Quick-curing polyurethane seamless expansion joint material for roads and preparation method thereof

Abstract

The invention discloses a quick-curing polyurethane seamless expansion joint material for roads and a preparation method, and belongs to the technical field of road engineering materials. The material is prepared from polyether polyol, polycaprolactone glycol, a bisphenol A epoxy-polyether block isocyanate terminated prepolymer, a methyl phenyl silicon-boron hybrid hydroxyl chain extender, diphenylmethane diisocyanate, calcium carbonate, wollastonite, a hindered amine anti-aging agent and dioctyl phthalate. Wherein the bisphenol A epoxy-polyether block isocyanate terminated prepolymer is prepared by the following steps: reacting bisphenol A with epoxy chloropropane to generate epoxy resin, reacting with polytetramethylene ether glycol, and introducing isophorone diisocyanate; the methyl phenyl silicon-boron hybrid hydroxyl chain extender is prepared by carrying out hydrosilylation and ethylene glycol reaction on methyl trimethoxy silane, 3-glycidyl ether oxypropyl trimethoxy silane and allylboronic acid pinacol ester; and the methyl phenyl silicon-boron hybrid hydroxyl chain extender is prepared by carrying out hydrosilylation on methyl trimethoxy silane, 3-glycidyl ether oxypropyl trimethoxy silane and allylboronic acid pinacol ester. The material has the advantages of quick curing property, weather resistance and high-temperature stability, and is suitable for road seamless expansion joint scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering materials, and particularly relates to a fast-curing polyurethane seamless expansion joint material for roads and a preparation method. BACKGROUND

[0002] As the core carrier of the traffic network, the expansion joint structure of the road is the key design to cope with environmental stresses such as thermal expansion and cold contraction, load vibration, etc. The traditional road expansion joint materials mainly include asphalt-based, chloroprene rubber-based and polysulfide sealant types. These materials have played an important role in early engineering construction, but with the surge in traffic flow, the complexification of climate conditions and the popularization of heavy-load vehicles, their performance limitations have become increasingly prominent. Although the asphalt-based material has a relatively low cost, its weather resistance is weak and it is prone to cracking and peeling under the action of ultraviolet light, rain and temperature changes, etc., and needs frequent maintenance. Although the chloroprene rubber-based material has a certain elasticity, it has insufficient oil stain resistance and is prone to swelling and aging after long-term contact with vehicle lubricating oil, and its curing period is generally long, usually several hours to several tens of hours, which is low in construction efficiency. Although the polysulfide sealant has good adhesion, it is prone to softening and flowing in high-temperature environments and brittle cracking in low-temperature environments, and cannot adapt to the long-term use requirements in large temperature difference areas. These defects of traditional materials not only increase the road maintenance cost, but also pose a potential threat to driving safety, so the development of high-performance expansion joint materials has become an important research direction in the field of road engineering.

[0003] Polyurethane materials have gradually become an ideal choice to replace traditional materials due to their high elasticity, wear resistance, excellent adhesion and good chemical corrosion resistance. However, the existing polyurethane expansion joint materials still have many deficiencies. First, the curing process of conventional polyurethane relies on the step-by-step polymerization reaction of isocyanate groups and hydroxyl groups, and the surface drying time usually takes several hours, and the complete curing often takes more than 24 hours, which leads to the need for long-time lane closure during road repair, seriously affecting the traffic efficiency. Second, the weather resistance of polyurethane is limited by the molecular structure, and unmodified polyurethane is prone to photo-oxidative degradation under ultraviolet light, which shows a decrease in tensile strength and elongation at break, and obvious aging phenomenon after several years of outdoor use. In addition, the high-temperature resistance of polyurethane is insufficient, and permanent deformation is easily produced in the material under high summer temperatures or repeated rolling of heavy-load vehicles, which leads to the failure of the expansion joint function. Although existing technologies try to improve the performance by adding fillers, anti-aging agents or using blending modification methods, the effect is limited, and it is difficult to simultaneously consider fast curing, weather resistance and high-temperature stability, which cannot meet the urgent needs of modern road engineering for high-performance expansion joint materials.

[0004] To address the aforementioned technical bottlenecks, this invention proposes an innovative solution. By designing two novel modified compounds, focusing on both the crosslinking reaction mechanism and molecular segment functionalization, the overall performance of polyurethane materials is synergistically improved. One modified compound introduces dual curing reaction sites (epoxy ring-opening and isocyanate polymerization), shortening the curing time and increasing the crosslinking density; the other modified compound constructs silicon-boron hybrid segments, enhancing the material's weather resistance and high-temperature stability. The synergistic effect of these two modified compounds effectively solves the defects of traditional polyurethanes, such as slow curing, easy aging, and poor high-temperature performance. Ultimately, a seamless expansion joint material for roads, possessing rapid curing, weather resistance, and high-temperature stability, is prepared, providing a new technical path for improving the durability and maintenance efficiency of road engineering. Summary of the Invention

[0005] The purpose of this invention is to provide a fast-curing polyurethane seamless expansion joint material for roads and its preparation method, which solves the technical problems of existing expansion joint materials having poor weather resistance, slow curing, and easy softening at high temperatures; and existing polyurethanes having good elasticity but long curing time, insufficient weather resistance, and poor high-temperature stability.

