtain a molten epoxy resin EP; then HBPSi is slowly added to the molten epoxy resin EP under stirring and stirred for 10-20 min, followed by the addition of WS2 / MXene hybrid dispersed in acetone and continued stirring for 5-10 min, followed by the addition of curing agent DDS, which is injected into a glass mold coated with a release agent, placed in a vacuum drying oven at 130-140°C and air bubbles are removed using a vacuum pump for 30-40 min, and finally the mold is transferred to a blast drying oven for curing reaction by programmed temperature increase, naturally cooled, and demolded to obtain a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material.

[0016] The curing reaction process is: First, heat the temperature from room temperature to 170-180°C at a rate of 5-10°C / min and keep warm for 4-4.5 hours; then heat the temperature to 230-240°C at a rate of 5-10°C / min and keep warm for 2-2.5 hours.

[0017] The mass ratio of epoxy resin EP, HBPSi, WS2 / MXene hybrid, and curing agent DDS is 83.6:2.2-11.1:0.22-1.1:26.4.

[0018] Another technical solution adopted by the present invention is an epoxy resin composite material prepared by a preparation method of WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material.

[0019] The present invention advantageously combines WS2 with layered MXene to create a layer-by-layer WS2 / MXene composite. The excellent compressive strength, wear reduction, and heat resistance of WS2, combined with the exceptional tribological and self-lubricating properties of MXene, result in a composite material with superior performance compared to a single lubricating reinforcing phase, demonstrating a significant synergistic lubrication effect. Furthermore, the prepared dendritic HBPSi contains numerous internal voids, which reduce the crosslink density and thus improve the toughness of the epoxy resin-based composite. Furthermore, due to the hydroxyl end groups of HBPSi, it readily integrates into the network structure during the early stages of the curing reaction. As the curing process progresses, the hyperbranched molecules form a permeating scaffold, where each hyperbranched crosslink and its directly connected region can be considered an "effective sphere." When these "effective spheres" penetrate the epoxy network, the toughness and other properties of the composite material are significantly enhanced. Therefore, based on these advantages, the resulting WS2 / MXene / HBPSi-EP composite exhibits both excellent mechanical and tribological properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a scanning electron microscope image of WS2 / MXene-1 prepared in Example 1 of the present invention; Figure 2 is a scanning electron microscope image of WS2 / MXene-2 prepared in Example 2 of the present invention; Figure 3 This is a scanning electron microscope image of WS2 / MXene-0.5 prepared in Example 3 of the present invention; Figure 4 Schematic diagram of the synthesis process of HBPSi with a hydroxyl terminal group in the method of the present invention; Figure 5 The method of the present invention is the method of HBPSi with a hydroxyl terminal group. 1 H NMR spectrum; Figure 6 The method of the present invention is the method of HBPSi with a hydroxyl terminal group. 13 C NMR spectrum; Figure 7 The bending strength diagram of HBPSi-EP composite material system with different HBPSi addition amounts; Figure 8 The bending strength diagram of WS2 / MXene / HBPSi-EP composite material system with 4 wt% HBPSi and different addition amounts of WS2 / MXene-1 nanofillers; Figure 9 The impact strength diagram of HBPSi-EP composite material system with different HBPSi addition amounts; Figure 10Impact strength diagram of WS2 / MXene / HBPSi-EP composite material system with 4 wt% HBPSi and different addition amounts of WS2 / MXene-1 nanofillers; Figure 11 The bar graph shows the average friction coefficient of pure EP resin and WS2 / MXene / 4 wt% HBPSi-EP composites with different addition amounts of WS2 / MXene-1 nanofillers. DETAILED DESCRIPTION The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched with HCl+LiF and subjected to ultrasonic-centrifugal delamination treatment multiple times to obtain a few-layer MXene dispersion, and the few-layer MXene dispersion is freeze-dried to obtain a few-layer MXene powder; Step 2: Ultrasonic dispersion of the few-layer MXene powder prepared in step 1 in DMF to form a MXene / DMF mixture; then, tungsten chloride hexahydrate (WCl6) and a sulfur source precursor are sequentially added to the MXene / DMF mixture for hydrothermal reaction, followed by washing and freeze-drying to obtain a WS2 / MXene hybrid; The mass ratio of few-layer MXene powder, WCl6 and sulfur source precursor is 1~4:0.8~3.5:1.6~7; The sulfur source precursor is any one of thiourea, sodium sulfide or thioacetamide; The hydrothermal reaction temperature is 150-190°C, the reaction time is 12-24 hours, the freeze-drying temperature is -60°C~-50°C, and the freeze-drying time is 24-72 hours.

