High-efficiency stable asphalt emulsifier, emulsified asphalt and preparation method of high-efficiency stable asphalt emulsifier

Abstract

The invention relates to the technical field of building admixtures, in particular to a high-efficiency stable asphalt emulsifier, emulsified asphalt and a preparation method thereof. The efficient stable asphalt emulsifier provided by the invention combines the advantages of a nonionic emulsifier and a cationic emulsifier, so that the emulsifying capacity is remarkably improved, the emulsifying range is expanded, the storage stability of emulsified asphalt is improved, and the stability of asphalt emulsion can be remarkably improved. The preparation method comprises the following steps: polymerizing pentaerythritol allyl ether, ethylene oxide and polyethylene polyamine to prepare an intermediate; and then copolymerizing the intermediate with a styrene compound and a polyether macromonomer EPEG (Ethylene Glycol) to finally prepare the emulsifier. The emulsified asphalt provided by the invention has good storage stability, can meet the requirements of different transportation distances in actual construction, and has important actual application value.

Description

Technical Field

[0001] The invention relates to the technical field of building admixtures, and in particular to a high-efficiency and stable asphalt emulsifier, emulsified asphalt and a preparation method thereof. Background Art

[0002] Asphalt mixture flexible pavement has gradually replaced traditional cement concrete rigid pavement in recent years and has become the most commonly used pavement material due to its advantages of fast construction speed, low maintenance cost, comfortable driving experience and low noise. Cold mix emulsified asphalt construction technology has shown broad application prospects in road construction because it can quickly open up traffic, save energy and reduce environmental pollution.

[0003] In recent years, with the rapid development of highway construction in my country, a large number of highway asphalt pavements have entered the maintenance period, and the resulting waste asphalt pavement materials have increased at a rate of about 15% per year. Therefore, the recycling of waste asphalt pavement materials has received more and more attention. At the same time, with the deepening of the public's understanding of environmental protection and circular economy, environmentally friendly emulsified asphalt cold recycling technology has been promoted and applied nationwide.

[0004] Asphalt emulsifier is a surfactant that can evenly disperse asphalt particles in an aqueous solution and give the emulsified asphalt a certain storage stability. In the cold regeneration process of emulsified asphalt, the performance of the emulsified asphalt is particularly critical. Only when the emulsified asphalt is stable, does not precipitate and separate, and has an appropriate working time can it meet specific construction requirements. However, the storage stability effect of the asphalt emulsifier in the prior art is not ideal during use. Summary of the invention

[0005] In order to solve the problem of poor asphalt stability mentioned in the above background, the present invention provides a high-efficiency and stable asphalt emulsifier, the structural formula of which is: ; Among them, R1 is a polyether chain obtained by polymerization of ethylene oxide, R2 is a polyethylene polyamine chain segment, R3 is a styrene-based compound, and R4 is an EPEG polyether chain segment.

[0006] The present invention also provides a method for preparing the above-mentioned efficient and stable asphalt emulsifier, comprising the following steps: S100, adding tetrapentanol allyl ether and a catalyst into a reaction kettle, evacuating the reactor; replacing with N2 for 1 to 5 times, raising the temperature to 100 to 200° C., introducing ethylene oxide into the reaction kettle, the reaction pressure is 0.2 to 5 MPa, and reacting for 1 to 3 hours; S200, when the pressure of the reactor stops decreasing, evacuate the reactor, preferably to -0.1 MPa, add polyethylene polyamine to the reactor, and maintain the temperature at 100-200° C. When the pressure of the reactor stops decreasing, the reaction is terminated, and the intermediate is obtained; Wherein, the molar ratio of tetrapentanol allyl ether, ethylene oxide and polyethylene polyamine is 1: (2-10): (3-6); S300, the intermediate, styrene compound and polyether macromonomer EPEG are mixed in a mass ratio of (1-6): (2-4): 100, water is added to dissolve them, and then they are dripped into a reactor filled with water together with an initiator aqueous solution and a molecular weight regulator aqueous solution, stirred, and reacted at a reaction temperature of 5-20°C and a dripping time of 1.0-5.0h to obtain the efficient and stable asphalt emulsifier.

[0007] On the basis of the above embodiment, further, the polyolefin polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine; The catalyst is one or more of sodium methoxide, sodium tert-butoxide, sodium ethoxide, lithium aluminum tetrahydride, sodium hydroxide, potassium hydroxide, sodium cyanide, and metallic sodium. The amount of the catalyst used is 0.1% to 0.4% of the mass of ethylene oxide.

