Nano-grafting composite modifier and preparation method thereof, high-performance modified asphalt and preparation method thereof

Abstract

The application relates to the technical field of road engineering, and discloses a nano-grafting composite modifier, a preparation method thereof, high-performance modified asphalt and a preparation method thereof. Nano materials are dispersed in a cosolvent by using an ultrasonic device, the temperature is kept at 70-90 DEG C, the ultrasonic power is greater than or equal to 1000 W, the ultrasonic time is 30-40 minutes, and a uniformly-distributed emulsion is formed; the emulsion is modified by using a surface treatment agent, the ultrasonic time is 60-90 minutes, and a uniformly-stable nano material dispersion slurry is formed; a grafting monomer and a polymer are high-speed mixed and melt-extruded, the reaction temperature is 160 DEG C to 200 DEG C, the screw rotation speed is 150 rpm to 300 rpm, and a polymer grafting particle is obtained; and the nano material dispersion slurry and the polymer grafting particle are high-speed mixed and melt-extruded, and a nano-grafting composite modifier is obtained. By using the ultrasonic dispersion-melt grafting cooperation process, the dispersion, compatibility and stability problems of the nano materials in the asphalt are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering, in particular, to a nano-grafting composite modifier and a preparation method thereof. In addition, the present application also relates to a high-performance modified asphalt comprising the nano-grafting composite modifier and a preparation method thereof. BACKGROUND

[0002] At present, high molecular polymers (such as styrene-butadiene-styrene block copolymer, i.e. SBS) are generally used in engineering to modify asphalt in order to improve the elasticity and crack resistance of asphalt. However, due to the lack of sufficient stable chemical interfacial interaction between the elastic polymer such as SBS and the asphalt matrix, the modified asphalt and the asphalt matrix are prone to phase separation and migration in long-term storage or high-temperature environment, resulting in continuous attenuation of the performance of the modified asphalt and inability to maintain stable road performance for a long time.

[0003] On the other hand, with the development of nanotechnology, nanoparticles (such as nanosilica, nanotitanium dioxide, organic montmorillonite, etc.) are considered to be ideal modified materials for enhancing the durability of asphalt materials due to their large specific surface area, excellent ultraviolet reflection and shielding effect, and high oxygen barrier and isolation performance, and have gradually attracted attention and attention of the industry. However, practical application shows that due to the high surface energy and extremely small particle size of nanomaterials, they are prone to agglomeration in high-viscosity asphalt systems, and traditional simple physical blending methods are difficult to achieve uniform dispersion and stable combination of nanomaterials in asphalt systems. This agglomeration phenomenon greatly limits the modification effect of nanomaterials, which is manifested as insignificant performance improvement of nano-modified asphalt, poor stability, long-term storage prone to sedimentation, delamination and even failure.

[0004] In view of the above problems, the prior art has attempted to improve the dispersion performance of nanomaterials in asphalt through nanomaterial surface modification technology (such as silane coupling agent surface treatment), intercalation technology and mechanical stirring reinforcement technology. However, these methods can only achieve preliminary dispersion and cannot achieve long-term stable and uniform dispersion state. In addition, although individual studies use ultrasonic technology to disperse nanomaterials, the dispersion effect of pure physical ultrasonic action is prone to decay over time, and the long-term stability problem of nanomaterials in asphalt has not been effectively solved. At the same time, some studies have applied polymer grafting technology to asphalt modification, but due to the lack of systematic research on the interface synergy between nanomaterials and polymers, the long-term dispersion and stability problem of nanomaterials in high-temperature and high-viscosity asphalt systems has not been solved. SUMMARY

[0005] The application provides a nano-grafting composite modifier and a preparation method thereof, and a high-performance modified asphalt and a preparation method thereof.

[0006] According to one aspect of the application, a preparation method of a nano-grafting composite modifier is provided, which comprises the following steps: S100, dispersing nano-materials in a cosolvent by using an ultrasonic device, keeping the temperature at 70-90 DEG C, performing ultrasonic dispersion treatment in the oil phase by using the ultrasonic device, the ultrasonic power is greater than or equal to 1000 W, the ultrasonic time is 30-40 minutes, and a uniform emulsion is formed; S200, modifying the emulsion by using a surface treatment agent, keeping the temperature at 70-90 DEG C, the ultrasonic power is greater than or equal to 1000 W, the ultrasonic time is 60-90 minutes, and a uniform and stable nano-material dispersion slurry is formed; S300, uniformly mixing a grafting monomer and a polymer at a high speed, and then feeding them into a double-screw extruder for melt extrusion, the reaction temperature is 160-200 DEG C, the screw rotation speed is 150-300 rpm, and a polymer grafted particle is obtained; and S400, uniformly mixing the nano-material dispersion slurry and the polymer grafted particle at a high speed, and then feeding them into the double-screw extruder for melt extrusion, and a nano-grafting composite modifier is obtained.

[0007] Further, the nano-materials are selected from one or more of organic montmorillonite, nano-silicon dioxide and nano-titanium dioxide.

[0008] Further, the grafting monomer is selected from one or both of glycidyl methacrylate and maleic anhydride.

[0009] Further, the polymer is a styrene-butadiene-styrene block copolymer.

[0010] Further, the surface treatment agent is a silane coupling agent, and one of KH-550 and KH-570 is selected; and / or the cosolvent is naphthenic oil.

[0011] Further, the grafting monomer is glycidyl methacrylate (GMA); both KH-570 and GMA contain a methacryl group, and can be grafted with SBS under the action of an initiator.

[0012] Further, the initiator is one of dicumyl peroxide (DCP) and benzoyl peroxide (BPO).

[0013] According to another aspect of the present application, there is also provided a nano-grafting composite modifier prepared by the preparation method of the nano-grafting composite modifier.

[0014] According to another aspect of the present application, there is also provided a preparation method of high-performance modified asphalt, which comprises the following steps: S500, high-speed shearing blending the nano-grafting composite modifier with an ultraviolet absorber, a stabilizer, a rubber oil with aromatic hydrocarbon as the main component, and a matrix asphalt in a molten state, the shearing rotation speed being 4000 rpm to 6000 rpm, and the mixing time being 30 minutes to 60 minutes; S600, performance development treatment of the blended mixture prepared in S500 to prepare a high-performance modified asphalt material.

