Instant high-viscosity modified asphalt based on reversible dynamic bonds and preparation method thereof

Abstract

The invention discloses instant high-viscosity modified asphalt based on reversible dynamic bonds and a preparation method thereof, and belongs to the technical field of modified asphalt, the instant high-viscosity modified asphalt comprises the following raw materials by weight: 100 parts of matrix asphalt, 2-8 parts of a reversible crosslinking polyurethane modifier, and 1-2 parts of a compatilizer; comprising the following steps: heating matrix asphalt to 130-140 DEG C, melting and stirring, then adding a compatilizer and a reversible cross-linked polyurethane modifier into the molten matrix asphalt, keeping the temperature, shearing at a shearing rate of 1500 rpm for 30 minutes, putting into a drying oven at 50-60 DEG C, curing for 4-6 hours, and cooling to room temperature to obtain the instant high-viscosity modified asphalt, according to the present invention, the matrix asphalt is modified by using the reversible cross-linked polyurethane modifier, such that the prepared modified asphalt has characteristics of instant dissolution and high viscosity, is significantly superior to the pavement performance of the traditional asphalt, further has characteristics of good re-processing, can be recycled, and has extremely high circular economic value.

Description

Technical Field

[0001] The invention belongs to the technical field of modified asphalt, and in particular relates to an instant high-viscosity modified asphalt based on reversible dynamic bonds and a preparation method thereof. Background Art

[0002] Asphalt is currently widely used in the field of road engineering due to its low cost and good mechanical properties. With the continuous increase in current traffic volume and load, higher requirements are placed on the performance of asphalt road pavement materials. During its service life, asphalt pavement is often affected by repeated loads from wheels and natural conditions (heat, oxygen, rain), and is prone to rutting, potholes, and cracking, which seriously affect the comfort and safety of road driving. Therefore, it is necessary to modify asphalt to improve its road performance.

[0003] Polyurethane has good elasticity, wear resistance and weather resistance, which can improve the crack resistance, durability and weather resistance of asphalt materials, improve road performance and extend service life. According to the physical properties of modified asphalt, the polyurethane modifier commonly used in polyurethane modified asphalt is thermosetting. Thermosetting polyurethane modifiers are cross-linked and solidified through chemical bonds to form a network structure. This chemical cross-linked network structure not only affects the high-temperature melting and effective viscosity reduction of the base asphalt, but also has irreversibility, so that the recycling of thermosetting polyurethane modified asphalt requires a higher temperature, and even cannot achieve its effective recycling, resulting in the accumulation of waste materials, which greatly reduces its circular economic value. Summary of the invention

[0004] The purpose of the present invention is to provide a fast-dissolving and highly viscous modified asphalt based on reversible dynamic bonds and a preparation method thereof. By adding and using a reversible cross-linked polyurethane modifier, a three-dimensional network structure formed by cross-linking is introduced into the base asphalt, thereby improving the low-temperature toughness and viscosity of the modified asphalt. Moreover, under high temperature conditions, the dynamic bonds in the reversibly cross-linked polyurethane modifier break, thereby improving the fast-dissolving performance and reprocessability of the modified asphalt, thereby solving the technical problems raised in the background technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A fast-dissolving high-viscosity modified asphalt based on reversible dynamic bonds, comprising the following raw materials in parts by weight: 100 parts of base asphalt, 2-8 parts of reversibly cross-linked polyurethane modifier, and 1-2 parts of compatibilizer;

[0007] The reversibly cross-linked polyurethane modifier is prepared by the following steps:

[0008] Heat polytetrahydrofuran at 100°C to melt and evacuate for 2h to remove moisture, cool to 60°C, drop a mixed solution of dibutyltin dilaurate and N,N-dimethylformamide, then slowly drop hexamethylene diisocyanate, and after the dropwise addition is completed, stir and react for 4-6h at 60°C under nitrogen protection to obtain a prepolymer solution; add a chain extender and a reversible crosslinker to the prepolymer solution, react at 45°C for 18-24h, and vacuum dry to obtain a reversible crosslinked polyurethane modifier. Under the conditions of N,N-dimethylformamide as solvent and dibutyltin dilaurate as catalyst, a polymerization reaction is carried out with polytetrahydrofuran as the soft segment and hexamethyl diisocyanate as the hard segment to obtain an isocyanate-terminated prepolymer; then chain extension and crosslinking are carried out to obtain a polyurethane modifier containing carbon-carbon reversible dynamic covalent bonds as crosslinking points.