[0022] Step 3: Tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG), and triethanolamine (TEA) are mixed uniformly and reacted in a nitrogen atmosphere under condensation reflux using a "one-pot polycondensation method" with a gradient temperature increase and controlled heating rate to obtain a hydroxyl-terminated hyperbranched polysiloxane (HBPSi); The gradient temperature rising process is: from 70℃ to 145℃ for reaction and keeping the temperature for 4.5-10h; specifically: When heating from 70℃ to 95℃, the heating rate is 15-20℃ / h and the holding time is 1-2h; When heating from 95℃ to 120℃, the heating rate is 10-15℃ / h and the holding time is 2-5h; When heating from 120℃ to 135℃, the heating rate is 5-10℃ / h and the holding time is 1-2h; When the temperature rises from 135°C to 145°C, the heating rate is 2-5°C / h and the holding time is 0.5-1h.

[0023] The molar ratio of tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG) and triethanolamine (TEA) is 1:1:1~2.

[0024] Step 4: Using epoxy resin EP as the resin matrix, diaminodiphenyl sulfone (DDS) as the curing agent, WS2 / MXene hybrid as the lubricating additive, and HBPSi as the toughening agent, a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material was prepared by a melt blending process combined with a staged temperature-increasing curing method; specifically: The epoxy resin EP is stirred at 130-140 °C for 15-30 minutes to obtain a molten epoxy resin EP; then HBPSi is slowly added to the molten epoxy resin EP while stirring, and stirred for 10-20 minutes to mix uniformly. Then, the WS2 / MXene hybrid dispersed in acetone is added and stirred for 5-10 minutes. Then, the curing agent DDS is added and injected into a glass mold coated with a release agent. The mold is then placed in a vacuum drying oven at 130-140 °C and a vacuum pump is used to remove bubbles for 30-40 minutes. Finally, the mold is transferred to a blast drying oven to perform a curing reaction by programmed temperature increase, naturally cooled, and demolded to obtain a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material. The curing reaction process is as follows: first, heat the temperature from room temperature to 170-180°C at a heating rate of 5-10°C / min, and keep it warm for 4-4.5 hours; then heat the temperature to 230-240°C at a heating rate of 5-10°C / min, and keep it warm for 2-2.5 hours.

[0025] The mass ratio of epoxy resin EP, HBPSi, WS2 / MXene hybrid, and curing agent DDS is 83.6:2.2-11.1:0.22-1.1:26.4.

[0026] The preparation method of the WS2 / MXene / HBPSi-EP composite material of the present invention comprises the following steps: first, preparing WS2 / MXene fillers in different proportions by a hydrothermal method, synthesizing a novel HBPSi with a hydroxyl end group by a condensation reaction using tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG) and triethanolamine (TEA) as raw materials, modifying a resin by using HBPSi to serve as a matrix, adding HBPSi to a molten resin matrix and heating for prepolymerization, then incorporating WS2 / MXene fillers as a solid lubricant into the matrix and adding a curing agent 4,4-diaminophenylsulfone (DDS), and curing and molding by a casting method to prepare a WS2 / MXene / HBPSi-EP composite material having good interface bonding strength, high mechanical strength, low friction and high wear resistance; thereby, when the resin-based composite material is used in the aerospace field, it can reduce the friction coefficient, reduce friction and wear failure problems, improve the precision of components and extend their overall service life.

[0027] This paper proposes a method for preparing a composite material by synergistically introducing HBPSi and WS2 / MXene nanocomposite particles into an epoxy resin (EP) matrix. This method is simple, adaptable, and has good scalability and application prospects. By rationally designing the component ratio and dispersion strategy, the resulting WS2 / MXene / HBPSi-EP composite material exhibits significant improvements in both mechanical and friction properties. Specifically, the introduction of HBPSi significantly improves the material's toughness and interfacial bonding strength, while the synergistic effect of WS2 and MXene effectively reduces the material's friction coefficient and enhances wear resistance, achieving coordinated regulation of structural strengthening and friction performance enhancement. This composite material has broad application potential in the electronics industry, automotive manufacturing, aerospace, and other fields.

[0028] Example 1 The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched with HCl+LiF and subjected to ultrasonic-centrifugal delamination treatment multiple times to obtain a few-layer MXene dispersion, and the few-layer MXene dispersion is freeze-dried to obtain a few-layer MXene powder; Specifically, LiF and HCl were mixed and reacted for 3 minutes, and then Ti3AlC2 powder was slowly added to the uniform mixture of LiF and HCl, and stirred at 35°C for 24 hours to obtain a fully reacted mixed dispersion; then, the mixed dispersion was washed with deionized water at a centrifugal speed of 3500 rpm until the pH of the supernatant reached 7.0, and then ultrasonically treated at 180W for 20 minutes. Finally, the mixture was centrifuged at a speed of 3500 rpm for 5 minutes to obtain a MXene dispersion. The dispersion was freeze-dried for 24 hours to obtain a few-layer MXene powder. In step 2, the MXene powder (700 mg) prepared in step 1 was ultrasonically dispersed in 50 mL of DMF and stirred for 30 minutes. Next, 1.2 g of WCl₂ and 2.3 g of TAA were added to the MXene dispersion and magnetically stirred at 50°C for 1 hour. The resulting mixture was then placed in a 100 mL hydrothermal reactor and allowed to react in an electric forced-air drying oven at 180°C for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, and the resulting black precipitate was washed several times with DIW, ethanol, and acetone. Finally, the resulting product was dried in a freeze dryer at -60°C for 48 hours and labeled as WS₂ / MXene-1.

