A multi-filler synergistically reinforced high abrasion resistant tread rubber composition and mixing process

Abstract

The application discloses a kind of multi-filler synergistic reinforced high wear-resistant tread rubber compositions and mixing process, it is related to rubber material technical field, by using the multi-filler synergistic modification system of modified white carbon black and polydopamine coated barium titanate nanowire compound, it can simultaneously build stable static reinforcing network and dynamic stress response mechanism, effectively solve the problem that traditional tread rubber dynamic wear resistance is poor, filler is easy to aggregate, and network is easily damaged under dynamic load;Among them, the white carbon black modified by silane coupling agent can be uniformly dispersed in rubber matrix, improve the static mechanical strength and structural stability of rubber;Barium titanate nanowire modified by polydopamine coating has piezoelectric response characteristics and interface reactivity, can form firm covalent bonding interface by interface chemical bonding reaction during high temperature mixing process and rubber molecular chain.

Description

Technical Field

[0001] This invention relates to the field of rubber materials technology, specifically to a high wear-resistant tread rubber composition and mixing process with multi-filler synergistic reinforcement. Background Technology

[0002] Tire tread is the core rubber component that comes into direct contact with the road surface during vehicle operation. Its wear resistance and dynamic mechanical stability directly determine the tire's service life, driving safety, and energy consumption. With the development of new energy vehicles towards higher speeds and lighter weights, as well as the popularization of travel scenarios in complex road conditions, the industry has put forward more stringent requirements for the wear resistance, dynamic deformation resistance, and fatigue resistance of tread rubber.

[0003] Currently, high-performance tire tread rubbers generally use natural rubber, solution-polymerized styrene-butadiene rubber, or butadiene rubber as single or blended matrix materials. The mainstream modification technology uses silica combined with silane coupling agents as the core reinforcement system. Based on the advantages of silica in low rolling resistance and high wet skid resistance, silica replaces the traditional carbon black reinforcement system, improving the basic mechanical properties and driving performance of the tread rubber. This is the mainstream technical solution for high-end tire tread modification at present. By controlling the specific surface area, dosage, and coupling process of silica, the filler dispersion and interfacial bonding force can be optimized to a certain extent, improving the static reinforcement effect of rubber. It is widely used in the industrial production of various passenger car and commercial vehicle tires.

[0004] However, existing tread rubber reinforcement and modification technologies have significant technical shortcomings, making it difficult to adapt to the wear resistance requirements of complex dynamic service conditions: Traditional single-reinforcement systems of silica only have a static filling and reinforcement function, with limited functionality and no dynamic stress response capability. During high-speed tire driving and repeated compression and friction, the filler network is prone to slippage and breakage, failing to dissipate dynamic frictional stress and deformation energy, resulting in continuous tread wear and severe attenuation of fatigue resistance. At the same time, unmodified silica has a large number of hydrophilic silanol groups on its surface, which are highly polar and easily agglomerate and disperse unevenly in non-polar rubber matrices, causing stress concentration inside the rubber compound and further aggravating local wear defects. In addition, conventional mixing processes can only achieve physical blending of fillers and rubber, with interfacial bonding mainly based on physical action, resulting in weak bonding strength and easy interface debonding problems under dynamic loads.

[0005] Existing technologies can only slightly improve wear resistance by optimizing filler ratios and improving basic mixing processes, but cannot construct a dynamic wear resistance enhancement mechanism, making it difficult to meet the industrialization requirements of long life and high wear resistance for high-end tires. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a high-wear-resistant tread rubber composition and mixing process with multi-filler synergistic reinforcement. By constructing a synergistic reinforcement system that combines the static reinforcement of modified silica with the dynamic piezoelectric response of polydopamine-coated barium titanate nanowires (BTNWs@PDA), the dynamic stress is converted and dissipated in real time by fully utilizing the piezoelectric properties of BTNWs@PDA. Combined with the high-strength static reinforcement advantage of modified silica, the synergistic effect of multi-filler is achieved, effectively overcoming the technical problems of poor dynamic wear resistance, weak interfacial bonding, and insufficient stress dispersion ability of traditional tread rubber.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: On one hand, a multi-filler synergistically reinforced high-wear-resistant tread rubber composition, comprising: a rubber matrix: 100 parts; polydopamine-coated barium titanate nanowires (BTNWs@PDA): 5-30 parts; silica: 20-60 parts; a silane coupling agent: 2-10 parts; a vulcanizing agent: 1-3 parts; a vulcanization accelerator: 0.5-2.5 parts; an activator: 3-8 parts; an antioxidant: 1-3 parts; and a plasticizer: 5-15 parts.

