A method for preparing modified graphene masterbatch

Abstract

The invention relates to the technical field of graphene materials, and discloses a method for preparing a modified graphene masterbatch, comprising: (1) dispersing graphene oxide in a solvent, ultrasonically dispersing, adjusting the pH value to 5-7, and obtaining a graphene oxide dispersion liquid; (2) adding a silane coupling agent solution to the graphene oxide dispersion liquid, heating and reacting, and obtaining a graphene oxide-coupling agent reaction liquid; (3) cooling the graphene oxide-coupling agent reaction liquid, adding a reducing agent to carry out a reduction reaction, and obtaining modified graphene, and then dispersing the modified graphene in a solvent to obtain a modified graphene dispersion liquid; (4) adding the modified graphene dispersion liquid to latex, adding a flocculant, and mixing and stirring until floccules are obtained to obtain a modified graphene masterbatch. The modified graphene masterbatch of the invention is easy to be evenly dispersed in rubber, has a strong interface effect with rubber, and the prepared rubber has excellent mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of graphene materials, and in particular to a method for preparing a modified graphene masterbatch. Background Art

[0002] Rubber used in aviation tires, heavy-duty tires and high-performance automobile tires is required to have high mechanical properties, wear resistance, aging resistance, low dynamic heat generation and good heat dissipation, etc. However, the rubber material itself has low strength, poor aging resistance and heat dissipation, and generally the performance of rubber is improved by adding reinforcing agents. Commonly used reinforcing agents are carbon black and white carbon black, among which carbon black is the earliest reinforcing filler used in tires, and has a good reinforcing effect on the mechanical, wear resistance, and aging resistance of tire rubber. However, when carbon black is used as a reinforcing filler, the three important properties of the tire: wear resistance, anti-slip and rolling resistance have a mutually restrictive relationship between them. These three properties are called the devil's triangle of tires. When silica and coupling agent are used as fillers and the load is low, the wear resistance of the tire can be increased, the dynamic heat generation of the tire can be reduced, and the tire can have good anti-skid properties. However, when subjected to high loads, the friction between the tire and the ground increases, and the heat generated increases. Since silica has poor thermal conductivity, the tire does not dissipate heat well, the temperature rises, and the wear increases significantly. Therefore, silica is not suitable for tires that bear high loads, such as aviation tires, load-bearing tires, etc.

[0003] Graphene is the strongest new material known, with a tensile strength of 125GPa, an elastic modulus of 1.1TPa, and a strength limit of 42N / m. 2 If graphene is used as a reinforcing filler, the mechanical properties such as tensile strength and tear strength of tire rubber and its wear resistance can be improved; the thermal conductivity of graphene at room temperature is 5300W / (m·K), so the addition of graphene can increase the thermal conductivity of rubber and reduce the compression heat generated by rubber; graphene has outstanding electrical conductivity, and its electron mobility can reach 150,000cm 2 / (v·s), is the electron mobility in single crystal silicon (1400cm 2 / (v·s)) is more than 100 times that of graphene, and the conductivity can reach 108S / m. The electron mobility is basically not affected by temperature. The addition of graphene can improve the conductivity of rubber, thereby enhancing the antistatic property of rubber; graphene can bind free radicals and has obvious barrier properties to air, which can improve the anti-aging property of rubber. It can be seen that graphene materials can improve the comprehensive performance of rubber and are suitable for aviation tires, heavy-load tires, etc.

