Fluorosilicone (FVMQ) is a type of elastomer composed of a silicone polymer chain with additional fluorinated side chains. It is a modified form of silicone that offers remarkable stability, excellent resistance to compression set under extreme temperatures, and enhanced protection against non-polar solvents, fuels, oils, acids, and alkaline chemicals. This material is widely used in various industrial, automotive, and aerospace applications where there is a need for static sealing and cushioning.
Properties of Fluorosilicone
Fluorosilicone contains trifluoro propyl groups that make it highly versatile for outdoor sealing applications or environments with frequent exposure to sunlight, ozone, chlorination, or aromatic hydrocarbons. Here are the key properties of fluorosilicone:
- Temperature range: -60 to 200°C
- Compression set: Fair/good
- Strength: Fair
- Low-temperature properties: Excellent
- Abrasion resistance: Poor
- Gas permeability: Fair
- Weather resistance: Excellent
- Water resistance: Excellent
- Ozone resistance: Excellent
- Mineral oil resistance: Excellent
- Chemical resistance: Excellent
- Flame resistance: Excellent
- Heat resistance: Excellent
Additionally, this material is known for being exceptionally clean, with low odor and taste, and it demonstrates superior color stability.
Advantages of Fluorosilicone
Fluorosilicone combines the advantageous properties of both fluorocarbons and silicones. Here are the properties and benefits of fluorosilicone rubber:
Solvent Resistance: FVMQ elastomers exhibit exceptional resistance to solvents. They are an excellent choice for applications requiring resistance to oxidizing chemicals, as well as aromatic and chlorinated solvent bases.
Oil Resistance: Fluorosilicones provide the highest level of fuel resistance among popular elastomers. This makes them ideal for static seals in aerospace fuel systems.
Extreme Temperature Performance: Fluorosilicone elastomer seals demonstrate remarkable resistance to low temperatures, with usability down to -80°C. They also maintain stability at high temperatures, making them perfect for aviation applications. FFKM O-Rings, which are made from fluorosilicone, exhibit high thermal and chemical resistance, making them well-suited for chemical applications.
Resilience: FVMQ elastomer is a resilient compound that offers low compression set characteristics. This is crucial because the elastomer retains its shape under strain, ensuring the sealing force remains intact and reducing the risk of leaks.
Disadvantages Of Fluorosilicone
Before you decide to use fluorosilicone, there are certain drawbacks that you should be aware of. Let’s discuss them.
First, Fluorosilicone is known to be expensive. This is primarily due to the complex and time-consuming synthesis process of the fluorosilicone rubber monomer. Additionally, the inclusion of fluorine-containing groups increases the difficulty of the vulcanization process, leading to high production costs.
Secondly, fluorosilicone is not well-suited for environments that require abrasion resistance. It may not perform optimally when subjected to abrasive conditions.
Thirdly, although fluorosilicone exhibits strong chemical resistance overall, it may not fare well against substances such as brake fluids, ketones, hydrazine, amines, aldehydes, and ketones.
Therefore, it is important to consider these limitations before utilizing fluorosilicone in your applications.
Applications
Fluorosilicone is commonly utilized in aerospace fuel systems due to its exceptional resistance properties. It is also frequently employed in static sealing applications and automotive fuel systems.
The unique characteristics of fluorosilicone make it well-suited for sealing solutions in engines, machinery, and other mechanical systems. Some of the common components for fluorosilicone sealing include:
O-rings: These ring-shaped seals are typically placed within a groove on one or both of the connected parts, creating a seal that blocks the escape of air and fluids. O-rings fill the space between the coupled components.
Gaskets: Gaskets serve as flexible seals between two joined components. They are usually flat and relatively thin, with bolt or pin penetrations through them. When compressed between two flat surfaces, gaskets provide sealing as well as vibration control.
Seals: This term encompasses various components that prevent fluid or air leakage, block contaminants, or maintain pressure. O-rings and gaskets are examples of seals. However, the term is generally used for sealing solutions specific to certain applications, held in place by compression. For instance, oil seals are found in engines.
Tubing: O-rings, gaskets, and seals occupy the space between two connected parts in a machine or engine, enabling the transfer of fluids or air between them without any leakage. In addition to preventing fluid and vapor leakage, these components safeguard mechanical systems from debris and maintain consistent pressures to ensure optimal performance.
Fluorosilicone is suitable for a wide range of applications due to its unmatched flexibility and thermal and environmental stability. For more information, contact A1 Silicones