Materials

Silicone Rubber

Description

Silicone Rubber is an inorganic rubber whose ability to retain its physical properties at elevated temperatures is superior to most other materials. It is also flexible at very low temperatures however its relatively poor tensile, tear strength and abrasion resistance limits use to static applications. These weaknesses can be improved somewhat by reinforcement with fine, high surface area fillers which are compatible chemically with the silicone polymer itself. Silicone does possess extraordinary resistance to oxidation and ozone degradation due to the absence of unsaturated double bonds in the polymer backbone. Since it is fully saturated, only peroxides can be used for hot vulcanization processes. Resistance of silicone vulcanizates to gas permeation is generally considered to be poor, as much as 100 times greater than nitrile or butyl, but it is frequently specified in food and beverage applications as it does not impart any taste or odor. However, the automotive industry accounts for almost 50% of silicone usage in the U.S. annually.

Composition

Silicone Rubber

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 450 °F
*Excellent, good, fair and poor are intended to serve as general guidelines only. Actual testing in the application environment is always recommended.