Environment-friendly high-elasticity high-toughness modified asphalt and preparation method thereof

Abstract

The environment-friendly high-elasticity and high-toughness modified asphalt comprises the following components in parts by mass: 100 parts of matrix asphalt, 5-7 parts of a polymer modifier, 4-6 parts of a compatilizer, 3-5 parts of a tackifier, 5-10 parts of a flexibilizer, 0.5-1.5 parts of a dispersant and 0.1-0.2 part of a stabilizer. The environment-friendly high-elasticity high-toughness modified asphalt provided by the invention has excellent high viscosity, high elasticity and stability, and can reduce the emission of VOCs (volatile organic compounds) in the asphalt processing and using processes and reduce the harm of asphalt smoke to surrounding people and environment. The invention also provides a preparation method of the environment-friendly high-elasticity high-toughness modified asphalt.

Description

Technical Field

[0001] The present invention belongs to the technical field of road construction materials, and particularly relates to an environmentally friendly high-elastic and high-toughness modified asphalt. The present invention also provides a preparation method for the environmentally friendly high-elastic and high-toughness modified asphalt. Background Art

[0002] In recent years, with the continuous increase in highway maintenance requirements, the ultra-thin overlay, as a preventive maintenance measure, has attracted high attention in the industry due to its advantages of low cost and high efficiency. However, since the thickness of the ultra-thin overlay is only 1 / 5 to 1 / 2 of the thickness of the ordinary surface layer, under the same traffic load, the stress and strain conditions it bears are more severe, which puts higher requirements on the modified asphalt for ultra-thin overlays.

[0003] Currently, most of the asphalt products used for ultra-thin overlays are mainly polymer-modified asphalt, which is generally prepared from polymer modifiers, compatibilizers, and stabilizers. The prepared high-viscosity modified asphalt usually pays more attention to improving the high-temperature performance of the modified asphalt, ignoring the low-temperature crack resistance of the modified asphalt. And due to the large amount of SBS added, its storage stability is poor, making it difficult to ensure the durability of the mixture. At the same time, due to the increase in the softening point, the temperature of the asphalt during processing and use increases significantly, exacerbating the emission of asphalt VOCs and generating more asphalt fumes, which have an adverse impact on the physical health of construction workers and the environment. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an environmentally friendly high-elastic and high-toughness modified asphalt to reduce or avoid the problems mentioned above. The present invention also provides its preparation method.

[0005] The present invention provides an environmentally friendly high-elastic and high-toughness modified asphalt, which comprises the following components in parts by mass: 100 parts of matrix asphalt, 5 - 7 parts of polymer modifier, 4 - 6 parts of compatibilizer, 3 - 5 parts of tackifier, 5 - 10 parts of toughening agent, 0.5 - 1.5 parts of dispersant, and 0.1 - 0.2 parts of stabilizer.

[0006] Preferably, the polymer modifier is an SBS modifier, one or more of a linear structure or a star structure; the compatibilizer is aromatic hydrocarbon rubber oil; the tackifier is polyisoprene grafted maleic acid monomethyl ester; the toughening agent is functionalized polyurethane; the dispersant is polyphosphoric acid with a mass fraction of H3PO4 of 115%; the stabilizer is sulfur.

[0007] Preferably, the functionalized polyurethane comprises the following raw materials in parts by weight: 8 parts of amino-functionalized carbon nanotubes, 30 parts of N, N-dimethylformamide, 20 parts of polycaprolactone, 50 parts of diphenylmethane diisocyanate, and 30 parts of 1,4-butanediol.

[0008] Preferably, the method for preparing the functionalized polyurethane is as follows: Add the aminated carbon nanotubes into N, N-dimethylformamide, and ultrasonically disperse and stir evenly; then add polycaprolactone and diphenylmethane diisocyanate, and react at a constant temperature of 80 °C for 2 h; then cool down to 40 °C, add 1,4-butanediol and stir for 30 min, and then vacuum dry at 80 °C for 2 h and heat in an oven at 100 °C for 12 h to obtain the functionalized polyurethane.

