What is silicone? how is it made?

What is silicone?

In our daily life, there are many common silicone products. Such as silicone nipple, silicone baking molds, silicone gloves, silicone dinnerware and etc. There are also silicone straws in the juice machine, silicone seal gasket in the industrial machine. Peoples may ask what’s silicone? And what’s silicon, silica?

Silicon

Silicon is not the same thing as silicone. Silicon is one element in the periodic table, abbreviated to “Si”. Its atomic number is 14, and the atomic mass ratio is 28.085. Silicon belongs to the third period on the periodic table of the IVA group of metal-like elements。

Silicon is an extremely common element in nature. It rarely appears as element form in nature, most widely found in rocks, gravel, and dust in the form of complex silicates or silicon dioxide. Such as Feldspar KAlSi₃O₈, kaolin Al₂Si₂O₅(OH)₄, talc Mg₃(Si₄O₁₀)(OH)₂, mica KAl₂(AlSi₃O₁₀)(OH)₂, asbestos H₄Mg₃Si₂O₉ and etc. In the earth’s crust, silicon is the second most abundant element (weight ratio is 26.4%), follow the oxygen (49.4%)

Silica:

Silicon is a metalloid element. Silicon can be oxidization to silicon dioxide like metal elements. This silicon dioxide is also known as silica. So Silica is silicon dioxide, with the chemical formula: SiO₂. Si(Silicon) can be oxidized reaction to SiO₂(Silica / Silicon dioxide). SiO₂ can also redox reaction to Si. We just need to provide suit chemical reaction conditions.

Silicone:

Silicone is also known as siloxanes or silicone polymer. It is a man-made polymer made up of silicon (Si), oxygen (O), carbon (C), and hydrogen (H). Silicones polymer is produced to chemical forms including Silicone Oil, Silicon Resin, and Silicone Rubber. They depend on molecular length, weight, and molecular construction (linear or mesh). The key functional group is in the Quora images as follows.

Silicone Oil is one kind of oligomer. Silicone oil is non-volatile, non-congealable, low-viscosity, and insulation at 200℃. So it’s high-quality lubricating oil especially used in the high-temperature machine system.

Silicon Resin has mesh and 3D construction. It’s flexible resin, can resist high-temperature and especially good electrical insulator. It can be used as the insulation coating material, adhesions, and so on.

Silicone Rubber includes Liquid Silicone Rubber(LSR), which are mainly used in the injection molds machine to make silicone products, such as silicone nipper and transparent silicone straws. And there’s also the solid silicone rubber, need to process in the rubber mixing mill, then heating pressure and vulcanized to silicone products, such as the silicone baking mold, silicone gloves, silicone cups and etc.

So the silicone products on our website are also called silicone rubber. The silicone rubber products are made from natural silicon dioxide.

How is silicone made?

The normal chemical synthesis of the silicone polymer is the direct synthesis process. That’s Silicon (Si) powder and halohydrocarbon (dichloromethane (CH₃Cl)or chlorobenzene(C₆H₅Cl )) reaction at high-temperature and catalyst conditions, get the mixed product Alkyl halosilane(main is R₂SiCl₂ and RSiCl₃).

When we want to make Silicone Rubber, we need high purity of halosilane (CH₃)₂SiCl₂, purity ratio about 99.9%. The halosilane is extremely easy hydrolysis to silanol (CH₃)₂Si(OH)₂. Silanol vulcanized to silicone rubber by the condition of high-temperature, vulcanizing agent, and filler.

While the silicon resin is the special ratio of halosilane (CH₃)₂SiCl₂ and CH₃SiCl₃ mixture hydrolysis and condensation polymerization reaction to the mesh polymer.

In the next article, we share how to make silicone rubber products in our factory.

We share some silicone rubber products for your reference.