High-performance natural rubber containing modified silica sol and preparation method thereof

Abstract

The invention discloses high-performance natural rubber containing modified silica sol and a preparation method of the high-performance natural rubber, and belongs to the technical field of rubber materials. The preparation method comprises the following steps: plastifying natural rubber in an open mill for 10-12 minutes, then adding modified silica sol, modified vanillin, stearic acid, a vulcanization accelerator CZ, zinc oxide, carbon black, sulfur powder and an anti-aging agent 4010 into the natural rubber, uniformly mixing, standing for 24-28 hours, and carrying out vulcanization molding by adopting a plate vulcanizing machine under the conditions of 140-160 DEG C and 18-20 MPa, so as to obtain the rubber material. The high-performance natural rubber containing the modified silica sol is obtained. The natural rubber provided by the invention has good mechanical properties and aging resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rubber materials, and more particularly relates to a high-performance natural rubber containing modified silica sol and a preparation method thereof. BACKGROUND

[0002] Traditional natural rubber has become one of the most important general-purpose natural polymer materials due to excellent elasticity and flexibility, and has an irreplaceable position in the fields of tires, conveyor belts, medical materials and the like. However, with the increasing requirements of modern industry on the performance of materials, the tensile strength and aging resistance of traditional natural rubber are difficult to meet the high-strength requirements. Although the use of conventional fillers for modifying natural rubber can partially improve the mechanical properties, it may increase the processing energy consumption and has certain limitations. Therefore, how to avoid this phenomenon is the key to solving the problem. Patent application CN117247478A discloses a safe and environmentally friendly natural rubber and a preparation method thereof. The natural rubber has no damage to the environment, no corrosion to the equipment, and low influence on human health, but the aging resistance needs to be improved. SUMMARY

[0003] TECHNICAL PROBLEM In view of the deficiencies of the prior art, the application provides a high-performance natural rubber containing modified silica sol and a preparation method thereof. The natural rubber has good mechanical properties and aging resistance.

[0004] TECHNICAL SCHEME

[0005] In order to solve the above problems, the technical scheme adopted by the application is as follows: The preparation method of the high-performance natural rubber containing modified silica sol comprises the following steps: (1) Preparation of modified silica sol; (2) Preparation of modified vanillin; (3) The natural rubber is placed in an open mill for plasticizing for 10-12 min, and then the modified silica sol, modified vanillin, stearic acid, vulcanization accelerator CZ, zinc oxide, carbon black, sulfur powder and antioxidant 4010 are added to the natural rubber, mixed uniformly, and then placed for 24-28 h. Under the conditions of 140-160 DEG C and 18-20 MPa, the flat plate vulcanizing machine is used for vulcanization molding to obtain the high-performance natural rubber containing modified silica sol.

[0006] Further, the preparation method of the modified silica sol in the step (1) is as follows: Step one: under the protection of nitrogen gas, dissolve gallic acid in N,N- dimethylformamide solvent, then add 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride, N-hydroxysuccinimide, and stir magnetically for 0.5-1 h to react, then add p-phenylenediamine to the reaction system, and react at 30-40℃ in the dark for 4-6 h. After the reaction is completed, wash and dry, purify to obtain intermediate 1; Step two: add silica sol, deionized water, ammonia, and anhydrous ethanol to the reactor, stir in a 20-25℃ circulating water bath for 30-40 min, then slowly drop γ-glycidyl ether oxypropyl trimethoxysilane into it, continue to stir for 3-5 h, then centrifuge, filter, wash and dry to obtain intermediate 2 after the reaction is completed. Step three: add intermediate 1 and intermediate 2 to N,N-dimethylformamide solvent, mix well, then add triethylamine, and react at 40-60℃ for 12-16 h. After the reaction is completed, centrifuge, wash and dry to obtain modified silica sol.

