A rubber nanocomposite containing modified MXene and a preparation method thereof

Abstract

The application discloses a rubber nanocomposite containing modified MXene and a preparation method thereof, and belongs to the technical field of tire rubber materials. The technical scheme comprises natural rubber and modified MXene. The modified MXene is obtained by stirring and ultrasonically mixing MXene dispersion liquid, cellulose nanowire (CNF) dispersion liquid and unsaturated alkyl amine and fully reacting. The application is applied to tire rubber materials, solves the problems that existing MXene is prone to aggregation and has limited interfacial bonding force with a rubber matrix, can greatly enhance the interfacial interaction between the MXene and the rubber matrix, improve the compatibility of the MXene and the rubber matrix, and improve the mechanical properties of the rubber nanocomposite.

Description

Technical Field

[0001] This invention belongs to the field of tire rubber material technology, and particularly relates to a rubber nanocomposite material containing modified MXene and its preparation method. Background Technology

[0002] Novel two-dimensional nanosheets, MXene, are considered ideal fillers for preparing high-performance polymer-based nanocomposites due to their low density and excellent mechanical, electrical, and thermal properties. Introducing MXene as a reinforcing material into a rubber matrix can significantly improve the rubber's mechanical strength, abrasion resistance, airtightness, and multifunctional properties. While most MXenes possess good chemically active surfaces, their hydrophilic properties lead to poor compatibility with the rubber matrix and difficulty in uniform dispersion, making them prone to aggregation and resulting in stress concentration in the material.

[0003] To improve the compatibility of MXene with the rubber matrix, alkylamines are often used to functionalize MXene, thereby improving the compatibility of the material with the polymer matrix and thus enhancing its dispersibility in the polymer to some extent. However, these long-chain alkylamines are usually saturated alkanes, and their interaction with the rubber matrix is ​​mainly van der Waals forces, resulting in limited interfacial bonding, especially when the rubber undergoes dynamic deformation, leading to poor performance improvement. In addition, Chinese patent CN119192691A discloses a rubber composition comprising natural rubber and fillers; wherein the fillers include two-dimensional transition metal carbon / nitrogen compound MXene and cellulose nanocrystals (CNC), which improve the mechanical and crystallinity properties of the rubber composite material by adding MXene and CNC.

[0004] However, the aforementioned patented rubber composition still suffers from poor dispersion of MXene in the rubber matrix and limited interfacial bonding, which in turn leads to low compatibility and bonding strength between MXene and CNC and the rubber, and the filler is prone to aggregation and slippage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the technical problem to be solved by this invention is the poor dispersibility and limited interfacial bonding of MXene in rubber matrices. This invention proposes a modified MXene-containing rubber nanocomposite material and its preparation method, which can greatly enhance the dispersibility and interfacial interaction of MXene in rubber matrices, improve the compatibility of MXene with rubber matrices, and enhance the mechanical properties of rubber nanocomposite materials.

[0006] To solve the aforementioned technical problem, the technical solution adopted by the present invention is as follows: The present invention provides a rubber nanocomposite material containing modified MXene, comprising natural rubber and modified MXene; the modified MXene is obtained by stirring and ultrasonically mixing MXene dispersion, CNF dispersion and unsaturated alkylamine, and allowing them to react fully; the aspect ratio of CNF is 100:1-200:1.

[0007] In some embodiments, the general formula for unsaturated alkylamines is CH2=CH-(CH2). n -NH2 or HC≡C-(CH2) m -NH2, n=1-8, m=1-8.

[0008] In some embodiments, the material may also include reinforcing materials, activators, antioxidants, vulcanizing agents, and vulcanization accelerators.

[0009] In some embodiments, the mass ratio of natural rubber, modified MXene, reinforcing material, activator, antioxidant, vulcanizing agent, and vulcanization accelerator is 100:1-15:15-35:2-10:1-5:1-4:0.3-3.0.

[0010] In some embodiments, the reinforcing material is carbon black N220 or carbon black N234; the activator is a mixture of zinc oxide and stearic acid, with a mass ratio of zinc oxide to stearic acid of 3.0-6.0:1-3; the antioxidant is a mixture of antioxidant 6PPD and antioxidant TMQ, with a mass ratio of antioxidant 6PPD to antioxidant TMQ of 0.5-3.0:0.5-2.0; the vulcanizing agent is ordinary sulfur or insoluble sulfur; and the vulcanization accelerator is N-tert-butyl-2-benzothiazole sulfinamide or N-cyclohexyl-2-benzothiazole sulfinamide.

