Preparation and curing method of high-viscosity temperature self-adjusting bio-based polyurethane pavement material

Abstract

The invention discloses a preparation method and a curing method of a high-viscosity temperature self-adjusting bio-based polyurethane pavement material, and belongs to the technical field of road engineering materials. According to the invention, firstly, the bio-based material is used for modifying the asphalt to improve the viscosity and the stability of the asphalt, and then the modified asphalt and the bio-based polyurethane phase change material are combined, so that the viscosity, the durability and the temperature self-adjusting capability of the material are remarkably improved, and when the material is used for pavement construction, the rutting resistance and the crack resistance of a pavement can be remarkably enhanced; the energy consumption and the production cost are reduced, the carbon emission is reduced, the service life of the pavement is effectively prolonged, and the problems that the existing phase-change material mainly depends on petroleum-based raw materials and does not conform to the sustainable development goal and the green and environment-friendly concept are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of road engineering materials, and more specifically relates to a preparation method of a high-viscosity self-temperature regulating bio-based polyurethane pavement material and a curing method thereof. Background Art

[0002] In modern road engineering, with the continuous increase in traffic volume and vehicle load, traditional asphalt pavement materials face severe challenges such as insufficient durability, high-temperature deformation and low-temperature embrittlement. These problems not only shorten the service life of the road, but also frequently increase the need for maintenance, resulting in reduced traffic efficiency and safety. Therefore, the development of more durable and higher-performance modified asphalt materials has become a key research direction. Modified asphalt is usually enhanced by adding polymers to enhance viscosity and stability, thereby improving its ability to resist high-temperature deformation and low-temperature cracking. However, most of the widely used modified asphalts currently rely on petroleum-based polymers, which not only increases costs, but also consumes a lot of energy in the production process, causing adverse effects on the environment. In addition, petroleum-based asphalt is sensitive to temperature changes and is prone to aging in extreme climates. To this end, researchers have begun to explore the application of bio-based materials to reduce dependence on petroleum and reduce the burden on the environment.

[0003] As a renewable resource, bio-based materials show unique advantages in asphalt modification. The chemical structure of vegetable oil can be used to synthesize self-cross-linking polyurethane, which can improve the viscosity and stability of asphalt, thereby effectively extending the durability of roads. Compared with traditional petroleum-based materials, bio-based materials are not only renewable, but also have less pollution in the production process, which helps to reduce carbon emissions. However, the performance of bio-based materials in high-temperature rutting resistance, low-temperature cracking resistance and long-term durability still needs to be improved. Extreme temperature changes will accelerate the aging and loss of asphalt materials. Phase change materials (PCM) can absorb and release heat during temperature fluctuations, helping to alleviate softening and rutting problems at high temperatures, as well as cracking problems at low temperatures. However, current PCMs mainly rely on petroleum-based raw materials, which is inconsistent with the goal of sustainable development.

[0004] Therefore, it is of great significance to develop a green high-performance pavement material with excellent rutting resistance, low-temperature crack resistance and long-term durability. Summary of the invention

[0005] The purpose of the present invention is to provide a high-viscosity self-temperature-regulating bio-based polyurethane pavement material preparation and curing method thereof, so as to solve the problem that the existing phase change materials mainly rely on petroleum-based raw materials, which is inconsistent with the goal of sustainable development and the concept of green environmental protection. The present invention prepares a green high-performance pavement material. By introducing a bio-based polyurethane phase change material with a self-temperature-regulating function, the asphalt automatically adjusts its viscosity when the temperature changes to enhance its anti-rutting performance. The phase change material releases heat at low temperatures to improve its low-temperature crack resistance and long-term durability.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is to provide a high-viscosity self-temperature-adjusting bio-based polyurethane modified asphalt, comprising the following raw materials in parts by weight: 3 to 5 parts of bio-based polyurethane phase change material and 90 to 110 parts of bio-based polyurethane high-viscosity modified asphalt;

[0008] The bio-based polyurethane high-viscosity modified asphalt comprises the following raw materials in parts by weight: 60-70 parts of base asphalt, 10-20 parts of bio-oil, 0.5-1 part of oligomeric polyol, 0.5-2 parts of chain extender and 15-25 parts of isocyanate.

