Wide-temperature-range high-damping polyurethane IPN material and preparation method thereof

Abstract

The invention provides a wide-temperature-range high-damping polyurethane IPN material, and in the preparation of the polyurethane IPN material, the R value of polyurethane is accurately controlled to be 1, so that an isocyanate group (-NCO) and a hydroxyl group (-OH) in polyhydric alcohol are completely reacted in a stoichiometric ratio, and a stable carbamate group (-NH-COO-) is generated. A polybutyl methacrylate molecular chain introduced into the system contains strong polar ester groups (-COO <->), and the polar groups and-NH <-> in carbamate groups form strong intermolecular hydrogen bonds. The multiple hydrogen bonds interact to jointly form a complex network structure of the IPN material, and the hydrogen bonds between the hard segment and the soft segment of the polyurethane and the interface hydrogen bonds between the polyurethane and the polybutyl methacrylate have a synergistic effect, so that the internal friction between molecular chains is remarkably increased. The multi-layer and multi-type intermolecular acting force synergistic effect enables the polyurethane IPN material to show more excellent damping performance.

Description

Technical Field

[0001] The invention relates to a high-damping polyurethane IPN material with a wide temperature range and a preparation method thereof, and belongs to the field of polyurethane damping materials. Background Art

[0002] With the development of industrialization, noise and vibration pollution has become an environmental problem that cannot be ignored, and has caused significant negative impacts on human health, industrial production and the ecological environment. Traditional damping materials such as rubber vibration damping pads that are widely used at present have obvious limitations. They are prone to failure or brittleness when the ambient temperature changes greatly, and it is difficult to meet the vibration reduction and noise reduction needs in complex environments. For example, the hardness of engine suspension rubber parts increases sharply at a low temperature of -30°C (Shore A hardness increases from 60 to 85), resulting in vibration reduction failure and causing resonance in the car compartment; in a high temperature environment of 80°C, the rubber softens (the storage modulus decreases by 50%), and it is unable to suppress the high-frequency vibration of the turbocharger, accelerating the fatigue fracture of the components.

[0003] In order to meet this challenge, various damping materials have emerged. Their unique structural characteristics make them show significant advantages in vibration reduction and noise reduction. Among the many damping material preparation methods, polymer blending, copolymerization and interpenetrating polymer network (IPN) technologies have been widely used. Polyurethane is cross-linked through hydrogen bonds and van der Waals forces between hard segments and soft segments to form a polymer with a network structure. At the same time, the introduced polybutyl methacrylate molecular chain contains a strong polar ester group (-COO-) that can form a strong intermolecular hydrogen bond with the -NH- in the carbamate group. Multiple hydrogen bond interactions together constitute the complex network structure of the IPN material, making the polyurethane IPN material show more excellent damping performance and achieve the application goal of high damping (tanδmax=1.37) in a wide temperature range (the temperature range of tanδ≥0.3 is 140℃). Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a wide temperature range high damping polyurethane IPN material and a preparation method thereof, and to design and prepare a wide temperature range high damping polyurethane IPN material. Compared with the conventional system formula, the designed formula can not only achieve high damping performance under wide temperature range conditions, but also meet the needs of industrial mass production. This method can obtain a polyurethane damping material that meets the wide temperature range vibration reduction needs at a low cost.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows.

[0006] A high-damping polyurethane IPN material with a wide temperature range, wherein the polyurethane IPN material is obtained by mixing and curing in two steps;

[0007] The raw materials of polyurethane IPN materials include isocyanate, polytriol, butyl methacrylate, ethylene glycol dimethacrylate and dodecyl peroxide;

[0008] Taking the total mass of isocyanate, polytriol and butyl methacrylate as 100%, the mass percentage of each component is:

[0009] Isocyanate 5%-10%

[0010] Polytriol 40%-45%

[0011] Butyl methacrylate 40%-50%

[0012] and the molar ratio of isocyanate in the isocyanate to hydroxyl in the polytriol is 1;

[0013] Taking the total mass of butyl methacrylate as 100%, the mass percentage of ethylene glycol dimethacrylate is: 1%-5%;

[0014] Calculated based on the total mass of butyl methacrylate being 100%, the mass percentage content of dodecyl peroxide is 0.5%-1%.

