High-wear-resistance anti-aging new energy auxiliary frame connecting bush and preparation method thereof

Abstract

The invention relates to the field of auxiliary frame connecting bushings, in particular to a high-wear-resistance anti-aging new energy auxiliary frame connecting bush and a preparation method thereof, and aims at solving the problems that an auxiliary frame connecting bush is insufficient in wear resistance, poor in anti-aging performance and the like. The preparation method comprises the following steps: by taking a modified polyurethane solution as a matrix, sequentially adding modified nano silicon dioxide, modified multi-walled carbon nanotubes and polytetrafluoroethylene micro powder, uniformly mixing through ultrasonic dispersion and mechanical stirring, adding an anti-aging agent and polypropylene glycol dicyclohexyl acetate step by step, and sequentially stirring and uniformly mixing, so as to obtain a finished product. And adding dicumyl peroxide as a cross-linking agent, stirring until the system is uniform, injecting into a mold, carrying out thermal insulation cross-linking and vacuum drying, and demolding to obtain the high-wear-resistance anti-aging new energy auxiliary frame connecting bushing. The high-wear-resistance anti-aging new energy auxiliary frame connecting bush has the characteristics of high wear resistance and aging resistance and excellent mechanical strength and use stability.

Description

Technical Field

[0001] This invention relates to the field of subframe connecting bushings, specifically to a high wear-resistant and anti-aging new energy subframe connecting bushing and its preparation method. Background Technology

[0002] New energy vehicles are equipped with large-capacity battery packs, which increases the vehicle's curb weight compared to traditional fuel vehicles. This results in a significant increase in the static and dynamic impact loads on the subframe. At the same time, the noise, vibration, and harshness (NVH) characteristics of the power system of new energy vehicles are more demanding. As a key vibration damping and load-bearing component, the subframe connecting bushing must simultaneously meet multiple requirements such as high load-bearing capacity, wear resistance, aging resistance, and vibration and noise reduction.

[0003] The existing subframe connecting bushings for new energy vehicles have the following main defects: insufficient wear resistance. Using ordinary natural rubber or unmodified polyurethane solution as the elastomer matrix, the surface of the elastomer is prone to wear, scratches, and even metal-elastomer interface delamination under long-term heavy load and high-frequency vibration conditions; poor aging resistance. Traditional bushing materials have weak resistance to ultraviolet aging and thermo-oxidative aging, and are prone to hardening and cracking, leading to failure of vibration damping performance. Therefore, developing a new energy vehicle subframe connecting bushing that combines high wear resistance, aging resistance, and high mechanical properties has become a technical problem that the industry urgently needs to solve. Summary of the Invention

[0004] In order to overcome the above-mentioned technical problems, the purpose of this invention is to provide a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following components by weight: 100-200 parts modified polyurethane solution, 3-6 parts modified nano silica, 1-2 parts modified multi-walled carbon nanotubes, 2-4 parts polytetrafluoroethylene micro powder, 7-14 parts polypropylene glycol dicyclohexyl acetate, 1-2 parts anti-aging agent, and 0.7-1.4 parts dicumyl peroxide. The anti-aging agent is composed of ultraviolet absorber UV-327, antioxidant 1010 and antioxidant 168 in a mass ratio of 4:3:3; The particle size of the polytetrafluoroethylene micro powder is 1-5 μm; The modified polyurethane solution is prepared by the following steps: Step a1: Add 1,6-hexanediol, dimethyl carbonate, and tetrabutyl titanate to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and reflux condenser. Purge with nitrogen for protection and stir at 60-65℃ and a stirring rate of 280-300 r / min for 60-70 min. Then raise the temperature to 125-130℃ and react for 4-5 h. After that, cool to 80℃ and connect to a vacuum rotary evaporator. Rotate at -0.1 MPa and 80℃ for 35-40 min. Then transfer to a vacuum drying oven and dry at 60℃ and -0.1 MPa for 2-3 h to obtain polycarbonate diol. Step a2: Add itaconic acid, allyl glycidyl ether, p-hydroxyanisole, and triphenylphosphine to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and reflux condenser. Purge with nitrogen for protection and stir the reaction at 90-95℃ and a stirring rate of 300-400 r / min for 2-2.2 h. Then raise the temperature to 105-110℃ and continue the reaction for 2.5-3 h. After the reaction is complete, wash with deionized water 3-4 times. Then distill under reduced pressure at 120-125℃ and a vacuum degree of -0.095 MPa to obtain a diol with a side double bond. Step a3: Polycarbonate diol, side-bonded diol, ethyl acetate, and p-hydroxyanisole are added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and reflux condenser. Nitrogen gas is introduced for protection, and the mixture is stirred at a stirring rate of 300-400 r / min for 5-7 min. Dicyclohexylmethane diisocyanate is added, and stirring is continued for 25-30 min. Stannous isooctanoate is added, and the temperature is raised to 75-80℃. Stirring is continued for 9-9.5 h to obtain a modified polyurethane solution.

[0006] In a preferred embodiment of the present invention, the ratio of 1,6-hexanediol, dimethyl carbonate and tetrabutyl titanate in step a1 is 25-31g: 17-21g: 0.08-0.10g.

[0007] In a preferred embodiment of the present invention, the ratio of itaconic acid, allyl glycidyl ether, p-hydroxyanisole and triphenylphosphine in step a2 is 13-26g: 22.8-45.6g: 0.05-0.10g: 0.2-0.4g.

[0008] In a preferred embodiment of the present invention, the ratio of polycarbonate diol, side-bonded diol, ethyl acetate, p-hydroxyanisole, dicyclohexylmethane diisocyanate, and stannous isooctanoate in step a3 is 70-140g: 3.66-7.32g: 36-72g: 0.2-0.4g: 14.5-29.0g: 0.11-0.22g.

[0009] The polypropylene glycol dicyclohexyl acetate is prepared by the following steps: Cyclohexane, cyclohexylacetic acid, polypropylene glycol, and p-toluenesulfonic acid were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and Dean-Stark water separator. Nitrogen gas was introduced for protection. The mixture was refluxed at a constant temperature of 69-70°C and a stirring rate of 300-400 rpm for 2-3 hours, during which the water level in the water separator was observed. Heating was stopped when no change in the water level was observed for 60 minutes. After the system cooled to below 40°C, it was transferred to a rotary evaporator and evaporated at 50°C and a rotation speed of 80-100 rpm. Rotary distillation was carried out for 30-40 min under a vacuum of -0.1 MPa. The product was then transferred to a separatory funnel, saturated sodium carbonate solution was added and shaken. After standing and separating the layers, the lower aqueous phase was discarded. The upper layer was washed 3-4 times, followed by washing once with deionized water. After standing and separating the layers, the aqueous phase was discarded. Anhydrous magnesium sulfate was added to the product in the separatory funnel, and the product was allowed to dry for 24 h. The product was then filtered, and the filtrate was subjected to vacuum distillation at a temperature of 120-130 °C and a vacuum of -0.095 MPa. The distillate was collected to obtain polypropylene glycol dicyclohexyl acetate.

[0010] In a preferred embodiment of the present invention, the ratio of cyclohexane, cyclohexylacetic acid, polypropylene glycol, p-toluenesulfonic acid, saturated sodium carbonate solution, and anhydrous magnesium sulfate is 60-65 mL: 26-52 g: 22-44 g: 1.2-1.3 g: 50-54 mL: 10-16 g.

