Tank load wheel natural rubber material and preparation method thereof

Abstract

This invention belongs to the field of rubber, specifically relating to a natural rubber material for tank road wheels and its preparation method. The natural rubber material for tank road wheels comprises the following raw materials: natural rubber, zinc 10-undecenoate, aluminum acrylate, methyl 4-vinylbenzoate, benzoyl peroxide, modified carbon black, modified short-cut carbon fibers, stearic acid, antioxidant, aluminum hydroxide, dibutyl phthalate, and sulfur. The rubber material prepared by this invention has a Shore A hardness of 58-60, a tensile strength as high as 37.54 MPa, and elongation at break and stress at 300% elongation can reach 547.26% and 9.65 MPa, respectively. It exhibits excellent comprehensive performance and has good application potential in materials such as tank road wheel tracks.

Description

Technical Field

[0001] This invention belongs to the field of rubber, specifically relating to a natural rubber material for tank road wheels and its preparation method. Background Technology

[0002] Tank road wheel rubber is a key functional component of the tank running system. It is mainly used for buffering, shock absorption and wear resistance between the road wheel and the track and the ground. Its performance directly affects the tank's ride comfort, track life and battlefield adaptability.

[0003] The rubber of the road wheels absorbs the impact of ground bumps and track drive through its own elastic deformation, reducing vibration damage to the vehicle body and internal equipment, while improving passenger comfort. The road wheels are in direct contact with the track links; the rubber layer reduces metal-to-metal friction, minimizing wear on both the tracks and road wheels and extending their service life. The elastic deformation of the rubber adapts to complex terrain (such as mud, gravel, and slopes), ensuring stable support of the tracks by the road wheels and maintaining the tank's smoothness and maneuverability.

[0004] Invention patent CN114891280A discloses a super-tear-resistant track belt rubber composition, belonging to the field of super-tear-resistant track rubber technology. It comprises the following raw materials in parts by weight: 140-160 parts of water-processed mixed functional group modified silica natural rubber, 10-30 parts of reinforcing filler, 10-20 parts of silane coupling agent, 1-6 parts of plasticizer, 5-10 parts of activator, 2-6 parts of antioxidant, 1-5 parts of vulcanizing agent, and 2-5 parts of vulcanization accelerator. 0.1-0.5 parts of anti-scorching agent; using water-mixed functional group modified silica natural rubber to replace natural rubber and 80% silica can promote more effective and uniform dispersion of silica in latex. Silica and natural rubber have a good physical coupling effect during flocculation, which can effectively improve the dispersion between fillers, reduce the energy consumption of internal mixing and the Mooney viscosity of the formula, solve the problem of poor mixing and extrusion processability of high silica formulas, and greatly improve the service life of tank tracks in hot deserts.

[0005] Chinese patent application CN113896962A discloses a rubber material for shock-absorbing products in armored vehicles. The composition and proportions of this rubber material are as follows: per 100 parts by weight of raw rubber, NANCAR1043A is 70 parts, NANCAR1965 is 30 parts, zinc oxide is 5-8 parts, accelerator D is 0.1-0.2 parts, accelerator DM is 0.4-0.6 parts, stearic acid is 1-3 parts, antioxidant NAPM is 2-4 parts, carbon black N339 is 25-35 parts, carbon black N660 is 25-35 parts, dibutyl phthalate is 10-13 parts, anti-cracking agent B10 is 1-2 parts, sulfur is 0.05 parts, and accelerator TMTD is 1-3 parts. This invention increases the mechanical properties and improves the performance of rubber products, solves the technical problems of corrosion and aging, and meets the performance requirements of modern tanks.

[0006] Patent CN103756079B discloses a method for improving the performance of rubber-coated track pads using compound-modified cerium oxide. The method involves modifying cerium oxide with at least two modifiers, and adding 0.1-10% compound-modified cerium oxide through mechanical blending while maintaining the original rubber production formula and process. This improves the performance of the rubber-coated track pads, particularly their abrasion resistance and tear resistance. The resulting rubber exhibits increased tensile strength and tear strength by 11% and 41%, respectively, and reduced abrasion by 16%. It is suitable for rubber tracks used in large machinery such as tanks, boom cranes, and agricultural harvesters.

