An environment-friendly rubber asphalt additive, environment-friendly rubber asphalt and a preparation method thereof

Abstract

The application discloses an environment-friendly rubber asphalt additive, environment-friendly rubber asphalt and a preparation method thereof. The environment-friendly rubber asphalt additive comprises the following components in percentage by weight: modified PDA-tourmaline nanoparticles 1-5 parts; and a dispersing agent 1-10 parts; the dispersing agent is selected from one or more of soybean oil, rapeseed oil, peanut oil, palm oil and sunflower oil; the modified PDA-tourmaline nanoparticles have a size of 100-300 nm, and the surface of the modified PDA-tourmaline nanoparticles is modified by a large number of hydroxyl groups. Through in-situ capture of the environment-friendly rubber asphalt additive, the amount of small molecule compounds released by rubber asphalt under the influence of high temperature is reduced, the environmental problems existing in the production and construction of rubber asphalt are solved, and the environment-friendly rubber asphalt additive has good social benefits and application prospect.

Description

Technical Field

[0001] This invention belongs to the field of modified asphalt, specifically relating to an environmentally friendly rubber asphalt additive, environmentally friendly rubber asphalt, and its preparation method. Background Technology

[0002] While cars have brought convenience to residents' travel after entering thousands of households, the waste rubber tires generated at the same time have put enormous pressure on environmental protection projects due to their difficulty in handling, degradation, and recycling.

[0003] Crushing and granulating waste tires, then adding them to asphalt and producing rubber-modified asphalt through high-speed shearing and other methods is currently an effective way to deal with waste tires. Rubber-modified asphalt has good high and low temperature performance and excellent fatigue resistance, making it an ideal material for special pavements such as airport runways and racing tracks. However, there are also some problems in the preparation and use of rubber-modified asphalt. For example, rubber asphalt needs to be heated to high temperatures during preparation and pavement construction. Under high-temperature conditions, both asphalt and rubber powder release large amounts of toxic, harmful, and irritating gases such as sulfides and VOCs, which harm the ecological environment and affect human health. In addition, rubber powder usually has poor compatibility with asphalt and poor storage stability, and is prone to segregation, which affects its road performance.

[0004] Some researchers have reduced the amount of smoke emitted from rubber asphalt by adding adsorbents or warm mix additives; however, the performance of rubber asphalt materials prepared using these methods is affected to some extent. Furthermore, related studies have shown that directly adding traditional base asphalt neutralizers to rubber asphalt can reduce smoke emissions to some extent. These neutralizers inhibit the volatilization of small molecules by reacting with volatile small-molecule compounds in asphalt to form larger molecular weight compounds. However, the preparation and application temperatures of rubber asphalt are higher than those of ordinary base asphalt, and the newly formed larger molecular weight compounds may undergo secondary volatilization, causing environmental pollution.

[0005] CN110079105A discloses a method for preparing sepiolite-loaded soluble rubber powder-modified asphalt. This method utilizes sepiolite powder as a dispersion carrier, where sheared rubber powder particles are first adsorbed by the sepiolite powder, and then a sepiolite-loaded rubber powder modifier is added to the asphalt. In this process, the sepiolite powder acts as twofold: first, a carrier, dispersing the rubber powder within the asphalt system and improving the compatibility between the rubber powder and asphalt; second, it acts as an adsorbent, reducing the release of rubber and asphalt fumes to some extent through its adsorption capacity. However, the sepiolite powder mentioned in this method is an inorganic material. Its addition to asphalt can cause stress concentration during service, leading to microcracks in the asphalt pavement and affecting its road performance. Furthermore, the method of reducing asphalt and rubber fumes using sepiolite powder is a reversible physical adsorption method. Since the construction temperature of rubber-modified asphalt is high, the fumes adsorbed by the sepiolite powder may be released again at high temperatures, causing environmental pollution.

[0006] CN108659558B discloses a rubber-modified asphalt viscosity reducer and deodorizing agent and its preparation method. This method reduces the rubber odor and asphalt fumes generated during the production, mixing, and paving of rubber-modified asphalt by adding the asphalt viscosity reducer and deodorizing agent. However, while the additives used in this method reduce the viscosity and construction temperature of the rubber-modified asphalt, they also decrease the adhesion between the rubber-modified asphalt and aggregates, thereby reducing the water damage resistance of the asphalt pavement.