[0011] Another aspect of the present invention provides a method for preparing a rubber nanocomposite material containing modified MXene according to any of the above technical solutions, including the preparation of modified MXene and the preparation of composite material; The preparation of modified MXene includes: adding lithium fluoride to a container containing hydrochloric acid, stirring magnetically at room temperature, then gradually adding Ti3AlC2 powder to the solution under slow stirring, reacting at 40°C for a period of time to etch the Al layer, washing the product by centrifugation until the pH value reaches 6 to obtain a multilayer MXene nanosheet suspension, sonicating the multilayer MXene nanosheet suspension under nitrogen protection to fully exfoliate MXene to obtain an MXene dispersion; stirring and sonicating the MXene dispersion, unsaturated alkylamine, and CNF dispersion to obtain modified MXene after sufficient reaction.

[0012] In some embodiments, the mass fraction of MXene in the MXene dispersion is 1.0%; the mass fraction of CNF in the CNF dispersion is 1.0%; and the mass ratio of MXene dispersion, CNF dispersion, and unsaturated alkylamine is 1:1:3 to 1:1:20.

[0013] In some embodiments, the MXene dispersion, CNF dispersion, and unsaturated alkylamine are stirred and ultrasonically mixed, and the reaction temperature is 160-180°C, and the reaction time is 8-24 hours.

[0014] In some embodiments, the preparation of the composite material includes: mixing natural rubber, modified MXene, reinforcing material, activator, and antioxidant in an internal mixer until uniform, then extruding and pressing the mixture into sheets to obtain a masterbatch; adding the masterbatch, vulcanizing agent, and vulcanization accelerator to an internal mixer, mixing until uniform, then extruding and pressing the mixture into sheets to obtain a final compound; and vulcanizing the final compound to obtain a rubber nanocomposite material containing modified MXene.

[0015] In some embodiments, in the step of obtaining the masterbatch, the mixing temperature is 160-175°C and the mixing time is 5-15 minutes; in the step of obtaining the final rubber, the mixing temperature is 95-110°C and the mixing time is 10-20 minutes; in the step of vulcanizing the final rubber, the vulcanization temperature is 141-151°C and the vulcanization time is 30-65 minutes.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a rubber nanocomposite material containing modified MXene, which is modified with CNF and unsaturated alkylamines. On the one hand, the 1D / 2D hybrid nanostructure formed by MXene and CNF enhances the interfacial interaction between MXene and the rubber matrix, improving the dispersion performance and distribution stability of MXene in the rubber matrix. On the other hand, by modifying MXene and CNF with unsaturated alkylamines, the compatibility between the material and the matrix is ​​increased, and the unsaturated bonds at their ends can directly participate in the cross-linking reaction during rubber vulcanization, thereby forming a strong covalent bond connection between MXene nanosheets and CNF nanowires and the rubber matrix. This greatly enhances the interfacial interaction between the reinforcing material and the rubber matrix, solves the problem of easy agglomeration of nanofillers, and significantly improves the mechanical properties of the prepared rubber nanocomposite material while significantly reducing its heat generation. Detailed Implementation

[0017] The technical solutions in specific embodiments of the present invention will be described in detail and completely below. Obviously, the described embodiments are only some specific implementations of the overall technical solution of the present invention, and not all implementations. Based on the overall concept of the present invention, all other embodiments obtained by those skilled in the art fall within the protection scope of the present invention.

[0018] The present invention provides a rubber nanocomposite material containing modified MXene, comprising natural rubber and modified MXene; the modified MXene is obtained by stirring and ultrasonically mixing MXene dispersion, CNF dispersion and unsaturated alkylamine, and reacting fully; the aspect ratio of CNF is 100:1-200:1.

[0019] The aforementioned rubber nanocomposite containing modified MXene utilizes CNF and unsaturated alkylamines to modify MXene. On one hand, the 1D / 2D hybrid nanostructure formed by MXene and CNF enhances the interfacial interaction between MXene and the rubber matrix, improving the dispersion performance and distribution stability of MXene in the rubber matrix. On the other hand, by modifying MXene and CNF with unsaturated alkylamines, the compatibility between the material and the matrix is ​​increased, while the unsaturated bonds at their ends can directly participate in the cross-linking reaction during rubber vulcanization. This results in the formation of strong covalent bonds between MXene nanosheets and CNF nanowires and the rubber matrix, greatly enhancing the interfacial interaction between the reinforcing material and the rubber matrix. This solves the problem of easy agglomeration of nanofillers, significantly improving the mechanical properties of the prepared rubber nanocomposite and significantly reducing its heat generation.

[0020] It should be noted that the above technical solution limits the addition of CNF to modify MXene during the preparation process of modified MXene, rather than preparing a composite material by mixing unsaturated chain alkylated MXene, CNF, and natural rubber after obtaining unsaturated chain alkylated MXene. The reason is that this method enables CNF to first form a 1D / 2D hybrid nanostructure with MXene, and stabilize this structure in the subsequent surface modification process.

