Sulfur-modified graphene / carbon black composite material, preparation method and application thereof

Abstract

The application discloses a sulfur-modified graphene / carbon black composite material and a preparation method thereof. The composite material comprises graphene, sulfur and carbon black, and the sulfur is connected with the graphene through a C-S bond. The sulfur-modified graphene / carbon black composite material of the application comprises a C-S covalent bond, improves the graphene and rubber matrix interface interaction, and simultaneously, due to the presence of the carbon black, the dispersion of the graphene in the rubber is promoted. The sulfur-modified graphene / carbon black composite material of the application can finally be added to the rubber in the form of powder, and can realize uniform dispersion in the rubber, without changing the production process of the existing tire industry, and has great advantages in industrialization.

Description

Technical Field

[0001] This invention belongs to the field of preparation and application technology of nanocomposite materials, and particularly relates to a sulfur-modified graphene / carbon black composite material for tire reinforcement, its preparation method and application. Background Technology

[0002] Graphene, a two-dimensional carbon nanomaterial with a thickness of only one atom layer, possesses an ultra-high specific surface area and excellent electrical, mechanical, thermal, and optical properties, demonstrating enormous application potential in the field of nano-reinforcement. Theoretical studies have proven that adding a small amount of graphene to tires will greatly improve their overall performance. It can not only reduce tire weight by replacing traditional carbon black, but also leverage its own properties to endow tires with high strength, high wear resistance, low heat generation, and strong grip.

[0003] Due to the strong interlayer interactions of graphene, direct addition will cause aggregation in rubber, preventing it from exerting its excellent properties. Furthermore, the lack of active functional groups on the graphene surface results in only weak interactions with rubber molecular chains, hindering effective stress transfer and creating stress concentration points in the rubber, leading to significant stress defects and reduced or even absent reinforcement effects. Therefore, inventing a simple and feasible method that can both increase the interaction between graphene and rubber and improve the dispersion of graphene in rubber is of significant practical importance.

[0004] Chinese Patent 202210610940.7 discloses a one-step method for reducing and modifying graphene oxide to form a controllable crosslinked natural rubber and its preparation. The method utilizes a water-soluble sulfide to reduce and modify graphene oxide in one step, obtaining sulfide-modified reduced graphene oxide. This dispersion is then added to natural rubber latex, and a graphene masterbatch is obtained using an aqueous phase synergistic precipitation process. Finally, a controllable crosslinked graphene / natural rubber composite material is prepared, with sulfides loaded on reduced graphene oxide as the main crosslinking points. By increasing the crosslinking density and the binder content of the composite material, the thermal conductivity, mechanical properties, and wear resistance of the natural rubber products are improved. Furthermore, Chinese patent 202210075239.X discloses a chemical in-situ deposition process for preparing vulcanizing agent-modified graphene and its controllable crosslinked natural rubber composite material. First, graphene oxide is coated on the surface of spherical thermally conductive functional particles, and then the vulcanizing agent is adsorbed on the graphene surface to obtain vulcanizing agent-modified three-dimensional graphene particles. These particles are then added to natural rubber latex, and graphene masterbatch is prepared using an aqueous phase synergistic precipitation process. Finally, a controllable crosslinked graphene-modified natural rubber composite material with excellent performance is obtained, using the vulcanizing agent loaded on graphene as the crosslinking point. By controlling the crosslinking density and crosslinking point position of the composite material, the heat generation, thermal conductivity, and mechanical properties of natural rubber products are improved, and the service life of natural rubber products is extended. The aforementioned patents all improve the interfacial interaction between graphene and natural rubber molecules through controlled crosslinking, thereby improving various properties of natural rubber products. However, in order to ensure the uniform dispersion of graphene, they all employ a complex aqueous phase co-flocculation process, involving a series of treatments such as flocculation, washing, dewatering, and drying, which is not easy to promote and implement in large-scale tire production processes. Summary of the Invention

[0005] To address the aforementioned technical deficiencies, this invention provides a sulfur-modified graphene / carbon black composite material, its preparation method, and its application. The aim is to improve the interfacial interaction between graphene and rubber in tires, as well as the dispersion of graphene in rubber, thereby fully leveraging the reinforcing effect of graphene on rubber. This results in a sulfur-modified graphene / carbon black composite material and a high-strength, high-wear-resistant, and low-heat-generating tire rubber.

