Asphalt modifier containing thermoplastic elastomer-polyurethane graft copolymer and application of asphalt modifier in modified asphalt

Abstract

The invention discloses an asphalt modifier containing a thermoplastic elastomer-polyurethane grafted copolymer and application of the asphalt modifier in modified asphalt. The preparation method comprises the following steps: preparing a modifier I from a functionalized thermoplastic elastomer and an amino-containing compound in proportion, and reacting the modifier I with a polyurethane prepolymer to generate a modifier II; the modifier II or the combination of the modifier I and the modifier II is used as the asphalt modifier, so that the pavement performance such as high and low temperature performance, rutting resistance, fatigue resistance and the like of the modified asphalt is improved.

Description

Technical Field

[0001] The invention relates to an asphalt modifier, in particular to an asphalt modifier containing a thermoplastic elastomer-polyurethane graft copolymer, and also to application of the asphalt modifier in modified asphalt. Background Art

[0002] Asphalt is one of the most important binders in modern road construction. Its performance directly determines the durability, rutting resistance, and environmental adaptability of the pavement. With the surge in global traffic and the frequent occurrence of extreme weather conditions, traditional petroleum-based asphalt is no longer able to meet the stringent requirements of high-grade highways for high- and low-temperature performance, fatigue resistance, and service life. Statistics show that road damage caused by inadequate asphalt performance results in tens of billions of yuan in economic losses annually. Furthermore, the production process of traditional asphalt mixtures is energy-intensive and emits significant carbon emissions. Therefore, the development of high-performance modified asphalt technology has become a critical issue in the transportation infrastructure sector.

[0003] Thermoplastic elastomers such as SBS (styrene-butadiene-styrene block copolymer) and SEBS (styrene-ethylene-butylene-styrene block copolymer) are used as asphalt modifiers, significantly enhancing asphalt performance through their unique molecular structure. By physically crosslinking to form a three-dimensional elastic network, they significantly enhance asphalt's high-temperature rutting resistance and low-temperature cracking resistance. However, since there is no significant chemical reaction between SBS modifiers and asphalt, SBS-modified asphalt exhibits poor thermal storage stability and is prone to segregation. Furthermore, due to the presence of unsaturated double bonds in its molecular structure, SBS exhibits relatively poor aging resistance. SEBS, a hydrogenated modification of SBS, significantly improves its resistance to thermal oxidative aging and offers excellent UV stability, making it more suitable for harsh environments such as high temperatures and high UV radiation. However, its modification effect on asphalt, particularly its ductility, is less than ideal, and it is also expensive. The polyolefin elastomer (POE) possesses a unique structure that combines the durability of polyolefins with the softness of elastomers, enabling it to maintain excellent elasticity even in high-temperature environments. POE also exhibits excellent weathering and aging resistance, extending its service life. However, its limited improvement in high-temperature performance of asphalt and its high price limit its application in asphalt modification. Polyurethane, as a high-performance polymer material, exhibits significant advantages in asphalt modification. Its molecular chain is rich in carbamate groups, which impart excellent elasticity, adhesion, and fatigue resistance. When blended with asphalt, it forms an interpenetrating network structure, significantly enhancing the asphalt's high-temperature rutting resistance, low-temperature crack resistance, and fatigue resistance.

[0004] To overcome the performance deficiencies of the aforementioned polymer-modified asphalt, recent research has begun modifying asphalt by combining SBS with polyurethane. CN 109553991 A discloses a high-viscosity modified asphalt based on an SBS / polyurethane composite and its preparation method. This method involves heating the base asphalt to a molten state, adding an SBS modifier, and then mixing and swelling the mixture to produce the SBS-modified asphalt. Stabilizers, chain extenders, and coupling agents are then added, followed by a polyurethane prepolymer. The isocyanate groups in the polyurethane prepolymer's molecular structure react chemically with the hydroxyl and amino groups in the asphalt components. During this process, the polyurethane does not react with the SBS, and the resulting modified asphalt is equivalent to a mixture of SBS-modified asphalt and polyurethane-modified asphalt. CN119752203 A provides a modified asphalt mixture and a preparation method thereof, the preparation method comprising: heating and mixing asphalt, rubber oil, and SBS thermoplastic elastomer to obtain component A containing SBS modified asphalt; adding component B (initiator dibenzoyl peroxide or azobisisobutyronitrile) to component A and heating and mixing to obtain component A activated by free radicals; adding a polyurethane modifier (polyurethane prepolymer) as component C to obtain a polyurethane and SBS composite modified asphalt mixture. This method uses component B to increase the hydroxyl, amine, carboxylic acid, and other groups in the asphalt. The isocyanate in the polyurethane prepolymer can chemically react with the groups in component A (such as hydroxyl, amine, carboxylic acid, etc.) after free radical activation, thereby improving the performance of the asphalt. In this method, the isocyanate groups in the polyurethane mainly react chemically with the internal groups of the asphalt. WO2023115672A1 discloses an asphalt modifier, which includes a thermoplastic elastomer, a polyurethane elastomer, a petroleum resin, a heat-sensitive resin, a stabilizer and a plasticizer. In this method, the thermoplastic elastomer and the polyurethane elastomer are added to the asphalt by physical mixing. CN 118638428 B discloses a direct-cast fast-melting high-viscoelastic anti-fatigue asphalt modifier and its preparation method and application, wherein an elastomer (a 2:2:1 mixture of linear SBS, star-shaped SBS and styrene-butadiene rubber), a blocked isocyanate and a blocked polyurethane prepolymer, a plasticizer and a low-grade asphalt are mixed and prepared by mixing and granulating with a twin-screw extruder. In this method, the elastomer, the blocked isocyanate and the blocked polyurethane prepolymer are also added to the asphalt by physical mixing.

