Silicones chemistry is one of the most versatile chemistries on the planet, rendering it full of possibilities and producing a wide range of formulations and uses from aesthetic to technical. Due to their molecular structure, silicones have an exceptional breadth of chemical and physical properties and can be manufactured in more than 2,000 different forms including solids, liquids, semi-viscous pastes, greases, oils and rubber. Silicones are important components of countless popular everyday products.
Silicone production starts from sand or quartz (silica); after use they eventually decompose back to sand. The first step in making silicones is the retrieval of the element silicon from silica, the second most abundant element found in the earth’s crust and the raw material from which all silicone chemistry finds it roots.
From silicon to silicone. Silicones are not to be confused with the chemical element silicon, a crystalline metalloid widely used in computers and other electronic equipment. In contrast, silicones not only contain silicon atoms but also oxygen, carbon and hydrogen and thus possess different chemical and physical properties than elemental silicon. Although they contain organic components, silicones are generally more stable and inert than typical organic substances.
SiO2 + C ==> Si + CO2
CH3 OH + HCl ==> CH3Cl + H2O
By reacting silicon with methyl chloride, the first step within a complicated sequence of chemical reactions to form silicones is performed. These reactions form a wide variety of polymeric chains and networks constructed around a backbone of Si-O-Si repeating units. The repeating units of the polymer explain the versatility of silicones, lending them an exceptional breadth of chemical and physical properties, including solids, liquids, greases, oils, resins and rubber (elastomers). Modifying the silicon molecule through the addition of carbon molecules produces polymers that in essence combine the physical qualities of a metal with the diversity of plastics. Thus, silicone chemistry makes it possible to create multi-purpose and flexible products, as well as products which can withstand extreme temperatures without the risk of disintegrating or losing their shape.