[0006] The present invention achieves the above objectives through the following technical solutions: A fast-curing, seamless polyurethane expansion joint material, comprising the following raw materials in parts by weight: Polyether polyol: 200-400 parts by weight; Polycaprolactone diol: 100-200 parts by weight; Bisphenol A epoxy-polyether block isocyanate-terminated prepolymer: 50-150 parts by weight; Methylphenylsilylboron hybrid hydroxyl chain extender: 30-80 parts by weight; 4,4'-Diphenylmethane diisocyanate: 150-250 parts by weight; Calcium carbonate: 300-500 parts by weight; Wollastonite: 100-200 parts by weight; Hindered amine anti-aging agents: 5-15 parts by weight; Dioctyl phthalate: 50-100 parts by weight; The preparation method of the bisphenol A epoxy-polyether block isocyanate-terminated prepolymer includes: A1, dissolving bisphenol A in acetone, adding epichlorohydrin, and reacting at 60-64°C under sodium hydroxide catalysis to obtain bisphenol A epoxy resin; reacting the bisphenol A epoxy resin with polytetramethylene ether glycol at 120-124°C under nitrogen protection to remove the byproduct water and obtain an epoxy-polyether block intermediate; A2, dissolving the intermediate in anhydrous tetrahydrofuran, adding isophorone diisocyanate, and reacting at 80-82°C under dibutyltin dilaurate catalysis.

[0007] In this invention, the preparation process of bisphenol A epoxy-polyether block isocyanate-terminated prepolymer involves two key chemical reactions, progressively constructing the molecular chain structure through nucleophilic substitution, condensation, and addition reactions. In the first step, the hydroxyl group (-OH) in the bisphenol A molecule exhibits strong nucleophilicity under sodium hydroxide catalysis, attacking the epoxy group (three-membered ring structure) of epichlorohydrin, initiating the ring-opening reaction of epichlorohydrin. The epoxy ring of epichlorohydrin is extremely unstable under alkaline conditions; the two hydroxyl groups of bisphenol A sequentially attack the two carbon atoms of the epoxy ring, leading to ring rupture and the formation of a new carbon-oxygen bond (CO), while simultaneously generating sodium chloride as a byproduct. This process is repeated, and the bisphenol A molecule gradually grows through the bridging effect of epichlorohydrin, eventually forming a linear bisphenol A epoxy resin, whose molecular chain retains a large number of epoxy groups (-COC-), providing crosslinking sites for subsequent reactions. Subsequently, the bisphenol A epoxy resin undergoes a condensation reaction with polytetramethylene ether glycol (PTMG) under high temperature and nitrogen protection. In the polytetramethylene ether glycol (PTG) molecular chain, the terminal hydroxyl group (-OH) undergoes a nucleophilic addition-elimination reaction with the epoxy group of the epoxy resin: the hydroxyl oxygen atom attacks the electron-deficient carbon atom of the epoxy ring, causing the epoxy ring to open and form a new CO bond, while simultaneously removing a water molecule. This process repeats, with the rigid epoxy segment of the epoxy resin and the flexible polyether segment of the PTG connected by ether bonds (-O-), forming an epoxy-polyether block intermediate. Nitrogen protection isolates the intermediate from moisture in the air, preventing side reactions (such as hydrolysis) between the hydroxyl groups and water, thus ensuring the integrity of the block structure. In the second step, the terminal hydroxyl group of the epoxy-polyether block intermediate undergoes an addition reaction with the isocyanate group (-NCO) of isophorone diisocyanate (IPDI). Under the catalysis of dibutyltin dilaurate, the lone pair electrons of the hydroxyl oxygen atom attack the carbon atom of the isocyanate group (nucleophilic addition), forming an unstable urethane intermediate. Subsequently, carbon dioxide is released (or proton transfer), ultimately forming a stable urethane bond (-NH-COO-). Because both epoxy and hydroxyl groups exist in the intermediate molecular chain, the isocyanate group can react simultaneously with the epoxy group (ring-opening addition) and the hydroxyl group (step-growth polymerization), forming a "dual-curing" crosslinking network: after ring opening, the epoxy group reacts with the isocyanate to generate crosslinking points containing urea bonds (-NH-CO-NH-), while the hydroxyl group reacts with the isocyanate to form urethane bonds. This dual crosslinking mechanism significantly improves the reactivity and crosslinking density of the prepolymer, laying the foundation for subsequent reactions with polyols to prepare polyurethane materials.

[0008] According to a preferred embodiment of the present invention, the polyether polyol was purchased from Wanhua Chemical Group Co., Ltd., and the model is WANOL® PPG-2000.

[0009] According to a preferred embodiment of the present invention, the polycaprolactone diol was purchased from Shandong Longhua Polymer Materials Co., Ltd., and the model number is LH-PCL-1000.

[0010] According to a preferred embodiment of the present invention, the bisphenol A was purchased from Shanghai Petrochemical Co., Ltd., and the model number is S-100.

[0011] According to a preferred embodiment of the present invention, the acetone was purchased from Jiangsu Huachang Chemical Co., Ltd., and the product is industrial grade acetone.

[0012] According to a preferred embodiment of the present invention, the epichlorohydrin was purchased from Shandong Haili Chemical Co., Ltd., and its model number is HAI-LIC-36.

[0013] According to a preferred embodiment of the present invention, the sodium hydroxide was purchased from Zhongtai Chemical Co., Ltd., and the product type is caustic soda flakes (industrial grade).

[0014] According to a preferred embodiment of the present invention, the polytetramethylene ether glycol was purchased from Wanhua Chemical Group Co., Ltd., and the product name is WANOL® PTMG-2000.

[0015] According to a preferred embodiment of the present invention, the tetrahydrofuran is purchased from Jiangsu Yida Chemical Co., Ltd., and is industrial grade tetrahydrofuran.

[0016] According to a preferred embodiment of the present invention, the isophorone diisocyanate was purchased from Wanhua Chemical Group Co., Ltd., and the model is WANICT® IPDI-100.

