Three-step method environment-friendly SBS modified asphalt regenerant as well as preparation method and application thereof

Abstract

The invention relates to a preparation method and application of a three-step method environment-friendly SBS modified asphalt regenerant, and the regenerant is composed of modified bio-oil, functionalized desulfurized rubber, a solubilizer, an anti-oxidation aging agent, an anti-light aging agent, a multi-sulfydryl chain reconstruction auxiliary agent, a reversible thioether cross-linking agent and other components. The matrix and polymer network structure of the aged SBS modified asphalt is repaired through light oil supplement and chemical reaction. The preparation method comprises the following steps: introducing a polar functional group into ultrasonic transesterification modified bio-oil to improve wettability; the surface activity of the desulfurized rubber is improved through plasma low-temperature treatment; high-speed shearing and closed-loop control reaction are combined to realize rubber particle dispersion and network reconstruction; chemical crosslinking and aging regeneration are realized through cooperation of specific components. The prepared regenerant is doped into aged SBS modified asphalt at the temperature of 145-165 DEG C according to the proportion of 4-20 wt% to prepare regenerated asphalt.

Description

Technical Field

[0001] The invention belongs to the technical field of road asphalt material regeneration, and particularly relates to a three-step environmentally friendly SBS modified asphalt regeneration agent and a preparation method and application thereof. Background Art

[0002] Asphalt pavement regeneration technology is an effective means of reusing waste pavement milling materials. The choice of regeneration agent directly impacts the final regeneration results. Currently, most commercially available regeneration agents are chemically synthesized materials based on petroleum products. While these agents have a good effect on restoring aged asphalt, they inevitably lead to resource depletion and environmental pollution. With growing environmental awareness and the demand for sustainable resource utilization, the development of green regeneration agents based on renewable resources and waste materials has become a new research direction.

[0003] Vegetable oils such as epoxidized soybean oil and rapeseed oil are renewable and biodegradable, which to a certain extent improve the environmental issues of traditional mineral oil-based regeneration agents. However, the chemical structure of vegetable oil molecules is relatively simple. Although they can supplement the missing light oil in asphalt, they cannot deeply repair the molecular structure fractures and cross-linking of aged asphalt, resulting in limited regeneration effects. High molecular polymer regeneration agents can improve the elasticity and crack resistance of regenerated asphalt, but their compatibility with the asphalt matrix is ​​often a problem. Since high molecular polymers are not easy to mix evenly with asphalt, regeneration agents are prone to uneven dispersion or separation in asphalt, resulting in unstable regeneration effects. In addition, these polymer materials are mostly synthetic materials, and the production process involves a large number of chemical synthesis steps, which brings environmental burdens, and the high material cost limits their widespread application. Summary of the Invention

[0004] In response to the problems in the prior art of plant oil-based regeneration agents, which have strong lubrication properties but weak structural reconstruction capabilities, and high-molecular polymer-based regeneration agents, which have poor compatibility with aged SBS and are complex to prepare, the present invention provides a three-step environmentally friendly SBS modified asphalt regeneration agent, its preparation method, and application. The present invention uses ultrasonic transesterification-modified bio-oil and low-temperature plasma functionalized desulfurized rubber as basic raw materials, introduces a polythiol chain reconstruction aid and a reversible sulfide dynamic crosslinker, and cooperates with an antioxidant and an anti-light aging agent to jointly construct a regeneration agent system; the regeneration agent adopts a three-step method to gradually strengthen the dispersion, reaction, and stabilization processes. The preparation process is simple, controllable, low-energy, and environmentally friendly. The resulting product can achieve efficient regeneration of SBS modified asphalt from various sources and different degrees of aging, significantly improving the mechanical properties and polymer network structure reconstruction capabilities of the regenerated asphalt, effectively inhibiting secondary aging, improving its high-temperature rutting resistance and low-temperature cracking resistance, and solving the problem of insufficient durability of traditional regenerated asphalt.

[0005] The technical solutions of the present invention are as follows: A three-step environmentally friendly SBS modified asphalt regeneration agent, and its preparation method and application.

