Fatigue-resistant polyurethane microporous elastomer damping mat and method of making same

Abstract

This invention belongs to the field of polyurethane technology and proposes a fatigue-resistant polyurethane microporous elastomer vibration damping pad and its preparation method. The pad material is composed of component A and component B in a mass ratio of 50~100:100. By mass parts, component A includes: 40~60 parts of polyether polyol C1, 40~60 parts of isocyanate D1, and 5~15 parts of isocyanate D2; component B includes: polyether polyol C2... The composition comprises 60-80 parts of a modified crosslinking agent, 20-40 parts of a modified foaming agent, 0.03-0.09 parts of deionized water, 0-1.5 parts of a color paste, 0.5-3.0 parts of a weather-resistant agent, 0.1-1.0 parts of a modified foaming agent, and 0.3-1.0 parts of a catalyst; component B further comprises a physical foaming agent accounting for 5-20% of the total volume of components A and B; the modified foaming agent is a polyether-modified polysiloxane, whose polyether side chain contains a side-methyltetrahydrofuran segment; the modified crosslinking agent is a multi-arm polyether with trimethylolpropane as an initiator, whose molecular chain contains a tetrahydrofuran segment. This technical solution simultaneously solves the technical problems of inconsistent and unevenly distributed cell size, strong amine odor, and poor fatigue resistance after long-term use in existing technologies.

Description

Technical Field

[0001] This invention belongs to the field of polyurethane technology and relates to a fatigue-resistant polyurethane microporous elastomer vibration damping pad and its preparation method. Background Technology

[0002] Polyurethane microporous elastomer vibration damping pads are key elastic support components in the rail transit field, widely used under iron pads, rails, concrete, and ballast, serving to reduce vibration, noise, and provide cushioning. As high-speed railways develop towards higher speeds and heavier loads, more stringent requirements are being placed on the performance of vibration damping pads.

[0003] The performance of polyurethane microporous elastomers largely depends on their internal microporous structure. A uniform, dense microporous structure with consistent pore size can significantly reduce the dynamic-to-static stiffness ratio and improve toughness and fatigue resistance. Therefore, effectively controlling the cell morphology to achieve a microporous structure with uniform pore size and distribution is crucial for preparing high-performance vibration damping pads.

[0004] To improve the cell structure during polyurethane foaming, foam stabilizers are indispensable additives. In existing technologies, polyether-modified siloxane foam stabilizers are widely used. These are mainly polymerized from ethylene oxide, propylene oxide, and silicone oil. During the material mixing stage, foam stabilizers can increase the compatibility between material components, allowing isocyanates and active hydroxyl compounds to fully contact and promote the reaction. Simultaneously, foam stabilizers can reduce the surface tension of the material slurry, promote the generation of gas nuclei, and control the uniformity and pore size of the cells during nucleus growth. In addition, foam stabilizers can adjust the compatibility of the insoluble polyurea generated from the reaction of isocyanates and water with the system, ensuring uniform cell growth during foaming. In polyurethane microporous elastomer vibration damping pad systems, conventional foam stabilizers have weak emulsifying ability between the active hydroxyl compound components and the isocyanate components. This leads to poor cell size consistency in the product, mainly manifested as uneven pore size distribution and significant differences in cell structure, thus causing unstable pad performance. Meanwhile, excessively large local bubbles can reduce the overall performance of the pad. After long-term use, the rupture of large bubbles will increase the rigidity of the pad, thus affecting its service life.

[0005] On the other hand, the structure of the crosslinking agent also has a significant impact on the reaction process and cell growth of polyurethane microporous elastomers. Traditional small-molecule crosslinking agents such as glycerol and trimethylolpropane are too reactive, reacting rapidly with isocyanates in the early stages of material mixing, leading to a sharp increase in system viscosity, which is detrimental to cell nucleation and growth, often resulting in small and uneven pore size. Therefore, those skilled in the art have attempted to develop low-molecular-weight polyether-type crosslinking agents. For example, Chinese patent CN119331211A discloses a polyurethane material for highway bridge bearings, which uses a polyether triol prepared by reacting trimethylolpropane as an initiator with tetrahydrofuran as a crosslinking agent to improve the material's pressure resistance and anti-crystallization ability. However, this patent's application scenario is solid bridge bearings, and it does not optimize or study the core indicators of vibration damping pads such as dynamic-to-static stiffness ratio and fatigue resistance, failing to meet the requirements of low dynamic-to-static stiffness ratio and long-term fatigue resistance for rail transit vibration damping pads.

[0006] Furthermore, conventional amine catalysts such as triethylenediamine and dimethylcyclohexylamine are commonly used in the preparation of existing polyurethane microporous elastomer damping pads. These catalysts, after the reaction, fail to bond to the polyurethane molecular chain and slowly migrate and volatilize from the product, resulting in a strong amine odor that does not meet increasingly stringent environmental protection requirements. Simultaneously, traditional foaming processes often employ low-pressure mechanical stirring at 3000-6000 rpm to mix components A and B, resulting in limited mixing efficiency and difficulty in ensuring uniform bubble distribution. Moreover, using water alone as a chemical foaming agent generates more urea bonds, reducing the material's flexibility and hindering the improvement of fatigue resistance.

[0007] In summary, existing technologies for preparing polyurethane microporous elastomer vibration damping pads still have the following problems: (1) inconsistent cell size and uneven distribution lead to unstable product performance and poor fatigue resistance; (2) high amine odor volatility in the products results in poor environmental performance; and (3) performance degradation occurs due to cell structure deterioration after long-term use. Therefore, it is urgent to develop a polyurethane microporous elastomer material that can solve the above problems simultaneously. Summary of the Invention

[0008] This invention proposes a fatigue-resistant polyurethane microporous elastomer vibration damping pad and its preparation method, aiming to simultaneously solve the problems of inconsistent cell size and uneven distribution in existing products; the problem of high amine odor volatility in existing products; and the problem of reduced fatigue resistance of the pad after long-term use.

[0009] The technical solution of this invention is implemented as follows:

[0010] A fatigue-resistant polyurethane microporous elastomer vibration damping pad, the raw material is composed of component A and component B in a mass ratio of 50~100:100;

[0011] By mass, component A comprises: 40-60 parts of polyether polyol C1, 40-60 parts of isocyanate D1, and 5-15 parts of isocyanate D2;

[0012] By weight, component B comprises: 60-80 parts of polyether polyol C2, 20-40 parts of modified crosslinking agent, 0.03-0.09 parts of deionized water, 0-1.5 parts of color paste, 0.5-3.0 parts of weather-resistant agent, 0.1-1.0 parts of modified foaming agent, and 0.3-1.0 parts of catalyst; component B also comprises a physical foaming agent accounting for 5-20% of the total volume of components A and B.

[0013] The modified foam stabilizer is a polyether-modified polysiloxane, whose polyether side chain contains a side methyltetrahydrofuran segment.

[0014] The modified crosslinking agent is a multi-arm polyether with trimethylolpropane as the initiator, and its molecular chain contains tetrahydrofuran segments.

