NBR O-Rings

Nitrile rubber, often referred to as Buna N, is the most widely utilized elastomer for O-rings and various sealing applications. It is a copolymer composed of butadiene and acrylonitrile (ACN). The term “Buna N” is derived from “butadiene” and “natrium,” the Latin word for sodium, which is the catalyst used in the polymerization of butadiene. The “N” in Buna N represents acrylonitrile.

The butadiene component provides elasticity and low temperature flexibility. It also contains an unsaturated double Nitrile – Buna N Polybutadiene-acrylonitrile Molecular structure of nitrile bond crucial for crosslinking or vulcanization. However, this same double bond is susceptible to heat, chemicals, and oxidation.