Reinforced high polymer modified asphalt and preparation method thereof

Abstract

The invention discloses reinforced high polymer modified asphalt and a preparation method thereof, and relates to the technical field of modified asphalt. The reinforced high polymer modified asphalt is prepared from the following raw materials in parts by weight: 100 parts of matrix asphalt, 4 to 6 parts of SBS (Styrene Butadiene Styrene), 0.3 to 0.6 part of cross-linking agent, 2 to 3.5 parts of plasticizer, 1 to 3 parts of anti-aging agent and 1.5 to 3 parts of nano filler, the preparation method comprises the following steps: reacting 2-formylphenylboronic acid with methanol to generate a dimethyl 2-formylphenylboronic acid compound; the preparation method comprises the following steps: reacting a 2-formylphenylboronic acid dimethyl ester compound with 1-amino-1-dodecanol to generate a boric acid ester-imine long-chain compound; and reacting the borate-imine long-chain compound with 3-glycidyl ether oxypropyl trimethoxy silane to generate the plasticizer. The reinforced high polymer modified asphalt prepared by the invention has good interface adhesion, high and low temperature stability (high-temperature deformation resistance and low-temperature crack resistance) and self-repairing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of modified asphalt, and in particular to a reinforced polymer modified asphalt and a preparation method thereof. Background Art

[0002] In recent years, with the increasing demand for heavier traffic loads and long-life pavements, traditional base asphalt has struggled to meet the comprehensive performance requirements of high-temperature rutting resistance, low-temperature cracking resistance, and durability. Polymer-modified asphalt (such as SBS and SBR) introduces an elastomeric network through physical blending. While this significantly improves the asphalt's high- and low-temperature performance, it still faces challenges in practical applications, such as high-temperature deformation resistance, low-temperature cracking resistance, insufficient interfacial adhesion, and a lack of self-healing capabilities. First, to improve construction and workability, the industry generally adds traditional plasticizers such as mineral oil and phthalates. However, these plasticizers only weaken the intermolecular forces of asphaltene through molecular lubrication. Over time, these plasticizers are prone to migration, volatilization, or exudation, resulting in increased asphalt stiffness modulus and low-temperature embrittlement. Second, interfacial bonding between asphalt and aggregate is crucial for pavement structural stability. However, in existing modified systems, the bond between SBS and aggregate relies primarily on van der Waals forces and physical adsorption, making interfacial debonding prone to water erosion or freeze-thaw cycles. Furthermore, asphalt pavements inevitably develop microcracks during use. Traditional modified asphalt lacks a self-healing mechanism, making crack propagation prone to fatigue failure. While existing dynamic covalent bond modifications (such as disulfide bonds) can achieve reversible crosslinking, they require temperatures above 80°C, far exceeding the pavement's temperature, and can easily lead to "too soft at high temperatures" or "too hard at low temperatures." These issues severely limit the practical application of polymer-modified asphalt.

[0003] The Chinese invention patent with publication number CN107383904A discloses a polymer-modified asphalt, its preparation method, and a polymer-modified asphalt waterproofing membrane. The polymer-modified asphalt is made from raw materials containing the following components: 60-65 parts of petroleum asphalt, 12-14 parts of SBS, 2-4 parts of SEBS, 2-4 parts of SIS, 2-4 parts of a cross-linking agent, 2-4 parts of an anti-aging agent, and 7-20 parts of an inorganic filler. The polymer asphalt waterproofing membrane of this invention meets the heat resistance requirements at 120°C and does not break at low temperatures of -50°C. It has excellent waterproof performance, but its interfacial adhesion is poor and it lacks self-repairing ability. Therefore, the development of a new modification system that combines high and low temperature stability, strong interfacial adhesion, and self-repairing functions has become a research hotspot in the field of road materials. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a reinforced polymer modified asphalt and a preparation method thereof.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions: A reinforced polymer modified asphalt comprising the following raw materials in parts by weight: Base asphalt: 100 parts; SBS: 4-6 servings; Cross-linking agent: 0.3-0.6 parts; Plasticizer: 2-3.5 parts; Anti-aging agent: 1-3 parts; Nanofiller: 1.5-3 parts; The plasticizer is firstly prepared by reacting 2-formylphenylboronic acid with methanol to obtain 2-formylphenylboronic acid dimethyl ester compound, then introducing 1-amino-1-dodecanol to generate borate-imine long-chain compound, and then adding 3-glycidyloxypropyltrimethoxysilane to react to obtain the plasticizer.