[0015] Preferably, by mass parts, component B comprises: 60-80 parts of polyether polyol C2, 20-40 parts of modified crosslinking agent, 0.04-0.08 parts of deionized water, 0.5-1 parts of color paste, 1.6-2.8 parts of weather-resistant agent, 0.4-0.9 parts of modified foaming agent, and 0.3-1.0 parts of catalyst; component B further comprises a physical foaming agent accounting for 5-15% of the total volume of components A and B.

[0016] Preferably, the modified foam stabilizer is a silicone oil modified with side-methyltetrahydrofuran, or a silicone oil modified by copolymerization of tetrahydrofuran and side-methyltetrahydrofuran.

[0017] Preferably, the modified foam stabilizer is prepared by hydrosilylation reaction of hydrogen-containing polysiloxane and allyl copolyether in a mass ratio of 1:50~100, wherein the allyl copolyether contains a side-methyltetrahydrofuran segment; or, contains tetrahydrofuran and a side-methyltetrahydrofuran segment.

[0018] Preferably, the preparation method of the hydrogen-containing polysiloxane includes the following steps:

[0019] By mass fraction, 45-115 parts of 202 hydrogen-containing silicone oil, 6-10 parts of octamethylcyclotetrasiloxane, and 6 parts of hexamethyldisiloxane are mixed, and sulfuric acid is added as a catalyst. The amount of sulfuric acid is 0.2%-0.7% of the total mass of the above raw materials. While stirring, the temperature is raised to 55-65℃ and kept at this temperature for 4-6 hours. Then, the solvent is removed under reduced pressure to obtain hydrogen-containing polysiloxane.

[0020] Preferably, the preparation method of the allyl copolyether includes the following steps: mixing 1-2 parts of allyl alcohol, 0-28 parts of tetrahydrofuran, 11-35 parts of side-methyltetrahydrofuran, and 11-46 parts of ethylene oxide by mass, then adding boron trifluoride diethyl ether complex as a catalyst, the amount of catalyst being 0.2%-0.7% of the total mass of the above raw materials, and reacting at 0-5°C for 2-3 hours to obtain the allyl copolyether.

[0021] Preferably, the preparation method of the modified crosslinking agent includes the following steps:

[0022] Potassium alkoxide is prepared by reacting trimethylolpropane with potassium hydroxide; then, 4 parts of potassium alkoxide are taken by mass, and 35-60 parts of tetrahydrofuran, 25-50 parts of ethylene oxide and 20-40 parts of propylene oxide are added. The mixture is reacted at 125-135℃ for 4-6 hours, and then neutralized and filtered to obtain the final product.

[0023] Preferably, a catalyst is also added to the hydrosilylation reaction. The catalyst is a chloroplatinic acid solution. The amount of chloroplatinic acid in the chloroplatinic acid solution is 0.4% to 0.6% of the total mass of the hydrogen-containing polysiloxane and allyl copolyether. The reaction temperature is 95 to 105°C and the reaction time is 2 to 3 hours.

[0024] Preferably, the chloroplatinic acid solution is prepared by diluting chloroplatinic acid with isopropanol to a concentration of 0.1-0.3 wt%.

[0025] Preferably, in the preparation of the potassium alkoxide, the mass ratio of trimethylolpropane to potassium hydroxide is 1:5-7, and the reaction temperature is 90~100℃.

[0026] Preferably, in the hydrosilylation reaction, a catalyst is also added, wherein the amount of the catalyst chloroplatinic acid is 0.4% to 0.6% of the total mass of the hydrogen-containing polysiloxane and allyl copolyether, the reaction temperature is 95 to 105°C, and the reaction time is 2 to 3 hours.

[0027] Preferably, the polyether polyol C1 has a molecular weight of 600-3000 and a functionality of 2, and is selected from one or more of polytetrahydrofuran polyol, side-methyl polytetrahydrofuran polyol, polyoxypropylene polyol, polytetrahydrofuran-ethylene oxide coether polyol, and side-methyl polytetrahydrofuran-propylene oxide coether polyol.

[0028] Preferably, the polyether polyol has a C1 molecular weight of 1000-2000 and a functionality of 2, and is a polytetrahydrofuran polyol or a polytetrahydrofuran-ethylene oxide co-polyether polyol.

[0029] Preferably, the polyether polyol has a C2 molecular weight of 600-2000 and a functionality of 2, and is selected from one or more of polytetrahydrofuran polyol, side-methyl polytetrahydrofuran polyol, polypropylene oxide-ethylene oxide copolyol, polytetrahydrofuran-propylene oxide copolyether polyol, side-methyl polytetrahydrofuran-ethylene oxide copolyether polyol, and side-methyl polytetrahydrofuran-propylene oxide-ethylene oxide copolyether polyol.

[0030] Preferably, the polyether polyol has a C2 molecular weight of 1000-2000 and a functionality of 2, and is selected from polytetrahydrofuran polyol, side-methyl polytetrahydrofuran polyol, or polytetrahydrofuran-propylene oxide coether polyol.

[0031] Preferably, the isocyanate D1 is selected from one or more of diphenylmethane diisocyanate, naphthalene diisocyanate, toluene diisocyanate, and terephthalic diisocyanate.

[0032] Preferably, the isocyanate D1 is diphenylmethane diisocyanate.

[0033] Preferably, the isocyanate D2 is selected from one or more of toluene diisocyanate, carbodiimide-modified MDI, polymethylene polyphenyl isocyanate, 2,4-MDI and 4,4-MDI.

[0034] Preferably, the isocyanate D2 is toluene diisocyanate or carbodiimide-modified MDI.

[0035] Preferably, component A is prepared by the following method: heating polyether polyol C1 to 105~115℃ and vacuum dehydrating it until the water content is less than 100ppm, cooling it to 50~70℃, adding isocyanate D1, heating it to 70~90℃ and reacting for 1~3h until the NCO content is >5%, cooling it to 50~70℃, adding isocyanate D2 and stirring evenly.

[0036] Preferably, the weather-resistant additive is composed of an antioxidant and an ultraviolet absorber in a mass ratio of 1:3 to 5.

[0037] Preferably, the catalyst is composed of a metal catalyst and a reactive organic amine catalyst in a mass ratio of 1:3 to 10, wherein the metal catalyst is selected from one or more of organotin, organobismuth, and organozinc.

[0038] Preferably, the physical foaming agent is selected from compressed air, carbon dioxide, and nitrogen.

[0039] This invention also provides a method for preparing the fatigue-resistant polyurethane microporous elastomer vibration damping pad described in Technical Topic 1, comprising the following steps:

[0040] S1. Preheat the mold and spray it with release agent;

[0041] S2. Mix component A and component B at 150~180 bar and pour the mixture into the mold.

[0042] S3. After casting, the surface of the material is subjected to flame degassing treatment, followed by heat preservation and curing, demolding, trimming, and curing to obtain the polyurethane microporous elastomer vibration damping pad product.

[0043] Preferably, the preheating temperature is 50~70℃.

[0044] Preferably, in step S2, the temperature of component A is controlled at 35~45℃ and the temperature of component B is controlled at 45~60℃. The pressure of 150~180 bar is maintained by the feeding system, and components A and B are fed together to the pouring head, mixed and poured into the mold.

