A high-viscosity and high-elasticity modified asphalt and asphalt composition

Abstract

The invention discloses a high-viscosity and high-elasticity modified asphalt and an asphalt composition, which belong to the field of asphalt and solve the technical problem that the existing asphalt materials lack high-viscosity and high-elasticity modified asphalt suitable for diverse climates. The high-viscosity and high-elasticity modified asphalt suitable for diverse climates is prepared from the following raw materials in parts by mass: 100 parts of road petroleum asphalt, 2.5-4 parts of epoxidized modified styrene-butadiene-styrene block copolymer, 5-10 parts of hyperbranched polyester modified styrene-isoprene-styrene block copolymer, 5-10 parts of tackifying resin, 1-2 parts of rubber powder, 1-2 parts of oleic acid amide, 2-3 parts of bagasse fiber, and 2-10 parts of other functional additives. The modified asphalt has the advantages of high viscosity and high elasticity and is suitable for diverse climates.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt preparation, and specifically relates to a high-viscosity and high-elasticity modified asphalt and an asphalt composition. Background Art

[0002] Sichuan has an extremely complex terrain, including the Sichuan Basin, the surrounding mountains and the western plateau, which leads to a great diversity of climate types. In particular, the surrounding mountains and the western plateau are affected by the rapid rise in altitude and the undulating terrain, showing typical "microclimate weather" and "vertical change weather", which is characterized by "four seasons in one mountain and different weather in ten miles". The Sichuan Basin has a mid-subtropical humid climate, characterized by high temperature and heavy rain in summer and mild and little rain in winter. The average summer temperature is about 29.3℃, and the extreme high temperature is about 35.7℃; the average winter temperature is about 6℃, and the extreme low temperature is about -7.1℃. The annual precipitation is about 1000 mm, showing the characteristics of high temperature and heavy rain. The surrounding mountains are the junction of the Sichuan Basin hills and the surrounding plateau mountains, and the terrain tends to be high outside and low inside. In general, the terrain is steep and undulating, with high mountains and deep valleys, which is manifested by the superposition of vertical differentiation at different regional scales, resulting in multiple climate types from temperate to mountainous cold zones. The western Sichuan plateau is located on the southeast wing of the Qinghai-Tibet Plateau and the eastern part of the Hengduan Mountains. The Hengduan Mountains are a series of parallel ridges and valleys running nearly north-south, with mountains and rivers arranged alternately. The overall terrain is high in the west and low in the east, with complex landforms, and the height difference between ridges and valleys is generally between 1000 and 3000 meters. The average temperature in summer is about 16.9℃, and the extreme high temperature is about 24.1℃; the extreme low temperature in winter is about -36℃, the annual precipitation is about 600 mm, and the ultraviolet radiation is strong. The Panxi Plateau mainly includes Liangshan Prefecture, Panzhihua and Ya'an near Liangshan Prefecture. The topography is mainly dominated by mountain ridges, hills and river valleys in the plateau area, with an average altitude of 1000 to 3000 meters. The winter is particularly warm, 5 to 6℃ higher than the basin area, with high temperatures all year round and strong ultraviolet radiation. The average temperature in summer is about 30.9℃, and the extreme high temperature is 39.9℃; the extreme low temperature in winter is -1.9℃, and the annual precipitation is about 1050 mm. It can be seen that Sichuan Province has extremely diverse climates.

[0003] Asphalt is a temperature-sensitive material. It tends to soften under high temperature conditions, causing permanent deformation, which leads to rutting on the road surface. However, it tends to harden under low temperature conditions, causing thermal shrinkage cracking and forming road cracks. Due to the complex and diverse climatic conditions in Sichuan Province, conventional modified asphalt materials are difficult to meet the use requirements under different climatic conditions at the same time.