[0006] The plasticizer is prepared by the following method: S1: Under nitrogen protection, 2-formylphenylboronic acid and methanol were mixed evenly, and 98% concentrated H2SO4 was added dropwise. The mixture was reacted for 6-8 hours, and post-treated to obtain dimethyl 2-formylphenylboronic acid; S2: Under nitrogen protection, dimethyl 2-formylphenylboronate, 1-amino-1-dodecanol, and anhydrous ethanol are mixed and reacted for 4-5 hours, followed by post-treatment to generate a borate-imine long-chain compound; S3: Under nitrogen protection, mix the borate-imine long-chain compound with anhydrous THF, add 3-glycidyloxypropyltrimethoxysilane, add boron trifluoride ether complex dropwise in an ice bath, react for 6-7 hours, add triethylamine dropwise, and post-treat to obtain a plasticizer.

[0007] In step S1, the molar ratio of 2-formaldehyde phenylboronic acid to methanol is 1:(5-10).

[0008] In step S2, the molar ratio of the dimethyl 2-formaldehyde phenylboronic acid compound to 1-amino-1-dodecanol is 1:(1.1-1.2).

[0009] In step S3, the molar ratio of the borate-imide long-chain compound to 3-glycidyloxypropyltrimethoxysilane is 1:(1.05-1.1).

[0010] The matrix asphalt is AH-70 road petroleum asphalt; the cross-linking agent is sulfur; the anti-aging agent is one of 2,2'-methylenebis(4-methyl-6-tert-butylphenol) and 4,4'-thiobis(6-tert-butyl-3-methylphenol); and the nanofiller is one of nano titanium dioxide and graphene oxide.

[0011] A method for preparing a reinforced polymer modified asphalt comprises the following steps: (1) Weigh by weight: 100 parts of base asphalt, 4-6 parts of SBS, 0.3-0.6 parts of crosslinking agent, 2-3.5 parts of plasticizer, 1-3 parts of anti-aging agent, and 1.5-3 parts of nanofiller; (2) Add the matrix asphalt into the reactor, heat it to 150-160℃, add SBS while stirring, and shear at high speed for 40-60min; then add plasticizer, nanofiller, crosslinker and anti-aging agent, stir for 2-3h, cool to room temperature, stir at low speed for 1h, and obtain reinforced polymer modified asphalt after full homogenization.

[0012] Due to the adoption of the above technical solution, the beneficial effects of the present invention include: (1) The borate-imide five-membered ring ligand structure in the plasticizer prepared by the present invention acts on the crosslinking points of the asphalt network, and the structure can undergo reversible breakage or reorganization at low and high temperatures. At low temperatures, the BN bond breaks, and the long-chain alkyl group inserts into the asphalt layer, lowering the glass transition temperature and improving low-temperature ductility. At high temperatures, the BN bond reorganizes to form a dynamic crosslinking network that interpenetrates with the SBS polymer, inhibiting permanent deformation and improving the high-temperature rutting resistance of the asphalt. The BN coordination bond can be re-coordinated under thermal or mechanical stimulation, achieving autonomous healing of microcracks, realizing the self-repairing performance of the asphalt, and extending the service life of the pavement.

[0013] (2) The long-chain alkyl groups in the plasticizer prepared by the present invention can reduce the viscosity of asphalt, making it easier to apply at high temperatures. The long-chain alkyl groups strengthen the structure of asphalt through the interaction between the asphalt molecules, making it more stable at high temperatures and reducing rutting deformation. The siloxane structure acts on the aggregate surface, enhancing the interfacial bonding strength between the asphalt and the filler, thereby improving the interfacial bonding performance of the asphalt. DETAILED DESCRIPTION

[0014] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to these embodiments.