[0045] Preferably, the temperature for heat preservation and curing is 120~125℃, and the time is 5~10min.

[0046] Preferably, the curing temperature is 23~25℃ and the curing time is 12-15 days.

[0047] The working principle and beneficial effects of this invention are as follows:

[0048] 1. This invention achieves precise control over the cell structure of polyurethane microporous elastomers through the synergistic effects of modified foaming agents, modified crosslinking agents, reactive catalysts, physical / chemical composite foaming agents, and high-pressure casting processes. During the mixing stage, the polyurethane material is emulsified uniformly and thoroughly. During the emulsification stage, gas nuclei are evenly distributed throughout the polyurethane mixture. During the foaming stage, the gas slowly grows towards these uniformly distributed nuclei, achieving precise control over the cell structure of the polyurethane microporous elastomer. This invention uses reactive amine catalysts instead of ordinary amine catalysts. These reactive amine catalysts are grafted onto the polyurethane backbone, reducing amine emissions and making the product more environmentally friendly. The aforementioned synergistic effects simultaneously solve three major technical problems existing in the prior art: inconsistent and uneven cell size and distribution, strong amine odor, and increased stiffness and poor fatigue resistance after long-term use. The product significantly outperforms existing technologies in terms of cell structure, dynamic-to-static stiffness ratio, fatigue resistance, mechanical strength, resilience, and environmental friendliness. It is particularly suitable for vibration reduction requirements in high-frequency, high-load rail transit such as high-speed railways and has broad application prospects.

[0049] 2. In this invention, a modified foam leveler is used instead of a traditional silicone oil foam leveler. The modified foam leveler contains a side-terminated methyltetrahydrofuran segment, which increases the compatibility between the raw materials in component B and between components A and B, resulting in good overall compatibility between the materials in components A and B.

[0050] 3. This invention introduces a physical foaming agent to replace part of the water and employs a high-pressure collision foaming process instead of the traditional high-speed physical stirring process. The introduction of this physical foaming agent enhances the fluidity of component B. Combined with a modified foam leveling agent, the two work synergistically to ensure uniform distribution of air nuclei, resulting in products with uniformly sized and distributed bubbles. Simultaneously, the introduction of the physical foaming agent reduces water usage, thereby reducing the urea bond content in the pad product and improving the material's flexibility. Attached Figure Description

[0051] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0052] Figure 1 The images shown are scanning electron microscope (SEM) images of the polyurethane microporous elastomer vibration damping pad prepared in Example 1 of the present invention; wherein (a) is a scanning electron microscope image magnified 250 times, (b) is a scanning electron microscope image magnified 500 times, and (c) is a histogram of the cell diameter distribution magnified 500 times.

[0053] Figure 2 The images shown are scanning electron microscope (SEM) images of the polyurethane microporous elastomer vibration damping pad prepared in Example 2 of the present invention; wherein (a) is a scanning electron microscope image magnified 250 times, (b) is a scanning electron microscope image magnified 500 times, and (c) is a histogram of the cell diameter distribution magnified 500 times.

[0054] Figure 3 The images shown are scanning electron microscope (SEM) images of the polyurethane microporous elastomer vibration damping pad prepared in Example 3 of the present invention; wherein (a) is a scanning electron microscope image magnified 250 times, (b) is a scanning electron microscope image magnified 500 times, and (c) is a histogram of the cell diameter distribution magnified 500 times.

[0055] Figure 4 The images shown are scanning electron microscope (SEM) images of the polyurethane microporous elastomer vibration damping pads prepared in Comparative Example 1; where (a) is a scanning electron microscope image magnified 250 times, (b) is a scanning electron microscope image magnified 500 times, and (c) is a histogram of the cell diameter distribution magnified 500 times.

[0056] Figure 5 The images shown are scanning electron microscope (SEM) images of the polyurethane microporous elastomer vibration damping pads prepared in Comparative Example 2; where (a) is a 250x magnified SEM image and (b) is a 500x magnified SEM image. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods or testing methods involved in the embodiments of the present invention are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the art, which are very clear and obvious in the relevant application fields. Those skilled in the art can understand the conventional process steps and apply the corresponding equipment based on the names, and implement them according to conventional conditions or the conditions recommended by the manufacturer. There are no special restrictions on the source of the various instruments, equipment, raw materials or reagents used in the embodiments of the present invention. They are all conventional products that can be purchased through regular commercial channels, and can also be prepared according to conventional methods known to those skilled in the art.

[0058] The raw materials used in the following examples and comparative examples are as follows:

[0059] Carbodiimide-modified MDI: Model: WANNATE® CDMDI-100H; purchased from Wanhua Chemical.

[0060] Catalyst BCAT-E28A was purchased from Guangzhou Yourun Synthetic Materials Co., Ltd.

[0061] Catalyst RZET-HD (RZETA®-HD), a reactive organic amine catalyst, was purchased from Tosoh Corporation.

[0062] Polytetrahydrofuran-ethylene oxide copolyether polyol with a molecular weight of 1000: model PolyTHF 1000copolymer, purchased from BASF.

[0063] Side-methyl polytetrahydrofuran-propylene oxide copolyether with a molecular weight of 1000: model MN-1000MP (2-MTHF-PO copolydiol), purchased from Lanxing Dongda.

[0064] Catalyst BX-EM23, an organic bismuth-zinc composite environmentally friendly catalyst, model: BX-EM23, was purchased from Guangzhou Yourun Synthetic Materials Co., Ltd.

[0065] 202 Hydrogen-containing silicone oil, also known as polymethylhydrosiloxane, CAS: 63148-57-2.

[0066] 2-Methyltetrahydrofuran, CAS: 96-47-9.

[0067] Preparation Example 1: Preparation of Modified Foaming Agent

[0068] (1) Preparation of hydrogen-containing polysiloxane

[0069] By mass fraction, 80 parts of 202 hydrogen-containing silicone oil with a molecular weight of 200-300, 8 parts of octamethylcyclotetrasiloxane, 6 parts of hexamethyldisiloxane, and 0.5% of sulfuric acid catalyst (the total mass of the reactants, i.e., the total mass of 202 hydrogen-containing silicone oil, octamethylcyclotetrasiloxane, and hexamethyldisiloxane) were added to the reactor. The mixture was then stirred and heated to 60°C and held at that temperature for 5 hours. The solvent was then removed under reduced pressure of -0.095 MPa for 50 minutes to obtain hydrogen-containing polysiloxane.

[0070] (2) Preparation of allyl copolyether

[0071] By mass fraction, at 5℃±2℃, 1 part allyl alcohol, 14 parts tetrahydrofuran, 18 parts p-methyltetrahydrofuran, 28 parts ethylene oxide, and a catalyst boron trifluoride diethyl ether complex accounting for 0.5% of the total mass of the reactants (i.e., the total mass of allyl alcohol, tetrahydrofuran, p-methyltetrahydrofuran and ethylene oxide) were added to the reactor. After reacting for 3 hours, water was added to stop the reaction. The reaction was then carried out under reduced pressure at -0.095 MPa and 85℃ for 40 minutes to obtain allyl copolyether.

