Emulsified soap liquid for asphalt and preparation method of graphene modified emulsified asphalt

Abstract

The invention provides an emulsified soap liquid for asphalt and a preparation method of graphene modified emulsified asphalt, and relates to the field of modified asphalt, a coupling agent or a surfactant is taken and dissolved in a solvent, a graphene oxide dispersion liquid is added into the solvent in proportion for modification, and an emulsifier solvent is obtained; adjusting the pH value of the emulsifier solvent, and dissolving the asphalt emulsifier under a heating condition to obtain emulsified soap liquid; heating asphalt, adding the heated asphalt and the prepared emulsified soap liquid into colloid mill equipment in proportion, and uniformly grinding to obtain emulsified asphalt; the self-made graphene oxide dispersion liquid modified by the silane coupling agent or the surfactant is used as a solvent of the asphalt emulsifier to replace water in the prior art to dissolve the asphalt emulsifier, the prepared emulsified soap liquid is in a solution state, good in stability and capable of being used for more than 3 months after being prepared at a time, the problem that soap liquid in the prior art needs to be prepared on site is solved, and the emulsified soap liquid has good application prospects. The formula is simple, the emulsified asphalt is high in viscosity and good in stability, and the emulsified asphalt can be rapidly formed and recover the normal use effect of roads.

Description

Technical Field

[0001] The present invention relates to the technical field of modified asphalt, and in particular to a method for preparing an emulsified soap solution for asphalt and graphene-modified emulsified asphalt. Background Art

[0002] Highway maintenance is a very important part of road construction. Finding better road maintenance technology and materials, improving road maintenance effects, and reducing maintenance costs have become increasingly hot topics.

[0003] Emulsified asphalt is an oil-in-water (O / W) asphalt emulsion formed by melting viscous asphalt and then mechanically dispersing it into fine droplets in water containing an emulsifier and stabilizer. Emulsified asphalt remains fluid at room temperature and does not require heating during construction. This offers advantages such as low environmental pollution, a long construction season, room-temperature construction, and reduced energy consumption. It is widely used in road maintenance and pre-maintenance construction.

[0004] However, with the increasing volume and load of traffic, relying solely on traditional emulsified asphalt can no longer meet the requirements of modern road pavement pre-maintenance technology. Most emulsified asphalt currently on the market suffers from structural instability and low viscosity, requiring significant time for stabilization during construction before the road can be restored to service. Furthermore, the long-term effects of high temperatures, water, and vehicle loads can lead to a range of hazards, including cracking, deformation, loosening, and interlayer shifting.

[0005] As a new material with unique physical and chemical properties, graphene oxide shows great potential for modifying traditional materials. Incorporating graphene into emulsified asphalt can bring the following improvements: 1. Improved durability: The addition of graphene oxide effectively enhances the crack resistance, durability, and wear resistance of the emulsified asphalt. Graphene oxide's high strength significantly improves the strength of asphalt concrete, extending the service life of the pavement. 2. Improved performance stability: Graphene oxide fills micropores in asphalt mixtures, increasing the density of the mixture, reducing the likelihood of cracks, and enhancing the stability and durability of the pavement. 3. Improved construction conditions: While the addition of graphene oxide may not directly improve the construction requirements of emulsified asphalt, its improved performance of asphalt concrete can, to a certain extent, reduce pavement damage caused by poor construction quality, thereby reducing subsequent maintenance costs. The research results of graphene oxide composite modified emulsified asphalt are of great significance for promoting the application of graphene oxide materials in the engineering industry and the development of asphalt pavement materials in my country, and have broad application prospects.

[0006] Prior art, Chinese invention patent application CN111548638A discloses a graphene-emulsified asphalt formula and process. By combining graphene with emulsified asphalt, this formulation allows the emulsified asphalt to quickly form and restore normal road use. However, this formulation and process requires the addition of an emulsifying additive containing a mixture of HCl, NaOH, MgCl2, CaCl2, and Na2SiO3. Furthermore, components A and B must be prepared separately. Emulsified soap solutions are generally unstable, so they must be prepared freshly before use, making the process complex and cumbersome. Summary of the Invention

[0007] In response to the above-mentioned problems existing in the prior art, the present invention provides a method for preparing an emulsified soap solution for asphalt and a graphene-modified emulsified asphalt. The 5-day storage stability value of the prepared emulsified soap solution can be as low as 1%, and the storage stability exceeds 3 months. The graphene-modified emulsified asphalt prepared using the emulsified soap solution has high viscosity and a stable emulsion state, can be quickly formed and restored to normal road use, has good physical and chemical properties at low, medium and high temperatures, and has excellent rutting resistance, corrosion resistance and water resistance.