[0007] In summary, existing technologies have not completely solved the problems of large amounts of fumes and strong irritating odors released during the production and construction of rubber asphalt. Summary of the Invention

[0008] To address the problems existing in the prior art, this invention provides an environmentally friendly rubber asphalt additive, environmentally friendly rubber asphalt, and a method for preparing the same. By utilizing the in-situ trapping effect of the environmentally friendly rubber asphalt additive, the amount of small molecule compounds released from rubber asphalt under high temperatures is reduced, thus solving the environmental problems associated with rubber asphalt production and construction. This invention has significant social benefits and promising application prospects.

[0009] The environmentally friendly rubber asphalt additive of the present invention comprises the following components by weight: 1-5 parts of modified polydopamine (PDA)-trammer nanoparticles; 1-10 parts of dispersant; the dispersant is selected from one or more of soybean oil, rapeseed oil, peanut oil, palm oil, and sunflower oil; Furthermore, the modified PDA-tourmaline nanoparticles have a size of 100-300 nm.

[0010] Furthermore, the surface of the modified PDA-tourmaline nanoparticles is modified with a large number of hydroxyl groups.

[0011] Furthermore, the preparation method of the modified PDA-tourmaline nanoparticles includes the following steps: S1: Add an appropriate amount of Tris buffer solution to the flask, then add dopamine hydrochloride and tourmaline nanoparticles. Pass air into the flask and stir continuously until the color of the reaction system no longer darkens. Stop the reaction and filter, wash and freeze-dry the bottom solid powder to obtain PDA-tourmaline nanoparticles. S2: Add the PDA-tourmaline nanoparticles obtained in S1 to an organic solvent, then add an alkaline catalyst, and heat and stir in the dark for a period of time. S3: Keeping the stirring and heating conditions of S2 unchanged, slowly add 2,3,4-trihydroxy-benzoyl chloride dropwise to the S2 system. After the addition is complete, continue stirring and reacting for a period of time. After the reaction is complete, filter, wash and freeze-dry the solid powder in the system to obtain modified PDA-tourmaline nanoparticles.

[0012] Furthermore, the airflow rate in step S1 is 1-3 L / min.

[0013] Furthermore, the concentration of the Tris buffer solution in step S1 is 10 mM, and the pH value is 8-9.

[0014] Furthermore, the tourmaline nanoparticles described in step S1 have a size of 80-100 nm.

[0015] Furthermore, the mass ratio of tourmaline nanoparticles to Tris buffer in step S1 is 1:10-30.

[0016] Furthermore, the concentration of dopamine in the reaction system described in step S1 is 2-15 mg / mL.

[0017] Furthermore, the organic solvent in step S2 is selected from one or more of acetone, benzene, carbon tetrachloride, diethyl ether, toluene, dichloromethane, chloroform, methanol, or ethanol.

[0018] Furthermore, in step S2, the stirring speed is 300-500 rpm, the stirring temperature is 20-60℃, and the stirring time is 5-10 h.

[0019] Furthermore, the alkaline catalyst in step S2 is selected from one or more of sodium hydroxide, potassium hydroxide, triethylamine, ethylenediamine, anhydrous sodium carbonate, or anhydrous potassium carbonate.

[0020] Furthermore, in step S2, the mass ratio of PDA-tourmaline nanoparticles to organic solvent is 1:10-30, and the mass ratio of PDA-tourmaline nanoparticles to alkaline catalyst is 1:1.

[0021] Furthermore, the mass ratio of PDA-tourmaline nanoparticles to 2,3,4-trihydroxy-benzoyl chloride in step S3 is 1:5-15.

[0022] Furthermore, the stirring time in step S3 is 5-13 hours.

[0023] Furthermore, an appropriate amount of modified PDA-tourmaline nanoparticles can be added to the dispersant and stirred at 300-500 rpm for 1-3 hours at 25-45℃ to obtain an environmentally friendly rubber asphalt additive.

