SILICONE RUBBER
| DESCRIPTION |
| Silicone rubber is an inorganic rubber that's superior to most other materials in the ability to retain its physical properties at elevated temperatures. It is also flexible at exceptionally low operating temperatures, though its relatively poor tensile strength, tear strength and resistance to abrasion reduces its use to static applications. These shortcomings can be ameliorated to a degree by reinforcement with fine, high surface area fillers, which are chemically compatible with the silicone polymer itself. Silicone does possess exceptional resistance to ozone and oxidation degradation because of the absence of unsaturated double bonds in the polymer backbone. Only peroxides can be used for hot vulcanization processes, because it is fully saturated. Resistance of silicone vulcanizates to gas permeation is widely considered poor, as much as 100 times greater than nitrile or butyl. However, since it does not impart any taste or odor, silicone rubber is frequently designated for food and beverage applications. |
| COMPOSITION |
| Medium density inorganic rubber consisting primarily of polymethylsiloxane and variations. |
| 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 |
| Dilute acids | • | |||
| Dilute alkalis | • | |||
| Ketones | • | |||
| Ozone | • | |||
| Petroleum oils | • | |||
| Steam | • | |||
| Vegetable oils | • | |||
| Water | • | |||
| Weather | • |
| OPERATING TEMPERATURE |
| -65 to 400 °F |
*Excellent, good, fair and poor are general guidelines only. Actual testing in the application environment is always recommended.