[0006] This invention provides a sulfur-modified graphene / carbon black composite material, comprising graphene, sulfur, and carbon black, wherein the sulfur is connected to the graphene via CS bonds.

[0007] According to one embodiment of the present invention, the mass ratio of graphene, sulfur and carbon black is 1:0.2 to 4.2:0.1 to 10; preferably, 1:0.2 to 1.7:0.5 to 3.

[0008] According to another embodiment of the present invention, the graphene has a size of less than 3 μm, and the carbon black has a particle size of 20–30 nm.

[0009] The present invention also provides a method for preparing the above-mentioned composite material, comprising: S1: adding carbon black and graphene oxide to deionized water respectively, and dispersing them to obtain a carbon black aqueous dispersion and a graphene oxide aqueous dispersion; S2: adding the carbon black aqueous dispersion to the graphene oxide aqueous dispersion, and mixing to obtain a graphene oxide / carbon black aqueous dispersion; S3: adding a thiourea solution to the graphene oxide / carbon black aqueous dispersion, and after reaction, filtration, washing with water, and drying, obtaining a sulfur-modified graphene / carbon black composite material.

[0010] According to one embodiment of the present invention, the dispersion in step S1 and / or the mixing in step S2 includes one or more of high-speed stirring, high-speed shear emulsification, ultrasonication, ball milling, and homogenization; preferably, the dispersion method of graphene oxide in step S1 is high-speed stirring followed by ultrasonication, the dispersion method of carbon black in step S1 is high-speed stirring followed by high-speed shear emulsification, and the mixing method of step S2 is high-speed stirring followed by ultrasonication and finally homogenization.

[0011] According to another embodiment of the present invention, the high-speed stirring speed is 600-1000 rpm, the high-speed shear emulsification shear rate is 8000-18000 rpm, the ultrasonic power is 800-1600 W and the frequency is 20-40 kHz, and the homogenization pressure is 500-1500 bar.

[0012] According to another embodiment of the present invention, in step S3, during the reaction process, mechanical external force is continuously used to promote full contact between thiourea molecules and graphene oxide. The mechanical external force includes one or more of high-speed stirring, ultrasound, and ball milling. Preferably, in step S3, the reaction is carried out under ultrasonic stirring, the reaction temperature is 20-100°C, and the reaction time is 0.5-48 h. The drying temperature is 50-120°C. More preferably, the reaction temperature is 80°C, the reaction time is 15 h, and the drying temperature is 105°C.

[0013] According to another embodiment of the present invention, the carbon black includes one or more of reinforcing carbon black, conductive carbon black, and pigment carbon black; preferably, the carbon black is water-based carbon black.

[0014] The present invention also provides a rubber comprising the above-mentioned sulfur-modified graphene / carbon black composite material.

[0015] The present invention further provides a method for preparing the above-mentioned rubber, wherein the above-mentioned sulfur-modified graphene / carbon black composite material powder is mixed evenly with the rubber.

[0016] The sulfur-modified graphene / carbon black composite material of this invention includes CS covalent bonds, which enhances the interfacial interaction between graphene and the rubber matrix. Simultaneously, the presence of carbon black promotes the dispersion of graphene in the rubber. This sulfur-modified graphene / carbon black composite material can ultimately be added to rubber in powder form and achieves uniform dispersion without altering existing tire industry production processes, offering significant advantages for industrialization. The preparation method of this invention first adsorbs carbon black particles onto the surface of graphene oxide, then uses thiourea as a sulfur source, utilizing the reaction between the oxygen-containing functional groups of graphene oxide and thiourea to form CS covalent bonds. The carbon black particles adsorbed on the graphene oxide surface, acting as a dispersant, serve as a commonly used reinforcing filler in tires, eliminating the influence of traditional graphene dispersants (surfactants, etc.) on the reinforcing effect. The preparation process of the sulfur-modified graphene / carbon black composite material is simple and can be completed using conventional equipment, which is beneficial for industrial production. Attached Figure Description

[0017] Figure 1 This is a SEM image of the sulfur-modified graphene / carbon black composite material prepared in Example 1.