[0015] Example 1 Preparation of plasticizer: S1: 0.1 mol of 2-formylphenylboronic acid and 0.5 mol of anhydrous methanol were added to a reaction flask in sequence, stirred, and 1 ml of 98% concentrated H2SO4 was slowly added dropwise for 10 min. Under nitrogen protection, the temperature was raised to reflux, and the reaction was stirred for 6 h (water was removed using a water separator during the reaction). The mixture was cooled to room temperature and slowly poured into 50 ml of saturated sodium bicarbonate solution. The mixture was extracted with 100 ml of ethyl acetate, washed with 60 ml of deionized water and 30 ml of saturated sodium chloride solution in sequence, dried over 15 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 50 ° C for 2 h, and dried under vacuum at 60 ° C for 3 h to obtain 2-formylphenylboronic acid dimethyl ester. The reaction equation is as follows:

[0016] Its H-NMR spectrum data are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 9.54 (s, 1H), 7.75-7.70 (m, 1H), 7.45 (dd, J = 7.3, 2.1 Hz, 1H), 7.33-7.26 (m, 1H), 7.09 (td, J = 7.6, 2.1 Hz,1H), 3.57 (s, 6H).

[0017] S2: In a reaction flask, add 180 ml of anhydrous ethanol, 0.1 mol of 2-formylphenylboronic acid dimethyl ester compound and 0.11 mol of 1-amino-1-dodecanol (CAS: 40899-01-2), stir, add 0.6 ml of glacial acetic acid dropwise, protect with nitrogen, heat and reflux, stir and react for 4 hours, evaporate at 50°C for 40 minutes, dissolve the residue in 30 ml of dichloromethane, wash with 20 ml of saturated sodium bicarbonate solution, 20 ml of deionized water, and 10 ml of saturated sodium chloride solution in sequence, dry with 15 g of anhydrous magnesium sulfate, filter to remove the desiccant, evaporate at 50°C for 1 hour, and purify by silica gel column chromatography to obtain a borate-imine long-chain compound; the reaction equation is as follows:

[0018] Its H-NMR spectrum data are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 7.87 (s, 1H), 7.37-7.32 (m, 1H), 7.25-7.16 (m, 2H), 7.09 (td, J = 7.1, 2.7 Hz, 1H), 5.21 (d, J = 5.2 Hz, 1H), 4.61 (d, J = 5.2 Hz, 1H), 3.57 (s, 6H), 1.91 (d, J = 12.8 Hz, 1H), 1.79 (d, J= 12.3 Hz, 1H), 1.44 (d, J = 12.8 Hz, 1H), 1.40-1.31 (m, 3H), 1.33-1.25 (m,14H), 0.89 (s, 3H).

[0019] S3: During the reaction, add 0.1 mol of a long-chain borate-imide compound and 250 ml of anhydrous THF, protect with nitrogen, stir for 10 minutes, slowly add 0.105 mol of 3-glycidyloxypropyltrimethoxysilane, and stir for 15 minutes. Under an ice bath, add 0.005 mol of boron trifluoride ether complex dropwise over 10 minutes. After the reaction is complete for 6 hours, slowly add 0.01 mol of triethylamine dropwise, stir for 10 minutes, and remove THF by rotary evaporation at 40°C for 1 hour. Dissolve the residue in 30 ml of dichloromethane and purify by silica gel column chromatography to obtain a plasticizer. The reaction equation is shown below:

[0020] Its H-NMR spectrum data are as follows: 1 H NMR (500 MHz, Chloroform-d) δ 7.83 (s, 1H), 7.37-7.32 (m, 1H), 7.25-7.16 (m, 2H), 7.12-7.05 (m, 1H), 4.78 (s, 1H), 3.96 (d, J = 5.2 Hz, 1H), 3.75-3.69 (m, 2H), 3.62 (d, J = 12.3 Hz, 1H), 3.57 (d, J = 3.8 Hz, 16H), 3.47(d, J = 12.8 Hz, 1H), 3.42 (dd, J = 12.3, 5.2 Hz, 2H), 1.96 (d, J = 12.3 Hz,1H), 1.89 (d, J = 12.3 Hz, 1H), 1.72 (d, J = 12.3 Hz, 1H), 1.60 (d, J = 12.3Hz, 1H), 1.49-1.39 (m, 2H), 1.36 (s, 2H), 1.33-1.25 (m, 14H), 1.09 (d, J =12.3 Hz, 1H), 1.00 (d, J = 12.3 Hz, 1H), 0.89 (s, 3H).

