A wide-damping temperature range polyurethane material and a preparation method thereof

Abstract

This invention relates to a wide-temperature-range polyurethane material and its preparation method, belonging to the field of polyurethane preparation technology. The polyurethane is a novel polyurethane damping material that meets the requirements for wide-temperature-range damping materials. Furthermore, the polyether triol used in this material has good processability and weather resistance, and can form a cross-linked network structure with isocyanate. Simultaneously, the selection of the R value allows for excess isocyanate, which can further react with moisture and other substances in the air to form urea bonds. The high hydrogen bond strength facilitates microphase separation in the polyurethane material, thus enabling the system to maintain high damping even after reaching a peak at low temperatures.

Description

Technical Field

[0001] This invention relates to a wide-damping temperature range polyurethane material and its preparation method, belonging to the field of polyurethane preparation technology. Background Technology

[0002] Noise pollution is considered one of the four major environmental hazards. Vibration and noise permeate people's lives, seriously affecting their physical and mental health and threatening the safe operation of equipment and facilities. my country's noise pollution prevention and control regulations are constantly being improved, placing higher demands on vibration reduction and noise control. Damping materials, due to their unique structural characteristics, can effectively mitigate the hazards caused by vibration and noise. Polyurethane, in particular, is mainly composed of hard and soft segments. Hard segments are typically formed by the reaction of isocyanates with polyols or chain extenders, while soft segments are mainly composed of polyether or polyester long chains. Polyurethane molecules crosslink through hydrogen bonds and van der Waals forces between hard and soft segments, forming a polymer with a network structure. Simultaneously, polyurethane molecules exhibit a certain arrangement pattern at the microscopic level. This unique network structure, crosslinking method, and microscopic arrangement give polyurethane excellent mechanical and damping properties. Currently, rubber damping pads are commonly used to address vibration and noise hazards in the construction industry. However, the effective damping temperature range of these materials often only meets the needs of low or high temperature regions. Furthermore, seasonal temperature changes can easily cause the material's performance to deteriorate or become brittle, limiting its effectiveness in solving vibration and noise reduction problems. Therefore, developing polyurethane materials with a wide damping temperature range to meet the requirements for vibration and noise reduction capabilities at various temperatures is an urgent problem to be solved. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a polyurethane material with a wide damping temperature range and its preparation method. A polyurethane material with a wide damping temperature range is designed and prepared. Compared with conventional formulations, the designed formulation and system not only have damping performance under various environments, but also meet the needs of industrial mass production. This method can obtain a polyurethane damping material that meets the vibration reduction requirements of a wide temperature range at low cost.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows.

[0005] A wide-damping temperature range polyurethane material, which is obtained by one-step mixing and curing molding;

[0006] Based on the total mass of raw materials required to prepare this polyurethane material being 100%, the components and their mass fractions of each raw material are as follows:

[0007] Isocyanates 80%–85%

[0008] Polytriol 15%–20%

[0009] The R value of the system is 3-5, where R is the molar ratio of isocyanate to hydroxyl group.

[0010] Preferably, the isocyanate in the raw material is at least one selected from diphenylmethane diisocyanate (MDI), toluene diisocyanate (HDI), and isophorone diisocyanate (IPDI);

[0011] Preferably, the polyterol in the raw material is at least one of polycaprolactone triol and polyoxypropylene triol, and the molecular weight of the polyterol is 4500-5000.

[0012] A method for preparing a wide-damping temperature range polyurethane material, comprising the following steps:

[0013] (1) In a three-necked flask, the polytriol in the raw material is subjected to vacuum dehydration treatment;

[0014] (2) Under a protective gas atmosphere, the isocyanate in the raw material is added to the flask described in (1) and mixed with the polytriol at high temperature for reaction;

[0015] (3) The product obtained in (2) is cured at high temperature to obtain the wide damping temperature range polyurethane material.

[0016] Preferably, in step (1), the temperature during dehydration is 110-120℃, the vacuum degree during dehydration is -0.1MPa, and the dehydration time is 2-4h.

[0017] Preferably, in step (2), the protective gas is N2, the reaction temperature is 80-90℃, and the reaction time is 4-8h;

[0018] Preferably, in step (3), the curing temperature is 80-90℃ and the curing time is 36-48h.

[0019] Beneficial effects

[0020] This invention provides a wide-temperature-range polyurethane material. This polyurethane is a novel type of polyurethane damping material that meets the application requirements of wide-temperature-range damping materials. Furthermore, the polyether triol used in this material exhibits good processability and weather resistance. The long-chain polyether triol forms a loose cross-linked network structure with isocyanate, which has a weak inhibitory effect on the movement of molecular chain segments. Excess isocyanate reacts with water in the air to generate a series of molecular chains with varying molecular weights. The higher molecular weight portions serve as the material's skeletal network, maintaining the material's basic structure and mechanical properties, while the relatively lower molecular weight portions act as plasticizers, increasing the overall mobility of the molecular chains. This results in the material exhibiting high energy absorption and dissipation effects across a wide temperature range, thereby improving the material's damping performance.

[0021] This invention provides a wide-damping temperature range polyurethane material, which is obtained by mixing and curing two raw materials, isocyanate and polytriol, in a certain ratio. The selection and dosage of these two raw materials can ensure that the prepared polyurethane material has a complete and orderly cross-linked network, thereby further improving the mechanical strength and damping performance of the polyurethane material.

[0022] This invention provides a polyurethane material with a wide damping temperature range. It is necessary to control the ratio of polyterol to isocyanate components in the raw materials; too high or too low a ratio will limit the material's damping temperature range to the low-temperature region. When the R value is between 3 and 5, the degree of crosslinking of the material meets the application conditions for a wide temperature range, thereby enabling the material's effective damping to cover a wide temperature range.

