Passivating agent for inactivating free radicals of recycled asphalt as well as preparation method and application of passivating agent

Abstract

The invention relates to a passivating agent for inactivating free radicals of recycled asphalt as well as a preparation method and application of the passivating agent, and relates to the technical field of resource utilization of road waste asphalt concrete. The passivator for recycling asphalt free radical inactivation comprises the following raw materials: 100 parts of allylamine, 80-160 parts of hydroquinone, 2-5 parts of a first catalyst and 0.2-2 parts of a stabilizer, the allyl amine is a mixture of monoallyl amine, diallyl amine and triallyl amine. By preparing the free radical passivator rich in carbon-carbon double bonds, on one hand, active inhibition of the free radical induced aging effect of the aged asphalt in the recycled asphalt pavement is achieved, and aging of the asphalt is remarkably delayed; on the other hand, by introducing carbon-carbon double bonds on the molecular chain of the free radical passivator, the elasticity of the aged asphalt is recovered, comprehensive repair of the performance of the aged asphalt is achieved, the regeneration utilization rate of the waste asphalt mixture is remarkably increased, and important theoretical and practical significance is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of resource utilization of waste asphalt concrete for highways, and in particular to a passivating agent for deactivating free radicals of recycled asphalt, and a preparation method and application thereof. Background Art

[0002] With the acceleration of global urbanization and the continuous expansion of infrastructure construction, highway transportation, as an important support for economic development, has become a focus of attention for all countries in its construction and maintenance. However, the problem of waste asphalt concrete waste generated during highway construction and maintenance has become increasingly prominent. In recent years, the amount of waste asphalt concrete generated each year due to road overhaul, reconstruction and expansion has reached tens of millions of tons. How to effectively treat and reuse these waste materials has become an environmental and resource issue that needs to be solved urgently.

[0003] Waste asphalt concrete is mainly composed of asphalt, stone, sand and other additives, and has a high recycling value. However, traditional treatment methods such as landfill and direct incineration not only occupy a large amount of land resources, but also may cause environmental pollution; and the actual recycling rate of waste asphalt concrete resource utilization is less than 30%, resulting in a large waste of resources. Therefore, it is urgent to develop high-value utilization technology for waste asphalt concrete.

[0004] In the process of recycling waste asphalt concrete, the free radical problem of asphalt is one of the key factors affecting the performance of recycled materials. On the one hand, many free radicals are generated in the aging process of asphalt, which continuously induce the accelerated aging of new asphalt during the regeneration of waste asphalt mixture and the service of recycled asphalt pavement; on the other hand, during the construction and service of asphalt pavement, most of the carbon-carbon double bonds in asphalt are reduced or even disappeared due to oxidation, fracture or polymerization, resulting in a sharp decrease in asphalt elasticity and adhesion. The combination of the above two factors leads to poor durability of recycled asphalt pavement, which seriously restricts the resource utilization of waste asphalt mixture. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a passivating agent for recovering asphalt free radical deactivation, and a preparation method and application thereof.

[0006] In a first aspect, the present invention provides a passivating agent for recovering asphalt free radical deactivation, wherein the passivating agent for recovering asphalt free radical deactivation comprises the following raw materials in parts by weight:

[0007] 100 parts of allylamine, 80-160 parts of hydroquinone, 2-5 parts of the first catalyst and 0.2-2 parts of a stabilizer;

[0008] The allylamine is a mixture of monoallylamine, diallylamine and triallylamine.

[0009] Furthermore, the passivating agent for recovering asphalt free radical deactivation comprises the following raw materials in parts by weight:

[0010] 100 parts of allylamine, 120 parts of hydroquinone, 4 parts of the first catalyst and 0.9 parts of the stabilizer.

[0011] Furthermore, the first catalyst is a palladium catalyst, and the palladium catalyst includes palladium chloride; the stabilizer is an organic tin compound, and the organic tin compound includes dibutyltin dilaurate.

[0012] Furthermore, the preparation method of the allylamine comprises the following steps:

[0013] Stirring and mixing ammonia water, a second catalyst, an extractant and a phase transfer accelerator to obtain a first mixed solution;

[0014] Add allyl chloride dropwise to the first mixed solution, and after the addition is complete, perform a constant temperature reaction to obtain a second mixed solution;

[0015] The second mixed liquid is allowed to stand for stratification, and the obtained oil layer is distilled and purified to obtain the allylamine.

