Vegetable oil-based SBS modified asphalt block polymer composite regenerant and application thereof

Abstract

The invention discloses a plant oil-based SBS modified asphalt block polymer composite regenerant and application thereof, and belongs to the technical field of plant oil-based regenerant, the plant oil-based SBS modified asphalt block polymer composite regenerant is composed of plant oil and a plant oil-based block polymer, the preparation method of the vegetable oil-based block polymer comprises the following steps: preparing and grafting acid, acid anhydride or amide containing active carbon-carbon double bonds by epoxy vegetable oil according to a grafting reaction principle to obtain modified epoxy vegetable oil; dissolving the modified epoxy vegetable oil and polystyrene or a derivative thereof in tetrahydrofuran, carrying out free radical polymerization reaction to obtain a doped vegetable oil-based block polymer, and carrying out reduced pressure distillation treatment on the doped vegetable oil-based block polymer to obtain a vegetable oil-based block polymer; the vegetable oil-based SBS modified asphalt block polymer composite regenerant is simple in preparation method, is used as an aged SBS modified asphalt regenerant, recovers the rheological property of aged asphalt to the level of fresh SBS modified asphalt, takes renewable vegetable oil as a raw material, is low in cost, and has excellent environmental benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of vegetable oil-based regenerants, and particularly relates to a vegetable oil-based SBS modified asphalt block polymer composite regenerant and its application. Background Art

[0002] Styrene-butadiene-styrene block copolymer (SBS) modified asphalt has been widely used in pavement engineering such as high-grade highways and airport runways due to its excellent high and low temperature performance, fatigue resistance, and anti-aging performance. However, during long-term use, under the combined action of traffic loads and environmental factors, SBS modified asphalt gradually ages, and its road performance significantly deteriorates, seriously affecting the service life of the pavement and driving safety. As a large number of early-built SBS modified asphalt pavements gradually enter the maintenance and renovation period, a large amount of waste SBS modified asphalt mixture is generated. If these waste materials are directly discarded, it will not only cause a great waste of resources but also cause serious environmental pollution. Therefore, the recycling of aged SBS modified asphalt has important practical significance, which not only meets the requirements of resource conservation and environmental protection but also reduces the road construction cost and promotes the sustainable development of road engineering.

[0003] Traditional regenerants mainly regulate the chemical composition and rheological properties of aged SBS modified asphalt by supplementing light oil. These light oils can increase the content of light components in the aged asphalt, improve the fluidity and flexibility of the asphalt to a certain extent, reduce its viscosity, and restore some of its road performance. However, traditional regenerants can only supplement the light components of the asphalt phase and cannot effectively restore the polymer molecular network structure damaged due to aging in SBS modified asphalt. The excellent performance of SBS modified asphalt largely depends on its unique polymer molecular network structure, which will undergo changes such as fracture and degradation during the aging process. Due to its poor recovery effect on the rheological properties of aged SBS modified asphalt, its application in high-grade pavements is limited.

[0004] In order to repair the polymer molecular network structure in aged SBS modified asphalt, some studies have tried to regenerate aged SBS modified asphalt with fresh SBS modifiers, and restore the polymer molecular network structure in the aged asphalt by supplementing fresh SBS. This method can effectively improve the performance of the recycled asphalt to a certain extent. However, the price of SBS modifiers is relatively high, and the use of a large amount of fresh SBS modifiers for regeneration will significantly increase the regeneration cost. In addition, SBS mainly comes from petrochemical products, and its production process consumes a large amount of fossil resources, which does not conform to the concept of sustainable development.

[0005] Based on the above background, there is an urgent need to develop a new type of efficient and environmentally friendly SBS modified asphalt recycling technology. This patent prepares a block polymer synthesized from vegetable oil to replace SBS, and together with vegetable oil, it is used to compound and recycle aged SBS modified asphalt. This composite recycling agent is inexpensive and uses sustainable materials. It can not only effectively restore the performance of aged SBS modified asphalt but also meet the requirements of green and sustainable development, with broad application prospects. Summary of the Invention

[0006] Technical problems to be solved: Aiming at the problems in the prior art such as low recycling efficiency, poor environmental benefits, and high manufacturing costs of SBS modified asphalt recycling agents, the present invention provides a vegetable oil-based SBS modified asphalt block polymer composite recycling agent and its application, promoting the sustainable transformation of road infrastructure construction.

[0007] Technical solutions:

[0008] The vegetable oil-based SBS modified asphalt block polymer composite recycling agent is composed of 8 - 12 parts of vegetable oil and 3 - 6 parts of vegetable oil-based block polymer according to the mass ratio.

[0009] As a preferred technical solution of the present invention: The vegetable oil is one or several of waste vegetable oil, soybean oil, rapeseed oil, castor oil, cottonseed oil, peanut oil, corn oil, olive oil, sunflower oil, high-oleic rapeseed oil, high-oleic peanut oil, high-oleic olive oil, high-oleic sunflower oil, high-oleic avocado oil, high-oleic camellia oil, high-oleic soybean oil, and derivatives of the above vegetable oils.

[0010] As a preferred technical solution of the present invention, the preparation method of the vegetable oil-based block polymer includes the following steps:

[0011] The first step: According to the mass ratio, 100 parts of epoxy vegetable oil, 0.2 - 0.8 parts of catalyst, and 0.05 - 0.30 parts of inhibitor hydroquinone are mixed evenly at a constant temperature of 80°C, and then 20 - 60 parts of acid, anhydride, or amide containing active carbon-carbon double bonds are added dropwise. The reaction is carried out at a constant temperature of 90 - 150°C for 6 - 12 h to obtain modified epoxy vegetable oil grafted with active carbon-carbon double bonds.