[0021] The above technical solution also limits the aspect ratio of CNF. The reason is that a smaller aspect ratio will not be able to intercalate and anchor MXene, while an excessively large aspect ratio will cause entanglement between CNF and MXene, affecting the dispersion of the hybrid structure in the rubber matrix.

[0022] This invention modifies MXene and CNF by using unsaturated alkylamines containing carbon-carbon double or triple bonds as functionalizing agents. These alkylamines react with MXene and CNF in an aqueous phase to cap and alkylate the material surfaces. MXene is intercalated and anchored through CNF, forming 1D / 2D hybrid nanostructures with better dispersibility. The amino groups of the unsaturated alkylamines react with oxygen-containing groups such as hydroxyl groups on the surfaces of MXene and CNF, covalently grafting them onto MXene and CNF.

[0023] This invention (rubber nanocomposite material containing modified MXene) utilizes unsaturated alkylamines to modify the hybrid structure while enabling the unsaturated bonds to directly participate in the crosslinking reaction during rubber vulcanization. Strong covalent bonds are formed between MXene and CNF and the rubber matrix, greatly enhancing interfacial interactions and to some extent solving the problem of easy agglomeration of nanofillers. This improves the tensile strength, tear strength, tensile stress at a given elongation, and hardness of the rubber nanocomposite material.

[0024] This invention provides a rubber nanocomposite material containing modified MXene and its preparation method. First, the precursor MAX(Ti3AlC2) is exfoliated into monolayer or few-layer MXene(Ti3C2T) through selective chemical etching and physical stripping processes. x Nanosheets were then formed. Subsequently, the amino groups of the unsaturated alkylamine reacted with the oxygen-containing groups such as hydroxyl groups on the surface of MXene and CNF, covalently grafting them onto the hybrid structure to obtain unsaturated alkylated MXene and CNF. Simultaneously, MXene and CNF underwent intercalation and anchoring during the modification process, forming an unsaturated alkylated modified 1D / 2D hybrid nanostructure. The unsaturated bonds at the alkyl chain ends could directly participate in the crosslinking reaction during rubber vulcanization, thus forming a strong covalent bond between MXene and CNF and the rubber matrix. This greatly enhanced the interfacial interaction between the two, partially solving the problem of easy agglomeration of nanofillers, thereby improving the tensile strength, tear strength, tensile stress, and hardness of the rubber composite. Furthermore, the high thermal conductivity of MXene allowed the heat generated by the rubber compound to be released quickly, significantly weakening the softening phenomenon caused by heat in the rubber composite and reducing tire rolling resistance.

[0025] In some embodiments, the general formula for unsaturated alkylamines is CH2=CH-(CH2). n -NH2 or HC≡C-(CH2) m -NH2, n=1-8, m=1-8.

[0026] In some embodiments, the unsaturated alkylamine is selected from any one of acrylamine, hexenamine, octenamine, propyneamine, pentyneamine, and heptyneamine.

[0027] In some embodiments, the mixture further includes reinforcing materials, activators, antioxidants, vulcanizing agents, and vulcanization accelerators. In some embodiments, the mass ratio of natural rubber, modified MXene, reinforcing materials, activators, antioxidants, vulcanizing agents, and vulcanization accelerators is 100:1-15:15-35:2-10:1-5:1-4:0.3-3.0.

[0028] In the technical solution of this invention, according to the above-mentioned mass ratio requirements, the reinforcing material and modified MXene can complement each other, the activator can maximize the activation of reactive sites, and the antioxidant can maintain the performance stability during use; the dosage of vulcanizing agent and accelerator affects the formation of monosulfide bonds (low degree of crosslinking), disulfide bonds and polysulfide bonds (moderate degree of crosslinking, low degree of vulcanization reversion).

[0029] In some embodiments, the reinforcing material is carbon black N220 or carbon black N234. In the technical solution of this invention, the carbon black has an iodine absorption value of 118-122 g / kg, a moderate CTAB specific surface area, and a basically identical structure, thus providing excellent wear resistance and higher tensile strength.

[0030] In some embodiments, the activator is a mixture of zinc oxide and stearic acid, with a mass ratio of zinc oxide to stearic acid of 3.0-6.0:1-3. Preferably, the mass ratio of zinc oxide to stearic acid is 5.0:2, which provides better active sites for the reaction of rubber and filler, forming a greater amount of zinc stearate mixture.

[0031] In some embodiments, the antioxidant is a mixture of antioxidant 6PPD and antioxidant TMQ, with a mass ratio of antioxidant 6PPD to antioxidant TMQ of 0.5-3.0:0.5-2.0. Preferably, the mass ratio of antioxidant 6PPD to antioxidant TMQ is 2.5:1.5, which provides better protection for the properties of the finished rubber product, improves performance stability, and delays aging.