[0015] Further, the performance development treatment in step S600 specifically comprises: continuing to keep the blended mixture prepared in S500 at a temperature of 170 DEG C to 180 DEG C for performance development treatment, and continuously stirring for 20 minutes to 30 minutes, so that the nano-grafting composite modifier is further diffused in the asphalt matrix and fully fused with the matrix, and the composite structure of the nano material and the polymer is ensured to reach the best distribution state in the asphalt system, so that the various performances of the prepared modified asphalt material are fully improved and stabilized, and finally a high-performance modified asphalt material with excellent performance is obtained.

[0016] Further, the ultraviolet absorber is at least one selected from nano-titanium dioxide and nano-zinc oxide; and / or the stabilizer is sulfur.

[0017] According to another aspect of the present application, there is also provided a high-performance modified asphalt prepared by the preparation method of the high-performance modified asphalt.

[0018] The present application has the following beneficial effects:

[0019] In the preparation method of the nano-grafting composite modifier, the nano material is first subjected to ultrasonic dispersion treatment, and then a surface treatment agent is further treated, so as to avoid the agglomeration of the nano material caused by the surface treatment agent; the cavitation effect of micro-jet, shock wave and the like generated by high-power ultrasonic (>=1000W) and the high-temperature (70 DEG C-90 DEG C) environment are used to destroy the agglomerates of the nano material, so as to realize the uniform dispersion in the oil; the surface treatment agent modifies the surface of the nano material through physical adsorption or chemical bonding, reduces the surface energy of the nano material, and then enhances the compatibility of the nano material with the oil, and inhibits the re-agglomeration; the grafting monomer is subjected to free radical grafting reaction with the polymer in the melt extrusion process, to form a grafting segment, the active groups of the grafting segment are further crosslinked with the nano material after the surface treatment, the non-polar segment is compatible with the asphalt, and a "anchoring-compatibility" dual-functional interface is constructed; the high shear force (150 rpm-300 rpm) of the screw promotes the melt mixing and reaction mass transfer, and then improves the grafting rate.

[0020] The preparation method of the nano-grafting composite modifier of the application reduces the viscosity of the oil by preheating at 70-90 DEG C in the ultrasonic stage, and improves the dispersion efficiency; the nano-materials dispersed by ultrasonic form stable slurry in the oil, providing high-activity surface for subsequent grafting reaction; the high-temperature of 160-200 DEG C in the extrusion stage activates the grafting reaction, and the screw shearing force promotes the uniform distribution of the nano-materials in the polymer matrix; during the melt extrusion, the grafting monomers can be directly anchored on the surface of the pre-dispersed nano-materials through chemical bonds, avoiding secondary agglomeration.

[0021] The preparation method of the nano-grafting composite modifier of the application has the ultrasonic stage temperature of 70-90 DEG C in the step S100 and the step S200, the viscosity of the oil is reduced, the cavitation threshold is reduced, and the ultrasonic energy transmission efficiency is maximized; if the ultrasonic stage temperature is less than 70 DEG C, the viscosity of the oil increases, resulting in serious ultrasonic energy dissipation and reduced dispersion efficiency; if the ultrasonic stage temperature is greater than 90 DEG C, the volatilization of the cosolvent is intensified, and the stability of the slurry is reduced.

[0022] The preparation method of the nano-grafting composite modifier of the application has the ultrasonic power of 1000 W or more, and the power density is greater than 50 W / L, and the cavitation intensity is sufficient to strip the nano-agglomerates; when the ultrasonic power is less than 1000 W, the dispersion time is prolonged, and D50 is greater than 1 mu m.

[0023] The preparation method of the nano-grafting composite modifier of the application has the melt extrusion stage temperature of 160-200 DEG C in the step S300 and the step S400, the activation energy of the grafting reaction is matched, and the grafting rate is improved; if the melt extrusion stage temperature is less than 160 DEG C, the reaction rate is too low, and the grafting rate is low; if the melt extrusion stage temperature is greater than 200 DEG C, the polymer is degraded, and the melt flow index is suddenly changed.

[0024] The preparation method of the nano-grafting composite modifier of the application has the melt extrusion stage screw rotation speed of 150-300 rpm in the step S300 and the step S400, the shearing rate is high, and the nano-material / polymer melt is fully mixed and interfacial reaction is realized.

[0025] The preparation method of the nano-grafting composite modifier of the application solves the dispersion, compatibility and stability problems of the nano-materials in the asphalt through the ultrasonic dispersion-melt grafting synergistic process, avoids the secondary agglomeration problem of the traditional step-by-step process, improves the interfacial bonding energy, simultaneously improves the high-temperature rutting resistance and low-temperature cracking resistance, increases the penetration ratio after ultraviolet aging, and realizes efficient and stable industrial production.

[0026] In addition to the purposes, features and advantages described above, the application has other purposes, features and advantages. The application is further described below in detail. DETAILED DESCRIPTION

[0027] The following describes embodiments of the present application in detail, but the present application can be implemented in various different ways as defined and covered by the following. The raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods, unless otherwise specified.

