Anti-seismic polyurethane protective glue as well as preparation method and application thereof

Abstract

The invention relates to an anti-seismic polyurethane protective adhesive as well as a preparation method and application thereof. The anti-seismic polyurethane protective glue is prepared from the following raw materials: a composite chain extender, isocyanate and polyol, the composite chain extender is selected from a combination comprising a nitrogen-containing chain extender and a sulfur-containing chain extender. The anti-seismic polyurethane protective glue has excellent elongation and tensile strength, also has good anti-seismic performance and protective performance on concrete, and can provide long-acting anti-seismic and anti-seepage protection for water, underwater and water level change areas of an upstream dam body of a water conservancy dam.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials and hydraulic engineering, and particularly relates to an anti-seismic polyurethane protective glue as well as a preparation method and application thereof. BACKGROUND

[0002] In the field of building engineering and hydraulic engineering, especially in earthquake-prone areas, concrete structures need to have good anti-seismic performance. As a commonly used building sealing and protective material, the performance of polyurethane protective glue directly affects the durability and anti-seismic effect of concrete structures.

[0003] At present, solvent-based and solvent-free aspartic polyurea, epoxy and polyurethane series products on the market have deficiencies in the balance of elongation and strength, and are insufficient in anti-seepage and anti-seismic performance protection of dam bodies, have many leakage points and have extremely high maintenance costs in the later period. At the same time, some traditional preparation processes involve the use of a large amount of organic solvents, which not only pollute the environment but also have safety hazards. In addition, the existing similar patents have limitations in molecular structure design and preparation route, and cannot fully exert the potential of polyurethane materials in the anti-seismic protection of concrete.

[0004] Therefore, it is of great practical significance to develop an anti-seismic polyurethane protective glue with high performance, environmental protection and innovative preparation route. SUMMARY

[0005] To solve the above technical problems, the present application provides an anti-seismic polyurethane protective glue as well as a preparation method and application thereof. The anti-seismic polyurethane protective glue has excellent elongation and tensile strength, and at the same time has good anti-seismic performance and protective performance for concrete, and can provide long-acting anti-seismic and anti-leakage protection for the upstream dam body of a water conservancy dam, the underwater and water level fluctuation area.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides an anti-seismic polyurethane protective glue, and the preparation raw materials of the anti-seismic polyurethane protective glue include a composite chain extender, isocyanate and polyol.

[0008] The composite chain extender is selected from a combination of nitrogen-containing chain extenders and sulfur-containing chain extenders.

[0009] The preparation raw material of the anti-seismic polyurethane protective glue is optimized, nitrogen-containing chain extender and sulfur-containing chain extender are used as composite chain extenders, the advantages of the chemical structures and reaction characteristics of the two can be better combined, the two can play a synergistic effect, so that the strength of the obtained anti-seismic polyurethane protective glue is improved, and the elongation rate is also ensured, the anti-seismic performance and the protection performance on concrete are excellent, under the action of dynamic load such as earthquake, energy can be effectively absorbed and dispersed, the concrete structure can be protected from damage, and then the anti-seismic polyurethane protective glue can be well applied to the anti-seismic material of the dam body of the water conservancy project, and long-acting anti-seismic and anti-leakage protection can be provided for the dam body on the water, underwater and water level fluctuation area of the water conservancy dam.

[0010] The amino group in the nitrogen-containing chain extender can react with the isocyanate group in the isocyanate to form a urea bond with high strength and rigidity, so that the intermolecular force can be enhanced, and the overall strength of the obtained anti-seismic polyurethane protective glue can be improved; the mercapto group in the sulfur-containing chain extender can react with the isocyanate group in the isocyanate to form a certain flexible thiourethane bond, and the existence of sulfur atoms increases the interaction between molecular chains, further improves the crosslinking density and the flexibility of the obtained anti-seismic polyurethane protective glue, through the synergistic effect of the two, the obtained anti-seismic polyurethane protective glue can improve the tensile strength while ensuring the elongation rate.

[0011] The following is a preferred technical scheme of the present application, but is not a limitation on the technical scheme provided by the present application. Through the following preferred technical scheme, the purpose and beneficial effects of the present application can be better achieved and realized.

[0012] As a preferred technical scheme of the present application, the molar ratio of the nitrogen-containing chain extender and the sulfur-containing chain extender is (1-2):1, wherein (1-2) can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2, and specific point values between the above point values, limited to the length and for the sake of simplicity, the present application does not exhaustively list the specific point values included in the range.