[0072] (3) Preparation of modified foaming agent

[0073] By mass percentage, 1 part of the hydrogen-containing polysiloxane prepared in step (1), 100 parts of the allyl copolyether prepared in step (2), and 50 parts of solvent toluene were added to the reactor. The mixture was heated to 100°C, and a chloroplatinic acid solution was added while stirring. The chloroplatinic acid in the chloroplatinic acid solution accounted for 0.5% of the total mass of the reactants (i.e., the total mass of the hydrogen-containing polysiloxane and the allyl copolyether). After reacting for about 3 hours, NaHCO3 was added for neutralization. Finally, toluene was removed under reduced pressure of -0.095 MPa for 50 minutes to obtain tetrahydrofuran and side-methyltetrahydrofuran copolymerized modified silicone oil as a modified foaming agent. The chloroplatinic acid solution was prepared by diluting chloroplatinic acid with isopropanol to a concentration of 0.2 wt%.

[0074] Preparation Example 2: Preparation of Modified Foaming Agent

[0075] (1) Preparation of hydrogen-containing polysiloxane

[0076] By mass fraction, 80 parts of 202 hydrogen-containing silicone oil with a molecular weight of 200-300, 8 parts of octamethylcyclotetrasiloxane, 6 parts of hexamethyldisiloxane, and 0.5% of sulfuric acid catalyst (the total mass of the reactants, i.e., the total mass of 202 hydrogen-containing silicone oil, octamethylcyclotetrasiloxane, and hexamethyldisiloxane) were added to the reactor. The mixture was then stirred and heated to 60°C and held at that temperature for 5 hours. The solvent was then removed under reduced pressure of -0.095 MPa for 50 minutes to obtain hydrogen-containing polysiloxane.

[0077] (2) Preparation of allyl copolyether

[0078] By mass fraction, at 5℃±2℃, 1 part allyl alcohol, 34.7 parts p-methyltetrahydrofuran (molar amount same as the total amount of tetrahydrofuran and p-methyltetrahydrofuran in Preparation Example 1), 28 parts ethylene oxide, and 0.5% of boron trifluoride diethyl ether catalyst (i.e., the total mass of allyl alcohol, tetrahydrofuran, p-methyltetrahydrofuran and ethylene oxide) were added to the reactor. After reacting for 3 hours, water was added to stop the reaction. The reaction was then distilled under reduced pressure at -0.095 MPa and 85℃ for 40 minutes to obtain allyl copolyether.

[0079] (3) Preparation of modified foaming agent

[0080] By mass percentage, 1 part of the hydrogen-containing polysiloxane prepared in step (1), 100 parts of the allyl copolyether prepared in step (2), and 50 parts of solvent toluene were added to the reactor. The mixture was heated to 100°C, and a chloroplatinic acid solution was added while stirring. The chloroplatinic acid in the chloroplatinic acid solution accounted for 0.5% of the total mass of the reactants (i.e., the total mass of the hydrogen-containing polysiloxane and the allyl copolyether). After reacting for about 3 hours, NaHCO3 was added for neutralization. Finally, toluene was removed under reduced pressure of -0.095 MPa for 50 minutes to obtain tetrahydrofuran and side-methyltetrahydrofuran copolymerized modified silicone oil as a modified foaming agent. The chloroplatinic acid solution was prepared by diluting chloroplatinic acid with isopropanol to a concentration of 0.2 wt%.

[0081] Preparation Example 3: Preparation of Modified Foaming Agent

[0082] (1) Preparation of hydrogen-containing polysiloxane

[0083] By mass fraction, 80 parts of 202 hydrogen-containing silicone oil with a molecular weight of 200-300, 8 parts of octamethylcyclotetrasiloxane, 6 parts of hexamethyldisiloxane, and 0.5% of sulfuric acid catalyst (the total mass of the reactants, i.e., the total mass of 202 hydrogen-containing silicone oil, octamethylcyclotetrasiloxane, and hexamethyldisiloxane) were added to the reactor. The mixture was then stirred and heated to 60°C and held at that temperature for 5 hours. The solvent was then removed under reduced pressure of -0.095 MPa for 50 minutes to obtain hydrogen-containing polysiloxane.

[0084] (2) Preparation of allyl copolyether

[0085] By mass fraction, at 5℃±2℃, 1 part allyl alcohol, 29 parts tetrahydrofuran (molar amount equal to the total amount of tetrahydrofuran and p-methyltetrahydrofuran in Preparation Example 1), 28 parts ethylene oxide, and 0.5% of boron trifluoride diethyl ether catalyst (i.e., the total mass of allyl alcohol, tetrahydrofuran, p-methyltetrahydrofuran and ethylene oxide) were added to the reactor. After reacting for 3 hours, water was added to stop the reaction. The reaction was then distilled under reduced pressure at -0.095 MPa and 85℃ for 40 minutes to obtain allyl copolyether.

[0086] (3) Preparation of modified foaming agent

[0087] By mass percentage, 1 part of the hydrogen-containing polysiloxane prepared in step (1), 100 parts of the allyl copolyether prepared in step (2), and 50 parts of solvent toluene were added to the reactor. The mixture was heated to 100°C, and a chloroplatinic acid solution was added while stirring. The chloroplatinic acid in the chloroplatinic acid solution accounted for 0.5% of the total mass of the reactants (i.e., the total mass of the hydrogen-containing polysiloxane and the allyl copolyether). After reacting for about 3 hours, NaHCO3 was added for neutralization. Finally, toluene was removed under reduced pressure of -0.095 MPa for 50 minutes to obtain tetrahydrofuran and side-methyltetrahydrofuran copolymerized modified silicone oil as a modified foaming agent. The chloroplatinic acid solution was prepared by diluting chloroplatinic acid with isopropanol to a concentration of 0.2 wt%.

[0088] Preparation Example 4: Preparation of Modified Foaming Agent

[0089] (1) Preparation of hydrogen-containing polysiloxane

[0090] By mass fraction, 45 parts of 202 hydrogen-containing silicone oil with a molecular weight of 200-300, 10 parts of octamethylcyclotetrasiloxane, 6 parts of hexamethyldisiloxane, and 0.2% of sulfuric acid catalyst (the total mass of the reactants, i.e., the total mass of 202 hydrogen-containing silicone oil, octamethylcyclotetrasiloxane, and hexamethyldisiloxane) were added to the reactor. The mixture was then heated to 65°C while stirring and held at that temperature for 4 hours. The solvent was removed under reduced pressure of -0.09 MPa for 60 minutes to obtain hydrogen-containing polysiloxane.

[0091] (2) Preparation of allyl copolyether

[0092] By mass fraction, at 3℃±2℃, 28 parts of allyl alcohol, 28 parts of tetrahydrofuran, 11 parts of p-methyltetrahydrofuran, 46 parts of ethylene oxide, and a catalyst boron trifluoride diethyl ether complex accounting for 0.7% of the total mass of the reactants (i.e., the total mass of allyl alcohol, tetrahydrofuran, p-methyltetrahydrofuran and ethylene oxide) were added to the reactor. After reacting for 2 hours, water was added to stop the reaction. The reaction was then carried out under reduced pressure at -0.099 MPa and 80℃ for 60 minutes to obtain allyl copolyether.