[0032] In some embodiments, the vulcanizing agent is ordinary sulfur or insoluble sulfur. Preferably, the insoluble sulfur is insoluble sulfur OT-20.

[0033] In some embodiments, the vulcanization accelerator is N-tert-butyl-2-benzothiazole sulfinamide (accelerator NS) or N-cyclohexyl-2-benzothiazole sulfinamide (accelerator CZ).

[0034] Another aspect of the present invention provides a method for preparing a rubber nanocomposite material containing modified MXene according to any of the above technical solutions, including the preparation of modified MXene and the preparation of composite material; The preparation of modified MXene includes: adding lithium fluoride to a container containing hydrochloric acid, stirring magnetically at room temperature, then gradually adding Ti3AlC2 powder to the solution under slow stirring, reacting at 40°C for a period of time to etch the Al layer, washing the product by centrifugation until the pH value reaches 6 to obtain a multilayer MXene nanosheet suspension, sonicating the multilayer MXene nanosheet suspension under nitrogen protection to fully exfoliate MXene to obtain an MXene dispersion; stirring and sonicating the MXene dispersion, CNF dispersion, and unsaturated alkylamine to obtain modified MXene after sufficient reaction.

[0035] In some embodiments, the mass fraction of MXene in the MXene dispersion is 1.0%; the mass fraction of CNF in the CNF dispersion is 1.0%; and the mass ratio of MXene dispersion, CNF dispersion, and unsaturated alkylamine is 1:1:3 to 1:1:20.

[0036] In some embodiments, the MXene dispersion, CNF dispersion, and unsaturated alkylamine are stirred and ultrasonically mixed, and the reaction temperature is 160-180°C, and the reaction time is 8-24 hours.

[0037] In some embodiments, after sufficient reaction, the mixture is centrifuged and washed. The centrifugation conditions are: centrifugation at 3500-8000 rpm for 5-20 minutes. The washing steps include: gradient washing of the centrifuged solid precipitate with acetone, ethanol and deionized water, wherein the acetone is washed 3 times, the ethanol is washed 3 times, and the deionized water is washed until the pH of the supernatant is 6.5-7.0.

[0038] Preferably, the mass ratio of MXene dispersion, CNF dispersion, and unsaturated alkylamine is 1:1:15; the reaction temperature is 170℃, the reaction time is 16 hours, and the centrifugation conditions are: centrifugation at 7000 rpm for 10 minutes. In this invention, the preparation method of unsaturated chain alkylated MXene and CNF is simple, the reaction time is short, and MXene and CNF exhibit good reactivity with unsaturated alkylamine, achieving a rapid reaction between MXene and CNF and unsaturated alkylamine. After the reaction, excess MXene, CNF, and unsaturated alkylamine are removed using acetone, ethanol, and deionized water, respectively, improving the purity of the unsaturated chain alkylated MXene and CNF. As a comparison, unsaturated chain alkylated MXene without CNF is prepared according to the same process described above.

[0039] In some embodiments, the preparation of the composite material includes: mixing natural rubber, modified MXene, reinforcing material, activator, and antioxidant in an internal mixer until uniform, then extruding and pressing the mixture into sheets to obtain a masterbatch; adding the masterbatch, vulcanizing agent, and vulcanization accelerator to an internal mixer, mixing until uniform, then extruding and pressing the mixture into sheets to obtain a final compound; and vulcanizing the final compound to obtain a rubber nanocomposite material containing modified MXene.

[0040] In some embodiments, in the step of obtaining the masterbatch, the mixing temperature is 160-175°C and the mixing time is 5-15 minutes; in the step of obtaining the final rubber, the mixing temperature is 95-110°C and the mixing time is 10-20 minutes; in the step of vulcanizing the final rubber, the vulcanization temperature is 141-151°C and the vulcanization time is 30-65 minutes.

[0041] Preferably, in the step of obtaining the masterbatch, the mixing temperature is 170°C and the mixing time is 10 minutes; in the step of obtaining the final rubber, the mixing temperature is 100°C and the mixing time is 15 minutes; in the step of vulcanizing the final rubber, the vulcanization temperature is 151°C and the vulcanization time is 40 minutes.

[0042] To provide a clearer and more detailed description of the modified MXene-containing rubber nanocomposite material and its preparation method provided in the embodiments of the present invention, the following description will be based on specific embodiments.

[0043] Example 1 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The nanosheets were obtained by selectively etching away Al from MAX (Ti3AlC2). Lithium fluoride (5 g) was added to a polytetrafluoroethylene container containing 100 mL of 8 M hydrochloric acid and magnetically stirred at room temperature for 30 minutes. Subsequently, 5 g of MAX powder was gradually added to the solution with slow stirring, and the reaction was carried out at 40°C for 20 hours to etch the Al layer. The product was washed by centrifugation with deionized water (7500 rpm, 5 minutes) until the pH reached 6, yielding multilayer MXene (Ti3C2T) nanosheets. x MXene nanosheet suspension. The resulting suspension was sonicated for 120 minutes under nitrogen protection to fully exfoliate MXene, yielding MXene (Ti3C2T). x Aqueous dispersion of nanosheets.

