Anti-rutting bio-based asphalt modifier and preparation method thereof

Abstract

The invention relates to the technical field of road building materials, in particular to an anti-rutting bio-based asphalt modifier and a preparation method thereof.The anti-rutting bio-based asphalt modifier is prepared from 40-60 parts of bio-based polymer, 12-18 parts of reinforcing filler, 10-12 parts of plasticizer, 2-5 parts of cross-linking agent and 1-3 parts of antioxidant; the preparation method of the anti-rut bio-based asphalt modifier comprises the following steps: adding the bio-based polymer, the reinforcing filler, the plasticizer, the cross-linking agent and the antioxidant into a high-speed mixer to obtain a mixture, adding the mixture into a double-screw extruder, carrying out melt blending extrusion, cooling and pelletizing to obtain the anti-rut bio-based asphalt modifier. The prepared anti-rut bio-based asphalt modifier significantly improves the high-temperature stability of an asphalt mixture, effectively inhibits the generation of ruts, has good low-temperature crack resistance, and can enhance the durability of a road and prolong the service life of the road.

Description

Technical Field

[0001] This application relates to the field of road construction materials technology, and more specifically, it relates to a rutting-resistant bio-based asphalt modifier and its preparation method. Background Technology

[0002] Asphalt pavements are prone to rutting under high temperature and heavy load conditions. Rutting not only affects the smoothness and driving comfort of the pavement, but also leads to pavement deformation, reduces pavement service life, and increases maintenance costs. Traditional asphalt modifiers, such as SBS (styrene-butadiene-styrene block copolymer), can improve asphalt performance to some extent, but they suffer from high cost, limited resources, and the need for further improvement in some properties. Meanwhile, increasingly stringent environmental requirements are prompting the search for greener and more sustainable asphalt modification solutions. Bio-based materials, due to their renewable and environmentally friendly advantages, have gradually become a research hotspot in the field of asphalt modification. However, existing bio-based asphalt modifiers still have shortcomings in terms of rutting resistance, compatibility with asphalt, and the complexity of their preparation processes, making it difficult to meet the needs of practical engineering. Therefore, developing a high-performance, low-cost, and simple-to-prepare rutting-resistant bio-based asphalt modifier is of significant practical importance. Summary of the Invention

[0003] To address the technical problems mentioned in the background section, this application provides a rutting-resistant bio-based asphalt modifier.

[0004] This application provides a rutting-resistant bio-based asphalt modifier, employing the following technical solution: A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40-60 parts of bio-based polymer, 12-18 parts of reinforcing filler, 10-12 parts of plasticizer, 2-5 parts of crosslinking agent, and 1-3 parts of antioxidant.

[0005] Preferably, the preparation steps of the bio-based polymer are as follows: Waste vegetable oil, bio-based polyol, and maleic anhydride were added to a reactor. Under stirring, the temperature was raised to 180-220℃, a catalyst was added, and the reaction was stirred for 3-5 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240-280℃, adipic acid dihydrazide was added, and polycondensation was carried out for 2-4 hours under a vacuum of <100Pa. The product was then dried and dehydrated to obtain the bio-based polymer matrix.

[0006] Preferably, the bio-based polyol is xylitol and / or sorbitol.

[0007] Preferably, the mass ratio of the waste vegetable oil, bio-based polyol, and maleic anhydride is 100-120:40-50:3-8.

[0008] Preferably, the amount of adipic acid dihydrazide added is 1-3% of the total mass of waste vegetable oil and bio-based polyol.

[0009] Preferably, the preparation of the reinforcing filler includes the following preparation steps: Step 1: After crushing the natural fiber, disperse it in an alkaline solution and stir at 40-60℃ for 1-3 hours. After washing and drying, immerse it in a 1-3% silane coupling agent solution, adjust the pH of the solution to 4-6, and stir at 30-50℃ for 2-4 hours. After filtration, washing, and drying, obtain the pretreated fiber. Step 2: Disperse the pretreated fibers in a polymer solution and stir the reaction at 60-80℃ for 4-8 hours. After the reaction is completed, wash and dry to obtain the reinforcing filler.