[0008] The technical solution of the present invention to solve the above technical problems is as follows:

[0009] On the one hand, the present invention provides a method for preparing an emulsified soap solution for asphalt, which is characterized in that a coupling agent or a surfactant is dissolved in a solvent, and then a graphene oxide dispersion is added thereto in proportion for modification to obtain an emulsifier solvent; after adjusting the pH of the emulsifier solvent to a pH value suitable for the asphalt emulsifier, the asphalt emulsifier is dissolved under heating conditions to obtain an emulsified soap solution with a certain mass concentration.

[0010] Furthermore, the coupling agent is a silane coupling agent, specifically one or more of γ-glycidylpropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane. The surfactant is a polyether polyol, polyoxyethylene sorbitan tristearate, and the like, including but not limited to Tween 80, Tween 65, or surfactant 4900.

[0011] Furthermore, the mass ratio of the coupling agent or surfactant to graphene oxide is 0.5 to 20:1.

[0012] Furthermore, the solvent for dissolving the coupling agent or surfactant is water or ethanol.

[0013] Furthermore, in the graphene oxide dispersion, the diameter of the graphene oxide flakes is no more than 5 μm.

[0014] Furthermore, the heating temperature is controlled at 55-75° C. during the process of dissolving the emulsifier.

[0015] Furthermore, the asphalt emulsifier is at least one of a cationic quaternary ammonium salt emulsifier, a cationic lignin amine emulsifier, a neutral emulsifier, and an anionic emulsifier.

[0016] On the other hand, the present invention provides a method for preparing emulsified asphalt, characterized in that the asphalt is heated and then added to a colloid mill in proportion with an emulsified soap solution, and ground evenly to obtain the emulsified asphalt, wherein the emulsified soap solution is prepared by the method for preparing the emulsified soap solution for asphalt as described above.

[0017] Furthermore, the concentration of the emulsified soap solution is 2% to 8%, and the mixing mass ratio of the asphalt to the emulsified soap solution is 6:4.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention uses a homemade silane coupling agent or surfactant-modified graphene oxide dispersion as a solvent for the asphalt emulsifier, replacing the water used in the prior art as the emulsifier solvent, to dissolve the asphalt emulsifier, thereby preparing an emulsified soap solution for asphalt. The soap solution is in a solution state, has good stability, and can be used for more than three months after a single preparation. This solves the problem of the prior art soap solution requiring fresh preparation. In addition, the formula is simpler and avoids the use of emulsifying additives (such as mixtures of HCl, NaOH, MgCl2, CaCl2, Na2SiO3, etc. in the prior art). The 5-day storage stability value of the prepared emulsified soap solution can be as low as less than 1%, and the storage stability exceeds 3 months.

[0020] 2. The emulsified asphalt obtained by emulsifying asphalt with a homemade emulsified soap solution has high viscosity and good stability, can be quickly formed and restored to normal use of the road, has good physical and chemical properties at low, medium and high temperatures, and has excellent rutting resistance, corrosion resistance and waterproof properties. DETAILED DESCRIPTION

[0021] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0022] In the following examples and comparative examples, the specifications of the main raw materials used are as follows:

[0023] Graphene oxide dispersion, produced by Shandong Jinlite New Materials Co., Ltd., has a solid content of 0.05% to 3%, a flake diameter of 100nm to 5μm, and a thickness of 1 to 10 atomic layers.

[0024] Asphalt emulsifier, lignin-based emulsified asphalt A2, L5 or quaternary ammonium salt emulsified asphalt M3 produced by Shandong Shengquan Company.

[0025] Example 1

[0026] The preparation method of the graphene-modified emulsified asphalt of this embodiment is carried out according to the following steps:

[0027] S1. Preparation of coupling agent-modified graphene oxide dispersion: Silane coupling agent KH570 was dissolved in water and hydrolyzed for 30 min, wherein the hydrolysis concentration of the silane coupling agent was 8 wt.%, and 0.3% graphene oxide dispersion was added to the hydrolyzed solution of the silane coupling agent, wherein the ratio of the silane coupling agent to graphene oxide was 20:1, and the mixture was modified at 80°C for 8 h to obtain a coupling agent-modified graphene oxide dispersion, which was used as an emulsifier solvent in the next step;

[0028] S2. Preparation of emulsified soap solution: Adjust the pH of the emulsifier solvent prepared in S1 to 2.5 using hydrochloric acid as a pH adjuster. Weigh the lignin-based emulsified asphalt A2 and add it to the pH-adjusted emulsifier solvent. Dissolve the asphalt emulsifier A2 at 60°C to prepare a 7.5% concentration of A2 emulsified soap solution.

[0029] S3. Preparation of graphene-modified emulsified asphalt: The asphalt was heated to 140°C and fed into a colloid mill together with the emulsified soap solution obtained in S2 at a ratio of 6:4 (w / w). The asphalt was subjected to mechanical actions such as pressurization, shearing, and grinding for 5 minutes to form uniform, fine particles that were stably and evenly dispersed in the soap solution to form an oil-in-water asphalt emulsion, thereby obtaining emulsified asphalt.