[0012] The second step: According to the mass ratio, 100 parts of modified epoxy vegetable oil grafted with active carbon-carbon double bonds, 20 - 40 parts of polystyrene or its derivatives, 0.03 - 0.08 parts of initiator, and 0.4 - 0.8 parts of chain transfer agent are dissolved in tetrahydrofuran. After mixing evenly, it is purged with nitrogen for 15 - 30 minutes, and then the reaction is carried out at a constant temperature of 60 - 120°C and a stirring rate of 800 - 1200 r / min for 4 - 8 h.

[0013] Step 3: After treatment by vacuum distillation, a pure vegetable oil-based block polymer is obtained.

[0014] As a preferred technical solution of the present invention: in the first step, the epoxy vegetable oil is one or more of epoxy soybean oil, epoxy rapeseed oil, epoxy castor oil, epoxy cottonseed oil, epoxy peanut oil, epoxy corn oil, epoxy olive oil, epoxy sunflower oil, high-oleic acid epoxy rapeseed oil, high-oleic acid epoxy peanut oil, high-oleic acid epoxy olive oil, high-oleic acid epoxy sunflower oil, high-oleic acid epoxy avocado oil, high-oleic acid epoxy camellia oil, high-oleic acid epoxy soybean oil, and derivatives of the above epoxy vegetable oils.

[0015] As a preferred technical solution of the present invention: the catalyst in the first step is one or more of N,N-dimethylaniline, triphenylphosphine, triethylamine, N,N-dimethylbenzylamine, and 1,4-diazabicyclo[2.2.2]octane.

[0016] As a preferred technical solution of the present invention: the acid, anhydride or amide containing an active carbon-carbon double bond in the first step is one or more of acrylic acid, methacrylic acid, crotonic acid, 3-methylcrotonic acid, maleic anhydride, fumaric anhydride, acrylamide, and N,N-dimethylacrylamide.

[0017] As a preferred technical solution of the present invention: the polystyrene or its derivative in the second step is one or more of polystyrene, poly(p-methylstyrene), poly(o-methylstyrene), poly(m-methylstyrene), and poly(α-methylstyrene).

[0018] As a preferred technical solution of the present invention: the initiator in the second step is one or more of dicumyl peroxide, potassium persulfate, azobisisobutyronitrile, azobisisopentanenitrile, azobisisoheptonitrile, and dimethyl 2,2'-azobis(2-methylpropionate).

[0019] As a preferred technical solution of the present invention: the chain transfer agent in the second step is one or more of benzyl diethyldithiocarbamate, cumyl dithiobenzoate, benzyl N,N-diphenyldithiocarbamate, ethyl 3-oxo-2-butyltrithiocarbonate, and 1-phenylethyl diphenyl disulfide.

[0020] The present application also discloses the application of any of the above vegetable oil-based SBS modified asphalt block polymer composite rejuvenators in the hot recycling of aged SBS modified asphalt. Under the condition of 150 - 180 °C, 6 - 12 parts by mass of the vegetable oil-based SBS modified asphalt block polymer composite rejuvenator are added to 100 parts of aged SBS modified asphalt according to the mass ratio. The mixture is sheared by a high-speed shearer at a shear rate of 2000 - 3000 r / min for 20 - 40 minutes to obtain the vegetable oil-based block polymer composite recycled aged SBS modified asphalt; it is left standing at room temperature for 1 day, and the performance of the vegetable oil-based block polymer composite recycled aged SBS modified asphalt is tested.

[0021] Principle explanation: SBS modified asphalt gradually undergoes an aging reaction under the coupling factors of the environment and load. The light components in the asphalt volatilize, and the heavy components undergo an oxidation reaction to generate highly polar functional groups such as carbonyl and sulfoxide groups, enhancing the interaction between the components of the asphalt and obtaining asphaltene-colloid nanoaggregates; in terms of performance, the aged SBS modified asphalt has an increased hardness and is more prone to temperature and fatigue cracking; vegetable oil can effectively supplement the light components in the aged SBS modified asphalt; moreover, due to the straight-chain structure of vegetable oil molecules, it has excellent diffusion performance in aged asphalt and can effectively penetrate into the nanoaggregates in the aged SBS modified asphalt; the polar functional groups on the vegetable oil molecules will further affect the electron cloud structure of asphaltenes, playing a role in dissociating the nanoaggregates and restoring the colloidal structure of the aged asphalt phase; the vegetable oil-based block polymer will supplement the disintegrated polymer cross-linked network structure in the aged SBS modified asphalt, endowing the recycled SBS modified asphalt with excellent elasticity and toughness; in addition, the vegetable oil-based block polymer absorbs vegetable oil in the recycled SBS modified asphalt and undergoes a swelling reaction, "locking" the vegetable oil molecules and reducing the volatility of the vegetable oil molecules, thereby endowing the vegetable oil-based block polymer composite recycled SBS modified asphalt with excellent anti-aging and anti-fatigue properties.

