Polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt, and preparation method and application thereof

Abstract

This invention discloses a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt, its preparation method, and its application, belonging to the field of road material technology. By weight, it comprises 100 parts emulsified asphalt, 5-15 parts waterborne epoxy resin emulsion, 3-9 parts polyether-type polyurethane prepolymer, 0.5-2 parts nanocellulose dispersion, and a curing agent. The curing agent is added at 10%-60% of the waterborne epoxy resin emulsion. The waterborne epoxy resin emulsion is composed of a mixture of waterborne epoxy resin and an epoxy resin diluent. The polyether-type polyurethane prepolymer is synthesized from diisocyanate, polyether polyol, and a catalyst. This modified emulsified asphalt addresses the technical problems of low adhesion, easy cracking at low temperatures, and poor water resistance in ordinary emulsified asphalt, as well as the high brittleness and insufficient low-temperature performance of waterborne epoxy resin emulsified asphalt.

Description

Technical Field

[0001] This invention belongs to the field of road material technology, specifically relating to a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt, its preparation method, and its application. Background Technology

[0002] Emulsified asphalt has advantages such as convenient construction, energy saving and environmental protection, and the ability to be mixed at room temperature, and has been widely used in preventive maintenance and repair projects for roads. However, the low adhesion, easy cracking at low temperatures, and poor water resistance of ordinary emulsified asphalt can no longer meet the performance requirements brought about by traffic volume and environmental impact. In order to improve the performance of emulsified asphalt, traditional methods include modification with single water-based epoxy resin, modification with single polyurethane, and epoxy resin-rubber blend modification. However, modified emulsified asphalt still has problems such as high brittleness after curing, insufficient low-temperature performance, and delayed opening to traffic. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt, its preparation method and application, to solve the technical problems of low adhesion, easy cracking at low temperature and poor water resistance of ordinary emulsified asphalt, and high brittleness and insufficient low temperature performance of modified emulsified asphalt.

[0004] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen, comprising, by weight, 100 parts emulsified bitumen, 5-15 parts aqueous epoxy resin emulsion, 3-9 parts polyether-type polyurethane prepolymer, 0.5-2 parts nanocellulose dispersion, and a curing agent, wherein the amount of curing agent is 10%-60% of the aqueous epoxy resin emulsion; The aqueous epoxy resin emulsion is composed of 100 parts of aqueous epoxy resin and 30-50 parts of epoxy resin diluent. The polyether-type polyurethane prepolymer is synthesized from diisocyanate, polyether polyol, and catalyst, with an isocyanate index of 1.8-2.2; the mass of the catalyst is 0.1%-0.5% of the mass of the polyether polyol. The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen includes polyurethane flexible segments, epoxy resin rigid segments, and nanocellulose. The polyurethane flexible segments and epoxy resin rigid segments form an interpenetrating network structure. The polyurethane flexible segments and epoxy resin rigid segments interpenetrate and are randomly entangled. The nanocellulose is uniformly dispersed at the network nodes without obvious agglomeration, forming a dense and continuous phase interface structure.

[0005] In one embodiment, the emulsified asphalt has a solid content of 30%-70% and a pH value of 2-5; the nanocellulose in the nanocellulose dispersion has a diameter of 50nm-60nm, an aspect ratio of 120-180, and a concentration of 5%; the curing agent is polyamide 651 curing agent or T31 curing agent.

[0006] In one embodiment, the waterborne epoxy resin is any one or a mixture of two or more of bisphenol glycidyl ether epoxy resin, aliphatic glycidyl ether, glycidyl ester type epoxy resin, and glycidyl amine type epoxy resin; wherein, the bisphenol glycidyl ether epoxy resin is bisphenol A type epoxy resin, bisphenol F type epoxy resin, or bisphenol AD ​​type epoxy resin.

[0007] In one embodiment, the epoxy resin diluent is 1,6 One or more of hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, and C12-C14 alkyl glycidyl ether.

[0008] In one embodiment, the diisocyanate is one or a mixture of two or more of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate; The polyether polyol is one or a mixture of two or more of long-chain polyhydroxy polyether, polypropylene glycol and polytetrahydrofuran polyol, and its number average molecular weight is not higher than 2000. The catalyst is dibutyltin dilaurate.