[0018] Figure 2 This is a distribution diagram of sulfur in the sulfur-modified graphene / carbon black composite material prepared in Example 1.

[0019] Figure 3 The thermogravimetric analysis curves of the sulfur-modified graphene / carbon black composite material prepared in Example 1 are shown.

[0020] Figure 4 This is a SEM image of the rubber cross-section of the sulfur-modified graphene / carbon black composite material prepared in Example 1.

[0021] Figure 5 This is a schematic diagram of the crosslinking of the sulfur-modified graphene / carbon black composite material and the rubber molecular chain of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments.

[0023] The sulfur-modified graphene / carbon black composite material of the present invention comprises graphene, sulfur, and carbon black, wherein sulfur and graphene are linked by CS bonds. This enhances the interfacial interaction between graphene and the rubber matrix. Simultaneously, the presence of carbon black promotes the dispersion of graphene in the rubber. Carbon black particles, a commonly used reinforcing filler in tires, eliminate the influence of traditional graphene dispersants (surfactants, etc.) on the reinforcing effect. The sulfur-modified graphene / carbon black composite material of the present invention can ultimately be added to rubber in powder form and achieves uniform dispersion in the rubber without altering existing tire industry production processes, offering significant advantages for industrialization.

[0024] In an optional embodiment, the mass ratio of graphene, sulfur, and carbon black is 1:0.2–4.2:0.1–10. When the sulfur ratio is below 0.2, additional vulcanizing agent is required; when the sulfur ratio is above 4.2, it exceeds the sulfur content required in the vulcanization process, causing the rubber to harden. When the carbon black ratio is below 0.1, graphitization cannot be prevented during the drying process, thus affecting the uniformity of the composite material dispersion in the rubber; when the carbon black ratio is above 10, it will over-coat the graphene, preventing it from fully contacting and reacting with thiourea. More preferably, the mass ratio of graphene, sulfur, and carbon black is 1:0.2–1.7:0.5–3.

[0025] In an optional embodiment, the graphene is smaller than 3 μm in size, and the carbon black has a particle size of 20–30 nm. A graphene size larger than 3 μm will weaken the reinforcing effect on the rubber; smaller graphene sizes provide better reinforcement, and smaller-sized graphene is preferred.

[0026] The present invention also provides a method for preparing the above-mentioned composite material, comprising: S1: adding carbon black and graphene oxide to deionized water respectively, and dispersing them to obtain a carbon black aqueous dispersion and a graphene oxide aqueous dispersion; S2: adding the carbon black aqueous dispersion to the graphene oxide aqueous dispersion, and mixing to obtain a graphene oxide / carbon black aqueous dispersion; S3: adding a thiourea solution to the graphene oxide / carbon black aqueous dispersion, and after reaction, filtration, washing with water, and drying, obtaining a sulfur-modified graphene / carbon black composite material.

[0027] In optional embodiments, the dispersion in step S1 and / or the mixing in step S2 includes one or more of high-speed stirring, high-speed shear emulsification, ultrasonication, ball milling, and homogenization. Preferably, the dispersion method for graphene oxide in step S1 is high-speed stirring followed by ultrasonication. The dispersion method for carbon black in step S1 is high-speed stirring followed by high-speed shear emulsification. The mixing method in step S2 is high-speed stirring followed by ultrasonication, and finally homogenization.