[0007] Chinese patent application CN101475713B discloses a rubber composition, specifically a rubber composition for tracked equipment. The main component of this composition is hydrogenated nitrile butadiene rubber, supplemented with other auxiliary materials such as unsaturated carboxylic acid metal salts. This rubber composition possesses excellent physical and mechanical properties and resistance to heat and oxygen aging, making it particularly suitable for track blocks in tracked equipment such as tanks, armored vehicles, tracked tractors, and excavators. It significantly reduces the impact between the metal tracks and the ground, mitigating the noise generated and preventing damage to road surfaces (especially highways) caused by the metal tracks.

[0008] Chinese Patent No. CN111484654B discloses a thermally conductive rubber material and a rubber track. The preparation method of this rubber material includes a step of mixing a raw material composition; wherein, by weight, the raw material composition includes: 100 parts of rubber raw material; 20-30 parts of carbon fiber after a first pretreatment; 25-35 parts of hexagonal boron nitride powder after a second pretreatment; and 25-35 parts of nanoparticles after a third pretreatment; wherein the average length of the carbon fiber is 3mm-10mm; wherein the average particle size of the hexagonal boron nitride powder is 10μm-200μm; wherein the average particle size of the nanoparticles is 5nm-100nm, and the nanoparticles are selected from one or more of metal powders and metal oxide powders; wherein the first pretreatment includes treating the carbon fiber with a silane coupling agent followed by CO2 plasma etching; wherein the second pretreatment includes treating the hexagonal boron nitride powder with a silane coupling agent; and wherein the third pretreatment includes treating the nanoparticles with a solution containing octadecylamine and stearic acid.

[0009] While posing significant challenges to hardness, the rubber materials for tank road wheels also need to maintain high tensile strength, elongation at break, and stress at a given elongation. Further improving the overall performance of this type of rubber material remains a technical problem that needs to be solved. Summary of the Invention

[0010] To address the aforementioned technical problems, this invention provides a natural rubber material for tank road wheels and a method for preparing the same.

[0011] The natural rubber material for tank road wheels provided by this invention comprises the following raw materials: natural rubber, zinc 10-undecenoate, aluminum acrylate, methyl 4-vinylbenzoate, benzoyl peroxide, modified carbon black, modified short-cut carbon fiber, stearic acid, antioxidant, aluminum hydroxide, dibutyl phthalate, and sulfur.

[0012] Preferably, the amounts of the above raw materials, by weight, are: 40-60 parts natural rubber, 3-8 parts zinc 10-undecenoate, 3-8 parts aluminum acrylate, 5-10 parts methyl 4-vinylbenzoate, 0.3-2 parts benzoyl peroxide, 20-35 parts modified carbon black, 2-5 parts modified chopped carbon fiber, 0.5-3 parts stearic acid, 1-3 parts antioxidant, 4-10 parts aluminum hydroxide, 1-3 parts dibutyl phthalate, and 0.2-1.8 parts sulfur.

[0013] Preferably, the amount of natural rubber used, by weight, can be any value or range of 40, 42, 44, 45, 48, 50, 52, 55, 57, or 60 parts.

[0014] Preferably, the amount of zinc 10-undecenoate can be any value or range from 3, 3.5, 4, 4.5, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 7, 7.5, to 8 parts by weight.

[0015] Preferably, the amount of aluminum acrylate used, by weight, can be any value or range from 3, 3.5, 4, 4.5, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 7, 7.5, to 8 parts.

[0016] Preferably, the weight ratio of zinc 10-undecenoate to aluminum acrylate is 1:0.5-1.5 or 1:0.8-1.3.

[0017] Preferably, the amount of methyl 4-vinylbenzoate used, by weight, can be any value or range of 5, 5.5, 6, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, 8.5, 9, 9.5, or 10 parts.

[0018] Preferably, the amount of benzoyl peroxide used, by weight, can be any value or range from 0.3, 0.5, 0.6, 0.8, 1, 1.2, 1.5, 1.8, to 2 parts.

[0019] Preferably, the amount of modified carbon black used can be any value or range of 20, 22, 25, 28, 30, 32, 34, or 35 parts by weight.