[0008] On the basis of the above embodiment, further, the structural formula of the styrene compound is as follows: ; Among them, R on the benzene ring is C m H n O- or -F, m is 1 to 4, n is 3 to 9, and is ortho, meta or para to the vinyl group; The styrene compound includes at least one of 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 2-fluorostyrene, 3-fluorostyrene and 4-fluorostyrene.

[0009] On the basis of the above embodiment, further, the polyether macromonomer EPEG is at least one of ethoxy vinyl polyethylene glycol ether and 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 600 to 3000; The weight average molecular weight of the intermediate is 300-1000.

[0010] On the basis of the above embodiments, further, the total amount of water used makes the mass concentration of the high-efficiency and stable emulsifier be 50% to 80%, and the amount of the initiator and the molecular weight regulator are 0.5% to 3.0% and 0.2% to 2.0% of the total mass of the intermediate, the styrene compound, and the polyether macromonomer EPEG, respectively.

[0011] On the basis of the above embodiment, further, the initiator is at least one of a water-soluble inorganic peroxide initiator, a water-soluble redox initiator system or a water-soluble azo initiator; wherein, The water-soluble inorganic peroxygen initiator is at least one of ammonium persulfate and potassium persulfate; The water-soluble redox initiation system is at least one of hydrogen peroxide-bleaching powder, hydrogen peroxide-ascorbic acid, and persulfate-sodium bisulfite; The water-soluble azo initiator is at least one of azobisisobutylamidine hydrochloride, azobisisopropylimidazoline hydrochloride, azobiscyanovaleric acid, and azobisisopropylimidazoline; The molecular weight regulator is at least one of thioglycolic acid, mercaptopropionic acid, mercaptoethanol, isopropanol, sodium hypophosphite, trisodium phosphate, sodium formate, sodium acetate and dodecanethiol.

[0012] The present invention also provides an emulsified asphalt, comprising the following raw materials in parts by weight: Matrix asphalt: 40-70 parts, water-based epoxy resin: 2-20 parts, high-efficiency stable emulsifier: 1-3 parts, stabilizer: 1-2 parts, deionized water: 25-50 parts.

[0013] The structural formula of the highly efficient and stable emulsifier is as follows: ; Among them, R1 is a polyether chain obtained by polymerization of ethylene oxide, R2 is a polyethylene polyamine chain segment, R3 is a styrene-based compound, and R4 is an EPEG polyether chain segment.

[0014] The present invention also provides a method for preparing the emulsified asphalt as described above, comprising the following steps: Step a, heating the matrix asphalt to 130° C. to 150° C. to melt it into a low-viscosity liquid to obtain molten matrix asphalt, and keeping it warm for later use; Step b, adding a high-efficiency stable emulsifier, a water-based epoxy resin, and a stabilizer into deionized water and heating the mixture to 60° C. to 70° C., and adjusting the pH value of the solution to 2 to 3 with hydrochloric acid during stirring to obtain a soap solution; Step c: introducing the molten matrix asphalt and the soap solution into a shearing machine at the same time, and shearing for 10 to 30 minutes to obtain emulsified asphalt. On the basis of the above embodiment, further, the stabilizer is at least one of anhydrous calcium chloride, sodium chloride, and hydroxyethyl cellulose ether; The water-based epoxy resin is an environmentally friendly water-based epoxy resin prepared by emulsifying, dispersing or modifying E51 type epoxy resin with NN-dimethylethylenediamine and using water as a medium. The particle size of the environmentally friendly water-based epoxy resin is 0.1 to 1 micron.

[0015] The technical solution of the present invention has the following principles and beneficial effects: 1. The efficient and stable asphalt emulsifier provided by the present invention combines the advantages of non-ionic emulsifiers and cationic emulsifiers, which not only significantly improves the emulsification ability, but also expands the emulsification range and significantly improves the storage stability of emulsified asphalt.

