To grasp the multitude of ways silicone rubber can be used, it is important to realise its origins. In this blog, we take a look at where silicone comes from to understand more about its characteristics.

What are the difference types of silicone rubber?

To understand what silicone is you first need to know the different types of rubber available. In its purest form, natural rubber is more commonly recognised as latex and actually comes directly from a rubber tree. These trees were first discovered in South America and usage of the rubber from within them dates back to the Olmec culture (Olmec literally means “Rubber People”!).

Anything which is not formed from this natural rubber is therefore man-made and is known as synthetic.

A new substance made by mixing various materials together is called a synthetic polymer. If the polymer displays elastic properties, it is identified as an elastomer.

What is silicone rubber made from?

Silicone is identified as a synthetic elastomer as it is a polymer which displays viscoelasticity – that is to say it shows both viscosity and elasticity. Colloquially people call these elastic characteristics rubber.

Silicone itself is made up of carbon, hydrogen, oxygen and silicon. Note that the ingredient contained within silicone is spelt differently. The ingredient silicon comes from silica which is derived from sand. The process to make silicon is complex and involves many stages. This arduous process contributes to silicone rubber’s premium price compared to natural rubber.

The silicone-making process involves extracting silicon from silica and passing it through hydrocarbons. It’s then mixed with the other chemicals to create silicone.

How is silicone rubber made?

Silicone rubber is a combination of an inorganic Si-O backbone, with organic functional groups attached.  The silicon-oxygen bond gives silicone its high temperature resistance and flexibility over a wide range of temperatures.

The silicone polymer is mixed with reinforcing fillers and processing aids to form a stiff gum, which can then be crosslinked at elevated temperature using either peroxides or polyaddition curing.  Once crosslinked the silicone becomes a solid, elastomeric material.