[0009] The present invention firstly uses bio-oil, oligomeric polyols, chain extenders and isocyanates to modify asphalt to improve the viscosity and stability of asphalt, and then combines the modified asphalt with a bio-based polyurethane phase change material to significantly improve the viscosity, durability and temperature self-regulation ability of the material. When used in road construction, it can significantly enhance the road surface's rutting resistance and cracking resistance, and also reduce energy consumption and production costs, reduce carbon emissions, and effectively extend the service life of the road surface, solving the problem that the existing phase change materials mainly rely on petroleum-based raw materials, which is inconsistent with the goal of sustainable development and the concept of green environmental protection. In the present invention, the bio-based polyurethane phase change material is also prepared by bio-oil, which conforms to the concept of green environmental protection on the basis of significantly improving the material's rutting resistance and cracking resistance.

[0010] Optionally, the bio-oil includes one or more of castor oil, coconut oil, and palm oil; the isocyanate includes hexamethylene diisocyanate and / or hexamethylene diisocyanate; the chain extender includes 1,4-butanediol and / or ethylene glycol; and the oligomeric polyol includes polyoxypropylene glycol and / or polytetramethylene glycol.

[0011] Preferably, the bio-oil, chain extender and oligomeric polyol are dried before use to remove moisture; the drying temperature is independently 100-120° C., and the drying time is independently 2-3 hours.

[0012] Preferably, the bio-based polyurethane phase change material is prepared from bio-oil, isocyanate, chain extender and solvent, specifically comprising the following steps:

[0013] Dissolving bio-oil in a solvent to obtain a mixed solution; first adding isocyanate to the mixed solution for prepolymerization, then adding a chain extender for chain extension reaction, and drying the product after completion to obtain the bio-based polyurethane phase change material;

[0014] The bio-oil includes one or more of castor oil, coconut oil and palm oil; the isocyanate includes hexamethylene diisocyanate and / or hexamethylene diisocyanate; the chain extender includes 1,4-butanediol and / or ethylene glycol; and the solvent includes N,N-dimethylformamide.

[0015] Similarly, before preparing the bio-based polyurethane phase change material, the bio-oil and the chain extender are dried to remove moisture; the drying temperature is independently 100-120° C., and the drying time is independently 2-3 hours.

[0016] Preferably, the isocyanate index during the preparation of the bio-based polyurethane phase change material is R=1.

[0017] Preferably, the molar ratio of the unreacted -NCO in the prepolymer obtained by the prepolymerization to the -OH in the chain extender is 1:1.

[0018] Preferably, in the bio-based polyurethane phase change material, the mass ratio of bio-oil to solvent is 1:8-12, and the molar ratio of -OH in bio-oil, -NCO in isocyanate and -OH in chain extender is 1:4-6:3-5; the dissolution temperature is 50-60°C, and the dissolution stirring speed is 100-150r / min; the prepolymerization is carried out under a protective gas atmosphere, the prepolymerization temperature is 60-80°C, the prepolymerization stirring speed is 100-150r / min, and the prepolymerization time is 3-4h; the chain extension reaction is carried out under a protective gas atmosphere, the chain extension reaction temperature is 60-80°C, the chain extension reaction stirring speed is 100-150r / min, and the chain extension reaction time is 2-3h; the protective gas includes nitrogen; the drying temperature is 95-110°C, and the drying time is 48-52h; the particle size of the bio-based polyurethane phase change material is ≤0.075mm.

[0019] The second technical solution of the present invention is to provide a method for preparing the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt, comprising the following steps:

[0020] According to the prescribed amount, bio-oil, oligomeric polyols and chain extenders are added to the preheated base asphalt for the first mixing, then the bio-based polyurethane phase change material is added for the second mixing, and finally isocyanate is added for the third mixing to obtain the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt.