[0006] The regeneration agent is composed of the following components by weight: 50-70 parts of bio-oil, 40-60 parts of devulcanized rubber, 3-9 parts of solubilizer, 1-2 parts of antioxidant, 1-2 parts of anti-light aging agent, 0.5-5 parts of polythiol chain reconstruction auxiliary agent and 0.5-3 parts of reversible thioether dynamic crosslinking agent; The bio-oil is selected from one or a combination of soybean oil, rapeseed oil, palm oil, kitchen waste oil, and their derivatives; preferably, bio-based functional oil modified by ultrasonic transesterification (500W, 20kHz, 60°C, 30min) is used, which has good polar group introduction ability, significantly improves wettability and dispersibility, and provides a stable foundation for the regeneration system; The devulcanized rubber is derived from one or more of natural rubber, styrene-butadiene rubber, butadiene rubber, chloroprene rubber or nitrile rubber, with a desulfurization rate of ≥50%. It is functionalized using low-temperature radio frequency plasma (power 100W, pressure 200Pa, temperature ≤60°C, time 20min) to introduce polar functional groups such as hydroxyl, carboxyl and amine groups on its surface to enhance interfacial affinity with bio-oil and cross-linking agents.

[0007] The present invention constructs a regeneration agent system through a three-step process of "wetting-dispersion-stabilization": During the wetting stage, the polar groups in the bio-oil wrap around the surface of the devulcanized rubber, destroying the original interface structure between the particles and forming a synergistic wetting environment with the base oil; In the dispersion stage, high-speed shearing (160°C, 4000 rpm, 40-60 min) is used to deagglomerate the rubber particles, reducing the particle size and increasing the specific surface area. Additives are required to prevent agglomeration caused by van der Waals forces. During the stabilization stage, polythiol chain reconstruction aids and reversible thioether cross-linking agents are introduced to adsorb and act on the particle surface and internal structure, reduce the solid-liquid interfacial tension through chemical cross-linking, reconstruct the SBS polymer network structure, and achieve particle-level stable dispersion and compatibility and stability of the regeneration agent system.

[0008] In addition, by adding antioxidants (such as N-phenyl-α-naphthylamine, p-aminodiphenylamine, etc.) and anti-light aging agents (such as benzotriazole ultraviolet absorbers and piperidine ester light stabilizers), the regeneration agent is given excellent anti-aging ability, thereby improving its long-term stability and performance retention ability in actual engineering applications.

