Asphalt regenerant as well as preparation method and application thereof

Abstract

The invention relates to the technical field of asphalt modifiers, and particularly discloses an asphalt regenerant as well as a preparation method and application thereof. The asphalt modifier comprises an oil phase, a polymer phase, a nano reinforced phase and a functional additive phase, wherein the oil phase comprises petrochemical oil and vegetable oil; the polymer phase comprises four-arm radiation star-shaped SBS and a rubber powder lysis solution; the nano reinforced phase comprises silane coupling agent modified nano montmorillonite and graphene; the functional additive phase comprises maleic anhydride grafted polyethylene and sucrose ester. The asphalt regenerant provided by the invention is suitable for various types of aged asphalt, in particular to aged polymer modified asphalt, each failure phase of the aged polymer modified asphalt is accurately repaired through a multi-phase synergistic mechanism, full-dimension regeneration of the aged polymer modified asphalt from a molecular scale to macroscopic performance is realized, and the asphalt regenerant has a wide application prospect. Excellent applicability and reliability are shown in regeneration of various types of aged asphalt, and a powerful guarantee is provided for high-quality implementation of road engineering.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt modifiers, and particularly relates to an asphalt rejuvenator, a preparation method thereof, and an application thereof. Background Art

[0002] Traditional asphalt mixtures have poor road performance under harsh environments and heavy traffic conditions and are difficult to be directly used as paving materials for highways. Polymer-modified asphalt not only has good thermal stability and temperature cracking resistance, but also greatly improves the bonding performance between asphalt and aggregates.

[0003] Currently, the main methods for rejuvenating aged SBS-modified asphalt are adding rejuvenators, base asphalt, and SBS-type modified asphalt. Among them, the rejuvenator can better restore the road performance of aged SBS-modified asphalt and effectively improve its utilization rate. SBS-modified asphalt rejuvenators can generally be divided into two categories: ① Oil-supplementing rejuvenators, such as aromatic oil, naphthenic oil, vegetable oil, etc., which reduce viscosity, restore penetration and fluidity by supplementing the lost light oil components in the aged asphalt. ② Polymer-repairing rejuvenators, which attempt to reconstruct the polymer network in asphalt and partially restore elasticity and crack resistance by adding new SBS particles, rubber powder, or thermoplastic elastomers. Such rejuvenators can improve performance through physical filling in ordinary asphalt, but have limited effects on the aging repair of SBS-modified asphalt. At present, there are sufficient research results to confirm that oil-supplementing and polymer-repairing rejuvenators have good effects in restoring ordinary petroleum asphalt. However, due to its unique "asphalt-polymer" multiphase composite structure, the aging and rejuvenation characteristics of SBS-modified asphalt are essentially different from those of base asphalt. The aging of SBS-modified asphalt not only involves the oxidation of asphalt components and the loss of oil components, but also is accompanied by the breakage of SBS chain segments, the collapse of the crosslinked network, and the peeling of the phase interface. Using an oil-supplementing rejuvenator may damage the SBS network, resulting in a decrease in high-temperature rutting resistance. When using a polymer-repairing rejuvenator, the polarity difference between the aged SBS and the newly added polymer may lead to weakened interfacial bonding and easily cause secondary phase separation. Therefore, developing an efficient, low-cost, and easily prepared rejuvenator suitable for polymer-modified asphalt is of great practical significance for promoting the development of polymer-modified asphalt pavement rejuvenation technology and improving the sustainability of road engineering. Summary of the Invention

[0004] Aiming at the problems such as poor repair effect of asphalt rejuvenators on aged polymer-modified asphalt in the prior art, the present invention provides an asphalt rejuvenator, a preparation method thereof, and an application thereof.

[0005] To solve the above technical problems, the technical solution provided by the present invention is:

[0006] An asphalt rejuvenator, the raw materials of which include: an oil phase, a polymer phase, a nano-enhancing phase, and a functional auxiliary phase;

[0007] Among them, the oil phase includes petrochemical oil and vegetable oil; the polymer phase includes four-arm radial star SBS and rubber powder cracking liquid; the nano-enhanced phase includes silane coupling agent-modified nano-montmorillonite and graphene; the functional additive phase includes maleic anhydride grafted polyethylene and sucrose ester.

[0008] Compared with the prior art, the asphalt rejuvenator provided by the present invention has the following advantages:

[0009] (1) At low temperatures, due to the enhanced interaction between asphaltene molecules, the original flexibility of aged asphalt is restricted, and embrittlement and cracking are likely to occur. The oil phase components of the present invention adopt a polar gradient design. The long-chain fatty acids in vegetable oil can penetrate between polar asphaltene clusters, bind to asphaltenes through hydrogen bonds, weaken π-π stacking, relieve the flexibility restriction caused by strong intermolecular interactions, and improve low-temperature ductility; while petrochemical oil supplements non-polar light components, reduces viscosity, and restores the fluidity of aged asphalt.

