Modified thermal cracking carbon black / white carbon black composite material and preparation method thereof

Abstract

The invention provides a modified thermal cracking carbon black / white carbon black composite material and a preparation method thereof, and belongs to the technical field of rubber composite materials. The composite material comprises a natural rubber matrix, and plasma modified pyrolysis carbon black (P-CBp) and white carbon black which are dispersed in the natural rubber matrix. Wherein the P-CBp is obtained by plasma treatment for 3 minutes at the discharge power of 400W in a high-purity argon atmosphere. When the mass fraction of the P-CBp and the mass fraction of the white carbon black are 20 phr and 60 phr respectively, the composite material shows relatively high crosslinking density and excellent wear resistance. Researches show that the P-CBp can effectively improve the dispersibility of the white carbon black in the rubber and form a stable particle network, so that the interface interaction between the filler and the rubber is enhanced. Therefore, a new way is provided for preparing the high-performance green tire tread rubber, and resource utilization of the waste tires is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber composite materials, and in particular relates to a modified thermal cracking carbon black / white carbon black composite material and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry and the continued growth in tire consumption, the widespread use of traditional carbon black (CB) in tire production has led to increasingly serious environmental pollution. Carbon black production consumes a lot of energy and produces significant carbon emissions, and its impact on the environment during tire use and disposal cannot be ignored. Therefore, finding a more environmentally friendly and sustainable alternative material has become a key focus of the industry.

[0003] In this context, silica has gradually been widely used in green tire manufacturing due to its good wear resistance, low rolling resistance and environmental protection properties. However, silica is rich in silanol (Si-OH) groups on its surface, has strong hydrophilicity and surface activity, and is prone to agglomeration, resulting in uneven dispersion in the rubber matrix, which in turn affects the mechanical properties and service life of the rubber composite. At the same time, pyrolysis carbon black (CBp), as a by-product of pyrolysis recovery of waste tires, has the advantages of low cost and high resource recycling value. However, CBp still faces many challenges in practical applications, such as high surface ash content, small specific surface area, underdeveloped pore structure and low surface functional group activity. These factors significantly limit its reinforcement effect in rubber products, making it difficult to reach the performance level of commercial carbon black.

[0004] Currently, the use of CBp or silica alone, or a simple physical mixture of the two, in rubber filling systems generally suffers from defects such as poor filler dispersion and weak interfacial bonding with the rubber matrix. This results in reduced wear resistance of the composite material, making it unable to meet the stringent material performance requirements of high-performance tires. Therefore, there is an urgent need to develop new technical means or modification methods to effectively enhance the synergistic reinforcement effect between CBp and silica, improve their dispersion state and interfacial interaction in the rubber matrix, and thus achieve the dual goals of efficient resource utilization and improved material performance. Summary of the Invention

[0005] The object of the present invention is to provide a modified thermal cracking carbon black / white carbon black composite material and a preparation method thereof, so as to achieve the goals of efficient resource utilization and improved material performance.

[0006] To achieve the above object, the present invention provides the following technical solutions: First, the present invention provides a modified thermal cracking carbon black / white carbon black composite material, comprising a natural rubber matrix and plasma-modified thermal cracking carbon black and white carbon black dispersed in the natural rubber matrix; Preferably, the plasma-modified thermal carbon black is prepared by treating the carbon black in a high-purity argon atmosphere at a discharge power of 400 W for 3 minutes.

[0007] Preferably, the raw materials for preparing the modified thermal cracking carbon black / white carbon black composite material include the following components, calculated by mass: 100 parts of natural rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant RD, 1 part of paraffin oil, 20-60 phr of plasma-modified thermal cracking carbon black, 20-60 parts of white carbon black, 2-6 parts of silane coupling agent Si-69, 0.4-1.2 parts of accelerator D, 1.2 parts of accelerator NS and 2 parts of sulfur.

[0008] Preferably, the raw materials for preparing the modified thermal cracking carbon black / white carbon black composite material include the following components, calculated by mass: 100 parts of natural rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant RD, 1 part of paraffin oil, 20 phr of plasma-modified thermal cracking carbon black, 60 parts of white carbon black, 6 parts of silane coupling agent Si-69, 1.2 parts of accelerator D, 1.2 parts of accelerator NS and 2 parts of sulfur.