[0029] Step 3: Design the molar ratio of monomers TEOS, NPG, and TEA to be 1:1:1, that is, the molar ratio of -OH to -OCH2CH3 is 5:4. 0.35 mol TEOS, 0.35 mol NPG, and 0.35 mol TEA are added to a 250 mL four-necked round-bottom flask equipped with a stirring rod, a condenser, nitrogen, and a thermometer. The flask is heated to 70°C in an oil bath and stirred. After the NPG is fully dissolved, the temperature is continued to be raised to 95°C and maintained until the distillate is produced. Then, the temperature is stepped to 135°C for 4 hours until the distillation temperature of the by-product drops to about 50°C. The reaction is completed and the heating is stopped. Finally, a hydroxyl-terminated hyperbranched polysiloxane is synthesized, which is recorded as HBPSi.

[0030] In step 4, 83.6 g of epoxy resin (EP) was stirred at 130°C for 10 min. Then, 4 wt% HBPSi was slowly added to the molten EP under stirring for 15 min until uniformly mixed. Next, 0.6 wt% of the filler WS2 / MXene-1 was dispersed in acetone, poured into a beaker, and stirred for 5 min. Then, 26.4 g of the curing agent (DDS) was added. The prepolymer was then carefully poured into a glass mold coated with a release agent and placed in a vacuum drying oven at 130°C. Air bubbles were removed using a vacuum pump for approximately 30 min. Finally, the mold was transferred to a forced-air drying oven and cured by a programmed temperature ramp (170°C for 4 h followed by 230°C for 2 h). After curing was complete and the mixture was allowed to cool naturally, the WS2 / MXene / HBPSi-EP composite was obtained.

[0031] The gradient heating process is: When heating from 70℃ to 95℃, the heating rate is 15℃ / h and the holding time is 1h; When heating from 95℃ to 120℃, the heating rate is 10℃ / h and the holding time is 2h; When heating from 120℃ to 135℃, the heating rate is 5℃ / h and the holding time is 1h; When the temperature rises from 135°C to 145°C, the heating rate is 2°C / h and the holding time is 1h.

[0032] Example 2 The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched and layered using HCl+LiF to prepare a MXene dispersion, and the dispersion is freeze-dried to obtain MXene powder; Specifically, after LiF and HCl were mixed and reacted for 5 minutes, Ti3AlC2 powder was slowly added to the uniform mixture of LiF and HCl, and stirred at 40°C for 30 hours to obtain a fully reacted mixed dispersion; then, the mixed dispersion was washed with deionized water at a centrifugal speed of 3500 rpm until the pH of the supernatant reached 7.0, and then ultrasonically treated at 200W for 25 minutes. Finally, the MXene dispersion was obtained by centrifugation at a speed of 3500 rpm for 5 minutes. The dispersion was freeze-dried for 28 hours to obtain a few-layer MXene powder.

[0033] In step 2, the MXene powder (350 mg) prepared in step 1 was ultrasonically dispersed in 50 mL of DMF and stirred for 30 minutes. Next, 1.2 g of WCl₂ and 2.3 g of TAA were added to the MXene dispersion and magnetically stirred at 50°C for 1 hour. The resulting mixture was then placed in a 100 mL hydrothermal reactor and reacted in an electric forced-air drying oven at 180°C for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, and the resulting black precipitate was washed several times with DIW, ethanol, and acetone. Finally, the resulting product was dried in a freeze dryer at -50°C for 48 hours and labeled as WS₂ / MXene-2.

[0034] In step 3, the molar ratio of the monomers TEOS, NPG, and TEA is designed to be 1:1:1, that is, the molar ratio of -OH to -OCH2CH3 is 5:4. 0.35 mol of TEOS, 0.35 mol of NPG, and 0.35 mol of TEA are added to a 250 mL four-necked round-bottom flask equipped with a stirring rod, a condenser, nitrogen, and a thermometer. The flask is heated to 70 ° C in an oil bath and stirred. After the NPG is fully dissolved, the temperature is continued to be raised to 95 ° C and maintained until the distillate is produced. Then, the temperature is stepped to 135 ° C for 4 hours until the distillation temperature of the by-product drops to about 50 ° C. The reaction is completed and the heating is stopped. Finally, a hydroxyl-terminated hyperbranched polysiloxane is synthesized, which is recorded as HBPSi.