[0010] Preferably, the polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 5-10:3-8:1-3:100-150.

[0011] Preferably, the mass ratio of the pretreated fiber to the polymer solution is 3-5:12-18.

[0012] Preferably, the plasticizer is tributyl citrate.

[0013] Preferably, the crosslinking agent is an isocyanate crosslinking agent.

[0014] Preferably, the isocyanate crosslinking agent is one or more of hexamethylene diisocyanate, hexamethylene diisocyanate trimer, diphenylmethane diisocyanate, and toluene diisocyanate.

[0015] Preferably, the antioxidant is composed of hindered phenolic antioxidants and phosphite antioxidants in a mass ratio of 3-5:1-2.

[0016] Preferably, the hindered phenolic antioxidant is one or more of antioxidant 1010, antioxidant 1076, and antioxidant BHT.

[0017] Preferably, the phosphite antioxidant is one or more of antioxidant 168, antioxidant 626, and antioxidant TPP.

[0018] This application also provides a method for preparing a rutting-resistant bio-based asphalt modifier, using the following technical solution: A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation method; According to the formula ratio, bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to a high-speed mixer in sequence and mixed for 15-30 minutes at a speed of 800-1200 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder for melt blending and extrusion. After cooling and pelletizing, an anti-rutting bio-based asphalt modifier is obtained.

[0019] Preferably, the twin-screw extruder operates at a temperature of 160-220℃ and a rotation speed of 200-300 rpm. In summary, this application has the following beneficial effects: In the preparation of bio-based polymers, this application uses waste vegetable oil, sorbitol, and maleic anhydride for copolymerization. The double bonds and carboxyl groups of maleic anhydride can undergo esterification reactions with the hydroxyl groups of waste vegetable oil and the polyhydroxyl groups of sorbitol, introducing polar sites into the polymer molecular chain, enhancing the interfacial forces with asphalt and reinforcing fillers, and avoiding segregation. In the later stage of the reaction, adipic acid dihydrazide is introduced. Adipic acid dihydrazide undergoes a chain extension reaction with the ester groups in the polymer, extending the molecular chain and constructing a denser three-dimensional network structure, strengthening the stability of the network structure, increasing the molecular weight and mechanical strength of the polymer, and significantly enhancing its high-temperature resistance to deformation.

[0020] This application utilizes three high-molecular polymers—polyhydroxyalkanoate, polylactic acid, and polybutylene adipate-terephthalate—to synergistically treat fiber materials. Polylactic acid possesses high rigidity and strength, and when combined with polyhydroxyalkanoate, which exhibits good flexibility, and polybutylene adipate-terephthalate, which has good compatibility, the three polymers can balance the rigidity and flexibility of the filler, enhance its "skeletal support" role in asphalt, increase the rigidity of the filler, and extend its service life through the synergistic effect of the antioxidants. Hindered phenols can capture free radicals, and phosphites decompose hydrogen peroxide. The combination of these two forms a "dual antioxidant barrier," significantly improving long-term thermo-oxidative stability and extending the service life of the pavement. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the embodiments.

[0022] Antioxidant 1010 used in the embodiments and comparative examples of this application was purchased from Dongguan Xingyuan Chemical Co., Ltd.; antioxidant TPP was purchased from Shanghai Kaiyin Chemical Co., Ltd.; adipic acid dihydrazide was purchased from Jinan Jingyu Chemical Co., Ltd.; hexamethylene diisocyanate was purchased from Jize Xingran Chemical Co., Ltd.; polyhydroxyalkanoate was purchased from Dongguan Shengli New Materials Co., Ltd.; polylactic acid was purchased from Hubei Xinghengye Technology Co., Ltd.; and polybutylene adipate-butylene terephthalate was purchased from Wuhan Shuer Biotechnology Co., Ltd.