[0021] Example 2 Preparation of plasticizer: S1: 0.1 mol of 2-formylphenylboronic acid and 0.75 mol of anhydrous methanol were added to a reaction flask in sequence, and the mixture was stirred. 1 ml of 98% concentrated H2SO4 was slowly added dropwise over 10 min. The mixture was protected by nitrogen and heated to reflux. The mixture was stirred and reacted for 7 h (water was removed using a water separator during the reaction). The mixture was cooled to room temperature and slowly poured into 50 ml of saturated sodium bicarbonate solution. The mixture was extracted with 100 ml of ethyl acetate, and the mixture was washed with 60 ml of deionized water and 30 ml of saturated sodium chloride solution in sequence. The mixture was dried over 15 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 50 °C for 2 h. The mixture was then dried under vacuum at 60 °C for 3 h to obtain dimethyl 2-formylphenylboronic acid. S2: In a reaction flask, add 200 ml of anhydrous ethanol, 0.1 mol of 2-formylphenylboronic acid dimethyl ester compound and 0.115 mol of 1-amino-1-dodecanol, stir, add 0.6 ml of glacial acetic acid dropwise, protect with nitrogen, heat and reflux, react with stirring for 4.5 hours, and evaporate at 50°C for 40 minutes. Dissolve the residue with 30 ml of dichloromethane, wash with 20 ml of saturated sodium bicarbonate solution, 20 ml of deionized water, and 10 ml of saturated sodium chloride solution in sequence, dry with 15 g of anhydrous magnesium sulfate, filter to remove the desiccant, evaporate at 50°C for 1 hour, and purify by silica gel column chromatography to obtain a borate-imine long-chain compound; S3: During the reaction, add 0.1 mol of a long-chain borate-imine compound and 300 ml of anhydrous THF under nitrogen protection and stir for 10 minutes. Slowly add 0.108 mol of 3-glycidyloxypropyltrimethoxysilane and stir for 15 minutes. Under an ice bath, add 0.005 mol of boron trifluoride ether complex dropwise over 10 minutes. After 7 hours of reaction, slowly add 0.01 mol of triethylamine dropwise and stir for 10 minutes. Remove THF by rotary evaporation at 45°C for 1 hour. Dissolve the residue in 30 ml of dichloromethane and purify by silica gel column chromatography to obtain a plasticizer.

[0022] Example 3 Preparation of plasticizer: S1: 0.1 mol of 2-formylphenylboronic acid and 1 mol of anhydrous methanol were added to a reaction flask in sequence, and the mixture was stirred. 1 ml of 98% concentrated H2SO4 was slowly added dropwise over 10 min. The mixture was protected by nitrogen and heated to reflux. The mixture was stirred and reacted for 8 h (water was removed using a water separator during the reaction). The mixture was cooled to room temperature and slowly poured into 50 ml of saturated sodium bicarbonate solution. The mixture was extracted with 100 ml of ethyl acetate, and the mixture was washed with 60 ml of deionized water and 30 ml of saturated sodium chloride solution in sequence. The mixture was dried over 15 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 50 °C for 2 h. The mixture was then dried under vacuum at 60 °C for 3 h to obtain dimethyl 2-formylphenylboronic acid. S2: In a reaction flask, add 200 ml of anhydrous ethanol, 0.1 mol of 2-formylphenylboronic acid dimethyl ester compound and 0.12 mol of 1-amino-1-dodecanol, stir, add 0.6 ml of glacial acetic acid dropwise, protect with nitrogen, heat and reflux, stir and react for 5 h, evaporate at 50°C for 60 min, dissolve the residue with 30 ml of dichloromethane, wash with 20 ml of saturated sodium bicarbonate solution, 20 ml of deionized water, and 10 ml of saturated sodium chloride solution in sequence, dry with 15 g of anhydrous magnesium sulfate, filter to remove the desiccant, evaporate at 50°C for 1 h, and purify by silica gel column chromatography to obtain a borate-imine long-chain compound; S3: During the reaction, 0.1 mol of a long-chain borate-imine compound and 300 ml of anhydrous THF were added under nitrogen protection and stirred for 10 minutes. 0.11 mol of 3-glycidyloxypropyltrimethoxysilane was slowly added and stirred for 15 minutes. Under an ice bath, 0.005 mol of boron trifluoride ether complex was added dropwise over 10 minutes. After 7 hours of reaction, 0.01 mol of triethylamine was slowly added dropwise and stirred for 10 minutes. The THF was removed by rotary evaporation at 45°C for 1 hour. The residue was dissolved in 30 ml of dichloromethane and purified by silica gel column chromatography to obtain a plasticizer.

