Styrene butadiene rubber (SBR)

AL-Gummi Styrol-Butadien-Kautschuk

Styrene-butadiene rubber is the oldest and, in terms of quantity used, the most important synthetic rubber. Styrene-butadiene rubber (SBR) was developed at the beginning of the 20th century with the aim of obtaining a cheap alternative to expensive natural rubber and reducing dependence on imports from Brazil and East Asia. At the same time, it was intended to compensate for the sometimes scarce availability of natural rubber, especially for countries like Germany.
With the development of modern synthesis processes, SBR has become the most commonly produced synthetic rubber and is indispensable for passenger car tyres, especially due to its excellent wet grip properties.

Compared to NR, SBR has better abrasion resistance, higher heat and ageing resistance, but low elasticity and less favourable cold flexibility.

To improve the mechanical properties of SBR, it is often blended with NR.

Property spectrum of SBR

Hardness 30 to 90 Shore A and harder (hard rubber)
Elongation at break normally between 100 and 800%, also up to 1000
Maximum temperature +70° C
Minimum temperature -30°C
Electrical properties good insulating properties to electrically conductive (depending on formulation)
Gas permeability
Resistance to ageing and ozone slightly better than NR, can be improved by protective agents.
Chemical resistance as NR, slightly better mineral oil resistance

Applications of SBR

SBR is a typical general purpose rubber. Two thirds of the world production is used for tyre production. SBR is a good compromise between abrasion and wet slip resistance. It is usually used in the same way as NR, but very often NR is blended with SBR, e.g. in tyre construction. SBR is also used for technical rubber goods such as conveyor belts, plates, construction profiles and floor coverings.