Aging-resistant high-flame-retardant multifunctional rubber composite material and preparation method thereof

Abstract

The application provides an anti-aging high-flame-retardant multifunctional rubber composite material and a preparation method thereof, which is prepared by uniformly mixing a rubber matrix, a quantum dot intercalated layered metal phosphide composite serving as a filler and hydrolytically condensed with a silane coupling agent with a mercapto group, stearic acid, zinc oxide, a vulcanizing agent, an accelerator and paraffin wax, and then hot-pressing vulcanization, wherein the quantum dot intercalated layered metal phosphide composite is dispersed in the rubber matrix in a covalent and non-covalent manner, the addition of the quantum dots can block the aging phenomenon caused by the free radical chain reaction, and the quantum dot intercalated layered metal phosphide composite and the zinc oxide have a multi-element synergistic flame-retardant effect.The multifunctional composite rubber material is prepared by using the quantum dot intercalated layered metal phosphide, has excellent mechanical, anti-aging and flame-retardant properties, has a wide application range, and can be industrially produced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rubber composites, and particularly relates to a high-flame-retardant multifunctional rubber composite material with aging resistance and a preparation method thereof. BACKGROUND

[0002] Due to the excellent mechanical properties of the three-dimensional network structure of rubber, the rubber has been widely used in production and life, such as rubber tires, sealing elements, damping systems, soft robots, wearable electronic devices and flexible sensors. However, in the use process of the rubber, the rubber will be subjected to physical and chemical and biological factors such as heat, oxygen, ozone, light, mold, mechanical stress, etc., and thus oxidation degradation or structural reaction will occur, resulting in softening, stickiness, hardening, cracking, mold growth, color change and mechanical property reduction of the rubber, and the rubber gradually loses the use value. Therefore, it is of great significance to improve the aging resistance of the rubber for practical application and energy saving and emission reduction.

[0003] At present, there are two methods for the anti-aging treatment of rubber: physical protection and chemical protection. The physical protection mainly avoids the direct contact of the rubber with various aging factors, such as surface plating or treatment. The use environment of the rubber product is usually harsh, and thus the physical protection has low timeliness. The chemical protection mainly adds anti-aging agents to achieve the protection, wherein the protection effect of the phenolic anti-aging agent is poor, and the phenolic anti-aging agent has an adverse effect on the vulcanization of the rubber. The protection effect of the amine anti-aging agent is high, but the amine anti-aging agent will pollute and discolor the rubber. In addition, the migration of the anti-aging agent in the rubber matrix and the volatilization of the anti-aging agent at high temperature will cause the decrease of the anti-aging effect, and even accelerate the aging of the rubber. Therefore, it is of great significance and practical value to develop a new type of high-efficiency rubber anti-aging additive.

[0004] Metal phosphides are a kind of two-dimensional sheet inorganic materials, which have excellent rigidity, stability, flame retardancy, and unique surface effect and quantum size effect. These materials filled in the rubber material can not only enhance the mechanical properties, thermal stability and acid and alkali corrosion resistance, but also endow the rubber with many new functions. In recent years, metal phosphides have been widely reported in production practice and have great application value. However, simple physical mixing is difficult to control the uniform dispersion of the metal phosphides in the rubber matrix, and the thermodynamic incompatibility between the metal phosphides and the rubber matrix may cause local stress concentration, thereby seriously damaging the mechanical properties of the material. Rubber products with aging resistance and good mechanical properties are paid full attention.

[0005] In addition, rubber is a flammable material, and in daily and specific application scenarios, such as rubber conveyor belts used in mines and rubber products used in vehicles and ships, fireproof and flame-retardant properties are required to ensure the safety of life and property. Therefore, in order to meet the diversified needs of production and life, prevent rubber aging and degeneration, prolong the service life, and improve the safety, it is urgent to develop a kind of multifunctional rubber with excellent mechanical properties, aging resistance and high flame retardant properties. SUMMARY

[0006] The present application aims to overcome the defects of the prior art and provide a kind of aging-resistant high-flame-retardant multifunctional rubber composite material.

[0007] Another object of the present application is to provide a preparation method of the above-mentioned aging-resistant high-flame-retardant multifunctional rubber composite material.

