High-fatigue-resistance automobile chassis rubber bushing and preparation method thereof

Abstract

The invention relates to a high-fatigue-resistance automobile chassis rubber bushing and a preparation method thereof, and belongs to the technical field of automobile parts, and the high-fatigue-resistance automobile chassis rubber bushing is obtained by carrying out banburying, open milling, vulcanization and other steps on silicone rubber, supported mullite fibers, glass beads, zinc stearate and calcium carbonate. A high-strength framework of the mullite fiber provides axial and circumferential bearing capacity, the layered TBACa2Nb3O10 nanosheets have strong negative charges and are combined with groups containing positive charges, such as amino groups, on the modified mullite fiber in a form of strong electrostatic interaction, so that the layered TBACa2Nb3O10 nanosheets are uniformly dispersed on the surface of the mullite fiber, intermolecular slippage can be generated by the layered structure of the layered TBACa2Nb3O10 nanosheets, and the surface of the layered TBACa2Nb3O10 nanosheets is coated with the modified mullite fiber. The shear stress is absorbed, so that the stress concentration factor of the bushing is reduced under the alternating load, the effects of dispersing the stress and inhibiting crack propagation are achieved, and the fatigue resistance of the automobile chassis rubber bushing is improved.

Description

Technical Field

[0001] This invention belongs to the field of automotive parts technology and relates to a high fatigue-resistant automotive chassis rubber bushing and its preparation method. Background Technology

[0002] Automotive chassis rubber bushings are key elastic components in the suspension system and chassis guiding mechanism, undertaking the core functions of connecting the vehicle body and chassis components, damping vibrations, isolating noise, and bearing multi-directional loads. Their performance directly affects the vehicle's handling stability, ride comfort, and safety reliability. As the automotive industry moves towards electrification, intelligentization, and lightweighting, chassis rubber bushings face more stringent operating conditions and technical challenges. Traditional rubber bushings consist of a metal skeleton (inner / outer tube) and a vulcanized rubber body, achieving vibration damping through the elastic deformation of the rubber. Their core performance parameters include static stiffness (support), dynamic stiffness (vibration isolation), dynamic-to-static stiffness ratio, and fatigue life. In practical applications, the bushings must withstand complex multiaxial alternating stresses. Especially on bumpy roads or during high-speed cornering, the rubber body is prone to internal stress concentration due to large deformations, leading to cracks that propagate and ultimately fatigue failure.

[0003] Chinese invention application CN110001329B discloses an automotive chassis bushing and its molding method. The innermost layer of the bushing is a fiber woven composite layer, and the outermost layer is a unidirectional fiber pultruded composite layer or a fiber woven composite layer. There is at least one unidirectional fiber pultruded composite layer between the innermost and outermost layers. This invention overcomes the shortcomings of weak circumferential strength and insufficient wear resistance of unidirectional fiber composite materials and weak axial strength of fiber woven composite layers. It ensures that the circumferential and axial strength and wear resistance of the bushing meet the requirements for use, and reduces the probability of circumferential failure and cracking failure of the bushing.

[0004] The automotive chassis bushing in the aforementioned patent is composed of a multi-layer structure. When a car is driving on a rough road, it will experience continuous vibration. Under high-frequency alternating loads, the multi-layer structure will experience interlayer slippage. During continuous friction, the local temperature will rise, which will accelerate the fatigue aging of the material and cause cracks. Summary of the Invention

[0005] The purpose of this invention is to provide a high fatigue-resistant automotive chassis rubber bushing and its preparation method. By adding loaded mullite fibers, glass microspheres, zinc stearate and calcium carbonate to silicone rubber, the fatigue resistance of the chassis rubber bushing is improved.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a high fatigue-resistant automotive chassis rubber bushing, the method comprising: placing a metal shell and a mandrel into a flat vulcanizing mold, injecting molten mixed rubber into the mold cavity, keeping the mold closed, reacting and molding, trimming, and reducing the diameter, characterized in that the mixed rubber is prepared by the following steps: Step 1: Modified mullite fibers are obtained by modifying mullite fibers with dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane.

