Modified styrene-butadiene rubber composite material and preparation method thereof

Abstract

The embodiment of the invention provides a modified styrene-butadiene rubber composite material and a preparation method thereof. The modified styrene-butadiene rubber composite material comprises at least one of octavinyl siloxane grafted polystyrene and double-bond-containing silicon dioxide grafted polystyrene, and styrene-butadiene rubber. According to the invention, octavinyl siloxane or double-bond-containing silicon dioxide is adopted to graft polystyrene, and the grafted polystyrene is utilized to modify styrene-butadiene rubber, so that the interface friction of the material is increased, and the modified styrene-butadiene rubber composite material has good mechanical properties and damping performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a modified styrene-butadiene rubber composite material and a preparation method thereof. BACKGROUND

[0002] Styrene-butadiene rubber is an important synthetic rubber, which is prepared by copolymerization of butadiene and styrene, skillfully combining the properties of the two monomers, and has good wear resistance and processing performance. It is widely used in tire, sealing, damping material and other fields, and has become one of the indispensable materials in modern industry. However, styrene-butadiene rubber also has inherent defects, such as insufficient damping performance, maximum loss factor tan delta < 0.8, and damping temperature range < 30℃, which is difficult to meet the vibration and noise reduction requirements of high-speed trains, aerospace and other high-demand scenarios.

[0003] In view of the problem of insufficient damping performance of styrene-butadiene rubber, the existing technology mainly breaks through from the aspects of blending modification and filler modification. In the aspect of blending modification, polar materials such as ethylene-propylene-diene rubber and epoxidized natural rubber are introduced to broaden the damping temperature range by using micro-phase separation structure; in the aspect of filler modification, inorganic fillers such as graphite and silicon dioxide are focused on, such as introducing polyurethane-based porous carbon fiber to improve internal friction by using the interface friction between the filler and the rubber matrix.

[0004] However, the system compatibility is poor during blending, which easily leads to fluctuation of the mechanical properties of the rubber material; ordinary fillers also easily cause agglomeration, and the damping performance is improved low; therefore, how to improve the damping performance of styrene-butadiene rubber while ensuring the stability of the mechanical properties of the material is a problem to be solved. SUMMARY

[0005] The present application provides a modified styrene-butadiene rubber composite material and a preparation method thereof, the modified styrene-butadiene rubber composite material comprising: at least one of octavinylsiloxane grafted polystyrene and double bond containing silica grafted polystyrene, and styrene-butadiene rubber, the styrene-butadiene rubber is modified by using octavinylsiloxane grafted polystyrene and / or double bond containing silica grafted polystyrene, so that the composite material has good mechanical properties and greatly improves the damping performance of the material.

[0006] In a first aspect, the present application provides a modified styrene-butadiene rubber composite material, the modified styrene-butadiene rubber composite material comprising: at least one of octavinylsiloxane grafted polystyrene and double bond containing silica grafted polystyrene, and styrene-butadiene rubber.

[0007] According to an embodiment of the present application, the content of the styrene-butadiene rubber is 70% to 88%; and / or, the content of the octavinylsiloxane grafted polystyrene is 1.5% to 7%; and / or, the content of the double bond containing silica grafted polystyrene is 2% to 20%.

[0008] According to an embodiment of the present application, the octavinylsiloxane grafted polystyrene has a molecular weight of 500,000-1,000,000.

[0009] According to an embodiment of the present application, the double bond containing silica grafted polystyrene has a molecular weight of 500,000-1,000,000.

[0010] According to a second aspect of the present application, there is provided a method for preparing the modified styrene-butadiene rubber composite material according to the first aspect, the method comprising the following steps:

[0011] Mixing at least one of the octavinylsiloxane grafted polystyrene and the double bond containing silica grafted polystyrene with the styrene-butadiene rubber, and then performing a mixing and vulcanization process to obtain the modified styrene-butadiene rubber composite material.

[0012] According to an embodiment of the present application, the styrene-butadiene rubber has a dosage of 40-70 parts; and / or, the octavinylsiloxane grafted polystyrene has a dosage of 1-5 parts; and / or, the double bond containing silica grafted polystyrene has a dosage of 1-15 parts.

