Wet-bonding low-temperature flexible polyurethane material for bridge floor slurry pumping treatment and preparation method of wet-bonding low-temperature flexible polyurethane material

Abstract

The invention discloses a wet-bonding low-temperature flexible polyurethane material for bridge floor slurry pumping treatment and a preparation method of the wet-bonding low-temperature flexible polyurethane material. The wet-bonding low-temperature flexible polyurethane material comprises the following raw materials: 1.3-5 parts of cyclic carbonate, 5-10 parts of epoxy resin, 2-5 parts of a water absorbent, 10-15 parts of modified polyurethane, 70-85 parts of a softening curing agent, 0.5-2.5 parts of an enhanced curing agent, 0.5-1 part of a silane coupling agent, 0.5-1 part of a defoaming agent and 5-10 parts of a diluent. Wherein the softening curing agent is prepared from the following raw materials in parts by weight: 1000 parts of polyether polyol, 1-2 parts of isocyanate, 45-230 parts of aliphatic diamine and 0.5-1.5 parts of a catalyst. A non-NCO curing mode is adopted, the influence of water vapor in a use environment on the performance of polyurethane is effectively avoided, meanwhile, water vapor in a treatment environment is absorbed and digested, the excellent cohesive strength and bonding strength and good low-temperature flexibility of a polyurethane material are guaranteed, and effective treatment of the bridge floor spurting disease is achieved.

Description

Technical Field

[0001] This invention belongs to the field of bridge asphalt pavement maintenance, specifically relating to a wet-bonded low-temperature flexible polyurethane material for treating bridge deck pumping and its preparation method. Background Technology

[0002] A 10cm asphalt concrete surface layer is a typical paving structure for mountain highways. As the service life increases, rainwater enters the interlayer through cracks in the road surface and remains there for a long time. After being rolled over by vehicles and subjected to dynamic water pressure shearing, obvious interlayer defects, loosening, and even voids often appear between the cement base and the asphalt concrete surface layer. At the same time, large-scale pumping occurs on the road surface, further accelerating the loosening and breakage of the asphalt concrete surface layer.

[0003] Currently, for the problem of pumping in asphalt concrete pavement of cement bridges, in areas with mild damage, a thin overlay is often applied to achieve the dual effect of sealing the base layer and improving pavement functional parameters. However, the effect is limited, and pumping often recurs after a period of time. For severely damaged sections with pumping, loosening, and cracking, local patching and repaving are used, but this cannot provide a holistic solution and also presents the problem of waterproofing at the joint between the old and new pavements. There is a lack of targeted treatment solutions for interlayer defects. Polyurethane grouting materials, with their high expansion ratio, high strength, and fast curing characteristics, are currently widely used in the treatment of cracks and voids in semi-rigid base layers of highways, but have not yet been effectively applied to the treatment of pumping on bridge decks. The pumping defects on bridge decks often contain a large amount of standing water and cement slurry. The standing water and dust pose a great challenge to the adhesion, water sealing, and durability of the materials and substrates. At the same time, the expansion and contraction caused by seasonal and temperature changes place higher demands on the low-temperature flexibility of the materials. The asphalt concrete layer of the bridge deck is only 10cm thick, and the requirements for the expansion rate and cohesive strength of the grouting material are significantly different from those for the base course grouting of highways.

[0004] Therefore, by developing a grouting material with high bonding strength and good low-temperature flexibility under conditions of heavy water and mud, the treatment effect of polymer grouting technology on bridge deck pumping defects can be significantly improved. In view of the existing problems in the treatment of bridge deck pumping defects, the inventor, based on years of rich experience and professional knowledge in this field, combined with theoretical analysis and innovative research, has developed a wet-bonding low-temperature flexible polyurethane material for bridge deck pumping treatment and its preparation method. Summary of the Invention

[0005] This invention aims to provide a wet-bonding low-temperature flexible polyurethane material for treating bridge surface pumping and its preparation method. The non-polyurethane elastomer has a large deformation rate, high weather resistance, and strong adhesion, which can effectively fill and seal cracks. It has stable performance over a long period of time, is crack-resistant, and effectively seals water. The graded crushed stone mixture is used as a top layer to fill and form a structure, improving the similarity with the original pavement structure. The sprayed material enhances the surface texture, eliminates resin gloss, and further improves the appearance similarity, thereby achieving seamless and traceless repair of road surface cracks.

