Anti-aging MIL-68 (Al)-Zn / SBR (styrene butadiene rubber) composite modifier as well as preparation method and application thereof

Abstract

The invention discloses an MIL-68 (Al)-Zn / SBR (styrene butadiene rubber) composite modifier as well as a preparation method and application thereof, and belongs to the technical field of asphalt processing. The composite modifier is prepared from the following raw materials in percentage by mass: 30.00 weight percent to 37.00 weight percent of MIL-68 (Al)-Zn, 52.00 weight percent to 57.00 weight percent of SBR (Styrene Butadiene Rubber), 0.30 weight percent to 0.50 weight percent of an accelerant and 10.70 weight percent to 12.50 weight percent of a compatilizer; the preparation method of the MIL-68 (Al)-Zn comprises the following steps: S1, dissolving soluble aluminum salt and terephthalic acid into a solvent, adding a proper amount of monocarboxylic acid as a regulator, reacting at a certain temperature, centrifuging and collecting a precipitation product; and washing and drying the product to obtain the metal organic framework defect type MIL-68 (Al) crystal. And S2, adding the defect type MIL-68 (Al) (500 mg) into a mixture of soluble zinc salt (500 mg) and N, N-dimethylformamide (10 mL), and then carrying out a reaction at a certain temperature. And naturally cooling to room temperature, centrifugally collecting the obtained product, and washing for multiple times to obtain the MIL-68 (Al)-Zn. The modifier disclosed by the invention can be used for efficiently storing aromatic components, so that the effect of inhibiting gelation of the aromatic components is achieved, and the anti-aging performance of the asphalt is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of asphalt processing, and particularly relates to an anti-aging MIL-68(Al)-Zn / SBR composite modifier and its preparation method and application. Background Art

[0002] SBR (styrene-butadiene rubber) modified asphalt pavement has been widely used in highway construction due to its superior road performance, good skid resistance, comfortable driving experience, low cost, and high safety. However, during long-term use, SBR modified asphalt is affected by external environmental factors such as heat, oxygen, and ultraviolet light, resulting in changes in its chemical composition and molecular structure, that is, aging occurs. This aging will cause diseases such as rutting, spalling, cracks, and potholes on the road surface, thus significantly shortening the service life of SBR modified asphalt. In order to develop SBR modified asphalt with more excellent comprehensive performance, its anti-aging ability must be enhanced. Whether it is thermal-oxidative aging or ultraviolet aging, the aging process of asphalt usually shows the transformation of components and structure: aromatic components gradually transform into resins and finally form asphaltenes. During this process, the contents of aromatic components and resins continuously decrease, and the original colloidal structure of asphalt gradually gels. This structural change will lead to a decline in asphalt performance, such as an increase in viscosity, a decrease in ductility and adhesion, etc., ultimately seriously affecting the service life of asphalt pavement. Therefore, retaining the aromatic components in asphalt and inhibiting the gelation of its structure are the keys to improving the anti-aging performance of SBR modified asphalt.

[0003] In order to improve the anti-aging performance of asphalt, scholars at home and abroad have conducted a large number of studies and explored various modification methods. Among them, metal-organic frameworks (MOFs) are considered to be a potential asphalt modification material due to their high specific surface area, adjustable pore structure, and surface chemical properties. MOFs materials are formed by the self-assembly of metal ions and organic ligands, have a rich pore structure and adjustable chemical properties, and can effectively adsorb and store small molecule substances. By introducing MOFs materials into asphalt, the aging process of asphalt can be delayed and its anti-aging performance can be improved. Currently, some studies have proposed generating functional derivatives (MOFs-R, R = NH2, OH, COOH, etc.) by introducing different functional groups in MOFs, but their application effects in asphalt modification are not ideal because the active sites provided by the functional groups are limited; and the introduction of functional groups may block pores, reduce the specific surface area, affect the adsorption efficiency, resulting in unsatisfactory anti-aging effects. Summary of the Invention

[0004] In view of the deficiencies of the above-mentioned existing technologies, one of the objectives of the present invention is to provide a MIL-68(Al)-Zn / SBR composite modifier. On the one hand, through the structural regulation of MIL-68(Al)-Zn, aromatic components can be stored efficiently in asphalt for a long time, inhibiting the gelation of the asphalt structure. On the other hand, by introducing Zn as an active site, chemical interactions occur with benzene series molecules in asphalt, forming stable chemical adsorption. This chemical adsorption not only increases the adsorption amount of benzene series substances but also enhances the selectivity for benzene series substances. In addition, the introduced MIL-68(Al)-Zn has benzene rings and thus has the ability to absorb ultraviolet light.

