Highly bonded polyurethane elastomer for bridge expansion joints and method for the production thereof

Abstract

The application discloses a kind of bridge expansion joint with high bonding polyurethane elastomer and preparation method thereof, belong to road bridge material technical field.The bridge expansion joint with high bonding polyurethane elastomer is mixed by A component, B component and C component;A component preparation raw material includes following weight fraction of each component: water glass 50~90 parts, polyether polyol 10~50 parts, catalyst 0.5~3 parts, defoaming agent 0.5~1 part, ultraviolet resistance agent 0.5~1 part, silane coupling agent 0.5~1 part;B component preparation raw material includes following weight fraction of each component: organic silicon modified polyurethane prepolymer 16~19 parts, plasticizer 1~4 parts;C component preparation raw material includes following weight fraction of each component: 100 parts of silica gel base rubber particles, silane coupling agent 3~5 parts.The bridge expansion joint with high bonding polyurethane elastomer effectively improves the bonding performance between elastomer and base material and the synergy between each component of elastomer itself, thereby improving its crack resistance as a whole.

Description

Technical Field

[0001] This invention belongs to the field of road and bridge materials technology, specifically relating to a high-adhesion polyurethane elastomer for bridge expansion joints and its preparation method. Background Technology

[0002] Polyurethane materials used in seamless expansion joint paving of bridges have high modulus and deformation capacity, which can effectively resist wear from traffic loads and meet the deformation requirements between expansion joints. However, with the increase of service life, on the one hand, gaps of varying sizes often appear between the polyurethane material and the concrete interface, allowing rainwater to seep into the pavement structure and cause damage. On the other hand, the polyurethane mixture itself is prone to cracking, damaging the expansion joint surface layer and shortening its service life.

[0003] Seamless expansion joint pavement structures for bridges need to absorb both low-frequency vibration deformation caused by temperature differences and high-frequency vibration deformation caused by traffic loads. Polyurethane materials, with their high elastic modulus, can effectively support the traffic loads on the road surface, while also possessing high wear and tear resistance. However, in actual use, cracking frequently occurs at the interface between the resin material and the substrate, as well as between the resin and the aggregate. Interface cracking is mainly due to the fact that the cohesive strength of polyurethane itself is much higher than the bond strength between the resin and the substrate. Under the impact of high-frequency traffic loads, it cannot effectively release the impact kinetic energy of the vehicles, causing the resin to shift due to inertia and leading to interface cracking. Cracking between the resin and the aggregate is similarly caused by the significant difference in their moduli, resulting in a bond strength lower than the resin's own strength.

[0004] Patent CN114933884B discloses a modified polyurethane material for bridge expansion joints and its preparation method. The modified polyurethane material for bridge expansion joints exhibits high thixotropy in the first-stage epoxy curing reaction, effectively preventing flow and improving the smoothness of the pavement surface. The second-stage polyurethane desealing and curing reaction has a stable reaction rate, resulting in high strength and good flexibility of the cured product. Throughout the curing process, the viscosity and thixotropy of the resin system are controllable, exhibiting excellent workability. This patent primarily addresses interfacial cracking caused by temperature differences, but it does not solve the problem of interfacial cracking caused by the polyurethane's own cohesive strength being much higher than the bond strength between the resin and the substrate.

[0005] In view of the defects existing in the use of polyurethane materials for expansion joints, the inventor, based on years of experience and expertise in this field, combined with theoretical analysis and research innovation, has developed a high-adhesion polyurethane elastomer for bridge expansion joints and its preparation method. Summary of the Invention

[0006] To address the issues of interface cracking and material self-cracking in polyurethane materials used for seamless bridge expansion joint paving in existing technologies, this invention provides a high-adhesion polyurethane elastomer for bridge expansion joints and its preparation method. The high-adhesion polyurethane elastomer for bridge expansion joints effectively improves the adhesion between the elastomer and the substrate, as well as the synergy among the components of the elastomer, thereby enhancing its overall crack resistance.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A high-adhesion polyurethane elastomer for bridge expansion joints is composed of a mixture of component A, component B and component C, wherein the mass ratio of component A, component B and component C is 5-10:20:6-12.

