SBR
Styrene Butadiene Rubber
Glass Transition (Tg)
-55 to -50 °C
Melting Point (Tm)
—
Density
0.94 g/cm³
CAS Number
9003-55-8
Recycling Code
None
Category
Elastomer
Repeat Unit
–[CH₂–CH=CH–CH₂]ₓ–[CH₂–CH(C₆H₅)]ᵧ–
The repeating unit is the smallest structural fragment whose repetition builds the whole chain. Subscripts show the relative share of each unit in copolymers.
Key Properties
The highest-volume synthetic rubber; better abrasion and ageing resistance than NR but lower resilience and tear strength.
Applications
Passenger-car tyre treads, shoe soles, conveyor belts.