[0022] Beneficial effects:

[0023] Compared with the prior art, the present application has the following advantages:

[0024] 1. Compared with reactive composite rejuvenators, the vegetable oil-based polymer composite rejuvenator of the present application completely abandons highly volatile toxic components; traditional reactive rejuvenators will release isocyanate vapors during high-temperature mixing or construction processes, which are highly carcinogenic and easily cause respiratory diseases, seriously threatening the health of construction workers and causing VOCs (volatile organic compounds) pollution; while this rejuvenator uses natural vegetable oils and their derivatives as the core raw materials, and the VOCs emissions during processing and service are reduced by more than 80%, significantly improving the construction environment and reducing occupational health risks;

[0025] 2. Traditional SBS production consumes a large amount of butadiene. In this application, vegetable oil-based polymers are used to replace butadiene, significantly improving the carbon footprint of aged SBS modifiers. At the same time, waste vegetable oil is used as a raw material to achieve "treating waste with waste". Life cycle assessment shows that the carbon footprint of the vegetable oil-based block polymer composite regenerant is reduced by 45% compared with the traditional SBS regeneration scheme, providing an effective path for the low-carbon and sustainable transformation of road materials;

[0026] 3. Through the synergistic effect of vegetable oil-based block polymers and vegetable oil, this composite regenerant can significantly improve the balance of high and low temperature performance of recycled asphalt. Experiments show that the high temperature rutting resistance factor of the vegetable oil-based block polymer composite regenerant can restore the aged SBS modified asphalt from 1.2 kPa to 2.8 kPa, which is better than 2.5 kPa of the fresh SBS regeneration group; in terms of low temperature performance, the creep stiffness of the recycled asphalt is reduced from 450 MPa to 220 MPa, and the critical cracking temperature is improved from -14 °C to -20 °C. The above performance improvements extend the PG grading of the aged SBS modified asphalt from PG 70-22 to PG 76-28, meeting the service requirements of extremely cold regions and heavy traffic sections;

[0027] 4. In the aged SBS modified asphalt, the vegetable oil-based block polymer reconstructs the three-dimensional polymer network structure through dynamic cross-linking or physical entanglement, significantly improving the anti-fatigue performance of the material. Through the comparison of linear amplitude sweep tests, it is found that the fatigue life of the asphalt treated with this regenerant is increased from 12,000 times to 35,000 times, with an increase of 192%; further confirmed by Fourier transform infrared spectroscopy analysis, the carboxyl group in the regenerant forms hydrogen bonds or ester bonds with the broken chain end groups of the aged SBS, inhibiting the propagation of microcracks; in addition, the cross-linked network gives the recycled asphalt a higher elastic recovery rate, effectively delaying the generation of reflective cracks, and it is estimated that the service life of the road surface is extended by 30%-40%. Detailed implementation mode

[0028] The present invention will be further described in detail below with reference to examples and comparative examples. It should be noted that the specific examples described herein are only used to explain the present invention and do not limit the scope and application of the present invention.

[0029] The performance testing method of the vegetable oil-based block polymer composite recycled SBS modified asphalt refers to the "Technical Specification for Construction of Highway Asphalt Pavements" (Industry Standard of the People's Republic of China, JTG F40-2004).

[0030] Example 1

[0031] The vegetable oil-based SBS modified asphalt block polymer composite regenerant, according to the mass ratio, the vegetable oil-based SBS modified asphalt block polymer composite regenerant is composed of 10 parts of waste vegetable oil and 3 parts of vegetable oil-based block polymer.

[0032] The preparation method of the vegetable oil-based block polymer comprises the following steps:

[0033] First step: According to the mass ratio, 100 parts of epoxidized soybean oil, 0.2 part of catalyst N,N-dimethylaniline, and 0.05 part of inhibitor hydroquinone are mixed evenly at a constant temperature of 80°C, and then placed in a clean three-necked flask. After the solution temperature rises to 90°C, 20 parts of acrylic acid are added dropwise to the mixed solution drop by drop within 1 hour, and the dropping rate is controlled at 1-2 drops / second. At a constant temperature of 90°C, the reaction is carried out for 6 hours. After the reaction product is extracted with n-hexane, it is dried by rotary evaporation to remove n-hexane, and a light yellow transparent viscous liquid is obtained, which is the modified epoxidized soybean oil grafted with acrylic acid;

[0034] Second step: According to the mass ratio, 100 parts of the modified epoxidized soybean oil, 20 parts of polystyrene, 0.03 part of initiator diisopropylbenzene peroxide, and 0.4 part of chain transfer agent benzyl diethyldithiocarbamate are dissolved in tetrahydrofuran at room temperature, mixed evenly, and purged with nitrogen for 15 minutes. After the solution temperature rises to 60°C, the reaction is carried out at a constant temperature for 4 hours under the condition that the stirring rate is 800 r / min;

[0035] Third step: After treatment by vacuum distillation, the excess reactants are removed, and a light red viscoelastic solid is obtained, which is the pure vegetable oil-based block polymer.

[0036] The application of the vegetable oil-based SBS modified asphalt block polymer composite regenerant in the thermal regeneration of aged SBS modified asphalt. Under the condition of 150°C, according to the mass ratio, 10 parts of waste vegetable oil and 3 parts of the vegetable oil-based block polymer are successively added to 100 parts of aged SBS modified asphalt, and the mixture is sheared by a high-speed shearer at a shear rate of 2000 r / min for 20 minutes to obtain the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt; it is left standing at room temperature for 1 day, and the performance test of the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt is carried out.

