A dual-damping temperature zone polyurethane material and a method for preparing the same

Abstract

The present application relates to a kind of double-damping temperature range polyurethane material and its preparation method, belong to polyurethane preparation technical field, double-damping temperature range polyurethane material refers to polyurethane material has good low temperature damping performance and high temperature damping performance.The polyurethane material is obtained by mixing curing of A, B two components, the selection and dosage setting of each substance in A, B material can ensure that the crosslinking network of perfect and neat exists in the prepared polyurethane material, wherein the-NCO end-capped polyurethane prepolymer prepared by B material is polymerized with the larger ternary alcohol, and the free volume is larger, this part of chain segment is easy to move, so that material can produce glass transition at low temperature, thus providing the damping performance at low temperature, and the introduction of ternary alcohol chain extender in A material can make the polyurethane material prepared in dense distribution small crosslinking frame, these small crosslinking frame is not easy to move, only in the high-temperature environment, chain segment can be moved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of double damping temperature range polyurethane material and its preparation method, belong to polyurethane preparation technical field, double damping temperature range polyurethane material refers to polyurethane material has good low temperature damping performance and high temperature damping performance. BACKGROUND

[0002] With the continuous advancement of urbanization and industrialization, the noise and vibration pollution problem of urban and industrial areas is increasingly prominent. Highways, airports, factories, construction sites, etc. are the main sources of noise and vibration. The development of vibration and noise reduction materials can effectively reduce the spread and influence range of noise and vibration, and improve the environmental quality of urban and industrial areas. Polyurethane is known as the "fifth plastic" due to its excellent mechanical properties, good deformation ability, strong biocompatibility and solvent resistance, and diverse application range. At the same time, polyurethane material has excellent vibration and noise reduction ability, which can effectively absorb vibration and reduce noise. However, for the current problem of strong vibration and loud noise in the area near the engine of vehicles and airplanes in plateau areas, the widely used material is rubber shock pad. The effective damping temperature range of this type of shock pad is usually between -50℃ and -20℃. However, the temperature in the area near the engine of a vehicle in a plateau area will quickly rise from low to high after starting, so the damping material in this area mainly needs low and high temperature damping performance, which is difficult for existing damping materials to simultaneously consider. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a kind of double damping temperature range polyurethane material and its preparation method. By improving and innovating the basic formula, a polyurethane material containing double damping temperature range is designed and prepared. Compared with the conventional formula, the designed formula and system not only have damping performance in high and low temperature environments, but also can meet the demand of industrialized mass production. This method can realize polyurethane damping material covering low temperature damping area and high temperature damping area at low cost.

[0004] To achieve the above purpose, the technical scheme of the present application is as follows.

[0005] A kind of double damping temperature range polyurethane material, which is formed by mixing and curing A material and B material;

[0006] The total mass of the raw materials for preparing the A material is 100%, and the mass fraction of each raw material component is as follows:

[0007] Polyglycol 80%~90%

[0008] Triol chain extender 10%~20%

[0009] The raw material components and their mass fractions are as follows, based on the total mass of the raw materials for preparing the B material being 100%:

[0010] Isocyanate 45% to 55%

[0011] Triol or polytrio 45% to 55%

[0012] The R value of the B material is 4 to 8;

[0013] Preferably, the polyhydric alcohol in the A material is at least one or more of polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and polyethylene glycol (PEG), and the molecular weight of the polyhydric alcohol is 960 to 1200;

[0014] Preferably, the triol chain extender in the A material is at least one of trimethylolpropane (TMP), triethanolamine (TEA), and glycerol (GLY);

[0015] Preferably, the isocyanate in the B material is at least one of diphenylmethane diisocyanate (MDI), toluene diisocyanate (HDI), and isophorone diisocyanate (IPDI);

[0016] Preferably, the triol or polytrio in the B material is at least one or more of polycaprolactone triol, castor oil, and polyoxypropylene triol, and the molecular weight of the triol or polytrio is 900 to 1100;

[0017] Preferably, the molar ratio R' of isocyanate in the B material to hydroxyl in the A material is 1 to 1.1:1, and the hydroxyl in the A material refers to the sum of the number of hydroxyl groups of the polyhydric alcohol and the triol chain extender;

[0018] Preferably, the mass ratio of the triol or polytrio in the B material to the triol chain extender in the A material is 3 to 7:1.