[0005] To achieve the above objectives, the present invention adopts the following technical solutions:

[0006] A MIL-68(Al)-Zn / SBR composite modifier, by mass fraction, comprises the following raw materials: MIL-68(Al)-Zn 30.00wt% - 37.00wt%, SBR 52.00wt% - 57.00wt%, accelerator 0.30wt% - 0.50wt%, compatibilizer 10.70wt% - 12.50wt%;

[0007] According to the above technical features, the preparation method of the MIL-68(Al)-Zn modifier comprises the following steps:

[0008] S1. Dissolve soluble aluminum salt and terephthalic acid in a solvent, add an appropriate amount of monocarboxylic acid as a regulator, react at a certain temperature, and centrifuge to collect the precipitate product; wash and dry the product to obtain metal-organic framework defective MIL-68(Al) (MIL-68(Al)-defect) crystals.

[0009] S2. Add the metal-organic framework defective MIL-68(Al) crystals to a mixture of soluble zinc salt and solvent, then react at a certain temperature, naturally cool to room temperature, centrifuge to collect the obtained product, and wash several times to obtain MIL-68(Al)-Zn.

[0010] Furthermore, the mass ratio of the soluble aluminum salt to terephthalic acid is 1:1;

[0011] Furthermore, the mass ratio of the metal-organic framework defective MIL-68(Al) crystals to the soluble zinc salt is 1:1.

[0012] Furthermore, in the above step S1, the soluble aluminum salt is at least one of aluminum chloride, aluminum nitrate, and aluminum sulfate; and / or, the concentration of the soluble aluminum salt in the solvent is 1.50wt% - 2.50wt%.

[0013] Further, in the above step S1, the solvent is at least one of N,N-dimethylformamide, γ-valerolactone, N,N-diethylformamide, and ethanol.

[0014] Further, in the above step S1, the monocarboxylic acid is at least one of formic acid, acetic acid, and benzoic acid.

[0015] Further, in the above step S1, the reaction temperature is 120~150 °C, and the reaction time is 12~24 h.

[0016] Further, in the above step S1, the washing liquid is N,N-dimethylformamide and methanol.

[0017] Further, in the above step S1, the drying temperature is 100~150 °C, and the drying time is 10~20 h.

[0018] Further, in the above step S2, the soluble zinc salt is at least one of zinc chloride, zinc nitrate, and zinc sulfate.

[0019] Further, in the above step S2, the reaction temperature is 80~100 °C, and the reaction time is 20~30 h.

[0020] Further, in the above step S2, the washing liquid is N,N-dimethylformamide and methanol.

[0021] Further, the above asphalt is petroleum asphalt, with a penetration at 25 °C of 60~120 dmm, a softening point of 40~55 °C, and an elongation at 10 °C of 15~25 cm.

[0022] In the composite modifier of the present invention, MIL-68(Al)-Zn can efficiently store aromatic components during the aging process of asphalt, thereby inhibiting the gelation of the asphalt structure and enhancing the anti-aging performance of the asphalt. In addition, MIL-68(Al)-Zn has good compatibility with SBR, and MIL-68(Al)-Zn can cooperate with SBR to improve the modification effect of the composite modifier, significantly enhancing the anti-aging performance of the asphalt. Further, in the present invention, by regulating the structure of MIL-68(Al), defect sites are introduced, and the structure defects are modified with single-atom metal Zn. On the one hand, Zn serves as an active site and undergoes Zn···π benzene interaction with benzene series molecules in the asphalt to form stable chemisorption. This chemisorption not only increases the adsorption amount of benzene series substances but also enhances the selectivity for benzene series substances; on the other hand, O-H framework (O-H framework)···π benzene (π benzene), π framework (π framework)···π benzene and Zn···π benzene The three adsorption mechanisms act synergistically to further enhance the adsorption effect.