[0007] Step 2: Synthesize KCa2Nb3O using potassium carbonate, calcium carbonate, and niobium pentoxide as raw materials. 10 Powder, Ca2Nb3O is adsorbed by strong electrostatic adsorption. 10 The powder is uniformly loaded onto the surface of the modified mullite fiber to obtain the loaded mullite fiber.

[0008] Step 3: Add silicone rubber, supported mullite fiber, glass microspheres, zinc stearate and calcium carbonate to a rubber and plastic internal mixer for internal mixing to obtain masterbatch; then add masterbatch, iron oxide red and 25% bismuth submersible to a two-roll mill, perform 8 thin passes, and mill for 7-10 minutes. Place under sealed conditions for 12-14 hours to obtain composite compound.

[0009] Furthermore, the preparation process of modified mullite fibers is as follows: Dihydroxydimethoxysilane, 3-aminopropyltriethoxysilane, and a 50 vol% aqueous ethanol solution were added to a reaction vessel. The pH was adjusted to 4-5 with hydrochloric acid, and hydrolysis was carried out for 2-3 hours. Then, mullite fibers washed with acetone were added, and the mixture was heated at 60-70℃ for 4-5 hours. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain modified mullite fibers.

[0010] Furthermore, the ratio of dihydroxydimethoxysilane, 3-aminopropyltriethoxysilane, aqueous ethanol solution, and mullite fiber is 20-30g: 15-20g: 300-400mL: 140-150g.

[0011] Furthermore, the preparation process of supported mullite fibers is as follows: A 2 mol / L oxalic acid solution and KCa2Nb3O 10 The powder is added to the reactor and shaken on a shaker for 2-3 days. Then, a 40wt% tetrabutylammonium hydroxide aqueous solution is added and shaken on a shaker for 8-10 days. The pH is adjusted to 8-9 with ammonia. Modified mullite fiber and titanate coupling agent are added and shaken for 20-24 hours. The mixture is then filtered and dried to obtain supported mullite fiber.

[0012] Furthermore, oxalic acid solution, KCa2Nb3O 10The ratio of powder, tetrabutylammonium hydroxide aqueous solution, modified mullite fiber and titanate coupling agent is 50-60mL: 20-30g: 360-400mL: 130-150g: 0.5-0.8g.

[0013] Furthermore, KCa2Nb3O 10 The powder preparation process is as follows: Potassium carbonate, calcium carbonate, and niobium pentoxide were added to a mortar and ground together to obtain a mixed powder. The mixed powder was placed in a muffle furnace and heated to 1100-1150℃ at a heating rate of 10℃ / min, held at that temperature for 24-26 hours, and then cooled to room temperature to obtain KCa2Nb3O. 10 powder.

[0014] Furthermore, the mass ratio of potassium carbonate, calcium carbonate, and niobium pentoxide is 11-15:10-12:30-40.

[0015] Furthermore, the mass ratio of silicone rubber, supported mullite fiber, glass microspheres, zinc stearate, and calcium carbonate is 130-150:45-55:5-10:1-1.5:5-10.

[0016] Furthermore, the mixing temperature is 140-145℃, the rotation speed is 100-120 r / min, and the time is 12-15 min.

[0017] Furthermore, the mass ratio of masterbatch rubber, iron oxide red, and 25% bismuth subsalicylate is 186-226:3-5:0.8-2.

[0018] The beneficial effects of this invention are: 1. In this invention, silicone rubber, supported mullite fiber, glass microspheres, zinc stearate, and calcium carbonate are mixed, open-milled, and vulcanized to obtain a high-fatigue-resistant automotive chassis rubber bushing. The high-strength skeleton of the mullite fiber provides axial and circumferential load-bearing capacity, and the layered TBACa2Nb3O 10 Nanosheets possess a strong negative charge and combine with positively charged groups such as amino groups on modified mullite fibers through strong electrostatic interactions, thereby uniformly dispersing on the surface of the mullite fibers. Their layered structure can generate intermolecular slippage, absorb shear stress, and reduce the stress concentration factor of the bushing under alternating loads. This achieves the effect of dispersing stress and inhibiting crack propagation, thus improving the fatigue resistance of automotive chassis rubber bushings.