[0009] Preferably, the preparation method of the modified thermal cracking carbon black / white carbon black composite material comprises the following steps: (1) Natural rubber, zinc oxide, stearic acid, and antioxidant RD were sequentially added to an internal mixer and mixed for a period of time, and then plasma-modified thermal cracking carbon black, white carbon black, silane coupling agent Si-69, and paraffin oil were added. After the first mixing, the rubber was discharged; (2) The rubber material discharged in (1) is left at room temperature for more than or equal to 6 hours; (3) Second mixing and rubber removal in the internal mixer; (4) adding sulfur, accelerator D and accelerator NS to the rubber material discharged in (3) in an open mill, tapping and refining the rubber to obtain a rubber mix; (5) After standing at room temperature for 6 hours or more, the rubber mixture is vulcanized using a flat plate vulcanizer to obtain the modified thermal cracked carbon black / white carbon black composite material.

[0010] Preferably, the initial temperature of the first mixing is 90°C, and the binder removal temperature is 150°C; the initial temperature of the second mixing is 100°C, and the binder removal temperature is 150°C; The vulcanization temperature is 150°C.

[0011] Secondly, the present invention provides an application of the composite material in preparing a tire tread rubber having high mechanical properties and wear resistance, wherein the mechanical properties are tensile strength, hardness and rebound performance.

[0012] Finally, the present invention provides a method for preparing a pyrolysis carbon black / white carbon black composite material with high mechanical properties and wear resistance, the preparation method comprising a pyrolysis carbon black modification stage and a pyrolysis carbon black / white carbon black composite material preparation stage; The mechanical properties are tensile strength, hardness and resilience.

[0013] Preferably, the step of the thermal cracking carbon black modification stage is to place the thermal cracking carbon black in a high-purity argon atmosphere, set the discharge power to 400 W, and treat for 3 minutes to obtain plasma-modified thermal cracking carbon black.

[0014] Preferably, the steps of the thermal cracking carbon black / white carbon black composite material preparation stage are: (1) Add natural rubber, zinc oxide, stearic acid, and antioxidant RD into the internal mixer in sequence. After the torque stabilizes, add plasma-modified thermal cracking carbon black, white carbon black, silane coupling agent Si-69, and paraffin oil in sequence. After the mixing temperature reaches 150°C, discharge the rubber. (2) Place the rubber material discharged from (1) at room temperature; (3) Mixing is performed for the second time in an internal mixer, and the rubber is discharged after the mixing temperature reaches 150°C; (4) adding sulfur, accelerator D and accelerator NS to the rubber material discharged from (3) on an open mill, tapping and refining the rubber to obtain a rubber mix; (5) After standing at room temperature, the rubber mixture is vulcanized at 150° C. using a flat plate vulcanizer to obtain the thermal cracked carbon black / white carbon black composite material having high mechanical properties and wear resistance.

[0015] The beneficial effects of the present invention are: The present invention utilizes plasma etching to remove ash from the CBp surface, reducing particle size and increasing surface active sites, allowing it to form a hydrogen bond network with the silanol groups of white carbon black, thereby improving the dispersion of silica in the NR matrix. The "physical isolation" effect of P-CBp inhibits silica agglomeration, forming a stable particle network, and improving the poor dispersion and weak reinforcement effects of traditional fillers. The synergistic effect of P-CBp and silica forms a strong interfacial interaction and a stable particle network, giving the composite material a high crosslinking density and excellent wear resistance. It can be used in the preparation of green tire tread rubber and promote the resource utilization of waste tires. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 shows the (a-b) TEM images and (c) particle size distribution of CBp and P-CBp primary particles; FIG2 shows (a) the acetone dispersion state and (bc) XPS detection results of CBp and P-CBp aggregates; Figure 3 shows the crosslinking density of NR composites filled with different ratios of Silica / P-CBp and Silica / CBp; Figure 4 shows the (a) DIN wear volume and (b) Akron wear volume of NR composites filled with different ratios of Silica / P-CBp and Silica / CBp; Figure 5 shows the change of friction coefficient of the composite material with time at a speed of 0.5 m / s: (a) the result of pressure of 40 N; (b) the result of pressure of 60 N; Figure 6 shows the wear surface morphology of the grinding wheel of NR composites filled with different ratios of Silica / P-CBp and Silica / CBp; Figure 7 shows the TEM images of NR composites filled with different proportions of Silica / P-CBp and Silica / CBp. DETAILED DESCRIPTION

[0017] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.