[0005] In summary, thermoplastic elastomer compounded polyurethane modified asphalt is an asphalt mixture that improves elastic modulus and deformation resistance through special modification technology. It is mainly used to enhance the durability and rutting resistance of pavement structures, and is particularly suitable for road projects under high load, high temperature or harsh environments. Thermoplastic elastomer compounded polyurethane modified asphalt has become a research hotspot in the field of road engineering due to its excellent rutting resistance, fatigue resistance and long-term service stability. Thermoplastic elastomer compounded polyurethane modified asphalt modifier can significantly enhance the deformation resistance of the mixture by improving the elastic recovery ability and modulus of the asphalt binder, thereby extending the life of the pavement. Although the existing technology involves thermoplastic elastomers such as SBS and polyurethane composite modified asphalt, it is mainly for each to modify the asphalt. Due to the large difference in polarity between thermoplastic elastomers such as SBS and polyurethane, the performance of the final modified asphalt has various deficiencies, such as segregation problems and poor low temperature performance (ductility) compared to SBS modified asphalt. It has not yet been put into practical application in engineering, and its overall performance needs to be further improved. Summary of the Invention

[0006] In response to the shortcomings of the existing technology, the present invention provides an asphalt modifier, which contains a functionalized thermoplastic elastomer-polyurethane graft copolymer, which can greatly improve the rutting resistance and fatigue resistance of the modified asphalt, has good compatibility with asphalt, is not easy to segregate, and has good high and low temperature performance.

[0007] The specific technical solutions of the present invention are as follows:

[0008] An asphalt modifier includes a modifier II, wherein the modifier II is a thermoplastic elastomer-polyurethane graft copolymer. The preparation method of the modifier II includes the following steps:

[0009] (1) mixing a functionalized thermoplastic elastomer with an oil additive, and after the functionalized thermoplastic elastomer is fully swollen, adding an amine-containing compound to the mixture and mixing uniformly;

[0010] (2) The mixture obtained in the above step (1) is first added to a twin-screw extruder for melting, blending, and reaction, and then a polyurethane prepolymer is added to the twin-screw extruder, melted, blended, reacted, and extruded into granules to obtain modifier II.

[0011] Furthermore, in the above step (1), the functionalized thermoplastic elastomer is formed by grafting functional groups onto a thermoplastic elastomer, and the thermoplastic elastomer includes SBS (styrene-butadiene-styrene block copolymer), SEBS (styrene-ethylene-butylene-styrene block copolymer), POE (polyolefin elastomer), and the functionalized groups include maleic anhydride groups (MAH), epoxy groups (GMA) or acrylic acid groups (AA). The functionalized thermoplastic elastomer can be SBS-g-MAH, SEBS-g-MAH, POE-g-MAH, SEBS-g-GMA, POE-g-GMA, SBS-g-AA, SEBS-g-AA, POE-g-AA, etc.

[0012] Furthermore, in step (1), the weight-average molecular weight of the functionalized thermoplastic elastomer is 100,000 to 150,000, for example, 100,000, 105,000, 110,000, 115,000, 120,000, 125,000, 130,000, 135,000, 140,000, 145,000, 150,000, etc., and the grafting rate of the functionalized group is 0.5 to 1.5%.

[0013] Furthermore, in step (1), the oil additive includes cyclohexane oil, and the cyclohexane oil can be at least one of KN4006, KN4010, KN4016, KN4020, etc.