[0019] 2. In this invention, silicone rubber provides elastic cushioning, and load-bearing mullite fibers enhance rigidity, forming a structure of rigid support plus elastic coating, which improves the rubber bushing's ability to withstand impact loads and allows the rubber bushing to maintain excellent performance under high-frequency vibration. Glass microspheres reduce the friction coefficient of the bushing through slippage, further reducing stress concentration, and work synergistically with calcium carbonate to improve the wear resistance of the automotive chassis rubber bushing.

[0020] 3. In this invention, the crosslinking of silicone rubber is initiated by a vulcanizing machine using bis(2,5-dihydroxypropyl)siloxane. Iron oxide red assists in vulcanization and improves heat resistance. The decomposition of bis(2,5-dihydroxypropyl)siloxane generates free radicals, which react with the vinyl groups of the silicone rubber to form a three-dimensional crosslinked network. Dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane grafted onto the surface of the supported mullite fibers simultaneously participate in crosslinking, increasing the crosslinking density of the rubber bushing and improving the interfacial compatibility between the supported mullite fibers and the silicone rubber. The titanate coupling agent not only enhances the crosslinking properties of TBACa2Nb3O4 but also... 10 The interfacial bonding between nanosheets and modified mullite fibers also improves compatibility with silicone rubber, thereby enhancing the rubber bushing's resistance to permanent deformation. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0022] Example 1: This example provides a method for preparing a high fatigue-resistant automotive chassis rubber bushing, comprising the following steps: S1: Add 140g of mullite fiber and 3L of acetone solution to a reaction vessel, sonicate for 2 hours, remove, wash three times with deionized water, and dry at 80℃; add 20g of dihydroxydimethoxysilane, 15g of 3-aminopropyltriethoxysilane and 300mL of 50vol% ethanol aqueous solution to the reaction vessel, adjust the pH to 4 with hydrochloric acid, hydrolyze for 2 hours, then add 140g of mullite fiber, heat at 60℃ for 4 hours to graft dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane onto the mullite fiber, cool to room temperature, filter, wash the precipitate three times with deionized water, and dry to obtain modified mullite fiber.

[0023] S2: Add 11g of potassium carbonate, 10g of calcium carbonate, and 30g of niobium pentoxide to a mortar and grind them together to obtain a mixed powder. Place the mixed powder in a muffle furnace and heat it to 1100℃ at a rate of 10℃ / min. Hold the temperature for 24 hours and then cool it to room temperature to obtain KCa2Nb3O. 10 Powder; then add 50 mL of 2 mol / L oxalic acid solution and 20 g of KCa2Nb3O 10The powder was added to the reactor and shaken on a shaker for 2 days to remove potassium. + H + and Ca2Nb3O 10 - Then add 360 mL of a 40 wt% tetrabutylammonium hydroxide aqueous solution, and shake on a shaker for 8 days to remove H2. + Received TBA + and Ca2Nb3O 10 - The pH was adjusted to 8 with ammonia, then 130g of modified mullite fiber and 0.5g of titanate coupling agent were added. The mixture was shaken for 20 hours. This process removed the hydroxyl groups and TBACa2Nb3O from the modified mullite fiber. 10 The surface negative charge forms a strong electrostatic adsorption, thereby causing TBACa2Nb3O 10 The modified mullite fiber was evenly distributed on the surface of the mullite fiber, centrifuged and filtered, and then dried at 120℃ for 3 hours to obtain the loaded mullite fiber.

