Silicone Rubber: The Definitive Guide

Silicone is a highly resistant elastomer rubber. The elastomer has several standout properties which distinguish it from organic rubber. Moreover, the elastomer was first introduced during the second world war in 1943 as a rubber-like material.

Table of Contents

Moreover, it has several applications based on excellent temperature resistance, optical clarity, and electrical insulation. But what are these applications? How do silicone rubber features benefit these applications? We will learn everything in this definitive silicone rubber guide!

What is Silicone Rubber?

Silicone rubbers are composed of silicone as the dominant molecule. However, they also contain carbon, oxygen, and hydrogen molecules. Hence, these rubbers offer various physical properties thanks to the unusual combination. The most prominent physical properties include high-temperature Resistance, good weathering performance, high stability, and non-reactiveness. Hence it is used as a great alternative to organic rubbers.

silicone rubber mold

Also, it is vital to note that manufacturers use fillers with silicone rubbers. Fillers help reduce the material’s cost and alter physical properties. We will have a detailed section on silicone fillers later in the article. Coming back to silicone rubber, the material has an easy manufacturing process compared to organic rubbers. On top of it, it is effortless to mold it into any shape you want, just like any organic rubber-like material.

Silicone Rubber Types

Silicone rubber offers excellent opportunities for coloring, mixing, manufacturing process, etc. Hence you can say it is one of the most versatile rubber materials in the industry.

Therefore, you will find that the material has been used in many applications. You will also come across ozone resistance silicone rubbers. However, despite all this, the following are the most commonly used forms of silicone rubber:

silicone rubber

Fluorosilicone Rubber

Fluorosilicone rubber offers excellent Resistance to oil, fuel, and some specific solvents. On top of it, this type of silicone rubber can withstand extreme temperatures. This includes highly freezing temperatures as well as scorching temperatures.

Moreover, fluorosilicone rubber is resistant to chlorinated and aromatic hydrocarbons, sunlight, Ozone, and air. Therefore, many outdoor appliances and applications use fluorosilicone for its properties.

However, despite the great things about fluorosilicone, there are some drawbacks. These include low tensile strength and poor abrasion resistance. Hence, we never recommend Fluorosilicone for dynamic applications to our customers. On top of it, it does not perform well in applications that involve ketones or brake fluids. 

Liquid Silicone and Solid Silicone Rubbers

The other two popular silicone rubbers are:

Solid Silicone Rubber has relatively long polymer chains and a higher molecular weight. Moreover, manufacturers tend to use traditional production techniques to manufacture it. It is also called room-temperature vulcanized rubber due to its vulcanization process.

Liquid Silicone Rubber: on the other hand, it has low molecular weight. On top of it, this type of silicone also has shorter polymer chains. However, this requires some unique production methods, such as extrusion or injection molding.

liquid silicone molds

Silicone Rubber Properties

The strong silicon-oxygen chain in silicone rubbers makes room for various beneficial properties. It is because the silicon-oxygen chain is the strongest. This is also what makes silicone rubber more useful than organic rubber. Some of the most valuable properties include the following:

  • Silicone rubber material has excellent non-adhesive properties. Hence, it is instrumental in applications where non-sticky rubber products are needed.
  • Silicone rubber material has low toxicity. Hence, certain silicone rubbers have FDA approval for use in the food and medical industries. You can learn more about food grade vs. medical silicone rubber here.
  • Silicone rubber shows excellent Resistance to sunlight, Ozone, and oxygen. Hence, it is suitable for harsh outdoor applications.
  • Silicone rubbers have low glass transition temperatures. This means silicone becomes more flexible at lower temperatures.
  • The silicone rubber material also offers incredible clarity. This is especially true for liquid silicone rubber, which is manufactured using special equipment. The optical transparency opens the way for even more applications. 
  • Silicone rubber also does not react with most chemicals. Thus, the low chemical reactivity also makes it suitable for chemical applications.
  • Silicone rubber has high bio-compatibility. This also opens the way for many bio-chemical applications which other rubbers can’t withstand. 
  • Silicone rubber has high-temperature Resistance. Generally, it is between the range of -55 to 300 degree Celsius. However, the content for a specific grade of silicone rubber depends on various factors, including manufacturing technique, fillers, compounding, etc. 
  • Silicone rubber also performs exceptionally well in mechanical terms. This means it has high elongation and resists regular wear and tear effortlessly. 
  • Due to its superb insulation properties, silicone rubber is also used as an insulator. 
  • Silicone rubbers also offer excellent resistance to particle and electromagnetic radiation, including alpha, beta, gamma, and UV. You can also find ozone resistance silicone rubbers in the market.

What is Silicone Rubber Used for?

Silicone materials, alone or compounded, have several uses in various industries. The most prominent industries and services include: 

  • Construction: silicone rubbers product perform well in harsh weather conditions. As a result, they are suitable products for the construction industry. For example, coatings, adhesives, and sealants. Another thing about silicone is that it bonds well with metal. This also helps in construction for adhesive purposes.silicone adhesive sealant
  • Medical: a specific grade of silicone rubbers with the right properties and approvals is suitable for medical applications. Produces used include medical tubes, defoamers, and adhesives. 
  • Electrical: They use silicone products in the form of lubricants, housings, sealants, insulation tapes, and whatnot. Moreover, arrestors and insulators require a thick form of rubber which silicone can achieve if the injection molding technique is used. liqiuid silicone for LEDs
  • Aerospace: silicone also has several applications in the aerospace industry. For instance, the material has the suitable properties of gaskets, seals, and tooling materials. Moreover, even some spacesuit fabrics use properties of silicone. On top of it, many aircraft components and maintenance tools use silicone rubber. 
  • Consumer Goods: This is another big industry that widely uses silicone products. These include food containers, toys, cosmetics, jewelry, and more. Every other product that we use in our daily lives uses silicone in one form or the other.consumer silicone goods
  • Automotive: silicone undoubtedly holds great importance in the automotive industry. It is used for weather and vibration-resistant parts. However, only specific grades of silicone, such as fluorosilicone, that can withstand fuels and oil are used in this industry. 