[0093] (3) Preparation of modified foaming agent

[0094] By mass fraction, 1 part of the hydrogen-containing polysiloxane prepared in step (1), 50 parts of the allyl copolyether prepared in step (2), and 40 parts of solvent toluene were added to the reactor. The mixture was heated to 95°C, and a chloroplatinic acid solution was added while stirring. The chloroplatinic acid in the chloroplatinic acid solution accounted for 0.4% of the total mass of the reactants (i.e., the total mass of the hydrogen-containing polysiloxane and the allyl copolyether). After reacting for about 2 hours, NaHCO3 was added for neutralization. Finally, toluene was removed under reduced pressure of -0.09 MPa for 60 minutes to obtain tetrahydrofuran and side-methyltetrahydrofuran copolymerized modified silicone oil as a modified foaming agent. The chloroplatinic acid solution was prepared by diluting chloroplatinic acid with isopropanol to a concentration of 0.1-0.3 wt%.

[0095] Preparation Example 5: Preparation of Modified Foaming Agent

[0096] (1) Preparation of hydrogen-containing polysiloxane

[0097] By mass fraction, 115 parts of 202 hydrogen-containing silicone oil with a molecular weight of 200-300, 6 parts of octamethylcyclotetrasiloxane, 6 parts of hexamethyldisiloxane, and sulfuric acid catalyst accounting for 0.7% of the total mass of the reactants (i.e., the total mass of 202 hydrogen-containing silicone oil, octamethylcyclotetrasiloxane, and hexamethyldisiloxane) were added to the reactor. The mixture was then stirred and heated to 55°C and held at that temperature for 6 hours. The solvent was removed under reduced pressure of -0.099 MPa for 30 minutes to obtain hydrogen-containing polysiloxane.

[0098] (2) Preparation of allyl copolyether

[0099] By mass fraction, at 3℃±2℃, 1 part allyl alcohol, 5 parts tetrahydrofuran, 24 parts p-methyltetrahydrofuran, 11 parts ethylene oxide, and a catalyst boron trifluoride diethyl ether complex accounting for 0.2% of the total mass of the reactants (i.e., the total mass of allyl alcohol, tetrahydrofuran, p-methyltetrahydrofuran and ethylene oxide) were added to the reactor. After reacting for 3 hours, water was added to stop the reaction. The reaction was then carried out by vacuum distillation at -0.095 MPa and 90℃ for 30 minutes to obtain allyl copolyether.

[0100] (3) Preparation of modified foaming agent

[0101] By mass percentage, 1 part of the hydrogen-containing polysiloxane prepared in step (1), 80 parts of the allyl copolyether prepared in step (2), and 60 parts of solvent toluene were added to the reactor. The mixture was heated to 105°C, and a chloroplatinic acid solution was added while stirring. The chloroplatinic acid in the chloroplatinic acid solution accounted for 0.6% of the total mass of the reactants (i.e., the total mass of the hydrogen-containing polysiloxane and the allyl copolyether). After reacting for about 3 hours, NaHCO3 was added for neutralization. Finally, toluene was removed under reduced pressure of -0.099 MPa for 30 minutes to obtain tetrahydrofuran and side-methyltetrahydrofuran copolymerized modified silicone oil as a modified foaming agent. The chloroplatinic acid solution was prepared by diluting chloroplatinic acid with isopropanol to a concentration of 0.1-0.3 wt%.

[0102] Preparation Example 6: Preparation of Modified Crosslinking Agent

[0103] (1) Add 1 part of trimethylolpropane and 7 parts of potassium hydroxide catalyst to reactor 1 by mass, heat to 100°C, remove moisture under vacuum, keep warm for 2 hours, and obtain potassium alkoxide.

[0104] (2) By mass fraction, add 4 parts of potassium alkoxide, 39 parts of tetrahydrofuran, 35 parts of ethylene oxide and 26 parts of propylene oxide obtained in step (1) to reactor 2. While stirring, raise the temperature to 130°C and keep it at that temperature for 5 hours. After the reaction is completed, lower the temperature to 70°C and slowly add phosphoric acid to neutralize to pH 7 while stirring. Continue stirring for 40 minutes. Remove the neutralized salt by filtration at 70°C to obtain the modified crosslinking agent.

[0105] Preparation Example 7: Preparation of Modified Crosslinking Agent

[0106] (1) Add 1 part of trimethylolpropane and 5 parts of potassium hydroxide catalyst to reactor 1 by mass, heat to 90°C, remove moisture under vacuum, keep warm for 2 hours, and obtain potassium alkoxide.

[0107] (2) By mass fraction, add 4 parts of potassium alkoxide, 35 parts of tetrahydrofuran, 35 parts of ethylene oxide and 26 parts of propylene oxide obtained in step (1) to reactor 2. While stirring, heat to 125°C and keep warm for 4 hours. After the reaction is completed, cool down to 70°C and slowly add phosphoric acid to neutralize to pH 7 while stirring. Continue stirring for 40 minutes. Remove the neutralized salt by filtration at 70°C to obtain the modified crosslinking agent.

[0108] Preparation Example 8: Preparation of Modified Crosslinking Agent

[0109] (1) Add 1 part of trimethylolpropane and 7 parts of potassium hydroxide catalyst to reactor 1 by mass, heat to 90°C, remove moisture under vacuum, keep warm for 2 hours, and obtain potassium alkoxide.

[0110] (2) By mass, add 4 parts of potassium alkoxide, 60 parts of tetrahydrofuran, 25 parts of ethylene oxide, and 40 parts of propylene oxide obtained in step (1) to reactor 2. While stirring, raise the temperature to 130°C and keep it at that temperature for 5 hours. After the reaction is completed, lower the temperature to 60°C and slowly add phosphoric acid to neutralize to pH 7.5 while stirring. Continue stirring for 30 minutes. Remove the neutralized salt by filtration at 80°C to obtain the modified crosslinking agent.

[0111] Preparation Example 9: Preparation of Modified Crosslinking Agent

[0112] (1) Add 1 part of trimethylolpropane and 7 parts of potassium hydroxide catalyst to reactor 1 by mass, heat to 95°C, remove moisture under vacuum, keep warm for 2 hours, and obtain potassium alkoxide.

[0113] (2) By mass, add 4 parts of potassium alkoxide, 40 parts of tetrahydrofuran, 50 parts of ethylene oxide, and 20 parts of propylene oxide obtained in step (1) to reactor 2. While stirring, raise the temperature to 130°C and keep it at that temperature for 5 hours. After the reaction is completed, lower the temperature to 80°C and slowly add phosphoric acid to neutralize to pH 6.5 while stirring. Continue stirring for 60 minutes. Remove the neutralized salt by filtration at 60°C to obtain the modified crosslinking agent.