[0023] Example 4 Preparation of reinforced polymer modified asphalt: (1) Weigh by weight: 1000 g of base asphalt (AH-70 road petroleum asphalt), 40 g of SBS, 3 g of crosslinking agent (sulfur), 20 g of plasticizer (prepared in Example 1), 10 g of anti-aging agent (2,2'-methylenebis(4-methyl-6-tert-butylphenol)), and 15 g of nanofiller (nano-titanium dioxide); (2) Add the matrix asphalt into the reactor, heat it to 150°C, add SBS while stirring at 1000 rpm, and high-speed shear at 3000 rpm for 60 min; then add plasticizer, nanofiller, crosslinker and anti-aging agent, stir for 3 h, cool to room temperature, stir at a low speed of 300 rpm for 1 h, and obtain reinforced polymer modified asphalt after full homogenization.

[0024] Example 5 Preparation of reinforced polymer modified asphalt: (1) Weigh by weight: 1000 g of base asphalt (AH-70 road petroleum asphalt), 50 g of SBS, 4 g of crosslinking agent (sulfur), 30 g of plasticizer (prepared in Example 2), 20 g of anti-aging agent (4,4'-thiobis(6-tert-butyl-3-methylphenol)), and 20 g of nanofiller (graphene oxide); (2) Add the matrix asphalt into the reactor and heat it to 155°C. Add SBS while stirring at 1000 rpm and high-speed shear at 3000 rpm for 50 min. Then add plasticizer, nanofiller, crosslinker and anti-aging agent, stir for 2.5 h, cool to room temperature, stir at a low speed of 300 rpm for 1 h, and obtain reinforced polymer modified asphalt after full homogenization.

[0025] Example 6 Preparation of reinforced polymer modified asphalt: (1) Weigh by weight: 1000 g of base asphalt (AH-70 road petroleum asphalt), 60 g of SBS, 6 g of crosslinking agent (sulfur), 35 g of plasticizer (prepared in Example 3), 30 g of anti-aging agent (2,2'-methylenebis(4-methyl-6-tert-butylphenol)), and 30 g of nanofiller (graphene oxide); (2) Add the matrix asphalt into the reactor, heat it to 160°C, add SBS while stirring at 1000 rpm, and high-speed shear at 3000 rpm for 40 minutes; then add plasticizer, nanofiller, crosslinker and anti-aging agent, stir for 2 hours, cool to room temperature, stir at a low speed of 300 rpm for 1 hour, and obtain reinforced polymer modified asphalt after sufficient homogenization.

[0026] Comparative Example 1 The raw material composition and process of the reinforced polymer modified asphalt are basically the same as those in Example 5, except that no modified plasticizer is added to the composition.

[0027] Comparative Example 2 The raw material composition and process of the reinforced polymer modified asphalt are basically the same as those in Example 5, except that the plasticizer is replaced by an equal weight of a plasticizer prepared by the following method: The preparation method of the plasticizer is basically the same as that of Example 2, except that the 2-formylphenylboronic acid in step S1 is replaced by an equal weight of 2-carboxybenzaldehyde.

[0028] Comparative Example 3 The raw material composition and process of the reinforced polymer modified asphalt are basically the same as those in Example 5, except that the plasticizer is replaced by an equal weight of a plasticizer prepared by the following method: The preparation method of the plasticizer is basically the same as that of Example 2, except that the 1-amino-1-dodecanol in step S2 is replaced by an equal weight of 2-aminocyclohexanol.