[0008] The technical scheme of the present application is as follows: a kind of aging-resistant high-flame-retardant multifunctional rubber composite material, which is prepared by uniformly mixing rubber matrix, quantum dot intercalated layered metal phosphide composite as filler and hydrolysis-condensation with silane coupling agent with mercapto, stearic acid, zinc oxide, vulcanizing agent, accelerator and paraffin wax, and then hot pressing vulcanization, the general formula of the silane coupling agent with mercapto is HS-(CH2) n -Si-O-R1R2R3, wherein the quantum dot intercalated layered metal phosphide composite hydrolysis-condensed with the silane coupling agent with mercapto is dispersed in the rubber matrix in a covalent and non-covalent manner; at the same time, the oxygen-containing and amine-containing groups on the surface of the quantum dots capture the free radicals generated during the use of rubber to block the aging phenomenon caused by free radical chain reaction.

[0009] In a preferred embodiment of the present application, the rubber matrix includes natural rubber, styrene-butadiene rubber and silicone rubber.

[0010] In a preferred embodiment of the present application, the quantum dots include carbon quantum dots and boron nitride quantum dots.

[0011] In a preferred embodiment of the present application, the layered metal phosphide includes layered zirconium phosphate, layered cobalt phosphate, layered iron phosphate and layered nickel phosphate.

[0012] In a preferred embodiment of the present application, the rubber matrix includes natural rubber, styrene-butadiene rubber and silicone rubber, the quantum dots include carbon quantum dots and boron nitride quantum dots, and the layered metal phosphide includes layered zirconium phosphate, layered cobalt phosphate, layered iron phosphate and layered nickel phosphate.

[0013] Further preferably, the rubber matrix is natural rubber or styrene-butadiene rubber, the quantum dots are carbon quantum dots, and the layered metal phosphide is layered zirconium phosphate or layered iron phosphate.

[0014] Further preferably, the mercapto-terminated silane coupling agent includes 3-mercaptopropyl trimethoxysilane and 3-mercaptopropyl triethoxysilane.

[0015] In a preferred embodiment of the present application, the mass ratio of the rubber matrix, the quantum dot intercalated layered metal phosphide composite hydrolytically condensed with the mercapto-terminated silane coupling agent, stearic acid, zinc oxide, a vulcanizing agent, an accelerator and paraffin is 60-100:10-80:1-3:2-4:1-4:1-3:1-3.

[0016] Further preferably, the mass ratio of the rubber matrix, the quantum dot intercalated layered metal phosphide composite hydrolytically condensed with the mercapto-terminated silane coupling agent, stearic acid, zinc oxide, a vulcanizing agent, an accelerator and paraffin is 100:20:2:3:2.5:1:1.

[0017] The preparation method of the above-mentioned anti-aging high-flame-retardant multifunctional rubber composite material is characterized in that it comprises the following steps:

[0018] (1) stripping the layered metal phosphide;

[0019] (2) intercalating quantum dots into the layered metal phosphide prepared in step (1) and hydrolytically condensing the layered metal phosphide with a mercapto-terminated silane coupling agent to obtain a quantum dot intercalated layered metal phosphide composite hydrolytically condensed with the mercapto-terminated silane coupling agent;

[0020] (3) uniformly mixing a rubber matrix, the quantum dot intercalated layered metal phosphide composite hydrolytically condensed with the mercapto-terminated silane coupling agent, stearic acid, zinc oxide, a vulcanizing agent, an accelerator and paraffin;

[0021] (4) hot-pressing and vulcanizing the material obtained in step (3) to obtain an anti-aging high-flame-retardant multifunctional rubber composite material.

[0022] In a preferred embodiment of the present application, the intercalation method includes physical blending intercalation and chemical covalent intercalation.

[0023] The present application has the following beneficial effects:

[0024] 1. The quantum dots in the present application have extremely high molar absorption coefficients in the ultraviolet region, and the oxygen-containing and amine-containing groups on the surface can capture and eliminate oxygen-containing free radicals, and the sp 2 hybrid layer and the aromatic ring conjugated structure can stabilize the active electrons, effectively preventing the molecular chain from being broken and cross-linked due to aging during the use of the rubber, thereby preventing the rubber from cracking and fading; in addition, the synergistic effect of the metal phosphide and the quantum dot hybrid composite can endow the rubber composite material with excellent mechanical, flame-retardant, friction-resistant and corrosion-resistant properties.

