Long-acting hydrophobic asphalt pavement maintenance energy-absorbing seal coat material and preparation method thereof

Abstract

The invention discloses a long-acting hydrophobic asphalt pavement maintenance energy-absorbing seal coat material and a preparation method, and belongs to the technical field of road engineering.The preparation method comprises the steps that after perfluoropolyether is dissolved in an organic solvent, 4, 4 '-diphenylmethane diisocyanate is added for a reaction, a reaction auxiliary is added in the reaction process, and the 4, 4'-diphenylmethane diisocyanate is obtained after the reaction is completed; a 4, 4 '-diphenylmethane diisocyanate prepolymer is used as a component A; then blending a mixture of polytetrafluoroethylene particles and softened rubber with amine-terminated polyether to obtain a component B; and finally, mixing the component A and the component B in air to form a composite material, spraying the composite material on a road to form a first polymer coating, forming a gravel aggregate layer on the first polymer coating, and finally forming a first polymer coating on the aggregate layer to obtain the energy-absorbing seal coat material. According to the method, the fluorine-containing compound is used for modifying the 4, 4 '-diphenylmethane diisocyanate, so that excellent hydrophobic performance and wear resistance can be provided for the raw materials, and the effects of improving the drainage performance of the pavement, reducing the water damage of the pavement and prolonging the service life of the pavement are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, in particular to a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealing material and a preparation method thereof. Background Art

[0002] Asphalt pavement maintenance energy-absorbing seal is a new type of pavement seal with a force-absorbing effect. Its highly elastic and flexible binder provides excellent load-bearing and buffering properties on the original pavement through energy dissipation, making it suitable for preventive road maintenance and road reconstruction.

[0003] Pavement water damage is a major form of asphalt pavement failure on Chinese highways. Over time, asphalt pavements gradually lose their internal cohesion due to erosion by ambient water, leading to a decline in the pavement's structural performance and causing problems such as pitting, looseness, and potholes, which in turn seriously impact driving comfort and safety. Existing high-performance energy-absorbing materials for asphalt pavement maintenance offer excellent load-bearing and buffering properties, but further improving their hydrophobic properties is difficult to achieve to prevent water damage in my country's rainy southern regions and frozen northern regions. To address this situation, there is an urgent need to develop a long-lasting, hydrophobic energy-absorbing sealant for asphalt pavement maintenance. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing seal material and a preparation method, which solves the technical problem that the pavement maintenance energy-absorbing seal material in the prior art is difficult to achieve both hydrophobic performance and road performance.

[0005] The present invention is achieved through the following technical solutions: A method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant material comprises the following steps: After dissolving perfluoropolyether in an organic solvent, 4,4'-diphenylmethane diisocyanate is added to react, and a reaction aid is added during the reaction. After the reaction is completed, a 4,4'-diphenylmethane diisocyanate prepolymer is obtained as component A; Calculated by weight, the perfluoropolyether is 15-25 parts and the 4,4'-diphenylmethane diisocyanate is 80-120 parts; blending a mixture of polytetrafluoroethylene particles and softened rubber with amino-terminated polyether to obtain component B; By weight, 5-25 parts of polytetrafluoroethylene and 8 parts of rubber; Component A and component B are mixed in air to form a composite material which is sprayed on the road to form a first polymer coating layer, a crushed stone aggregate layer is formed on the first polymer coating layer, and finally a first polymer coating layer is formed on the aggregate layer to obtain an energy absorbing seal material.

[0006] Preferably, the reaction aids include a cross-linking agent, a defoaming agent, a leveling agent and a lubricant. Preferably, the cross-linking agent is trimethyl borate, and its mass fraction is 8 parts; The defoaming agent is polyether-modified polydimethylsiloxane, and the leveling agent is polyether-modified polydimethylsiloxane. The total mass fraction of the defoaming agent and the leveling agent is 1 part.

[0007] The lubricant is ethylene bisstearamide, and its mass fraction is 1 part.