[0023] Another object of the present invention is to provide a method for preparing the MIL-68(Al)-Zn / SBR composite modifier, comprising the following steps:

[0024] P1. Prepare the MIL-68(Al)-Zn, SBR, accelerator and compatibilizer according to their respective mass fractions, and then place them in a mixer to stir and mix together. The blending temperature is 80-90°C and the speed is 1300-1500 r / min;

[0025] P2. Add the blend obtained in step P1 to a granulator to granulate to obtain the MIL-68(Al)-Zn / SBR composite modifier.

[0026] Further, the stabilizer is sulfur.

[0027] Further, the accelerator is at least one of tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, bis(1,5-pentamethylene)tetramthiuram disulfide.

[0028] Further, the compatibilizer is third-stage reduced crude oil.

[0029] Using the MIL-68(Al)-Zn / SBR composite modifier to prepare anti-aging SBR modified asphalt, the obtained anti-aging MIL-68(Al)-Zn / SBR modified asphalt comprises the following raw materials in mass fractions: asphalt 88.50 wt% - 90.50 wt%, MIL-68(Al)-Zn / SBR composite modifier 7.00 wt% - 11.00 wt%, stabilizer 0.50 wt%.

[0030] The present invention also provides a method for preparing the anti-aging modified asphalt, comprising the following steps: Prepare the asphalt, MIL-68(Al)-Zn / SBR composite modifier and stabilizer according to their respective mass fractions; then heat the asphalt to a flowing state, and slowly add the MIL-68(Al)-Zn / SBR composite modifier and stabilizer while stirring, keep the temperature at 170-180°C, stir at a speed of 4000-6000 rpm for 1-3 h, and then continue to stir at a speed of 400-600 rpm for 1-3 h to obtain the anti-aging modified asphalt.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] (1) In the composite modifier of the present invention, MIL-68(Al)-Zn adjusts metal ions and organic ligands, and then designs and regulates pore characteristics and surface chemical characteristics. When benzene series substances volatilize during the aging process of asphalt, MIL-68(Al)-Zn can efficiently store them, achieving the purpose of storing aromatic components to inhibit the gelation of the asphalt structure, that is, it can effectively improve the anti-aging performance of asphalt.

[0033] (2) MIL-68(Al)-Zn in the composite modifier of the present invention not only has O-H framework ···π benzene and π framework ···π benzene interactions, but also introduces Zn as an active site to have Zn···π benzene interactions with benzene series molecules in asphalt, forming stable chemisorption. This chemisorption not only increases the adsorption amount of benzene series substances, but also enhances the selectivity for benzene series substances. In addition, the three adsorption mechanisms of O-H framework ···π benzene , π framework ···π benzene and Zn···π benzene act synergistically to further enhance the adsorption effect.

[0034] (3) MIL-68(Al)-Zn in the composite modifier of the present invention has benzene rings, which, together with the benzene rings in the stored aromatic components, have excellent ultraviolet absorption ability, can inhibit the influence of ultraviolet light on asphalt, that is, can effectively improve the anti-aging performance of asphalt. The presence of organic ligands in the structure of MIL-68(Al)-Zn in the composite modifier of the present invention can enhance the affinity between the MOF material and SBR particles, so that the two have good compatibility and stability. MIL-68(Al)-Zn can cooperate with SBR to improve the modification effect of the composite modifier and significantly improve the anti-aging performance of asphalt. Specific Embodiments

[0035] The technical solutions of the present invention will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope protected by the present invention. Any equivalent transformation or substitution made by those skilled in the art according to the following embodiments also belongs to the scope protected by the present invention.