[0008] The polydopamine-coated barium titanate nanowires consist of barium titanate nanowires and a polydopamine layer coating their surface, forming a core-shell structure. The diameter of the barium titanate nanowires is 50-200 nm, and the aspect ratio is 10-50:1. The thickness of the polydopamine layer is 2-10 nm; The polydopamine-coated barium titanate nanowires and silica form a static reinforcement-dynamic piezoelectric response synergistic enhancement system.

[0009] Further, the rubber matrix is ​​at least one of solution-polymerized styrene-butadiene rubber, natural rubber, and cis-butadiene rubber; the silica is precipitated silica or fumed silica, with a BET specific surface area of ​​100-300 m² / g. 2 / g.

[0010] Furthermore, the silane coupling agent is at least one of bis-[γ-(triethoxysilane)propyl]tetrasulfide, bis-[γ-(triethoxysilane)propyl]disulfide, or γ-mercaptopropyltriethoxysilane.

[0011] Furthermore, the antioxidant is at least one of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (antioxidant 4020) or 2,2,4-trimethyl-1,2-dihydroquinoline polymer (antioxidant RD); the plasticizer is at least one of environmentally friendly aromatic oil (TDAE), naphthenic oil or aromatic oil; and the vulcanization accelerator is at least one of N-cyclohexyl-2-benzothiazole sulfenamide (accelerator CZ), dibenzothiazole disulfide (accelerator DM) or diphenylguanidine (accelerator D).

[0012] On the other hand, a compounding process for a multi-filler synergistically reinforced high-abrasion-resistant tread rubber composition includes the following steps: S1. The titanium source is hydrothermally reacted with a strong alkaline solution at 180-220℃ for 24-72 hours. After acid washing, it is hydrothermally reacted with a barium source at 160-200℃ for 12-36 hours to obtain barium titanate nanowires with a diameter of 50-200nm and an aspect ratio of 10:1-50:1. S2. The prepared barium titanate nanowires were dispersed in a Tris-HCl buffer solution with a pH of 8.0-9.0, and dopamine hydrochloride was added. The mixture was stirred and reacted at room temperature under aerobic conditions for 12-24 hours to allow dopamine to self-polymerize and form polydopamine, which then coated the surface of the barium titanate nanowires. After centrifugation, washing, and drying, polydopamine-coated barium titanate nanowires BTNWs@PDA were obtained. S3. Disperse silica in anhydrous ethanol, add silane coupling agent, stir and react for 2-6 hours at pH 4.0-5.5 and 60-90℃, centrifuge, wash and dry to obtain silane coupling agent modified silica; S4. Add the rubber matrix to the internal mixer for plasticizing, and add the prepared modified silica, BTNWs@PDA, activator, antioxidant and plasticizer in sequence. Mix at a high temperature of 130-150℃ for 6-10 minutes to make high temperature masterbatch. Discharge the glue, cool and let stand to obtain masterbatch. S5. After cooling the prepared masterbatch, add vulcanizing agent and vulcanization accelerator, mix at low temperature for 2-5 minutes, discharge the rubber, cool and let stand to obtain the final rubber. S6. The final rubber compound is molded and vulcanized at 140-170℃ and 10-20MPa for 10-40 minutes to obtain a high wear-resistant tread rubber composition with synergistic reinforcement of multiple fillers.

[0013] Furthermore, the specific steps of S1 are as follows: Mix the titanium source (selected from tetrabutyl titanate, tetraisopropyl titanate or titanium dioxide) with an aqueous sodium hydroxide solution with a concentration of 8-15 mol / L at a mass ratio of 1:5-1:15, and stir for 30-60 minutes to form a uniform suspension. The suspension was transferred to a stainless steel hydrothermal reactor lined with polytetrafluoroethylene, sealed, and placed in a forced-air drying oven. The reaction was carried out at a constant temperature of 180-220℃ for 24-72 hours. After the reaction, the mixture was allowed to cool naturally to room temperature. The resulting white precipitate was repeatedly washed with deionized water until neutral (pH=7-8), and then subjected to acid exchange treatment with 0.1-1 mol / L dilute hydrochloric acid solution for 2-6 hours to exchange sodium ions for hydrogen ions, yielding a titanic acid (H2Ti3O7) nanowire precursor. This precursor was washed with deionized water until no chloride ions were detected (no white precipitate was found when tested with 0.1 mol / L silver nitrate solution) and set aside for later use. The prepared titanate nanowire precursor was dispersed in deionized water, and a barium source (selected from barium acetate, barium chloride or barium hydroxide) was added to make the molar ratio of barium ions to titanate nanowires Ba / Ti = 1-1.5:1. The pH was adjusted to 11-13 with ammonia water, and after stirring for 30 minutes, it was transferred to a hydrothermal reactor and reacted at a constant temperature of 160-200℃ for 12-36 hours. After the reaction is completed, the product is allowed to cool naturally. The product is then washed 3-5 times with deionized water and anhydrous ethanol, and dried in a vacuum drying oven at 60-80℃ for 12-24 hours to obtain barium titanate nanowires (BTNWs) with a diameter of 50-200 nm and an aspect ratio of 10-50:1. The obtained BTNWs were confirmed by X-ray diffraction (XRD) to have a typical perovskite structure, and transmission electron microscopy (TEM) showed that they had a uniform morphology and were well dispersed.