[0004] In summary, it is particularly necessary to develop a high-viscosity and high-elasticity modified asphalt suitable for diverse climates. Therefore, the present invention requires a high-viscosity and high-elasticity asphalt suitable for diverse climates to solve the above-mentioned problems. Summary of the invention

[0005] The purpose of the present invention is to provide a high-viscosity and high-elasticity asphalt to solve the demand for the use of asphalt in a complex natural environment. To achieve the above purpose, the present invention provides the following technical solutions: a high-viscosity and high-elasticity modified asphalt, made from the following raw materials in parts by mass: 100 parts of petroleum asphalt, 2.5-4 parts of epoxidized modified styrene-butadiene-styrene block copolymer, 5-10 parts of hyperbranched polyester modified styrene-isoprene-styrene block copolymer, 5-10 parts of tackifying resin, 1-2 parts of rubber powder, 1-2 parts of oleic acid amide, 2-3 parts of bagasse fiber, 2-10 parts of other functional additives; wherein the epoxidized modified styrene-butadiene-styrene block copolymer has a relative molecular weight of 100,000-150,000, and the proportion of styrene block is 30-35%, wherein the relative molecular weight of the hyperbranched polyester modified styrene-isoprene-styrene block copolymer is 200,000-250,000, and the proportion of styrene block in the styrene-isoprene-styrene block copolymer is 15-20%.

[0006] Preferably, the epoxidized modified styrene-butadiene-styrene block copolymer can be prepared by an in-situ epoxidation process. Specifically, the epoxidized SBS can be prepared by oxidation of formic acid and hydrogen peroxide, and the mass fraction of epoxy groups is 1.5-3%.

[0007] Styrene-butadiene-styrene block copolymer is an important type of thermoplastic elastomer, which has the advantages of high tensile strength, low surface friction coefficient, good low temperature resistance, excellent processing performance, etc. It is widely used in asphalt modification, but styrene-butadiene-styrene block copolymer (SBS) also has the disadvantages of low polarity, poor weather resistance, lack of compatibility and adhesion with polar materials, etc. The present invention applies epoxy-modified SBS to asphalt modification to improve the physical properties of asphalt, and improves the weather resistance of asphalt by combining with other components, thereby expanding its scope of application.

[0008] Styrene-isoprene-styrene block copolymer (SIS) has isolated soft rubber segments in the middle and hard plastic segments on both sides. It has the performance of vulcanized rubber at room temperature and is plastic at high temperature. It has the advantages of good elasticity and bonding strength, low temperature resistance, good solubility, etc. It is also one of the main materials for asphalt modification. However, SIS has the disadvantages of low polarity, poor oil resistance and solvent resistance because polystyrene and polyisoprene are non-polar substances and have poor miscibility with polar substances. The present invention introduces a hyperbranched structure into the styrene-isoprene-styrene block copolymer structure so that they have more contact points when interacting between molecules and usually have better solubility, which helps them to be evenly dispersed in the mixed system and improves their compatibility with other components.

[0009] The hyperbranched polyester modified styrene-isoprene-styrene block copolymer used in the present invention is obtained by esterification reaction of terminal hydroxyl hyperbranched polyester and terminal carboxyl styrene-isoprene-styrene block copolymer.

[0010] Preferably, the hyperbranched polyester is prepared by reacting hydroxymethyl acid and hydroxymethyl alkane with a catalyst. More preferably, the hyperbranched polyester is a second-generation AB2 type hydroxyl-terminated hyperbranched polyester synthesized from trimethylolpropane and 2,2-dimethylolpropionic acid under the catalysis of p-toluenesulfonic acid.

[0011] Preferably, the degree of branching of the second-generation AB2-type hydroxyl-terminated hyperbranched polyester is 0.45.

[0012]

[0013] Preferably, the carboxyl-terminated styrene-isoprene-styrene block copolymer is a carboxylated styrene-isoprene-styrene block copolymer prepared using phthalic anhydride as an acylating agent.

[0014]

[0015] Preferably, the petroleum asphalt is road petroleum asphalt No. 70 or road petroleum asphalt No. 90.

[0016] Preferably, other functional additives in the raw materials include one or more molding agents selected from stearic acid, synthetic rubber, and potassium chloride.

[0017] Preferably, other functional additives in the raw materials include one or more stabilizers selected from the group consisting of nano titanium dioxide, modified polyether grafted silicone, and hydroxy zinc complexes.

