What are the top 5 rubber materials and their applications?

There is far more to rubber than just the natural latex you see harvested from rubber trees. In fact, countless synthetic rubbers have been developed over the decades that combine the elasticity of natural rubber with an added injection of various other beneficial properties, such as chemical, thermal, and ozone resistance. Here, TRP Polymer Solutions explores five of the most innovative types of polymers that we use to develop high-quality rubber products.

What is rubber made from?

Before exploring our best five rubber materials, it’s important to first define what rubber is and what it is made from.

Rubber is a highly elastic type of polymer, and is formed differently depending on whether it is a natural or synthetic rubber.

Natural rubber is harvested as latex sap from rubber trees. This is collected, coagulated, and processed into solid rubber, which produces the classic elastic material with high flexibility and resilience.

Synthetic rubber is man-made, and is produced by polymerising petroleum-derived monomers (such as styrene, butadiene, or isoprene) into long elastomer chains. As this process starts from crude oil or coal derivatives, man-made rubbers can be tailored to have physical and chemical properties for specific applications.

Rubber can then be further refined through compounding and vulcanising to reinforce its innate properties. 

The properties of various types of rubber give them unique characteristics that make them suitable for specialised applications. Below, we go into further detail about which polymers are the most useful as a result of their dependability and versatility.

1. FKM (Viton®)

Fluoroelastomers (FKM) deliver excellent resistance to steam and a wide range of chemicals, including high-octane and oxygenated fuels. Many people refer to FKM by the DuPont brand name Viton®, which has become synonymous with this material. It is FKM’s carbon-fluorine bonds that make it resistant to many chemicals, high temperatures and oxidation. All of which make FKM the ideal choice for high-quality rubber O-rings.

As well as the aforementioned benefits, FKM also offers a number of other advantageous properties. Not only does it boast a broad operating temperature range of -45°C to +204°C, but FKM also offers excellent gas and liquid permeation resistance, good mechanical properties, and higher resistance to burning than non-fluorinated hydrocarbons. It is also suitable for explosive decompression, CIP, SIP, and FDA applications as a food-safe rubber.

Perfluoroelastomers (FFKM)

Perfluoroelastomers, or FFKM, were introduced in the 1960s in a bid to combine the mechanical properties of FKM with the chemical resistance of PTFE. Originally the sole preserve of space programmes, FFKM has since crossed over into many other industrial applications. It is easy to see why when you consider FFKM’s broad operating temperature of -30°C to +330°C and near universal resistance to more than 1,800 chemicals.

FFKM is a popular choice of material for rubber O-rings and rubber gaskets due to its favourable chemistry. Like FKM, FFKM is made up of carbon-fluorine bonds but is fluorinated to the maximum degree possible (72.5%), whilst still retaining essential elastomeric properties. As such, FFKM is widely employed for various industries, including chemical processing, seals for the oil and gas sector, aerospace seals, and motorsport seals, to name but a few.

Styrene-butadiene rubber (SBR)

Styrene-butadiene rubber (SBR) is the highest-volume general-purpose synthetic rubber in production today. SBR is a copolymer of butadiene (75%) and styrene (25%) and is ideal for static sealing applications within an operating temperature of between –25°C and +90°C. Available in shore hardnesses ranging from 40 to 95 IHRD, SBR is often used as a more cost-effective alternative to natural rubber across a wide range of rubber products.

SBR was developed in the late 1920s by German chemist Walter Bock. Bock’s discovery gave rise to an affordable synthetic rubber that exhibits excellent strength, abrasion resistance, crack endurance and heat-ageing properties. Unsurprisingly, these characteristics have led to SBR’s prevalence across many application areas, including rollers, rubber gaskets, conveyor belts, hoses, cable insulation and – most famously – car tyres.

Neoprene (CR)

Neoprene is yet another former DuPont trade name that has infiltrated modern vocabulary. The synthetic rubber in question is actually known as chloroprene (CR). Developed in 1930 by American chemist Arnold Collins, Neoprene rubber is produced through the polymerisation of chloroprene to produce polychloroprene chips. These are then melted and mixed with foaming agents and carbon pigments to create sheets of neoprene.

Neoprene is waterproof, corrosion-resistant and thermally stable over a wide temperature range of -40°C to +120°C. It also offers good all-round chemical resistance, durability, tear resistance, and adheres easily to metals and fabrics. Its versatility has seen neoprene adopted in many different rubber products, including rubber gaskets, hoses, cable insulation, belts and springs. Neoprene is perhaps best known as the go-to material for wetsuits.

Ethylene Propylene Diene Monomer (EPDM)

Ethylene Propylene Diene Monomer (EPDM) is a synthetic rubber renowned for its resistance to weathering, UV and ozone. It is an affordable, general-purpose elastomer that really comes into its own in sub-zero temperatures as low as -50°C. EPDM was developed in the 1960s, as chemists sought to develop a synthetic rubber that combined elasticity with good UV and ozone resistance. EPDM also promises excellent tear, abrasion, and steam resistance.

Part of a family of rubbers that feature a saturated chain of the polymethylene type, EPDM also performs admirably in applications involving dilute acids, ketones, and alkalis. Given all of these desirable characteristics, EPDM is a general-purpose material commonly used in the manufacture of rubber O-rings, automotive cooling systems, window and glove box seals for nuclear applications, and other seals destined for extreme weathering conditions.

Contact TRP Polymer Solutions today

Make TRP Polymer Solutions your custom rubber moulding manufacturer of choice, with decades of experience to produce a range of rubber products to your precise specifications. To find out more about our high-quality polymer products and manufacturing processes, or to discuss your requirements in more detail, please contact TRP Polymer Solutions on +44(0)1432 268899 or sales@trp.co.uk.