There is no way you can choose the right silicone rubber for yourself if you don’t understand where silicone rubber comes from. Many people search to understand this daily, so this article is here to give you a solution.
Meaning of Silicone Rubber
Silicone rubber is a versatile material with a unique backbone of silicon-based compounds that make it stretch and bend without breaking or brittle. As durable and elastic as it is, it maintains good stability across various temperature ranges from −55 to 300 °C (−70 to 570 °F). Silicone rubber combines flexibility, chemical, UV radiation, and heat resistance. What this means is that you can use silicone rubber in various applications and various hostile environments.
Origin Of Silicone Rubber
The first silicone rubber was developed in the 19th century (the year 1824 to be precise) by a Swedish chemist known as Jöns Jackob Berzelius. He discovered silicone rubber when he used potassium to isolate only silicon.
After the isolation, Jöns Jackob Berzelius further used chlorine to heat the silicon which then gave the silicon rigorous combustion. After all these processes are done, silicon tetrachloride comes as a result of the above process.
You might ask yourself what this material is used for. Well, silicon tetrachloride is part of the material you can use to manufacture silicone in today’s world.
Since then, there has been rigorous research and refining by different chemists to discover the chemistry of silicon to manufacture various types of silicone rubber for industrial and everyday use.
Raw Materials Used For Silicone Rubber
Silicon
Silicon is the second most surplus natural compound you’ll find in sand and rocks. It’s a chemical element with the symbol Si and belongs to the atomic number 14 category. Due to its shiny, gray metallic luster, tetravalent metalloid, and semiconductor, you cannot underestimate silicon’s usefulness in the mineral world.
Silicon is also the main material used to manufacture silicone. Although it does not usually come in pure form. However, you need to first extract silicon from silica after you have extracted them, the next thing is to isolate them.
The purpose of the isolation is to remove the materials from impurities to ensure they meet the standard of manufacturing silicone rubber. However, you need to make sure there is enough silicon in the silica in order not to complicate the production of your silicone rubber.
Oxygen
Oxygen is the hero behind the unique properties of silicone. It features a molecular structure that encompasses silicone and oxygen atoms, the purpose of this is to form a siloxane backbone which is usually represented with a symbol (Si-O-Si). Of course, you would want to choose Si-O bonds over carbon-based bonds due to their strongness.
The strongness contributes to silicone’s excellent flexibility, durability, and ability to resist various environmental factors and extreme temperatures. Additionally, oxygen is a chemical element that’s usually represented by the symbol O with the atomic number 8. They have a molecular structure that features alternating silicon and oxygen atoms, and they are also resistant to UV radiation, ozone, and oxidative aging.
How Silicone Rubber Is Made
Silicon Extraction From Silica Through High Heat
As stated earlier, silicon is the material for making silicone rubber. The first thing you need to do is to find them from Sand and rocks. Then you can separate the silicon from impurities by heating the silica at a high temperature. This process is necessary if you want the highest quality silica.
For you to extract silicon, you need an environment that has enough carbon or magnesium. Not only that but it must also be done in a high or low-temperature environment. This process automatically separates silicon from silica, then there’s the formation of molten mass. The next thing to do is to get pure silicon by further processing it. After all these processes you will have a result of silicon molecules which you can use to manufacture silicone rubber in different industries.
Mix Silicone and Methyl Chloride
In this stage, you need to combine methyl chloride to purify the silicon to start a chemical reaction. The purpose of adding methyl chloride is to act as a melting agent, to quicken the inclusion of methyl groups (CH3) to the silicon atoms.
Stylish methyl chlorosilanes are derived from silicon reaction, this reaction cannot be underestimated when you are manufacturing silicone polymers. Next, flexibility is obtained from the chemical structure of the silicone rubber when it changes due to the attachment of the methyl groups to the silicon atoms. A base is formed after this step for the elastomer to take shape. This is commercially called silicone rubber.
Formulate Siloxane Polymers
Next, to manufacture silicone rubber, you need to form siloxane polymers. A condensation reaction called hydrolysis is the way you can achieve this. This process means the methyl chlorosilanes produced will interact with water.
During the hydrolysis process, hydrogen groups (OH) take the place of chlorine atoms, thus allowing for the formation of siloxane bonds (-Si-O-Si-). Silicon atoms are joined to each other by creating long siloxane polymer chains. With these polymers, silicone rubber becomes flexible, durable, and has thermal stability which is part of silicone’s excellent properties.
Include Additives and Curing Agents
After creating the siloxane polymers, you then need to add fillers and curing agents for you to get your actual properties when You are creating silicone rubber.
Examples of fillers you can use are silica or carbon black, they are very good if you want to improve properties like abrasion resistance, mechanical properties, or thermal conductivity. They do the work of controlling and processing the viscosity properties of silicone rubber formulation.
Benefits Of Silicone Rubber
- Silicone rubber has excellent heat resistance making it suitable for use in extreme environments.
- It is hygienic, meaning you can use it in the food and medical industry.
- Silicone rubber has excellent resistance to various chemicals, making it suitable for various industries.
- It has good electrical insulation, making it useful in various electronics.
- You can use silicone rubber in rain due to its water resistance properties.
Forms Of Silicone Rubber
Liquid Silicone Rubber (LSR)
LSR is a very versatile silicone rubber that offers a low compression set with a fast cure time at high temperatures. You can inject liquid silicone rubber into a mold cavity to manufacture it apart due to its two-part platinum-cured elastomer. They withstand temperatures ranging from -65°C to 260°C, have excellent flowability, and are used to produce consumer products and medical devices.
High-Temperature Vulcanized Silicone Rubber (HTV)
High-temperature silicone rubber usually cures at high temperatures. The temperature needed to cure ranges from 150°C to 300°C. Due to HTV silicone’s high heat cure, they have excellent properties like high tensile strength, flame retardancy, and excellent heat resistance.
Room Temperature Vulcanizing Rubber (RTV)
Room temperature silicone rubber is the type of silicone that does not need any special heat to cure. This means that they can cure themselves even at a normal room temperature. Examples of what it’s used for are mold making, sealing, potting electronics, etc.
Conclusion
Silicone rubber has been in existence for decades, and it is made from silicon. When you familiarize yourself with the history, the material, and the gradual process in which you can manufacture silicone as it’s in this guide, it’ll help you have a better understanding of where silicone rubber comes from.
More Resources:
Why Doesn’t Silicone Melt or Burn: A Look at Facilitator Of Silicone Temperature Range – Source: TOGOHK
What Is Silicone Temperature Range:Comprehensive Guide To Silicone Temperature Range – Source: TOGOHK
Silicone Melting Temperature: All You Need To Know – Source: TOGOHK
Silicone Manufacturing Process: Step-By-Step Guide – Source: TOGOHK
Complete Guide To Silicone Allergy – Source: TOGOHK