[0024] S3: Add 130g of silicone rubber, 45g of supported mullite fiber, 5g of glass microspheres, 1g of zinc stearate and 5g of calcium carbonate to a rubber and plastic internal mixer for internal mixing. The processing temperature is 140℃, the internal mixer speed is 100r / min, and the mixing time is 12min to obtain the masterbatch. Then add 186g of masterbatch, 3g of iron oxide red and 0.8g of bis(2,5)5 to a two-roll mill in sequence, perform 8 thin passes, and then perform open mixing in a two-roll mill for 7min. Place under sealed conditions for 12h to obtain the composite compound.

[0025] S4: Place the metal shell and mandrel sprayed with binder (KH-550) into the vulcanization mold of the flat vulcanizing machine, close the mold, and the flat vulcanizing machine injects the molten composite rubber into the mold cavity. Keep the mold locked for 300s under the conditions of 165℃ and 10MPa. After the composite rubber and sulfur have fully reacted and formed, open the mold, take out the part, trim the edges, and reduce the diameter to obtain the high fatigue-resistant automotive chassis rubber bushing.

[0026] Example 2: This example provides a method for preparing a high-fatigue-resistant automotive chassis rubber bushing. S1: Add 145g of mullite fiber and 3.5L of acetone solution to a reaction vessel, ultrasonically disperse for 2.5h, remove, wash 4 times with deionized water, and dry at 85℃; add 25g of dihydroxydimethoxysilane, 17g of 3-aminopropyltriethoxysilane and 350mL of 50vol% ethanol aqueous solution to the reaction vessel, adjust the pH to 4 with hydrochloric acid, hydrolyze for 2.5h, then add 145g of mullite fiber, heat at 65℃ for 4.5h to graft dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane onto the mullite fiber, cool to room temperature, filter, wash the precipitate 4 times with deionized water, and dry to obtain modified mullite fiber.

[0027] S2: Add 13g potassium carbonate, 11g calcium carbonate, and 35g niobium pentoxide to a mortar and grind them together to obtain a mixed powder. Place the mixed powder in a muffle furnace and heat it to 1125℃ at a rate of 10℃ / min, hold it at that temperature for 25h, and then cool it to room temperature to obtain KCa2Nb3O. 10 Powder; then add 55 mL of 2 mol / L oxalic acid solution and 25 g of KCa2Nb3O 10 The powder was added to the reactor and shaken on a shaker for 2 days to remove potassium. + H + and Ca2Nb3O 10 - Then add 380 mL of a 40 wt% tetrabutylammonium hydroxide aqueous solution, and shake on a shaker for 9 days to remove H2. + Received TBA + and Ca2Nb3O 10 - The pH was adjusted to 8 with ammonia, then 140g of modified mullite fiber and 0.65g of titanate coupling agent were added. The mixture was shaken for 22 hours. The hydroxyl groups on the modified mullite fiber and TBACa2Nb3O... 10 The surface negative charge forms a strong electrostatic adsorption, thereby causing TBACa2Nb3O 10 The modified mullite fibers were evenly distributed on the surface of the fibers, centrifuged and filtered, and then dried at 125°C for 3.5 hours to obtain the loaded mullite fibers.

[0028] S3: Add 140g of silicone rubber, 50g of supported mullite fiber, 7.5g of glass microspheres, 1.25g of zinc stearate and 7.5g of calcium carbonate to a rubber and plastic internal mixer for internal mixing. The processing temperature is 142℃, the internal mixer speed is 110r / min, and the mixing time is 13min to obtain the masterbatch. Then, add 206g of masterbatch, 4g of iron oxide red and 1.4g of bis(2,5)5 to a two-roll mill in sequence, perform 8 thin passes, and then perform open milling for 8min. Let it stand under sealed conditions for 13h to obtain the composite compound.

[0029] S4: Place the metal shell and mandrel sprayed with binder (KH-550) into the vulcanization mold of the flat vulcanizing machine, close the mold, and the flat vulcanizing machine injects the molten composite rubber into the mold cavity. Keep the mold locked for 300s under the conditions of 170℃ and 12MPa. After the composite rubber and sulfur have fully reacted and formed, open the mold, take out the part, trim the edges, and reduce the diameter to obtain a high fatigue-resistant automotive chassis rubber bushing.