[0028] The preparation method of the nanografting composite modifier of the embodiment comprises the following steps: S100, adding a nanomaterial into a cosolvent, and performing ultrasonic dispersion treatment in the oil at a temperature of 70-90 DEG C by using an ultrasonic device, wherein the ultrasonic power is greater than or equal to 1000 W, and the treatment time is 30-40 minutes, so as to form a nanomaterial emulsion with uniform distribution; S200, modifying the emulsion by using a surface treatment agent, wherein the ultrasonic power is greater than or equal to 1000 W, the treatment time is 60-90 minutes, and the temperature is 70-90 DEG C, so as to obtain a nanomaterial dispersion slurry; S300, uniformly mixing a grafting monomer and a polymer at a high speed, and then feeding them into a double-screw extruder for melt extrusion, wherein the reaction temperature is 160-200 DEG C, and the screw rotation speed is 150-300 rpm, so as to obtain polymer grafted particles; and S400, uniformly mixing the nanomaterial dispersion slurry and the polymer grafted particles at a high speed, and then feeding them into the double-screw extruder for melt extrusion, so as to obtain the nanografting composite modifier. In the preparation method of the nanografting composite modifier, the nanomaterial is first treated by ultrasonic dispersion, and then a surface treatment agent is added for further treatment, so as to avoid the agglomeration of the nanomaterial caused by the surface treatment agent; the cavitation effect of microjet flow, shock wave and the like and the high-temperature (70-90 DEG C) environment generated by high-power ultrasonic (greater than or equal to 1000 W) are used to destroy the agglomerates of the nanomaterial, so as to realize the uniform dispersion of the nanomaterial in the oil; the surface treatment agent modifies the surface of the nanomaterial by physical adsorption or chemical bonding, so as to reduce the surface energy of the nanomaterial, and then enhance the compatibility of the nanomaterial with the oil and inhibit the re-agglomeration; the grafting monomer is subjected to a free radical grafting reaction with the polymer during the melt extrusion process, so as to form a grafting segment; the active groups of the grafting segment are further crosslinked with the nanomaterial after the surface treatment; the non-polar segment is compatible with the asphalt, so as to construct a "anchoring-compatibility" dual-functional interface; and the high shear force (150-300 rpm) of the screw promotes the melt mixing and reaction mass transfer, and then improves the grafting rate. In the preparation method of the nanografting composite modifier, the preheating at 70-90 DEG C in the ultrasonic stage reduces the viscosity of the oil, and improves the dispersion efficiency; the nanomaterial after the ultrasonic dispersion forms a stable slurry in the oil, so as to provide a high-activity surface for the subsequent grafting reaction; the high temperature of 160-200 DEG C in the extrusion stage activates the grafting reaction, and at the same time, the shear force of the screw promotes the uniform distribution of the nanomaterial in the polymer matrix; during the melt extrusion, the grafting monomer is directly anchored on the surface of the pre-dispersed nanomaterial by chemical bonds, so as to avoid secondary agglomeration. In the preparation method of the nanografting composite modifier, the temperature in the ultrasonic stage in steps S100 and S200 is 70-90 DEG C, the viscosity of the oil is reduced, the cavitation threshold is reduced, and the ultrasonic energy transmission efficiency is maximized; if the temperature in the ultrasonic stage is less than 70 DEG C, the viscosity of the oil increases, which leads to serious ultrasonic energy dissipation and reduces the dispersion efficiency; and if the temperature in the ultrasonic stage is greater than 90 DEG C, the volatilization of the cosolvent is intensified, and the stability of the slurry is reduced.The preparation method of the nano-grafting composite modifier has ultrasonic power of no less than 1000 W and power density of more than 50 W / L, and the cavitation intensity is sufficient to peel off the nano-agglomerates; when the ultrasonic power is less than 1000 W, the dispersion time is prolonged, and D50 is greater than 1 mu m. In the preparation method of the nano-grafting composite modifier, the temperature of the melt extrusion stage in steps S300 and S400 is 160 DEG C-200 DEG C, the grafting reaction activation energy is matched, and the grafting rate is improved; if the temperature of the melt extrusion stage is less than 160 DEG C, the reaction rate is too low, and the grafting rate is low; if the temperature of the melt extrusion stage is greater than 200 DEG C, the polymer is degraded, and the melt flow index is suddenly changed. In the preparation method of the nano-grafting composite modifier, the screw rotation speed of the melt extrusion stage in steps S300 and S400 is 150 rpm-300 rpm, the shear rate is high, and the nano material / polymer melt is fully mixed and interfacial reaction is realized. The preparation method of the nano-grafting composite modifier solves the problems of dispersion, compatibility and stability of the nano material in the asphalt, avoids the secondary agglomeration problem of the traditional step-by-step process, improves the interfacial bonding energy, simultaneously improves the high-temperature anti-rutting property and the low-temperature anti-cracking property, increases the penetration ratio after ultraviolet aging, and realizes efficient and stable industrial production.

[0029] In the embodiment, the nano material is selected from one or more of organic montmorillonite, nano silicon dioxide and nano titanium dioxide.

[0030] The local high temperature and high pressure generated by the ultrasonic power (≥1000W) act on the interlayer of the organic montmorillonite, overcome the van der Waals force, expand the interlayer spacing of the organic montmorillonite, and form nanoscale exfoliated layers; the oil is used as a dispersion medium, and the lower molecular weight of the oil is easy to insert into the interlayer of the organic montmorillonite under the action of ultrasonic impact, thereby improving the affinity with the oil; the surface modifier can absorb the exposed hydroxyl groups on the surface, is bonded to the surface of the OMMT through Si-O-Si, and endows the OMMT with active functional groups, thereby improving the dispersity; in the melt extrusion stage (160-200℃), the grafted monomers react with the amino groups (-NH2) or carbon double bonds (C=C) on the surface of the montmorillonite through imidization, epoxy ring opening or free radical grafting, thereby forming amide bonds (-NH-CO-) or copolymer carbon chains; the high-speed shearing force of the screw (150-300 rpm) makes the montmorillonite layers orient along the flow direction, and the grafted segments penetrate the interlayer gap, thereby forming a “polymer-montmorillonite” interpenetrating network structure; the ultrasonic cavitation activates the surface active sites (such as hydroxyl groups and organic ammonium groups) of the exfoliated montmorillonite, and can improve the grafting reaction efficiency; the dispersed montmorillonite layers in the oil are directly involved in the melt grafting reaction after modification, thereby avoiding the weak interfacial bonding problem in the traditional dry modification. Through the ultrasonic dispersion-melt grafting synergistic process, the organic montmorillonite realizes efficient exfoliation and interfacial chemical bonding of the nanoscale layers, the layer network limits the flow of asphalt, and the grafted chain toughens and resists cracks; ultraviolet shielding and free radical capture synergistically delay aging.

[0031] Nanoscale silica and nanoscale titanium dioxide, the cavitation bubble collapse shock wave and microjet generated by the ultrasonic power (≥1000W) destroys the hydrogen-bonded aggregates of nano-SiO2; the ultrasonic treatment in the oil promotes the condensation reaction between the surface hydroxyl groups (-OH) of nano-SiO2 and the silane coupling agent (KH550, KH570), forms a hydrophobic surface, and improves the dispersion stability of nano-SiO2 in asphalt; in the melt extrusion stage (160-200℃), the grafted monomers react with the surface hydroxyl groups, amino groups and carbon double bonds of nano-SiO2 through esterification, imidization and free radical copolymerization, thereby forming a cross-linked strong bond, which can also be combined with the polymer main chain free radical (using KH570, with the participation of an initiator), thereby constructing a “nanoparticle-grafted chain-polymer matrix” three-in-one interface; the high-speed shearing force of the screw (150-300 rpm) further refines the nano-SiO2 aggregates and promotes the uniform distribution of the grafted chain in the polymer melt; the ultrasonic treatment simultaneously realizes the dispersion and surface coupling agent modification of nano-SiO2, thereby improving the density of the grafting reaction active sites and the grafting rate; the pre-dispersed nano-SiO2 in the oil directly participates in the melt grafting reaction, and the interfacial bonding energy is improved. Through the ultrasonic dispersion-melt grafting synergistic process, the nanoscale silica realizes the uniform dispersion and interfacial chemical bonding of the high specific surface area nanoparticles; the rigid particles hinder the flow of asphalt, and the grafted chain toughens and resists cracks; ultraviolet reflection and free radical capture synergistically resist aging.

