In order to grasp the multiple ways of silicone application and fabrication, it is critical to comprehend its origins. In this article, we will discover how to produce silicone and understand its characteristics.
What is Silicone Made of ?
Silicone is a versatile polymer, it has both viscosity and elasticity, this characteristic is visco-elasticity. Colloquially, people call these elastic material as rubber, so silicone is also known as silicone rubber. In nowadays, we apply silicone widely in elastomer, oils, greases, caulks and other materials.
As we know, silicone consists of carbon, hydrogen, oxygen and silicon. We should notice the important distinction between silicone and silicon. Silicon is a chemical element, its natural form is compound of Silica. However, Silicone refers to a wide class of polymer with siloxane bond(chemical formula -Si-O-Si-) and various attached organic compounds.
Common organic synthetic polymers consist of multiple carbon atoms with -C-C- bonds. While silicone is an inorganic synthetic polymer, it is main chain is repetition of silicon (Si) and oxygen (O) atoms with -Si-O-Si- bonds. Organic units combine with silicone molecules as side chains, in order to create various properties.
How is Silicone Produced?
The silicone production process includes extracting silicon from silica, combining silicon with hydrocarbons, then mixing with other chemicals to create silicone.
Step-by-step guide of silicone production:
- Isolate silicon from silica: At first, we will heat a large volume of quartz sand to high temperature as high as 1800℃. Then get pure and isolated silicon, cool down these silicons and grind into very fine powder.
- Combine silicone with methyl chloride: Combine the fine powder with methyl chloride, and heat these mixtures again. The heat temperature will trigger reaction in these components, then form the mixtures of methyl chlorosilane. Methyl chlorosilane is a mixture with different compounds, the essential component is dimethyldichlorosilane, which is the major block of silicone.
- Complex distillation: As different chlorosilanes have different boiling points, a complex distillation technology can separate the various components in methyl chlorosilanes. Precise temperature controlling in distillation process will get high concentration dimethyldichlorosilane.
- Water reaction: After distillation, we add water into dimethyldichilorosilane, then reaction into separate compounds of disilanol and hydrochloric acid. Then hydrochloric acid will act as a catalyst for the disianol, to condense into polydimethylsiloxane.
Polydimethylsiloxane contains the siloxane bond, this is the backbone of silicone. On this base, a variety of methods will polymerize different silicone, each method depends on desired properties of final silicone products.
The production of silicone is complex. However, mass scale production result to a relatively low cost. Versatile silicone is becoming the most popular elastomer for commercial and industrial applications.
How is Silicone Rubber Made?
Silicone rubber is a combination of Si-O backbones with organic functional groups. Furthermore, this silicon-oxygen bond in silicone gives it high temperature resistance and flexibility in a wide range of temperatures. Meanwhile, we can mix silicone polymer with reinforcing fillers and processing aids to form stiff gum, then apply peroxides or poly-addition to cure at elevated temperature. In this process, cross-linking is formed in silicone molecular level, silicone will become a solid and elastomeric material.
In Miwo, our engineering team apply advanced LSR molding technology to accelerate LSR curing process. In this curing process, platinum-catalyst is able to accelerate the solidification, and avoid any noxious by-products in vulcanization. We have 20,000 m2 facility in Dongguang, China. Our annual silicone rubber consumption reach to 20,000 tonnes. We have full trace-ability and account-ability of all production process, in order to ensure the highest quality management.
How is Silicone Rubber Made?
Silicone rubber is a combination of Si-O backbones with organic functional groups. Furthermore, this silicon-oxygen bond in silicone gives it high temperature resistance and flexibility in a wide range of temperatures. Meanwhile, we can mix silicone polymer with reinforcing fillers and processing aids to form stiff gum, then apply peroxides or poly-addition to cure at elevated temperature. In this process, cross-linking is formed in silicone molecular level, silicone will become a solid and elastomeric material.
In Miwo, our engineering team apply advanced LSR molding technology to accelerate LSR curing process. In this curing process, platinum-catalyst is able to accelerate the solidification, and avoid any noxious by-products in vulcanization. We have 20,000 m2 facility in Dongguang, China. Our annual silicone rubber consumption reach to 20,000 tonnes. We have full trace-ability and account-ability of all production process, in order to ensure the highest quality management.
What are the Benefits of Silicone?
The Silicone rubber production process and material composition make it popular for wide applications. It can withstand extreme fluctuations of temperature from -60℃ to 250 ℃. In addition, it also has excellent environmental resistance to Ozone, UV and other weathering stresses. This make it ideal for outdoor sealing and protection of electrical components. Silicone is a lightweight and versatile material, it is widely used to reduce vibrations, stabilize joints and decrease noise in mass transit applications, in order to increase customer comfort.
What is Silicone Melting Point?
Unlike other rubbers, silicone can withstand temperature extreme from above 250℃ to minus 60℃. Indeed, silicone rubber never melt once reach to melting points, no matter how hot it gets.
So what is the melting point of silicon? If we heat silicone to 150℃ for extended period, there is no change. However, once heat temperature reach to 250℃, it will become harder with less stretchy over long time. Meanwhile, it will quickly harden once in temperature of 300℃. Silicone rubber will never melt, even exposed to these high temperatures. We also need to notice that the ignition point of silicone is around 450℃, never heat silicone above this temperature.
What is the Difference between Rubber and Silicone Rubber ?
Silicone and rubber are all belong to the class of elastomer. They have similar characteristics, but there are several differing properties. The molecular structure of silicone and rubber are different. This difference is reaction to various environments.
Natural rubber can only withstand temperature of 80℃ before its melting and degrading. On the other hand, silicone can withstand temperature of 250℃. So silicone provides better flame resistance than natural rubber, it is the best choice for high temperature applications.
Silicone also has better resistance of chemical, weather and UV than rubber. In outdoor applications, rubber will break down extremely quickly, while silicone rubber can withstand environmental elements far more effectively.
To learn more information of silicone rubber, contact our engineering team now.
