Modified asphalt as well as preparation method and application thereof

Abstract

The invention discloses modified asphalt as well as a preparation method and application thereof. The modified asphalt comprises activated matrix asphalt and a modifier, and the modifier is a quaternary ammonium compound containing an epoxy functional group. The surface of the modified asphalt has cationic characteristics, so that the dispersion degree of the modified asphalt in water or other liquid media is improved, and the emulsified asphalt with good performance can be easily prepared.

Description

Technical Field

[0001] The present invention belongs to the field of asphalt modification, and particularly relates to a modified asphalt, a preparation method thereof and an application thereof. Background Art

[0002] Due to its good adhesion, ductility and deformability, asphalt is widely used in road paving, roof waterproofing, pipeline anti-corrosion and other fields. However, because the nature of asphalt itself is relatively stable and there are few surface active groups, there may be some problems when it is applied in some special fields. For example, when preparing epoxy asphalt, due to the large difference in polarity between asphalt and epoxy resin, there will be poor compatibility, easy delamination after curing, and it cannot form a good whole, which affects the strength of the material. Another example is that when preparing high-solid-content emulsified asphalt, problems such as difficult emulsification or unstable performance are likely to occur. In addition, when preparing polymer-modified asphalt, there will also be poor compatibility between asphalt and polymer, resulting in segregation due to unstable heat storage, which seriously affects the use performance of polymer-modified asphalt.

[0003] The above series of problems mainly result from the relatively inert nature of the base asphalt. In order to obtain asphalt with higher activity, a modification technology of chemically grafting asphalt with active compounds has emerged, that is, a compound with an active functional group cross-links and / or chemically bonds with asphalt, so that the performance of asphalt is greatly improved. There are currently two reported methods for chemically grafting asphalt. One is to graft using -NH 2 and -OH in asphalt, and the other is to further graft by D-A addition using the conjugated diene structure in asphalt. The latter generally requires a catalyst and a high-temperature and high-pressure environment. Based on this, a variety of technologies have been proposed, such as grafting active monomers onto polymers; functionalizing polymers with acrylic acid, carboxylic acid, terminal amino groups, glycidyl methacrylate (GMA), maleic anhydride (MAH), etc.; reacting polyurethane prepolymers with the side groups of asphalt containing active groups (mainly -OH, usually present in asphaltenes) through free -NCO groups to modify asphalt. The results show that the chemically modified polyurethane asphalt has good anti-deformation, anti-aging, fatigue resistance and high-temperature storage properties. Modifying the base asphalt with a suitable anhydride and then preparing epoxy asphalt with the anhydrified asphalt can better solve the problem of poor compatibility between the base asphalt and epoxy resin. Similarly, grafting reaction of anhydride with high-molecular polymers such as SBS can also solve the compatibility problem between SBS and other high-molecular polymers and asphalt to a certain extent.

[0004] In addition, small molecules with active groups have also been used for asphalt modification, such as dodecylbenzenesulfonic acid, thiourea dioxide, and dodecenyl succinic anhydride (DSA). Since asphaltene contains heteroatom groups, it can form an ion pair with strong bonding interaction with dodecylbenzenesulfonic acid, which can effectively improve the rheological properties and thermodynamic properties of asphalt. DSA combines with polar compounds in asphalt, affecting the combination and dispersion degree of asphalt components, thereby softening the asphalt.

[0005] When preparing emulsified asphalt, especially emulsified asphalt with a high solid content, problems such as difficulty in emulsification or instability even after emulsification are likely to occur. If the base asphalt is surface-modified before preparing emulsified asphalt to make it surface-active, the problem of emulsifying high-solid-content asphalt can be better solved. However, due to the surface inertness of asphalt molecules, it is very difficult to modify their surfaces. The previous method was to knead asphalt and cationic monomers together using equipment such as a kneader relying on strong mechanical external forces. Although the asphalt showed certain cationic characteristics, this was only a physical mixture, and the asphalt molecules did not chemically react with the cationic monomers. During the application process, the cationic monomers would separate from the asphalt molecules, and the effect was extremely limited. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a modified asphalt and its preparation method and application. The modified asphalt of the present invention has cationic characteristics on its surface, improving the dispersion degree of the modified asphalt in water or other liquid media, and thus it is easy to prepare emulsified asphalt with good performance.