[0013] By optimizing the molar ratio of the nitrogen-containing chain extender and the sulfur-containing chain extender in the composite chain extender, the obtained anti-seismic polyurethane protective glue has more excellent elongation rate and tensile strength, so that it can be better applied to the anti-seismic protection of the dam body of the water conservancy project. When the molar ratio of the two is low, the tensile strength is reduced due to the lack of nitrogen-containing chain extender, the obtained anti-seismic polyurethane protective glue is easy to be torn after repeated vibration, and the anti-seismic performance is reduced; when the molar ratio of the two is high, the flexibility is reduced due to the lack of sulfur-containing chain extender, the elongation rate is reduced, the obtained anti-seismic polyurethane protective glue is easy to appear brittle fracture after repeated vibration, and the anti-seismic performance is reduced.

[0014] Preferably, the nitrogen-containing chain extender includes any one or a combination of at least two of ethylenediamine, propylenediamine, butylenediamine, or hexamethylenediamine.

[0015] Preferably, the sulfur-containing chain extender includes dimercaprol.

[0016] Preferably, the molar ratio of the composite chain extender to the isocyanate is 1:(3.5-4.2), wherein (3.5-4.2) can be, for example, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1 or 4.2, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0017] Preferably, the isocyanate comprises 4,4'-diphenylmethane diisocyanate and / or toluene diisocyanate.

[0018] Preferably, the isocyanate is selected from a combination including 4,4'-diphenylmethane diisocyanate and toluene diisocyanate.

[0019] In this invention, by compounding 4,4'-diphenylmethane diisocyanate (MDI) and toluene diisocyanate (TDI), a shock-resistant polyurethane protective adhesive can achieve a comprehensive technical effect with excellent flexibility and strength. MDI has high reactivity and a rigid structure, which can improve the strength of the resulting shock-resistant polyurethane protective adhesive; TDI can regulate the reaction rate and the flexibility of the resulting shock-resistant polyurethane protective adhesive.

[0020] As a preferred embodiment of the present invention, the molar ratio of 4,4'-diphenylmethane diisocyanate and toluene diisocyanate is (4-6):1, wherein (4-6) can be, for example, 4, 4.2, 4.4, 4.6, 4.8, 5, 5.2, 5.4, 5.6, 5.8 or 6, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0021] In this invention, by controlling the molar ratio of MDI to TDI within the range of (4-6):1, the hard segment structure of the resulting polyurethane protective adhesive can be better optimized, ensuring that the elongation is not excessively sacrificed while increasing strength. The rigid benzene ring structure of MDI can form strong intermolecular forces and physical cross-linking points, improving the overall strength of the resulting polyurethane protective adhesive. By combining it with other raw material components, the strength of the resulting shock-resistant polyurethane protective adhesive can reach 10 MPa. The introduction of TDI, due to the different reactivity of isocyanate groups at different positions in its structure, can play a regulating role in the reaction process, avoiding an overly vigorous reaction. At the same time, its relatively small molecular structure helps to increase the flexibility of the molecular chain to a certain extent.

[0022] When the molar ratio of the two is low, the strength of the resulting seismic-resistant polyurethane protective adhesive is poor. In this case, the protective effect is reduced due to insufficient strength, and after repeated vibration, the number of cracks is likely to increase and expand, resulting in poor seismic performance. When the molar ratio of the two is high, the elongation of the resulting seismic-resistant polyurethane protective adhesive is poor. In this case, due to insufficient flexibility, it is unable to effectively disperse stress, and after repeated vibration, the number of cracks is likely to increase and expand, resulting in poor seismic performance.

[0023] Preferably, the polyol comprises a polyether polyol.

[0024] The polyether polyol in this invention possesses excellent flexibility and hydrolysis resistance, providing flexible chain segments for polyurethane and contributing to improved elongation of the resulting shock-resistant polyurethane protective adhesive. The presence of ether bonds in the polyether polyol molecular structure endows the molecular chain with good flexibility, allowing it to effectively stretch under external force, thereby imparting high elongation to the polyurethane protective adhesive.

[0025] Preferably, the polyether polyol includes any one or a combination of at least two of polyethylene glycol (PEG), polypropylene glycol (PPG), polypropylene triol (PGPR), polypropylene-ethylene glycol, or polytetrahydrofuran glycol (PTMEG), and more preferably polytetrahydrofuran glycol.

[0026] The regular structure of polytetrahydrofuran diol in this invention enables its intermolecular forces to be relatively stable, allowing it to arrange and slide in an orderly manner during stretching, thus providing a good foundation for achieving the high elongation of the obtained polyurethane protective adhesive.

[0027] Preferably, the number average molecular weight of the polyether polyol is 2000-4000, for example, it can be 2000, 2200, 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800 or 4000, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0028] Preferably, based on a polyol mass percentage of 100%, the mass percentage of the silane coupling agent is 1-2%, for example, it can be 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0029] As a preferred embodiment of the present invention, the raw materials for preparing the anti-seismic polyurethane protective adhesive also include additives.

[0030] Preferably, the additives include any one or a combination of at least two of fillers, antioxidants, or ultraviolet absorbers.