[0024] This invention also provides a odor-free rubber-modified asphalt, comprising the following components by weight: 50-500 parts of base bitumen; 5-50 parts of waste rubber powder; 1-10 parts of environmentally friendly rubber asphalt additive; Furthermore, the base asphalt is heated to 163-203℃, and then environmentally friendly rubber asphalt additives and waste rubber powder are added. The mixture is sheared at a shearing speed of 4000-6000 rpm for 0.5-4 hours to obtain environmentally friendly rubber asphalt.

[0025] The base asphalt is commercially available No. 70 and No. 90 road asphalt, preferably No. 90 Grade A asphalt.

[0026] Compared with the prior art, the environmentally friendly rubber asphalt additive and environmentally friendly rubber asphalt of the present invention have the following technical advantages: (1) Compared with traditional asphalt deodorizing agents, which suffer from poor high-temperature stability, poor storage stability, and are prone to secondary volatilization after reacting with smoke molecules, the environmentally friendly rubber asphalt additive of the present invention, with its modified PDA-tourmaline nanoparticles, releases a large number of negative ions under heating, generating an electrostatic field that captures the more active and irritating smoke molecules undergoing Brownian motion at high temperatures onto its surface. Furthermore, the smoke molecules are oxidized and degraded by a large number of hydroxyl groups on the PDA surface under high-temperature conditions, effectively preventing their secondary volatilization into the air and significantly reducing the harm caused by asphalt fumes to the environment and human body.

[0027] (2) The environmentally friendly rubber asphalt additive of the present invention has modified PDA-tourmaline nanoparticles with nanoscale size and a large number of amino groups on its surface. It not only has good compatibility with asphalt, but can also form hydrogen bonds with rubber particles to form a network structure, which greatly improves the compatibility between rubber and asphalt, avoids the occurrence of segregation, and improves the performance of rubber asphalt. Attached Figure Description

[0028] Figure 1 This is an electron microscope image of the modified PDA-tourmaline nanoparticles described in this invention. Detailed Implementation

[0029] The sulfides in the environmentally friendly rubber asphalt flue gas of this invention were tested using an Agilent 7890 gas chromatograph according to the national standard GB_T 28727-2012 Gas Analysis - Determination of Sulfides by Flame Photometric Gas Chromatography; the VOC content in the asphalt flue gas was tested using a TVA-2020 VOC detector with an FID detector.

[0030] To further illustrate the relevant features and technical means of the present invention, the present invention will be clearly and thoroughly described below in conjunction with the embodiments. It should be noted that the base asphalt used in the following embodiments is Sinopec Donghai brand No. 90 Grade A asphalt.

[0031] Example 1 S1: Add 50 parts by weight of 10mM Tris buffer solution with pH 8.5 and 5 parts by weight of tourmaline nanoparticles to a flask, then add dopamine hydrochloride to make the concentration of dopamine hydrochloride in the solution 2mg / mL, and further purge air into the flask at a flow rate of 1L / min. Stir for 24 hours at a temperature of 25℃ and a speed of 300rpm. After stirring, filter, wash and freeze-dry the bottom solid powder to obtain PDA-tourmaline nanoparticles. S2: Add 1 part by mass of the PDA-tourmaline nanoparticles prepared in S1 to 30 parts by mass of toluene, then add 1 part by mass of potassium hydroxide, and heat and stir at 60°C and 300 rpm for 10 h in the dark. S3: Keeping the stirring and heating conditions of S2 unchanged, slowly add 10 parts by mass of 2,3,4-trihydroxy-benzoyl chloride to the S2 system. After the addition is completed, continue stirring and react for 12 hours. After the reaction is completed, filter, wash and freeze-dry the solid powder in the system to obtain modified PDA-tourmaline nanoparticles. S4: Add 1 part by mass of modified PDA-tourmaline nanoparticles to 1 part by mass of rapeseed oil, and stir and mix for 1 hour at 25°C and 300 rpm to obtain an environmentally friendly rubber asphalt additive. S5: Heat 93 parts by weight of base asphalt to 163°C, then add 5 parts by weight of waste rubber powder and 2 parts by weight of environmentally friendly rubber asphalt additive, and shear at high speed at 4000 rpm for 2 hours at 163°C to obtain environmentally friendly rubber modified asphalt.

[0032] Example 2 Except for step S3, in which 15 parts by mass of 2,3,4-trihydroxy-benzoyl chloride are added, the rest is the same as in Example 1.

