styreenbutadienrubber

Styrene-butadiene rubber (SBR) is a synthetic elastomer produced by the copolymerization of styrene and butadiene. It is the most widely used synthetic rubber and is especially important in tire tread compounds. SBR can be made by emulsion polymerization (ESBR) or by solution polymerization (SSBR). ESBR is produced in an aqueous emulsion and then coagulated, yielding high molecular weight polymers suitable for general-purpose tires. SSBR is synthesized in hydrocarbon solvents and allows more precise control of architecture, making it favorable for high-performance tires and specialty applications.

Properties and performance of SBR depend on the styrene content and the arrangement of monomers. In general, SBR offers good abrasion resistance, aging stability, and processing characteristics, at a relatively low cost. Its low-temperature performance is limited compared with natural rubber, and the material’s hardness and heat resistance increase with higher styrene content. SBR is commonly compounded with fillers such as carbon black or silica to tailor properties; silica-filled systems often require coupling agents to improve tire rolling resistance and wet grip.

Curing of SBR is achieved through sulfur vulcanization, forming a crosslinked network that sets elasticity and mechanical strength. The choice of accelerators, fillers, and processing conditions influences cure rate and final properties.

Applications include tire treads and belts, as well as footwear, seals, hoses, vibration dampers, and various molded or extruded goods. SSBR and ESBR enable a range of performance levels, from economical daily-use products to high-performance tires, balancing wear resistance, processability, and durability.