[0015] The isocyanate is at least one of diphenylmethane diisocyanate (MDI), toluene diisocyanate (HDI), and isophorone diisocyanate (IPDI);

[0016] The polytriol is at least one of polycaprolactone triol and polyoxypropylene triol;

[0017] The molecular weight of the polytriol is 4500-5000.

[0018] A method for preparing a wide temperature range high damping polyurethane IPN material, comprising:

[0019] (1) In a three-necked flask, subject the polytriol to vacuum dehydration treatment;

[0020] (2) under a protective gas atmosphere, adding isocyanate into the flask described in (1), and mixing with the polytriol at high temperature for reaction;

[0021] (3) cooling the product obtained in (2) to room temperature to obtain a polyurethane matrix;

[0022] (4) adding the product obtained in (3) into another three-necked flask, and then sequentially adding butyl methacrylate, ethylene glycol dimethacrylate, and dodecanoyl peroxide, and mixing and reacting under a protective gas atmosphere;

[0023] (5) Curing the product in (4) at high temperature to obtain the polyurethane IPN material.

[0024] Preferably, in step (1), the temperature during the dehydration treatment is 110-120°C, the vacuum degree during the dehydration treatment is -0.1MPa, and the dehydration treatment time is 2-4h;

[0025] Preferably, in step (2), the protective gas is N 2 , the reaction temperature is 80-90°C, and the reaction time is 4-8h;

[0026] Preferably, in step (4), the protective gas is N 2 , the reaction temperature is 65°C and the reaction time is 2-4h;

[0027] Preferably, in step (5), the curing temperature is 85° C. and the curing time is 12 h.

[0028] Beneficial Effects

[0029] The present invention provides a wide temperature range high damping polyurethane IPN material, wherein the polyurethane is a novel polyurethane damping material, which can meet the use requirements of wide temperature range high damping materials. Polyol is a highly active trihydroxy polyether, and its molecular structure contains multiple hydroxyl groups (-OH), which can fully react with isocyanate groups (-NCO) to form a stable polyurethane cross-linked network structure. When the R value is equal to 1, the molar ratio of -NCO to -OH reaches a stoichiometric balance, the reaction is complete, the generated polyurethane molecular chain structure is uniform, the cross-linking density is moderate, and the molecular chain of the polyol has a certain flexibility, while the rigid segment provided by the isocyanate enhances the mechanical strength of the material. When the R value is equal to 1, the ratio of the flexible segment to the rigid segment reaches an optimum, so that the material can maintain a certain rigidity under dynamic load, and can realize energy dissipation through the movement of the molecular chain, thereby ensuring good damping performance.

[0030] The present invention provides a high-damping polyurethane IPN material with a wide temperature range. The polyurethane material is obtained by mixing and curing two raw materials, isocyanate and polytriol, in a certain ratio. The selection and dosage of the two can ensure that a complete and neat cross-linked network exists in the prepared polyurethane material, thereby further improving the mechanical strength and damping performance of the polyurethane material.

[0031] The present invention provides a high-damping polyurethane IPN material with a wide temperature range. In the preparation of the polyurethane material, both ends of the isocyanate contain -NCO groups, and the polytriol contains -OH groups. Finished products with different effects can be obtained by adjusting the ratio of the raw materials. The method is simple in steps, and the experimental formula can be changed according to production needs, so that industrial production can be carried out.

[0032] The present invention provides a wide temperature range high damping polyurethane IPN material. In the preparation of the polybutyl methacrylate, the polymer molecular chain contains a relatively long butyl ester side chain (-COOCH 2 CH 2 CH 2 CH 3 ), these side chains have certain flexibility and freedom. When subjected to external force, relative movement will occur between the molecular chains, resulting in internal friction, thereby converting mechanical energy into heat energy and achieving energy dissipation. When the molecular weight distribution of the polymer is wide, the length of the polymer chain is different, the ability and frequency range of chain segment movement are wider, and thus vibration energy can be absorbed in a wider frequency range. In addition, the presence of a moderate cross-linking structure in the material can increase the interaction force between the molecular chains, while limiting the excessive movement of the molecular chains, further improving its damping performance.

