Silicones are a type of synthetic polymer, a material made of smaller, repeating chemical units called monomers that are bonded together in long chains. Silicone consists of a silicon-oxygen backbone, with “sidechains” consisting of hydrogen and/or hydrocarbon groups attached to the silicon atoms. Because its backbone does not contain carbon, silicone is considered an inorganic polymer, which differs from the many organic polymers whose backbones are made of carbon.

The silicon-oxygen bonds in the silicone backbone are highly stable, binding together more strongly than the carbon-carbon bonds present in many other polymers. Thus, silicone tends to be more resistant to heat than conventional, organic polymers.

Silicone’s sidechains render the polymer hydrophobic, making it useful for applications that may require repelling water. The sidechains, which most commonly consist of methyl groups, also make it difficult for silicone to react with other chemicals and prevents it from sticking to many surfaces. These properties can be tuned by changing the chemical groups attached to the silicon-oxygen backbone.

Silicone in Everyday Life

Silicone is durable, easy to manufacture, and stable over a wide range of chemicals and temperatures. For these reasons, silicone has been highly commercialized and is used in many industries, including automotive, construction, energy, electronics, chemical, coatings, textiles, and personal care. The polymer also has a variety of other applications, ranging from additives to printing inks to the ingredients found deodorants.

Discovery of Silicone

The chemist Frederic Kipping first coined the term “silicone” to describe compounds he was making and studying in his laboratory. He reasoned that he should be able to make compounds similar to the ones that could be made with carbon and hydrogen, since silicon and carbon shared many similarities. The formal name for describing these compounds was “silicoketone,” which he shortened to silicone.

Kipping was far more interested in accumulating observations about these compounds than figuring out exactly how they worked. He spent many years preparing and naming them. Other scientists would help discover the fundamental mechanisms behind silicones.

In the 1930s, a scientist from the company Corning Glass Works was trying to find a proper material to include in insulation for electrical parts. Silicone worked for the application due to its ability to solidify under heat. This first commercial development led silicone to be widely manufactured.

Silicone vs. Silicon vs. Silica

Though “silicone” and “silicon” are spelled similarly, they are not the same.

Silicone contains silicon, an atomic element with an atomic number of 14. Silicon is a naturally occurring element with many uses, most notably as a semiconductors in electronics. Silicone, on the other hand, is manmade and does not conduct electricity, as it is an insulator. Silicone cannot be used as part of a chip inside a cell phone, though it is a popular material for cell phone cases.

"Silica," which sounds like “silicon,” refers to a molecule consisting of a silicon atom joined to two oxygen atoms. Quartz is made of silica.