[0020] Preferably, the method for preparing modified carbon black includes: mixing carbon black with concentrated nitric acid, heating and stirring to carry out a reflux reaction, filtering, washing to obtain the material, then adding it to a solution containing a silane coupling agent, heating and reacting, filtering, washing and drying to obtain the material.

[0021] Preferably, in the preparation method of modified carbon black: the weight ratio of carbon black to concentrated nitric acid is 1:10-50. The concentration of concentrated nitric acid is 65wt%-90wt%. The reflux reaction temperature and time are 60-80℃ for 3-10 hours. Washing is performed using deionized water. The weight ratio of the material to the solution containing the silane coupling agent is 1:10-50. In the solution containing the silane coupling agent, the solvent is a 20-40wt% aqueous ethanol solution, and the concentration of the silane coupling agent is 0.5-2.5wt%. The silane coupling agent is propenyltrimethoxysilane. The heating reaction is carried out at 40-55℃ for 1-4 hours.

[0022] Preferably, the amount of modified chopped carbon fiber can be any value or range from 2, 2.2, 2.5, 2.8, 3, 3.2, 3.5, 3.8, 4, 4.2, 4.5, 4.8, and 5 parts by weight.

[0023] Preferably, the method for preparing modified chopped carbon fibers includes: soaking chopped carbon fibers in an alkaline solution, soaking them in an acidic solution, rinsing them with water, then heating them with an aqueous solution of propylene-trimethoxysilane ethanol, filtering them, and drying them.

[0024] Preferably, in the preparation method of modified chopped carbon fibers: the alkaline solution is a 1-4 wt% sodium hydroxide solution; the acid solution is a 3-5 wt% nitric acid solution; the soaking time for each soaking step is 5-10 minutes; the propylenetrimethoxysilane ethanol-water solution is composed of propylenetrimethoxysilane and an ethanol-water solution with a concentration of 20-40 wt%, wherein the concentration of propylenetrimethoxysilane is 0.5-2.5 wt%; the heat treatment is performed by heating to 40-55°C and reacting for 1-4 hours.

[0025] Preferably, the amount of stearic acid used, by weight, can be any value or range from 0.5, 0.8, 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, to 3 parts.

[0026] Preferably, the amount of antioxidant can be any value or range from 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, or 3 parts by weight.

[0027] Preferably, the amount of aluminum hydroxide used can be any value or range from 4, 4.5, 5, 5.5, 6, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, 8.5, 9, 9.5, to 10 parts by weight.

[0028] Preferably, the amount of dibutyl phthalate used, by weight, can be any value or range of 1, 1.2, 1.5, 1.8, 2, 2.2, 2.5, 2.8, or 3 parts.

[0029] Preferably, the amount of sulfur used, by weight, can be any value or range from 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.5, 1.7, to 1.8 parts.

[0030] This invention also provides a method for preparing natural rubber material for tank road wheels, comprising the following steps:

[0031] (1) Add natural rubber to the internal mixer, turn on the rotor, heat, then add stearic acid and antioxidant, and mix; add modified carbon black and mix; then add aluminum hydroxide and modified short carbon fiber, and mix; then add dibutyl phthalate and continue mixing, discharge the rubber, cool, and let stand to obtain the compound rubber.

[0032] (2) Add the compounded rubber to the open mill and control the temperature. Set the roller gap. After mixing, add zinc 10-undecenoate, aluminum acrylate and methyl 4-vinylbenzoate and mix. Then add benzoyl peroxide and sulfur and mix. Adjust the roller gap to get the sheet and set it aside.

[0033] (3) The rubber sheet is vulcanized in a flat vulcanizing machine and cooled to obtain the natural rubber material for tank road wheels.

[0034] Preferably, the preparation method includes:

[0035] (1) Add natural rubber to the internal mixer, turn on the rotor to rotate at 30-100 rpm and heat to 60-90℃, then add stearic acid and antioxidant, and mix for 1-3 minutes; add modified carbon black in multiple batches and mix for 2-5 minutes; add aluminum hydroxide and modified short carbon fiber in multiple batches and mix for 2-5 minutes; then add dibutyl phthalate and continue mixing for 2-5 minutes, discharge the rubber, cool, and let stand to obtain the compound;

[0036] (2) Add the mixed rubber to the open mill and control the temperature (not higher than 60℃, for example 50-60℃). Set the roller gap to 1-3mm and mix for 2-4 minutes. Then add zinc 10-undecenoate, aluminum acrylate and methyl 4-vinylbenzoate and mix for 2-4 minutes. Then add benzoyl peroxide and sulfur and mix for 2-5 minutes. Then adjust the roller gap to 3-5mm and get the sheet for later use.