[0033] The invention provides a high-damping polyurethane IPN material with a wide temperature range. In the preparation of the polyurethane IPN material, the polyurethane R value is precisely controlled to be 1, so that the isocyanate group (-NCO) and the hydroxyl group (-OH) in the polyol reach a stoichiometric ratio and react completely to generate a stable carbamate group (-NH-COO-). This precise stoichiometric control promotes the formation of a uniform and stable hydrogen bond network structure between the hard segment and the soft segment inside the material, thereby significantly improving the mechanical properties and damping properties of the material. At the same time, the polybutyl methacrylate molecular chain introduced into the system contains a strong polar ester group (-COO-), and these polar groups form strong intermolecular hydrogen bonds with the -NH- in the carbamate group. This multiple hydrogen bond interaction together constitutes a complex network structure of the IPN material, wherein the hydrogen bonds between the polyurethane hard segment and the soft segment and the interfacial hydrogen bonds between the polyurethane and the polybutyl methacrylate synergistically act to significantly increase the internal friction between the molecular chains. This multi-level and multi-type synergistic effect of intermolecular forces enables the polyurethane IPN material to exhibit more excellent damping properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The loss factor-temperature curves of the polyurethane materials in Examples 1 to 3 and Comparative Examples 1 to 3 are shown. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with specific embodiments.

[0036] Example 1

[0037] In this embodiment, the molecular weight of diphenylmethane diisocyanate is 250, and the molecular weight of polycaprolactone triol is 4950. The R value of the system is 1, and the mass ratio of polyurethane to butyl methacrylate is 6:4.

[0038] (1) In a three-necked flask, dehydrate 27.88 g of polycaprolactone triol at 110° C. and -0.1 MPa vacuum for 4 h;

[0039] (2) Add 2.12 g of diphenylmethane diisocyanate to the flask described in (1) under a protective gas of N 2 The temperature was raised to 80°C in the atmosphere, and the raw materials were stirred at a rate of 200 r / min to make them uniformly mixed, and reacted with polycaprolactone triol for 4 hours;

[0040] (3) cooling the product obtained in (2) at room temperature;

[0041] (4) The product of (3) was added to a new three-necked flask, and 20 g of butyl methacrylate, 0.20 g of ethylene glycol dimethacrylate, and 0.10 g of dodecyl peroxide were added in sequence. 2 The temperature was raised to 65°C under atmosphere, and the mixture was stirred at a rate of 200 r / min to allow the mixture to react fully for 2 h.

[0042] (5) The product obtained in (4) was cured at 85°C for 12 hours to obtain a high-damping polyurethane IPN material with a wide temperature range.

[0043] Example 2

[0044] In this embodiment, the molecular weight of isophorone diisocyanate is 222, and the molecular weight of polycaprolactone triol is 4750. The R value of the system is 1, and the mass ratio of polyurethane to butyl methacrylate is 6:4.

[0045] (1) In a three-necked flask, dehydrate 28.03 g of polycaprolactone triol at 110° C. and -0.1 MPa vacuum for 4 h;

[0046] (2) Add 1.97 g of isophorone diisocyanate to the flask described in (1) under a protective gas of N 2 The temperature was raised to 80°C in the atmosphere, and the raw materials were stirred at a rate of 200 r / min to make them uniformly mixed, and reacted with polycaprolactone triol for 4 hours;

[0047] (3) cooling the product obtained in (2) at room temperature;

[0048] (4) The product of (3) was added to a new three-necked flask, and 20 g of butyl methacrylate, 0.20 g of ethylene glycol dimethacrylate, and 0.10 g of dodecyl peroxide were added in sequence. 2 The temperature was raised to 65°C under atmosphere, and the mixture was stirred at a rate of 200 r / min to allow the mixture to react fully for 2 h.

[0049] (5) The product obtained in (4) was cured at 85°C for 12 hours to obtain a high-damping polyurethane IPN material with a wide temperature range.