[0007] Further, the amount ratio of gallic acid, N,N-dimethylformamide, 1-(3- dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride, N-hydroxysuccinimide, and p-phenylenediamine in step one is 2.06-2.1 g:40-45 mL:2.3-2.34 g:1.38-1.42 g:0.6-0.64 g.

[0008] Further, the amount ratio of silica sol, deionized water, ammonia, anhydrous ethanol, and γ-glycidyl ether oxypropyl trimethoxysilane in step two is 30-30.5 g:30-32 g:45-48 mL:70-73 g:0.46-0.5 g.

[0009] Further, the amount ratio of N,N-dimethylformamide, intermediate 1, intermediate 2, and triethylamine in step three is 25-30 mL:1.44-1.48 g:2.12-2.16 g:0.02-0.03 g.

[0010] Further, the preparation method of modified vanillin in step (2) is: add vanillin and 2-amino-1,3,4-thiadiazole to ethanol solvent, stir and mix, reflux at 70-80℃ for 8-12 h, then filter, wash and dry after the reaction is completed, and purify to obtain modified vanillin.

[0011] Further, the amount ratio of ethanol, vanillin, and 2-amino-1,3,4-thiadiazole is 30-40 mL:3.04-3.08 g:2.02-2.06 g.

[0012] Further, the weight parts of each component in the (3) step are: 45-50 parts of natural rubber, 3-5 parts of modified silica sol, 1-3 parts of modified vanillin, 1-2 parts of stearic acid, 0.8-1.5 parts of vulcanization accelerator CZ, 2-4 parts of zinc oxide, 5-8 parts of carbon black, 1-2 parts of sulfur powder, and 0.5-0.8 parts of antioxidant 4010.

[0013] The application also protects a high-performance natural rubber containing modified silica sol, which is prepared by the preparation method described in any one of the above.

[0014] Beneficial technical effects Compared with the prior art, the beneficial effects of the application are: (1) The intermediate 1 is obtained by the reaction of gallic acid and p-phenylenediamine, and then grafted to the surface of the silica sol, which improves the compatibility of the silica sol and the natural rubber, makes the dispersion more uniform, can form a stronger interfacial interaction with the rubber matrix, significantly improves the mechanical properties of the rubber, and effectively prevents the migration and volatilization of the small molecule antioxidant due to the firm grafting of the gallic acid part and the p-phenylenediamine part on the surface of the filler, and synergistically plays a heat-resistant and aging-resistant role, so that the aging resistance of the natural rubber is improved; the Schiff base group can participate in the vulcanization crosslinking reaction to form a covalent bond network, improve the crosslinking density, and enhance the mechanical properties of the natural rubber, and the Schiff base structure itself, the phenolic hydroxyl group and the sulfur atom in the thiadiazole ring can capture free radicals to inhibit the oxidative chain reaction, further improving the aging resistance of the natural rubber.

[0015] (2) The high-performance natural rubber containing modified silica sol of the application is obtained by the preparation method of the application, and has all the beneficial effects of the preparation method of the application. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the reaction synthesis formula of intermediate 1.

[0017] Figure 2 is the reaction synthesis formula of modified vanillin. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application is described clearly and completely. Obviously, the described embodiments are part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0019] For better understanding of the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings and specific embodiments of the specification.

[0020] The reagents used in the following specific embodiments are analytical pure, and the other reagents are industrial grade. Silica sol: density 1.29 g·cm -3 , average particle size 60 nm, pH about 8, solid mass fraction 40%, specific surface area 200 m 2 ·g -1 , manufacturer Shanghai Maikelin Biochemical Technology Co., Ltd.; Natural rubber: SCR-WF brand, manufacturer Hainan Natural Rubber Industry Group Co., Ltd.; Vulcanization accelerator CZ: industrial grade, manufacturer Shandong Shangshun Chemical Co., Ltd.; Carbon black: N330 brand, industrial grade, manufacturer Runfa Chemical Technology Co., Ltd.; Sulfur powder: industrial grade, manufacturer Hebei Jingxian Brothers Chemical Co., Ltd.; Antioxidant 4010: industrial grade, manufacturer Ningbo Aikemu New Material Co., Ltd.