[0016] Furthermore, in terms of mass percentage, the concentration of the aqueous ammonia is 20-30%; the second catalyst is a copper catalyst, and the copper catalyst includes cuprous iodide; the extractant is a benzene solvent, and the benzene solvent includes chlorobenzene; the phase transfer promoter is an organic ammonium salt, and the organic ammonium salt includes tetrabutylammonium bromide.

[0017] Furthermore, the working condition parameters of the stirring and mixing include: temperature of 25±1°C, time of 30±2min; the working condition parameters of the isothermal reaction include: temperature of 35±1°C, time of 180±5min; the weight ratio of the ammonia water, the second catalyst, the extractant, the phase transfer promoter and the allyl chloride is 100:(0.1~0.5):(35~45):(0.1~0.3):(35~45).

[0018] Furthermore, in terms of mass percentage, the concentration of the aqueous ammonia is 25%; the weight ratio of the aqueous ammonia, the second catalyst, the extractant, the phase transfer promoter and the allyl chloride is 100:0.3:40:0.2:40.

[0019] In a second aspect, the present invention provides a method for preparing a passivating agent for recovering asphalt free radical deactivation as described in any one of the first aspects, the preparation method comprising the following steps:

[0020] preparing anhydrous ethanol solution of hydroquinone and anhydrous ethanol solution of allylamine;

[0021] Add the first catalyst to the anhydrous ethanol solution of hydroquinone and stir at a constant temperature, then drop the anhydrous ethanol solution of allylamine into it under the condition of constant temperature and stirring, add a stabilizer after the dropwise addition to continue the reaction, and cool after the reaction to obtain a third mixed solution;

[0022] The third mixed liquid is subjected to ethanol evaporation treatment to obtain the passivating agent.

[0023] Furthermore, the molar concentration of the anhydrous ethanol solution of hydroquinone is 0.5-1.5 mol / L; the molar concentration of the anhydrous ethanol solution of allylamine is 1.5-2.5 mol / L; the temperature of the constant temperature stirring is 55-65° C.; and the time for continuing the reaction by adding the stabilizer after the dropwise addition is 4-6 hours.

[0024] In a third aspect, the present invention provides the use of the passivating agent for recovering asphalt free radical deactivation as described in any one of the first aspect and the second aspect in the recycling and regeneration of waste asphalt concrete.

[0025] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0026] The embodiment of the present invention provides a passivator for deactivating free radicals in recycled asphalt, and a preparation method and application thereof. The passivator starts from the mechanism of chain initiation, chain growth and chain termination of free radicals, and prepares a free radical passivator rich in carbon-carbon double bonds. On the one hand, it can achieve active inhibition of the free radical-induced aging effect of aged asphalt in regenerated asphalt pavement, and significantly delay the aging of asphalt; on the other hand, by introducing carbon-carbon double bonds on the molecular chain of the free radical passivator, the elasticity of aged asphalt is restored, and the comprehensive repair of the performance of aged asphalt is achieved, thereby ensuring the durability of the regenerated asphalt pavement and significantly improving the recycling rate of waste asphalt mixtures. It has important theoretical and practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] Figure 1 A schematic diagram of the passivation mechanism of a passivating agent for recovering asphalt free radical deactivation provided in an embodiment of the present invention.

[0030] Figure 2 A schematic flow chart of a method for preparing a passivating agent for recovering asphalt free radical deactivation provided in an embodiment of the present invention.

[0031] Figure 3 The infrared characterization spectrum of the passivating agent for recovering asphalt free radical deactivation provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0034] In a first aspect, the present invention provides a passivating agent for recovering asphalt free radical deactivation, wherein the passivating agent for recovering asphalt free radical deactivation comprises the following raw materials in parts by weight:

[0035] 100 parts of allylamine, 80-160 parts of hydroquinone, 2-5 parts of the first catalyst and 0.2-2 parts of a stabilizer;

[0036] The allylamine is a mixture of monoallylamine, diallylamine and triallylamine.

[0037] The present invention provides a passivator for deactivating free radicals of aged asphalt, wherein the passivator is prepared by reacting allylamine prepared in advance with p-diphenol under certain catalytic conditions and adding a trace stabilizer of dibutyltin dilaurate, that is, preparing the passivator allylaminobenzoquinone. After free radical passivation, the aging-inducing effect of the aged asphalt on the new asphalt is fundamentally weakened, and at the same time, carbon-carbon double bonds are introduced into the aged asphalt to restore the elasticity of the aged asphalt, so that the durability of the regenerated asphalt pavement is substantially improved, and it is expected to realize the large-scale utilization of waste asphalt mixtures.

