Aging and heat resistant modified asphalt for road paving

Abstract

The application provides an anti-aging and heat-resistant modified asphalt for road paving and belongs to the technical field of asphalt materials. The application realizes the improvement of anti-aging and high-temperature resistance through the synergistic effect of multiple components; the application constructs a network structure through the two-step reaction of vinyl silicon grafting and metallocene titanium hydrogenation with SBS as a base body, simultaneously introduces functional additives such as antioxidants and epoxy soybean oil, and forms a physical-chemical dual anti-aging mechanism. The application considers the key performance requirements such as high-temperature stability (SBS network), anti-ultraviolet aging (nano zinc oxide) and anti-oxidative degradation (phosphite) in the proportioning of components. The service life of road asphalt under high temperature is greatly prolonged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of asphalt materials, and particularly relates to a heat-resistant and aging-resistant modified asphalt for road paving. BACKGROUND

[0002] Asphalt is a black-brown complex mixture composed of hydrocarbons and non-metallic derivatives of different molecular weights, is a kind of high-viscosity organic liquid, mostly exists in the form of liquid or semi-solid petroleum, and has a black surface and is soluble in carbon disulfide and carbon tetrachloride. Asphalt is a kind of waterproof, moisture-proof and corrosion-resistant organic cementing material, and is mainly used in the industries of coating, plastic and rubber, and road paving.

[0003] The chemical composition of asphalt is complex, and the asphalt is separated into four types of saturated components, aromatic components, colloid and asphaltene by the Kolbe method for the purpose of studying its technical properties.

[0004] At present, according to the road use environment and traffic demand, the asphalt needs to have the following key performances:

[0005] High-temperature stability: preventing high-temperature deformation such as rutting and heaving, and requiring high softening point and strong anti-flow performance.

[0006] Anti-aging property: resisting performance degradation caused by factors such as ultraviolet rays and oxidation, and prolonging the service life (such as by adding anti-aging agents or polymer modification).

[0007] Fatigue resistance: coping with heavy traffic and repeated loads, and requiring high toughness and low stiffness modulus.

[0008] And according to the differences of different regions, low-temperature crack resistance, water damage resistance and the like may also be required.

[0009] In view of the performance problems of natural asphalt, the modification of the asphalt at present is mainly realized by adding SBS (styrene-butadiene-styrene block copolymer) and physical blending, aiming to improve the road performance; however, SBS has many different technical parameters and further improvement space. SUMMARY

[0010] The present application aims at the problem of insufficient performance of the asphalt for road use at present, and provides a heat-resistant and aging-resistant modified asphalt for road paving and a preparation method thereof.

[0011] In order to achieve the above purpose, the present application provides a heat-resistant and aging-resistant modified asphalt for road paving, which comprises the following components in parts by mass:

[0012] Asphalt 100

[0013] Modifier 5-8

[0014] Antioxidant 0.5-1.5

[0015] Epoxidized soybean oil 2-4

[0016] The modifier consists of the following components:

[0017] SBS base 100

[0018] Vinyl silicon 10-15

[0019] Initiator 0.2-0.3

[0020] Titanocene 0.1-0.2

[0021] The preparation method of the modifier comprises the following steps:

[0022] S1: mixing SBS base, vinyl silicon and initiator, and reacting in an organic solvent to obtain grafted SBS;

[0023] S2: placing grafted SBS and titanocene in an organic solvent, and performing hydrogenation grafting through high-pressure reaction to obtain the modifier.

[0024] Preferably, the initiator is benzoyl peroxide and / or azobisisobutyronitrile.

[0025] Preferably, the vinyl silicon is vinyl triethoxysilane and / or triacetoxy vinyl silane.

[0026] Preferably, in step S1 of the preparation method of the modifier, the reaction conditions are temperature 80-90℃ and time 6-8h.

[0027] Preferably, in step S2 of the preparation method of the modifier, the reaction conditions are hydrogen pressure 2.0-5.0 MPa, temperature 120-150℃, and reaction time 4-6 hours.

[0028] Preferably, after step S2 of the preparation method of the modifier, residual titanocene is removed by ethanol precipitation, and then dried.

[0029] Preferably, the antioxidant is a phosphite antioxidant.

[0030] Preferably, it further comprises the component: nano zinc oxide 1.5-3 parts.

[0031] Preferably, the SBS base is of star structure; and the S / B block ratio is 30-40:60-70.

[0032] The preparation method of the aforementioned anti-aging and heat-resistant modified asphalt for road paving: mixing the modifier and asphalt, stirring, and then heating and shearing; then adding the remaining components and stirring.