[0021] Example 1 The present embodiment provides a high-performance natural rubber containing modified silica sol, and the preparation method specifically includes the following steps: (1) Under the protection of nitrogen gas, 2.06 g of gallic acid was dissolved in 40 mL of N,N-dimethylformamide solvent, and then 2.3 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.38 g of N-hydroxysuccinimide were added. Stirring for 0.5 h, then add 0.6 g of p-phenylenediamine to the reaction system, and react at 30°C for 4 h in the dark. After the reaction was completed, it was washed and dried, and then purified to obtain intermediate 1; (2) Add 30 g of silica sol, 30 g of deionized water, 45 mL of ammonia water, and 70 g of anhydrous ethanol to the reactor, and stir in a 20°C circulating water bath for 30 min. Then slowly drop 0.46 g of γ-glycidyl ether propyltrimethoxysilane into it, and continue to stir for 3 h. After the reaction was completed, centrifugation, suction filtration, washing and drying were performed to obtain intermediate 2; (3) Add 1.44 g of intermediate 1 and 2.12 g of intermediate 2 to 25 mL of N,N-dimethylformamide solvent, mix well, then add 0.02 g of triethylamine, and react at 40°C for 12 h. After the reaction was completed, centrifugation, washing and drying were performed to obtain modified silica sol; (4) 3.04 g of vanillin, 2.02 g of 2-amino-1,3,4-thiadiazole were added into 30 mL of ethanol solvent, the mixture was stirred and refluxed at 70°C for 8 h, after the reaction was completed, the product was filtered, washed and dried, and then purified to obtain modified vanillin; (5) 45 parts by weight of natural rubber was put into an open mill for plasticizing for 10 min, then 3 parts by weight of modified silica sol, 1 part by weight of modified vanillin, 1 part by weight of stearic acid, 0.8 part by weight of vulcanization accelerator CZ, 2 parts by weight of zinc oxide, 5 parts by weight of carbon black, 1 part by weight of sulfur powder and 0.5 part by weight of antioxidant 4010 were added into the natural rubber, and the mixture was uniformly mixed, then was placed for 24 h, and then was vulcanized and formed into high-performance natural rubber containing modified silica sol by using a flat vulcanizing machine under the conditions of 140°C and 18 MPa.

[0022] Example 2 The present embodiment provides a kind of high-performance natural rubber containing modified silica sol, and its preparation method specifically includes the following steps: (1) under the protection of nitrogen gas, 2.1 g of gallic acid was dissolved in 45 mL of N,N-dimethylformamide solvent, then 2.34 g of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride and 1.42 g of N-hydroxysuccinimide were added, and the mixture was stirred magnetically for 1 h to react, then 0.64 g of p-phenylenediamine was added to the reaction system, and the mixture was reacted at 40°C for 6 h in the dark, after the reaction was completed, the product was washed and dried, and then purified to obtain intermediate 1; (2) 30.5 g of silica sol, 32 g of deionized water, 48 mL of ammonia water and 73 g of anhydrous ethanol were added into a reactor, and the mixture was stirred in a 25°C circulating water bath for 40 min, then 0.5 g of γ-glycidyl ether propyltrimethoxysilane was slowly added dropwise, and the mixture was continuously stirred for 5 h, after the reaction was completed, the product was centrifuged, filtered, washed and dried to obtain intermediate 2; (3) 1.48 g of intermediate 1 and 2.16 g of intermediate 2 were added into 30 mL of N,N-dimethylformamide solvent, and the mixture was uniformly mixed, then 0.03 g of triethylamine was added, and the mixture was reacted at 60°C for 16 h, after the reaction was completed, the product was centrifuged, washed and dried to obtain modified silica sol; (4) 3.08 g of vanillin and 2.06 g of 2-amino-1,3,4-thiadiazole were added into 40 mL of ethanol solvent, the mixture was stirred and refluxed at 80°C for 12 h, after the reaction was completed, the product was filtered, washed and dried, and then purified to obtain modified vanillin; (5) 50 parts by weight of natural rubber was put into an open mill for plasticizing for 12 min, then 5 parts by weight of modified silica sol, 3 parts by weight of modified vanillin, 2 parts by weight of stearic acid, 1.5 parts by weight of vulcanization accelerator CZ, 4 parts by weight of zinc oxide, 8 parts by weight of carbon black, 2 parts by weight of sulfur powder, and 0.8 parts by weight of antioxidant 4010 were added into the natural rubber and mixed uniformly, and then the mixture was left to stand for 28 h, and then the mixture was vulcanized and formed into high-performance natural rubber containing modified silica sol by using a flat vulcanizing machine under the conditions of 160°C and 20 MPa.