[0006] To achieve the above objectives, the present invention specifically adopts the following technical solution: The raw materials for preparing a wet-bonding low-temperature flexible polyurethane material for treating bridge deck pumping include the following components in parts by weight: 1.3-5 parts cyclic carbonate, 5-10 parts epoxy resin, 2-5 parts water absorbent, 10-15 parts modified polyurethane, 70-85 parts flexible curing agent, 0.5-2.5 parts reinforcing curing agent, 0.5-1 part silane coupling agent, 0.5-1 part defoamer, and 5-10 parts diluent.

[0007] The cyclic carbonate is one or more of 5- to 10-membered cyclic carbonates, such as five-membered and six-membered cyclic carbonates. Cyclic carbonates can react with amines to form polyurethane groups, effectively avoiding the influence of moisture on curing performance and ensuring performance stability.

[0008] The epoxy resin is a bisphenol A type epoxy resin, such as E-44 or E-51. The epoxy resin cures with amine curing agents, providing early curing strength to the material and effectively preventing damage to the cured structure from epoxy factors such as vehicle vibration, allowing for earlier opening to traffic.

[0009] The absorbent is a molecular sieve activated powder, such as Arkema SA1720 or G5. The powdered molecular sieve has a small particle size, allowing it to disperse evenly within the resin. It can quickly absorb water stains inside the resin, ensuring the inner wall remains dry and improving the adhesion between the polyurethane and the substrate. Simultaneously, moisture permeates through the molecular sieve into the resin, triggering a wet curing reaction of the silane-modified polyurethane. This process consumes moisture while simultaneously increasing the resin's cohesive strength.

[0010] The modified polyurethane is a silane-modified polyurethane, such as Covestro XP 2774, XP 2636, and XP 2458. The silane-modified polyurethane is distributed in small, uniform amounts within the resin, contacting the inner wall of the affected area. It absorbs moisture from the capillaries of the substrate, forming a chemical bond with the substrate and increasing bond strength. Furthermore, it reacts with the moisture absorbed by the molecular sieve activated powder, consuming the absorbed moisture while simultaneously increasing the resin's cohesive strength.

[0011] The reinforcing curing agent is a polyether amine curing agent, such as D230 or D40, which can effectively promote the curing rate of first-order epoxy resin and form early strength.

[0012] The silane coupling agent is one or more of KH-550, KH-560, and A-500; the defoamer is BYK-066N and / or BYK-054; and the diluent is dioctyl phthalate and / or dibutyl phthalate.

[0013] The preparation method of the flexible curing agent includes the following steps: S1. Add 1000 parts by weight of polyether polyol into a four-necked flask, bubble with N2, heat to 120°C, dehydrate under reduced pressure at -0.1 MPa for 2 h, and then cool to 90°C. S2. Add 1-2 parts by weight of isocyanate to a flask and add 0.5-1.5 parts by weight of catalyst. React at 90°C for 1-2 hours to obtain NCO-terminated polyurethane prepolymer. S3. Add 45-230 parts by weight of aliphatic diamine to a flask and react at 90°C for 1-2 hours to obtain amino-terminated polyurethane prepolymer, which is the flexible curing agent.

[0014] The specific reaction formula is as follows:

[0015] The polyether polyol is a linear polyether polyol with dual functionality and a molecular weight ≥2000, such as PPG-2000, PPG-3000, and PPG-5000. The introduction of long-chain linear flexible segments can effectively improve the flexibility of polyurethane, meet the deformation requirements of road surfaces caused by temperature differences and traffic disturbances, effectively seal water, and prevent cracking.

[0016] The isocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate, and polymethylene polyphenyl polyisocyanate.

[0017] The catalyst is an organotin catalyst, such as T-12 or T-9.