[0028] In an optional embodiment, the high-speed stirring speed is 600-1000 rpm, the high-speed shear emulsification shear rate is 8000-18000 rpm, the ultrasonic power is 800-1600 W, the frequency is 20-40 kHz, and the homogenization pressure is 500-1500 bar.

[0029] In an optional embodiment, during step S3, mechanical force is continuously applied to ensure sufficient contact between thiourea molecules and graphene oxide during the reaction. This mechanical force includes one or more of high-speed stirring, ultrasound, and ball milling. Preferably, the reaction in step S3 is carried out under ultrasonic stirring at a temperature of 20–100°C for 0.5–48 h; the drying temperature is 50–120°C. More preferably, the reaction temperature is 80°C for 15 h; the drying temperature is 105°C.

[0030] In optional embodiments, the carbon black includes one or more of reinforcing carbon black, conductive carbon black, and pigment carbon black. Preferably, the carbon black is water-based carbon black.

[0031] The present invention also provides a rubber comprising the above-mentioned sulfur-modified graphene / carbon black composite material.

[0032] The present invention further provides a method for preparing the above-mentioned rubber, wherein the above-mentioned sulfur-modified graphene / carbon black composite material powder is mixed evenly with the rubber.

[0033] The present invention will be further described below through specific examples. However, these examples are merely exemplary and do not constitute any limitation on the scope of protection of the present invention.

[0034] Unless otherwise specified, all reagents, materials and instruments used in the following examples and comparative examples are commercially available.

[0035] Example 1

[0036] S1: Add graphene oxide (1 μm in size) to 500 mL of deionized water, stir at high speed for 10 min, and sonicate for 30 min to obtain a uniformly dispersed graphene oxide dispersion with a graphene oxide content of 5 mg / mL; add aqueous carbon black (30 nm in particle size) to 100 mL of deionized water, stir at high speed for 10 min, and emulsify at high speed for 45 min to obtain a uniformly dispersed aqueous carbon black dispersion with an aqueous carbon black content of 25 mg / mL.

[0037] S2: Add the aqueous carbon black dispersion to the graphene oxide dispersion, stir at high speed for 30 min, sonicate for 1 h, and homogenize at 1000 bar for 2 h to obtain the graphene oxide / carbon black aqueous dispersion.

[0038] S3: Transfer the graphene oxide / carbon black aqueous dispersion to a three-necked flask, and stir while sonicating. At the same time, add 10g of thiourea to 100mL of deionized water to dissolve and obtain a thiourea solution. Then add the thiourea solution to the graphene oxide / carbon black aqueous dispersion, heat to 80℃ in a water bath, react for 15h, filter, wash with water, and dry at 105℃ for 8h to obtain sulfur-modified graphene / carbon black composite material, denoted as S-GO / CB.

[0039] Example 2

[0040] The only adjustment was to the aqueous carbon black content in step S1 of Example 1, which was 2.5 mg / mL, while the other conditions remained the same as in Example 1.

[0041] Example 3

[0042] The only difference is that the mass of thiourea in step S3 of Example 1 is adjusted to 5g, while other conditions remain the same as in Example 1.

[0043] Example 4

[0044] The only adjustment was to the aqueous carbon black content in step S1 of Example 1, which was 250 mg / mL, while the other conditions remained the same as in Example 1.

[0045] Example 5

[0046] The only change was that the mass of thiourea in step S3 of Example 1 was 25g, and all other conditions were the same as in Example 1.

[0047] Example 6

[0048] The only difference is that the mass of thiourea in step S3 of Example 1 is adjusted to 1.25g, while other conditions remain the same as in Example 1.

[0049] Comparative Example 1

[0050] S1: Add graphene oxide to 500 mL of deionized water, stir at high speed for 10 min and sonicate for 30 min to obtain a uniformly dispersed graphene oxide dispersion with a graphene oxide content of 5 mg / mL; add waterborne carbon black to 100 mL of deionized water, stir at high speed for 10 min and emulsify at high speed for 45 min to obtain a uniformly dispersed waterborne carbon black dispersion with a waterborne carbon black content of 25 mg / mL.