[0031] In this invention, fillers enhance the mechanical properties (strength and toughness) of the obtained shock-resistant polyurethane protective adhesive; antioxidants and ultraviolet absorbers improve the aging resistance of the obtained shock-resistant polyurethane protective adhesive. Among them, antioxidants can capture free radicals in the system, inhibit the oxidation reaction, and prevent the degradation of polyurethane molecular chains; ultraviolet absorbers can absorb ultraviolet energy and convert it into harmless forms such as heat energy, avoiding damage to the polyurethane molecular structure by ultraviolet rays, thereby improving the service life of the obtained shock-resistant polyurethane protective adhesive in outdoor environments.

[0032] Preferably, based on the total mass percentage of the raw materials for preparing the anti-seismic polyurethane protective adhesive being 100%, the mass percentage of the filler is 5-10%, for example, it can be 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% or 10%, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0033] As a preferred embodiment of the present invention, the filler comprises nano-silica.

[0034] This invention selects nano-silica as a reinforcing filler with a particle size between 50-100nm. It has a large specific surface area and surface activity, and can form physical or chemical bonds with polyurethane molecules, thereby forming strong interactions such as hydrogen bonds and van der Waals forces. When subjected to force, it can effectively transfer stress, thereby better enhancing the mechanical properties (strength and toughness) of the obtained shock-resistant polyurethane protective adhesive, and thus improving its shock resistance and durability.

[0035] Preferably, based on the total mass percentage of the raw materials used to prepare the anti-seismic polyurethane protective adhesive being 100%, the mass percentage of the antioxidant is 0.2-0.5%, for example, it can be 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%, as well as specific values ​​between the above-mentioned values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0036] It should be noted that the present invention does not impose any special limitations on the specific type of antioxidant. Conventional antioxidants in the art are applicable, including but not limited to: antioxidant 1010, antioxidant 1076, antioxidant 168, antioxidant 264, antioxidant 2264, antioxidant 1098, antioxidant 245, antioxidant 300 or antioxidant 330, etc.

[0037] Preferably, based on the total mass percentage of the raw materials for preparing the anti-seismic polyurethane protective adhesive being 100%, the mass percentage of the ultraviolet absorber is 0.2-0.5%, for example, it can be 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0038] It should be noted that there are no special limitations on the specific type of ultraviolet absorber in this invention. Conventional ultraviolet absorbers in the art are applicable, including but not limited to UV-324, UV-326, UV-327, UV-329, UV-531, UV-541 or UV-1157, etc.

[0039] In a second aspect, the present invention provides a method for preparing the anti-seismic polyurethane protective adhesive as described in the first aspect, the method comprising the following steps:

[0040] Polyol and isocyanate are subjected to urethane reaction to obtain prepolymer, a composite chain extender is added to carry out chain extension reaction, and then optional additives are added and mixed to obtain the shock-resistant polyurethane protective adhesive.

[0041] As a preferred embodiment of the present invention, the polyol further includes a dehydration treatment step before undergoing the urethane reaction.

[0042] This invention effectively removes water from polyols by pre-dehydrating them, preventing the reaction of water with isocyanates to produce carbon dioxide bubbles, which would otherwise affect product quality.

[0043] Preferably, the dehydration treatment method includes vacuum dehydrating the polyol at 100-110°C for 2-3 hours, wherein 100-110°C can be, for example, 100°C, 101°C, 102°C, 103°C, 104°C, 105°C, 106°C, 107°C, 108°C, 109°C, or 110°C, and 2-3 hours can be, for example, 2 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours, or 3 hours, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0044] Preferably, in the urethane reaction, the molar ratio of the OH group in the polyol to the NCO group in the isocyanate is 1:(1.3-1.7), where (1.3-1.7) can be, for example, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, or 1.7, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0045] It should be noted that in the calculation of the amount of substance (mol) of polyol, the average number-average molecular weight of the polyol is used as the molar mass. Then, the molar amount of OH groups in the polyol is the amount of substance of the polyol × the number of -OH groups per mole of polyol. The molar amount of NCO groups in isocyanate refers to the total amount of -NCO in the isocyanate used.

[0046] As a preferred embodiment of the present invention, the esterification reaction includes a first-stage reaction and a second-stage reaction.

[0047] Preferably, the temperature of the first stage reaction is 70-75℃ and the time is 1-1.5h. The 70-75℃ can be, for example, 70℃, 71℃, 72℃, 73℃, 74℃ or 75℃, and the 1-1.5h can be, for example, 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0048] Preferably, the temperature of the second stage reaction is 75-80℃ and the time is 1-1.5h. The 75-80℃ can be, for example, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃, and the 1-1.5h can be, for example, 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0049] Compared with the traditional isothermal reaction method, the present invention sets up a first-stage reaction and a second-stage reaction, so that the esterification reaction is carried out in a gradient temperature manner, thereby making the reaction more stable and effectively avoiding the occurrence of side reactions caused by local overheating, which in turn helps to improve the quality stability of the prepolymer.

