A siloxane-grafted polyurethane elastomer material and its preparation method and application

Abstract

The present invention belongs to the technical field of polyurethane elastomers, and specifically relates to a siloxane-grafted polyurethane elastomer material, and a preparation method and application thereof. The preparation method provided by the present invention is as follows: terminal hydroxyl polybutadiene and a first isocyanate are mixed to undergo a polycondensation reaction to obtain a polycondensation product; the polycondensation product, vinyl trimethoxysilane and an initiator are mixed to undergo a grafting reaction to obtain a siloxane-grafted prepolymer; trihydroxy polyether and a second isocyanate are mixed to undergo a first polymerization reaction to obtain a polyether prepolymer; the siloxane-grafted prepolymer, the polyether prepolymer, a chain extender and a catalyst are mixed to undergo a second polymerization reaction to obtain the siloxane-grafted polyurethane elastomer material. The siloxane-grafted polyurethane elastomer material obtained by the preparation method provided by the present invention has low internal heat generation, small rate of change of elastic modulus under low temperature environment, and high damping performance, and is suitable as a substrate for seismic isolation bearings.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane elastomers, and in particular relates to a siloxane-grafted polyurethane elastomer material and a preparation method and application thereof. Background Art

[0002] Seismic isolation bearings refer to the supporting devices set up by buildings or bridges to meet the requirements of seismic isolation. An isolation layer is added between the upper structure of the building or bridge and the foundation to play a soft connection with the ground, which can offset about 80% of the energy of the earthquake. At present, the rubber seismic isolation bearing is widely used, which is made of multiple layers of steel plates and natural rubber alternately stacked. The steel plate is used as a stiffening material for the rubber bearing, which changes the characteristic of the small vertical stiffness of the rubber body, so that it can not only reduce the horizontal earthquake effect, but also withstand large vertical loads. However, natural rubber has the characteristics of good elasticity and insufficient damping and seismic isolation. Therefore, it is necessary to add carbon black, damping materials, etc. to improve the damping performance of natural rubber. However, after adding a certain amount of carbon black, damping materials, etc., the damping performance of natural rubber will not continue to increase after reaching the limit. The high damping rubber bearings prepared from natural rubber generally have an equivalent damping ratio of 12%~15%, which is difficult to reach more than 20%; and natural rubber has poor aging and weather resistance. After long-term use, the seismic isolation bearing will have cracks on the surface and unstable mechanical properties due to material aging.

[0003] Compared with natural rubber, polyurethane materials have the advantages of high mechanical properties, strong load-bearing capacity, good aging and ozone resistance, and long service life.

[0004] However, although polyurethane material has excellent low-temperature resistance and will not crack in an environment of -70°C, its performance will change significantly in a low-temperature environment, manifested as an increase in elastic modulus, a decrease in flexibility, a decrease in the vertical and horizontal deformation capacity of the seismic isolation bearing, and even shear cracking, which will destroy the performance of the bearing.

[0005] The silicone-polyurethane copolymer synthesized with silicone as the soft segment exhibits good low-temperature flexibility and weather resistance. At present, there are two main ways to modify polyurethane with silicone. One is to use polydimethylsiloxane terminated with active hydroxyl groups to form a block copolymer with polyurethane; the other is to use polydimethylsiloxane with active groups in the side chain to form a silicone-polyurethane copolymer by grafting reaction with polyurethane. In the former, the siloxane chain segment is embedded in the main chain of polyurethane, and the ability to migrate to the surface is restrained by the main chain. Therefore, in order to obtain a better surface modification effect, a large amount of polydimethylsiloxane needs to be added, which leads to a decrease in the mechanical properties of polyurethane; in the latter, the siloxane chain is suspended on the main chain of polyurethane, which is conducive to the migration of silicon atoms to the surface, and can better improve the low-temperature flexibility and weather resistance of polyurethane.

[0006] However, on the other hand, polyurethane materials also have the problem of high endogenous heat generation, which leads to poor weather resistance, restricting the long-term use of polyurethane under high-frequency vibration conditions. Summary of the invention

[0007] The object of the present invention is to provide a siloxane-grafted polyurethane elastomer material and a preparation method and application thereof. The siloxane-grafted polyurethane elastomer material provided by the present invention has low internal heat generation, small elastic modulus change rate under low temperature environment, and high damping performance, and is suitable as a substrate for seismic isolation bearings.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] The present invention provides a method for preparing a siloxane-grafted polyurethane elastomer material, comprising the following steps:

[0010] The terminal hydroxyl polybutadiene and the first isocyanate are mixed to undergo a polycondensation reaction to obtain a polycondensation product; the polycondensation product, vinyl trimethoxysilane and an initiator are mixed to undergo a grafting reaction to obtain a siloxane grafted prepolymer;

[0011] The trihydroxy polyether and the second isocyanate are mixed to carry out a first polymerization reaction to obtain a polyether prepolymer;

[0012] The siloxane-grafted prepolymer, the polyether prepolymer, the chain extender and the catalyst are mixed to carry out a second polymerization reaction to obtain the siloxane-grafted polyurethane elastomer material.

[0013] Preferably, the first isocyanate comprises diphenylmethane diisocyanate and / or 1,5-naphthalene diisocyanate;

[0014] The molar ratio of the hydroxy-terminated polybutadiene to the first isocyanate is (20-35):(25-40);

[0015] The temperature of the polycondensation reaction is 30-55° C., and the insulation time of the polycondensation reaction is 1-2.5 h.