[0037] (3) The film is vulcanized in a flat vulcanizing machine at a vulcanization temperature of 140-160℃, a pressure of 10-15MPa, and a time of 20-40 minutes. Then it is cooled to obtain the natural rubber material for tank road wheels.

[0038] The advantages of this invention compared to the prior art are:

[0039] The rubber material prepared by this invention has a Shore A hardness of about 58-60, a tensile strength as high as 37.54 MPa, an elongation at break and a stress at 300% elongation of 547.26% and 9.65 MPa, respectively. It has excellent comprehensive performance and has good application in materials such as tank road wheel tracks.

[0040] In this invention, zinc 10-undecenoate and aluminum acrylate significantly enhance the hardness, strength, and 300% tensile stress of the material. In the rubber system of this invention, under the action of an initiator, the aforementioned zinc 10-undecenoate and aluminum acrylate undergo free radical polymerization, grafting, and crosslinking reactions with methyl 4-vinylbenzoate, natural rubber, etc., improving the mechanical properties of the material. Simultaneously, in this system, zinc 10-undecenoate and aluminum acrylate not only coordinate with carboxylates through Zn and Al ions, but also combine with silane groups and oxygen-containing groups on the surface of modified fillers (modified carbon black and modified carbon fibers) to construct a cross-interface three-dimensional metal coordination network, regulating the structure and properties of the rubber material; thus comprehensively enhancing the mechanical properties of the rubber system. The simultaneous use of zinc 10-undecenoate and aluminum acrylate in this invention further improves the overall performance, and when the ratio of the two is in the range of 1:0.5-1.5, the resulting rubber material exhibits even better overall performance.

[0041] This invention utilizes modified short-cut carbon fibers to impart excellent strength and hardness to rubber materials. The modified short-cut carbon fibers obtained by treatment with propylene-trimethoxysilane effectively enhance the hardness, strength, and 300% tensile stress of the rubber material. This invention employs immersion in alkaline and acidic solutions to enhance the interaction between the short carbon fibers and the coupling agent, as well as the coordination effect with Zn and Al ions. Simultaneously, the coupling treatment with propylene-trimethoxysilane increases the dispersion ability of the carbon fibers in the system and their compatibility with the rubber system, thereby enhancing the overall performance of the material.

[0042] This invention treats and modifies carbon black with concentrated nitric acid, which can effectively improve the hardness, strength and elongation at break of rubber materials. Furthermore, the use of propylene-trimethoxysilane, compared with other coupling agents, can further improve the hardness and strength of the material, giving the rubber material excellent comprehensive properties.

[0043] The rubber material prepared by this invention has excellent properties and good application effects. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments. The embodiments described below are merely some embodiments of the present invention, and modifications made based on the technical principles described in the present invention should fall within the protection scope of the present invention.

[0045] I. Preparation of Rubber Materials

[0046] Rubber material 1:

[0047] By weight, the raw material composition is as follows: 55 parts natural rubber (Indonesian No. 1 smoked sheet RSS 1), 6 parts zinc 10-undecenoate, 6 parts aluminum acrylate, 5.5 parts methyl 4-vinylbenzoate, 1 part benzoyl peroxide, 30 parts modified carbon black, 4.5 parts modified chopped carbon fiber, 1.2 parts stearic acid, 2 parts antioxidant MB, 8.5 parts aluminum hydroxide, 2 parts dibutyl phthalate and 1.5 parts sulfur; the weight ratio of zinc 10-undecenoate to aluminum acrylate is 1:1.