[0030] Example 3: This example provides a method for preparing a high fatigue-resistant automotive chassis rubber bushing. S1: Add 150g of mullite fiber and 4L of acetone solution to a reaction vessel, sonicate for 3h, remove, wash 5 times with deionized water, and dry at 90℃; add 30g of dihydroxydimethoxysilane, 20g of 3-aminopropyltriethoxysilane and 400mL of 50vol% ethanol aqueous solution to the reaction vessel, adjust the pH to 5 with hydrochloric acid, hydrolyze for 3h, then add 150g of mullite fiber, heat at 70℃ for 5h to graft dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane onto the mullite fiber, cool to room temperature, filter, wash the precipitate 5 times with deionized water, and dry to obtain modified mullite fiber.

[0031] S2: Add 15g potassium carbonate, 12g calcium carbonate, and 40g niobium pentoxide to a mortar and grind them together to obtain a mixed powder. Place the mixed powder in a muffle furnace and heat it to 1150℃ at a rate of 10℃ / min, hold it at that temperature for 26h, and then cool it to room temperature to obtain KCa2Nb3O. 10 Powder; then add 60 mL of 2 mol / L oxalic acid solution and 30 g of KCa2Nb3O 10 The powder was added to the reactor and shaken on a shaker for 3 days to remove potassium. + H + and Ca2Nb3O 10 - Then add 400 mL of a 40 wt% tetrabutylammonium hydroxide aqueous solution, and shake on a shaker for 10 days to remove H2. + Received TBA + and Ca2Nb3O 10 - The pH was adjusted to 9 with ammonia, then 150g of modified mullite fiber and 0.8g of titanate coupling agent were added. The mixture was shaken for 24 hours. This process removed the hydroxyl groups and TBACa2Nb3O from the modified mullite fiber. 10 The surface negative charge forms a strong electrostatic adsorption, thereby causing TBACa2Nb3O 10 The modified mullite fiber was evenly distributed on the surface of the mullite fiber, centrifuged and filtered, and then dried at 130℃ for 4 hours to obtain the loaded mullite fiber.

[0032] S3: Add 150g of silicone rubber, 55g of supported mullite fiber, 10g of glass microspheres, 1.5g of zinc stearate and 10g of calcium carbonate to a rubber and plastic internal mixer for internal mixing. The processing temperature is 145℃, the internal mixer speed is 120r / min, and the mixing time is 15min to obtain the masterbatch. Then, add 226g of masterbatch, 5g of iron oxide red and 2g of bis(2,5)5 to a two-roll mill in sequence, perform 8 thin passes, and then perform open milling for 10min. Place under sealed conditions for 14h to obtain the composite compound.

[0033] S4: Place the metal shell and mandrel sprayed with binder (KH-550) into the vulcanization mold of the flat vulcanizing machine, close the mold, and the flat vulcanizing machine injects the molten composite rubber into the mold cavity. Keep the mold locked for 300s under the conditions of 175℃ and 15MPa. After the composite rubber and sulfur have fully reacted and formed, open the mold, take out the part, trim the edges, and reduce the diameter to obtain the high fatigue-resistant automotive chassis rubber bushing.

[0034] Comparative Example 1: Based on Example 1, step S3 removes the loaded mullite fibers, while the remaining steps remain unchanged, to prepare a high fatigue-resistant automotive chassis rubber bushing.

[0035] Comparative Example 2: Based on Example 1, in step S3, the modified mullite fiber prepared in step S1 was used instead of the loaded mullite fiber, while the other steps remained unchanged, and a high fatigue-resistant automotive chassis rubber bushing was prepared.

[0036] Comparative Example 3: Based on Example 1, in step S2, mullite fiber was used instead of modified mullite fiber, while the other steps remained unchanged, and a high fatigue-resistant automotive chassis rubber bushing was prepared.

