NITRILE RUBBER
| DESCRIPTION |
| Based on cost, nitrile rubber (or NBR) is the least expensive of all oil resistant elastomers. Given its low cost, resistance to many chemicals, and good physical properties, nitrile is one of the most popular rubber materials. The acrylonitrile content of this highly polar elastomer offers outstanding oil and gas permeation resistance, which also increases as the ACN level increases. Unfortunately, increased acrylonitrile content compromises low temperature flexibility while it increases compound hardness. Typical ACN content ranges between 18% to 50%. Nitrile should not be exposed to moderate to high levels of atmospheric ozone or direct sunlight, which results in rapid deterioration. However, NBR accepts many antidegradants, notably PVC, which offer a degree of improvement of these properties. Nitriles are typically sulfur cured, but peroxide curing is possible as well, which results in improved compression set. |
| COMPOSITION |
| Medium density copolymer of butadiene and acrylonitrile |
| PHYSICAL PROPERTIES* | Excellent | Good | Fair | Poor |
| Abrasion resistance | • | |||
| Compression set | • | |||
| Elongation | • | |||
| Flame resistance | • | |||
| Gas permeability | • | |||
| Low temperature flexibility | • | |||
| Tear resistance | • | |||
| Tensile strength | • |
| CHEMICAL RESISTANCE* | Excellent | Good | Fair | Poor |
| Brake fluid | • | |||
| Dilute acids | • | |||
| Dilute alkalis | • | |||
| Hydraulic fluids | • | |||
| Ketones | • | |||
| Ozone | • | |||
| Petroleum oils | • | |||
| Silicone fluids | • | |||
| Steam | • | |||
| Strong acids | • | |||
| Transmission fluids | • | |||
| Water | • | |||
| Weather | • |
| OPERATING TEMPERATURE |
| -30 to 250 °F |
*Excellent, good, fair and poor are general guidelines only. Actual testing in the application environment is always recommended.