[0023] Example 3 The present embodiment provides a kind of high-performance natural rubber containing modified silica sol, and its preparation method specifically includes the following steps: (1) under the protection of nitrogen gas, 2.08 g of gallic acid is dissolved in 42 mL of N,N-dimethylformamide solvent, then 2.32 g of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride and 1.4 g of N-hydroxysuccinimide are added, and the reaction is carried out by magnetic stirring for 0.75 h, then 0.62 g of p-phenylenediamine is added to the reaction system, and the reaction is carried out at 35°C for 5 h in the dark, after the reaction is completed, washing and drying, purification, to obtain intermediate 1; (2) 30.2 g of silica sol, 31 g of deionized water, 46 mL of ammonia water and 72 g of anhydrous ethanol are added to a reactor, stirred in a 22°C circulating water bath for 35 min, then 0.48 g of γ-glycidyl ether propyltrimethoxysilane is slowly added dropwise, and the reaction is continued for 4 h, after the reaction is completed, centrifugation, suction filtration, washing and drying, to obtain intermediate 2; (3) 1.46 g of intermediate 1 and 2.14 g of intermediate 2 are added to 28 mL of N,N-dimethylformamide solvent and mixed uniformly, then 0.02 g of triethylamine is added, and the reaction is carried out at 50°C for 14 h, after the reaction is completed, centrifugation, washing and drying, to obtain modified silica sol; (4) 3.06 g of vanillin and 2.04 g of 2-amino-1,3,4-thiadiazole are added to 35 mL of ethanol solvent and stirred and mixed, and the reaction is carried out at 75°C for 10 h, after the reaction is completed, filtration, washing and drying, purification, to obtain modified vanillin; (5) 48 parts by weight of natural rubber was put into an open mill for plasticizing for 11 min, then 4 parts by weight of modified silica sol, 2 parts by weight of modified vanillin, 1.5 parts by weight of stearic acid, 1 part by weight of vulcanization accelerator CZ, 3 parts by weight of zinc oxide, 6 parts by weight of carbon black, 1.5 parts by weight of sulfur powder, and 0.6 parts by weight of antioxidant 4010 were added into the natural rubber, and mixed uniformly, and then, after standing for 26 h, the mixture was vulcanized and formed into high-performance natural rubber containing modified silica sol by using a flat vulcanizing machine under the conditions of 150°C and 19 MPa.