[0018] Preferably, other functional additives in the raw materials include antioxidants selected from tert-butylhydroquinone and butylated hydroxyanisole.

[0019] Preferably, other functional additives in the raw materials include compatibilizers selected from coal tar, rubber oil, cycloparaffin oil, aromatic oil, furfural extracted oil, castor oil, and epoxidized soybean oil.

[0020] Preferably, the tackifying resin is selected from coumarone resin and terpene resin.

[0021] Preferably, plant fibers such as bagasse fibers are introduced into the raw materials of the present invention, which can improve the mechanical properties of asphalt on the one hand, and improve the low-temperature crack resistance of asphalt on the other hand. Bagasse fibers are widely available and low in cost.

[0022] In addition, rubber powder is introduced into the asphalt raw material of the present invention, and the rubber powder can improve the softening point and anti-rutting ability of asphalt, reduce the permanent deformation of asphalt pavement at high temperature, improve the flexibility of asphalt, improve its crack resistance under low temperature conditions, and reduce the formation of cracks. Oleic acid amide can be used as a thickener and stabilizer for asphalt to improve the viscosity and shear resistance of asphalt, thereby improving its performance in applications such as pavement. The addition of oleic acid amide can improve the stability of asphalt at high temperature, reduce the fluidity of asphalt at high temperature, and thus improve the anti-rutting ability of the pavement.

[0023] The present invention also provides a method for preparing high-viscosity and high-elasticity asphalt, comprising the following specific steps:

[0024] (1) Heat petroleum asphalt to 180-190°C by mass and stir continuously;

[0025] (2) Slowly add other raw materials into the asphalt according to mass and shear them using a high-speed shearing machine;

[0026] (3) Add other functional additives according to mass and continue stirring to obtain high-viscosity and high-elastic asphalt.

[0027] The present invention also provides a high-viscosity and high-elasticity asphalt composition, comprising the aforementioned high-viscosity and high-elasticity modified asphalt.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. SBS has the dual properties of rubber and plastic and is an excellent asphalt modification material, but SBS has low polarity and poor compatibility with asphalt. The present invention overcomes the inherent defects of styrene-butadiene-styrene block copolymer and styrene-isoprene-styrene block copolymer through the coordination of epoxidation-modified styrene-butadiene-styrene block copolymer and hyperbranched polyester-modified styrene-isoprene-styrene block copolymer, improves the compatibility with asphalt and other components, improves the penetration, softening point, elongation and viscosity of asphalt, improves the high-temperature stability of asphalt, reduces low-temperature brittleness, reduces the risk of low-temperature cracking of the road surface, and also improves the fatigue resistance of the road surface;

[0030] 2. The low-temperature performance of modified asphalt is improved by adding rubber powder. Since the addition of rubber powder will cause the coating performance of asphalt to deteriorate, the addition of oleic acid amide improves the coating performance of asphalt and increases the fluidity and high-temperature performance of asphalt. The combination of rubber powder and oleic acid amide can adapt to the climate with large humidity differences in the Sichuan Basin and improve the durability of asphalt.

[0031] 3. Due to the addition of bagasse fiber, the fiber bundles of bagasse fiber have good temperature resistance and the one-dimensional structure of the fiber provides high temperature stability and reinforcement for the asphalt. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0033] Example

[0034] 1. Preparation of epoxidized styrene-butadiene-styrene block copolymers

[0035] SBS was dissolved in toluene. After SBS was completely dissolved, formic acid (purity of 88%) was added. Stirring was carried out at 70°C. Hydrogen peroxide (concentration of 30%) was added. The ratio of formic acid to hydrogen peroxide (V / V) was 1:2. The amount of hydrogen peroxide was 20% of the mass of SBS. After reacting for 2 hours, epoxidized SBS was obtained. The mass fraction of epoxy groups was 2.8%. The mass fraction of epoxy groups was determined by chemical titration.

