Carbon black composite intercalated styrene-butadiene rubber and preparation method thereof

Abstract

The invention belongs to the field of rubber materials, and particularly relates to carbon black composite intercalated styrene-butadiene rubber and a preparation method thereof. The method comprises the following steps: 1) proportioning the following raw materials in percentage by mass: 12-30 wt% of modified carbon black, 3-9 wt% of layered silicate, 1.5-4.2 wt% of an auxiliary agent and the balance of styrene-butadiene rubber; 2) carrying out pre-mixing treatment on styrene butadiene rubber to obtain a rubber base material; (3) mixing the rubber base material, and sequentially adding the modified carbon black, the layered silicate and the auxiliary agent into the rubber base material in the treatment process to obtain a rubber precursor; 4, gradient temperature treatment is conducted on the rubber precursor, and then compression molding is conducted to obtain the carbon black composite intercalated styrene butadiene rubber. According to the carbon black composite intercalated styrene butadiene rubber and the preparation method thereof, a carbon black-silicate two-phase filler system is constructed, the synergistic effect of two materials is utilized, the modulus of the material is improved, the barrier property is enhanced, and dual optimization of the mechanical property and oil resistance / solvent resistance of the material is achieved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of rubber materials, and particularly relates to a carbon black composite intercalated styrene-butadiene rubber and a preparation method thereof. BACKGROUND

[0002] In the field of rubber materials, traditional styrene-butadiene rubber (SBR) has poor compatibility with commonly used fillers such as carbon black due to its low molecular chain polarity. This incompatibility easily causes filler agglomeration in the rubber matrix, which has a significant negative impact on the mechanical properties and electrical conductivity of the material.

[0003] To improve the dispersion of fillers in styrene-butadiene rubber, the prior art usually adopts methods such as increasing the amount of carbon black or surface modification of the filler. However, these methods have problems such as a significant increase in energy consumption, a significant increase in production cost, and an increase in material brittleness, which severely limit the performance of styrene-butadiene rubber in practical applications. In addition, single filler systems have limitations in meeting the performance requirements of the material, making it difficult to achieve both high strength and good electrical conductivity.

[0004] Notably, intercalation technology of layered silicates (such as montmorillonite) has shown some effect in improving the modulus of the material. Unfortunately, the synergistic effect between this technology and carbon black has not been fully explored and applied.

[0005] Therefore, it is particularly important to develop a styrene-butadiene rubber modified by carbon black and layered silicate composite intercalation. This new type of styrene-butadiene rubber is expected to achieve efficient dispersion of fillers in the rubber matrix, exhibit multifunctional synergistic effect, and have cost advantage, thereby showing broad application prospects in multiple fields.

[0006] Further analysis shows that styrene-butadiene rubber itself has many inherent defects. The strength of pure styrene-butadiene rubber is relatively low, and high-activity reinforcing agents must be added for practical application. However, the dispersion of the reinforcing agent in the rubber is poor, which has been affecting the optimization of the performance of styrene-butadiene rubber. From the perspective of microstructure, the trans structure of styrene-butadiene rubber accounts for a large proportion, the molecular structure lacks regularity, and the side groups have benzene rings, which directly leads to problems such as large hysteresis loss, high heat generation, low elasticity, and poor cold resistance of the rubber material. Before vulcanization, the rubber material shows characteristics such as large shrinkage, low strength, and poor adhesion; and during vulcanization, the vulcanization speed is relatively slow. Even after vulcanization, the rubber shows good resistance to flex cracking, but the crack propagation speed is fast, and the hot tear performance is not ideal. These defects limit the wide application of styrene-butadiene rubber in different environments and working conditions to some extent. SUMMARY

[0007] The technical scheme of the present application aims at the technical problems of poor filler dispersibility and insufficient mechanical properties of traditional styrene-butadiene rubber, and provides a carbon black composite intercalated styrene-butadiene rubber and a preparation method thereof.

[0008] The main purpose of the present application is to: 1. improve the mechanical strength of rubber.

[0009] 2. improve the compatibility of each component in rubber.

[0010] 3. further optimize the oil resistance and solvent resistance of rubber.

[0011] To achieve the above-mentioned purpose, the present application adopts the following technical scheme.

[0012] A preparation method of carbon black composite intercalated styrene-butadiene rubber, the method comprises: 1) the raw materials are proportioned according to the following mass percentage: modified carbon black 12-30 wt%, layered silicate 3-9 wt%, auxiliary agent 1.5-4.2 wt%, and the rest is styrene-butadiene rubber.

[0013] 2) pre-mixing treatment is performed on the styrene-butadiene rubber to obtain a rubber base material.

[0014] 3) the rubber base material is mixed, and the modified carbon black, layered silicate and auxiliary agent are sequentially added to the rubber base material during the treatment process to obtain a rubber precursor.

[0015] 4) the rubber precursor is treated at a gradient temperature, and then pressed to obtain the carbon black composite intercalated styrene-butadiene rubber.