[0050] Example 3

[0051] In this embodiment, the molecular weight of toluene diisocyanate is 174, and the molecular weight of polyoxypropylene triol is 4500. The R value of the system is 1, and the mass ratio of polyurethane to butyl methacrylate is 5:5.

[0052] (1) In a three-necked flask, dehydrate 22.40 g of polyoxypropylene triol at 110° C. and -0.1 MPa vacuum for 4 h;

[0053] (2) Add 2.60 g of toluene diisocyanate into the flask described in (1) under a protective gas of N 2 The temperature was raised to 80°C in the atmosphere, and the raw materials were stirred at a rate of 200 r / min to make them uniformly mixed, and reacted with polyoxypropylene triol for 4 hours;

[0054] (3) cooling the product obtained in (2) at room temperature;

[0055] (4) The product of (3) was added to a new three-necked flask, and 25 g of butyl methacrylate, 0.25 g of ethylene glycol dimethacrylate, and 0.125 g of dodecyl peroxide were added in sequence. 2 The temperature was raised to 65°C under atmosphere, and the mixture was stirred at a rate of 200 r / min to allow the mixture to react fully for 2 h.

[0056] (5) The product obtained in (4) was cured at 85°C for 12 hours to obtain a high-damping polyurethane IPN material with a wide temperature range.

[0057] Comparative Example 1

[0058] In this comparative example 1, the molecular weight of diphenylmethane diisocyanate is 250, and the molecular weight of polyether diol is 2000. The R value of the system is 1, and the mass ratio of polyurethane to butyl methacrylate is 6:4.

[0059] (1) In a three-necked flask, dehydrate 26.67 g of polyether diol at 110° C. and -0.1 MPa vacuum for 4 h;

[0060] (2) Add 3.33 g of toluene diisocyanate into the flask described in (1) under a protective gas of N 2 The temperature was raised to 80°C in the atmosphere, and the raw materials were stirred at a rate of 200 r / min to make them uniformly mixed, and reacted with the polyether diol for 4 hours;

[0061] (3) cooling the product obtained in (2) at room temperature;

[0062] (4) The product of (3) was added to a new three-necked flask, and 20 g of butyl methacrylate, 0.20 g of ethylene glycol dimethacrylate, and 0.10 g of dodecyl peroxide were added in sequence. 2 The temperature was raised to 65°C under atmosphere, and the mixture was stirred at a rate of 200 r / min to allow the mixture to react fully for 2 h.

[0063] (5) The product obtained in (4) was cured at 85°C for 12 hours to obtain a high-damping polyurethane IPN material with a wide temperature range.

[0064] Comparative Example 2

[0065] In this embodiment, the molecular weight of diphenylmethane diisocyanate is 250, and the molecular weight of polycaprolactone triol is 4950. The R value of the system is 2, and the mass ratio of polyurethane to butyl methacrylate is 6:4.

[0066] (1) In a three-necked flask, dehydrate 26.05 g of polyether diol at 110° C. and -0.1 MPa vacuum for 4 h;

[0067] (2) Add 3.95 g of toluene diisocyanate into the flask described in (1) and place under a protective gas of N 2 The temperature was raised to 80°C in the atmosphere, and the raw materials were stirred at a rate of 200 r / min to make them uniformly mixed, and reacted with the polyether diol for 4 hours;

[0068] Steps (3) to (5) are the same as those in Comparative Example 1.

[0069] Comparative Example 3

[0070] In this embodiment, the molecular weight of diphenylmethane diisocyanate is 250, and the molecular weight of polycaprolactone triol is 4950. The R value of the system is 3, and the mass ratio of polyurethane to butyl methacrylate is 6:4.

[0071] (1) In a three-necked flask, 24.44 g of polyether diol was dehydrated at 110° C. and -0.1 MPa vacuum for 4 h;

[0072] (2) Add 5.56 g of toluene diisocyanate into the flask described in (1) under a protective gas of N 2 The temperature was raised to 80°C in the atmosphere, and the raw materials were stirred at a rate of 200 r / min to make them uniformly mixed, and reacted with the polyether diol for 4 hours;

[0073] Steps (3) to (5) are the same as those in Comparative Example 1.