[0010] (2) During the long-term use of aged asphalt, due to molecular chain breakage, its elasticity and shear resistance are greatly reduced. The four-arm radial star SBS in the polymer phase of the present invention can provide multi-arm cross-linking sites, react with the broken ends of aged asphalt through dynamic sulfur bonds (S-S / S-C), reconstruct a three-dimensional elastic network, and restore the elasticity of asphalt; the rubber powder cracking liquid can fill the pores of aged asphalt, and at the same time, the sulfides contained therein react with asphaltenes through S-π interaction, thereby enhancing the interfacial binding force between the polymer phase and the asphaltene phase; in addition, the sulfides in the rubber powder cracking liquid can further enhance the cross-linking density and greatly improve the shear resistance of asphalt.

[0011] (3) At high temperatures, the softening and flow of aged asphalt intensify, and diseases such as ruts are likely to occur on the road surface. The silanol groups (-SiOH) on the surface of the silane coupling agent-modified nano-montmorillonite in the nano-enhanced phase of the present invention can form hydrogen bonds with the carboxyl groups in asphaltenes, which is conducive to the insertion of nano-sheets of montmorillonite between asphaltene clusters, physically blocking their stacking and inhibiting the softening and flow of asphalt at high temperatures; the conjugated structure of graphene can absorb ultraviolet light, reduce the rate of photo-oxidative aging, thereby extending the service life of asphalt. At the same time, the excellent thermal conductivity of graphene helps to quickly conduct heat and reduce temperature sensitivity. The synergistic effect of the two not only avoids the disadvantages of traditional rejuvenators reducing the high-temperature performance of recycled asphalt, but also significantly enhances the stability of asphalt under high-temperature and heavy-load conditions.

[0012] (4) Aged asphalt, especially aged polymer modified asphalt, is prone to interfacial peeling problems, and when using polymer repair regeneration agents, the polarity difference between the aged polymer asphalt and the newly added polymer may lead to weakened interfacial bonding, which is easy to cause secondary phase separation. The polar anhydride groups of the maleic anhydride grafted polyethylene in the functional additive phase of the present invention can anchor the asphaltene, and the non-polar polyethylene segments are affinity with the oil phase (or polymer), which is beneficial to significantly reduce the phase separation problem in the asphalt system, enhance the compatibility between the components, and make the regenerated asphalt form a stable and uniform system; sucrose ester forms micelles, encapsulates nanoparticles and polymer phases, reduces the interfacial tension between the oil phase and the polymer phase, and prevents phase separation during storage of the regeneration agent. The two can work together to eliminate interphase peeling and achieve homogeneous regeneration; in addition, sucrose ester is also beneficial to promote the rapid and uniform mixing of the regeneration agent when mixed with the aged asphalt, significantly improving the repair efficiency and the quality of the repaired asphalt;

[0013] (5) From the perspective of environmental protection and sustainability, the rubber powder pyrolysis liquid comes from the pyrolysis of waste tires and other rubber products, which converts these originally waste resources into key components of asphalt regeneration agents, realizes the efficient recycling of resources, reduces the pollution of waste rubber to the environment, and reduces dependence on new raw materials. Vegetable oil, as an important component of the oil phase, comes from renewable resources and provides strong support for sustainable road construction.

[0014] It should be noted that the asphalt regeneration agent provided by the present invention is suitable for various types of aged asphalt, and is particularly suitable for aged polymer modified asphalt. Through a multiphase synergistic mechanism, it can accurately repair each failed phase of the aged polymer modified asphalt, thereby achieving full-dimensional regeneration of the aged polymer modified asphalt from the molecular scale to the macroscopic performance.

[0015] Furthermore, the asphalt regeneration agent comprises the following raw material components in percentage by weight: 51% to 55% of an oil phase, 31% to 35% of a polymer phase, 7% to 10% of a nano-enhanced phase and 2% to 4% of a functional additive phase.

[0016] Furthermore, the oil phase comprises petrochemical oil and vegetable oil in a mass ratio of (2.8-3.2):(0.8-1.2).

[0017] Preferably, the vegetable oil is epoxidized soybean oil, and the petrochemical oil is aromatic oil.

[0018] The combined effect of epoxidized soybean oil and aromatic oil can significantly improve the fluidity and low-temperature flexibility of asphalt, effectively slow down the aging of asphalt, and extend the service life of the pavement.

[0019] Furthermore, the polymer phase comprises four-arm radiation star SBS and rubber powder pyrolysis liquid in a mass ratio of (17.5-18.5):(6.5-7.5).