[0035] In step 4, 83.6 g of epoxy resin (EP) was stirred at 130°C for 10 minutes. Then, 4 wt% HBPSi was slowly added to the molten EP under stirring and mixed thoroughly for 15 minutes. Next, 0.8 wt% of the filler WS2 / MXene-2 was dispersed in acetone, poured into a beaker, and stirred for another 5 minutes. Then, 26.4 g of the curing agent DDS was added. The prepolymer was carefully poured into a glass mold coated with a release agent and placed in a vacuum drying oven at 130°C. A vacuum pump was used to remove air bubbles for approximately 30 minutes. Finally, the mold was transferred to a forced air drying oven and cured by programmed temperature ramping. After curing was complete and the mixture was allowed to cool naturally, the WS2 / MXene / HBPSi-EP composite was obtained.

[0036] When heating from 70℃ to 95℃, the heating rate is 15℃ / h and the holding time is 1h; When heating from 95℃ to 120℃, the heating rate is 10℃ / h and the holding time is 2h; When heating from 120℃ to 135℃, the heating rate is 5℃ / h and the holding time is 1h; When the temperature rises from 135°C to 145°C, the heating rate is 2°C / h and the holding time is 1h.

[0037] Example 3 The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched and layered using HCl+LiF to prepare a MXene dispersion, and the dispersion is freeze-dried to obtain MXene powder; Specifically, after LiF and HCl were mixed and reacted for 5 minutes, Ti3AlC2 powder was slowly added to the uniform mixture of LiF and HCl, and stirred at 35°C for 35 hours to obtain a fully reacted mixed dispersion; then, the mixed dispersion was washed with deionized water at a centrifugal speed of 3500 rpm until the pH of the supernatant reached 7.0, and ultrasonically treated at 205W for 30 minutes. Finally, the MXene dispersion was obtained by centrifugation at a speed of 3500 rpm for 5 minutes. The dispersion was freeze-dried for 40 hours to obtain a few-layer MXene powder.

[0038] In step 2, the MXene powder (1.4 g) prepared in step 1 was ultrasonically dispersed in 50 mL of DMF and stirred for 30 minutes. Next, 1.2 g of WCl₂ and 2.3 g of TAA were added to the MXene dispersion and magnetically stirred at 50°C for 1 hour. The resulting mixture was then placed in a 100 mL hydrothermal reactor and allowed to react in an electric forced-air drying oven at 180°C for 24 hours. After the reaction was complete, the mixture was cooled to room temperature, and the resulting black precipitate was washed several times with DIW, ethanol, and acetone. Finally, the resulting product was dried in a freeze dryer at -55°C for 48 hours and labeled as WS₂ / MXene-0.5.

[0039] In step 3, the molar ratio of the monomers TEOS, NPG, and TEA is designed to be 1:1:1, that is, the molar ratio of -OH to -OCH2CH3 is 5:4. 0.35 mol of TEOS, 0.35 mol of NPG, and 0.35 mol of TEA are added to a 250 mL four-necked round-bottom flask equipped with a stirring rod, a condenser, nitrogen, and a thermometer. The flask is heated to 70°C in an oil bath and stirred. After the NPG is fully dissolved, the temperature is continued to be raised to 95°C and maintained until the distillate is produced. Then, the temperature is stepped to 135°C for 4 hours until the distillation temperature of the by-product drops to about 50°C. The reaction is completed and the heating is stopped. Finally, a hydroxyl-terminated hyperbranched polysiloxane is synthesized, which is recorded as HBPSi.

[0040] In step 4, 83.6 g of epoxy resin (EP) was stirred at 130°C for 10 minutes. Then, 4 wt% HBPSi was slowly added to the molten EP under stirring for 15 minutes until uniformly mixed. Next, 1 wt% of the filler WS2 / MXene-0.5 was dispersed in acetone, poured into a beaker, and stirred for another 5 minutes. Then, 26.4 g of the curing agent (DDS) was added. The prepolymer was then carefully poured into a glass mold coated with a release agent and placed in a vacuum drying oven at 130°C. A vacuum pump was used to remove air bubbles for approximately 30 minutes. Finally, the mold was transferred to a forced-air drying oven and cured by programmed temperature ramping. After curing was complete and allowed to cool naturally, the mold was removed to yield the WS2 / MXene / HBPSi-EP composite.

[0041] The gradient heating process is: When heating from 70℃ to 95℃, the heating rate is 15℃ / h and the holding time is 1h; When heating from 95℃ to 120℃, the heating rate is 10℃ / h and the holding time is 2h; When heating from 120℃ to 135℃, the heating rate is 5℃ / h and the holding time is 1h; When the temperature rises from 135°C to 145°C, the heating rate is 2°C / h and the holding time is 1h.