[0037] Comparative Example 1

[0038] The preparation method of the SBS modifier composite regenerated aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170°C, and successively add 4 parts of SBS modifier and 10 parts of rubber oil to 100 parts of aged SBS modified asphalt according to the mass ratio. The mixture is sheared by a high-speed shearer at a shear rate of 3000 r / min for 30 minutes to obtain the SBS modifier composite regenerated aged SBS modified asphalt; it is left standing at room temperature for 1 day, and the performance test of the SBS modifier composite regenerated aged SBS modified asphalt is carried out.

[0039] Table 1 Basic parameters of the regenerated SBS modified asphalt prepared in Example 1 and Comparative Example 1

[0040]

[0041]

[0042] As can be seen from Table 1, the regeneration effect of the vegetable oil-based block polymer composite regenerated asphalt is similar to that of the SBS modified regenerated asphalt, and even has a higher rotational viscosity than the SBS modified regenerated asphalt, indicating that the vegetable oil-based block polymer composite regenerated asphalt has better high-temperature performance.

[0043] Example 2

[0044] The vegetable oil-based SBS modified asphalt block polymer composite regenerant. According to the mass ratio, the vegetable oil-based SBS modified asphalt block polymer composite regenerant is composed of 10 parts of soybean oil and 4 parts of vegetable oil-based block polymer.

[0045] The preparation method of the vegetable oil-based block polymer includes the following steps:

[0046] The first step: According to the mass ratio, 100 parts of epoxidized rapeseed oil, 0.3 part of the catalyst triphenylphosphine, and 0.05 part of the inhibitor hydroquinone are mixed evenly at a constant temperature of 80 °C and then placed in a clean three-necked flask; when the solution temperature rises to 100 °C, 30 parts of methacrylic acid are added dropwise to the mixed solution, and the addition is completed within 1 h, and the dropping rate is controlled at 1-2 drops / second. At a constant temperature of 100 °C, the reaction is carried out for 7 h. After the reaction product is extracted with n-hexane, it is dried by rotary evaporation on a rotary evaporator to remove n-hexane, and a light yellow transparent viscous liquid is obtained, which is the modified epoxidized rapeseed oil grafted with methacrylic acid required.

[0047] The second step: 100 parts of the modified epoxidized rapeseed oil, 25 parts of poly(p-methylstyrene), 0.04 part of the initiator potassium persulfate, and 0.5 part of the chain transfer agent cumyl dithiobenzoate are dissolved in tetrahydrofuran at room temperature, mixed evenly, and purged with nitrogen for 20 minutes. After the solution temperature rises to 70 °C, the reaction is carried out at a constant temperature for 5 h under the condition that the stirring rate is 1000 r / min.

[0048] The third step: After treatment by vacuum distillation, the excess reactants are removed to obtain a light red viscoelastic solid, which is the pure vegetable oil-based block polymer.

[0049] Application of vegetable oil-based SBS modified asphalt block polymer composite rejuvenator in hot recycling of aged SBS modified asphalt. Under the condition of 160 °C, 10 parts of soybean oil and 4 parts of vegetable oil-based block polymer were sequentially added to 100 parts of aged SBS modified asphalt according to the mass ratio. The mixture was sheared by a high-speed shearer at a shear rate of 2500 r / min for 25 minutes to obtain vegetable oil-based block polymer composite recycled aged SBS modified asphalt. It was left standing at room temperature for 1 day, and the performance of the vegetable oil-based block polymer composite recycled aged SBS modified asphalt was tested.

[0050] Comparative Example 2

[0051] Preparation method of SBS modifier composite recycled aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170 °C, and sequentially add 4 parts of SBS modifier and 10 parts of rubber oil to 100 parts of aged SBS modified asphalt according to the mass ratio. The mixture was sheared by a high-speed shearer at a shear rate of 3000 r / min for 30 minutes to obtain SBS modifier composite recycled aged SBS modified asphalt. It was left standing at room temperature for 1 day, and the performance of the SBS modifier composite recycled aged SBS modified asphalt was tested.

[0052] Table 2 Basic parameters of the recycled SBS modified asphalt prepared in Example 2 and Comparative Example 2

[0053]

[0054] As can be seen from Table 2, the vegetable oil-based block polymer composite rejuvenator can effectively restore the ductility of aged SBS modified asphalt, and improve the ductility at 5 °C to exceed the level of unaged SBS modified asphalt. In addition, the viscosity of the recycled asphalt is similar to that of the unaged SBS modified asphalt. This indicates that the vegetable oil-based block polymer composite recycled asphalt can effectively restore the low-temperature performance of aged SBS modified asphalt while maintaining good high-temperature performance.

[0055] Example 3

[0056] Vegetable oil-based SBS modified asphalt block polymer composite rejuvenator. According to the mass ratio, the vegetable oil-based SBS modified asphalt block polymer composite rejuvenator is composed of 9 parts of rapeseed oil and 4 parts of vegetable oil-based block polymer.

[0057] The preparation method of the vegetable oil-based block polymer includes the following steps:

[0058] Step 1: Weigh 100 parts of epoxy castor oil, 0.4 parts of catalyst triethylamine, and 0.10 parts of inhibitor hydroquinone according to the mass ratio, mix them evenly at a constant temperature of 80 °C, and place them in a clean three-necked flask. When the solution temperature rises to 110 °C, add 40 parts of crotonic acid dropwise, and finish dropping within 1 h. Control the dropping speed at 1 - 2 drops / second. React at a constant temperature of 110 °C for 8 h. After extracting the reaction product with n-hexane, spin-dry it on a rotary evaporator to remove n-hexane, and obtain a brownish-yellow transparent viscous liquid, which is the modified epoxy castor oil grafted with crotonic acid as required.