[0017] According to a preferred embodiment of the present invention, the dibutyltin dilaurate was purchased from Nanjing Shuguang Fine Chemical Co., Ltd., and the model is DBTDL (industrial grade catalyst).

[0018] According to a preferred embodiment of the present invention, the 4,4'-diphenylmethane diisocyanate was purchased from Wanhua Chemical Group Co., Ltd., and the product name is WANICT® MDI-50.

[0019] According to a preferred embodiment of the present invention, the calcium carbonate was purchased from Jiangxi Guangyuan Chemical Co., Ltd., and the model was GY-500 (average particle size 5μm).

[0020] According to a preferred embodiment of the present invention, the wollastonite was purchased from Jiangxi Aote Fine Powder Co., Ltd., and the model is AO-100 (average particle size 10μm).

[0021] According to a preferred embodiment of the present invention, the hindered amine anti-aging agent is purchased from Lianlong New Materials Co., Ltd., and the model is LA-57 (general-purpose hindered amine).

[0022] According to a preferred embodiment of the present invention, the dioctyl phthalate was purchased from Jinling Petrochemical Co., Ltd., and the product is industrial grade dioctyl phthalate.

[0023] According to a preferred embodiment of the present invention, in step A1, the reaction time at 60-64°C is 4-6 hours; the reaction time under nitrogen protection is 2-4 hours.

[0024] According to a preferred embodiment of the present invention, in step A2, the reaction time at 80-82°C is 1-3 hours.

[0025] According to a preferred embodiment of the present invention, the preparation method of the methylphenylsiloxane-boron hybrid hydroxyl chain extender includes: B1, adding methyltrimethoxysilane, 3-glycidyl etheroxypropyltrimethoxysilane and allyl borate pinacol ester to toluene, and carrying out a hydrosilylation reaction at 80-82°C under the action of a platinum catalyst to obtain a siloxane intermediate containing a boron epoxy group; B2, dissolving the intermediate in ethanol, adding ethylene glycol, and reacting at 100-106°C under the catalysis of concentrated sulfuric acid.

[0026] In this invention, the preparation of a methylphenylsilylboron hybrid hydroxyl chain extender involves constructing a silicon-boron hybrid chain segment through hydrosilylation and condensation reactions. The core of this process is the selective activation of silicon-hydrogen bonds using a platinum catalyst, followed by the introduction of functional groups via condensation reactions. In the first step, methyltrimethoxysilane (a silane containing methyl and methoxy groups), 3-glycidyl etheroxypropyltrimethoxysilane (a silane containing epoxy groups), and allyl borate pinacol ester (a compound containing boron and allyl groups) are mixed in toluene solvent. A platinum catalyst (such as isopropanol chloroplatinate solution) acts as the active center, catalyzing the addition reaction between the silicon-hydrogen bond (-Si-H) and the unsaturated alkene bond (C=C) of allyl borate pinacol ester. The platinum catalyst lowers the activation energy by adsorbing the silicon-hydrogen bond and the alkene bond, promoting the breakage of the silicon-hydrogen bond and its combination with the π electrons of the alkene bond to form a new Si-C bond. In this process, the methoxy group (-OCH3) of methyltrimethoxysilane and the epoxy group (-COC-) of 3-glycidyl etheroxypropyltrimethoxysilane are retained, while the borate ester group (-BO-) of allyl borate pinacol ester is added to the siloxane chain via an addition reaction, forming a siloxane intermediate containing a boron epoxy group. In the second step, the siloxane intermediate dissolves in ethanol and undergoes a condensation reaction with ethylene glycol under concentrated sulfuric acid catalysis. The methoxy group (-OCH3) in the intermediate molecular chain is protonated under acidic conditions to form an easily leaving hydrated ion (-OH2). +The hydroxyl group (-OH) of ethylene glycol acts as a nucleophile, attacking the positively charged center, leading to the removal of the methoxy group and the formation of a new CO bond. Simultaneously, the other hydroxyl group of ethylene glycol binds to the borate ester group (-BO-) in the intermediate through hydrogen bonding or coordination, further stabilizing the molecular structure. This reaction not only removes low-molecular-weight methanol byproducts but also adjusts the length and flexibility of the siloxane chain by introducing ethylene glycol, ultimately forming a methylphenylsiloxane-boron hybrid chain extender with a terminal hydroxyl group (-OH). In its molecular chain, the siloxane (-Si-O-Si-) provides weather resistance, the phenyl group (-C6H5) enhances high-temperature stability, and the borate ester group (-BO-) provides additional crosslinking sites for subsequent reactions with isocyanates.

[0027] According to a preferred embodiment of the present invention, the methyltrimethoxysilane was purchased from Hubei Xingfa Chemical Group Co., Ltd., and the model is XH-MTMS.

[0028] According to a preferred embodiment of the present invention, the 3-glycidyl etheroxypropyltrimethoxysilane was purchased from Nanjing Shuguang Fine Chemical Co., Ltd., and its model number is KH-560.

[0029] According to a preferred embodiment of the present invention, the allyl borate pinacol ester was purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd., and the model number is RA-BA-100.

[0030] According to a preferred embodiment of the present invention, the toluene is purchased from Sinopec Zhenhai Refining & Chemical Company and is industrial grade toluene.

[0031] According to a preferred embodiment of the present invention, the platinum catalyst was purchased from Guizhou Platinum Industry Co., Ltd., and the model is SY-Pt-01 (isopropanol chloroplatinic acid solution).

[0032] According to a preferred embodiment of the present invention, the ethanol is purchased from COFCO Biotechnology Co., Ltd., and is industrial-grade anhydrous ethanol.

