What are the differences between different types of fluorosilicone FVMQ?
Fluorosilicone rubber, also known as FVMQ, is a unique type of elastomer that combines the best properties of fluorocarbons and silicones. This material offers excellent resistance to heat, oil, fuel, and chemicals, along with good flexibility over a wide temperature range. As a leading fluorosilicone FVMQ supplier, I have extensive experience in dealing with different types of FVMQ. In this blog, I will delve into the differences between these various types to help you make informed decisions when it comes to your specific applications.
Chemical Composition and Structure
The fundamental difference between different types of fluorosilicone FVMQ lies in their chemical composition and molecular structure. Fluorosilicone rubbers are based on a polysiloxane backbone with fluorinated side groups. The type and amount of fluorinated groups, as well as the cross - linking agents used during vulcanization, significantly affect the properties of the final product.
For example, some FVMQ types may have a higher proportion of trifluoropropyl groups attached to the silicone backbone. These groups enhance the chemical resistance of the rubber, especially against fuels, oils, and solvents. On the other hand, the structure of the cross - links formed during vulcanization can also vary. Cross - links can be formed through different mechanisms, such as bisphenol or peroxide vulcanization.
Vulcanization Methods and Their Impact
Bisphenol Vulcanized Fluororubber Raw Rubber
Bisphenol vulcanization is a traditional method used to cross - link fluorosilicone FVMQ. In this process, bisphenol compounds are used as cross - linking agents. The resulting rubber has several distinct characteristics. Bisphenol Vulcanized Fluororubber Raw Rubber typically offers good compression set resistance, which means it can maintain its shape and sealing properties even under long - term compression. It also has relatively high tensile strength and elongation at break, making it suitable for applications where mechanical strength is crucial.
However, bisphenol - vulcanized FVMQ may have some limitations. It may not be as resistant to high - temperature aging as some other types. Over time, exposure to high temperatures can cause the rubber to harden and lose some of its flexibility. Additionally, the bisphenol compounds used in the vulcanization process may pose some environmental and health concerns, although proper handling and manufacturing processes can mitigate these risks.
Peroxy Vulcanized Fluororubber Raw Rubber
Peroxide vulcanization is another popular method for producing fluorosilicone FVMQ. Peroxy Vulcanized Fluororubber Raw Rubber has its own set of advantages. This type of vulcanization results in a more stable cross - link structure, which gives the rubber excellent resistance to high - temperature aging. The rubber can maintain its mechanical properties, such as flexibility and strength, even after prolonged exposure to high temperatures.
Peroxide - vulcanized FVMQ also has better resistance to chemicals and oxidation compared to bisphenol - vulcanized rubber. It is often used in applications where the rubber will be exposed to harsh chemical environments or high - temperature oxidative conditions. However, peroxide - vulcanized rubber may have a slightly lower compression set resistance compared to bisphenol - vulcanized rubber, which could be a drawback in some sealing applications.
Physical and Mechanical Properties
Hardness
The hardness of different types of fluorosilicone FVMQ can vary widely. Hardness is typically measured on the Shore A scale. Some FVMQ grades may have a Shore A hardness of around 40 - 50, which is relatively soft and flexible. These soft grades are often used in applications where good sealing and conformability are required, such as gaskets and O - rings.
On the other hand, harder grades with a Shore A hardness of 70 - 80 or higher are available. These harder grades offer better resistance to abrasion and mechanical wear. They are commonly used in applications where the rubber will be subjected to high - pressure or high - friction conditions, such as in automotive engine components or industrial machinery.
Tensile Strength and Elongation
Tensile strength is the maximum stress a rubber can withstand before breaking, while elongation at break measures the percentage increase in length of the rubber before it fractures. Different types of FVMQ can have varying tensile strength and elongation properties.
Bisphenol - vulcanized FVMQ generally has good tensile strength and elongation at break values. It can stretch to a certain extent before breaking, which is beneficial in applications where the rubber needs to deform without failing. Peroxide - vulcanized FVMQ may have slightly different values, depending on the specific formulation. In some cases, peroxide - vulcanized rubber may have a higher tensile strength but a lower elongation at break compared to bisphenol - vulcanized rubber.
Compression Set
Compression set is an important property for sealing applications. It measures the ability of a rubber to recover its original shape after being compressed for a certain period. Bisphenol - vulcanized FVMQ usually has good compression set resistance, especially at lower temperatures. However, as mentioned earlier, its performance may degrade at high temperatures.
Peroxide - vulcanized FVMQ, while having good high - temperature resistance, may have a slightly higher compression set at lower temperatures. This means that it may not recover its original shape as well as bisphenol - vulcanized rubber after being compressed at room temperature.
Chemical Resistance
One of the key advantages of fluorosilicone FVMQ is its excellent chemical resistance. Different types of FVMQ can offer varying degrees of resistance to different chemicals.
FVMQ with a higher proportion of fluorinated groups generally has better resistance to fuels, oils, and solvents. For example, in the automotive industry, FVMQ is used in fuel system components because of its ability to withstand contact with gasoline, diesel, and other fuels.
In addition to fuel resistance, FVMQ also shows good resistance to acids, bases, and other chemicals. However, the specific chemical resistance can be affected by the vulcanization method. Peroxide - vulcanized FVMQ often has better overall chemical resistance compared to bisphenol - vulcanized FVMQ, especially in harsh chemical environments.
Temperature Resistance
Fluorosilicone FVMQ is known for its wide temperature range performance. Different types of FVMQ can have different temperature resistance capabilities.
Bisphenol - vulcanized FVMQ can typically operate in a temperature range of - 50°C to 200°C. It can withstand short - term exposure to higher temperatures, but long - term exposure to temperatures above 200°C may cause degradation of its properties.
Peroxide - vulcanized FVMQ, on the other hand, has better high - temperature resistance. It can operate continuously at temperatures up to 250°C and can withstand short - term exposure to even higher temperatures. This makes it suitable for applications in high - temperature environments, such as in aerospace and industrial ovens.
Applications
The differences in properties between different types of fluorosilicone FVMQ lead to different application areas.
Bisphenol - Vulcanized FVMQ Applications
Due to its good compression set resistance and mechanical properties at lower temperatures, bisphenol - vulcanized FVMQ is commonly used in automotive sealing applications. It is used in gaskets, O - rings, and other sealing components in engines, transmissions, and fuel systems. It is also used in some consumer products, such as seals in household appliances, where the temperature requirements are not extremely high.
Peroxide - Vulcanized FVMQ Applications
Peroxide - vulcanized FVMQ's excellent high - temperature and chemical resistance make it ideal for aerospace applications. It is used in seals, gaskets, and hoses in aircraft engines and fuel systems. In the industrial sector, it is used in high - temperature processing equipment, such as in chemical plants and power generation facilities.
Conclusion
In conclusion, different types of fluorosilicone FVMQ have distinct differences in chemical composition, vulcanization methods, physical and mechanical properties, chemical resistance, and temperature resistance. These differences determine their suitability for various applications.
As a fluorosilicone FVMQ supplier, I understand the importance of choosing the right type of rubber for your specific needs. Whether you require a rubber with excellent compression set resistance for a sealing application or one with high - temperature resistance for a harsh environment, we can provide you with the appropriate FVMQ product.
If you are interested in purchasing fluorosilicone FVMQ or have any questions about our products, please feel free to contact us for further discussion. We are committed to providing high - quality products and professional technical support to meet your requirements.
References
- "Handbook of Elastomers" by B. D. Cullity
- "Rubber Technology" by Maurice Morton
- Industry reports on fluorosilicone rubber applications and properties