[0025] 2. This invention significantly expands the interlayer spacing of quantum dot intercalated sheet metal phosphides by using quantum dot intercalation, improving the tight stacking of sheet metal phosphides, thereby achieving nanoscale dispersion in the rubber matrix. This effectively avoids local defects caused by the addition of large-sized sheet metal phosphides to the rubber matrix, which can lead to stress concentration and severe damage to mechanical properties. Furthermore, it significantly enhances the interaction between organic and inorganic components, i.e., enhances their interaction with the rubber matrix, thus endowing the rubber composite material with excellent mechanical properties.

[0026] 3. In this invention, quantum dots are uniformly adsorbed on the surface of sheet metal phosphides and will not agglomerate due to static or drying operations, thus exhibiting excellent stability and durability. When added to a rubber matrix, the tight bond between quantum dots and sheet metal phosphides prevents migration and volatilization from the rubber under conditions such as high temperature, liquid environment, and low pressure.

[0027] 4. In this invention, by controlling the amount of quantum dots added, the degree of peeling of the sheet metal phosphide can be adjusted, thereby controlling its dispersion and compatibility in the rubber matrix.

[0028] 5. In this invention, by adjusting the amount of quantum dot intercalation layer metal phosphide composite added, the mechanical, flame retardant, wear-resistant, acid and alkali corrosion resistant, and aging resistant properties of rubber composite materials can be controlled within a wide range.

[0029] 6. The rubber composite material of the present invention has obvious modification effect, simple preparation process, mild preparation conditions, low cost, and good industrial production potential.

[0030] 7. The effect of the quantum dot intercalated sheet metal phosphide composite in this invention on improving the aging resistance of rubber is positively correlated with the double bond content in the rubber main chain; the quantum dot intercalated sheet metal phosphide composite and zinc oxide have a multi-element synergistic flame retardant effect. Attached Figure Description

[0031] Figure 1 This is an optical photograph of the rubber prepolymer in Example 1 of the present invention.

[0032] Figure 2 This is the vulcanization curve of the rubber prepolymer in Example 1 of the present invention.

[0033] Figure 3 This is an optical photograph of the rubber composite material in Example 1 of the present invention.

[0034] Figure 4 The images shown are (a) SEM images of α-ZrP, (b) TEM images of E-ZrP, and (c) TEM images of CDs-ZrP from Embodiment 1 of the present invention.

[0035] Figure 5XRD patterns of α-ZrP, E-ZrP and CDs-ZrP in Example 1 of the present application.

[0036] Figure 6 UV-Vis absorption spectra of CDs, E-ZrP and CDs-ZrP in Example 1 of the present application. DETAILED DESCRIPTION

[0037] The technical solutions of the present application are further described and explained in detail below by means of specific embodiments in conjunction with the accompanying drawings.

[0038] Example 1

[0039] (1) Exfoliation of layered zirconium phosphate (α-ZrP): 2 g of α-ZrP was dissolved in 50 mL of deionized water, 4 mL of exfoliation agent tetramethylammonium hydroxide (TMAH) was added, and after stirring uniformly, ultrasonic treatment was performed for 1 h, and then centrifugation was performed for 10 min to obtain an exfoliated layered zirconium phosphate (E-ZrP) solution.

[0040] (2) Preparation of quantum dot intercalated layered zirconium phosphate composite: 4 mL of carbon quantum dot (CDs) (2 g) solution was added to 30 mL of the E-ZrP solution prepared in step (1), and after stirring vigorously at room temperature for 24 h, centrifugation was performed for 10 min, and then freeze-drying was performed for 24 h, and the obtained solid was hydrolyzed and condensed with 3-mercaptopropyl triethoxysilane under acidic conditions (pH = 3-5), and vacuum drying was performed for 12 h to obtain a quantum dot intercalated layered zirconium phosphate composite CDs-ZrP.

[0041] (3) Uniform mixing of rubber, quantum dot intercalated layered zirconium phosphate composite and other additives: 100 parts of natural rubber, 20 parts of the CDs-ZrP prepared in step (2), 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of vulcanizing agent sulfur, 1 part of accelerator N-cyclohexyl-2-benzothiazole sulfenamide and 1 part of paraffin were mixed in a weight ratio, and after mixing in a Banbury mixer for 8 min, a rubber prepolymer as shown in Figure 1 was obtained by sheeting through an open mill.