[0051] S2: Transfer the aqueous dispersion of graphene oxide and the aqueous dispersion of aqueous carbon black to three-necked flasks respectively, and stir while sonicating. At the same time, add 10g of thiourea to 100mL of deionized water to dissolve and obtain a thiourea solution. Then, add 50mL of thiourea solution to the aqueous dispersion of graphene oxide and the aqueous dispersion of aqueous carbon black respectively, heat to 80℃ in a water bath, react for 15h, filter, wash with water, and dry at 105℃ for 8h to obtain sulfur-modified graphene and sulfur-modified carbon black, denoted as S-GO and S-CB respectively.

[0052] Comparative Example 2

[0053] S1: Add graphene oxide to 500 mL of deionized water, stir at high speed for 10 min and sonicate for 30 min to obtain a uniformly dispersed graphene oxide dispersion with a graphene oxide content of 5 mg / mL; add waterborne carbon black to 100 mL of deionized water, stir at high speed for 10 min and emulsify at high speed for 45 min to obtain a uniformly dispersed waterborne carbon black dispersion with a waterborne carbon black content of 25 mg / mL.

[0054] S2: Add the aqueous carbon black dispersion to the graphene oxide dispersion, stir at high speed for 30 min, sonicate for 1 h, and homogenize at 1000 bar for 2 h to obtain the graphene oxide / carbon black aqueous dispersion.

[0055] S3: Transfer the graphene oxide / carbon black aqueous dispersion to a three-necked flask, stir while sonicating, heat to 80°C in a water bath, react for 15 h, filter, wash with water, and dry at 105°C for 8 h to obtain the graphene oxide / carbon black composite material, denoted as GO / CB.

[0056] Experimental Example

[0057] The materials from Examples 1-3 and Comparative Examples 1-2 were added to the rubber matrix according to the formulation in Table 1 to obtain tire rubber.

[0058] Table 1 Formula Table

[0059]

[0060] Methods for preparing rubber:

[0061] (1) Add natural rubber and carbon black to the internal mixer according to the ratio. When the mixing temperature reaches 110°C, add zinc oxide, stearic acid, antioxidant RD, antioxidant 4020 and microcrystalline wax. When the mixing temperature reaches 150°C, discharge the rubber to obtain the masterbatch.

[0062] (2) Mix the masterbatch after internal mixing on a two-roll mill, with the roll temperature controlled at 50±5℃. After the rubber is piled up on the roll, add sulfur or S-GO / CB or S-GO+S-CB or sulfur+GO / CB, accelerator NS, anti-vulcanization agent PK900 and anti-scorching agent CTP. Mix evenly by two-sided three-cutting, triangular wrapping, rolling and other methods, and then remove from the roll to obtain the final rubber.

[0063] To fully demonstrate the reinforcing effect of sulfur-modified graphene / carbon black composites, the mechanical properties, compression heat generation, and abrasion properties of the rubber were further tested using the following methods:

[0064] Tensile strength: The testing standard was GB / T528-2009, and the equipment used was Instron 3365;

[0065] Tear strength: The testing standard is GB / T528-2009, and the equipment used is Instron 3365;

[0066] Compression heat generation: The testing standard is ASTM D623-07(2014), and the equipment used is Alpha Model II;

[0067] Akron wear: The testing standard is GB / T1689-2014, and the equipment used is Taiwan High Speed ​​Rail GT-7012-A.

[0068] The test results are shown in Table 2.