[0033] The present application optimizes the anti-aging of asphalt in multiple aspects, specifically including:

[0034] The modifier mainly uses modified SBS, introduces vinyl silicon monomer into SBS, and realizes hydrogenation modification, so as to solve the problems of poor double bond reactivity and compatibility through a step-by-step process design. The introduction of vinyl silicon can significantly improve the thermal stability of SBS; and the siloxane group forms a chemical bond with the polar components (such as asphaltene) in the asphalt, reducing the risk of phase separation. The hydrogenation eliminates the double bond of the butadiene segment of SBS, reduces the oxidation rate of ultraviolet rays, and the siloxane network of vinyl silicon further blocks the diffusion of oxygen. The hydrogenated SEB skeleton has enhanced high temperature resistance, and the rigid support of silicon-based makes the dynamic stability of asphalt improved.

[0035] The SBS selects a star structure and a high styrene content; the star structure has a higher crosslinking density than linear SBS, improving the high-temperature rutting resistance; the high styrene content (30-40%) increases the proportion of PS hard segment, enhances the rigidity of the material, and has better high-temperature performance.

[0036] The antioxidant is selected as a phosphite antioxidant: by capturing free radicals to interrupt the oxidation chain reaction and inhibit the polymerization of asphaltene.

[0037] Nano zinc oxide is used to reflect ultraviolet rays and reduce photo-oxidative aging; and fill the micro-defects of asphalt to improve the shear deformation resistance. The phosphite antioxidant in the present application removes free radicals, and nano zinc oxide shields ultraviolet rays, so as to synergistically resist photo-oxidative aging in a physical and chemical combination manner.

[0038] The epoxy groups in epoxy soybean oil react with the polar components of asphalt to enhance the homogeneity of the system; at the same time, the plasticizing effect of epoxy soybean oil reduces the glass transition temperature (Tg), and compensates for the increase in hardness caused by SBS modification.

[0039] The present application has at least the following beneficial technical effects:

[0040] The present application realizes the improvement of aging resistance and high temperature resistance through the synergistic effect of multiple components; the present application uses SBS as the matrix, constructs a network structure through two-step reaction of vinyl silicon grafting and metallocene hydrogenation, and introduces functional additives such as antioxidants and epoxy soybean oil, to form a physical-chemical dual anti-aging mechanism. The proportioning of each component of the present application considers the key performance requirements such as high temperature stability (SBS network), ultraviolet aging resistance (nano zinc oxide), and antioxidant degradation (phosphite), etc. The service life of road asphalt at high temperature is greatly prolonged. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0042] In the description of the present application, the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0043] In the description of the present application, the term "for example" is used to indicate "as an example, illustration or explanation". Any embodiment described as "for example" in the present application is not necessarily interpreted as more preferred or more advantageous than other embodiments. The following description is given in order to enable any person skilled in the art to implement and use the present application. In the following description, details are listed for the purpose of explanation. It should be understood that those skilled in the art can realize the present application without using these specific details. In other examples, well-known structures and processes will not be described in detail in order to avoid unnecessary details making the description of the present application obscure. Therefore, the present application is not intended to be limited to the shown embodiments, but is consistent with the broadest scope of the principles and characteristics disclosed.

[0044] The experimental methods used in the specific embodiments are conventional methods, and the materials, reagents, etc. used are commercially available, unless otherwise specified.

[0045] In the present application, unless otherwise specified, "%" represents mass percentage; the raw materials, reagents, etc. used are conventional commercially available products.

[0046] The asphalt used in the present application is No. 90 asphalt.

[0047] The organic solvent used in the present application is cyclohexane.

[0048] The specific surface area of the nano-zinc oxide used in the present application is 55 m 2 / g; the loose bulk density is 0.2 g / cm 3 ; the particle size range is 15-20 nm; the zinc oxide content is ≥99%.

[0049] The phosphite used in the present application is Irgafos 168; i.e. tris[2.4-di-tert-butylphenyl] phosphite.

[0050] The epoxy soybean oil used in the present application has a viscosity of 325 mpa.s, a light shielding rate of 1.473 (25℃), and a molecular weight of 950.

[0051] The metallocene titanium used in the present application is dichloro metallocene titanium.