[0009] This invention also provides a method for preparing polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen, comprising the following steps: Nanocellulose was dispersed in deionized water and then subjected to ultrasonic treatment to obtain a nanocellulose dispersion. Polyether polyol and diisocyanate were mixed, and a catalyst was added for a constant-temperature reaction to obtain a polyether-type polyurethane prepolymer; then, a nanocellulose dispersion was added and the reaction was continued to obtain a polyether-type polyurethane prepolymer containing nanocellulose. A water-based epoxy resin and an epoxy resin diluent are mixed and stirred to obtain a water-based epoxy resin emulsion. Aqueous epoxy resin emulsion and polyether-type polyurethane prepolymer containing nanocellulose were added to emulsified asphalt, and the mixture was sheared, then a curing agent was added and stirred to obtain polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt.

[0010] In one embodiment, the ultrasonic treatment uses a power of 300W-500W for 20min-40min; the concentration of nanocellulose in the nanocellulose dispersion is 0.04g / mL-0.1g / mL.

[0011] In one embodiment, the mass ratio of the polyether polyol to the diisocyanate is 1:(1.8-2.2), the isothermal reaction temperature is 60℃-90℃, and the time is 1.5h-3h; the continued reaction time is 0.5h-1h.

[0012] In one embodiment, the shearing process is performed at a rotation speed of 1500 r / min to 2000 r / min for a shearing time of 3 min to 5 min; the stirring process is performed at a rotation speed of 1500 r / min for a stirring time of 5 min.

[0013] The present invention also provides an application of polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen as a bonding layer in cement or asphalt base layers.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt. Compared with existing ordinary emulsified asphalt and conventional modification technologies, it uses a polyurethane prepolymer and epoxy resin to construct an interpenetrating network structure. Utilizing the reaction characteristics of the urethane groups (-NHCOO) and isocyanate groups (-NCO) in the polyurethane with the hydroxyl groups in the epoxy resin, the two polymers form a synergistic effect, combining the excellent low-temperature resistance and mechanical toughness of polyurethane with the structural stability of epoxy resin. This significantly improves the high-temperature stability and low-temperature flexibility of the modified emulsified asphalt, completely solving the core defects of poor high-temperature stability and low-temperature crack resistance of ordinary emulsified asphalt, and broadening its applicable environmental range. Furthermore, nanocellulose itself possesses high strength, high Young's modulus, and high specific surface area, and is widely available and renewable, making it an excellent reinforcing and modifying material. Appropriate addition of cellulose nanocrystals can improve the mechanical properties of the modified emulsified asphalt. This invention introduces nanocellulose into a polyurethane prepolymer system through in-situ dispersion technology, effectively avoiding the technical problems of easy agglomeration and sedimentation of nanocellulose in asphalt matrix, and achieving uniform dispersion of it in the system. This allows the advantages of its high specific surface area and high strength to be fully utilized, which can not only significantly improve the overall mechanical properties of modified emulsified asphalt, but also further increase the crosslinking density of the system, enhance the strength, water resistance and toughness of the material, and maximize the modification effect.

[0015] The modified emulsified asphalt provided by this invention exhibits excellent storage stability under sealed conditions at 15-60℃, fully meeting national standards. It does not experience demulsification or clumping during storage, facilitating long-term storage and transportation. Furthermore, its preparation process is simple and convenient, allowing for mixing and construction at room temperature without the need for high-temperature heating, thus reducing construction energy consumption and operational difficulty. In addition, this modified emulsified asphalt demonstrates excellent adhesion to aggregates, concrete pavements, and asphalt pavements, exhibiting strong compatibility and wide applicability. It can be widely used in road maintenance and preventative maintenance projects, possessing significant practical application value and promising prospects for wider application. Attached Figure Description

[0016] Figure 1 SEM image of polyether polyurethane-epoxy interpenetrating network modified emulsified bitumen provided by the present invention. Figure 2 The microphase structure diagrams of the polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen provided by the present invention at different temperatures are shown from left to right as 30℃, 120℃ and 150℃. Figure 3 This is a schematic diagram of the polyether-type polyurethane-epoxy interpenetrating network structure in the polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt provided by the present invention. Detailed Implementation

[0017] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0018] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0019] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0020] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0021] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0022] Polyurethane contains urethane groups (-NHCOO) or isocyanate groups (-NCO), and polyether-type polyurethane exhibits excellent low-temperature resistance and mechanical toughness. The -NCO groups in polyurethane can react with the hydroxyl groups in epoxy resin to form an interpenetrating network polymer, combining the advantages of both polyurethane and epoxy resin, thus exhibiting excellent mechanical properties. Nanocellulose, as a widely available, high-strength, and renewable nanomaterial, possesses high specific surface area and high strength. Introducing it into the polyurethane-epoxy system can improve properties such as strength, water resistance, and toughness.