[0042] (4) Preparation of rubber composite material: 3.5 g of the rubber prepolymer prepared in step (3) was weighed, and the vulcanization curve was tested by a non-rotor vulcanizing instrument (as shown in Figure 2 ), and the optimum vulcanization time was determined to be 12.9 min, and after hot pressing in a flat plate hot press at a pressure of 15 MPa and a temperature of 150 ℃ for 12.9 min, an anti-aging high-flame-retardant multifunctional rubber composite material as shown in Figure 3 was prepared.

[0043] Example 2

[0044] The difference between this example and Example 1 is that the natural rubber is replaced by styrene-butadiene rubber. 100 parts of styrene-butadiene rubber, 20 parts of the CDs-ZrP, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part and paraffin 1 part are mixed in a mixer for 8 min, and then a rubber prepolymer is obtained by sheeting through an open mill.

[0045] The remaining steps are the same as in Example 1, and the anti-aging high-flame-retardant multifunctional rubber composite material is obtained.

[0046] Example 3

[0047] The difference between this example and Example 1 is that the zirconium phosphate nanosheets in steps (1) and (2) are replaced by iron phosphate nanosheets. Specifically, the exfoliation of the iron phosphate nanosheets: 2 g of iron phosphate nanosheets are dissolved in 50 mL of deionized water, 4 mL of exfoliating agent tetramethylammonium hydroxide (TMAH) is added, and after stirring uniformly, ultrasonic treatment is performed for 1 h, and then centrifugation is performed for 10 min to obtain an exfoliated iron phosphate nanosheet solution. Preparation of quantum dot intercalated iron phosphate nanosheet composite: 4 mL of carbon quantum dot (CDs) (2 g) solution is added to the 30 mL of exfoliated iron phosphate nanosheet solution, and after stirring vigorously at room temperature for 24 h, centrifugation is performed for 10 min, and then freeze-drying is performed for 24 h, the obtained solid is hydrolyzed and condensed with 3-mercaptopropyl triethoxysilane under acidic conditions (pH = 3-5), and vacuum drying is performed for 12 h to obtain a quantum dot intercalated iron phosphate composite. 100 parts of natural rubber, 20 parts of the quantum dot intercalated iron phosphate composite, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part and paraffin 1 part are mixed in a mixer for 8 min, and then a rubber prepolymer is obtained by sheeting through an open mill.

[0048] The preparation method of the quantum dot intercalated iron phosphate modified natural rubber composite material in this example is the same as in Example 1.

[0049] Comparative Example 1

[0050] The difference between this comparative example and Example 1 is that step (2) is omitted. 100 parts of natural rubber, 20 parts of E-ZrP, 20 parts of CDs, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part, and paraffin 1 part are mixed in a mixer for 8 min, and then a rubber prepolymer is obtained by sheeting through an open mill.

[0051] The remaining steps are the same as in Example 1, and the comparative rubber composite material is obtained.

[0052] Comparative Example 2

[0053] The difference between this comparative example and Example 2 is that step (2) is omitted. 100 parts of styrene-butadiene rubber, 20 parts of E-ZrP, 20 parts of CDs, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part and paraffin wax 1 part are mixed in an internal mixer for 8 min, and then a rubber pre-polymer is obtained by sheeting through an open mill.

[0054] The remaining steps are the same as Example 1, and a comparative rubber composite material is prepared.

[0055] Comparative Example 3

[0056] The difference between this comparative example and Example 1 is that the sheet layer of zirconium phosphate in step (1) is replaced by a sheet layer of iron phosphate (see Example 3 for details), and step (2) is omitted. 100 parts of natural rubber, 20 parts of exfoliated iron phosphate, 20 parts of CDs, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part and paraffin wax 1 part are mixed in an internal mixer for 8 min, and then a rubber pre-polymer is obtained by sheeting through an open mill.

[0057] The remaining steps are the same as Example 1, and a comparative rubber composite material is prepared.

[0058] Comparative Example 4

[0059] The difference between this comparative example and Example 1 is that step (2) is omitted and CDs are not added. 100 parts of natural rubber, 20 parts of E-ZrP, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part, paraffin wax 1 part are mixed in an internal mixer for 8 min, and then a rubber pre-polymer is obtained by sheeting through an open mill.