[0016] Preferably, the molar ratio of the vinyltrimethoxysilane to the first isocyanate is (50-80):(25-40);

[0017] The temperature of the grafting reaction is 75-95° C., and the insulation time of the grafting reaction is 1-3 hours.

[0018] Preferably, the initiator is benzoyl peroxide;

[0019] The molar ratio of the initiator to the first isocyanate is (0.5-2):(25-40).

[0020] Preferably, the second isocyanate includes diphenylmethane diisocyanate and / or 1,5-naphthalene diisocyanate; the trihydroxy polyether includes polyoxypropylene triol and / or polyoxypropylene-oxyethylene triol;

[0021] The molar ratio of the trihydroxy polyether to the second isocyanate is (30-40):(60-75);

[0022] The temperature of the first polymerization reaction is 80-110° C., and the insulation time of the first polymerization reaction is 2.5-3 hours.

[0023] Preferably, the siloxane grafted prepolymer is calculated based on the amount of the first isocyanate;

[0024] The polyether prepolymer is calculated based on the amount of the second isocyanate;

[0025] The molar ratio of the siloxane grafted prepolymer to the polyether prepolymer is (25-40):(60-75);

[0026] The temperature of the second polymerization reaction is room temperature, and the time of the second polymerization reaction is 20 to 40 minutes.

[0027] Preferably, the chain extender is 3,3'-dichloro-4,4'-diphenylmethanediamine; the molar ratio of the chain extender to the sum of the first isocyanate and the second isocyanate is (10-20):100;

[0028] The catalyst is dibutyltin dilaurate and / or stannous octoate; the molar ratio of the catalyst to the sum of the first isocyanate and the second isocyanate is (0.1-0.5):100.

[0029] The present invention provides a siloxane-grafted polyurethane elastomer material, which is prepared by the preparation method described in the above technical scheme; the molecular structure of the siloxane-grafted polyurethane elastomer material includes a main chain structure and a side chain structure, the main chain structure contains isocyanate units, trihydroxy polyether units and terminal hydroxyl polybutadiene units; the isocyanate units and the trihydroxy polyether units form a three-dimensional network structure;

[0030] The branched structure contains vinyltrimethoxysilane units.

[0031] The invention provides a siloxane-grafted polyurethane elastomer seismic isolation bearing, which is prepared from the siloxane-grafted polyurethane elastomer material described in the above technical solution.

[0032] The present invention provides a method for preparing a siloxane-grafted polyurethane elastomer seismic isolation bearing, comprising the following steps:

[0033] The siloxane-grafted polyurethane elastomer material described in the above technical solution is reacted and molded in a mold, and a polyurethane molded body is obtained after demoulding;

[0034] The polyurethane molded body is aged to obtain the siloxane-grafted polyurethane elastomer vibration-damping and isolation bearing.

[0035] The invention provides a preparation method of a siloxane-grafted polyurethane elastomer material, comprising the following steps: mixing terminal hydroxyl polybutadiene and a first isocyanate for polycondensation reaction to obtain a polycondensation product; mixing the polycondensation product, vinyl trimethoxysilane and an initiator for grafting reaction to obtain a siloxane-grafted prepolymer; mixing trihydroxy polyether and a second isocyanate for a first polymerization reaction to obtain a polyether prepolymer; mixing the siloxane-grafted prepolymer, the polyether prepolymer, a chain extender and a catalyst for a second polymerization reaction to obtain the siloxane-grafted polyurethane elastomer material. The present invention successfully introduces terminal hydroxyl polybutadiene and trihydroxy polyether into the polyurethane molecular structure through the above method. The molecular long chain of terminal hydroxyl polybutadiene is a non-polar structure, the cohesive energy of trihydroxy polyether is weak, and the intermolecular force is small. Therefore, the present invention significantly reduces the disadvantage of large endogenous heat caused by large intermolecular force due to a large number of polar groups and hydrogen bonds in the polyurethane molecule by introducing terminal hydroxyl polybutadiene and trihydroxy polyether into the molecular structure. At the same time, the trihydroxy polyether reacts with isocyanate to generate a three-dimensional network structure polyurethane, which improves the mechanical properties of the polyurethane, plays a role in increasing the bearing capacity of the polyurethane, and increases the motion resistance between the molecular chains of the polyurethane elastomer, thereby improving the damping performance of the polyurethane elastomer. Second, the present invention introduces terminal hydroxyl polybutadiene into the main chain of the polyurethane elastomer, and grafts siloxane on the side chain. The glass transition temperature of terminal hydroxyl polybutadiene is low, and the polyurethane elastomer material prepared therefrom has better low-temperature performance. However, because the terminal hydroxyl polybutadiene molecule contains double bonds, the aging performance deteriorates. The present invention uses vinyl trimethoxy silane to polymerize with the double bonds in the terminal hydroxyl polybutadiene molecule, which not only reduces the aging risk caused by the presence of double bonds, but also improves the aging performance of the elastomer material while maintaining the excellent low temperature of the polyurethane elastomer material; and further reduces the elastic modulus and hardness change rate of the polyurethane elastomer material under low temperature conditions without affecting the mechanical properties and damping properties of the polyurethane elastomer material, thereby improving the low-temperature deformation performance of the polyurethane material. In summary, the siloxane-grafted polyurethane elastomer material obtained by the preparation method provided by the present invention has low endogenous heat generation, small elastic modulus change rate under low temperature environment, and high damping performance, and is suitable as a substrate for seismic isolation bearings. DETAILED DESCRIPTION

[0036] The present invention provides a method for preparing a siloxane-grafted polyurethane elastomer material, comprising the following steps:

[0037] The terminal hydroxyl polybutadiene and the first isocyanate are mixed to undergo a polycondensation reaction to obtain a polycondensation product; the polycondensation product, vinyl trimethoxysilane and an initiator are mixed to undergo a grafting reaction to obtain a siloxane grafted prepolymer;

[0038] The trihydroxy polyether and the second isocyanate are mixed to carry out a first polymerization reaction to obtain a polyether prepolymer;

[0039] The siloxane-grafted prepolymer, the polyether prepolymer, the chain extender and the catalyst are mixed to carry out a second polymerization reaction to obtain the siloxane-grafted polyurethane elastomer material.