[0009] The present invention also provides a method for preparing the above-mentioned environment-friendly highly elastic and tough modified asphalt, which comprises the following steps: 1) Heat the matrix asphalt to 170-180 °C by mass, add the SBS modifier and compatibilizer, and perform high-speed shearing for 30 min at a shearing rate of 5000 r / min; 2) Add the tackifier, toughener, and dispersant into the asphalt by mass, adjust the temperature to 180-190 °C and continue shearing for 90 min at a shearing rate of 8000 r / min; 3) Add the stabilizer by mass, and perform low-speed stirring and development at 180-190 °C for 30 min at a stirring rate of 300 r / min to obtain the environment-friendly highly elastic and tough modified asphalt.

[0010] The environment-friendly highly elastic and tough modified asphalt provided by the present invention has the following characteristics: 1) The addition of polyphosphoric acid promotes the swelling and development of the SBS modifier in the asphalt, promotes the SBS modifier to disperse into smaller sizes and be more evenly distributed.

[0011] 2) The polyisoprene in the main chain of the polyisoprene grafted maleic acid monomethyl ester undergoes a polymerization reaction with the uniformly shear-dispersed SBS small molecules and participates in the construction of the cross-linked network structure of SBS. At the same time, the carboxyl group contained in the maleic acid monomethyl ester in its side chain undergoes an esterification reaction with the alcohol substances in the asphalt to form new chemical bonds, so that the polymer cross-linked network structure is anchored in the asphalt through the intermolecular binding force, increasing the internal frictional resistance of the modified asphalt, thereby greatly improving the viscoelasticity of the SBS modified asphalt and showing excellent high-viscosity, high-elasticity and stable properties.

[0012] 3) The polyurethane in the toughener is functionally modified by the aminated carbon nanotubes, which improves the strength of the polyurethane and enhances its toughening effect; at the same time, the isocyanate groups contained in the polyurethane have relatively high activity and will undergo chemical reactions with the functional groups in the modified asphalt to form new chemical bonds and functional groups such as C=O and C-O. Combining with the intercalation effect of the carbon nanotubes, the cross-linked structure of the modified asphalt is made more stable, thereby greatly improving the toughening effect of the modifier.

[0013] 4) Utilize the extremely large specific surface area of amino-functionalized carbon nanotubes and their selective adsorption effect on organic pollutants in asphalt to reduce the emissions of VOCs during asphalt processing and use, and reduce the harm of asphalt fumes to the surrounding people and the environment. Detailed implementation manners

[0014] For a clearer understanding of the technical features, objectives, and effects of the present invention, the present invention will now be further described through specific embodiments.

[0015] The present invention provides an environmentally friendly highly elastic and tough modified asphalt, which comprises the following components in parts by mass: 100 parts of matrix asphalt, 5 - 7 parts of polymer modifier, 4 - 6 parts of compatibilizer, 3 - 5 parts of tackifier, 5 - 10 parts of toughening agent, 0.5 - 1.5 parts of dispersant, and 0.1 - 0.2 parts of stabilizer.

[0016] The polymer modifier is an SBS modifier, which is one or more of a linear structure or a star structure; the compatibilizer is aromatic hydrocarbon rubber oil; the tackifier is polyisoprene grafted with monomethyl maleate; the toughening agent is functionalized polyurethane; the dispersant is polyphosphoric acid, and one or more of which has an H3PO4 mass fraction of 105%, 115%, and 117%; the stabilizer is sulfur.

[0017] The preparation method of the above-mentioned environmentally friendly highly elastic and tough modified asphalt comprises the following steps: 1) Heat the matrix asphalt to 170 - 180 °C by mass, add the SBS modifier and the compatibilizer, and perform high-speed shearing for 30 min at a shearing rate of 5000 r / min; 2) Add the tackifier, toughening agent, and dispersant to the asphalt by mass, adjust the temperature to 180 - 190 °C and continue shearing for 90 min at a shearing rate of 8000 r / min; 3) Add the stabilizer by mass, and perform low-speed stirring and development at 180 - 190 °C for 30 min at a stirring rate of 300 r / min to obtain the environmentally friendly highly elastic and tough modified asphalt.