[0016] As a preferred, the modified carbon black in step 1) is prepared by the following method: carbon black, azobisdimethylaminoformamide hydrochloride, polyvinylpyrrolidone, styrene, ammonia and deionized water are uniformly mixed according to a mass ratio of 3: (0.8-1.2):1:0.5:1: (4-6), ultrasonic dispersion for 20 min, reaction under the condition of nitrogen atmosphere, temperature of 70-80 ℃ and rotation speed of 200-300 rpm for 8-12 h, and then centrifugal drying to prepare modified carbon black; the layered silicate in step 1) is montmorillonite.

[0017] As a preferred, the auxiliary agent in step 1) comprises a vulcanizing agent, an antioxidant and an accelerator; the mass percentage of the auxiliary agent in the raw materials is: vulcanizing agent 0.6-1.8 wt%, antioxidant 0.6-1.2 wt%, and accelerator 0.3-1.2 wt%; when the auxiliary agent is added in step 3), the vulcanizing agent is added first and mixed for 3-5 min, and then the antioxidant and the accelerator are added.

[0018] As a preferred, the pre-mixing in step 2) is heat preservation stirring in an environment with a temperature of 80-100 ℃ for 20-30 min.

[0019] Preferably, the mixing in step 3) is carried out at a temperature of 75-80 ℃ for 15-30 min; during the mixing in step 3), the modified carbon black is first added and mixed for at least 5 min, then the layered silicate is added and mixed for at least 3 min, and finally the additive is added and mixed.

[0020] Preferably, the gradient temperature treatment in step 4) comprises a first stage mixing, a second stage mixing, and a third stage aging treatment; the first stage mixing is carried out at a temperature of 80-100 ℃ for 20-30 min; the second stage mixing is carried out at a temperature of 120-140 ℃ for 20-30 min; and the third stage aging treatment is carried out at a temperature of 65-70 ℃ for 10-20 min.

[0021] The core of the technical solution in the present application is that the modified carbon black is combined with the montmorillonite to construct a "carbon black-silicate" dual-phase filler system. Compared with the traditional application method of single filler, the present application utilizes the synergistic effect of the two materials to effectively overcome the limitations of single filler in function. Among them, the carbon black plays a reinforcing role to enhance the tensile strength of the material; the montmorillonite improves the modulus and enhances the barrier property of the material through its unique intercalation structure, thereby improving the wear resistance and oil / solvent resistance. Through this combination, the mechanical properties and oil / solvent resistance of the material are simultaneously optimized.

[0022] In the technical solution of the present application, modified carbon black plays a crucial role. Specifically, by surface modification treatment of carbon black, its surface energy can be significantly reduced. This change greatly enhances the compatibility between modified carbon black and styrene-butadiene rubber, thereby effectively improving the dispersibility of carbon black in styrene-butadiene rubber. More importantly, the active sites generated on the surface of modified carbon black can form hydrogen bonds or van der Waals forces with the hydroxyl groups on the edges of silicate layers, thereby building a unique "carbon black-silicate" network structure. At the same time, under the action of shear force, rubber molecular chains will gradually insert into the interlayer of silicate, finally forming an "intercalation-exfoliation" structure. This structure enables the silicate layers to build a physical barrier in the matrix material, which not only effectively hinders the propagation of cracks, but also significantly improves the rigidity and barrier properties of the material. The coupling of dynamic vulcanization and intercalation is a major innovation of the present application. During dynamic vulcanization, intercalation and dispersion of montmorillonite are simultaneously achieved, successfully avoiding the high energy consumption and low production efficiency problems existing in traditional step-by-step process. During dynamic vulcanization, rubber molecular chains will undergo crosslinking reaction on one hand and orientation arrangement on the other hand, thereby forming a more regular and ordered network structure. It is worth noting that the intercalation process of montmorillonite can be completed simultaneously at this stage, effectively ensuring the close combination of the interface between filler and rubber matrix. With the help of carbon black surface modification and silicate intercalation technology, the dispersion uniformity of fillers in the rubber matrix is greatly improved, and the agglomeration phenomenon is significantly reduced. Therefore, special attention should be paid to the addition order of materials during the mixing process, and modified carbon black should be added first to create an environment suitable for the addition of montmorillonite, and other additives should be added after the preliminary completion of montmorillonite compounding, in order to reduce the influence of additives on this process.

[0023] In the present application, another core element is to use gradient temperature to optimize the treatment of rubber molecular chains.

[0024] In the first stage, setting a higher temperature has multiple positive effects. Higher temperature can significantly improve the flowability of rubber molecular chains, creating favorable conditions for the further uniform dispersion of fillers (such as modified carbon black, montmorillonite, etc.) in the rubber matrix. This process not only helps fillers to be more fully integrated into the rubber system, but also effectively reduces the viscosity of the system. The reduction of viscosity directly leads to the reduction of mixing energy consumption, improving production efficiency while reducing production cost.