[0050] Preferably, the esterification reaction is carried out in a protective gas atmosphere.

[0051] Preferably, the protective gas includes any one or a combination of at least two of nitrogen, argon, and helium.

[0052] As a preferred embodiment of the present invention, the composite chain extender is added in batches.

[0053] Compared with the traditional process of adding chain extenders all at once, the present invention adds the composite chain extender in batches for reaction, which can better control the growth rate of molecular chains, make the molecular chain structure more regular, and thus optimize the mechanical properties of the resulting shock-resistant polyurethane protective adhesive.

[0054] Preferably, the batch addition is performed 2-4 times, for example, 2 times, 3 times or 4 times.

[0055] Preferably, when the composite chain extender is added in batches, the mass of the composite chain extender added each time is the same.

[0056] Specifically, when the number of batches added is n (n is 2, 3 or 4), the mass of the composite chain extender added each time is 1 / n of the total mass of the composite chain extender.

[0057] Preferably, the chain extension reaction is carried out at a temperature of 70-80°C for a time of 1.5-2.5 hours. The 70-80°C can be, for example, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, or 80°C. The 1.5-2.5 hours can be, for example, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, 2 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, or 2.5 hours. Specific values ​​within the ranges mentioned above are not exhaustively listed here for space limitations and for the sake of brevity.

[0058] It should be noted that, in order to make the mixture of the additives and the system after the chain extension reaction more uniform, the filler can be added first, followed by the antioxidant and ultraviolet absorber. For example, the method of adding the additives in this invention includes the following steps:

[0059] After the chain extension reaction, add filler and stir for 1-1.5 hours, then add antioxidant and ultraviolet absorber and stir for 0.5-1 hours.

[0060] Among them, 1-1.5h can be, for example, 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, and 0.5-1h can be, for example, 0.5h, 0.6h, 0.7h, 0.8h, 0.9h or 1, as well as the specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0061] Preferably, the filler needs to undergo a pretreatment step before being added.

[0062] Preferably, the pretreatment method of the filler includes drying the filler at 120-130℃ for 2-2.5h, cooling it to 20-30℃, and then ultrasonically dispersing it with a dispersant for 30-40min to obtain a filler dispersion.

[0063] This invention pretreats the filler to form a filler dispersion, and by adding the filler dispersion in combination with stepwise mixing with other additives, the full effect of each component can be better ensured.

[0064] Among these, 120-130℃ can be, for example, 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, or 130℃; 2-2.5h can be, for example, 2h, 2.1h, 2.2h, 2.3h, 2.4h, or 2.5h; 20-30℃ can be, for example, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, or 30℃; 30-40min can be, for example, 30min, 31min, 32min, 33min, 34min, 35min, 36min, 37min, 38min, 39min, or 40min; and specific point values ​​between the above-mentioned point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0065] Preferably, the dispersant comprises DISPERBYK-2009 dispersant.

[0066] Preferably, the amount of dispersant added is 20-50% of the filler mass, for example, it can be 20%, 25%, 30%, 35%, 40%, 45% or 50%, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0067] Preferably, the mixing process further includes a post-processing step.

[0068] Preferably, the post-processing method includes vacuum degassing.

[0069] Preferably, the vacuum degree of the vacuum degassing is ≤0.1MPa, for example, it can be 0.1MPa, 0.099MPa, 0.098MPa, 0.097MPa, 0.096MPa, 0.095MPa, 0.094MPa, 0.093MPa, 0.092MPa, 0.091MPa or 0.09MPa, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0070] Preferably, the vacuum degassing temperature is 40-60℃, for example, it can be 40℃, 42℃, 45℃, 48℃, 50℃, 52℃, 55℃, 58℃ or 60℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0071] Preferably, the vacuum degassing time is 1-2 hours, for example, it can be 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours or 2 hours, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0072] Specifically, the preparation method of the seismic-resistant polyurethane protective adhesive includes the following steps:

[0073] Under a protective gas atmosphere, the polyol is heated to 100-110℃ for vacuum dehydration for 2-3 hours, then cooled to 70-75℃, isocyanate is added, and the first stage reaction is carried out for 1-1.5 hours. After that, the temperature is raised to 75-80℃ for the second stage reaction for 1-1.5 hours to obtain the prepolymer. The molar ratio of OH groups in the polyol to NCO groups in the isocyanate is 1:(1.3-1.7).

[0074] The composite chain extender is added to the prepolymer in batches at 70-80℃, and the chain extension reaction is carried out for 1.5-2.5h. Then, filler is added and stirred for 1-1.5h. Antioxidant and ultraviolet absorber are added and stirred for 0.5-1h. Vacuum degassing is carried out for 1-2h under vacuum degree ≤0.1MPa to obtain the shock-resistant polyurethane protective adhesive.