[0033] Example 3 Except for step S4, where soybean oil is used as the dispersant, the rest is the same as step 1.

[0034] Example 4 Except for step S5, where the amount of environmentally friendly rubber asphalt additive added is 1 part by mass, the rest is the same as step 1.

[0035] Example 5 Except for step S5, where the amount of environmentally friendly rubber asphalt additive added is 4 parts by weight, the rest is the same as step 1.

[0036] Comparative Example 1 S1: Add 1 part by weight of tourmaline nanoparticles to 1 part by weight of rapeseed oil, and stir and mix for 1 hour at 25°C and 300 rpm to obtain an environmentally friendly rubber asphalt additive. S2: Heat 93 parts by weight of base asphalt to 163°C, then add 5 parts by weight of waste rubber powder and 2 parts by weight of environmentally friendly rubber asphalt additive, and shear at high speed at 4000 rpm for 2 hours at 163°C to obtain environmentally friendly rubber modified asphalt.

[0037] Comparative Example 2 S1: Add 50 parts by weight of 10mM Tris buffer solution with pH 8.5 and 5 parts by weight of tourmaline nanoparticles to a flask, then add dopamine hydrochloride to make the concentration of dopamine hydrochloride in the solution 2mg / mL, and further purge air into the flask at a flow rate of 1L / min. Stir for 24 hours at a temperature of 25℃ and a speed of 300rpm. After stirring, filter, wash and freeze-dry the bottom solid powder to obtain PDA-tourmaline nanoparticles. S2: Add 1 part by weight of PDA-tourmaline nanoparticles to 1 part by weight of rapeseed oil, and stir and mix for 1 hour at 25°C and 300 rpm to obtain an environmentally friendly rubber asphalt additive. S3: Heat 93 parts by weight of base asphalt to 163°C, then add 5 parts by weight of waste rubber powder and 2 parts by weight of environmentally friendly rubber asphalt additive, and shear at high speed at 4000 rpm for 2 hours at 163°C to obtain environmentally friendly rubber modified asphalt.

[0038] Comparative Example 3 S1: Add 50 parts by weight of 10mM Tris buffer solution with pH 8.5 and 5 parts by weight of tourmaline nanoparticles to a flask, then add dopamine hydrochloride to make the concentration of dopamine hydrochloride in the solution 2mg / mL, and further purge air into the flask at a flow rate of 1L / min. Stir for 24 hours at a temperature of 25℃ and a speed of 300rpm. After stirring, filter, wash and freeze-dry the bottom solid powder to obtain PDA-tourmaline nanoparticles. S2: Add 1 part by mass of the PDA-tourmaline nanoparticles prepared in S1 to 30 parts by mass of toluene, then add 1 part by mass of potassium hydroxide, and heat and stir at 60°C and 300 rpm for 10 h in the dark. S3: Keeping the stirring and heating conditions of S2 unchanged, slowly add 10 parts by mass of 2,3,4-trihydroxy-benzoyl chloride to the S2 system. After the addition is completed, continue stirring and react for 12 hours. After the reaction is completed, filter, wash and freeze-dry the solid powder in the system to obtain modified PDA-tourmaline nanoparticles. S4: Heat 93 parts by weight of base asphalt to 163°C, then add 5 parts by weight of waste rubber powder and 1 part by weight of modified PDA-tourmaline nanoparticles. Under the condition of 163°C, high-speed shearing at 4000 rpm for 2 hours can produce environmentally friendly rubber-modified asphalt.

[0039] Comparative Example 4 S1: Rubber-modified asphalt is prepared by heating 93 parts by weight of base asphalt to 163°C, then adding 5 parts by weight of waste rubber powder and shearing at 4000 rpm for 2 hours at 163°C.

[0040] Test case The basic properties and segregation tests were performed on the rubber-modified asphalt samples (for the segregation test, the asphalt sample was poured into a segregation tube and stored at 163℃ for 48 hours, and the difference in softening points between the upper and lower parts of the segregation tube was tested). The data obtained are shown in Table 1 below.