[0008] Preferably, the preparation method of component A is as follows: After preheating the organic solvent to 60°C, the dried perfluoropolyether was added and thoroughly stirred to dissolve. Then, dehydrated 4,4'-diphenylmethane diisocyanate was added and mixed with the mixture and a catalyst was added to carry out a fluorination reaction. The reaction temperature was set to 85°C and the reaction time was 2 h. During the reaction, a reaction aid was added until the reaction was fully completed to obtain a fluorinated 4,4'-diphenylmethane diisocyanate prepolymer.

[0009] Preferably, the rubber is ethylene-propylene-dicyclopentadiene ethylene propylene diene monomer (EPDM) rubber.

[0010] Preferably, the amino-terminated polyether is polyoxypropylene diamine.

[0011] Preferably, the preparation method of component B is as follows: The softened rubber and polytetrafluoroethylene particles are stirred evenly, and then polyoxypropylene diamine and a defoaming agent are added and blended, and the blended product is cooled to room temperature to obtain a component.

[0012] Preferably, the volume ratio of component A to component B is 55:48.

[0013] An energy-absorbing sealing layer material prepared by the preparation method comprises, from bottom to top, a first polymer spray coating layer, a crushed stone layer, and a second polymer spray coating layer.

[0014] A highway, the road surface of which is made of the energy-absorbing sealing material.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present application provides a method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing seal material. By reacting perfluoropolyether and 4,4'-diphenylmethane diisocyanate under specific conditions, the obtained prepolymer component A not only inherits the strong hydrophobicity of perfluoropolyether, but also has excellent mechanical properties, providing a good hydrophobic basis for the entire seal material. At the same time, the polytetrafluoroethylene particles and softened rubber mixture as component B further enhance the wear resistance and weather resistance of the material, extending the service life of the seal; secondly, the energy-absorbing seal material adopts a "sandwich" seal structure, that is, a layer of polymer coating is first sprayed, then a crushed stone aggregate layer is laid, and finally another layer of polymer coating is sprayed. This structural design effectively improves the bonding force between the seal and the aggregate, reduces the peeling of the aggregate, and enhances the overall stability and durability of the seal. In addition, the design of the double-layer polymer coating not only improves the hydrophobic properties of the seal, but also enhances its ability to absorb and dissipate road traffic loads, thereby improving the performance and driving safety of the road surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 is the reaction formula of the fluorination reaction of the present invention; Figure 2 This is the FTIR infrared spectrum of the 4,4'-diphenylmethane diisocyanate prepolymer of the present invention. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0020] A method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant material comprises the following steps: Step 1, preparing component A; After dissolving perfluoropolyether in an organic solvent, 4,4'-diphenylmethane diisocyanate is added to react, and a reaction aid is added during the reaction. After the reaction is completed, a 4,4'-diphenylmethane diisocyanate prepolymer is obtained as component A; Calculated by weight, the perfluoropolyether is 15-25 parts, and the 4,4'-diphenylmethane diisocyanate is 80-120 parts.

[0021] Step 2, preparing component B; A mixture of polytetrafluoroethylene particles and softened EPDM rubber is blended with amino-terminated polyether to obtain component B; By weight, 5-25 parts of polytetrafluoroethylene; 8 parts of EPDM rubber; Step 3: Mix component A and component B in air to form a composite material, spray it on the road to form a first polymer coating layer, form a crushed stone aggregate layer on the first polymer coating layer, and finally form a first polymer coating layer on the aggregate layer to obtain an energy absorbing seal material.

[0022] In some embodiments, the component A further includes a catalyst, and the catalyst is any one of dibutyltin dilaurate, triethylamine, stannous octoate, or bismuth neodecanoate.

[0023] After mixing the perfluoropolyether solvent and 4,4'-diphenylmethane diisocyanate, a catalyst is added to accelerate the reaction process.

[0024] In some embodiments, the reaction aid includes a cross-linking agent, a defoaming agent, a leveling agent, and a lubricant.

[0025] The cross-linking agent is trimethyl borate, and its mass fraction is 8 parts.