[0014] Furthermore, in step (1), the amino-containing compound may be at least one of MOCA (4,4'-methylenebis(2-chloroaniline)), a derivative of MOCA, a substitute for MOCA, etc. Among them, the derivative of MOCA may be hydrogenated MOCA (3,3'-diamino-4,4'-diphenylmethane). The substitute for MOCA may be MCDEA (4,4'-methylene-bis-(3-chloro-2,6-diethylaniline)), DETDA (diethyltoluenediamine), DMTDA (dimethylthiotoluenediamine), MBDA (4,4'-methylenebis[N-sec-butylaniline]), polyetheramine (a polymer having a polyether structure as the main chain and an amino group as the terminal active functional group, with the chemical formula C 3n+ 3H 6n+10On N2) and other compounds containing amino functional groups. Among them, polyetheramines include D230 curing agent, D400 curing agent, T403 curing agent, etc.

[0015] Furthermore, in step (1), the mass ratio of the oil additive to the functionalized thermoplastic elastomer is 5 to 15:100, for example, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, 11:100, 12:100, 13:100, 14:100, or 15:100.

[0016] Furthermore, in step (1), the molar ratio of the functionalized groups (e.g., -MAH, -GMA, -AA) in the functionalized thermoplastic elastomer to the amino groups (-NH2) in the amino-containing compound is 0.15 to 0.8:1, for example, 0.15:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1.

[0017] Furthermore, in step (1), after the functionalized thermoplastic elastomer is mixed with the oil additive, the functionalized thermoplastic elastomer is swelled in the oil additive for 8-12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours.

[0018] Furthermore, in step (2), the polyurethane prepolymer is a polyether or polyester polyurethane prepolymer, and the isocyanate content in the polyurethane prepolymer is less than or equal to 10wt%. The polyurethane prepolymer is usually a commercially available product and can be SC7702, SC7931, Adiprene@LF MDI polyurethane prepolymer, At least one of aliphatic polyurethane prepolymer, polyether T80 prepolymer, etc.

[0019] Furthermore, in step (2), the molar ratio of the isocyanate group (-NCO) in the polyurethane prepolymer to the functional group (e.g., -MAH, -GMA, -AA) in the functionalized thermoplastic elastomer is 2 to 6:1, for example, 2:1, 3:1, 4:1, 5:1, 6:1.

[0020] Furthermore, in step (2), the mixture of step (1) is first added to a twin-screw extruder, the temperature of the twin-screw extruder is controlled at 150-180°C, and melt blending is carried out for 2-5 minutes. Then, a polyurethane prepolymer is added from the middle of the twin-screw extruder, the temperature of the twin-screw extruder is controlled at 140-160°C, melt blending is carried out for 1-3 minutes, and then extrusion granulation is carried out. This order of addition allows the functionalized thermoplastic elastomer to react with the amino-containing compound first to form a graft, and then the graft reacts with the polyurethane prepolymer to obtain the final product. The extrudate obtained by extrusion granulation is cooled, pelletized, and sieved to obtain a granular modifier II, and the particle size of the modifier II is 1-4 mm.

[0021] Furthermore, the asphalt modifier further comprises a modifier I, which is a grafted product obtained by reacting a functionalized thermoplastic elastomer with an amine-containing compound. The preparation method of the modifier I comprises the following steps: adding the mixture of step (1) above to a twin-screw extruder, melt blending, and extruding and granulating to obtain the modifier I.

[0022] Furthermore, to prepare Modifier I, a mixture of a functionalized thermoplastic elastomer, an oil additive, and an amine-containing compound is melt-granulated in a twin-screw extruder at a temperature of 150-180°C for 3-5 minutes, followed by extrusion and granulation. The extruded material is cooled, pelletized, and sieved to obtain granular Modifier I of the desired size. The resulting granules of Modifier I range from 1 to 4 mm.

[0023] Furthermore, in the asphalt modifier, the mass ratio of modifier I to modifier II is preferably 1-15:1-10, for example, 1:10, 8:10, 1:1, 8:5, 10:8, 15:1.

[0024] The present invention also provides a modified asphalt comprising a base asphalt, an asphalt modifier, a compatibilizer, a tackifying resin, and an antioxidant. The asphalt modifier, as described above, is Modifier II, or a mixture of Modifier I and Modifier II. Modifier I and Modifier II are added separately during the preparation of the modified asphalt.

[0025] Furthermore, based on 100 parts by mass of the base asphalt, the amount of modifier I is 0 to 15 parts by weight, for example, 0 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, and 15 parts.

[0026] Furthermore, based on 100 parts by mass of the base asphalt, the amount of modifier II is 1 to 10 parts by weight, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, and 10 parts.

[0027] Furthermore, based on 100 parts by weight of the base asphalt, the amount of the compatibilizer is 1 to 5 parts by weight, for example, 1 part, 2 parts, 3 parts, 4 parts, or 5 parts.