[0018] The aliphatic diamine is one or more aliphatic primary diamines with a molecular weight ≤300. Specifically, it is one or more of ethylenediamine, hexamethylenediamine, or trimethylhexamethylenediamine. The flexible curing agent, end-capped with a primary diamine, can be used in the curing reaction with cyclic carbonates, effectively avoiding the influence of moisture on the curing performance. Beneficial effects

[0019] (1) The grouting material has a moderate viscosity of about 1000 mPa.s, with good fluidity and permeability. It can effectively diffuse into the depth of the disease and is not easily diluted or washed away by the water inside the disease, thus avoiding performance degradation caused by contact with water. After the water is squeezed out, it can quickly absorb the damp water stains on the inner wall and achieve interface drying. The grouting material can penetrate into the capillary of the relatively dry interface. The silane-modified polyurethane in the grouting material forms -Si-O- bonds with the inorganic substrate and internal dust, forming a chemical bond to the base surface and chemically consolidating the mud dust, effectively improving the wet bonding strength between the grouting material and the mud-containing interface. (2) The water-absorbing resin is evenly dispersed inside the grouting material. The water stains absorbed from the interface diffuse into the grouting material through the water-absorbing resin and slowly release water vapor, thereby triggering the wet curing reaction of the silane-modified polyurethane inside the grouting material, improving the cohesive strength of the grouting material. At the same time, the epoxy resin in the material undergoes a one-stage cross-linking reaction with the reinforcing curing agent, ensuring that a certain structural strength can be formed in the application environment with or without water in the early stage, ensuring the integrity of the system, shortening the curing time, and quickly opening the road after construction to avoid the reduction of structural strength caused by traffic disturbance. (3) The main cyclic carbonate in the grouting material undergoes a two-stage curing reaction with the curing agent at room temperature. The flexible curing agent can significantly improve the low-temperature flexibility and deformation rate of the grouting material, meeting the deformation requirements during the service of the road surface. The polyurethane grouting material prepared by this curing method effectively avoids the occurrence of side reactions such as foaming and expansion caused by water vapor and temperature. At the same time, the grouting material has stable performance after curing, good low-temperature flexibility, and high strength, which can effectively repair the disease and prevent secondary cracking and water seepage. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The manufacturers and models of raw materials used in each embodiment and comparative example are shown in Table 1 below: Example 1

[0022] Example 1 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The raw materials include the following components in parts by weight: 3.5 parts propylene carbonate, 8 parts epoxy resin E44, 3 parts water absorbent SA1720, 13 parts modified polyurethane XP 2774, 80 parts flexible curing agent, 1.8 parts reinforcing curing agent D230, 0.7 parts silane coupling agent KH-560, 0.8 parts defoamer BYK-066N, and 8 parts diluent DOP.

[0023] The preparation process of the flexible curing agent is as follows: S1. Add 1000g of PPG-3000 polyol to a four-necked flask, bubble with N2, heat to 120℃, dehydrate under reduced pressure at -0.1MPa for 2 h, and then cool to 90℃. S2. Add 2g of MDI-50 isocyanate to the flask according to the ratio, and add 1g of T12 catalyst. React at 90℃ for 1-2 hours to obtain NCO-terminated polyurethane prepolymer. S3. Add 80g of ethylenediamine to a flask and react at 90℃ for 1-2 hours to obtain amino-terminated polyurethane prepolymer. Example 2

[0024] Example 2 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The raw materials include the following components in parts by weight: 1.3 parts ethylene carbonate, 5 parts epoxy resin E51, 5 parts water absorbent SA1720, 15 parts modified polyurethane XP 2636, 70 parts flexible curing agent, 0.5 parts reinforcing curing agent D40, 0.5 parts silane coupling agent KH-550, 0.5 parts defoamer BYK-054, and 5 parts diluent DBP.