[0029] Comparative Example 4 The raw material composition and process of the reinforced polymer modified asphalt are basically the same as those in Example 5, except that the plasticizer is replaced by an equal weight of a plasticizer prepared by the following method: The preparation method of the plasticizer is basically the same as that of Example 2, except that the 1-amino-1-dodecanol in step S2 is replaced by an equal weight of 1-amino-2-pentanol.

[0030] Comparative Example 5 The raw material composition and process of the reinforced polymer modified asphalt are basically the same as those in Example 5, except that the plasticizer is replaced by an equal weight of a plasticizer prepared by the following method: The preparation method of the plasticizer is basically the same as that of Example 2, except that the 1-amino-1-dodecanol in step S2 is replaced by an equal weight of 2-aminooctadecane-1,3-diol.

[0031] Comparative Example 6 The raw material composition and process of the reinforced polymer modified asphalt are basically the same as those in Example 5, except that the plasticizer is replaced by an equal weight of a plasticizer prepared by the following method: The preparation method of the plasticizer is basically the same as that of Example 2, except that the 3-glycidyloxypropyltrimethoxysilane in step S3 is replaced by an equal weight of 3-glycidyloxypropyldimethylmethoxysilane.

[0032] The nanosilica used in the examples and comparative examples of this application was rutile silica with a particle size uniformly distributed between 5 and 50 nm, purchased from Shanghai Yuanye Biotechnology Co., Ltd.; the graphene oxide was SE243EW graphene oxide dispersion with a solid content of 42 wt%, purchased from Changzhou Sixth Element Materials Technology Co., Ltd.; the sulfur was S-80 type special sulfur powder with a mesh size of 400, purchased from Qingdao Luchuan Chemical Co., Ltd.; and the SBS was YH-791 linear SBS, purchased from Changsha Shenli Chemical Technology Co., Ltd.

[0033] The interfacial adhesion test of asphalt was conducted according to the standards in T / CECS G:D54-01-2020. The asphalt was first heated to prepare a smooth film 1-2 mm thick. Three standard liquids—distilled water, formamide, and ethylene glycol—were selected and the contact angles of the liquids on the asphalt film surface were measured using the sitting drop method on a contact angle meter. Five parallel tests were performed for each liquid and the average value was taken. Basalt aggregate was also selected, crushed, cleaned, and pressed into thin sheets. The contact angles of the aforementioned liquids on the aggregate surface were measured using the same method. The OWRK method was then used to calculate the dispersive and polar components of the surface free energy between the asphalt and the aggregate. Finally, the work of adhesion was calculated to evaluate the interfacial adhesion between the asphalt and the aggregate. The test results are shown in Table 1.

[0034] Asphalt high- and low-temperature performance testing was conducted according to the standards in JTG E20-2011, including high-temperature dynamic shear rheology testing (T 0628-2011) and low-temperature bond strength testing. Complex shear modulus and bond strength parameters were used as indicators to evaluate high-temperature deformation resistance and low-temperature crack resistance. The test results are shown in Table 1.

[0035] The self-healing performance test of asphalt was conducted according to the pull-out test method specified in GB / T 32989-2016. The reinforced polymer-modified asphalt prepared in the Examples or Comparative Examples was first heated and poured onto the surface of an aggregate specimen to form an approximately 1 mm thick asphalt film. An initial pull-out test was performed using a pull-out apparatus at a rate of 5 mm / min. The maximum pull-out force was recorded, and the initial bond strength (σ0) was calculated. The broken asphalt-aggregate specimens were then reattached, ensuring cross-sectional alignment. The specimens were then placed in a 60°C oven for 3 hours, cooled to room temperature, and subjected to another pull-out test to determine the repaired bond strength (σ1). The self-healing efficiency (H) was calculated as σ1 / σ0 × 100% to evaluate the self-healing ability of the reinforced polymer-modified asphalt. The test results are shown in Table 1.