[0018] In the following specific embodiments and comparative examples, the following raw materials are used: the matrix asphalt is Qilu 70# matrix asphalt; the SBS modifiers are linear SBS1301 and star-shaped SBS4303; the aromatic hydrocarbon rubber oil is 106# rubber oil of Shandong Furunda Chemical Co., Ltd.; polyphosphoric acid H 3 PO 4The mass fraction is 115%; the stabilizer is industrial sulfur; the polyisoprene grafted with monomethyl maleate, CAS: 128000-08-8; the functionalized polyurethane raw materials are: amino-functionalized carbon nanotubes, N,N-dimethylformamide CAS: 68-12-2, polycaprolactone CAS: 24980-41-4, diphenylmethane diisocyanate CAS: 101-68-8, 1,4-butanediol CAS: 110-63-4.

[0019] The functionalized polyurethane comprises the following raw materials in parts by weight: 8 parts of amino-functionalized carbon nanotubes, 30 parts of N,N-dimethylformamide, 20 parts of polycaprolactone, 50 parts of diphenylmethane diisocyanate, and 30 parts of 1,4-butanediol.

[0020] The preparation method of the functionalized polyurethane is as follows: Add the amino-functionalized carbon nanotubes into N,N-dimethylformamide, and disperse and stir evenly by ultrasonic wave; then add polycaprolactone and diphenylmethane diisocyanate, and carry out a constant-temperature reaction at 80°C for 2 h; then cool down to 40°C, add 1,4-butanediol and stir for 30 min, and then carry out vacuum drying at 80°C for 2 h and heat in an oven at 100°C for 12 h to obtain the functionalized polyurethane.

[0021] Example 1: It comprises the following components in parts by mass: 100 parts of matrix asphalt, 5 parts of SBS modifier, 4 parts of aromatic hydrocarbon rubber oil, 5 parts of polyisoprene grafted with monomethyl maleate, 10 parts of functionalized polyurethane, 1.5 parts of polyphosphoric acid, and 0.1 part of sulfur.

[0022] The SBS modifier is taken by mass ratio, linear SBS: star-shaped SBS = 2.5:1.

[0023] Example 2: It comprises the following components in parts by mass: 100 parts of matrix asphalt, 5 parts of SBS modifier, 4 parts of aromatic hydrocarbon rubber oil, 5 parts of polyisoprene grafted with monomethyl maleate, 10 parts of functionalized polyurethane, 1.5 parts of polyphosphoric acid, and 0.1 part of sulfur.

[0024] The SBS modifier is taken by mass ratio, linear SBS: star-shaped SBS = 2.5:1.

[0025] Example 3: It comprises the following components in parts by mass: 100 parts of matrix asphalt, 5 parts of SBS modifier, 4 parts of aromatic hydrocarbon rubber oil, 4 parts of polyisoprene grafted with monomethyl maleate, 8 parts of functionalized polyurethane, 1.5 parts of polyphosphoric acid, and 0.1 part of sulfur.

[0026] The SBS modifier is taken by mass ratio, linear SBS: star-shaped SBS = 2.5:1.

[0027] Example 4: It includes the following components in parts by mass: 100 parts of matrix asphalt, 6 parts of SBS modifier, 5 parts of aromatic hydrocarbon rubber oil, 3 parts of polyisoprene grafted maleic acid monomethyl ester, 8 parts of functionalized polyurethane, 1 part of polyphosphoric acid, and 0.15 part of sulfur.

[0028] The SBS modifier is taken according to the mass ratio, linear SBS: star-shaped SBS = 3:1.

[0029] Example 5: It includes the following components in parts by mass: 100 parts of matrix asphalt, 6 parts of SBS modifier, 5 parts of aromatic hydrocarbon rubber oil, 4 parts of polyisoprene grafted maleic acid monomethyl ester, 5 parts of functionalized polyurethane, 1 part of polyphosphoric acid, and 0.15 part of sulfur.

[0030] The SBS modifier is taken according to the mass ratio, linear SBS: star-shaped SBS = 3:1.

[0031] Example 6: It includes the following components in parts by mass: 100 parts of matrix asphalt, 7 parts of SBS modifier, 6 parts of aromatic hydrocarbon rubber oil, 3 parts of polyisoprene grafted maleic acid monomethyl ester, 8 parts of functionalized polyurethane, 1 part of polyphosphoric acid, and 0.2 part of sulfur.