[0044] Preparation of alkylated MXene with acrylamine: MXene dispersion (aqueous phase), CNF dispersion (aqueous phase), and acrylamine were added to deionized water at a mass ratio of 1:1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove the remaining solvent, thus preparing alkylated MXene with acrylamine.

[0045] The aspect ratio of CNF is 100:1.

[0046] Preparation of rubber nanocomposite material containing modified MXene: 100 parts by mass of natural rubber, 1.0 part by mass of modified MXene, 29.0 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing modified MXene.

[0047] Example 2 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of nanosheets is the same as in Example 1.

[0048] Preparation of hexenamine alkylated MXene: MXene dispersion (aqueous phase), CNF dispersion (aqueous phase), and hexenamine were added to deionized water at a mass ratio of 1:1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove residual solvent, thus preparing hexenamine alkylated MXene.

[0049] The aspect ratio of CNF is 200:1.

[0050] Preparation of modified rubber nanocomposite material: 100 parts by mass of natural rubber, 5.0 parts by mass of modified MXene, 25.0 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the modified MXene-containing rubber nanocomposite material.

[0051] Example 3 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of nanosheets is the same as in Example 1.

[0052] Preparation of octenamine alkylated MXene: MXene dispersion (aqueous phase), CNF dispersion (aqueous phase), and octenamine were added to deionized water at a mass ratio of 1:1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove the remaining solvent, thus preparing octenamine alkylated MXene.

[0053] The aspect ratio of CNF is 150:1.

[0054] Preparation of rubber nanocomposite material containing modified MXene: 100 parts by mass of natural rubber, 10.0 parts by mass of modified MXene, 20.0 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing modified MXene.

[0055] Example 4 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of nanosheets is the same as in Example 1.

[0056] Preparation of propyne alkylated MXene: MXene dispersion (aqueous phase), CNF dispersion (aqueous phase), and propyne were added to deionized water at a mass ratio of 1:1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove residual solvent, thus preparing propyne alkylated MXene.

[0057] The aspect ratio of CNF is 100:1.

[0058] Preparation of rubber nanocomposite material containing modified MXene: 100 parts by mass of natural rubber, 1.0 part by mass of modified MXene, 29.0 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing modified MXene.

[0059] Example 5 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of nanosheets is the same as in Example 1.

[0060] Preparation of alkylated MXene with pentyneamine: MXene dispersion (aqueous phase), CNF dispersion (aqueous phase), and pentyneamine were added to deionized water at a mass ratio of 1:1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove the remaining solvent, thus preparing alkylated MXene with pentyneamine.

[0061] The aspect ratio of CNF is 200:1.

[0062] Preparation of rubber nanocomposite material containing modified MXene: 100 parts by mass of natural rubber, 5.0 parts by mass of modified MXene, 25.0 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing modified MXene.

[0063] Example 6 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of nanosheets is the same as in Example 1.

[0064] Preparation of heptynylamine alkylated MXene: MXene dispersion (aqueous phase), CNF dispersion (aqueous phase), and heptynylamine were added to deionized water at a mass ratio of 1:1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove the remaining solvent, thus preparing heptynylamine alkylated MXene.

[0065] The aspect ratio of CNF is 150:1.

[0066] Preparation of rubber nanocomposite material containing modified MXene: 100 parts by mass of natural rubber, 10.0 parts by mass of modified MXene, 20.0 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing modified MXene.

[0067] Comparative Example 1 The preparation method of this comparative rubber nanocomposite material includes the following steps: According to the mass percentages, 100 parts of natural rubber, 30.0 parts of carbon black N234, 5.0 parts of zinc oxide, 2.0 parts of stearic acid, 2.5 parts of antioxidant 6PPD, and 1.5 parts of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part of ordinary sulfur, and 0.5 parts of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the comparative rubber nanocomposite material.

[0068] Comparative Example 2 The preparation method of this comparative rubber nanocomposite material includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of the nanosheets was the same as in Example 1. Unmodified dry MXene and CNF were prepared by freeze-drying their respective dispersions.

[0069] Preparation of rubber nanocomposite material containing unmodified MXene: 100 parts by weight of natural rubber, 2.5 parts by weight of unmodified MXene, 2.5 parts by weight of unmodified CNF, 25.0 parts by weight of carbon black N234, 5.0 parts by weight of zinc oxide, 2.0 parts by weight of stearic acid, 2.5 parts by weight of antioxidant 6PPD, and 1.5 parts by weight of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by weight of ordinary sulfur, and 0.5 part by weight of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing unmodified MXene.