[0009] The purpose of the present invention is achieved through the following technical solutions: A three-step method for preparing an environmentally friendly SBS modified asphalt regeneration agent comprises the following steps: S1. Raw material preparation: Prepare the following raw materials in parts by mass: 50-70 parts of bio-oil, 40-60 parts of devulcanized rubber, 3-9 parts of solubilizer, 1-2 parts of antioxidant, 1-2 parts of anti-light aging agent, 0.5-5 parts of polythiol chain reconstruction aid, and 0.5-3 parts of reversible thioether dynamic crosslinking agent; The bio-oil is one or a combination of soybean oil, rapeseed oil, palm oil, kitchen waste oil and their derivatives, and the mixture can be in any proportion; The desulfurized rubber is derived from one or more of natural rubber, styrene-butadiene rubber, butadiene rubber, chloroprene rubber or nitrile rubber, and the desulfurization rate is ≥50%; The solubilizer is one of maleic anhydride grafted polypropylene, maleic anhydride grafted SEBS (maleic anhydride grafted styrene-ethylene-butylene-styrene), maleic anhydride grafted tackifying resin, or a low molecular weight cross-linking auxiliary agent with a terminal carboxyl group or epoxy group structure; The antioxidant aging agent is one of N-phenyl-α-naphthylamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, and p-aminodiphenylamine; The anti-photoaging agent is one or a combination of an ultraviolet absorber and a light stabilizer, and the mixture can be in any proportion; the ultraviolet absorber is one of 2-hydroxy-4-methoxybenzophenone, 2,6-dimethylbenzotriazole, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole; the light stabilizer is one of bis(2,2,6,6-tetramethyl-4-piperidinyl) adipate, poly(4-methyl-2,6-dipentyl)piperidinyl succinate, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; The polythiol chain reconstruction aid is one of trimethylolpropane trimercaptopropionate (TMPMP), pentaerythritol tetramercaptopropionate (PETMP), and polythiol silane (such as silane-trimercaptopropyl); The reversible thioether dynamic crosslinking agent is one of diphenyl disulfide (DPDS), pyridinium disulfide (PDS), alkyl or aromatic disulfide crosslinking monomers; S2. Preparation of SBS modified asphalt regeneration agent, including the following steps: S2-1. After mixing the desulfurized rubber and the bio-oil according to a certain ratio, the mixture was placed in an ultrasonic reactor and ultrasonically treated for 20 to 40 minutes at a power of 500 W and a frequency of 20 kHz at 110° C. to promote the functionalization and wetting of the rubber surface, thereby obtaining a pretreated mixture A1. S2-2, transferring the mixture A1 into a high-speed shear reactor, and shearing at 160° C. and 4000 rpm for 40 to 60 min to achieve depolymerization and uniform dispersion of the rubber particles, to obtain a mixture A2; S2-3, adding a solubilizing agent to the mixture A2, and then introducing a polythiol chain reconstruction aid and a reversible thioether crosslinking agent, and continuing the reaction at 160° C. and 4000 rpm high-speed shear for 30 min to 50 min to initiate the reconstruction and stabilization of the SBS polymer network structure by the chemical crosslinking agent, to obtain a mixture A3; S2-4, adding an antioxidant and an anti-light aging agent, and stirring the mixture at 160° C. and 1500 rpm for 60 to 90 minutes using a mechanical stirrer to realize the anti-aging function of the regeneration agent and improve the stability, to obtain the final product mixture A4; S2-5. Degas the mixture A4 under vacuum conditions of -0.08 MPa to -0.1 MPa for 10 to 20 minutes to remove bubbles and improve stability. S2-6. Place the mixture A4 in a thermostat at 135° C. for 30 to 60 minutes to obtain a three-step environmentally friendly SBS modified asphalt regeneration agent.

[0010] In the present invention: Furthermore, the bio-oil described in S1 is modified by ultrasonic transesterification with the process parameters of 500W, 20kHz, 60℃, and 30min, thereby introducing polar groups such as carboxyl and hydroxyl groups, and giving the bio-oil new reactive groups after treatment, thereby improving wettability and dispersibility. After ultrasonic transesterification, the bio-oil has a carboxyl density of 0.5 mmol / g to 2.0 mmol / g, and a particle size distribution controlled within 1μm to 10μm, which helps to form a stable dispersion with polar additives.

[0011] Furthermore, the desulfurized rubber described in S1 is subjected to low-temperature radio frequency plasma functionalization treatment, and the process parameters are: power 100W, pressure 200Pa, temperature ≤60°C, time 20min, so as to introduce polar functional groups such as hydroxyl, carboxyl, and amino groups on the surface; the surface polar group content of the desulfurized rubber after plasma functionalization treatment is increased by more than 50% compared with before treatment, thereby improving the interfacial compatibility and interfacial affinity with bio-oil and cross-linking agent.

[0012] Furthermore, the solubilizer described in S1 has both polar lipophilic segments and non-polar segments, and achieves stable coexistence of rubber, bio-oil and additive system through interfacial tension regulation.

[0013] Furthermore, the reaction described in S2-3 is continued at 160°C and 4000rpm high-speed shear for 30min to 50min, and triple online sensors of temperature, torque, and pressure are equipped in the high-speed shear process and the cross-linking reaction section. The control ranges are 130°C to 170°C, 30N·m to 80N·m, and 0.2MPa to 0.8MPa, respectively, and the material dispersion and cross-linking uniformity are regulated by a PLC closed-loop system.

