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Silicones are synthetic polymers made from the products of nature. Although "silicone" is often used as a generic term for nearly all substances that contain a silicon atom, it is more properly described as an entirely synthetic polymer containing a Si-O backbone. To this backbone, organic groups are frequently attached to the silicon atoms via a Si-C bond. This general description defines the broad class of polymers known as silicones. The most common example is PDMS. This polymer has a repeating (CH3)2SiO unit. These materials are the basic building blocks of the silicone industry. Depending upon the number of repeat units in the polymer chain and the degree of cross-linking, at least six classes of commercially important products such as:
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- Fluids
- Emulsions
- Compounds
- Lubricants
- Resins
- Elastomers or rubbers
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Polymerization: |
Linear/ cyclic siloxane oligomers formed in the reaction.These are the basic raw materials (monomers) from which a host of useful silicone products can be made.
The process of conversion is called polymerization. It occurs by ring opening and/or condensation in the presence of an acid or base catalyst to form silicone fluids. During this reaction, which is commonly known as equilibration, the SiO bonds are constantly cleaved and reformed in a series of competing reactions involving both cyclic and linear species - building up molecular structure until an equilibrium distribution is reached. |
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| Silicones uses: |
Silicones are highly valued materials because they have a combination of physical properties not found in other polymers. They have outstanding heat stability and can be used in applications where organic materials would melt or decompose. Many silicones seem to be impervious to the effects of aging, weather, sunlight, moisture, heat, cold, and some chemical assaults. Some silicones are used to stick, bond, or couple things together – a glue.However, unique surface properties make silicones really different from other materials.
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Silicone fluids applications such as:
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