Modifying agent, modified asphalt and method for preparing the same

Abstract

The present application relates to modifier, modified asphalt and its preparation method, the mask fiber obtained by crushing the mask containing polypropylene fiber component, biological oil, surfactant, ball milling medium are mixed, grinding treatment, the initial preparation modified fiber slurry is obtained by adding styrene monomer, butyl methacrylate monomer, initiator, crosslinking agent, grinding, screening, the obtained initial preparation modified fiber slurry, polyether amine, accelerator are mixed, homogenization treatment, the modifier is obtained.The modifier described in the application can reduce the mixing temperature of asphalt, reduce energy consumption, reduce environmental pollution, increase the system stability of asphalt.The asphalt after adding the modifier has low-temperature crack resistance, is not prone to crack in cold environment, improves the service life of asphalt pavement.

Description

Technical Field

[0001] This invention relates to the field of asphalt modification technology, and in particular to a modifier for asphalt modification, modified asphalt, and a method for preparing the same. Background Technology

[0002] Asphalt is an organic binder with asphalt as its main component, composed of complex high-molecular hydrocarbons and their non-metallic derivatives. It is almost completely soluble in organic solvents such as carbon disulfide and benzene, and is black to dark brown in color. At room temperature, it can be liquid, semi-solid, or solid, exhibiting highly non-Newtonian liquid properties and composite viscoplastic or viscoelastic mechanical properties. Asphalt is impermeable, non-conductive, and resistant to acid, alkali, and salt corrosion, while also possessing good binding properties. Modified asphalt refers to asphalt binders that are mixed with admixtures such as rubber, resin, natural asphalt, finely ground rubber powder, or other materials to improve the performance of the asphalt. Modifiers are natural or artificial organic or inorganic materials added to asphalt or asphalt mixtures that can be melted and dispersed in the asphalt to improve or enhance the performance of asphalt pavements (by reacting with the asphalt or coating the aggregate surface).

[0003] Transportation is a crucial component of public infrastructure and a vital link in urban development. Asphalt roads, due to their smoothness and comfort, have seen frequent use in road traffic in recent years. With rising economic levels, higher demands are placed on the performance of asphalt, requiring properties such as low-temperature crack resistance, fatigue resistance, and a longer service life. Patent CN104448857A discloses a method for preparing low-temperature modified asphalt, utilizing pine tar and turpentine as cold-resistant modifiers to improve the low-temperature resistance of asphalt. Patent CN113621245A discloses a method for preparing low-temperature modified asphalt, using nano-zinc oxide for modification. Zinc oxide possesses high surface activation properties and certain adsorption properties, enabling it to bind well with asphalt and thus improving its low-temperature resistance. Developing more asphalt modifiers with economic and social benefits is of great significance.

[0004] Polymer fibers, such as glass fibers and polyacrylonitrile fibers, are commonly used in asphalt modification, effectively improving the water stability and low-temperature crack resistance of asphalt. Disposable masks play a crucial role in hygiene and epidemic prevention, with huge demand; therefore, the recycling and disposal of discarded masks is a real problem. Polypropylene fiber is a major component of disposable masks, and using waste disposable mask fibers as an asphalt modifier is an ideal way to reuse resources. However, since polypropylene fibers lose their reinforcing effect at around 170℃, the mixing temperature of asphalt must be addressed when using disposable mask fibers as a modifier. Developing a modifier that can improve low-temperature resistance, reduce asphalt mixing temperature, and simultaneously address the issue of large quantities of waste disposable mask fibers has significant theoretical and practical value. Summary of the Invention

[0005] One of the objectives of this invention is to provide a modifier and its preparation method, which can be used as an asphalt modifier, fully swells in asphalt, reduces the mixing temperature of asphalt, reduces energy consumption, reduces environmental pollution, and increases the system stability of asphalt.

[0006] The technical solution adopted by this invention to achieve its objective is as follows:

[0007] A method for preparing a modifier includes the following steps:

[0008] (1) The bio-oil, mask fiber, surfactant and ball milling media are mixed and ground. The mask fiber is obtained by crushing a mask containing polypropylene fiber components.

[0009] (2) Add styrene monomer, butyl methacrylate monomer, initiator and crosslinking agent to the mixture obtained in step (1) and grind it.

[0010] (3) The mixture obtained in step (2) is screened to obtain a preliminary modified fiber slurry;

[0011] (4) The modified fiber slurry obtained in step (3), polyetheramine, and accelerator are mixed and homogenized to obtain the modifier.

