Temperature-resistant self-repairing epoxy asphalt binder as well as preparation and application thereof

Abstract

The invention belongs to the field of asphalt modification, and particularly discloses a preparation method of a temperature-resistant self-repairing epoxy asphalt binder, which is obtained by curing a modified epoxy binder and asphalt, the modified epoxy adhesive is a curing mixture obtained by carrying out curing reaction on raw materials comprising epoxy resin and a dynamic curing agent; the dynamic curing agent comprises a disulfide curing agent. The invention also provides the epoxy asphalt binder prepared by the preparation method and application thereof. The asphalt obtained by the method disclosed by the invention has excellent high-temperature fluidity and self-repairing effect.

Description

Technical Field

[0001] The invention belongs to the field of modified asphalt, and specifically relates to a temperature-resistant self-repairing epoxy asphalt binder. Background Art

[0002] Asphalt pavement is an interface that directly interacts with vehicles, and it is of great significance in the entire pavement structure. During the long-term use of asphalt pavement, various degrees of damage are prone to occur, including rutting, cracks, subsidence, potholes, delamination, etc. After the damage occurs, it is not only not conducive to driving, but also causes a certain degree of damage to the steel plate, shortening the service life of the bridge. Therefore, how to effectively repair the tiny cracks and other diseases in the asphalt pavement is particularly important. Epoxy resin modified asphalt has the advantages of good flexibility, strong crack resistance, good temperature stability, strong fatigue resistance, and corrosion resistance. It has great advantages in the modification of asphalt.

[0003] In the existing research, the main research focuses on the selection of epoxy system and curing agent, epoxy system dosage, preparation process and mixing process of the mixture. Epoxy asphalt is to add epoxy resin to asphalt, and after curing reaction with curing agent, an irreversible curing material is formed. This curing material changes the thermoplastic properties of asphalt to a certain extent. Asphalt itself is a natural self-healing and self-repairing material. After the introduction of epoxy binder, the structural strength increases, but the self-healing ability decreases. In view of the damage and cracking problems caused by the use of epoxy asphalt pavement, it is mainly repaired by artificial means, that is, filling with external materials, and the damage caused by the material is not fundamentally prevented or repaired. Microcapsule technology is introduced into asphalt mixture. When the material is cracked and damaged, the microcapsules are stimulated, the capsule wall ruptures, and the released substances combine with the catalyst in the system to react in the cracks to achieve the repair effect. However, the limitation of this method is that the addition of microcapsules reduces the overall strength of the asphalt system, and the bonding effect between the two is poor, which hinders its further application and development.

[0004] Among the existing technologies, there is little research on the high-temperature self-healing properties of epoxy asphalt systems, and almost no research on epoxy asphalt that can maintain fluidity for a certain period of time without curing during high-temperature curing and has good mechanical properties after curing. Traditional amine curing agents irreversibly cross-link with epoxy resins, and the irreversible covalent network prevents the reprocessing, recycling, reshaping and reconfiguration of epoxy resins. Therefore, most aged, damaged and discarded epoxy resins are disposed of by incineration or landfill, which brings serious environmental pollution and waste of resources. Summary of the invention

[0005] In view of the problems of existing epoxy asphalt binders in terms of unsatisfactory high-temperature fluidity, self-healing performance and mechanical properties, the first purpose of the present invention is to provide a method for preparing a temperature-resistant and self-healing epoxy asphalt binder, aiming to prepare an epoxy asphalt binder with good high-temperature fluidity, high-temperature self-healing ability and mechanical properties.

[0006] The second purpose of the present invention is to provide a temperature-resistant self-repairing epoxy asphalt binder prepared by the preparation method and its application as a hot-mix steel box girder epoxy asphalt binder.

[0007] In order to solve the problems of epoxy asphalt binder, such as easy solidification at high temperature, poor fluidity, poor self-repair performance at high temperature and poor mechanical ability, the present invention has previously attempted to use an epoxy binder with good fluidity and high performance resistance as a modifier for the modification of the asphalt. However, studies have found that there are adaptation problems between asphalt and epoxy binder, and not all epoxy binders with good fluidity and temperature resistance can volatilize in asphalt to produce the expected modification effect. Therefore, the present invention has further studied and proposed the following solutions:

[0008] A method for preparing a temperature-resistant self-repairing epoxy asphalt binder, which is obtained by curing a modified epoxy adhesive and asphalt;

[0009] The modified epoxy adhesive is a solidified mixture of raw materials including epoxy resin and dynamic curing agent after a curing reaction;

[0010] The dynamic curing agent comprises a disulfide curing agent (also referred to as disulfide in the present invention).

[0011] The present invention innovatively discovers that by modifying asphalt with a modified epoxy binder containing disulfide as a curing agent, an unexpectedly good adaptation synergistic effect can be obtained, which can ensure the fluidity of the epoxy asphalt mixture during the curing process while taking into account the overall mechanical properties, giving it the ability to self-repair at high temperatures, while improving the strength and hardness of the material, thereby meeting the transportation operation requirements of the construction site and the performance requirements of actual applications.