[0026] The defoaming agent is polyether-modified polydimethylsiloxane; the leveling agent is polyether-modified polydimethylsiloxane, and the total mass fraction of the defoaming agent and the leveling agent is 1 part.

[0027] The lubricant is ethylene bisstearamide, and its mass fraction is 1 part.

[0028] The components and preparation process of component A are described in detail below.

[0029] In some embodiments, the perfluoropolyether has a double-terminal hydroxyl group and is used as a chemical hydrophobic modifier, and its molecular formula is HOCH2CF2(OCF2) p (OCF2CF2) q OCF2CH2OH, number average molecular weight is about 500-5000.

[0030] The perfluoropolyether is a dry perfluoropolyether, and the perfluoropolyether is placed in a vacuum oven for drying, the temperature is set to 50° C., and the drying is continued for 2 h to obtain the dry perfluoropolyether.

[0031] In some embodiments, the 4,4'-diphenylmethane diisocyanate is dehydrated 4,4'-diphenylmethane diisocyanate.

[0032] 4,4'-Diphenylmethane diisocyanate was placed in a three-necked flask for dehydration treatment. The temperature was maintained at 50°C for 1 h. Nitrogen was introduced during the dehydration to protect it.

[0033] 4, 4'-diphenylmethane diisocyanate, molecular weight is 250, and the molecular structure is as follows:

[0034] In some embodiments, the organic solvent is preheated to 60°C and then the dried perfluoropolyether is added and stirred thoroughly to dissolve until no significant residue remains. Dehydrated 4,4'-diphenylmethane diisocyanate is added and mixed with the organic solvent, and a catalyst is added. During this period, sufficient heating and stirring are continued. The reaction temperature is set to 85°C, the stirrer speed is set to 250 rpm, and the reaction time is 2 h. The main reaction formula of the fluorination reaction is as follows: Figure 1 During the reaction, trimethyl borate and polyether-modified polydimethylsiloxane were added until the reaction was complete to obtain a fluorinated 4,4'-diphenylmethane diisocyanate prepolymer, the FTIR infrared spectrum of which is shown in FIG. Figure 2 shown.

[0035] In some embodiments, the organic solvent is any one of perfluoro-2-butyltetrahydrofuran, tetrafluoropropanol, 1,3-bis(trifluoromethyl)benzene, trichlorotrifluoroethane, hexafluoro-m-xylene, toluene, perfluorotributylamine, perfluorotripropylamine, and dimethylformamide.

[0036] When perfluoro-2-butyltetrahydrofuran, tetrafluoropropanol, 1,3-bis(trifluoromethyl)benzene, perfluorotributylamine and perfluorotripropylamine are used as organic solvents, silane coupling agent KH550 is added to improve interface bonding strength and dispersibility.

[0037] The components and preparation process of component B are described in detail below.

[0038] In some embodiments, the polytetrafluoroethylene and EPDM rubber serve as hydrophobic modifiers, and also serve as hydrophobic and wear-resistant modifiers.

[0039] The molecular formula of polytetrafluoroethylene is (C2F4) n .

[0040] EPDM rubber, the rubber is ethylene-propylene-dicyclopentadiene ethylene-propylene-dicyclopentadiene terpolymer, the ethylene-propylene ratio is about 80:20, and the number average molecular weight is about 50,000. Its molecular formula is:

[0041] In some embodiments, the amino-terminated polyether is polyoxypropylene diamine, and its weight fraction is 80-120 parts.

[0042] In some embodiments, a defoaming agent, polyether-modified polydimethylsiloxane, is added during the blending of the mixture of polytetrafluoroethylene particles and EPDM rubber with the amino-terminated polyether.

[0043] In some embodiments, polytetrafluoroethylene is ground using a grinding and dispersion device to form fine particles of approximately 140 mesh. The EPDM rubber is heated at 280°C until softened and then slowly poured into a blender with the polytetrafluoroethylene for stirring at a speed of 200 rpm for 30 minutes, with heating maintained. This is then added to the grinding and dispersion device along with polyoxypropylene diamine, followed by the addition of a defoaming agent, polyether-modified polydimethylsiloxane, and further grinding to fully disperse the polytetrafluoroethylene in the polyoxypropylene diamine. The resulting blended modified product is then sealed after natural cooling and used as component B.