[0020] The synergistic effect of four-arm radiation star-shaped SBS and the pyrolysis liquid of waste rubber powder can fully blend the asphalt rejuvenator with the aged asphalt, firmly bond the new and old asphalt interfaces, effectively enhance the integrity of the pavement structure, and reduce the occurrence of pavement diseases such as cracks and looseness.

[0021] It should be noted that the four-arm radiation star-shaped SBS mentioned in the present invention refers to a four-arm radiation star-shaped styrene-butadiene random copolymer, and the copolymer contains four styrene-butadiene random copolymer arms.

[0022] Furthermore, the nano-reinforcing phase includes nano-montmorillonite modified by silane coupling agent and graphene with a mass ratio of (4.5 - 6.5):(2.5 - 3.5).

[0023] The nano-montmorillonite modified by silane coupling agent and graphene are uniformly dispersed in the asphalt system. Like tiny reinforcing skeletons, they can significantly improve the strength, modulus and fatigue resistance of the asphalt rejuvenator, enhance the ability of the pavement to resist the repeated action of vehicle loads, and reduce pavement deformation and damage.

[0024] Furthermore, the functional additive phase includes maleic anhydride grafted polyethylene and sucrose ester with a mass ratio of (1.9 - 2.1):(0.9 - 1.1).

[0025] The synergistic effect of maleic anhydride grafted polyethylene and sucrose ester can improve the compatibility between the polymer phase and the oil phase, as well as the uniform distribution of the nano-reinforcing phase in the asphalt, promote the uniform dispersion of each phase component, form a stable mixed system, which is conducive to giving full play to the performance advantages of each component, and improving the quality stability and performance consistency of the asphalt rejuvenator.

[0026] Furthermore, the preparation method of the four-arm radiation star-shaped SBS includes the following steps: under an inert atmosphere, dissolve styrene and butadiene in an organic solvent, add an organic lithium initiator at 58°C - 62°C, keep the temperature for reaction for 3h - 5h, add silicon tetrachloride, and continue to keep the temperature for reaction for 1h - 2h to obtain the four-arm radiation star-shaped SBS.

[0027] Combined with the above, the mass ratio of styrene to butadiene is (2.5 - 3.5):(7.5 - 6.5).

[0028] Combined with the above, the organic solvent is n-hexane.

[0029] Combined with the above, the total mass concentration of styrene and butadiene in the organic solvent is 14% - 16%.

[0030] Combined with the above, the organic lithium initiator is n-butyl lithium, and its addition amount is 0.1% - 0.2% of the total mass of styrene and butadiene.

[0031] Combined with the above, the addition amount of silicon tetrachloride is 0.03% to 0.07% of the total mass of styrene and butadiene.

[0032] Further, the preparation method of the rubber powder cracking liquid includes the following steps: heating the waste tire rubber powder to 275°C to 285°C, holding for cracking for 2h to 3h, separating the obtained cracking gas by a cyclone separator to remove carbon black, condensing the remaining cracking gas, and distilling the condensate to remove impurities with a boiling point < 150°C to obtain the rubber powder cracking liquid.

[0033] As a specific embodiment of the present invention, the preparation method of the rubber powder cracking liquid includes the following steps: adding waste tire powder into a cracking reaction kettle, heating it to 275°C to 285°C at a rate of 8°C / min to 12°C / min, keeping it at a constant temperature for 2h to 3h, and allowing the cracking gas to enter a cyclone separator (the cylinder diameter is 0.5 to 1.0m, and the height-diameter ratio is 3:1 to 5:1) at a rate of 18m / s to 22m / s. After the cracking gas passes through a separation section with a cone angle of 23° to 27°, the carbon black settles under the action of centrifugal force, and the carbon black is continuously discharged through a rotary valve. The remaining cracking gas is recovered by condensation (30 to 50°C), and then impurities with a boiling point < 150°C are removed by atmospheric distillation. The temperature of the bottom of the distillation column is controlled at 150 to 160°C, and the temperature of the top of the column is controlled at 100 to 110°C. Finally, the rubber powder cracking liquid (sulfur content is about 1.8%) is obtained at the bottom of the column.

[0034] Combined with the above, the particle size of the waste tire powder is 40 to 60 mesh, its ash content ≤ 8%, and the rubber hydrocarbon content ≥ 45%.

[0035] Further, the preparation method of the silane coupling agent modified nano-montmorillonite includes the following steps: dispersing nano-montmorillonite in deionized water to obtain a nano-montmorillonite dispersion; at 68°C to 70°C, adding a silane coupling agent to the nano-montmorillonite dispersion, adjusting the pH of the system to 4 to 5, holding for reaction for 4h to 5h, performing solid-liquid separation, washing, and drying to obtain the silane coupling agent modified nano-montmorillonite.