[0016] 2. The method for preparing an efficient and stable asphalt emulsifier provided by the present invention is to prepare an intermediate by polymerizing pentaerythritol allyl ether, ethylene oxide and polyethylene polyamine; then the intermediate is copolymerized with a styrene compound and a polyether macromonomer EPEG to finally prepare an emulsifier. The molecular structure of the efficient and stable asphalt emulsifier prepared by the present invention incorporates multiple structural features such as alkyl polyamines, benzene rings and vinyl polyoxyethylene ethers, and the groups cooperate with each other to form a micro-cross-linked network structure. In the asphalt emulsification process, these structures present a tight and orderly arrangement, which greatly enhances the electrostatic repulsion between molecules, makes the structure more stable, and thus significantly improves the stability of the asphalt emulsion.

[0017] 3. The emulsified asphalt provided by the present invention has good storage stability, can meet the requirements of different transportation distances in actual construction, and has important practical application value. DETAILED DESCRIPTION

[0018] 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 described clearly and completely below. 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.

[0019] 1. The present invention provides the following structural embodiment of a highly efficient and stable asphalt emulsifier: ; Among them, R1 is a polyether chain obtained by polymerization of ethylene oxide, R2 is a polyethylene polyamine chain segment, R3 is a styrene-based compound, and R4 is an EPEG polyether chain segment.

[0020] 2. The present invention provides the following preparation examples of efficient and stable asphalt emulsifiers: The preparation example of intermediate A is shown in the following table: Table 1

[0021] The preparation method of the above embodiment is as follows: add quaternary tetrapentanol allyl ether and a catalyst to a reactor, evacuate, replace with N2 3 times, heat the reaction to 100-200°C (specifically as shown in Table 1), introduce ethylene oxide into the reactor, the reaction pressure is 0.2-5MPa, and react for 1-3h. When the pressure of the reactor no longer decreases, evacuate to -0.1 MPa, add polyolefin polyamine to the reactor, maintain the temperature at 100-200°C (specifically as shown in Table 1), when the pressure of the reactor no longer decreases, the reaction is terminated, and intermediate A is obtained.

[0022] The prepared intermediate A, styrene compound and polyether macromonomer EPEG were mixed in a mass ratio of (1-6): (2-4): 100, and water was added to dissolve them. They were dripped into a reaction kettle filled with water together with an initiator aqueous solution and a molecular weight regulator aqueous solution. The stirrer was turned on to react at a reaction temperature of 5-20° C. and a dripping time of 1.0-5.0 h to obtain a highly efficient and stable emulsifier B. The components and parameters of the specific embodiment are shown in Table 2: Table 2

[0023] 3. According to the high-efficiency and stable asphalt emulsifier prepared in the above embodiment, the present invention also provides the following preparation embodiment of emulsified asphalt: 1) Heat 70# base asphalt to 130℃ to 150℃ to melt it into a low-viscosity liquid and keep it warm for later use.

[0024] 2) The above-mentioned high-efficiency stable emulsifier, water-based epoxy resin and stabilizer are added to deionized water and heated to 60° C. to 70° C. During the stirring process, the pH value of the solution is adjusted to 2 to 3 with hydrochloric acid to obtain a soap solution.

[0025] 3) The molten matrix asphalt and soap solution are introduced into a high-speed shearing machine at the same time, and high-speed shearing is performed for 10 to 30 minutes to obtain emulsified asphalt.

[0026] The specific embodiments are shown in the following table: Table 3 Example Base asphalt / g Waterborne epoxy resin / g Asphalt emulsifier / g Stabilizer / g Water / g pH Example 1 500 20 B1:20 Hydroxyethyl cellulose ether:15 260 2-3 Example 2 520 22 B2:17 Anhydrous calcium chloride: 16 280 2-3 Example 3 560 24 B3:18 , Sodium chloride: 15 300 2-3 Example 4 600 25 B4:20 Hydroxyethyl cellulose ether:16 320 2-3 Example 5 620 26 B5:22 Hydroxyethyl cellulose ether:17 325 2-3 Example 6 660 27 B6:23 Hydroxyethyl cellulose ether:18 330 2-3 The present invention also provides the following comparative examples of emulsified asphalt: Comparative Example 1: The process of Example 4 is used as the basic process, and the raw material composition and preparation method are basically the same, except that the emulsifier B4 prepared in Example 4 is not added.

[0027] Comparative Example 2: The process of Example 4 is used as the basic process, and the raw material composition and preparation method are basically the same, except that the mass of the emulsifier B4 prepared in Example 4 is replaced by octadecyltrimethylammonium chloride.

[0028] Comparative Example 3: The process of Example 4 is used as the basic process, and the raw material composition and preparation method are basically the same. The difference is that the mass of the emulsifier B4 prepared in Example 4 is replaced by octadecyltrimethylammonium chloride: polyether macromonomer = 1:1 compound.