[0021] Preferably, the preheating temperature of the matrix asphalt is 130-140°C; the temperature of the first mixing is 100-120°C, the stirring speed of the first mixing is 300-500 r / min, and the time of the first mixing is 10-15 min; the temperature of the second mixing is 100-120°C, the stirring speed of the second mixing is 500-700 r / min, and the time of the second mixing is 5-10 min; the temperature of the third mixing is 130-140°C, the stirring speed of the third mixing is 700-800 r / min, and the time of the third mixing is 15-20 min.

[0022] The present invention adds the bio-based polyurethane phase change material before introducing the isocyanate to ensure that after the isocyanate is added, the bio-based polyurethane phase change material can be fully dispersed in the asphalt phase to form a polyurethane network structure; in addition, by controlling the temperature of each mixing stage, it can ensure that the reaction is complete and the polyurethane network structure is formed while preventing thermal degradation. In addition, controlling the stirring speed and mixing time is also crucial to achieve uniform distribution of each component.

[0023] The present invention prepares a green high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt. By introducing a bio-based polyurethane phase change material with a self-temperature-regulating function, the asphalt automatically adjusts its viscosity when the temperature changes to enhance its anti-rutting performance. The phase change material releases heat at low temperatures to enhance its low-temperature crack resistance and long-term durability.

[0024] The third technical solution of the present invention is to provide the application of the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt in the preparation of high-viscosity self-temperature-regulating bio-based polyurethane pavement material.

[0025] The fourth technical solution of the present invention is to provide a high-viscosity self-temperature-adjusting bio-based polyurethane pavement material, wherein the high-viscosity self-temperature-adjusting bio-based polyurethane pavement material comprises mineral aggregate and the high-viscosity self-temperature-adjusting bio-based polyurethane modified asphalt;

[0026] The oil-to-stone ratio of the high-viscosity self-temperature-regulating bio-based polyurethane pavement material is 5.5-8%.

[0027] The fifth technical solution of the present invention is to provide a method for preparing the high-viscosity self-temperature regulating bio-based polyurethane pavement material, comprising the following steps:

[0028] The high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt and preheated mineral aggregate are mixed, and then molded and cured in sequence to obtain the high-viscosity self-temperature-regulating bio-based polyurethane pavement material.

[0029] Preferably, the preheating temperature of the mineral aggregate is 100-110°C, and the preheating time of the mineral aggregate is 4-4.5h; the mixing temperature is 120-130°C, and the mixing time is 130-150s; the curing includes an initial curing stage and a late curing stage, and the curing parameters are set as: initial curing temperature 100-130°C, initial curing time 7-8h, late curing temperature 20-30°C, and late curing time 24-48h.

[0030] Preferably, the molding is compaction molding, and the number of compaction times on both sides is 84 to 86 times.

[0031] The present invention can effectively adjust the adhesion between asphalt and mineral aggregate by controlling the oil-stone ratio, mixing parameters and curing parameters, ensure that the asphalt and mineral aggregate are evenly mixed under optimal conditions, and accelerate the complete reaction of high-viscosity self-temperature regulating bio-based polyurethane modified asphalt to enhance its water damage resistance and aging resistance. Combined with the high-viscosity self-temperature regulating bio-based polyurethane modified asphalt's own properties, it ensures that the obtained pavement material has high rutting resistance, low-temperature crack resistance and long-term durability.

[0032] The present invention discloses the following technical effects:

[0033] 1. Temperature self-regulation function: Bio-based polyurethane phase change materials have temperature self-regulation function, which can absorb heat at high temperature and release heat at low temperature. Combining it with high-viscosity bio-based polyurethane modified asphalt to prepare pavement materials can reduce high-temperature rutting and low-temperature cracking, and extend the service life of pavement materials;

[0034] 2. High viscosity and anti-deformation ability: Bio-based polyurethane high-viscosity modified asphalt enhances the anti-deformation performance of pavement materials, ensures stability at high temperatures, and prevents rutting;

[0035] 3. Low-temperature crack resistance: Bio-based polyurethane phase change materials improve the fracture strength and energy absorption capacity of pavement materials at low temperatures, and can effectively prevent low-temperature cracking of pavement materials;

