Styrene-butadiene rubber (SBR), a general-purpose synthetic rubber, produced from a copolymer of styrene and butadiene. Exceeding all other synthetic rubbers in consumption, SBR is used in great quantities in automobile and truck tires, generally as an abrasion-resistant replacement for natural rubber (produced from polyisoprene).

Styrene butadiene rubber (SBR) is one of the cheaper synthetic general purpose elastomers that is sometimes used as a substitute for natural rubber (NR). It can be produced by free-radical solution polymerization or by emulsion polymerizationeither warm at 30 to 60°C (hot rubber) or cold at temperatures near 0°C (cold rubber). Emulsion SBR (ESBR) continues to lose ground to solution SBR (SSBR) which is better suited for high-performance tires. Nevertheless, emulsion SBR grades still account for more than 75% of the total world capacity as of 2015. However, more and more SBR is produced by solution polymerization.