[0036] Table 1 Performance indicators of polymer modified asphalt

[0037] As can be seen from Table 1, the reinforced polymer modified asphalt prepared in Examples 4-6 of the present application has excellent interfacial adhesion, high and low temperature stability (high temperature deformation resistance and low temperature crack resistance) and self-repairing properties. This is because the siloxane group introduced into the plasticizer prepared in the present application is the key to improving interfacial adhesion performance. The trimethoxysilyl group at its end can be hydrolyzed to form silanol groups when exposed to water or high temperature during the asphalt construction process, and condenses with the hydroxyl groups or metal oxides on the aggregate surface to form Si-O-aggregate covalent bonds with larger bond energy, thereby achieving chemical anchoring of the asphalt and the aggregate, and solving the problem of weak bonding of traditional modified asphalt relying solely on van der Waals forces. At the same time, the boron atoms and nitrogen atoms in the introduced borate-imine five-membered ring ligand are both polar, and can form hydrogen bonds or dipole-dipole interactions with the polar sites on the aggregate surface, assisting the chemical anchoring of the siloxane group and further enhancing interfacial interactions. The introduced long-chain alkyl groups can penetrate into the micropores on the aggregate surface, increasing the contact area between the asphalt and the aggregate. Furthermore, the hydrophobic effect of the alkyl groups repels water, reducing water erosion at the interface. This, in synergistically with the chemical anchoring of the siloxane groups, enhances the durability of the interfacial bond. Furthermore, the BN coordination bonds within the five-membered borate-imide ring are dynamically reversible. After rupture, these coordination bonds can restructure and interpenetrate with the physical crosslinking network of the SBS polymer, forming a dynamic-physical dual crosslinking structure that significantly improves the complex shear modulus and anti-rutting factor of the asphalt. Furthermore, the molecular entanglement of the long-chain alkyl groups inhibits the sliding of asphaltene molecules, further enhancing high-temperature deformation resistance. They also insert into the asphaltene lamellar structure, weakening the π-π stacking and hydrogen bonding between asphaltene molecules, lowering the asphalt's glass transition temperature and increasing its ductility at low temperatures. Furthermore, the borate-imide ring ruptures at low temperatures, releasing thermal stress within the asphalt, preventing crack initiation and propagation and enhancing low-temperature crack resistance. The borate-imide five-membered ring in the plasticizer is the core functional group for self-repair, while the long-chain alkyl and siloxane groups synergistically enhance the self-repairing ability. The borate-imide ring is dynamically reversible. When the asphalt is mechanically damaged, the BN coordination bonds in the five-membered ring break, releasing the stress in the molecular chain. Under thermal stimulation or mechanical stress, the broken BN bonds realign, connecting the molecular chains on both sides of the crack and closing the crack. This reversibility enables asphalt self-repair. At the same time, the flexibility and hydrophobic effect of the long-chain alkyl groups promote the diffusion of asphalt molecules into the cracked area, accelerating the reorganization of the BN bonds and shortening the repair time. The chemical anchoring of the siloxane group to the aggregate maintains the bond strength of the repaired interface, preventing the crack from reoccurring in the same location and improving the durability of the self-repair.