[0011] In a preferred embodiment of the present invention, the polypropylene glycol is Aladdin reagent, catalog number P103209.

[0012] The modified nano-silica is prepared by the following steps: Nano-silica was dispersed in anhydrous ethanol and ultrasonically dispersed for 30-32 min at a power of 280-300 W. Then, γ-methacryloyloxypropyltrimethoxysilane was added and stirred for 2 h at a temperature of 55-60℃ and a stirring rate of 300-400 r / min. After that, it was placed in a vacuum drying oven and dried for 2-3 h at a temperature of 75-80℃ to obtain modified nano-silica.

[0013] In a preferred embodiment of the present invention, the particle size of the nano-silica is 20-50 nm.

[0014] In a preferred embodiment of the present invention, the ratio of nano-silica, anhydrous ethanol and γ-methacryloyloxypropyltrimethoxysilane is 1-2g: 50-100mL: 0.04-0.08g.

[0015] The modified multi-walled carbon nanotubes are prepared by the following steps: Multi-walled carbon nanotubes were added to a three-necked flask, concentrated nitric acid was poured in, and nitrogen gas was introduced for protection. The mixture was refluxed and stirred at 75-80℃ and a stirring rate of 250-300 rpm for 4-4.4 hours. After cooling, deionized water was added, and the mixture was centrifuged at 10000 rpm for 20-22 minutes. The supernatant was discarded, and the mixture was washed with distilled water. This washing and centrifugation process was repeated 5-6 times. The mixture was then vacuum-dried at 65-70℃ for 4 hours. Finally, it was added to anhydrous ethanol and ultrasonically dispersed for 30-32 seconds. Add γ-methacryloxypropyltrimethoxysilane-ethanol solution dropwise at a rate of 1-2 drops / s, under nitrogen protection, and stir for 3-3.2 h at a temperature of 55-60℃ and a stirring rate of 250-300 r / min. Centrifuge at 10000 r / min for 20-22 min, discard the supernatant, wash with isopropanol, and repeat the centrifugation and washing 3-4 times. Then, vacuum dry at a temperature of 55-60℃ for 4 h to obtain modified multi-walled carbon nanotubes.

[0016] In a preferred embodiment of the present invention, the ratio of the amount of multi-walled carbon nanotubes, concentrated nitric acid, deionized water, anhydrous ethanol, and γ-methacryloyloxypropyltrimethoxysilane-ethanol solution is 1-2g: 50-100mL: 200-400mL: 40-80mL: 10-20mL.

[0017] In a preferred embodiment of the present invention, the γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol in a ratio of 0.05g:10mL.

[0018] In a preferred embodiment of the present invention, the multi-walled carbon nanotubes have a diameter of 10-20 nm and a length of 1-5 μm.

[0019] In a preferred embodiment of the present invention, the concentrated nitric acid has a mass fraction of 68%.

[0020] Secondly, this application provides a method for preparing a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Modified nano-silica was added to the modified polyurethane solution and ultrasonically dispersed for 40-42 minutes at 60℃ and 400W, while simultaneously mechanically stirred at 400 rpm. Modified multi-walled carbon nanotubes were then added and ultrasonically dispersed for 30-32 minutes, followed by mechanical stirring for 60-62 minutes. Polytetrafluoroethylene (PTFE) micropowder was added and stirred for 30 minutes at 400 rpm. An anti-aging agent was added and stirred for 30-32 minutes at 280-300 rpm. Finally, polypropylene glycol was added. Dicyclohexyl acetate was heated to 63-65℃ and stirred for 40-42 minutes. Then, dicumyl peroxide was added and stirred for 10-12 minutes. The mixture was then poured into a polytetrafluoroethylene mold and vacuum degassed for 15-17 minutes under a pressure of -0.095 MPa. The mixture was then kept at 75-80℃ for 2-2.2 hours and then heated to 120℃ for crosslinking for 4 hours. After that, the mixture was allowed to cool naturally to room temperature and then placed in a vacuum drying oven at 65-70℃ for 12-13 hours. The mixture was then demolded to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

[0021] The beneficial effects of this invention are: This invention discloses a high-wear-resistant and anti-aging new energy vehicle subframe connecting bushing and its preparation method. Using a modified polyurethane solution as a matrix, modified nano-silica, modified multi-walled carbon nanotubes, and polytetrafluoroethylene powder are added sequentially. The mixture is then uniformly mixed via ultrasonic dispersion and mechanical stirring. An anti-aging agent and polypropylene glycol dicyclohexyl acetate are added stepwise and stirred until homogeneous. Dicumyl peroxide is then added as a crosslinking agent and stirred until the system is homogeneous. The mixture is then poured into a mold, subjected to heat preservation crosslinking, vacuum drying, and demolding to obtain the high-wear-resistant and anti-aging new energy vehicle subframe connecting bushing. The modified polyurethane solution serves as the core matrix, providing elasticity. Vibration reduction, providing crosslinking sites, strengthening the bond with fillers, and balancing strength and flexibility; polypropylene glycol dicyclohexyl acetate can optimize processing flowability, improve the material's flexibility and low-temperature toughness, reduce migration, and enhance hydrolysis and UV resistance; modified nano-silica can enhance material rigidity, improve wear resistance and hardness, ensure uniform dispersion, and strengthen load-bearing capacity and dimensional stability; modified multi-walled carbon nanotubes can improve the material's tensile strength and fatigue resistance, synergistically resist aging, improve thermal conductivity, and extend wear life; high wear-resistant and anti-aging new energy vehicle subframe connecting bushings have high wear resistance, anti-aging properties, and excellent mechanical strength and service stability.

[0022] In the preparation of high wear-resistant and anti-aging new energy vehicle subframe connecting bushings, a modified polyurethane solution was first prepared. Firstly, under the catalysis of tetrabutyl titanate, the hydroxyl group of 1,6-hexanediol underwent a nucleophilic substitution reaction with the alkoxy group of dimethyl carbonate, breaking the CO bond of dimethyl carbonate and forming a carbonate bond, while simultaneously removing the byproduct methanol. Then, the carboxyl group of itaconic acid underwent a ring-opening addition reaction with the epoxy group of allyl glycidyl ether, generating a functional diol containing two hydroxyl groups and one side double bond. Under the catalysis of triphenylphosphine, the -COOH group of itaconic acid acted as a nucleophile, attacking the three-membered ring of the epoxy group, generating a hydroxyl group after ring opening, while the carboxyl group was converted to an ester group. Hydroxyanisole captured free radicals, preventing the side double bond of allyl glycidyl ether from polymerizing during the reaction, ensuring the retention of the side double bond. Subsequently, a stepwise addition polymerization reaction of isocyanate and polyol occurred, generating a polymer backbone containing urethane bonds, while retaining the functional side double bond. The isocyanate group of dicyclohexylmethane diisocyanate exhibits strong electrophilicity, undergoing a nucleophilic addition reaction with the hydroxyl groups of polycarbonate diol and the diol with side double bonds. This reaction proceeds in two steps: first, -OH attacks the C atom of -NCO to form an intermediate product; second, anionic rearrangement generates a stable urethane bond. In this reaction, polycarbonate diol acts as the soft segment, providing elasticity; dicyclohexylmethane diisocyanate acts as the hard segment, providing mechanical strength; and the diol with side double bonds acts as a functional monomer, providing side double bonds to form the polyurethane backbone. This process retains the elasticity of polyurethane while possessing cross-linking reactivity. The hydroxyl-terminated design significantly enhances the interfacial bonding with nanomaterials, and the side double bonds, after cross-linking, form a dense network, significantly enhancing mechanical strength, wear resistance, and aging resistance. The soft segment polycarbonate chain is suitable for the vibration damping requirements of new energy vehicle subframe bushings, while the hard segment structure ensures load-bearing capacity. Its hydrolysis resistance and low migration characteristics are well-suited for humid operating conditions.