[0007] The first aspect of the present invention provides a modified asphalt, comprising: activated base asphalt and a modifier, wherein the modifier is a quaternary ammonium compound containing an epoxy functional group.

[0008] Further, the modifier contains the following structural formula:

[0009] Further, the modifier is preferably at least one of epoxypropyl dodecyldimethylammonium chloride and 2,3-epoxypropyl trimethylammonium chloride.

[0010] Further, based on the weight of the activated base asphalt, the content of the modifier accounts for 0.1 wt% - 10 wt% of the weight of the activated base asphalt.

[0011] Further, the activated base asphalt is prepared by reacting base asphalt with organic acid anhydride.

[0012] Further, the base asphalt is selected from one or more of petroleum asphalt and vacuum residue. The softening point of the base asphalt is 30°C - 70°C.

[0013] Further, the organic acid anhydride is a mono- and / or poly-organic acid anhydride, preferably at least one of maleic anhydride, polyethylene glycol anhydride, polyglutaric anhydride, polynonanoic anhydride, and polyisobutylene succinic anhydride.

[0014] In a second aspect of the present invention, a method for preparing the above modified asphalt is provided, including the following steps:

[0015] (1) Prepare an activated matrix asphalt;

[0016] (2) Mix the activated matrix asphalt with a modifier and an organic base, stir and react under the action of a catalyst, and then perform treatment under acidic conditions to obtain modified asphalt.

[0017] Further, in step (1), the method for preparing the activated matrix asphalt includes: heating the matrix asphalt to a molten state, adding 2% to 20% by weight of the organic acid anhydride based on the matrix asphalt, and introducing an inert gas to keep the reaction pressure at 0.2 to 2.0 MPa, the reaction temperature is 120 to 200 °C, and the reaction time is 2 to 8 hours to obtain the activated matrix asphalt. During the reaction, it is preferred to add an initiator. The initiator is at least one of azobisisobutyronitrile and dicumyl peroxide. The mass ratio of the initiator to the organic acid anhydride is 1:5 to 10.

[0018] Further, in step (2), first dissolve the activated matrix asphalt prepared in step (1) in an organic solvent, and then add the modifier and the organic base, and react under the condition of having a catalyst.

[0019] Further, the organic solvent is petroleum ether. The mass-volume ratio of the activated matrix asphalt to the amount of the organic solvent added is 1:1 to 10 g / mL.

[0020] Further, the organic base is at least one of triethylamine and 4-dimethylaminopyridine. The mass ratio of the organic base to the modifier is 1:1 to 10.

[0021] Further, in step (2), the catalyst is 1,5,7-tripropylheptyloxytrimethylammonium salt (TBD). The mass ratio of the catalyst to the amount of the modifier added is 0.01 to 0.1:1.

[0022] Further, in step (2), the reaction temperature is 25 to 80 °C, and the reaction time is 1 to 24 h.

[0023] Further, in step (2), the stirring speed is 90 to 2000 rpm.

[0024] Further, in step (2), after the reaction is completed, the organic solvent can be removed by a conventional method in the art, such as first using rotary evaporation and then heating evaporation until the organic solvent is completely removed to obtain the modified asphalt.

[0025] Further, in step (2), for the treatment under acidic conditions, an acidic solution can be added, such as an inorganic acid solution and / or an organic acid solution, preferably one or more of HCl solution, H 2 SO 4 solution, etc. The mass concentration of the acidic solution is 10 wt% to 30 wt%. 5 to 30 mL of the acidic solution is added per 100 g of the activated matrix asphalt.

[0026] Further, in step (2), the temperature for the treatment under acidic conditions is 80 to 120 °C, and the treatment time is 10 to 100 min.