[0048] The preparation method of modified carbon black includes: mixing carbon black N330 with 75wt% concentrated nitric acid at a weight ratio of 1:25, heating to 70℃ and stirring under reflux for 5 hours, filtering, washing the filter residue with deionized water to obtain the solid material, and then adding it to a solution containing propenyltrimethoxysilane (solvent is 35wt% ethanol solution, and the concentration of propenyltrimethoxysilane is 1.75wt%) at a weight ratio of 1:40, heating to 45℃ and stirring for 1.5 hours, filtering, washing the filter residue with deionized water, taking the washed solid and drying it to constant weight.

[0049] The preparation method of modified chopped carbon fiber includes: chopped carbon fiber (1-3 mm, Cangzhou Zhongli New Material Technology Co., Ltd.) is soaked in 2.5 wt% sodium hydroxide solution (room temperature, 8 minutes) and 2 wt% nitric acid solution (room temperature, 8 minutes), then rinsed with deionized water, and the solid material is taken. Then, it is heated to 45°C and stirred for 2 hours with a propylene-trimethoxysilane ethanol aqueous solution (35 wt% ethanol solution as solvent, propylene-trimethoxysilane concentration of 1.75 wt%) at a weight ratio of 1:25. Then, it is filtered, the filter residue is washed with deionized water, and the washed solid is dried to constant weight.

[0050] The method for preparing the rubber material includes:

[0051] (1) Add natural rubber to the internal mixer, turn on the rotor to rotate at 70 rpm and heat to 70°C, then add stearic acid and antioxidant MB, and mix for 2 minutes; divide into 4 batches and add modified carbon black, and mix for 4 minutes; divide into 3 batches and add aluminum hydroxide and polyacrylonitrile-based carbon fiber, and mix for 4 minutes; then add dibutyl phthalate and continue mixing for 3 minutes, discharge the rubber, cool to room temperature, and let stand for 8 hours to obtain the compound rubber;

[0052] (2) Add the compounded rubber to the open mill and control the temperature at 52°C. Set the roller gap to 2mm and mix for 3 minutes. Then add zinc 10-undecenoate, aluminum acrylate and methyl 4-vinylbenzoate and mix for 3 minutes. Then add benzoyl peroxide and sulfur and mix for 3 minutes. Then adjust the roller gap to 4mm and get the sheet for later use.

[0053] (3) The film is vulcanized in a flat vulcanizing machine at a vulcanization temperature of 155℃, a pressure of 12MPa and a time of 30 minutes, and then naturally cooled to room temperature to obtain the natural rubber material for tank road wheels.

[0054] Rubber material 2:

[0055] By weight, the raw material composition is as follows: 50 parts natural rubber (Indonesian No. 1 smoked sheet RSS 1), 4.4 parts zinc 10-undecenoate, 6.6 parts aluminum acrylate, 5 parts methyl 4-vinylbenzoate, 0.95 parts benzoyl peroxide, 26.5 parts modified carbon black, 4 parts modified chopped carbon fiber, 1.1 parts stearic acid, 1.8 parts antioxidant MB, 7.8 parts aluminum hydroxide, 1.65 parts dibutyl phthalate, and 1.3 parts sulfur; the weight ratio of zinc 10-undecenoate to aluminum acrylate is 1:1.5.

[0056] The preparation method of modified carbon black includes: mixing carbon black N330 with 75wt% concentrated nitric acid at a weight ratio of 1:27, heating to 75℃ and stirring under reflux for 4.5 hours, filtering, washing the filter residue with deionized water to obtain the solid material, and then adding it to a solution containing propenyltrimethoxysilane (solvent is 37.5wt% ethanol solution, propenyltrimethoxysilane concentration is 1.9wt%) at a weight ratio of 1:37, heating to 45℃ and stirring for 1.7 hours, filtering, washing the filter residue with deionized water, taking the washed solid and drying to constant weight to obtain the material.

[0057] The preparation method of modified chopped carbon fiber includes: chopped carbon fiber (1-3 mm, Cangzhou Zhongli New Material Technology Co., Ltd.) is soaked in 2.7 wt% sodium hydroxide solution (room temperature, 6 minutes) and 2.3 wt% nitric acid solution (room temperature, 7 minutes), then rinsed with deionized water, and the solid material is taken. Then, it is heated to 47°C and stirred for 1.8 hours with a propylene-trimethoxysilane ethanol aqueous solution (37 wt% ethanol solution as solvent, propylene-trimethoxysilane concentration of 1.9 wt%) at a weight ratio of 1:27. Then, it is filtered, the filter residue is washed with deionized water, and the washed solid is dried to constant weight.