[0029] Comparative Example 4: The process of Example 4 is used as the basic process, and the raw material composition and preparation method are basically the same. The difference is that the emulsifier B4 prepared in Example 4 is replaced by an equal mass of vinyl glycol ether, ethylene oxide and polyethylene polyamine to synthesize intermediate A, and then synthesize emulsifier B with EPEG for the preparation of emulsified asphalt.

[0030] Comparative Example 5: The process of Implementation Example 4 is used as the basic process, and the raw material composition and preparation method are basically the same. The difference is that the commercially available slow-cracking and fast-setting asphalt emulsifier CMK replaces B4 in equal amounts.

[0031] The emulsified asphalts prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to storage stability and Engela viscosity tests according to the requirements of JTG E20-2011 standard. The test results are shown in the following table.

[0032] Table 4 Example 1d storage stability / % 5d storage stability / % Demulsification speed Example 1 0.21 1.28 Slow crack Example 2 0.26 1.30 Slow crack Example 3 0.33 1.26 Slow crack Example 4 0.23 1.23 Slow crack Example 5 0.32 1.42 Slow crack Example 6 0.30 1.20 Slow crack Comparative Example 1 3.62 9.90 middle cleft Comparative Example 2 2.13 8.87 middle cleft Comparative Example 3 1.84 7.67 middle cleft Comparative Example 4 1.65 7.25 Slow crack Comparative Example 5 2.86 8.77 Slow crack It can be seen from the experimental results in the above table that the emulsified asphalt prepared by the present invention has good stability and slow demulsification speed. The specific analysis is as follows: (1) Stability comparison 1d Storage Stability(%): Example range: 0.21% to 0.33%; Comparative range: 1.65% to 3.62%; 5d Storage Stability(%): Example range: 1.26% to 1.42%; Comparative range: 7.25% to 9.9%; It can be seen from the above data that no matter whether it is 1 day or 5 days of storage stability, the data of the embodiment is significantly lower than that of the comparative example, indicating that the emulsified asphalt prepared by the present invention has obvious storage stability advantages.

[0033] (2) Comparison of demulsification speed Examples: All examples are "slow cracking"; Comparative Examples: Except for Comparative Example 4, the others all showed "middle crack"; This indicates that the demulsification rate of the emulsified asphalt prepared in the example is significantly slower than that of the comparative example, further proving that the emulsifier prepared in the present invention can improve the emulsification ability and stability.

[0034] In summary, the high-efficiency and stable asphalt emulsifier prepared by the present invention is used to prepare emulsified asphalt, has more excellent emulsification ability, and the prepared emulsified asphalt has excellent storage stability.

[0035] This efficient and stable asphalt emulsifier also exhibits excellent compatibility with all types of stone, and can effectively regulate the working time of cold recycled asphalt mixture, thereby meeting the needs of different transportation distances in actual construction.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly efficient and stable asphalt emulsifier, characterized in that: The structural formula is: ； Among them, R1 is a polyether chain obtained by polymerization of ethylene oxide, R2 is a polyethylene polyamine chain segment, R3 is a styrene-based compound, and R4 is an EPEG polyether chain segment.

2. A method for preparing the efficient and stable asphalt emulsifier according to claim 1, characterized in that: The following steps are involved: S100, adding tetrapentanol allyl ether and a catalyst into a reaction kettle, evacuating the reactor; replacing with N2 for 1 to 5 times, raising the temperature to 100 to 200° C., introducing ethylene oxide into the reaction kettle, the reaction pressure is 0.2 to 5 MPa, and reacting for 1 to 3 hours; S200, when the pressure of the reactor stops decreasing, evacuate the reactor, add polyethylene polyamine to the reactor, and maintain the temperature at 100-200° C. When the pressure of the reactor stops decreasing, the reaction is completed, and the intermediate is obtained; Wherein, the molar ratio of tetrapentanol allyl ether, ethylene oxide and polyethylene polyamine is 1: (2-10): (3-6); S300, the intermediate, styrene compound and polyether macromonomer EPEG are mixed in a mass ratio of (1-6): (2-4): 100, water is added to dissolve them, and then they are dripped into a reactor filled with water together with an initiator aqueous solution and a molecular weight regulator aqueous solution, stirred, and reacted at a reaction temperature of 5-20°C and a dripping time of 1.0-5.0h to obtain the efficient and stable asphalt emulsifier.

