SBR

Styrene-butadiene rubber (SBR) is a family of synthetic rubbers produced by copolymerizing styrene and butadiene. It is one of the most widely used synthetic rubbers, valued for good abrasion resistance, processing efficiency, and cost effectiveness. The styrene content is varied to tune hardness, elasticity, and aging behavior, typically in the range of 20% to 40% but adjustable depending on grade and application.

Production methods include emulsion polymerization, which yields emulsion SBR (E-SBR) as a latex that is coagulated and dried, and solution polymerization, which produces solution SBR (S-SBR) with higher molecular weight and more controlled microstructure. S-SBR often offers improved low-temperature properties and fuel efficiency, making it popular in high-performance tires. Carboxylated SBR (XSBR) adds carboxyl groups to improve filler interaction and processability.

Properties of SBR include good abrasion resistance, aging and weathering performance, and compatibility with common fillers like carbon black and silica. Compared with natural rubber, SBR typically has lower heat resistance and poorer low-temperature elasticity, though variant formulations (such as S-SBR and XSBR) can mitigate some performance gaps. Blending SBR with natural rubber or other elastomers allows tailored properties for specific uses.

Applications are broad but centered on tires, where SBR provides wear resistance and cost efficiency, particularly in tread compounds. It is also used in belts, hoses, footwear, seals, and various vibration-damping components, often in blends with other rubbers or reinforced with fillers.

Overall, SBR remains a versatile, cost-effective synthetic rubber, with E-SBR offering economical processing and S-SBR (including XSBR) enabling higher performance, especially in low rolling resistance tires.