[0023] This invention provides a polyurethane material with a wide damping temperature range. In the preparation of the polyurethane material, the isocyanate contains -NCO groups at both ends and the polyterol contains -OH groups. Different finished products with different effects can be obtained by adjusting the ratio of raw materials. The method is simple, the experimental formula can be modified according to production needs, and it can be industrialized.

[0024] This invention provides a polyurethane material with a wide damping temperature range. In the preparation of the polyurethane material, it is necessary to control the R value. If the R value is too low, the viscosity of the polyurethane will increase, making it difficult to extend the chain and shape the structure, thus making it impossible to obtain a polyurethane that can be used in practice. If the R value is too high, the reactivity will surge, making it difficult to control the molding and processing of the polyurethane. Attached Figure Description

[0025] Figure 1 The loss factor-temperature curves of the polyurethane materials described in Example 1 and Comparative Example 1 are shown. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments.

[0027] Example 1

[0028] 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.

[0029] (1) In a three-necked flask, 163g of polycaprolactone triol was dehydrated at 110℃ and under a vacuum of -0.1MPa for 4h.

[0030] (2) Add 37g of diphenylmethane diisocyanate to the flask described in (1), heat it to 80°C under a protective N2 atmosphere, stir the raw material at a rate of 200r / min to mix it evenly, and react it with polycaprolactone triol for 4h.

[0031] (3) The product obtained in (2) was cured at 80°C for 36 hours to obtain a polyurethane material with a wide damping temperature range.

[0032] Example 2

[0033] 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 4.

[0034] (1) In a three-necked flask, 156g of polycaprolactone triol was dehydrated at 110℃ and under a vacuum of -0.1MPa for 4h.

[0035] (2) Add 44g of isophorone diisocyanate to the flask described in (1), heat it to 80°C under a protective N2 atmosphere, stir the raw material at a rate of 200r / min to mix it evenly, and react it with polycaprolactone triol for 4h.

[0036] (3) The product obtained in (2) was cured at 80°C for 36 hours to obtain a polyurethane material with a wide damping temperature range.

[0037] Example 3

[0038] 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 5.

[0039] (1) In a three-necked flask, 155g of polyoxypropylene triol was dehydrated at 110℃ and under a vacuum of -0.1MPa for 4h.

[0040] (2) Add 45g of toluene diisocyanate to the flask described in (1), heat to 80°C under a protective N2 atmosphere, stir the raw materials at a rate of 200r / min to mix them evenly, and react with polyoxypropylene triol for 4h.

[0041] (3) The product obtained in (2) was cured at 80°C for 36 hours to obtain a polyurethane material with a wide damping temperature range.

[0042] Comparative Example 1

[0043] In Comparative Example 1, the molecular weight of diphenylmethane diisocyanate was 250, and the molecular weight of polyether diol was 2000. The R value of the system was 3.

[0044] (1) In a three-necked flask, 96g of polyether diol was dehydrated at 110℃ and under a vacuum of -0.1MPa for 4h.

[0045] (2) Add 144g of toluene diisocyanate to the flask described in (1), heat to 80°C under a protective N2 atmosphere, stir the raw materials at a rate of 200r / min to mix them evenly, and react with polyether diol for 4h.

[0046] (3) The product obtained in (2) was cured at 80°C for 24 hours to obtain polyurethane material.

[0047] Comparative Example 2

[0048] 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 1.05.

[0049] Steps (1)-(3) are the same as in Comparative Example 1.

[0050] Comparative Example 3

[0051] 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 6.

[0052] Steps (1)-(3) are the same as in Comparative Example 1.

[0053] The final products prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to DMA testing. The test conditions were compression mode, and a circular sample with a diameter of 8 mm and a thickness of 2 mm was used to perform a constant frequency variable temperature test at 10 Hz. The test temperature range was -100℃ to 100℃.

[0054] The results of Example 1 and Comparative Example 1 are as follows: Figure 1 As shown;

[0055] Example 1 exhibits a loss factor peak shape and phenomenon that are significantly different from those of Comparative Example 1;

[0056] Examples 2 and 3 have a similar damping temperature range effect to Example 1;

[0057] When the R value is between 1 and 3 or higher than 5, Comparative Examples 2 and 3 all exhibit similar damping temperature range effects to Comparative Example 1.

[0058] Examples 1-3 formed a cross-linked network, which not only exhibited a higher loss factor in the low-temperature region than Comparative Examples 1-3, but also showed higher damping in the high-temperature region, and showed a tendency to shift to even higher temperatures, thus broadening the operating temperature range of polyurethane materials as damping materials. Furthermore, the damping temperature range of the material can be controlled by changing the triol and isocyanate components used in the material, enabling targeted design.

[0059] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polyurethane material with a wide damping temperature range, characterized in that: The raw materials required to prepare this polyurethane material include: Diphenylmethane diisocyanate, with a molecular weight of 250; Polycaprolactone triol, with a molecular weight of 4950; The R-value of the system is 3; (1) In a three-necked flask, 163g of polycaprolactone triol was dehydrated at 110℃ and under a vacuum of -0.1MPa for 4h. (2) Add 37g of diphenylmethane diisocyanate to the flask described in (1), heat it to 80°C under a protective N2 atmosphere, stir the raw material at a rate of 200r / min to mix it evenly, and react it with polycaprolactone triol for 4h. (3) The product obtained in (2) was cured at 80°C for 36 hours to obtain a polyurethane material with a wide damping temperature range.

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