[0014] The present invention also relates to a three-step environmentally friendly SBS modified asphalt regeneration agent, which is obtained by adopting the preparation method of the above-mentioned three-step environmentally friendly SBS modified asphalt regeneration agent. The prepared three-step environmentally friendly SBS modified asphalt regeneration agent can achieve dual regeneration of the asphalt matrix and the SBS modifier in the aged SBS modified asphalt system. The prepared three-step environmentally friendly SBS modified asphalt regeneration agent is added to the aged SBS modified asphalt in an amount of 4% to 20% by mass, and after uniform stirring, the regenerated SBS modified asphalt is prepared.

[0015] The present invention also relates to an application of a three-step environmentally friendly SBS modified asphalt regeneration agent. The prepared three-step environmentally friendly SBS modified asphalt regeneration agent is added to aged SBS modified asphalt in an amount of 4% to 20% by mass. The aged SBS modified asphalt and the three-step environmentally friendly SBS modified asphalt regeneration agent are uniformly stirred. The prepared regenerated SBS modified asphalt is used in road engineering. After the addition of the regeneration agent, the mechanical properties and polymer network structure of the regenerated SBS modified asphalt are significantly restored.

[0016] Furthermore, the uniform stirring is carried out at 145° C. to 165° C., at 800 rpm to 1500 rpm, and for 30 min to 60 min, to achieve dual regeneration of the aged asphalt matrix and the SBS polymer.

[0017] Furthermore, the uniform stirring is carried out at 155° C., 1000 rpm, and a stirring time of 45 minutes.

[0018] Furthermore, the aged SBS modified asphalt is a mixture of any one or more of thin film oven aged asphalt (TFOT), rotary thin film oven aged asphalt (RTFOT), ultraviolet aged asphalt (UV), pressure aged asphalt (PAV), and waste extraction aged asphalt in any proportion.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Environmentally friendly and sustainable raw material selection: The three-step, environmentally friendly SBS-modified asphalt regeneration agent described in this invention utilizes two environmentally friendly renewable raw materials: ultrasonic transesterification-modified bio-oil and plasma-functionalized desulfurized rubber. Bio-oil is derived from renewable biomass oils such as soybean oil and rapeseed oil. Ultrasonic treatment introduces polar functional groups such as carboxyl and hydroxyl groups, improving wettability and dispersibility, and promoting uniform mixing and active release of the regeneration agent. Desulfurized rubber is treated with low-temperature radio frequency plasma to significantly increase the content of surface polar groups and enhance its compatibility with bio-oil and cross-linking agents. This technical approach not only effectively utilizes waste rubber resources, reducing waste emissions and environmental pollution, but also reduces production costs and energy consumption. It conforms to the concept of a green circular economy and promotes the efficient recycling of waste materials.

[0020] 2. Innovative three-step preparation process ensures product performance and stability: The present invention describes a three-step method for preparing an environmentally friendly SBS modified asphalt regeneration agent. The three-step preparation process designed includes ultrasonic and plasma pretreatment of raw materials, high-speed shear dispersion, and multi-component dynamic crosslinking, which takes into account both physical dispersion and chemical structure reconstruction. The pretreatment step promotes the exposure and wetting of functional groups on the surface of devulcanized rubber and bio-oil; high-speed shearing ensures the uniform depolymerization and dispersion of rubber particles; the introduction of multi-thiol chain reconstruction aids and reversible sulfide dynamic crosslinkers triggers the reconstruction and stabilization of the SBS polymer network structure. The process uses multi-parameter online monitoring and PLC closed-loop control to adjust temperature, shear force, and pressure in real time to ensure the uniformity and crosslinking degree of the material, achieve high-quality, batch-stable regeneration agent production, and improve the industrial adaptability and controllability of the preparation process.

[0021] 3. Achieve dual regeneration effects of asphalt matrix and SBS polymer: In aged SBS-modified asphalt, light components transform into macromolecular components and the SBS polymer molecular chains break, leading to performance degradation. The three-step, environmentally friendly SBS-modified asphalt regeneration agent prepared by the present invention effectively replenishes the light components missing from the asphalt matrix with bio-oil and promotes their diffusion into the desulfurized rubber, causing the rubber to swell and releasing light molecules. With the help of a crosslinking agent, the desulfurized rubber re-crosslinks with the asphalt matrix and SBS polymer network, forming a new three-dimensional crosslinked network. This simultaneously repairs the aged asphalt and polymer networks, significantly improving the mechanical properties and durability of the regenerated asphalt, achieving the innovative effect of dual regeneration.