[0009] Furthermore, the usage ratio of the polytetrahydrofuran, dibutyltin dilaurate, N,N-dimethylformamide and hexamethylene diisocyanate, the chain extender and the reversible cross-linking agent is 10g: 0.05g: 100mL: 1.8-2g: 0.5-1g: 1.82-3.03g.

[0010] Furthermore, the molecular weight of the polytetrahydrofuran is 1800-2000 g / mol. The reversibly cross-linked polyurethane modifier prepared within this molecular weight range has excellent mechanical properties and stability. If the molecular weight is too large, the processing performance of the modified asphalt will be affected.

[0011] Furthermore, the chain extender is 4-(4'-hydroxyphenyl)-2,3-naphthyrazine-1-one. The two active hydrogens on 4-(4'-hydroxyphenyl)-2,3-naphthyrazine-1-one can react with the isocyanate group in the prepolymer, and as a chain extender of the reversibly cross-linked polyurethane modifier, a twisted, non-coplanar naphthyrazine biphenyl structure is introduced into the polyurethane molecular skeleton, which can not only improve the thermal stability and mechanical properties of the reversibly cross-linked polyurethane modifier, but also improve the solubility of the reversibly cross-linked polyurethane modifier in the matrix asphalt.

[0012] Furthermore, the reversible cross-linking agent is prepared by the following steps:

[0013] Step A1, adding 4,4"-dihydroxybenzophenone and anhydrous potassium carbonate to N,N-dimethylformamide and stirring to mix, then adding 2-bromoethanol dropwise, stirring and reacting at 90° C. under nitrogen protection for 24 hours, cooling to room temperature and filtering to remove anhydrous potassium carbonate, adding the filtrate to deionized water for precipitation, vacuum filtering, and freeze-drying the precipitate to obtain an intermediate; the hydroxyl group of 4,4"-dihydroxybenzophenone undergoes a substitution reaction with 2-bromoethanol, thereby forming an ether bond in the structure of the intermediate;

[0014] Step A2, adding the intermediate to N, N-dimethylformamide and stirring to dissolve, then adding isopropanol and acetic acid to mix evenly, then exposing to ultraviolet radiation for reaction for 4-6 days, then pouring into deionized water for precipitation, and eluting with petroleum ether and ethyl acetate in a volume ratio of 1:1 for chromatography purification on a silica gel column to obtain a reversible cross-linking agent. Under ultraviolet irradiation and acetic acid as a catalyst, the carbonyl group in the intermediate captures hydrogen atoms from isopropanol to form a hydroxyl group, and then a reversible cross-linking agent containing both a benzopinacol structure and an ether bond is synthesized by dimerization.

[0015] Furthermore, the usage ratio of the 4,4"-dihydroxybenzophenone, anhydrous potassium carbonate, N,N-dimethylformamide and 2-bromoethanol is 8.5-8.6 g: 11-12 g: 20-30 mL: 11.3-12.5 g.

[0016] Furthermore, the usage ratio of the intermediate, N,N-dimethylformamide, isopropanol and acetic acid is 6g:20mL:30-50mL:0.1mL.

[0017] Furthermore, the wavelength of the ultraviolet light is 350-395nm, and the irradiance is 4-6mW / cm 3 .

[0018] Furthermore, the compatibilizer is octylphenol polyoxyethylene ether. Octylphenol polyoxyethylene ether has good solubility and dispersibility, can effectively improve the compatibility between the reversibly cross-linked polyurethane and the matrix asphalt, and improve the processing performance, compatibility and stability of the modified asphalt.