[0025] In the second stage, the temperature is adjusted to a moderate range, and the specific shear force is crucial for the exfoliation and intercalation process of montmorillonite. Under this condition, montmorillonite can be successfully exfoliated and inserted between the rubber molecular chains, thereby forming a nanoscale dispersion structure. This nanoscale dispersion structure has a non-negligible effect on improving the overall performance of the material, such as mechanical properties, barrier properties, etc. Therefore, attention should be paid to the fact that a higher rotational speed should be used for mixing during the second stage of mixing, and the rotational speed should generally be maintained at 90-150 rpm.

[0026] In the third stage, gradually reducing the temperature is the key operation. Gradual cooling can promote the ordered arrangement of rubber molecular chains, allowing them to form a stable crosslinked network during the crosslinking reaction. This stable crosslinked network structure helps to reduce stress concentration in the material and improve the stability and reliability of the material.

[0027] From the perspective of staged dispersion, the entire process presents a synergistic mechanism between the components. In a high-temperature environment, modified carbon black achieves uniform dispersion due to its good dispersion performance; as the temperature decreases to the medium temperature range, intercalation of silicates is successfully performed; and at low temperature, the rubber molecular chains are fixed, finally forming a gradient distribution structure of "carbon black-silicate-rubber". This unique gradient distribution structure fully utilizes the advantages of each component to optimize the combination of material performance.

[0028] In terms of interface reinforcement, the change in temperature gradient may activate various functional groups on the surface of the filler, such as hydroxyl groups and carboxyl groups. These activated functional groups can significantly enhance the interaction between the filler and the rubber matrix, whether through chemical bonding or physical adsorption, effectively improving the interface bonding strength. The improvement of interface bonding strength further improves the overall performance of the material, enabling the material to better transmit stress when subjected to external forces, thereby exhibiting superior mechanical properties and use performance. At the same time, the intercalation of the composite enables the styrene-butadiene rubber to have an internal rigid barrier interface, which significantly controls the swelling rate and oil permeation rate of the styrene-butadiene rubber in terms of solvent resistance.

[0029] The beneficial effects of the present application are: by constructing a "carbon black-silicate" dual-phase filler system, the present application utilizes the synergistic effect of the two materials to improve the modulus and barrier properties of the material, achieving dual optimization of the mechanical properties and oil resistance / solvent resistance of the material. DETAILED DESCRIPTION

[0030] The present application will be further described in greater detail by way of specific embodiments. Those skilled in the art will be able to implement the present application based on the description. In addition, the embodiments of the present application involved in the following description are generally only a part of the embodiments of the present application, not all the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative labor should be within the scope of protection of the present application.

[0031] Unless otherwise specified, the raw materials used in the embodiments of the present application are commercially available or available to those skilled in the art. Unless otherwise specified, the methods used in the embodiments of the present application are methods mastered by those skilled in the art. Unless otherwise specified, the stirring and mixing speeds in the embodiments of the present application are conventional speeds of 30 rpm.

[0032] Example 1: A preparation method of carbon black composite intercalated styrene-butadiene rubber, the ingredients are: 12 wt% modified carbon black, 3 wt% layered silicate, 0.6 wt% vulcanizing agent, 0.6 wt% antioxidant, 0.3 wt% accelerator, and the balance is styrene-butadiene rubber.

[0033] The preparation process is: 1) the styrene-butadiene rubber is stirred at a temperature of 80 ℃ for 30 min to obtain a rubber base material.

[0034] 2) Carbon black, azobisdimethylamid hydrochloride, polyvinylpyrrolidone, styrene, ammonia and deionized water are mixed uniformly according to a mass ratio of 3:0.8:1:0.5:1:4, ultrasonic dispersion for 20 min, reaction under the conditions of nitrogen atmosphere, temperature of 70 ℃ and rotation speed of 200 rpm for 12 h, followed by centrifugal drying, grinding into fine powder to prepare modified carbon black.

[0035] 3) The rubber base material is mixed at 75 ℃, the modified carbon black is initially added and mixed for 5 min, then the montmorillonite is added and mixed for 5 min, the sulfur is continuously added and mixed for 5 min, and finally the N-cyclohexyl-2-benzothiazole sulfenamide and antioxidant 4010NA are added to complete the mixing, the total mixing time is 35 min, to obtain a rubber precursor.

[0036] 4) The rubber precursor is mixed and stirred at a temperature of 80 ℃ for 30 min in the first stage, stirred at a temperature of 120 ℃ and a rotation speed of 100 rpm for 30 min in the second stage, and kept at a temperature of 65 ℃ for 20 min in the third stage. Then it is pressed and molded to obtain carbon black composite intercalated styrene-butadiene rubber after cooling.

[0037] The styrene-butadiene rubber prepared in the example is subjected to performance detection, and the specific detection steps and characterization results are as follows.