[0032] The SBS modifier is taken according to the mass ratio, linear SBS: star-shaped SBS = 3.5:1.

[0033] Example 7: It includes the following components in parts by mass: 100 parts of matrix asphalt, 7 parts of SBS modifier, 6 parts of aromatic hydrocarbon rubber oil, 3 parts of polyisoprene grafted maleic acid monomethyl ester, 8 parts of functionalized polyurethane, 0.5 part of polyphosphoric acid, and 0.2 part of sulfur.

[0034] The SBS modifier is taken according to the mass ratio, linear SBS: star-shaped SBS = 2.5:1.

[0035] Comparative Example 1: The difference from Example 1 is that polyisoprene grafted maleic acid monomethyl ester, functionalized polyurethane, and polyphosphoric acid are not added during the modification process.

[0036] Comparative Example 2: The difference from Example 1 is that polyisoprene grafted maleic acid monomethyl ester and functionalized polyurethane are not added during the modification process.

[0037] Comparative Example 3: The difference from Example 1 is that functionalized polyurethane is not added during the modification process, and at the same time, polyisoprene grafted maleic acid monomethyl ester is replaced with polyisoprene with the same dosage.

[0038] Comparative Example 4: The difference from Example 1 is that polyisoprene grafted maleic acid monomethyl ester is not added during the modification process, and at the same time, functionalized polyurethane is replaced with polyurethane with the same dosage.

[0039] Comparative Example 5: The difference from Example 1 is that polyphosphoric acid was not added during the modification process, and at the same time, polyisoprene grafted maleic acid monomethyl ester and functionalized polyurethane were replaced with polyisoprene and polyurethane with the same dosage.

[0040] The performance of the environmentally friendly high-elastic and high-tough modified asphalt prepared in Examples 1-7 of the present invention and the modified asphalt prepared in Comparative Examples 1-5 was tested. The experimental results are shown in Tables 1 and 2 below.

[0041] Table 1 Performance test results of the environmentally friendly high-elastic and high-tough modified asphalt prepared in Examples 1-7 Test Items Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Penetration at 25℃ / 0.1mm 54.5 50.3 55.3 52.6 53.1 49.2 47.6 Softening Point / ℃ 88.6 90.2 87.8 91.4 90.7 93.6 95.3 Ductility at 5℃ / cm 77.4 69.4 72.2 73.6 72.4 68.9 65.7 Elastic Recovery at 25℃ / % 98.8 97.5 98.2 98.0 98.3 98.7 98.5 Dynamic Viscosity at 60℃ / 10,000 Pa·s 48.2 51.2 46.2 52.6 53.1 54.4 58 Segregation, Softening Point Difference after 48h / ℃ 1.6 2.1 1.5 1.8 2.1 2.1 2.3 Table 2 Performance test results of the modified asphalt prepared in Comparative Examples 1-5 Test Items Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Penetration at 25℃ / 0.1mm 58.9 55.5 53.6 54.1 54.6 Softening Point / ℃ 78.8 82.6 84.1 85.0 83.7 Ductility at 5℃ / cm 36.8 27.3 29.4 43.2 48.1 Elastic Recovery at 25℃ / % 95.0 88.6 97.5 96.7 98.3 Dynamic Viscosity at 60℃ / 10,000 Pa·s 2.2 4.7 9.2 10.3 14.5 Segregation, Softening Point Difference after 48h / ℃ 5.8 2.3 2.7 2.1 2.9 In Tables 1 and 2 above, the performance test methods for the examples and comparative examples were all operated in accordance with the specification "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011).