[0037] The high fatigue-resistant automotive chassis rubber bushings prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests: Tensile test: The test was conducted on the GT-7001-HD8 universal tensile testing machine of the High-Speed ​​Railway Instrument Company, in accordance with the GB / T528-1998 standard. (1) Stress-strain curve: The test sample was a dumbbell-shaped sample with a total length of 115 mm, a waist width of 6 mm, and a thickness measured by the thickness measuring instrument. The tensile rate was 500 mm / min.

[0038] (2) Cyclic test: In the loading and unloading test, the test specimen is a small sample with a length of 75 mm, a width of 4 mm, and a thickness obtained by testing. The tensile rate is 500 mm / min, and the loading and unloading are carried out 3 times.

[0039] (3) Fracture energy test: A single-sided notched tensile test was used. The fixture specimen was 75 mm long, 5 mm wide, and the thickness was measured. Samples with a 1 mm notch and unnotched samples were prepared and tested at a tensile rate of 6 mm / min. The fracture energy was calculated using the Greensmith formula: G C =6W C / √λ c， In the formula, W is the work integrated through the stretching curve (the strain obtained by the curve is λ). c -1), λ c is the strain when the notched sample fractures under tension, and c is the notch length.

[0040] Fatigue threshold testing: The electromagnetic dynamic mechanical testing instrument (M-3000) from KEL Measurement & Control Co., Ltd. was used for testing. The sample was clamped between fixtures, with a length of 100mm, a width of 20mm, and a thickness of 1mm. During the experiment, loading and unloading were performed on the electromagnetic dynamic mechanical testing instrument at a frequency of 0.5Hz. The experiment was recorded by a digital camera. In the cyclic experiment, different amplitude values ​​were set, and pre-made notched samples were subjected to cyclic loading and unloading experiments on the instrument. The crack propagation rate of the sample was calculated by first recording the images with a digital camera, then using measurement software to calculate the crack length for different numbers of turns, and finally creating a scatter plot of the number of turns versus the propagation length. The crack propagation rate was obtained by fitting the data. The fatigue threshold was calculated by creating a scatter plot of crack propagation rate versus energy release rate based on the fitted crack propagation rate and the corresponding amplitude energy release rate. The value corresponding to the intersection of the scatter plot with the straight line and the energy release rate axis was the fatigue threshold.

[0041] The performance test results are shown in the table below: Table 1 Performance Test Results As shown in Table 1, the tensile strength, tear strength, and rupture energy of Comparative Example 2 are all lower than those of Examples 1-3, but higher than those of Comparative Example 1. The performance of Comparative Example 3 is slightly lower than that of Examples 1-3. This may be because the high-strength skeleton of mullite fiber provides axial and circumferential load-bearing capacity, improving rigidity. The layered TBACa2Nb3O 10 Nanosheets can generate intermolecular slippage and absorb shear stress, and the two have a synergistic effect. The performance of Comparative Example 3 is slightly lower than that of Examples 1-3. The dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane grafted on the surface of the supported mullite fiber participate in cross-linking at the same time, which increases the cross-linking density of the rubber bushing, resulting in higher tensile strength and tear strength of the automotive chassis rubber bushing.

[0042] The number of cycles required to reach the fatigue threshold in Examples 1-3 was greater than that in Comparative Examples 1-3, possibly because the high-strength skeleton of the mullite fiber provided axial and circumferential load-bearing capacity, and the layered TBACa2Nb3O 10 Nanosheets possess a strong negative charge and combine with positively charged groups such as amino groups on modified mullite fibers through strong electrostatic interactions, thereby uniformly dispersing on the surface of the mullite fibers. Their layered structure can generate intermolecular slippage, absorb shear stress, and reduce the stress concentration factor of the bushing under alternating loads. This achieves the effect of dispersing stress and inhibiting crack propagation, thus improving the fatigue resistance of automotive chassis rubber bushings.