[0023] In the preparation of high-wear-resistant and anti-aging new energy vehicle subframe connecting bushings, a polypropylene glycol dicyclohexyl acetate was prepared. The sulfonic acid group of p-toluenesulfonic acid donated a proton, which combined with the carboxyl group of cyclohexyl acetate, protonating the carbonyl group of the carboxyl group, enhancing its electrophilicity, and lowering the activation energy of subsequent nucleophilic attack. The hydroxyl group of polypropylene glycol acted as a nucleophile, attacking the protonated carbon atom of the carboxyl group to form an intermediate product. This intermediate product underwent proton transfer, removing one molecule of water and simultaneously forming a stable ester bond. The released proton reactivated the next round of reaction, achieving a catalytic cycle. Since the esterification reaction is reversible, the generated water would inhibit the continued reaction. Therefore, utilizing the azeotropic properties of cyclohexane and water, the azeotropic vapors were condensed and separated using a Dean-Stark water separator to separate and remove the aqueous phase, continuously reducing the water concentration in the system. The reaction is driven to proceed completely towards ester formation. Polypropylene glycol dicyclohexyl acetate can significantly improve the flexibility and bending deformation adaptability of elastomers by weakening the intermolecular forces of polyurethane and lowering the glass transition temperature. It can also reduce the melt viscosity, making the polyurethane flow better during mixing and molding. The steric hindrance formed by its dicyclohexyl structure and the hydrophobic barrier constructed by the polyether backbone endow polypropylene glycol dicyclohexyl acetate with extremely low migration rate and excellent hydrolysis resistance and UV resistance, which can delay the photo-oxidative degradation of materials and extend the service life of bushings. The lipophilic cyclohexyl group and hydrophilic polyether chain in the polypropylene glycol dicyclohexyl acetate molecule have good compatibility with both the soft and hard segments of polyurethane. They can enhance the interfacial bonding force by forming a hydrogen bond network, achieving complementary synergy of elasticity, rigidity and load-bearing capacity.

[0024] In the process of preparing high wear-resistant and anti-aging new energy vehicle subframe connecting bushings, modified nano-silica and modified multi-walled carbon nanotubes were prepared. The modified nano-silica was ultrasonically dispersed in anhydrous ethanol and then grafted with γ-methacryloxypropyltrimethoxysilane to introduce carbon-carbon double bonds on the surface. The modified multi-walled carbon nanotubes were first acidified and oxidized with concentrated nitric acid to introduce active sites such as carboxyl and hydroxyl groups, and then grafted with double bonds through γ-methacryloxypropyltrimethoxysilane-ethanol solution. The core of both modifications is to introduce functional groups that match the double bonds on the solution side of the modified polyurethane, while improving the dispersibility of nanomaterials in the polyurethane matrix, enhancing the interfacial bonding force with the matrix, and avoiding agglomeration. This lays the foundation for subsequent cross-linking and curing to form a dense network, ultimately enhancing the mechanical strength, wear resistance, and anti-aging properties of the new energy vehicle subframe bushing. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1:

[0027] This embodiment describes a method for preparing a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Step s1: Add 25g of 1,6-hexanediol, 17g of dimethyl carbonate and 0.08g of tetrabutyl titanate to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Purge with nitrogen for protection and stir at 60℃ and 280r / min for 60min. Then raise the temperature to 125℃ and react for 4h. Then lower the temperature to 80℃ and connect to a vacuum rotary evaporator. Rotate at -0.1MPa and 80℃ for 35min. Then transfer to a vacuum drying oven and dry at 60℃ and -0.1MPa for 2h to obtain polycarbonate diol. Step s2: 13g itaconic acid, 22.8g allyl glycidyl ether, 0.05g p-hydroxyanisole and 0.2g triphenylphosphine were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at 90℃ and a stirring rate of 300r / min for 2h. Then the temperature was raised to 105℃ and the reaction was continued for 2.5h. After the reaction was completed, the mixture was washed three times with deionized water. Then it was distilled under reduced pressure at 120℃ and a vacuum degree of -0.095MPa to obtain a diol with a side double bond. Step s3: 70g of polycarbonate diol, 3.66g of side-bonded diol, 36g of ethyl acetate and 0.2g of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at a stirring rate of 300r / min for 5min. 14.5g of dicyclohexylmethane diisocyanate was added, and the mixture was stirred for another 25min. 0.11g of stannous isooctanoate was added, and the temperature was raised to 75℃. The mixture was stirred for another 9h to obtain a modified polyurethane solution. Step s4: Add 60 mL of cyclohexane, 26 g of cyclohexylacetic acid, 22.0 g of polypropylene glycol (Aladdin reagent, catalog number P103209), and 1.2 g of p-toluenesulfonic acid to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and a Dean-Stark water separator (with a reflux condenser installed on the water separator). Purge with nitrogen for protection and maintain a constant temperature under reflux for 2 hours at 69°C and a stirring rate of 300 r / min. Observe the water level in the water separator during this period. Stop heating when there is no change in the water level for 60 minutes. After the system cools to below 40°C, transfer it to a rotary distillation unit. The product was rotary evaporated for 30 min at 50℃, 80 r / min, and -0.1 MPa. The solution was then transferred to a separatory funnel, 50 mL of saturated sodium carbonate solution was added and shaken. After standing and separating the layers, the lower aqueous phase was discarded. The upper layer was washed three times, then washed once with deionized water. After standing and separating the layers, the aqueous phase was discarded. 10 g of anhydrous magnesium sulfate was added to the product in the separatory funnel, and the mixture was allowed to dry for 24 h. The mixture was then filtered, and the filtrate was distilled under reduced pressure at 120℃ and -0.095 MPa. The distillate was collected to obtain polypropylene glycol dicyclohexyl acetate. Step s5: Disperse 1g of nano-silica (the particle size of nano-silica is 20nm) in 50mL of anhydrous ethanol and ultrasonically disperse it for 30min at a power of 280W. Then add 0.04g of γ-methacryloyloxypropyltrimethoxysilane and stir the reaction for 2h at a temperature of 55℃ and a stirring rate of 300r / min. Then place it in a vacuum drying oven and dry it at a temperature of 75℃ for 2h to obtain modified nano-silica. Step s6: Add 1g of multi-walled carbon nanotubes (10nm in diameter and 1μm in length) to a three-necked flask, pour in 50mL of concentrated nitric acid (68% by mass), purge with nitrogen for protection, and reflux and stir at 75℃ and 250r / min for 4h. After cooling, add 200mL of deionized water, centrifuge at 10000r / min for 20min, discard the supernatant, wash with distilled water, repeat centrifugation and washing 5 times, then vacuum dry at 65℃ for 4h, then add to 40mL of anhydrous ethanol, sonicate for 30min, and add 10 drops of ethanol. A γ-methacryloxypropyltrimethoxysilane-ethanol solution (γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol at a ratio of 0.05 g: 10 mL) was prepared. The dropping rate was controlled at 1 drop / s, and nitrogen gas was introduced for protection. The reaction was stirred at 55 °C and 250 r / min for 3 h. The mixture was then centrifuged at 10000 r / min for 20 min, the supernatant was discarded, and the mixture was washed with isopropanol. The centrifugation and washing were repeated 3 times. Finally, the mixture was vacuum dried at 55 °C for 4 h to obtain modified multi-walled carbon nanotubes. Step s7: Add 3 parts of modified nano-silica to 100 parts of modified polyurethane solution, and ultrasonically disperse for 40 min at 60℃ and 400W, while simultaneously mechanically stirring at a stirring rate of 400 r / min. Then add 1 part of modified multi-walled carbon nanotubes, ultrasonically disperse for 30 min and mechanically stir for 60 min. Add 2 parts of polytetrafluoroethylene micropowder (the particle size of polytetrafluoroethylene micropowder is 1 μm), and stir for 30 min at a stirring rate of 400 r / min. Add 1 part of anti-aging agent (the anti-aging agent is composed of UV absorber UV-327, antioxidant 1010 and antioxidant 168 in a mass ratio of 4:1). The mixture (composed of 3 parts polypropylene glycol dicyclohexyl acetate) was stirred at a stirring rate of 280 r / min for 30 min, then 7 parts polypropylene glycol dicyclohexyl acetate were added, the temperature was raised to 63℃ and stirring was continued for 40 min, then 0.7 parts dicumyl peroxide were added and stirred for 10 min, then poured into a polytetrafluoroethylene mold, vacuum degassed for 15 min under a pressure of -0.095 MPa, kept at 75℃ for 2 h, then heated to 120℃ for crosslinking for 4 h, then naturally cooled to room temperature, and then placed in a vacuum drying oven and dried at 65℃ for 12 h, then demolded to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