[0069] Table 2 Results of rubber performance tests

[0070]

[0071] As shown in Table 2, the mechanical properties of Examples 1-6 and Comparative Examples 1-2 are superior to the basic formulation. This indicates that graphene has a significant advantage in reinforcing rubber compared to traditional carbon black reinforcing agents, especially in Examples 1-6, where the mechanical properties are significantly improved. Further comparison between Example 1 and Comparative Example 1 reveals little difference in their mechanical properties. This is because the amount of graphene-reinforced filler added is only 1.5 parts, resulting in minimal agglomeration in the rubber. Nevertheless, it is evident that the carbon black adsorbed on the surface of graphene oxide does indeed facilitate the dispersion of graphene in the rubber during subsequent processes. Figure 1 SEM images of the microstructure of the S-GO / CB prepared in Example 1 show that carbon black particles adhere to the graphene surface, preventing the stacking of graphene sheets. Figure 2 EDS analysis of sulfur elements on the surface of the S-GO / CB prepared in Example 1 showed that sulfur was uniformly distributed on the surface of the graphene / carbon black composite material. Further thermogravimetric analysis (TGA) of the S-GO / CB prepared in Example 1 was performed using a simultaneous thermal analysis system. Figure 3 It can be seen that the sulfur content in S-GO / CB is 67%. This proves that the method of the present invention can effectively reduce thiourea and form sulfur on the graphene surface.

[0072] Depend on Figure 1 and Figure 2 Based on the photographs, it can be reasonably inferred that the carbon black on the surface of the composite material can promote the dispersion of graphene in the rubber, and the sulfur element on its surface will enhance the interfacial interaction between graphene and rubber by participating in vulcanization crosslinking, thus synergistically improving the reinforcing effect of graphene on rubber.

[0073] Further comparison of Example 1 and Comparative Example 2 shows that the sulfur-modified graphene / carbon black composite material exhibits a more significant reinforcing effect on rubber compared to the unmodified graphene / carbon black composite material. This is because the sulfur on the surface acts as a crosslinking point for the rubber molecular chains, increasing the interfacial interaction between graphene and rubber. Figure 4 It can be demonstrated that adding the S-GO / CB rubber composite material prepared in Example 1 can enhance the interfacial interaction between graphene and rubber. For example... Figure 4As shown in the figure, the cross-section of the above-mentioned rubber composite material after low-temperature brittle fracture is characterized by SEM. It can be seen from the figure that S-GO / CB and the rubber matrix are tightly bonded, and the surface shows the rubber that has been adsorbed. This indicates that its wrinkled topology and the sulfur element on the surface are conducive to improving the interfacial interaction between graphene and rubber. Figure 5 This is a schematic diagram illustrating the crosslinking of the sulfur-modified graphene / carbon black composite material with rubber molecular chains according to the present invention. Figure 5 Explain the mechanism by which this invention improves the reinforcing effect of composite materials on rubber. For example... Figure 5 As shown, sulfur on the surface of S-GO / CB serves as a crosslinking point for rubber molecular chains, successfully constructing a three-dimensional crosslinking network between graphene and rubber molecular chains. This network effectively transfers the stress on the rubber matrix to the graphene with excellent mechanical properties, thereby exhibiting a more significant reinforcing effect.

[0074] The addition of graphene significantly reduced the heat of compression in rubber. This is because graphene has a very large specific surface area, and a small amount of graphene can achieve the reinforcing effect of multiple parts of carbon black. Therefore, in this invention, 1 part of composite material replaced 5 parts of carbon black, effectively reducing the frictional heat of the reinforcing filler. Furthermore, since the reinforcing filler in Example 1 and Comparative Example 1 participated in the crosslinking of the rubber, increasing the confinement effect on the rubber molecular chains, the improvement in heat of compression was more significant in the former two examples compared to Comparative Example 2, which did not participate in crosslinking. This further illustrates that the strong interfacial interaction between the reinforcing filler and the rubber matrix, covalently bonded, is crucial for the reinforcing effect.

[0075] Similarly, when reinforcing fillers form a covalently cross-linked network with the rubber matrix, the interaction between them is stronger. More rubber molecular chains are confined to the filler surface, increasing the bound rubber content, improving the rubber's ability to resist crack growth, and reducing tread wear. Moreover, as the filler's dispersibility improves, the bound rubber content increases, further enhancing wear resistance. Therefore, designing reinforcing fillers to form a covalent bond with rubber molecular chains while simultaneously improving their dispersibility in the rubber matrix is ​​of great significance for manufacturing high-strength, high-wear-resistant, and low-heat-generating tires.