[0019] A method for preparing an instant high-viscosity modified asphalt based on a reversible dynamic bond comprises the following steps:

[0020] The base asphalt is heated to 130-140°C and melted with stirring. Then, the compatibilizer and the reversibly cross-linked polyurethane modifier are added to the molten base asphalt. The temperature is maintained and sheared at a shear rate of 1500rpm for 30 minutes to allow the reversibly cross-linked polyurethane modifier to be decross-linked and evenly dispersed in the base asphalt. The base asphalt is then placed in an oven at 50-60°C for curing for 4-6 hours. At low temperature, the reversibly cross-linked polyurethane modifier is reorganized into a cross-linked network structure. After cooling to room temperature, a quick-dissolving and highly viscous modified asphalt is obtained.

[0021] Beneficial effects:

[0022] The reversible crosslinking agent prepared by the present invention contains a benzopinacol structure in its molecule, and the benzopinacol structure is the center, and is connected with ether bonds and hydroxyl groups on all sides. The benzopinacol structure has excellent chemical stability and mechanical properties at room temperature, but under heating conditions, the carbon-carbon bond in the center can be cracked to form a diphenylmethanol structure containing free radicals. During the cooling process, the two diphenylmethanol structures containing free radicals can be restored to the original benzopinacol structure through recombination, so that the crosslinking agent has thermal reversibility; at the same time, the ether bond in the reversible crosslinking agent cooperates with the benzopinacol structure, which can improve the flexibility and stability of the reversible crosslinking agent;

[0023] The invention uses polytetrahydrofuran and hexamethylene diisocyanate as raw materials to synthesize an isocyanate-terminated prepolymer, and then uses 4-(4'-hydroxyphenyl)-2,3-naphthyridin-1-one and a reversible crosslinking agent to perform chain extension and crosslinking, and simultaneously introduces a naphthyridinyl biphenyl structure and a benzopinacol structure into a polyurethane molecule to prepare a reversible crosslinked polyurethane modifier with a crosslinked network structure; through the coordinated coordination of the naphthyridinyl biphenyl structure and the benzopinacol structure, the prepared polyurethane modifier not only has a reversible crosslinking effect, but also has excellent toughness, stability and solubility;

[0024] The invention performs warm mixing and modification on a reversible cross-linked polyurethane modifier and a base asphalt. On the one hand, at the heating and melting temperature of the base asphalt, the cross-linking points of the benzopinacol structure of the reversible cross-linked polyurethane modifier are cracked, and the network polymer is converted into a low-viscosity linear polymer, which is evenly dispersed with the base asphalt under the action of high-speed shearing and has good compatibility. In addition, the linear structure contains a diazine biphenyl structure, which improves the solubility of the reversible cross-linked polyurethane modifier in the base asphalt, and can be evenly dispersed in a short time. On the other hand, after cooling, these linear polymers are reorganized in the base asphalt to re-form a polymer with a stable network structure, which is evenly distributed in the base asphalt matrix, significantly improving the performance indicators of the modified asphalt such as the penetration, softening point, ductility and viscosity, and obtaining a highly viscous modified asphalt, which has a road performance significantly better than that of traditional asphalt. More importantly, the modification of the base asphalt by the reversible cross-linked polyurethane modifier gives the modified asphalt good reprocessability, and the modified asphalt can be recycled at a relatively low temperature, thereby improving its circular economic value. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] This embodiment provides a reversible cross-linking agent, which is prepared by the following steps:

[0028] Step A1, 8.5 g of 4,4"-dihydroxybenzophenone and 11 g of anhydrous potassium carbonate were added to 20 mL of N,N-dimethylformamide and stirred to mix, then 11.3 g of 2-bromoethanol was added dropwise, and the mixture was stirred and reacted at 90° C. under nitrogen protection for 24 h, and the mixture was cooled to room temperature and filtered, and the filtrate was added to deionized water for precipitation. After vacuum filtration, the precipitate was freeze-dried to obtain an intermediate;

[0029] Step A2: 6 g of the intermediate was added to 20 mL of N,N-dimethylformamide and stirred to dissolve, then 30 mL of isopropanol and 0.1 mL of acetic acid were added and mixed evenly, and then exposed to ultraviolet light with a wavelength of 350 nm and a wavelength of 6 mW / cm 3 The reaction mixture was irradiated at an irradiation rate of 1:1 for 4 days, then poured into deionized water for precipitation, and purified by chromatography on a silica gel column eluted with petroleum ether and ethyl acetate in a volume ratio of 1:1 to obtain a reversible cross-linking agent.

