Wear-resistant liquid silica gel composite material and preparation method thereof

Abstract

The invention relates to the technical field of liquid silicone rubber, and particularly discloses a wear-resistant liquid silicone rubber composite material and a preparation method thereof. The composite material comprises a component A and a component B, wherein the component A comprises vinyl-terminated silicone oil, nano aluminum oxide double-modified by a polyhydroxy polymer and a vinyl silane coupling agent, and a platinum catalyst; the component B comprises vinyl-terminated silicone oil, hydrogen-containing silicone oil, an inhibitor and active polysilazane, the active polysilazane is modified polysilazane containing vinyl or epoxy group, and the active group of the active polysilazane can chemically react with the active group on the surface of the modified nano aluminum oxide to form a chemically bonded interface transition layer. According to the invention, through a dual modification strategy and introduction of active polysilazane, a chemically bonded rigid-flexible bicontinuous network structure is constructed, so that the wear resistance of the composite material is improved while excellent tensile strength, tear strength and elongation at break are maintained.

Description

Technical Field

[0001] This invention relates to the field of liquid silicone rubber technology, and more specifically to a wear-resistant liquid silicone composite material and its preparation method. Background Technology

[0002] Liquid silicone rubber (LSR) has been widely used in medical devices, the automotive industry, electronics, and consumer goods due to its excellent biocompatibility, resistance to high and low temperatures, chemical stability, and transparency. However, pure liquid silicone rubber has low mechanical strength, especially poor abrasion resistance. Under dynamic friction or high load conditions, the surface of the product is easily worn, leading to functional failure or shortened service life. This greatly limits its application in areas with high abrasion resistance requirements, such as drive belts, rollers, and seals.

[0003] To improve the wear resistance of liquid silicone rubber, existing technologies typically employ the strategy of adding inorganic rigid fillers (such as nano-silica, alumina, silicon carbide, etc.). The introduction of these high-hardness fillers can form a wear-resistant layer on the silicone rubber surface, resisting frictional damage. However, this technical approach faces two major industry pain points: First, the surface energy difference between inorganic fillers and the organosilicon matrix is ​​significant, resulting in extremely poor compatibility. Nanoscale filler particles are prone to agglomeration under strong surface energy, making uniform dispersion in the matrix difficult. These agglomerates become stress concentration points, inducing material failure. Second, traditional methods of modifying fillers with single modifiers (such as silane coupling agents alone) to improve compatibility, while improving dispersion to some extent, often excessively increase the interfacial rigidity between the filler and the matrix. This restricts the slippage and extension of silicone rubber molecular chains under stress, leading to a significant decrease in the material's tensile strength, tear strength, and elongation at break, creating a technical limitation where "wear resistance and mechanical properties are difficult to balance."

[0004] Therefore, developing a liquid silicone composite material that can both achieve uniform dispersion of inorganic wear-resistant fillers in liquid silicone rubber and simultaneously improve or maintain the excellent mechanical properties of the matrix has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a wear-resistant liquid silicone composite material and its preparation method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, on the one hand, the present invention provides a wear-resistant liquid silicone composite material, comprising component A and component B, wherein the mass ratio of component A to component B is 10:(0.8-1.2). Component A comprises, by weight: 100 parts vinyl-terminated silicone oil, 5-20 parts modified nano-alumina, and 0.1-1 parts platinum catalyst; The modified nano-alumina is prepared by surface synergistic modification of nano-alumina with a polyhydroxy polymer and a vinyl silane coupling agent. Component B, by weight, comprises: 100 parts of vinyl-terminated silicone oil, 2-10 parts of hydrogen-containing silicone oil, 0.05-0.5 parts of inhibitor, and 1-8 parts of active polysilazane. The active polysilazane is a modified polysilazane containing vinyl or epoxy groups, and the active groups in the active polysilazane can chemically react with the active groups on the surface of the modified nano-alumina to form a chemically bonded organic-inorganic interface transition layer in the composite material.