[0004] However, graphene sheets contain a large number of π electrons, and there is a strong π-π interaction between the sheets. They are easy to agglomerate and difficult to disperse evenly in rubber. If graphene agglomerates in rubber, it will cause stress concentration and reduce the mechanical properties of rubber. The interaction between rubber molecules and graphene is mainly van der Waals force, and the interface effect is weak. When rubber is strained under stress, rubber molecules and graphene sheets slip. On the one hand, graphene cannot effectively bear the stress acting on the rubber matrix, and on the other hand, friction heat is generated, which increases the dynamic heat generation of rubber. Summary of the invention

[0005] In view of this, the present invention provides a method for preparing a modified graphene masterbatch to solve the technical problems that the existing graphene material is difficult to disperse in rubber and the interface effect between the rubber molecules and the graphene material is weak.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for preparing a modified graphene masterbatch comprises the following steps:

[0008] (1) dispersing graphene oxide in a solvent, performing ultrasonic dispersion, and adjusting the pH value to 5-7 to obtain a graphene oxide dispersion;

[0009] (2) adding a silane coupling agent solution to the graphene oxide dispersion, heating the dispersion to react, and obtaining a graphene oxide-coupling agent reaction solution;

[0010] (3) After cooling the graphene oxide-coupling agent reaction liquid, adding a reducing agent to carry out a reduction reaction to obtain modified graphene, and then dispersing the modified graphene in a solvent, stirring, and ultrasonicating to obtain a modified graphene dispersion;

[0011] (4) adding the modified graphene dispersion into latex, ultrasonicating, adding a flocculant and mixing and stirring until floccules are formed, washing, and drying to obtain a modified graphene masterbatch.

[0012] Preferably, in the above-mentioned method for preparing the modified graphene masterbatch, the specific surface area of ​​the graphene oxide in step (1) is 100-300 m 2 / g, the flake diameter is 2-20μm, and the oxygen content is 40%-60%.

[0013] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the solvent in step (1) is water and / or an organic solvent, and the organic solvent includes any one or more of tetrahydrofuran, dimethylformamide, dimethylacetamide, ethylene glycol, and N-methylpyrrolidone.

[0014] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the ultrasonic dispersion time in step (1) is 0.3-3h;

[0015] And / or before the ultrasonic dispersion, the method further comprises: adding alkali to adjust the pH value to 8-14, wherein the alkali comprises any one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, ammonia water, triethylamine, triethylenediamine, 4-dimethylaminopyridine, pyridine, and N-methylmorpholine.

[0016] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the concentration of the graphene oxide dispersion in step (1) is 100-5000 mg / L.

[0017] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the pH value is adjusted to 5-7 by adding acid after ultrasonic dispersion in step (1), and the acid includes any one or more of hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, benzoic acid, phthalic acid, citric acid, and terephthalic acid.

[0018] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the silane coupling agent solution is an ethanol solution of a silane coupling agent.

[0019] Preferably, in the above-mentioned method for preparing the modified graphene masterbatch, the general formula of the silane coupling agent in step (2) is Z-(CH2) m -[Si(X) a (Y) 3-a ] n ;

[0020] Where X is C1-C 18 Alkoxy or C5-C 18 a is an integer of 1 to 3, and Y is C1-C 18 Alkyl, C5-C 18 Cycloalkyl and C6-C 18 The aromatic group, m is an integer of 0-10, n is 1 or 2; Z includes any one or more of vinyl, alkylamino, amino, epoxy, mercapto, polysulfanyl, and acryloyloxy.

[0021] Preferably, in the method for preparing the modified graphene masterbatch, the mass ratio of the graphene oxide to the silane coupling agent is 1:(0.1-10).

[0022] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the reaction temperature of the heating reaction in step (2) is 30-100° C., and the reaction time is 1-10 h.

[0023] Preferably, in the method for preparing the modified graphene masterbatch, before the reduction reaction in step (3), the step further includes: cooling the graphene oxide-coupling agent reaction solution to below 40° C. and adjusting the pH value to 7-10.

[0024] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the reducing agent in step (3) includes any one or more of sodium citrate, glucose, ascorbic acid, sodium borohydride, hydrazine hydrate, hydroiodic acid, polyvinyl pyrrolidone, polyvinyl alcohol, ethylene glycol and formaldehyde.

[0025] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the reaction temperature of the reduction reaction in step (3) is 30°C-100°C, and the reaction time is 0.1h-10h.

