What is Silicone Rubber?

What is Silicone Rubber? - Solid Solutions

Silicone rubber was a product of the research carried out by Eugene G. Rochow, a professor of chemistry at Corning Glass Works in the 1940s. However, the history of Silicon-based compounds dates back to 1824 when a Swedish chemist, Jöns Jackob Berzelius, first synthesized silicon hydrides. Berzelius discovered that reacting elemental silicon with hydrogen generated a new compound called silicon hydride, which he called silane. 

In 1901, Frederick Kipping created organic silicon compounds called silicone resins. Rochow, building on the work of Berzelius and Kipping, discovered that reacting silicon with methyl chloride produced a new compound with unique properties, which was later commercialized as silicone rubber by Dow Corning Corporation in the 1950s.

What is Silicone Rubber? 

1:1 Silicone rubber is a two-part liquid material that is commonly used for molding or casting different objects, tools, or parts. The name "1:1" refers to the mixing ratio of its two components – the base (Part A) and the catalyst (Part B) – which have equal volumes or weights. When mixed together, these two parts will begin a chemical reaction, which triggers the material to cure or solidify into a durable rubber form.

Here are some more details about 1:1 silicone rubber:

Properties: 1:1 Silicone rubber has numerous favorable properties that make it a popular choice for many applications. Some of the main properties include good elongation, tear strength and resilience. It also has good resistance to heat, weathering, and chemicals, making it suitable for use in harsh environments.

Working time and cure time: 1:1 Silicone rubber typically has a relatively short working time (pot life), ranging from a few minutes to an hour. Pot life depends on factors such as temperature, humidity, and the amount of material used. After mixing, the silicone rubber will begin to cure, with curing time depending on the thickness of the material applied.

Applications: 1:1 Silicone rubber is versatile and can be used in numerous applications such as prototype casting, sculpting, and replicating objects, molds and tools for various manufacturing processes or arts and crafts.

Handling and storage: It is essential to handle and store 1:1 Silicone rubber properly. The material must be thoroughly mixed before use, preferably in a clean and measured mixing container, to ensure an even curing process. Each component should be stored in a cool, dry place, away from direct sunlight, sources of heat, and humidity, to avoid the material from expiring or undergoing premature curing.

Overall, 1:1 Silicone rubber is an excellent rubber material for molding, casting, and replicating objects of various sizes and shapes, while maintaining high durability and resilience to harsh environments.

What is Silicone Rubber made from? 

Silicone Rubber

Silicone rubber is a synthetic elastomer that is made from a variety of materials, including silicon, oxygen, carbon, and hydrogen. The starting material for silicone rubber is silica, which is derived from sand or quartz. The silica is then subjected to a series of chemical reactions to produce polycrystalline silicon, which is further processed into a silicone base polymer.

The silicone base polymer is then combined with other ingredients, including cross-linking agents, fillers, and additives, to achieve the desired properties and characteristics of the silicone rubber. The mixing and processing of the ingredients into a homogeneous mixture is typically done through a process called compounding, which can vary depending on the specific application and the final desired product.

After the compounding is complete, the mixture is typically molded, extruded or formed by a number of different methods to produce the final silicone rubber product. The curing and cross-linking of the silicone rubber typically occurs through a heat-curing or a room temperature vulcanizing (RTV) process, depending on the specific formulation and application of the silicone rubber.

Silicone rubber has unique physical, chemical and mechanical properties that make it suitable for a variety of applications. Some of the key properties of silicone rubber include:

High and Low Temperature Resistance: Silicone rubber can withstand extreme temperatures, ranging from -60°C to 230°C, without significant changes in its elasticity, hardness, or any other physical properties. This enables its use in applications where materials need to withstand extreme hot and cold temperatures.

Chemical Resistance: Due to its inorganic backbone, silicone rubber is highly resistant to chemicals such as acids, alkalis, oils and solvents that may cause damage to other polymers. This makes it ideal in industries where contact with chemicals is frequent.

Electrical Insulation: The insulating properties of silicone rubber are unparalleled, making it suitable for electrical insulation applications where high voltage and current are present.

Compression Set Resistance: Silicone rubber has excellent resistance to compression set, which is the development of an indentation in a material after it has been compressed for a period of time. This property makes it suitable for use in gaskets, o-rings, and seals.

Tear and Abrasion Resistance: Due to its physical structure, silicone rubber has high tear strength and is resistant to abrasion. This makes it ideal for applications where wear and tear are a concern, such as conveyor belts or automotive hoses.

Water Resistance: Silicone rubber is highly resistant to water, making it a suitable material for use in applications where exposure to moisture is a concern.

Biocompatibility: Silicone rubber is biocompatible and is commonly used in medical and food processing applications where human contact is frequent.

In summary, the specific physical, chemical and mechanical properties of silicone rubber make it a popular and versatile material used in various applications. Its resistance to extreme temperatures, chemical resistance, electrical insulation properties, and tear and abrasion resistance make it ideal for use in a wide range of industries including automotive, aerospace, electronics, consumer products, medical and food processing.