[0040] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0041] The present invention mixes terminal hydroxyl polybutadiene and a first isocyanate (hereinafter referred to as the first mixture) for polycondensation reaction to obtain a polycondensation product; and mixes the polycondensation product, vinyl trimethoxysilane and an initiator (hereinafter referred to as the second mixture) for grafting reaction to obtain a siloxane grafted prepolymer.

[0042] The present invention first mixes terminal hydroxyl polybutadiene and a first isocyanate to carry out polycondensation reaction to obtain a polycondensation product.

[0043] In the present invention, the average molecular weight of the hydroxy-terminated polybutadiene is preferably 2000-3500, more preferably 2500-3000.

[0044] In the present invention, the viscosity of the hydroxy-terminated polybutadiene is 15 to 30 Pa.S, more preferably 18 to 25 Pa.S.

[0045] In the present invention, before the first mixing, the hydroxy-terminated polybutadiene is preferably dehydrated. In the present invention, the dehydration is preferably vacuum drying, the vacuum drying temperature is preferably 110-120° C., and the vacuum drying insulation time is 1.5-2.5 h.

[0046] In the present invention, the main reason for the high heat generation of polyurethane is that the molecule contains a large number of polar groups and hydrogen bonds, and the intermolecular force is large. Therefore, terminal hydroxyl polybutadiene is introduced into the molecular structure, and its molecular long chain is a non-polar structure, and the intermolecular force is small, which reduces the heat generation of polyurethane elastomer; and the glass transition temperature of terminal hydroxyl polybutadiene is low, and the polyurethane elastomer material prepared therefrom has better low-temperature performance. However, because the terminal hydroxyl polybutadiene molecule contains double bonds, the aging performance will be worse. In the present invention, vinyl trimethoxy silane is used to polymerize with the double bonds in the terminal hydroxyl polybutadiene molecule, which reduces the aging risk caused by the presence of double bonds, and improves the aging performance of the elastomer material while maintaining the excellent low temperature of the polyurethane elastomer material.

[0047] In the present invention, the first isocyanate preferably includes diphenylmethane diisocyanate (MDI) and / or 1,5-naphthalene diisocyanate (NDI).

[0048] In the present invention, the first isocyanate forms a hard segment in the polyurethane elastomer, affecting the softening melting temperature and high temperature performance of the polyurethane elastomer. The polyurethane prepared by aromatic isocyanate in the present invention preferably has a hard segment containing a rigid aromatic ring, thereby increasing the cohesive strength of the hard segment, and having better material strength and high temperature resistance.

[0049] In the present invention, the molar ratio of the hydroxy-terminated polybutadiene to the first isocyanate is preferably (20-35):(25-40), and more preferably (25-30):(30-35).

[0050] In the present invention, the temperature of the first mixing is preferably 30-55°C.

[0051] In the present invention, the temperature of the polycondensation reaction is preferably 30-55°C, more preferably 35-50°C.

[0052] In the present invention, the holding time of the polycondensation reaction is preferably 1 to 2.5 h, more preferably 1.5 to 2 h.

[0053] After obtaining the polycondensation product, the present invention conducts a second grafting reaction by mixing the polycondensation product, vinyltrimethoxysilane and an initiator to obtain a siloxane grafted prepolymer.

[0054] In the present invention, the density of the vinyltrimethoxysilane is preferably 0.960 to 0.980 g / cm 3 .

[0055] In the present invention, Si-O of the vinyl trimethoxysilane has high thermal stability, weather resistance and low temperature resistance, and gives the product good ozone resistance, UV resistance and low temperature flexibility. The double bonds at the ends of the molecular chains undergo addition reactions with the double bonds in the terminal hydroxyl polybutadiene macromolecules through the action of an initiator, so that the vinyl trimethoxysilane is grafted onto the polyurethane macromolecular chain, and the elastic modulus and hardness change rate of the polyurethane elastomer material in a low temperature state are further reduced without affecting the mechanical properties and damping properties of the polyurethane elastomer material, thereby improving the low temperature deformation performance of the polyurethane material.

[0056] In the present invention, the molar ratio of the vinyltrimethoxysilane to the first isocyanate is preferably (50-80):(25-40), more preferably (55-75):(25-40), and further preferably (60-70):(25-40).

[0057] In the present invention, the initiator is preferably benzoyl peroxide.

[0058] In the present invention, the initiator initiates polymerization of double bonds in the molecular chain.

[0059] In the present invention, the molar ratio of the initiator to the first isocyanate is preferably (0.5-2):(25-40), and more preferably (0.6-1.8):(25-40).

[0060] In the present invention, the temperature of the grafting reaction is preferably 75-95° C., more preferably 80-85° C. In the present invention, the holding time of the grafting reaction is preferably 1-3 h, more preferably 1.5-2.5 h.