[0007] Component A introduces nano-alumina synergistically modified by a polyhydroxy polymer and a vinyl silane coupling agent. The polyhydroxy polymer is adsorbed onto the surface of the nano-alumina through hydrogen bonding or dehydration condensation, forming a hydrophilic "anchoring layer" that improves initial dispersibility; the vinyl silane coupling agent introduces vinyl functional groups that can participate in hydrosilylation. This "dual-modification layer" design effectively prevents agglomeration and establishes a "flexible transition layer" and "chemical bridging points" between the filler and the matrix. The active polysilazane introduced in component B is the core of this invention. Its vinyl or epoxy groups can not only form a self-lubricating ceramic precursor structure, but also undergo interfacial chemical reactions with the hydroxyl or vinyl groups on the surface of the modified nano-alumina, constructing a chemically bonded gradient interfacial layer. This feature tightly links components A and B through chemical reactions, forming a "rigid-flexible bicontinuous network" structure throughout the entire material.

[0008] Preferably, the active polysilazane is at least one of vinyl-modified polysilazane or epoxy-modified polysilazane.

[0009] Preferably, the polyhydroxy polymer is at least one of polyvinyl alcohol, allyl alcohol polyoxyethylene ether, or hydroxyethyl acrylate copolymer.

[0010] Preferably, the vinyl silane coupling agent is at least one of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltri(2-methoxyethoxy)silane.

[0011] Preferably, component A further comprises 0.5-5 parts by weight of a component with a specific surface area of ​​150-300 m². 2 / g of fumed silica. If a small amount of fumed silica is added to component A, it can form a "hybrid filling" effect with modified nano-alumina, further adjusting the thixotropy and reinforcing effect of the system, and synergistically improving the overall mechanical properties.

[0012] Preferably, the hydrogen content of the hydrogen-containing silicone oil in component B is 0.18%-1.0% by mass, and the viscosity is 10-500 mPa·s.

[0013] On the other hand, the present invention also discloses a method for preparing the above-mentioned wear-resistant liquid silicone composite material, comprising the following steps: (1) Preparation of component A: Mix vinyl-terminated silicone oil and modified nano-alumina according to the ratio and stir evenly. Then add platinum catalyst and degas under vacuum to obtain component A; (2) Preparation of component B: Mix vinyl-terminated silicone oil, hydrogen-containing silicone oil, inhibitor and active polysilazane evenly according to the formula, and obtain component B after vacuum degassing; (3) Mixing and curing: Mix component A obtained in step (1) and component B obtained in step (2) in a mass ratio, and heat and cure to obtain wear-resistant liquid silicone composite material.

[0014] Preferably, in step (1), the preparation method of the modified nano-alumina includes the following steps: Nano-alumina is dispersed in a solvent, and a polyhydroxy polymer and a vinyl silane coupling agent are added. The mixture is reacted at 50-80℃ for 2-6 hours. After separation and drying, the modified nano-alumina is obtained. The mass ratio of the polyhydroxy polymer, vinyl silane coupling agent and nano-alumina is (0.5-2):(0.5-3):10.

[0015] Preferably, in step (1), the stirring rate is 500-1500 rpm, the stirring time is 30-60 min, and the vacuum degree is -0.06~-0.1 MPa.

[0016] Preferably, in step (3), the heating and curing temperature is 100-150℃ and the curing time is 5-30min.

[0017] The beneficial effects of this invention are as follows: (1) By using a “dual modification” strategy of polyhydroxy polymer and vinyl silane coupling agent, a flexible interface layer with both dispersibility and reactivity is constructed on the surface of nano alumina, which significantly improves the compatibility and dispersion uniformity of inorganic filler and liquid silicone rubber matrix.

[0018] (2) Introducing polysilazane containing active functional groups allows it to not only form self-lubricating ceramic precursor micro-regions during the curing process, but also to undergo interfacial chemical reactions with active groups on the surface of modified nano-alumina, thereby constructing a chemically bonded gradient interface layer between rigid particles and flexible matrix, and achieving effective stress transfer and dissipation.

[0019] (3) Rigid wear-resistant particles and flexible lubricating phases are tightly bonded together through chemically bonded interfaces, forming a "rigid-flexible dual-continuous network" structure that runs through the entire material. This unique structure enables the composite material to maintain excellent tensile strength, tear strength, and elongation at break while achieving a breakthrough improvement in wear resistance, realizing a dual leap in mechanical properties and wear resistance. Its synergistic effect far exceeds that of simple physical blending. Detailed Implementation

[0020] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0021] It should be noted that all reagents and raw materials used in this invention are commercially available, and the reagents are of analytical grade.