[0014] Furthermore, the specific steps of S2 are as follows: The prepared barium titanate nanowires (BTNWs) were added to Tris-HCl buffer solution (concentration 10-50 mmol / L, pH=8.0-9.0) at a mass-volume ratio of 1-5 g / L, and ultrasonically dispersed for 30-60 min (ultrasonic power 200-500 W, frequency 40 kHz) to uniformly disperse the barium titanate nanowires in the buffer solution and obtain a stable suspension. Dopamine hydrochloride was added to the prepared suspension, with a mass ratio of BTNWs to dopamine hydrochloride of 10-3:1. The mixture was stirred at 200-500 r / min for 12-24 hours at room temperature. During the reaction, air or oxygen was continuously introduced (flow rate 0.1-0.5 L / min) to promote the oxidative self-polymerization of dopamine. In this process, dopamine under weakly alkaline and aerobic conditions undergoes oxidative self-polymerization to generate polydopamine (PDA). PDA forms hydrogen bonds and coordination bonds with the hydroxyl groups on the surface of barium titanate nanowires through catechol groups, and self-assembles to coat the surface of the nanowires to form a uniform core-shell structure. After the reaction was completed, the product suspension was centrifuged at 8000-12000 r / min for 10-20 minutes, the supernatant was discarded, and the precipitate was washed twice with deionized water and twice with anhydrous ethanol to remove unreacted monomers and physically adsorbed polydopamine oligomers. The washed product was dried in a vacuum drying oven at 50-70℃ for 12-24 hours and then ground through a 200-mesh sieve to obtain polydopamine-coated barium titanate nanowires (BTNWs@PDA). Thermogravimetric analysis (TGA) determined that the polydopamine coating content in the prepared BTNWs@PDA was 3-15 wt% (based on the mass of BTNWs). Transmission electron microscopy (TEM) showed that the coating thickness was 2-10 nm, and the coating was uniform and continuous.

[0015] Furthermore, the specific steps of S3 are as follows: Silica (BET specific surface area 100-300m²) 2 Add 50-150 g / L of silica to a mixed solvent of anhydrous ethanol and deionized water (anhydrous ethanol:deionized water = 80:20-95:5, volume ratio) at a mass-volume ratio, and stir at 300-600 r / min for 15-30 minutes at room temperature to fully wet and disperse the silica. Add silane coupling agent to the obtained suspension, the amount of silane coupling agent added is 5-15 wt% of the mass of silica; adjust the pH to 4.0-5.5 with glacial acetic acid or ammonia, and stir the reaction at 300-500 r / min at 60-90℃ for 2-6 hours. During the reaction, the silane coupling agent first hydrolyzes under acidic conditions to generate silanol (Si-OH) groups. Subsequently, the silanol groups undergo a dehydration condensation reaction with the silanol groups on the surface of silica to form Si-O-Si covalent bonds, thus grafting organic segments onto the surface of silica. After the reaction was completed, the suspension was centrifuged at 6000-10000 r / min for 10 minutes. The precipitate was washed twice with anhydrous ethanol to remove unreacted silane coupling agent and byproducts. It was dried in a vacuum drying oven at 60-80℃ for 6-12 hours and ground through a 200-mesh sieve to obtain silane coupling agent modified silica. Characterized by Fourier transform infrared spectroscopy (FTIR), the modified silica showed a wavelength of 2920 cm⁻¹. -1 and 2850cm -1 Characteristic absorption peaks of -CH2 and -CH3 appear at 1100 cm⁻¹. -1 The enhanced absorption peak of the Si-O-Si bond indicates that the silane coupling agent was successfully grafted onto the surface of silica. The water contact angle of the modified silica increased by 80-110° from 10-20° before modification, indicating that the surface changed from hydrophilic to hydrophobic.