[0075] The anti-seismic polyurethane protective adhesive provided by this invention does not use organic solvents in its preparation process, meeting environmental protection requirements and reducing environmental pollution and harm to the health of construction workers. Compared with traditional solvent-based polyurethane protective adhesives, it effectively avoids the large-scale volatilization of organic solvents during production and use, reducing the risk of fire, and significantly improving the air quality at the construction site.

[0076] Thirdly, the present invention provides an application of the seismic-resistant polyurethane protective adhesive as described in the first aspect in the seismic-resistant materials of dam bodies in hydraulic engineering.

[0077] Compared with the prior art, the present invention has at least the following beneficial effects:

[0078] (1) The raw materials for preparing the anti-seismic polyurethane protective adhesive provided by the present invention use nitrogen-containing chain extenders and sulfur-containing chain extenders as composite chain extenders, which can improve the strength of the obtained anti-seismic polyurethane protective adhesive while ensuring its good elongation, so that it has good seismic performance and concrete protection performance. Furthermore, the present invention uses composite chain extenders and specific isocyanates for compounding in molecular structure design, and strictly controls the reaction conditions at each stage in the preparation process, which greatly improves the controllability and stability of product performance, so that the elongation and strength performance of the obtained anti-seismic polyurethane protective adhesive fluctuates within a very small range, and can be well applied to concrete seismic protection, stably meeting the actual engineering needs.

[0079] (2) The anti-seismic polyurethane protective adhesive provided by the present invention has excellent strength and flexibility, with an elongation of 400-1050% and a tensile strength of 4.5-10.5MPa. Furthermore, by selecting and proportioning its raw materials and optimizing its preparation method, the resulting anti-seismic polyurethane protective adhesive can have an elongation of 750-1050% and a tensile strength of 7.5-10.5MPa, achieving a seismic resistance level of 1. Thus, under dynamic loads such as earthquakes, it can more effectively absorb and disperse energy, and better protect concrete structures from damage. Detailed Implementation

[0080] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0081] Unless otherwise specified, all raw materials and reagents used in the following examples and comparative examples are commercially available products. Some raw material information is shown in Table 1.

[0082] Table 1

[0083]

[0084] Example 1

[0085] This embodiment provides a shock-resistant polyurethane protective adhesive and its preparation method. The raw materials for preparing the shock-resistant polyurethane protective adhesive include a composite chain extender (3g ethylenediamine and 6.2g dimercaptopropanol, with a molar ratio of 1:1), isocyanate (75g MDI and 12g TDI, with a molar ratio of 4.3:1), polytetrahydrofurandiol 1, 10g nano silica, 0.5g antioxidant 1010, and 0.5g ultraviolet absorber UV-531.

[0086] Pretreatment of filler: 10g of nano silica was dried at 125℃ for 2.2h, cooled to 25℃ and then ultrasonically dispersed with 3g of DISPERBYK-2009 dispersant for 35min to obtain nano silica dispersion 1.

[0087] The preparation method of the earthquake-resistant polyurethane protective adhesive includes the following steps:

[0088] Under nitrogen protection, polytetrahydrofuran diol 1 was added to a reactor, heated to 105°C for vacuum dehydration for 2.5 h, cooled to 72°C, and MDI and TDI were added. After reacting for 1.2 h, the temperature was raised to 78°C and reacted for 1.3 h to obtain a prepolymer. The molar ratio of OH groups in polytetrahydrofuran diol 1 to NCO groups in isocyanates (MDI and TDI) was 1:1.5.

[0089] After mixing ethylenediamine and dimercaprol evenly, half of their total mass was added to the prepolymer at 75°C. After reacting for 35 minutes, the remaining half was added, and the reaction continued for 1.2 hours. Nano silica dispersion 1 was added, and the mixture was stirred for 1.2 hours. Then, antioxidants and ultraviolet absorbers were added, and the mixture was stirred and mixed for 0.75 hours. The mixture was then degassed under a vacuum of 0.098 MPa for 1.5 hours to obtain the shock-resistant polyurethane protective adhesive.

[0090] Example 2

[0091] This embodiment provides a shock-resistant polyurethane protective adhesive and its preparation method. The raw materials for preparing the shock-resistant polyurethane protective adhesive include a composite chain extender (5g ethylenediamine and 5.1g dimercaptopropanol, with a molar ratio of 2:1), isocyanate (90g MDI and 14g TDI, with a molar ratio of 4.5:1), polytetrahydrofurandiol 2, 24g nano silica, 1.2g antioxidant 1010, and 1.2g ultraviolet absorber UV-531.

[0092] Pretreatment of filler: 24g of nano silica was dried at 120℃ for 2h, cooled to 20℃ and then ultrasonically dispersed with 5g of DISPERBYK-2009 dispersant for 40min to obtain nano silica dispersion 2.