[0022] Vinyl-terminated silicone oil was purchased from Zhejiang Jutai New Material Technology Co., Ltd., model number JT4202. Nano-alumina was purchased from Shenzhen Jingcai Chemical Co., Ltd., model number JC-L200. Polyvinyl alcohol (PVA) was sourced from Inner Mongolia Shuangxin Environmental Protection Materials Co., Ltd., model number PVA17-88. Vinyltrimethoxysilane was sourced from Nanjing Liangui Chemical Co., Ltd., model number USi-401. Platinum catalyst was sourced from Heraeus Precious Metals Technology (China) Co., Ltd., CAS number: 68478-92-2. Fumed silica was sourced from Xinte Energy Co., Ltd., model number T200L. Hydrogen-containing silicone oil was purchased from Guangzhou Jucheng Zhaoye Organosilicon Raw Material Co., Ltd., model number JC-H206. Vinyl-modified polysilazane was purchased from Anhui Mingyi Silicon Industry Co., Ltd., model number MY9118. Epoxy-modified polysilazane was purchased from Zhonggui New Material (Quanzhou) Co., Ltd., model number ZG-GX01. The polysilazane was purchased from Hangzhou Qingci New Material Technology Co., Ltd., model number TC-P11.

[0023] Example 1 (1) Preparation of modified nano-alumina: 10g of nano-alumina was dispersed in 100mL of ethanol aqueous solution (ethanol:water volume ratio of 98:2), 1g of polyvinyl alcohol and 2g of vinyltrimethoxysilane were added, the temperature was raised to 65℃, and the reaction was stirred for 4h. After the reaction was completed, the nano-alumina was separated by centrifugation, washed three times with ethanol, and dried under vacuum at 80℃ to constant weight to obtain modified nano-alumina; (2) Preparation of component A: In a planetary mixer, add 100g of vinyl-terminated silicone oil, 12g of modified nano-alumina and 2.5g of fumed silica, stir at 1000 rpm for 45min, then add 0.5g of platinum catalyst, continue stirring for 10min, and degas under a vacuum of -0.08 MPa for 20min to obtain component A.

[0024] (3) Preparation of component B: In another container, 100g of vinyl-terminated silicone oil, 5g of hydrogen-containing silicone oil, 0.1g of ethynylcyclohexanol (inhibitor) and 4g of vinyl-modified polysilazane are mixed and stirred at 800 rpm for 35 min and degassed under a vacuum of -0.07MPa for 15 min to obtain component B.

[0025] (4) Mixing and curing: Mix component A and component B at a mass ratio of 10:1, inject into a mold, and pressurize in a flat vulcanizing machine at 120°C for 15 minutes to obtain wear-resistant liquid silicone composite material.

[0026] Example 2 (1) Preparation of modified nano-alumina: 10g of nano-alumina was dispersed in 100mL of ethanol aqueous solution (ethanol:water volume ratio of 98:2), 0.5g of polyvinyl alcohol and 0.5g of vinyltrimethoxysilane were added, the temperature was raised to 50℃, and the reaction was stirred for 6h. After the reaction was completed, the nano-alumina was separated by centrifugation, washed three times with ethanol, and dried under vacuum at 70℃ to constant weight to obtain modified nano-alumina; (2) Preparation of component A: In a planetary mixer, add 100g of vinyl-terminated silicone oil, 5g of modified nano-alumina and 0.5g of fumed silica, stir at 500 rpm for 60min, then add 0.1g of platinum catalyst, continue stirring for 10min, and degas under a vacuum of -0.06MPa for 25min to obtain component A.

[0027] (3) Preparation of component B: In another container, 100g of vinyl-terminated silicone oil, 2g of hydrogen-containing silicone oil, 0.05g of ethynylcyclohexanol (inhibitor) and 1g of vinyl-modified polysilazane are mixed and stirred at 600 rpm for 50 min, and degassed under a vacuum of -0.06MPa for 20 min to obtain component B.

[0028] (4) Mixing and curing: Mix component A and component B at a mass ratio of 10:0.8, inject into a mold, and cure under pressure in a flat vulcanizing machine at 100°C for 30 minutes to obtain wear-resistant liquid silicone composite material.