[0036] Furthermore, the mass fractions of MIL-68(Al)-Zn in the MIL-68(Al)-Zn / SBR composite modifier include: 30.00 wt%, 31.00 wt%, 32.00 wt%, 33.00 wt%, 34.00 wt%, 35.00 wt%, 36.00 wt%, 37.00 wt%;

[0037] The mass fractions of SBR of 52% - 57% include: 52.00 wt%, 53.00 wt%, 54.00 wt%, 55.00 wt%, 56.00 wt%, 57.00 wt%;

[0038] The mass fractions of the accelerator include: 0.30 wt%, 0.40 wt%, 0.50 wt%;

[0039] The mass fractions of the compatibilizer include: 10.70 wt%, 10.80 wt%, 10.90 wt%, 11.00 wt%, 11.10 wt%, 11.20 wt%, 11.30 wt%, 11.40 wt%, 11.50 wt%, 11.60 wt%, 11.70 wt%, 11.80 wt%, 11.90 wt%, 12.00 wt%, 12.10 wt%, 12.20 wt%, 12.30 wt%, 12.40 wt%, 12.50 wt%.

[0040] Furthermore, the mass fractions of asphalt in the aging-resistant SBR modified asphalt include: 88.50 wt%, 88.60 wt%, 88.70 wt%, 88.80 wt%, 88.90 wt%, 90.00 wt%, 90.10 wt%, 90.20 wt%, 90.30 wt%, 90.40 wt%, 90.50 wt%;

[0041] The mass fractions of the MIL-68(Al)-Zn / SBR composite modifier include: 7.00 wt%, 8.00 wt%, 9.00 wt%;

[0042] The mass fraction of the stabilizer is 0.50%.

[0043] In the following examples and comparative examples, soluble aluminum salt, soluble zinc salt, N,N-dimethylformamide were purchased from Shanghai MacLean Biochemical Technology Co., Ltd., terephthalic acid was purchased from Shanghai Haohong Biomedical Technology Co., Ltd., methanol was purchased from Shanghai Titan Technology Co., Ltd.; SBR was purchased from Hunan Yueyang Baling Petrochemical Co., Ltd., tetramethylthiuram disulfide was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., and three-line oil was purchased from Changqing Oilfield Branch of China National Petroleum Corporation; all raw materials are common raw materials on the market. Unless otherwise specified, the asphalt in the following examples and comparative examples is road petroleum asphalt, with a needle penetration of 60~120dmm at 25℃, a softening point of 40~55℃, and an elongation of 15~25cm at 10℃.

[0044] Example 1

[0045] This embodiment provides a MIL-68 (Al) -Zn / SBR composite modifier, which is composed of the following raw materials by mass fraction: 33.00wt% MIL-68 (Al) -Zn, 54.00wt% SBR, 0.50wt% tetramethylthiuram disulfide, and 12.50wt% three-line oil; the amount of the regulator formic acid is 3mL.

[0046] The preparation method of MIL-68(Al)-Zn comprises the following steps:

[0047] S1. Mix aluminum chloride hexahydrate, terephthalic acid, and N,N-dimethylformamide in a mass ratio of 1:1:58, add 3 mL of formic acid as a regulator, and load into a polytetrafluoroethylene reactor after ultrasonic dissolution; react in an oven at 130°C for 18 hours, and collect the precipitate by centrifugation; wash the product with N,N-dimethylformamide and methanol for 3 times respectively and collect it by centrifugation; place the product in an oven at 100°C and dry it for 12 hours to obtain a metal organic framework defective MIL-68 (Al) crystal.

[0048] S2. Add defective MIL-68(Al) (500 mg) to a mixture of zinc chloride (500 mg) and N,N-dimethylformamide (10 mL), and then react in an oven at 85°C for 24 h. After cooling naturally to room temperature, the resulting product was collected by centrifugation and washed several times with N,N-dimethylformamide and methanol to obtain MIL-68(Al)-Zn crystals.

[0049] The preparation method of the MIL-68(Al)-Zn / SBR composite modifier of this embodiment comprises the following steps:

[0050] P1. Prepare MIL-68(Al)-Zn, SBR, tetramethylthiuram disulfide, and reduced third-line oil according to their respective mass fractions, and then place them in a mixer for blending. The blending temperature is 85 °C, the speed is 1400 r / min, and the time is 10 min;

[0051] P2. Add the blend obtained in step P1 to a granulator to granulate and obtain the MIL-68(Al)-Zn / SBR composite modifier. The head temperature is 175 °C.