[0026] Preferably, in the above-mentioned method for preparing the modified graphene masterbatch, step (3) also includes: cooling, filtering and washing the reaction liquid after the reduction reaction to obtain the modified graphene.

[0027] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the solvent in step (3) is water and / or an organic solvent, and the organic solvent includes any one or more of tetrahydrofuran, dimethylformamide, dimethylacetamide, ethylene glycol, N-methylpyrrolidone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and ethylene glycol monobutyl ether.

[0028] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the latex in step (4) includes natural latex and / or synthetic latex.

[0029] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the ultrasonic time in step (4) is 0-30 min, and the mixing and stirring time is 10-60 min.

[0030] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the flocculant in step (4) includes any one of sulfuric acid, acetic acid, calcium chloride, and dinitrile diamine formaldehyde condensate.

[0031] Preferably, in the above-mentioned method for preparing modified graphene masterbatch, the drying in step (4) is vacuum drying at 60°C.

[0032] The present invention also provides a modified graphene masterbatch, which is prepared by the above method.

[0033] The present invention also provides an application of a modified graphene masterbatch, wherein the modified graphene masterbatch is used as a tire rubber reinforcing filler; or the modified graphene masterbatch is mixed with a rubber matrix to prepare a tire rubber composition, wherein the tire rubber includes aviation tire rubber, heavy-load tire rubber, high-end car tire rubber, etc.

[0034] The present invention provides a modified graphene masterbatch, which has the following beneficial effects compared with the prior art:

[0035] The modified graphene masterbatch prepared by the method of the present invention is easy to be evenly dispersed in rubber and has a strong interface effect with the rubber. When the modified graphene masterbatch is used as a reinforcing filler for rubber, the prepared rubber has the characteristics of excellent mechanical properties, good wear resistance, low dynamic heat generation, strong aging resistance and antistatic properties, and is suitable for aircraft tires, heavy-load tires, high-performance automobile tires and other tires with high travel speed and high load bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 is the XRD pattern of graphene oxide and modified graphene in Example 1;

[0038] Figure 2 The figures are scanning electron microscope images of graphene materials and rubber; wherein, A: graphene; B: modified graphene prepared in Example 1; C: rubber without adding graphene material; D: rubber with modified graphene masterbatch prepared in Example 1 added. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The main purpose of the embodiment of the present invention is to prepare a modified graphene masterbatch that is easy to disperse evenly in rubber and has a strong interface effect with the rubber. The modified graphene masterbatch can significantly improve the mechanical, wear resistance, anti-aging, anti-static, heat dissipation and other properties of the rubber, and reduce the dynamic heat generation of the rubber. It is particularly suitable for tires with high travel speeds and high loads, such as aviation tires, heavy-load tires, high-performance automobile tires, etc.

[0041] The embodiment of the present invention provides a method for preparing a modified graphene masterbatch, which comprises the following steps:

[0042] (1) adjusting the pH value of the graphene oxide aqueous solution to 8-14, stirring to make it uniformly dispersed, ultrasonicating for 0.3-3 hours, and then adjusting the pH value to 5-7 to obtain a graphene oxide dispersion;

[0043] (2) preparing an ethanol solution of a silane coupling agent, adding the ethanol solution of the silane coupling agent to a graphene oxide dispersion under stirring, heating to a certain temperature for reaction, and obtaining a graphene oxide-coupling agent reaction solution;

[0044] (3) cooling the graphene oxide-coupling agent reaction liquid to below 40° C., adjusting the pH value to 7-10, then adding a reducing agent to the reaction liquid, heating to a certain temperature for reduction reaction, reacting for a certain time, cooling, filtering, washing, and obtaining modified graphene;

[0045] (4) dispersing the modified graphene in water or an organic solvent, stirring, and ultrasonicating to obtain a modified graphene dispersion; then adding the modified graphene dispersion to latex under stirring, adding a flocculant after ultrasonic mixing, continuing to mix and stir until floccules are formed, washing, and drying to obtain a modified graphene masterbatch.