[0012] In the present invention, the epoxy binder formed by the disulfide as a curing component is the key to unexpectedly synergistically improving the high-temperature fluidity, high-temperature self-healing performance and mechanical properties of the epoxy asphalt binder.

[0013] The disulfide curing agent is a compound having a structure of formula 1

[0014] R1-SS-R1

[0015] Formula 1

[0016] The R1 is an alkyl or aromatic group with a substituent; wherein the substituent is an ester group, a carboxyl group, an amino group or a hydroxyl group. wherein the alkyl group with a substituent is, for example, a C1-C10 alkyl group with one or more substituents. the aromatic group with a substituent is, for example, a group with one or more substituents on the aromatic ring. the aromatic ring is, for example, a benzene ring, a five-membered heterocyclic ring or a six-membered heterocyclic ring.

[0017] Preferably, the disulfide is a compound of formula 1-A:

[0018] In the present invention, the preferred formula 1-A can further improve the high-temperature fluidity and self-healing effect of asphalt.

[0019] The dynamic curing agent further comprises an auxiliary curing agent, and the auxiliary curing agent is an aliphatic amine; the aliphatic amine is preferably at least one of polyetheramine, diethyltoluenediamine, metaphenylenediamine, and octadecylamine.

[0020] The present invention also found that the combination of disulfide and the auxiliary curing agent can further cooperate to help further improve the high-temperature fluidity, self-healing ability and mechanical ability of the modified asphalt binder.

[0021] Preferably, in the dynamic curing agent, the weight content of the auxiliary curing agent is below 60wt.%, preferably 30-50wt%.

[0022] In the present invention, the content of the dynamic curing agent in the raw materials is 40-50wt%.

[0023] In the present invention, the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, p-aminophenol triglycidyl epoxy resin, and 4,4'-diaminodiphenyl ether tetraglycidyl epoxy resin.

[0024] In the present invention, the modified epoxy adhesive is a curing mixture of the raw materials that is thermally cured at 100 to 300° C. (preferably 150 to 200° C.);

[0025] Preferably, the thermal curing time is 4-10 minutes.

[0026] In the present invention, the modified epoxy adhesive and asphalt are mixed and cured to obtain the binder.

[0027] In the present invention, the curing temperature is above 150°C, preferably 160 to 250°C;

[0028] Preferably, the curing time is more than 1 hour, preferably 1 to 10 hours, and further can be 2 to 5 hours.

[0029] In the present invention, after high temperature curing, conventional curing treatment may be performed, and the temperature of the oxidation treatment is, for example, 40 to 80° C. The curing time may be more than 1 day, preferably 2 to 5 days.

[0030] The present invention also provides a temperature-resistant self-repairing epoxy asphalt binder prepared by the preparation method.

[0031] The present invention also provides an application of the temperature-resistant self-healing epoxy asphalt binder obtained by the preparation method. For example, it can be used in any application scenario that requires flow construction at high temperature or requires high-temperature self-healing ability. For example, it can be used as hot-mix steel box girder epoxy asphalt.

[0032] Beneficial effects:

[0033] The present invention innovatively uses a disulfide-cured modified epoxy resin binder to modify asphalt, which can unexpectedly achieve synergy and solve the problem of easy curing during the asphalt processing stage and unsatisfactory mechanical and high-temperature self-repairing properties. The present invention further found that combining disulfide with the auxiliary curing agent can further synergistically improve the adaptation effect of the modified epoxy binder on asphalt, which helps to further improve the high-temperature fluidity, mechanical and self-repairing properties of the asphalt composition. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative work are within the scope of protection of the present invention.

[0035] In the present invention, the epoxy resin may be any brand of epoxy resin known in the industry. For example, in the following cases, unless otherwise stated, the bisphenol A epoxy resin is McLean E51 resin.

[0036] The 4,4'-diaminodiphenyl ether tetraglycidyl epoxy resin is AG-80 from Adamas.

[0037] The polyetheramine is Aladdin D2000.

[0038] test:

[0039] Fluidity at elevated temperatures by direct observation;

[0040] The tensile rate of the mechanical test was 500 mm / min;

[0041] Self-repairing is achieved by creating scratches on the sample with a blade, and then leaving it to stand at a high temperature of 180°C for repair. After repair, the mechanical properties of the sample are measured, compared with the original sample, and the repair ratio is calculated.

[0042] Example 1

[0043] Bisphenol A epoxy resin and curing agent (4,4'-diaminodiphenyl disulfide) with a mass ratio of 56:44 were placed in a container, dissolved at a high temperature of 180°C, and mechanically stirred for 5 minutes to form a uniform mixture Y1. The epoxy resin mixture Y1 with a mass ratio of 40:60 was mixed with the base asphalt Y2 placed at 180°C for about 1 hour, stirred for about 5 minutes, placed in an oven at 180°C for curing for 3 hours, then transferred to an oven at 60°C for 3 to 4 days, and then placed at room temperature for 1 to 2 days to obtain an epoxy asphalt binder.

[0044] At high temperature of 180°C, it solidifies in 2.5 hours and has basically no fluidity. Its mechanical properties are 3.4MPa-254%, and its self-healing ability is 64% at 180°C for 1 hour.