[0022] 4. Multi-level anti-aging system improves the durability of regeneration agent: This three-step, environmentally friendly SBS-modified asphalt regeneration agent combines the excellent anti-aging properties of functionalized desulfurized rubber, the effective passivation of active groups by an antioxidant, and the absorption and shielding of UV rays by a photoresist, achieving multiple anti-aging protection mechanisms. This multi-layered anti-aging system effectively inhibits oxidation reactions and light damage in the asphalt and modified polymer, significantly slowing the aging of the regeneration agent and regenerated asphalt, ensuring stable structure and performance even in complex environments, significantly extending service life and reliability in engineering applications.

[0023] 5. The preparation process is simple and efficient, with strong applicability and significant cost advantages: The present invention describes a three-step method for preparing an environmentally friendly SBS-modified asphalt regeneration agent. This method utilizes rationally designed reaction steps and conditions to achieve efficient and controllable regeneration agent production. Ultrasonic and high-speed shearing processes significantly shorten reaction time, while vacuum degassing and constant temperature insulation ensure product uniformity and stability. The process is simple and easy to implement, reducing technical requirements for equipment and operators. Furthermore, the use of environmentally friendly, renewable raw materials and energy-saving processes effectively reduces energy consumption and waste emissions, overall lowering production costs and enhancing the product's market competitiveness and promotional value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0025] Figure 1 This is a diagram showing the preparation mechanism of a three-step environmentally friendly SBS modified asphalt regeneration agent according to the present invention; Figure 2 This is a verification diagram of the application effect of the three-step environmentally friendly SBS modified asphalt regeneration agent described in the present invention (phase angle curve of regenerated asphalt). DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0027] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0028] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0029] Example 1: A three-step method for preparing an environmentally friendly SBS modified asphalt regeneration agent, such as Figure 1 As shown, the following steps are included: 1) Premixing and functionalization: 50 parts of devulcanized rubber prepared from natural rubber after plasma pretreatment and 60 parts of epoxidized soybean oil treated by ultrasonic transesterification were mixed in a certain proportion, placed in an ultrasonic reactor, set at a power of 500 W and a frequency of 20 kHz, and ultrasonically treated at 110° C. for 20 to 40 minutes to promote surface functionalization of the rubber particles and liquid phase wetting, to obtain a mixture A1; 2) Depolymerization and dispersion: Transferring the mixture A1 to a high-speed shear reactor, and subjecting it to a shear reaction at 160°C and a rotation speed of 4000 rpm for 40 to 60 minutes, thereby achieving further depolymerization and uniform dispersion of the rubber particles under the action of high temperature and high shear, to obtain a mixture A2; 3) Cross-linking network reconstruction: To mixture A2, 6 parts of a maleic anhydride-grafted tackifying resin were added, followed by 3 parts of a polythiol chain reconstruction aid (TMPMP) and 2 parts of a reversible thioether dynamic crosslinker (DPDS). The mixture was then sheared at 160°C and 4000 rpm for 30–50 minutes to induce local reconstruction and stabilization of the SBS polymer structure through chemical crosslinking, forming a homogeneous mixture A3. 4) Introduction of anti-aging components: Add one part of an antioxidant (p-aminodiphenylamine) and two parts of an antioxidant (one part of 2-hydroxy-4-methoxybenzophenone and one part of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate) to mixture A3, and stir using a mechanical stirrer at 160°C and 1500 rpm for 60 to 90 minutes to uniformly disperse the antioxidant components and enhance the durability and stability of the system, thereby obtaining mixture A4. 5) Vacuum degassing: The mixture A4 was placed in a vacuum environment of -0.08 MPa to -0.1 MPa for degassing for 10 to 20 minutes to remove mixed bubbles and improve the dispersion stability and storage performance of the regeneration agent; 6) Constant temperature aging: Finally, the degassed mixture A4 was placed in a constant temperature box at 135° C. and kept warm for 30 to 60 minutes to complete the reaction aging process, thereby obtaining a finished three-step environmentally friendly SBS modified asphalt regeneration agent.