[0044] In some embodiments, 1 part of carbon black is also included.

[0045] In some embodiments, the crushed stone aggregate is high-strength, wear-resistant, angular basalt, limestone or diabase, with a particle size of 1.18-2.36 mm and 2.36-4.75 mm, and its mass fraction is 1000 parts of aggregate. In some embodiments, the original road surface is leveled, dried, and cleaned, and the necessary equipment is prepared. The crushed stone material is pre-mixed. The prepared components A and B are then poured into the storage tanks of the spray equipment and sealed. The spray volume and rate are set, and the spray equipment is started.

[0046] Components A and B are thoroughly mixed in the air through a nozzle, reacting rapidly to form a composite material before spraying. Evenly applied, the first polymer coating is formed. Immediately after spraying, the evenly mixed aggregate is spread to form a single layer of crushed stone. After spreading, the stone is leveled to prevent stacking. The spraying equipment is restarted to spray the crushed stone layer to form a second polymer coating. After curing, a "sandwich-style" preventive energy-absorbing seal is formed.

[0047] Correspondingly, the present application also provides a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealing material, comprising a first layer of polymer spray coating, a crushed stone spreading layer, and a second layer of polymer spray coating from bottom to top; The polymer spray coating comprises a basic material, a modified material (perfluoropolyether ethylene propylene diene monomer rubber and polytetrafluoroethylene) and an auxiliary agent.

[0048] This polymer spray coating absorbs the forces transmitted by traffic loads, improving the durability of the surface structure of roads, bridge decks, and tunnels. It also provides waterproofing, anti-skid, and abrasion resistance. This long-lasting, hydrophobic, energy-absorbing sealant can be used on roads, bridge decks, and tunnel surfaces.

[0049] Example 1 A method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant material comprises the following steps: Step 1, treatment of 4, 4' diphenylmethane diisocyanate: 4,4'-Diphenylmethane diisocyanate was placed in a three-necked flask for dehydration treatment. The temperature was maintained at 50°C for 1 h. Nitrogen was introduced during the dehydration to protect it.

[0050] Step 2, treatment of perfluoropolyether: The perfluoropolyether was dried in a vacuum oven at 50 °C for 2 h.

[0051] Step 3: Prepare a fluorinated 4,4'-diphenylmethane diisocyanate prepolymer as component A: Take a sufficient amount of organic solvent, preheat it to 60°C, add 20 parts of dried perfluoropolyether, and stir thoroughly to dissolve until no obvious residue remains. Add 120 parts of dehydrated 4,4'-diphenylmethane diisocyanate and mix with it, add dibutyltin dilaurate, continue to heat and stir thoroughly, set the reaction temperature to 85°C, set the stirrer speed to 250rpm, and the reaction time to 2 hours. During the reaction, add 5 parts of trimethyl borate and 1 part of polyether-modified polydimethylsiloxane until the reaction is complete, and obtain a fluorine-containing 4,4'-diphenylmethane diisocyanate prepolymer. Its FTIR infrared spectrum is shown in the figure below. Figure 2 shown.

[0052] Step 4: Grind polytetrafluoroethylene and add EPDM rubber, and blend with amino-terminated polyether as component B: Grind 15 parts of polytetrafluoroethylene (PTFE) into fine particles of approximately 140 mesh using a grinding and dispersion device. Heat 10 parts of EPDM rubber at 280°C until softened, then slowly pour it into a blender along with the PTFE and stir at 200 rpm for 30 minutes, maintaining heating. This mixture is then added to the grinding and dispersion device along with 120 parts of polyoxypropylene diamine. Add 1 part of polyether-modified polydimethylsiloxane (a defoamer) and grind again to fully disperse the PTFE in the polyoxypropylene diamine. The resulting blended modified product is then cooled naturally and sealed, ready for use as component B.