[0029] Example 3 (1) Preparation of modified nano-alumina: 10g of nano-alumina was dispersed in 100mL of ethanol aqueous solution (ethanol:water volume ratio of 98:2), 2g of polyvinyl alcohol and 3g of vinyltrimethoxysilane were added, the temperature was raised to 80℃, and the reaction was stirred for 2h. After the reaction was completed, the nano-alumina was separated by centrifugation, washed three times with ethanol, and dried under vacuum at 90℃ to constant weight to obtain modified nano-alumina; (2) Preparation of component A: In a planetary mixer, add 100g of vinyl-terminated silicone oil, 20g of modified nano-alumina and 5g of fumed silica, stir at 1500 rpm for 30min, then add 1g of platinum catalyst, continue stirring for 10min, and degas under a vacuum of -0.1MPa for 15min to obtain component A.

[0030] (3) Preparation of component B: In another container, 100g of vinyl-terminated silicone oil, 10g of hydrogen-containing silicone oil, 0.5g of ethynylcyclohexanol (inhibitor) and 8g of vinyl-modified polysilazane are mixed and stirred at 1200 rpm for 25 min, and degassed under a vacuum of -0.1MPa for 10 min to obtain component B.

[0031] (4) Mixing and curing: Mix component A and component B at a mass ratio of 10:1.2, inject into the mold, and pressurize and cure in a flat vulcanizing machine at 150°C for 10 minutes to obtain wear-resistant liquid silicone composite material.

[0032] Example 4 (1) Preparation of modified nano-alumina: 10g of nano-alumina was dispersed in 100mL of ethanol aqueous solution (ethanol:water volume ratio of 98:2), 1.2g of polyvinyl alcohol and 2g of vinyltrimethoxysilane were added, the temperature was raised to 70℃, and the reaction was stirred for 3.5h. After the reaction was completed, the nano-alumina was separated by centrifugation, washed three times with ethanol, and dried under vacuum at 85℃ to constant weight to obtain modified nano-alumina; (2) Preparation of component A: In a planetary mixer, add 100g of vinyl-terminated silicone oil, 15g of modified nano-alumina and 3g of fumed silica, stir at 1200 rpm for 40min, then add 0.7g of platinum catalyst, continue stirring for 10min, and degas under a vacuum of -0.09MPa for 18min to obtain component A.

[0033] (3) Preparation of component B: In another container, 100g of vinyl-terminated silicone oil, 8g of hydrogen-containing silicone oil, 0.3g of ethynylcyclohexanol (inhibitor) and 5g of epoxy-modified polysilazane are mixed and stirred at 900 rpm for 40 min, and degassed under a vacuum of -0.08MPa for 15 min to obtain component B.

[0034] (4) Mixing and curing: Mix component A and component B at a mass ratio of 10:1.2, inject into the mold, and pressurize and cure in a flat vulcanizing machine at 130°C for 12 minutes to obtain wear-resistant liquid silicone composite material.

[0035] Comparative Example 1 Compared with Example 1, the difference is that step (1) is omitted, and in step (2), 10g of unmodified nano alumina is directly used to replace the modified nano alumina in Example 1.

[0036] Comparative Example 2 Compared with Example 1, the difference is that in step (1), only 3g of a single vinyl silane coupling agent, vinyltrimethoxysilane, is used to modify nano-alumina, and polyvinyl alcohol is not used in this process.

[0037] Comparative Example 3 Compared with Example 1, the difference is that in step (1), only 3g of single polyvinyl alcohol is used to modify nano-alumina, and the vinyl silane coupling agent vinyltrimethoxysilane is not used in this process.

[0038] Comparative Example 4 Compared with Example 1, the difference is that in step (3), vinyl-modified polysilazane is not added to component B.

[0039] Comparative Example 5 Compared with Example 1, the difference is that in Component B, 4g of vinyl-modified polysilazane is replaced by a mixture of 4g polysilazane and 0.2g vinyltrimethoxysilane.

[0040] Comparative Example 6 Compared with Example 1, the difference is that step (1) is cancelled and modified nano-alumina is not added to component A in step (2).