[0114] Example 1

[0115] A fatigue-resistant polyurethane microporous elastomer vibration damping pad, the raw material is composed of component A and component B in a mass ratio of 100:100;

[0116] By mass parts, component A comprises: 60 parts of polyether polyol C1, 60 parts of isocyanate D1, and 5 parts of isocyanate D2;

[0117] By mass, component B comprises: 65 parts of polyether polyol C2, 30 parts of modified crosslinking agent (prepared in Preparation Example 6), 0.05 parts of deionized water, 1 part of color paste, 1.6 parts of weather-resistant additive, 0.8 parts of modified foaming agent (prepared in Preparation Example 1), and 0.57 parts of catalyst; component B also comprises 10% of nitrogen gas, a physical foaming agent, in the total volume of components A and B.

[0118] Among them, polyether polyol C1 is PTMEG 2000, isocyanate D1 is diphenylmethane diisocyanate MDI, and isocyanate D2 is carbodiimide-modified MDI; polyether polyol C2 is PTMEG 1000, the color paste is blue, the weathering aids are 0.4 parts antioxidant 1135 and 1.2 parts ultraviolet absorber UV328, and the catalysts are 0.07 parts BCAT-E28A and 0.5 parts RZET-HD.

[0119] The preparation method of the above-mentioned fatigue-resistant polyurethane microporous elastomer vibration damping pad includes the following steps:

[0120] S0. Component A is prepared by the following method: Polyether polyol C1 is heated to 110°C and vacuum dehydrated until the water content is less than 100 ppm, cooled to 60°C, isocyanate D1 is added, the temperature is raised to 80°C and reacted for 2 hours until the NCO content is >5%, cooled to 60°C, and isocyanate D2 is added and stirred evenly; The preparation method of component B includes the following steps: Polyether polyol C2, modified crosslinking agent, deionized water, color paste, weather-resistant agent, modified foaming agent and catalyst are mixed, and physical foaming agent is added during stirring at 2500 r / min, and injected into the corresponding high-pressure polyurethane casting machine tank; the physical foaming agent is added at a pressure of 0.5 MPa, and online mixing and conveying are carried out at a gas flow rate of 10 L / min and a mixture flow rate of 90 L / min.

[0121] S1. Control the mold temperature at 60℃ before pouring, and spray polyurethane release agent into the mold in advance and let it dry.

[0122] S2. Control the temperature of component A to 40℃ and the temperature of component B to 50℃. Mix component A and component B at 170 bar and pour into the mold.

[0123] S3. After casting, the surface of the material is subjected to flame degassing treatment, the mold is covered, and the material is cured at 120℃ for 7 minutes. Then, the material is demolded, the edges are trimmed, and the material is cured at 24℃ for 14 days to obtain the polyurethane microporous elastomer vibration damping pad product.

[0124] Example 2

[0125] A fatigue-resistant polyurethane microporous elastomer vibration damping pad, the raw material is composed of component A and component B in a mass ratio of 50:100;

[0126] By mass, component A comprises: 60 parts of polyether polyol C1, 50 parts of isocyanate D1, and 12 parts of isocyanate D2;

[0127] By mass, component B comprises: 80 parts of polyether polyol C2, 30 parts of modified crosslinking agent (prepared in Preparation Example 6), 0.08 parts of deionized water, 1 part of color paste, 1.8 parts of weather-resistant agent, 0.4 parts of modified foaming agent (prepared in Preparation Example 1), and 0.33 parts of catalyst; component B also comprises compressed air, a physical foaming agent accounting for 15% of the total volume of components A and B.

[0128] Among them, polyether polyol C1 is PTMEG 2000, isocyanate D1 is diphenylmethane diisocyanate MDI, and isocyanate D2 is MDI-50; polyether polyol C2 is side-methyl PTMEG 1000, the color paste is green color paste, the weathering aid is 0.3 parts antioxidant 1010, 1.5 parts ultraviolet absorber UV292, and the catalyst is 0.03 parts stannous octoate and 0.3 parts RZET-HD.

[0129] The preparation method of the above-mentioned fatigue-resistant polyurethane microporous elastomer vibration damping pad includes the following steps:

[0130] S0. Component A is prepared by the following method: Polyether polyol C1 is heated to 105°C and vacuum dehydrated until the water content is less than 100 ppm, then cooled to 70°C, isocyanate D1 is added, the temperature is raised to 70°C and reacted for 3 hours until the NCO content is >5%, then cooled to 50°C, and isocyanate D2 is added and stirred evenly. The preparation method of component B includes the following steps: Polyether polyol C2, modified crosslinking agent, deionized water, color paste, weather-resistant agent, modified foaming agent and catalyst are mixed, and physical foaming agent is added during high-speed stirring, and injected into the corresponding high-pressure polyurethane casting machine tank; physical foaming agent is added during stirring at 2000 r / min, and injected into the corresponding high-pressure polyurethane casting machine tank; the physical foaming agent is added at a pressure of 0.6 MPa, and online mixing and conveying are carried out with a gas flow rate of 10 L / min and a mixed material flow rate of 90 L / min.

[0131] S1. Control the mold temperature at 70℃ before pouring, and spray polyurethane release agent into the mold in advance and let it dry.

[0132] S2. Control the temperature of component A to 35℃ and the temperature of component B to 60℃. Mix component A and component B under 150 bar conditions and then pour them into the mold.

[0133] S3. After casting, the surface of the material is subjected to flame degassing treatment, the mold is covered, and the material is cured at 125℃ for 5 minutes. Then, the material is demolded, the edges are trimmed, and the material is cured at 25℃ for 12 days to obtain the polyurethane microporous elastomer vibration damping pad product.

[0134] Example 3

[0135] A fatigue-resistant polyurethane microporous elastomer vibration damping pad, the raw material is composed of component A and component B in a mass ratio of 80:100;

[0136] By mass parts, component A comprises: 40 parts of polyether polyol C1, 40 parts of isocyanate D1, and 15 parts of isocyanate D2;

[0137] By mass fraction, component B comprises: 60 parts of polyether polyol C2, 40 parts of modified crosslinking agent (prepared in Preparation Example 6), 0.04 parts of deionized water, 1 part of color paste, 1.9 parts of weather-resistant agent, 0.9 parts of modified foaming agent (prepared in Preparation Example 1), and 0.46 parts of catalyst; component B also comprises a physical foaming agent accounting for 5% of the total volume of components A and B.

[0138] Among them, polyether polyol C1 is polytetrahydrofuran-ethylene oxide copolyether polyol with a molecular weight of 1000, isocyanate D1 is diphenylmethane diisocyanate MDI, and isocyanate D2 is TDI; polyether polyol C2 is side-methyl polytetrahydrofuran-propylene oxide copolyether with a molecular weight of 1000, the color paste is black color paste, the weather-resistant additives are 0.4 parts antioxidant 1135, 1.5 parts ultraviolet absorber UV292, and the catalysts are 0.06 parts BX-EM23 and 0.4 parts RZET-HD.