[0060] The remaining steps are the same as Example 1, and a comparative rubber composite material is prepared.

[0061] Comparative Example 5

[0062] The difference between this comparative example and Example 2 is that step (2) is omitted and CDs are not added. 100 parts of styrene-butadiene rubber, 20 parts of E-ZrP, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part, paraffin wax 1 part are mixed in an internal mixer for 8 min, and then a rubber pre-polymer is obtained by sheeting through an open mill.

[0063] The remaining steps are the same as Example 2, and a comparative rubber composite material is prepared.

[0064] Comparative Example 6

[0065] The difference between the present comparative example and Example 1 is that 3-mercaptopropyltriethoxysilane in step (2) is replaced by γ-aminopropyltriethoxysilane. 100 parts of natural rubber, 20 parts of carbon quantum dot intercalated layered zirconium phosphate composite, 2 parts of stearic acid, 3 parts of zinc oxide, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part, and paraffin 1 part are mixed in a mixer for 8 min, and then a rubber pre-polymer is obtained by sheeting through an open mill.

[0066] The remaining steps are the same as those in Example 1, and a comparative rubber composite is prepared.

[0067] Comparative Example 7

[0068] The difference between the present comparative example and Example 1 is that layered zirconium phosphate is replaced by layered graphene. Graphene is mechanically exfoliated by a mortar, 4 mL of carbon quantum dot (CDs) (2 g) solution is added to 30 mL of graphene aqueous solution, and the mixture is stirred vigorously at room temperature for 24 h, followed by centrifugation for 10 min and freeze-drying for 24 h. The obtained solid is hydrolyzed and condensed with 3-mercaptopropyltriethoxysilane under acidic conditions (pH = 3-5), and vacuum dried for 12 h to obtain a quantum dot intercalated graphene composite. 100 parts of natural rubber, 20 parts of quantum dot intercalated graphene composite, 2 parts of stearic acid, 2.5 parts of sulfur, N-cyclohexyl-2-benzothiazole sulfenamide 1 part, and paraffin 1 part are mixed in a mixer for 8 min, and then a rubber pre-polymer is obtained by sheeting through an open mill.

[0069] The remaining steps are the same as those in Example 1, and a comparative rubber composite is prepared.

[0070] Example 4

[0071] The following performance tests are carried out on Examples 1-3 and Comparative Examples 1-4 of the present application, and the test items and methods are as follows:

[0072] Hardness test: The hardness of the rubber composite prepared as described above is determined according to the method specified in GB / T 531.1-2008.

[0073] Stress-strain performance test: The 100% modulus, 300% modulus, tensile strength and elongation at break of the rubber composite prepared as described above are determined according to the method specified in GB / T 528-2009.

[0074] Combustion performance test: The limiting oxygen index and vertical burning grade of the rubber composite prepared as described above are determined according to the method specified in GB / T 10707-2008.

[0075] UV aging resistance test: According to the method specified in GB / T 16585-1996, the sample is placed in a UV aging chamber and subjected to UV radiation for 70 days. The mechanical properties of the aged sample are then determined according to the stress-strain performance test method described above, and the rate of change of sample properties is calculated.

[0076] All test results are shown in Tables 1 and 2 below.

[0077] Table 1. Experimental characterization results of samples 1-3

[0078]

[0079]

[0080] Table 2. Experimental characterization results of samples 1–7

[0081]

[0082] Experimental data analysis:

[0083] The morphology of unexfoliated zirconium phosphate α-ZrP was observed by SEM. Figure 4 (a) The original α-ZrP exhibits a polygonal structure with a diameter of approximately 1 μm, a smooth surface, and tightly stacked layers. The exfoliated zirconium phosphate E-ZrP and quantum dot-intercalated zirconium phosphate CDs-ZrP were characterized by TEM, as shown below. Figure 4 As shown in (b), the shape regularity of E-ZrP decreases and its thickness thins, indicating that the stacking of zirconium phosphate layers is improved. After quantum dot intercalation, CDs-ZrP ( Figure 4 (c) The layered skeleton structure of the material is maintained, the aggregation between the layers is further improved, and uniformly attached CDs are observed on the material surface.