[0036] 2. Preparation of hyperbranched polyester modified styrene-isoprene-styrene block copolymers

[0037] The second generation AB2 type hydroxyl-terminated hyperbranched polyester was synthesized by using trimethylolpropane and 2,2-dimethylolpropionic acid as raw materials, reacting at 140℃ for 3h under the catalysis of p-toluenesulfonic acid and vacuuming for 1h. The branching degree was 0.45 and the molecular weight was 1800g / mol.

[0038] Phthalic anhydride is used as an acylation agent, AlCl3 is used as a catalyst, and the reaction is carried out at 80°C for 4 hours to prepare a carboxylated styrene-isoprene-styrene block copolymer, wherein the styrene-isoprene-styrene block copolymer is selected from D1111 of Kraton Corporation.

[0039]

[0040] Then, the hyperbranched polyester modified styrene-isoprene-styrene block copolymer is obtained by esterifying the prepared terminal hydroxyl hyperbranched polyester and the terminal carboxyl styrene-isoprene-styrene block copolymer.

[0041] 3. Preparation of modified asphalt

[0042] The dosage of each asphalt component is 100 parts of 70# petroleum asphalt, 3 parts of epoxidized modified styrene-butadiene-styrene block copolymer prepared in step 1, 8 parts of hyperbranched polyester modified styrene-isoprene-styrene block copolymer prepared in step 2, 8 parts of tackifying resin, 1.5 parts of rubber powder, 1.5 parts of oleic acid amide, 2.5 parts of bagasse fiber, and 5 parts of other functional additives (see Table 1 for details); wherein the epoxidized modified styrene-butadiene-styrene block copolymer has a relative molecular weight of 130,000, and the proportion of styrene block is 32%, wherein the relative molecular weight of the hyperbranched polyester modified styrene-isoprene-styrene block copolymer is 230,000, and the proportion of styrene block in the styrene-isoprene-styrene block copolymer is 17%.

[0043] The molding agent is selected from 0.5 parts of stearic acid, 0.5 parts of synthetic rubber, and 0.5 parts of potassium chloride.

[0044] The stabilizer is selected from 0.5 parts of nano titanium dioxide, 0.5 parts of modified polyether grafted silicone, and 0.5 parts of hydroxy zinc complex.

[0045] The antioxidants selected were 0.5 parts of butylhydroquinone and 0.5 parts of butylated hydroxyanisole.

[0046] The compatibilizer is a high aromatic oil with an aromatic content of more than 90%.

[0047] The tackifying resin is coumarone resin.

[0048] According to the mass percentage, heat the petroleum asphalt to 180-190℃ and stir continuously; slowly add other raw materials into the asphalt according to the prescribed amount, stir mechanically to swell for 1 hour, and then use a high-speed shearing machine to shear for 1 hour, the temperature shall not exceed 190℃, add other functional additives according to the mass percentage and continue shearing for 0.5 hours, after stopping the shearing, maintain the temperature at 180℃ and continue stirring for 3 hours to obtain high-viscosity and high-elasticity asphalt.

[0049] Different from the embodiment, the comparative examples 1-17 are different in the added materials, and the specific additions are shown in Table 1 below. The linear SBS used is SBS1301-1 (YH791H) from Yueyang Baling Petrochemical Co., Ltd., and the block ratio S / B is 30 / 70. SIS is D1111 from Kraton.

[0050]

[0051]

[0052] The experimental indicators of the modified asphalt under the conditions of Examples 1-9 and Comparative Examples 1-17 are shown in Table 2.

[0053]

[0054] As can be seen from the above table, the epoxidized styrene-butadiene-styrene block copolymer has excellent high temperature resistance, good low temperature resistance, and excellent processing performance, and the polarity is increased after modification, which increases the compatibility with polar materials; the styrene-isoprene-styrene block copolymer modified by the hyperbranched polyester has the performance of vulcanized rubber at room temperature, and is plastic at high temperature, and has good elasticity and bonding strength, low temperature resistance, good solubility resistance, low solution viscosity, and fast curing. The epoxidized styrene-butadiene-styrene block copolymer and the hyperbranched polyester modified styrene-isoprene-styrene block copolymer cooperate to overcome the inherent defects of the styrene-butadiene-styrene block copolymer and the styrene-isoprene-styrene block copolymer, improve the compatibility with asphalt and other components, and improve the viscosity of the asphalt under the premise of ensuring the ductility and penetration of the modified asphalt, and have good low temperature resistance and high elasticity;