[0023] Examples 1-3 provide a rutting-resistant bio-based asphalt modifier and its preparation method.

[0024] Example 1 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40 parts of bio-based polymer, 12 parts of reinforcing filler, 10 parts of plasticizer, 2 parts of crosslinking agent, and 1 part of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 3:1. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 180°C, and tetrabutyl titanate (0.8% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 3 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240°C, and adipate dihydrazide was added. The mixture was subjected to polycondensation reaction for 2 hours under a vacuum of 50 Pa. After drying and dehydration, a bio-based polymer matrix was obtained. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 100:40:3, and the amount of adipate dihydrazide added was 1% of the total mass of waste vegetable oil and sorbitol.

[0025] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 10. Stir and react at 300rpm for 1 hour at 40℃. After washing three times with deionized water, dry at 40℃ for 10 hours. Then, immerse it in a 1% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 4, and stir and react at 30℃ for 2 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 300 rpm for 4 hours at 60°C. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 5:3:1:100. The mass ratio of the pretreated fibers to the polymer solution is 3:12.

[0026] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 15 minutes at a speed of 800 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 160℃ and a speed of 200 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0027] Example 2 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 50 parts of bio-based polymer, 15 parts of reinforcing filler, 11 parts of plasticizer, 4 parts of crosslinking agent, and 2 parts of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 4:1.5. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 200°C, and tetrabutyl titanate (1% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 4 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 260°C, and adipate dihydrazide was added. The mixture was subjected to polycondensation reaction for 3 hours under a vacuum of 50 Pa. After drying and dehydration, a bio-based polymer matrix was obtained. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 110:45:5, and the amount of adipate dihydrazide added was 2% of the total mass of waste vegetable oil and sorbitol.

[0028] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 11. Stir and react at 50℃ and 400rpm for 2 hours. After washing three times with deionized water, dry at 50℃ for 11 hours. Then, immerse it in a 2% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 5, and stir and react at 40℃ for 3 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 70°C and 400 rpm for 6 hours. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 80:5:3:125. The mass ratio of the pretreated fibers to the polymer solution is 4:15.

[0029] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 20 minutes at a speed of 1000 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 190℃ and a speed of 250 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0030] Example 3 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 60 parts of bio-based polymer, 18 parts of reinforcing filler, 12 parts of plasticizer, 5 parts of crosslinking agent, and 3 parts of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 5:2. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 220°C, and tetrabutyl titanate (1.2% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 5 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 280°C, and adipate dihydrazide was added. The mixture was subjected to polycondensation reaction for 4 hours under a vacuum of 50 Pa. After drying and dehydration, a bio-based polymer matrix was obtained. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 120:50:8, and the amount of adipate dihydrazide added was 3% of the total mass of waste vegetable oil and sorbitol.

[0031] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 13. Stir and react at 60℃ and 500rpm for 3 hours. After washing three times with deionized water, dry at 60℃ for 12 hours. Then, immerse it in a 3% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 6, and stir and react at 50℃ for 4 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 80°C and 500 rpm for 8 hours. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 10:8:3:150. The mass ratio of the pretreated fibers to the polymer solution is 5:18.

[0032] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed at 1200 rpm for 30 minutes to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 220℃ and a speed of 300 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0033] Comparative Example 1 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40 parts of bio-based polymer, 12 parts of reinforcing filler, 10 parts of plasticizer, 2 parts of crosslinking agent, and 1 part of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 3:1. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil and sorbitol were added to a reaction vessel and heated to 180°C under stirring. Tetrabutyl titanate, accounting for 0.8% of the total mass of waste vegetable oil and sorbitol, was added and stirred for 3 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240°C and adipic acid dihydrazide was added. Polycondensation reaction was carried out for 2 hours under a vacuum of 50 Pa. The product was then dried and dehydrated to obtain a bio-based polymer matrix. The mass ratio of waste vegetable oil to sorbitol was 100:40, and the amount of adipic acid dihydrazide added was 1% of the total mass of waste vegetable oil and sorbitol.