[0012] Preferably, the mask fibers are flocculent with a length not exceeding 2 cm, or the mask fibers have an area not exceeding 2 cm². 2 Fragments, preferably no more than 1cm in size. 2 The mask containing polypropylene fiber components can be derived from recycled disposable medical masks or disposable non-medical masks, wherein the proportion of polypropylene fiber is 20wt% to 50wt%.

[0013] Preferably, the weight ratio of bio-oil, mask fiber, surfactant, styrene monomer, butyl methacrylate monomer, initiator, and crosslinking agent is 100:(4-6):(1-5):(5-8):(6-10):(3-4):(2-4).

[0014] Preferably, the grinding media in steps (1) and (2) is agate ball; the weight ratio of the grinding media to the bio-oil is (20-30):100 by weight.

[0015] Preferably, the weight ratio of the initial modified fiber pulp, polyetheramine, and accelerator in step (3) is 100:(10-15):(4-8).

[0016] Preferably, the ball milling media comprises three particle size grades: 9–12 mm, 6–8 mm, and 3–5 mm, respectively, with a weight ratio of (1-3):(1-3):(1-3), for example, 1:1:1, 1:3:3, or 2:3:3. Different ball ratios and a reasonable combination of large and small balls constitute a gradation that can improve ball mill activation, especially the reaction efficiency of liquid-phase oil milling.

[0017] Preferably, the bio-oil is selected from one or more of olive oil, rapeseed oil, and soybean oil; the surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyl ammonium bromide, and sodium dodecylbenzene sulfonate; the butyl methacrylate monomer is selected from one or more of butyl methacrylate, neopentyl glycol dimethacrylate, and octafluoropentyl methacrylate; the initiator is selected from benzoyl peroxide or azobisisobutyronitrile; the crosslinking agent is selected from any one of zinc oxide, sulfur powder, and di-tert-butylbenzene peroxide; the polyetheramine is selected from one or more of polyetheramine D-230, polyetheramine D-400, and polyetheramine ED-900; and the accelerator is selected from one or more of N,N'-carbonyldiimazole, dicyclohexylcarbodiimide, or diisopropylcarbodiimide.

[0018] Preferably, the grinding time in steps (1) and (2) is 20 to 40 minutes.

[0019] Preferably, step (4) involves high-speed shear homogenization at a pressure below standard atmospheric pressure, such as 0.7 or 0.5 standard atmospheres, 3000 r / min or 2500 r / min; the homogenization time is 2 to 4 hours.

[0020] The present invention also provides a modifier prepared by the above method.

[0021] The second objective of this invention is to provide a modified asphalt and its preparation method, so that the obtained modified asphalt has low-temperature resistance, good ductility in low-temperature environments, and a lower critical cracking temperature.

[0022] The technical solution adopted by this invention to achieve its objective is as follows:

[0023] A method for preparing modified asphalt includes the following steps: mixing raw asphalt and a modifier uniformly at 130-150°C; wherein the modifier is prepared by the above method.

[0024] Preferably, during the preparation process, the raw material asphalt is first heated to 150°C, and then the modifier is added.

[0025] Preferably, the mixing conditions include first stirring at a constant temperature of 150°C to fully melt the raw asphalt into a fluid state, and then placing the mixture under a high-speed shearing machine for further stirring.

[0026] Preferably, the weight ratio of the raw material asphalt to the modifier is 100:(8-10).

[0027] Preferably, the raw material asphalt is selected from No. 70 asphalt or No. 90 asphalt.

[0028] Preferably, the method for preparing the modified asphalt further includes adding one or more of the following: a UV shielding agent, a plasticizer, a stabilizer, and an anti-aging agent. Specifically, by weight, the ratio of the UV shielding agent to the raw asphalt is (3-5):100. The ratio of the plasticizer to the raw asphalt is (1-2):100. The ratio of the stabilizer to the raw asphalt is (1-2):100. The ratio of the anti-aging agent to the raw asphalt is (2-4):100.

[0029] Preferably, the UV shielding agent is selected from one or more of carbon black, titanium dioxide, talc, clay powder, and zinc oxide; the plasticizer is selected from one or more of dioctyl phthalate, dibutyl phthalate, and diethyl phthalate; and the stabilizer is selected from aliphatic hydrocarbon resins, aromatic hydrocarbon resins, cycloalkanes resins, sodium sulfonate, sodium stearate, calcium stearate, zinc stearate, zinc oxide, calcium oxide, methylene dinaphthalene sulfonate, methylene diisopropylnaphthalene sulfonate, and alkylphenoxy polyoxyethylene. The anti-aging agent is selected from one or a mixture of several of the following: sodium ethylene sulfate, polyvinyl alcohol, polyacrylic acid, sodium dodecanoate, N-cyclohexyl-p-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, and o-cresol p-toluenesulfonate; the anti-aging agent is selected from one or a mixture of several of the following: 2,6-di-tert-butyl-4-methylphenol, styrylated phenol, 4,4'-dihydroxybiphenyl, 2,5-di-tert-butylhydroquinone, 2-mercaptobenzimidazole, 2-mercaptobenzimidazole zinc salt, and N-cyclohexyl-p-ethoxyaniline.

