High performance fluoroelastomer material and method for its preparation

Abstract

The application provides a high-performance fluororubber material and a preparation method thereof. The high-performance fluororubber material comprises the following components in parts by weight: 60-90 parts of fluororubber, 5-10 parts of modified EPDM, 0.5-3 parts of plasticizer, 15-40 parts of reinforcing agent, 1-5 parts of vulcanizing agent and 0.5-2 parts of acid absorbent. The high-performance fluororubber material prepared by the application has high tensile strength, elongation at break and thermal conductivity, low compression permanent set, high mechanical properties, high thermal conductivity, high elasticity, good anti-aging performance and low compression deformation, and has high material reliability and long service life.

Description

Technical Field

[0001] This invention belongs to the field of rubber materials technology, and particularly relates to a high-performance fluororubber material and its preparation method. Background Technology

[0002] Fluororubber, with its excellent high-temperature resistance, oil and media resistance, and chemical stability, has become a core material for key seals and pipelines in the automotive industry. As automobiles move towards lightweighting and high power, even more stringent requirements are being placed on the overall performance of fluororubber.

[0003] Because engine compartment temperatures are consistently maintained between 150℃ and 200℃, and the localized temperatures of battery packs in new energy vehicles can exceed 180℃ during operation, fluororubber urgently needs high thermal conductivity to rapidly transfer heat and prevent localized overheating that could lead to safety hazards. Furthermore, since pipelines and seals are frequently subjected to tensile and bending deformations during vehicle operation, fluororubber must possess both high strength to resist assembly stress and vibration impacts, and low compression set to ensure long-term sealing reliability. However, current automotive fluororubber materials still face technical bottlenecks in practical applications, making it difficult to simultaneously meet the synergistic requirements of high strength, high thermal conductivity, and low compression set.

[0004] Currently, although some studies have attempted to modify fluororubber through blending and the addition of fillers, it is often difficult to achieve the aforementioned properties simultaneously. For example, simply adding high thermal conductivity fillers (such as metal oxides and nitrides) can improve the thermal conductivity of fluororubber materials, but because the fillers are easily unevenly dispersed in the matrix, forming defects, their mechanical properties are significantly reduced.

[0005] Therefore, developing a novel fluororubber material that can synergistically resolve the contradiction between high strength, high elasticity, high thermal conductivity and low compression set, and has excellent comprehensive performance, has become an urgent problem for those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a high-performance fluororubber material and its preparation method to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides a high-performance fluororubber material, which comprises the following components in parts by weight: 60-90 parts of fluororubber, 5-10 parts of modified EPDM rubber, 0.5-3 parts of plasticizer, 15-40 parts of reinforcing agent, 1-5 parts of vulcanizing agent, and 0.5-2 parts of acid scavenger.

[0008] The reinforcing agent is a composite of carbon black and modified silicon carbide.

[0009] As a further improvement, the synthesis of the modified silicon carbide includes the following steps:

[0010] Fluorosilane was added to anhydrous ethanol to prepare a mixed solution. Then, silicon carbide was added to the mixed solution and the mixture was stirred. After stirring was completed, the solution was post-treated to obtain modified silicon carbide.

[0011] To improve the compatibility of the hydrophobically modified silicon carbide, preferably, the fluorinated silane is heptadecafluorodecyltriethoxysilane.

[0012] As a further improvement, the carbon black has a particle size of 200-400 nm.

[0013] As a further improvement, the mass ratio of carbon black to modified silicon carbide is 3-6:1.

[0014] As a further improvement, the fluororubber is at least one of polyvinylidene fluoride rubber, tetrafluoropropylene rubber, and perfluoroether rubber.

[0015] For better stability, the fluororubber is preferably a perfluoroether rubber.

[0016] As a further improvement, the modified EPDM rubber is maleic anhydride modified EPDM rubber.

[0017] As a further improvement, the plasticizer is at least one selected from methyl fluorosilicone oil, vinyl fluorosilicone oil, diethyl phthalate, and dioctyl phthalate.

[0018] For greater elasticity, the plasticizer is preferably methyl fluorosilicone oil.

[0019] As a further improvement, the vulcanizing agent is at least one selected from dicumyl peroxide, 4,4'-(hexafluoroisopropylidene)bisphenol, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0020] For higher strength, the vulcanizing agent is preferably 4,4'-(hexafluoroisopropylidene)bisphenol.