[0032] In addition, the nano-titanium dioxide also has ultraviolet inhibition ability. The nano-titanium dioxide realizes the double breakthrough of photoactivity regulation and interface strengthening through the ultrasonic dispersion-melt grafting synergistic process, and the ultraviolet shielding rate and the pollutant degradation rate are improved; the rut factor is improved, and the storage segregation rate is reduced.

[0033] In this embodiment, the grafting monomer is selected from one or both of glycidyl methacrylate or maleic anhydride. By selecting glycidyl methacrylate (GMA) or maleic anhydride (MAH) as the grafting monomer, combined with the ultrasonic dispersion-melt grafting synergistic process, the interface bonding, functionalization and performance synergy of the nano-grafting composite modifier can be significantly optimized. As the grafting monomer, GMA, the epoxy group of GMA undergoes ring-opening reaction with the nano material (the hydroxyl group of the nano material is exposed after ultrasonic treatment or the amino group is imparted after KH-550 surface modification), and then the interface bonding energy is improved; the polarity of the epoxy group enhances the compatibility of the nano material and the asphaltene, and inhibits segregation; the unreacted epoxy group of GMA can be used as a subsequent crosslinking site, and further undergoes ring-opening reaction with the active groups (such as phenolic hydroxyl group and carboxyl group) of the asphalt, thereby improving the dispersibility of the polymer and the nano material in the asphalt matrix, and forming a more complex crosslinked interpenetrating network. As the grafting monomer, MAH increases the polarity of the SBS macromolecule through its anhydride group, strengthens the polarity of the asphalt molecule and the SBS macromolecule, and makes the whole more likely to present a network crosslinked structure. At the same time, the two carboxylic acid groups formed by the MAH anhydride group can simultaneously connect the asphalt molecule and the coupling agent nano inorganic particle, which also increases the possibility of forming a network structure inside. At the same time, grafting MAH can improve the thermal and oxidative stability of SBS, because the relative reduction of C=C double bond and its position active α-H content makes the initial oxidation temperature rise and the oxidation induction period prolong.

[0034] GMA grafted SBS is as follows:

[0035]

[0036] MAH grafted SBS is as follows:

[0037]

[0038] In this embodiment, the polymer is a styrene-butadiene-styrene block copolymer. By selecting styrene-butadiene-styrene block copolymer (SBS) as the polymer matrix, combined with the ultrasonic dispersion-melt grafting synergy process, its unique microstructure and performance advantages can be fully utilized to achieve high performance of nano-grafted composite modifier. The styrene hard segment (PS) provides rigid support, limits the high-temperature flow of asphalt, and improves the rut resistance; the butadiene soft segment (PB) provides elasticity, absorbs stress, and enhances low-temperature crack resistance; the two-phase separation structure forms a physical crosslinking network, achieving the mechanical properties of "rigidity and flexibility". The unsaturated double bond (C=C) of the butadiene segment can undergo free radical grafting reaction with the grafting monomer (such as maleic anhydride MAH) to form chemical bonding; the benzene ring structure provides thermal stability and is suitable for high-temperature melt extrusion process. Ultrasonic dispersion optimizes the SBS / nano-material interface, and the ultrasonic cavitation effect peels off the nano-material (such as OMMT) agglomerates, while shearing the SBS molecular chain to expose more double bond reaction sites; ultrasonic treatment in the oil promotes the physical adsorption (van der Waals force) and pre-grafting reaction of SBS and nano-materials. Melt grafting strengthens multi-scale combination, SBS-nano material chemical bonding, melt extrusion; screw shear force induces nano-materials to distribute along the SBS phase interface, OMMT lamellae parallel to the flow direction, SiO2 / TiO2 fill the PS-PB phase gap. SBS physical network, nano-material rigid reinforcement, grafting chain interface toughening synergistically enhance the mechanical properties; nano-material UV shielding, grafting agent antioxidant, SBS elastic buffer synergistically enhance durability. The ultrasonic dispersion-melt grafting synergy process with SBS as the polymer matrix realizes the breakthrough performance improvement of nano-grafted composite modifier through multi-scale interface design and functional synergy; the synergistic effect of SBS and nano-materials / grafting agents reduces the material usage, while being compatible with existing asphalt processing equipment.

[0039] In this embodiment, the surface treatment agent is a silane coupling agent, one of KH-550 / KH-570; and / or the co-solvent is naphthenic oil. By selecting a silane coupling agent as the surface treatment agent, and an aromatic hydrocarbon type rubber oil as the co-solvent, in combination with the ultrasonic dispersion-melt grafting synergistic process, the dispersibility, interfacial bonding and process stability of the nanomaterials can be significantly optimized. The siloxane group (—Si—O—) of the silane coupling agent (such as KH550, KH570) condenses with the surface hydroxyl group (—OH) of the nanomaterials (such as nano OMMT, nano SiO2, nano TiO2), forming a Si—O—Si covalent bond, reducing the surface energy and enhancing the hydrophobicity; the organic segment (such as amino, double bond) of the silane chemically crosslinks with the asphalt molecules or the GMA / MAH grafted polymer monomers, further enhancing the interfacial bonding energy; the Zeta potential absolute value of the nanomaterials modified by the silane increases in the oil, inhibiting agglomeration. The pre-activated surface of the silane provides more grafting sites, and the grafting rate is improved; the silane layer blocks the penetration of water / oxygen, and the mass loss rate after ultraviolet aging is reduced. The low polarity of naphthenic oil matches the hydrophobic end of silane, driving the silane molecules to form a dense monolayer arrangement on the surface of the nanomaterials, and the interfacial bonding energy is improved; the flexible segment of naphthenic hydrocarbon in naphthenic oil is embedded in the silane network, forming a "elastic interfacial layer" to inhibit interfacial debonding caused by stress concentration; its low volatile nature ensures the integrity of the silane-nanomaterial bond during high-temperature extrusion, and the interfacial bonding energy retention rate increases after thermal-oxidative aging; this system changes the interfacial bonding of the nanofiller-asphalt matrix from physical adsorption to chemical-mechanical interlocking through solvent-mediated interfacial topological reconstruction, achieving a synergistic leap in the toughness and durability of the composite material.