[0033] According to a preferred embodiment of the present invention, the ethylene glycol is purchased from Sinopec Shanghai Petrochemical Co., Ltd., and is industrial grade ethylene glycol.

[0034] According to a preferred embodiment of the present invention, the concentrated sulfuric acid was purchased from Hubei Xingfa Chemical Group Co., Ltd., and the type was industrial grade concentrated sulfuric acid (98%).

[0035] According to a preferred embodiment of the present invention, the planetary mixer is purchased from Changzhou Zili Intelligent Equipment Co., Ltd., and the model is ZL-500 planetary mixer.

[0036] According to a preferred embodiment of the present invention, the mold was purchased from Suzhou Precision Mold Manufacturing Co., Ltd., and the model is a customized seamless expansion joint mold (DN-200 type).

[0037] According to a preferred embodiment of the present invention, in step B1, the hydrosilylation reaction takes 6-8 hours.

[0038] According to a preferred embodiment of the present invention, in step B2, the reaction time at 100-106°C is 3-4 hours.

[0039] This invention also provides a method for preparing the aforementioned fast-curing polyurethane seamless expansion joint material, comprising the following steps: S1. Mix polyether polyol and polycaprolactone diol, and dehydrate them at 110-116℃ and a vacuum of -0.09MPa; add bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and methylphenylsilicon boron hybrid hydroxyl chain extender, and stir at 80-84℃; cool to 60-62℃, add 4,4'-diphenylmethane diisocyanate, and continue stirring to obtain the prepolymer; S2. The prepolymer is mixed with calcium carbonate, wollastonite, hindered amine anti-aging agent and dioctyl phthalate in a planetary mixer at 100-104℃ and vacuum degree -0.09MPa, and then injected into a mold and vulcanized at 120-126℃.

[0040] In this invention, the preparation of the fast-curing polyurethane seamless expansion joint material involves a stepwise polymerization reaction of polyol and isocyanate, combining the synergistic effect of the two modified compounds to form a three-dimensional cross-linked network. First, a mixture of polyether polyol (such as PTMG-2000) and polycaprolactone diol (PCL-1000) is dehydrated under high-temperature vacuum conditions to remove free water and prevent it from reacting with isocyanate to generate carbon dioxide (leading to bubble defects). The dehydrated polyol system is then mixed with bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and a methylphenylsilylboron hybrid hydroxyl chain extender, and stirred at 80-84°C. At this point, the isocyanate groups (-NCO) of the prepolymer undergo a stepwise addition reaction with the hydroxyl groups (-OH) of the polyol to form urethane bonds (-NH-COO-), forming the initial polyurethane prepolymer. Simultaneously, the epoxy groups in the prepolymer (from bisphenol A epoxy resin) undergo a ring-opening addition reaction with the hydroxyl groups to form urea bonds (-NH-CO-NH-), further increasing the cross-linking density of the prepolymer. Subsequently, the prepolymer is mixed with fillers such as calcium carbonate and wollastonite, as well as hindered amine anti-aging agents and dioctyl phthalate, and further reacted in a planetary mixer under high temperature and vacuum. Calcium carbonate and wollastonite, as fillers, react with the isocyanate groups of the prepolymer through physical adsorption and chemical bonding, enhancing the interfacial bonding between the material and the filler. The hindered amine anti-aging agent inhibits the photo-oxidative degradation of polyurethane by capturing free radicals (such as alkyl free radicals generated by UV excitation). Dioctyl phthalate, as a plasticizer, reduces the viscosity of the system and improves processing fluidity. Finally, the mixed material is injected into a mold and vulcanized at 120-126°C. At this time, the remaining isocyanate groups undergo rapid cross-linking reactions with the epoxy groups (from bisphenol A epoxy-polyether block prepolymer) and hydroxyl groups (from methylphenylsiloxane-boron hybrid chain extender) of the modified compound, forming a three-dimensional network structure with urethane bonds, urea bonds, and siloxane-boronate covalent bonds as the core. This structure endows the material with high elasticity (polyether / polycaprolactone soft segments), fast curing (dual curing mechanism), weather resistance (siloxane segments), and high temperature stability (phenyl and borate ester groups), ultimately producing a fast-curing polyurethane seamless expansion joint material that meets the needs of road engineering.

[0041] According to a preferred embodiment of the present invention, in step S1, the dehydration time is 2-4 hours; the stirring time at 80-84°C is 30-40 minutes; and the stirring time is continued for 2-3 hours.

[0042] According to a preferred embodiment of the present invention, in step S2, the mixing time is 1-2 hours and the vulcanization time is 2-3 hours.

[0043] The present invention also provides an application of the aforementioned fast-curing polyurethane seamless expansion joint material or the fast-curing polyurethane seamless expansion joint material prepared by the aforementioned preparation method in roads.

[0044] The beneficial effects of this invention are as follows: The fast-curing polyurethane seamless expansion joint material described in this invention exhibits significant advantages in terms of fast curing, weather resistance, and comprehensive mechanical properties through innovative structural design and manufacturing process. It effectively solves many pain points of traditional road expansion joint materials in practical applications and provides strong support for the long-term stable operation of road engineering.