[0055] By adding rubber powder, the low-temperature performance of modified asphalt is further improved. Since the addition of rubber powder will cause the coating performance of asphalt to deteriorate, the addition of oleic acid amide improves the coating performance of asphalt and increases the fluidity and high-temperature performance of asphalt. The combined use of rubber powder and oleic acid amide can adapt to the climate with large humidity differences in the Sichuan Basin and improve the durability of asphalt.

[0056] Bagasse fiber is added. The fiber bundles of bagasse fiber have good temperature resistance and the one-dimensional fiber structure provides temperature stability and reinforcement for asphalt, improving the adhesion and shear resistance of asphalt. In addition, the stability of bagasse fiber can greatly improve the low-temperature and high-temperature stability of high-viscosity and high-elasticity asphalt.

[0057] It should be noted that the above-mentioned embodiments only express the specific implementation methods of the present application, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the protection scope of the present application. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A high-viscosity and high-elastic modified asphalt, characterized in that: The invention is prepared from the following raw materials in parts by mass: 100 parts of petroleum asphalt, 2.5-4 parts of epoxidized modified styrene-butadiene-styrene block copolymer, 5-10 parts of hyperbranched polyester modified styrene-isoprene-styrene block copolymer, 5-10 parts of tackifying resin, 1-2 parts of rubber powder, 1-2 parts of oleic acid amide, 2-3 parts of bagasse fiber, and 2-10 parts of other functional additives; wherein the epoxidized modified styrene-butadiene-styrene block copolymer has a relative molecular weight of 100,000-150,000, and the proportion of styrene block is 30-35%, and the relative molecular weight of the hyperbranched polyester modified styrene-isoprene-styrene block copolymer is 200,000-250,000, and the proportion of styrene block in the styrene-isoprene-styrene block copolymer is 15-20%; The hyperbranched polyester modified styrene-isoprene-styrene block copolymer is obtained by reacting a hydroxyl-terminated hyperbranched polyester with a carboxyl-terminated styrene-isoprene-styrene block copolymer; The hyperbranched polyester is a second-generation AB2 type hydroxyl-terminated hyperbranched polyester synthesized from trimethylolpropane and 2,2-dimethylolpropionic acid under the catalysis of p-toluenesulfonic acid; The branching degree of the second-generation AB2 type hydroxyl-terminated hyperbranched polyester is 0.

45.

2. The high-viscosity and high-elastic modified asphalt according to claim 1, characterized in that: The mass fraction of epoxy groups in the epoxidation-modified styrene-butadiene-styrene block copolymer is 1.5-3%.

3. The high-viscosity and high-elastic modified asphalt according to claim 1, characterized in that: The petroleum asphalt is No. 70 road petroleum asphalt or No. 90 road petroleum asphalt.

4. The high-viscosity and high-elastic modified asphalt according to claim 1, characterized in that: The other functional additives include one or more stabilizers selected from nano titanium dioxide, modified polyether grafted silicone, and hydroxy zinc complex.

5. The high-viscosity and high-elastic modified asphalt according to claim 1, characterized in that: The other functional auxiliary agents include antioxidants selected from tert-butylhydroquinone and butylated hydroxyanisole.

6. The high-viscosity and high-elastic modified asphalt according to claim 1, characterized in that: The other functional additives include compatibilizers selected from rubber oil, naphthenic oil, aromatic oil, furfural extracted oil, third-line oil, fourth-line oil, castor oil, and epoxidized soybean oil.

7. The high-viscosity and high-elastic modified asphalt according to claim 1, characterized in that: The tackifying resin is selected from coumarone resin and terpene resin.

8. An asphalt composition, characterized in that: It comprises the high-viscosity and high-elastic modified asphalt described in any one of claims 1 to 7.

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