[0041] The composite material samples obtained in Examples 1-4 and Comparative Examples 1-6 were subjected to relevant performance tests. The test standards and methods are as follows: 1. Tensile strength and elongation at break: The tensile strength and elongation at break were determined according to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber". A dumbbell-shaped specimen was used, and the test was conducted on a universal testing machine at a constant tensile speed of 500 mm / min until the specimen broke. The maximum tensile stress before fracture was recorded as the tensile strength (unit: MPa), and the percentage elongation at fracture was recorded as the elongation at break (unit: %). At least five specimens were tested for each sample, and the arithmetic mean was taken as the final result.

[0042] 2. Tear Strength Test: The tear strength test was conducted according to GB / T 529-2008 "Determination of Tear Strength of Vulcanized Rubber or Thermoplastic Rubber (Pants-shaped, Right-angled and Crescent-shaped Specimens)". Right-angled specimens (without notches) were used, and the test was performed on a universal testing machine at a tensile speed of 500 mm / min. The maximum force during the tearing process was recorded. The tear strength was calculated by dividing the maximum force by the specimen thickness (unit: kN / m). At least five specimens were tested for each sample, and the arithmetic mean was taken as the final result.

[0043] 3. Abrasion Resistance Test (DIN Abrasion): The test is conducted according to DIN 53516, "Determination of abrasion resistance of vulcanized or thermoplastic rubber". A cylindrical specimen with a diameter of 16±0.2 mm and a thickness of 6-10 mm is used. A load of 10 N is applied to the specimen on a DIN abrasion tester, and the specimen is abraded for 40 meters at a speed of 40±1 rpm on a roller covered with 60# diamond paper. The volumetric abrasion amount is calculated by weighing the difference in mass of the specimen before and after abrasion and combining this with the specimen density.

[0044] The test results are shown in Table 1.

[0045] Table 1 Performance Test Results As shown in the table above, the overall performance of Comparative Examples 1-3 is inferior to that of Example 1. In particular, Comparative Example 1 (unmodified) exhibits extremely low tensile strength (4.2 MPa) and tear strength (15.3 kN / m), indicating severe agglomeration of the unmodified filler, which becomes a stress concentration point. While Comparative Examples 2 (silane-modified only) and 3 (polymer-modified only) show improved performance, they are still significantly lower than that of Example 1 (dual modification). This demonstrates that the "dual modification" strategy of this invention has significant advantages in improving filler dispersibility and interfacial bonding, effectively transferring stress and thus simultaneously improving mechanical properties such as tensile strength and tear strength.

[0046] Comparative Example 4 (without polysilazane) abrasion resistance (38.5mm) 3 It is significantly worse than Example 1 (24.6mm) 3 Meanwhile, the tensile strength (7.7 MPa) was also lower than that of Example 1 (8.1 MPa), proving that polysilazane not only improves wear resistance, but also has a positive effect on improving mechanical properties of the formed interface structure.

[0047] Comparative Example 4, relying solely on dual-modified nano-alumina for reinforcement, exhibits certain mechanical properties, but suffers from poor wear resistance (DIN wear 38.5 mm) due to the lack of a flexible lubricating phase and interfacial chemical bonding structure. 3 Comparative Example 5 introduced reactive vinyl functional groups into the inactive polysilazane system by adding 0.2g of vinyltrimethoxysilane, eliminating the possibility of performance differences due to insufficient functional group quantity. However, since its active functional groups originated from small molecule coupling agents rather than the polysilazane macromolecular backbone, it could not form an integrated chemically bonded gradient interface layer with the modified nano-alumina during the curing process. It could only achieve a hybrid structure of "inactive host physical coating + small molecule chemical anchors," resulting in insufficient stress transfer efficiency. Therefore, its performance (DIN wear 33.0mm) was affected. 3 Although its tear strength (27.2 kN / m) is better than Comparative Example 4, it is still significantly worse than Example 1 (24.6 mm). 3The comparison of 32.8 kN / m strongly demonstrates that active polysilazane, through the active groups on its macromolecular backbone, constructs a chemically bonded gradient interface layer with modified nano-alumina, which plays an irreplaceable role in achieving synergistic improvement of mechanical properties and wear resistance.