[0025] The preparation process of the flexible curing agent is as follows: S1. Add 1000g of PPG-2000 polyol to a four-necked flask, bubble with N2, heat to 120℃, dehydrate under reduced pressure at -0.1MPa for 2 h, and then cool to 90℃. S2. Add 2g of TDI-80 isocyanate to the flask according to the ratio, and add 0.5g of T-9 catalyst. React at 90℃ for 1-2 hours to obtain NCO-terminated polyurethane prepolymer. S3. Add 230g of hexamethylenediamine to a flask and react at 90℃ for 1-2 hours to obtain amino-terminated polyurethane prepolymer. Example 3

[0026] Example 3 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The raw materials include the following components in parts by weight: 5 parts propylene carbonate, 10 parts epoxy resin E12, 2 parts water absorbent G5, 10 parts modified polyurethane XP2458, 85 parts flexible curing agent, 2.5 parts reinforcing curing agent D230, 1 part silane coupling agent A-500, 1 part defoamer BYK-066N, and 10 parts diluent DOP.

[0027] The preparation process of the flexible curing agent is as follows: S1. Add 1000g of PPG-5000 polyol to a four-necked flask, bubble with N2, heat to 120℃, dehydrate under reduced pressure at -0.1MPa for 2 h, and then cool to 90℃. S2. Add 1g of M20S isocyanate to the flask according to the proportion, and add 1.5g of T12 catalyst. React at 90℃ for 1-2 hours to obtain NCO-terminated polyurethane prepolymer. S3. Add 50g of ethylenediamine to a flask and react at 90℃ for 1-2 hours to obtain amino-terminated polyurethane prepolymer. Example 4

[0028] Example 4 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The raw materials include the following components in parts by weight: 3 parts propylene carbonate, 10 parts epoxy resin E12, 2.5 parts water absorbent SA1720, 12 parts modified polyurethane XP 2774, 73 parts flexible curing agent, 2.5 parts reinforcing curing agent D40, 0.7 parts silane coupling agent KH-560, 1.1 parts defoamer BYK-066N, and 8 parts diluent DOP.

[0029] The preparation process of the flexible curing agent is as follows: S1. Add 1000g of PPG-3000 polyol to a four-necked flask, bubble with N2, heat to 120℃, dehydrate under reduced pressure at -0.1MPa for 2 h, and then cool to 90℃. S2. Add 2g of MDI-50 isocyanate to the flask according to the ratio, and add 1g of T12 catalyst. React at 90℃ for 1-2 hours to obtain NCO-terminated polyurethane prepolymer. S3. Add 80g of ethylenediamine to a flask and react at 90℃ for 1-2 hours to obtain amino-terminated polyurethane prepolymer.

[0030] Comparative Example 1 Comparative Example 1 provides a wet-bonding low-temperature flexible polyurethane material for treating bridge deck pumping, which differs from Example 1 in that it does not contain cyclic carbonate.

[0031] Comparative Example 2 Comparative Example 2 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks, which differs from Example 1 in that no epoxy resin is added.

[0032] Comparative Example 3 Comparative Example 3 provides a wet-bonding low-temperature flexible polyurethane material for treating bridge deck pumping, which differs from Example 1 in that no water-absorbing agent is added.

[0033] Comparative Example 4 Comparative Example 4 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The difference from Example 1 is that no modified polyurethane is added.

[0034] Comparative Example 5 Comparative Example 5 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The difference from Example 1 is that the polyether polyol PPG-3000 is replaced with an equal mass of PTMEG.

[0035] Comparative Example 6 Comparative Example 6 provides a wet-bonding low-temperature flexible polyurethane material for treating pumping slurry on bridge decks. The difference from Example 1 is that the polyether polyol PPG-3000 is replaced with an equal mass of 330.

[0036]

[0037] Note: The specific test items and basic test standards are as follows: acid and alkali resistance refer to GB / T 9756-2018; abrasion resistance refer to GB / T9756-2018; elongation at break and tensile strength refer to GB / T_1040.1-2018; asphalt aging refer to JTG / E20-2011; adhesion test method refers to GB / T16777-2008; low temperature performance refers to GB 18242-2008.