[0028] Example 2:

[0029] This embodiment describes a method for preparing a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Step s1: Add 28g of 1,6-hexanediol, 19g of dimethyl carbonate, and 0.09g of tetrabutyl titanate to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and reflux condenser. Purge with nitrogen for protection and stir at 63°C and 290r / min for 65min. Then raise the temperature to 127°C and react for 4.5h. After that, lower the temperature to 80°C and connect to a vacuum rotary evaporator. Rotate the evaporator at -0.1MPa and 80°C for 37min. Then transfer the evaporator to a vacuum drying oven and dry at 60°C and -0.1MPa for 2.5h to obtain polycarbonate diol. Step s2: 19.5g itaconic acid, 34.2g allyl glycidyl ether, 0.075g p-hydroxyanisole and 0.3g triphenylphosphine were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at 93℃ and a stirring rate of 350r / min for 2.1h. Then the temperature was raised to 107℃ and the reaction was continued for 2.7h. After the reaction was completed, the mixture was washed three times with deionized water. Then it was distilled under reduced pressure at 123℃ and a vacuum degree of -0.095MPa to obtain a diol with a side double bond. Step s3: 105g of polycarbonate diol, 5.49g of side-bonded diol, 54g of ethyl acetate and 0.3g of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at a stirring rate of 350r / min for 6min. 21.75g ​​of dicyclohexylmethane diisocyanate was added, and the mixture was stirred for another 27min. 0.165g of stannous isooctanoate was added, and the temperature was raised to 77℃. The mixture was stirred for another 9.2h to obtain a modified polyurethane solution. Step s4: Add 62.5 mL of cyclohexane, 39 g of cyclohexylacetic acid, 33 g of polypropylene glycol (Aladdin reagent, catalog number P103209), and 1.25 g of p-toluenesulfonic acid to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and a Dean-Stark water separator (with a reflux condenser installed on the water separator). Purge with nitrogen for protection and maintain a constant temperature under reflux for 2.5 h at 69 °C and a stirring rate of 350 r / min. Observe the water level in the water separator during this period. Stop heating when there is no change in the water level for 60 consecutive minutes. Allow the system to cool to below 40 °C and transfer to a rotary vortex. The product was rotary evaporated for 35 min at 50℃, 90 r / min, and -0.1 MPa. The product was then transferred to a separatory funnel, 52 mL of saturated sodium carbonate solution was added and shaken. After standing and separating the layers, the lower aqueous phase was discarded. The upper layer was washed three times, then washed once with deionized water. After standing and separating the layers, the aqueous phase was discarded. 13 g of anhydrous magnesium sulfate was added to the product in the separatory funnel and allowed to dry for 24 h. The product was then filtered. The filtrate was then distilled under reduced pressure at 125℃ and -0.095 MPa. The distillate was collected to obtain polypropylene glycol dicyclohexyl acetate. Step s5: Disperse 1.5g of nano silica (particle size of nano silica is 20-50nm) in 75mL of anhydrous ethanol and ultrasonically disperse for 31min at a power of 290W. Then add 0.06g of γ-methacryloyloxypropyltrimethoxysilane and stir for 2h at a temperature of 57℃ and a stirring rate of 350r / min. Then place it in a vacuum drying oven and dry at a temperature of 77℃ for 2.5h to obtain modified nano silica. Step s6: Add 1.5g of multi-walled carbon nanotubes (15nm in diameter and 3μm in length) to a three-necked flask, pour in 75mL of concentrated nitric acid (68% by mass), purge with nitrogen for protection, and reflux at 77℃ and 270r / min for 4.2h. After cooling, add 300mL of deionized water, centrifuge at 10000r / min for 21min, discard the supernatant, wash with distilled water, repeat centrifugation and washing 5 times, then vacuum dry at 67℃ for 4h, then add to 60mL of anhydrous ethanol, sonicate for 31min, and add dropwise 1 5 mL of γ-methacryloxypropyltrimethoxysilane-ethanol solution (γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol at a volume ratio of 0.05 g: 10 mL), with a dropping rate controlled at 1 drop / s, nitrogen gas was introduced for protection, and the reaction was stirred at 57 °C and a stirring rate of 270 r / min for 3.1 h. After centrifugation at 10000 r / min for 21 min, the supernatant was discarded, and the solution was washed with isopropanol. The centrifugation and washing were repeated 4 times. Then, the solution was vacuum dried at 57 °C for 4 h to obtain modified multi-walled carbon nanotubes. Step s7: Add 4 parts of modified nano-silica to 150 parts of modified polyurethane solution, and ultrasonically disperse for 41 min at 60℃ and 400W, while simultaneously mechanically stirring at 400 r / min. Then add 1.5 parts of modified multi-walled carbon nanotubes, ultrasonically disperse for 31 min and mechanically stir for 61 min. Add 3 parts of polytetrafluoroethylene micropowder (3 μm particle size), and stir for 30 min at 400 r / min. Finally, add 1.5 parts of anti-aging agent (the anti-aging agent consists of UV absorber UV-327, antioxidant 1010, and antioxidant 168 in a mass ratio of 4:3). The mixture (composed of 3 parts) was stirred at a stirring rate of 290 r / min for 31 min, then 10.5 parts of polypropylene glycol dicyclohexyl acetate were added, the temperature was raised to 64℃ and stirring was continued for 41 min, then 1.05 parts of dicumyl peroxide were added and stirred for 11 min, then poured into a polytetrafluoroethylene mold, vacuum degassed at a pressure of -0.095 MPa for 16 min, kept at a temperature of 77℃ for 2.1 h, then heated to 120℃ for crosslinking for 4 h, then naturally cooled to room temperature, and then placed in a vacuum drying oven at a temperature of 67℃ for 12.5 h, and demolded to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