[0030] Example 2: Compared with Example 1, the type and proportion of bio-oil were changed. The bio-oil in Example 1 was replaced with 70 parts of ultrasonic transesterification-modified rapeseed oil. The other materials and processes were consistent with Example 1.

[0031] Example 3: Compared with Example 1, the type and ratio of rubber were changed. The devulcanized rubber in Example 1 was replaced with a mixture of devulcanized rubber prepared from 60 parts of butadiene rubber and devulcanized rubber prepared from natural rubber, with a ratio of 1:1. The mixture was subjected to the same plasma functionalization treatment; the remaining materials and processes remained consistent with Example 1.

[0032] Example 4: Compared with Example 1, 3 parts of maleic anhydride grafted SEBS were added to mixture A2, and 1 part of polythiol chain reconstruction aid - PETMP and 3 parts of reversible thioether dynamic crosslinker - PDS were added in sequence. The other materials and processes were consistent with Example 1.

[0033] Comparative Example 1: Compared with Example 1, devulcanized rubber made from natural rubber was selected, but no plasma functionalization treatment was performed. Other materials and processes remained consistent with those in Example 1.

[0034] Comparative Example 2: Compared with Example 1, epoxidized soybean oil was used as the bio-oil, and ultrasonic transesterification treatment was not performed. Other materials and processes were consistent with Example 1.

[0035] Comparative Example 3: Compared with Example 1, no solubilizer was added, and the other materials and processes were consistent with Example 1.

[0036] Comparative Example 4: Compared with Example 1, no anti-aging agent was added, and the remaining materials and processes were consistent with those of Example 1.

[0037] Comparative Example 5: Compared with Example 1, no polythiol chain reconstruction agent and reversible thioether dynamic cross-linking agent were added, and the other materials and processes were consistent with those of Example 1.

[0038] Experimental Example 1 Aged SBS modified asphalt after RTFOT and PAV treatment without adding rejuvenating agent.

[0039] Experimental Example 2 to Example 5: The regeneration agents prepared in Examples 1 to 4 were added to the aged SBS modified asphalt treated with RTFOT and PAV, respectively. The prepared regeneration agents were added to the aged SBS asphalt at a dosage of 10 wt%, and stirred at 1000 rpm at 155 °C for 45 min to obtain regenerated asphalt.

[0040] Experimental Example 6 to Example 10: The regeneration agents prepared in Comparative Examples 1 to 5 were respectively added to the aged SBS modified asphalt treated with RTFOT and PAV. The prepared regeneration agents were added to the aged SBS asphalt at a dosage of 10 wt%, and stirred at 1000 rpm at 155 °C for 45 min to obtain regenerated asphalt.

[0041] Results and Discussion In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0042] Table 1: Physical properties of recycled asphalt

[0043] 1. The regeneration effect evaluation test was conducted in accordance with the relevant test requirements in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGE20-2011). The performance indicators of the regenerated asphalt are shown in Table 1. As shown in Table 1, the three-step environmentally friendly SBS modified asphalt regeneration agent prepared in Examples 1 to 4 can significantly improve the performance of aged asphalt. Based on the three major indicators, the regeneration agents prepared with different formulas or processes can all maintain a stable regeneration effect. The mass loss of Examples 1 to 4 was all lower than the 0.8% required by the specification; the softening point difference in the segregation test was all lower than 2.2°C, indicating that the regenerated asphalt produced using the regeneration agents produced in Examples 1 to 4 has excellent anti-aging properties and storage stability.

[0044] 2. Comparing Comparative Examples 1 and 2 with Examples 1 to 4, it can be seen that the recovery effects of the three major indicators of the regenerated asphalt prepared using Comparative Examples 1 to 2 are significantly worse than those of Examples 1 to 4, and the anti-aging performance and storage stability no longer meet the regulatory requirements. This shows that pre-functionalization treatment of devulcanized rubber and residual oil is very necessary.