[0059] Step 2: Weigh 100 parts of modified epoxy castor oil, 30 parts of poly-o-methylstyrene, 0.05 parts of initiator azobisisobutyronitrile, and 0.6 parts of chain transfer agent benzyl N,N-diphenylcarbamodithioate according to the mass ratio, dissolve them in tetrahydrofuran at room temperature, mix them evenly, and purge with nitrogen for 25 minutes. After the solution temperature rises to 80 °C, react at a constant temperature for 6 h under the condition of a stirring rate of 1200 r / min.

[0060] Step 3: After treatment by vacuum distillation, remove the excess reactants to obtain a light red viscoelastic solid, which is the pure vegetable oil-based block polymer.

[0061] Application of vegetable oil-based SBS modified asphalt block polymer composite regenerant in the thermal regeneration of aged SBS modified asphalt: At 170 °C, weigh 9 parts of rapeseed oil and 4 parts of vegetable oil-based block polymer according to the mass ratio, and add them to 100 parts of aged SBS modified asphalt in sequence. Use a high-speed shear machine to shear the mixture at a shear rate of 3000 r / min for 30 minutes to obtain vegetable oil-based block polymer composite regenerated aged SBS modified asphalt. Let it stand at room temperature for 1 day, and conduct performance tests on the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt.

[0062] Comparative Example 3

[0063] Preparation method of SBS modifier composite regenerated aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170 °C, weigh 4 parts of SBS modifier and 10 parts of rubber oil according to the mass ratio, and add them to 100 parts of aged SBS modified asphalt in sequence. Use a high-speed shear machine to shear the mixture at a shear rate of 3000 r / min for 30 minutes to obtain SBS modifier composite regenerated aged SBS modified asphalt. Let it stand at room temperature for 1 day, and conduct performance tests on the SBS modifier composite regenerated aged SBS modified asphalt.

[0064] Table 3 Basic parameters of the regenerated SBS modified asphalt prepared in Example 3 and Comparative Example 3

[0065]

[0066]

[0067] As can be seen from Table 3, compared with the SBS-modified regenerated asphalt, the vegetable oil-based block polymer composite regenerated asphalt has excellent performance in terms of elastic recovery ability. The elastic recovery ability of the regenerated asphalt is higher than that of the unaged SBS-modified asphalt.

[0068] Example 4

[0069] The vegetable oil-based SBS-modified asphalt block polymer composite regenerant. According to the mass ratio, the vegetable oil-based SBS-modified asphalt block polymer composite regenerant is composed of 8 parts of castor oil and 3 parts of vegetable oil-based block polymer.

[0070] The preparation method of the vegetable oil-based block polymer includes the following steps:

[0071] The first step: According to the mass fraction ratio, 100 parts of epoxidized cottonseed oil, 0.5 part of catalyst N,N-dimethylbenzylamine and 0.15 part of inhibitor hydroquinone are mixed evenly at a constant temperature of 80 °C, and then placed in a clean three-necked flask; when the solution temperature rises to 120 °C, 40 parts of 3-methylcrotonic acid are added dropwise, and the dropping is completed within 1 h, and the dropping rate is controlled at 1-2 drops / second. Under a constant temperature of 120 °C, the reaction is carried out for 8 h. After the reaction product is extracted with n-hexane, it is dried on a rotary evaporator to remove n-hexane, and a light yellow transparent viscous liquid is obtained, which is the modified epoxidized cottonseed oil grafted with 3-methylcrotonic acid as required;

[0072] The second step: According to the mass ratio, 100 parts of modified epoxidized cottonseed oil, 35 parts of poly(m-methylstyrene), 0.06 part of initiator azodiisopentanenitrile and 0.8 part of chain transfer agent 3-oxo-2-butyl trithiocarbonate are dissolved in tetrahydrofuran at room temperature, mixed evenly, and purged with nitrogen for 30 minutes. After the solution temperature rises to 90 °C, the reaction is carried out at a constant temperature for 8 h under the condition that the stirring rate is 1200 r / min;

[0073] The third step: After treatment by vacuum distillation, the excess reactants are removed to obtain a light red viscoelastic solid, which is the pure vegetable oil-based block polymer.

[0074] Application of vegetable oil-based SBS modified asphalt block polymer composite rejuvenator in thermal regeneration of aged SBS modified asphalt. Under the condition of 180 °C, 8 parts of castor oil and 3 parts of vegetable oil-based block polymer were added to 100 parts of aged SBS modified asphalt in sequence by mass ratio. The mixture was sheared by a high-speed shearer at a shear rate of 2000 r / min for 35 minutes to obtain vegetable oil-based block polymer composite regenerated aged SBS modified asphalt; it was left standing at room temperature for 1 day, and the performance test of vegetable oil-based block polymer composite regenerated aged SBS modified asphalt was carried out.

[0075] Comparative Example 4

[0076] Preparation method of SBS modifier composite regenerated aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170 °C, add 4 parts of SBS modifier and 10 parts of rubber oil to 100 parts of aged SBS modified asphalt in sequence by mass ratio. The mixture was sheared by a high-speed shearer at a shear rate of 3000 r / min for 30 minutes to obtain SBS modifier composite regenerated aged SBS modified asphalt; it was left standing at room temperature for 1 day, and the performance test of SBS modifier composite regenerated aged SBS modified asphalt was carried out.