[0023] Based on this, the present invention provides a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt, its preparation method and application. It proposes a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt with higher bonding strength, better low-temperature flexibility and water resistance. It can solve the shortcomings of ordinary emulsified asphalt, such as low adhesion, easy cracking at low temperature and poor water resistance, as well as the brittleness and insufficient low-temperature performance of water-based epoxy resin emulsified asphalt. It has important engineering value for improving the performance of road maintenance materials and extending the service life of pavement.

[0024] One aspect provides a polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt, which is composed of emulsified asphalt, aqueous epoxy resin emulsion, polyether-type polyurethane prepolymer, nanocellulose dispersion and curing agent. By weight, it includes 100 parts of emulsified asphalt, 5-15 parts of aqueous epoxy resin emulsion, 3-9 parts of polyether-type polyurethane prepolymer, and 0.5-2 parts of nanocellulose. The curing agent is added at 10%-60% of the aqueous epoxy resin emulsion.

[0025] The waterborne epoxy resin emulsion is composed of 100 parts of waterborne epoxy resin and 30-50 parts of epoxy resin diluent.

[0026] The polyether-type polyurethane prepolymer is synthesized from diisocyanate, polyether polyol and catalyst. The isocyanate index is 1.8-2.2, the mass ratio of polyether polyol to diisocyanate is 1:(1.8-2.2), and the catalyst is 0.1%-0.5% of the mass of polyether polyol.

[0027] The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen includes polyurethane flexible segments, epoxy resin rigid segments, and nanocellulose. The polyurethane flexible segments and epoxy resin rigid segments form an interpenetrating network structure. The polyurethane flexible segments and epoxy resin rigid segments interpenetrate and are randomly entangled. The nanocellulose is uniformly dispersed at the network nodes without obvious agglomeration, forming a dense and continuous phase interface structure.

[0028] Preferably, the emulsified asphalt has a solid content of 30%-70% and a pH value of 2-5. The nanocellulose in the nanocellulose dispersion has a diameter of 50nm-60nm, an aspect ratio of 120-180, and a concentration of 5%; the curing agent is polyamide 651 curing agent or T31 curing agent.

[0029] Preferably, the epoxy resin diluent is 1,6 One or more of hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, and C12-C14 alkyl glycidyl ether.

[0030] Preferably, the waterborne epoxy resin is any one or a mixture of two or more of bisphenol glycidyl ether epoxy resin, aliphatic glycidyl ether, glycidyl ester type epoxy resin and glycidyl amine type epoxy resin; wherein, the bisphenol glycidyl ether epoxy resin is bisphenol A type epoxy resin, bisphenol F type epoxy resin or bisphenol AD ​​type epoxy resin.

[0031] Preferably, the polyether polyol is one or a mixture of two or more of long-chain polyhydroxy polyether, polypropylene glycol and polytetrahydrofuran polyol, with a number average molecular weight of not more than 2000.

[0032] Preferably, the diisocyanate is one or a mixture of two or more of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate.

[0033] Preferably, the catalyst is dibutyltin dilaurate.

[0034] On the other hand, a method for preparing polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen is provided, the preparation method being as follows: (1) Preparation of nanocellulose dispersion: Disperse nanocellulose powder in deionized water, add it to an ultrasonic disperser, and ultrasonically treat it for 20-40 min at a power of 300-500W to obtain a uniformly dispersed nanocellulose dispersion with a concentration of 0.04-0.1 g / mL in the dispersion.

[0035] (2) Preparation of polyether polyurethane prepolymer: Polyether polyol and diisocyanate are mixed at a mass ratio of 1:(1.8-2.2), a catalyst is added, and the mixture is reacted at a constant temperature of 60-90℃ for 1.5-3h; nanocellulose dispersion is added, and the reaction is continued for 0.5-1h to obtain polyether polyurethane prepolymer containing nanocellulose.

[0036] (3) Preparation of waterborne epoxy resin emulsion: Mix waterborne epoxy resin and epoxy resin diluent, stir at room temperature for 10-20 min to obtain waterborne epoxy resin emulsion.