[0019] A preparation method of a double-damping temperature zone polyurethane material, the steps comprising:

[0020] (1) Under the protection of a protective gas, mix the isocyanate in the B material with the triol or polytrio, and perform a prepolymerization reaction to obtain a prepolymerization product, i.e., the B material;

[0021] (2) Mix the polyhydric alcohol and the triol chain extender to obtain the A material;

[0022] (3) Under air-isolating conditions, preheat and mix the B material and the A material at a temperature of 45 to 50°C, and after curing, obtain the polyurethane material;

[0023] Preferably, in step (1), the prepolymerization temperature is 80 to 85°C, and the prepolymerization time is 4 to 8h;

[0024] Preferably, in step (3), the curing temperature is 70-90 DEG C, and the curing time is 4-8h.

[0025] Preferably, in step (1), the content of isocyanate in the B material is calculated by titration: the B material is added to a di-n-butylamine-toluene solution, heated and stirred at 45-55 DEG C to obtain a titration sample solution, then isopropyl alcohol is added, an indicator is added dropwise, and dilute hydrochloric acid is used for titration to obtain the content of isocyanate.

[0026] The preparation method of the indicator is as follows: bromocresol green is dissolved in a sodium hydroxide solution to obtain the indicator, and the mass of the bromocresol green to the volume of the sodium hydroxide solution in the indicator is 1g:1000mL.

[0027] The concentration of the sodium hydroxide solution is 0.1mol / L.

[0028] The use amount ratio of the indicator to the titration sample solution is 1g:1000mL.

[0029] The concentration of the di-n-butylamine-toluene solution is 0.05-0.2mol / L, and the use amount ratio of the B material to the di-n-butylamine-toluene solution is 3g:70-150mL.

[0030] The volume ratio of the titration sample solution to isopropyl alcohol is 1:2.

[0031] Preferably, the concentration of the dilute hydrochloric acid is 0.05-0.2mol / L.

[0032] Preferably, the mass relationship of the B material to the polyhydric alcohol and triol chain extender in the A material satisfies the formula:

[0033] (m1 x a %) / 42=R' x ((m2 / N1) x 2+(m3 / N2) x 3)

[0034] In the formula, m1, m2 and m3 are the masses of the polyhydric alcohol and triol chain extender in the B material and the A material respectively; N1 and N2 are the molecular weights of the polyhydric alcohol and triol chain extender in the A material respectively; and a % is the mass fraction of isocyanate in the B material obtained by titration.

[0035] Beneficial effects

[0036] The application provides a double-damping temperature range polyurethane material, which is a novel polyurethane damping material, has a high loss factor, can meet the use requirements of damping materials under low-temperature and high-temperature working conditions, and has a low synthesis cost and can be mass-produced.

[0037] The application provides a double-damping temperature range polyurethane material, which is obtained by curing two components A and B with a certain R value (ratio of isocyanate groups to hydroxyl groups in the material), and the selection and amount of each substance in the A and B materials can ensure that a perfect and neat crosslinking network exists in the prepared polyurethane material, wherein the -NCO terminated polyurethane prepolymer prepared from the B material is polymerized with a larger volume of triol, so that the free volume is larger, the chain segment of this part is easy to move, so that the material can produce glass transition at low temperature, thereby providing damping performance at low temperature, and the introduction of the triol chain extender in the A material can make the prepared polyurethane material densely distribute small crosslinking frames, and the small crosslinking frames are not easy to move, and only at high temperature, the chain segment can move. The synergistic effect of the two can make the prepared polyurethane material have damping performance at low temperature and high temperature at the same time.

[0038] The application provides a double-damping temperature range polyurethane material, and the proportion of the triol or polytriol component of the B material to the triol chain extender component of the A material in the AB mixed material needs to be controlled; if the proportion is too high or too low, the damping temperature range of the material only appears in the high-temperature region; only when the proportion is appropriate, the material has a regular double crosslinking network, and two glass transition temperatures appear, so that the damping temperature range of the material changes from high temperature to high and low temperature regions.