[0036] 4. Optimization of thermal conductivity: High-viscosity self-temperature-adjusting bio-based polyurethane modified asphalt has a lower thermal conductivity, which can slow down the material's heating rate, reduce temperature fluctuations, and improve the stability of pavement materials at high temperatures;

[0037] 5. Environmental protection and sustainability: High-viscosity self-temperature-adjusting bio-based polyurethane modified asphalt uses bio-based raw materials such as castor oil, which reduces dependence on oil, reduces carbon emissions, and meets green environmental protection needs;

[0038] 6. High performance and durability: By modifying asphalt with bio-based polyurethane, the viscosity, compatibility and dispersibility of bio-based polyurethane high-viscosity modified asphalt are improved, making it excellent in resistance to rutting, cracking and thermal stress, and suitable for application in the preparation of pavement materials under extreme climates. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a flow chart for preparing the bio-based polyurethane phase change material, high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt and high-viscosity self-temperature-regulating bio-based polyurethane pavement material described in the examples. DETAILED DESCRIPTION

[0040] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0041] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0042] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0043] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0044] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0045] The mineral aggregates used in the following examples and comparative examples adopt AC-13 type grading, as shown in Table 1.

[0046] Table 1 Screen sizes and corresponding pass percentages of AC-13 graded sieves

[0047] Screen size (mm) 16 13.2 9.5 4.75 2.36 1.18 0.6 0.3 0.15 0.075 Pass rate (%) 100 95 76.5 53 37 26.5 19 13.5 10 6

[0048] Some of the raw materials used and their purchase sources are shown in Table 2.

[0049] Table 2 Raw materials and their purchase sources

[0050]

[0051] Unless otherwise specified, other raw materials are commercially available products. Different manufacturers and models of commercially available products do not affect the performance of the obtained materials.

[0052] The normal temperature involved in the present invention is 25±5°C unless otherwise specified.

[0053] Examples 1 to 3

[0054] Examples 1 to 3 provide the preparation of the bio-based polyurethane phase change material, and the specific steps are as follows:

[0055] S1. Dehydrate the weighed castor oil and 1,4-butanediol under vacuum at 120°C for 2.5 hours to remove moisture.

[0056] S2. A three-necked round-bottom flask was used as a reaction container. During the synthesis process, nitrogen was introduced for protection. N,N-dimethylformamide (whose mass was 10 times that of castor oil) was added to the reaction container, and then castor oil was added thereto. The mixture was stirred and dissolved at a temperature of 50°C and a stirring rate of 150 r / min. Then, hexamethylene diisocyanate (added according to the isocyanate index R=1) was added. The mixture was stirred for 3 hours at a temperature of 80°C and a stirring rate of 120 r / min to generate a polyurethane prepolymer. Finally, dehydrated 1,4-butanediol was added (the molar ratio of -NCO that did not participate in the reaction in the generated polyurethane prepolymer to -OH in the chain extender (1,4-butanediol) was 1:1), and the mixture was stirred for 2 hours at a temperature of 80°C and a stirring rate of 150 r / min to obtain a mixture.

[0057] S3. Pour the mixture obtained in S2 into a tetrafluoroethylene strip mold, vacuum dry it at 100° C. for 48 hours to obtain a solid bio-based polyurethane phase change material, grind and sieve it to a particle size of ≤0.075 mm to obtain a bio-based polyurethane phase change material.

[0058] The amounts of castor oil, 1,4-butanediol and hexamethylene diisocyanate used in Examples 1 to 3 are shown in Table 3.

[0059] Table 3 Amounts of castor oil, 1,4-butanediol and hexamethylene diisocyanate in Examples 1 to 3

[0060]

[0061] The amounts of castor oil, hexamethylene diisocyanate and 1,4-butanediol in Table 3 were calculated based on the condition that "the molar ratio of -OH in castor oil, -NCO in hexamethylene diisocyanate and -OH in 1,4-butanediol is 1:4-6:3-5".

[0062] The phase change parameters of the bio-based polyurethane phase change materials obtained in Examples 1 to 3 were measured by differential scanning calorimetry (DSC). The results are shown in Table 4.