[0077] Table 4 Basic parameters of the regenerated SBS modified asphalt prepared in Example 4 and Comparative Example 4

[0078]

[0079] As can be seen from Table 4, the vegetable oil-based block polymer composite regenerated asphalt can restore the comprehensive performance of the aged SBS modified asphalt to the unaged level. This is because the vegetable oil-based block polymer can effectively supplement the polymer cross-linked network structure that disintegrates during the aging process of SBS modified asphalt.

[0080] Example 5

[0081] Vegetable oil-based SBS modified asphalt block polymer composite rejuvenator. The vegetable oil-based SBS modified asphalt block polymer composite rejuvenator is composed of 11 parts of peanut oil and 5 parts of vegetable oil-based block polymer by mass ratio.

[0082] The preparation method of the vegetable oil-based block polymer includes the following steps:

[0083] Step 1: According to the mass fraction ratio, 100 parts of epoxidized peanut oil, 0.6 part of catalyst 1,4-diazabicyclo[2.2.2]octane and 0.20 part of inhibitor hydroquinone are mixed evenly at a constant temperature of 80 °C and then placed in a clean three-necked flask. After the solution temperature rises to 130 °C, 40 parts of maleic anhydride are added dropwise. The addition is completed within 1 h, and the dropping rate is controlled at 1 - 2 drops / second. At a constant temperature of 130 °C, the reaction is carried out for 6 h. After the reaction product is extracted with n-hexane, it is dried by rotary evaporation to remove n-hexane, and a brownish-yellow transparent viscous liquid is obtained, which is the modified epoxidized peanut oil grafted with maleic anhydride as required;

[0084] Step 2: According to the mass ratio, 100 parts of modified epoxidized peanut oil, 40 parts of poly(α-methylstyrene), 0.08 part of initiator diisopropyl peroxide and 0.8 part of chain transfer agent 1-phenylethyl disulfide are dissolved in tetrahydrofuran at room temperature. After mixing evenly, it is purged with nitrogen for 30 minutes. After the solution temperature rises to 120 °C, the reaction is carried out at a constant temperature for 5 h under the condition of a stirring rate of 900 r / min;

[0085] Step 3: After treatment by vacuum distillation, the excess reactants are removed to obtain a light red viscoelastic solid, which is a pure vegetable oil-based block polymer.

[0086] Application of vegetable oil-based SBS modified asphalt block polymer composite regenerant in the thermal regeneration of aged SBS modified asphalt. At 180 °C, according to the mass ratio, 11 parts of peanut oil and 5 parts of vegetable oil-based block polymer are added to 100 parts of aged SBS modified asphalt in sequence. The mixture is sheared by a high-speed shearer at a shear rate of 3000 r / min for 40 minutes to obtain vegetable oil-based block polymer composite regenerated aged SBS modified asphalt. It is left standing at room temperature for 1 day, and the performance of vegetable oil-based block polymer composite regenerated aged SBS modified asphalt is tested.

[0087] Comparative Example 5

[0088] Preparation method of SBS modifier composite regenerated aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170 °C, and add 4 parts of SBS modifier and 10 parts of rubber oil to 100 parts of aged SBS modified asphalt in sequence according to the mass ratio. The mixture is sheared by a high-speed shearer at a shear rate of 3000 r / min for 30 minutes to obtain SBS modifier composite regenerated aged SBS modified asphalt. It is left standing at room temperature for 1 day, and the performance of SBS modifier composite regenerated aged SBS modified asphalt is tested.

[0089] Table 5 Basic parameters of the regenerated SBS modified asphalt prepared in Example 5 and Comparative Example 5

[0090]

[0091]

[0092] As can be seen from Table 5, compared with the SBS modified regenerated asphalt, the vegetable oil-based block polymer composite regenerated asphalt has more excellent performance in terms of penetration. This is because vegetable oil can effectively supplement the light components lost by SBS modified asphalt during the aging process, thus restoring the colloidal structure of the aged asphalt phase.

[0093] Example 6

[0094] The vegetable oil-based SBS modified asphalt block polymer composite regenerant, according to the mass ratio, the vegetable oil-based SBS modified asphalt block polymer composite regenerant is composed of 12 parts of high-oleic rapeseed oil and 6 parts of vegetable oil-based block polymer.

[0095] The preparation method of the vegetable oil-based block polymer includes the following steps:

[0096] The first step: According to the mass fraction ratio, 100 parts of high-oleic acid epoxidized rapeseed oil, 0.2 part of catalyst N,N-triphenylphosphine and 0.30 part of inhibitor hydroquinone are mixed evenly at a constant temperature of 80 °C, and then placed in a clean three-necked flask; when the solution temperature rises to 100 °C, 20 parts of maleic anhydride are added dropwise, and the dropping is completed within 1 h, and the dropping rate is controlled at 1-2 drops / second. Under a constant temperature of 100 °C, the reaction is carried out for 6 h. After the reaction product is extracted with n-hexane, it is dried by rotary evaporation to remove n-hexane, and a brownish-yellow transparent viscous liquid is obtained, which is the modified high-oleic acid epoxidized rapeseed oil grafted with maleic anhydride as required;

[0097] The second step: According to the mass ratio, 100 parts of the modified high-oleic acid epoxidized rapeseed oil, 20 parts of polystyrene, 0.03 part of initiator dimethyl azobisisobutyrate and 0.4 part of chain transfer agent 1-phenylethyl disulfide are dissolved in tetrahydrofuran at room temperature, mixed evenly, and then purged with nitrogen for 20 minutes. After the solution temperature rises to 80 °C, the reaction is carried out at a constant temperature for 6 h under the condition of a stirring rate of 1000 r / min;

[0098] The third step: After treatment by vacuum distillation, the excess reactants are removed to obtain a light red viscoelastic solid, which is the pure vegetable oil-based block polymer.