[0027] The third aspect of the present invention provides an application of the above-mentioned modified asphalt in road construction.

[0028] Further, the application is specifically that the modified asphalt is mixed with an emulsifier to prepare a modified emulsified asphalt, and then mixed with stone materials for road construction.

[0029] Further, the preparation of the modified emulsified asphalt includes: heating water to 60 °C to 80 °C, adjusting the pH value to 2 to 4, adding an emulsifier, and stirring evenly to prepare a soap solution; heating the modified asphalt to melting and adding it to the soap solution, and maintaining the mixture at 80 °C to 90 °C for grinding and emulsification to obtain the modified emulsified asphalt.

[0030] Further, the emulsifier is a conventional emulsifier in the art, such as at least one of tallow propylene diamine, nonylphenol polyoxyethylene ether, etc. The stone materials are conventional stone materials in the art.

[0031] Further, based on the mass of the modified emulsified asphalt, the content of the modified asphalt is 50% to 80%, the content of the emulsifier is 1% to 5%, and the content of water is 15% to 45%.

[0032] Further, the mass ratio of the stone materials to the modified emulsified asphalt is 8 to 10:1.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] (1) For the modified asphalt of the present invention, a specific modifier is used, which contains an amino group and an epoxy group structure. This modifier can achieve cross-linking / dispersion between components in the asphalt, realize intermolecular grafting, and has stronger surface activity.

[0035] (2) The preparation method of the modified asphalt of the present invention can be carried out under mild conditions, without high pressure, and is easy to operate; the compounds are easily obtained, have a wide applicability, and the product performance has strong controllability.

[0036] (3) In the preparation method of the modified asphalt of the present invention, the modified asphalt is positively charged after acid treatment, and excellent emulsified asphalt can be prepared, while most of the stones used for paving roads are negatively charged. When this emulsified asphalt is applied to cold-laid and cold-mixed road mixtures, after demulsification, the modified asphalt therein is easy to combine with the stones, increasing the adhesion and anti-stripping ability, and improving the overall service performance of the mixture. Specific Embodiments

[0037] The technical solutions of the present invention will be described in detail below in conjunction with embodiments, but the present invention is not limited to the following embodiments. In the present invention, wt% is the mass fraction.

[0038] Example 1

[0039] Heat 300 g of vacuum residue with a softening point of 39.6 °C to a molten state in a reaction kettle, add 26.4 g of maleic anhydride and 4.2 g of azobisisobutyronitrile, and introduce N 2 Keep the pressure in the reaction kettle at 1.2 MPa and react at 135 °C for 4 hours to obtain activated matrix asphalt.

[0040] Take 200 g of the above-prepared activated matrix asphalt and dissolve it in 250 mL of petroleum ether. Add 17.2 g of epoxypropyl dodecyldimethylammonium chloride and 8.4 g of triethylamine, add 0.2 g of 1,5,7-tripropylheptyloxytrimethylammonium salt, and stir with a mechanical stirrer at a rotation speed of 1200 rpm and stir and react at 60 °C for 15 h. After the reaction is completed, remove the solvent by rotary evaporation. Then slowly add 25 mL of hydrochloric acid with a concentration of 30 wt% to the above residue and continue to stir at 90 °C for 60 min to obtain modified asphalt.

[0041] Heat 60 mL of water to 70 °C, add hydrochloric acid with a concentration of 20 wt% in the hot water, adjust the pH value to 2.5, add tallow propylene diamine, and stir evenly to prepare a soap solution; take 170.4 g of the above modified asphalt and heat it to molten state and slowly add it to the prepared soap solution, and keep it at 90 °C for mixing, grinding and emulsifying to obtain modified emulsified asphalt, wherein the content of the modified asphalt is 71 wt%, the content of the emulsifier is 4 wt%, and the content of water is 25 wt%.