[0042] Example 4 The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched and layered using HCl+LiF to prepare a MXene dispersion, and the dispersion is freeze-dried to obtain MXene powder; Specifically, after LiF and HCl were mixed and reacted for 3 minutes, Ti3AlC2 powder was slowly added to the uniform mixture of LiF and HCl, and stirred at 40°C for 48 hours to obtain a fully reacted mixed dispersion; then the mixed dispersion was washed with deionized water at a centrifugal speed of 3500 rpm until the pH of the supernatant reached 7.0, and ultrasonically treated at 210W for 30 minutes. Finally, the MXene dispersion was obtained by centrifugation at a speed of 3500 rpm for 5 minutes. The dispersion was freeze-dried for 72 hours to obtain a few-layer MXene powder.

[0043] In step 2, the MXene powder (700 mg) prepared in step 1 was ultrasonically dispersed in 50 mL of DMF and stirred for 30 min. 1.2 g of WCl6 and 2.3 g of CH4N2S were then added to the MXene dispersion and magnetically stirred at 50 °C for 1 h. The resulting mixture was then placed in a hydrothermal reactor (100 mL) and reacted in an electric forced-air drying oven at 180 °C for 24 h. After the reaction was complete, the mixture was cooled to room temperature, and the resulting black precipitate was washed several times with DIW, ethanol, and acetone. Finally, the product was dried in a freeze dryer at -60 to -50 °C for 48 h to obtain WS2 / MXene-4. In step 3, the molar ratio of the monomers TEOS, NPG, and TEA is designed to be 1:1:1, that is, the molar ratio of -OH to -OCH2CH3 is 5:4. 0.35 mol of TEOS, 0.35 mol of NPG, and 0.35 mol of TEA are added to a 250 mL four-necked round-bottom flask equipped with a stirring rod, a condenser, a nitrogen atmosphere, and a thermometer. The flask is heated to 70°C in an oil bath and stirred. After the NPG is fully dissolved, the temperature is continued to be raised to 95°C and maintained until the distillate is produced. Then, the temperature is stepped to 135°C for 4 hours until the distillation temperature of the by-product drops to around 50°C. The reaction is completed and heating is stopped. Finally, a hydroxyl-terminated hyperbranched polysiloxane is synthesized, which is denoted as HBPSi.

[0044] In step 4, 83.6 g of epoxy EP resin was stirred at 130°C for 10 minutes. Then, 4 wt% HBPSi was slowly added to the molten EP while stirring for 15 minutes until uniformly mixed. Next, 0.6 wt% of the filler WS2 / MXene-4 was dispersed in acetone, poured into a beaker, and stirred for another 5 minutes. Then, 26.4 g of the curing agent DDS was added. The prepolymer was then carefully poured into a glass mold coated with a release agent and placed in a vacuum drying oven at 130°C. A vacuum pump was used to remove air bubbles for approximately 30 minutes. Finally, the mold was transferred to a forced air drying oven and cured by programmed temperature. After curing was complete and allowed to cool naturally, the mold was removed to yield the WS2 / MXene / HBPSi-EP composite.

[0045] The gradient heating process is: When heating from 70℃ to 95℃, the heating rate is 15℃ / h and the holding time is 1h; When heating from 95℃ to 120℃, the heating rate is 10℃ / h and the holding time is 2h; When heating from 120℃ to 135℃, the heating rate is 5℃ / h and the holding time is 1h; When the temperature rises from 135°C to 145°C, the heating rate is 2°C / h and the holding time is 1h.

[0046] The morphology of the WS2 / MXene-1 material prepared in Example 1 of the present invention is shown in FIG. Figure 1 As shown in the figure, it can be concluded that when the filler ratio is evenly distributed, there are a large number of WS2 flakes with high specific surface area and good dispersion.

[0047] The morphology of the WS2 / MXene-2 material prepared in Example 2 of the present invention is shown in FIG. Figure 2 As shown in the figure, it can be concluded that when there is too much WS2, a large number of nanoparticles are aggregated on the surface of MXene nanosheets, and the dispersion is slightly reduced.

[0048] The morphology of the WS2 / MXene-0.5 material prepared in Example 3 of the present invention is shown in FIG. Figure 3 As shown in the figure, it can be concluded that when too much MXene is added, a multilayer structure stacked on top of each other will appear, limiting its dispersibility.

[0049] Figure 4 Schematic diagram of the synthesis of hyperbranched polysiloxane, indicating that hydroxyl-terminated HBPSi was finally synthesized. Figure 5 and Figure 6 The H NMR spectrum and C NMR spectrum of the prepared HBPSi-OH-1 indicate that HBPSi-OH-1 was successfully synthesized.

[0050] Depend on Figure 7 and Figure 9 It can be concluded that the addition of 4 wt.% of HBPSi with hydroxyl end groups to modify EP showed better flexural strength of 163.11 MPa and impact strength of 27.05 kJ / m 2 , its bending strength and impact strength show a trend of first increasing and then decreasing.