[0040] KH570 treated nano-inorganic particles, as shown below:

[0041]

[0042] KH550 treated nano-inorganic particles, as shown below:

[0043]

[0044] The nanografting composite modifier of this embodiment is prepared by the preparation method of the nanografting composite modifier described above.

[0045] The preparation method of the high-performance modified asphalt of the embodiment adopts the above-mentioned nano-grafting composite modifier and comprises the following steps: S500, high-speed shearing blending of the nano-grafting composite modifier, an ultraviolet absorber, a stabilizer and a matrix asphalt in a molten state is performed, the shearing rotation speed is 4000 rpm to 6000 rpm, and the mixing time is 30 minutes to 60 minutes; and S600, the blended mixture prepared in S500 is subjected to performance development treatment to prepare a high-performance modified asphalt material. In step S500, the high-speed shearing blending effectively breaks the residual agglomerates (such as OMMT lamellas and SiO2 / TiO2 particles) of the nano-grafting composite modifier under high-speed shearing at 4000 rpm to 6000 rpm, so that the particle size of the residual agglomerates is controlled within a certain small range (for example, 100 nm to 300 nm); the active groups (such as anhydride groups and epoxy groups) of the grafting agent are chemically crosslinked with the phenolic hydroxyl groups or carboxyl groups of the asphalt molecules to further improve the interfacial binding energy and improve the dispersibility of the polymer and the nano material; the ultraviolet absorber is uniformly dispersed to form a molecular-level ultraviolet shielding layer to reduce the photo-oxidation rate of the asphalt; the stabilizer delays thermal-oxidative aging through a free radical capture mechanism (such as quenching ·OH and ROO·); when the nano OMMT is used, the uniform distribution of lamellar structures formed through the preparation process of the embodiment can inhibit the penetration of oxygen and delay thermal-oxidative aging; the molten asphalt system is optimized, the shearing at high temperature reduces the viscosity of the system, and the physical and chemical reaction of the nano material with the grafting segment or the asphalt molecules is promoted to form a physical-chemical crosslinking network; in step S600, the performance development treatment is performed, the nano material is arranged in a direction, and in the development process, the nano lamellas (such as OMMT) are oriented along the stress relaxation direction to form an ordered barrier network; the stabilizer and the ultraviolet absorber are uniformly distributed through molecular diffusion to inhibit the macroscopic phase separation of the modifier and the asphalt. The combination of high-speed shearing and development treatment breaks through the dispersion-stability contradiction of the traditional step-by-step process; the low-temperature treatment in the development stage can reduce the energy consumption compared with the traditional high-temperature mixing. Through the synergy of high-speed shearing blending and performance development treatment, the nano-grafting composite modifier, the ultraviolet absorber and the stabilizer are uniformly dispersed in the asphalt, the interfacial strength is improved, and long-term stability is achieved.

[0046] In the embodiment, the performance development treatment in step S600 specifically comprises: continuously maintaining the blended mixture prepared in S500 at a temperature of 170 ℃ to 180 ℃ for performance development treatment, continuously stirring for 20 minutes to 30 minutes, further diffusing the nano-grafting composite modifier in the asphalt matrix and fully fusing the nano-grafting composite modifier with the matrix, ensuring that the composite structure of the nano material and the polymer reaches the best distribution state in the asphalt system, so that the performance of the prepared modified asphalt material is fully improved and stabilized, and finally a high-performance modified asphalt material with excellent performance is obtained.

[0047] In this embodiment, the ultraviolet absorber is selected from at least one of nano-titanium dioxide and nano-zinc oxide; and / or the stabilizer is sulfur. In the nano-grafting composite modified asphalt, nano-titanium dioxide (TiO2) and nano-zinc oxide (ZnO) are selected as the ultraviolet absorber, and sulfur is selected as the stabilizer, which can synergistically improve the anti-aging property, durability and chemical stability of the material. Nano-titanium dioxide (TiO2) generates hydroxyl radicals (·OH) and superoxide radicals (·O2 - ) under ultraviolet excitation, and decomposes asphalt aging products (such as carbonyl compounds). Nano-zinc oxide (ZnO) captures photo-generated electron-hole pairs on the surface defect state of nano-particles, and inhibits the photocatalytic side reaction. The synergistic effect of TiO2 and ZnO inhibits the photocatalytic activity of TiO2 (through an electron transfer mechanism), and protects the components of asphalt from degradation.

[0048] The high-performance modified asphalt of the embodiment is prepared by the preparation method of the high-performance modified asphalt.

[0049] In the implementation, a high-performance modified asphalt material and a preparation method thereof are provided, in particular to a preparation method based on the ultrasonic dispersion of nano-materials and the reaction extrusion technology of polymer grafting. First, the nano-materials and a surface treatment agent are ultrasonically dispersed in a cosolvent, and then a grafting monomer and a polymer are subjected to a melt grafting reaction through a reaction extrusion device to prepare a nano-grafting composite modifier. Subsequently, the nano-grafting composite modifier is mixed with base asphalt, an ultraviolet absorber and a stabilizer at a high speed, and is subjected to performance development treatment, so as to finally prepare the high-performance modified asphalt. The present application combines physical ultrasonic dispersion with chemical grafting reaction, realizes the deep dispersion and long-term stability of the nano-materials in the asphalt system, significantly improves the high and low temperature performance, ultraviolet aging resistance and storage stability of the modified asphalt, and is suitable for road engineering applications under extreme environmental conditions such as severe cold and high ultraviolet. The specific steps include the following:

[0050] (1) Nano-material ultrasonic dispersion pretreatment:

[0051] The nano-materials (such as organic montmorillonite, nano-silicon dioxide or nano-titanium dioxide) are added to a cosolvent (such as aromatic rubber oil), and are subjected to high-power ultrasonic dispersion treatment at a temperature of 70-90°C using an ultrasonic device, with an ultrasonic power not less than 1000W and an ultrasonic treatment time of 30-40 minutes, to form a uniformly distributed emulsion. The emulsion is modified using a surface treatment agent at a temperature of 70-90°C, with an ultrasonic power ≥1000W and an ultrasonic time of 60-90 minutes, to prepare a uniformly stable nano-material suspension dispersion system. The initial agglomeration structure of the nano-particles is effectively broken, and a highly dispersed nano-suspension system is obtained, which provides excellent primary dispersion effect for the subsequent reaction.