[0038] like Figure 1 As shown, a schematic diagram of the passivation mechanism of the passivating agent for recovering asphalt free radical deactivation provided by an embodiment of the present invention is shown, and the passivation mechanism is briefly described as follows:

[0039] The mechanism of allylaminobenzoquinone's inhibition of free radicals in aged asphalt is as follows: allylaminobenzoquinone and highly active free radicals undergo an inhibition reaction (see Figure 1), the newly generated free radicals are very stable and it is difficult for them to initiate polymerization or cross-linking of other asphalt molecules. They can only terminate by self-disproportionation. The phenol generated in the reaction product is oxidized into benzoquinone, which continues to play the role of free radical inhibition, thereby maintaining the passivation effect and ultimately achieving active inhibition of asphalt free radicals.

[0040] Therefore, the passivator provided by the present invention starts from the fundamental reason that the regenerated asphalt pavement has poor durability due to the existence of the induced aging effect of free radicals, and basically eliminates the induced aging effect by deactivating and passivating the free radicals; at the same time, by introducing carbon-carbon double bonds into the molecular structure of the passivator, the elasticity of the aged asphalt is effectively restored, thereby ensuring the durability of the regenerated pavement.

[0041] Preferably, the passivating agent is mainly prepared from the following raw materials in parts by weight:

[0042] 100 parts of allylamine, 90-130 parts of hydroquinone, 3-4 parts of catalyst, and 0.5-1.5 parts of stabilizer.

[0043] Preferably, the passivating agent is mainly prepared from the following raw materials in parts by weight:

[0044] 100 parts of allylamine, 120 parts of hydroquinone, 4 parts of catalyst, and 0.9 parts of stabilizer.

[0045] The invention provides a passivating agent for deactivating free radicals of aged asphalt, which is made through a specific process from homemade allylamine, hydroquinone, catalyst and stabilizer. It can deactivate the free radicals of aged asphalt in waste asphalt mixture, reduce its activity, and thereby reduce its ability to induce aging of new asphalt.

[0046] Among them, p-diphenol is chemically pure, a white crystalline powder, and its chemical formula is C6H6O2. It is the main raw material of the passivator and can be oxidized to p-dibenzoquinone under certain conditions. The catalyst is palladium chloride, and its chemical formula is PdCl2. Its main function is to control the reaction rate of p-diphenol and allylamine in the oxidation process to generate the passivator, thereby improving the purity of the product; the stabilizer is dibutyltin dilaurate, and its chemical formula is C 32 H 64 O4Sn, its main function is to improve the stability of the passivator during storage and use, and to ensure the long-term effectiveness of the passivator in inactivating free radicals in the regenerated asphalt pavement.

[0047] Preferably, the allylamine is prepared by the following steps:

[0048] (1) 100 parts of 25.0% ammonia water, 0.3 parts of cuprous iodide, 40 parts of chlorobenzene and 0.2 parts of tetrabutylammonium bromide were added in sequence into a 1000 mL three-necked flask equipped with a magnetic stirrer and a reflux condenser (using 5° C. anhydrous ethanol as the condensing medium), and the three-necked flask was placed in a water bath thermostat.

[0049] (2) Turn on the magnetic stirring, control the speed at 500±50r / min, and keep the temperature at about 25°C for 30min;

[0050] (3) Use an acid burette to slowly drip 12 parts of allyl chloride into a three-necked flask at a rate of 10 to 15 drops / min. After the dripping is complete, raise the water bath temperature to 35±2°C and maintain the temperature for 3 hours. When the reaction is complete, allow the mixture to stand and separate into layers.

[0051] (4) Separate the oil layer and purify it by distillation to obtain allyl amine.

[0052] In the second aspect, based on the same inventive concept, the present invention provides a method for preparing a passivating agent for recovering asphalt free radical deactivation as described in any one of the first aspects, such as Figure 2 As shown, the preparation method comprises the following steps:

[0053] preparing anhydrous ethanol solution of hydroquinone and anhydrous ethanol solution of allylamine;

[0054] Add the first catalyst to the anhydrous ethanol solution of hydroquinone and stir at a constant temperature, then drop the anhydrous ethanol solution of allylamine into it under the condition of constant temperature and stirring, add a stabilizer after the dropwise addition to continue the reaction, and cool after the reaction to obtain a third mixed solution;

[0055] The third mixed liquid is subjected to ethanol evaporation treatment to obtain the passivating agent.