[0018] Example 1 Obtaining plasma-modified CBp (1) Dry thermal cracking carbon black (CBp, purchased from Qingdao Ixstar Technology Co., Ltd., product number: EN330) was placed in a drum-type plasma reactor; (2) After the interior of the reactor is vacuumed, high-purity argon (Ar) is introduced as a protective gas and plasma generating gas until the gas environment is stable; (3) The discharge power was 400 W, and the drum plasma treatment was performed for 3 minutes to obtain plasma-modified CBp (P-CBp).

[0019] Example 2 Preparation of natural rubber S / P-60 filled with modified thermal carbon black hybrid The composition of this natural rubber S / P-60 is as follows: Natural rubber 100 phr (Jiangsu Guanlian New Materials Technology Co., Ltd., model SVR-CV60), zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, plasma-modified CBp 60 phr, white carbon black 20 phr, silane coupling agent Si-69 2 phr, accelerator D 0.4 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0020] The preparation method of the natural rubber S / P-60 is as follows: The experimental samples were prepared through a two-stage mixing process.

[0021] (1) The first stage is the mixing process using an internal mixer.

[0022] The internal mixer conditions were set at 90°C and 70 r / min.

[0023] The mixing process is as follows: weighed natural rubber is placed in the mixer and the top bolt is lowered; wait for the torque to become flat, and then add the small ingredients (ZnO, SA, RD) at 1 minute 30 seconds; After the torque becomes flat again, add fillers Silica and CBp twice at 2 min 30 s and 4 min (Si-69 is mixed into Silica and added together, and paraffin oil is added after Silica is added); Mix for 5 minutes and then drain. Let it stand at room temperature for 12 hours and then mix for the second time (set the internal mixer conditions at 100℃ and 70r / min). Drain after the internal mixing temperature reaches 150℃. (2) Two-stage process through open mill; Place the rubber between the two rollers, wrap the rollers, add sulfur S, accelerator D and accelerator NS; tap the rubber, refining it, make triangle packages, cut the bubbles, obtain the mixed rubber, and keep it at room temperature for 6 hours for use.

[0024] (3) Preparation of vulcanized rubber The mixed rubber was vulcanized at 150°C using a flat plate vulcanizer to obtain vulcanized rubber.

[0025] Example 3 Preparation of natural rubber S / P-40 filled with modified thermal carbon black hybrid The composition of this natural rubber S / P-40 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, plasma-modified CBp 40 phr, white carbon black 40 phr, silane coupling agent Si-69 4 phr, accelerator D 0.8 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0026] The preparation method is the same as that of Example 2, except for the difference in the added ingredients, the other conditions are the same.

[0027] Example 4 Preparation of natural rubber S / P-20 filled with modified thermal carbon black hybrid The composition of this natural rubber S / P-20 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, plasma-modified CBp 20 phr, white carbon black 60 phr, silane coupling agent Si-69 6 phr, accelerator D 1.2 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0028] The preparation method is the same as that of Example 2, except for the difference in the added ingredients, the other conditions are the same.

[0029] Comparative Example 1 Preparation of natural rubber S / P-80 filled with modified thermal carbon black hybrid The composition of this natural rubber S / P-80 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, plasma modified CBp 80 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0030] The preparation method is the same as that of Example 2, except for the difference in the added ingredients, the other conditions are the same.

[0031] Comparative Example 2 Preparation of modified thermal carbon black filled natural rubber S / P-0 The composition of this natural rubber S / P-0 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, white carbon black 80 phr, silane coupling agent Si-69 8 phr, accelerator D 1.6 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0032] The preparation method is the same as that of Example 2, except for the difference in the added ingredients, the other conditions are the same.

[0033] Comparative Example 3 Preparation of natural rubber S / C-80 filled with thermal carbon black hybrid The composition of this natural rubber S / C-80 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, CBp 80 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0034] The preparation method is the same as that of Example 2, except for the difference in the added ingredients, the other conditions are the same.