[0034] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 10. Stir and react at 300rpm for 1 hour at 40℃. After filtration and washing three times with deionized water, dry at 40℃ for 10 hours. Then, immerse it in a 1% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 4, and stir and react at 30℃ for 2 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 300 rpm for 4 hours at 60°C. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 5:3:1:100. The mass ratio of the pretreated fibers to the polymer solution is 3:12.

[0035] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 15 minutes at a speed of 800 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 160℃ and a speed of 200 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0036] Comparative Example 2 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40 parts of bio-based polymer, 12 parts of reinforcing filler, 10 parts of plasticizer, 2 parts of crosslinking agent, and 1 part of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 3:1. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 180°C, and tetrabutyl titanate (0.8% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 3 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240°C, and polycondensation was carried out for 2 hours under a vacuum of 50 Pa. The mixture was then dried and dehydrated to obtain a bio-based polymer matrix. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 100:40:3.

[0037] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 10. Stir and react at 300rpm for 1 hour at 40℃. After filtration, wash three times with deionized water, dry at 40℃ for 10 hours, and then immerse it in a 1% (w / w) γ-aminopropyltriethoxysilane solution. Adjust the pH to 4 and stir and react at 30℃ for 2 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 300 rpm for 4 hours at 60°C. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 5:3:1:100. The mass ratio of the pretreated fibers to the polymer solution is 3:12.

[0038] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 15 minutes at a speed of 800 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 160℃ and a speed of 200 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0039] Comparative Example 3 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40 parts of bio-based polymer, 12 parts of reinforcing filler, 10 parts of plasticizer, 2 parts of crosslinking agent, and 1 part of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 3:1. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 180°C, and tetrabutyl titanate (0.8% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 3 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240°C, and adipate dihydrazide was added. The mixture was subjected to polycondensation reaction for 2 hours under a vacuum of 50 Pa. After drying and dehydration, a bio-based polymer matrix was obtained. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 100:40:3, and the amount of adipate dihydrazide added was 1% of the total mass of waste vegetable oil and sorbitol.

[0040] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 10. Stir and react at 300rpm for 1 hour at 40℃. After washing three times with deionized water, dry at 40℃ for 10 hours. Then, immerse it in a 1% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 4, and stir and react at 30℃ for 2 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 300 rpm for 4 hours at 60°C. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polybutylene adipate-butylene terephthalate and dichloromethane in a mass ratio of 6.5:2.5:100. The mass ratio of the pretreated fibers to the polymer solution is 3:12.

[0041] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 15 minutes at a speed of 800 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 160℃ and a speed of 200 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0042] Comparative Example 4 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40 parts of bio-based polymer, 12 parts of reinforcing filler, 10 parts of plasticizer, 2 parts of crosslinking agent, and 1 part of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is composed of antioxidant 1010 and antioxidant TPP in a mass ratio of 3:1. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 180°C, and tetrabutyl titanate (0.8% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 3 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240°C, and adipate dihydrazide was added. The mixture was subjected to polycondensation reaction for 2 hours under a vacuum of 50 Pa. After drying and dehydration, a bio-based polymer matrix was obtained. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 100:40:3, and the amount of adipate dihydrazide added was 1% of the total mass of waste vegetable oil and sorbitol.

[0043] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 10. Stir and react at 300rpm for 1 hour at 40℃. After washing three times with deionized water, dry at 40℃ for 10 hours. Then, immerse it in a 1% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 4, and stir and react at 30℃ for 2 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 300 rpm for 4 hours at 60°C. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid and dichloromethane in a mass ratio of 5.5:3.5:100, and the mass ratio of pretreated fibers to polymer solution is 3:12.