[0070] Comparative Example 3 Same as Example 1, except that MXene was modified with acrylamine and cellulose nanocrystals (CNC).

[0071] Comparative Example 4 Same as Example 1, except that the aspect ratio of CNF is 50:1.

[0072] Comparative Example 5 Same as Example 1, except that the aspect ratio of CNF is 300:1.

[0073] Comparative Example 6 The preparation method of the rubber nanocomposite material containing modified MXene in this embodiment includes the following steps: MXene (Ti3C2T) x The aqueous dispersion of nanosheets is the same as in Example 1.

[0074] Preparation of hexenamine alkylated MXene (CNF-free): MXene dispersion (aqueous phase) and hexenamine were added to deionized water at a mass ratio of 1:15. After stirring for 20 minutes, a stable solution was obtained by ultrasonic separation at 20 kHz using a cell disruptor. The obtained solution was transferred to a polytetrafluoroethylene reactor and reacted at 170℃ for 16 hours. The mixed solution was centrifuged at 7000 rpm for 10 minutes to obtain a solid precipitate, which was washed with a gradient of acetone, ethanol, and deionized water until the pH of the supernatant was 6.5-7.0. The solid precipitate was then freeze-dried for 24 hours to remove residual solvent, thus preparing hexenamine alkylated MXene.

[0075] Preparation of rubber nanocomposite material containing hexenamine alkylated MXene (unmodified CNF): 100 parts by mass of natural rubber, 2.5 parts by mass of hexenamine alkylated MXene, 2.5 parts by mass of unmodified CNF, 25 parts by mass of carbon black N234, 5.0 parts by mass of zinc oxide, 2.0 parts by mass of stearic acid, 2.5 parts by mass of antioxidant 6PPD, and 1.5 parts by mass of antioxidant TMQ were placed in a small internal mixer and mixed at 170°C for 10 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the masterbatch. The obtained masterbatch, 1.0 part by mass of ordinary sulfur, and 0.5 part by mass of vulcanization accelerator NS were placed in a small internal mixer and mixed at 100°C for 15 minutes. After uniform mixing, the mixture was extruded and pressed into sheets to obtain the final compound. The obtained final compound was vulcanized at 151°C for 40 minutes to prepare the rubber nanocomposite material containing modified MXene (unmodified CNF).

[0076] Performance testing The rubber nanocomposites prepared in Examples 1-6 and Comparative Examples 1-6 were subjected to performance testing, and the test results are shown in Table 1. The testing standards for 300% tensile stress and tensile strength were based on GB / T 528-2009; hardness testing standards were based on GB / T 531.1-2008; resilience testing standards were based on GB / T 1681-2009; DIN abrasion index testing standards were based on GB / T 9867-2008; dynamic mechanical analysis (DMA) testing standards were based on GB / T 9870-2006; and compression heat generation testing standards were based on GB / T1687.3-2016.

[0077] Table 1 Performance test table of rubber nanocomposites prepared in Examples 1-6 and Comparative Examples 1-6

[0078] As shown in Table 1: The modified MXene-containing rubber nanocomposite material prepared in Example 1 achieved a 300% constant tensile stress of 22.07 MPa, a tensile strength of 24.33 MPa, a hardness of 62.7, a resilience of 42.8, a DIN abrasion index of 112%, a tanδ of 0.0775 at 60℃, and a compression heat of 24.13℃. All of these properties are significantly better than those of the rubber nanocomposite material prepared in Comparative Example 1 without MXene, effectively improving tire safety and service life. The modified MXene-containing rubber nanocomposite material prepared in Example 2 achieved a 300% constant tensile stress of 24.46 MPa, a tensile strength of 28.97 MPa, a hardness of 65.6, a resilience of 45.9, a DIN abrasion index of 119%, a tanδ of 0.0732 at 60℃, and a compression heat of 22.96℃. All of these properties are significantly better than those of the rubber nanocomposite material prepared in Comparative Example 1 without MXene, effectively improving tire safety and service life. The modified MXene-containing rubber nanocomposite material prepared in Example 3 achieved a 300% constant tensile stress of 19.99 MPa, a tensile strength of 22.38 MPa, a hardness of 66.2, a resilience of 39.7, a DIN abrasion index of 110%, a tanδ of 0.0835 at 60℃, and a compression heat of 28.71℃. All of these properties are significantly better than those of the rubber nanocomposite material prepared without MXene in Comparative Example 1, effectively improving tire safety and service life. The modified MXene-containing rubber nanocomposite material prepared in Example 4 exhibits a 300% constant elongation stress of 23.88 MPa, a tensile strength of 25.87 MPa, a hardness of 64.2, a resilience of 40.2, a DIN abrasion index of 117%, a tanδ of 0.0702 at 60℃, and a compression heat of 22.37℃. All of these properties are significantly superior to those of the rubber nanocomposite material prepared in Comparative Example 1 without MXene, effectively improving tire safety and service life. The modified MXene-containing rubber nanocomposite material prepared in Example 5 achieved a 300% constant tensile stress of 25.18 MPa, a tensile strength of 30.07 MPa, a hardness of 67.2, a resilience of 44.7, a DIN abrasion index of 122%, a tanδ of 0.0668 at 60℃, and a compression heat of 20.93℃. All of these properties are significantly better than those of the rubber nanocomposite material prepared without MXene in Comparative Example 1, effectively improving the safety and service life of the tire. The modified MXene-containing rubber nanocomposite material prepared in Example 6 exhibits a 300% constant elongation stress of 21.03 MPa, a tensile strength of 23.45 MPa, a hardness of 68.1, a resilience of 38.8, a DIN abrasion index of 115%, a tanδ of 0.0812 at 60℃, and a compression heat of 27.15℃. All of these properties are significantly superior to the rubber nanocomposite material prepared without MXene in Comparative Example 1, effectively improving tire safety and service life.