[0045] In terms of rapid curing, the material's curing efficiency represents a significant leap forward compared to traditional polyurethane materials. Traditional polyurethane curing relies on the stepwise polymerization reaction between isocyanate groups and hydroxyl groups, typically requiring several hours for surface drying and over 24 hours for complete curing. This necessitates prolonged lane closures during road maintenance, severely impacting traffic flow. This invention, however, introduces a bisphenol A epoxy-polyether block isocyanate-terminated prepolymer. Its molecular structure contains both epoxy and isocyanate groups, enabling a dual-curing reaction with the hydroxyl groups of polyols. The epoxy groups undergo ring-opening addition to form chemical crosslinks, while the isocyanate groups and hydroxyl groups gradually polymerize to form the polyurethane backbone. This synergistic dual-curing mechanism drastically shortens the reaction time, significantly reducing surface drying time and allowing complete curing to be completed within hours. This greatly improves construction efficiency, reduces road closure time, and effectively alleviates traffic congestion.

[0046] In terms of weather resistance, the material's resistance to environmental aging is significantly enhanced. Traditional polyurethane materials are prone to photo-oxidative degradation or hydrolytic aging under environmental factors such as ultraviolet light, rain erosion, and sudden temperature changes, resulting in decreased tensile strength, reduced elongation at break, and obvious cracking and peeling after only a few years of outdoor use. This invention introduces a methylphenylsilylboron hybrid hydroxyl chain extender. The siloxane groups in its molecular chain have excellent ultraviolet light absorption capabilities, effectively inhibiting photo-oxidative reactions. The phenyl groups enhance the stability of the molecular chain through steric hindrance, reducing the damage to the molecular structure caused by external factors. At the same time, the covalent bonds formed by the reaction of borate ester groups and isocyanate further improve the density of the cross-linked network, reducing the penetration rate of moisture and ultraviolet light. Under the synergistic effect of multiple actions, the material can still maintain good mechanical properties when exposed to the outdoor environment for a long time, effectively extending the service life of the expansion joint and reducing the maintenance frequency.

[0047] In terms of comprehensive mechanical properties and high-temperature stability, the material exhibits excellent adaptability and reliability. Traditional polyurethane materials, limited by their molecular structure, have low glass transition temperatures. Under high-temperature environments in summer or repeated crushing by heavy vehicles, they are prone to permanent deformation, leading to the failure of expansion joints. In low-temperature environments, they may become brittle and crack, making them unsuitable for use in areas with large temperature differences. This invention, through the compound design of polyether polyol and polycaprolactone diol, ensures that the flexible chain segments of the material maintain high elasticity, while the polar groups of polycaprolactone enhance intermolecular forces. The phenyl groups in the methylphenylsiliconboron hybrid hydroxyl chain extender improve the material's heat resistance, while the borate ester groups enhance structural stability at high temperatures through cross-linking. In addition, the addition of calcium carbonate and wollastonite fillers further enhances the material's tear strength and compressive strength. Considering these factors, the material is not prone to softening and flowing in high-temperature environments, is not prone to brittleness and cracking in low-temperature environments, and maintains good elastic recovery under repeated heavy vehicle loads. This effectively ensures the functional stability of expansion joints under different climatic and load conditions, providing solid support for the safe operation of road engineering. Detailed Implementation

[0048] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0049] Example 1 Preparation of bisphenol A epoxy-polyether block isocyanate-terminated prepolymer: 100g of bisphenol A was slowly added to 200g of acetone and stirred until completely dissolved. Then, 150g of epichlorohydrin was added, and the mixture was reacted in a constant temperature water bath at 60℃ for 6 hours under the catalysis of sodium hydroxide (5g, 5wt% aqueous solution). The reaction was continuously stirred to ensure that the hydroxyl groups of bisphenol A fully reacted with the epoxy groups of epichlorohydrin to undergo a ring-opening substitution reaction, generating bisphenol A epoxy resin. After the reaction was completed, the generated sodium chloride byproduct was removed by filtration, yielding a clear bisphenol A epoxy resin solution. The acetone was recovered by vacuum distillation of the above bisphenol A epoxy resin solution to obtain solid bisphenol A epoxy resin. 120g of bisphenol A epoxy resin and 80g of polytetramethylene ether glycol were added to a three-necked flask. Under nitrogen protection, the mixture was heated to 120°C and stirred for 4 hours. Water generated during the reaction was removed using a water separator, promoting the condensation reaction between the epoxy groups and the terminal hydroxyl groups of the polytetramethylene ether glycol to form an epoxy-polyether block intermediate. After the reaction, the system was cooled to room temperature to obtain the epoxy-polyether block intermediate. 100g of the epoxy-polyether block intermediate was dissolved in 300g of anhydrous tetrahydrofuran, and isophorone diisocyanate (IPDI, 33.4g, calculated based on an NCO content of 37.5%) was added. The mixture was reacted in an oil bath at 80°C for 3 hours under the catalysis of 0.1g of dibutyltin dilaurate. The -NCO content was monitored by infrared spectroscopy during the reaction. The reaction was stopped when the theoretical value was reached, yielding a bisphenol A epoxy-polyether block isocyanate-terminated prepolymer.