[0037] (4) Preparation of modified emulsified asphalt: Add waterborne epoxy resin emulsion and polyether polyurethane prepolymer containing nanocellulose to the emulsified asphalt, and shear at 1500-2000 r / min for 3-5 min in a high-speed shear machine; add curing agent, and stir at 1500 r / min for 5 min to prepare polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt.

[0038] The present invention also provides the application of the above-mentioned polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt sprayed on cement or asphalt base layers as a bonding layer.

[0039] like Figure 2 As shown, during the temperature range of 30-150℃, the microstructure of the polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt remained a uniform and stable three-dimensional network structure, without significant segregation or swelling. Simultaneously, the interpenetrating network generated through polymerization effectively limited the dissolution and deformation of the emulsified asphalt, improving its thermal stability and rutting resistance.

[0040] like Figure 1 and Figure 3 As shown, in the polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt, the flexible polyurethane segments and the rigid epoxy resin segments interpenetrate to form a three-dimensional interpenetrating network. Nanocellulose is uniformly anchored at the network crosslinking points. The microstructure shows a continuous phase with no obvious phase separation or nanoparticle aggregation, and the phase interface is tightly bonded.

[0041] In summary, this invention improves the compatibility between the polymer and the asphalt phase by constructing a stable interpenetrating network structure, significantly enhancing the high-temperature stability, low-temperature crack resistance, adhesion, and water stability of the modified emulsified asphalt, while ensuring good storage stability. The product of this invention exhibits good adhesion to aggregates, concrete pavements, and asphalt pavements, and can be widely used in pavement maintenance or preventative maintenance.

[0042] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0043] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0044] Example 1 A method for preparing polyether polyurethane-epoxy interpenetrating network modified emulsified bitumen, the specific steps of which are as follows: (1) Preparation of nanocellulose dispersion: 5g of nanocellulose (50nm in diameter and 150 in aspect ratio) powder was dispersed in 100ml of deionized water, added to an ultrasonic disperser, and ultrasonically treated for 30min at 500W to obtain a uniformly dispersed nanocellulose dispersion.

[0045] (2) Preparation of polyether-type polyurethane prepolymer: 100g of polyether diol (molecular weight 2000) was mixed with 180g of toluene diisocyanate, and 0.3g of dibutyltin dilaurate was added. The mixture was reacted at 70℃ for 2h. 0.5% nanocellulose dispersion of emulsified asphalt was added and the reaction was continued for 1h to obtain polyether-type polyurethane prepolymer containing nanocellulose.

[0046] (3) Preparation of waterborne epoxy resin emulsion: Mix 100g of bisphenol A type epoxy resin and 40g of glycidyl ether reactive diluent, stir at room temperature for 20min to obtain waterborne epoxy resin emulsion.

[0047] (4) Preparation of modified emulsified asphalt: Add 8g of waterborne epoxy resin emulsion and 4g of polyether polyurethane prepolymer containing nanocellulose to 100g of emulsified asphalt, and shear at 2000r / min for 3min in a high-speed shearing machine; add 3g of curing agent, and stir at 1500r / min for 5min to prepare polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt.

[0048] Example 2 A method for preparing polyether polyurethane-epoxy interpenetrating network modified emulsified bitumen, the specific steps of which are as follows: (1) Preparation of nanocellulose dispersion: 5g of nanocellulose (50nm in diameter and 150 in aspect ratio) powder was dispersed in 100ml of deionized water, added to an ultrasonic disperser, and ultrasonically treated for 30min at 500W to obtain a uniformly dispersed nanocellulose dispersion.

[0049] (2) Preparation of polyether-type polyurethane prepolymer: 100g of polyether diol (molecular weight 2000) was mixed with 180g of toluene diisocyanate, and 0.3g of dibutyltin dilaurate was added. The mixture was reacted at 70℃ for 2h. 1.0% nanocellulose dispersion of emulsified asphalt was added and the mixture was reacted for another 1h to obtain polyether-type polyurethane prepolymer containing nanocellulose.

[0050] (3) Preparation of waterborne epoxy resin emulsion: Mix 100g of bisphenol A type epoxy resin and 40g of glycidyl ether reactive diluent, stir at room temperature for 20min to obtain waterborne epoxy resin emulsion.

[0051] (4) Preparation of modified emulsified asphalt: Add 10g of waterborne epoxy resin emulsion and 6g of polyether polyurethane prepolymer containing nanocellulose to 100g of emulsified asphalt, and shear at 2000r / min for 3min in a high-speed shearing machine; add 4g of curing agent, and stir at 1500r / min for 5min to prepare polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt.