[0016] Furthermore, the specific steps of S4 are as follows: Add 100 parts by weight of rubber matrix into an internal mixer. Set the initial temperature of the internal mixer to 60-80℃ and the rotor speed to 40-60 r / min. Plasticize for 1-3 minutes to soften the rubber matrix and form a uniform melt. After mastication is complete, add the compounding agents in stages according to the following order: First stage of feeding: Add the prepared modified silica (1 / 2-2 / 3 of the total amount), the silane coupling agent supplement (3-5 wt% of the modified silica mass, used to compensate for high-temperature volatilization loss) and 1 / 2 of the total amount of the prepared BTNWs@PDA to the internal mixer, and mix for 2-3 minutes. Second stage of feeding: Add the remaining modified silica, the remaining BTNWs@PDA, and the activator (zinc oxide and stearic acid), antioxidant and plasticizer, and continue to mix for 2-4 minutes; Throughout the mixing process, the internal mixer temperature gradually rises from the initial 60-80℃ to 130-150℃ (discharge temperature), the rotor speed is 50-80 r / min, and the total mixing time is 6-10 minutes; When the material temperature in the internal mixer reaches 140-150℃, maintain constant temperature mixing for 1-2 minutes to fully promote the silanization reaction between the silane coupling agent and silica-rubber (reaction temperature ≥140℃) and the interfacial chemical bonding reaction between the catechol groups on the surface of BTNWs@PDA and the carbon-carbon double bonds (C=C) on the rubber molecular chain (reaction temperature ≥130℃). After mixing, discharge the glue at a temperature of 140-150℃. Pass the masterbatch through a two-roll mill 3-5 times at a roller gap of 2-4mm and a roller temperature of 40-60℃ to promote dispersion. Then, sheet the masterbatch and cool it to room temperature (≤40℃) to obtain the masterbatch. Let it stand for 8-24 hours. High-temperature mixing promotes the silanization reaction between silane coupling agent-modified silica and the rubber matrix, generating silica-Si-rubber covalent bonds. On the other hand, it triggers the interfacial chemical bonding reaction between the catechol groups in the PDA layer on the BTNWs@PDA surface and the C=C double bonds in the rubber molecular chain, realizing the interfacial chemical bonding between the piezoelectric filler and the rubber matrix, laying the interfacial foundation for enhanced piezoelectric response under subsequent dynamic service conditions.

[0017] Furthermore, the specific steps of S5 are as follows: The prepared masterbatch is preheated on a two-roll mill at a roller temperature of 40-50℃ for 1-2 minutes to soften the masterbatch and wrap it around the rollers. The roller gap is adjusted to 3-5mm. The prepared masterbatch is transferred into an internal mixer. The initial temperature of the internal mixer is set to 30-40℃. A vulcanizing agent (sulfur) and a vulcanization accelerator are added. The mixture is mixed for 2-5 minutes at a low temperature of 40-60℃, with a rotor speed of 20-40 r / min and a maximum temperature not exceeding 70℃. Immediately after mixing, discharge the rubber (discharge temperature ≤70℃). Pass the final rubber through a two-roll mill 3-4 times at a roll gap of 1-3mm and a roll temperature of 30-40℃ to further distribute the vulcanizing agent and accelerator evenly. Then, sheet out and cool to room temperature (≤25℃) to obtain the final rubber. Let it stand for 4-12 hours.

[0018] Furthermore, the specific steps of S6 are as follows: The final rubber compound is hot-mixed on a two-roll mill at a roller temperature of 30-40℃ for 1-2 minutes to enhance the fluidity of the rubber compound. The rubber compound is weighed according to the mold size and filled into a flat vulcanizing mold that has been pre-coated with release agent and preheated to 140-150℃. Compression vulcanization is performed using a flat vulcanizing machine. The vulcanization temperature is 140-170℃, the vulcanization pressure is 10-20MPa, and the vulcanization time depends on the vulcanizer's settings. 90 It is determined that the curing time is usually 10-40 minutes. During the curing process, the rubber molecular chains undergo cross-linking reaction under the action of sulfur and accelerator, forming a dense curing network. At the same time, the residual catechol groups further undergo interfacial chemical bonding reaction with unreacted rubber double bonds at high temperature, enhancing the interfacial cross-linking density. After vulcanization, the mold and rubber compound are cooled to below 60°C by water cooling at a rate of 10-20°C / min on a flat vulcanizing machine. The vulcanized rubber is then demolded and allowed to cool naturally to 25°C at room temperature, resulting in a high wear-resistant tread rubber composition with synergistic reinforcement by multiple fillers.

