What's the Difference Between Silicone and Fluorosilicone?

Silicone and fluorosilicone are two types of elastomers that are commonly used in a variety of applications. While they are both made from oxygen, carbon, and hydrogen, they differ in their chemical makeup and properties.

One of the main differences between silicone and fluorosilicone is the type of polymer chain they contain. Silicone is made from a silicone polymer chain, while fluorosilicone is made from a fluoro silicone polymer chain. The fluoro silicone polymer chain contains fluorine atoms, which give fluorosilicone unique chemical and physical properties compared to regular silicone.

One of the most notable differences between the two is their resistance to heat and chemical degradation. Silicone has a relatively low resistance to heat and can start to break down at temperatures above 300°F (149°C). In contrast, fluorosilicone has a much higher resistance to heat and can withstand temperatures up to 400°F (204°C) before breaking down. Fluorosilicone is also more resistant to chemical degradation and can withstand exposure to a wider range of chemicals compared to regular silicone.

Another difference between silicone and fluorosilicone is their mechanical properties. Silicone is known for its excellent flexibility and elongation, making it ideal for applications that require a material to be stretched and deformed. Fluorosilicone, on the other hand, has lower flexibility and elongation compared to silicone but higher tensile strength and tear resistance. This makes fluorosilicone suitable for applications that require a strong and durable material.

In terms of durability, fluorosilicone tends to have a longer lifespan compared to regular silicone. This is because it is more resistant to heat and chemical degradation, which can cause silicone to break down over time. Fluorosilicone is also less prone to swelling and shrinking, making it more stable in different environments.

Hardness is another key difference between silicone and fluorosilicone. Silicone typically has a shore hardness of anywhere from 20 to 80 on the Shore A scale, while fluorosilicone can range from 40 to 80. The higher the number, the harder and more rigid the material is.

Another main difference between silicone and fluorosilicone is their FDA compatibility. Silicone is generally regarded as food-safe and can be used for a wide range of applications, including seals and gaskets in contact with foodstuffs. Fluorosilicone, on the other hand, is not typically approved by the FDA for use in contact with food.

Silicone and fluorosilicone have different uses depending on their properties. Silicone is commonly used in a wide range of applications, including seals, gaskets, hoses, and medical devices, due to its excellent flexibility and elongation. Fluorosilicone is primarily used in aerospace, automotive, and oil and gas industries, where its heat and chemical-degradation resistance are needed. Fluorosilicone is also used in applications where a strong and durable material is needed, such as O-rings, seals, and gaskets.