[0056] Preferably, a method for preparing a passivating agent for deactivating free radicals of aged asphalt comprises the following steps:

[0057] First, dissolve hydroquinone with an appropriate amount of anhydrous ethanol to prepare a solution with a concentration of 1.0 mol / L. Take 100 ml of the solution and transfer it to a 500 ml three-necked flask with a magnetic stirrer. Then add palladium chloride catalyst, place the flask in a 60°C water bath, turn on the magnetic stirrer, and control the speed at 1000±50r / min.

[0058] Dissolve allylamine in anhydrous ethanol to prepare a solution with a concentration of 2.0 mol / L. Slowly drip the solution into the hydroquinone solution in a three-necked flask until the solution changes from pink to dark red. Stop dripping and add a trace amount of dibutyltin dilaurate stabilizer. Continue the reaction for 5 hours. After the reaction is completed, remove the water bath heating device, cool to room temperature, and stop stirring. Ethanol is evaporated with a rotary evaporator to obtain the passivating agent-allylaminobenzoquinone.

[0059] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0060] Example 1

[0061] A passivating agent for deactivating free radicals of aged asphalt is prepared from the following raw materials in parts by weight:

[0062] Allylamine 100 parts, hydroquinone 120 parts, catalyst 4 parts, stabilizer 0.9 parts.

[0063] The catalyst is palladium chloride, the stabilizer is dibutyltin dilaurate, the allylamine is homemade, and the hydroquinone is chemically pure.

[0064] The preparation method of the above-mentioned passivating agent for deactivating free radicals of aged asphalt comprises the following steps:

[0065] (1) Allylamine rich in carbon-carbon double bonds is prepared by the following steps:

[0066] a. Add a certain amount of 25.0% ammonia water, cuprous iodide, chlorobenzene and tetrabutylammonium bromide in sequence into a 1000ml three-necked flask with a magnetic stirring and reflux condensation device (using 5°C anhydrous ethanol as the condensation medium), and place the three-necked flask in a water bath thermostat.

[0067] b. Turn on the magnetic stirring, control the speed at 500±50r / min, and keep the temperature at about 25℃ for 30min;

[0068] c. Use an acid burette to slowly drip an appropriate amount of allyl chloride into the three-necked flask, and control the dripping rate at 10-15 drops / min. After the dripping is completed, raise the water bath temperature to 35±2℃ and keep the temperature constant for 3h. When the reaction is complete, let it stand and separate.

[0069] d. Separate the oil layer and perform distillation purification at a temperature of 93°C to obtain allylamine;

[0070] Wherein, the weight ratio of the ammonia water, the cuprous iodide, the chlorobenzene, the tetrabutylammonium bromide and the allyl chloride is 100:0.3:40:0.2:40.

[0071] (2) The passivating agent is prepared by the following steps:

[0072] First, dissolve hydroquinone with an appropriate amount of anhydrous ethanol to prepare a solution with a concentration of 1.0 mol / L; measure 100 ml of the solution and transfer it to a 500 ml three-necked flask with a magnetic stirrer, then add palladium chloride catalyst, and place the flask in a 60°C water bath to maintain a constant temperature, turn on the magnetic stirrer, and control the speed at 1000±50r / min; then dissolve allylamine with anhydrous ethanol to prepare a solution with a concentration of 2.0 mol / L, and slowly drip the solution into the hydroquinone solution in the three-necked flask. After the dripping is completed, the solution changes from pink to dark red. After the dripping is stopped, dibutyltin dilaurate stabilizer is added, and the reaction is continued for 5 hours. After the reaction is completed, the water bath heating device is removed, and the mixture is cooled to room temperature and stirring is stopped; the ethanol is evaporated by a rotary evaporator to obtain the passivating agent allylaminobenzoquinone, and its infrared characterization spectrum is as follows: Figure 3 shown.

[0073] Example 2

[0074] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that the passivating agent for deactivating free radicals of aged asphalt is prepared from the following raw materials in parts by weight: 100 parts of allylamine, 130 parts of hydroquinone, 4 parts of catalyst, and 0.9 parts of stabilizer; the remaining steps and parameters are the same.