[0009] The raw materials for preparing component A include the following components in parts by weight: 50-90 parts water glass, 10-50 parts polyether polyol, 0.5-3 parts catalyst, 0.5-1 part defoamer, 0.5-1 part UV stabilizer, and 0.5-1 part silane coupling agent.

[0010] The raw materials for preparing component B include the following components in parts by weight: 16-19 parts of silicone-modified polyurethane prepolymer and 1-4 parts of plasticizer.

[0011] The raw materials for preparing component C include the following components in parts by weight: 100 parts of silicone-based rubber particles and 3-5 parts of silane coupling agent;

[0012] The organosilicon-modified polyurethane prepolymer is prepared by grafting hydroxyl silicone oil onto the surface of a linear polyurethane prepolymer. The linear polyurethane prepolymer can effectively adjust the strength and toughness of the polyurethane, while the grafting of hydroxyl silicone oil introduces Si-O bonds into the structure, effectively improving compatibility with other materials.

[0013] Furthermore, the organosilicon-modified polyurethane prepolymer has an average molecular weight of 10,000 to 20,000.

[0014] The raw materials for preparing the organosilicon-modified polyurethane prepolymer include the following components in parts by weight: 20-40 parts isocyanate, 60-80 parts polyether polyol, 0.5-2 parts stannous octoate, and 5-10 parts hydroxyl silicone oil.

[0015] Preferably, in the raw materials for preparing organosilicon-modified polyurethane prepolymer, the isocyanate is one or more of MDI and TDI, the hydroxyl content of the hydroxyl silicone oil is 0.5%-1.5%, and the molecular weight of the hydroxyl silicone oil is <2500.

[0016] The preparation method of the organosilicon-modified polyurethane prepolymer includes the following steps:

[0017] S1: Place the polyether polyol in a reaction vessel and heat it to 110-120℃ for vacuum dehydration;

[0018] S2: After the vacuum dehydration treatment is completed, cool down to 50-60℃, add stannous octoate and isocyanate in sequence, slowly raise the temperature to 75-85℃, and react at a constant temperature for 2-3 hours;

[0019] S3: At a constant temperature of 70-80℃, add a certain amount of hydroxyl silicone oil, continue the reaction for 50-70 minutes, and then cool to room temperature to obtain organosilicon-modified polyurethane prepolymer.

[0020] Preferably, the water glass is sodium-based water glass with a modulus of 2.2–3.4 and a density of 1.368–1.559 g / mL, such as liquid 2, liquid 3, liquid 4, etc. Water glass can adjust the amount of SiO2 generated, further adjust the modulus and damping performance of the elastomer, and improve the coordination between the cohesive strength and interfacial bonding strength of the elastomer as well as the damping parameters.

[0021] Preferably, the polyether polyol in component A and the raw material for preparing the silicone-modified polyurethane prepolymer is one or two of PEG, PPG, and PTMEG, with a molecular weight of not less than 2000, such as PEG-2000, PPG2000, PPG4000, PTMEG3000, etc. Linear polyols can effectively adjust the flexibility, strength and modulus of polyurethane within a wide range.

[0022] Preferably, the catalyst is one or more of amine curing agents or organometallic curing agents, such as A-1, A33E, T-9, etc.; the defoamer is an organosilicon defoamer, such as BYK-066N, BYK-077, etc.; the UV stabilizer is a benzotriazole UV stabilizer, such as UV-1, UV-327, UV-571, etc.; and the plasticizer is one or a mixture of two of dibutyl phthalate, tri(2-chloropropyl) phosphate, and diphenyl toluene phosphate.