[0013] According to an embodiment of the present application, the preparation steps of the octavinylsiloxane grafted polystyrene or the double bond containing silica grafted polystyrene comprise the following steps:

[0014] Mixing styrene, octavinylsiloxane or double bond containing silica and an initiator, and then performing a reaction process at a first preset temperature for a first preset time to obtain the octavinylsiloxane grafted polystyrene or the double bond containing silica grafted polystyrene.

[0015] According to an embodiment of the present application, the initiator comprises one of benzoyl peroxide or azobisisobutyronitrile.

[0016] And / or, the initiator has a dosage of 0.5%-2% of the mass of the styrene.

[0017] According to an embodiment of the present application, the first preset temperature is 60-90℃; and / or, the first preset time is 1-3 hours.

[0018] The present invention provides a modified styrene-butadiene rubber composite material and a preparation method thereof. Octavinylsiloxane or double-bonded silica is used to graft polystyrene. The physical compatibility of polystyrene with the styrene units of styrene-butadiene rubber is utilized to uniformly disperse the octavinylsiloxane-grafted polystyrene and / or the double-bonded silica-grafted polystyrene in a styrene-butadiene rubber matrix, thereby maximizing the interface contact area. In addition, the octavinylsiloxane and / or double-bonded silica can both add a large number of microscopic interfaces to the material, thereby increasing the internal friction of the rubber matrix molecules and significantly improving the damping performance of the material. Therefore, the modified styrene-butadiene rubber composite material provided by the present invention has both good mechanical properties and damping properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flow chart of the preparation method of the modified styrene-butadiene rubber composite material provided in this application;

[0020] Figure 2 This is a flow chart of the preparation steps of octavinylsiloxane-grafted polystyrene or double-bond silica-grafted polystyrene provided in this application. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below. The specific embodiments listed below are only for describing the principles and features of the present invention. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts are within the scope of protection of the present invention.

[0022] A first aspect of the present invention provides a modified styrene-butadiene rubber composite material, comprising: at least one of octavinylsiloxane-grafted polystyrene and double-bond silica-grafted polystyrene, and styrene-butadiene rubber.

[0023] Styrene-butadiene rubber combines good wear resistance and processing properties, but its inherent damping performance is insufficient, making it unable to meet the vibration and noise reduction requirements of its applications. Octavinylsiloxane has a nanoscale rigid cage structure that restricts the movement of rubber molecular chains. When the molecular chains vibrate, interfacial slip friction is generated, consuming mechanical energy and converting it into heat. It also has a large number of uniform micropores, thereby increasing the microscopic interface within the rubber matrix. Double-bond-modified silica changes its surface properties, improving its compatibility with the rubber matrix and making it more evenly dispersed in the rubber, reducing agglomeration and forming more interfacial regions. The strong interaction between the double-bonded silica and the rubber molecular chains further restricts the movement of the chain segments, making interfacial friction more significant.

[0024] Therefore, the modified styrene-butadiene rubber composite provided by the application adopts octavinylsiloxane or double-bond-containing silicon dioxide to graft polystyrene, utilizes the physical compatibility of polystyrene and the styrene unit of the styrene-butadiene rubber to make the polystyrene grafted with octavinylsiloxane and / or the polystyrene grafted with double-bond-containing silicon dioxide uniformly dispersed in the styrene-butadiene rubber matrix, maximizes the interface contact area, and the octavinylsiloxane and / or the double-bond-containing silicon dioxide can increase a large number of micro-interfaces of the material, so that the internal friction of the rubber matrix molecules is increased, and the damping performance of the material is greatly improved, so that the modified styrene-butadiene rubber composite has good mechanical properties and damping performance at the same time.

[0025] In a specific embodiment, the content of the styrene-butadiene rubber is 70% to 88%; and / or, the content of the polystyrene grafted with octavinylsiloxane is 1.5% to 7%; and / or, the content of the polystyrene grafted with double-bond-containing silicon dioxide is 2% to 20%.