[0030] The present invention also provides a modified asphalt prepared by the above method.

[0031] This application first uses oil milling activation to graft butyl methacrylate monomers and styrene monomers onto polypropylene-containing mask fibers, forming a butyl methacrylate-styrene monomer copolymer. Compared to conventional solution methods, this effectively improves reaction efficiency, increases production energy efficiency, shortens the production cycle, and significantly reduces organic residues and environmental pollution. Then, combined with chemimechanical synthesis, the resulting fiber modifier forms a three-dimensional chemically cross-linked structure, increasing oil loading and facilitating swelling in asphalt. This lowers the asphalt mixing temperature, reduces energy consumption, minimizes environmental pollution, and increases the stability of the asphalt system. Asphalt with the added modifier exhibits low-temperature crack resistance, is less prone to cracking in cold environments, and extends the lifespan of asphalt pavements. Detailed Implementation

[0032] To better understand the present invention, the following embodiments are further illustrations of the present invention, but the content of the present invention is not limited to the following embodiments.

[0033] The following examples all use the same discarded disposable medical masks as the source of mask fibers, with a polypropylene fiber content of approximately 20-50 wt%. The processing method involves directly crushing the masks in a shredder for 5 minutes to obtain block-shaped mask fibers with an average surface area of ​​1 cm². 2 .

[0034] Example 1

[0035] (1) Oil-based activation of waste mask fibers

[0036] 100 parts by weight of soybean oil, 4 parts by weight of mask fiber, 1 part by weight of sodium dodecyl sulfate, and 20 parts by weight of agate balls were added to a grinding mill. The agate balls had three particle sizes: 10 mm, 7 mm, and 4 mm, with a ball milling media weight ratio of 1:3:3. Grinding was carried out for 30 minutes. Then, 5 parts by weight of styrene monomer, 6 parts by weight of butyl methacrylate monomer, 3 parts by weight of azobisisobutyronitrile, and 2 parts by weight of di-tert-butylbenzene peroxide were added to the grinding mill, and grinding was continued for another 30 minutes. After sieving, the initial modified fiber slurry was obtained.

[0037] (2) Preparation of fiber modifier for waste masks

[0038] 100 parts by weight of pre-prepared modified fiber slurry, 10 parts by weight of polyetheramine D-230, and 4 parts by weight of dicyclohexylcarbodiimide were homogenized at 0.7 standard atmospheres under high-speed shearing at 3000 r / min for 3 hours to obtain waste mask fiber modifier.

[0039] (3) Preparation of modified asphalt from discarded face masks

[0040] 100 parts by weight of 70# modified asphalt is heated to 150°C, and 8 parts by weight of waste mask fiber modifier, 3 parts by weight of UV shielding agent, 1 part by weight of plasticizer, 1 part by weight of stabilizer and 2 parts by weight of anti-aging agent are added. The mixture is stirred under constant temperature conditions to make the asphalt fully melt and flow. The melted asphalt is then placed under a high-speed shearing machine and stirred thoroughly for 40 minutes to obtain waste mask modified asphalt.

[0041] Example 2

[0042] (1) Oil-based activation of waste mask fibers

[0043] The process is the same as in Example 1, except that:

[0044] The weight parts of soybean oil, mask fiber, sodium lauryl sulfate, and agate balls are 100 parts, 4 parts, 2 parts, and 25 parts, respectively.

[0045] The weight parts of styrene monomer, butyl methacrylate monomer, azobisisobutyronitrile, and di-tert-butylbenzene peroxide are 6 parts, 7 parts, 3 parts, and 2 parts, respectively.

[0046] (2) Preparation of fiber modifier for waste masks

[0047] The process is the same as in Example 1, except that:

[0048] The initial modified fiber pulp, polyetheramine D-230, and dicyclohexylcarbodiimide were present in weight parts of 100, 11, and 5, respectively.

[0049] (3) Preparation of modified asphalt from discarded face masks

[0050] The process is the same as in Example 1.