[0042] Example 2

[0043] Heat 300 g of petroleum asphalt with a softening point of 41.5 °C to a molten state in a reaction kettle, add 34.5 g of polyisobutylene succinic anhydride and 3.8 g of diisopropylbenzene peroxide, and introduce N 2Keep the pressure of the reaction kettle at 0.8 MPa and react for 5.0 hours at 155 °C to obtain the activated matrix asphalt.

[0044] Take 200 g of the activated matrix asphalt prepared above and dissolve it in 300 mL of petroleum ether. Add 21.5 g of 2,3-epoxypropyltrimethylammonium chloride and 6.6 g of 4-dimethylaminopyridine. Add 0.6 g of 1,5,7-tripropylheptyloxytrimethylammonium salt, and stir using mechanical stirring at a rotation speed of 1400 rpm and react with stirring at 70 °C for 12 h. After the reaction is completed, remove the solvent by rotary evaporation. Then, slowly add 15 mL of hydrochloric acid with a concentration of 30 wt% dropwise to the above residue, and continue to stir at 105 °C for 35 min to obtain the modified asphalt.

[0045] Heat 65 mL of water to 75 °C, add hydrochloric acid with a concentration of 20 wt% to the hot water, adjust the pH value to 2, add nonylphenol polyoxyethylene ether, and stir evenly to prepare a soap solution. Take 146.6 g of the above modified asphalt, heat it to melting, and slowly add it to the prepared soap solution, and keep mixing and grinding at 90 °C for emulsification to obtain the modified emulsified asphalt, wherein the content of the modified asphalt is 67.5 wt%, the content of the emulsifier is 2.5 wt%, and the content of water is 30 wt%.

[0046] Example 3

[0047] Heat 300 g of petroleum asphalt with a softening point of 46.6 °C to a molten state in a reaction kettle, add 19.2 g of pentaglutaric anhydride and 2.6 g of azobisisobutyronitrile, and introduce N 2 Keep the pressure of the reaction kettle at 1.5 MPa and react for 6.5 hours at 170 °C to obtain the activated matrix asphalt.

[0048] Take 200 g of the activated matrix asphalt prepared above and dissolve it in 380 mL of petroleum ether. Add 15.6 g of epoxypropyl dodecyldimethylammonium chloride and 3.6 g of triethylamine. Add 0.22 g of 1,5,7-tripropylheptyloxytrimethylammonium salt, and stir using mechanical stirring at a rotation speed of 1100 rpm and react with stirring at 65 °C for 18 h. After the reaction is completed, remove the solvent by rotary evaporation. Then, slowly add 20 mL of hydrochloric acid with a concentration of 30 wt% dropwise to the above residue, and continue to stir at 110 °C for 50 min to obtain the modified asphalt.

[0049] Heat 55 mL of water to 80 °C, add hydrochloric acid with a concentration of 20 wt% to the hot water, adjust the pH value to 4, add tallow propylene diamine, and stir evenly to prepare a soap solution; take 192.3 g of the above modified asphalt, heat it to melting, and slowly add the prepared soap solution, keep it at 90 °C for mixing, grinding and emulsifying to obtain modified emulsified asphalt, wherein the content of the modified asphalt is 74.8 wt%, the content of the emulsifier is 3.8 wt%, and the content of water is 21.4 wt%.

[0050] Example 4

[0051] Heat 300 g of petroleum asphalt with a softening point of 56.5 °C to a molten state in a reaction kettle, add 31.5 g of maleic anhydride and 4.0 g of azobisisobutyronitrile, and introduce N 2 Keep the pressure in the reaction kettle at 1.6 MPa and react at 160 °C for 5.0 hours to obtain activated matrix asphalt.

[0052] Take 200 g of the above-prepared activated matrix asphalt and add it to 420 mL of petroleum ether for dissolution, add 19.4 g of epoxypropyl dodecyldimethylammonium chloride and 4.2 g of triethylamine, add 0.3 g of 1,5,7-tripropylheptyloxytrimethylammonium salt, stir with a mechanical stirrer at a rotation speed of 1700 rpm, and stir and react at 70 °C for 14.5 h. After the reaction is completed, remove the solvent by rotary evaporation. Then slowly add 30 mL of dilute hydrochloric acid with a concentration of 30 wt% dropwise and continue to stir at 120 °C for 45 min to obtain modified asphalt.