[0050] Preparation of methylphenylsilylboron hybrid hydroxyl chain extender: 50g of methyltrimethoxysilane, 30g of 3-glycidyl etheroxypropyltrimethoxysilane, and 20g of allyl borate pinacol ester were added to 200g of toluene. After stirring and mixing evenly, a platinum catalyst (0.1g, isopropanol chloroplatinate solution) was added, and the mixture was reacted in a constant temperature water bath at 80℃ for 8 hours, resulting in a hydrosilylation reaction. The silanium-hydrogen bonds of methyltrimethoxysilane added to the olefinic bonds of allyl borate pinacol ester to form a siloxane intermediate containing boron epoxy groups. After the reaction was completed, the catalyst was removed by filtration, and the toluene was recovered by vacuum distillation to obtain the siloxane intermediate. 100g of the siloxane intermediate was dissolved in 200g of ethanol, and 10g of ethylene glycol was added. The mixture was reacted in a constant temperature water bath at 100℃ for 4 hours under the catalysis of 0.5g concentrated sulfuric acid. During the reaction, the methoxy group of the siloxane intermediate undergoes a condensation reaction with the hydroxyl group of ethylene glycol, removing methanol byproducts. Simultaneously, the other hydroxyl group of ethylene glycol coordinates with the borate ester group of the siloxane intermediate, forming a methylphenylsiloxane-boron hybrid hydroxyl chain extender with terminal hydroxyl groups. Preparation of fast-curing polyurethane seamless expansion joint material: Polyether polyol (PTMG-2000, 300g) and polycaprolactone diol (PCL-1000, 150g) are added to a planetary mixer, heated to 110℃, and stirred and dehydrated under a vacuum of -0.09MPa for 4 hours until the moisture content of the system is below 0.05%. After dehydration, the temperature is lowered to 80℃, and 100g of bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and 50g of methylphenylsiloxane-boron hybrid hydroxyl chain extender are added. Stirring continues for 40 minutes to uniformly disperse the two modified compounds in the polyol system. Subsequently, the system was cooled to 60°C, and 200g of 4,4'-diphenylmethane diisocyanate (MDI) was slowly added while stirring for 3 hours. This allowed the isocyanate groups (-NCO) to fully react with the hydroxyl groups (-OH) of the polyol, while simultaneously the epoxy groups and hydroxyl groups of the bisphenol A epoxy-polyether block prepolymer underwent a ring-opening addition reaction to form a polyurethane prepolymer. 1000g of the prepolymer, along with 400g of calcium carbonate, 150g of wollastonite, 10g of hindered amine anti-aging agent, and 75g of dioctyl phthalate, were added to a planetary mixer and mixed for 2 hours at 100°C and a vacuum of -0.09MPa to ensure uniform dispersion of the fillers and additives. After mixing, the material was poured into a mold preheated to 120°C and vulcanized for 3 hours. After demolding, a fast-curing seamless polyurethane expansion joint material was obtained.

[0051] Example 2 The specific implementation method is the same as in Example 1, except that the preparation of the bisphenol A epoxy-polyether block isocyanate-terminated prepolymer is as follows: 120g of bisphenol A is dissolved in 220g of acetone, 160g of epichlorohydrin is added, and the mixture is reacted at 62°C for 5h under the catalysis of 6g of sodium hydroxide to obtain bisphenol A epoxy resin; 130g of bisphenol A epoxy resin and 90g of polytetramethylene ether glycol are reacted at 122°C under nitrogen protection for 3h to remove the byproduct water and obtain an epoxy-polyether block intermediate; 110g of the intermediate is dissolved in 330g of anhydrous tetrahydrofuran, 36.7g of isophorone diisocyanate is added, and the mixture is reacted at 81°C for 2h under the catalysis of 0.1g of dibutyltin dilaurate to obtain the bisphenol A epoxy-polyether block isocyanate-terminated prepolymer. Preparation of methylphenylsilylboron hybrid hydroxyl chain extender: 60g of methyltrimethoxysilane, 40g of 3-glycidyl etheroxypropyltrimethoxysilane, and 25g of allyl borate pinacol ester were added to 220g of toluene and subjected to a hydrosilylation reaction at 81℃ for 7h under the action of 0.1g of platinum catalyst to obtain a siloxane intermediate containing boron epoxy group; 110g of the intermediate was dissolved in 220g of ethanol, and 12g of ethylene glycol was added. The reaction was carried out at 102℃ for 3.5h under the catalysis of 0.6g of concentrated sulfuric acid to obtain the methylphenylsilylboron hybrid hydroxyl chain extender.

[0052] Preparation of fast-curing polyurethane seamless expansion joint material: 350g of polyether polyol and 180g of polycaprolactone diol were mixed and dehydrated at 112℃ and vacuum degree -0.09MPa for 3h; 120g of bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and 60g of methylphenylsilicon boron hybrid hydroxyl chain extender were added and stirred at 82℃ for 35min; the temperature was lowered to 61℃, and 220g of 4,4'-diphenylmethane diisocyanate was added and stirred for 2.5h to obtain a prepolymer; 1100g of the prepolymer was mixed with 450g of calcium carbonate, 180g of wollastonite, 12g of hindered amine anti-aging agent and 80g of dioctyl phthalate in a planetary mixer at 102℃ and vacuum degree -0.09MPa for 1.5h, and then injected into a mold and vulcanized at 122℃ for 2.5h to obtain the fast-curing polyurethane seamless expansion joint material.