[0079] The MXene-free rubber nanocomposite material prepared in Comparative Example 1 achieved a 300% constant elongation stress of 14.21 MPa, a tensile strength of 17.25 MPa, a hardness of 56.0, a resilience of 35.1, a DIN abrasion index of 87%, a tanδ of 0.1658 at 60℃, and a compression heat of 38.98℃.

[0080] The aforementioned properties are significantly lower than those of the modified MXene-containing rubber nanocomposites prepared in Examples 1-6. This is because the unsaturated alkyl segments are distributed at the interface between MXene and rubber, and their terminal unsaturated bonds can directly participate in the crosslinking reaction during rubber vulcanization, thereby forming a strong covalent bond between MXene and the rubber matrix. This enhances the interfacial interaction between the two, resulting in higher interfacial bonding force. In addition, alkylated MXene has better modulus and thermal conductivity, which improves the mechanical properties of rubber while reducing the heat generation and hysteresis loss of the rubber nanocomposites.

[0081] The rubber nanocomposite material containing unmodified MXene and CNF prepared in Comparative Example 2 achieved a 300% constant elongation stress of 18.02 MPa, a tensile strength of 20.33 MPa, a hardness of 58.4, a resilience of 36.9, a DIN abrasion index of 103%, a tanδ of 0.1402 at 60℃, and a compression heat of 36.37℃.

[0082] Compared to the rubber nanocomposites with modified MXene prepared in Examples 2 or 5 (with equal parts MXene and carbon black), the properties of the unmodified MXene and CNF nanocomposites were significantly reduced. This is because unmodified MXene and CNF have high surface energies and are prone to aggregation. Aggregation results in poor dispersibility in natural rubber, reducing the mechanical properties of the rubber nanocomposites. Furthermore, unmodified MXene and CNF have fewer reactive sites with natural rubber, making it difficult to establish effective crosslinking. The interface between MXene and CNF and natural rubber is also difficult to generate high interfacial forces, thus hindering the development of their excellent thermal conductivity and mechanical properties, leading to significant performance loss in the unmodified MXene rubber nanocomposites.

[0083] The rubber nanocomposite material containing modified MXene prepared in Comparative Example 3 (CNF replaced with CNC) achieved a 300% tensile stress of 20.74 MPa, a tensile strength of 22.03 MPa, a hardness of 60.7, a resilience of 37.3, a DIN abrasion index of 105%, a tanδ of 0.0915 at 60℃, and a compression heat of 30.22℃. Compared to Example 1, all properties decreased. This is because the CNC nanocomposite material has a smaller aspect ratio, resulting in a weaker intercalation and anchoring effect for MXene.

[0084] The modified MXene-containing rubber nanocomposite material (CNF aspect ratio of 50) prepared in Comparative Example 4 achieved a 300% constant tensile stress of 20.88 MPa, a tensile strength of 22.11 MPa, a hardness of 60.9, a resilience of 37.6, a DIN abrasion index of 108%, a tanδ of 0.0903 at 60℃, and a compression heat of 30.05℃. Compared to Example 1, all properties decreased. This is because the smaller aspect ratio of the CNF results in a weaker intercalation and anchoring effect for MXene.

[0085] The rubber nanocomposite material containing modified MXene (CNF aspect ratio of 300) prepared in Comparative Example 5 achieved a 300% constant tensile stress of 20.46 MPa, a tensile strength of 21.35 MPa, a hardness of 60.1, a resilience of 37.0, a DIN abrasion index of 104%, a tanδ of 0.0922 at 60℃, and a compression heat of 30.40℃. Compared to Example 1, all properties decreased. This is because the excessively large aspect ratio led to entanglement between CNF and MXene, affecting the dispersion of the hybrid structure in the rubber matrix.