[0099] Application of vegetable oil-based SBS modified asphalt block polymer composite regenerant in hot regeneration of aged SBS modified asphalt. Under the condition of 160 °C, 12 parts of high-oleic rapeseed oil and 6 parts of vegetable oil-based block polymer were sequentially added to 100 parts of aged SBS modified asphalt according to the mass ratio. The mixture was sheared by a high-speed shearer at a shear rate of 2500 r / min for 25 minutes to obtain vegetable oil-based block polymer composite regenerated aged SBS modified asphalt. It was left standing at room temperature for 1 day, and the performance of the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt was tested.

[0100] Comparative Example 6

[0101] Preparation method of SBS modifier composite regenerated aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170 °C, and sequentially add 4 parts of SBS modifier and 10 parts of rubber oil to 100 parts of aged SBS modified asphalt according to the mass ratio. The mixture was sheared by a high-speed shearer at a shear rate of 3000 r / min for 30 minutes to obtain SBS modifier composite regenerated aged SBS modified asphalt. It was left standing at room temperature for 1 day, and the performance of the SBS modifier composite regenerated aged SBS modified asphalt was tested.

[0102] Table 6 Basic parameters of the regenerated SBS modified asphalt prepared in Example 6 and Comparative Example 6

[0103]

[0104] As can be seen from Table 6, the vegetable oil-based block polymer composite regenerant can restore the high-temperature and low-temperature properties of the aged SBS modified asphalt to the level of unaged SBS modified asphalt at the same time, demonstrating excellent comprehensive regeneration ability.

[0105] Example 7

[0106] Vegetable oil-based SBS modified asphalt block polymer composite regenerant. According to the mass ratio, the vegetable oil-based SBS modified asphalt block polymer composite regenerant is composed of 10 parts of high-oleic soybean oil and 4 parts of vegetable oil-based block polymer.

[0107] The preparation method of the vegetable oil-based block polymer includes the following steps:

[0108] Step 1: According to the mass fraction ratio, 100 parts of high-oleic acid epoxy soybean oil, 0.4 parts of the catalyst triphenylphosphine, and 0.25 parts of the inhibitor hydroquinone are mixed evenly at a constant temperature of 80 °C, and then placed in a clean three-necked flask. After the solution temperature rises to 120 °C, 30 parts of acrylamide are added dropwise, and the addition is completed within 1 hour. The dropping rate is controlled at 1 - 2 drops / second. At a constant temperature of 120 °C, the reaction is carried out for 8 hours. After the reaction product is extracted with n-hexane, it is dried by rotary evaporation to remove n-hexane, and a light yellow transparent viscous liquid is obtained, which is the modified high-oleic acid epoxy soybean oil grafted with acrylamide as required.

[0109] Step 2: According to the mass ratio, 100 parts of the modified high-oleic acid epoxy soybean oil, 30 parts of poly(p-methylstyrene), 0.05 parts of the initiator diisopropylbenzene peroxide, and 0.6 parts of the chain transfer agent benzyl diethyldithiocarbamate are dissolved in tetrahydrofuran at room temperature, mixed evenly, and purged with nitrogen for 30 minutes. After the solution temperature rises to 100 °C, the reaction is carried out at a constant temperature for 8 hours under the condition of a stirring rate of 1200 r / min.

[0110] Step 3: After treatment by vacuum distillation, the excess reactants are removed to obtain a light red viscoelastic solid, which is the pure vegetable oil-based block polymer.

[0111] Application of vegetable oil-based SBS modified asphalt block polymer composite regenerant in the thermal regeneration of aged SBS modified asphalt. At 180 °C, according to the mass ratio, 10 parts of high-oleic acid epoxy soybean oil and 4 parts of the vegetable oil-based block polymer are added to 100 parts of aged SBS modified asphalt in sequence. The mixture is sheared by a high-speed shearer at a shear rate of 2500 r / min for 25 minutes to obtain the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt. It is left standing at room temperature for 1 day, and the performance of the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt is tested.

[0112] Comparative Example 7

[0113] Preparation method of SBS modifier composite regenerated aged SBS modified asphalt: Heat the aged SBS modified asphalt to 170 °C, and add 4 parts of SBS modifier and 10 parts of rubber oil to 100 parts of aged SBS modified asphalt in sequence according to the mass ratio. The mixture is sheared by a high-speed shearer at a shear rate of 3000 r / min for 30 minutes to obtain the SBS modifier composite regenerated aged SBS modified asphalt. It is left standing at room temperature for 1 day, and the performance of the SBS modifier composite regenerated aged SBS modified asphalt is tested.

[0114] Table 7 Basic parameters of the regenerated SBS modified asphalt prepared in Example 7 and Comparative Example 7

[0115]

[0116]

[0117] As can be seen from Table 7, compared with the SBS modified regenerated asphalt, the vegetable oil-based block polymer composite regenerated asphalt has excellent performance in terms of high temperature, low temperature, fatigue, etc. In addition, since its principle is vegetable oil, the use of petroleum-based materials is greatly reduced, achieving the sustainable development of road engineering materials.