[0026] For example, the content of the styrene-butadiene rubber is 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88% or a range formed by any two of the above values. The content of the polystyrene grafted with octavinylsiloxane is 1.5%, 2%, 3%, 4%, 5%, 6%, 7% or a range formed by any two of the above values. The content of the polystyrene grafted with double-bond-containing silicon dioxide is 2%, 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20% or a range formed by any two of the above values. By controlling the content of the styrene-butadiene rubber, the polystyrene grafted with octavinylsiloxane and the polystyrene grafted with double-bond-containing silicon dioxide in the modified styrene-butadiene rubber composite, the damping performance of the material can be improved while ensuring that the material has good mechanical properties, so that the synergistic effect of each component in the material is maximized.

[0027] In a specific embodiment, the molecular weight of the polystyrene grafted with octavinylsiloxane is 50,000 to 100,000; and / or, the molecular weight of the polystyrene grafted with double-bond-containing silicon dioxide is 50,000 to 100,000. For example, the molecular weight of the polystyrene grafted with octavinylsiloxane is 50,000, 60,000, 70,000, 80,000, 90,000, 100,000 or a range formed by any two of the above values. The molecular weight of the polystyrene grafted with double-bond-containing silicon dioxide is 50,000, 60,000, 70,000, 80,000, 90,000, 100,000 or a range formed by any two of the above values. By controlling the molecular weight of the polystyrene grafted with octavinylsiloxane and the polystyrene grafted with double-bond-containing silicon dioxide within the above range, the polystyrene grafted with octavinylsiloxane and the polystyrene grafted with double-bond-containing silicon dioxide are more easily dispersed in the rubber matrix, and the agglomeration phenomenon is reduced, so that the uniformity of the interface interaction is improved, and by controlling the molecular weight, the chain segment movement under dynamic load can be more effectively generated, the internal friction is increased, and the damping performance of the material is improved.

[0028] The second aspect of the present invention provides a method for preparing the modified styrene-butadiene rubber composite material as in the first aspect, Figure 1 As shown, the preparation method comprises the following steps:

[0029] S101, mixing at least one of octavinylsiloxane-grafted polystyrene and double-bond silica-grafted polystyrene with styrene-butadiene rubber, and performing kneading and vulcanization to obtain a modified styrene-butadiene rubber composite material.

[0030] Specifically, at least one of octavinylsiloxane-grafted polystyrene and double-bond silica-grafted polystyrene, and styrene-butadiene rubber are added to an internal mixer, the mixing temperature and time are set, and then the mixture obtained after mixing is placed on a flat vulcanizer and the vulcanization temperature and time are set. After completion, a modified styrene-butadiene rubber composite material is obtained.

[0031] Among them, the mixing temperature is 120℃~160℃, and the time is 5min~15min; the vulcanization temperature is 150℃~180℃, and the time is 10min~20min.

[0032] It is understandable that additives, including antioxidants and processing aids, will be added during mixing. The amount of antioxidant is 1 to 4 parts, and the amount of processing aid is 1 to 3 parts. Sulfur can be used and vulcanization accelerators can be added during vulcanization. The amount of sulfur is 1 to 3 parts, and the amount of vulcanization accelerator is 0.5 to 2 parts.

[0033] Among them, the antioxidant may include at least one of antioxidant RD, antioxidant 4010NA, and antioxidant 4020. The addition of an appropriate amount of antioxidant can delay the aging of the rubber and increase the service life of the rubber material; the processing aid can be stearic acid, which can make the filler evenly dispersed in the rubber matrix; the vulcanization accelerator can include at least one of N-cyclohexyl-2-benzothiazole sulfenamide and tetramethylthiuram disulfide, which can accelerate the vulcanization speed of styrene-butadiene rubber, shorten the vulcanization time, reduce the vulcanization reaction temperature, and reduce the amount of vulcanizing agent used.

[0034] Internal mixing can mix all the substances evenly, and vulcanization treatment can make the styrene-butadiene rubber cross-link from a linear structure to a three-dimensional network structure, thereby greatly improving the mechanical properties of the rubber such as tensile strength, elasticity, hardness, tensile strength, etc., and significantly improving the damping performance of the material.