[0093] The preparation method of the earthquake-resistant polyurethane protective adhesive includes the following steps:

[0094] Under nitrogen protection, polytetrahydrofuran diol 2 was added to a reaction vessel, heated to 100°C for vacuum dehydration for 3 hours, cooled to 70°C, and MDI and TDI were added. After reacting for 1.5 hours, the temperature was raised to 75°C and reacted for another 1.5 hours to obtain a prepolymer. The molar ratio of OH groups in polytetrahydrofuran diol 2 to NCO groups in isocyanates (MDI and TDI) was 1:1.3.

[0095] After mixing ethylenediamine and dimercaprol evenly, half of their total mass was added to the prepolymer at 70°C. After reacting for 40 minutes, the remaining half was added, and the reaction continued for 1.5 hours. Then, nano-silica dispersion 2 was added, and the mixture was stirred for 1.5 hours. Finally, antioxidants and ultraviolet absorbers were added, and the mixture was stirred and mixed for 1 hour. The mixture was then degassed under a vacuum of 0.096 MPa for 2 hours to obtain the shock-resistant polyurethane protective adhesive.

[0096] Example 3

[0097] This embodiment provides a shock-resistant polyurethane protective adhesive and its preparation method. The raw materials for preparing the shock-resistant polyurethane protective adhesive include a composite chain extender (4g ethylenediamine and 4.1g dimercaptopropanol, with a molar ratio of 2:1), isocyanate (85g MDI and 13g TDI, with a molar ratio of 4.6:1), polytetrahydrofurandiol 3, 11g nano silica, 0.55g antioxidant 1010, and 0.55g ultraviolet absorber UV-531.

[0098] Pretreatment of filler: 11g of nano silica was dried at 130℃ for 2h, cooled to 30℃ and then ultrasonically dispersed with 4g of DISPERBYK-2009 dispersant for 30min to obtain nano silica dispersion 3.

[0099] The preparation method of the earthquake-resistant polyurethane protective adhesive includes the following steps:

[0100] Under nitrogen protection, polytetrahydrofuran diol 3 was added to a reaction vessel, heated to 110°C for vacuum dehydration for 2 hours, cooled to 75°C, and MDI and TDI were added. After reacting for 1 hour, the temperature was raised to 80°C and reacted for 1 hour to obtain a prepolymer. The molar ratio of OH groups in polytetrahydrofuran diol 3 to NCO groups in isocyanates (MDI and TDI) was 1:1.7.

[0101] After mixing ethylenediamine and dimercaprol evenly, half of their total mass is added to the prepolymer at 80°C. After reacting for 30 minutes, the remaining half is added, and the reaction continues for 1 hour. Nano-silica dispersion 3 is added, and the mixture is stirred for 1 hour. Then, antioxidants and ultraviolet absorbers are added, and the mixture is stirred and mixed for 0.5 hours. The mixture is then degassed under a vacuum of 0.095 MPa for 1 hour to obtain the shock-resistant polyurethane protective adhesive.

[0102] Example 4

[0103] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of ethylenediamine and dimercaprol is adjusted from 1:1 to 0.5:1, that is, 2g of ethylenediamine and 8.3g of dimercaprol are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0104] Example 5

[0105] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of ethylenediamine and dimercaprol is adjusted from 1:1 to 1.5:1, that is, 3.6g of ethylenediamine and 5g of dimercaprol are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0106] Example 6

[0107] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of ethylenediamine and dimercaprol is adjusted from 1:1 to 2:1, that is, 4g of ethylenediamine and 4.1g of dimercaprol are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0108] Example 7

[0109] This embodiment provides a shock-resistant polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of ethylenediamine and dimercaprol is adjusted from 1:1 to 2.5:1, that is, 4.3g of ethylenediamine and 3.5g of dimercaprol are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0110] Example 8

[0111] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of MDI to TDI is adjusted from 4.3:1 to 3.5:1, that is, 72g of MDI and 14.3g of TDI are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0112] Example 9

[0113] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of MDI to TDI is adjusted from 4.3:1 to 5:1, that is, 77.2g of MDI and 10.7g of TDI are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0114] Example 10

[0115] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of MDI to TDI is adjusted from 4.3:1 to 6:1, that is, 79.2g of MDI and 9.2g of TDI are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0116] Example 11

[0117] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Example 1 is that the molar ratio of MDI to TDI is adjusted from 4.3:1 to 6.5:1, that is, 92.3g of MDI and 9.9g of TDI are added. The other raw materials, addition amounts and preparation methods are the same as in Example 1.

[0118] Example 12

[0119] This embodiment provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this embodiment and Embodiment 1 is that nano-silica is not added. All other raw materials, amounts added, and preparation methods are the same as in Embodiment 1.