Silicone Rubber Classifications

Silicone rubber has five different classifications based on the method used for syncretization. All of these are classified as synthetic rubber: 

  1. Fluoro: known for high Resistance to chemicals, including solvents, oils, and fuels. You will often come across this classification termed fluoro silicone rubber. 
  2. Methyl: the industry classifies this syncretization of silicone as methyl silicone rubber. More technical terms include dimethyl silicone elastomer.
  3. Vinyl and Methyl: Common terms used to refer to this include methyl vinyl silicone rubber/elastomer. 
  4. Vinyl, Phenyl, Methyl: when all these three come together, they make silicone an excellent performer in frigid temperatures. The industry refers to it as PVMQ silicone. 
  5. Phenyl and Methyl: phenyl silicone rubber also proves to be excellent in low-temperature conditions.

Silicone Rubber: Fillers and Additives

Manufacturers add fillers, crosslinkers, and additives to enhance or alter the properties of silicone. Let’s look at each separately: 


Fillers such as metal or carbon make silicone more conductive to electric current. Moreover, customers ask for other properties of silicone, which the manufacturer then figures out to add suitable fillers. However, look out for unapproved fillers by the FDA.


This help makes silicone rubber more stable. The most commonly used crosslinker for silicone curing includes dim peroxide. 


Additives in silicone are added in the form of stabilizers, color pigments, or flame retardants. Each additive serves its purpose as it makes silicone rubber versatile.

Silicone Rubber Benefits and Advantages

Silicone has tons of benefits and advantages. The most standout benefits include: 

silicone rubber benefits
  • Stability (Thermal): silicone rubber tends to retain its properties in extreme temperatures thanks to its heat-resistant attributes. This includes both cold and hot conditions. Hence, the rubber does not lose shape, flexibility, or durability. 
  • Versatility: silicone offers incredible moldability. As a result, manufacturers can turn it into any desired precise shape. Moreover, formulation changes in silicone allow for varying properties specific to your needs. This includes altering the material’s strength, flexibility, and electrical conductivity. 
  • Color-ability: silicone rubber adapts color quite smoothly. This allows for vivid and precise coloring of the material per the customer’s demands. 
  • Moisture Repulsion: silicone rubber offers repulsion to moisture and water. Hence, the material provides suitable characteristics for moisture sealant applications. 
  • Environmental Resistance: silicon can withstand harsh environments and weather conditions pretty easily. Hence, you can use it for outdoor applications that come in contact with flames, UV rays, and chemicals. But is silicone eco-friendly? Learn more here.
  • Electrical Insulator: silicone offers excellent electrical insulation. Hence, the material has commendable benefits for the electrical industry, especially high-powered LEDs. However, if you want a more conductive version of silicone, ask the manufacturer to add metal or carbon to the material. 
  • Hardness: when we talk about hardness, we don’t just mean silicone is rugged. Instead, we suggest that silicone comes in different ranges of shore hardness. As a result, you can order silicone products with specific hardness and flexibility depending on the application. 
  • Durable: silicone has high reliability and durability. This means it turns out to be an excellent investment in the long run. Moreover, the reliability of silicone makes it a suitable material for critical applications. 


To conclude, the popular elastomer silicone has proven to be a great addition to the rubber industry. It has made specific critical applications easier and helped save on cost thanks to its high durability. The above definitive guide must have helped you learn everything about silicone. 

Contact Hongju For The Most Premium Silicone Rubber Products!

If you are interested in silicone rubber keypads, gaskets, grommets, seals, and other products, come to Hongju. We have a highly diversified silicone product portfolio. On top of it, we have the technical equipment and the right mindset to manufacture special custom orders for our clients. Check out some of our products and call us now!

Get Instant Quote Now!

Share The Post Now:


Hey there, I’m David!

I’m the founder of Hongju Silicone. I have been in this field for more than two decades. If you are looking for custom-made silicone rubber products, feel free to ask me any questions.

You may also find these topics interesting

injection molding vs. 3d printing

Injection Molding vs. 3D Printing: The Ultimate Comparison

Whenever you search for the most flexible and effective manufacturing techniques, two methods always stand out in the crowd injection molding and 3D printing. These processes make the ultimate foundation of many industries such as automotive, healthcare, etc. Regardless of what manufacturing industry you belong to, it is quite important to compare both options you have.

Read More »
foam rubber vs. sponge rubber

Foam Rubber vs. Sponge Rubber: What’s the Difference?

If you’re in the manufacturing or healthcare sectors, you’ve probably faced the dilemma of “foam rubber vs. sponge rubber: what’s the difference?” It’s not a trivial question; choosing the right rubber material can significantly impact everything from thermal insulation to shock absorption.

Read More »

Send Your Inquiry

*We respect your confidentiality and all information is protected.

Download Catalog

Fill in the form below, and we will send you our entire catalog immediately!