[0038] After mixing the raw materials of each embodiment and comparative example, performance tests were conducted. As shown in Table 2, Examples 1-2 are several preferred embodiments of the present invention. The data shows that the wet-bonding low-temperature flexible polyurethane material prepared using the above method and materials has a moderate initial viscosity of 1000 cps, effectively resists dispersion, has a slow viscosity rise rate within the first 10 minutes, and has good fluidity and diffusion properties. After grouting for 1 hour, a first-stage reaction is formed, and the tensile strength can reach more than 1.5 MPa, effectively resisting disturbance and allowing traffic to be opened. After curing for 7 days, the tensile strength is >4 MPa, the elongation is >300%, the bond strength is >2 MPa, the low-temperature flexibility at -20℃ is excellent, and the environmental humidity has no effect on the mechanical properties and bond strength of the resin.

[0039] Comparative Example 1, lacking cyclic carbonate, resulted in the inability of the flexible curing agent to cure, leading to low overall structural strength, poor low-temperature flexibility, and poor adhesive strength. Comparative Example 2, lacking epoxy resin, lacked the early structural strength formed by epoxy resin curing in the initial stage of grouting, hindering timely traffic development after grouting and ultimately resulting in relatively low strength. Comparative Example 3, lacking a water-absorbing agent, resulted in a significant water film between the grouting material and the affected area, leading to a substantial decrease in material adhesive strength. Comparative Example 4, lacking modified polyurethane, failed to adequately absorb interface water stains, resulting in decreased adhesive strength. Comparative Example 5, replacing polyether polyol PPG-3000 with an equal mass of PTMEG, increased the initial viscosity of the grouting material, decreased its permeability and flexibility, and rendered it ineffective at preventing low-temperature cracking. Comparative Example 6, replacing polyether polyol PPG-3000 with an equal mass of 330, increased the cohesive strength of the grouting material but reduced its low-temperature flexibility.

[0040] The embodiments described above are merely examples 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 low-temperature flexible polyurethane material for wet bonding in the treatment of pumping slurry on bridge decks, characterized in that, The raw materials of the polyurethane material include the following components in parts by weight: 1.3-5 parts cyclic carbonate, 5-10 parts epoxy resin, 2-5 parts water absorbent, 10-15 parts modified polyurethane, 70-85 parts flexible curing agent, 0.5-2.5 parts reinforcing curing agent, 0.5-1 part silane coupling agent, 0.5-1 part defoamer, and 5-10 parts diluent.

2. The low-temperature flexible polyurethane material for wet bonding in bridge deck pumping repair according to claim 1, characterized in that, The cyclic carbonate is one or more of 5- to 10-membered cyclic carbonates.

3. The low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 1, characterized in that, The epoxy resin is a bisphenol A type epoxy resin.

4. The low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 1, characterized in that, The absorbent is molecular sieve activated powder.

5. A low-temperature flexible polyurethane material for wet bonding in bridge deck pumping repair according to claim 1, characterized in that, The modified polyurethane is a silane-modified polyurethane.

6. The low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 1, characterized in that, The enhanced curing agent is a polyetheramine curing agent.

7. A low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 1, characterized in that, The silane coupling agent is one or more of KH-550, KH-560, and A-500; the defoamer is BYK-066N and / or BYK-054; and the diluent is dioctyl phthalate and / or dibutyl phthalate.

8. The low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 1, characterized in that, The preparation method of the flexible curing agent includes the following steps: S1. Add 1000 parts by weight of polyether polyol into a four-necked flask, bubble with N2, heat to 120°C, dehydrate under reduced pressure at -0.1 MPa for 2 h, and then cool to 90°C. S2. Add 1-2 parts by weight of isocyanate to a flask and add 0.5-1.5 parts by weight of catalyst. React at 90°C for 1-2 hours to obtain NCO-terminated polyurethane prepolymer. S3. Add 45-230 parts by weight of aliphatic diamine to a flask and react at 90°C for 1-2 hours to obtain amino-terminated polyurethane prepolymer, which is the flexible curing agent.

9. A low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 8, characterized in that, The polyether polyol is a linear polyether polyol with dual functionality and a molecular weight ≥2000; the isocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate, and polymethylene polyphenyl polyisocyanate; the catalyst is an organotin catalyst.

10. A low-temperature flexible polyurethane material for wet bonding in bridge deck pumping treatment according to claim 8, characterized in that, The aliphatic diamine is one or more of the aliphatic primary diamines with a molecular weight ≤300.

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