[0061] In the present invention, the siloxane grafted prepolymer is preferably sealed for standby use.

[0062] In the present invention, a trihydroxy polyether and a second isocyanate are mixed (hereinafter referred to as the third mixture) to carry out a first polymerization reaction to obtain a polyether prepolymer.

[0063] In the present invention, the trihydroxy polyether preferably includes polyoxypropylene triol and / or polyoxypropylene-oxyethylene triol.

[0064] In the present invention, the average molecular weight of the trihydroxy polyether is preferably 2000 to 8000, more preferably 2500 to 7000, and even more preferably 3000 to 6000.

[0065] In the present invention, at 25° C., the viscosity of the trihydroxy polyether is preferably 300 to 1000 mPa.s, more preferably 350 to 900 mPa.s, and further preferably 400 to 800 mPa.s.

[0066] In the present invention, at 25° C., the acid value of the trihydroxy polyether is preferably 20 to 80 mgKOH / g, more preferably 25 to 70 mgKOH / g, and further preferably 30 to 60 mgKOH / g.

[0067] In the present invention, the cohesive energy of the polyether polyol is relatively weak, the flexibility is good, and the elongation at break is greater, which endows the polyurethane elastomer material with better elastic deformation and recovery ability after deformation, and reduces the internal heat generation of the polyurethane elastomer; the functionality of the trihydroxy polyether is 3, and it can react with isocyanate to form a three-dimensional network structure polyurethane, improve the mechanical properties of the polyurethane, play a role in increasing the bearing capacity of the polyurethane, and increase the movement resistance between the molecular chains of the polyurethane elastomer, thereby improving the damping performance of the polyurethane elastomer.

[0068] In the present invention, before the third mixing, the trihydroxy polyether is preferably subjected to a dehydration treatment. In the present invention, the dehydration treatment is preferably vacuum drying, the vacuum drying temperature is preferably 110-120° C., and the vacuum drying insulation time is 2-2.5 h.

[0069] In the present invention, the second isocyanate preferably includes diphenylmethane diisocyanate (MDI) and / or 1,5-naphthalene diisocyanate (NDI).

[0070] In the present invention, the second isocyanate also forms a hard segment in the polyurethane elastomer, affecting the softening melting temperature and high temperature performance of the polyurethane elastomer. The polyurethane prepared by the preferred aromatic isocyanate in the present invention has a hard segment containing a rigid aromatic ring, thereby increasing the cohesive strength of the hard segment, and having good material strength and high temperature resistance.

[0071] In the present invention, the molar ratio of the trihydroxy polyether to the second isocyanate is preferably (30-40):(60-75), and more preferably (32-38):(60-75).

[0072] In the present invention, the temperature of the third mixing is preferably 50-75°C, more preferably 55-70°C.

[0073] In the present invention, the temperature of the first polymerization reaction is preferably 80-110° C., more preferably 85-105° C. In the present invention, the insulation time of the first polymerization reaction is preferably 2.5-3 h.

[0074] In the present invention, the polyether prepolymer is sealed and stored.

[0075] After obtaining the siloxane grafted prepolymer and the polyether prepolymer, the present invention mixes the siloxane grafted prepolymer, the polyether prepolymer, the chain extender and the catalyst (hereinafter referred to as the fourth mixing) to carry out a second polymerization reaction to obtain the siloxane grafted polyurethane elastomer material.

[0076] In the present invention, the siloxane grafted prepolymer is calculated based on the amount of the first isocyanate; the polyether prepolymer is calculated based on the amount of the second isocyanate; the molar ratio of the siloxane grafted prepolymer to the polyether prepolymer is preferably (25~40):(60~75), more preferably (30~35):(65~70).

[0077] In the present invention, the chain extender is preferably 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA).

[0078] In the present invention, MOCA enhances the mechanical properties of polyurethane elastomers such as tensile strength, while balancing the toughness technical indicators - tear strength and elongation at break, deformation and impact absorption energy, and shortens the post-vulcanization time in terms of technology.

[0079] In the present invention, the molar ratio of the chain extender to the sum of the first isocyanate and the second isocyanate is preferably (10-20):100, more preferably (12-17):100.

[0080] In the present invention, the catalyst is preferably dibutyltin dilaurate and / or stannous octoate. In the present invention, the catalyst accelerates the reaction of the polyurethane elastomer and the post-vulcanization time.

[0081] In the present invention, the molar ratio of the catalyst to the sum of the first isocyanate and the second isocyanate is preferably (0.1-0.5):100, more preferably (0.2-0.4):100.

[0082] In the present invention, the temperature of the second polymerization reaction is room temperature, and the time of the second polymerization reaction is preferably 20 to 40 minutes. In the present invention, the second polymerization reaction is preferably carried out under stirring, and the stirring speed is preferably 3000 to 5000 r / min.

[0083] The preparation method of the siloxane-grafted polyurethane elastomer material provided by the present invention is calculated based on 100 molar parts of the first isocyanate and the second isocyanate, the trihydroxy polyether is 15 to 30 molar parts, the terminal hydroxyl polybutadiene is 20 to 35 molar parts, the chain extender is 10 to 20 molar parts, the catalyst is 0.1 to 0.5 molar parts, the vinyl trimethoxy silane is 50 to 80 molar parts, and the initiator is 0.5 to 2 molar parts.