[0075] Example 3

[0076] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that the passivating agent for deactivating free radicals of aged asphalt is prepared from the following raw materials in parts by weight: 100 parts of allylamine, 140 parts of hydroquinone, 4 parts of catalyst, and 0.9 parts of stabilizer; the remaining steps and parameters are the same.

[0077] Example 4

[0078] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that the passivating agent for deactivating free radicals of aged asphalt is prepared from the following raw materials in parts by weight: 100 parts of allylamine, 60 parts of hydroquinone, 4 parts of catalyst, and 0.9 parts of stabilizer; the remaining steps and parameters are the same.

[0079] Example 5

[0080] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that the passivating agent for deactivating free radicals of aged asphalt is prepared from the following raw materials in parts by weight: 100 parts of allylamine, 180 parts of hydroquinone, 4 parts of catalyst, and 0.9 parts of stabilizer; the remaining steps and parameters are the same.

[0081] Comparative Example 1

[0082] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that dipropylamine (structural formula: CH3-CH2-CH2-NH-CH2-CH2-CH3; CAS number: 142-84-7) without carbon-carbon double bonds is used in equal amounts to replace allylamine, and the remaining steps and parameters are the same.

[0083] Comparative Example 2

[0084] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that an equal amount of o-diphenol is used instead of p-diphenol, and the remaining steps and parameters are the same.

[0085] Comparative Example 3

[0086] This example provides a passivating agent for deactivating free radicals of aged asphalt and a preparation method thereof. The only difference from Example 1 is that no stabilizer is added, and the remaining steps and parameters are the same.

[0087] Test Case

[0088] In this example, the passivating agents provided in the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 3 are applied to the recycling and reuse of waste asphalt concrete to examine its performance.

[0089] Test method: The passivators provided in the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 3 are respectively added to the aged asphalt in a molten state at 140±5°C in the same ratio of m(passivator): m(aged asphalt) = 1.5:100, and the stirring device is turned on to maintain the rotation speed at 2000±100r / min. After 5 minutes, the stirring is stopped and cooled to room temperature to obtain three kinds of regenerated asphalts after free radical passivation. The aged asphalt before free radical passivation is used as a blank control, and the free radical concentration in each sample is tested by using the MS5000 electron paramagnetic resonance spectrometer EPR produced by FREIBERG, Germany. The infrared spectrum of each sample is performed by using the VERTEX 70 infrared analyzer produced by Bruker, Switzerland. The changes in the carbon-carbon double bond content in the aged asphalt and the elastic recovery rate are tested in accordance with the "Testing Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" JTG E20-2011. The relevant test results are listed in Table 1 below.

[0090] Table 1 Properties of regenerated asphalt obtained by hydrogenation reduction of aged asphalt

[0091]

[0092]

[0093] The above experimental comparison shows that the asphalt pavement is seriously aged due to the coupling of natural factors such as light, oxygen and water in the long-term service process. The free radical concentration in the aged asphalt has reached 1.23×10 11 molecule / cm 3 , while the carbon-carbon double bond index is only 0.0001236, which can no longer meet the requirements of traffic conditions. After free radical passivation, not only the free radical concentration is reduced by 3 to 4 orders of magnitude, but also the carbon-carbon double bond content is increased by 1 to 2 orders of magnitude, which is reflected in the significant improvement of elastic recovery rate on a macro scale. By comparing the three embodiments, it is found that when the mass ratio of allylamine to hydroquinone is 1:2 (ie, embodiment 1), the passivator obtained has the best comprehensive effect; when p-diphenol is excessive, the excess p-diphenol is oxidized to benzoquinone, which continues to play a role in free radical passivation, but the carbon-carbon double bond content is significantly reduced, resulting in a decrease in the elastic recovery rate of the aged asphalt; if the amount of p-diphenol is too low, although the elastic recovery performance of the obtained aged asphalt is not greatly affected, the passivation effect of the passivator on the free radicals is significantly reduced, which is reflected in the fact that the free radical concentration in the aged asphalt is significantly higher than that in other embodiments. Therefore, the ratio of allylamine to hydroquinone outside the protection scope of the claims, the passivator obtained will have an adverse effect on the road anti-aging performance or elastic recovery performance of the regenerated asphalt pavement. In addition, the test results of the comparative example show that the passivator prepared by replacing allylamine with an equal amount of dipropylamine without carbon-carbon double bonds has a strong capture effect on free radicals in aged asphalt, but the elastic recovery rate of aged asphalt has not been significantly improved. If the equal amount of o-diphenol is used to replace p-diphenol, the passivator obtained is significantly inferior to Example 1 in terms of the capture effect of free radicals and the elastic recovery of aged asphalt; Considering that the passivator obtained belongs to the benzoquinone class of substances, it has a strong volatility above the melting temperature (120°C) of aged asphalt in RAP. If an appropriate amount of stabilizer is not added, the passivator will volatilize, thereby weakening the passivation effect of free radicals.