[0120] Comparative Example 1

[0121] This comparative example provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this example and Example 1 is that the composite chain extender (3g ethylenediamine and 4g dimercaptopropanol in a molar ratio of 1:1) is replaced with 7.5g ethylenediamine. All other raw materials, amounts added, and preparation methods are the same as in Example 1.

[0122] Comparative Example 2

[0123] This comparative example provides an anti-vibration polyurethane protective adhesive and its preparation method. The only difference between this example and Example 1 is that the composite chain extender (3g ethylenediamine and 4g dimercaprol, with a molar ratio of 1:1) is replaced with 10.3g dimercaprol. All other raw materials, amounts added, and preparation methods are the same as in Example 1.

[0124] The anti-seismic polyurethane protective adhesives obtained in Examples 1-12 and Comparative Examples 1-2 were subjected to performance tests. The test methods / standards are as follows:

[0125] (1) Tensile test: According to standard GB / T 528-2009, the elongation and tensile strength of the anti-vibration polyurethane protective adhesive were tested using a universal testing machine;

[0126] (2) Seismic performance simulation: using silane treatment agent (Evonik) BHN) pre-treatment of concrete samples was performed, followed by application of seismic-resistant polyurethane protective adhesive with a dry film thickness of 2mm. After 7 days of curing at room temperature, concrete specimens were obtained. Using a seismic simulation shaking table, and following Chinese JGJ / T 101 (Level 5) and referencing American ATC-63 (Level 5) seismic waves, the surface crack width and structural changes of the concrete specimens were tested after three simulated earthquakes. Level 1 refers to no visible cracks or only minor surface cracks (width ≤ 0.1mm); Level 2 refers to a small number of localized bending or shear cracks (width 0.1-0.3mm); Level 3 refers to an increase in the number and expansion of cracks, with the appearance of a main crack (width 0.3-1.0mm); Level 4 refers to a main crack width > 1.0mm, with some areas showing concrete spalling and crumbling (especially in the plastic hinge zone), and significant exposed reinforcement; Level 5 refers to severe crumbling and collapse of the component, with complete exposure and significant buckling of the reinforcement (such as column reinforcement buckling).

[0127] The test results are shown in Table 2.

[0128] Table 2

[0129] Elongation (%) Tensile strength (MPa) Shake resistance Example 1 1050 10.5 Grade 1 Example 2 1050 10.2 Grade 1 Example 3 980 10.5 Grade 1 Example 4 500 5.5 Grade 2 Example 5 900 9.5 Grade 1 Example 6 750 7.5 Grade 1 Example 7 400 6.5 Grade 2 Example 8 550 4.5 Grade 2 Example 9 1050 9.5 Grade 1 Example 10 950 8.5 Grade 1 Example 11 420 5.5 Grade 2 Example 12 950 8.5 Grade 2 Comparative Example 1 250 3.5 Grade 3 Comparative Example 2 300 5.5 Grade 3

[0130] The test results show that:

[0131] (1) As can be seen from Examples 1 to 12, the present invention optimizes the design of the raw materials for preparing the anti-seismic polyurethane protective adhesive by using nitrogen-containing chain extenders and sulfur-containing chain extenders as composite chain extenders, which enables the obtained anti-seismic polyurethane protective adhesive to have good tensile strength (4.5-10.5MPa) and excellent elongation (400-1050%), thus giving it excellent seismic performance (level 1-2).

[0132] (2) By comparing Example 1 with Examples 4-7, it can be seen that the molar ratio of ethylenediamine and dimercaprol in the composite chain extender of Example 4 is relatively low, while the molar ratio of ethylenediamine and dimercaprol in the composite chain extender of Example 7 is relatively high. The elongation and tensile strength of the resulting anti-seismic polyurethane protective adhesive are significantly reduced, and the seismic performance is worse. This shows that by optimizing the molar ratio of nitrogen-containing chain extender and sulfur-containing chain extender in the composite chain extender, the present invention can further improve the elongation and tensile strength of the resulting anti-seismic polyurethane protective adhesive, thus giving it better mechanical properties and improving its seismic performance and its protective performance against concrete.

[0133] (3) By comparing Example 1 with Examples 8-11, it can be seen that the molar ratio of MDI to TDI in the isocyanate of Example 8 is low, while the molar ratio of MDI to TDI in the isocyanate of Example 9 is high. The elongation and tensile strength of the anti-seismic polyurethane protective adhesives obtained by both examples are significantly reduced, and the seismic performance is worse. This shows that by optimizing the molar ratio of MDI to TDI in the isocyanate, the present invention can further improve the elongation and tensile strength of the obtained anti-seismic polyurethane protective adhesive, so that it has better mechanical properties, thereby improving its seismic performance and its protective performance against concrete.