[0038] Mechanical property detection: The rubber material prepared in the example was prepared into a dumbbell-shaped detection sample with a thickness of 2 mm and a gauge length of 25 mm according to GB / T 528-2009 "Vulcanized or thermoplastic rubber. Determination of tensile stress-strain properties". The maximum elongation strength and elongation at break of the rubber material were recorded at a tensile rate of 500 mm / min.

[0039] Hardness detection: The rubber material prepared in the example was detected by vertical pressing the surface of the detection sample using a Shore A hardness tester according to GB / T 531.1-2008 "Vulcanized or thermoplastic rubber indentation hardness test method". The reading was taken after 5 seconds of stabilization.

[0040] Abrasion resistance detection: The rubber material prepared in the example was prepared into a detection sample with a diameter of 16 mm and a length of 6 mm, and its mass was recorded. Then it was tested on an Akron abrasion tester at 1.61 km of travel, and the mass after abrasion was weighed and the mass difference was calculated to calculate the volume abrasion amount.

[0041] Distance expansion detection: The rubber material prepared in the example was ground to 200 mesh, and the distance expansion of the carbon black composite intercalation was recorded by XRD scanning.

[0042] Oil resistance / solvent resistance detection: The rubber material prepared in the example was prepared into a square sheet standard sample with a size of 50 mm x 50 mm x 2 mm, and immersed in methane at 23 °C for 24 h. The swelling rate of the standard sample was calculated.

[0043] Table 1: Characterization results of Example 1 sample:

[0044] Analyzing the above Table 1 characterization results, the carbon black composite intercalated styrene-butadiene rubber prepared in Example 1 exhibits excellent mechanical properties. The maximum tensile strength reaches 30.2 MPa, and the elongation at break is 451.6%, which indicates that the material has high strength and good toughness when subjected to external forces, effectively resisting deformation and fracture. The Shore A hardness value is 75.3, which makes the material have better adaptability and wear resistance in practical application. The abrasion resistance detection result shows that the volume abrasion amount is 0.04 cm 3 / 1.6 km, which is relatively low, further confirming the excellent wear resistance of the material. The distance expansion is 3.5 nm, which reflects the successful construction of the carbon black composite intercalation structure and the effective dispersion of silicate layers in the rubber matrix.

[0045] Compared with traditional styrene-butadiene rubber, the carbon black composite intercalated styrene-butadiene rubber prepared in Example 1 has significant improvement in mechanical properties, wear resistance and the like. And compared with the swelling rate of traditional styrene-butadiene rubber as high as 150-200%, the swelling rate of the rubber of the present application only decreases greatly, indicating that the oil resistance / solvent resistance has been significantly optimized and improved. This is mainly due to the synergistic effect of modified carbon black and montmorillonite, and the optimization of gradient temperature treatment process. The modified carbon black significantly improves the dispersibility and compatibility in the styrene-butadiene rubber through surface modification treatment, thereby enhancing the tensile strength and wear resistance of the material. At the same time, the intercalated structure of montmorillonite effectively improves the modulus and barrier properties of the material, further improving the wear resistance. The gradient temperature treatment process improves the stability and reliability of the material by optimizing the arrangement of rubber molecular chains and crosslinking network structure.

[0046] Example 2: A preparation method of carbon black composite intercalated styrene-butadiene rubber, the ingredients are: 21 wt% modified carbon black, 6 wt% layered silicate, 1.2 wt% vulcanizing agent, 0.9 wt% antioxidant, 0.9 wt% accelerator, and the balance is styrene-butadiene rubber.

[0047] The preparation process is: 1) the styrene-butadiene rubber is heated and stirred at a temperature of 90 ℃ for 25 min to obtain a rubber base material.

[0048] 2) The carbon black, azobisdimethylamidinum hydrochloride, polyvinylpyrrolidone, styrene, ammonia and deionized water are mixed uniformly according to a mass ratio of 3:1:1:0.5:1:5, ultrasonic dispersion for 20 min, reaction for 10 h under the conditions of nitrogen atmosphere, temperature of 75 ℃ and rotation speed of 250 rpm, and then centrifugal drying and grinding into fine powder to prepare modified carbon black.

[0049] 3) The rubber base material is mixed at 78 ℃, the modified carbon black is added initially and mixed for 5 min, then the montmorillonite is added and mixed for 5 min, the sulfur is continuously added and mixed for 3 min, and finally the N-cyclohexyl-2-benzothiazole sulfenamide and antioxidant 4010NA are added to complete the mixing, the total mixing time is 30 min, to obtain a rubber precursor.

[0050] 4) The rubber precursor is mixed and stirred at a temperature of 90 ℃ for 25 min in the first stage, stirred at a temperature of 130 ℃ and a rotation speed of 125 rpm for 25 min in the second stage, and kept at a temperature of 68 ℃ for 15 min in the third stage. Then it is pressed and molded to obtain the carbon black composite intercalated styrene-butadiene rubber after cooling.

[0051] The styrene-butadiene rubber prepared in the example is subjected to performance detection, and the specific detection steps and characterization results are as follows.

