Nitrile, also referred to as Buna-N, rubber is one of many synthetic rubbers used to manufacture gaskets and seals. Nitrile rubber (also known as NBR) is a family of unsaturated copolymers of propenenitrile and certain butadiene monomers. Nitrile rubbers generally have good resistance to oil, fuel, diluted acids, alkalies and many other types of chemicals. A general rule of thumb is the more nitrile within a polymer, the higher its oil resistance. However the tradeoff will be a lower amount of flexibility.
Automotive engines when operating properly tend to function around 195 to 205 Fahrenheit after they have warmed up. Operational ranges of nitrile rubber seals are -30 to 250 Fahrenheit, which make it an ideal candidate for engine gaskets and seals. Because it has resistance to oils and fuels, this gives nitrile the ability to resist swelling when see this type of exposure. The last thing you want to worry about during operation is for the gasket to swell and reduce its capability to properly seal. Nitrile rubber has also been used to manufacture o-rings for automotive air-condition systems.
The aerospace industry has to take into consideration everything involved with their design. Selecting a seal or gasket that can handle and withstand the repeated exposure to high temperatures and harsh conditions can be difficult and if the improperly material is chosen, it can lead to catastrophic failure. Nitrile’s ability to resist the elements makes it a prime material for aerospace industry.
Nitrile resistance qualities include, but not limited too.
- Petroleum oils
- Water (up to 212 Fahrenheit)
- Salt & Alkali solution
- Weak acids
- Certain chemicals