[0063] Table 4 Phase change parameters of bio-based polyurethane phase change materials obtained in Examples 1 to 3

[0064]

[0065] Embodiments 4 to 6

[0066] Examples 4 to 6 provide the preparation of the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt, and the specific steps are as follows:

[0067] S1. Put 70 parts of 70# base asphalt into an oven and preheat it at 140°C to a fully fluid state, then add it to a stirring tank, heat and maintain the temperature at 120°C, then add 15 parts of castor oil, 1 part of polyoxypropylene glycol and 1 part of 1,4-butanediol into the stirring tank, and stir at a rate of 350r / min for 15 minutes.

[0068] S2. Add the bio-based polyurethane phase change material prepared in Example 3 into a stirring tank according to the amount in Table 5, maintain the temperature at 120° C., and stir for 10 min at a stirring rate of 500 r / min.

[0069] S3. Add 15 parts of isocyanate into a stirring tank, stir for 15 minutes at a temperature of 130°C and a stirring rate of 700 r / min, and place the stirred modified asphalt into an oven at a temperature of 100°C for 7 hours to obtain a high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt.

[0070] Table 5 Amount of bio-based polyurethane phase change material prepared in Example 3 in Examples 4 to 6

[0071]

[0072] Embodiment 7-8

[0073] Examples 7 to 8 provide the preparation of the high-viscosity self-temperature regulating bio-based polyurethane pavement material, and the specific steps are as follows:

[0074] S1. Preheat 4700 g of mineral aggregate prepared with AC-13 grade in an oven at 110°C for 4.5 h.

[0075] S2. Add 370 g (7.8% oil-stone ratio) of the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt prepared in Example 6 and the mineral aggregate obtained in S1 into a preheated mixing pot at a temperature of 130°C, maintain the above temperature and mix for 75 seconds, pour in the mineral powder after mixing evenly, and mix for another 75 seconds, and compact 85 times (double-sided compaction times) at room temperature to form.

[0076] S3. Curing the formed specimens. The specific curing parameters are shown in Table 6 to obtain a high-viscosity self-temperature-regulating bio-based polyurethane pavement material.

[0077] Table 6 Setting of health parameters of Examples 7 to 8

[0078]

[0079] Comparative Example 1

[0080] The difference from Example 4 is that the addition of the bio-based polyurethane phase change material prepared in Example 3 is omitted, and the rest is the same as Example 4.

[0081] Comparative Example 2

[0082] This comparative example uses finished styrene-butadiene-styrene modified asphalt.

[0083] Performance test of modified asphalt obtained in Examples 4 to 6 and Comparative Examples 1 to 2:

[0084] 1. The performance of the modified asphalt obtained in Examples 4 to 6 and Comparative Examples 1 to 2 was tested by three major indicators of asphalt and dynamic shear rheology test (DSR). The specific method is as follows and the results are shown in Table 7.

[0085] Test method: The test is carried out in accordance with the provisions of "Technical Specifications for Highway Asphalt Pavement Construction" JTG20 and AASHTO MP19-10.

[0086] Table 7 Properties of modified asphalt obtained in Examples 4 to 6 and Comparative Examples 1 to 2

[0087]

[0088] It can be seen from Table 7 that the modified asphalt obtained in the present invention has a high softening point, a small ductility, a high viscosity, a large elastic recovery rate, and a low irrecoverable creep compliance compared to the comparative example, which indicates that the modified asphalt obtained in the present invention has good high-temperature stability, strong deformation resistance, excellent elastic properties, good low-temperature crack resistance, and strong anti-aging performance.

[0089] 2. The temperature regulating performance of the modified asphalt obtained in Examples 4 to 6 and Comparative Examples 1 to 2 was tested using a grating temperature sensor, and the method was as follows:

[0090] First, 400g of modified asphalt was heated to a molten state and packaged in aluminum boxes. The grating temperature sensor was inserted into the middle of the modified asphalt and fixed. It was left to stand at room temperature for 5 hours until the asphalt was completely solidified. It was then placed in a 16°C water bath and placed on a bracket. After keeping warm for 2 hours, it was moved to a 67°C water bath to complete the heating process and the delay time was recorded. After the detector temperature stabilized for 30 minutes, it was moved back to the 16°C water bath to complete the cooling process and the delay time was recorded. The results are shown in Table 8.

