What rubber materials can withstand high heat?

Excessive heat can gradually degrade rubber materials, leading to deteriorating performance and premature failure. As such, high-temperature applications require high-temperature, heat-resistant materials that offer dependable performance no matter what. Martin’s Rubber, a leading rubber mouldings manufacturer, provides a guide to the best heat-resistant material available.

 

Natural rubber material should not be used in applications with continuous temperatures above 85 °C; for some high-temperature applications, that simply isn’t high enough. However, specific synthetic grades of rubber material have been chemically engineered to deliver superlative heat resistance in excess of 300 °C.

Here is our guide to five of the most impressive high-temperature-resistant rubbers we use here at Martin’s Rubber. For more in-depth information, please consult our material properties guide.

Silicone

Silicone is the number one heat resistant rubber material available. It offers outstanding high-temperature resistance, with some compounds able to withstand temperatures up to 305°C. Although suitable for applications involving exposure to UV, ozone, and weathering, silicone is not recommended for use at specific temperatures and may not always offer the mechanical properties required.

 

Silicone is not a high-strength material, and it tears easily. Having said that, we have unique compound grades that deliver better tear resistance than standard silicone. Fluorosilicone also offers high-temperature stability but with added chemical resistance.

FKM (Viton)

FKM is a family of fluoroelastomers commonly referred to by DuPont’s Viton brand name. FKM is an excellent high-temperature-resistant rubber that retains its good mechanical properties and chemical resistance (oils, fuels, lubricants, and most mineral acids), even at extremely high temperatures.

 

Products moulded in FKM remain elastic when exposed to air oven ageing up to 205°C or intermittent exposures up to 316°C. Commonly used in O-rings and other moulded or extruded products, this extreme-temperature rubber also provides the best fluid resistance of any commercial rubber.

CSM (Hypalon)

CSM (CSPE in the US) is another synthetic rubber best known by its now-defunct DuPont brand name, Hypalon. Chlorosulphonated polyethene rubber, to give it its chemical name, offers excellent resistance to dry heat up to +120°C.

 

CSM also provides excellent resistance to ozone, UV, weathering, and corrosive chemicals when cured. CSM exhibits good electrical properties, low flammability, and low gas permeability. However, this high-temperature rubber material offers relatively poor fuel resistance and a low compression set.

HNBR

Hydrogenated acrylonitrile-butadiene rubber (HNBR) is a unique elastomer derived from conventional nitrile rubber by hydrogenating unsaturated bonds in the butadiene. HNBR is an exceptionally high-temperature-resistant rubber that can withstand temperatures higher than conventional nitrile up to +150 °C.

 

HNBR also offers excellent resistance to oils, fuels, chemicals, steam, and ozone and exceptional tensile and tear strength. It also provides good abrasion resistance. However, this particular extreme-temperature rubber is relatively expensive and incompatible with aromatic oils or polar organic solvents.

EPDM

Synthetic rubber, ethylene-propylene-diene monomer (EPDM), is a copolymer of ethylene, propylene, and diene monomers. This synthetic high-temperature-resistant rubber offers excellent heat resistance, performing optimally up to +150°C. It also delivers excellent tear, abrasion, steam, and compression set resistance.

 

While resistant to dilute acids, ketones, and alkalis, EPDM rubber offers poor resistance to petroleum-based fuels, most oils, and non-polar solvents. EPDM is often used as a lower-cost polymer thanks to its many favourable characteristics, especially its heat resistant properties.

Find the Perfect Heat-Resistant Material for Your Application

With a wide variety of high-temperature-resistant rubber materials, we can help you find the right one for your application. If you need help choosing the most suitable heat-resistant material, speak to a technical expert at Martin’s Rubber today to ensure you select the right one. For more information, contact us or check out our technical articles.