[0028] Furthermore, based on 100 parts by weight of the base asphalt, the amount of the tackifying resin is 0.5 to 3 parts by weight, for example, 0.5 part, 1 part, 2 parts, or 3 parts.

[0029] Furthermore, based on 100 parts by mass of the base asphalt, the amount of the antioxidant is 0.04 to 1 part by weight, for example, 0.04 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, and 1 part.

[0030] Furthermore, the matrix asphalt refers to 70# asphalt or 90# asphalt.

[0031] Furthermore, the compatibilizer is a mixture of polyurethane diluent, naphthenic oil, and aromatic oil, and the mass ratio of polyurethane diluent, naphthenic oil, and aromatic oil is 1:10-15:10-15. The polyurethane diluent can be a commonly used diluent disclosed in the prior art, such as DOWANOL TM DPM, Propylene carbonate, The naphthenic oil may be one or more of WE, WH-TH004, polyurethane diluent GTA733, etc. The naphthenic oil may be one or more of KN4006, KN4010, KN4016, KN4020, etc. The aromatic oil may be one or more of 150BS base oil, TDAE (environmentally friendly aromatic oil), naphthenic extracted oil, etc.

[0032] Furthermore, the tackifying resin can be selected from tackifying resins commonly used in the asphalt field, such as one or more of C5 petroleum resin (such as BT-R100, BT-R110, BT-R120), C9 petroleum resin (such as BT-C100, BT-C110, BT-C120), C5 / C9 copolymer petroleum resin (such as BT-G100, BT-G110, BT-G120), rosin resin, terpene resin (such as T4100, T420), coumarone resin, etc., and the softening point of the tackifying resin is 80-130°C.

[0033] Furthermore, the antioxidant may be selected from antioxidants commonly used in the asphalt field, such as one or more of antioxidant 1010, antioxidant 1076, antioxidant 264, antioxidant CA, antioxidant 164, and the like.

[0034] The present invention also provides a method for preparing the modified asphalt. The raw materials are generally mixed in the order of base asphalt → compatibilizer → modifier I (if any) → modifier II → tackifying resin and antioxidant, and the modified asphalt is obtained by shearing and incubation.

[0035] Furthermore, the preparation method of the modified asphalt includes the following steps: adding a compatibilizer to the base asphalt, adding modifier I (if any) after shear stirring, adding modifier II after shear stirring, adding a tackifying resin and an antioxidant after shear stirring, and incubating after shear stirring to obtain the modified asphalt.

[0036] Furthermore, after each raw material is added, it is sheared for a period of time before the next raw material is added. After all raw materials are added, they are incubated for a period of time to obtain modified asphalt. The shearing temperature is generally 150-180°C, for example, 150°C, 160°C, 170°C, and 180°C. The shearing speed is generally 3500-4500 rpm. The shearing time is generally 10-20 minutes, for example, 10 minutes, 15 minutes, and 20 minutes. The incubation temperature is generally 160-180°C, for example, 160°C, 170°C, and 180°C. The incubation time is generally 120-150 minutes, for example, 120 minutes, 130 minutes, 140 minutes, and 150 minutes.

[0037] The present invention also provides a method for improving asphalt properties, comprising adding an asphalt modifier to asphalt, wherein the asphalt modifier is Modifier II, or a combination of Modifier I and Modifier II. The mass ratio of Modifier I to base asphalt is 0 to 15:100, for example, 0:100, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, 11:100, 12:100, 13:100, 14:100, and 15:100. The mass ratio of modifier II to base asphalt is 1 to 10:100, for example, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, or 10:100. Preferably, the asphalt modifier is used to improve the rutting resistance and / or fatigue resistance and / or high and low temperature performance of the asphalt.

[0038] The asphalt modifier of the present invention breaks through the performance bottleneck of traditional modifiers through material component design and process optimization. Compared with the existing technology, the present invention has the following advantages:

[0039] 1. The modifier of the present invention uses a functionalized thermoplastic elastomer as a matrix, introduces active grafting sites, and then reacts with polyurethane (PU) to form a multi-level network structure in the asphalt, which significantly increases the modulus of the modified asphalt, significantly improves the high and low temperature performance, and increases the road surface's rutting resistance, fatigue resistance, and crack resistance, resulting in excellent road performance.

[0040] 2. This invention uses grafts of functionalized thermoplastic elastomers and amine-containing compounds, as well as functionalized thermoplastic elastomer-polyurethane graft copolymers, either alone or in combination, as modifiers for asphalt modification. The functionalized elastomer and polyurethane are connected through a chemical bonding mechanism, enhancing the modifying effect of the modifier. The functionalized thermoplastic elastomer-polyurethane graft copolymers combine the elasticity of thermoplastic elastomers with the strength, fatigue resistance, and wear resistance of polyurethane (PU), synergistically enhancing the mechanical properties of asphalt. This results in stronger rutting resistance at high temperatures, significantly improved crack resistance at low temperatures, and a longer fatigue life.

