Description
Hydrogenation of nitrile rubber removes most of the residual unsaturation in the polymer to make it far less vulnerable to attack by heat, ozone, and oxygen. In fact, due to superior oil and temperature resistance, Highly Saturated Nitrile can sometimes be substituted for more costly fluorocarbon rubber. It is frequently used in automotive air conditioning systems employing R-134a refrigerants. HNBR can be can be either peroxide or sulfur cured, depending on the degree of unsaturation achieved by the hydrogenation process, but peroxide is almost always used due to the good heat stabiIity properties of the peroxide crosslinks. It can be compounded for both low and high temperature use.
Composition
Highly Saturated Nitrile
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 |
| Automatic transmission fluid |
• |
|
|
|
| Automotive refrigerants |
• |
|
|
|
| Oxygenated fuels |
|
• |
|
|
| Ozone |
|
|
• |
|
| Petroleum oils |
• |
|
|
|
| Sour crude oil |
|
• |
|
|
| Weather |
|
|
• |
|
Operating Temperature
-40 to 300 °F
*Excellent, good, fair and poor are intended to serve as general guidelines only. Actual testing in the application environment is always recommended. |