[0038] The performance indicators of the reinforced polymer-modified asphalts prepared in Comparative Examples 1-6 were inferior to those in the Examples, further demonstrating the excellent effectiveness of the plasticizer prepared in this application in reinforced polymer-modified asphalt. The main reason for the significant reduction in self-healing ability in Comparative Examples 1 and 2 is that the borate-imide five-membered ring structure cannot be formed, which lacks the conditions for achieving dynamic reversibility. Comparative Examples 3-5 replace 1-amino-1-dodecanol with 2-aminocyclohexanol without a long-chain structure, 1-amino-2-pentanol with a shorter chain, and 2-aminooctadecane-1,3-diol with a longer chain. The high and low temperature performance of these two examples are worse than those of the examples. This is because 2-aminocyclohexanol has no long-chain alkyl group and cannot be inserted into the asphalt layer, so the intermolecular force of the asphalt is not weakened; the alkyl chain of 1-amino-2-pentanol is too short, and the depth of insertion into the asphalt layer is limited, so the effect of weakening the intermolecular force is weak; the long chain of 2-aminooctadecane-1,3-diol is too hydrophobic, and the high polarity of the dihydroxy group is not compatible with the weak polarity system of asphalt, which makes phase separation prone to occur, resulting in poor performance. The reinforced polymer modified asphalt prepared in Comparative Example 6 has poorer interfacial bonding performance than that prepared in Example 6, mainly because the hydrolysis sites of 3-glycidyloxypropyldimethylmethoxysilane are reduced, the steric hindrance is increased, and a cross-linked network cannot be formed, resulting in a dual weakening of chemical anchoring and physical effects, and a significant decrease in interfacial bonding performance.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. However, any equivalent changes, modifications and evolutions made by ordinary technicians in this field without departing from the scope of the technical solution of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A reinforced polymer modified asphalt, characterized in that: The composition comprises the following raw materials in parts by weight: Base asphalt: 100 parts; SBS: 4-6 servings; Cross-linking agent: 0.3-0.6 parts; Plasticizer: 2-3.5 parts; Anti-aging agent: 1-3 parts; Nanofiller: 1.5-3 parts; The plasticizer is firstly prepared by reacting 2-formylphenylboronic acid with methanol to obtain 2-formylphenylboronic acid dimethyl ester compound, then introducing 1-amino-1-dodecanol to generate borate-imine long-chain compound, and then adding 3-glycidyloxypropyltrimethoxysilane to react to obtain the plasticizer.

2. The reinforced polymer modified asphalt according to claim 1, characterized in that: The plasticizer is prepared by the following method: S1: Under nitrogen protection, 2-formylphenylboronic acid and methanol were mixed evenly, and 98% concentrated H2SO4 was added dropwise. The mixture was reacted for 6-8 hours, and post-treated to obtain dimethyl 2-formylphenylboronic acid; S2: Under nitrogen protection, dimethyl 2-formylphenylboronate, 1-amino-1-dodecanol, and anhydrous ethanol are mixed and reacted for 4-5 hours, followed by post-treatment to generate a borate-imine long-chain compound; S3: Under nitrogen protection, mix the borate-imine long-chain compound with anhydrous THF, add 3-glycidyloxypropyltrimethoxysilane, add boron trifluoride ether complex dropwise in an ice bath, react for 6-7 hours, add triethylamine dropwise, and post-treat to obtain a plasticizer.

3. The reinforced polymer modified asphalt according to claim 2, characterized in that: In step S1, the molar ratio of 2-formaldehyde phenylboronic acid to methanol is 1:(5-10).

4. The reinforced polymer modified asphalt according to claim 2, characterized in that: In step S2, the molar ratio of the dimethyl 2-formaldehyde phenylboronic acid compound to 1-amino-1-dodecanol is 1:(1.1-1.2).

5. The reinforced polymer modified asphalt according to claim 2, characterized in that: In step S3, the molar ratio of the borate-imide long-chain compound to 3-glycidyloxypropyltrimethoxysilane is 1:(1.05-1.1).

6. The reinforced polymer modified asphalt according to claim 1, characterized in that: The matrix asphalt is AH-70 road petroleum asphalt.

7. The reinforced polymer modified asphalt according to claim 1, characterized in that: The cross-linking agent is sulfur.

8. The reinforced polymer modified asphalt according to claim 1, characterized in that: The anti-aging agent is one of 2,2'-methylenebis(4-methyl-6-tert-butylphenol) and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

9. The reinforced polymer modified asphalt according to claim 1, characterized in that: The nano filler is one of nano titanium dioxide and graphene oxide.

10. A method for preparing the reinforced polymer modified asphalt according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Weigh by weight: 100 parts of base asphalt, 4-6 parts of SBS, 0.3-0.6 parts of crosslinking agent, 2-3.5 parts of plasticizer, 1-3 parts of anti-aging agent, and 1.5-3 parts of nanofiller; (2) Add the matrix asphalt into the reactor, heat it to 150-160℃, add SBS while stirring, and shear at high speed for 40-60min; then add plasticizer, nanofiller, crosslinker and anti-aging agent, stir for 2-3h, cool to room temperature, stir at low speed for 1h, and obtain reinforced polymer modified asphalt after full homogenization.

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