[0030] Example 2

[0031] This embodiment provides a reversible cross-linking agent, which is prepared by the following steps:

[0032] Step A1, 8.6 g of 4,4"-dihydroxybenzophenone and 11.5 g of anhydrous potassium carbonate were added to 25 mL of N,N-dimethylformamide and stirred to mix, then 12 g of 2-bromoethanol was added dropwise, and the mixture was stirred and reacted at 90° C. under nitrogen protection for 24 h, and the mixture was cooled to room temperature and filtered, and the filtrate was added to deionized water for precipitation. After vacuum filtration, the precipitate was freeze-dried to obtain an intermediate;

[0033] Step A2: 6 g of the intermediate was added to 20 mL of N,N-dimethylformamide and stirred to dissolve, then 40 mL of isopropanol and 0.1 mL of acetic acid were added and mixed evenly, and then exposed to ultraviolet light with a wavelength of 380 nm and a wavelength of 5 mW / cm 3 The reaction mixture was irradiated at an irradiation rate of 5 d, then poured into deionized water for precipitation, and purified by chromatography on a silica gel column eluted with petroleum ether and ethyl acetate in a volume ratio of 1:1 to obtain a reversible cross-linking agent.

[0034] Example 3

[0035] This embodiment provides a reversible cross-linking agent, which is prepared by the following steps:

[0036] Step A1, 8.6 g of 4,4"-dihydroxybenzophenone and 12 g of anhydrous potassium carbonate were added to 30 mL of N,N-dimethylformamide and stirred to mix, then 12.5 g of 2-bromoethanol was added dropwise, and the mixture was stirred and reacted at 90° C. under nitrogen protection for 24 h, and the mixture was cooled to room temperature and filtered, and the filtrate was added to deionized water for precipitation. After vacuum filtration, the precipitate was freeze-dried to obtain an intermediate;

[0037] Step A2: 6 g of the intermediate was added to 20 mL of N,N-dimethylformamide and stirred to dissolve, then 50 mL of isopropanol and 0.1 mL of acetic acid were added and mixed evenly, and then exposed to ultraviolet light with a wavelength of 395 nm and a wavelength of 4 mW / cm 3 The reaction was irradiated at an irradiation of 6 days, then poured into deionized water for precipitation, and purified by chromatography on a silica gel column eluted with petroleum ether and ethyl acetate in a volume ratio of 1:1 to obtain a reversible cross-linking agent.

[0038] Comparative Example 1

[0039] This comparative example provides a cross-linking agent, which does not contain carbon-carbon dynamic covalent bonds in its structure, and is prepared by the following steps:

[0040] 15.4 g of tetrakis(4-hydroxyphenyl)methane and 12 g of anhydrous potassium carbonate were added to 30 mL of N,N-dimethylformamide and stirred to mix. Then 22.5 g of 2-bromoethanol was added dropwise. The mixture was stirred and reacted at 90° C. under nitrogen protection for 24 h. The mixture was cooled to room temperature and filtered. The filtrate was added to deionized water for precipitation. After vacuum filtration, the precipitate was freeze-dried to obtain a cross-linking agent.

[0041] Comparative Example 2

[0042] Compared with Example 3, this comparative example does not perform the operation of step A1, and directly uses 4,4"-dihydroxybenzophenone as an intermediate for subsequent irradiation reaction, and the remaining raw materials and steps are the same.