[0076] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A sulfur-modified graphene / carbon black composite material, characterized in that, It includes graphene, sulfur, and carbon black, wherein the sulfur is connected to the graphene via CS bonds; the mass ratio of the graphene, sulfur, and carbon black is 1:0.2~4.2:0.1~10; The preparation method of the sulfur-modified graphene / carbon black composite material includes: S1: Carbon black and graphene oxide are added to deionized water and dispersed to obtain carbon black aqueous dispersion and graphene oxide aqueous dispersion, respectively. S2: Add the carbon black aqueous dispersion to the graphene oxide aqueous dispersion and mix to obtain a graphene oxide / carbon black aqueous dispersion. S3: Add thiourea solution to the graphene oxide / carbon black aqueous dispersion, and obtain sulfur-modified graphene / carbon black composite material by reaction, filtration, washing with water and drying.

2. The composite material according to claim 1, characterized in that, The mass ratio of graphene, sulfur, and carbon black is 1:0.2~1.7:0.5~3.

3. The composite material according to claim 1, characterized in that, The graphene has a size of less than 3 μm, and the carbon black has a particle size of 20~30 nm.

4. A method for preparing the composite material according to any one of claims 1-3, characterized in that, include: S1: Carbon black and graphene oxide are added to deionized water and dispersed to obtain carbon black aqueous dispersion and graphene oxide aqueous dispersion, respectively. S2: Add the carbon black aqueous dispersion to the graphene oxide aqueous dispersion and mix to obtain a graphene oxide / carbon black aqueous dispersion. S3: Add thiourea solution to the graphene oxide / carbon black aqueous dispersion, and obtain sulfur-modified graphene / carbon black composite material by reaction, filtration, washing with water and drying.

5. The preparation method according to claim 4, characterized in that, The dispersion in step S1 and / or the mixing in step S2 include one or more of the following: high-speed stirring, high-speed shear emulsification, ultrasonication, ball milling, and homogenization.

6. The preparation method according to claim 5, characterized in that, The dispersion method of graphene oxide in step S1 is to first stir at high speed and then sonicate. The dispersion method of carbon black in step S1 is to first stir at high speed and then emulsify by high-speed shearing. The mixing method in step S2 is to first stir at high speed, then sonicate, and finally homogenize.

7. The preparation method according to claim 5, characterized in that, The high-speed stirring speed is 600~1000 rpm, the high-speed shear emulsification shear rate is 8000~18000 rpm, the ultrasonic power is 800~1600 W and the frequency is 20~40 kHz, and the homogenization pressure is 500~1500 bar.

8. The preparation method according to claim 4, characterized in that, In step S3, during the reaction process, mechanical external force is continuously used to promote full contact between thiourea molecules and graphene oxide. The mechanical external force includes one or more of high-speed stirring, ultrasound, and ball milling.

9. The preparation method according to claim 8, characterized in that, In step S3, the reaction is carried out under ultrasonic stirring at a temperature of 20-100 °C for a time of 0.5-48 h; the drying temperature is 50-120 °C.

10. The preparation method according to claim 9, characterized in that, The reaction temperature was 80 ℃, the reaction time was 15 h, and the drying temperature was 105 ℃.

11. The preparation method according to claim 4, characterized in that, The carbon black includes one or more of reinforcing carbon black, conductive carbon black, and pigment carbon black.

12. The preparation method according to claim 4, characterized in that, The carbon black is water-based carbon black.

13. A type of rubber, characterized in that, Including the sulfur-modified graphene / carbon black composite material according to any one of claims 1-3.

14. A method for preparing the rubber according to claim 13, characterized in that, The sulfur-modified graphene / carbon black composite material powder according to any one of claims 1-3 is mixed evenly with rubber.

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