[0052] Example 3 A method for preparing polyether polyurethane-epoxy interpenetrating network modified emulsified bitumen, the specific steps of which are as follows: (1) Preparation of nanocellulose dispersion: 5g of nanocellulose (50nm in diameter and 150 in aspect ratio) powder was dispersed in 100ml of deionized water, added to an ultrasonic disperser, and ultrasonically treated for 30min at 500W to obtain a uniformly dispersed nanocellulose dispersion.

[0053] (2) Preparation of polyether-type polyurethane prepolymer: 100g of polyether triol (molecular weight 2000) and 180g of toluene diisocyanate were mixed, and 0.3g of dibutyltin dilaurate was added. The mixture was reacted at 70℃ for 2h. 10.5% nanocellulose dispersion of emulsified asphalt was added and the mixture was reacted for another 1h to obtain polyether-type polyurethane prepolymer containing nanocellulose.

[0054] (3) Preparation of waterborne epoxy resin emulsion: Mix 100g of bisphenol A type epoxy resin and 40g of glycidyl ether reactive diluent, stir at room temperature for 20min to obtain waterborne epoxy resin emulsion.

[0055] (4) Preparation of modified emulsified asphalt: Add 15g of waterborne epoxy resin emulsion and 8g of polyether polyurethane prepolymer containing nanocellulose to 100g of emulsified asphalt, and shear at 2000r / min for 3min in a high-speed shearing machine; add 6g of curing agent, and stir at 1500r / min for 5min to prepare polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt.

[0056] Comparative Example 1 PC Type 3 slow-cracking, fast-setting cationic emulsified asphalt is a commonly used model in road engineering. Its specific parameters meet the requirements of the national standard "Technical Specification for Construction of Highway Asphalt Pavement" (JTG F40-2004), as follows: The selected material is a slow-cracking, fast-setting cationic emulsified asphalt, model PC-3, with the following technical specifications: evaporation residue content ≥50%, sieve residue (1.18mm) ≤0.1%, slow demulsification rate, storage stability (5d) ≤5%, (1d) ≤1%, penetration (25℃, 100g, 5s) 80-100 (0.1mm), softening point ≥45℃, and ductility (5℃) ≥20cm; no modifiers are added, and it is only a conventional ordinary emulsified asphalt.

[0057] Comparative Example 2 A method for preparing waterborne epoxy-modified emulsified asphalt, comprising the following specific steps: (1) Preparation of waterborne epoxy resin emulsion: Mix 100g of bisphenol A type epoxy resin and 40g of glycidyl ether reactive diluent, stir at room temperature for 20min to obtain waterborne epoxy resin emulsion.

[0058] (2) Preparation of modified emulsified asphalt: Add 10g of waterborne epoxy resin emulsion to 100g of emulsified asphalt, and shear at 2000r / min for 3min in a high-speed shearing machine; add 4g of curing agent, and stir at 1500r / min for 5min to prepare waterborne epoxy modified emulsified asphalt.

[0059] Comparative Example 3 A method for preparing waterborne polyurethane-modified emulsified asphalt, comprising the following specific steps: (1) Preparation of polyether-type polyurethane prepolymer: 100g of polyether diol (molecular weight 2000) was mixed with 180g of toluene diisocyanate, and 0.3g of dibutyltin dilaurate was added. The mixture was reacted at 70℃ for 2h to obtain polyether-type polyurethane prepolymer.

[0060] (2) Preparation of modified emulsified asphalt: Add 6g of polyether-type polyurethane prepolymer to 100g of emulsified asphalt, and shear at 2000r / min for 3min in a high-speed shear machine; add 3g of curing agent, and stir at 1500r / min for 5min to prepare polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt.

[0061] Comparative Example 4 A polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt without nanocellulose is prepared by the following steps: (1) Preparation of polyether-type polyurethane prepolymer: 100g of polyether diol (molecular weight 2000) was mixed with 180g of toluene diisocyanate, and 0.3g of dibutyltin dilaurate was added. The mixture was reacted at 70℃ for 2h to obtain polyether-type polyurethane prepolymer.

[0062] (2) Preparation of waterborne epoxy resin emulsion: Mix 100g of bisphenol A type epoxy resin and 40g of glycidyl ether reactive diluent, stir at room temperature for 20min to obtain waterborne epoxy resin emulsion.