[0043] Example 4

[0044] This embodiment provides a reversibly cross-linked polyurethane modifier, which is prepared by the following steps:

[0045] 10 g of polytetrahydrofuran with a molecular weight of 1800 g / mol was heated and melted at 100° C. and evacuated for 2 h. After cooling to 60° C., a mixed solution of 0.05 g of dibutyltin dilaurate and 100 mL of N,N-dimethylformamide was added dropwise, and then 1.8 g of hexamethylene diisocyanate was slowly added dropwise. After the addition was completed, the mixture was stirred and reacted at 60° C. for 4 h under nitrogen protection to obtain a prepolymer solution. 0.5 g of 4-(4'-hydroxyphenyl)-2,3-naphthylidene-1-one and 1.82 g of the reversible crosslinking agent prepared in Example 1 were added to the prepolymer solution, reacted at 45° C. for 18 h, and vacuum dried to obtain a reversible crosslinking polyurethane modifier.

[0046] Example 5

[0047] This embodiment provides a reversibly cross-linked polyurethane modifier, which is prepared by the following steps:

[0048] 10 g of polytetrahydrofuran with a molecular weight of 2000 g / mol was heated and melted at 100° C. and vacuumed for 2 h. After cooling to 60° C., a mixed solution of 0.05 g of dibutyltin dilaurate and 100 mL of N,N-dimethylformamide was added dropwise, and then 1.9 g of hexamethylene diisocyanate was slowly added dropwise. After the addition was completed, the mixture was stirred and reacted at 60° C. for 5 h under nitrogen protection to obtain a prepolymer solution. 0.8 g of 4-(4'-hydroxyphenyl)-2,3-naphthyridin-1-one and 2.6 g of the reversible crosslinking agent prepared in Example 2 were added to the prepolymer solution, reacted at 45° C. for 20 h, and vacuum dried to obtain a reversible crosslinking polyurethane modifier.

[0049] Example 6

[0050] This embodiment provides a reversibly cross-linked polyurethane modifier, which is prepared by the following steps:

[0051] 10 g of polytetrahydrofuran with a molecular weight of 2000 g / mol was heated and melted at 100° C. and evacuated for 2 h. After cooling to 60° C., a mixed solution of 0.05 g of dibutyltin dilaurate and 100 mL of N,N-dimethylformamide was added dropwise, and then 2 g of hexamethylene diisocyanate was slowly added dropwise. After the addition was completed, the mixture was stirred and reacted at 60° C. under nitrogen protection for 6 h to obtain a prepolymer solution. 1 g of 4-(4'-hydroxyphenyl)-2,3-naphthylidene-1-one and 3.03 g of the reversible crosslinking agent prepared in Example 3 were added to the prepolymer solution, reacted at 45° C. for 24 h, and vacuum dried to obtain a reversible crosslinking polyurethane modifier.

[0052] Comparative Example 3

[0053] This comparative example is different from Example 6 in that hydroquinone dihydroxyethyl ether is used as a chain extender to replace 4-(4'-hydroxyphenyl)-2,3-naphthyridin-1-one in equal amounts, and the remaining raw materials and steps are the same to obtain a polyurethane modifier.

[0054] Comparative Example 4

[0055] The difference between this comparative example and Example 6 is that the cross-linking agent prepared in Comparative Example 1 is used to replace the reversible cross-linking agent prepared in Example 3, and the remaining raw materials and steps are the same to obtain a polyurethane modifier.

[0056] Comparative Example 5

[0057] The difference between this comparative example and Example 6 is that the cross-linking agent prepared in Comparative Example 2 is used to replace the reversible cross-linking agent prepared in Example 3, and the remaining raw materials and steps are the same to obtain a polyurethane modifier.