[0084] The present invention provides a siloxane-grafted polyurethane elastomer material, which is prepared by the preparation method described in the above technical scheme; the molecular structure of the siloxane-grafted polyurethane elastomer material includes a main chain structure and a side chain structure, the main chain structure contains isocyanate units, trihydroxy polyether units and terminal hydroxyl polybutadiene units; the isocyanate units and the trihydroxy polyether units form a three-dimensional network structure;

[0085] The branched structure contains vinyltrimethoxysilane units.

[0086] The invention provides a siloxane-grafted polyurethane elastomer seismic isolation bearing, which is prepared from the siloxane-grafted polyurethane elastomer material described in the above technical solution.

[0087] The present invention provides a method for preparing a siloxane-grafted polyurethane elastomer seismic isolation bearing, comprising the following steps:

[0088] The siloxane-grafted polyurethane elastomer material described in the above technical solution is reacted and molded in a mold, and a polyurethane molded body is obtained after demoulding;

[0089] The polyurethane molded body is aged to obtain the siloxane-grafted polyurethane elastomer vibration-damping and isolation bearing.

[0090] The present invention forms the siloxane-grafted polyurethane elastomer material described in the above technical solution by reaction in a mold, and obtains a polyurethane molded body after demoulding.

[0091] In the present invention, the siloxane-grafted polyurethane elastomer material described in the above technical solution is preferably quickly poured into a mold to perform the reaction molding.

[0092] In the present invention, the reaction molding temperature is preferably 80-100°C, more preferably 85-95°C.

[0093] In the present invention, the reaction molding is preferably kept warm for 20 to 80 minutes before demoulding, and more preferably 25 to 75 minutes.

[0094] After obtaining the polyurethane molded body, the present invention matures the polyurethane molded body to obtain the siloxane-grafted polyurethane elastomer seismic isolation bearing.

[0095] In the present invention, the aging temperature is preferably 60-80°C, more preferably 65-75°C.

[0096] In the present invention, the aging holding time is preferably 6 to 24 hours, more preferably 10 to 24 hours.

[0097] Compared with the prior art, the siloxane-grafted polyurethane elastomer seismic isolation bearing provided by the present invention has the following beneficial effects:

[0098] (1) The present invention introduces terminal hydroxyl polybutadiene and trihydroxy polyether into the molecular structure of polyurethane to reduce the internal heat generation of polyurethane elastomer. The main reason for the high heat generation of polyurethane is that the molecule contains a large number of polar groups and hydrogen bonds, and the intermolecular force is large. The molecular long chain of terminal hydroxyl polybutadiene is a non-polar structure, and the cohesive energy of trihydroxy polyether is weak, and the intermolecular force is small. Therefore, the terminal hydroxyl polybutadiene and trihydroxy polyether are introduced into the molecular structure to reduce the internal heat generation of polyurethane elastomer.

[0099] (2) The present invention introduces terminal hydroxyl polybutadiene into the main chain of the polyurethane elastomer and introduces siloxane into the side chain to enhance the flexibility of the elastomer material at low temperatures and reduce the rate of change of the elastic modulus under low temperature conditions. The glass transition temperature of terminal hydroxyl polybutadiene is low, and the polyurethane elastomer material prepared therefrom has better low temperature performance. However, because the terminal hydroxyl polybutadiene molecule contains double bonds, the aging performance will deteriorate. In the present invention, vinyl trimethoxy silane is used to undergo a polymerization reaction with the double bonds in the terminal hydroxyl polybutadiene molecule, thereby reducing the aging risk caused by the presence of double bonds, and improving the aging performance of the elastomer material while maintaining the excellent low temperature performance of the polyurethane elastomer material. The siloxane-grafted terminal hydroxyl polybutadiene prepolymer prepared by the present invention grafts siloxane onto the polyurethane elastomer molecular chain, further reducing the elastic modulus and hardness change rate of the polyurethane elastomer material at low temperatures without affecting the mechanical properties and damping properties of the polyurethane elastomer material, thereby improving the low temperature deformation performance of the polyurethane material.

[0100] (3) The present invention reacts trihydroxy polyether with isocyanate to generate a three-dimensional network structure polyurethane, thereby improving the mechanical properties of the polyurethane, increasing the load-bearing capacity of the polyurethane, and increasing the movement resistance between the molecular chains of the polyurethane elastomer, thereby improving the damping performance of the polyurethane elastomer.

[0101] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0102] Example 1

[0103] (1) Preparation of siloxane-grafted hydroxy-terminated polybutadiene prepolymer

[0104] 20 mol parts of terminal hydroxyl polybutadiene were vacuum dehydrated at 110°C for 1.5 hours, cooled to 30°C, added with 25 mol parts of MDI for reaction for 1 hour, heated to 75°C, added with 50 mol parts of vinyltrimethoxysilane and 0.5 mol parts of benzoyl peroxide for reaction for 1 hour to obtain a siloxane grafted prepolymer, which was sealed for later use.

[0105] (2) Preparation of polyether prepolymer

[0106] 40 mol parts of polyoxypropylene triol were vacuum dehydrated at 110° C. for 2 h, cooled to 50° C., added with 75 mol parts of MDI, and heated to 80° C. for reaction for 2.5 h to obtain a polyether prepolymer, which was sealed for later use.

[0107] (3) Preparation of polyurethane elastomer

[0108] The siloxane grafted prepolymer, the polyether prepolymer, 10 mole parts of MOCA, and 0.1 mole parts of dibutyltin dilaurate were mixed and stirred at a rotation speed of 3000 r / min for 20 minutes to obtain a polyurethane elastomer material.