[0030] Example 2

[0031] The preparation method of the graphene-modified emulsified asphalt of this embodiment is carried out according to the following steps:

[0032] S1. Preparation of coupling agent-modified graphene oxide dispersion: Silane coupling agent KH550 was dissolved in water and hydrolyzed for 30 min, wherein the hydrolysis concentration of the silane coupling agent was 8 wt.%, and 0.3% graphene oxide dispersion was added to the hydrolyzed solution of the silane coupling agent, wherein the ratio of the silane coupling agent to graphene oxide was 10:1, and the mixture was modified at 80°C for 8 h to obtain a coupling agent-modified graphene oxide dispersion, which was used as an emulsifier solvent in the next step;

[0033] S2. Preparation of emulsified soap solution: Adjust the pH of the emulsifier solvent prepared in S1 to 2 using hydrochloric acid as a pH adjuster. Weigh the lignin-based emulsified asphalt L5 and add it to the pH-adjusted emulsifier solvent. Dissolve the asphalt emulsifier L5 at 55°C to prepare a 2% concentration of L5 emulsified soap solution.

[0034] S3. Preparation of graphene-modified emulsified asphalt: The asphalt was heated to 140°C and fed into a colloid mill together with the emulsified soap solution obtained in S2 at a ratio of 6:4 (w / w). The asphalt was subjected to mechanical actions such as pressurization, shearing, and grinding for 5 minutes to form uniform, fine particles that were stably and evenly dispersed in the soap solution to form an oil-in-water asphalt emulsion, thereby obtaining emulsified asphalt.

[0035] Example 3

[0036] The preparation method of the graphene-modified emulsified asphalt of this embodiment is carried out according to the following steps:

[0037] S1. Preparation of surfactant-modified graphene oxide dispersion: dissolve the surfactant Tween 80 in water and stir for 30 minutes until completely dissolved. Add 3% concentration of graphene oxide dispersion to the Tween 80 solution, wherein the ratio of Tween 80 to graphene oxide is 4:1. Modify at room temperature for 1 hour to obtain modified graphene oxide dispersion, which is used as the emulsifier solvent in the next step.

[0038] S2. Preparation of emulsified soap solution: Adjust the pH of the emulsifier solvent prepared in S1 to 3 using hydrochloric acid as a pH adjuster. Weigh quaternary ammonium salt emulsified asphalt M3 and add it to the pH-adjusted emulsifier solvent. Dissolve the asphalt emulsifier M3 at 75°C to prepare an 8% concentration of M3 emulsified soap solution.

[0039] S3. Preparation of graphene-modified emulsified asphalt: The asphalt was heated to 140°C and fed into a colloid mill together with the emulsified soap solution obtained in S2 at a ratio of 6:4 (w / w). The asphalt was subjected to mechanical actions such as pressurization, shearing, and grinding for 5 minutes to form uniform, fine particles that were stably and evenly dispersed in the soap solution to form an oil-in-water asphalt emulsion, thereby obtaining emulsified asphalt.

[0040] Example 4

[0041] The preparation method of the emulsified asphalt in this embodiment is basically the same as that in Example 3, except that the surfactant Tween 80 in step S1 is replaced by Tween 65.

[0042] Example 5

[0043] The preparation method of emulsified asphalt in this embodiment is basically the same as that in Example 3, except that the surfactant Tween 80 in step S1 is replaced by surfactant 4900, and the mass ratio of surfactant 4900 to graphene oxide is 0.5:1.

[0044] Comparative Example 1

[0045] The preparation method of the emulsified asphalt in this comparative example is basically the same as that in Example 1, except that the coupling agent-modified graphene oxide in step S1 is replaced by graphene oxide that is not modified with a coupling agent, that is, the graphene oxide dispersion is directly used.

[0046] The experimental results showed that when unmodified graphene oxide was directly used to replace the water-soluble asphalt emulsifier in step S2, flocculation and precipitation occurred, and the experiment failed.

[0047] Comparative Example 2

[0048] The preparation method of emulsified asphalt in this comparative example is basically the same as that in Example 1, except that step S1 is not included. In step S2, water is directly used as the emulsifier solvent to dissolve the asphalt emulsifier to prepare the emulsified soap solution. The steps are as follows:

[0049] S1. Preparation of emulsified soap solution: Take asphalt emulsifier A2, dissolve it in water at 55-75°C, and prepare A2 emulsified soap solution with a concentration of 7.5%;

[0050] S2. Preparation of graphene-modified emulsified asphalt: The asphalt is heated to 130-150°C and fed into a colloid mill together with the emulsified soap solution obtained in S1 at a ratio of 6:4 (w / w). The asphalt is subjected to mechanical actions such as pressurization, shearing, and grinding for 5 minutes to form uniform, fine particles that are stably and evenly dispersed in the soap solution to form an oil-in-water asphalt emulsion, thereby obtaining emulsified asphalt.

