What is SBR

What is SBR?



SBR, also known as BunaS, is a synthetic copolymer of styrene and butadiene. SBR was originally developed to replace natural rubber in tires and its use in the manufacture of tires continues to the present day. SBR and natural rubber account for 90% of the total world rubber consumption.

SBR has a typical service temperature range between –50° F and +225° F.


SBR has similar properties to natural rubber, but SBR has superior water resistance, heat resistance, abrasion resistance, low temperature flexibility, and heat aging properties (i.e., in excess heat SBR hardens and becomes brittle instead of softening like natural rubber does). SBR also has good electrical insulation, alcohol resistance, oxygenated solvent resistance, and mild acid resistance. SBR can be successfully bonded to a wide range of materials.


SBR has poor resistance to oils, fuels, hydraulic fluids, strong acids, greases, fat, and most hydrocarbons. Without special additives, SBR is vulnerable to ozone, oxygen and sunlight.


SBR is recommended for applications where water, automotive brake fluid, or alcohols with a low molecular weight are present. Common applications include tire, tubes, gaskets, belts, hoses, seals, shock mounts, skirt board rubber, lining rubber, and conveyor belt covers. SBR is not normally produced in o-ring form.