[0084] The crystal structures of α-ZrP, E-ZrP, and CDs-ZrP were further characterized by XRD, such as... Figure 5 As shown, α-ZrP exhibits good crystallinity. According to the Bragg equation, the interlayer spacing of α-ZrP is... (2θ=11.70°); After exfoliation, the (002) crystal plane diffraction peak of E-ZrP shifted to the left to 2θ=5.50°, which is due to the exfoliating agent TMAH cation sandwiched between zirconium phosphate layers; After CDs intercalation hybridization, the (002) crystal plane diffraction peak angle of CDs-ZrP shifted to 2θ=4.65°, indicating that the interlayer spacing of zirconium phosphate CDs-ZrP after quantum dot intercalation is further increased, which greatly reduces the stacking between zirconium phosphate layers.

[0085] The UV-Vis absorption spectra of E-ZrP, CDs, and CDs-ZrP are as follows:Figure 6 The characteristic absorption peaks of CDs appear at 220 nm, 240 nm and 281 nm, which are related to n-π* transition of C=N in quantum dots, π-π* transition of C=C in benzene ring and n-π* transition of N-containing functional groups, respectively. Compared with E-ZrP, the characteristic absorption peaks attributed to quantum dots appear on the UV-Vis absorption spectrum of CDs-ZrP intercalated with CDs, which indicates that the zirconium phosphate is successfully intercalated with CDs to form a hybrid, and the CDs-ZrP has good ultraviolet absorption capacity.

[0086] The test data of Examples 1-3 and Comparative Examples 1-7 are shown in Tables 1 and 2 above. According to the test results, the modulus at 100% elongation of Examples 1, 2 and 3 intercalated with quantum dots are all greater than 3.2 MPa, the modulus at 300% elongation are all greater than 12.3 MPa, the tensile strength are all greater than 27.9 MPa, and the elongation at break are all greater than 515%. Compared with Comparative Examples 1-3 prepared by simple blending, the mechanical properties are greatly improved, which is attributed to the fact that the quantum dot intercalation process improves the stacking between the layers of the layered metal phosphide, improves the dispersion compatibility in the rubber matrix, and significantly improves the interfacial interaction with the rubber matrix. The limiting oxygen index of Examples 1-3 is greater than 28.4%, and the vertical burning performance reaches the FV-0 flame retardant level, which can meet the use requirements of various rubber tires and conveyor belts for the flame retardance of rubber composites.

[0087] The limiting oxygen index of Comparative Examples 1-3 is 24.5-25.3%, and the vertical burning performance is FV-2 flame retardant level, which indicates that compared with the simple blending of quantum dots and layered metal phosphide, the synergistic effect of the two after the quantum dot intercalation of the layered metal phosphide can improve the flame retardance.

[0088] After all the samples are subjected to artificial ultraviolet aging treatment for 70 days, the stress and strain change rates of the samples before and after ultraviolet aging are compared to evaluate the ultraviolet aging resistance of the samples. The stress change rate of Examples 1-3 is less than 13.3%, and the strain change rate is less than 16.4%. The ultraviolet aging resistance of Comparative Examples 1-3 decreases significantly. In Comparative Example 4, since no quantum dots are added, the stress and strain change rates of the sample after ultraviolet aging treatment are both greater than 79.4%. By comparing Examples 1 and 2 with Comparative Examples 4 and 5 without adding carbon quantum dots, it is found that since the main chain of natural rubber has more unsaturated double bonds, the addition of quantum dot intercalated layered metal phosphide in natural rubber has higher anti-aging performance improvement.

[0089] Explore the effect of the end group structure of silane coupling agent on the mechanical properties of rubber composites: use γ-aminopropyl triethoxysilane (end group is amine group) to surface silanize the quantum dot intercalated layered metal phosphide composite, and prepare a natural rubber composite (comparative example 6). Compared with example 1, the mechanical properties of the amine group modified show a certain degree of decline, which is due to the addition reaction of the mercapto group in example 1 with the double bond on the rubber main chain. The inorganic filler is dispersed in the rubber matrix by covalent and non-covalent action, which improves the interaction force strength between the inorganic filler and the rubber matrix, thereby improving the mechanical properties of the rubber composite.

[0090] A composite rubber material with layered graphene instead of layered metal phosphide is prepared (comparative example 7), and its flame retardant properties are tested. Its vertical burning level is N, and the LOI is 20.4%. Compared with example 1 (LOI 29.8%), its flame retardant properties decrease significantly, which shows that the quantum dot intercalated layered metal phosphide in example 1 plays an important role in flame retardant, and the multi-element synergistic effect between zinc oxide and quantum dot intercalated layered metal phosphide promotes the further improvement of the flame retardant effect.