[0139] The preparation method of the above-mentioned fatigue-resistant polyurethane microporous elastomer vibration damping pad includes the following steps:

[0140] S0. Component A is prepared by the following method: Polyether polyol C1 is heated to 115°C and vacuum dehydrated until the water content is less than 100 ppm, cooled to 50°C, isocyanate D1 is added, the temperature is raised to 90°C and reacted for 1 hour until the NCO content is >5%, cooled to 70°C, and isocyanate D2 is added and stirred evenly; The preparation method of component B includes the following steps: Polyether polyol C2, modified crosslinking agent, deionized water, color paste, weather-resistant agent, modified foaming agent and catalyst are mixed, physical foaming agent is added during high-speed stirring, and injected into the corresponding high-pressure polyurethane casting machine tank; physical foaming agent is added during stirring at 3000 r / min and injected into the corresponding high-pressure polyurethane casting machine tank; the physical foaming agent is added at a pressure of 0.4 MPa, online mixing and conveying, gas flow rate of 10 L / min, and mixture flow rate of 90 L / min.

[0141] S1. Control the mold temperature at 50℃ before pouring, and spray polyurethane release agent into the mold in advance and let it dry.

[0142] S2. Control the temperature of component A to 45℃ and the temperature of component B to 45℃. Mix component A and component B at 180 bar and pour into the mold.

[0143] S3. After casting, the surface of the material is subjected to flame degassing treatment, the mold is covered, and the material is cured at 120℃ for 10 minutes. Then, the material is demolded, the edges are trimmed, and the material is cured at 23℃ for 15 days to obtain the polyurethane microporous elastomer vibration damping pad product.

[0144] Example 4

[0145] The only difference from Example 1 is that the modified foaming agent used is the modified foaming agent prepared in Preparation Example 2. Specifically:

[0146] A fatigue-resistant polyurethane microporous elastomer vibration damping pad, the raw material is composed of component A and component B in a mass ratio of 100:100;

[0147] By mass parts, component A comprises: 60 parts of polyether polyol C1, 60 parts of isocyanate D1, and 5 parts of isocyanate D2;

[0148] By mass, component B comprises: 65 parts of polyether polyol C2, 30 parts of modified crosslinking agent (prepared in Preparation Example 6), 0.05 parts of deionized water, 1 part of color paste, 1.6 parts of weather-resistant agent, 0.8 parts of modified foaming agent (prepared in Preparation Example 2), and 0.57 parts of catalyst; component B also comprises 10% of nitrogen gas, a physical foaming agent, in the total volume of components A and B.

[0149] Among them, polyether polyol C1 is PTMEG 2000, isocyanate D1 is diphenylmethane diisocyanate MDI, and isocyanate D2 is carbodiimide-modified MDI; polyether polyol C2 is PTMEG 1000, the color paste is blue, the weathering aids are 0.4 parts antioxidant 1135 and 1.2 parts ultraviolet absorber UV328, and the catalysts are 0.07 parts BCAT-E28A and 0.5 parts RZET-HD.

[0150] The preparation method of the above-mentioned fatigue-resistant polyurethane microporous elastomer vibration damping pad includes the following steps:

[0151] S0. Component A is prepared by the following method: Polyether polyol C1 is heated to 110°C and vacuum dehydrated until the water content is less than 100 ppm, cooled to 60°C, isocyanate D1 is added, the temperature is raised to 80°C and reacted for 2 hours until the NCO content is >5%, cooled to 60°C, and isocyanate D2 is added and stirred evenly; The preparation method of component B includes the following steps: Polyether polyol C2, modified crosslinking agent, deionized water, color paste, weather-resistant agent, modified foaming agent and catalyst are mixed, and physical foaming agent is added during stirring at 2500 r / min, and injected into the corresponding high-pressure polyurethane casting machine tank; the physical foaming agent is added at a pressure of 0.5 MPa, and online mixing and conveying are carried out at a gas flow rate of 10 L / min and a mixture flow rate of 90 L / min.

[0152] S1. Control the mold temperature at 60℃ before pouring, and spray polyurethane release agent into the mold in advance and let it dry.

[0153] S2. Control the temperature of component A to 40℃ and the temperature of component B to 50℃. Mix component A and component B at 170 bar and pour into the mold.

[0154] S3. After casting, the surface of the material is subjected to flame degassing treatment, the mold is covered, and the material is cured at 120℃ for 7 minutes. Then, the material is demolded, the edges are trimmed, and the material is cured at 24℃ for 14 days to obtain the polyurethane microporous elastomer vibration damping pad product.

[0155] Example 5

[0156] A fatigue-resistant polyurethane microporous elastomer vibration damping pad, the raw material is composed of component A and component B in a mass ratio of 100:100;

[0157] By mass parts, component A comprises: 60 parts of polyether polyol C1, 60 parts of isocyanate D1, and 5 parts of isocyanate D2;

[0158] By mass, component B comprises: 65 parts of polyether polyol C2, 30 parts of modified crosslinking agent (prepared in Preparation Example 7), 0.05 parts of deionized water, 0.5 parts of color paste, 2.8 parts of weather-resistant agent, 0.5 parts of modified foaming agent (prepared in Preparation Example 1), and 1 part of catalyst; component B also comprises compressed air, a physical foaming agent accounting for 10% of the total volume of components A and B.

[0159] Among them, polyether polyol C1 is PTMEG 2000, isocyanate D1 is diphenylmethane diisocyanate MDI, and isocyanate D2 is carbodiimide-modified MDI; polyether polyol C2 is PTMEG 1000, the color paste is blue, the weathering aids are 0.7 parts antioxidant 1010 and 2.1 parts ultraviolet absorber UV328, and the catalysts are 0.1 parts stannous octoate and 0.9 parts RZET-HD.

[0160] The preparation method of the above-mentioned fatigue-resistant polyurethane microporous elastomer vibration damping pad includes the following steps:

[0161] S0. Component A is prepared by the following method: Polyether polyol C1 is heated to 110°C and vacuum dehydrated until the water content is less than 100 ppm, cooled to 60°C, isocyanate D1 is added, the temperature is raised to 80°C and reacted for 2 hours until the NCO content is >5%, cooled to 60°C, and isocyanate D2 is added and stirred evenly; The preparation method of component B includes the following steps: Polyether polyol C2, modified crosslinking agent, deionized water, color paste, weather-resistant agent, modified foaming agent and catalyst are mixed, and physical foaming agent is added during stirring at 2500 r / min, and injected into the corresponding high-pressure polyurethane casting machine tank; the physical foaming agent is added at a pressure of 0.5 MPa, and online mixing and conveying are carried out at a gas flow rate of 10 L / min and a mixture flow rate of 90 L / min.

[0162] S1. Control the mold temperature at 60℃ before pouring, and spray polyurethane release agent into the mold in advance and let it dry.

[0163] S2. Control the temperature of component A to 40℃ and the temperature of component B to 50℃. Mix component A and component B at 170 bar and pour into the mold.

[0164] S3. After casting, the surface of the material is subjected to flame degassing treatment, the mold is covered, and the material is cured at 120℃ for 7 minutes. Then, the material is demolded, trimmed, and cured at 24℃ for 14 days to obtain the polyurethane microporous elastomer vibration damping pad product.

[0165] The polyurethane pads prepared in the examples and comparative examples were analyzed using scanning electron microscopy. Figure 1-5 It can be seen that the polyurethane pad prepared by the present invention has dense pores, uniform bubble distribution, and the bubbles tend to be of similar size.

[0166] Comparative Example 1

[0167] The only difference from Example 1 is that no modified crosslinking agent was added.

