Styrene-Butadiene Rubber (SBR)

The most widely used synthetic rubber in the world is SBR, a copolymer of styrene and butadiene. SBR was also called Buna® S (from the first trade name of Bayer). Where SBR rubber is used the most is in tire by blending it with natural rubber and butadiene rubber. SBR is weak and unusable without reinforcement by carbon black, but with carbon black it is strong and abrasion resistant. The defects of SBR are poor resistant to oil and not suitable in weathering, UV, oxygen, ozone because of the double bond in the polymer backbone.

Cure system

Standard SBR compounds are sulfur-cured.

Other Common Variations

  • SBR is usually mixed with NR and BR and applied in tire productions
  • SBRs are mostly applied seals for non-mineral oil based brake fluid.

Buna® is a registered trademark of ARLANXEO. 

General Information

ASTM D 1418 Designation
Standard Color(s)
ISO/DIN 1629 Designation
Hardness Range
50-70 Shore A
ASTM D2000 / SAE J 200 Codes
Relative Cost

Service Temperatures

Standard Low Temperature
-55°C / -67°F
Special Compound Low Temperature
Standard High Temperature
100°C / 212°F
Special Compound High Temperature

Performs Well In...

  • Water
  • Alcohol
  • Silicone oil and grease
  • Non-mineral oil based brake fluid
  • Weak acids

Doesn’t Perform Well In...

  • Petroleum oils and fuels
  • Aromatic, aliphatic, or halogenated
  • Hydrocarbons
  • Strong acids
  • Mineral oils