[0052] Use the above MIL-68(Al)-Zn / SBR composite modifier to prepare aging-resistant MIL-68(Al)-Zn / SBR modified asphalt. The aging-resistant MIL-68(Al)-Zn / SBR modified asphalt is composed of the following raw materials by mass fraction: 90.50 wt% asphalt, 9.00 wt% MIL-68(Al)-Zn modifier, and 0.50 wt% sulfur;

[0053] The preparation method of the aging-resistant MIL-68(Al)-Zn / SBR modified asphalt is as follows:

[0054] Heat the asphalt to a flowing state, and slowly add the MIL-68(Al)-Zn / SBR composite modifier and stabilizer while stirring. Keep the temperature at 170 - 180 °C, stir at a speed of 4000 - 6000 rpm for 1 - 3 h, and then continue to stir at a speed of 400 - 600 rpm for 1 - 3 h to obtain the aging-resistant modified asphalt.

[0055] Example 2

[0056] The MIL-68(Al)-Zn / SBR composite modifier provided in this example is composed of the following raw materials by mass fraction: 37.00 wt% MIL-68(Al)-Zn, 52.00 wt% SBR, 0.30 wt% tetramethylthiuram disulfide, and 10.70 wt% reduced third-line oil; the dosage of the regulator formic acid is 3 mL.

[0057] The preparation method of the MIL-68(Al)-Zn modifier is the same as that in Example 1.

[0058] The preparation method of the MIL-68(Al)-Zn / SBR composite modifier is the same as that in Example 1;

[0059] The above-mentioned MIL-68(Al)-Zn / SBR composite modifier is used to prepare anti-aging MIL-68(Al)-Zn / SBR modified asphalt. The anti-aging MIL-68(Al)-Zn / SBR modified asphalt is composed of the following raw materials by mass fraction: asphalt 92.50wt%, MIL-68(Al)-Zn / SBR composite modifier 7.00wt%, sulfur 0.50wt%.

[0060] The preparation method of the anti-aging MIL-68(Al)-Zn / SBR modified asphalt is the same as that in Example 1.

[0061] Example 3

[0062] The MIL-68(Al)-Zn / SBR composite modifier provided in this example is composed of the following raw materials by mass fraction: 30.00wt% MIL-68(Al)-Zn, 57.00wt% SBR, 0.50wt% tetramethylthiuram disulfide, 12.50wt% catalytic slurry; the dosage of the regulator formic acid is 3 mL.

[0063] The preparation method of the MIL-68(Al)-Zn modifier is the same as that in Example 1.

[0064] The preparation method of the MIL-68(Al)-Zn / SBR composite modifier is the same as that in Example 1;

[0065] The above-mentioned MIL-68(Al)-Zn / SBR composite modifier is used to prepare anti-aging MIL-68(Al)-Zn / SBR modified asphalt. The anti-aging MIL-68(Al)-Zn / SBR modified asphalt is composed of the following raw materials by mass fraction: asphalt 88.50wt%, MIL-68(Al)-Zn / SBR composite modifier 11.00wt%, sulfur 0.50wt%.

[0066] The preparation method of the anti-aging MIL-68(Al)-Zn / SBR modified asphalt is the same as that in Example 1.

[0067] Example 4

[0068] The MIL-68(Al)-Zn / SBR composite modifier in this example is basically the same as that in Example 1, except that in step S1, the added formic acid regulator is 1 mL.

[0069] Example 5

[0070] The MIL-68(Al)-Zn / SBR composite modifier in this example is basically the same as that in Example 1, except that in step S1, the added formic acid regulator is 5 mL.

[0071] Comparative Example 1

[0072] The composite modifier of this comparative example is composed of the following raw materials by mass fraction: 87.00 wt% SBR, 0.50 wt% tetramethylthiuram disulfide, and 12.50 wt% cut 3 oil.

[0073] That is, compared with Example 1, the composite modifier of this comparative example lacks MIL-68(Al)-Zn.