[0023] Preferably, the silane coupling agent in components A and C is an amino-containing organosilicon coupling agent, such as KH-550, KH-570, KH-791, etc.

[0024] Preferably, the silicone-based rubber particles are one or more of methyl vinyl silicone rubber, methyl phenyl vinyl silicone rubber, fluorosilicone rubber, and nitrile silicone rubber. The silicone-based rubber particles have a modulus similar to that of polyurethane and a high damping coefficient. The Si-O bonds improve compatibility with polyurethane. After activation with an amine silane coupling agent, they can react with the polyurethane prepolymer to form chemical bonds, thereby increasing the bonding strength between them.

[0025] On the other hand, the present invention also provides a method for preparing the high-adhesion polyurethane elastomer for bridge expansion joints, specifically including the following steps:

[0026] (1) Preparation of component A:

[0027] Place the polyether polyol, catalyst, UV stabilizer, and silane coupling agent in a reaction vessel according to the specified ratio, and stir for 50-70 minutes; add water glass and defoamer according to the specified ratio, and continue stirring for 50-70 minutes to obtain component A.

[0028] (2) Preparation of component B:

[0029] Place the plasticizer in the reactor according to the ratio, start stirring and heat to 110-120℃ for vacuum dehydration treatment; after the vacuum dehydration treatment is completed, cool down to 30-50℃, add polyurethane prepolymer, continue stirring for 50-70 minutes, and cool to room temperature to obtain component B.

[0030] (3) Preparation of component C:

[0031] The silane coupling agent is sprayed evenly onto the surface of the rubber particles according to the specified ratio, and then allowed to stand for 50-70 minutes to activate, thus obtaining component C.

[0032] (4) When using, mix components A, B and C to obtain the high-adhesion polyurethane elastomer for bridge expansion joints.

[0033] The beneficial effects of the present invention through the above technical solution are:

[0034] (1) The silane coupling agent in the activated silicone rubber particles and the silane coupling agent in component A can react with the organosilicon modified polyurethane prepolymer in component B to form polyurea chemical bonds, which makes the polyurethane elastomer and the rubber particles form chemical bonds, greatly improving the bonding strength between them. At the same time, the SiO2 generated by the reaction of water glass in component A and organosilicon modified polyurethane prepolymer in component B, the silicone rubber particles, and the organosilicon modified polyurethane prepolymer all contain Si-O bonds, which effectively improves their compatibility and coordination. The three work together to effectively prevent cracking inside the mixture.

[0035] (2) The expansion joint uses room temperature cast polyurethane elastomer connected to the road surface through steel components. Its bonding strength with steel is 4-5 MPa. By introducing linear polyether polyol, water glass, silicone rubber, etc., the cohesive strength of polyurethane elastomer is adjusted so that the bonding strength between elastomer and steel, the modulus of elastomer and silicone rubber are comparable and coordinated with each other, thereby effectively avoiding interface cracking and detachment caused by excessive strength difference.

[0036] (3) The SiO2 generated by the reaction of water glass and polyurethane prepolymer, combined with silicone rubber particles, can significantly improve the damping performance of polyurethane elastomer, thereby effectively absorbing the lateral high-frequency vibration stress of traffic load, reducing the instantaneous deformation amplitude of elastomer, and thus significantly reducing the risk of interface cracking; at the same time, the Si-O bonds inside the system give the material excellent weather resistance and aging resistance, significantly delaying the material performance decay rate and reducing the risk of cracking.

[0037] (4) Water glass can effectively absorb the carbon dioxide generated by the reaction between polyurethane prepolymer and water, preventing the system from expanding and deforming. At the same time, the acid-base balance of the water glass system is disrupted during the reaction, forming high thixotropy, which can effectively resist the problem of large slope flow during on-site construction and improve the workability of construction. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific implementation methods, features and effects of a high-adhesion polyurethane elastomer for road expansion joints and its preparation method according to the present invention are described in detail below.