[0052] (2) Polymer grafting reaction extrusion modification:

[0053] The grafting monomer (such as glycidyl methacrylate (GMA) or maleic anhydride (MAH)) and the polymer (such as SBS elastomer) are premixed in proportion, and then fed into a twin-screw reaction extruder for melt grafting reaction. The reaction temperature is controlled at 160-200°C, the screw rotation speed is controlled at 150-300 rpm, and the extrusion reaction time is 3-8 minutes. Then the primary extrusion material is high-speed mixed with the nano-ultrasonic dispersion slurry obtained in step (1) and then secondarily extruded. During the extrusion process, the grafting monomer covalently bonds with the polymer chain segment, and at the same time is further anchored to the surface of the nanomaterial, significantly improving the interfacial bonding ability of the nanomaterial and the polymer. In addition, the high shear effect applied during the extrusion process also realizes the secondary deep dispersion of the nanomaterial, further improving the uniform distribution and interfacial stability of the nanoparticles.

[0054] (3) High-speed shear blending of nano-grafting composite modifier and asphalt:

[0055] The nano-grafting composite modifier prepared in step (2) is mixed with the preheated and molten base asphalt (such as No. 70 asphalt), and an appropriate amount of ultraviolet absorber (such as nano-titanium dioxide or zinc oxide) and stabilizer (such as sulfur) is added, and the mixture is treated by high-speed shearing equipment at a rotation speed of 4000-6000 rpm for 30-60 minutes, so that the composite modifier is uniformly dispersed in the asphalt matrix and a stable multiphase composite system is formed.

[0056] (4) Performance development process of high-performance modified asphalt:

[0057] The above mixed system after high-speed shearing is continuously maintained at 170-180°C for performance development treatment, and stirring is continued for 20-30 minutes, so that the nano-grafting composite modifier further diffuses in the asphalt matrix and fully fuses with the matrix, ensuring that the composite structure of the nanomaterial and the polymer reaches the best distribution state in the asphalt system, so that the various properties of the prepared modified asphalt material are fully improved and stabilized, and finally a high-performance modified asphalt material with excellent performance is obtained.

[0058] The application realizes the "double dispersion" effect of nanomaterials, i.e., primary ultrasonic physical dispersion and secondary dispersion of chemical-mechanical coupling, innovatively. Specifically, the first ultrasonic treatment significantly reduces the agglomeration degree of nanomaterials, and the mechanical shearing and chemical reaction in the second grafting extrusion process further reduce the size of nanomaterials, enhance the dispersion uniformity and interface stability, and finally build a stable nanomaterial-polymer covalent network structure. This structure effectively improves the high and low temperature performance, ultraviolet aging resistance and storage stability of the modified asphalt material, and is especially suitable for road engineering applications in high-cold and strong ultraviolet environment. It has outstanding innovation and technical advantages in solving the dispersion problem of nanomaterials, optimizing the interface structure of the modifier and improving the performance of asphalt materials, and can effectively meet the comprehensive performance requirements of high-performance asphalt materials in road engineering.

[0059] The application realizes the primary dispersion of nanomaterials by ultrasonic treatment, breaks the agglomeration structure, and improves the specific surface area of the material. In the grafting extrusion process, the grafting reaction not only realizes chemical bonding, but also further promotes the "redispersion" of nanomaterials due to shearing and hot melting, and builds a stable interface structure. The nanomaterials are uniformly distributed in the asphalt, enhancing the barrier property, reflectivity and aging resistance. The softening point of the modified asphalt is significantly improved, the low temperature ductility is improved, and the performance retention rate after aging is improved. The compatibility of the grafting composite modifier with asphalt is good, the storage stability is excellent, and it is suitable for application in complex environments such as highlands and severe cold. The application realizes uniform dispersion while establishing "structure locking" through grafting reaction.

[0060] Example 1

[0061] The base asphalt (70#) is weighed at 100 parts, the organic montmorillonite is weighed at 3 parts, the silane coupling agent KH-550 or KH-570 is used as a surface treatment agent at 0.3 parts, the naphthenic oil is weighed at 15 parts, the SBS polymer is weighed at 10 parts, the grafting monomer GMA (glycidyl methacrylate) or MAH (maleic anhydride) is weighed at 1 part, the nano-TiO2 (ultraviolet absorber) is weighed at 1 part, and the sulfur (stabilizer) is weighed at 0.8 parts.

[0062] First, the organic montmorillonite is mixed with the naphthenic oil, and ultrasonic dispersion is carried out at 80℃ for 40 minutes (power 1200w) to obtain a uniformly distributed emulsion; then the obtained emulsion is mixed with the silane coupling agent, and ultrasonic dispersion is carried out at 80℃ for 90 minutes (power 1200w) to obtain a uniformly stable nanodispersion slurry;

[0063] SBS and grafting monomer were mixed at high speed, then melt-grafted by twin-screw extruder. The barrel of extruder included feeding section, initial section and 7 intermediate sections, the temperature of each section was 170℃, 175℃, 175℃, 175℃, 175℃, 175℃, 180℃, 185℃, 190℃ respectively, and the screw rotation speed was 200rpm;

[0064] Then the above material was mixed with nano dispersion slurry, and melt-grafted by twin-screw reaction extruder. The temperature of each section of the extruder was 170℃, 175℃, 175℃, 175℃, 175℃, 175℃, 175℃, 180℃, 180℃ from feeding end to discharging end, and the screw rotation speed was 170rpm, to obtain nano-grafted composite modifier;