[0039] The application provides a double-damping temperature range polyurethane material, and in the preparation of the polyurethane material, the isocyanate groups are terminated by -NCO groups in the B component raw material composition, and the polyols are terminated by -OH groups; after the preliminary synthesis of the prepolymer, the two can be stored for a long time at room temperature. Subsequently, different types of high molecular chain segments (such as PTMG, PPG, etc.) and chain extension crosslinking agents (such as TMP, GLY, etc.) in the A component raw material can be added according to different production needs, and the above raw materials can be polymerized to produce polyurethane materials at room temperature, and then different effects of the finished product can be obtained by adjusting the ratio of the A and B materials; the method steps are simple, the experimental formula can be changed according to production needs, and industrial production can be carried out.

[0040] The application provides a double-damping temperature range polyurethane material, and in the preparation of the polyurethane material, the preheating temperature of the prepolymer needs to be kept at 45-50 DEG C, which is the key to the preservation of the prepolymer, and the prepolymer will self-polymerize under the action of a temperature of 55-80 DEG C. The two ends of the prepolymer are terminated by isocyanate groups (-NCO), and have a tendency to polymerize with the hydroxyl groups in the chain extender and crosslinking agent in the main raw material in a normal temperature environment, so that the reaction can proceed in a positive direction and the reaction rate can be accelerated.

[0041] The present application provides a kind of double damping temperature range polyurethane material, in the preparation of the polyurethane material, it needs to control the isocyanate content of prepolymer, too low isocyanate content will lead to the viscosity of polyurethane increases, it is not easy to chain extension, structure is difficult to form, cannot obtain the polyurethane that can be practically applied;Too high isocyanate content will lead to the reaction activity surge, it is not easy to control the forming and processing of polyurethane. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The loss factor-temperature curve of the polyurethane material described in Examples 1-3 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0043] The present application will be further described in conjunction with specific examples.

[0044] Example 1

[0045] In this example, the molecular weight of castor oil is 960, and the molecular weight of polypropylene glycol is 1000. The mass ratio of castor oil to trimethylolpropane is 3.93:1.

[0046] (1) 62 g of diphenylmethane diisocyanate and 36 g of castor oil were added to a 250 mL three-necked flask, and the raw materials were stirred at a speed of 200 r / min to mix them uniformly under nitrogen atmosphere. After 4 h of reaction, a polyurethane prepolymer, i.e., B material, was obtained.

[0047] (2) 0.3856 g of the B material obtained in step (1) was dissolved in 25 mL of a toluene solution of di-n-butylamine, and was heated at 50°C for 20 min to dissolve it completely. Then, 50 mL of isopropyl alcohol was added for dilution, and 4 drops of indicator were added dropwise. Titration with 0.1023 mol / L of dilute hydrochloric acid showed that the isocyanate content in the prepolymer was 12.58%.

[0048] (3) The prepolymer titrated in step (2) was preheated to 50°C, and the main raw materials, i.e., polypropylene glycol and trimethylolpropane, after dehydration, were preheated to 50°C.

[0049] (4) 16.00 g of polypropylene glycol and 3.00 g of trimethylolpropane in step (3) were added to the container in sequence, and then 31.00 g of the prepolymer was added. The solution was stirred at a speed of 2000 r / min for 20 s. After being poured into a container made of polytetrafluoroethylene, it was placed in an oven at 70°C for 4 h to solidify, thereby obtaining a double damping temperature range polyurethane material.

[0050] Example 2

[0051] In this example, the molecular weight of polycaprolactone triol is 1000, and the molecular weight of polybutylene glycol is 1000. The ratio of polycaprolactone triol to triethanolamine is 5.19:1.

[0052] (1) 50 g of isophorone diisocyanate and 50 g of polycaprolactone triol were added to a 250 mL three-necked flask, the raw materials were stirred at a rate of 200 r / min to mix them uniformly under nitrogen atmosphere, and the polyurethane prepolymer was obtained after 4 h of reaction.

[0053] (2) 0.3841 g of the prepolymer obtained in step (1) was dissolved in 25 mL of a toluene solution of di-n-butylamine, and was heated at 50°C for 20 min to dissolve it fully, 50 mL of isopropyl alcohol was added for dilution, and 4 drops of bromocresol green indicator were added dropwise; the isocyanate content in the prepolymer was 12.35% as determined by titration with 0.1023 mol / L dilute hydrochloric acid.

[0054] (3) The prepolymer titrated in step (2) was preheated to 50°C, and the main raw materials, polybutylene glycol and triethanolamine after dehydration, were preheated to 50°C.

