Silicone - Silicone Rubber (Si)

Typical Trade Names:

• Silastic - Dow Corning Corp.
• No trade name - General Electric
• No trade name - Union Carbide & Carbon
• No trade name - Stauffer Chemical Company

The silicones are a group of elastomeric materials made from silicone, oxygen, hydrogen and carbon. As a group, the silicones have poor tensil strength, tear resistance and abrasion resistance. Special compounds have been made which have exceptional heat and compression set resistance. High strength compounds have also been developed but their strength does not compare to conventional rubber. Silicones possess excellent resistance to temperature extremes. Flexibility below -175 degrees FR (-114 degrees C) has been demonstrated and Parker has compounded silicone materials which will resist temperatures to 700 degrees F (371 degrees C) for short periods. The maximum temperature at which silicones are recommended for continuous service in dry air is 450 degrees F (232 degrees C). Silicone's retention of properties at these high temperatures is superior to other elastic materials.

Silicone compounds are not normally recommended for dynamic sealing applications due to relatively low strength and high coefficient of friction.

Many silicone compounds have a higher than normal mold shrinkage that results in finished parts being under-size when produced in standard molds.

Silicones are recommended for:

• High-aniline point oils
• Dry heat
• Chlorinated di-phenyls

Silicones are not recommended for:

• Most petroleum fluids
• Ketones (MEK, acetone)