[0065] ①KH550+GMA: the epoxy group in GMA can be opened by amine group to form β-hydroxyl amine bond, crosslinking SBS chain and montmorillonite (1). In addition, GMA grafted SBS can also crosslink with asphalt molecules (2), and the amino group on the surface of KH550 treated nanomaterials can also crosslink with asphalt molecules to form amide bond or imine bond (3). The specific reaction is as follows:

[0066] (1)

[0067] (2)

[0068] (3)

[0069] ②KH-550 (γ-aminopropyl triethoxysilane) + MAH (maleic anhydride): after hydrolysis, KH-550 can bond with the surface hydroxyl group of montmorillonite, leaving the terminal amine group (-NH2) fixed on the surface of nanomontmorillonite. After MAH grafts SBS, the anhydride ring is opened with the amine group to form amide / imide structure, achieving covalent crosslinking (4). At the same time, MAH grafted SBS can also crosslink with asphalt molecules (5), and the amino group on the surface of KH550 treated nanomaterials can also crosslink with asphalt molecules to form amide bond or imine bond (6). The specific reaction is as follows:

[0070] (4)

[0071] (5)

[0072] (6)

[0073] III KH-570 + GMA: the double bond of GMA copolymerizes with the double bond on the surface of SBS and KH-570 to form a bridging structure (7), and the epoxy group can participate in further crosslinking in asphalt (8). Details are shown as follows:

[0074] (7)

[0075] (8)

[0076] IV KH-570 + MAH: (SBS-g-MAH), (KH570-nanomaterial) MAH is difficult to copolymerize with the methacryl group in KH-570, but under the action of residual initiator, KH-570 can be crosslinked with SBS by free radical polymerization as GMA (9), and MAH-g-SBS not participating in secondary crosslinking can react with asphalt or weakly polar (10). Details are shown as follows:

[0077] (9)

[0078] (10)

[0079] The obtained modifier is mixed with preheated and molten asphalt, and nano-TiO2 and sulfur are added, and high-speed shearing mixing is carried out at 170°C and 5000 rpm for 45 minutes, and then the temperature is kept at 170°C for 30 minutes for performance development, so that the modifier is fully stabilized and uniformly distributed in the asphalt matrix, and finally high-performance modified asphalt with excellent performance is prepared.

[0080] Example 2

[0081] The same as the steps of Example 1, but using nano-SiO2 instead of organic montmorillonite.

[0082] Example 3

[0083] The same as the steps of Example 1, but using nano-TiO2 instead of organic montmorillonite.

[0084] The following comparative example is used to clarify the effect of the "nanosonication dispersion + polymer grafting reaction extrusion" synergistic mechanism on the modification:

[0085] Comparative Example 1 (traditional physical blending, no ultrasonic, no grafting)

[0086] All raw materials in Example 1 were directly added into the molten asphalt matrix (170°C) without ultrasonic treatment and grafting extrusion, only high speed shearing for 60 minutes at 5000 rpm and performance development for 30 minutes. The modified asphalt softening point was 69.8°C, the 5°C ductility was only 14.7 cm, the aging ductility drop rate was as high as 38.6%, the storage stability difference reached 5.6°C, and the performance was poor.

[0087] Comparative Example 2 (ultrasonic only, no grafting extrusion)

[0088] The nanomaterials in Example 1 were ultrasonically dispersed, but not grafting extruded, and the ultrasonic slurry was directly mixed with other materials in Example 1 in the asphalt, then high speed sheared and performance developed under the same conditions as Example 1.

[0089] Comparative Example 3 (grafting extrusion only, no ultrasonic dispersion)

[0090] The nanomaterials in Example 1 were not ultrasonically dispersed, and the other ingredients in Example 1 were directly melt grafting extruded, then blended with asphalt, and the other process conditions were consistent with Example 1.

[0091] Comparative Example 4 (ultrasonic and grafting were performed separately, not co-extruded)

[0092] The nanomaterials were first ultrasonically dispersed, then melt extruded with other ingredients in Example 1 to prepare grafting polymers, and finally both were added to the asphalt for mixing without co-extrusion, and the other process conditions were consistent with Example 1.

[0093] The modified asphalts prepared in the above examples and comparative examples were tested for performance according to the “Highway Engineering Asphalt and Asphalt Mixture Test Regulations” JTG E20-2011, including high temperature softening point (T 0606-2011), low temperature ductility (T 0605-2011), and polymer modified asphalt storage stability (T 0661-2011). The ultraviolet aging was tested according to “ASTM D4799 / D4799M”, and the experimental conditions were set according to the existing literature on ultraviolet simulation of asphalt in the Tibetan region. The specific parameters were: the ultraviolet aging test box was provided with 6 high-pressure mercury lamps (40w) with a wavelength of 320nm as the ultraviolet light source, the distance between the asphalt sample and the lamp was controlled at 300mm, and the ultraviolet aging simulation was carried out at 60°C for 6 days. Finally, the residual penetration test (JTG E20-2011 T0604-2011) was carried out. The performance test comparison of each sample is shown in Table 1 below:

[0094] Table 1 Performance test data table of different examples and comparative examples

[0095]

[0096] The above results fully show that the nanomaterial ultrasonic dispersion and polymer grafting reaction extrusion synergistic technology significantly improves the dispersion uniformity and interface stability of the nanomaterial in the asphalt, thereby greatly improving the high and low temperature performance, ultraviolet aging resistance and long-term storage stability of the modified asphalt, and is especially suitable for road engineering use in severe cold and strong ultraviolet environment areas.

[0097] The reasons for the differences in each performance index are analyzed as follows:

[0098] 1. The performance of Examples 1-3 can be seen that, in terms of softening point, i.e. high temperature stability of the modified asphalt, Examples 1 are all superior to Examples 2-3. This is because the nanomaterial in Example 1 uses organic montmorillonite, which has a typical layered silicate structure, and after ultrasonic pretreatment, the interlayer structure is optimized, including: expansion of the interlayer spacing and increase of the interlayer peeling degree. In addition, Example 1 is only inferior to Example 2 in terms of ultraviolet aging resistance, which can be concluded that the organic montmorillonite not only serves as an anchor point for polymer grafting modification in this embodiment, but also the intercalation and exfoliation structure after ultrasonic optimization further improves its role of limiting the movement and penetration of oxygen into the polymer, improving the high temperature stability and ultraviolet aging resistance.