[0019] Compared with existing technologies, this multi-filler synergistically reinforced high-wear-resistant tread rubber composition and mixing process have the following beneficial effects: I. This invention employs a multi-filler synergistic modification system combining modified silica and polydopamine-coated barium titanate nanowires. This system simultaneously constructs a stable static reinforcing network and a dynamic stress response mechanism, effectively solving the problems of poor dynamic wear resistance, easy agglomeration of fillers, and easy network destruction under dynamic loads in traditional tire tread rubber. Specifically, the silica surface-modified with a silane coupling agent can be uniformly dispersed in the rubber matrix, improving the static mechanical strength and structural stability of the rubber compound. The polydopamine-coated barium titanate nanowires possess piezoelectric response characteristics and interfacial reactivity. They can form a strong covalent bond interface with the rubber molecular chains through interfacial chemical bonding reactions during high-temperature mixing. During tire driving under pressure and friction deformation, they can sense dynamic stress in real time and dissipate energy, inhibiting fatigue wear and structural damage to the rubber matrix.

[0020] Second, the present invention adopts a segmented preparation process, which first constructs a filler reinforcement network through high-temperature segmented intensive mixing, then disperses and vulcanizes the system through low-temperature mixing, and finally performs precise molding vulcanization. This process not only ensures the full bonding reaction between the filler and the rubber interface, but also effectively avoids the problems of premature scorching of the vulcanization system and decomposition and failure of additives, and significantly optimizes the density and uniformity of the rubber crosslinking network.

[0021] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0023] Figure 1 A flowchart of the mixing process for a multi-filler synergistically reinforced high abrasion-resistant tread rubber composition; Figure 2 This is a flowchart of step S3 in the compounding process of a multi-filler synergistically reinforced high abrasion-resistant tread rubber composition. Detailed Implementation

[0024] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0025] Example 1: As Figure 1 As shown, 10g of tetrabutyl titanate was slowly added to 100mL of a 10mol / L NaOH aqueous solution. The mixture was magnetically stirred at room temperature for 45 minutes to form a milky white, uniform suspension. The suspension was transferred to a 200mL stainless steel hydrothermal reactor lined with polytetrafluoroethylene (PTFE), sealed, and placed in a 200℃ drying oven for 48 hours. After the reaction, the mixture was allowed to cool naturally to room temperature. The resulting white precipitate was repeatedly washed with deionized water until pH 7.5, then soaked in 0.5mol / L dilute hydrochloric acid solution for 4 hours for acid exchange. After washing with deionized water until no white precipitate was detected by 0.1mol / L AgNO3 solution (Cl... - (Complete removal) yields the titanate nanowire precursor.

[0026] The prepared titanate nanowire precursor was dispersed in 150 mL of deionized water, and barium acetate (Ba / Ti molar ratio = 1.2:1.0) was added. The pH was adjusted to 12 with ammonia. After stirring for 30 minutes, the mixture was transferred to a 200 mL hydrothermal reactor and reacted at 180 °C for 24 hours. After natural cooling, the product was washed four times alternately with deionized water and anhydrous ethanol and dried in a vacuum drying oven at 70 °C for 18 hours to obtain barium titanate nanowires (BTNWs) with a diameter of approximately 100 nm and an aspect ratio of approximately 30:1.

[0027] Add 5g of the above BTNWs to 1000mL of 10mmol / L Tris-HCl buffer solution (pH=8.5) and sonicate for 45 minutes (ultrasonic power 300W, frequency 40kHz) to obtain a stable BTNWs suspension.

[0028] Add 1g of dopamine hydrochloride (BTNWs:dopamine=5:1) to the suspension, stir at 350r / min at 25℃ for 18 hours, and simultaneously introduce air at a flow rate of 0.2L / min.

[0029] After the reaction was completed, the mixture was centrifuged at 10,000 r / min for 15 minutes. The precipitate was washed twice with deionized water and twice with anhydrous ethanol. It was then dried in a vacuum drying oven at 60℃ for 18 hours and ground through a 200-mesh sieve to obtain BTNWs@PDA. The coating amount of PDA was determined to be 8.5 wt% by TGA and the coating thickness was observed to be approximately 5 nm by TEM. The coating was continuous and uniform.

[0030] like Figure 2 As shown, 40g of silica (VN3, BET=175m) was added. 2 Add (g) to a mixture of anhydrous ethanol and deionized water (volume ratio 90:10) in 400 mL and stir at 450 r / min for 20 minutes at room temperature.

[0031] Add 4g of Si69 (10wt% of the mass of silica) to the suspension, adjust the pH to 4.5 with glacial acetic acid, and stir at 400r / min at 78℃ for 4 hours.