[0036] Combined with the above, the nano-montmorillonite is sodium-based montmorillonite.

[0037] Combined with the above, the mass ratio of the nano-montmorillonite to deionized water is 1:(15 to 20).

[0038] Combined with the above, the silane coupling agent is KH-550, and its addition amount is 8% to 12% of the mass of the nano-montmorillonite.

[0039] In the second aspect, the present invention provides a preparation method of an asphalt rejuvenator, including the following steps:

[0040] S1. Mix epoxy soybean oil and aromatic oil evenly to obtain an oil phase. Heat the oil phase to 58°C - 62°C, and sequentially add sucrose ester, four-arm star-shaped SBS, and rubber powder cracking solution, and mix evenly to obtain a premix.

[0041] S2. Disperse silane coupling agent-modified nano-montmorillonite and graphene in a toluene solution of maleic anhydride-grafted polyethylene to obtain a dispersion.

[0042] S3. Add the dispersion to the premix, perform shear emulsification, and vacuum degassing to obtain an asphalt modifier.

[0043] Furthermore, the concentration of the toluene solution of maleic anhydride-grafted polyethylene is 13wt% - 15wt%.

[0044] Furthermore, the shear emulsification is carried out using a high-speed shear emulsifier at 58°C - 62°C at 4500r / min - 5500r / min for 20min - 40min.

[0045] In a third aspect, the present invention provides a recycled polymer-modified asphalt, the raw materials of which include the asphalt rejuvenator described in any one of the above.

[0046] In a fourth aspect, the present invention provides a preparation method of a recycled polymer-modified asphalt, including the following steps:

[0047] Heat the aged polymer-modified asphalt to a flow state, add the asphalt rejuvenator described in any one of the above, and mix evenly to obtain a recycled polymer-modified asphalt.

[0048] Furthermore, the addition amount of the asphalt modifier is 5% - 7% of the mass of the aged polymer-modified asphalt.

[0049] In a fifth aspect, the present invention further provides an asphalt mixture, including the above asphalt rejuvenator or recycled polymer-modified asphalt.

[0050] In a sixth aspect, the present invention further provides the application of the above asphalt rejuvenator or recycled polymer-modified asphalt as a road construction material in road maintenance or road construction.

[0051] The asphalt rejuvenator provided by the present invention can effectively repair the low-temperature, high-temperature properties, elasticity and anti-shear properties of aged asphalt through the synergistic effect of various components, greatly extend the service life of the road surface, and has good compatibility with a variety of asphalts, and can match with a variety of different types of asphalts and aggregates, and is applicable to the repair and new construction projects of various road engineering, showing excellent applicability and reliability in the regeneration of various types of aged asphalt, providing a strong guarantee for the high-quality implementation of road engineering, and at the same time laying a solid foundation for the construction of environmentally friendly and resource-saving roads. Detailed implementation manners

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] Example 1

[0054] 1. The preparation method of the four-arm radial star-shaped SBS comprises the following steps:

[0055] Under an inert atmosphere, styrene and butadiene are dissolved in cyclohexane according to a mass ratio of 3:7, and the total mass concentration of styrene and butadiene is 15%. It is transferred to a reaction kettle, heated to 60 °C, n-butyllithium is added, and the reaction is kept warm for 4 h. Then, silicon tetrachloride is added, and the addition amount of silicon tetrachloride is 0.05% of the total mass of styrene and butadiene. The reaction is continued to be kept warm for 1 h to obtain the four-arm radial star-shaped SBS.

[0056] 2. The preparation method of the rubber powder cracking liquid comprises the following steps:

[0057] Using 40-mesh waste tire powder as the raw material, with its ash content ≤ 8% and rubber hydrocarbon content ≥ 45%, the waste tire powder is added to a cracking reaction kettle, heated to 275 °C - 285 °C at a rate of 10 °C / min, and kept at a constant temperature for 2 h - 3 h. The cracking gas enters a cyclone separator (the cylinder diameter is 0.8 m, and the height-to-diameter ratio is 4:1) at a rate of 20 m / s. After the cracking gas passes through the separation section with a cone angle of 25°, the carbon black settles under the action of centrifugal force, and the carbon black is continuously discharged through a rotary valve. The remaining cracking gas is recovered by condensation (30 - 50 °C), and then impurities with a boiling point < 150 °C are removed by atmospheric distillation. The temperature of the bottom of the distillation column is controlled at 150 - 160 °C, and the temperature of the top of the column is controlled at 100 - 110 °C. Finally, the rubber powder cracking liquid (sulfur content is about 1.8%) is obtained at the bottom of the column.