[0099] 2. In the present application, each example and comparative example contains secondary cases of different combinations of silane coupling agent / chemical grafting agent, with ①, ②, ③, ④ as the distinction. As can be seen from Examples 1-3, ③ shows more excellent high temperature stability, ultraviolet aging resistance and storage stability. The components in ①, ②, ③, ④ are analyzed respectively: the main feature in ① is KH-550+GMA, in this combination, KH-550 can undergo epoxy ring-opening reaction with GMA, making GMA lose the ability to crosslink with asphalt; the main feature in ② is KH-550+MAH, and the amino group is easily reacted with the anhydride ring, which is worse than ① in grafting effect; the main feature in ③ is KH-570+GMA, in this combination, KH-570 and GMA do not react with each other, and under the action of the initiator, KH-570 and GMA can both undergo polymerization grafting reaction with SBS, forming a complex crosslinking system; the main feature in ④ is KH-570+MAH, which do not react with each other, but compared with ③, MAH has a shorter main chain and crosslinks by ester bond, making the distance between asphalt and SBS molecules small and the molecular force large, which has a bad effect on the low temperature rheological properties of the modified asphalt. Since ③ and ④ have high crosslinking degree, they are both inferior to ① and ② in terms of low temperature rheological properties.

[0100] 3. According to the data analysis of Example 1, Comparative Examples 1-4, it can be seen that Comparative Examples 1-4 are all inferior to Example 1 in terms of comprehensive performance, and through analysis we can obtain different rules of ①, ②, ③, ④ in Comparative Examples 1-4 compared with Example 1.

[0101] (1) In Comparative Example 1-2, no melt grafting process is used, and the difference between the two is whether the nanomaterial is ultrasonically pretreated. Compared with Example 1, in terms of high-temperature stability, due to the absence of melt grafting treatment, a large amount of free KH-550 reacts with GMA and MAH, resulting in a large consumption, which cannot play a role in chemical crosslinking to improve the rheology and storage stability of asphalt. Especially after ultrasonic treatment, the organic montmorillonite and SBS are severely agglomerated and poorly dispersed, which further results in poor high and low temperature rheological properties, ultraviolet aging resistance and storage stability.

[0102] (2) In Comparative Example 3-4, melt grafting treatment is used, and the difference between the two is whether the organic montmorillonite is ultrasonically pretreated. Unlike Comparative Example 1-2, after melt grafting, there is less residual GMA and MAH, and SBS is well dispersed. At the same time, after melt grafting, a stable network structure can be formed to improve the high and low temperature rheological properties and storage stability of asphalt, and reduce the sensitivity to ultraviolet radiation. Compared with Example 1, the nanomaterial in Comparative Example 3 is not ultrasonically treated, the content of free silane coupling agent is high, and the nanomaterial naturally agglomerates, which is less effective than Example 1 in modifying asphalt; the nanomaterial in Comparative Example 4 is not melt extruded, but only gets secondary dispersion during the preparation of asphalt, and lacks the "vacuum still" effect of melt extrusion, so the three-phase crosslinking system of organic montmorillonite, SBS and asphalt is not fully formed.

[0103] The remaining matters of the present application are known technologies.

[0104] The technical features of the above examples can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above examples are described, but as long as the combinations of the technical features do not contradict, they should be considered as within the scope of the present application.

[0105] The above examples only express several embodiments of the present application, and the description is more specific and detailed, but it should not be construed as limiting the scope of the application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

[0106] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a nano-grafted composite modifier, characterized in that: The following steps are involved: S100, using ultrasonic equipment to disperse the nanomaterial in the cosolvent, maintaining the temperature at 70°C to 90°C, and performing ultrasonic dispersion treatment in the oil using the ultrasonic equipment, with an ultrasonic power of ≥1000W and an ultrasonic time of 30 minutes to 40 minutes, to form a uniformly distributed emulsion; The nanomaterial is selected from one or more of organic montmorillonite, nano silicon dioxide, and nano titanium dioxide; The cosolvent is naphthenic oil; S200, modifying the emulsion with a surface treatment agent, maintaining the temperature at 70°C to 90°C, ultrasonic power ≥ 1000W, and ultrasonic time for 60 minutes to 90 minutes to form a uniform and stable nanomaterial dispersion slurry; The surface treatment agent is KH-550 or KH-570; S300, the grafting monomer and the polymer are uniformly mixed at high speed, and then fed into a twin-screw extruder for melt extrusion, the reaction temperature is 160° C. to 200° C., and the screw speed is 150 rpm to 300 rpm to obtain polymer grafted particles; The grafting monomer is selected from one or both of glycidyl methacrylate and maleic anhydride; The polymer is a styrene-butadiene-styrene block copolymer; S400, mixing the nano material dispersion slurry and the polymer grafted particles at high speed, and then feeding the mixture into a twin-screw extruder for melt extrusion to obtain a nano grafted composite modifier.

2. A nano-grafted composite modifier, characterized in that: The nano-grafted composite modifier is prepared by the preparation method of the nano-grafted composite modifier according to claim 1.

3. A method for preparing high-performance modified asphalt, using the nano-grafted composite modifier according to claim 2, characterized in that: The following steps are involved: S500, high-speed shear blending of the nano-grafted composite modifier, an ultraviolet absorber, a stabilizer, a rubber oil with aromatic hydrocarbons as the main component, and a molten matrix asphalt, with a shear speed of 4000 rpm to 6000 rpm and a mixing time of 30 minutes to 60 minutes; S600, performing a performance development treatment on the blended mixture prepared in S500 to prepare a high-performance modified asphalt material; The performance development treatment in step S600 specifically includes: continuing to maintain the blended mixture prepared in S500 at 170°C to 180°C for performance development treatment, and continuously stirring for 20 minutes to 30 minutes, so that the nano-grafted composite modifier diffuses in the asphalt matrix and fully integrates with the matrix, ensuring that the composite structure of the nanomaterial and the polymer reaches the optimal distribution state in the asphalt system, so that the various properties of the prepared modified asphalt material can be fully improved and stabilized, and finally a high-performance modified asphalt material with excellent performance is obtained.

4. The method for preparing high-performance modified asphalt according to claim 3, characterized in that: The ultraviolet absorber is selected from at least one of nano titanium dioxide and nano zinc oxide; The stabilizer is sulfur.

5. A high performance modified asphalt, characterized in that: The high-performance modified asphalt is prepared by the preparation method of claim 3 or 4.

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