[0053] Heat 50 mL of water to 80 °C, add hydrochloric acid with a concentration of 20 wt% to the hot water, adjust the pH value to 3, add tallow propylene diamine, and stir evenly to prepare a soap solution; take 197.5 g of the above modified asphalt to melting and slowly add the prepared soap solution, keep it at 80 °C for mixing, grinding and emulsifying to obtain modified emulsified asphalt, wherein the content of the modified asphalt is 77.4 wt%, the content of the emulsifier is 3 wt%, and the content of water is 19.6 wt%.

[0054] Comparative Example 1

[0055] Heat 55 mL of water to 80 °C, add hydrochloric acid with a concentration of 20 wt% to the hot water, adjust the pH value to 4, add tallow propylene diamine, and stir evenly to prepare a soap solution; heat 192.3 g of petroleum asphalt with a softening point of 46.6 °C to a molten state, slowly add the prepared soap solution, keep it at 90 °C for mixing, grinding and emulsifying to obtain modified emulsified asphalt, wherein the content of the modified asphalt is 74.8 wt%, the content of the emulsifier is 3.8 wt%, and the content of water is 21.4 wt%.

[0056] Comparative Example 2

[0057] 300 g of petroleum asphalt with a softening point of 46.6 °C was heated to a molten state in a reaction kettle, 19.2 g of pentaglutaric anhydride, 2.6 g of azobisisobutyronitrile were added, and N was introduced. 2 The pressure in the reaction kettle was maintained at 1.5 MPa, and the reaction was carried out at 170 °C for 6.5 hours to obtain activated matrix asphalt.

[0058] 200 g of the activated matrix asphalt prepared above was added to 380 mL of petroleum ether for dissolution, 15.6 g of epoxypropyl dodecyldimethylammonium chloride and 3.6 g of triethylamine were added, and mechanical stirring was used for stirring at a rotation speed of 1100 rpm. The stirring reaction was carried out at 65 °C for 18 h. The solvent was removed by rotary evaporation. Then, 20 mL of hydrochloric acid with a concentration of 30 wt% was slowly added dropwise to the above residue, and the stirring was continued at 110 °C for 50 min to obtain modified asphalt.

[0059] 55 mL of water was heated to 80 °C, hydrochloric acid with a concentration of 20 wt% was added to the hot water, the pH value was adjusted to 4, and tallow propylene diamine was added and stirred evenly to prepare a soap solution; 192.3 g of the above modified asphalt was heated to melting and slowly added to the prepared soap solution, and emulsification was carried out by mixing and grinding at 90 °C to obtain modified emulsified asphalt, wherein the content of the modified asphalt was 74.8 wt%, the content of the emulsifier was 3.8 wt%, and the content of water was 21.4 wt%.

[0060] Preparation of modified emulsified asphalt mixture: According to the AC-10 aggregate gradation, 10% of the modified emulsified asphalt prepared in Examples 1-4 and Comparative Examples 1-2 above was added respectively. 1% of cement was added and dry-mixed with the aggregate for 60 s before mixing the emulsified asphalt mixture, the modified emulsified asphalt was added, and stirring was carried out for 90 s to complete the mixing of the mixture. Marshall specimens were formed by compacting 50 times on each side, and accelerated curing was carried out in an environmental chamber at 105 °C for 24 h without demolding. Then, the Marshall specimens were taken out, and after the specimens were cooled, they were compacted 25 times on each side again to complete the preparation of the specimens.

[0061] The properties of the modified asphalt and the properties of the modified emulsified asphalt mixture obtained in the above examples are shown in Table 1 and Table 2 respectively. It can be seen from the data in Table 1 that after the asphalt was modified by the modifier of the present invention, the softening point was improved to a certain extent and it had a positive charge. The data in Table 2 show that the performance of the emulsified asphalt mixture prepared therefrom was enhanced.