[0051] Comparative Example 3

[0052] The preparation method of the emulsified asphalt in this comparative example is basically the same as that in Example 1, except that the coupling agent-modified graphene oxide prepared in step S1 is replaced by a graphene dispersion of the same concentration.

[0053] The experimental results show that the dissolution of asphalt emulsifier A2 using graphene dispersion as emulsifier solvent under the same conditions in step S2 can proceed smoothly. However, during the preparation of graphene-modified emulsified asphalt in step S3, a large amount of agglomeration occurred when it was added to the asphalt colloid mill, and the experiment failed.

[0054] Comparative Example 4

[0055] The preparation method of the emulsified asphalt of the comparative example is basically the same as that of Example 1, except that the coupling agent in step S1 is replaced by sodium lauryl sulfate.

[0056] The experimental results showed that in step S2, flocculation occurred after the modified graphene oxide dispersion was mixed with the asphalt emulsifier (A2), and the experiment failed.

[0057] Comparative Example 5

[0058] The preparation method of the emulsified asphalt of the comparative example is basically the same as that of Example 1, except that the coupling agent in step S1 is replaced by the surfactant Span 80.

[0059] The experimental results showed that in step S2, flocculation occurred after the modified graphene oxide dispersion was mixed with the asphalt emulsifier (A2), and the experiment failed.

[0060] The emulsified soap solutions and emulsified asphalts prepared in the above examples and comparative examples were subjected to storage stability and softening point performance tests, respectively. The test standards were based on the Technical Guidelines for Micro-surfacing and Slurry Seal "JTG / TF40-02-2005". The test results are shown in Table 1.

[0061] Table 1 Performance test results

[0062]

[0063] The experimental results from the comparative examples and the data in Table 1 indicate that the graphene-modified emulsified soap solutions prepared in this invention maintain a stability of over three months. The 5-day storage stability of the modified graphene oxide emulsified asphalt meets regulatory requirements. The softening point and 175°C viscosity of the evaporation residue are both higher than those before emulsification, while the penetration and ductility are slightly lower. This indicates that the modification method of this invention improves the high-temperature performance and rutting resistance of the emulsified asphalt. However, both the graphene dispersions and unmodified graphene oxide dispersions from the prior art are unsuitable for direct use as emulsifier solvents in this process.

Claims

1. A method for preparing an emulsified soap solution for asphalt, characterized in that: A coupling agent or surfactant is dissolved in a solvent, and then added to a graphene oxide dispersion in proportion for modification to obtain an emulsifier solvent; after adjusting the pH of the emulsifier solvent, an asphalt emulsifier is dissolved under heating conditions to obtain an emulsified soap solution.

2. The method for preparing an emulsified soap solution for asphalt according to claim 1, characterized in that: The coupling agent is a silane coupling agent, and the surfactant is Tween 80, Tween 65 or surfactant 4900.

3. The method for preparing emulsified soap solution for asphalt according to claim 1, characterized in that: The mass ratio of the coupling agent or surfactant to graphene oxide is 0.5 to 20:

1.

4. The method for preparing an emulsified soap solution for asphalt according to claim 1, characterized in that: The solvent for dissolving the coupling agent or surfactant is water or ethanol.

5. The method for preparing emulsified soap solution for asphalt according to claim 1, characterized in that: In the graphene oxide dispersion, the diameter of the graphene oxide flakes is no greater than 5 μm.

6. The method for preparing emulsified soap solution for asphalt according to claim 1, characterized in that: During the dissolution of the emulsifier, the heating temperature is controlled at 55-75°C.

7. The method for preparing emulsified soap solution for asphalt according to claim 1, characterized in that: The asphalt emulsifier is at least one of a cationic quaternary ammonium salt emulsifier, a cationic lignin amine emulsifier, a neutral emulsifier, and an anionic emulsifier.

8. A method for preparing graphene-modified emulsified asphalt, characterized in that: The asphalt is heated, and then added to a colloid mill device in proportion with an emulsified soap solution, and ground evenly to obtain emulsified asphalt, wherein the emulsified soap solution is prepared by the preparation method of the emulsified soap solution for asphalt according to any one of claims 1 to 7.

9. The method for preparing graphene-modified emulsified asphalt according to claim 8, wherein The concentration of the emulsified soap solution is 2% to 8%.

10. The method for preparing graphene-modified emulsified asphalt according to claim 8, wherein: The mixing mass ratio of the asphalt to the emulsified soap solution is 6:4.

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