[0051] Example 3

[0052] (1) Oil-based activation of waste mask fibers

[0053] The process is the same as in Example 1, except that:

[0054] The surfactant selected is dicyclohexylcarbodiimide, and the weight parts of soybean oil, mask fiber, dicyclohexylcarbodiimide, and agate balls are 100 parts, 5 parts, 3 parts, and 25 parts, respectively.

[0055] The weight parts of styrene monomer, butyl methacrylate monomer, azobisisobutyronitrile, and di-tert-butylbenzene peroxide are 7 parts, 8 parts, 3 parts, and 3 parts, respectively.

[0056] (2) Preparation of fiber modifier for waste masks

[0057] The process is the same as in Example 1, except that:

[0058] The initial modified fiber pulp, polyetheramine D-230, and dicyclohexylcarbodiimide were present in weight parts of 100, 12, and 6, respectively.

[0059] (3) Preparation of modified asphalt from discarded face masks

[0060] The process is the same as in Example 1, except that:

[0061] The weight parts of 70# modified asphalt, mask fiber modifier, ultraviolet shielding agent, plasticizer, stabilizer and anti-aging agent are 100 parts, 9 parts, 4 parts, 2 parts, 2 parts and 3 parts, respectively.

[0062] Example 4

[0063] (1) Oil-based activation of waste mask fibers

[0064] The process is the same as in Example 1, except that:

[0065] The surfactant selected is dicyclohexylcarbodiimide, and the weight parts of soybean oil, mask fiber, dicyclohexylcarbodiimide, and agate balls are 100 parts, 5 parts, 4 parts, and 25 parts, respectively.

[0066] The weight parts of styrene monomer, butyl methacrylate monomer, azobisisobutyronitrile, and di-tert-butylbenzene peroxide are 7 parts, 9 parts, 3 parts, and 3 parts, respectively.

[0067] (2) Preparation of fiber modifier for waste masks

[0068] The process is the same as in Example 1, except that:

[0069] The initial modified fiber pulp, polyetheramine D-230, and dicyclohexylcarbodiimide were present in weight parts of 100, 13, and 7, respectively.

[0070] (3) Preparation of modified asphalt from discarded face masks

[0071] The process is the same as in Example 1, except that:

[0072] The weight parts of 70# modified asphalt, mask fiber modifier, ultraviolet shielding agent, plasticizer, stabilizer and anti-aging agent are 100 parts, 9 parts, 5 parts, 2 parts, 2 parts and 4 parts respectively.

[0073] Example 5

[0074] (1) Oil-based activation of waste mask fibers

[0075] The process is the same as in Example 1, except that:

[0076] The surfactant selected is dicyclohexylcarbodiimide, and the weight parts of soybean oil, mask fiber, dicyclohexylcarbodiimide, and agate balls are 100 parts, 6 parts, 5 parts, and 30 parts, respectively.

[0077] The weight parts of styrene monomer, butyl methacrylate monomer, azobisisobutyronitrile, and di-tert-butylbenzene peroxide are 8 parts, 10 parts, 4 parts, and 4 parts, respectively.

[0078] (2) Preparation of fiber modifier for waste masks

[0079] The process is the same as in Example 1, except that:

[0080] The initial modified fiber pulp, polyetheramine D-230, and dicyclohexylcarbodiimide were present in weight parts of 100, 15, and 8, respectively.

[0081] (3) Preparation of modified asphalt from discarded face masks

[0082] The process is the same as in Example 1, except that:

[0083] The weight parts of 70# modified asphalt, mask fiber modifier, ultraviolet shielding agent, plasticizer, stabilizer and anti-aging agent are 100 parts, 10 parts, 5 parts, 2 parts, 2 parts and 4 parts respectively.

[0084] Example 6

[0085] The difference between this comparative preparation method and Example 4 is that in step (1), the particle size of the agate balls is changed. The three particle size grades of the agate balls are 12mm, 8mm and 5mm respectively, and the weight ratio of the ball milling media of the three particle sizes is 1:3:3.

[0086] Example 7

[0087] The difference between this comparative preparation method and Example 4 is that in step (1), the agate ball gradation is changed, and the three particle size grades of the agate balls are 10mm, 7mm and 4mm respectively, and the weight ratio of the three particle sizes of the ball milling media is 2:3:3.

[0088] Comparative Example 1

[0089] This comparison includes only the following steps:

[0090] 100 parts by weight of 70# modified asphalt was heated to 150°C. 5 parts by weight of UV shielding agent, 2 parts by weight of plasticizer, 2 parts by weight of stabilizer and 4 parts by weight of anti-aging agent (same as in Example 4) were added and stirred under constant temperature conditions to fully melt the asphalt into a fluid state. The melted asphalt was then placed under a high-speed shearing machine and stirred thoroughly for 40 minutes to obtain waste mask modified asphalt.

