THE ENDLESS POSSIBILITIES OF RUBBER
Nitrile Butadiene Rubber, NBR
The Rubber: |
First introduced to the market by Bayer in 1930 under the name Buna-N. |
Resistance and properties: |
Based on 2 monomers, acrylonitrile and butadiene. The higher the acrylonitrile content, the more resistant the elastomer is to aliphatic hydrocarbons. The lower the ACN content, the better it resists low temperatures. A subdivision can be made: High ACN content, higher than 45% Medium ACN content, between 30% and 45% Low ACN content, lower than 30% Gas permeability is low. Low compression set, heat ageing, ozone resistance and abrasion resistance can be improved by means of special compounding. Normally usable up to +100 deg C, and with special compounding up to around +120 deg C. This is an inexpensive rubber with high resistance to aliphatic hydrocarbons, oils and fuels. However, resistance to aromatic oils is poor. |
Downsides: |
Not ozone or weather resistant. Not resistant to aromatic oils, chlorinated hydrocarbons (trichloroethylene) or strong acids. |
Applications: | Frequently used for hydraulic and fuel seals. |