[0053] Example 3 The specific implementation method is the same as in Example 1, except that the preparation of the bisphenol A epoxy-polyether block isocyanate-terminated prepolymer is as follows: 140g of bisphenol A is dissolved in 240g of acetone, 170g of epichlorohydrin is added, and the mixture is reacted at 64°C for 4h under the catalysis of 7g of sodium hydroxide to obtain bisphenol A epoxy resin; 140g of bisphenol A epoxy resin is reacted with 100g of polytetramethylene ether glycol at 124°C under nitrogen protection for 2h to remove the byproduct water and obtain an epoxy-polyether block intermediate; 120g of the intermediate is dissolved in 360g of anhydrous tetrahydrofuran, 40g of isophorone diisocyanate is added, and the mixture is reacted at 82°C for 1h under the catalysis of 0.1g of dibutyltin dilaurate to obtain the bisphenol A epoxy-polyether block isocyanate-terminated prepolymer. Preparation of methylphenylsilylboron hybrid hydroxyl chain extender: 70g of methyltrimethoxysilane, 50g of 3-glycidyl etheroxypropyltrimethoxysilane, and 30g of allyl borate pinacol ester were added to 240g of toluene and subjected to a hydrosilylation reaction at 82℃ for 6h under the action of 0.1g of platinum catalyst to obtain a siloxane intermediate containing boron epoxy group; 120g of the intermediate was dissolved in 240g of ethanol, and 15g of ethylene glycol was added. The reaction was carried out at 104℃ for 3h under the catalysis of 0.7g of concentrated sulfuric acid to obtain the methylphenylsilylboron hybrid hydroxyl chain extender. Preparation of fast-curing polyurethane seamless expansion joint material: 400g of polyether polyol and 200g of polycaprolactone diol were mixed and dehydrated at 116℃ and vacuum degree -0.09MPa for 2h; 150g of bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and 80g of methylphenylsilicon boron hybrid hydroxyl chain extender were added and stirred at 84℃ for 30min; the temperature was lowered to 62℃, and 250g of 4,4'-diphenylmethane diisocyanate was added and stirred for another 2h to obtain a prepolymer; 1200g of the prepolymer was mixed with 500g of calcium carbonate, 200g of wollastonite, 15g of hindered amine anti-aging agent and 100g of dioctyl phthalate in a planetary mixer at 104℃ and vacuum degree -0.09MPa for 1h, and then injected into a mold and vulcanized at 126℃ for 2h to obtain the fast-curing polyurethane seamless expansion joint material.

[0054] Comparative Example 1 The specific implementation method is the same as in Example 1, except that the preparation of the fast-curing polyurethane seamless expansion joint material is as follows: 300g of polyether polyol and 150g of polycaprolactone diol are mixed and dehydrated at 110°C and a vacuum of -0.09MPa for 4 hours; 100g of polyether polyol (replacing bisphenol A epoxy-polyether block isocyanate end-capped prepolymer) and 50g of methylphenylsilicon boron hybrid hydroxyl chain extender are added, and the mixture is stirred at 80°C for 40 minutes; the temperature is lowered to 60°C, 200g of 4,4'-diphenylmethane diisocyanate is added, and the mixture is stirred for another 3 hours to obtain the prepolymer.

[0055] Comparative Example 2 The specific implementation method is the same as in Example 1, except that the preparation of the fast-curing polyurethane seamless expansion joint material is as follows: 300g of polyether polyol and 150g of polycaprolactone diol are mixed and dehydrated at 110°C and a vacuum of -0.09MPa for 4 hours; 100g of bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and 50g of polycaprolactone diol (replacing the methylphenylsiliconborate hybrid hydroxyl chain extender) are added and stirred at 80°C for 40 minutes; the temperature is lowered to 60°C, 200g of 4,4'-diphenylmethane diisocyanate is added, and stirring is continued for 3 hours to obtain the prepolymer.

[0056] Comparative Example 3 The specific implementation method is the same as in Example 1, except that the preparation of the fast-curing polyurethane seamless expansion joint material is as follows: 300g of polyether polyol and 150g of polycaprolactone diol are mixed and dehydrated at 110°C and a vacuum of -0.09MPa for 4 hours; 100g of polyether polyol and 50g of polycaprolactone diol (replacing bisphenol A epoxy-polyether block isocyanate end-capped prepolymer and methylphenylsilicon boron hybrid hydroxyl chain extender) are added and stirred at 80°C for 40 minutes; the temperature is lowered to 60°C, 200g of 4,4'-diphenylmethane diisocyanate is added, and stirring is continued for 3 hours to obtain the prepolymer.

[0057] Performance testing The anti-fouling road marking compositions prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests according to the following methods: 1. Curing time test: Referring to GB / T 16777-2008 "Waterproof Coatings for Buildings", the sample was coated on a polytetrafluoroethylene board with a thickness of about 2mm. The surface drying time (not sticky to the touch) and the hard drying time (can withstand 10kg pressure without deformation) were tested at room temperature (25℃).

[0058] 2. Tensile strength and elongation at break test: According to GB / T 528-2009, the sample is cut into dumbbell-shaped specimens (gauge length 25mm, width 6mm), and tested using a universal testing machine at 25℃ and 50% humidity. The tensile rate is 500mm / min, and the maximum tensile force (to calculate tensile strength) and elongation at break are recorded.

[0059] 3. Weather resistance test: Place the sample in a UV aging test chamber (wavelength 290-400nm, irradiance 0.89W / m²). 2 After irradiation at 60℃ for 1000h, the tensile strength retention rate (strength after aging / initial strength × 100%) and elongation at break of the aged samples were tested.

[0060] 4. High-temperature compression set test: According to GB / T 1683-2006, the sample is made into a specimen with a diameter of 12 mm and a thickness of 6 mm. It is pre-compressed to 60% of the original thickness at 80℃, kept for 24 h and then cooled to room temperature. The compression set rate is measured as ((original thickness - compressed thickness) / original thickness × 100%).

[0061] 5. Low-temperature embrittlement temperature test: According to GB / T 5470-2008, the sample is made into an 80×10×4mm specimen, placed in a low-temperature test chamber, and cooled at a rate of -5℃ / min. The highest temperature at which the sample breaks (embrittlement temperature) is recorded.