[0052] Mechanical property detection: The rubber material prepared in the example was prepared into a detection sample with a thickness of 2 mm and a gauge length of 25 mm according to the dumbbell type detection sample specification in GB / T 528-2009 "Vulcanized rubber or thermoplastic rubber. Determination of tensile stress-strain properties". The maximum elongation strength and elongation at break of the rubber material were recorded at a tensile rate of 500 mm / min.

[0053] Hardness detection: The rubber material prepared in the example was detected using a Shore A hardness tester according to GB / T 531.1-2008 "Vulcanized rubber or thermoplastic rubber indentation hardness test method". The sample surface was vertically indented, and the reading was taken after 5 seconds of stabilization.

[0054] Abrasion resistance detection: The rubber material prepared in the example was prepared into a detection sample with a diameter of 16 mm and a length of 6 mm, and its mass was recorded. Then, it was tested on an Akron abrasion tester at 1.61 km of travel, and the mass after abrasion was weighed and the mass difference was calculated to calculate the volume abrasion amount.

[0055] Distance expansion detection: The rubber material prepared in the example was ground to 200 mesh, and the distance expansion of the carbon black composite intercalation was recorded by XRD scanning.

[0056] Oil resistance / solvent resistance detection: The rubber material prepared in the example was prepared into a square sheet standard sample with a size of 50 mm x 50 mm x 2 mm, and immersed in methane at 23 °C for 24 h. The swelling rate of the standard sample was calculated.

[0057] Table 2: Characterization results of Example 2 samples:

[0058] Analyzing the above characterization results in Table 2, in Example 2, by adjusting the content of carbon black and silicate and the parameters such as temperature and rotation speed during preparation, the carbon black composite intercalated styrene-butadiene rubber prepared exhibits excellent mechanical properties. The maximum tensile strength is 30.3 MPa, the elongation at break is 451.8%, the Shore hardness value is 75.4, the abrasion resistance volume abrasion amount is 0.03 cm³ / 1.6 km, the distance expansion is 3.7 nm, and the swelling rate is 46.2%. These data show that the material in Example 2 achieves a high level in terms of mechanical properties, hardness, abrasion resistance, and oil resistance / solvent resistance, and the carbon black composite intercalation structure is effectively constructed.

[0059] Compared with Example 1, Example 2 makes slight adjustments in the formula and process, but the performance of the prepared carbon black composite intercalated styrene-butadiene rubber does not decrease significantly, but rather improves in some indicators. This further confirms the stability and reliability of the method provided by the present application, as well as the superiority of the synergistic effect of modified carbon black and montmorillonite. In Example 2, by increasing the content of modified carbon black and silicate, and appropriately adjusting the temperature and speed conditions in the preparation process, the performance of the material can be further optimized. Increasing the content of modified carbon black can enhance the tensile strength and wear resistance of the material, while increasing the content of silicate can help improve the modulus and barrier properties of the material. At the same time, the optimization of the gradient temperature treatment process can also promote the arrangement of the rubber molecular chain and the formation of the crosslinked network structure, thereby improving the stability and reliability of the material.

[0060] Example 3: A method for preparing a carbon black composite intercalated styrene-butadiene rubber, with the following ingredients: 30 wt% modified carbon black, 9 wt% layered silicate, 1.8 wt% vulcanizing agent, 1.2 wt% antioxidant, 1.2 wt% accelerator, and the balance being styrene-butadiene rubber.

[0061] The preparation process is as follows: 1) The styrene-butadiene rubber is heated and stirred at a temperature of 100 °C for 20 min to obtain a rubber base material.

[0062] 2) Carbon black, azobisdimethylamidinum hydrochloride, polyvinylpyrrolidone, styrene, ammonia, and deionized water are mixed uniformly in a mass ratio of 3:1.2:1:0.5:1:6, ultrasonically dispersed for 20 min, reacted in a nitrogen atmosphere at a temperature of 80 °C and a speed of 300 rpm for 8 h, then centrifuged and dried, ground into fine powder, and prepared into modified carbon black.

[0063] 3) The rubber base material is mixed at 80 °C, with the initial addition of modified carbon black for 5 min, followed by the addition of montmorillonite for 3 min, the addition of sulfur for 3 min, and finally the addition of N-cyclohexyl-2-benzothiazole sulfenamide and antioxidant 4010NA to complete the mixing, with a total mixing time of 20 min, to obtain a rubber precursor.

[0064] 4) The rubber precursor is mixed and stirred at a temperature of 100 °C for 20 min in the first stage, at a temperature of 140 °C and a speed of 150 rpm for 20 min in the second stage, and at a temperature of 70 °C for 10 min in the third stage. Then it is pressed and formed into a carbon black composite intercalated styrene-butadiene rubber after cooling.

[0065] The styrene-butadiene rubber prepared in the example is subjected to performance testing, with the specific testing steps and characterization results as follows.