[0058] The method for preparing the rubber material includes:

[0059] (1) Add natural rubber to the internal mixer, turn on the rotor to rotate at 70 rpm and heat to 75°C, then add stearic acid and antioxidant MB, and mix for 2.5 minutes; divide into 4 batches and add modified carbon black, mix for 3.5 minutes; divide into 3 batches and add aluminum hydroxide and polyacrylonitrile-based carbon fiber, mix for 3.5 minutes; then add dibutyl phthalate and continue mixing for 2.5 minutes, discharge the rubber, cool to room temperature, and let stand for 10 hours to obtain the compound rubber;

[0060] (2) Add the mixed rubber to the open mill and control the temperature at 54°C. Set the roller gap to 2mm and mix for 2.5 minutes. Then add zinc 10-undecenoate, aluminum acrylate and methyl 4-vinylbenzoate and mix for 3 minutes. Then add benzoyl peroxide and sulfur and mix for 3.5 minutes. Then adjust the roller gap to 4mm and get the sheet for later use.

[0061] (3) The film is vulcanized in a flat vulcanizing machine at a vulcanization temperature of 157°C, a pressure of 13MPa, and a time of 28 minutes. Then it is naturally cooled to room temperature to obtain the natural rubber material for tank road wheels.

[0062] Rubber material 3: Compared with rubber material 1, it lacks 6 parts of zinc 10-undecenoate and 6 parts of aluminum acrylate, otherwise it is the same; the preparation method of the rubber material is as follows:

[0063] (1) Add natural rubber to the internal mixer, turn on the rotor to rotate at 70 rpm and heat to 70°C, then add stearic acid and antioxidant MB, and mix for 2 minutes; divide into 4 batches and add modified carbon black, and mix for 4 minutes; divide into 3 batches and add aluminum hydroxide and polyacrylonitrile-based carbon fiber, and mix for 4 minutes; then add dibutyl phthalate and continue mixing for 3 minutes, discharge the rubber, cool to room temperature, and let stand for 8 hours to obtain the compound rubber;

[0064] (2) Add the compounded rubber to the open mill and control the temperature at 52°C. Set the roller gap to 2mm and mix for 3 minutes. Then add methyl 4-vinylbenzoate and mix for 3 minutes. Then add benzoyl peroxide and sulfur and mix for 3 minutes. Then adjust the roller gap to 4mm and get the sheet for later use.

[0065] (3) The film is vulcanized in a flat vulcanizing machine at a vulcanization temperature of 155℃, a pressure of 12MPa and a time of 30 minutes, and then naturally cooled to room temperature to obtain the natural rubber material for tank road wheels.

[0066] Rubber material 4: Compared with rubber material 1, 6 parts of zinc 10-undecenoate and 6 parts of aluminum acrylate are replaced with 12 parts of zinc 10-undecenoate, all other aspects are the same; the preparation method of the rubber material includes:

[0067] (1) Add natural rubber to the internal mixer, turn on the rotor to rotate at 70 rpm and heat to 70°C, then add stearic acid and antioxidant MB, and mix for 2 minutes; divide into 4 batches and add modified carbon black, and mix for 4 minutes; divide into 3 batches and add aluminum hydroxide and polyacrylonitrile-based carbon fiber, and mix for 4 minutes; then add dibutyl phthalate and continue mixing for 3 minutes, discharge the rubber, cool to room temperature, and let stand for 8 hours to obtain the compound rubber;

[0068] (2) Add the mixed rubber to the open mill and control the temperature at 52°C. Set the roller gap to 2mm and mix for 3 minutes. Then add zinc 10-undecenoate and methyl 4-vinylbenzoate and mix for 3 minutes. Then add benzoyl peroxide and sulfur and mix for 3 minutes. Then adjust the roller gap to 4mm and get the sheet for later use.

[0069] (3) The film is vulcanized in a flat vulcanizing machine at a vulcanization temperature of 155℃, a pressure of 12MPa and a time of 30 minutes, and then naturally cooled to room temperature to obtain the natural rubber material for tank road wheels.