[0041] 3. The present invention chemically bonds thermoplastic elastomers such as SBS with polyurethane to form a three-dimensional interpenetrating network structure in asphalt. During the use of modified asphalt, the phase separation problem caused by the poor compatibility of SBS (non-polar) and polyurethane (polar) when the elastomer and polyurethane are physically blended is completely solved.

[0042] 4. The chemical bonding of elastomers such as SBS and polyurethane in the present invention not only constructs a three-dimensional interpenetrating network structure and significantly improves the homogeneity of the modified asphalt, but also increases the tensile strength and elastic recovery rate of the modified asphalt through the molecular-level interface strengthening mechanism, thereby achieving synergistic optimization of various properties within a wide temperature range.

[0043] 5. The amino groups in modifier I react with the isocyanate groups in modifier II to achieve chemical cross-linking. At the same time, these active groups can also react with hydroxyl groups, carboxyl groups, etc. in asphalt to make the formed three-dimensional interpenetrating network structure more stable, which helps to solve the problem of rapid attenuation of modified asphalt performance during high-temperature storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is the production flow chart of modifier I.

[0045] Figure 2 This is the production flow chart of modifier II.

[0046] Figure 3 This is the infrared spectrum of modifier I generated by the reaction of SBS-M and MOCA.

[0047] Figure 4 This is the infrared spectrum of modifier II generated by the reaction of modifier I and polyurethane prepolymer.

[0048] Figure 5 Fluorescence microscopy phase distribution diagram of the modified asphalt obtained in Example 1.

[0049] Figure 6 Fluorescence microscopic phase distribution diagram of the modified asphalt obtained in Comparative Example 2. DETAILED DESCRIPTION

[0050] The technical solutions provided by the present invention are described in detail below with reference to the following examples, but they should not be construed as limiting the scope of protection of the present invention. In the following examples and comparative examples, unless otherwise specified, the concentrations are all percentages by mass.

[0051] In the following examples and comparative examples, the raw materials and instruments used are shown in the following table:

[0052]

[0053]

[0054]

[0055] In the following examples and comparative examples, the molar amount of the functionalized group in the thermoplastic elastomer is calculated as follows: mass percentage of the functionalized group × mass of the thermoplastic elastomer used / molar mass of the functionalized group; the molar amount of the isocyanate group in the polyurethane prepolymer is calculated as follows: mass percentage of the isocyanate group × mass of the polyurethane prepolymer used / molar mass of the functionalized group.

[0056] Example 1

[0057] (1) Add 10 parts by weight of KN4020 to 100 parts by weight of SBS-MAH and stir to mix. After swelling for 10 hours, add 5.5 parts by weight of MOCA to the mixture and mix well using a mixer.

[0058] (2) Add the above mixture to a twin-screw extruder to react SBS-MAH and MOCA to generate SBS-MAH-MOCA grafts. The twin-screw extruder is divided into five temperature zones along the direction of material movement, and the temperatures of each temperature zone are set to 150°C, 160°C, 170°C, 170°C, and 180°C, respectively. The feed temperature is 120°C and the extrusion temperature is 170°C. Add the above mixture from the first temperature zone to the twin-screw extruder at a feed rate of 5kg / min, so that SBS-MAH and MOCA react in the twin-screw extruder to generate SBS-MAH-MOCA grafts. The total residence time of the material in the twin-screw extruder is 3-5min. The extruded material is water-cooled, pelletized, and sieved to obtain granular modifier I with a particle size of 1-4mm.

[0059] The reaction formula of SBS-MAH and MOCA is as follows:

[0060]

[0061] The infrared spectrum of the obtained SBS-MAH-MOCA grafted product is as follows: Figure 3 As shown in the figure, it can be seen that 3485cm-1 Asymmetric NH stretching vibration of primary amine, 3385 cm -1 Corresponding to the symmetrical NH stretching vibration of primary amine, 1630 cm -1 is the stretching vibration peak of the carbonyl group (C=0) in the amide bond, 1510 cm -1 It is the superposition peak of NH bending vibration and CN stretching vibration in amide bond.