[0035] Comparative Example 4 Preparation of natural rubber S / C-60 filled with thermal carbon black hybrid The composition of this natural rubber S / C-60 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, CBp 60 phr, white carbon black 20 phr, silane coupling agent Si-69 2 phr, accelerator D 0.4 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0036] Comparative Example 5 Preparation of natural rubber S / C-40 filled with thermal carbon black hybrid The composition of this natural rubber S / C-40 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, CBp 40 phr, white carbon black 40 phr, silane coupling agent Si-69 4 phr, accelerator D 0.8 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0037] Comparative Example 6 Preparation of natural rubber S / C-20 filled with thermal carbon black hybrid The composition of this natural rubber S / C-20 is as follows: Natural rubber 100 phr, zinc oxide 5 phr, stearic acid 2 phr, antioxidant RD 1 phr, paraffin oil 1 phr, modified CBp 20 phr, white carbon black 60 phr, silane coupling agent Si-69 6 phr, accelerator D 1.2 phr, accelerator NS 1.2 phr and sulfur 2 phr.

[0038] The preparation method is the same as that of Example 2, except for the difference in the added ingredients, the other conditions are the same.

[0039] Experimental test 1 P-CBp and CBp particle size test: P-CBp and CBp were scanned using a transmission electron microscope (TEM) (JEM-2100, Japan) at an accelerating voltage of 200 KV. 0.001 g of P-CBp and CBp were weighed and placed in clean containers respectively. The containers were labeled with the sample names, and 10 mL of ethanol solution was added. Ultrasonication was performed using an ultrasonic machine for 5 min to obtain TEM test samples. The particle size distribution of P-CBp and CBp was analyzed.

[0040] The microscopic morphologies of the unmodified CBp primary particles and the plasma-modified CBp primary particles are shown in Figure 1 (a-b), and the particle size distribution obtained by statistics is shown in Figure 1 (c).

[0041] from Figure 1 The results show that the average particle size of the unmodified CBp primary particles is in the range of 60.9 ± 9.21 nm, and the particle size of the P-CBp after plasma modification is reduced to 43.7 ± 6.28 nm, a decrease of about 17.2 nm, indicating that the size of the modified P-CBp primary particles is significantly reduced, and at the same time, the particle size distribution becomes narrower.

[0042] Experimental test 2 Acetone dispersion test: The dispersion of P-CBp and CBp was analyzed by acetone dispersion method. First, equal amounts of P-CBp and CBp were added to two transparent glass containers, and then equal amounts of acetone were poured in. After 24 hours, the two solutions were observed. The results are shown in the figure below. Figure 2 (a) shown.

[0043] from Figure 2 (a) As can be seen, the CBp solution is clear and transparent. In the acetone solution, CBp aggregates quickly settle to the bottom of the bottle, showing obvious phase separation. This is because the low polarity of CBp makes it poorly compatible with the acetone solution, making it difficult for CBp to be evenly dispersed in the acetone solution. In contrast, the P-CBp dispersion is turbid and has good suspension stability. This is because the plasma has a polarization effect on the CBp surface, which allows P-CBp to be better dispersed in the acetone solution.

[0044] X-ray Photoelectron Spectroscopy (XPS) Test: The filler group content and elemental composition were determined by X-ray photoelectron spectroscopy (XPS, ESCALAB 250Xi, USA). The C1s spectrum was obtained by scanning and energy calibration of carbon elements. The deconvolution was performed by Avantage peak fitting software. The results were as follows: Figure 2 (b) and Figure 2 (c) from Figure 2 (b) and Figure 2 (c) Comparing the spectral peaks of CBp before and after modification reveals a significant decrease in the content of -*C=C- and a significant increase in -*CC- in P-CBp. This phenomenon indicates that the degree of unsaturation in the carbon chain increases during the modification process. Regarding oxygen-containing functional groups, the content of -*C=O- and -*CO- in P-CBp is higher than that in CBp, indicating that plasma modification has a significant impact on the surface functionalization and carbon bond structure of CBp.

[0045] Experimental test 3 Vulcanization characteristics test: The vulcanization characteristics were tested using a rotorless rheometer. A 5 g circular sample was cut from the rubber mix. The experimental temperature was set at 150 °C and the experimental time was 30 min. The sample was then placed in a constant temperature mold cavity to start the vulcanization characteristics experiment and obtain the vulcanization parameters.