[0051] Depend on Figure 8 It can be concluded that the flexural strength of the composite material is further improved after adding different amounts of WS2 / MXene nanofillers with 4 wt.% HBPSi-EP as the matrix. At the same time, the flexural strength of the composite material with an addition amount of 0.6 wt.% WS2 / MXene filler reaches a maximum of 178.85 MPa, and its flexural strength shows a trend of first increasing and then decreasing.

[0052] Depend on Figure 10 It can be concluded that the impact strength of the composite material with 4 wt.% HBPSi-EP as the matrix and different addition amounts of WS2 / MXene nanofillers are further improved. At the same time, the impact strength of the composite material with an addition amount of 0.6 wt.% WS2 / MXene filler reaches a maximum of 34.75 kJ / m 2 , its impact strength shows a trend of first increasing and then decreasing.

[0053] Depend on Figure 11 It can be seen that the average friction coefficient of the 0.6 wt.% WS2 / MXene / HBPSi-EP composite is 0.30, which is 50.0% lower than the friction coefficient of 0.60 of the unfilled EP resin. This shows that the presence of WS2 / MXene has a friction-reducing effect on the EP resin.

[0054] Example 5 The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched with HCl+LiF and subjected to ultrasonic-centrifugal delamination treatment multiple times to obtain a few-layer MXene dispersion, and the few-layer MXene dispersion is freeze-dried to obtain a few-layer MXene powder; Step 2: Ultrasonic dispersion of the few-layer MXene powder prepared in step 1 in DMF to form a MXene / DMF mixture; then, tungsten chloride hexahydrate (WCl6) and a sulfur source precursor are sequentially added to the MXene / DMF mixture for hydrothermal reaction, followed by washing and freeze-drying to obtain a WS2 / MXene hybrid; The mass ratio of MXene:WCl6:sulfur source precursor is 2:1:5; the sulfur source precursor is thiourea; The hydrothermal reaction temperature was 150°C, the reaction time was 12 h, the freeze-drying temperature was -50°C, and the freeze-drying time was 24 h.

[0055] Step 3: Tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG), and triethanolamine (TEA) are mixed uniformly and reacted in a nitrogen atmosphere under condensation reflux using a "one-pot polycondensation method" with a gradient temperature increase and controlled heating rate to obtain a hydroxyl-terminated hyperbranched polysiloxane (HBPSi); The gradient heating process is: When heating from 70℃ to 95℃, the heating rate is 15℃ / h and the holding time is 2h; When heating from 95℃ to 120℃, the heating rate is 10℃ / h and the holding time is 3h; When heating from 120℃ to 135℃, the heating rate is 5℃ / h and the holding time is 2h; When the temperature rises from 135°C to 145°C, the heating rate is 2°C / h and the holding time is 0.5h.

[0056] The molar ratio of tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG) and triethanolamine (TEA) is 1:1:1.

[0057] Step 4: Stir the epoxy resin EP at 130°C for 30 minutes to obtain a molten epoxy resin EP; then slowly add HBPSi to the molten epoxy resin EP while stirring, stir for 10 minutes to mix evenly, then add the WS2 / MXene hybrid dispersed in acetone, continue stirring for 5 minutes, then add the curing agent DDS, inject it into a glass mold coated with a release agent, and then place it in a vacuum drying oven at 130°C and use a vacuum pump to remove bubbles for 40 minutes. Finally, transfer the mold to a blast drying oven to perform a curing reaction by programmed temperature increase, cool naturally, and demold to obtain a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material; The curing reaction process is as follows: first, the temperature is increased from room temperature to 170°C at a heating rate of 5°C / min, and kept warm for 4 hours; then, the temperature is increased to 230°C at a heating rate of 5°C / min, and kept warm for 2 hours.

[0058] The mass ratio of epoxy resin EP, HBPSi, WS2 / MXene hybrid and curing agent DDS is 83.6:2.2:0.22:26.4.

[0059] Example 6 The preparation method of the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material of the present invention is specifically implemented according to the following steps: Step 1: Ti3AlC2 is etched with HCl+LiF and subjected to ultrasonic-centrifugal delamination treatment multiple times to obtain a few-layer MXene dispersion, and the few-layer MXene dispersion is freeze-dried to obtain a few-layer MXene powder; Step 2: Ultrasonic dispersion of the few-layer MXene powder prepared in step 1 in DMF to form a MXene / DMF mixture; then, tungsten chloride hexahydrate (WCl6) and a sulfur source precursor are sequentially added to the MXene / DMF mixture for hydrothermal reaction, followed by washing and freeze-drying to obtain a WS2 / MXene hybrid; The mass ratio of MXene:WCl6:sulfur source precursor is 2:3:4; the sulfur source precursor is sodium sulfide; the hydrothermal reaction temperature is 190℃, the reaction time is 24h, the freeze-drying temperature is -60℃, and the freeze-drying time is 72h.