[0062] (3) The twin-screw extruder is divided into five temperature zones along the direction of material movement, and the temperatures in each temperature zone are 150°C, 160°C, 170°C, 170°C, and 180°C, respectively. The feeding temperature is 120°C and the extrusion temperature is 170°C. The mixture of step (1) is added to the twin-screw extruder from the first temperature zone at a feed rate of 3.5 kg / min. After the mixture of step (1) is melt-blended in the twin-screw extruder for 2-3 minutes, the polyurethane prepolymer is added from the middle of the twin-screw extruder. SC7702 was melt blended for 1-2 minutes and then extruded into pellets. The twin-screw extruder material was water-cooled, pelletized, and sieved to obtain granular Modifier II with a particle size of 1-4 mm. The polyurethane prepolymer feed rate was 1.4 kg / min.

[0063] In step (3), SBS-MAH and MOCA are first reacted in a twin-screw extruder to generate an SBS-MAH-MOCA graft, which is then reacted with a polyurethane prepolymer to obtain a thermoplastic elastomer-polyurethane graft copolymer (SBS-MAH-MOCA-PU). The reaction formula of the SBS-MAH-MOCA graft and the polyurethane prepolymer is as follows:

[0064]

[0065] The infrared spectrum of the obtained thermoplastic elastomer-polyurethane graft copolymer is as follows: Figure 4 As shown in the figure, it can be seen that 1730cm -1 It is the infrared characteristic peak of carbamate bond.

[0066] (4) Add 2 parts by weight of compatibilizer (polyurethane diluent DOWANOL TMDPM, cyclohexane oil KN4020, and aromatic oil 150BS (mixed in a mass ratio of 1:10:10) were added to 100 parts by weight of 70# base asphalt, and sheared and stirred at 170°C and 4000 rpm for 10 minutes, then 4 parts by weight of modifier I were added, and sheared and stirred at 180°C and 4000 rpm for 20 minutes, then 6 parts by weight of modifier II were added, and sheared and stirred at 180°C and 4000 rpm for 20 minutes, finally 1 part by weight of tackifying resin (terpene resin T4100) and 0.05 parts by weight of antioxidant 1010 were added, and sheared and stirred at 180°C and 4000 rpm for 10 minutes, and then incubated at 180°C for 120 minutes to obtain modified asphalt.

[0067] The fluorescence microscopic phase distribution diagram of the modified asphalt obtained is as follows: Figure 5 As shown in the figure, it can be seen that the black part is the asphalt phase, and the polymer is a continuous three-dimensional network structure uniformly dispersed in the asphalt, among which the cross-linking points are mainly formed by the reaction of modifier I and modifier II.

[0068] Example 2

[0069] Modified asphalt was prepared according to the method of Example 1, except that in step (4), modifier I was not added and the amount of modifier II added was 10 parts by weight.

[0070] Example 3

[0071] Modified asphalt was prepared according to the method of Example 1, except that in step (4), the amount of modifier I added was 2 parts by weight, and the amount of modifier II added was 8 parts by weight.

[0072] Example 4

[0073] Modified asphalt was prepared according to the method of Example 1, except that in step (4), the amount of modifier I added was 3 parts by weight, and the amount of modifier II added was 7 parts by weight.

[0074] Example 5

[0075] Modified asphalt was prepared according to the method of Example 1, except that in step (4), the amount of modifier I added was 8 parts by weight, and the amount of modifier II added was 2 parts by weight.

[0076] Example 6

[0077] Modified asphalt was prepared according to the method of Example 1, except that in step (4), the amount of compatibilizer added was 1 part by weight, the amount of modifier I added was 2 parts by weight, and the amount of modifier II added was 2 parts by weight.

[0078] Example 7

[0079] Modified asphalt was prepared according to the method of Example 1, except that: in step (1), 100 parts by weight of SBS-MAH was replaced by 100 parts by weight of SEBS-MAH; in step (3), the polyurethane prepolymer SC7702 was replaced by polyether T80 prepolymer 8130, and the feeding rate of polyether T80 prepolymer 8130 was 2 kg / min.

[0080] Example 8

[0081] Modified asphalt was prepared according to the method of Example 1, except that: in step (1), 100 parts by weight of SBS-MAH was replaced by 100 parts by weight of PEO-MAH; in step (3), the polyurethane prepolymer SC7702 replacement SC7931, The feed rate of SC7931 is 1.6 kg / min.

[0082] Example 9

[0083] Modified asphalt was prepared according to the method of Example 1, except that: in step (4), 100 parts by weight of 70# base asphalt was replaced by 100 parts by weight of 90# base asphalt, 1 part by weight of tackifying resin (terpene resin T4100) was replaced by 2 parts by weight of tackifying resin (C5 / C9 copolymer petroleum resin BT-G100), and 0.05 parts by weight of antioxidant 1010 was replaced by 0.05 parts by weight of antioxidant 1076.