[0074] Comparative Example 2

[0075] The composite modifier of this comparative example is composed of the following raw materials by mass fraction: 87.00 wt% MIL-68(Al)-Zn, 0.50 wt% tetramethylthiuram disulfide, and 12.50 wt% cut 3 oil.

[0076] That is, compared with Example 1, the composite modifier of this comparative example lacks SBR.

[0077] Comparative Example 3

[0078] The composite modifier of this comparative example is basically the same as that of Comparative Example 2, and the difference is only that defective MIL-68(Al) (that is, the defective MIL-68(Al) crystal obtained in step S1 in the preparation method of MIL-68(Al)-Zn in Example 1) is used to replace MIL-68(Al)-Zn);

[0079] Comparative Example 4

[0080] The preparation method of the MIL-68(Al)-Zn / SBR composite modifier provided in this comparative example is the same as that of Example 1.

[0081] The above MIL-68(Al)-Zn / SBR composite modifier is used to prepare aging-resistant MIL-68(Al)-Zn / SBR modified asphalt. The aging-resistant MIL-68(Al)-Zn / SBR modified asphalt is composed of the following raw materials by mass fraction: 98.50 wt% asphalt, 1.00 wt% MIL-68(Al)-Zn / SBR composite modifier, and 0.50 wt% sulfur.

[0082] The preparation method of the aging-resistant MIL-68(Al)-Zn / SBR modified asphalt is the same as that of Example 1.

[0083] Comparative Example 5

[0084] The preparation method of the MIL-68(Al)-Zn / SBR composite modifier provided in this comparative example is the same as that of Example 1.

[0085] The above MIL-68(Al)-Zn / SBR composite modifier is used to prepare aging-resistant MIL-68(Al)-Zn / SBR modified asphalt. The aging-resistant MIL-68(Al)-Zn / SBR modified asphalt is composed of the following raw materials by mass fraction: asphalt 79.50 wt%, MIL-68(Al)-Zn / SBR composite modifier 20.00 wt%, sulfur 0.50 wt%.

[0086] The preparation method of the aging-resistant MIL-68(Al)-Zn / SBR modified asphalt is the same as that of Example 1.

[0087] Testing the anti-aging performance of modified asphalt

[0088] The modified asphalt prepared in the above examples and comparative examples was respectively subjected to short-term thermal-oxidative aging (RTFOT, temperature 163 °C, aging time 5 hours) and ultraviolet accelerated aging test (UV, ultraviolet light intensity 1200 μW / cm 2 , temperature 60 °C, aging time 9 days); then the properties of each sample before and after aging were tested, and the residual penetration, softening point increment, and ductility retention rate were calculated. The test results are listed in Table 1.

[0089] Residual penetration = penetration after aging / penetration before aging × 100%;

[0090] Softening point increment = softening point after aging - softening point before aging;

[0091] Ductility retention rate = ductility after aging / ductility before aging × 100%.

[0092] Table 1 Test results of the anti-aging performance of the modified asphalt prepared in each example and comparative example.

[0093]

[0094] Compared with Example 1, in Comparative Example 1, SBR was directly used to modify asphalt. After thermal-oxidative aging and ultraviolet aging, its residual penetration and ductility retention rate were lower than those of the modified asphalt using the MIL-68(Al)-Zn / SBR composite modifier, and at the same time, the softening point increment was larger. This indicates that the anti-aging performance of a single SBR modifier is inferior to that of the composite modification system.

[0095] The test results of directly using MIL-68(Al)-Zn to modify asphalt in Comparative Example 2 showed that its residual penetration and ductility retention rate after aging were also lower than those of the composite modified asphalt, and the softening point increment was also larger. This shows that the modification effect of a simple metal-organic framework material has limitations, and a composite system with a polymer is required to exert a synergistic effect.

[0096] In Comparative Example 3, when defective MIL-68(Al) was used alone, the aging performance index was also inferior to that of the composite modified asphalt. This verified the important role of zinc element in the material system, indicating that the metal modification of MIL-68(Al)-Zn was necessary for improving the material performance.