[0091] Table 8 Self-temperature regulating properties of modified asphalt obtained in Examples 4 to 6 and Comparative Examples 1 to 2

[0092]

[0093] It can be seen from Table 8 that the modified asphalt obtained in the present invention has excellent self-temperature regulating performance. Using it in the preparation of pavement materials can reduce high-temperature rutting and low-temperature cracking of pavement materials and extend the service life of pavement materials.

[0094] Comparative Example 3

[0095] The difference from Example 8 is that the "high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt prepared in Example 6" is replaced by the "finished styrene-butadiene-styrene modified asphalt of Comparative Example 1", and the rest is the same as Example 8.

[0096] Comparative Example 4

[0097] The difference from Comparative Example 3 is that the mixing temperature "130°C" is replaced by "180°C", and the rest is the same as Comparative Example 3.

[0098] Comparative Example 5

[0099] The difference from Example 8 is that the steps in the initial stage of health preservation are omitted, and the rest are the same as Example 8.

[0100] Comparative Example 6

[0101] The difference from Example 8 is that the amount of high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt prepared in Example 6 is replaced with 320 g (oil-stone ratio 6.8%), and the rest is the same as Example 8.

[0102] Performance tests of the pavement materials obtained in Examples 7 to 8 and Comparative Examples 3 to 6:

[0103] The performance of the pavement materials obtained in Examples 7 to 8 and Comparative Examples 3 to 6 was tested by a dynamic semicircular bending test (SCB). The results are shown in Table 9.

[0104] Table 9 Performance of pavement materials obtained in Examples 7 to 8 and Comparative Examples 3 to 6

[0105]

[0106] It can be seen from Table 9 that the fracture strength and low-temperature fracture energy of the pavement material obtained by the present invention are higher than those of the comparative example, and the rutting depth can be controlled within the range of 1.4 to 2.1 mm.

[0107] The modified asphalt obtained by the present invention shows outstanding advantages in thermal management, deformation resistance, durability and environmental protection performance. It can effectively absorb and store heat in a high temperature environment, and release the stored heat at a low temperature, slowing down the temperature drop, reducing the risk of low-temperature cracking, realizing the self-temperature regulating function and extending the service life of the pavement. Compared with the traditional styrene-butadiene-styrene modified asphalt, the high viscosity self-temperature regulating bio-based polyurethane modified asphalt of the present invention has a viscosity that is 15% higher than that of the comparative example 2 at high temperature, and the elastic recovery rate of the material is as high as 98.6%. The addition of bio-based polyurethane phase change material significantly adjusts the temperature change rate of the modified asphalt, realizing the self-temperature regulating performance of the high viscosity self-temperature regulating bio-based polyurethane pavement material. The fracture strength of the pavement material prepared by the present invention is increased to 4.43Mpa, and a high toughness is maintained in the low-temperature fracture energy test (2587.15J / m 2 ), showing excellent crack resistance. Compared with styrene-butadiene-styrene modified asphalt, it not only achieves better technical effects than styrene-butadiene-styrene modified asphalt, but also has a mixing temperature 50°C lower than styrene-butadiene-styrene modified asphalt. In addition, the present invention uses renewable bio-based raw materials, reduces dependence on petroleum-based raw materials, reduces carbon emissions, and meets the green environmental protection requirements of sustainable development.

[0108] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0109] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt, characterized in that: The method comprises the following raw materials in parts by weight: 3 to 5 parts of bio-based polyurethane phase change material and 90 to 110 parts of bio-based polyurethane high-viscosity modified asphalt; The bio-based polyurethane high-viscosity modified asphalt comprises the following raw materials in parts by weight: 60-70 parts of base asphalt, 10-20 parts of bio-oil, 0.5-1 part of oligomeric polyol, 0.5-2 parts of chain extender and 15-25 parts of isocyanate.