[0084] Example 10

[0085] The modified asphalt was prepared according to the method of Example 1, except that: in step (4), 100 parts by weight of 70# matrix asphalt was replaced by 100 parts by weight of 90# matrix asphalt, the compatibilizer was replaced by a mixture of polyurethane diluent WH-TH004, cyclohexane oil KN4006, and cyclohexane extracted oil in a mass ratio of 1:10:10, the compatibilizer dosage was 2 parts by weight, 1 part by weight of tackifying resin (terpene resin T4100) was replaced by 1 part by weight of C5 petroleum resin BT-R100, and 0.05 part by weight of antioxidant 1010 was replaced by 0.05 part by weight of antioxidant 1076.

[0086] Comparative Example 1

[0087] (1) Add 10 parts by weight of KN4020 to 100 parts by weight of SBS-MAH and stir to mix. After swelling for 10 hours, add 5.5 parts by weight of MOCA to the mixture and mix well using a mixer.

[0088] (2) Add 2 parts by weight of compatibilizer (polyurethane diluent DOWANOL TMDPM, naphthenic oil KN4020, aromatic oil 150BS (mixed in a mass ratio of 1:10:10) were added to 100 parts by weight of 70# matrix asphalt, and sheared and stirred at 170°C and 4000 rpm for 10 minutes, then 8.3 parts by weight of the mixture of step (1) were added, and sheared and stirred at 180°C and 4000 rpm for 20 minutes, and then 1.7 parts by weight of polyurethane prepolymer was added. SC7702 was shear-stirred at 180°C and 4000 rpm for 20 min, and finally 1 part by weight of tackifying resin (terpene resin T4100) and 0.05 part by weight of antioxidant 1010 were added, and the mixture was shear-stirred at 180°C and 4000 rpm for 10 min, and then incubated at 180°C for 120 min to obtain modified asphalt.

[0089] The fluorescence microscopic phase distribution diagram of the modified asphalt obtained is as follows: Figure 6 As shown in the figure, the black part is the asphalt phase and the white circle is the polyurethane. It can be seen that in the physically blended modified asphalt, the polymer is a monodisperse phase, and the polymer is unevenly dispersed in the asphalt, and the polyurethane is physically agglomerated.

[0090] Comparative Example 2

[0091] The compatibilizer (polyurethane diluent DOWANOL TM 2 parts by weight of DPM, naphthenic oil KN4010, and aromatic oil 150BS (configured in a mass ratio of 1:10:10) were added to 70# matrix asphalt, and sheared and stirred at 170°C and 4000 rpm for 10 minutes. Then 5 parts by weight of SBS were added, and sheared and stirred at 180°C and 4000 rpm for 20 minutes. Then 0.3 parts by weight of azobisisobutyronitrile was added, and sheared and stirred at 180°C and 4000 rpm for 20 minutes. Then, polyurethane prepolymer was added. 5 parts by weight of SC7702 were shear-stirred at 180°C and 4000 rpm for 20 min, and then 1 part by weight of tackifying resin (terpene resin T4100) and 0.05 parts by weight of antioxidant 1010 were added, and the mixture was shear-stirred at 180°C and 4000 rpm for 10 min, and then incubated at 180°C for 120 min to obtain modified asphalt.

[0092] Comparative Example 3

[0093] The modified asphalt was prepared according to the method of Example 1, except that: in step (3), the polyurethane prepolymer SC7702 and the mixture of step (1) are simultaneously added into the twin-screw extruder from the first temperature zone.

[0094] Comparative Example 4

[0095] Modified asphalt was prepared according to the method of Example 1, except that in step (4), modifier II was not added and the amount of modifier I added was 10 parts by weight.

[0096] The properties of the modified asphalts prepared in the above examples and comparative examples were tested, and the performance parameters and test methods are shown in the following table:

[0097] Test standards Needle penetration GB / T 0604 Elongation GB / T 0605 Softening point GB / T 0606 Solubility GB / T 0607 Kinematic viscosity GB / T 0602 Rutting factor G* / sinδ AASHTO TP5 Complex modulus G* AASHTO TP5

[0098] The test results are shown in the following table:

[0099] Table 1

[0100]

[0101]

[0102] As shown in Table 1, the rutting factor G* / sinδ value, composite modulus G* value, and ductility value of the modified asphalt of the present invention are significantly increased compared with the comparative example, indicating that the modified asphalt of the present invention has better high and low temperature performance, rutting resistance, fatigue resistance and other road performance.

[0103] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An asphalt modifier, characterized by: The invention comprises a modifier II, wherein the modifier II is prepared by the following method: (1) mixing a functionalized thermoplastic elastomer with an oil additive, and after the functionalized thermoplastic elastomer is fully swollen, adding an amine-containing compound to the mixture and mixing uniformly; (2) The mixture obtained in the above step (1) is first added to a twin-screw extruder for melting, blending, and reaction, and then a polyurethane prepolymer is added to the twin-screw extruder, melted, blended, reacted, and extruded into granules to obtain modifier II.

