Full definition
Styrene-Butadiene Rubber — the world's most produced synthetic elastomer (approximately 6 million tonnes/year), originally developed as a wartime replacement for natural rubber. SBR offers good abrasion resistance, acceptable aging stability, and low cost, making it the general-purpose workhorse of the rubber industry. Styrene content typically 23.5% (standard) — higher styrene increases hardness and stiffness but reduces resilience and low-temperature flexibility. Properties: hardness 40-90 Shore A, tensile 10-25 MPa (with carbon black reinforcement), elongation 300-600%, resilience lower than NR (50-60% vs 80%). ASTM D2000 classification: AA (standard), BA (higher grades). Production types: emulsion SBR (E-SBR, for general products) and solution SBR (S-SBR, better rolling resistance, for modern tire treads). Limitations: poor oil resistance, poor ozone resistance without antiozonant additives. Applications: tire treads and sidewalls (largest use), industrial rubber sheet and flooring, conveyor belt covers, gaskets, footwear soles, hose covers, and roll coverings. Often blended with NR or BR to optimize properties.