[0044] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 15 minutes at a speed of 800 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 160℃ and a speed of 200 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0045] Comparative Example 5 A rutting-resistant bio-based asphalt modifier comprises the following raw materials in parts by weight: 40 parts of bio-based polymer, 12 parts of reinforcing filler, 10 parts of plasticizer, 2 parts of crosslinking agent, and 1 part of antioxidant. The plasticizer is tributyl citrate, the crosslinking agent is hexamethylene diisocyanate, and the antioxidant is antioxidant 1010. The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, sorbitol, and maleic anhydride were added to a reaction vessel. Under stirring, the temperature was raised to 180°C, and tetrabutyl titanate (0.8% of the total mass of waste vegetable oil, sorbitol, and maleic anhydride) was added. The mixture was stirred and reacted for 3 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240°C, and adipate dihydrazide was added. The mixture was subjected to polycondensation reaction for 2 hours under a vacuum of 50 Pa. After drying and dehydration, a bio-based polymer matrix was obtained. The mass ratio of waste vegetable oil, sorbitol, and maleic anhydride was 100:40:3, and the amount of adipate dihydrazide added was 1% of the total mass of waste vegetable oil and sorbitol.

[0046] The preparation of the reinforcing filler includes the following steps: Step 1: After crushing natural bamboo fiber to a particle size of 50μm, disperse it in a sodium hydroxide solution with a pH of 10. Stir and react at 300rpm for 1 hour at 40℃. After washing three times with deionized water, dry at 40℃ for 10 hours. Then, immerse it in a 1% (w / w) γ-aminopropyltriethoxysilane solution, adjust the pH to 4, and stir and react at 30℃ for 2 hours. After filtration, washing, and drying, pretreated fiber is obtained. Step 2: Disperse the pretreated fibers in a polymer solution and stir at 300 rpm for 4 hours at 60°C. After the reaction is complete, wash and dry to obtain the reinforcing filler. The polymer solution is composed of polyhydroxyalkanoates, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 5:3:1:100. The mass ratio of the pretreated fibers to the polymer solution is 3:12.

[0047] A method for preparing a rutting-resistant bio-based asphalt modifier includes the following preparation steps: According to the formula ratio, the bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to the high-speed mixer in sequence and mixed for 15 minutes at a speed of 800 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder with a working temperature of 160℃ and a speed of 200 rpm for melt blending and extrusion. After cooling and pelletizing, the rutting-resistant bio-based asphalt modifier is obtained.

[0048] Performance testing Add 70# base asphalt to a heating tank and heat it to melt at 140°C. Stir at 100 rpm until homogeneous. Then add the rutting-resistant bio-based asphalt modifiers prepared in Examples 1-3 and Comparative Examples 1-5 respectively. The amount of rutting-resistant bio-based asphalt modifier added is 4.5% of the mass of 70# base asphalt. Stir at 100 rpm while adding to ensure homogeneity. Raise the temperature to 155°C and perform high-speed shear dispersion at 3000 rpm for 35 minutes. After shearing, lower the temperature of the modified asphalt to 150°C and stir at 200 rpm for 30 minutes to obtain the modified asphalts.

[0049] Rutting dynamic stability test: The test shall be conducted in accordance with T 0719-2011 of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; Freeze-thaw splitting test: The test was conducted in accordance with T0729-2011 of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; Softening point: Tested according to T 0606-2011 of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; Ductility test: The test was conducted in accordance with T 0605-2011 of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; Penetration test: The test shall be conducted in accordance with T0604-2011 of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; The specific test results are shown in Table 1.