3. The method for preparing the efficient and stable asphalt emulsifier according to claim 2, characterized in that: The polyolefin polyamine is one or more of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine; The catalyst is one or more of sodium methoxide, sodium tert-butoxide, sodium ethoxide, lithium aluminum tetrahydride, sodium hydroxide, potassium hydroxide, sodium cyanide, and metallic sodium. The amount of the catalyst used is 0.1% to 0.4% of the mass of ethylene oxide.

4. The method for preparing the efficient and stable asphalt emulsifier according to claim 2, characterized in that: The structural formula of the styrene compound is as follows: ； Among them, R on the benzene ring is C m H n O- or -F, m is 1 to 4, n is 3 to 9, and is ortho, meta or para to the vinyl group; The styrene compound includes at least one of 2-methoxystyrene, 3-methoxystyrene, 4-methoxystyrene, 2-fluorostyrene, 3-fluorostyrene and 4-fluorostyrene.

5. The method for preparing the efficient and stable asphalt emulsifier according to claim 2, characterized in that: The polyether macromonomer EPEG is at least one of ethoxy vinyl polyethylene glycol ether and 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 600 to 3000; The weight average molecular weight of the intermediate is 300-1000.

6. The method for preparing the efficient and stable asphalt emulsifier according to claim 2, characterized in that: The total amount of water used makes the mass concentration of the high-efficiency stable emulsifier 50% to 80%, and the amount of the initiator and the molecular weight regulator are 0.5% to 3.0% and 0.2% to 2.0% of the total mass of the intermediate, the styrene compound and the polyether macromonomer EPEG respectively.

7. The method for preparing the efficient and stable asphalt emulsifier according to claim 2, characterized in that: The initiator is at least one of a water-soluble inorganic peroxide initiator, a water-soluble redox initiator system or a water-soluble azo initiator; wherein, The water-soluble inorganic peroxygen initiator is at least one of ammonium persulfate and potassium persulfate; The water-soluble redox initiation system is at least one of hydrogen peroxide-bleaching powder, hydrogen peroxide-ascorbic acid, and persulfate-sodium bisulfite; The water-soluble azo initiator is at least one of azobisisobutylamidine hydrochloride, azobisisopropylimidazoline hydrochloride, azobiscyanovaleric acid, and azobisisopropylimidazoline; The molecular weight regulator is at least one of thioglycolic acid, mercaptopropionic acid, mercaptoethanol, isopropanol, sodium hypophosphite, trisodium phosphate, sodium formate, sodium acetate and dodecanethiol.

8. An emulsified asphalt, characterized in that: The invention comprises the following raw materials in parts by weight: Base asphalt: 40-70 parts, water-based epoxy resin: 2-20 parts, high-efficiency stable emulsifier: 1-3 parts, stabilizer: 1-2 parts, deionized water: 25-50 parts; The structural formula of the highly efficient and stable emulsifier is as follows: ； Among them, R1 is a polyether chain obtained by polymerization of ethylene oxide, R2 is a polyethylene polyamine chain segment, R3 is a styrene-based compound, and R4 is an EPEG polyether chain segment.

9. The method for preparing emulsified asphalt according to claim 8, characterized in that: The following steps are involved: Step a, heating the matrix asphalt to 130° C. to 150° C. to melt it into a low-viscosity liquid to obtain molten matrix asphalt, and keeping it warm for later use; Step b, adding a high-efficiency stable emulsifier, a water-based epoxy resin, and a stabilizer into deionized water and heating the mixture to 60° C. to 70° C., and adjusting the pH value of the solution to 2 to 3 with hydrochloric acid during stirring to obtain a soap solution; Step c: introducing the molten matrix asphalt and the soap solution into a shearing machine at the same time, and shearing for 10 to 30 minutes to obtain emulsified asphalt.

10. The method for preparing emulsified asphalt according to claim 9, characterized in that: The stabilizer is at least one of anhydrous calcium chloride, sodium chloride, and hydroxyethyl cellulose ether; The water-based epoxy resin is an environmentally friendly water-based epoxy resin prepared by emulsifying, dispersing or modifying E51 type epoxy resin with NN-dimethylethylenediamine and using water as a medium. The particle size of the environmentally friendly water-based epoxy resin is 0.1 to 1 micron.

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