[0053] Step 5: Prepare the energy-absorbing seal for asphalt pavement maintenance: Level, dry and clean the original road surface, prepare the instruments and equipment required for construction, and mix the gravel materials in advance. Pour the prepared components A and B into the storage tank of the spraying equipment at a volume ratio of 55:48 and seal them. Set the spraying amount and rate, and start the spraying equipment. Use the nozzle to fully mix components A and B in the air, react quickly to form a composite material, and then spray it. After uniform spraying, the first layer of polymer coating is formed. The spraying amount of the polymer binder in this layer is 2 kg / m 2 Immediately after spraying, evenly mixed aggregates were spread to form a single layer of crushed stone. The crushed stone was 1000 parts. After spreading, the crushed stone was leveled to prevent stacking. The spraying equipment was started again to spray the crushed stone layer to form a second layer of polymer coating. The amount of polymer binder sprayed on this layer was 1 kg / m 2 After curing and solidification, a "sandwich-type" preventive maintenance energy-absorbing seal layer is finally formed.

[0054] To verify the hydrophobicity, mechanical properties, and road performance of the polymer binder of this embodiment, a two-component polymer binder specimen was prepared to test its hydrophobicity, tear resistance, and impact resistance; an asphalt pavement maintenance energy-absorbing seal specimen was prepared to test its wear resistance, water damage resistance, and interlayer adhesion. The specific methods are as follows: (1) Referring to “Measurement of contact angle of plastic film with water” (GB / T 30693-2014), the contact angle and rolling angle were used to evaluate the hydrophobicity of the material.

[0055] (2) Refer to “Vulcanized rubber or thermoplastic rubber — Determination of tear strength” (GB / T 529-2008) and use tear strength to evaluate the tearing properties of the material.

[0056] (3) With reference to "Plastics. Determination of pendulum impact properties. Part 1: Non-mechanical impact tests" (ISO 179-1-2010), the impact strength is used to evaluate the impact resistance of the material.

[0057] (4) With reference to the Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering (JTGE20-2011), the 1-hour wet wheel abrasion value was used to evaluate the wear resistance of the material, and the 6-day wet wheel abrasion value was used to evaluate the water damage resistance of the material.

[0058] (5) With reference to the Technical Specifications for Design and Construction of Highway Steel Bridge Deck Pavement (JTG / T 3364-02-2019), the adhesion pull-out strength was used to evaluate the interlayer bonding performance of the sealing material.

[0059] The performance test results of this embodiment are shown in Table 1.

[0060] Example 2 A long-lasting hydrophobic asphalt pavement maintenance energy-absorbing seal material, comprising a polymer coating and crushed stone, wherein the polymer coating has a polymer content of 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , or 4 kg / m for 2.36-4.75 mm 2 .

[0061] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: The asphalt pavement maintenance energy-absorbing seal material is made of the following raw materials, calculated by weight: 20 parts of perfluoropolyether, 15 parts of polytetrafluoroethylene, 10 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0062] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0063] Example 3 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0064] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: The invention is made of the following raw materials in parts by weight: 15 parts of perfluoropolyether, 15 parts of polytetrafluoroethylene, 10 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black and 120 parts of polyoxypropylene diamine.

[0065] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0066] Example 4 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0067] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: The invention is made of the following raw materials in parts by weight: 20 parts of perfluoropolyether, 15 parts of polytetrafluoroethylene, 10 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black and 120 parts of polyoxypropylene diamine.

[0068] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0069] Example 5 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0070] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: It is made of the following raw materials in parts by weight: It is made of the following raw materials in parts by weight: 20 parts of perfluoropolyether, 10 parts of polytetrafluoroethylene, 10 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0071] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0072] Example 6 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0073] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: It is made of the following raw materials in parts by weight: It is made of the following raw materials in parts by weight: 20 parts of perfluoropolyether, 5 parts of polytetrafluoroethylene, 10 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0074] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0075] Example 7 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0076] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: The invention is made of the following raw materials in parts by weight: in parts by weight, 20 parts of fluoropolyether, 10 parts of polytetrafluoroethylene, 10 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black and 120 parts of polyoxypropylene diamine.