[0118] From the specific experimental data given in Examples 1 to 7, it can be seen that the vegetable oil-based SBS modified asphalt block polymer composite regenerant of the present invention can not only supplement the lost light components in the aged SBS modified asphalt, but also supplement the polymer cross-linked network structure disintegrated in the SBS modified asphalt. In terms of performance, it is shown that the vegetable oil-based SBS modified asphalt block polymer composite regenerant can effectively improve the high temperature, low temperature and fatigue performance of the aged SBS modified asphalt. And, compared with the SBS composite regenerant as a regenerant, it shows a more comprehensive regeneration effect, and can restore the rheological properties of the aged SBS modified asphalt to be close to the level of fresh SBS modified asphalt. In addition, the vegetable oil-based block polymer regenerant uses vegetable oil as a raw material, significantly improving the carbon footprint of the regeneration of the aged SBS modified asphalt, and has outstanding performance in terms of environmental and economic benefits.

[0119] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to be equivalent embodiments with equivalent changes, but as long as the content does not depart from the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. Vegetable oil-based SBS modified asphalt block polymer composite regeneration agent, characterized by: The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent is composed of 8-12 parts of vegetable oil and 3-6 parts of vegetable oil-based block polymer in terms of mass proportion.

2. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 1, characterized in that: The vegetable oil is one or more of waste vegetable oil, soybean oil, rapeseed oil, castor oil, cottonseed oil, peanut oil, corn oil, olive oil, sunflower oil, high oleic rapeseed oil, high oleic peanut oil, high oleic olive oil, high oleic sunflower oil, high oleic avocado oil, high oleic camellia oil, high oleic soybean oil, and derivatives of the above vegetable oils.

3. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 1, characterized in that: The method for preparing the vegetable oil-based block polymer comprises the following steps: The first step: 100 parts of epoxy vegetable oil, 0.2-0.8 parts of catalyst, and 0.05-0.30 parts of inhibitor hydroquinone are mixed uniformly at a constant temperature of 80°C, and 20-60 parts of acid, anhydride or amide containing active carbon-carbon double bonds are added dropwise, and the mixture is reacted at a constant temperature of 90-150°C for 6-12 hours to obtain modified epoxy vegetable oil grafted with active carbon-carbon double bonds; Step 2: Dissolve 100 parts of modified epoxidized vegetable oil grafted with active carbon-carbon double bonds, 20-40 parts of polystyrene or its derivatives, 0.03-0.08 parts of initiator, and 0.4-0.8 parts of chain transfer agent in tetrahydrofuran according to the mass ratio, mix them evenly, seal and purge with nitrogen for 15-30 minutes, and react for 4-8 hours at a constant temperature of 60-120°C and a stirring rate of 800-1200r / min; Step 3: After vacuum distillation, pure vegetable oil-based block polymer is obtained.

4. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 3, characterized in that: In the first step, the epoxidized vegetable oil is one or more of epoxidized soybean oil, epoxidized rapeseed oil, epoxidized castor oil, epoxidized cottonseed oil, epoxidized peanut oil, epoxidized corn oil, epoxidized olive oil, epoxidized sunflower oil, high oleic epoxidized rapeseed oil, high oleic epoxidized peanut oil, high oleic epoxidized olive oil, high oleic epoxidized sunflower oil, high oleic epoxidized avocado oil, high oleic epoxidized camellia oil, high oleic epoxidized soybean oil, and derivatives of the above epoxidized vegetable oils.

5. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 3, characterized in that: The catalyst in the first step is one or more of N,N-dimethylaniline, triphenylphosphine, triethylamine, N,N-dimethylbenzylamine and 1,4-diazabicyclo[2.2.2]octane.

6. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 3, characterized in that: The acid, anhydride or amide containing active carbon-carbon double bonds in the first step is one or more of acrylic acid, methacrylic acid, crotonic acid, 3-methylcrotonic acid, maleic anhydride, fumaric anhydride, acrylamide and N,N-dimethylacrylamide.

7. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 3, characterized in that: In the second step, the polystyrene or its derivative is one or more of polystyrene, poly-p-methylstyrene, poly-o-methylstyrene, poly-m-methylstyrene and poly-α-methylstyrene.

8. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 3, characterized in that: The initiator in the second step is one or more of dicumyl peroxide, potassium persulfate, azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptanenitrile and dimethyl azobisisobutyrate.

9. The vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to claim 3, characterized in that: The chain transfer agent in the second step is one or more of benzyl diethyldithiocarbamate, cumyl dithiobenzoate, N,N-diphenylaminobenzyl dithiocarbamate, 3-oxo-2-butyl ethyl trithiocarbonate, and 1-phenylethyl dithiophene ethyl ester.

10. Use of the vegetable oil-based SBS modified asphalt block polymer composite regeneration agent according to any one of claims 1 to 9 in thermal regeneration of aged SBS modified asphalt, characterized in that: Under the condition of 150-180°C, 6-12 parts of vegetable oil-based SBS modified asphalt block polymer composite regeneration agent are added to 100 parts of aged SBS modified asphalt according to the mass ratio, and the mixture is sheared at a shear rate of 2000-3000r / min for 20-40 minutes using a high-speed shearing machine to obtain a vegetable oil-based block polymer composite regenerated aged SBS modified asphalt; the mixture is allowed to stand at room temperature for 1 day, and the performance of the vegetable oil-based block polymer composite regenerated aged SBS modified asphalt is tested.

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