[0066] Mechanical property detection: The rubber material prepared in the example was prepared into a dumbbell-shaped detection sample with a thickness of 2 mm and a gauge length of 25 mm according to GB / T 528-2009 "Vulcanized rubber or thermoplastic rubber. Determination of tensile stress-strain properties". The maximum elongation strength and elongation at break of the rubber material were recorded at a tensile rate of 500 mm / min.

[0067] Hardness detection: The rubber material prepared in the example was detected by vertical pressing the surface of the detection sample using a Shore A hardness tester according to GB / T 531.1-2008 "Vulcanized rubber or thermoplastic rubber indentation hardness test method". The reading was taken after 5 seconds of stabilization.

[0068] Wear resistance detection: The rubber material prepared in the example was prepared into a detection sample with a diameter of 16 mm and a length of 6 mm, and its mass was recorded. Then, it was tested on an Akron abrasion tester at a stroke of 1.61 km, and the mass after abrasion was weighed and the mass difference was calculated to calculate the volume abrasion amount.

[0069] Distance expansion detection: The rubber material prepared in the example was ground to 200 mesh, and the distance expansion of the carbon black composite intercalation was recorded by XRD scanning.

[0070] Oil resistance / solvent resistance detection: The rubber material prepared in the example was prepared into a square sheet standard sample with a size of 50 mm x 50 mm x 2 mm, and immersed in methane at 23 °C for 24 h. The swelling rate of the standard sample was calculated.

[0071] Table 3: Characterization results of Example 3 samples:

[0072] Analyzing the above Table 3 characterization results, in Example 3, by further adjusting the content of carbon black and silicate and the temperature, rotation speed and time parameters in the preparation process, the carbon black composite intercalated styrene-butadiene rubber prepared also exhibits excellent mechanical properties. The maximum tensile strength is 30.2 MPa, the elongation at break is 451.7 %, the Shore hardness value is 75.3, the wear resistance volume abrasion amount is 0.05 cm³ / 1.6 km, the distance expansion is 3.2 nm, and the swelling rate is 43.1 %. These data show that the material in Example 3 maintains a high level in mechanical properties, hardness, wear resistance and oil resistance / solvent resistance, and the carbon black composite intercalation structure is effectively maintained.

[0073] Compared with Example 1 and Example 2, Example 3 made a greater adjustment in the formula and process, but the prepared carbon black composite intercalated styrene-butadiene rubber did not show a significant decline in performance, which further verified the flexibility and stability of the method provided by the application. In Example 3, by further increasing the content of modified carbon black and appropriately adjusting the content of silicate, as well as optimizing the temperature and rotation speed conditions in the preparation process, an excellent carbon black composite intercalated styrene-butadiene rubber was successfully prepared. The characterization results of Example 3 also showed that the material not only maintained high mechanical properties, but also exhibited good wear resistance and stability of the carbon black composite intercalated structure. This is mainly due to the synergistic effect of modified carbon black and montmorillonite, as well as the optimization of the gradient temperature treatment process.

[0074] Comparative Example 1: Based on Example 2, this example only changes the styrene-butadiene rubber component, and the remaining steps are the same as Example 2. The specific settings are as follows: Table 4: Comparison table of styrene-butadiene rubber components of Comparative Example 1 and Example 2:

[0075] The performance test method of the product of Comparative Example 1 is completely consistent with Example 1, and the characterization results are shown in Table 5 below.

[0076] Table 5: Characterization results of Comparative Example 1 sample:

[0077] Analyzing the above Table 5 characterization results, in the comparative example, by making different changes to the styrene-butadiene rubber component, the role of modified carbon black and montmorillonite in carbon black composite intercalated styrene-butadiene rubber was explored. Compared with Example 2, D1-1 group only uses modified carbon black as a rubber base modifier material, and its maximum tensile strength decreases to 20.4 MPa, the elongation at break is 391.7 %, the Shore hardness value is 69.4, the volume wear amount of wear resistance increases to 0.16 cm³ / 1.6 km, and the swelling rate is 132.3 %. These data show that the use of only modified carbon black can improve some properties of the material, but compared with the synergistic effect of modified carbon black and montmorillonite in Example 2, the overall performance has declined. And due to the inability to form a composite intercalation barrier, the swelling rate of the rubber increases sharply, indicating that the synergistic intercalation barrier of carbon black-montmorillonite is very helpful to improve the oil resistance / solvent resistance of the rubber.

[0078] D1-2 group only uses montmorillonite as a rubber base material modifier, the maximum tensile strength is 23.7 MPa, the elongation at break is 426.1 %, the Shore hardness value is 62.4, the volume wear resistance is increased to 0.21 cm³ / 1.6 km, and the swelling rate is as high as 162.8 %, which is not different from conventional styrene-butadiene rubber. Compared with D1-1 group, the performance of D1-2 group is slightly improved, but it is still significantly lower than example 2. This further confirms the important role of modified carbon black in improving the tensile strength and wear resistance of the material. In terms of oil resistance / solvent resistance, the main layer of montmorillonite theoretically plays a role in intercalation barrier oil resistance / solvent resistance, but the swelling rate of the sample in this example is extremely high. Theoretically, the layered montmorillonite has good barrier effect and rigidity can effectively limit oil penetration and swelling, but in this sample, the montmorillonite is directly used and does not form a uniform dispersion and form a barrier intercalation structure in the rubber. Instead, it may cause segregation, agglomeration and other conditions, resulting in a significant decrease in performance, and even structural defects leading to a higher swelling rate than the D1-1 sample.