[0041] Table 1. Asphalt performance test and storage stability test data The main components that give asphalt fumes their pungent odor are sulfides and VOCs. To test these components, asphalt samples were transferred to a sealed container (cylindrical, 25cm x 25cm) with a gas extraction port and stored at 183℃ for 6 hours. After storage, the gas from the sealed container was extracted and stored in a gas bag. The sulfide and VOC content in the gas was tested using a gas chromatograph and a TVA-2020 VOC detector. The data obtained are shown in Table 2 below.

[0042] Table 2. Asphalt VOCs Test Data

Claims

1. An environmentally friendly rubber asphalt additive, characterized in that... The product comprises, by weight, the following components: 1-5 parts of modified polydopamine (PDA)-tourmaline nanoparticles; 1-10 parts of dispersant; The modified PDA-tourmaline nanoparticles have a size of 100-300 nm; the surface of the modified PDA-tourmaline nanoparticles is modified with a large number of hydroxyl groups; the dispersant is selected from one or more of soybean oil, rapeseed oil, peanut oil, palm oil or sunflower oil; The method for preparing the modified PDA-tourmaline nanoparticles, Includes the following steps: S1: Add an appropriate amount of Tris buffer solution to a flask, followed by dopamine hydrochloride and tourmaline nanoparticles. Purge the flask with air and stir continuously until the color of the reaction system no longer darkens. Stop the reaction, filter, wash, and freeze-dry the bottom solid powder to obtain PDA-tourmaline nanoparticles. S2: Add the PDA-tourmaline nanoparticles obtained in S1 to an organic solvent, followed by an alkaline catalyst. Heat and stir in the dark for a period of time. S3: Keeping the stirring and heating conditions of S2 unchanged, slowly add 2,3,4-trihydroxybenzoyl chloride dropwise to the system in S2. After the addition is complete, continue stirring for a period of time. After the reaction is complete, filter, wash, and freeze-dry the solid powder in the system to obtain modified PDA-tourmaline nanoparticles. The tourmaline nanoparticles have a size of 80-100 nm; the mass ratio of the tourmaline nanoparticles to the Tris buffer is 1:10-30; and the concentration of dopamine in the reaction system is 2-15 mg / mL. The organic solvent mentioned in step S2 is selected from one or more of acetone, benzene, carbon tetrachloride, diethyl ether, toluene, dichloromethane, chloroform, methanol, or ethanol; In step S2, the mass ratio of PDA-tourmaline nanoparticles to organic solvent is 1:10-30, and the mass ratio of PDA-tourmaline nanoparticles to alkaline catalyst is 1:

1. The mass ratio of PDA-tourmaline nanoparticles to 2,3,4-trihydroxy-benzoyl chloride in step S3 is 1:5-15.

2. The environmentally friendly rubber asphalt additive according to claim 1, characterized in that: The stirring temperature in step S1 is 25-45℃, the stirring speed is 300-500rpm, and the stirring time is 24-48h; the air flow rate in step S1 is 1-3L / min; the concentration of the Tris buffer solution is 10mM, and the pH value is 8-9.

3. The environmentally friendly rubber asphalt additive according to claim 1, characterized in that: The stirring speed in step S2 is 300-500 rpm, the stirring temperature is 20-60℃, and the stirring time is 5-10 h.

4. The environmentally friendly rubber asphalt additive according to claim 1, characterized in that: The alkaline catalyst in step S2 is selected from one or more of sodium hydroxide, potassium hydroxide, triethylamine, ethylenediamine, anhydrous sodium carbonate, or anhydrous potassium carbonate.

5. A method for preparing the environmentally friendly rubber asphalt additive according to claim 1, characterized in that: Modified PDA-tourmaline nanoparticles were added to a dispersant and stirred at 300-500 rpm for 1-3 hours at 25-45℃ to obtain an environmentally friendly rubber asphalt additive.

6. A mild-tasting rubber-modified asphalt, characterized in that... It includes the following components by weight: 50-500 parts of base bitumen; 5-50 parts of waste rubber powder; 1-10 parts of the environmentally friendly rubber asphalt additive as described in claim 1.

7. A method for preparing the odor-neutral rubber-modified asphalt according to claim 6, characterized in that: The base asphalt is heated to 163-203℃, and environmentally friendly rubber asphalt additives and waste rubber powder are added. The mixture is sheared at a shear rate of 4000-6000 rpm for 0.5-4 hours to obtain environmentally friendly rubber asphalt.

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