[0109] (4) Molding of polyurethane elastomer seismic isolation bearings

[0110] The polyurethane elastomer material is quickly poured into the mold, maintained at 80°C for reaction molding, demolded after 20 minutes, and then aged at 60°C for 6 hours to obtain the finished product.

[0111] Example 2

[0112] (1) Preparation of siloxane-grafted hydroxy-terminated polybutadiene prepolymer

[0113] 35 mol parts of terminal hydroxyl polybutadiene were vacuum dehydrated at 120°C for 2.5 hours, cooled to 55°C, added with 40 mol parts of 1,5-naphthalene diisocyanate (NDI) and reacted for 2.5 hours, heated to 95°C, added with 80 mol parts of vinyl trimethoxysilane and 2 mol parts of benzoyl peroxide and reacted for 3 hours to obtain a siloxane grafted prepolymer, which was sealed for later use.

[0114] (2) Preparation of polyether prepolymer

[0115] 30 mol parts of polyoxypropylene-ethylene oxide triol were vacuum dehydrated at 120°C for 2.5 hours, cooled to 75°C, added with 60 mol parts of 1,5-naphthalene diisocyanate (NDI), heated to 110°C and reacted for 3 hours to obtain a polyether prepolymer, which was sealed for later use.

[0116] (3) Preparation of polyurethane elastomer

[0117] The siloxane grafted prepolymer, the polyether prepolymer, 20 mol parts of MOCA and 0.5 mol parts of stannous octoate were mixed and stirred at a rotation speed of 5000 r / min for 40 minutes to obtain a polyurethane elastomer material.

[0118] (4) Molding of polyurethane elastomer seismic isolation bearings

[0119] The polyurethane elastomer material is quickly poured into the mold, maintained at 100°C for reaction molding, demolded after 80 minutes, and then aged at 80°C for 24 hours to obtain the finished product.

[0120] Example 3

[0121] (1) Preparation of siloxane-grafted hydroxy-terminated polybutadiene prepolymer

[0122] 25 mol parts of terminal hydroxyl polybutadiene were vacuum dehydrated at 113°C for 1.8 hours, cooled to 35°C, added with 15 mol parts of MDI and 15 mol parts of 1,5-naphthalene diisocyanate (NDI) and reacted for 1.5 hours, heated to 80°C, added with 60 mol parts of vinyl trimethoxysilane and 1 mol part of benzoyl peroxide and reacted for 1.5 hours to obtain a siloxane grafted prepolymer, which was sealed for later use.

[0123] (2) Preparation of polyether prepolymer

[0124] 20 mol parts of polyoxypropylene triol and 18 mol parts of polyoxypropylene-ethylene oxide triol were vacuum dehydrated at 113°C for 2.1 hours, cooled to 55°C, and then 35 mol parts of MDI and 35 mol parts of 1,5-naphthalene diisocyanate (NDI) were added, and the temperature was raised to 85°C for reaction for 2.6 hours to obtain a polyether prepolymer, which was sealed for later use.

[0125] (3) Preparation of polyurethane elastomer

[0126] The siloxane grafted prepolymer, the polyether prepolymer, 12 mol parts of MOCA, 0.1 mol parts of dibutyltin dilaurate and 0.1 mol parts of stannous octoate were mixed and stirred at a rotation speed of 3500 r / min for 25 minutes to obtain a polyurethane elastomer material.

[0127] (4) Molding of polyurethane elastomer seismic isolation bearings

[0128] The polyurethane elastomer material is quickly poured into the mold, maintained at 85°C for reaction molding, demolded after 30 minutes, and then aged at 65°C for 10 hours to obtain the finished product.

[0129] Example 4

[0130] (1) Preparation of siloxane-grafted hydroxy-terminated polybutadiene prepolymer

[0131] 30 mol parts of terminal hydroxyl polybutadiene were vacuum dehydrated at 115°C for 2.2 hours, cooled to 45°C, added with 36 mol parts of MDI for reaction for 2.0 hours, heated to 85°C, added with 70 mol parts of vinyltrimethoxysilane and 1.5 mol parts of benzoyl peroxide for reaction for 2.0 hours to obtain a siloxane grafted prepolymer, which was sealed for later use.

[0132] (2) Preparation of polyether prepolymer

[0133] 15 mol parts of polyoxypropylene triol and 20 mol parts of polyoxypropylene-ethylene oxide triol were vacuum dehydrated at 113°C for 2.3 hours, cooled to 60°C, added with 64 mol parts of MDI, heated to 90°C and reacted for 2.7 hours to obtain a polyether prepolymer, which was sealed for later use.

[0134] (3) Preparation of polyurethane elastomer

[0135] The siloxane grafted prepolymer, the polyether prepolymer, 18 mol parts of MOCA, and 0.3 mol parts of dibutyltin dilaurate were mixed and stirred at a rotation speed of 4000 r / min for 30 minutes to obtain a polyurethane elastomer material.

[0136] (4) Molding of polyurethane elastomer seismic isolation bearings

[0137] The polyurethane elastomer material is quickly poured into the mold, maintained at 90°C for reaction molding, demolded after 50 minutes, and then aged at 70°C for 15 hours to obtain the finished product.