[0024] Example 4 The present embodiment provides a kind of high-performance natural rubber containing modified silica sol, and its preparation method specifically includes the following steps: (1) under the protection of nitrogen gas, 2.07 g of gallic acid is dissolved in 41 mL of N,N-dimethylformamide solvent, then 2.31 g of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride and 1.39 g of N-hydroxysuccinimide are added, and the reaction is stirred magnetically for 0.6 h, then 0.61 g of p-phenylenediamine is added to the reaction system, and the reaction is carried out at 33°C for 4 h in the dark, after the reaction is completed, washing and drying, purification, to obtain intermediate 1; (2) 30.1 g of silica sol, 30.5 g of deionized water, 46 mL of ammonia water and 71 g of anhydrous ethanol are added to the reactor, stirred in a 21°C circulating water bath for 32 min, then 0.47 g of γ-glycidyl ether propyltrimethoxysilane is slowly added dropwise, and the stirring reaction is continued for 3 h, after the reaction is completed, centrifugation, suction filtration, washing and drying, to obtain intermediate 2; (3) 1.45 g of intermediate 1 and 2.13 g of intermediate 2 are added to 26 mL of N,N-dimethylformamide solvent, mixed uniformly, then 0.02 g of triethylamine is added, and the reaction is carried out at 45°C for 13 h, after the reaction is completed, centrifugation, washing and drying, to obtain modified silica sol; (4) 3.05 g of vanillin and 2.03 g of 2-amino-1,3,4-thiadiazole are added to 32 mL of ethanol solvent, stirred and mixed, and the reaction is carried out at 72°C for 9 h, after the reaction is completed, filtration, washing and drying, purification, to obtain modified vanillin; (5) 46 parts by weight of natural rubber was put into an open mill for plasticizing for 10 minutes, then 3 parts by weight of modified silica sol, 2 parts by weight of modified vanillin, 1 part by weight of stearic acid, 0.9 parts by weight of vulcanization accelerator CZ, 2 parts by weight of zinc oxide, 6 parts by weight of carbon black, 1 part by weight of sulfur powder, and 0.6 parts by weight of antioxidant 4010 were added into the natural rubber, and mixed uniformly. After standing for 25 hours, the mixture was vulcanized and formed into high-performance natural rubber containing modified silica sol by using a flat vulcanizing machine under the conditions of 145°C and 18 MPa.

[0025] Example 5 The present embodiment provides a kind of high-performance natural rubber containing modified silica sol, and its preparation method specifically includes the following steps: (1) under the protection of nitrogen gas, 2.09 g of gallic acid is dissolved in 44 mL of N,N-dimethylformamide solvent, then 2.33 g of 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride, 1.41 g of N-hydroxysuccinimide are added, and the reaction is carried out by magnetic stirring for 0.8 h, then 0.63 g of p-phenylenediamine is added to the reaction system, and the reaction is carried out at 38°C for 6 h in the dark. After the reaction is completed, it is washed and dried, purified to obtain intermediate 1; (2) 30.4 g of silica sol, 31.5 g of deionized water, 47 mL of ammonia water, 72 g of anhydrous ethanol are added to the reactor, stirred in a 24°C circulating water bath for 38 min, then 0.49 g of γ-glycidyl ether propyltrimethoxysilane is slowly added dropwise, and the stirring reaction is continued for 5 h. After the reaction is completed, centrifugation, suction filtration, washing and drying are carried out to obtain intermediate 2; (3) 1.47 g of intermediate 1, 2.15 g of intermediate 2 are added to 29 mL of N,N-dimethylformamide solvent, mixed uniformly, then 0.03 g of triethylamine is added, and the reaction is carried out at 55°C for 15 h. After the reaction is completed, centrifugation, washing and drying are carried out to obtain modified silica sol; (4) 3.07 g of vanillin, 2.05 g of 2-amino-1,3,4-thiadiazole are added to 38 mL of ethanol solvent, stirred and mixed, and the reaction is carried out at 78°C under reflux for 11 h. After the reaction is completed, filtration, washing and drying are carried out, and purification is carried out to obtain modified vanillin; (5) 49 parts by weight of natural rubber was put into an open mill for plasticizing for 12 min, then 5 parts by weight of modified silica sol, 3 parts by weight of modified vanillin, 2 parts by weight of stearic acid, 1.2 parts by weight of vulcanization accelerator CZ, 4 parts by weight of zinc oxide, 7 parts by weight of carbon black, 2 parts by weight of sulfur powder, 0.7 parts by weight of antioxidant 4010 were added into the natural rubber, and mixed uniformly. After standing for 27 h, the flat vulcanizing machine was used for vulcanization molding under the condition of 155 ℃ and 20 MPa, and high-performance natural rubber containing modified silica sol was obtained.