2. The high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt according to claim 1, characterized in that: The bio-based polyurethane phase change material is prepared from bio-oil, isocyanate, chain extender and solvent, and specifically comprises the following steps: The bio-oil is dissolved in a solvent to obtain a mixed solution; isocyanate is first added to the mixed solution for prepolymerization, and then a chain extender is added for chain extension reaction, and after completion, the product is dried to obtain the bio-based polyurethane phase change material.

3. The high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt according to claim 1 or 2, characterized in that: The bio-oil independently includes one or more of castor oil, coconut oil and palm oil; and / or, the isocyanate independently includes hexamethylene diisocyanate and / or hexamethylene diisocyanate; and / or, the chain extender independently includes 1,4-butanediol and / or ethylene glycol; and / or, the solvent includes N,N-dimethylformamide; and / or, the oligomeric polyol includes polyoxypropylene glycol and / or polytetrahydrofuran diol.

4. The high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt according to claim 2, characterized in that: In the bio-based polyurethane phase change material, the mass ratio of bio-oil to solvent is 1:8-12, and the molar ratio of -OH in bio-oil, -NCO in isocyanate and -OH in chain extender is 1:4-6:3-5; and / or, the dissolution temperature is 50-60°C, and the dissolution stirring speed is 100-150r / min; and / or, the prepolymerization is carried out under a protective gas atmosphere, the prepolymerization temperature is 60-80°C, and the prepolymerization stirring speed is 100-150r / m in, the prepolymerization time is 3 to 4 hours; and / or, the chain extension reaction is carried out under a protective gas atmosphere, the chain extension reaction temperature is 60 to 80° C., the chain extension reaction stirring speed is 100 to 150 r / min, and the chain extension reaction time is 2 to 3 hours; and / or, the protective gas includes nitrogen; and / or, the drying temperature is 95 to 110° C., and the drying time is 48 to 52 hours; and / or, the particle size of the bio-based polyurethane phase change material is ≤0.075 mm.

5. The method for preparing the high-viscosity self-temperature regulating bio-based polyurethane modified asphalt according to any one of claims 1 to 4, characterized in that: The steps include: According to the prescribed amount, bio-oil, oligomeric polyols and chain extenders are added to the preheated base asphalt for the first mixing, then the bio-based polyurethane phase change material is added for the second mixing, and finally isocyanate is added for the third mixing to obtain the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt.

6. The preparation method according to claim 5, characterized in that: The preheating temperature of the matrix asphalt is 130-140°C; and / or, the temperature of the first mixing is 100-120°C, the stirring speed of the first mixing is 300-500r / min, and the time of the first mixing is 10-15min; and / or, the temperature of the second mixing is 100-120°C, the stirring speed of the second mixing is 500-700r / min, and the time of the second mixing is 5-10min; and / or, the temperature of the third mixing is 130-140°C, the stirring speed of the third mixing is 700-800r / min, and the time of the third mixing is 15-20min.

7. Use of the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt according to any one of claims 1 to 4 in the preparation of high-viscosity self-temperature-regulating bio-based polyurethane pavement materials.

8. A high-viscosity self-temperature regulating bio-based polyurethane pavement material, characterized in that: The high-viscosity self-temperature-regulating bio-based polyurethane pavement material comprises mineral aggregate and the high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt according to any one of claims 1 to 4; The oil-to-stone ratio of the high-viscosity self-temperature-regulating bio-based polyurethane pavement material is 5.5-8%.

9. The method for preparing the high-viscosity self-temperature regulating bio-based polyurethane pavement material according to claim 8, characterized in that: The steps include: The high-viscosity self-temperature-regulating bio-based polyurethane modified asphalt and preheated mineral aggregate are mixed, and then molded and cured in sequence to obtain the high-viscosity self-temperature-regulating bio-based polyurethane pavement material.

10. The preparation method according to claim 9, characterized in that: The preheating temperature of the mineral aggregate is 100-110°C, and the preheating time of the mineral aggregate is 4-4.5h; and / or, the mixing temperature is 120-130°C, and the mixing time is 130-150s; and / or, the curing includes an initial curing stage and a late curing stage, and the curing parameters are set as: initial curing temperature 100-130°C, initial curing time 7-8h, late curing temperature 20-30°C, and late curing time 24-48h.

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