[0063] (3) Preparation of modified emulsified asphalt: Add 10g of waterborne epoxy resin emulsion and 6g of polyether polyurethane prepolymer to 100g of emulsified asphalt, and shear at 2000r / min for 3min in a high-speed shearing machine; add 4g of curing agent, and stir at 1500r / min for 5min to prepare polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt without nanocellulose.

[0064] Comparative Example 5 A polyurethane-epoxy modified emulsified asphalt without an interpenetrating network structure is prepared by the following steps: (1) Preparation of polyether polyurethane: 100g of polyether diol (molecular weight 2000) was mixed with 180g of toluene diisocyanate, and 0.3g of dibutyltin dilaurate was added. The mixture was reacted at 70℃ for 2h to obtain polyether polyurethane prepolymer. The polyether polyurethane prepolymer was poured into a beaker, cooled to room temperature, and curing agent E300 (dimethylthiotoluene diamine) was added. After stirring evenly, the mixture was cured at room temperature for 24h to prepare polyether polyurethane.

[0065] (2) Preparation of waterborne epoxy resin: Mix 100g of bisphenol A type epoxy resin and 40g of glycidyl ether reactive diluent, stir at room temperature for 20min to obtain waterborne epoxy resin emulsion, then add 4g of curing agent, stir evenly and cure at room temperature for 24h to prepare epoxy resin.

[0066] (3) Preparation of modified emulsified asphalt: Add 10g of waterborne epoxy resin and 6g of polyether polyurethane to 100g of emulsified asphalt, and shear at 2000r / min for 8min in a high-speed shearing machine to prepare polyether polyurethane-epoxy modified emulsified asphalt without interpenetrating network structure.

[0067] The modified emulsified asphalt prepared in this comparative example does not possess a polyether-type polyurethane-epoxy interpenetrating network, and its performance is lower than that of the modified emulsified asphalt prepared in the examples. This is because waterborne epoxy resin molecules have strong rigidity and high polarity, with epoxy groups and hydroxyl groups as the main active groups; while single polyurethane (waterborne) molecules have strong flexibility and relatively low polarity, with urethane bonds and isocyanate groups (or hydroxyl groups) as the core groups. The two have a large difference in polarity, and direct mixing easily leads to "layering, flocculation, and precipitation," making it impossible to form a uniform and stable mixture. Even if it is stirred evenly for a short period of time, it will quickly separate after standing, making it unusable for subsequent construction or curing.

[0068] The performance of the emulsified asphalt prepared in Examples 1-3 and Comparative Examples 1-5 was tested, and the test results are shown in Table 1. Test method: Conventional performance test: Evaporation residue was prepared, and the three major indicators of evaporation residue of different modified emulsified asphalts were tested in accordance with the test specifications of "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGE20-2011).

[0069] Adhesion strength: at 100 mm 100 mm On a 30 mm cement test block, apply 0.8 g / cm³. 2 The modified emulsified asphalt was evenly coated with a certain amount of spray and then cured at 25°C before the bonding strength was tested.

[0070] Tensile test: The tensile test shall be conducted in accordance with the "Test Methods for Properties of Resin Castings" (GB / T 2567-2021).

[0071] Storage stability test: The storage stability test shall be conducted in accordance with T 0655-1993 "Storage Stability Test of Emulsified Asphalt".

[0072] Rutting factor: The test was conducted in accordance with AASHTO-T315 "Test method for determining the rheological properties of asphalt binder using a dynamic shear rheometer".

[0073] Table 1 Emulsified asphalt technical parameters in the examples

[0074] Table 2 Comparative technical parameters of emulsified asphalt

[0075] As shown in Tables 1 and 2 above, the polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt prepared in this invention exhibits significantly improved performance compared to ordinary emulsified asphalt. This results in a 27-37% reduction in penetration and a 29-49% reduction in elongation at break, while increasing ductility, softening point, tensile strength, storage stability, bond strength, and rutting factor by 1-7%, 12-18%, 111-146%, 33-83%, 103-253%, and 29-90%, respectively. The overall performance of the polyether polyurethane-epoxy interpenetrating network modified emulsified asphalt is superior to that of existing ordinary emulsified asphalt and single-polymer modified emulsified asphalt. The core reason for this performance improvement lies in the "forced mutual solubility" and "synergistic effect" generated by the interpenetrating network structure formed by polyurethane and epoxy resin. Simultaneously, the uniform dispersion of nanocellulose within the system constructs a multi-level reinforcing structure, further enhancing the system's compatibility, mechanical properties, and dispersion stability, effectively addressing the shortcomings of existing technologies.