[0138] Example 5

[0139] (1) Preparation of siloxane-grafted hydroxy-terminated polybutadiene prepolymer

[0140] 28 mol parts of terminal hydroxyl polybutadiene were vacuum dehydrated at 118°C for 2.2 hours, cooled to 50°C, added with 34 mol parts of 1,5-naphthalene diisocyanate (NDI) and reacted for 2.4 hours, heated to 90°C, added with 65 mol parts of vinyl trimethoxysilane and 1.8 mol parts of benzoyl peroxide and reacted for 2.5 hours to obtain a siloxane grafted prepolymer, which was sealed for later use.

[0141] (2) Preparation of polyether prepolymer

[0142] 33 mol parts of polyoxypropylene triol were vacuum dehydrated at 118° C. for 2.4 h, cooled to 65° C., and then 66 mol parts of 1,5-naphthalene diisocyanate (NDI) were added, and the temperature was raised to 100° C. for reaction for 2.8 h to obtain a polyether prepolymer, which was sealed for later use.

[0143] (3) Preparation of polyurethane elastomer

[0144] The siloxane grafted prepolymer, the polyether prepolymer, 15 mol parts of MOCA and 0.4 mol parts of stannous octoate were mixed and stirred at a rotation speed of 4500 r / min for 35 minutes to obtain a polyurethane elastomer material.

[0145] (4) Molding of polyurethane elastomer seismic isolation bearings

[0146] The polyurethane elastomer material is quickly poured into the mold, maintained at 95°C for reaction molding, demolded after 60 minutes, and then aged at 75°C for 20 hours to obtain the finished product.

[0147] Comparative Example 1

[0148] Compared with Example 1, the terminal hydroxyl polybutadiene is replaced by terminal hydroxyl siloxane, and the Si-O bond is introduced into the polyurethane main chain, comprising the following steps:

[0149] (1) Preparation of hydroxy-terminated siloxane prepolymer

[0150] 20 mol parts of terminal hydroxyl siloxane were vacuum dehydrated at 110° C. for 1.5 h, cooled to 30° C., and then 25 mol parts of MDI were added to react for 1 h to obtain a terminal hydroxyl siloxane prepolymer, which was sealed for later use.

[0151] (2) Preparation of polyether prepolymer

[0152] 40 mol parts of polyoxypropylene triol were vacuum dehydrated at 110° C. for 2 h, cooled to 50° C., added with 75 mol parts of MDI, and heated to 80° C. for reaction for 2.5 h to obtain a polyether prepolymer, which was sealed for later use.

[0153] (3) Preparation of polyurethane elastomer

[0154] The terminal hydroxyl siloxane prepolymer, the polyether prepolymer, 10 mol parts of MOCA, and 0.1 mol parts of dibutyltin dilaurate were mixed and stirred at a rotation speed of 3000 r / min for 20 minutes to obtain a polyurethane elastomer material.

[0155] (4) Molding of polyurethane elastomer seismic isolation bearings

[0156] The polyurethane elastomer material is quickly poured into the mold, maintained at 80°C for reaction molding, demolded after 20 minutes, and then aged at 60°C for 6 hours to obtain the finished product.

[0157] Comparative Example 2

[0158] Compared with Example 2, in which the hydroxy-terminated polybutadiene was not graft-modified, the following steps were included:

[0159] (1) Preparation of hydroxy-terminated polybutadiene prepolymer

[0160] 35 mol parts of hydroxy-terminated polybutadiene were vacuum dehydrated at 120° C. for 2.5 h, cooled to 55° C., and then 40 mol parts of 1,5-naphthalene diisocyanate (NDI) were added and reacted for 2.5 h to obtain a siloxane-grafted prepolymer, which was sealed for later use.

[0161] (2) Preparation of polyether prepolymer

[0162] 30 mol parts of polyoxypropylene-ethylene oxide triol were vacuum dehydrated at 120°C for 2.5 hours, cooled to 75°C, added with 60 mol parts of 1,5-naphthalene diisocyanate (NDI), heated to 110°C and reacted for 3 hours to obtain a polyether prepolymer, which was sealed for later use.

[0163] (3) Preparation of polyurethane elastomer

[0164] The hydroxy-terminated polybutadiene prepolymer, the polyether prepolymer, 20 mol portions of MOCA, and 0.5 mol portions of stannous octoate were mixed and stirred at a rotation speed of 5000 r / min for 40 minutes to obtain a polyurethane elastomer material.

[0165] (4) Molding of polyurethane elastomer seismic isolation bearings

[0166] The polyurethane elastomer material is quickly poured into the mold, maintained at 100°C for reaction molding, demolded after 80 minutes, and then aged at 80°C for 24 hours to obtain the finished product.

[0167] Comparative Example 3

[0168] Compared with Example 3, the following steps are included:

[0169] (1) Preparation of hydroxyl oligomers

[0170] 25 mol parts of terminal hydroxyl polybutadiene, 20 mol parts of polyoxypropylene triol and 18 mol parts of polyoxypropylene-ethylene oxide triol, 60 mol parts of vinyl trimethoxy silane and 1.0 mol part of benzoyl peroxide are vacuum dehydrated at 113°C for 2.1 hours to prepare a hydroxyl oligomer, and the mixture is cooled to 55°C for use.

[0171] (2) Preparation of prepolymer

[0172] 50 mol parts of MDI, 50 mol parts of 1,5-naphthalene diisocyanate (NDI), 12 mol parts of MOCA, 0.1 mol parts of dibutyltin dilaurate and 0.1 mol parts of stannous octoate were mixed and stirred at a rotation speed of 3500 r / min for 25 minutes to obtain a prepolymer.