[0070] Rubber material 5: Compared with rubber material 1, 6 parts of zinc 10-undecenoate and 6 parts of aluminum acrylate are replaced with 12 parts of aluminum acrylate, all other aspects are the same; the preparation method of the rubber material includes:

[0071] (1) Add natural rubber to the internal mixer, turn on the rotor to rotate at 70 rpm and heat to 70°C, then add stearic acid and antioxidant MB, and mix for 2 minutes; divide into 4 batches and add modified carbon black, and mix for 4 minutes; divide into 3 batches and add aluminum hydroxide and polyacrylonitrile-based carbon fiber, and mix for 4 minutes; then add dibutyl phthalate and continue mixing for 3 minutes, discharge the rubber, cool to room temperature, and let stand for 8 hours to obtain the compound rubber;

[0072] (2) Add the compounded rubber to the open mill and control the temperature at 52°C. Set the roller gap to 2mm and mix for 3 minutes. Then add aluminum acrylate and methyl 4-vinylbenzoate and mix for 3 minutes. Then add benzoyl peroxide and sulfur and mix for 3 minutes. Then adjust the roller gap to 4mm and get the sheet for later use.

[0073] (3) The film is vulcanized in a flat vulcanizing machine at a vulcanization temperature of 155℃, a pressure of 12MPa and a time of 30 minutes, and then naturally cooled to room temperature to obtain the natural rubber material for tank road wheels.

[0074] Rubber Material 6: Compared with Rubber Material 1, the short-cut carbon fiber is not modified, and the modified short-cut carbon fiber is replaced with an equal amount of short-cut carbon fiber. All other aspects are the same.

[0075] Rubber material 7: Compared with rubber material 1, in the preparation of modified short-cut carbon fiber, propylene-trimethoxysilane is replaced with an equal amount of other silane coupling agent KH550, and everything else is the same.

[0076] Rubber Material 8: Compared with Rubber Material 1, the carbon black is not modified, and the modified carbon black is replaced with an equal amount of carbon black N330. Everything else is the same.

[0077] Rubber Material 9: Compared with Rubber Material 1, in the preparation of modified carbon black, propylene-trimethoxysilane is replaced with an equal amount of other silane coupling agent KH550, and everything else is the same.

[0078] Rubber material 10: Compared with rubber material 1, 6 parts of zinc 10-undecenoate and 6 parts of aluminum acrylate are replaced with 10 parts of zinc 10-undecenoate and 2 parts of aluminum acrylate, with a ratio of 1:0.2, and all other aspects are the same.

[0079] Rubber Material 11: Compared with Rubber Material 1, the preparation method of modified carbon black includes: adding carbon black N330 to a solution containing propylenetrimethoxysilane at a weight ratio of 1:37 (the solvent is 37.5wt% ethanol solution, and the concentration of propylenetrimethoxysilane is 1.9wt%), heating to 45℃ and stirring for 1.7 hours, then filtering, washing the filter residue with deionized water, taking the washed solid and drying it to constant weight; everything else is the same.

[0080] II. Rubber Material Testing

[0081] The test method adopts the method described in the People's Republic of China National Military Standard GJB 2628-96. The indicators and corresponding test methods are shown in Table 1.

[0082] Table 1: Indicators and Testing Methods

[0083]

[0084] The performance of the rubber material prepared above was tested using the test methods in Table 1. The test results are shown in Tables 2-4.

[0085] Table 2: Hardness and Stress at a Constant Elongation

[0086]

[0087] Table 3: Tensile strength before and after aging

[0088]

[0089] Table 4: Elongation at break before and after aging

[0090]

[0091] According to the test results in Table 2-4, the rubber material prepared by this invention has a Shore A hardness of about 58-60, a tensile strength of up to 37.54 MPa, an elongation at break and a stress at 300% elongation of 547.26% and 9.65 MPa, respectively. It has excellent comprehensive performance and is well applied in materials such as tank road wheel tracks.