[0030] Example 3:

[0031] This embodiment describes a method for preparing a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Step s1: Add 31g of 1,6-hexanediol, 21g of dimethyl carbonate and 0.10g of tetrabutyl titanate to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Purge with nitrogen and stir at 65℃ and 300r / min for 70min. Then raise the temperature to 130℃ and react for 5h. Then lower the temperature to 80℃ and connect to a vacuum rotary evaporator. Rotate at -0.1MPa and 80℃ for 40min. Then transfer to a vacuum drying oven and dry at 60℃ and -0.1MPa for 3h to obtain polycarbonate diol. Step s2: 26g itaconic acid, 45.6g allyl glycidyl ether, 0.10g p-hydroxyanisole and 0.4g triphenylphosphine were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at 95℃ and a stirring rate of 400r / min for 2.2h. Then the temperature was raised to 110℃ and the reaction was continued for 3h. After the reaction was completed, the mixture was washed 4 times with deionized water. Then it was distilled under reduced pressure at 125℃ and a vacuum degree of -0.095MPa to obtain a diol with a side double bond. Step s3: 140g of polycarbonate diol, 7.32g of side-bonded diol, 72g of ethyl acetate and 0.4g of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at a stirring rate of 400r / min for 7min. 29.0g of dicyclohexylmethane diisocyanate was added, and the mixture was stirred for another 30min. 0.22g of stannous isooctanoate was added, and the temperature was raised to 80℃. The mixture was stirred for another 9.5h to obtain a modified polyurethane solution. Step s4: Add 65 mL of cyclohexane, 52 g of cyclohexylacetic acid, 44 g of polypropylene glycol (Aladdin reagent, catalog number P103209), and 1.3 g of p-toluenesulfonic acid to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and a Dean-Stark water separator (with a reflux condenser installed on the water separator). Purge with nitrogen for protection and maintain a constant temperature under reflux for 3 hours at 70°C and a stirring rate of 400 rpm. Observe the water level in the water separator during this period. Stop heating when there is no change in the water level for 60 minutes. After the system cools to below 40°C, transfer it to a rotary evaporator. The product was rotary evaporated for 40 min at 50℃, 100 r / min, and -0.1 MPa. The solution was then transferred to a separatory funnel, 54 mL of saturated sodium carbonate solution was added and shaken. After standing and separating the layers, the lower aqueous phase was discarded. The upper layer was washed four times, then washed once with deionized water. After standing and separating the layers, the aqueous phase was discarded. 16 g of anhydrous magnesium sulfate was added to the product in the separatory funnel, and the mixture was allowed to dry for 24 h. The mixture was then filtered, and the filtrate was distilled under reduced pressure at 130℃ and -0.095 MPa. The distillate was collected to obtain polypropylene glycol dicyclohexyl acetate. Step s5: Disperse 2g of nano-silica (50nm particle size) in 100mL of anhydrous ethanol and ultrasonically disperse for 32min at 300W. Then add 0.08g of γ-methacryloyloxypropyltrimethoxysilane and stir for 2h at 60℃ and 400r / min. Then place in a vacuum drying oven and dry at 80℃ for 3h to obtain modified nano-silica. Step s6: Add 2g of multi-walled carbon nanotubes (20nm in diameter and 5μm in length) to a three-necked flask, pour in 100mL of concentrated nitric acid (68% by mass), purge with nitrogen for protection, and reflux at 80℃ and 300r / min for 4.4h. After cooling, add 400mL of deionized water, centrifuge at 10000r / min for 22min, discard the supernatant, wash with distilled water, repeat centrifugation and washing 6 times, then vacuum dry at 70℃ for 4h, then add to 80mL of anhydrous ethanol, sonicate for 32min, and add dropwise 2 0 mL of γ-methacryloxypropyltrimethoxysilane-ethanol solution (γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol at a ratio of 0.05 g: 10 mL) was used. The dropping rate was controlled at 2 drops / s, and nitrogen gas was introduced for protection. The reaction was stirred at 60 °C and 300 r / min for 3.2 h. After centrifugation at 10000 r / min for 22 min, the supernatant was discarded, and the solution was washed with isopropanol. The centrifugation and washing were repeated 4 times. Then, the solution was vacuum dried at 60 °C for 4 h to obtain modified multi-walled carbon nanotubes. Step s7: Add 6 parts of modified nano-silica to 200 parts of modified polyurethane solution, and ultrasonically disperse for 42 min at 60℃ and 400W, while simultaneously mechanically stirring at a stirring rate of 400 r / min. Then add 2 parts of modified multi-walled carbon nanotubes, ultrasonically disperse for 32 min and mechanically stir for 62 min. Add 4 parts of polytetrafluoroethylene micropowder (particle size of 5 μm), and stir for 30 min at a stirring rate of 400 r / min. Add 2 parts of anti-aging agent (the anti-aging agent consists of UV absorber UV-327, antioxidant 1010 and antioxidant 168 in a mass ratio of 4:1). The mixture (composed of 3 parts by 3 parts) was stirred at a stirring rate of 300 r / min for 32 min, then 14 parts of polypropylene glycol dicyclohexyl acetate were added, the temperature was raised to 65℃ and stirring was continued for 42 min, then 1.4 parts of dicumyl peroxide were added and stirred for 12 min, then poured into a polytetrafluoroethylene mold, vacuum degassed at a pressure of -0.095 MPa for 17 min, kept at 80℃ for 2.2 h, then heated to 120℃ for crosslinking for 4 h, then naturally cooled to room temperature, and then placed in a vacuum drying oven at 70℃ for 13 h, and demolded to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