[0052] Example 1

[0053] The preparation method of the modified asphalt comprises the following steps:

[0054] S1 weighing: the following components are included according to mass fraction:

[0055] Asphalt 100

[0056] Modifier 5

[0057] Irgafos 168 0.5

[0058] Epoxy soybean oil 2

[0059] Nano zinc oxide 1.5

[0060] The modifier is composed of the following components:

[0061] SBS base material 100

[0062] Vinyl triethoxysilane 10

[0063] Benzoyl peroxide 0.2

[0064] Metallocene titanium 0.1

[0065] The preparation method of the modifier comprises the following steps:

[0066] A: the SBS base material, vinyl triethoxysilane and benzoyl peroxide are mixed and reacted in cyclohexane, and after the reaction, the unreacted monomers are removed by Soxhlet extraction; the grafted SBS is obtained;

[0067] The reaction condition is that the temperature is 80℃ and the time is 8h;

[0068] The SBS base material is a star structure, and the S / B block ratio is 40:60.

[0069] B: the grafted SBS and metallocene titanium are put into cyclohexane, and hydrogenation grafting is carried out by high-pressure reaction; after the reaction is completed, the residual metallocene titanium is removed by ethanol precipitation, and then dried; the modifier is obtained.

[0070] The reaction condition is that the hydrogen pressure is 2.0 MPa, the temperature is 150℃, and the reaction time is 6 hours.

[0071] S2 swelling: the modifier is added into the asphalt at 170±10℃, and stirred at low speed for 60 minutes;

[0072] S3 shearing: shearing at 180±10℃ for 20 minutes using a colloid mill;

[0073] S4 development: after shearing, the remaining components are added and incubated for 2h with stirring; the modified asphalt is obtained.

[0074] Example 2

[0075] The method for preparing the modified asphalt comprises the following steps:

[0076] S1 weighing: the following components are included by mass fraction:

[0077] Asphalt 100

[0078] Modifier 6

[0079] Irgafos 168 1.0

[0080] Epoxy soybean oil 3

[0081] Nano zinc oxide 2.5

[0082] The modifier is composed of the following components:

[0083] SBS base material 100

[0084] Vinyl triethoxysilane 12

[0085] Benzoyl peroxide 0.2

[0086] Titanocene 0.1

[0087] The method for preparing the modifier comprises the following steps:

[0088] A: the SBS base material, vinyl triethoxysilane and benzoyl peroxide are mixed and reacted in cyclohexane, and after the reaction, the unreacted monomers are removed by Soxhlet extraction; the grafted SBS is obtained.

[0089] The reaction condition is a temperature of 90℃ and a time of 6h.

[0090] The SBS base material is a star structure, and the S / B block ratio is 40:60.

[0091] B: the grafted SBS and the titanocene are put into cyclohexane, and hydrogenation grafting is carried out by high-pressure reaction; after the reaction is completed, the residual titanocene is removed by ethanol precipitation, and then dried; the modifier is obtained.

[0092] The reaction condition is a hydrogen pressure of 3.5MPa, a temperature of 135℃ and a reaction time of 4.5h.

[0093] S2 swelling: Add modifier into asphalt at 170±10℃, stirring at low speed for 60 minutes;

[0094] S3 shearing: Shearing at high speed for 20 minutes at 180±10℃ using colloid mill;

[0095] S4 development: After shearing, add the rest of the components, and keep stirring for 2 hours; get modified asphalt.

[0096] Example 3

[0097] The method for preparing modified asphalt comprises the following steps:

[0098] S1 weighing: The following components are included according to mass fraction:

[0099] Asphalt 100

[0100] Modifier 8

[0101] Irgafos 168 1.5

[0102] Epoxy soybean oil 4

[0103] Nano zinc oxide 3

[0104] The modifier is composed of the following components:

[0105] SBS base material 100

[0106] Triacetoxyvinylsilane 15

[0107] Azobisisobutyronitrile 0.3

[0108] Titanocene 0.2

[0109] The method for preparing the modifier comprises the following steps:

[0110] A: Mix SBS base material, triacetoxyvinylsilane and azobisisobutyronitrile, and react in cyclohexane; after reaction, remove unreacted monomers by Soxhlet extraction; get grafted SBS;

[0111] The reaction condition is temperature 90℃, and time 6h;

[0112] The SBS base material is star structure; and S / B block ratio is 30:70.

[0113] B: Put grafted SBS and titanocene into cyclohexane, and perform hydrogenation grafting by high-pressure reaction; after reaction, remove residual titanocene by ethanol precipitation, and then dry; get modifier.

[0114] The reaction condition is hydrogen pressure 5.0MPa, temperature 120℃, and reaction time 4.0h.

[0115] S2 swelling: adding modifier into bitumen at 170±10℃, stirring at low speed for 60 minutes;

[0116] S3 shearing: shearing at high speed for 20 minutes at 180±10℃ using colloid mill;

[0117] S4 development: adding the remaining components after shearing, stirring for 2h; obtaining modified bitumen.