[0173] (3) Preparation of polyurethane elastomer

[0174] The hydroxyl oligomer and the prepolymer were mixed and stirred at a rotation speed of 3500 r / min for 25 minutes and the temperature was controlled at 40° C. to obtain a polyurethane elastomer material.

[0175] (4) Molding of polyurethane elastomer seismic isolation bearings

[0176] The polyurethane elastomer material is quickly poured into the mold, maintained at 85°C for reaction molding, demolded after 30 minutes, and then aged at 65°C for 10 hours to obtain the finished product.

[0177] Test Case

[0178] The specific performance test results of the products prepared in Examples 1-4 and Comparative Examples 1-2 are shown in Table 1.

[0179] (1) The tensile modulus test is carried out in accordance with the standard "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber" (GB / T 528-2008).

[0180] (2) The compression heat generation test is carried out in accordance with the standard "Determination of temperature rise and fatigue resistance of vulcanized rubber in flexure test Part 3: Compression flexure test (constant strain type)" (GB / T 1687.3-2016). The test conditions are room temperature test, stroke 4.45 mm, and pressure 1.0 MPa.

[0181] (3) The equivalent damping ratio test is carried out in accordance with the standard Rubber bearings Part 1: Test methods for seismic isolation rubber bearings (GB / T 20688.1-2007).

[0182] Table 1 Performance test results

[0183]

[0184] As can be seen from Table 1, the present invention introduces terminal hydroxyl polybutadiene and grafted vinyl trimethoxy silane into the polyurethane macromolecule, so that the seismic isolation bearing has the characteristics of low endogenous heat, small elastic modulus change rate in low temperature environment and high damping performance.

[0185] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a siloxane-grafted polyurethane elastomer material, characterized in that: The following steps are involved: The hydroxy-terminated polybutadiene and the first isocyanate are mixed to undergo a polycondensation reaction to obtain a polycondensation product; The polycondensation product, vinyltrimethoxysilane and an initiator are mixed to undergo a grafting reaction to obtain a siloxane grafted prepolymer; The trihydroxy polyether and the second isocyanate are mixed to carry out a first polymerization reaction to obtain a polyether prepolymer; The siloxane-grafted prepolymer, the polyether prepolymer, the chain extender and the catalyst are mixed to carry out a second polymerization reaction to obtain the siloxane-grafted polyurethane elastomer material.

2. The preparation method according to claim 1, characterized in that: The first isocyanate includes diphenylmethane diisocyanate and / or 1,5-naphthalene diisocyanate; The molar ratio of the hydroxy-terminated polybutadiene to the first isocyanate is (20-35):(25-40); The temperature of the polycondensation reaction is 30-55° C., and the insulation time of the polycondensation reaction is 1-2.5 h.

3. The preparation method according to claim 1 or 2, characterized in that: The molar ratio of the vinyltrimethoxysilane to the first isocyanate is (50-80):(25-40); The temperature of the grafting reaction is 75-95° C., and the insulation time of the grafting reaction is 1-3 hours.

4. The preparation method according to claim 1 or 2, characterized in that: The initiator is benzoyl peroxide; The molar ratio of the initiator to the first isocyanate is (0.5-2):(25-40).

5. The preparation method according to claim 1, characterized in that: The second isocyanate includes diphenylmethane diisocyanate and / or 1,5-naphthalene diisocyanate; the trihydroxy polyether includes polyoxypropylene triol and / or polyoxypropylene-oxyethylene triol; The molar ratio of the trihydroxy polyether to the second isocyanate is (30-40):(60-75); The temperature of the first polymerization reaction is 80-110° C., and the insulation time of the first polymerization reaction is 2.5-3 hours.

6. The preparation method according to claim 1, characterized in that: The siloxane grafted prepolymer is calculated based on the amount of the first isocyanate; The polyether prepolymer is calculated based on the amount of the second isocyanate; The molar ratio of the siloxane grafted prepolymer to the polyether prepolymer is (25-40):(60-75); The temperature of the second polymerization reaction is room temperature, and the time of the second polymerization reaction is 20 to 40 minutes.

7. The preparation method according to claim 1, characterized in that: The chain extender is 3,3'-dichloro-4,4'-diphenylmethanediamine; the molar ratio of the chain extender to the sum of the first isocyanate and the second isocyanate is (10-20):100; The catalyst is dibutyltin dilaurate and / or stannous octoate; the molar ratio of the catalyst to the sum of the first isocyanate and the second isocyanate is (0.1-0.5):

100.

8. A siloxane-grafted polyurethane elastomer material, characterized in that: The siloxane-grafted polyurethane elastomer material is prepared by the preparation method according to any one of claims 1 to 7; the molecular structure of the siloxane-grafted polyurethane elastomer material includes a main chain structure and a branched chain structure, the main chain structure contains an isocyanate unit, a trihydroxy polyether unit and a terminal hydroxyl polybutadiene unit; the isocyanate unit and the trihydroxy polyether unit form a three-dimensional network structure; The branched structure contains vinyltrimethoxysilane units.

9. A siloxane-grafted polyurethane elastomer seismic isolation bearing, characterized in that: It is prepared from the siloxane-grafted polyurethane elastomer material described in claim 8.

10. A method for preparing a siloxane-grafted polyurethane elastomer seismic isolation bearing, characterized in that: The following steps are involved: Reaction-molding the siloxane-grafted polyurethane elastomer material according to claim 8 in a mold, and obtaining a polyurethane molded body after demoulding; The polyurethane molded body is aged to obtain the siloxane-grafted polyurethane elastomer vibration-damping and isolation bearing.

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