StyrenButadienKautschuk

Styrene-butadiene rubber (SBR) is a synthetic rubber obtained by polymerizing styrene and butadiene to form a random copolymer. In commercial grades, styrene content typically ranges from about 23 to 40 percent by weight, with the balance comprised of butadiene. The material combines the processability of styrene with the elasticity of butadiene, producing a versatile rubber suitable for a wide range of applications. SBR is most commonly produced by emulsion polymerization (ESBR) in water using surfactants and free-radical initiators; a related class, solution-polymerized styrene-butadiene rubber (SSBR), is made in hydrocarbon solvents under anionic polymerization and allows tighter control of molecular architecture for enhanced performance.

Properties of SBR include good abrasion resistance, good aging and ozone resistance, and ease of processing. Its heat resistance and wet grip are generally lower than those of natural rubber or polybutadiene, but performance can be tuned by blending, applying fillers, and using different comonomer ratios. Endurance characteristics depend on styrene content and molecular weight distribution.

Applications are dominated by tire manufacturing, where SBR is used in tread and sidewall compounds owing to abrasion resistance and processing advantages. It is also used in belts, hoses, seals, footwear, and various molded or extruded components.

Historically, SBR emerged as a practical alternative to natural rubber in the early to mid-20th century and has become a dominant material in the rubber industry. Environmental considerations include solvent use for SSBR production and energy demands of polymerization, but ESBR production remains water-based and relatively efficient.