2. The asphalt modifier according to claim 1, characterized in that: In step (1), the oil additive includes naphthenic oil, and the naphthenic oil is preferably at least one of KN4006, KN4010, KN4016, and KN4020; Preferably, in step (1), the functionalized thermoplastic elastomer is formed by grafting a functional group onto a thermoplastic elastomer, the thermoplastic elastomer comprises SBS, SEBS or POE, and the functional group comprises a maleic anhydride group, an epoxy group or an acrylic acid group; Preferably, in step (1), the weight average molecular weight of the functionalized thermoplastic elastomer is 100,000 to 150,000, and the grafting rate of the functionalized group is 0.5 to 1.5%; Preferably, in step (1), the amino-containing compound includes at least one of MOCA, a derivative of MOCA, and a substitute for MOCA, the MOCA derivative includes hydrogenated MOCA, and the MOCA substitute includes at least one of MCDEA, DETDA, DMTDA, MBDA, and polyetheramine.

3. The asphalt modifier according to claim 1, characterized in that: In step (1), the mass ratio of the oil additive to the functionalized thermoplastic elastomer is 5 to 15:100; Preferably, in step (1), the molar ratio of the functionalized groups in the functionalized thermoplastic elastomer to the amino groups in the amino-containing compound is 0.15 to 0.8:1; Preferably, in step (1), the swelling time is 8-12 hours.

4. The asphalt modifier according to claim 1, characterized in that: In step (2), the polyurethane prepolymer is a polyether polyurethane prepolymer or a polyester polyurethane prepolymer, preferably SC7702 polyurethane prepolymer, SC7931 polyurethane prepolymer, Adiprene@LF MDI polyurethane prepolymer, At least one of an aliphatic polyurethane prepolymer and a polyether T80 prepolymer; Preferably, in step (2), the molar ratio of the isocyanate groups in the polyurethane prepolymer to the functional groups in the functionalized thermoplastic elastomer is 2-6:1; Preferably, in step (2), the temperature of the twin-screw extruder is controlled at 150-180° C., the mixture of step (1) is added, and melt blending is performed for 2-5 minutes, then the temperature of the twin-screw extruder is controlled at 140-160° C., the polyurethane prepolymer is added to the twin-screw extruder, melt blending is performed for 1-3 minutes, and then extrusion granulation is performed.

5. The asphalt modifier according to any one of claims 1 to 4, characterized in that: The asphalt modifier also contains modifier I. The preparation method of modifier I comprises the following steps: adding the mixture of step (1) in claim 1 into a twin-screw extruder, melt blending, extrusion granulation, and obtaining modifier I; preferably, the temperature of the twin-screw extruder is 150-180°C, and the melt blending is performed for 3-5 minutes.

6. The asphalt modifier according to claim 5, characterized in that: The mass ratio of modifier I to modifier II is 1-15:1-10.

7. A modified asphalt, characterized in that: Contains the following components in parts by weight:

8. The modified asphalt according to claim 7, characterized in that: The compatibilizer is a mixture of polyurethane diluent, naphthenic oil, and aromatic oil, and the mass ratio of polyurethane diluent, naphthenic oil, and aromatic oil is 1:10-15:10-15; Preferably, the polyurethane diluent is DOWANOL TM DPM, Propylene carbonate, One or more of WE, WH-TH004, and polyurethane diluent GTA733; Preferably, the naphthenic oil is one or more of KN4006, KN4010, KN4016, and KN4020; Preferably, the aromatic oil is one or more of 150BS base oil, TDAE, and naphthenic extracted oil.

9. The modified asphalt according to claim 7, characterized in that: The softening point of the tackifying resin is 80-130° C.; preferably, the tackifying resin is one or more of C5 petroleum resin, C9 petroleum resin, C5 / C9 copolymerized petroleum resin, rosin resin, terpene resin, and coumarone resin; Preferably, the antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 264, antioxidant CA, and antioxidant 164.

10. A method for preparing the modified asphalt according to any one of claims 7 to 9, characterized in that : Add the compatibilizer to the base asphalt, add the modifier I after shearing and stirring, add the modifier II after shearing and stirring, add the tackifying resin and antioxidant after shearing and stirring, and hatch after shearing and stirring to obtain modified asphalt; Preferably, each raw material is sheared for a period of time after being added before the next raw material is added. After all raw materials are added, they are incubated for a period of time to obtain modified asphalt; The shearing temperature is 150-180° C., the shearing speed is 3500-4500 rpm, the shearing time is 10-20 min, the incubation temperature is 160-180° C., and the incubation time is 120-150 min.

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