[0035] In a preferred embodiment, the amount of styrene butadiene rubber is 40-70 parts; and / or, the amount of octavinylsiloxane grafted polystyrene is 1-5 parts; and / or, the amount of double bond containing silica grafted polystyrene is 1-15 parts. For example, the amount of styrene butadiene rubber is 40, 45, 50, 55, 60, 65, 70 parts or a range defined by any two of the above values. The amount of octavinylsiloxane grafted polystyrene is 1, 2, 3, 4, 5 parts or a range defined by any two of the above values. The amount of double bond containing silica grafted polystyrene is 1, 2, 5, 8, 10, 12, 15 parts or a range defined by any two of the above values. By controlling the amount of raw materials during preparation, the synergistic effect of the components can be maximized, greatly improving the damping performance of the material, and the modified styrene butadiene rubber composite material prepared has good mechanical properties and excellent damping performance.

[0036] In a specific embodiment, the preparation steps of octavinylsiloxane grafted polystyrene or double bond containing silica grafted polystyrene, as shown in Figure 2 , include the following steps:

[0037] S201, mixing styrene, octavinylsiloxane or double bond containing silica and initiator, reacting at a first preset temperature for a first preset time to obtain octavinylsiloxane grafted polystyrene or double bond containing silica grafted polystyrene.

[0038] Wherein, the first preset temperature refers to the temperature at which the free radical reaction of styrene and octavinylsiloxane or double bond containing silica occurs, such as 60°C.

[0039] Wherein, the first preset time refers to the time for which the reaction of styrene and octavinylsiloxane or double bond containing silica occurs, such as 1h.

[0040] Wherein, the octavinylsiloxane is a cage polysilsesquioxane, and the molecular formula is , with a purity of ≥98%.

[0041] Specifically, styrene, octavinylsiloxane or double bond containing silica, and initiator are added to a reaction kettle, the temperature of the reaction kettle is adjusted to the first preset temperature, free radical polymerization occurs, and octavinylsiloxane grafted polystyrene or double bond containing silica grafted polystyrene is obtained after reacting for a first preset time.

[0042] Due to the high activity of the vinyl functional groups on the surface of the octavinylsiloxane and the double-bond-containing silica, the octavinylsiloxane and the double-bond-containing silica are prone to react with styrene, and a stable chemical bond can be formed between the styrene monomers and the grafting monomers through the free radical polymerization initiated by the initiator, thereby ensuring the structural stability of the grafted copolymer and the simplicity of the process.

[0043] The double-bond-containing silica can be prepared in advance by the following steps: mixing the silica and a silane coupling agent in an ethanol / water solvent, hydrolyzing at a temperature of 40-60°C for 0.5-2h, and drying by centrifugation to obtain the double-bond-containing silica.

[0044] Optionally, the silane coupling agent includes at least one of vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane; the amount of the silane coupling agent is 1.0-3.0% of the mass of the silica; and the volume ratio of the ethanol / water solvent is 8:1-10:1.

[0045] In a preferred embodiment, the initiator includes one of benzoyl peroxide or azobisisobutyronitrile; and / or, the amount of the initiator is 0.5-2% of the mass of the styrene. Illustratively, the amount of the initiator is 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2% of the mass of the styrene or a range defined by any two of the above values. By controlling the type and amount of the initiator, not only the reaction efficiency is improved, but also the molecular weight of the octavinylsiloxane-grafted polystyrene or the double-bond-containing silica-grafted polystyrene can be controlled within a desired range, thereby improving the damping performance of the material.

[0046] In a preferred embodiment, the first preset temperature is 60-90°C; and / or, the first preset time length is 1-3h. Illustratively, the first preset temperature is 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or a range defined by any two of the above values. The first preset time length is 1h, 1.2h, 1.5h, 2h, 2.5h, 3h or a range defined by any two of the above values. By controlling the reaction temperature and time for preparing the octavinylsiloxane-grafted polystyrene or the double-bond-containing silica-grafted polystyrene, the efficiency of the polymerization reaction and the stability of the product performance can be significantly improved, and the butadiene-styrene rubber composite material obtained by modifying the polymer has good damping performance.

[0047] The following will specifically introduce a synthetic rubber and a preparation method thereof provided by the present application through specific examples.

[0048] Unless otherwise specified, the reagents, materials and instruments used in the following examples are conventional reagents, conventional materials and conventional instruments in the art, which can be commercially available, and the reagents involved can also be synthesized by conventional methods in the art.