[0032] Comparative Example 1: This comparative example illustrates a method for preparing a high-wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Step s1: Add 60 mL of cyclohexane, 26 g of cyclohexylacetic acid, 22.0 g of polypropylene glycol (Aladdin reagent, catalog number P103209), and 1.2 g of p-toluenesulfonic acid to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and a Dean-Stark water separator (with a reflux condenser installed on the water separator). Purge with nitrogen for protection and maintain a constant temperature under reflux for 2 hours at 69°C and a stirring rate of 300 r / min. Observe the water level in the water separator during this period. Stop heating when there is no change in the water level for 60 minutes. After the system cools to below 40°C, transfer it to a rotary distillation unit. The product was rotary evaporated for 30 min at 50℃, 80 r / min, and -0.1 MPa. The solution was then transferred to a separatory funnel, 50 mL of saturated sodium carbonate solution was added and shaken. After standing and separating the layers, the lower aqueous phase was discarded. The upper layer was washed three times, then washed once with deionized water. After standing and separating the layers, the aqueous phase was discarded. 10 g of anhydrous magnesium sulfate was added to the product in the separatory funnel, and the mixture was allowed to dry for 24 h. The mixture was then filtered, and the filtrate was distilled under reduced pressure at 120℃ and -0.095 MPa. The distillate was collected to obtain polypropylene glycol dicyclohexyl acetate. Step s2: 1g of nano silica (with a particle size of 20nm) was dispersed in 50mL of anhydrous ethanol and ultrasonically dispersed for 30min at a power of 280W. Then, 0.04g of γ-methacryloyloxypropyltrimethoxysilane was added and stirred for 2h at a temperature of 55℃ and a stirring rate of 300r / min. After that, it was placed in a vacuum drying oven and dried at a temperature of 75℃ for 2h to obtain modified nano silica. Step s3: Add 1g of multi-walled carbon nanotubes (10nm in diameter and 1μm in length) to a three-necked flask, pour in 50mL of concentrated nitric acid (68% by mass), purge with nitrogen for protection, and reflux and stir at 75℃ and 250r / min for 4h. After cooling, add 200mL of deionized water, centrifuge at 10000r / min for 20min, discard the supernatant, wash with distilled water, repeat centrifugation and washing 5 times, then vacuum dry at 65℃ for 4h, then add to 40mL of anhydrous ethanol, sonicate for 30min, and add dropwise 10 A γ-methacryloxypropyltrimethoxysilane-ethanol solution (γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol at a ratio of 0.05 g: 10 mL) was prepared. The dropping rate was controlled at 1 drop / s, and nitrogen gas was introduced for protection. The reaction was stirred at 55 °C and 250 r / min for 3 h. The mixture was then centrifuged at 10000 r / min for 20 min, the supernatant was discarded, and the mixture was washed with isopropanol. The centrifugation and washing were repeated 3 times. Finally, the mixture was vacuum dried at 55 °C for 4 h to obtain modified multi-walled carbon nanotubes. Step s4: Add 3 parts of modified nano-silica to 100 parts of polyurethane (the polyurethane is BASF Elastollan S90A from Germany), and ultrasonically disperse for 40 min at 60℃ and 400W, while simultaneously mechanically stirring at a stirring rate of 400 r / min. Then add 1 part of modified multi-walled carbon nanotubes, ultrasonically disperse for 30 min, and mechanically stir for 60 min. Add 2 parts of polytetrafluoroethylene micropowder (the particle size of the polytetrafluoroethylene micropowder is 1 μm), and stir for 30 min at a stirring rate of 400 r / min. Add 1 part of anti-aging agent (the anti-aging agent is composed of UV absorber UV-327, antioxidant 1010, and antioxidant 168 in a mass ratio of 4:3:3), and stir. The mixture was stirred at a rate of 280 r / min for 30 min, then 7 parts of polypropylene glycol dicyclohexyl acetate were added, the temperature was raised to 63℃ and stirring was continued for 40 min, then 0.7 parts of dicumyl peroxide were added and stirred for 10 min, then poured into a polytetrafluoroethylene mold, vacuum degassed for 15 min under a pressure of -0.095 MPa, kept at 75℃ for 2 h, then heated to 120℃ for crosslinking for 4 h, then naturally cooled to room temperature, and then placed in a vacuum drying oven and dried at 65℃ for 12 h, then demolded to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

[0033] Comparative Example 2: This comparative example illustrates a method for preparing a high-wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Step s1: Add 25g of 1,6-hexanediol, 17g of dimethyl carbonate and 0.08g of tetrabutyl titanate to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Purge with nitrogen for protection and stir at 60℃ and 280r / min for 60min. Then raise the temperature to 125℃ and react for 4h. Then lower the temperature to 80℃ and connect to a vacuum rotary evaporator. Rotate at -0.1MPa and 80℃ for 35min. Then transfer to a vacuum drying oven and dry at 60℃ and -0.1MPa for 2h to obtain polycarbonate diol. Step s2: 13g itaconic acid, 22.8g allyl glycidyl ether, 0.05g p-hydroxyanisole and 0.2g triphenylphosphine were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at 90℃ and a stirring rate of 300r / min for 2h. Then the temperature was raised to 105℃ and the reaction was continued for 2.5h. After the reaction was completed, the mixture was washed three times with deionized water. Then it was distilled under reduced pressure at 120℃ and a vacuum degree of -0.095MPa to obtain a diol with a side double bond. Step s3: 70g of polycarbonate diol, 3.66g of side-bonded diol, 36g of ethyl acetate and 0.2g of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at a stirring rate of 300r / min for 5min. 14.5g of dicyclohexylmethane diisocyanate was added, and the mixture was stirred for another 25min. 0.11g of stannous isooctanoate was added, and the temperature was raised to 75℃. The mixture was stirred for another 9h to obtain a modified polyurethane solution. Step s4: Disperse 1g of nano-silica (the particle size of nano-silica is 20nm) in 50mL of anhydrous ethanol and ultrasonically disperse it for 30min at a power of 280W. Then add 0.04g of γ-methacryloyloxypropyltrimethoxysilane and stir the reaction for 2h at a temperature of 55℃ and a stirring rate of 300r / min. Then place it in a vacuum drying oven and dry it at a temperature of 75℃ for 2h to obtain modified nano-silica. Step s5: Add 1g of multi-walled carbon nanotubes (10nm in diameter and 1μm in length) to a three-necked flask, pour in 50mL of concentrated nitric acid (68% by mass), purge with nitrogen for protection, and reflux and stir at 75℃ and 250r / min for 4h. After cooling, add 200mL of deionized water, centrifuge at 10000r / min for 20min, discard the supernatant, wash with distilled water, repeat centrifugation and washing 5 times, then vacuum dry at 65℃ for 4h, then add to 40mL of anhydrous ethanol, sonicate for 30min, and add dropwise 10 A γ-methacryloxypropyltrimethoxysilane-ethanol solution (γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol at a ratio of 0.05 g: 10 mL) was prepared. The dropping rate was controlled at 1 drop / s, and nitrogen gas was introduced for protection. The reaction was stirred at 55 °C and 250 r / min for 3 h. The mixture was then centrifuged at 10000 r / min for 20 min, the supernatant was discarded, and the mixture was washed with isopropanol. The centrifugation and washing were repeated 3 times. Finally, the mixture was vacuum dried at 55 °C for 4 h to obtain modified multi-walled carbon nanotubes. Step s6: Add 3 parts of modified nano-silica to 100 parts of modified polyurethane solution, and ultrasonically disperse for 40 min at 60℃ and 400W, while simultaneously mechanically stirring at 400 r / min. Then add 1 part of modified multi-walled carbon nanotubes, ultrasonically disperse for 30 min, and mechanically stir for 60 min. Add 2 parts of polytetrafluoroethylene micropowder (particle size of 1 μm), and stir for 30 min at 400 r / min. Add 1 part of anti-aging agent (the anti-aging agent consists of UV absorber UV-327 and antioxidant 1...). The mixture of 010 and antioxidant 168 in a mass ratio of 4:3:3 was stirred at a stirring rate of 280 r / min for 30 min. Then, 0.7 parts of dicumyl peroxide were added and stirred for 10 min. The mixture was then poured into a polytetrafluoroethylene mold and vacuum degassed for 15 min under a pressure of -0.095 MPa. The mold was then kept at 75℃ for 2 h and then heated to 120℃ for crosslinking for 4 h. After that, the mixture was allowed to cool naturally to room temperature and then placed in a vacuum drying oven and dried at 65℃ for 12 h. The mold was then removed to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