[0046] In some embodiments of the present invention, adjusting the pH value to alkaline in step (1) comprises: adding a soluble base to the graphene oxide aqueous solution to adjust the pH value to a corresponding value, wherein the soluble base includes but is not limited to one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, ammonia water, triethylamine, triethylenediamine, 4-dimethylaminopyridine, pyridine, N-methylmorpholine, etc.;

[0047] Adjusting the pH value to acidic includes: adding a soluble acid to the graphene oxide solution after ultrasound so that the pH value reaches a corresponding value, and the soluble acid includes but is not limited to one or more of hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, malonic acid, succinic acid, benzoic acid, phthalic acid, citric acid, terephthalic acid, etc.

[0048] In some embodiments of the present invention, the concentration of graphene oxide in the graphene oxide dispersion is 100 mg / L-5000 mg / L, preferably 500 mg / L-3000 mg / L.

[0049] In some embodiments of the present invention, the general formula of the silane coupling agent is as follows: Z-(CH2) m -[Si(X) a (Y) 3-a ] n ;

[0050] Wherein, X is a C1-C18 alkoxy group or a C5-C18 cycloalkyloxy group, a is an integer of 1-3, Y is a C1-C18 alkyl group, a C5-C18 cycloalkyl group or a C6-C18 aryl group, m is an integer of 0-10, and n is 1 or 2; Z can be selected from one or more of vinyl, alkylamino, amino, epoxy, mercapto, polysulfanyl, acryloyloxy, etc.;

[0051] In some embodiments of the present invention, the mass ratio of graphene oxide to silane coupling agent is 1:(0.1-10); the reaction temperature is 30-100° C., and the reaction time is 1-10 h.

[0052] In some embodiments of the present invention, the reducing agent includes but is not limited to one or more of sodium citrate, glucose, ascorbic acid, sodium borohydride, hydrazine hydrate, hydroiodic acid, polyvinyl pyrrolidone, polyvinyl alcohol, ethylene glycol and formaldehyde; the temperature of the reduction reaction is 30°C-100°C, and the time of the reduction reaction is 0.1h-10h.

[0053] In some embodiments of the present invention, a modified graphene aqueous dispersion or organic solvent dispersion is prepared, and the organic solvent used to disperse the modified graphene includes: tetrahydrofuran, dimethylformamide, dimethylacetamide, ethylene glycol, N-methylpyrrolidone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and ethylene glycol monobutyl ether, etc.; the latex includes one or more of natural latex and other synthetic latexes; the ultrasonic time after the modified graphene and latex are mixed is 0-30 minutes, and the mixing and stirring time is 10-60 minutes.

[0054] In some embodiments of the present invention, the flocculant is sulfuric acid, acetic acid, calcium chloride, dinitrile diamine formaldehyde condensate, etc., and the drying method of the modified graphene masterbatch can be vacuum drying at 60°C, but the present invention is not limited thereto.

[0055] The invention connects coupling agent molecules to graphene oxide sheets to increase the interlamellar spacing, so that the modified graphene can be evenly dispersed in the rubber; during vulcanization, the modified graphene is connected to the rubber by covalent bonds, so that the interface effect between the modified graphene and the rubber is increased; the modified graphene is directly dispersed in a solvent after filtering and washing, and then mixed with latex, and the rubber molecules are intercalated between the modified graphene sheets to prevent the sheets from overlapping, so that the large specific surface area of ​​the graphene material can be fully utilized, and a small amount of addition can cover the rubber. The method is suitable for large-scale industrial production.

[0056] In some embodiments of the present invention, there is also disclosed an application of the modified graphene masterbatch as a tire rubber reinforcing filler.

[0057] In some embodiments of the present invention, a tire rubber composition is also disclosed, comprising a tire rubber matrix and a modified graphene masterbatch, wherein the tire rubber matrix may be various tire rubber matrices known in the art, for example, various matrix rubbers and various fillers, additives, etc. known in the art, which will not be described in detail herein. In the tire rubber composition, the amount of the modified graphene masterbatch may generally be 5% to 50% based on the total weight of the tire rubber composition.