[0086] The rubber nanocomposite material containing hexenamine-alkylated MXene (unmodified CNF) prepared in Comparative Example 6 achieved a 300% tensile stress of 22.01 MPa, a tensile strength of 24.22 MPa, a hardness of 62.1, a resilience of 42.3, a DIN abrasion index of 110%, a tanδ of 0.0787 at 60℃, and a compression heat of 24.77℃. Compared to Comparative Example 1, all properties were improved. This is because the modified MXene has better dispersion properties in the rubber matrix, and the unsaturated bonds on the surface covalently bond MXene and rubber molecular chains, improving the binding force. Compared to Example 2, all properties were decreased. This is because the lack of CNF modification resulted in poor CNF dispersion properties, limiting the improvement of the rubber matrix properties by the reinforcing material.

Claims

1. A rubber nanocomposite material containing modified MXene, characterized in that, Including natural rubber and modified MXene; The modified MXene was obtained by stirring and ultrasonically mixing MXene dispersion, CNF dispersion, and unsaturated alkylamine, and allowing them to react fully. The aspect ratio of the CNF is 100:1-200:

1.

2. The rubber nanocomposite material containing modified MXene according to claim 1, characterized in that, The general formula for the unsaturated alkylamine is CH2=CH-(CH2). n -NH2 or HC≡C-(CH2) m -NH2, n=1-8, m=1-8.

3. The rubber nanocomposite material containing modified MXene according to claim 1, characterized in that, It also includes reinforcing materials, activators, antioxidants, vulcanizing agents, and vulcanization accelerators.

4. The rubber nanocomposite material containing modified MXene according to claim 3, characterized in that, The mass ratio of the natural rubber, the modified MXene, the reinforcing material, the activator, the antioxidant, the vulcanizing agent, and the vulcanization accelerator is 100:1-15:15-35:2-10:1-5:1-4:0.3-3.

0.

5. The rubber nanocomposite material containing modified MXene according to claim 3, characterized in that, The reinforcing material is carbon black N220 or carbon black N234; the activator is a mixture of zinc oxide and stearic acid, wherein the mass ratio of zinc oxide to stearic acid is 3.0-6.0:1-3; the antioxidant is a mixture of antioxidant 6PPD and antioxidant TMQ, wherein the mass ratio of antioxidant 6PPD to antioxidant TMQ is 0.5-3.0:0.5-2.0; the vulcanizing agent is ordinary sulfur or insoluble sulfur; the vulcanization accelerator is N-tert-butyl-2-benzothiazole sulfinamide or N-cyclohexyl-2-benzothiazole sulfinamide.

6. The method for preparing the rubber nanocomposite material containing modified MXene according to any one of claims 1-5, characterized in that, This includes the preparation of modified MXene and the preparation of composite materials; The preparation of the modified MXene includes: Lithium fluoride was added to a container containing hydrochloric acid and magnetically stirred at room temperature. Then, Ti3AlC2 powder was gradually added to the solution under slow stirring to etch the Al layer. The product was washed by centrifugation to obtain a multilayer MXene nanosheet suspension. The multilayer MXene nanosheet suspension was ultrasonically treated under nitrogen protection to fully exfoliate the MXene and obtain the MXene dispersion. The MXene dispersion, CNF dispersion, and unsaturated alkylamine were stirred and ultrasonically mixed to obtain the modified MXene after sufficient reaction.

7. The preparation method according to claim 6, characterized in that, The mass ratio of the MXene dispersion, the CNF dispersion, and the unsaturated alkylamine is 1:1:3 to 1:1:

20.

8. The preparation method according to claim 6, characterized in that, The MXene dispersion, CNF dispersion, and unsaturated alkylamine were stirred and ultrasonically mixed. The reaction temperature was 160-180℃ and the reaction time was 8-24 hours.

9. The preparation method according to claim 6, characterized in that, The preparation of the composite material includes: mixing the natural rubber, the modified MXene, the reinforcing material, the activator, and the antioxidant in a mixer until uniform, then extruding and pressing the mixture into sheets to obtain a masterbatch; The masterbatch, vulcanizing agent, and vulcanization accelerator are added to an internal mixer, mixed evenly, and then extruded and pressed into sheets to obtain the final rubber. The final rubber compound is vulcanized to obtain the rubber nanocomposite material containing modified MXene.

10. The preparation method according to claim 9, characterized in that, In the step of obtaining the masterbatch, the mixing temperature is 160-175℃ and the mixing time is 5-15 minutes; in the step of obtaining the final rubber, the mixing temperature is 95-110℃ and the mixing time is 10-20 minutes; in the step of vulcanizing the final rubber, the vulcanization temperature is 141-151℃ and the vulcanization time is 30-65 minutes.

Images