[0046] The results of the vulcanization characteristic parameters of NR composites filled with different proportions of Silica / P-CBp and Silica / CBp are shown in Table 1.

[0047] Table 1 Vulcanization properties of NR composites filled with different ratios of Silica / P-CBp and Silica / CBp

[0048] It can be seen from Table 1 that the more CBp and P-CBp filling amounts are, the longer the curing time (t c90 ) is longer, because when CBp or P-CBp is overfilled, agglomeration occurs, which slows down the vulcanization rate. The scorch time (t c10 ) is lower than that of the Silica / CBp (S / C) filling system, indicating that the polar surface of P-CBp can enhance the synergistic effect with Silica and promote the vulcanization reaction.

[0049] For the torque difference (M H -ML), M of S / P filling system HThe -ML value is higher than that of the S / C filled system because P-CBp effectively improves the dispersion of silica in the NR rubber matrix and enhances the filler-rubber interaction.

[0050] Experimental test 4 Cross-link density detection: Cut each set of vulcanized rubber specimens into triangles, squares, and parallelograms. Weigh and record the initial weight. Place the samples in corresponding glass containers (labeled with numbers). Pour 100 mL of toluene solution into each glass container at room temperature and soak for 72 hours. After swelling, use tweezers to remove the sample. Clean any remaining toluene from the surface of the sample and weigh and record the final weight. Dry the sample in a vacuum oven at 60°C for 24 hours. Weigh and record the final weight.

[0051] The volume fraction of rubber (Vr) is calculated according to formula 2-1, and the crosslink density of rubber (γ) is calculated using the Flory-Rehner theory using the following formula:

[0052]

[0053] Where W0 is the mass of the sample in air before swelling, W S is the mass of the sample in air after swelling, W d is the mass of the sample after drying, and b is the mass fraction of filler in the composite material. r is the density of the vulcanized rubber, ρ s is the density of the solvent. s is the molar volume of toluene, V r is the volume fraction of the rubber phase in the swollen vulcanizate at equilibrium. λ is the interaction parameter between natural rubber and toluene, and γ is the crosslink density of the vulcanizate.

[0054] The test results are as follows Figure 3 shown.

[0055] from Figure 3 It can be seen that at the same dosage, the crosslinking density value of the Silica / P-CBp hybrid filled NR composite material is significantly higher than that of the Silica / CBp hybrid filled NR composite material, among which the S / P-20 crosslinking density value is the largest.

[0056] Experimental test 5 Static mechanical properties testing Tensile test: The tensile test was performed using a universal tensile testing machine (GT-TCS-2000) at room temperature in accordance with the GB / T 528-2009 standard.

[0057] The physical and mechanical properties of NR composites filled with different ratios of S / P and S / C are shown in Table 2.

[0058] Table 2 Stress-strain properties of NR composites filled with different ratios of Silica / P-CBp and Silica / CBp

[0059] As can be seen from Table 2, the tensile strength of the Silica / P-CBp hybrid filling system is higher than that of the Silica / CBp hybrid filling system, indicating that P-CBp has a better reinforcement effect than CBp.

[0060] Experimental test 6 Wear performance DIN abrasion: The test standard is GB / T 531.1-2008. DIN abrasion test is performed at room temperature using a roller abrader (MZ-4061).

[0061] Akron abrasion: The test standard is GB / T 1689-2014. Akron abrasion test is performed at room temperature using an Akron abrasion machine (GT-7012-A).

[0062] The results obtained are as follows Figure 4 As shown, from Figure 4 It can be seen that the greater the CBp and P-CBp loading, the worse the composite's wear resistance. At the same combined ratio, the silica / P-CBp filler system exhibits significantly better wear resistance than the silica / CBp filler system. S / P-20 exhibits the lowest DIN and Akron wear volume values, even surpassing the pure silica filler system. This is primarily due to two factors: firstly, a strong interaction between the filler and the rubber forms at this ratio; secondly, the addition of P-CBp improves the silica's dispersion, creating a synergistic particle network that enhances the composite's wear resistance.