[0058] Example 1

[0059] A method for preparing a modified graphene masterbatch comprises the following steps:

[0060] (1) dispersing 1 g of graphene oxide in 1000 ml of aqueous solution, stirring evenly, adding sodium hydroxide aqueous solution to adjust the pH value to 9-10, ultrasonically dispersing for 0.3 h, adding hydrochloric acid solution to adjust the pH value to 5, and obtaining a graphene oxide dispersion;

[0061] (2) adding 1 g of silane coupling agent Si-69 to 10 ml of ethanol solution, mixing well, and then adding to the graphene oxide dispersion, heating and reacting at 70° C. for 5 h to obtain a graphene oxide-coupling agent reaction solution;

[0062] (3) cooling the graphene oxide-coupling agent reaction liquid to below 40° C. and adjusting the pH value to 7-8, adding a reducing agent hydrazine hydrate, heating to 70° C. for reduction reaction, the reaction time is 5 hours, cooling to room temperature, filtering, washing, and obtaining modified graphene, and then dispersing the modified graphene in water, stirring, and ultrasonicating to obtain a modified graphene dispersion;

[0063] (4) adding the modified graphene dispersion to natural rubber latex, and ultrasonicating for 15 minutes until uniform dispersion; preparing a 3% acetic acid aqueous solution, pouring the modified graphene / natural rubber latex into the acetic acid aqueous solution, adding a flocculant and mixing and stirring for 30 minutes until floccules are obtained, washing, and vacuum drying at 60° C. to obtain a modified graphene masterbatch.

[0064] The specific surface area of ​​the graphene oxide in step (1) is 100-300m 2 / g, the flake diameter is 2-20μm, and the oxygen content is 40%-60%.

[0065] like Figure 1 , which is the XRD diagram of graphene oxide and modified graphene in Example 1, and Table 1 is the interlamellar spacing of the graphene material calculated according to the position of the X-ray diffraction peak of the graphene material and the Bragg formula.

[0066] Table 1 Interlayer spacing of graphene materials

[0067] Graphene Modified graphene 2θ(°) 26.5 20.9 Interlayer spacing (nm) 0.335 0.425

[0068] Obviously, compared with ordinary graphene, the modified graphene of the present invention can effectively increase the interlamellar spacing, so that the graphene can be more evenly dispersed in the rubber.

[0069] Example 2

[0070] A method for preparing a modified graphene masterbatch comprises the following steps:

[0071] (1) dispersing 2 g of graphene oxide in 1000 ml of dimethylformamide, stirring evenly, adding potassium hydroxide aqueous solution to adjust the pH value to 12-14, ultrasonically dispersing for 1.5 h, adding phosphoric acid solution to adjust the pH value to 6, and obtaining a graphene oxide dispersion;

[0072] (2) adding 0.1 g of silane coupling agent Si-69 to 1 ml of ethanol solution, mixing well, and then adding to the graphene oxide dispersion, heating and reacting at 30° C. for 10 h to obtain a graphene oxide-coupling agent reaction solution;

[0073] (3) cooling the graphene oxide-coupling agent reaction solution to below 40° C. and adjusting the pH value to 8-9, adding reducing agent sodium borohydride, heating to 100° C. for reduction reaction, the reaction time is 0.5 h, cooling to room temperature, filtering, washing, and obtaining modified graphene, and then dispersing the modified graphene in a tetrahydrofuran solution, stirring, and ultrasonicating to obtain a modified graphene dispersion;

[0074] (4) adding the modified graphene dispersion to latex and ultrasonicating for 5 minutes until uniform dispersion; preparing a 5% calcium chloride aqueous solution, pouring the modified graphene / natural latex into the calcium chloride aqueous solution, adding a flocculant and mixing and stirring for 30 minutes until floccules are obtained, washing, and vacuum drying at 60° C. to obtain a modified graphene masterbatch.