[0058] Example 7

[0059] This embodiment provides a fast-dissolving high-viscosity modified asphalt based on reversible dynamic bonds, comprising the following raw materials in parts by weight: 100 parts of 70# base asphalt, 2 parts of the reversible cross-linked polyurethane modifier prepared in Example 4, and 1 part of a compatibilizer;

[0060] The instant high-viscosity modified asphalt based on reversible dynamic bonds is prepared by the following steps:

[0061] The base asphalt is heated to 130°C and melted and stirred. Then, the compatibilizer and reversibly cross-linked polyurethane modifier are added to the molten base asphalt. The temperature is maintained and sheared at a shear rate of 1500 rpm for 30 minutes. Then, it is placed in an oven at 50°C for curing for 6 hours. After cooling to room temperature, a quick-dissolving and highly viscous modified asphalt is obtained.

[0062] Example 8

[0063] This embodiment provides an instant high-viscosity modified asphalt based on reversible dynamic bonds, comprising the following raw materials in parts by weight: 100 parts of 70# base asphalt, 5 parts of the reversible cross-linked polyurethane modifier prepared in Example 5, and 1.5 parts of a compatibilizer;

[0064] The instant high-viscosity modified asphalt based on reversible dynamic bonds is prepared by the following steps:

[0065] The base asphalt is heated to 135°C and melted and stirred. Then, the compatibilizer and reversibly cross-linked polyurethane modifier are added to the molten base asphalt. The temperature is maintained and sheared at a shear rate of 1500 rpm for 30 minutes. Then, it is placed in an oven at 55°C for curing for 5 hours. After cooling to room temperature, a quick-dissolving and highly viscous modified asphalt is obtained.

[0066] Example 9

[0067] This embodiment provides a fast-dissolving high-viscosity modified asphalt based on reversible dynamic bonds, comprising the following raw materials in parts by weight: 100 parts of 70# base asphalt, 8 parts of the reversible cross-linked polyurethane modifier prepared in Example 6, and 2 parts of a compatibilizer;

[0068] The instant high-viscosity modified asphalt based on reversible dynamic bonds is prepared by the following steps:

[0069] The base asphalt is heated to 140°C and melted and stirred. Then, the compatibilizer and reversibly cross-linked polyurethane modifier are added to the molten base asphalt. The temperature is maintained and sheared at a shear rate of 1500 rpm for 30 minutes. Then, it is placed in an oven at 60°C for curing for 4 hours. After cooling to room temperature, a quick-dissolving and highly viscous modified asphalt is obtained.

[0070] Comparative Example 6

[0071] The difference between this comparative example and Example 9 is that the polyurethane modifier prepared in Comparative Example 3 is used to replace the reversibly cross-linked polyurethane modifier prepared in Example 6 in equal amount, and the other raw materials and steps are the same.

[0072] Comparative Example 7

[0073] The difference between this comparative example and Example 9 is that the polyurethane modifier prepared in Comparative Example 4 is used to replace the reversibly cross-linked polyurethane modifier prepared in Example 6 in equal amount, and the other raw materials and steps are the same.

[0074] Comparative Example 8

[0075] The difference between this comparative example and Example 9 is that the polyurethane modifier prepared in Comparative Example 5 is used to replace the reversibly cross-linked polyurethane modifier prepared in Example 6 in an equal amount, and the other raw materials and steps are the same.

[0076] The modified asphalts prepared in Examples 7 to 9 and Comparative Examples 6 to 8 were tested for performance according to the JTG E20-2011 test procedure. The results are shown in Table 1:

[0077] Table 1

[0078] Test items Example 7 Example 8 Example 9 Comparative Example 6 Comparative Example 7 Comparative Example 8 Needle penetration (25℃, 0.1mm) 46.1 45.7 44.3 56.2 45.5 44.1 Softening point(℃) 80.8 81.3 82.5 61.5 84.6 67.4 5℃ elongation (cm) 31.5 33.4 34.6 37.3 32.2 26.7 25℃ Viscosity(N·m) 27.7 28.2 29.8 22.4 25.5 21.9 60℃ dynamic viscosity (Pa·s) 163000 171000 178000 135000 146000 224000

[0079] It can be seen from the data in Table 1 that the modified asphalts prepared in Examples 7 to 9 have a smaller needle penetration, indicating that they have high strength, better anti-deformation ability, and are not prone to rutting under heavy loads; the modified asphalts prepared in Examples 7 to 9 have a higher softening point, excellent heat resistance, and are not easily deformed in a high-temperature service environment; the modified asphalts prepared in Examples 7 to 9 have higher ductility and viscosity, and have better strength and toughness; the modified asphalts prepared in Examples 7 to 9 have appropriate dynamic viscosity, which not only maintains excellent anti-rutting ability, but also does not affect the fluidity and processability of the modified asphalt.