[0021] As a further improvement, the acid absorbent is at least one of calcium oxide, magnesium oxide, calcium hydroxide, and lead oxide.

[0022] To prevent corrosion from acidic gases during processing, the acid absorbent is preferably magnesium oxide and calcium oxide.

[0023] This invention also provides a method for preparing a high-performance fluororubber material, comprising the following steps:

[0024] (1) Add fluororubber, modified EPDM rubber and plasticizer into a mixer and mix at 80-100℃ for 1-5 minutes. Then add reinforcing agent and acid absorber and mix for 1-5 minutes. Finally add vulcanizing agent and mix at 120-130℃ with a hammer for 0.5-2 minutes. Discharge the material and pass it through rollers and sheet to obtain the compound rubber.

[0025] (2) The compound obtained in step (1) is vulcanized at 160-170℃ and 10-15MPa for 5-10 minutes, and then kept at 170-190℃ for 2-6 hours to obtain high-performance fluororubber material.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention provides a high-performance fluororubber material and its preparation method. The high-performance fluororubber material has high tensile strength, elongation at break and thermal conductivity, indicating strong mechanical properties, high thermal conductivity and good aging resistance. It also has a low compression set, indicating high elasticity and is not prone to compression deformation. The material has high reliability and long service life.

[0028] Silicon carbide, as a high-strength and high-thermal-conductivity material, can be better matched with the surface energy of fluororubber after hydrophobic modification with fluorosilane. The synergistic intermolecular forces can improve its compatibility with fluororubber and make its distribution more uniform, which can effectively improve the mechanical properties, thermal conductivity and anti-aging properties of fluororubber materials. Detailed Implementation

[0029] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0030] In the following examples, except for modified silicon carbide and KH-570 modified silicon carbide, all other compound monomers and related reagents used were commercially available. Specifically, the perfluoroether rubber was purchased from Fuzhou Taipuda New Material Co., Ltd., model TPD-PFE-1000R; the maleic anhydride modified EPDM rubber was purchased from Dongguan Shenghao Plastic Raw Materials Co., Ltd., product number 5541254; the methyl fluorosilicone oil was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., model NFS7100-G50; the carbon black was purchased from Shanxi Longfa Carbon Black Technology Co., Ltd., model N991; and the silicon carbide was purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd., model N / A.

[0031] The synthesis of modified silicon carbide A includes the following steps:

[0032] 2g of heptadecafluorodecyltriethoxysilane was added to 200mL of anhydrous ethanol to prepare a mixed solution. Then, 10g of silicon carbide was added to the mixed solution and the mixture was stirred for 2h. Finally, it was dried at 90℃ for 4h to obtain modified silicon carbide A.

[0033] The synthesis of modified silicon carbide B includes the following steps:

[0034] 2g of silane coupling agent KH-570 was added to 250mL of anhydrous ethanol to prepare a mixed solution. Then, 10g of silicon carbide was added to the mixed solution and the mixture was stirred for 2h. Finally, it was dried at 100℃ for 4h to obtain modified silicon carbide B.

[0035] The preparation methods of Examples 1-3 and Comparative Examples 1-3 include the following steps:

[0036] (1) According to the weight parts, fluororubber, modified EPDM rubber and plasticizer are put into the internal mixer and mixed at 80°C for 1 min. Then, the reinforcing agent and acid absorber are added and mixed for 2 min. Finally, the vulcanizing agent is added and the mixture is hammered at 120°C for 1 min. The mixture is then discharged and passed through rollers and sheet to obtain the compound rubber.

[0037] (2) The compound obtained in step (1) is vulcanized at 160°C and 12MPa for 5 minutes, and then kept at 180°C for 4 hours to obtain high-performance fluororubber material.

[0038] The components and their weight proportions used in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below:

[0039] Table 1

[0040]

[0041] The high-performance fluororubber materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested for tensile strength, elongation at break, thermal conductivity, and compression set. The specific test methods are as follows:

[0042] Tensile strength: tested according to GB / T 528-2009 standard;

[0043] Elongation at break: As per GB / T 528-2009 standard;

[0044] Thermal conductivity: As per GB / T 11205-2009 standard;

[0045] Compression set: The compression set was measured according to GB / T 7759.1-2015 standard, using a compression device with a compression rate of 25%, and the test conditions were 200℃×24h.