[0075] The specific surface area of ​​the graphene oxide in step (1) is 100-300m 2 / g, the flake diameter is 2-20μm, and the oxygen content is 40%-60%.

[0076] Example 3

[0077] A method for preparing a modified graphene masterbatch comprises the following steps:

[0078] (1) Dispersing 5 g of graphene oxide in 1000 ml of N-methylpyrrolidone, stirring evenly, adding a sodium carbonate aqueous solution to adjust the pH value to 8-9, ultrasonically dispersing for 3 h, adding a phthalic acid solution to adjust the pH value to 7, and obtaining a graphene oxide dispersion;

[0079] (2) adding 10 g of silane coupling agent KH570 into 100 ml of ethanol solution, mixing well, adding into graphene oxide dispersion, heating at 100° C. for 1 h to obtain graphene oxide-coupling agent reaction solution;

[0080] (3) cooling the graphene oxide-coupling agent reaction solution to below 40° C. and adjusting the pH value to 9-10, adding a reducing agent polyvinyl alcohol, heating to 30° C. for reduction reaction, the reaction time is 10 hours, cooling to room temperature, filtering, washing, and obtaining modified graphene, and then dispersing the modified graphene in an ethylene glycol solution, stirring, and ultrasonicating to obtain a modified graphene dispersion;

[0081] (4) adding the modified graphene dispersion to latex, ultrasonicating for 30 min until uniform dispersion, preparing a 3% acetic acid aqueous solution, pouring the modified graphene / natural latex into the acetic acid aqueous solution, adding a flocculant and mixing for 10 min until floccules are obtained, washing, and vacuum drying at 60° C. to obtain a modified graphene masterbatch.

[0082] The specific surface area of ​​the graphene oxide in step (1) is 100-300m 2 / g, the flake diameter is 2-20μm, and the oxygen content is 40%-60%.

[0083] Comparative Example 1

[0084] Comparative Example 1 is substantially the same as Example 1, except that:

[0085] (1) Disperse 1 g of graphene oxide in 1000 ml of aqueous solution, stir evenly, and perform ultrasonic dispersion for 0.3 h. Add hydrochloric acid solution to adjust the pH value to 5 to obtain a graphene oxide dispersion.

[0086] Comparative Example 2

[0087] Comparative Example 2 is substantially the same as Example 1, except that:

[0088] (2) 15 g of silane coupling agent Si-69 was added to 10 ml of ethanol solution, mixed evenly, and then added to the graphene oxide dispersion, and heated at 70° C. for reaction for 5 h to obtain a graphene oxide-coupling agent reaction solution.

[0089] Comparative Example 3

[0090] Comparative Example 3 is substantially the same as Example 1, except that:

[0091] (3) The graphene oxide-coupling agent reaction solution is cooled to below 40° C., and the pH value is adjusted to 11, and then a reducing agent hydrazine hydrate is added, and the temperature is raised to 70° C. for reduction reaction, and the reaction time is 5 hours. The solution is cooled to room temperature, filtered, and washed to obtain modified graphene, and then the modified graphene is dispersed in water, stirred, and ultrasonicated to obtain a modified graphene dispersion.

[0092] Comparative Example 4

[0093] Comparative Example 4 is substantially the same as Example 1, except that:

[0094] (3) Cooling the graphene oxide-coupling agent reaction solution to below 40° C. and adjusting the pH value to 6, adding a reducing agent hydrazine hydrate, heating to 70° C. for reduction reaction, the reaction time is 5 hours, cooling to room temperature, filtering, washing, and obtaining modified graphene, and then dispersing the modified graphene in water, stirring, and ultrasonicating to obtain a modified graphene dispersion.

[0095] Comparative Example 5

[0096] Comparative Example 5 is substantially the same as Example 1, except that:

[0097] (2) Add 1 g of silane coupling agent Si-69 into 10 ml of ethanol solution, mix well, and then add into graphene oxide dispersion liquid, heat and react at 110° C. for 5 h to obtain graphene oxide-coupling agent reaction liquid.