[0134] (4) By comparing Example 1 and Example 12, it can be seen that without the addition of nano silica in Example 12, the tensile strength of the resulting anti-seismic polyurethane protective adhesive is reduced and the seismic performance is worse. This shows that by using nano silica as a reinforcing filler, the present invention can significantly improve the tensile strength of the resulting anti-seismic polyurethane protective adhesive, thereby improving its seismic performance and durability.

[0135] (5) By comparing Example 1 with Comparative Examples 1 and 2, it can be seen that Comparative Examples 1 and 2 both selected to add a single chain extender instead of the specific composite chain extender in this invention. The elongation and tensile strength of the seismic protective polyurethane adhesives obtained by both were significantly reduced, and their seismic performance was significantly worse. This shows that the use of the specific composite chain extender in this invention can effectively improve the elongation and tensile strength of the obtained seismic protective polyurethane adhesive, thereby giving it excellent seismic performance and making it well applied to the protection of concrete.

[0136] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A shock-resistant polyurethane protective adhesive, characterized in that, The raw materials for preparing the anti-seismic polyurethane protective adhesive include composite chain extenders, isocyanates, and polyols. The composite chain extender is selected from a combination of nitrogen-containing chain extenders and sulfur-containing chain extenders.

2. The anti-seismic polyurethane protective adhesive according to claim 1, characterized in that, The molar ratio of the nitrogen-containing chain extender to the sulfur-containing chain extender is (1-2):1; Preferably, the nitrogen-containing chain extender includes any one or a combination of at least two of ethylenediamine, propylenediamine, butylenediamine, or hexamethylenediamine; Preferably, the sulfur-containing chain extender comprises dimercaprol; Preferably, the molar ratio of the composite chain extender to the isocyanate is 1:(3.5-4.2).

3. The anti-seismic polyurethane protective adhesive according to claim 1 or 2, characterized in that, The isocyanate includes 4,4'-diphenylmethane diisocyanate and / or toluene diisocyanate; Preferably, the isocyanate is selected from a combination including 4,4'-diphenylmethane diisocyanate and toluene diisocyanate; Preferably, the molar ratio of 4,4'-diphenylmethane diisocyanate to toluene diisocyanate is (4-6):

1.

4. The anti-seismic polyurethane protective adhesive according to any one of claims 1-3, characterized in that, The polyols include polyether polyols; Preferably, the number average molecular weight of the polyether polyol is 2000-4000.

5. The anti-seismic polyurethane protective adhesive according to any one of claims 1-4, characterized in that, The raw materials for preparing the anti-seismic polyurethane protective adhesive also include additives; Preferably, the additives include any one or a combination of at least two of fillers, antioxidants, or ultraviolet absorbers; Preferably, based on the total mass percentage of the raw materials for preparing the anti-seismic polyurethane protective adhesive being 100%, the mass percentage of the filler is 5-10%. Preferably, the filler comprises nano-silica; Preferably, based on the total mass percentage of the raw materials used in preparing the anti-seismic polyurethane protective adhesive being 100%, the mass percentage of the antioxidant is 0.2-0.5%. Preferably, the mass percentage of the ultraviolet absorber is 0.2-0.5%, based on the total mass percentage of the raw materials used in the preparation of the anti-seismic polyurethane protective adhesive being 100%.

6. A method for preparing the anti-seismic polyurethane protective adhesive as described in any one of claims 1-5, characterized in that, The preparation method includes the following steps: Polyol and isocyanate are subjected to urethane reaction to obtain prepolymer, a composite chain extender is added to carry out chain extension reaction, and then optional additives are added and mixed to obtain the shock-resistant polyurethane protective adhesive.

7. The preparation method according to claim 6, characterized in that, The polyol further includes a dehydration treatment step before undergoing the ammoniation reaction; Preferably, the dehydration treatment method includes vacuum dehydrating the polyol at 100-110°C for 2-3 hours; Preferably, in the urethane reaction, the molar ratio of the OH group in the polyol to the NCO group in the isocyanate is 1:(1.3-1.7).

8. The preparation method according to claim 6 or 7, characterized in that, The esterification reaction includes a first-stage reaction and a second-stage reaction; Preferably, the temperature of the first stage reaction is 70-75℃, and the time is 1-1.5h; Preferably, the temperature of the second stage reaction is 75-80℃, and the time is 1-1.5h; Preferably, the chain extension reaction is carried out at a temperature of 70-80°C for 1.5-2.5 hours.

9. The preparation method according to any one of claims 6-8, characterized in that, The mixing process also includes a post-processing step. Preferably, the post-processing method includes vacuum degassing; Preferably, the vacuum degree of the vacuum degassing is ≤0.1MPa; Preferably, the temperature for vacuum degassing is 40-60°C; Preferably, the vacuum degassing time is 1-2 hours.

10. The application of the seismic-resistant polyurethane protective adhesive as described in any one of claims 1-5 in the seismic-resistant materials of dam bodies in hydraulic engineering projects.

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