[0060] Step 3: Tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG), and triethanolamine (TEA) are mixed uniformly and reacted in a nitrogen atmosphere under condensation reflux using a "one-pot polycondensation method" with a gradient temperature increase and controlled heating rate to obtain a hydroxyl-terminated hyperbranched polysiloxane (HBPSi); The gradient heating process is: When heating from 70℃ to 95℃, the heating rate is 20℃ / h and the holding time is 2h; When heating from 95℃ to 120℃, the heating rate is 10℃ / h and the holding time is 5h; When heating from 120℃ to 135℃, the heating rate is 10℃ / h and the holding time is 1h; When the temperature rises from 135°C to 145°C, the heating rate is 5°C / h and the holding time is 1h.

[0061] The molar ratio of tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG) and triethanolamine (TEA) is 1:1:2.

[0062] Step 4: Stir the epoxy resin EP at 140°C for 30 minutes to obtain a molten epoxy resin EP; then slowly add HBPSi to the molten epoxy resin EP while stirring, stir for 20 minutes to mix evenly, then add the WS2 / MXene hybrid dispersed in acetone, continue stirring for 10 minutes, then add the curing agent DDS, inject it into a glass mold coated with a release agent, and then place it in a vacuum drying oven at 140°C and use a vacuum pump to remove bubbles for 30 minutes. Finally, transfer the mold to a blast drying oven to perform a curing reaction by programmed temperature increase, cool naturally, and demold to obtain a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material; The curing reaction process is as follows: first, the temperature is increased from room temperature to 180°C at a heating rate of 10°C / min and kept at that temperature for 4.5 h; then, the temperature is increased to 240°C at a heating rate of 10°C / min and kept at that temperature for 2.5 h.

[0063] The mass ratio of epoxy resin EP, HBPSi, WS2 / MXene hybrid and curing agent DDS is 83.6:10:1:26.4.

[0064] The mechanism of action of the present method is as follows: First, layered tungsten disulfide (WS2) nanosheets are combined with a novel two-dimensional carbide, MXene, to form a WS2 / MXene lubrication system. WS2, thanks to its low-shear interlaminar structure and high-temperature stability, forms a W-rich oxidized sulfide film at the friction interface, significantly reducing interfacial friction resistance and exhibiting excellent lubrication, particularly under high-temperature and dry friction conditions. MXene, on the other hand, also exhibits interlaminar slip properties. Its surface is rich in functional groups, such as –OH and –O, which can form hydrogen bonds or covalent linkages with the epoxy network, thereby strengthening interfacial adhesion and enhancing the load-bearing capacity of the composite. The synergistic effect of these two phases not only provides layered slip lubrication channels but also builds a stable and dense lubricating / anti-wear film during friction, effectively enhancing interfacial stability and wear resistance, forming a typical synergistic lubrication mechanism. Compared to single lubricating phases, the WS2 / MXene composite system exhibits significantly greater friction coefficient and wear rate reduction, with some studies demonstrating friction coefficient reductions exceeding 60%. Secondly, to further improve the toughness and overall structural stability of the composite, a silicon-containing hyperbranched polymer (HBPSi) was introduced as a toughening agent. HBPSi has a highly branched molecular structure rich in cavities and free volume. During the epoxy curing reaction, it reduces the crosslink density and improves the toughness and fracture energy of the material. Furthermore, its hydroxyl end groups allow it to rapidly embed into the reaction network during the initial curing phase, ensuring good chemical compatibility. As the curing reaction proceeds, HBPSi molecules form a three-dimensional "penetrating" scaffold within the resin matrix, dispersing stress concentration points and absorbing external energy through flexible chain segments. Each crosslink and its associated branched structure can be considered an "effective sphere," acting as a microscopic buffer and energy dissipator within the epoxy network, significantly enhancing the composite's fracture toughness and impact resistance. In this three-phase composite system, the flexible toughening mechanism of HBPSi complements the high load-bearing strength and self-lubricating properties of WS2 / MXene. On the one hand, the presence of HBPSi helps to three-dimensionally disperse the MXene and WS2 flakes, reducing agglomeration and improving the uniformity of the interfacial distribution. On the other hand, MXene and WS2 can serve as rigid reinforcing phases to enhance the mechanical properties of the epoxy matrix while synergistically constructing a stable lubricating film at the friction interface. In summary, the WS2 / MXene / HBPSi three-phase composite system achieves multiple synergies of lubrication, wear resistance, toughening, and mechanical reinforcement at the microscopic level through structural regulation and functional synergy, ultimately endowing the epoxy composite with excellent comprehensive properties, making it particularly suitable for extreme application environments such as high temperature and dry friction.