[0098] The graphene masterbatch prepared in the above Examples 1-3 and Comparative Examples 1-5 was used to prepare rubber according to the following formula: 100 parts of 3# smoked sheet rubber, 45 parts of carbon black N234, 1.5 parts of modified graphene masterbatch, 2 parts of stearic acid, 3 parts of zinc oxide, 1.5 parts of antioxidant RD, 2 parts of antioxidant 4020, 1.5 parts of sulfur, 1 part of accelerator, 1 part of anti-sulfurization reducing agent, and the group without adding graphene was used as a blank group to measure the mechanical properties of the rubber. The measurement results are shown in Table 2.

[0099] Table 2 Measurement results

[0100]

[0101]

[0102] As can be seen from Table 2, compared with the rubber without adding graphene and adding modified graphene of Comparative Examples 1-5, the rubber prepared by the modified graphene prepared by the method of the present invention has more excellent tensile strength, elongation at break, wear resistance and can effectively reduce compression heat generation and compression permanent deformation, and is particularly suitable for tires with high driving speed and high load.

[0103] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the scheme disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0104] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a modified graphene masterbatch, characterized in that: The following steps are involved: (1) dispersing graphene oxide in a solvent, performing ultrasonic dispersion, and adjusting the pH value to 5-7 to obtain a graphene oxide dispersion; (2) adding a silane coupling agent solution to the graphene oxide dispersion, heating the dispersion to react, and obtaining a graphene oxide-coupling agent reaction solution; (3) After cooling the graphene oxide-coupling agent reaction liquid, adding a reducing agent hydrazine hydrate to carry out a reduction reaction to obtain modified graphene, and then dispersing the modified graphene in a solvent, stirring, and ultrasonicating to obtain a modified graphene dispersion; (4) adding the modified graphene dispersion to latex, ultrasonicating, adding a flocculant and mixing and stirring until floccules are formed, washing, and drying to obtain a modified graphene masterbatch; The specific surface area of ​​the graphene oxide in step (1) is 100-300 m 2 / g, a sheet diameter of 2-20 μm, an oxygen content of 40%-60%; the concentration of the graphene oxide dispersion is 100-5000 mg / L; The ultrasonic dispersion time in step (1) is 0.3-3h; before the ultrasonic dispersion, the method further comprises: adding alkali to adjust the pH value to 8-14; The reaction temperature of the heating reaction in step (2) is 30-100°C and the reaction time is 1-10h; Before the reduction reaction in step (3), the step further includes: cooling the graphene oxide-coupling agent reaction solution to below 40° C. and adjusting the pH value to 7-10; The reaction temperature of the reduction reaction is 30°C-100°C, and the reaction time is 0.1h-10h; The general formula of the silane coupling agent in step (2) is Z-(CH2) m -[Si(X) a (Y) 3-a ] n ; Where X is C1-C 18 Alkoxy or C5-C 18 a is an integer of 1 to 3, and Y is C1-C 18 Alkyl, C5-C 18 Cycloalkyl or C6-C 18 aryl, m is an integer of 0-10, n is 1 or 2; Z includes any one or more of vinyl, alkylamino, amino, epoxy, mercapto, polysulfanyl, and acryloyloxy; The mass ratio of the graphene oxide to the silane coupling agent is 1:(0.1-10).

2. The method for preparing modified graphene masterbatch according to claim 1, characterized in that: The ultrasonic time in step (4) is 0-30 min, and the mixing time is 10-60 min.

3. The method for preparing modified graphene masterbatch according to claim 1, characterized in that, The flocculant in step (4) includes any one of sulfuric acid, acetic acid, calcium chloride, and dinitrile diamine formaldehyde condensate.

4. A modified graphene masterbatch, characterized in that: The method is prepared by any one of claims 1 to 3.

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