[0043] 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 method for preparing a high fatigue-resistant automotive chassis rubber bushing, the method comprising: The metal shell and mandrel are placed in a flat vulcanizing mold, and then the molten mixed adhesive is injected into the mold cavity. The mold is kept closed, and the mixture is reacted, trimmed, and reduced in diameter. The mixed adhesive is characterized by being prepared through the following steps: Step 1: Modify mullite fibers by using dihydroxydimethoxysilane and 3-aminopropyltriethoxysilane to obtain modified mullite fibers; Step 2: Synthesize KCa2Nb3O using potassium carbonate, calcium carbonate, and niobium pentoxide as raw materials. 10 Powder, Ca2Nb3O is adsorbed by strong electrostatic adsorption. 10 Powder is uniformly loaded onto the surface of modified mullite fibers to obtain supported mullite fibers; Step 3: Add silicone rubber, supported mullite fiber, glass microspheres, zinc stearate and calcium carbonate to a rubber and plastic internal mixer for internal mixing to obtain masterbatch; then add masterbatch, iron oxide red and 25% bismuth submersible to a two-roll mill, perform 8 thin passes, and mill for 7-10 minutes. Place under sealed conditions for 12-14 hours to obtain composite compound.

2. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 1, characterized in that, The preparation process of the modified mullite fiber described in step one is as follows: Dihydroxydimethoxysilane, 3-aminopropyltriethoxysilane, and a 50 vol% aqueous ethanol solution were added to a reaction vessel. The pH was adjusted to 4-5 with hydrochloric acid, and hydrolysis was carried out for 2-3 hours. Then, mullite fibers washed with acetone were added, and the mixture was heated at 60-70℃ for 4-5 hours. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain modified mullite fibers.

3. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 2, characterized in that, The ratio of dihydroxydimethoxysilane, 3-aminopropyltriethoxysilane, aqueous ethanol solution, and mullite fiber is 20-30g: 15-20g: 300-400mL: 140-150g.

4. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 1, characterized in that, The preparation process of the supported mullite fiber in step two is as follows: A 2 mol / L oxalic acid solution and KCa2Nb3O 10 The powder is added to the reactor and shaken on a shaker for 2-3 days. Then, a 40wt% tetrabutylammonium hydroxide aqueous solution is added and shaken on a shaker for 8-10 days. The pH is adjusted to 8-9 with ammonia. Modified mullite fiber and titanate coupling agent are added and shaken for 20-24 hours. The mixture is then filtered and dried to obtain supported mullite fiber.

5. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 4, characterized in that, The oxalic acid solution, KCa2Nb3O 10 The ratio of powder, tetrabutylammonium hydroxide aqueous solution, modified mullite fiber and titanate coupling agent is 50-60mL: 20-30g: 360-400mL: 130-150g: 0.5-0.8g.

6. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 5, characterized in that, The KCa2Nb3O 10 The powder preparation process is as follows: Potassium carbonate, calcium carbonate, and niobium pentoxide were added to a mortar and ground together to obtain a mixed powder. The mixed powder was placed in a muffle furnace and heated to 1100-1150℃ at a heating rate of 10℃ / min, held at that temperature for 24-26 hours, and then cooled to room temperature to obtain KCa2Nb3O. 10 powder; The mass ratio of potassium carbonate, calcium carbonate and niobium pentoxide is 11-15:10-12:30-40.

7. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 1, characterized in that, The mass ratio of silicone rubber, supported mullite fiber, glass microspheres, zinc stearate and calcium carbonate in step three is 130-150:45-55:5-10:1-1.5:5-10.

8. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 1, characterized in that, The mixing temperature is 140-145℃, the rotation speed is 100-120 r / min, and the time is 12-15 min.

9. The method for preparing a high fatigue-resistant automotive chassis rubber bushing according to claim 1, characterized in that, The mass ratio of the masterbatch, iron oxide red, and bis(2,5) is 186-226:3-5:0.8-2.

10. A high fatigue-resistant automotive chassis rubber bushing, prepared by the preparation method of a high fatigue-resistant automotive chassis rubber bushing according to any one of claims 1-9.

Images