[0026] Comparative Example 1 The high-performance natural rubber containing modified silica sol of the present comparative example 1 and example 1 had basically the same proportion, and the main difference was that gallic acid was used instead of intermediate 1.

[0027] Comparative Example 2 The high-performance natural rubber containing modified silica sol of the present comparative example 1 and example 1 had basically the same proportion, and the main difference was that vanillin was used instead of modified vanillin.

[0028] Comparative Example 3 The high-performance natural rubber containing modified silica sol of the present comparative example 1 and example 1 had basically the same proportion, and the main difference was that the plasticizing time in step (5) was 5 min.

[0029] Comparative Example 4 The high-performance natural rubber containing modified silica sol of the present comparative example 1 and example 1 had basically the same proportion, and the main difference was that the standing time in step (5) was 12 h.

[0030] Performance test: The high-performance natural rubber prepared in examples 1-5 and comparative examples 1-4 was subjected to performance test.

[0031] The tensile strength and elongation at break were tested according to GB / T528-2009, the tear strength was tested according to GB / T529-2008, and the compression fatigue temperature rise was tested according to GB / T1687.3-2016. The test results are shown in Table 1.

[0032] Table 1: Performance test Item Tensile strength (MPa) Elongation at break (%) Tear strength (MPa) Compression fatigue temperature rise (°C) Example 1 30.5 813.8 64.9 24.2 Example 2 31.8 815.4 65.3 25.0 Example 3 31.2 814.3 65.0 24.7 Example 4 30.9 814.1 65.0 24.5 Example 5 31.6 815.0 65.2 24.9 Comparative Example 1 27.4 771.8 58.7 31.2 Comparative Example 2 28.3 782.4 60.4 30.1 Comparative Example 3 26.0 752.6 55.1 35.6 Comparative Example 4 25.9 750.8 55.0 33.7 As can be seen from Table 1, the high-performance natural rubber prepared in Examples 1-5 has good mechanical properties and aging resistance. In Comparative Example 1, the lack of flexible spacer chain and stronger intermolecular force provided by the p-phenylenediamine structure results in a decrease in mechanical properties, and the antioxidant capacity mainly depends on the phenolic hydroxyl group of gallic acid without the synergy of p-phenylenediamine, and the compression fatigue temperature rise is greater than that of the examples; in Comparative Example 2, the Schiff base structure is lacking, and the small molecule vanillin is easy to volatilize and migrate, but due to the presence of modified silica sol, the mechanical properties decrease slightly, the compression fatigue temperature rise increases but does not exceed that of Comparative Example 1; in Comparative Example 3, due to insufficient plastication, the rubber and filler are difficult to disperse, there are many internal defects, and the dynamic heat generation is the most serious, so the mechanical properties decrease significantly, and the compression fatigue temperature rise increases significantly; in Comparative Example 4, the standing time is insufficient, and the fillers and additives are not fully dispersed and form stable structures, resulting in unstable dynamic performance, high heat generation, and a significant decrease in mechanical properties, and the compression fatigue temperature rise increases significantly but is lower than that of Comparative Example 3.

[0033] It should be noted that in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles, or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles, or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or device that includes the element.

[0034] The above examples are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

[0035] Those skilled in the art should understand that the above only describes some specific embodiments of the present application, not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications and improvements that do not exceed the scope of the claims should be considered as the protection scope of the present application.