[0077] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0078] Example 8 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0079] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: The invention is made of the following raw materials in parts by weight: in parts by weight, 20 parts of perfluoropolyether, 10 parts of polytetrafluoroethylene, 8 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0080] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0081] Example 9 A long-lasting hydrophobic energy-absorbing sealant for asphalt pavement maintenance, comprising a polymer coating and crushed stone. The polymer coating is 3.0 kg / m² in terms of spreading amount per square meter. 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0082] The preparation method of this embodiment is the same as that of embodiment 1, except that the ratio of the polymer coating is different, as follows: The invention is made of the following raw materials in parts by weight: in parts by weight, 20 parts of perfluoropolyether, 10 parts of polytetrafluoroethylene, 5 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0083] The test method of this embodiment is the same as that of embodiment 1, and the performance test results are shown in Table 1.

[0084] Comparative Example 1: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0085] In parts by weight, the polymer coating comprises 10 parts of polytetrafluoroethylene, 8 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0086] The difference between Comparative Example 1 and Example 8 is that no perfluoropolyether is added in the comparative example, and no fluorination reaction occurs in the subsequent process. The rest of the preparation method is the same.

[0087] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0088] Comparative Example 2: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0089] In parts by weight, the polymer coating includes 20 parts of perfluoropolyether, 8 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0090] The difference between Comparative Example 2 and Example 8 is that polytetrafluoroethylene is not added in the comparative example, and the rest of the preparation methods are the same.

[0091] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0092] Comparative Example 3: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0093] In parts by weight, the polymer coating comprises 25 parts of perfluoropolyether, 10 parts of polytetrafluoroethylene, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0094] The difference between Comparative Example 3 and Example 8 is that no EPDM rubber is added in the comparative example, and the rest of the preparation methods are the same.

[0095] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0096] Comparative Example 4: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0097] The difference between Comparative Example 4 and Comparative Example 8 is that perfluoropolyether is replaced by polyvinylidene fluoride.

[0098] In parts by weight, the polymer coating includes 25 parts of polyvinylidene fluoride, 10 parts of polytetrafluoroethylene, 8 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0099] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0100] Comparative Example 5: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0101] The difference between Comparative Example 5 and Example 5 is that no perfluoropolyether, polytetrafluoroethylene and EPDM rubber are added.

[0102] The polymer coating comprises, by weight, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylenebisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0103] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0104] Comparative Example 6: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0105] Comparative Example 6 differs from Example 8 in that the order of fluorination modification and blending modification is reversed, with polytetrafluoroethylene and EPDM rubber added first and perfluoropolyether added later to attempt fluorination. That is, the order of Steps 3 and 4 is reversed.

[0106] In parts by weight, the polymer coating includes 20 parts of perfluoropolyether, 10 parts of polytetrafluoroethylene, 8 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0107] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0108] Comparative Example 7: This comparative example provides an energy-absorbing sealant for asphalt pavement maintenance, including a polymer binder and crushed stone. The polymer coating is 3.0 kg / m 2 The amount of stone to be spread is divided by particle size, 1.18-2.36 mm is 2 kg / m 2 , 2.36-4.75 mm is 4 kg / m 2 .

[0109] In parts by weight, the polymer coating comprises 20 parts of perfluoropolyether, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylenebisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylenediamine.

[0110] The difference between Comparative Example 7 and Example 8 is that polytetrafluoroethylene and EPDM rubber are not added in the comparative example, and the rest of the preparation methods are the same.

[0111] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0112] Comparative Example 8: This comparative example provides an energy-absorbing sealant material for asphalt pavement maintenance, including a polymer binder and crushed stone. Calculated by spreading amount per square meter, the polymer coating is 3.0 kg / m2, and the stone spreading amount is divided by particle size: 1.18-2.36 mm is 2 kg / m2, and 2.36-4.75 mm is 4 kg / m2.