[0063] Experimental test 7: Tribological properties Continuous sliding wear tests were conducted using steel rings and grinding wheels at room temperature and dry conditions. The effects of different pressures on the friction coefficient and temperature were studied. The experimental conditions were: speed 0.5 m / s, pressure 40 N and 60 N. The wear rate Ws was calculated using the formula:

[0064] △m is the mass difference of the sample before and after the experiment, ρ is the density of the sample, F N is the normal force, and s is the sliding distance. Three measurements were performed for each test condition to obtain the sample's coefficient of friction (COF), temperature change, and wear rate results.

[0065] The results of the change of the friction coefficient of the composite material with time at a speed of 0.5 m / s are as follows Figure 5 shown.

[0066] from Figure 5 It can be seen that at the same CBp and P-CBp loadings, the friction coefficient of the P-CBp-filled composites is lower than that of the CBp-filled composites. Among them, S / P-20 always exhibits the lowest friction coefficient value.

[0067] The morphology of the composite material after grinding wheel wear observed by desktop scanning microscope is as follows: Figure 6 shown.

[0068] from Figure 6 The worn surfaces of the silica / CBp-filled S / C-80 and S / C-60 specimens exhibit large areas of debonding pits and large protrusions. This non-uniform wear morphology, caused by filler agglomeration, suggests poor dispersion of CBp in the rubber matrix. This generates large wear debris in stress-concentrated areas during friction, leading to increased composite material loss. The surfaces of the S / P-40 and S / P-20 specimens are relatively smooth, with the S / P-20 specimen in particular exhibiting minimal wear scars and debris, indicating the best wear resistance.

[0069] Experimental test 8 Filler dispersion S / P-40, S / P-20, S / P-0, S / C-40 and S / C-20 were selected to fill NR composite materials, and transmission electron microscopy (TEM) was used to observe the dispersion state of the fillers in the five groups of samples. The results are as follows: Figure 7 shown.

[0070] from Figure 7 It can be seen that the modified CBp particles are smaller and more uniform, and the Silica / P-CBp has good dispersion in the NR matrix, indicating that the modified CBp can effectively reduce its particle size, thereby enabling the Silica / P-CBp to better interact with the rubber matrix, effectively improving the dispersion, which corresponds to the friction and wear performance.

[0071] Experimental test 9 In order to further test the synergistic effect between P-CBp and Silica on improving the performance of composite materials, this experiment replaced Silica with N330 to test whether the combination of P-CBp and N330 for composite filling can improve the mechanical properties of the material.

[0072] N330 40 phr, P-CBp 10 phr, and the rest of the formula were the same as in Example 2, and N / P-10 was prepared according to the preparation method of Example 2; N330 30 phr, P-CBp 20 phr, and the rest of the formula were the same as in Example 2, and N / P-20 was prepared according to the preparation method of Example 2; N330 20 phr, P-CBp 30 phr, and the rest of the formula were the same as in Example 2, and N / P-30 was prepared according to the preparation method of Example 2; N330 10 phr, P-CBp 40 phr, and the rest of the formula were the same as in Example 2, and N / P-40 was prepared according to the preparation method of Example 2; N330 0phr, P-CBp 50 phr, and the rest of the formula were the same as in Example 2, and N / P-50 was prepared according to the preparation method of Example 2; Based on the same formula and preparation method as above, P-CBp was replaced with CBp to prepare N / C-0, N / C-10, N / C-20, N / C-30, N / C-40, and N / C-50.

[0073] The mechanical properties of the composite material were tested, and the results are shown in Table 3: Table 3 Mechanical properties test results of composite materials

[0074] As shown in Table 3, the natural rubber composites filled with a combination of P-CBp (plasma-modified thermal carbon black) and N330 carbon black showed no significant improvement in key mechanical properties, such as tensile strength, elongation at break, and modulus, compared to the unmodified CBp and N330 combination. This result suggests that P-CBp, when used in conjunction with conventional carbon black N330, fails to fully realize its potential advantages in terms of interfacial bonding and dispersion.

[0075] In contrast, when P-CBp is used in combination with silica, the composite material exhibits even better mechanical properties, including higher tensile strength, better resilience, and hardness. This indicates a special synergistic effect between P-CBp and silica.

Claims

1. A modified thermal cracking carbon black / white carbon black composite material, characterized in that: The invention comprises a natural rubber matrix and plasma-modified thermal cracked carbon black and white carbon black dispersed in the natural rubber matrix.