[0118] Example 4

[0119] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0120] The SBS is linear SBS; and the S / B block ratio is 40:60.

[0121] Example 5

[0122] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0123] The SBS is star-shaped SBS; and the S / B block ratio is 20:80.

[0124] Example 6

[0125] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0126] In the preparation method of the modifier, only step A is performed.

[0127] Example 7

[0128] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0129] In the preparation method of the modifier, only step B is performed.

[0130] Example 8

[0131] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0132] In the preparation method of the modifier, step B is performed first; and then step A is performed.

[0133] Example 9

[0134] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0135] The modifier only has SBS base material, and the base material is star-shaped structure, and the S / B block ratio is 40:60.

[0136] Example 10

[0137] The difference between the preparation method of the modified bitumen and that of Example 1 is that:

[0138] No modifier was added.

[0139] Example 11

[0140] The preparation method of the modified asphalt is different from that of Example 1 in that;

[0141] No Irgafos 168 was added.

[0142] Example 12

[0143] The preparation method of the modified asphalt is different from that of Example 1 in that;

[0144] No epoxy soybean oil was added.

[0145] Example 13

[0146] The preparation method of the modified asphalt is different from that of Example 1 in that;

[0147] No nano-zinc oxide was added.

[0148] Performance test

[0149] The products obtained in the above examples were subjected to aging test; the test method was as follows:

[0150] The products were placed in an ultraviolet aging test box for ultraviolet aging experiment; in the ultraviolet aging test box, the ultraviolet intensity was 1200 wu / cm 2 , the aging temperature was 60℃, and the aging time was 6 days; then the softening point, penetration and viscosity of the asphalt before and after aging were tested respectively; then the change degrees of the softening point, penetration and viscosity were calculated.

[0151] The smaller the change amount before and after aging, the better the aging resistance of the asphalt.

[0152] Table 1

[0153]

[0154] In Table 1, the penetration was (25℃, 100g); the viscosity was the kinematic viscosity at 60℃.

[0155] As shown in Table 1, the linear SBS in the application compared to star SBS (Example 4); S / B block ratio of S content reduction (Example 5); SBS grafting and hydrogenation or not, order (Example 6, 7, 8); whether to add SBS, Irgafos 168, epoxy soybean oil, nano zinc oxide (Example 9, 10, 11, 12, 13); all affect the change of softening point, penetration and viscosity before and after aging in varying degrees; and the change of each performance index is not consistent with the change of each different index or component; therefore, in order to optimize the comprehensive performance, each component of the application has its necessity.

[0156] The above detailed description is a specific description of one of the feasible embodiments of the application, which is not used to limit the patent scope of the application, and any equivalent implementation or change without departing from the application shall be included in the scope of the technical scheme of the application.

Claims

1. An age-resistant heat-modified bitumen for road paving, characterized in that, The components include the following by mass: Asphalt 100 Modifier 5-8 Antioxidant 0.5-1.5 Epoxy soybean oil 2-4 Nano zinc oxide 1.5-3 The modifier consists of the following ingredients: SBS base 100 Vinyl silicon 10-15 Initiator 0.2-0.3 Titanocene 0.1-0.2 The preparation method of the modifier includes the following steps: S1: Mix SBS base, vinyl silicon and initiator, and react in organic solvent to obtain grafted SBS; S2: Put the grafted SBS and titanocene into organic solvent, and perform high-pressure reaction to carry out hydrogenation grafting; obtain the modifier; In step S1 of the preparation method of the modifier: the reaction condition is temperature 80-90℃, and the time is 6-8h; In step S2 of the preparation method of the modifier: the reaction condition is hydrogen pressure 2.0-5.0 MPa, temperature 120-150℃, and reaction time 4-6 hours; The vinyl silicon is vinyl triethoxysilane and / or triacetoxy vinyl silane; The SBS base is a star structure; and the S / B block ratio is 30-40:60-70.

2. The age and heat resistant modified bitumen for road paving according to claim 1, characterized in that, The initiator is benzoyl peroxide and / or azobis isobutyronitrile.

3. The age and heat resistant modified bitumen for road paving according to claim 1, characterized in that, After step S2 of the preparation method of the modifier, residual titanocene is removed by ethanol precipitation, and then dried.

4. The age and heat resistant modified bitumen for road paving according to claim 1, characterized in that, The antioxidant is a phosphite antioxidant.

5. The process for the preparation of the ageing and heat resistant modified bitumen for road paving according to any one of claims 1 to 4, characterized by the fact that; Mix the modifier and asphalt, stir, then heat and shear; then add the remaining components, and stir with heat.

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