[0092] Comparing Materials 1 and 3, it is evident that zinc 10-undecenoate and aluminum acrylate significantly enhance the hardness, strength, and 300% tensile stress of the materials. Under the action of an initiator, these raw materials undergo free radical polymerization, grafting, and crosslinking with methyl 4-vinylbenzoate, natural rubber, and other materials. Simultaneously, in this system, zinc 10-undecenoate and aluminum acrylate not only coordinate with carboxylates through Zn and Al ions but also combine with silane groups and oxygen-containing groups on the surface of modified fillers (modified carbon black and modified carbon fibers) to construct a cross-interface three-dimensional metal coordination network, regulating the structure and properties of the rubber material, thereby enhancing the mechanical properties of the rubber system. Furthermore, comparing Materials 1, 4-5, and 10, it is clear that using both zinc 10-undecenoate and aluminum acrylate simultaneously is more effective than using only one, and a ratio of 1:0.5-1.5 yields rubber materials with superior overall performance.

[0093] According to tests of materials 1, 6, and 7, the modified short-cut carbon fiber used in this invention can impart excellent strength, hardness, and other properties to rubber materials. The modified short-cut carbon fiber obtained by treating the rubber material with propylene-based trimethoxysilane can effectively improve the hardness, strength, and 300% constant tensile stress of the rubber material.

[0094] According to tests 1, 8-9, and 11, carbon black treated with concentrated nitric acid and modified can effectively improve the hardness, strength, and elongation at break of rubber materials. Furthermore, the use of propylene-trimethoxysilane, compared to other coupling agents, can further enhance the hardness and strength of the materials, giving the rubber materials excellent comprehensive properties.

[0095] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A natural rubber material for tank road wheels, characterized in that, The raw materials used, by weight, are: 40-60 parts natural rubber, 3-8 parts zinc 10-undecenoate, 3-8 parts aluminum acrylate, 5-10 parts methyl 4-vinylbenzoate, 0.3-2 parts benzoyl peroxide, 20-35 parts modified carbon black, 2-5 parts modified chopped carbon fiber, 0.5-3 parts stearic acid, 1-3 parts antioxidant, 4-10 parts aluminum hydroxide, 1-3 parts dibutyl phthalate, and 0.2-1.8 parts sulfur; The weight ratio of zinc 10-undecenoate to aluminum acrylate is 1:0.5-1.

5. The preparation method of modified carbon black includes: mixing carbon black with concentrated nitric acid, heating and stirring to carry out reflux reaction, filtering, washing to obtain the material, then adding it to a solution containing silane coupling agent, heating to react, filtering, washing and drying to obtain the material; the silane coupling agent is propenyltrimethoxysilane. The preparation method of modified chopped carbon fiber includes: soaking chopped carbon fiber in an alkaline solution, soaking it in an acid solution, rinsing it with water, then heating it with an aqueous solution of propylene-trimethoxysilane ethanol, filtering it, and drying it.

2. The natural rubber material for tank road wheels according to claim 1, characterized in that, The weight ratio of carbon black to concentrated nitric acid is 1:10-50, and the reflux reaction temperature and time are 60-80℃ for 3-10 hours.

3. The natural rubber material for tank road wheels according to claim 1, characterized in that, The weight ratio of the material to the solution containing the silane coupling agent is 1:10-50; in the solution containing the silane coupling agent, the solvent is a 20-40wt% aqueous ethanol solution, and the concentration of the silane coupling agent is 0.5-2.5wt%.

4. A method for preparing the natural rubber material for tank road wheels according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Add natural rubber to the internal mixer, turn on the rotor, heat, then add stearic acid and antioxidant, and mix; add modified carbon black and mix; then add aluminum hydroxide and modified short carbon fiber, and mix; then add dibutyl phthalate and continue mixing, discharge the rubber, cool, and let stand to obtain the compound rubber. (2) Add the compounded rubber to the open mill and control the temperature. Set the roller gap. After mixing, add zinc 10-undecenoate, aluminum acrylate and methyl 4-vinylbenzoate and mix. Then add benzoyl peroxide and sulfur and mix. Adjust the roller gap to get the sheet and set it aside. (3) The rubber sheet is vulcanized in a flat vulcanizing machine and cooled to obtain the natural rubber material for tank road wheels.

5. The preparation method according to claim 4, characterized in that, (2) The temperature should not exceed 60℃.

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