[0097] In Comparative Examples 4 and 5, when too low and too high doses of the composite modifier were used respectively, all the performance indexes after aging decreased, and the softening point increment increased instead. This shows that there is an optimal range of the modifier addition amount, and both excessive or insufficient addition will affect the balance of the modification effect, corroborating that the medium dose used in Example 1 is the optimal choice.

[0098] The above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. For any person skilled in the art, the present invention can have various changes and modifications. Any simple equivalent changes and modifications made according to the protection scope of the present invention application and the content of the specification shall be included in the protection scope of the present invention.

Claims

1. A MIL-68(Al)-Zn / SBR composite modifier, characterized in that, The formulation of the MIL-68(Al)-Zn / SBR composite modifier is as follows: MIL-68(Al)-Zn 30.00 wt% - 37.00 wt%, SBR 52.00 wt% - 57.00 wt%, accelerator 0.30 wt% - 0.50 wt%, and compatibilizer 10.70 wt% - 12.50 wt%.

2. The MIL-68(Al)-Zn / SBR composite modifier according to claim 1, characterized in that, The preparation method of the MIL-68(Al)-Zn is as follows: Dissolve soluble aluminum salt and terephthalic acid in a solvent, add monocarboxylic acid, react at 120°C - 150°C, centrifuge to collect the precipitate, wash and dry to obtain metal-organic framework defective MIL-68(Al) crystals; Add the metal-organic framework defective MIL-68(Al) crystals to a mixture of soluble zinc salt and solvent, then react at 80°C - 100°C. After cooling to room temperature, centrifuge to collect the obtained product and wash to obtain MIL-68(Al)-Zn; Among them, the mass ratio of the soluble aluminum salt to terephthalic acid is 1:1; Among them, the mass ratio of the metal-organic framework defective MIL-68(Al) crystals to the soluble zinc salt is 1:

1.

3. The MIL-68(Al)-Zn / SBR composite modifier according to claim 2, characterized in that, The soluble aluminum salt includes at least one of aluminum chloride, aluminum nitrate, and aluminum sulfate; The soluble zinc salt includes at least one of zinc chloride, zinc nitrate, and zinc sulfate.

4. The MIL-68(Al)-Zn / SBR composite modifier according to claim 2, wherein The monocarboxylic acid includes at least one of formic acid, acetic acid, and benzoic acid.

5. The MIL-68(Al)-Zn / SBR composite modifier according to claim 2, characterized in that, The solvent is at least one of N,N-dimethylformamide, γ-valerolactone, N,N-diethylformamide, and ethanol.

6. A preparation method of the MIL-68(Al)-Zn / SBR composite modifier according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: Stir and mix the MIL-68(Al)-Zn, the SBR, the accelerator, and the compatibilizer according to any one of claims 1 - 5. The mixing temperature is 80 - 90°C, and the speed is 1300 - 1500 r / min; Granulate the blend obtained in the above step to obtain the MIL-68(Al)-Zn / SBR composite modifier.

7. The preparation method of the MIL-68(Al)-Zn / SBR composite modifier according to claim 1, wherein The accelerator includes at least one of tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, and bis(1,5-pentamethylene)tetramthiuram tetrasulfide.

8. The preparation method of the MIL-68(Al)-Zn / SBR composite modifier according to claim 1, wherein The compatibilizer is light decanted oil.

9. An anti-aging SBR modified asphalt, characterized in that, The mass fraction ratio of the aging-resistant SBR modified asphalt includes: asphalt 88.50 wt% - 90.50 wt%, the MIL-68(Al)-Zn / SBR composite modifier according to any one of claims 1 - 5 7.00 wt% - 11.00 wt%, and stabilizer 0.50 wt%.

10. A preparation method of the aging-resistant SBR modified asphalt described in claim 9, characterized in that, The preparation method includes the following steps: Heat the asphalt to a flowing state, add the MIL-68(Al)-Zn / SBR composite modifier and the stabilizer while stirring, keep the temperature at 170 - 180°C, stir at a speed of 4000 - 6000 rpm for 1 - 3 h, and then continue to stir at a speed of 400 - 600 rpm for 1 - 3 h to obtain the aging-resistant SBR modified asphalt.

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