[0049] Example 1

[0050] 1) Preparation of octavinylsiloxane grafted polystyrene: 50 g of styrene, 200 g of octavinylsiloxane and 0.5 g of benzoyl peroxide were added into a reaction kettle, and reacted at 80°C for 1.5 hours to obtain octavinylsiloxane grafted polystyrene;

[0051] 2) Preparation of modified butadiene-styrene rubber composite material: 60 g of butadiene-styrene rubber, 2 g of octavinylsiloxane grafted polystyrene, 2 g of sulfur, 1.5 g of vulcanization accelerator, 2 g of antioxidant and 2 g of stearic acid were added into an internal mixer, and mixed at 140°C for 8 minutes, followed by vulcanization at 160°C for 10 minutes on a flat vulcanizing machine to obtain a modified butadiene-styrene rubber composite material.

[0052] Example 2

[0053] The difference between this example and Example 1 is that the octavinylsiloxane grafted polystyrene in step 2) is 5 g. The rest of the conditions are the same as those in Example 1.

[0054] Example 3

[0055] The difference between this example and Example 1 is that the octavinylsiloxane grafted polystyrene in step 2) is 1 g. The rest of the conditions are the same as those in Example 1.

[0056] Example 4

[0057] 1) Preparation of double bond-containing silica grafted polystyrene: 25 g of styrene, 100 g of double bond-containing silica and 0.25 g of benzoyl peroxide were added into a reaction kettle, and reacted at 80°C for 1.5 hours to obtain double bond-containing silica grafted polystyrene;

[0058] 2) Preparation of modified butadiene-styrene rubber composite material: 60 g of butadiene-styrene rubber, 10 g of double bond-containing silica grafted polystyrene, 2 g of sulfur, 1.5 g of vulcanization accelerator, 2 g of antioxidant and 2 g of stearic acid were added into an internal mixer, and mixed at 140°C for 8 minutes, followed by vulcanization at 160°C for 10 minutes on a flat vulcanizing machine to obtain a modified butadiene-styrene rubber composite material.

[0059] Example 5

[0060] The difference between this example and Example 4 is that the double bond-containing silica grafted polystyrene in step 2) is 15 g. The rest of the conditions are the same as those in Example 4.

[0061] Example 6

[0062] The difference between this example and Example 4 is that the double bond-containing silica-grafted polystyrene 1g is used in Step 2). The rest of the conditions are the same as in Example 1.

[0063] Comparative Example 1

[0064] 60 g of styrene-butadiene rubber, 2 g of sulfur, 1.5 g of vulcanization accelerator, 2 g of antioxidant and 2 g of stearic acid were added into an internal mixer and mixed at 140 °C for 8 minutes, followed by vulcanization at 160 °C for 10 minutes on a flat vulcanization machine to obtain a styrene-butadiene rubber composite.

[0065] Test Example

[0066] I. The following tests were performed on the materials of the above examples and comparative examples:

[0067] 1. Content test of styrene-butadiene rubber, octavinylsiloxane-grafted polystyrene and double bond-containing silica-grafted polystyrene in the modified styrene-butadiene rubber composite

[0068] Test method: Fourier infrared spectroscopy was used to determine the synthetic rubber, The absorption peak appearing at 1730 cm-1 is related to the vibration absorption mode of The absorption peak appearing at 1600 cm-1 is also caused by the bending vibration of The absorption peak appearing at 1600 cm-1 is also caused by the bending vibration of The absorption peak appearing at 1600 cm-1 is also caused by the bending vibration of The absorption peak appearing at 1600 cm-1 is also caused by the bending vibration of

[0069] 2. Molecular weight test

[0070] Test method: The material was dissolved in THF to prepare a sample with a concentration of 2-2.5 mg / mL, and a gel permeation chromatograph was used to test the prepared sample, with an injection amount of 20 μL, a test temperature of 30 °C and a flow rate of 1 mL / min. The results are shown in Table 1.

[0071] 3. Tensile strength test

[0072] Test method: Referring to standard GB / T 528-92, a universal material testing machine was used to stretch at a rate of 500 mm / min until fracture, and the maximum stress value at fracture was taken as the tensile strength. The results are shown in Table 1.