[0055] (4) 16.30 g of polybutylene glycol and 2.96 g of triethanolamine in step (3) were added to the container in sequence, 30.74 g of the prepolymer was added, and the solution was stirred at a stirring rate of 2000 r / min for 20 s; after being poured into a container of polytetrafluoroethylene, it was placed in an oven at 70°C for 4 h to solidify, and a double-damping temperature zone polyurethane material was obtained.

[0056] Example 3

[0057] The molecular weight of the polyoxypropylene in this example was 1080, and the molecular weight of the polyethylene glycol was 1000. The mass ratio of polyoxypropylene to glycerol was 4.81:1.

[0058] (1) 55 g of toluene diisocyanate and 45 g of polyoxypropylene were added to a 250 mL three-necked flask, and the raw materials were stirred at a rate of 200 r / min to mix them uniformly after being heated to 80°C, and the polyurethane prepolymer was obtained after 4 h of reaction.

[0059] (2) 0.3526 g of the prepolymer obtained in step (1) was dissolved in 25 mL of a toluene solution of di-n-butylamine, and was heated at 50°C for 20 min to dissolve it fully, 50 mL of isopropyl alcohol was added for dilution, and 4 drops of bromocresol green indicator were added dropwise; the isocyanate content in the prepolymer was 12.53% as determined by titration with 0.1023 mol / L dilute hydrochloric acid.

[0060] (3) The prepolymer titrated in step (2) was preheated to 50°C, and the main raw materials, polybutylene glycol and triethanolamine after dehydration, were preheated to 50°C.

[0061] (4) To the container, 16.43 g of polyethylene glycol and 2.87 g of glycerol in step (3) were added successively, and then 30.70 g of the prepolymer was added. The solution was stirred at a stirring rate of 2000 r / min for 20 s. After being poured into a container of polytetrafluoroethylene, it was placed in an oven at 70 °C for curing for 4 h to obtain a double-damping temperature zone polyurethane material.

[0062] Comparative Example 1

[0063] In the present comparative example, the molecular weight of castor oil was 960, and the molecular weight of polypropylene glycol was 900. The same B material as in Example 1 was used, but the A material did not contain a small molecule crosslinking agent, but a diol chain extender.

[0064] Steps (1)-(2) were the same as in Example 1,

[0065] (3) The titrated prepolymer in step (2) was preheated to 50 °C, and the main raw material polypropylene glycol and 1,4-butanediol after dehydration were preheated to 50 °C.

[0066] (4) To the container, 22.32 g of polypropylene glycol and 2 g of 1,4-butanediol in step (3) were added successively, and then 25.68 g of the prepolymer was added. The solution was stirred at a stirring rate of 2000 r / min for 20 s. After being poured into a container of polytetrafluoroethylene, it was placed in an oven at 70 °C for curing for 4 h to obtain a polyurethane material.

[0067] Comparative Example 2

[0068] In the present comparative example, the molecular weight of polypropylene glycol was 1000. In the present comparative example, the prepolymer did not contain a triol or a polytrio, i.e., the prepolymer was a linear system, and the mass ratio of the macromolecular diol to the crosslinking agent in the A material was the same as in Example 1.

[0069] Steps (1)-(2) were the same as in Example 1,

[0070] (3) The titrated prepolymer in step (2) was preheated to 50 °C, and the main raw material polypropylene glycol and 1,4-butanediol after dehydration were preheated to 50 °C.

[0071] (4) To the container, 22.32 g of polypropylene glycol and 2 g of 1,4-butanediol in step (3) were added successively, and then 25.68 g of the prepolymer was added. The solution was stirred at a stirring rate of 2000 r / min for 20 s. After being poured into a container of polytetrafluoroethylene, it was placed in an oven at 70 °C for curing for 4 h to obtain a polyurethane material.

[0072] The final products prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to DMA test, the test condition was tensile mode, the long strip sample of 30mm x 5mm x 2mm was used to conduct the constant frequency temperature test at 10Hz, and the test temperature range was -100℃-100℃. The results are shown in Figure 1 As shown in the table, Examples 1-3 showed obvious loss factor peak shape and phenomenon different from Comparative Examples 1 and 2. Among them, Comparative Example 1 and Comparative Example 2 were samples prepared by using cross-linked B material and A material containing cross-linking chain extender respectively, while Examples 1-3 not only used cross-linked B material, but also introduced small molecule cross-linking agent in A material, forming a double cross-linking network. Not only the loss factor in the high temperature region was close to that of Comparative Examples 1-2, but also there was a trend to move to a higher temperature. Furthermore, Examples 1-3 with double cross-linking network produced a damping temperature range in the low temperature region, widening the use temperature range of polyurethane material as damping material. At the same time, the damping temperature range of the material can be adjusted by changing the dihydric alcohol and isocyanate components used in the matrix. The targeted design was realized.