[0039] The manufacturers and models of raw materials used in each embodiment and comparative example are as follows:

[0040] Polyether polyols PEG2000, PPG2000, and PPG4000 are produced by Haian Petrochemical Plant in Jiangsu Province; polyether polyol PTMEG3000 is produced by Mitsubishi Chemical Corporation of Japan; sodium-based water glass liquids 2, 3, and 4 are produced by Jinan Mingchuan Chemical; catalysts A-1, A33E, and T-9 are produced by Air Products of the United States; defoamer BYK-066N is produced by BYK Chemical; silane coupling agent KH550 is produced by Qingdao Hengda New Materials; UV stabilizer UV-327 is produced by Taiwan Yongguang Chemical; plasticizer DBP is produced by Shandong Kexing Chemical; silicone rubber granules are produced by Chengdu Senfa Rubber & Plastics Co., Ltd.; isocyanates MDI50 and TDI-80 are produced by Wanhua Chemical; hydroxyl silicone oil KF96 is produced by Shin-Etsu Chemical of Japan; and IOTA 2110 is produced by Anhui Aiyota Silicone Oil Co., Ltd.

[0041] Example 1:

[0042] The high-adhesion polyurethane elastomer for bridge expansion joints provided in this embodiment includes components A, B, and C.

[0043] The preparation process of silicone-modified polyurethane prepolymer is as follows:

[0044] S1: Place 60 parts of PPG2000 in a reactor and heat to 120℃ for vacuum dehydration for 120 min;

[0045] S2: Cool down to 60℃, start stirring (700-800r / min), add 0.5 parts T-9 and 40 parts MDI-50 in sequence according to the ratio, slowly heat up to 85℃, and react for 2 hours;

[0046] S3: Maintain a constant temperature of 85℃, continue stirring (700-800r / min), add 10 parts of KF96, stir for 50min, and cool to room temperature to obtain organosilicon-modified polyurethane prepolymer with an average molecular weight of approximately 14960.

[0047] The preparation process of high-adhesion polyurethane elastomer for bridge expansion joints is as follows:

[0048] Preparation of component A:

[0049] Place 50 parts PPG2000, 1.5 parts T-9, 0.5 parts UV-327, and 1 part KH-550 in a reactor according to the proportion, and stir at 70-80 r / min for 50 min; add 50 parts liquid 4 water glass and 0.5 parts BYK-066N according to the proportion, and continue stirring for 50 min to obtain component A.

[0050] Preparation of component B:

[0051] Place 20 parts of DBP in a reaction vessel according to the ratio, start stirring (70-80 r / min), heat to 120℃ and dehydrate under vacuum for 70 min; cool to 50℃, add 80 parts of silicone-modified polyurethane prepolymer, continue stirring for 50 min, and cool to room temperature to obtain component B.

[0052] Preparation of component C:

[0053] Three parts of KH-550 were evenly sprayed onto the surface of 100 parts of methyl vinyl silicone rubber granules according to the specified ratio, and the mixture was allowed to stand for 60 minutes to activate, thus obtaining component C.

[0054] Mixing components A, B, and C in a mass ratio of 25:100:45 yields a high-adhesion polyurethane elastomer for bridge expansion joints.

[0055] Example 2:

[0056] The high-adhesion polyurethane elastomer for bridge expansion joints provided in this embodiment includes components A, B, and C.

[0057] The preparation process of silicone-modified polyurethane prepolymer is as follows:

[0058] S1: Place 70 parts of PPG2000 in a reactor and heat to 110℃ for vacuum dehydration for 110 min;

[0059] S2: Cool down to 60℃, start stirring (700-800r / min), add 1 part T-9 and 30 parts TDI-80 in sequence according to the ratio, slowly heat up to 75℃, and react for 3 hours;

[0060] S3: Maintain a constant temperature of 85℃, continue stirring (700-800r / min), add 8 parts of IOTA 2110, stir for 50min, and cool to room temperature to obtain silicone-modified polyurethane prepolymer with an average molecular weight of 18830.