[0062] Table 1 Properties of modified asphalt / petroleum asphalt in examples and comparative examples

[0063] Property Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Softening point / °C 43.2 47.3 52.8 60.2 46.6 50.4 Zeta potential / mV +15.4 +17.4 +16.8 +18.8 - -

[0064] Table 2 Properties of modified emulsified asphalt mixture in examples and comparative examples

[0065]

[0066]

[0067] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A modified asphalt, characterized in that: the modified asphalt comprises: an activated matrix asphalt and a modifier, and the modifier is a quaternary ammonium compound containing an epoxy group functional group.

2. The modified asphalt according to claim 1, characterized in that: The modifier contains the following structural formula:

3. The modified asphalt according to claim 1 or 2, characterized in that: the modifier is at least one of epoxypropyl dodecyldimethylammonium chloride and 2,3-epoxypropyltrimethylammonium chloride.

4. The modified asphalt according to claim 1, characterized in that: based on the weight of the activated matrix asphalt, the content of the modifier accounts for 0.1 wt% to 10 wt% of the weight of the activated matrix asphalt.

5. The modified asphalt according to claim 1, characterized in that: the activated matrix asphalt is prepared by reacting a matrix asphalt with an organic acid anhydride; the matrix asphalt is selected from one or more of petroleum asphalt and vacuum residue; the softening point of the matrix asphalt is 30°C to 70°C; the organic acid anhydride is a mono- and / or poly-organic acid anhydride, preferably at least one of maleic anhydride, polyethylene glycol anhydride, polyglutaric anhydride, polynonanoic anhydride and polyisobutylene succinic anhydride.

6. A preparation method of the modified asphalt according to any one of claims 1-5, characterized in that: comprises the following steps: (1) Prepare an activated matrix asphalt; (2) Mix the activated matrix asphalt with a modifier and an organic base, stir and react under the action of a catalyst, and then carry out treatment under acidic conditions to obtain the modified asphalt.

7. The preparation method according to claim 6, characterized in that: in step (1), the method for preparing the activated matrix asphalt includes: heating the matrix asphalt to a molten state, adding 2% to 20% of the organic acid anhydride based on the weight of the matrix asphalt, and introducing an inert gas to keep the reaction pressure at 0.2 to 2.0 MPa, the reaction temperature is 120 to 200°C, and the reaction time is 2 to 8 hours to obtain the activated matrix asphalt.

8. The preparation method according to claim 7, characterized in that: during the preparation of the activated matrix asphalt, an initiator is added; the initiator is at least one of azobisisobutyronitrile and dicumyl peroxide; the mass ratio of the initiator added amount to the organic acid anhydride is 1:5 to 10.

9. The preparation method according to claim 6, characterized in that: in step (2), first dissolve the activated matrix asphalt prepared in step (1) in an organic solvent, then add the modifier and the organic base, and react under the condition of a catalyst.

10. The preparation method according to claim 9, characterized in that: the organic solvent is petroleum ether; the mass-volume ratio of the activated matrix asphalt to the added amount of the organic solvent is 1:1 to 10 g / mL.

11. The preparation method according to claim 9, characterized in that: the organic base is at least one of triethylamine and 4-dimethylaminopyridine; the mass ratio of the organic base to the modifier is 1:1 to 10.

12. The preparation method according to claim 6, characterized in that: In step (2), the catalyst is 1,5,7-tripropylheptyloxytrimethylammonium salt; the mass ratio of the catalyst to the modifier added is 0.01 to 0.1:

1.

13. According to the preparation method described in claim 6, characterized in that: In step (2), the temperature of the reaction is 25 to 80 °C, and the reaction time is 1 to 24 h.

14. According to the preparation method described in claim 6, characterized in that: In step (2), the temperature for treatment under acidic conditions is 80 to 120 °C, and the treatment time is 10 to 100 min.

15. Application of the modified asphalt according to any one of claims 1-5 or the modified asphalt prepared by the method according to any one of claims 6-14 in road construction.

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