[0032] After the reaction was completed, the precipitate was centrifuged at 8000 r / min for 10 minutes, washed twice with anhydrous ethanol, dried in a vacuum drying oven at 70℃ for 8 hours, ground through a 200-mesh sieve, and modified silica was obtained. FTIR characterization confirmed that Si69 was successfully grafted and the water contact angle increased from 15° to 95°.

[0033] Weigh each component according to the following formula (total amount in phr, total amount 150g): SSBR 100 parts, BTNWs@PDA 15 parts, modified silica 40 parts, Si69 supplement 2 parts, zinc oxide 4 parts, stearic acid 2 parts, antioxidant 4020 2 parts, TDAE 10 parts.

[0034] The initial temperature of the internal mixer was set to 70℃, the rotor speed was set to 50r / min, and the filling factor was set to 0.70.

[0035] Plasticizing stage: Add 100 parts SSBR and plasticize for 2 minutes.

[0036] First stage of feeding: Add 25 parts of modified silica (about 5 / 8 of the total amount), 2 parts of silane coupling agent, and 8 parts of BTNWs@PDA (about 1 / 2 of the total amount), and mix for 2 minutes.

[0037] Second stage of feeding: Add 15 parts of the remaining modified silica, 7 parts of the remaining BTNWs@PDA, 4 parts of zinc oxide, 2 parts of stearic acid, 2 parts of antioxidant 4020, and 10 parts of TDAE, and continue mixing for 4 minutes. During this period, the internal mixer temperature rises to 145℃ and is maintained at 145℃ for 1.5 minutes.

[0038] Debinding: Debind at 145℃, pass through a two-roll mill (roll gap 3mm, roll temperature 50℃) 4 times, cool the sheet to room temperature to obtain masterbatch, and let it stand for 12 hours.

[0039] After resting, the masterbatch was preheated on a two-roll mill at 45°C for 1.5 minutes and then rolled onto the rollers. It was then transferred to an internal mixer at an initial temperature of 35°C and a rotor speed of 30 r / min. Two parts of sulfur and 1.5 parts of accelerator CZ were added, and the mixture was mixed at 45°C for 3 minutes, with a maximum temperature of 65°C. The mixture was then discharged and passed through a two-roll mill (roll gap 2 mm, roller temperature 35°C) three times. The sheet was then cooled to 25°C to obtain the final rubber compound, which was then allowed to stand for 8 hours.

[0040] The final compound was hot-mixed on an open mill at 35°C and a roll temperature of 1.5 minutes (roll gap 2.5mm). The weighed compound was then poured into a mold on a flat vulcanizing machine preheated to 150°C and vulcanized at 150°C and 15MPa pressure according to t 90 (Measured 28 minutes) Vulcanize for 30 minutes. After vulcanization, cool down to 60°C with water at 15°C / min to demold, and let cool naturally to 25°C to obtain the tread rubber composition.

[0041] Example 2: The difference from Example 1 is that the rubber matrix is ​​a blend of NR / BR (60 / 40 phr), the amount of BTNWs@PDA is 10 parts, the amount of silica is 50 parts, and the amount of silane coupling agent added is 6 parts (12 wt% of silica). Other formulations and process conditions are as follows: The masterbatch mixing temperature is set to 140℃ for discharge, and the temperature is maintained for 1 minute. Vulcanization temperature 160℃, vulcanization time 25 minutes (t) 90 (Actual test time: 24 minutes).

[0042] All other operations are the same as in Example 1.

[0043] Example 3: The difference from Example 1 is that the rubber matrix is ​​an SSBR / BR blend (70 / 30 phr), the amount of BTNWs@PDA is 20 parts, the amount of silica is 30 parts, the amount of plasticizer TDAE is 12 parts, and other formulations are adjusted as follows: The masterbatch is mixed at 150℃ and discharged, and the temperature is maintained for 2 minutes. The vulcanization temperature is 155℃, and the vulcanization time is 32 minutes (t). 90 (Actual test time: 31 minutes).

[0044] All other operations are the same as in Example 1.

[0045] Comparative Example 1: The difference from Example 1 is that BTNWs@PDA is not added, the amount of silica is increased to 55 parts (the modification method is the same as in Example 1), and the remaining components and amounts are exactly the same as in Example 1.

[0046] The preparation method is the same as in Example 1.

[0047] Comparative Example 2: The difference from Example 1 is that 15 parts of uncoated barium titanate nanowires (BTNWs) were added instead of BTNWs@PDA, and 40 parts of silica were added. The barium titanate nanowires were added directly with the silica in step S4, without the step S2 treatment. The remaining components and preparation methods were the same as in Example 1.