[0076] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen, characterized in that, By weight, it comprises 100 parts emulsified asphalt, 5-15 parts waterborne epoxy resin emulsion, 3-9 parts polyether-type polyurethane prepolymer, 0.5-2 parts nanocellulose dispersion, and curing agent, wherein the amount of curing agent is 10%-60% of the waterborne epoxy resin emulsion; The aqueous epoxy resin emulsion is composed of 100 parts of aqueous epoxy resin and 30-50 parts of epoxy resin diluent. The polyether-type polyurethane prepolymer is synthesized from diisocyanate, polyether polyol, and catalyst, with an isocyanate index of 1.8-2.2; the mass of the catalyst is 0.1%-0.5% of the mass of the polyether polyol. The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen includes polyurethane flexible segments, epoxy resin rigid segments, and nanocellulose. The polyurethane flexible segments and epoxy resin rigid segments form an interpenetrating network structure. The polyurethane flexible segments and epoxy resin rigid segments interpenetrate and are randomly entangled. The nanocellulose is uniformly dispersed at the network nodes without obvious agglomeration, forming a dense and continuous phase interface structure.

2. The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 1, characterized in that, The emulsified asphalt has a solid content of 30%-70% and a pH value of 2-5; the nanocellulose in the nanocellulose dispersion has a diameter of 50nm-60nm and an aspect ratio of 120-180; the curing agent is polyamide 651 curing agent or T31 curing agent.

3. The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 1, characterized in that, The waterborne epoxy resin is any one or a mixture of two or more of the following: bisphenol glycidyl ether epoxy resin, aliphatic glycidyl ether, glycidyl ester type epoxy resin, and glycidyl amine type epoxy resin; wherein the bisphenol glycidyl ether epoxy resin is bisphenol A type epoxy resin, bisphenol F type epoxy resin, or bisphenol AD ​​type epoxy resin.

4. The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 1, characterized in that, The epoxy resin diluent is 1,6 One or more of hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, and C12-C14 alkyl glycidyl ether.

5. The polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 1, characterized in that, The diisocyanate is one or a mixture of two or more of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate; The polyether polyol is one or a mixture of two or more of long-chain polyhydroxy polyether, polypropylene glycol and polytetrahydrofuran polyol, with a number average molecular weight of not more than 2000. The catalyst is dibutyltin dilaurate.

6. A method for preparing a polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to any one of claims 1 to 5, characterized in that, Includes the following steps: Nanocellulose was dispersed in deionized water and then subjected to ultrasonic treatment to obtain a nanocellulose dispersion. Polyether polyol and diisocyanate were mixed, and a catalyst was added for a constant-temperature reaction to obtain a polyether-type polyurethane prepolymer; then, a nanocellulose dispersion was added and the reaction was continued to obtain a polyether-type polyurethane prepolymer containing nanocellulose. A water-based epoxy resin and an epoxy resin diluent are mixed and stirred to obtain a water-based epoxy resin emulsion. Aqueous epoxy resin emulsion and polyether-type polyurethane prepolymer containing nanocellulose were added to emulsified asphalt, and the mixture was sheared, then a curing agent was added and stirred to obtain polyether-type polyurethane-epoxy interpenetrating network modified emulsified asphalt.

7. The method for preparing a polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 6, characterized in that, The ultrasonic treatment uses a power of 300W-500W for 20min-40min; the concentration of nanocellulose in the nanocellulose dispersion is 0.04g / mL-0.1g / mL.

8. The method for preparing a polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 6, characterized in that, The mass ratio of the polyether polyol to the diisocyanate is 1:(1.8-2.2), the isothermal reaction temperature is 60℃-90℃, and the time is 1.5h-3h; the continued reaction time is 0.5h-1h.

9. A method for preparing a polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen according to claim 6, characterized in that, The shearing process is carried out at a rotation speed of 1500 r / min-2000 r / min for a shearing time of 3 min-5 min; the stirring process is carried out at a rotation speed of 1500 r / min for a stirring time of 5 min.

10. The application of a polyether-type polyurethane-epoxy interpenetrating network modified emulsified bitumen as a bonding layer in cement or asphalt base courses, as described in any one of claims 1 to 5.

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