Is Silicone Heat Resistant? Here’s What You Should Know

December 10, 2023

Silicone is a versatile material with an extensive list of industrial and domestic uses. It’s a highly flexible, durable polymer that one can mold into various forms. Silicone’s multifarious nature is highly desirable, as it gives one access to materials with high-specific temperature and wear tolerances. Now for the important question: is silicone heat resistant?

Silicone’s heat resistance is a broad subject, but the general answer is usually yes. Some silicone is highly resistant to heat, while others might lack that particular attribute. The range of heat resistance of silicone products fluctuates widely based on the intended use of the said product.

Silicone products like rubber sheets, industrial gaskets, sealants, automobile parts, insulators, and cookware are the ones that require the most heat resistance. Even still, they have different tolerance thresholds, so it can get confusing for the average consumer what they should get for their specific job.

Structure of Silicone

Before delving into the heat-resistant properties of silicone, let’s briefly go over what silicone is. Silicone, not to be confused with Silicon, is an artificial, synthetic elastic polymer that has high durability, wear resistance, and flexibility. It has much higher physical specs than naturally found elastomers.

Silicon, on the other hand, is a naturally occurring chemical that has a metallic luster and is usually brittle. You can find silicone in just about every hardware store. Silicon, on the other hand, is far rarer. But you’ll find some in your phone or computer’s memory chip.

While having widely different physical attributes, Silicon is the primary material in Silicone polymer. The exact material composition of Industrial Silicone may differ, but it’s usually a combination of Siloxane, oxygen, Carbon, and Hydrogen. You’ll find an illustrated and detailed explanation of the chemical structure of silicone in this video.

Temperature Threshold of Silicone and How They Vary

Silicone is a popular industrial material because of its low compression set, dielectric strength or electrical conductivity, and heat resistance. Silicone’s best attribute, however, is its thermal stability. High thermal stability allows it to maintain its structural integrity and chemical properties across an extensive temperature range.

Most industrial-grade silicone can operate within a temperature range from -100°c to 300°c. That’s a massive effective threshold that few other materials can match. Siloxane is the primary element that grants silicone its high thermal stability as it has a chemical structure that resists heat-related changes.

Consumer-grade silicone has slightly fewer specs than its industrial counterparts. Its effective temperature tolerance range starts at -60°c to 250°c. These are still extremely impressive numbers. Similar counterparts like PVC, Latex, and Vinyl are far less versatile.

PVC, Latex, and Vinyl all have much lower temperature resistance while offering similar or inferior durability. Some of these materials are highly toxic, while most silicones are entirely inert and safe.

Various Types of Silicone

There are countless silicone specimens for consumer applications, but they usually fall into a select few categories. While silicone products from the same category may differ in various parameters, the variation is less than what you’d see across different categories altogether.

Various Types of Silicone

Here are some of the most common Silicone variants:

1. Fluorosilicone Rubber

Fluorosilicone rubber is a type of solid silicone that usually comes in the form of sheets, sponges, or various molded shapes. These types of silicones are flexible, versatile, and have good durability and wear resistance. 

On the domestic side, Silicone foam and foam sheets like these are often used as insulation cushions. Industrially, the biggest users of fluoro silicone are the automotive and aerospace industries. Fluorosilicone wires, pipes, and insulation covers are also widely used. 

2. RTV Silicone

RTV stands for Room Temperature Vulcanizing. This type of silicone is usually sold in a liquid state, and it hardens into flexible rubber at room temperature. This silicone is the type you’ll likely see in sealants.

Such silicone has excellent insulating properties, so it’s also used for making gaskets, insulation sheets, and other similar products. However, the most common usage of RTV silicone is still in insulation sealants. Almost every kitchen bathroom insulation liquid sealant is some form of RTV.

You can roughly categorize RTV silicone products into appliance components, insulation sheets, and liquid sealants. RTV silicone is also seen in making high-quality adhesives. The only downside of RTV silicone is its price, which is significantly higher than other non-industrial silicone products.

3. LSR Silicone

LSR silicone stands for liquid silicone rubber. Unlike what the name suggests, it is not the primary type of silicone found in liquid sealants. Instead, LSR is mainly used for making medical gear, automotive parts, and other domestic and industrial products.

LSR is easy to mold, has excellent flexibility, and is completely inert when interacting with other chemicals, so it’s an ideal material for surgical components and food-grade containers. Liquid silicone has a complicated curing process, but it is extremely easy to shape through extrusion and even 3D printing.

4. HCR Silicone

The last one is HCR or Heat Cured Rubber. HCR is a popular material for thermal-intensive applications. Such silicone products have incredibly high fire resistance by default.

Non-corrosive and non-toxic properties make them a great choice for various industrial and domestic uses. Such silicone sheets also have low thermal conductivity, meaning they do not let temperature pass through them.

Hospitals and other places that require sanitary conditions often use such silicone sheets. Check out this video on the production process of HCR silicone.

Conclusion

That concludes our brief guide to various types of silicone. Let’s go over the main points quickly: is silicone heat resistant? Yes, it is. But, different silicone products have different heat resistance thresholds. Thermal resistance and thermal stability make silicone one of the premier materials for many consumer and industrial products.

If you want to learn more about silicone and various silicone products, then feel free to contact us. We have been manufacturing high-quality, heat-resistant silicone for the past 36 years and do our best to use our expertise to help you.

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