[0058] 3. The preparation method of the silane coupling agent-modified nano-montmorillonite comprises the following steps:

[0059] According to the material-liquid ratio of 1 g:20 mL, nano-sodium montmorillonite is added to deionized water, and ultrasonic dispersion is carried out for 30 min under the conditions of 40 kHz and 300 W to obtain a nano-montmorillonite dispersion liquid. It is transferred to a reaction kettle at 70 °C, KH-550 silane coupling agent is added, and the addition amount is 10% of the mass of nano-sodium montmorillonite. The pH of the system is adjusted to 4 - 5 with acetic acid, and the reaction is kept warm for 4 h, centrifuged at 3500 rpm, washed, and dried at 80 °C for 12 h to obtain the silane coupling agent-modified nano-montmorillonite.

[0060] In this embodiment, tetra-arm radial star SBS, rubber powder cracking solution, and silane coupling agent-modified nano-montmorillonite can also be prepared under other reaction conditions defined by the present invention. As long as it is within the scope defined by the present invention, comparable technical effects can be achieved.

[0061] Example 2

[0062] This embodiment provides an asphalt rejuvenator, which comprises raw material components with the following mass percentages: 51% of oil phase, 35% of polymer phase, 10% of nano-enhanced phase, and 4% of functional additive phase;

[0063] Among them, the oil phase comprises epoxidized soybean oil and aromatic oil with a mass ratio of 3:1; the polymer phase comprises tetra-arm radial star SBS and rubber powder cracking solution with a mass ratio of 18:7; the nano-enhanced phase comprises silane coupling agent-modified nano-montmorillonite and graphene with a mass ratio of 5:3; the functional additive phase comprises maleic anhydride-grafted polyethylene and sucrose ester with a mass ratio of 2:1.

[0064] The preparation method of the above asphalt rejuvenator comprises the following steps:

[0065] S1. Add epoxidized soybean oil and aromatic oil into a three-necked flask, heat it in a water bath to 60°C, add sucrose ester, stir at 400 r / min for 20 min to form a transparent liquid; then add tetra-arm radial star SBS and rubber powder cracking solution, and stir at a low speed of 200 r / min at 60°C for 10 min to obtain a premix;

[0066] S2. Disperse silane coupling agent-modified nano-montmorillonite and graphene in a toluene solution (concentration 15 wt%) of maleic anhydride-grafted polyethylene, and ultrasonically disperse for 30 min to obtain a dispersion;

[0067] S3. Add the dispersion into the premix, transfer it to a high-speed shear emulsifier, shear at 5000 r / min at 60°C for 30 min, then transfer it to a vacuum drying oven for vacuum defoaming, take it out after 10 min and cool it to room temperature to obtain an asphalt modifier.

[0068] Example 3

[0069] This embodiment provides an asphalt rejuvenator, which comprises raw material components with the following mass percentages: 54% of oil phase, 34% of polymer phase, 10% of nano-enhanced phase, and 2% of functional additive phase;

[0070] Among them, the oil phase comprises epoxidized soybean oil and aromatic oil with a mass ratio of 2.8:1.2; the polymer phase comprises tetra-arm radial star SBS and rubber powder cracking solution with a mass ratio of 17.5:7.5; the nano-enhanced phase comprises silane coupling agent-modified nano-montmorillonite and graphene with a mass ratio of 4.5:3.5; the functional additive phase comprises maleic anhydride-grafted polyethylene and sucrose ester with a mass ratio of 1.9:0.9.

[0071] The preparation method of the above asphalt rejuvenator comprises the following steps:

[0072] S1. Add epoxidized soybean oil and aromatic oil into a three-necked flask, heat it in a water bath to 58 °C, add sucrose ester, stir at 400 r / min for 20 min to form a transparent liquid; then add four-arm star-shaped SBS and rubber powder cracking liquid, and stir at a low speed of 200 r / min at 58 °C for 10 min to obtain a premix;

[0073] S2. Disperse the silane coupling agent-modified nano-montmorillonite and graphene in a toluene solution (concentration 13 wt%) of maleic anhydride-grafted polyethylene, and ultrasonically disperse for 30 min to obtain a dispersion;

[0074] S3. Add the dispersion into the premix, transfer it to a high-speed shear emulsifier, shear at 4500 r / min at 58 °C for 40 min, then transfer it to a vacuum drying oven for vacuum defoaming, take it out after 10 min and cool it to room temperature to obtain an asphalt modifier.