[0073] 4. Elongation at break test

[0074] Test method: refer to standard GB / T 528-92, using synthetic rubber universal testing machine, stretching at a rate of 500 mm / min until breaking, taking the elongation at break as the breaking elongation, the results are shown in Table 1.

[0075] 5. Shore A hardness test

[0076] Test method: refer to standard GB / T 531.1-2008, using Shore A hardness tester, vertically pressing the hardness tester on the sample surface, ensuring that the pressure pin of the pressure foot is at least 12 mm away from the edge of the sample; applying sufficient force to make the pressure foot fully contact the sample and keep the pressure foot parallel to the sample surface; after the pressure pin is pressed into the sample, reading the hardness value within 1 second; measuring 5 times at different positions of the sample at least 6 mm apart, taking the average value as the final result, the results are shown in Table 1.

[0077] 6. Damping performance test

[0078] Test method: set the dynamic mechanical property analyzer to tensile mode, set the thickness and width of the analyzed material sample to 2 mm and 6 mm, set the strain range to 0.1%, set the frequency to 10 Hz, set the temperature range to -80~80℃, set the heating rate to 3℃ / min, obtain the loss factor-temperature curve of the analyzed sample, take the maximum loss factor and the half-peak width of the curve peak as the parameters representing the damping performance of the measured sample, the results are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] As shown in Table 1, it can be seen from Comparative Example 1, Example 4 and Comparative Example 1 that the damping performance of the styrene-butadiene rubber modified by octavinylsiloxane grafted polystyrene or double bond-containing silica grafted polystyrene is greatly improved compared with the unmodified styrene-butadiene rubber; from Examples 1~6, it can be known that by controlling the content of the styrene-butadiene rubber, the molecular weight of the octavinylsiloxane grafted polystyrene, and the content of the double bond-containing silica grafted polystyrene in the modified styrene-butadiene rubber composite material within the above range, the damping performance of the material can be improved while the mechanical properties are stable.

[0083] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A modified styrene-butadiene rubber composite material, characterized in that: The modified styrene-butadiene rubber composite material comprises: at least one of octavinylsiloxane-grafted polystyrene and double-bond silica-grafted polystyrene, and styrene-butadiene rubber.

2. The modified styrene-butadiene rubber composite material according to claim 1, characterized in that The content of the styrene-butadiene rubber is 70% to 88%; and / or the content of the octavinylsiloxane-grafted polystyrene is 1.5% to 7%; and / or the content of the double-bond silica-grafted polystyrene is 2% to 20%.

3. The modified styrene-butadiene rubber composite material according to claim 1, characterized in that The molecular weight of the octavinylsiloxane-grafted polystyrene is 50,000 to 100,000; And / or, the molecular weight of the double-bond silica-grafted polystyrene is 50,000 to 100,000.

4. A method for preparing the modified styrene-butadiene rubber composite material according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: At least one of octavinylsiloxane grafted polystyrene and double bond silica grafted polystyrene and styrene-butadiene rubber are mixed, and the mixture is subjected to banburying and vulcanization to obtain the modified styrene-butadiene rubber composite material.

5. The preparation method according to claim 4, characterized in that The amount of the styrene-butadiene rubber is 40 to 70 parts; and / or the amount of the octavinylsiloxane-grafted polystyrene is 1 to 5 parts; and / or the amount of the double-bond silica-grafted polystyrene is 1 to 15 parts.

6. The preparation method according to claim 4, characterized in that The preparation steps of the octavinylsiloxane-grafted polystyrene or the double-bond-containing silica-grafted polystyrene include the following steps: Styrene, octavinylsiloxane or double-bonded silica and an initiator are mixed and reacted at a first preset temperature for a first preset time to obtain the octavinylsiloxane-grafted polystyrene or the double-bonded silica-grafted polystyrene.

7. The preparation method according to claim 6, characterized in that The initiator includes one of benzoyl peroxide or azobisisobutyronitrile; And / or, the amount of the initiator is 0.5% to 2% of the mass of the styrene.

8. The preparation method according to claim 6, characterized in that The first preset temperature is 60° C. to 90° C.; and / or the first preset time is 1 hour to 3 hours.

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