[0113] In parts by weight, the polymer coating comprises 8 parts of ethylene propylene diene monomer rubber, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0114] The difference between Comparative Example 8 and Example 8 is that no perfluoropolyether and polytetrafluoroethylene are added in the comparative example, and no fluorination reaction occurs in the subsequent process. The rest of the preparation method is the same.

[0115] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0116] Comparative Example 9: This comparative example provides an energy-absorbing sealant material for asphalt pavement maintenance, including a polymer binder and crushed stone. Calculated by spreading amount per square meter, the polymer coating is 3.0 kg / m2, and the stone spreading amount is divided by particle size: 1.18-2.36 mm is 2 kg / m2, and 2.36-4.75 mm is 4 kg / m2.

[0117] In parts by weight, the polymer coating comprises 10 parts of polytetrafluoroethylene, 120 parts of 4,4'-diphenylmethane diisocyanate, 5 parts of trimethyl borate, 1 part of polyether-modified polydimethylsiloxane, 1 part of ethylene bisstearamide, 1 part of carbon black, and 120 parts of polyoxypropylene diamine.

[0118] The difference between Comparative Example 9 and Example 8 is that no perfluoropolyether and EPDM rubber are added in the comparative example, and no fluorination reaction occurs in the subsequent process. The rest of the preparation method is the same.

[0119] The test method of this comparative example is the same as that of Example 1. The performance test results of the prepared energy-absorbing sealing layer material are shown in Table 1.

[0120] Table 1 Performance of polymer binder and energy-absorbing sealant for asphalt pavement maintenance

[0121] From Table 1 we can see that: Analysis of various indicators in Examples 1-9 and Comparative Examples 1-3 reveals that the three types of modified materials synergistically enhance the hydrophobicity and mechanical properties of the base material through chemical and physical modification. Compared to the unmodified material, the addition of perfluoropolyether significantly improves the base material's hydrophobicity; the addition of polytetrafluoroethylene and EPDM significantly enhances the base material's tear resistance and impact resistance, and also improves its hydrophobicity to a certain extent. The resulting long-lasting, hydrophobic, energy-absorbing seal for asphalt pavement maintenance exhibits excellent wear resistance, water damage resistance, and interlayer adhesion.

[0122] By analyzing various indicators of Examples 1 to 9 and Comparative Example 4, it can be found that the hydrophobic effect of the energy-absorbing seal made of perfluoropolyether is better than that of other commonly used hydrophobic modifiers.

[0123] By analyzing various indicators of Examples 1 to 9 and Comparative Example 5, it can be found that the polymer generated by the reaction using the dihydroxy-terminated perfluoropolyether has more excellent hydrophobic properties.

[0124] By analyzing various indicators of Examples 1 to 9 and Comparative Example 6, it can be found that exchanging the order of physical blending and chemical modification will lead to a certain degree of reduction in various material properties.

[0125] By analyzing the various indicators of Examples 1 to 9 and Comparative Examples 7 to 9, it can be found that the addition of polytetrafluoroethylene and EPDM rubber can significantly improve the hydrophobicity and mechanical properties of the materials, among which polytetrafluoroethylene has a more significant improvement on the hydrophobicity, and EPDM rubber has a more significant improvement on the mechanical properties.

[0126] Analysis of the various indicators of Examples 1 to 9 reveals that Example 8 exhibits the best overall performance in terms of trade-off between performance and cost. Adding more modifiers to this material does not result in a corresponding increase in hydrophobicity. The raw material composition is as follows: 20 parts perfluoropolyether, 10 parts polytetrafluoroethylene, 8 parts ethylene propylene diene monomer (EPDM), 120 parts 4,4'-diphenylmethane diisocyanate, 5 parts trimethyl borate, 1 part polyether-modified polydimethylsiloxane, 1 part ethylene bisstearamide, 1 part carbon black, 120 parts polyoxypropylene diamine, and 1000 parts aggregate.