2. The modified thermal cracking carbon black / white carbon black composite material according to claim 1, characterized in that: The plasma-modified thermal carbon black is prepared by treating the carbon black in a high-purity argon atmosphere at a discharge power of 400 W for 3 minutes.

3. The modified thermal cracking carbon black / white carbon black composite material according to claim 2, characterized in that: The raw materials for preparing the modified thermal cracking carbon black / white carbon black composite material include the following components, calculated by weight: 100 parts of natural rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant RD, 1 part of paraffin oil, 20-60 phr of plasma-modified thermal cracking carbon black, 20-60 parts of white carbon black, 2-6 parts of silane coupling agent Si-69, 0.4-1.2 parts of accelerator D, 1.2 parts of accelerator NS, and 2 parts of sulfur.

4. The modified thermal cracking carbon black / white carbon black composite material according to claim 3, characterized in that: The raw materials for preparing the modified thermal cracking carbon black / white carbon black composite material include the following components, calculated by weight: 100 parts of natural rubber, 5 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant RD, 1 part of paraffin oil, 20 phr of plasma-modified thermal cracking carbon black, 60 parts of white carbon black, 6 parts of silane coupling agent Si-69, 1.2 parts of accelerator D, 1.2 parts of accelerator NS, and 2 parts of sulfur.

5. The modified thermal cracking carbon black / white carbon black composite material according to claim 4, characterized in that: The preparation method of the modified thermal cracking carbon black / white carbon black composite material comprises the following steps: (1) Add the following components in order in an internal mixer for the first mixing: natural rubber, zinc oxide, stearic acid, and antioxidant RD; after mixing for a period of time, add plasma-modified thermal cracking carbon black, white carbon black, silane coupling agent Si-69, and paraffin oil, and discharge the rubber after mixing; (2) Place the rubber material discharged in (1) at room temperature; (3) Perform the second mixing and rubber removal in the internal mixer; (4) Add sulfur, accelerator D and accelerator NS to the rubber material discharged in (3) on an open mill, tap and refining the rubber to obtain a rubber mix; (5) After standing at room temperature, the rubber mixture is vulcanized using a flat plate vulcanizer to obtain the modified thermal cracked carbon black / white carbon black composite material.

6. The modified thermal cracking carbon black / white carbon black composite material according to claim 5, characterized in that: The initial temperature of the first mixing is 90°C, and the binder removal temperature is 150°C; the initial temperature of the second mixing is 100°C, and the binder removal temperature is 150°C; The room temperature storage time is greater than or equal to 6 hours, and the vulcanization temperature is 150°C.

7. Use of the composite material according to claims 1 to 6 in preparing tire tread rubber with high mechanical properties and wear resistance, characterized in that: The mechanical properties are tensile strength, hardness and resilience.

8. A method for preparing a thermal cracking carbon black / white carbon black composite material with high mechanical properties and wear resistance, characterized in that: The preparation method includes a thermal cracking carbon black modification stage and a thermal cracking carbon black / white carbon black composite material preparation stage; The mechanical properties are tensile strength, hardness and resilience.

9. The preparation method according to claim 8, characterized in that The steps of the thermal cracking carbon black modification stage are to place the thermal cracking carbon black in a high-purity argon atmosphere, set the discharge power to 400W, and treat for 3 minutes to obtain plasma-modified thermal cracking carbon black.

10. The preparation method according to claim 9, characterized in that The steps of the thermal cracking carbon black / white carbon black composite material preparation stage are: (1) Add the following materials into the internal mixer in sequence for the first internal mixing: natural rubber, zinc oxide, stearic acid, antioxidant RD, and then add plasma-modified thermal cracking carbon black, white carbon black, silane coupling agent Si-69 and paraffin oil in sequence after mixing and then discharge the rubber; (2) Place the rubber material discharged in (1) at room temperature; (3) Perform the second mixing and rubber removal in the internal mixer; (4) adding sulfur, accelerator D and accelerator NS to the rubber material discharged in (3) on an open mill, tapping and refining the rubber to obtain a rubber mix; (5) After standing at room temperature, the rubber mixture is vulcanized at 150° C. using a flat plate vulcanizer to obtain the thermal cracked carbon black / white carbon black composite material having high mechanical properties and wear resistance.

Images