[0094] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0095] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A passivating agent for recovering asphalt free radical deactivation, characterized in that: The passivating agent for recovering asphalt free radical deactivation comprises the following raw materials in parts by weight: 100 parts of allylamine, 80-160 parts of hydroquinone, 2-5 parts of the first catalyst and 0.2-2 parts of a stabilizer; The allylamine is a mixture of monoallylamine, diallylamine and triallylamine.

2. The passivating agent for recovering asphalt free radical deactivation according to claim 1, characterized in that: The passivating agent for recovering asphalt free radical deactivation comprises the following raw materials in parts by weight: 100 parts of allylamine, 120 parts of hydroquinone, 4 parts of the first catalyst and 0.9 parts of the stabilizer.

3. The passivating agent for recovering asphalt free radical deactivation according to claim 1, characterized in that: The first catalyst is a palladium catalyst, and the palladium catalyst includes palladium chloride; the stabilizer is an organic tin compound, and the organic tin compound includes dibutyltin dilaurate.

4. The passivating agent for recovering asphalt free radical deactivation according to claim 1, characterized in that: The preparation method of the allylamine comprises the following steps: Stirring and mixing ammonia water, a second catalyst, an extractant and a phase transfer accelerator to obtain a first mixed solution; Add allyl chloride dropwise to the first mixed solution, and after the addition is complete, perform a constant temperature reaction to obtain a second mixed solution; The second mixed liquid is allowed to stand for stratification, and the obtained oil layer is distilled and purified to obtain the allylamine.

5. The passivating agent for recovering asphalt free radical deactivation according to claim 4, characterized in that: In terms of mass percentage, the concentration of the aqueous ammonia is 20-30%; the second catalyst is a copper catalyst, and the copper catalyst includes cuprous iodide; the extractant is a benzene solvent, and the benzene solvent includes chlorobenzene; the phase transfer accelerator is an organic ammonium salt, and the organic ammonium salt includes tetrabutylammonium bromide.

6. The passivating agent for recovering asphalt free radical deactivation according to claim 4, characterized in that: The working condition parameters of the stirring and mixing include: temperature of 25±1°C and time of 30±2min; the working condition parameters of the isothermal reaction include: temperature of 35±1°C and time of 180±5min; the weight ratio of the ammonia water, the second catalyst, the extractant, the phase transfer promoter and the allyl chloride is 100:(0.1~0.5):(35~45):(0.1~0.3):(35~45).

7. The passivating agent for recovering asphalt free radical deactivation according to claim 4, characterized in that: In terms of mass percentage, the concentration of the aqueous ammonia is 25%; the weight ratio of the aqueous ammonia, the second catalyst, the extractant, the phase transfer promoter and the allyl chloride is 100:0.3:40:0.2:

40.

8. A method for preparing a passivating agent for recovering asphalt free radical deactivation according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: preparing anhydrous ethanol solution of hydroquinone and anhydrous ethanol solution of allylamine; Add the first catalyst to the anhydrous ethanol solution of hydroquinone and stir at a constant temperature, then drop the anhydrous ethanol solution of allylamine into it under the condition of constant temperature and stirring, add a stabilizer after the dropwise addition to continue the reaction, and cool after the reaction to obtain a third mixed solution; The third mixed liquid is subjected to ethanol evaporation treatment to obtain the passivating agent.

9. The method for preparing a passivating agent for recovering asphalt free radical deactivation according to claim 8, characterized in that: The molar concentration of the anhydrous ethanol solution of hydroquinone is 0.5-1.5 mol / L; the molar concentration of the anhydrous ethanol solution of allylamine is 1.5-2.5 mol / L; the temperature of the constant temperature stirring is 55-65° C.; after the dropwise addition, the stabilizer is added and the reaction is continued for 4-6 hours.

10. Use of the passivating agent for deactivating free radicals in asphalt recovery as claimed in any one of claims 1 to 9 in the recycling and regeneration of waste asphalt concrete.

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