[0079] The sample in D1-3 group uses commercially available carbon black N330 instead of the modified carbon black of the application. It can be seen that there is little difference in mechanical properties, and the most significant is the maximum elongation strength and elongation at break. This is mainly due to the distribution problem of carbon black, and the swelling rate is worse than the sample of example 2 of the application. This is mainly because ordinary carbon black cannot form active sites like the modified carbon black of the application, and form hydrogen bonds or van der Waals forces between the hydroxyl groups on the edges of the silicate layers to build a unique "carbon black-silicate" network structure. This leads to segregation and other phenomena, and montmorillonite cannot play its role in building a barrier intercalation structure.

[0080] D1-4 group changes the filler system, the maximum tensile strength is 29.3 MPa, the elongation at break is as high as 396.4 %, the Shore hardness value is increased to 76.6, the volume wear resistance is 0.25 cm³ / 1.6 km, and the swelling rate is 89.3 %. These data show that on the basis of the filler system of the application, adding other fillers to form a unique "carbon black-silicate" network structure has a great possibility of being destroyed, thereby causing the performance to decline in many aspects.

[0081] In the present application, the modified carbon black is uniformly dispersed in the rubber matrix in the form of nano-sized particles, and the silicate layers are constructed in a layered structure in the form of "intercalation-exfoliation". The two materials form a three-dimensional reinforcing network through interfacial interaction. The interaction (such as hydrogen bonding) between the modified groups on the surface of carbon black and the hydroxyl groups of silicate enhances the interfacial adhesion between the filler and the matrix, thereby reducing the stress concentration phenomenon. Carbon black enhances the tensile strength of rubber through the action of physical adsorption and chemical crosslinking points; while the silicate layers suppress the slip of molecular chains through the "pinning effect", thereby improving the modulus. The layered structure of silicate can form a self-lubricating layer during friction, effectively reducing surface wear; at the same time, its barrier effect also helps to reduce the crack propagation path. The construction of the vulcanization crosslinking network is synchronized with the intercalation process of silicate, effectively avoiding the problem of reduced interfacial compatibility that may occur in the step-by-step process.

[0082] Comparative Example 2: Based on Example 2, only the processing environment of the gradient temperature treatment of the rubber precursor is changed, and the remaining steps are the same as Example 2. The specific settings are as follows: Table 6: Processing environment comparison table of Comparative Example 2 and Example 2:

[0083] The performance test method of the product of the comparative example is completely consistent with Example 1, and the characterization results are shown in Table 7 below.

[0084] Table 7: Characterization results of Comparative Example 2 samples:

[0085] Analyzing the characterization results in Table 7 above, in the D2-1 experimental group of Comparative Example 2, the processing environment temperature of the rubber precursor is changed to explore the effect of temperature on the performance of carbon black composite intercalated styrene-butadiene rubber. Compared with Example 2, the D2-1 group uses a temperature of 150 ℃ environment for constant temperature processing, its maximum tensile strength decreases to 24.7 MPa, the elongation at break is 462.7 %, the Shore hardness value increases to 78.2, the wear resistance volume wear increases to 0.08 cm³ / 1.6 km, and the distance expansion is 2.9 nm. These data show that too high processing environment temperature can have an adverse effect on the mechanical properties of carbon black composite intercalated styrene-butadiene rubber, resulting in a decrease in tensile strength, while hardness and wear resistance increase. The decrease in distance expansion and the significant increase in swelling rate may mean that at high temperatures, the intercalation effect of silicate layers is damaged to some extent, thereby affecting the overall performance of the material.

[0086] And the D2-2 experimental group shows that the high-speed shearing of the second stage mixing also has an important influence on the construction and distribution of the intercalation structure. Compared with the D2-1 experimental group, the D2-2 experimental group has both advantages and disadvantages in mechanical properties, but the degree of deterioration of the swelling rate is greater than that of D2-1, which also shows the necessity of high-speed shearing.

[0087] Comparative Example 3: In this example, the traditional step vulcanization process was used, and the specific operation steps are as follows.

[0088] 1) The butadiene styrene rubber was stirred at a temperature of 90°C for 20 min to obtain a rubber base material.

[0089] 2) The rubber base material was added with 2 wt% of sulfur and 1.2 wt% of N-cyclohexyl-2-benzothiazole sulfenamide, and dynamically vulcanized at a temperature of 150°C for 15 min.