[0061] The preparation process of high-adhesion polyurethane elastomer material for bridge expansion joints is as follows:

[0062] Preparation of component A:

[0063] Place 40 parts PTMEG3000, 2 parts A-1, 0.5 parts UV-327, and 1 part KH-550 in a reactor according to the proportion, and stir at 70-80 r / min for 70 min; add 60 parts liquid 4 water glass and 0.5 parts BYK-066N according to the proportion, and continue stirring for 50 min to obtain component A.

[0064] Preparation of component B:

[0065] Place 20 parts of DBP in a reactor according to the ratio, start stirring (70-80 r / min), heat to 110℃ and dehydrate under vacuum for 70 min; cool to 30℃, add 80 parts of silicone-modified polyurethane prepolymer, continue stirring for 70 min, and cool to room temperature to obtain component B.

[0066] Preparation of component C:

[0067] Three parts of KH-550 were evenly sprayed onto the surface of 100 parts of methyl vinyl silicone rubber granules according to the specified ratio, and the mixture was allowed to stand for 70 minutes to activate, thus obtaining component C.

[0068] Mixing components A, B, and C in a mass ratio of 25:100:45 yields a high-adhesion polyurethane elastomer for bridge expansion joints.

[0069] Example 3:

[0070] The high-adhesion polyurethane elastomer for bridge expansion joints provided in this embodiment includes components A, B, and C.

[0071] The preparation process of silicone-modified polyurethane prepolymer is as follows:

[0072] S1: Place 60 parts of PTMEG3000 in a reaction vessel, heat to 115℃ and dehydrate under vacuum for 110-130 minutes;

[0073] S2: Cool down to 55℃, start stirring (700-800r / min), add 0.5 parts T-9 and 40 parts MDI-50 in sequence according to the ratio, slowly heat up to 80℃, and react for 2-3 hours;

[0074] S3: Maintain a constant temperature of 80℃, continue stirring (700-800r / min), add 10 parts of KF96, stir for 60min, and cool to room temperature to obtain an organosilicon-modified polyurethane prepolymer with an average molecular weight of 11356.

[0075] The preparation process of high-adhesion polyurethane elastomer material for bridge expansion joints is as follows:

[0076] Preparation of component A:

[0077] Place 20 parts PEG2000, 0.5 parts A33E, 1 part UV-327, and 1 part KH-550 in a reactor according to the proportion, and stir at 70-80 r / min for 60 min; add 80 parts liquid 4 water glass and 1 part BYK-066N according to the proportion, and continue stirring for 60 min to obtain component A.

[0078] Preparation of component B:

[0079] Place 5 parts of DBP in a reaction vessel according to the ratio, start stirring (70-80 r / min), heat to 110-120℃ and dehydrate under vacuum for 60 min; cool to 40℃, add 95 parts of silicone-modified polyurethane prepolymer, continue stirring for 600 min, and cool to room temperature to obtain component B.

[0080] Preparation of component C:

[0081] Five parts of KH-550 were evenly sprayed onto the surface of 100 parts of fluorosilicone rubber granules according to the specified ratio, and the mixture was allowed to stand for 60 minutes to activate, thus obtaining component C.

[0082] Mixing components A, B, and C in a mass ratio of 40:100:30 yields a high-adhesion polyurethane elastomer for bridge expansion joints.

[0083] Example 4:

[0084] The high-adhesion polyurethane elastomer for bridge expansion joints provided in this embodiment includes components A, B, and C.