[0034] Comparative Example 3: This comparative example illustrates a method for preparing a high-wear-resistant and anti-aging new energy vehicle subframe connecting bushing, comprising the following steps: Step s1: Add 25g of 1,6-hexanediol, 17g of dimethyl carbonate and 0.08g of tetrabutyl titanate to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Purge with nitrogen for protection and stir at 60℃ and 280r / min for 60min. Then raise the temperature to 125℃ and react for 4h. Then lower the temperature to 80℃ and connect to a vacuum rotary evaporator. Rotate at -0.1MPa and 80℃ for 35min. Then transfer to a vacuum drying oven and dry at 60℃ and -0.1MPa for 2h to obtain polycarbonate diol. Step s2: 13g itaconic acid, 22.8g allyl glycidyl ether, 0.05g p-hydroxyanisole and 0.2g triphenylphosphine were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at 90℃ and a stirring rate of 300r / min for 2h. Then the temperature was raised to 105℃ and the reaction was continued for 2.5h. After the reaction was completed, the mixture was washed three times with deionized water. Then it was distilled under reduced pressure at 120℃ and a vacuum degree of -0.095MPa to obtain a diol with a side double bond. Step s3: 70g of polycarbonate diol, 3.66g of side-bonded diol, 36g of ethyl acetate and 0.2g of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube and reflux condenser. Nitrogen gas was introduced for protection, and the mixture was stirred at a stirring rate of 300r / min for 5min. 14.5g of dicyclohexylmethane diisocyanate was added, and the mixture was stirred for another 25min. 0.11g of stannous isooctanoate was added, and the temperature was raised to 75℃. The mixture was stirred for another 9h to obtain a modified polyurethane solution. Step s4: Add 60 mL of cyclohexane, 26 g of cyclohexylacetic acid, 22.0 g of polypropylene glycol (Aladdin reagent, catalog number P103209), and 1.2 g of p-toluenesulfonic acid to a three-necked flask equipped with a stirrer, thermometer, gas delivery tube, and a Dean-Stark water separator (with a reflux condenser installed on the water separator). Purge with nitrogen for protection and maintain a constant temperature under reflux for 2 hours at 69°C and a stirring rate of 300 r / min. Observe the water level in the water separator during this period. Stop heating when there is no change in the water level for 60 minutes. After the system cools to below 40°C, transfer it to a rotary distillation unit. The product was rotary evaporated for 30 min at 50℃, 80 r / min, and -0.1 MPa. The solution was then transferred to a separatory funnel, 50 mL of saturated sodium carbonate solution was added and shaken. After standing and separating the layers, the lower aqueous phase was discarded. The upper layer was washed three times, then washed once with deionized water. After standing and separating the layers, the aqueous phase was discarded. 10 g of anhydrous magnesium sulfate was added to the product in the separatory funnel, and the mixture was allowed to dry for 24 h. The mixture was then filtered, and the filtrate was distilled under reduced pressure at 120℃ and -0.095 MPa. The distillate was collected to obtain polypropylene glycol dicyclohexyl acetate. Step s5: Add 100 parts of modified polyurethane solution and 2 parts of polytetrafluoroethylene micro powder (particle size of 1 μm) to a beaker, and mechanically stir for 60 min at 60℃ and 400 r / min. Add 1 part of anti-aging agent (the anti-aging agent is composed of UV absorber UV-327, antioxidant 1010 and antioxidant 168 in a mass ratio of 4:3:3), and stir for 30 min at 280 r / min. Then add 7 parts of polypropylene. Dicyclohexyl acetate of alcohol was heated to 63℃ and stirred for 40 min. Then, 0.7 parts of dicumyl peroxide were added and stirred for 10 min. The mixture was then poured into a polytetrafluoroethylene mold and vacuum degassed for 15 min under a pressure of -0.095 MPa. The mixture was then kept at 75℃ for 2 h and then heated to 120℃ for crosslinking for 4 h. After that, it was naturally cooled to room temperature and then placed in a vacuum drying oven and dried at 65℃ for 12 h. After demolding, a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing was obtained.

[0035] Performance testing: The high wear-resistant and anti-aging new energy vehicle subframe connecting bushings of Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing according to the following methods; The Martindale abrasion resistance was tested according to GB / T 21196.2-2007 "Textiles - Martindale Method - Determination of Abrasion Resistance of Fabrics - Part 2: Determination of Specimen Breakage". The test was extended to polyurethane elastomer bushings. The test conditions were: pressure 12 kPa, friction medium standard cotton cloth, and cumulative number of abrasions when the abrasion amount was ≤5 mg.

[0036] The Shore hardness was tested according to GB / T 531.1-2008 "Test method for indentation hardness of vulcanized rubber or thermoplastic rubber - Part 1: Shore hardness tester method (Shore hardness)". The ambient temperature was 23℃, and the sample was kept at a constant temperature for 2 hours before testing. The average value of 5 uniform measuring points was taken.

[0037] The tensile strength and elongation at break were tested according to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber". The test conditions were dumbbell-shaped specimens and a tensile rate of 500 mm / min. The average value of the test results of 5 specimens was taken.

[0038] The anti-aging performance was tested according to GB / T 16422.3-2014 "Laboratory Light Source Exposure Test Methods for Plastics - Part 3: Fluorescent Ultraviolet Lamps", with an ultraviolet irradiation intensity of 0.5 W / m². 2 The tensile strength retention rate was tested after aging at 60℃ and 50% humidity for 1000 hours.

[0039] The compression set was tested according to GB / T 7759.1-2015 "Determination of compression set of vulcanized rubber or thermoplastic rubber - Part 1: Under normal and high temperature conditions". The compression set was 25% and the temperature was 70℃. The deformation rate was calculated after 22 hours of heat treatment and 30 minutes of recovery.

[0040] The test results are shown in Table 1: Table 1: Test Results (Illustrated)

[0041] Referring to Table 1, based on the comparison between Examples 1-3 and Comparative Examples 1-3, it can be seen that the high wear-resistant and anti-aging new energy vehicle subframe connecting bushing has high wear resistance, anti-aging properties, and excellent mechanical strength and stability in use.

[0042] Based on the comparison between Example 1 and Comparative Example 1, it can be seen that the modified polyurethane solution in Example 1 is generated by reacting polycarbonate diol, side-double-bond diol, and dicyclohexylmethane diisocyanate. The side-double bonds can form a high-density cross-linked network with the cross-linking agent, and the polycarbonate segments have better hydrolysis resistance and UV resistance than ordinary polyurethane. Comparative Example 1 uses ordinary polyurethane, which has a significantly lower hardness than Example 1. Ordinary polyurethane has a low crosslinking density, making it prone to material transfer and wear during friction; its tensile strength decreases, the crosslinking network is weak, and the molecular chains are prone to slippage under stress, making it unable to effectively transfer stress; its UV aging retention rate decreases, as ordinary polyurethane segments lack UV-resistant groups, resulting in molecular chain breakage after aging; its compression set rate increases, and insufficient crosslinking leads to poor elastic recovery ability of the material, making it unable to rebound after long-term compression.

[0043] Based on the comparison between Example 1 and Comparative Example 2, it can be seen that Example 1 uses polypropylene glycol dicyclohexyl acetate as a plasticizer, which can improve the compatibility between the polyurethane matrix and the filler, reduce the glass transition temperature of the matrix, and improve the flexibility of the material. In Comparative Example 2, the absence of polypropylene glycol dicyclohexyl acetate leads to an increase in Shore hardness. Without the plasticizer, the matrix molecular chains are tightly packed, increasing brittleness; the elongation at break decreases, the molecular chains lack flexibility, and they are prone to breakage under stress, failing to meet the deformation requirements of the bushing during vibration; the wear resistance decreases, and brittle materials are prone to chipping during friction, accelerating the wear rate; the compression set increases, and poor flexibility prevents the release of internal stress after compression, exacerbating permanent deformation.