Uses and applications of silicone rubber

Silicone rubber is a versatile material that is commonly used in a wide range of applications due to its unique properties, such as high and low-temperature resistance, chemical resistance, and electrical insulation.

Here are some of the common uses and applications of silicone rubber:

Medical Devices: Silicone rubber is used in medical applications such as tubing, implants, and medical devices. It is biocompatible and can be sterilized easily, making it ideal for applications that require frequent contact with human tissues.

Consumer Products: Silicone rubber is used in the manufacture of a variety of consumer products, such as kitchen utensils, baby bottle nipples, cosmetic applicators, and bakeware. Its non-stick properties make it ideal for baking products that require easy release from the mold.

Automotive Industry: Silicone rubber is used in the manufacturing of gaskets, seals, hoses, and other automotive components. It can withstand high temperatures and is resistant to oil, grease, and other chemicals, making it ideal for use in demanding automotive applications.

Electronics: Silicone rubber is used for electrical insulation in electronic components such as keyboards, smartphones, computers, and other electronic devices. Its superior insulating properties can help protect against electrical interference and ensure the longevity of electronic components.

Aerospace Industry: Silicone rubber is used in the aerospace industry for many applications, such as coatings, seals, and gaskets. It is resistant to high and low-temperature extremes, making it suitable for various air and space applications.

Construction Industry: Silicone rubber is used in construction applications, such as roof coatings, sealants, and adhesives. It offers long-lasting, durable protection as it is resistant to weathering, UV rays, and other harsh environmental factors.

Food Processing Industry: Silicone rubber is used in the manufacture of baking sheets, molds, and other food processing equipment. It is non-reactive with food and can withstand high temperatures, making it ideal for use in cooking applications.

In summary, silicone rubber has versatile uses and applications due to its unique combination of physical, mechanical, and chemical properties. Its applications span across a broad spectrum of industries, including medical, electronics, automotive, aerospace, construction, and food processing, among others.

The Difference between Silicone Rubber and other rubbers

Silicone Rubber

Natural Rubber: Natural rubber is a widely used material in the rubber industry. Like silicone rubber, it is flexible, durable, and resistant to oil and abrasion. However, natural rubber is not as heat resistant as silicone rubber, and it can degrade over time when exposed to high temperatures.

Neoprene Rubber: Neoprene rubber is known for its excellent weathering and chemical resistance properties. It is commonly used in high-stress applications and is often used in wetsuits and other water-resistant products. However, neoprene is not as heat resistant as silicone, and it does not perform as well in low-temperature applications.

Nitrile Rubber: Nitrile rubber is a synthetic rubber that is known for its excellent resistance to oil, fuel, and other chemicals. It is commonly used in the automotive and aerospace industries due to its resistance to fuel and lubricants. Nitrile rubber, however, doesn't perform well in high-temperature applications and lacks the flexibility of silicone rubber.

EPDM Rubber: EPDM rubber is commonly used for outdoor applications, such as weather stripping and roofing. It is known for its excellent resistance to weathering, ozone, and UV radiation. However, EPDM does not perform well in high-temperature applications, and it is generally not as flexible as silicone.

Silicone rubber stands out among other types of rubbers due to its unique combination of properties, which includes high-temperature resistance, chemical resistance, and electrical insulation. While other rubbers like natural rubber, neoprene, nitrile, and EPDM have their unique characteristics, none can compare to the versatility of silicone rubber.

Like any other material, silicone rubber can encounter some problems during the manufacturing and processing stages. In this article, we will look at some of the common problems associated with silicone rubber and how to troubleshoot them.

Curing Time: One of the most common problems associated with silicone rubber is a prolonged curing time. This can happen due to various reasons such as inadequate mixing of the components, presence of contaminants, insufficient heat or humidity. If you notice that the curing time of the silicone rubber is longer than expected, you can troubleshoot the problem by checking the mixing ratio, checking for contaminants, and increasing the temperature or humidity if necessary.

Surface Defects: Another common problem with silicone rubber is surface defects such as air bubbles, swirls, and wrinkles. These defects can occur due to improper mixing, improper mold design, or contamination during the manufacturing process. The best solution is to use proper mixing techniques, design the mold properly, and ensure that the silicone rubber material is free from contaminants before processing.

Poor Adhesion: Poor adhesion is another problem that can occur when using silicone rubber. This can occur due to contamination of the surface or improper surface preparation. Proper surface preparation is essential for ensuring good adhesion. You can clean the surface using a solvent, roughen the surface using sandpaper or use primers to improve adhesion.

Tear and Tensile Strength Problems: Silicone rubber is known for its high tear and tensile strength. However, the strength of the material can be affected by various factors such as insufficient mixing or inappropriate curing temperatures. To troubleshoot these problems, you need to ensure that you mix the components properly and cure the material at the correct temperature and time.

In conclusion, silicone rubber is a versatile material with unique properties that make it ideal for a wide range of applications. However, you may encounter some problems when processing or manufacturing silicone rubber. By understanding the common problems associated with silicone rubber and implementing the appropriate solutions, you can ensure the quality of your final product.

We hope this helps you learn a bit more about Silicone Rubber 🙂

Silicone Rubber