[0075] Example 4

[0076] This example provides an asphalt rejuvenator, which comprises raw material components with the following mass percentages: 55% of oil phase, 33% of polymer phase, 9% of nano-enhancing phase and 3% of functional auxiliary phase;

[0077] Among them, the oil phase comprises epoxidized soybean oil and aromatic oil with a mass ratio of 3.2:0.8; the polymer phase comprises four-arm star-shaped SBS and rubber powder cracking liquid with a mass ratio of 18.5:6.5; the nano-enhancing phase comprises silane coupling agent-modified nano-montmorillonite and graphene with a mass ratio of 6.5:2.5; the functional auxiliary phase comprises maleic anhydride-grafted polyethylene and sucrose ester with a mass ratio of 2.1:1.1.

[0078] The preparation method of the above asphalt rejuvenator comprises the following steps:

[0079] S1. Add epoxidized soybean oil and aromatic oil into a three-necked flask, heat it in a water bath to 62 °C, add sucrose ester, stir at 400 r / min for 20 min to form a transparent liquid; then add four-arm star-shaped SBS and rubber powder cracking liquid, and stir at a low speed of 200 r / min at 62 °C for 10 min to obtain a premix;

[0080] S2. Disperse the silane coupling agent-modified nano-montmorillonite and graphene in a toluene solution (concentration 17 wt%) of maleic anhydride-grafted polyethylene, and ultrasonically disperse for 30 min to obtain a dispersion;

[0081] S3. Add the dispersion liquid to the premix, transfer it to a high-speed shear emulsifier, shear at 5500 r / min at 62 °C for 20 min, then transfer it to a vacuum drying oven for vacuum degassing, take it out after 10 min and cool it to room temperature to obtain the asphalt modifier.

[0082] Example 5

[0083] This example provides an asphalt rejuvenator, which includes the following raw material components in mass percentage: 55% of the oil phase, 35% of the polymer phase, 7% of the nano-enhanced phase, and 3% of the functional auxiliary phase.

[0084] Among them, the oil phase includes epoxidized soybean oil and aromatic oil with a mass ratio of 2.8:0.8; the polymer phase includes four-arm star-shaped SBS and rubber powder cracking liquid with a mass ratio of 18:7.5; the nano-enhanced phase includes silane coupling agent-modified nano-montmorillonite and graphene with a mass ratio of 5.5:3.5; the functional auxiliary phase includes maleic anhydride grafted polyethylene and sucrose ester with a mass ratio of 2:0.9.

[0085] The preparation method of the above asphalt rejuvenator includes the following steps:

[0086] S1. Add epoxidized soybean oil and aromatic oil to a three-necked flask, heat it in a water bath to 58 °C, add sucrose ester and stir at 400 r / min for 20 min to form a transparent liquid; then add four-arm star-shaped SBS and rubber powder cracking liquid, and stir at a low speed of 200 r / min at 58 °C for 10 min to obtain a premix.

[0087] S2. Disperse silane coupling agent-modified nano-montmorillonite and graphene in a toluene solution (concentration 16 wt%) of maleic anhydride grafted polyethylene, and ultrasonically disperse for 30 min to obtain a dispersion liquid.

[0088] S3. Add the dispersion liquid to the premix, transfer it to a high-speed shear emulsifier, shear at 4700 r / min at 58 °C for 35 min, then transfer it to a vacuum drying oven for vacuum degassing, take it out after 10 min and cool it to room temperature to obtain the asphalt modifier.

[0089] Application Example 1

[0090] This example provides a preparation method of recycled SBS asphalt, which includes the following steps:

[0091] Place the aged SBS asphalt in an oven, preheat it at 160 °C for 1 h until the aged SBS asphalt is completely fluid, transfer it to an oil bath at 160 °C, and add the asphalt rejuvenator prepared in Example 2 above to the aged SBS asphalt respectively. The addition amount is 6% of the mass of the aged SBS asphalt, and stir at a rate of 2000 r / min for 20 min to obtain recycled SBS asphalt.

[0092] Comparative Example 1

[0093] This comparative example provides an oil replenishment type regenerant, which includes 50% aromatic oil, 30% waste engine oil, and 20% rosin resin.

[0094] The aged SBS asphalt was regenerated in the exact same manner as in Application Example 1.

[0095] Comparative Example 2

[0096] This comparative example provides a common SBS repair type regenerant, which includes 75% aromatic oil, 20% common linear SBS, and 5% nano-silica.

[0097] The aged SBS asphalt was regenerated in the exact same manner as in Application Example 1.

[0098] Comparative Example 3

[0099] This comparative example provides an asphalt regenerant. The only difference from Example 1 is that the oil phase in Example 1 is replaced with single waste engine oil, and the other components are exactly the same.

[0100] The aged SBS asphalt was regenerated in the exact same manner as in Application Example 1.

[0101] Comparative Example 4

[0102] This comparative example provides an asphalt regenerant. The only difference from Example 1 is that the four-arm radiation star-shaped SBS in the polymer phase of Example 1 is replaced with common linear SBS, and the other components are exactly the same.