[0074] The final products prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to DMA test. The test conditions were compression mode. A circular sample with a diameter of 8 mm and a thickness of 2 mm was used to perform a fixed-frequency variable temperature test at 10 Hz. The test temperature range was -100°C to 100°C.

[0075] The results of Examples 1 to 3 and Comparative Examples 1 to 3 are as follows Figure 1 As shown;

[0076] Example 1 exhibits a loss factor peak shape and phenomenon that is significantly different from that of Comparative Example 1;

[0077] Embodiment 2 has a damping temperature range effect similar to that of Embodiment 1;

[0078] Examples 1 to 3 form an interpenetrating network, and the loss factor in the low temperature region is significantly higher than that of comparative examples 1 to 3. At the same time, the effective damping temperature range (tanδ≥0.3) of Examples 1 and 2 is 140°C, which has the widest damping temperature range, indicating that the synergistic effect of the damping performance of polyurethane and polybutyl methacrylate is achieved when the interpenetration ratio is 6:4, and a wide temperature range high damping polyurethane IPN material is prepared. The damping temperature range of the material is adjusted by changing the ratio of the polyurethane and polybutyl methacrylate components used in the material to achieve targeted design.

[0079] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-damping polyurethane IPN material with a wide temperature range, characterized in that: The raw materials of polyurethane IPN materials include isocyanate, polytriol, butyl methacrylate, ethylene glycol dimethacrylate and dodecyl peroxide; Taking the total mass of isocyanate, polytriol and butyl methacrylate as 100%, the mass percentage of each component is: Isocyanate 5%-10% Polytriol 40%-45% Butyl methacrylate 40%-50% and the molar ratio of isocyanate in the isocyanate to hydroxyl in the polytriol is 1; Taking the total mass of butyl methacrylate as 100%, the mass percentage of ethylene glycol dimethacrylate is: 1%-5%; Calculated based on the total mass of butyl methacrylate being 100%, the mass percentage content of dodecyl peroxide is 0.5%-1%.

2. A wide temperature range high damping polyurethane IPN material according to claim 1, characterized in that: The isocyanate is at least one of diphenylmethane diisocyanate, toluene diisocyanate and isophorone diisocyanate.

3. A wide temperature range high damping polyurethane IPN material according to claim 1 or 2, characterized in that: The polytriol is at least one of polycaprolactone triol and polyoxypropylene triol.

4. A wide temperature range high damping polyurethane IPN material according to claim 3, characterized in that: The molecular weight of the polytriol is 4500-5000.

5. A method for preparing a wide temperature range high damping polyurethane IPN material, characterized in that the steps include: In the first step, the polytriol is subjected to vacuum dehydration treatment; The second step is to mix the isocyanate with the polytriol subjected to vacuum dehydration treatment in the first step to react under a protective gas atmosphere, and cool to room temperature after the reaction is completed to obtain a polyurethane matrix; The third step is to mix the polyurethane matrix obtained in the second step with butyl methacrylate, ethylene glycol dimethacrylate and dodecyl peroxide under a protective gas atmosphere to react; The fourth step is to cure the product obtained after the reaction in the third step at high temperature to obtain a polyurethane IPN material.

6. The method for preparing a wide temperature range high damping polyurethane IPN material according to claim 5, characterized in that: In the first step, the temperature during vacuum dehydration treatment is 110-120° C., the vacuum degree is -0.1 MPa, and the time is 2-4 hours.

7. The method for preparing a wide temperature range high damping polyurethane IPN material according to claim 5, characterized in that: In the second step, the protective gas is N2, the temperature during mixing is 80-90°C, and the reaction time is 4-8h.

8. The method for preparing a wide temperature range high damping polyurethane IPN material according to claim 5, characterized in that: In the third step, the protective gas is N2, the temperature during mixing is 60-70°C, and the reaction time is 2-4h.

9. The method for preparing a wide temperature range high damping polyurethane IPN material according to claim 5, characterized in that: In the fourth step, the curing temperature is 80-90° C. and the curing time is 10-14 hours.

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