[0168] Comparative Example 2

[0169] The only difference from Example 1 is that no modified foam stabilizer was added.

[0170] Comparative Example 3

[0171] Compared with Example 1, the only difference is that no modified foam stabilizer and modified crosslinking agent were added.

[0172] Comparative Example 4

[0173] The only difference from Example 1 is that the modified foaming agent prepared in Preparation Example 3 was used.

[0174] To better illustrate the characteristics of the polyurethane microporous elastomer pad provided in the embodiments of the present invention, the products prepared in the comparative example and the embodiment will be tested for corresponding performance. The test methods are as follows:

[0175] Tensile strength testing was conducted in accordance with standard GB / T10654-2001;

[0176] The permanent compression set test was conducted according to standard GB / T 10653-2001, with a temperature of 70℃, a compression ratio of 30%, and a time of 22h.

[0177] The dynamic-to-static stiffness ratio test was conducted according to standard TB / T 3395.1;

[0178] Fatigue performance testing was conducted according to Appendix C of standard TB / T 3395.1 to obtain the static stiffness change rate after fatigue testing; test conditions: 3 million cycles, room temperature, loading frequency 4±1HZ;

[0179] The rebound rate was tested according to standard GB / T 6670-2008, with a drop height of 500mm ± 0.5mm and a test temperature of room temperature.

[0180] The results are shown in Table 1.

[0181] Table 1

[0182]

[0183] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fatigue resistant polyurethane microporous elastomeric vibration damping pad characterized by, The raw material consists of component A and component B in a mass ratio of 50~100:100; By mass, component A comprises: 40-60 parts of polyether polyol C1, 40-60 parts of isocyanate D1, and 5-15 parts of isocyanate D2; By weight, component B comprises: 60-80 parts of polyether polyol C2, 20-40 parts of modified crosslinking agent, 0.03-0.09 parts of deionized water, 0-1.5 parts of color paste, 0.5-3.0 parts of weather-resistant agent, 0.1-1.0 parts of modified foaming agent, and 0.3-1.0 parts of catalyst; component B also comprises a physical foaming agent accounting for 5-20% of the total volume of components A and B. The modified foam stabilizer is a polyether-modified polysiloxane, the polyether side chain of which contains a side methyltetrahydrofuran segment; the modified crosslinking agent is a multi-arm polyether with trimethylolpropane as the initiator, the molecular chain of which contains a tetrahydrofuran segment.

2. The fatigue resistant polyurethane microcellular elastomeric vibration damping mat according to claim 1, wherein, The modified foam stabilizer is prepared by hydrosilylation reaction of hydrogen-containing polysiloxane and allyl copolyether in a mass ratio of 1:50~100, wherein the allyl copolyether contains a side-methyltetrahydrofuran segment; or, contains tetrahydrofuran and a side-methyltetrahydrofuran segment.

3. The fatigue resistant polyurethane microcellular elastomeric damping mat according to claim 1, wherein, The preparation method of the hydrogen-containing polysiloxane includes the following steps: By mass fraction, 45-115 parts of 202 hydrogen-containing silicone oil, 6-10 parts of octamethylcyclotetrasiloxane, and 6 parts of hexamethyldisiloxane are mixed, and sulfuric acid is added as a catalyst. The amount of sulfuric acid is 0.2%-0.7% of the total mass of the above raw materials. While stirring, the temperature is raised to 55-65℃ and kept at this temperature for 4-6 hours. Then, the solvent is removed under reduced pressure to obtain hydrogen-containing polysiloxane.

4. The fatigue-resistant polyurethane microporous elastomer vibration damping pad according to claim 1, characterized in that, The preparation method of the allyl copolyether includes the following steps: 1-2 parts by mass of allyl alcohol, 0-28 parts by mass of tetrahydrofuran, 11-35 parts by mass of side-methyltetrahydrofuran, and 11-46 parts by mass of ethylene oxide are mixed, and then boron trifluoride diethyl ether complex is added as a catalyst. The amount of catalyst is 0.2%-0.7% of the total mass of the above raw materials. The mixture is reacted at 0-5°C for 2-3 hours to obtain the allyl copolyether.

5. The fatigue-resistant polyurethane microporous elastomer vibration damping pad according to claim 1, characterized in that, The preparation method of the modified crosslinking agent includes the following steps: Potassium alkoxide is prepared by reacting trimethylolpropane with potassium hydroxide; then, 4 parts of potassium alkoxide are taken by mass, and 35-60 parts of tetrahydrofuran, 25-50 parts of ethylene oxide and 20-40 parts of propylene oxide are added. The mixture is reacted at 125-135℃ for 4-6 hours, and then neutralized and filtered to obtain the final product.

6. The fatigue-resistant polyurethane microporous elastomer vibration damping pad according to claim 1, characterized in that, In the hydrosilylation reaction, a catalyst was also added. The amount of the catalyst, chloroplatinic acid, was 0.4% to 0.6% of the total mass of the hydrogen-containing polysiloxane and allyl copolyether. The reaction temperature was 95 to 105°C, and the reaction time was 2 to 3 hours.

7. The fatigue-resistant polyurethane microporous elastomer vibration damping pad according to claim 1, characterized in that, The polyether polyol has a C1 molecular weight of 600-3000 and a functionality of 2, and is selected from one or more of polytetrahydrofuran polyol, side-methyl polytetrahydrofuran polyol, polyoxypropylene polyol, polytetrahydrofuran-ethylene oxide copolyether polyol, and side-methyl polytetrahydrofuran-propylene oxide copolyether polyol. Alternatively, the polyether polyol has a C2 molecular weight of 600-2000 and a functionality of 2, and is selected from one or more of polytetrahydrofuran polyol, side-methyl polytetrahydrofuran polyol, polypropylene oxide-ethylene oxide copolyol, polytetrahydrofuran-propylene oxide copolyether polyol, side-methyl polytetrahydrofuran-ethylene oxide copolyether polyol, and side-methyl polytetrahydrofuran-propylene oxide-ethylene oxide copolyether polyol.

8. The fatigue-resistant polyurethane microporous elastomer vibration damping pad according to claim 1, characterized in that, The isocyanate D1 is selected from one or more of diphenylmethane diisocyanate, naphthalene diisocyanate, toluene diisocyanate, and terephthalic diisocyanate; Alternatively, the isocyanate D2 is selected from one or more of toluene diisocyanate, carbodiimide-modified MDI, polymethylene polyphenyl isocyanate, 2,4-MDI and 4,4-MDI.

9. The fatigue-resistant polyurethane microporous elastomer vibration damping pad according to claim 1, characterized in that, The catalyst is composed of a metal catalyst and a reactive organic amine catalyst in a mass ratio of 1:3 to 10, wherein the metal catalyst is selected from one or more of organotin, organobismuth, and organozinc.

10. A method for preparing a fatigue-resistant polyurethane microporous elastomer vibration damping pad as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Preheat the mold and spray it with release agent; S2. Mix component A and component B at 150~180 bar and pour the mixture into the mold. S3. After casting, the surface of the material is subjected to flame degassing treatment, followed by heat preservation and curing, demolding, trimming, and curing to obtain the polyurethane microporous elastomer vibration damping pad product.

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