[0044] Based on the comparison between Example 1 and Comparative Example 3, it can be seen that modified nano-silica can fill the pores of the polyurethane matrix, improving surface hardness and scratch resistance; modified multi-walled carbon nanotubes can enhance the mechanical toughness of the matrix, forming a point-line synergistic reinforcement network, and both have excellent compatibility with the matrix and are evenly dispersed after modification with silane coupling agents; in Comparative Example 3, no modified nano-silica or modified multi-walled carbon nanotubes were added, resulting in a decrease in wear resistance. The lack of nano-silica and carbon nanotubes weakened both the surface friction resistance and internal tear resistance of the material, leading to direct matrix wear during friction; the tensile strength decreased, and without the reinforcing effect of nanofillers, the matrix relied solely on its own cross-linked network for load bearing, resulting in insufficient mechanical support; the elongation at break decreased, and the bridging effect of carbon nanotubes was lost, preventing stress transmission through carbon nanotubes after molecular chain breakage, leading to a sharp decrease in toughness; the compression set increased, and the skeletal support effect of the fillers disappeared, making the matrix prone to plastic deformation under long-term compression and unable to return to its original state.

[0045] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, characterized in that, Includes the following components by weight: 100-200 parts modified polyurethane solution, 3-6 parts modified nano silica, 1-2 parts modified multi-walled carbon nanotubes, 2-4 parts polytetrafluoroethylene micro powder, 7-14 parts polypropylene glycol dicyclohexyl acetate, 1-2 parts anti-aging agent, and 0.7-1.4 parts dicumyl peroxide. The anti-aging agent is composed of ultraviolet absorber UV-327, antioxidant 1010 and antioxidant 168 in a mass ratio of 4:3:3; The particle size of the polytetrafluoroethylene micro powder is 1-5 μm; The modified polyurethane solution is prepared by the following steps: Step a1: Add 1,6-hexanediol, dimethyl carbonate and tetrabutyl titanate to a three-necked flask and stir to react. Then heat the mixture to react, cool it down, rotary evaporate and dry it to obtain polycarbonate diol. Step a2: Add itaconic acid, allyl glycidyl ether, p-hydroxyanisole and triphenylphosphine to a three-necked flask and stir to react. Then heat up to continue the reaction, wash, and distill under reduced pressure to obtain a diol with a side double bond. Step a3: Add polycarbonate diol, side-bonded diol, ethyl acetate and p-hydroxyanisole to a three-necked flask and stir. Add dicyclohexylmethane diisocyanate and continue stirring. Add stannous isooctanoate, heat and continue stirring to obtain a modified polyurethane solution.

2. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 1, characterized in that, The ratio of 1,6-hexanediol, dimethyl carbonate, and tetrabutyl titanate in step a1 is 25-31g: 17-21g: 0.08-0.10g; the ratio of itaconic acid, allyl glycidyl ether, p-hydroxyanisole, and triphenylphosphine in step a2 is 13-26g: 22.8-45.6g: 0.05-0.10g: 0.2-0.4g; and the ratio of polycarbonate diol, side-bonded diol, ethyl acetate, p-hydroxyanisole, dicyclohexylmethane diisocyanate, and stannous isooctanoate in step a3 is 70-140g: 3.66-7.32g: 36-72g: 0.2-0.4g: 14.5-29.0g: 0.11-0.22g.

3. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 1, characterized in that, The polypropylene glycol dicyclohexyl acetate was prepared by the following steps: Cyclohexane, cyclohexylacetic acid, polypropylene glycol, and p-toluenesulfonic acid were added to a three-necked flask and refluxed at a constant temperature. The mixture was then rotary evaporated and transferred to a separatory funnel. Saturated sodium carbonate solution was added and the mixture was shaken. The upper layer was washed repeatedly, and then anhydrous magnesium sulfate was added and allowed to stand. The mixture was then filtered and distilled under reduced pressure to collect the distillate, which yielded polypropylene glycol dicyclohexylacetic acid ester.

4. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 3, characterized in that, The ratio of cyclohexane, cyclohexylacetic acid, polypropylene glycol, p-toluenesulfonic acid, saturated sodium carbonate solution, and anhydrous magnesium sulfate is 60-65 mL: 26-52 g: 22-44 g: 1.2-1.3 g: 50-54 mL: 10-16 g.

5. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 1, characterized in that, The modified nano-silica is prepared by the following steps: Nano-silica was dispersed in anhydrous ethanol by ultrasonic dispersion, then γ-methacryloxypropyltrimethoxysilane was added, the mixture was stirred and reacted, and then dried to obtain modified nano-silica.

6. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 5, characterized in that, The ratio of nano-silica, anhydrous ethanol, and γ-methacryloyloxypropyltrimethoxysilane is 1-2g: 50-100mL: 0.04-0.08g; the particle size of the nano-silica is 20-50nm.

7. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 1, characterized in that, The modified multi-walled carbon nanotubes were prepared by the following steps: Multi-walled carbon nanotubes were added to a three-necked flask, concentrated nitric acid was poured in, the mixture was refluxed and stirred, cooled, then deionized water was added, centrifuged, washed, and then vacuum dried. The mixture was then added to anhydrous ethanol, ultrasonically dispersed, and γ-methacryloyloxypropyltrimethoxysilane-ethanol solution was added dropwise. The mixture was stirred, centrifuged, washed, and then vacuum dried to obtain modified multi-walled carbon nanotubes.

8. The high wear-resistant and anti-aging new energy vehicle subframe connecting bushing according to claim 7, characterized in that, The ratio of the multi-walled carbon nanotubes, concentrated nitric acid, deionized water, anhydrous ethanol, and γ-methacryloxypropyltrimethoxysilane-ethanol solution is 1-2 g: 50-100 mL: 200-400 mL: 40-80 mL: 10-20 mL; the γ-methacryloxypropyltrimethoxysilane-ethanol solution is a solution prepared by mixing γ-methacryloxypropyltrimethoxysilane and ethanol at a ratio of 0.05 g: 10 mL; the multi-walled carbon nanotubes have a diameter of 10-20 nm and a length of 1-5 μm; the concentrated nitric acid has a mass fraction of 68%.

9. A method for preparing a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing, characterized in that, The preparation of the high wear-resistant and anti-aging new energy vehicle subframe connecting bushing as described in any one of claims 1-8 includes the following steps: Modified nano-silica was added to a modified polyurethane solution, ultrasonically dispersed, and mechanically stirred. Modified multi-walled carbon nanotubes and polytetrafluoroethylene micropowder were then added, ultrasonically dispersed, and mechanically stirred. An anti-aging agent was added and stirred, followed by polypropylene glycol dicyclohexyl acetate. The mixture was heated and stirred continuously. Then, dicumyl peroxide was added and stirred. The mixture was then poured into a polytetrafluoroethylene mold, vacuum degassed, kept at a constant temperature, and then heated to crosslink. After cooling and drying, the mixture was demolded to obtain a high wear-resistant and anti-aging new energy vehicle subframe connecting bushing.

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