[0080] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0081] While embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the invention, and the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A fast-dissolving high-viscosity modified asphalt based on reversible dynamic bonds, characterized in that: The method comprises the following raw materials in parts by weight: 100 parts of base asphalt, 2-8 parts of reversibly cross-linked polyurethane modifier, and 1-2 parts of compatibilizer; The reversibly cross-linked polyurethane modifier is prepared by the following steps: Heat polytetrahydrofuran at 100°C to melt and evacuate for 2 hours to remove moisture, cool to 60°C, add a mixed solution of dibutyltin dilaurate and N,N-dimethylformamide, and then slowly add hexamethylene diisocyanate. After the addition is completed, stir and react for 4-6 hours at 60°C under nitrogen protection to obtain a prepolymer solution; add a chain extender and a reversible crosslinking agent to the prepolymer solution, react at 45°C for 18-24 hours, and vacuum dry to obtain a reversible crosslinked polyurethane modifier.

2. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 1, characterized in that: The dosage ratio of the polytetrahydrofuran, dibutyltin dilaurate, N,N-dimethylformamide, hexamethylene diisocyanate, chain extender and reversible crosslinking agent is 10g: 0.05g: 100mL: 1.8-2g: 0.5-1g: 1.82-3.03g.

3. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 1, characterized in that: The molecular weight of the polytetrahydrofuran is 1800-2000 g / mol.

4. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 1, characterized in that: The chain extender is 4-(4'-hydroxyphenyl)-2,3-naphthyridine-1-one.

5. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 1, characterized in that: The reversible crosslinking agent is prepared by the following steps: Step A1, adding 4,4"-dihydroxybenzophenone and anhydrous potassium carbonate to N,N-dimethylformamide and stirring to mix, then adding 2-bromoethanol dropwise, stirring and reacting at 90°C under nitrogen protection for 24 hours, cooling to room temperature and filtering, adding the filtrate to deionized water for precipitation, vacuum filtering, and drying the precipitate to obtain an intermediate; Step A2: Add the intermediate to N,N-dimethylformamide and stir to dissolve, then add isopropanol and acetic acid and mix evenly, then expose to ultraviolet irradiation for reaction for 4-6 days, then pour into deionized water for precipitation, and after purification, obtain a reversible cross-linking agent.

6. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 5, characterized in that: The usage ratio of the 4,4"-dihydroxybenzophenone, anhydrous potassium carbonate, N,N-dimethylformamide and 2-bromoethanol is 8.5-8.6 g: 11-12 g: 20-30 mL: 11.3-12.5 g.

7. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 5, characterized in that: The usage ratio of the intermediate, N,N-dimethylformamide, isopropanol and acetic acid is 6g:20mL:30-50mL:0.1mL.

8. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 5, characterized in that: The wavelength of the ultraviolet light is 350-395nm, and the irradiance is 4-6mW / cm 3 .

9. The instant high-viscosity modified asphalt based on reversible dynamic bonds according to claim 1, characterized in that: The compatibilizer is octylphenol polyoxyethylene ether.

10. The method for preparing an instant high-viscosity modified asphalt based on a reversible dynamic bond according to claim 1, characterized in that: The method comprises the following steps: heating the base asphalt to 130-140°C for melting and stirring, then adding a compatibilizer and a reversibly cross-linked polyurethane modifier into the molten base asphalt, maintaining the temperature and performing shearing, and then curing at a temperature of 50-60°C for 4-6 hours, and cooling to room temperature to obtain a quick-dissolving high-viscosity modified asphalt.