[0048] Comparative Example 3: The difference from Example 1 is that only BTNWs@PDA (15 parts) was added, without adding silica or silane coupling agent, the steps related to modified silica were omitted, and BTNWs@PDA was added directly in S4.

[0049] The remaining components and preparation methods are the same as in Example 1.

[0050] Performance testing: Table 1 Performance Test Items

[0051]

[0052] Test results: Table 2 Test Results of Examples

[0053]

[0054] Table 3 Comparative test results

[0055]

[0056] In summary, the DIN wear of Examples 1-3 was significantly lower than that of Comparative Examples 1-3. Specifically, the wear of Example 1 was reduced by approximately 29.2% compared to Comparative Example 1, indicating that the introduction of BTNWs@PDA significantly improved wear resistance under dynamic service conditions through the piezoelectric dynamic response enhancement mechanism. The wear of Example 1 was reduced by approximately 26.1% compared to Comparative Example 2, indicating that the polydopamine coating layer is extremely important for achieving the piezoelectric enhancement effect. BTNWs without PDA coating cannot effectively output the piezoelectric enhancement effect under dynamic deformation due to poor dispersibility and lack of chemical bonding at the interface, and may even act as stress concentration points at the interface, thus aggravating wear. The wear of Example 1 was reduced by approximately 48.5% compared to Comparative Example 3, indicating that the static reinforcement of silica is the basic framework, and the dynamic response enhancement of BTNWs@PDA must work synergistically with the static reinforcement of silica to achieve the best effect. Relying solely on piezoelectric fillers cannot obtain sufficient wear resistance.

[0057] The tensile and tear strengths of Examples 1-3 are superior to those of the comparative examples. This is because the modified silica forms covalent bonds with the rubber through a silane coupling agent, constructing a high-strength static cross-linking reinforcing network. BTNWs@PDA achieves interfacial chemical bonding through the interfacial chemical bonding reaction between the catechol groups and the rubber molecular chains, further enhancing the interfacial bonding strength. The synergistic dispersion of the two fillers avoids the agglomeration problem in a single high-filler system, allowing stress to be uniformly transmitted in the filler network. The tear strength of Comparative Example 2 is significantly lower than that of Example 1, indicating that the uncoated BTNWs lacks chemical bonding at the interface and is prone to becoming a crack initiation source under stress, leading to a decrease in tear strength.

[0058] The dynamic compression temperature rise of Examples 1-3 is lower than that of Comparative Examples 1-3. This is because the piezoelectric effect of BTNWs@PDA is conducive to the orientation and arrangement of molecular chains in the interface region, reducing the internal friction heat generation between molecular chains; and the good interfacial chemical bonding reduces the energy consumption of viscous slip at the filler-rubber interface. The low heat generation performance is conducive to extending the service life of the tire under high-speed driving conditions.

[0059] The piezoelectric coefficient d of Examples 1-3 33 The piezoelectric activity was 65-85 pC / N, confirming that BTNWs@PDA maintains good piezoelectric activity in the rubber matrix. (Comparative Example 2's d...) 33 With a value of only 18 pC / N, far lower than Example 1, it indicates that the uncoated BTNWs suffered severe loss of piezoelectric properties during the mixing process due to poor dispersion and interfacial debonding. This contrasts with Comparative Example 3, where the d... 33Although (78pC / N) is the same as in Example 1, the DIN wear rate is significantly deteriorated due to the lack of static reinforcing network of silica, proving that the piezoelectric effect alone is not enough to guarantee wear resistance and must be combined with silica.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-wear-resistant tread rubber composition with multi-filler synergistic reinforcement, characterized in that, include: Rubber matrix: 100 parts; Polydopamine-coated barium titanate nanowires (BTNWs@PDA): 5-30 parts; Silica: 20-60 parts; Silane coupling agent: 2-10 parts; Vulcanizing agent: 1-3 parts; Vulcanization accelerator: 0.5-2.5 parts; Activator: 3-8 parts; Antioxidant: 1-3 parts; Plasticizer: 5-15 parts; The polydopamine-coated barium titanate nanowires consist of barium titanate nanowires and a polydopamine layer coating their surface, forming a core-shell structure. The diameter of the barium titanate nanowires is 50-200 nm, and the aspect ratio is 10-50:

1. The thickness of the polydopamine layer is 2-10 nm; The polydopamine-coated barium titanate nanowires and silica form a static reinforcement-dynamic piezoelectric response synergistic enhancement system.