[0091] The above is only a preferred embodiment of the present application, and therefore cannot limit the scope of the present application. Any equivalent changes and modifications made in accordance with the scope of the present application and the content of the specification shall still be within the scope of the present application.

Claims

1. A multifunctional rubber composite material with aging resistance and high flame retardancy, characterized in that: This product is prepared by hot-pressing and vulcanizing a uniformly mixed rubber matrix, a quantum dot intercalated layered metal phosphide complex (as filler, hydrolyzed and condensed with a thiol-containing silane coupling agent), stearic acid, zinc oxide, vulcanizing agent, accelerator, and paraffin wax. The mass ratio of the rubber matrix, the quantum dot intercalated layered metal phosphide complex (as filler, hydrolyzed and condensed with a thiol-containing silane coupling agent), stearic acid, zinc oxide, vulcanizing agent, accelerator, and paraffin wax is 60-100: 10-80: 1-3: 2-4: 1-4: 1-3: 1-3. The general formula of the thiol-containing silane coupling agent is HS-(CH2). n -Si-O-R1R2R3, wherein the quantum dot intercalated sheet metal phosphide complex hydrolyzed and condensed with a silane coupling agent containing thiol groups is dispersed in the rubber matrix in a covalent and non-covalent manner; at the same time, the oxygen-containing and amine-containing groups on the surface of the above quantum dots capture free radicals generated during the use of rubber to block the aging phenomenon caused by free radical chain reactions.

2. The aging-resistant, highly flame-retardant, multifunctional rubber composite material as described in claim 1, characterized in that: The rubber matrix includes natural rubber, styrene-butadiene rubber, and silicone rubber.

3. The aging-resistant, highly flame-retardant, multifunctional rubber composite material as described in claim 1, characterized in that: The quantum dots include carbon quantum dots and boron nitride quantum dots.

4. The aging-resistant, highly flame-retardant, multifunctional rubber composite material as described in claim 1, characterized in that: The sheet metal phosphides include sheet zirconium phosphate, sheet cobalt phosphate, sheet iron phosphate, and sheet nickel phosphate.

5. The aging-resistant, highly flame-retardant, multifunctional rubber composite material as described in claim 1, characterized in that: The rubber matrix includes natural rubber, styrene-butadiene rubber, and silicone rubber; the quantum dots include carbon quantum dots and boron nitride quantum dots; and the sheet metal phosphides include sheet zirconium phosphate, sheet cobalt phosphate, sheet iron phosphate, and sheet nickel phosphate.

6. The aging-resistant, highly flame-retardant, multifunctional rubber composite material as described in claim 1, characterized in that: The silane coupling agents with thiol groups include 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.

7. The aging-resistant, highly flame-retardant, multifunctional rubber composite material as described in claim 1, characterized in that: The mass ratio of the rubber matrix, the quantum dot intercalated sheet metal phosphide complex as a filler and hydrolyzed and condensed with a mercapto-containing silane coupling agent, stearic acid, zinc oxide, vulcanizing agent, accelerator and paraffin is 100: 20: 2: 3: 2.5: 1:

1.

8. A method for preparing an aging-resistant, highly flame-retardant, multifunctional rubber composite material according to any one of claims 1 to 7, characterized in that: Includes the following steps: (1) Stripping the lamellar metal phosphides; (2) The sheet metal phosphide obtained in step (1) is subjected to quantum dot intercalation and hydrolyzed with a silane coupling agent with a mercapto group to obtain a quantum dot intercalated sheet metal phosphide composite hydrolyzed with a silane coupling agent with a mercapto group. (3) The rubber matrix, the quantum dot intercalated sheet metal phosphide complex hydrolyzed and condensed with a mercapto-containing silane coupling agent, stearic acid, zinc oxide, vulcanizing agent, accelerator and paraffin are uniformly mixed. (4) The material obtained in step (3) is subjected to hot-press vulcanization to obtain an aging-resistant, highly flame-retardant, multifunctional rubber composite material.

9. The preparation method according to claim 8, characterized in that: The intercalation methods include physical blending intercalation and chemical covalent intercalation.

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