[0073] In summary, the application includes but is not limited to the above examples, any equivalent replacement or partial improvement made under the spirit and principles of the application will be considered within the protection scope of the application.

Claims

1. A dual-damping temperature-range polyurethane material, characterized in that: This polyurethane material is obtained by mixing and curing component A and component B; Based on the total mass of raw materials used to prepare material A being 100%, the composition and mass fraction of each raw material are as follows: Polydiol 80%~90% Triol chain extenders 10%~20% Based on the total mass of raw materials used to prepare material B as 100%, the composition and mass fraction of each raw material are as follows: Isocyanates 45%~55% 45%~55% terol or polyterol The R value of material B is 4-8, where R is the ratio of isocyanate to hydroxyl groups. In the material A, the polydiol is at least one of polypropylene glycol, polybutane glycol, and polyethylene glycol, and the molecular weight of the polydiol is 960-1200. In the A material, the triol chain extender is at least one of trimethylolpropane, triethanolamine, and glycerol; In the B material, the isocyanate is at least one of diphenylmethane diisocyanate, toluene diisocyanate, and isophorone diisocyanate; In the B material, the triol or polytriol is at least one of polycaprolactone triol, castor oil, and polyoxypropylene triol, and the molecular weight of the triol or polytriol is 900-1100. In the B material, the molar ratio R' of isocyanate to hydroxyl groups in the A material is 1-1.1:1; In material A, the hydroxyl groups refer to the sum of the number of hydroxyl groups in the polydiol and the triol chain extender. In the B component, the mass ratio of the triol or polytriol to the triol chain extender in the A component is 3-7:

1.

2. A method for preparing the dual-damped temperature-range polyurethane material according to claim 1, characterized in that the steps are... include: (1) Under the protection of a protective gas, isocyanate is mixed with triol or polytriol and subjected to a prepolymerization reaction to obtain material B; (2) Mix the polydiol and triol chain extender to obtain material A; (3) Under air-isolated conditions, the B material and A material are preheated and mixed at a temperature of 45-50℃ and cured to obtain a dual-damping temperature range polyurethane material.

3. The method for preparing a dual-damped temperature-range polyurethane material according to claim 2, characterized in that: In step (1), the prepolymerization temperature is 80-85℃ and the prepolymerization time is 4-8h.

4. The method for preparing a dual-damped temperature-range polyurethane material according to claim 2, characterized in that: In step (3), the curing temperature is 70-90℃ and the curing time is 4-8h.

5. The method for preparing a dual-damped temperature-range polyurethane material according to claim 2, characterized in that: In step (1), the isocyanate content in the obtained material B is calculated by titration. The steps are as follows: The obtained material B was added to a toluene solution of di-n-butylamine, and the solution was heated and stirred at 45-55℃ to obtain a titration sample solution. Isopropanol is added to the titration sample solution, followed by the addition of an indicator, and the isocyanate content is obtained by titration with dilute hydrochloric acid.

6. The method for preparing a dual-damped temperature-range polyurethane material according to claim 5, characterized in that: The indicator is prepared by dissolving bromocresol green in sodium hydroxide solution to obtain the indicator, wherein the mass ratio of bromocresol green to sodium hydroxide solution in the indicator is 1 g: 1000 mL. The concentration of sodium hydroxide is 0.1 mol / L; The ratio of the indicator to the titrated sample solution is 1g:1000mL.

7. The method for preparing a dual-damped temperature-range polyurethane material according to claim 5, characterized in that: The mass relationship between the polydiol and triol chain extender in component B and component A satisfies the following formula: (m1×a%) / 42=R'×((m2 / N1)×2+(m3 / N2)×3) In the formula, m1, m2, and m3 are the masses of polydiol and triol chain extenders in material B and material A, respectively; N1 and N2 are the molecular weights of polydiol and triol chain extenders in material A, respectively; and a% is the mass fraction of isocyanate in material B obtained by titration.

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