Fluoroelastomer vs. HNBR

Attribute	Fluoroelastomer	HNBR
Chemical Resistance	Excellent resistance to chemicals, oils, and fuels	Good resistance to chemicals, oils, and fuels
Temperature Range	Can withstand high temperatures up to 200°C	Can withstand high temperatures up to 150°C
Compression Set	Low compression set	Higher compression set compared to Fluoroelastomer
Cost	Generally more expensive	Generally less expensive

Introduction

Fluoroelastomer and Hydrogenated Nitrile Butadiene Rubber (HNBR) are two popular elastomers used in various industries due to their excellent chemical resistance, high temperature stability, and durability. While both materials have similar properties, there are key differences that make them suitable for different applications.

Chemical Composition

Fluoroelastomers are made from fluorinated hydrocarbon polymers, such as vinylidene fluoride (VDF) and hexafluoropropylene (HFP). These polymers provide excellent resistance to chemicals, oils, and high temperatures. On the other hand, HNBR is a hydrogenated version of Nitrile Butadiene Rubber (NBR), which contains a higher percentage of hydrogen atoms. This hydrogenation process improves the material's resistance to heat, ozone, and chemicals.

Temperature Resistance

Fluoroelastomers are known for their exceptional temperature resistance, with the ability to withstand temperatures ranging from -20°C to 200°C. This makes them ideal for applications in harsh environments where high temperatures are a concern. HNBR, on the other hand, has a slightly lower temperature resistance compared to fluoroelastomers, with a working temperature range of -40°C to 150°C. While HNBR can still handle high temperatures, it may not be suitable for extreme heat applications.

Chemical Resistance

Both fluoroelastomers and HNBR exhibit excellent chemical resistance, making them suitable for use in industries where exposure to harsh chemicals is common. Fluoroelastomers are particularly resistant to acids, bases, fuels, and solvents, making them a popular choice for applications in the automotive, aerospace, and oil and gas industries. HNBR, on the other hand, is known for its resistance to oil, fuel, and hydraulic fluids, making it a preferred material for seals and gaskets in automotive and industrial applications.

Compression Set

Compression set refers to the ability of an elastomer to return to its original shape after being compressed. Fluoroelastomers have a low compression set, meaning they can maintain their shape and sealing properties over time. This makes them ideal for applications where long-term performance is critical. HNBR, on the other hand, has a higher compression set compared to fluoroelastomers, which may affect its sealing capabilities over time. However, HNBR can still provide good sealing performance in many applications.

Abrasion Resistance

Abrasion resistance is an important property for elastomers used in applications where wear and tear are common. Fluoroelastomers have excellent abrasion resistance, making them suitable for use in dynamic sealing applications where friction is a concern. HNBR, on the other hand, also exhibits good abrasion resistance, although it may not be as high as fluoroelastomers. Depending on the specific application requirements, either material can be chosen for its abrasion resistance properties.

Conclusion

In conclusion, both fluoroelastomers and HNBR offer excellent chemical resistance, temperature stability, and durability, making them versatile materials for a wide range of applications. While fluoroelastomers excel in high-temperature environments and harsh chemical exposures, HNBR is preferred for its resistance to oil, fuel, and hydraulic fluids. Understanding the specific requirements of the application is crucial in selecting the right material for optimal performance and longevity.