[0085] The preparation process of silicone-modified polyurethane prepolymer is as follows:

[0086] S1: Place 60 parts of PTMEG3000 in a reactor and heat to 120℃ for vacuum dehydration for 130 min;

[0087] S2: Cool down to 60℃, start stirring (700-800r / min), add 1.5 parts T-9 and 40 parts TDI-80 in sequence according to the ratio, slowly heat up to 85℃, and react for 3 hours;

[0088] S3: Maintain a constant temperature of 85℃, continue stirring (700-800r / min), add 5 parts of IOTA 2110, stir for 70min, and cool to room temperature to obtain silicone-modified polyurethane prepolymer with an average molecular weight of 12560.

[0089] The preparation process of high-adhesion polyurethane elastomer material for bridge expansion joints is as follows:

[0090] Preparation of component A:

[0091] Place 10 parts PTMEG3000, 3 parts A-1, 1 part UV-327, and 0.5 parts KH-550 in a reactor according to the proportion, and stir at 70-80 r / min for 70 min; add 90 parts liquid 2 water glass and 1 part BYK-066N according to the proportion, and continue stirring for 70 min to obtain component A.

[0092] Preparation of component B:

[0093] Place 5 parts of DBP in a reaction vessel according to the ratio, start stirring (70-80 r / min), heat to 120℃ and dehydrate under vacuum for 70 min; cool to 50℃, add 95 parts of silicone-modified polyurethane prepolymer, continue stirring for 70 min, and cool to room temperature to obtain component B.

[0094] Preparation of component C:

[0095] Five parts of KH-550 were evenly sprayed onto the surface of 100 parts of fluorosilicone rubber granules according to the specified ratio, and the mixture was allowed to stand for 70 minutes to activate, thus obtaining component C.

[0096] Mixing components A, B, and C in a mass ratio of 40:100:30 yields a high-adhesion polyurethane elastomer for bridge expansion joints.

[0097] Example 5:

[0098] The high-adhesion polyurethane elastomer for bridge expansion joints provided in this embodiment includes components A, B, and C.

[0099] The preparation process of silicone-modified polyurethane prepolymer is as follows:

[0100] S1: Place 80 parts of PPG2000 in a reaction vessel and heat to 110℃ for vacuum dehydration for 120 min;

[0101] S2: Cool down to 50℃, start stirring (700-800r / min), add 2 parts T-9 and 20 parts MDI-50 in sequence according to the ratio, slowly heat up to 75℃, and react for 2-3 hours;

[0102] S3: Maintain a constant temperature of 75℃, continue stirring (700-800r / min), add 5 parts of KF96, stir for 50min, and cool to room temperature to obtain organosilicon-modified polyurethane prepolymer with an average molecular weight of 17585.

[0103] The preparation process of high-adhesion polyurethane elastomer material for bridge expansion joints is as follows:

[0104] Preparation of component A:

[0105] Place 30 parts PTMEG3000, 1.5 parts T-9, 1 part UV-327, and 0.5 parts KH-550 in a reactor according to the proportion, and stir at 70-80 r / min for 50 min; add 70 parts liquid 3 water glass and 1 part BYK-066N according to the proportion, and continue stirring for 50 min to obtain component A.

[0106] Preparation of component B:

[0107] Place 5 parts of DBP in a reaction vessel according to the ratio, start stirring (70-80 r / min), heat to 110℃ and dehydrate under vacuum for 50 min; cool to 30℃, add 95 parts of silicone-modified polyurethane prepolymer, continue stirring for 50 min, and cool to room temperature to obtain component B.

[0108] Preparation of component C:

[0109] Five parts of KH-550 were evenly sprayed onto the surface of 100 parts of fluorosilicone rubber granules according to the specified ratio, and the mixture was allowed to stand for 50 minutes to activate, thus obtaining component C.

[0110] Mixing components A, B, and C in a mass ratio of 50:100:60 yields a high-adhesion polyurethane elastomer for bridge expansion joints.

[0111] Comparative Example 1:

[0112] This comparative example is based on Example 1. The difference between Comparative Example 1 and Example 1 is that the conventional polyurethane prepolymer is used instead of the silicone-modified polyurethane elastomer. All other conditions are the same as in Example 1.

