Silicone adhesives are available as both one part and
two part adhesives. Silicone adhesives are typically cure via reaction with ambient
humidity, although formulations are also available which can be cured by heat, mixing
of two components, or exposure to ultraviolet light. Silicones have good adhesion to many
substrates, but are limited in their utility as structural adhesives by their low cohesive
The one-part versions
, known as RTV silicones (room temperature
vulcanizing) are used most often as caulking and gasketing materials.
(RTV silicones) are one-component, solvent-free,
moisture curable compounds that cure to an elastic mass by absorption of moisture from
the air. Silicone sealants show excellent resistance to UV rays, various media and high
temperatures. The temperature resistance lies between -73°C and +260°C depending on the
product's formulation. The maximum admissible permanent movement is 25%. Silicone sealants
cannot be painted over..
Two part silicones
offer higher performance, and can be used for bonding
metal glass and ceramic components, especially used in the electronics industry. The
primary advantage of silicone adhesives and sealants are their temperature resistance.
Silicones can be formulated to withstand temperatures as high as 260°C, but provide
flexible bond lines or sealing throughout their service range.