2. The high abrasion-resistant tread rubber composition with multi-filler synergistic reinforcement according to claim 1, characterized in that, The rubber matrix is ​​at least one of solution-polymerized styrene-butadiene rubber, natural rubber, and cis-butadiene rubber; the silica is precipitated silica or fumed silica, with a BET specific surface area of ​​100-300 m² / g. 2 / g.

3. The high abrasion-resistant tread rubber composition with multi-filler synergistic reinforcement according to claim 1, characterized in that, The silane coupling agent is at least one of bis-[γ-(triethoxysilane)propyl]tetrasulfide, bis-[γ-(triethoxysilane)propyl]disulfide, or γ-mercaptopropyltriethoxysilane.

4. The high abrasion-resistant tread rubber composition with multi-filler synergistic reinforcement according to claim 1, characterized in that, The antioxidant is at least one of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine or 2,2,4-trimethyl-1,2-dihydroquinoline polymer; The plasticizer is at least one of environmentally friendly aromatic oil, naphthenic oil, or aromatic oil. The vulcanization accelerator is at least one of N-cyclohexyl-2-benzothiazole sulfenamide, dibenzothiazole disulfide, or diphenylguanidine.

5. A mixing process for a multi-filler synergistically reinforced high-wear-resistant tread rubber composition, used to prepare the multi-filler synergistically reinforced high-wear-resistant tread rubber composition according to any one of claims 1-4, characterized in that, The process includes the following steps: S1. The titanium source is hydrothermally reacted with a strong alkaline solution at 180-220℃ for 24-72 hours. After acid washing, it is hydrothermally reacted with a barium source at 160-200℃ for 12-36 hours to obtain barium titanate nanowires with a diameter of 50-200nm and an aspect ratio of 10:1-50:

1. S2. The prepared barium titanate nanowires were dispersed in a Tris-HCl buffer solution with a pH of 8.0-9.0, and dopamine hydrochloride was added. The mixture was stirred and reacted at room temperature under aerobic conditions for 12-24 hours to allow dopamine to self-polymerize and form polydopamine, which then coated the surface of the barium titanate nanowires. After centrifugation, washing, and drying, polydopamine-coated barium titanate nanowires BTNWs@PDA were obtained. S3. Disperse silica in anhydrous ethanol, add silane coupling agent, stir and react for 2-6 hours at pH 4.0-5.5 and 60-90℃, centrifuge, wash and dry to obtain silane coupling agent modified silica; S4. Add the rubber matrix to the internal mixer for plasticizing, and add the prepared modified silica, BTNWs@PDA, activator, antioxidant and plasticizer in sequence. Mix at a high temperature of 130-150℃ for 6-10 minutes to make high temperature masterbatch. Discharge the glue, cool and let stand to obtain masterbatch. S5. After cooling the prepared masterbatch, add vulcanizing agent and vulcanization accelerator, mix at low temperature for 2-5 minutes, discharge the rubber, cool and let stand to obtain the final rubber. S6. The final rubber compound is molded and vulcanized at 140-170℃ and 10-20MPa for 10-40 minutes to obtain a high wear-resistant tread rubber composition with synergistic reinforcement of multiple fillers.

6. The mixing process of a multi-filler synergistically reinforced high-wear-resistant tread rubber composition according to claim 5, characterized in that, In S2, the mass ratio of barium titanate nanowires to dopamine hydrochloride is 10-3:1, and air or oxygen is introduced during the reaction.

7. The mixing process of a multi-filler synergistically reinforced high-wear-resistant tread rubber composition according to claim 5, characterized in that, In step S3, the volume ratio of anhydrous ethanol to deionized water is 80:20-95:5, and the amount of silane coupling agent added is 5-15 wt% of the mass of silica.

8. The mixing process of a multi-filler synergistically reinforced high-wear-resistant tread rubber composition according to claim 5, characterized in that, In step S4, the high-temperature masterbatch mixing adopts a segmented feeding method: add 1 / 2-2 / 3 of the total modified silica, the supplementary amount of silane coupling agent, and 1 / 2 of the total BTNWs@PDA, and mix for 2-3 minutes; then add the remaining modified silica, the remaining BTNWs@PDA, as well as the activator, antioxidant, and plasticizer, and mix for 2-4 minutes; the internal mixer rotor speed is 50-80 r / min, the discharge temperature is 140-150℃, and after discharge, it is passed through the open mill 3-5 times.

9. The mixing process of a multi-filler synergistically reinforced high-wear-resistant tread rubber composition according to claim 5, characterized in that, In step S5, the temperature of the low-temperature mixing is 40-50℃, the rotor speed of the internal mixer is 20-40 r / min, and after the glue is discharged, it is thinly passed 3-4 times on the open mill at a roller temperature of 30-40℃.

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