[0042] From the comprehensive test results of the examples in Table 1 and the comparative examples in Table 2, it can be seen that the comprehensive performance of the environmentally friendly high-elastic and high-tough modified asphalt prepared in Examples 1-7 far exceeds that of Comparative Examples 1-5, indicating that the environmentally friendly high-elastic and high-tough modified asphalt prepared by the present invention has excellent performance, and all indicators meet the requirements of high-viscosity modified asphalt for application scenarios such as ultra-thin wearing courses and drainage pavements. Compared with the comparative examples, in Examples 1-7, polyphosphoric acid was used to promote the swelling and uniform dispersion of the SBS modifier in the asphalt; the dispersed SBS small molecules polymerized with the polyisoprene in the main chain of polyisoprene grafted maleic acid monomethyl ester, and the strength of the cross-linked network structure filled with polyisoprene was greatly enhanced. At the same time, through the bonding action of the maleic acid monomethyl ester functional group in its side chain with the asphalt, the three-dimensional network structure was anchored in the asphalt, increasing the internal frictional resistance of the modified asphalt, thereby greatly improving the viscoelasticity of the SBS modified asphalt, showing excellent high viscosity, high elasticity and stability. Therefore, the softening point, elastic recovery, viscosity and stability of the examples were greatly improved. The toughening effect of the functionalized polyurethane was enhanced after being strengthened by amino-functionalized carbon nanotubes; at the same time, the bonding action of the isocyanate group of the reactive group in the polyurethane with the functional group in the modified asphalt and the intercalation effect of the carbon nanotubes further improved the strength and stability of the three-dimensional network of the modifier in the modified asphalt, resulting in a large increase in the low-temperature ductility index of the modified asphalt; at the same time, the extremely large specific surface area of the amino-functionalized carbon nanotubes and its selective adsorption effect on organic pollutants in the asphalt will reduce the emission of asphalt VOCs during processing and production, and reduce the harm of asphalt fumes to the surrounding people and the environment.

[0043] Those skilled in the art should understand that although the present invention is described in terms of multiple embodiments, not every embodiment contains only one independent technical solution. This description in the specification is only for clarity. Those skilled in the art should understand the specification as a whole and consider the technical solutions involved in each embodiment as ways that can be combined with each other to form different embodiments to understand the scope of protection of the present invention.

[0044] The above are only illustrative specific embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An environmentally friendly high-elasticity and high-toughness modified asphalt, characterized in that: It includes the following components in parts by mass: 100 parts of base asphalt, 5-7 parts of polymer modifier, 4-6 parts of compatibilizer, 3-5 parts of tackifier, 5-10 parts of toughening agent, 0.5-1.5 parts of dispersant, and 0.1-0.2 parts of stabilizer.

2. The environmentally friendly high-elasticity and high-toughness modified asphalt according to claim 1 is characterized in that: The polymer modifier is an SBS modifier, one or more of a linear structure or a star structure; the compatibilizer is an aromatic hydrocarbon rubber oil; the tackifier is polyisoprene grafted monomethyl maleate; the toughening agent is a functionalized polyurethane; the dispersant is polyphosphoric acid, and the mass fraction of H3PO4 is 115%; and the stabilizer is sulfur.

3. The environmentally friendly high-elasticity and high-toughness modified asphalt according to claim 2 is characterized in that: The functionalized polyurethane comprises the following raw materials in parts by weight: 8 parts of amino carbon nanotubes, 30 parts of N,N-dimethylformamide, 20 parts of polycaprolactone, 50 parts of diphenylmethane diisocyanate, and 30 parts of 1,4-butanediol.

4. The environmentally friendly high-elasticity and high-toughness modified asphalt according to claim 3 is characterized in that: The functionalized polyurethane preparation method comprises the following steps: adding amino carbon nanotubes to N,N-dimethylformamide, and uniformly stirring by ultrasonic dispersion; subsequently adding polycaprolactone and diphenylmethane diisocyanate, and reacting at a constant temperature of 80°C for 2 hours; then cooling to 40°C, adding 1,4-butanediol, and stirring for 30 minutes; then vacuum drying at 80°C for 2 hours, and heating in an oven at 100°C for 12 hours to obtain the functionalized polyurethane.

5. A method for preparing the environmentally friendly high-elasticity and high-toughness modified asphalt according to claim 1, characterized in that: It includes the following steps: 1) Heat the base asphalt to 170-180℃, add SBS modifier and compatibilizer, and shear for 30 minutes at a shear rate of 5000r / min; 2) Add viscosity enhancer, toughening agent and dispersant to the asphalt according to the mass proportion, adjust the temperature to 180-190℃ and continue shearing for 90min at a shear rate of 8000r / min; 3) Add stabilizer according to the mass proportion, stir at a low speed of 180-190°C for 30 min at a stirring rate of 300 r / min to obtain an environmentally friendly high-elasticity and high-toughness modified asphalt.