[0113] The preparation process of conventional polyurethane prepolymers is as follows:

[0114] S1: Place 60 parts of PPG2000 in a reactor and heat to 120℃ for vacuum dehydration for 120 min;

[0115] S2: Cool down to 60℃, start stirring (700-800r / min), add 0.5 parts T-9 and 40 parts MDI-50 in sequence according to the ratio, slowly heat up to 85℃, react for 2 hours, cool down to room temperature, and obtain a conventional polyurethane prepolymer with an average molecular weight of 14996.

[0116] Comparative Example 2:

[0117] The comparative example is based on Example 1. The difference between Comparative Example 2 and Example 1 is that no silane coupling agent is used in components A and C, while all other conditions are the same as in Example 1.

[0118] Comparative Example 3:

[0119] This comparative example is based on Example 1. The difference between Comparative Example 1 and Example 1 is that water glass was not added when preparing component A, while all other conditions are the same as in Example 1.

[0120] Performance testing

[0121] The tensile strength and elongation were tested on the products obtained by mixing components A and B in Examples 1-5 and Comparative Examples 1-3, respectively. The test results and test methods are shown in Table 1 below.

[0122] The performance of the high-adhesion polyurethane elastomers for bridge expansion joints prepared in Examples 1-5 and Comparative Examples 1-3 were tested respectively. The test results and test methods are shown in Table 1 below.

[0123] Table 1. Test results and methods for the performance of high-adhesion polyurethane elastomers used in bridge expansion joints.

[0124]

[0125] As shown in Table 1 above, Examples 1 to 5 are several preferred embodiments of the present invention. As can be seen from the data, the polyurethane elastomer for expansion joints prepared using the above method and materials has a tensile strength of binder comparable to that of cement interface bonding strength, and has high damping performance. The damping loss factor tanδ (25℃) > 1.5, and the failure interface in both the bonding and compressive strength tests is the resin itself.

[0126] Compared to Example 1, Comparative Example 1 replaced the silicone-modified polyurethane prepolymer with the unmodified silicone prepolymer. The bond strength decreased to 2.6 MPa, the damping loss factor tanδ (25°C) was 1.2, and the bond failure was interfacial separation. The compressive failure interface was mainly between the resin and rubber particles. This is mainly because the silicone-modified prepolymer can effectively improve the damping performance of the elastomer, reduce instantaneous impact deformation, and improve the interfacial bond strength. At the same time, the silicone-modified prepolymer has high compatibility with SiO2 and silicone-based rubber particles, which can improve the bonding between internal materials.

[0127] Compared to Example 1, no aminosilane coupling agent was added to the system in Comparative Example 2. The damping loss factor tanδ (25°C) of the prepared polyurethane elastomer material was 1.1, and the bonding failure was interfacial separation. The compressive failure interface was mainly between the resin and the rubber particles. This was mainly due to the lack of Si-O bonds, which reduced the damping performance of the rubber particles, as well as their compatibility and bonding strength with the components inside the elastomer.

[0128] Compared to Example 1, Comparative Example 3 did not include water glass in the system, and SiO2 was no longer generated in the system. The tensile strength, damping coefficient, bonding strength and compressive strength all decreased significantly.

Claims

1. A high-adhesion polyurethane elastomer for bridge expansion joints, characterized in that, It is composed of a mixture of component A, component B and component C, wherein the mass ratio of component A, component B and component C is 5~10:20:6~12; The raw materials for preparing component A include the following components in parts by weight: 50-90 parts water glass, 10-50 parts polyether polyol, 0.5-3 parts catalyst, 0.5-1 part defoamer, 0.5-1 part UV stabilizer, and 0.5-1 part silane coupling agent. The raw materials for preparing component B include the following components in parts by weight: 16-19 parts of silicone-modified polyurethane prepolymer and 1-4 parts of plasticizer; The raw materials for preparing component C include the following components in parts by weight: 100 parts of silicone rubber particles and 3-5 parts of silane coupling agent; The organosilicon-modified polyurethane prepolymer is prepared by grafting hydroxyl silicone oil onto the surface of a linear polyurethane prepolymer.

2. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 1, characterized in that, The organosilicon-modified polyurethane prepolymer has an average molecular weight of 10,000 to 20,000.

3. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 1, characterized in that, The raw materials for preparing the organosilicon-modified polyurethane prepolymer include the following components in parts by weight: 20-40 parts isocyanate, 60-80 parts polyether polyol, 0.5-2 parts stannous octoate, and 5-10 parts hydroxyl silicone oil.

4. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 3, characterized in that, In the raw materials for preparing organosilicon-modified polyurethane prepolymer, the isocyanate is one or more of MDI and TDI, the hydroxyl content of the hydroxyl silicone oil is 0.5%-1.5%, and the molecular weight of the hydroxyl silicone oil is <2500.

5. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 3, characterized in that, The preparation method of the organosilicon-modified polyurethane prepolymer includes the following steps: S1: Place the polyether polyol in a reaction vessel and heat it to 110~120℃ for vacuum dehydration; S2: After the vacuum dehydration treatment is completed, cool down to 50~60℃, add stannous octoate and isocyanate in sequence, slowly raise the temperature to 75~85℃, and react at a constant temperature for 2~3 hours; S3: At a constant temperature of 70~80℃, add a certain amount of hydroxyl silicone oil, continue the reaction for 50~70 minutes, and then cool to room temperature to obtain organosilicon-modified polyurethane prepolymer.

6. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 1, characterized in that, The water glass is sodium-based water glass with a modulus of 2.2 to 3.4 and a density of 1.368 to 1.559 g / mL.

7. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 3, characterized in that, The polyether polyol in the raw materials for preparing component A and organosilicon-modified polyurethane prepolymer is one or two of PEG, PPG, and PTMEG, with a molecular weight of not less than 2000.

8. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 1, characterized in that, The catalyst is one or more of amine curing agents or organometallic curing agents; the UV stabilizer is a benzotriazole UV stabilizer; the plasticizer is one or a mixture of two of dibutyl phthalate, tri(2-chloropropyl) phosphate, and diphenyl toluene phosphate; the silane coupling agent in components A and C is an amino-containing organosilicon coupling agent.

9. The high-adhesion polyurethane elastomer for bridge expansion joints according to claim 1, characterized in that, The silicone-based rubber particles are one or more of methyl vinyl silicone rubber, methyl phenyl vinyl silicone rubber, fluorosilicone rubber, and cyanosilicone rubber.

10. The method for preparing the high-adhesion polyurethane elastomer for bridge expansion joints according to any one of claims 1-9, characterized in that, Specifically, the steps include the following: (1) Preparation of component A: Place the polyether polyol, catalyst, UV stabilizer, and silane coupling agent in a reaction vessel according to the specified ratio and stir for 50-70 minutes; add water glass and defoamer according to the specified ratio and continue stirring for 50-70 minutes to obtain component A. (2) Preparation of component B: Place the plasticizer in the reactor according to the ratio, turn on the stirring and heat to 110~120℃ for vacuum dehydration treatment; after the vacuum dehydration treatment is completed, cool down to 30-50℃, add the organosilicon-modified polyurethane prepolymer, continue stirring for 50~70min, and cool down to room temperature to obtain component B. (3) Preparation of component C: The silane coupling agent was sprayed evenly onto the surface of the rubber particles according to the proportion, and the particles were allowed to stand for 50-70 minutes to activate, thus obtaining component C. (4) When using, mix components A, B and C to obtain the high-adhesion polyurethane elastomer for bridge expansion joints.

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