[0045] 3. Comparing Example 3 with Examples 1 to 4, it can be seen that the three major indicators of the regenerated asphalt prepared in Comparative Example 3 are not much different from those of the regenerated asphalt prepared in Examples 1 to 4, but the anti-aging performance is relatively poor, and the storage stability is the worst among all experimental examples, which proves the key role of the solubilizer in the preparation of the regeneration agent.

[0046] 4. Compared with Examples 1 to 4, the regeneration effects of the three major indicators in Comparative Example 4 are also relatively poor, especially the anti-aging performance is greatly reduced, and the mass loss value is increased by nearly 4 times compared with the standard. Through comparison, it can be seen that the effect of the anti-aging agent is very obvious.

[0047] 5. Compared with Examples 1 to 4, the recovery effects of various indicators in Comparative Example 5 are poor, and the elongation data is particularly obvious. This is because the lack of polythiol chain reconstruction additives and reversible sulfide dynamic cross-linking agents leads to an imperfect polymer network structure inside the regenerated asphalt.

[0048] Obviously, by comparing with the comparative example, it can be found that the regeneration effect of the regeneration agent in the example is more stable. The comparison between Examples 1 to 4 shows that different conditions and different additives selected within the given condition range in the preparation step of the present invention all have good regeneration effects.

[0049] Figure 2 This is a three-step environmentally friendly SBS modified asphalt regeneration agent application effect verification diagram of the embodiment, showing the phase angle curve changes of the regenerated asphalt in the embodiment and the comparative example; the platform area of ​​the phase angle change curve can be used to judge the destruction and regeneration of the internal polymer network of the SBS modified asphalt. The more obvious the phase angle platform area, the more complete the polymer network structure. Figure 2 It can be seen that, compared with Comparative Examples 1 to 5, all embodiments of the present invention have excellent regeneration effects on the internal polymer network of the regenerated asphalt.

Claims

1. A three-step method for preparing an environmentally friendly SBS modified asphalt regeneration agent, characterized in that: The following steps are involved: S1. Raw material preparation: Prepare the following raw materials in parts by mass: 50-70 parts of bio-oil, 40-60 parts of devulcanized rubber, 3-9 parts of solubilizer, 1-2 parts of antioxidant, 1-2 parts of anti-light aging agent, 0.5-5 parts of polythiol chain reconstruction aid, and 0.5-3 parts of reversible thioether dynamic crosslinking agent; The bio-oil is one or a combination of soybean oil, rapeseed oil, palm oil, kitchen waste oil and their derivatives, and the mixture can be in any proportion; The desulfurized rubber is derived from one or more of natural rubber, styrene-butadiene rubber, butadiene rubber, chloroprene rubber or nitrile rubber, and the desulfurization rate is ≥50%; The solubilizer is one of maleic anhydride grafted polypropylene, maleic anhydride grafted SEBS, maleic anhydride grafted tackifying resin, or a low molecular weight cross-linking auxiliary agent with a terminal carboxyl group or epoxy group structure; The antioxidant aging agent is one of N-phenyl-α-naphthylamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, and p-aminodiphenylamine; The anti-photoaging agent is one or a combination of an ultraviolet absorber and a light stabilizer, and the mixture can be in any proportion; the ultraviolet absorber is one of 2-hydroxy-4-methoxybenzophenone, 2,6-dimethylbenzotriazole, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole; the light stabilizer is one of bis(2,2,6,6-tetramethyl-4-piperidinyl) adipate, poly(4-methyl-2,6-dipentyl)piperidinyl succinate, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; The polythiol chain reconstruction auxiliary agent is one of trimethylolpropane trimercaptopropionate, pentaerythritol tetramercaptopropionate, and polythiol silane (such as silane-trimercaptopropyl); The reversible sulfide dynamic crosslinking agent is one of diphenyl disulfide, pyridine disulfide, alkyl or aromatic disulfide crosslinking monomers; S2. Preparation of SBS modified asphalt regeneration agent, including the following steps: S2-1. After mixing the desulfurized rubber and the bio-oil according to a certain ratio, the mixture was placed in an ultrasonic reactor and ultrasonically treated for 20 to 40 minutes at a power of 500 W and a frequency of 20 kHz at 110° C. to promote the functionalization and wetting of the rubber surface, thereby obtaining a pretreated mixture A1. S2-2, transferring the mixture A1 into a high-speed shear reactor, and shearing at 160° C. and 4000 rpm for 40 to 60 min to achieve depolymerization and uniform dispersion of the rubber particles, to obtain a mixture A2; S2-3, adding a solubilizing agent to the mixture A2, and then introducing a polythiol chain reconstruction auxiliary agent and a reversible thioether crosslinking agent, and continuing to react at 160° C. and 4000 rpm high-speed shear for 30 min to 50 min to obtain a mixture A3; S2-4, adding an antioxidant and an anti-light aging agent, and stirring the mixture at 160° C. and 1500 rpm using a mechanical stirrer for 60 to 90 minutes to obtain a final product mixture A4; S2-5. Degas the mixture A4 under vacuum conditions of -0.08 MPa to -0.1 MPa for 10 to 20 minutes to remove bubbles. S2-6. Place the mixture A4 in a thermostat at 135° C. for 30 to 60 minutes to obtain a three-step environmentally friendly SBS modified asphalt regeneration agent.