Claims

1. A method for preparing a high performance natural rubber containing modified silica sol, characterized by, It comprises the following steps: (1) Preparation of modified silica sol; (2) Preparation of modified vanillin; (3) Put the natural rubber into the open mill for plastication for 10-12 min, then add the modified silica sol, modified vanillin, stearic acid, vulcanization accelerator CZ, zinc oxide, carbon black, sulfur powder and antioxidant 4010 into the natural rubber, mix uniformly, stand for 24-28 h, then use the flat vulcanizing machine to vulcanize and form under the condition of 140-160 ℃ and 18-20 MPa, to obtain the high-performance natural rubber containing modified silica sol.

2. The method for preparing high performance natural rubber containing modified silica sol according to claim 1, characterized in that, The preparation method of the modified silica sol in the step (1) is as follows: Step one: under the protection of nitrogen gas, dissolve the gallic acid in N,N-dimethylformamide solvent, then add 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride and N-hydroxysuccinimide into it, magnetically stir for 0.5-1 h to make it react, then add p-phenylenediamine into the reaction system, react under light shielding at 30-40 ℃ for 4-6 h, after the reaction is completed, wash and dry, purify to obtain intermediate 1; Step two: add silica sol, deionized water, ammonia water and anhydrous ethanol into the reactor, stir in the 20-25 ℃ circulating water bath for 30-40 min, then slowly drop γ-glycidyl ether oxypropyl trimethoxysilane into it, continue to stir for 3-5 h, after the reaction is completed, centrifuge, suction filter, wash and dry to obtain intermediate 2; Step three: add intermediate 1 and intermediate 2 into N,N-dimethylformamide solvent, mix uniformly, then add triethylamine, react at 40-60 ℃ for 12-16 h, after the reaction is completed, centrifuge, wash and dry to obtain the modified silica sol.

3. The method for preparing high performance natural rubber containing modified silica sol according to claim 2, characterized in that, The dosage ratio of gallic acid, N,N-dimethylformamide, 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride, N-hydroxysuccinimide and p-phenylenediamine in the step one is 2.06-2.1 g:40-45 mL:2.3-2.34 g:1.38-1.42 g:0.6-0.64 g.

4. The method for preparing high performance natural rubber containing modified silica sol according to claim 2, characterized in that, The dosage ratio of silica sol, deionized water, ammonia water, anhydrous ethanol and γ-glycidyl ether oxypropyl trimethoxysilane in the step two is 30-30.5 g:30-32 g:45-48 mL:70-73 g:0.46-0.5 g.

5. The method for preparing high performance natural rubber containing modified silica sol according to claim 2, characterized in that, The dosage ratio of N,N-dimethylformamide, intermediate 1, intermediate 2 and triethylamine in the step three is 25-30 mL:1.44-1.48 g:2.12-2.16 g:0.02-0.03 g.

6. The method for preparing high-performance natural rubber containing modified silica sol according to claim 1, characterized in that, The preparation method of the modified vanillin in the step (2) is as follows: add vanillin and 2-amino-1,3,4-thiadiazole into ethanol solvent, stir and mix, reflux react at 70-80 ℃ for 8-12 h, after the reaction is completed, filter, wash and dry, purify to obtain the modified vanillin.

7. The method for preparing a high performance natural rubber containing modified silica sol according to claim 6, characterized by, The dosage ratio of ethanol, vanillin and 2-amino-1,3,4-thiadiazole is 30-40 mL:3.04-3.08 g:2.02-2.06 g.

8. The method for preparing high-performance natural rubber containing modified silica sol according to claim 1, characterized in that, The weight parts of the components in the step (3) are: 45-50 parts of natural rubber, 3-5 parts of modified silica sol, 1-3 parts of modified vanillin, 1-2 parts of stearic acid, 0.8-1.5 parts of vulcanization accelerator CZ, 2-4 parts of zinc oxide, 5-8 parts of carbon black, 1-2 parts of sulfur powder, 0.5-0.8 parts of antioxidant 4010.

9. A high performance natural rubber containing modified silica sol, characterized in that, Prepared by the preparation method according to any one of claims 1-8.

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