[0062] 6. Performance test results: Table 1: Performance test results of each embodiment and comparative example

[0063] As shown in Table 1, Examples 1-3 significantly improved the core defects of traditional expansion joint materials by introducing bisphenol A epoxy-polyether block isocyanate-terminated prepolymer (dual curing mechanism) and methylphenyl silicon boron hybrid hydroxyl chain extender (silicon boron hybrid chain segment). Regarding curing time, Examples 1-3 achieved a surface drying time of only 25-30 minutes and a complete drying time of 1.5-2 hours, far faster than the 65-85 minutes surface drying time and 6-8 hours complete drying time of Comparative Examples 1-3, effectively solving the problem of low construction efficiency caused by the slow curing of traditional polyurethane (surface drying requires several hours, and complete curing exceeds 24 hours). In terms of weather resistance, Examples 1-3 retained 88-90% of tensile strength and 85-89% of elongation at break after 1000 hours of UV aging, significantly higher than the 58-65% and 52-58% of Comparative Examples 1-3, indicating a substantial improvement in their resistance to photo-oxidative degradation and solving the problem of poor weather resistance in traditional materials. Regarding high-temperature stability, Examples 1-3 exhibited a compression set of only 12-14% at 80°C, significantly lower than the 35-42% of Comparative Examples 1-3. Furthermore, their low-temperature embrittlement temperature reached -40 to -45°C (comparative examples showed -25 to -35°C), indicating that they are less prone to softening and deformation at high temperatures and possess stronger resistance to brittle fracture at low temperatures. This addresses the problems of traditional polyurethane's tendency to soften at high temperatures (flowing in summer) and become brittle at low temperatures (cracking in winter). In summary, these examples, through the synergistic effect of the two modified compounds, comprehensively solve the technical bottlenecks of existing expansion joint materials, including poor weather resistance, slow curing, and insufficient high-temperature stability.

[0064] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A fast-curing, seamless polyurethane expansion joint material, characterized in that, Including the following parts by weight of raw materials: Polyether polyol: 200-400 parts by weight; Polycaprolactone diol: 100-200 parts by weight; Bisphenol A epoxy-polyether block isocyanate-terminated prepolymer: 50-150 parts by weight; Methylphenylsilylboron hybrid hydroxyl chain extender: 30-80 parts by weight; 4,4'-Diphenylmethane diisocyanate: 150-250 parts by weight; Calcium carbonate: 300-500 parts by weight; Wollastonite: 100-200 parts by weight; Hindered amine anti-aging agents: 5-15 parts by weight; Dioctyl phthalate: 50-100 parts by weight; The preparation method of the bisphenol A epoxy-polyether block isocyanate-terminated prepolymer includes: A1, dissolving bisphenol A in acetone, adding epichlorohydrin, and reacting at 60-64°C under sodium hydroxide catalysis to obtain bisphenol A epoxy resin; reacting the bisphenol A epoxy resin with polytetramethylene ether glycol at 120-124°C under nitrogen protection to remove the byproduct water and obtain an epoxy-polyether block intermediate; A2, dissolving the intermediate in anhydrous tetrahydrofuran, adding isophorone diisocyanate, and reacting at 80-82°C under dibutyltin dilaurate catalysis.

2. The fast-curing seamless polyurethane expansion joint material according to claim 1, characterized in that, In step A1, the reaction time is 4-6 hours at 60-64℃; the reaction time is 2-4 hours under nitrogen protection.

3. The fast-curing seamless polyurethane expansion joint material according to claim 1, characterized in that, In step A2, the reaction time is 1-3 hours at 80-82℃.

4. The fast-curing seamless polyurethane expansion joint material according to claim 1, characterized in that, The preparation method of the methylphenylsiloxane-boron hybrid hydroxyl chain extender includes: B1, adding methyltrimethoxysilane, 3-glycidyl etheroxypropyltrimethoxysilane and allyl borate pinacol ester to toluene, and carrying out a hydrosilylation reaction at 80-82℃ under the action of platinum catalyst to obtain a siloxane intermediate containing boron epoxy group; B2, dissolving the intermediate in ethanol, adding ethylene glycol, and reacting at 100-106℃ under the catalysis of concentrated sulfuric acid.

5. The fast-curing seamless polyurethane expansion joint material according to claim 4, characterized in that, In step B1, the hydrosilylation reaction takes 6-8 hours.

6. The fast-curing seamless polyurethane expansion joint material according to claim 4, characterized in that, In step B2, the reaction time is 3-4 hours at 100-106℃.

7. A method for preparing a fast-curing polyurethane seamless expansion joint material according to any one of claims 1-6, characterized in that the step... include: S1. Mix polyether polyol with polycaprolactone diol and dehydrate at 110-116℃ and vacuum degree -0.09MPa; Add bisphenol A epoxy-polyether block isocyanate-terminated prepolymer and methylphenylsiliconborate hybrid hydroxyl chain extender, and stir at 80-84℃; cool to 60-62℃, add 4,4'-diphenylmethane diisocyanate, and continue stirring to obtain the prepolymer; S2. The prepolymer is mixed with calcium carbonate, wollastonite, hindered amine anti-aging agent and dioctyl phthalate in a planetary mixer at 100-104℃ and vacuum degree -0.09MPa, and then injected into a mold and vulcanized at 120-126℃.

8. The preparation method according to claim 7, characterized in that, In step S1, the dehydration time is 2-4 hours; the stirring time at 80-84℃ is 30-40 minutes; and the stirring time continues for 2-3 hours.

9. The preparation method according to claim 7, characterized in that, In step S2, the mixing time is 1-2 hours; the vulcanization time is 2-3 hours.

10. The application of a fast-curing polyurethane seamless expansion joint material according to any one of claims 1-6 or a fast-curing polyurethane seamless expansion joint material prepared by the preparation method according to any one of claims 7-9, characterized in that, Application of the fast-curing polyurethane seamless expansion joint material on roads.

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