2. The method for preparing a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 1, characterized in that: The bio-oil described in S1 was modified by ultrasonic transesterification with the process parameters of 500W, 20kHz, 60°C, and 30min. Polar groups such as carboxyl and hydroxyl groups were introduced to impart new reactive groups to the bio-oil after treatment, thereby improving wettability and dispersibility. The bio-oil after ultrasonic transesterification had a carboxyl density of 0.5 mmol / g to 2.0 mmol / g and a particle size distribution controlled at 1 μm to 10 μm.

3. The method for preparing a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 1, characterized in that: The devulcanized rubber described in S1 is subjected to low-temperature radio frequency plasma functionalization treatment, and the process parameters are: power 100 W, pressure 200 Pa, temperature ≤ 60° C., and time 20 min.

4. The method for preparing a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 1, characterized in that: The reaction described in S2-3 is continued at 160°C and 4000rpm high-speed shear for 30min to 50min. The high-speed shear process and the cross-linking reaction section are equipped with triple online sensors for temperature, torque, and pressure. The control ranges are 130°C to 170°C, 30N·m to 80N·m, and 0.2MPa to 0.8MPa, respectively. The material dispersion and cross-linking uniformity are regulated by a PLC closed-loop system.

5. A three-step environmentally friendly SBS modified asphalt regeneration agent, characterized in that: The method is based on the preparation method of a three-step environmentally friendly SBS modified asphalt regeneration agent according to any one of claims 1 to 4.

6. The use of a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 5, characterized in that: The prepared three-step environmentally friendly SBS modified asphalt regeneration agent is added to aged SBS modified asphalt in an amount of 4% to 20% by mass, the aged SBS modified asphalt and the three-step environmentally friendly SBS modified asphalt regeneration agent are mixed evenly, and the prepared regenerated SBS modified asphalt is used in road engineering.

7. The use of a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 6, characterized in that: The aged SBS modified asphalt is a mixture of any one or more of thin film oven aged asphalt, rotary thin film oven aged asphalt, ultraviolet aged asphalt, pressure aged asphalt and waste extraction aged asphalt in any proportion.

8. The use of a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 6, characterized in that: The uniform stirring is carried out at a temperature of 145° C. to 165° C., a rotation speed of 800 rpm to 1500 rpm, and a stirring time of 30 min to 60 min.

9. The use of a three-step environmentally friendly SBS modified asphalt regeneration agent according to claim 8, characterized in that: The uniform stirring is carried out at 155° C., a rotation speed of 1000 rpm, and a stirring time of 45 minutes.

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