[0103] The aged SBS asphalt was regenerated in the exact same manner as in Application Example 1.

[0104] Comparative Example 5

[0105] This comparative example provides an asphalt regenerant. The only difference from Example 1 is that the rubber powder cracking liquid in the polymer phase of Example 1 is removed, that is, the polymer phase only contains one substance, four-arm radiation star-shaped SBS, and the other components are exactly the same.

[0106] The aged SBS asphalt was regenerated in the exact same manner as in Application Example 1.

[0107] Comparative Example 6

[0108] This comparative example provides an asphalt regenerant. The only difference from Example 1 is that the four-arm radiation star-shaped SBS in the polymer phase of Example 1 is removed, that is, the polymer phase only contains one substance, rubber powder cracking liquid, and the other components are exactly the same.

[0109] The aged SBS asphalt was regenerated in the exact same manner as in Application Example 1.

[0110] Comparative Example 7

[0111] This comparative example provides an asphalt rejuvenator. The only difference from Example 1 is that the nano-enhanced phase in Example 1 is replaced by unmodified nano-montmorillonite and graphene in a ratio of 5:3, and the other components are exactly the same.

[0112] The aged SBS asphalt is regenerated in exactly the same manner as in Application Example 1.

[0113] Comparative Example 8

[0114] This comparative example provides an asphalt rejuvenator. The only difference from Example 1 is that the maleic anhydride grafted polyethylene in the functional additive phase in Example 1 is replaced by an equal amount of polyethylene, and the other components are exactly the same.

[0115] The aged SBS asphalt is regenerated in exactly the same manner as in Application Example 1.

[0116] Comparative Example 9

[0117] This comparative example provides an asphalt rejuvenator. The only difference from Example 1 is that the maleic anhydride grafted polyethylene in the functional additive phase in Example 1 is replaced by an equal amount of acrylic acid grafted polyethylene, and the other components are exactly the same.

[0118] The aged SBS asphalt is regenerated in exactly the same manner as in Application Example 1.

[0119] Performance Test

[0120] The rheological properties of all the above sample asphalts are tested by a dynamic shear rheometer (DSR). The ability of the asphalt to resist rutting, fatigue, cracking, etc. can be determined through the rheological indexes of the testable asphalt, so as to truly reflect the rheological characteristics of the asphalt.

[0121] The high-temperature rutting resistance ability is characterized by the rutting factor G* / sinδ, and the rutting factor is positively correlated with the high-temperature performance. The regenerated SBS asphalt is prepared into a sample with a diameter of 25 mm and a thickness of 1 mm for testing. The test parameters are set as follows: temperature 46°C, angular frequency 10 rad / s. According to the complex shear modulus G* and phase angle δ obtained from the test, the rutting factor G* / sinδ is calculated.

[0122] The intermediate temperature fatigue performance is characterized by the G-R value. The larger the G-R value, the more negative the relationship with the fatigue performance. The recycled SBS asphalt is prepared into test samples with a diameter of 8 mm and a thickness of 2 mm. Test parameter settings: 1% strain control mode, the frequency range is set to 0.1 rad / s to 100 rad / s, and the temperatures are 5°C, 15°C, and 25°C. The Sigmoidal model is used to fit the master curve of the complex shear modulus. Substitute the complex shear modulus and phase angle corresponding to 0.005 rad / s in the master curve into the following formula for calculation to obtain the G-R parameter.

[0123]

[0124] In the formula: G * ——Complex shear modulus (kPa); δ——Phase angle (rad).

[0125] Low-temperature anti-cracking performance test: The recycled SBS asphalt is prepared into test samples with a diameter of 4 mm and a thickness of 2.2 mm. Test parameter settings: The frequency range is set to 0.2 rad / s to 100 rad / s, and the temperatures are -6°C, -12°C, and -18°C. Two parameters are obtained: the stiffness modulus S value and the creep rate m value of the asphalt. The low-temperature rheological properties of the asphalt are characterized by the stiffness modulus S value and the creep rate m value. The stiffness modulus S value characterizes the low-temperature deformation ability of the asphalt, and the creep rate m characterizes the low-temperature stress relaxation ability of the asphalt. A smaller S value or a higher m value can indicate that the asphalt has better low-temperature performance.

[0126] Table 1

[0127]

[0128]

[0129] Using the asphalt modifiers prepared in Examples 3 to 5 to regenerate the aged SBS asphalt according to the method of Application Example 1 can achieve technical effects basically equivalent to those of Example 2.