[0048] Comparative Example 4 (containing only modified nano-alumina) exhibited better mechanical properties (tensile strength 7.7 MPa, tear strength 30.7 kN / m), but due to the lack of a flexible lubricating phase, its wear resistance was poor (DIN wear 38 mm). 3 Comparative Example 6 (containing only active polysilazane) imparted a high elongation at break (558%) to the material, but due to the lack of rigid skeleton support, its tensile strength (5.8 MPa) and abrasion resistance (51.7 mm) were also limited. 3 Both showed significant deterioration; however, in Example 1, the combination of the two resulted in tensile strength (8.1 MPa) and tear strength (32.8 kN / m) exceeding those of Comparative Example 4, and abrasion resistance (24.6 mm) also improved. 3 The modified nano-alumina is far superior to the two control groups, and the elongation at break (485%) remains good, which fully proves that the modified nano-alumina and the active polysilazane are not simply added together, but form a rigid-flexible bicontinuous network through chemical bonding interface, thereby achieving a synergistic improvement in mechanical properties and wear resistance.

[0049] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. Furthermore, it should be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0050] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A wear-resistant liquid silicone composite material, characterized in that, It includes component A and component B, wherein the mass ratio of component A to component B is 10:(0.8-1.2). Component A comprises, by weight: 100 parts vinyl-terminated silicone oil, 5-20 parts modified nano-alumina, and 0.1-1 parts platinum catalyst; The modified nano-alumina is prepared by surface synergistic modification of nano-alumina with a polyhydroxy polymer and a vinyl silane coupling agent. Component B, by weight, comprises: 100 parts of vinyl-terminated silicone oil, 2-10 parts of hydrogen-containing silicone oil, 0.05-0.5 parts of inhibitor, and 1-8 parts of active polysilazane. The active polysilazane is a modified polysilazane containing vinyl or epoxy groups, and the active groups in the active polysilazane can chemically react with the active groups on the surface of the modified nano-alumina to form a chemically bonded organic-inorganic interface transition layer in the composite material.

2. The wear-resistant liquid silicone composite material according to claim 1, characterized in that, The active polysilazane is at least one of vinyl-modified polysilazane or epoxy-modified polysilazane.

3. The wear-resistant liquid silicone composite material according to claim 1, characterized in that, The polyhydroxy polymer is at least one of polyvinyl alcohol, allyl alcohol polyoxyethylene ether, or hydroxyethyl acrylate copolymer.

4. The wear-resistant liquid silicone composite material according to claim 1, characterized in that, The vinyl silane coupling agent is at least one of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltri(2-methoxyethoxy)silane.

5. The wear-resistant liquid silicone composite material according to claim 1, characterized in that, Component A also includes 0.5-5 parts by weight of a substance with a specific surface area of ​​150-300 m². 2 / g of fumed silica.

6. The wear-resistant liquid silicone composite material according to claim 1, characterized in that, The hydrogen-containing silicone oil in component B has a hydrogen content of 0.18%-1.0% by mass and a viscosity of 10-500 mPa·s.

7. A method for preparing a wear-resistant liquid silicone composite material according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Preparation of component A: Mix vinyl-terminated silicone oil and modified nano-alumina according to the ratio and stir evenly. Then add platinum catalyst and degas under vacuum to obtain component A; (2) Preparation of component B: Mix vinyl-terminated silicone oil, hydrogen-containing silicone oil, inhibitor and active polysilazane evenly according to the formula, and obtain component B after vacuum degassing; (3) Mixing and curing: Mix component A obtained in step (1) and component B obtained in step (2) in a mass ratio, and heat and cure to obtain wear-resistant liquid silicone composite material.

8. The method for preparing the wear-resistant liquid silicone composite material according to claim 7, characterized in that, In step (1), the preparation method of the modified nano-alumina includes the following steps: Nano-alumina is dispersed in a solvent, and a polyhydroxy polymer and a vinyl silane coupling agent are added. The mixture is reacted at 50-80℃ for 2-6 hours. After separation and drying, the modified nano-alumina is obtained. The mass ratio of the polyhydroxy polymer, vinyl silane coupling agent and nano-alumina is (0.5-2):(0.5-3):

10.

9. The method for preparing the wear-resistant liquid silicone composite material according to claim 7, characterized in that, In step (1), the stirring speed is 500-1500 rpm, the stirring time is 30-60 min, and the vacuum degree is -0.06~-0.1 MPa.

10. The method for preparing the wear-resistant liquid silicone composite material according to claim 7, characterized in that, In step (3), the heating and curing temperature is 100-150℃ and the curing time is 5-30min.

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