[0050] Table 1. Performance parameters of the modified asphalt prepared in Examples 1-3 and Comparative Examples 1-5

[0051] As shown in Table 1, the rutting-resistant bio-based asphalt modifier prepared in this application significantly improves the high-temperature stability of asphalt mixtures, effectively inhibits rutting, and extends road service life. Simultaneously, it also possesses excellent low-temperature crack resistance, enhancing road durability. Furthermore, its production process is relatively simple, it has good compatibility with traditional asphalt, is easy to construct, and readily applicable. By improving road performance while simultaneously considering economic and environmental benefits, it represents an ideal material choice for modern road construction.

[0052] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A rutting-resistant bio-based asphalt modifier, characterized in that, The raw materials include the following parts by weight: 40-60 parts of bio-based polymer, 12-18 parts of reinforcing filler, 10-12 parts of plasticizer, 2-5 parts of crosslinking agent, and 1-3 parts of antioxidant.

2. The rutting-resistant bio-based asphalt modifier according to claim 1, characterized in that, The preparation steps of the bio-based polymer are as follows: Waste vegetable oil, bio-based polyol, and maleic anhydride were added to a reactor. Under stirring, the temperature was raised to 180-220℃, a catalyst was added, and the reaction was stirred for 3-5 hours. After the reaction was completed, low-boiling-point substances were removed by vacuum distillation. The temperature was raised to 240-280℃, adipic acid dihydrazide was added, and polycondensation was carried out for 2-4 hours under a vacuum of <100Pa. The product was then dried and dehydrated to obtain the bio-based polymer matrix.

3. The rutting-resistant bio-based asphalt modifier according to claim 2, characterized in that, The bio-based polyol is xylitol and / or sorbitol.

4. The rutting-resistant bio-based asphalt modifier according to claim 2, characterized in that, The mass ratio of the waste vegetable oil, bio-based polyol, and maleic anhydride is 100-120:40-50:3-8; the amount of adipic dihydrazide added is 1-3% of the total mass of the waste vegetable oil and bio-based polyol.

5. The rutting-resistant bio-based asphalt modifier according to claim 1, characterized in that, The preparation of the reinforcing filler includes the following steps: Step 1: After crushing the natural fiber, disperse it in an alkaline solution and stir at 40-60℃ for 1-3 hours. After washing and drying, immerse it in a 1-3% silane coupling agent solution, adjust the pH of the solution to 4-6, and stir at 30-50℃ for 2-4 hours. After filtration, washing, and drying, obtain the pretreated fiber. Step 2: Disperse the pretreated fibers in a polymer solution and stir the reaction at 60-80℃ for 4-8 hours. After the reaction is completed, wash and dry to obtain the reinforcing filler.

6. The rutting-resistant bio-based asphalt modifier according to claim 5, characterized in that, The polymer solution is composed of polyhydroxy fatty acid ester, polylactic acid, polybutylene adipate-butyl terephthalate and dichloromethane in a mass ratio of 5-10:3-8:1-3:100-150.

7. The rutting-resistant bio-based asphalt modifier according to claim 5, characterized in that, The mass ratio of the pretreated fiber to the polymer solution is 3-5:12-18.

8. The rutting-resistant bio-based asphalt modifier according to claim 1, characterized in that, The antioxidant is composed of hindered phenolic antioxidants and phosphite antioxidants in a mass ratio of 3-5:1-2.

9. A method for preparing the rutting-resistant bio-based asphalt modifier as described in any one of claims 1-8, characterized in that, The preparation steps include the following: According to the formula ratio, bio-based polymer, reinforcing filler, plasticizer, crosslinking agent and antioxidant are added to a high-speed mixer in sequence and mixed for 15-30 minutes at a speed of 800-1200 rpm to obtain a mixture. The mixture is then added to a twin-screw extruder for melt blending and extrusion. After cooling and pelletizing, an anti-rutting bio-based asphalt modifier is obtained.

10. The method for preparing the rutting-resistant bio-based asphalt modifier according to claim 9, characterized in that, The twin-screw extruder operates at a temperature of 160-220℃ and a speed of 200-300 rpm.

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