[0090] 3) The vulcanized rubber was transferred to a twin-screw extruder, 9 wt% of montmorillonite and 30 wt% of modified carbon black prepared by the same process of Example 2 were added, and intercalation compounding was carried out at a temperature of 130°C and a shear rate of 100 rpm.

[0091] 4) Molding, after cooling, the preparation method of carbon black intercalation butadiene styrene rubber was obtained.

[0092] The process used in this example was recorded, and part of the performance test was carried out with reference to Example 1, and the specific characterization results are as follows.

[0093] Energy consumption monitoring: The power consumption (kW) of the internal mixer and the twin-screw extruder was recorded in real time using an electric energy meter, and the unit energy consumption was recorded according to the following formula.

[0094] .

[0095] Table 8: Characterization results of Comparative Example 3 samples:

[0096] By analyzing the results in Table 8, it is found that the rubber material prepared by the traditional step-by-step vulcanization process in D3-1 group has slightly lower maximum tensile strength, elongation at break and Shore hardness than that in Example 2. Specifically, the maximum tensile strength of D3-1 group is 27.7 MPa, the elongation at break is 425.6 %, and the Shore hardness value is 75.1, which are all lower than the corresponding values in Example 2. In addition, the volume abrasion loss of D3-1 group is 0.09 cm³ / 1.6 km, which is similar to that of Example 2, but the unit energy consumption is as high as 2.5 kWh / kg, which is significantly higher than the 1.8 kWh / kg of Example 2. These data show that the traditional step-by-step vulcanization process not only has slightly lower mechanical properties than the method provided by the present application, but also has a large gap in energy consumption. This is mainly due to the separation of the vulcanization and intercalation steps in the traditional process, which may lead to a decrease in interfacial compatibility and thus affect the overall performance of the material. At the same time, the step-by-step process also increases the energy consumption and cost in the production process. Therefore, the preparation method provided by the present application not only maintains high performance, but also effectively reduces energy consumption.

Claims

1. A method for preparing a carbon black composite intercalated styrene-butadiene rubber, characterized by, The method comprises: 1) ingredient of raw materials in the following mass percentage: modified carbon black 12-30 wt%, layered silicate 3-9 wt%, auxiliary agent 1.5-4.2 wt%, and the rest is butadiene styrene rubber; 2) pre-mixing treatment of butadiene styrene rubber to obtain a rubber base material; 3) mixing of the rubber base material, wherein the modified carbon black, layered silicate and auxiliary agent are sequentially added to the rubber base material during the treatment process to obtain a rubber precursor; 4) gradient temperature treatment of the rubber precursor, followed by compression molding to obtain a carbon black composite intercalated butadiene styrene rubber.

2. The method for preparing carbon black composite intercalated styrene-butadiene rubber according to claim 1, characterized in that, In step 1), the modified carbon black is prepared by mixing carbon black, azobisdimethylamidine hydrochloride, polyvinylpyrrolidone, styrene, ammonia and deionized water in a mass ratio of 3: (0.8-1.2):1:0.5:1: (4-6) uniformly, ultrasonic dispersion for 20 min, reaction under the conditions of nitrogen atmosphere, temperature of 70-80 ℃ and rotation speed of 200-300 rpm for 8-12 h, and then centrifugal drying to obtain the modified carbon black; and the layered silicate in step 1) is montmorillonite.

3. The method for preparing carbon black composite intercalated styrene-butadiene rubber according to claim 2, characterized in that, In step 1), the auxiliary agent includes vulcanizing agent, antioxidant and accelerator; the mass percentage of the auxiliary agent in the raw materials is: vulcanizing agent 0.6-1.8 wt%, antioxidant 0.6-1.2 wt%, and accelerator 0.3-1.2 wt%; and the auxiliary agent is added in step 3) by first adding the vulcanizing agent and mixing for 3-5 min, and then adding the antioxidant and accelerator.

4. The method for preparing carbon black composite intercalated styrene-butadiene rubber according to claim 1, characterized in that, In step 2), the pre-mixing is heat preservation and stirring for 20-30 min at a temperature of 80-100 ℃.

5. The method for preparing carbon black composite intercalated styrene-butadiene rubber according to claim 1, characterized in that, In step 3), the mixing is mixing for 20-35 min at a temperature of 75-80 ℃; and in the mixing process of step 3), the modified carbon black is first added and mixed for at least 5 min, then the layered silicate is added and mixed for at least 3 min, and finally the auxiliary agent is added and continuously mixed.

6. The method for preparing carbon black composite intercalated styrene-butadiene rubber according to claim 1, characterized in that, In step 4), the gradient temperature treatment includes first stage mixing, second stage mixing and third stage aging treatment; the first stage mixing temperature is 80-100 ℃, and the mixing time is 20-30 min; the second stage mixing temperature is 120-140 ℃, and the mixing time is 20-30 min; and the third stage aging treatment temperature is 65-70 ℃, and the heat preservation time is 10-20 min.

7. A carbon black composite intercalated butadiene styrene rubber prepared by the method of any one of claims 1-6.

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