[0045] Example 2

[0046] Compared with Example 1, the only difference is that the curing agent is 4,4'-diaminodiphenyl disulfide and polyetheramine in a weight ratio of 1:1, and other operations and parameters are the same as Example 1.

[0047] The epoxy asphalt binder does not solidify at high temperature of 180℃ for 3 hours, maintains a good flow state, and the mechanical properties reach 2.3MPa-505%. The self-repair ability at 180℃ for 1 hour is about 88%;

[0048] Example 3

[0049] Compared with Example 1, the only difference is that the curing agent is 4,4'-diaminodiphenyl disulfide and octadecylamine in a weight ratio of 2:1, and other operations and parameters are the same as Example 1.

[0050] The epoxy asphalt binder does not solidify at high temperature of 180°C for 3 hours, maintains good fluidity, and has mechanical properties of 3.0MPa-276%. The self-healing ability at 180°C for 1 hour is about 82%.

[0051] Example 4

[0052] Compared with Example 1, the only difference is that the epoxy resin is 4,4'-diaminodiphenyl ether tetraglycidyl epoxy resin, the weight ratio of the epoxy resin to the curing agent is 60:40; and the weight ratio of the epoxy resin mixture Y1 to the asphalt Y2 is 50:50.

[0053] The epoxy asphalt binder does not solidify at high temperature of 180°C for 3 hours, maintains a good fluid state, and the mechanical properties reach 3.4MPa-409%. The self-healing ability at 180°C for 1 hour is about 68%. The addition of asphalt weakens the mechanical strength of the binder and improves its elongation at break to a certain extent.

[0054] Example 5

[0055] Compared with Example 1, the only difference is that the curing agent is 3,3'-dithiodipropionic acid, and the other operations and parameters are the same as Example 1.

[0056] At high temperature of 180°C, it is cured for 1.5 hours, and its mechanical properties are 2.6MPa-232%, and its self-healing ability is 58% at 180°C for 1 hour.

[0057] Comparative Example 1

[0058] Compared with Example 1, the only difference is that the curing agent is diethyltoluenediamine, and the other operations and parameters are the same as Example 1.

[0059] The epoxy asphalt binder is completely cured in 0.5h at high temperature of 180℃ and has no fluidity. The mechanical properties of the sample after curing reach 4.3MPa-128%, and the self-repairing ability is less than 30% at 180℃ for 1h.

[0060] Comparative Example 2

[0061] Compared with Example 1, the only difference is that the curing agent is glutaric anhydride and polyetheramine in a weight ratio of 9:1, and other operations and parameters are the same as Example 1.

[0062] The epoxy asphalt binder is basically cured at high temperature of 180℃ for 1 hour, and the binder has no fluidity (not meeting the requirements of the construction site), and is easily damaged and cracked in actual application. The mechanical properties of the sample after curing reach 3.4MPa-89%, and the self-repair ability at 180℃ for 1 hour is about 52%.

Claims

1. A method for preparing a temperature-resistant self-repairing epoxy asphalt binder, characterized in that: The modified epoxy adhesive and asphalt are cured to obtain; The modified epoxy adhesive is a solidified mixture of raw materials including epoxy resin and dynamic curing agent after a curing reaction; The dynamic curing agent comprises a disulfide curing agent.

2. The preparation method according to claim 1, characterized in that The disulfide curing agent is a compound having a structure of formula 1 R1-SS-R1 Formula 1 The R1 is a C1-C10 alkyl or aromatic group with a substituent; wherein the substituent is an ester group, a carboxyl group, an amino group or a hydroxyl group; Preferably, the disulfide curing agent is a compound of formula 1-A:

3. The preparation method according to claim 1, characterized in that: The dynamic curing agent further comprises an auxiliary curing agent, and the auxiliary curing agent is an aliphatic amine; Preferably, the aliphatic amine is at least one of polyetheramine, diethyltoluenediamine, meta-phenylenediamine and octadecylamine.

4. The preparation method according to claim 3, characterized in that: In the dynamic curing agent, the weight content of the auxiliary curing agent is below 60wt.%, preferably 30-50wt%.

5. The preparation method according to any one of claims 1 to 4, characterized in that: In the raw materials, the content of the dynamic curing agent is 40-50wt%.

6. The preparation method according to claim 1, characterized in that: The epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, p-aminophenol triglycidyl epoxy resin, and 4,4'-diaminodiphenyl ether tetraglycidyl epoxy resin.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The modified epoxy adhesive is a curing mixture of the raw materials that is thermally cured at 100 to 300°C; Preferably, the thermal curing time is 4-10 minutes.

8. The preparation method according to claim 1, characterized in that: The curing temperature is above 150°C, preferably 160-250°C; Preferably, the curing time is more than 1 hour, preferably 1 to 10 hours.

9. A temperature-resistant self-repairing epoxy asphalt binder prepared by the preparation method according to any one of claims 1 to 8.

10. An application of a heat-resistant self-repairing epoxy asphalt binder prepared by the preparation method according to any one of claims 1 to 8, characterized in that: It is used as hot mix steel box girder epoxy asphalt.

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