[0130] In summary, through the synergistic effect of the dynamic cross-linked polymer phase and the nano-filled phase, the present invention effectively restores the elastic network and colloidal stability of SBS asphalt. Through the interfacial polarity regulation of the functional additive phase and the oil phase, multi-phase compatibility regeneration is realized, successfully solving the problem of SBS modified asphalt regeneration, restoring the various performances of the aged SBS asphalt, and having high practical value.

[0131] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, or improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An asphalt rejuvenator, characterized in that, Its raw materials include: an oil phase, a polymer phase, a nano-enhancing phase, and a functional additive phase; Among them, the oil phase includes petrochemical oil and vegetable oil; the polymer phase includes four-arm radial star SBS and rubber powder cracking liquid; the nano-enhancing phase includes silane coupling agent-modified nano-montmorillonite and graphene; the functional additive phase includes maleic anhydride-grafted polyethylene and sucrose ester.

2. The asphalt rejuvenator according to claim 1, wherein, It includes raw material components with the following mass percentages: 51% - 55% of the oil phase, 31% - 35% of the polymer phase, 7% - 10% of the nano-enhancing phase, and 2% - 4% of the functional additive phase.

3. The asphalt rejuvenator according to claim 2, wherein The oil phase includes petrochemical oil and vegetable oil with a mass ratio of (2.8 - 3.2):(0.8 - 1.2); and / or The polymer phase includes four-arm radial star SBS and rubber powder cracking liquid with a mass ratio of (17.5 - 18.5):(6.5 - 7.5); and / or The nano-enhancing phase includes silane coupling agent-modified nano-montmorillonite and graphene with a mass ratio of (4.5 - 6.5):(2.5 - 3.5); and / or The functional additive phase includes maleic anhydride-grafted polyethylene and sucrose ester with a mass ratio of (1.9 - 2.1):(0.9 - 1.1).

4. The asphalt rejuvenator according to any one of claims 1 to 3, characterized in that, The vegetable oil is epoxy soybean oil, and the petrochemical oil is aromatic oil.

5. The asphalt rejuvenator according to any one of claims 1 to 3, characterized in that, The preparation method of the four-arm radial star SBS includes the following steps: Under an inert atmosphere, styrene and butadiene are dissolved in an organic solvent, an organic lithium initiator is added at 58°C - 62°C, the mixture is kept warm and reacted for 3h - 5h, silicon tetrachloride is added, and the reaction is continued under warm conditions for 1h - 2h to obtain the four-arm radial star SBS; and / or The preparation method of the rubber powder cracking liquid includes the following steps: The waste tire rubber powder is heated to 275°C - 285°C and kept warm for cracking for 2h - 3h. After the obtained cracking gas is separated by a cyclone separator to remove carbon black, the remaining cracking gas is condensed, and the condensate is distilled to remove impurities with a boiling point < 150°C to obtain the rubber powder cracking liquid; and / or The preparation method of the silane coupling agent-modified nano-montmorillonite includes the following steps: The nano-montmorillonite is dispersed in deionized water to obtain a nano-montmorillonite dispersion; at 68°C - 70°C, the silane coupling agent is added to the nano-montmorillonite dispersion, the pH of the system is adjusted to 4 - 5, and the reaction is carried out under warm conditions for 4h - 5h. Then, solid-liquid separation, washing, and drying are performed to obtain the silane coupling agent-modified nano-montmorillonite.

6. The preparation method of the asphalt rejuvenator according to any one of claims 1 to 5, characterized in that, It includes the following steps: S1, Mix epoxy soybean oil and aromatic oil evenly to obtain the oil phase; heat the oil phase to 58°C - 62°C, and successively add sucrose ester, four-arm radial star SBS, and rubber powder cracking liquid, and mix evenly to obtain a premix; S2, Disperse the silane coupling agent-modified nano-montmorillonite and graphene in a toluene solution of maleic anhydride-grafted polyethylene to obtain a dispersion; S3, Add the dispersion to the premix, perform shear emulsification and vacuum degassing to obtain an asphalt modifier.

7. A recycled polymer modified asphalt, characterized in that, Its raw materials include the asphalt rejuvenator according to any one of claims 1 - 5.

8. A preparation method of recycled polymer modified asphalt, characterized in that, It includes the following steps: Heat the aged polymer-modified asphalt to a fluid state, add the asphalt rejuvenator according to any one of claims 1 - 5, and mix evenly to obtain a regenerated polymer-modified asphalt.

9. An asphalt mixture, characterized in that, Comprising the asphalt rejuvenator according to any one of claims 1 to 5 or the regenerated polymer modified asphalt according to claim 7.

10. Application of the asphalt rejuvenator according to any one of claims 1 to 5 or the regenerated polymer modified asphalt according to claim 7 as a road construction material in road maintenance or road construction.

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