[0127] The energy-absorbing sealing material of this application has the following advantages: 1. The polymer coating of the present application is used to enhance the bonding force of aggregates, enhance the hydrophobicity of the pavement, and enhance the wear resistance and durability. Specifically, perfluoropolyether is used to chemically modify isocyanate, and polytetrafluoroethylene is used to physically blend and modify the polyurethane prepolymer; the perfluoropolyether has double-terminal hydroxyl groups and can effectively react with isocyanate. The modified asphalt pavement maintenance energy-absorbing seal prepared has excellent hydrophobicity and wear resistance. The polymer coating is formed by the reaction of components A and B, with a fast reaction speed and good reaction effect. The resulting reaction product has strong hydrophobicity and high wear resistance.

[0128] 2. Use perfluoropolyether, polytetrafluoroethylene and EPDM rubber to treat the base material. Perfluoropolyether has extremely high polarity and can provide strong hydrophobicity. Polytetrafluoroethylene and EPDM rubber have good hydrophobicity and wear resistance, which can produce toughening and strengthening effects on the material.

[0129] 3. The structure of the energy-absorbing sealing material of the present application is a "sandwich-type" sealing structure, which can effectively improve the coating of the bonding layer on the aggregate, reduce the peeling of the aggregate, ensure that the structure can bear higher traffic loads, and effectively improve the durability of the material.

[0130] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant material, characterized in that: The following steps are involved: After dissolving perfluoropolyether in an organic solvent, 4,4'-diphenylmethane diisocyanate is added to react, and a reaction aid is added during the reaction. After the reaction is completed, a 4,4'-diphenylmethane diisocyanate prepolymer is obtained as component A; Calculated by weight, the perfluoropolyether is 15-25 parts and the 4,4'-diphenylmethane diisocyanate is 80-120 parts; blending a mixture of polytetrafluoroethylene particles and softened rubber with amino-terminated polyether to obtain component B; By weight, 5-25 parts of polytetrafluoroethylene and 8 parts of rubber; Component A and component B are mixed in air to form a composite material which is sprayed on the road to form a first polymer coating layer, a crushed stone aggregate layer is formed on the first polymer coating layer, and finally a first polymer coating layer is formed on the aggregate layer to obtain an energy absorbing seal material.

2. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 1, characterized in that: The reaction aids include a cross-linking agent, a defoaming agent, a leveling agent and a lubricant.

3. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 2, characterized in that: The cross-linking agent is trimethyl borate, with a mass fraction of 8 parts; The defoaming agent is polyether-modified polydimethylsiloxane, and the leveling agent is polyether-modified polydimethylsiloxane. The total mass fraction of the defoaming agent and the leveling agent is 1 part; The lubricant is ethylene bisstearamide, and its mass fraction is 1 part.

4. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 1, characterized in that: The preparation method of component A is as follows: After preheating the organic solvent to 60°C, the dried perfluoropolyether was added and thoroughly stirred to dissolve. Then, dehydrated 4,4'-diphenylmethane diisocyanate was added and mixed with the mixture and a catalyst was added to carry out a fluorination reaction. The reaction temperature was set to 85°C and the reaction time was 2 h. During the reaction, a reaction aid was added until the reaction was fully completed to obtain a fluorinated 4,4'-diphenylmethane diisocyanate prepolymer.

5. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 1, characterized in that: The rubber is ethylene-propylene-dicyclopentadiene ethylene propylene diene monomer (EPDM) rubber.

6. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 1, characterized in that: The amino-terminated polyether is polyoxypropylene diamine.

7. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 1, characterized in that: The preparation method of component B is as follows: The softened rubber and polytetrafluoroethylene particles are stirred evenly, and then polyoxypropylene diamine and a defoaming agent are added and blended, and the blended product is cooled to room temperature to obtain a component.

8. The method for preparing a long-lasting hydrophobic asphalt pavement maintenance energy-absorbing sealant according to claim 1, characterized in that: The volume ratio of component A to component B is 55:

48.

9. An energy-absorbing sealing material prepared by the preparation method according to any one of claims 1 to 8, characterized in that: It includes a first polymer spray coating layer, a crushed stone layer, and a second polymer spray coating layer from bottom to top.

10. A highway, characterized in that: The road surface of the highway is made of the energy-absorbing sealing material according to claim 9.

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