Silane chemistry
Silanes are the basic building blocks of silicone chemistry. A silane is a
monomer with a chemical formula:
The epitome of versatility
R1, R2, R3, and R4 represent the
four chemical groups attached to the silicon atom. These groups can be:
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The same or different
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Reactive or non-reactive
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And the reactivity (if present) can be either organic or inorganic
This large number of possible combinations explains the versatility of
silanes and their ability to be used in a variety of ways with carbon-based
chemicals.
Inorganic reactivity
When inorganic reactive groups, such as chlorine, methoxy, or ethoxy
are directly attached to silicon atoms, they will hydrolyze in the presence of
water. They will then self-condense to form a stable siloxane structure ... or
bond to hydroxyl groups on the surface of inorganic materials, such as glass,
minerals, and metals.
Organic reactivity
A silane containing at least one carbon-silicon bond is known as an
organosilane. Specific organic reactivity can be built into a silane to
match the reactivity of specific organic materials.
Adding organically reactive groups, such as amino, chloro, epoxy, or
methacrylate, to silicon gives the molecule the potential to replicate organic
reactions.
By adding organically non-reactive groups, such as methyl, higher
alkyls, cycloalkyls, phenyl, or trifuoropropyl, desirable characteristics such
as hydrophobicity, organic compatibility, thermal stability, and solvent
resistance can be added to the silane molecule.
Dual reactivity
Silanes with both inorganic and organic reactivity act as coupling agents
and are used to chemically adhere generally incompatible substrates.
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