[0065] The proposed method successfully prepared a WS2 / MXene / HBPSi-EP composite. This composite system significantly enhances the tribological and mechanical properties of the material through the synergistic action of multiple components. WS2, due to its typical layered structure and weak van der Waals forces between layers, exhibits excellent low-shear resistance and thermal stability. MXene, with its good thermal conductivity, self-lubrication, and high surface activity, forms a stable lubricating interfacial film during friction. The combined effects of these two materials effectively reduce the coefficient of friction and improve wear resistance, achieving synergistic lubrication enhancement within the epoxy matrix. Furthermore, the introduction of HBPSi not only improves the toughness of the epoxy matrix but also plays a key role in interfacial compatibility. HBPSi is synthesized using tetraethyl orthosilicate (TEOS), neopentyl glycol (NPG), and triethanolamine (TEA) as monomers. A polycondensation reaction produces a hyperbranched structure with hydroxyl end groups, which facilitates the formation of a cross-linked network with the epoxy matrix, enhancing overall mechanical properties. HBPSi-modified WS2 / MXene / EP composites exhibit high toughness, low friction and high wear resistance. This work provides a feasible solution for the preparation of resin-based composites with excellent mechanical properties and friction properties.

Claims

1. A method for preparing a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material, characterized in that: Please follow the steps below to implement it: Step 1, preparing few-layer MXene powder; Step 2: Prepare WS2 / MXene hybrid using few-layer MXene powder, WCl6 and sulfur source precursor; Step 3, uniformly mixing ethyl orthosilicate, neopentyl glycol and triethanolamine, and performing a gradient temperature reaction under nitrogen atmosphere protection and condensation reflux to obtain HBPSi; In step 4, epoxy resin EP is used as the resin matrix, DDS is used as the curing agent, WS2 / MXene hybrid is used as the lubricating additive, and HBPSi is used as the toughening agent. A WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material is prepared by a melt blending process combined with a staged temperature rise curing method.

2. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 1, wherein: In the step 2, specifically: The few-layer MXene powder prepared in step 1 is ultrasonically dispersed in DMF to form a MXene / DMF mixture; then WCl6 and a sulfur source precursor are sequentially added to the MXene / DMF mixture for hydrothermal reaction, washed, and freeze-dried to obtain a WS2 / MXene hybrid.

3. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 2, wherein: The mass ratio of few-layer MXene powder, WCl6 and sulfur source precursor is 1~4:0.8~3.5:1.6~7; the sulfur source precursor is any one of thiourea, sodium sulfide or thioacetamide.

4. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 2, wherein: The hydrothermal reaction temperature is 150-190°C, the reaction time is 12-24 hours, the freeze-drying temperature is -60°C~-50°C, and the freeze-drying time is 24-72 hours.

5. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 1, wherein: In step 3, the gradient temperature increase reaction process is: heating from 70°C to 145°C and keeping the temperature for 4.5-10 hours; specifically: When heating from 70℃ to 95℃, the heating rate is 15-20℃ / h and the holding time is 1-2h; When heating from 95℃ to 120℃, the heating rate is 10-15℃ / h and the holding time is 2-5h; When heating from 120℃ to 135℃, the heating rate is 5-10℃ / h and the holding time is 1-2h; When the temperature rises from 135°C to 145°C, the heating rate is 2-5°C / h and the holding time is 0.5-1h.

6. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 1, wherein: In the step 3, the molar ratio of ethyl orthosilicate, neopentyl glycol and triethanolamine is 1:1:1-2.

7. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 1, wherein: In the step 4, specifically: The epoxy resin EP is stirred at 130-140°C for 15-30 min to obtain a molten epoxy resin EP; then HBPSi is slowly added to the molten epoxy resin EP under stirring and stirred for 10-20 min, followed by the addition of WS2 / MXene hybrid dispersed in acetone and continued stirring for 5-10 min, followed by the addition of curing agent DDS, which is injected into a glass mold coated with a release agent, placed in a vacuum drying oven at 130-140°C and air bubbles are removed using a vacuum pump for 30-40 min, and finally the mold is transferred to a blast drying oven for curing reaction by programmed temperature increase, naturally cooled, and demolded to obtain a WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material.

8. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 7, wherein: The curing reaction process is: First, heat the temperature from room temperature to 170-180°C at a rate of 5-10°C / min and keep warm for 4-4.5 hours; then heat the temperature to 230-240°C at a rate of 5-10°C / min and keep warm for 2-2.5 hours.

9. The method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to claim 7, wherein: The mass ratio of epoxy resin EP, HBPSi, WS2 / MXene hybrid, and curing agent DDS is 83.6:2.2-11.1:0.22-1.1:26.

4.

10. The epoxy resin composite material prepared by the method for preparing the WS2 / MXene / HBPSi synergistically reinforced epoxy resin composite material according to any one of claims 1 to 9.

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