[0091] Comparative Example 2

[0092] The difference between this comparative preparation method and Example 4 is that step (1) is omitted, that is, the mask fibers are not activated by oil milling, and the broken mask fibers are directly used to modify the asphalt.

[0093] Comparative Example 3

[0094] The difference between this comparative preparation method and Example 4 is that step (2) is omitted, that is, the oil-milled activated mask fibers are not mechanically mixed, and the oil-milled activated mask fibers are directly used to modify the asphalt.

[0095] The following are the product performance test results: The softening point test, penetration test (25℃), ductility test (5℃), and critical cracking temperature test were conducted on the low-temperature modified asphalt in each of the above examples. The specific data are listed in Table 1.

[0096] Table 1 Performance Test Table of Modified Asphalt

[0097]

[0098] Table 1 shows that, through experimental comparison, adding waste mask fiber modifier can reduce the mixing temperature of asphalt without changing its high-temperature performance, while simultaneously improving its low-temperature performance. Graft modification of fibers with butyl methacrylate and styrene monomers forms butyl methacrylate-styrene monomer copolymer fibers, improving the fibers' thermal stability and mechanical properties. The alkyl side chains of the butyl methacrylate-styrene monomer copolymer molecules are intertwined, forming physical cross-links, thus exhibiting a certain adsorption capacity for weakly polar solvents (bio-oil). The butyl methacrylate-styrene monomer copolymer fibers swell due to the interaction between the lipophilic groups within the copolymer fibers and oil molecules, forming internal linkages that contact the chain segments, enhancing the interaction forces and allowing it to exert a better modifying effect in asphalt.

[0099] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a modifier, characterized in that, Includes the following steps: (1) The bio-oil, mask fiber, surfactant and ball milling media are mixed and ground. The mask fiber is obtained by crushing a mask containing polypropylene fiber components. (2) Add styrene monomer, butyl methacrylate monomer, initiator and crosslinking agent to the mixture obtained in step (1) and grind it; (3) The mixture obtained in step (2) is screened to obtain the initial modified fiber slurry; (4) Mix the initial modified fiber slurry, polyetheramine and accelerator obtained in step (3), and homogenize them to obtain the modifier.

2. The method for preparing the modifier according to claim 1, characterized in that, The weight ratio of bio-oil, mask fiber, surfactant, styrene monomer, butyl methacrylate monomer, initiator, and crosslinking agent is 100: (4~6): (1~5): (5~8): (6~10): (3~4): (2~4).

3. The method for preparing the modifier according to claim 1, characterized in that, In step (4), the weight ratio of the initial modified fiber pulp, polyetheramine, and accelerator is 100:(10~15):(4~8).

4. The method for preparing the modifier according to claim 1, characterized in that, The ball milling media includes three particle size grades: 9~12mm, 6~8mm, and 3~5mm, respectively, and the weight ratio of the three particle sizes of the ball milling media is (1-3):(1-3):(1-3).

5. The method for preparing the modifier according to claim 1, characterized in that, The bio-oil is selected from one or more of olive oil, rapeseed oil, and soybean oil; the surfactant is selected from one or more of sodium dodecyl sulfate, hexadecyl ammonium bromide, and sodium dodecylbenzene sulfonate; the initiator is selected from benzoyl peroxide or azobisisobutyronitrile; the crosslinking agent is selected from any one of zinc oxide, sulfur powder, and di-tert-butylbenzene peroxide; the polyetheramine is selected from one or more of polyetheramine D-230, polyetheramine D-400, and polyetheramine ED-900; and the accelerator is selected from one or more of N,N'-carbonyldiimazole, dicyclohexylcarbodiimide, or diisopropylcarbodiimide.

6. The method for preparing the modifier according to claim 1, characterized in that, The mask fibers are either fluffy with a length not exceeding 2 cm, or have an area not exceeding 2 cm². 2 Fragmented.

7. A modifier, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 6.

8. A method for preparing modified asphalt, characterized in that, It is obtained by mixing raw asphalt with the modifier described in claim 7 at a temperature of 130~150°C.

9. The preparation method according to claim 8, characterized in that, The weight ratio of the raw material asphalt to the modifier is 100:(8~10).

10. A polypropylene fiber-modified asphalt, characterized in that, It is obtained by the preparation method described in any one of claims 8 to 9.

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