[0046] The test results are shown in Table 2:

[0047] Table 2

[0048]

[0049] As can be seen from the test results of Example 1 and Comparative Example 1 in Table 2, compared with the high-performance fluororubber material prepared using unmodified EPDM rubber, the high-performance fluororubber material prepared using maleic anhydride-modified EPDM rubber has higher tensile strength, elongation at break, and thermal conductivity, and lower compression set. This indicates that maleic anhydride-modified EPDM rubber can improve its compatibility with fluororubber, and when combined with other materials, it can further improve the mechanical properties and thermal conductivity of fluororubber materials, making them more resistant to aging, less prone to compression deformation, and with higher material reliability and longer service life.

[0050] As can be seen from the test results of Example 1 and Comparative Examples 2-3 in Table 2, compared with the use of carbon black and unmodified silicon carbide composite as reinforcing agents, or the use of carbon black and KH-570 modified silicon carbide composite as reinforcing agents in the preparation of high-performance fluororubber materials, the high-performance fluororubber materials prepared using carbon black and the modified silicon carbide composite obtained in this invention as reinforcing agents have a higher thermal conductivity. This indicates that the addition of modified silicon carbide in this invention can enhance the thermal conductivity of high-performance fluororubber materials, prevent local overheating and thermal aging, ensure long-term reliability of the materials, extend service life, and to a certain extent improve tensile strength and elongation at break, and reduce compression set, indicating good mechanical properties, high strength, good elasticity, and strong adaptability.

[0051] The test results of Examples 1-3 show that the high-performance fluororubber material prepared by the preparation method provided by the present invention has higher tensile strength, elongation at break and thermal conductivity, and lower compression set, indicating that it has strong mechanical properties, high thermal conductivity and is not prone to compression deformation. Furthermore, the test results of Examples 1-2 and Example 3 show that when the mass ratio of carbon black to modified silicon carbide is within a suitable range, the strength, thermal conductivity and elasticity of the fluororubber material prepared are better.

[0052] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high performance fluoroelastomer material characterized in that, The high-performance fluororubber material comprises the following components by weight: 60-90 parts of fluororubber, 5-10 parts of modified ethylene-propylene-diene rubber, 0.5-3 parts of plasticizer, 15-40 parts of reinforcing agent, 1-5 parts of vulcanizing agent, and 0.5-2 parts of acid absorbent. The reinforcing agent is a composite of carbon black and modified silicon carbide. The modified silicon carbide is synthesized by the following steps: The fluorine-containing silane is added to anhydrous ethanol to prepare a mixed solution, and then silicon carbide is added to the mixed solution for further stirring and mixing. After stirring, post-treatment is performed to obtain the modified silicon carbide. The mass ratio of the carbon black to the modified silicon carbide is 3-6:

1. The modified ethylene-propylene-diene rubber is maleic anhydride modified ethylene-propylene-diene rubber.

2. A high performance fluoroelastomer material according to claim 1, characterized in that, The particle size of the carbon black is 200-400 nm.

3. A high performance fluoroelastomer material according to claim 1, wherein, The fluororubber is at least one of p- fluorinated ether rubber, tetrapropyl fluororubber, and perfluoroether rubber.

4. A high performance fluoroelastomer material according to claim 1, wherein, The plasticizer is at least one of methyl fluorosilicone oil, vinyl fluorosilicone oil, diethyl phthalate, and dioctyl phthalate.

5. A high performance fluoroelastomer material as claimed in claim 1, wherein, The vulcanizing agent is at least one of dicumyl peroxide, 4,4'-(hexafluoroisopropylidene) bisphenol, and 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane.

6. A high performance fluoroelastomer material according to claim 1, wherein, The acid absorbent is at least one of calcium oxide, magnesium oxide, calcium hydroxide, and lead oxide.

7. The preparation method of the high-performance fluororubber material according to any one of claims 1-6, comprising the following steps: (1) The fluororubber, modified ethylene-propylene-diene rubber, and plasticizer are put into a mixer, and mixed at 80-100°C for 1-5 min. Then the reinforcing agent and acid absorbent are added and mixed for 1-5 min. Finally, the vulcanizing agent is added, and the mixer is operated at 120-130°C for 0.5-2 min. After that, the material is discharged and rolled to obtain the mixed rubber; (2) The mixed rubber obtained in step (1) is vulcanized at 160-170°C and 10-15 MPa for 5-10 min, and then kept at 170-190°C for 2-6 h to obtain the high-performance fluororubber material.

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