SBR: Styrene-butadiene rubber

Short Name
Styrene-butadiene rubber
EM - Elastomers
General Properties
Chemical Formula
Structural Formula


Glass Transition Temperature
-55 to -35 °C
Melting Temperature
(-20) °C
Melting Enthalpy
(170 (cis)) J/g
Decomposition Temperature
435 to 470 °C
Young's Modulus
2 to 10 MPa
Coefficient of Linear Thermal Expansion
180 *10¯6/K
Specific Heat Capacity
1.88 to 2.00 J/(g*K)
Thermal Conductivity
0.20 to 0.25 W/(m*K)
0.94 g/cm³
Rubber with hard and soft segments
General properties
Good aging and abrasion resistance
Cross-linking by means of sulfur accelerating systems or peroxides
Tire industry (cap of tires). Technical rubber goods (conveyor bands, seals). Mechanical engineering. Household articles (e.g., shoe soles)

Internet Links

NETZSCH Measurements

DSC 204 F1 Phoenix®
Sample Mass
13.10 mg
Isothermal Phase
8 min
Heating/Colling Rates
10 K/min
Al, pierced
N2 (40 ml/min)


In the DSC curve from the 1st heating (blue), SBR shows a glass transition at -45°C (midpoint), a broad, complex melting transition (with peak temperatures at 19°C and 58°C and a melting enthalpy of approx. 6 J/g in the 1st heating), caused by the
melting of additives and an exothermal effect (peak temperature: 168°C, enthalpy: approx. 10 J/g) that can be attributed to post-vulcanization. This exothermal effect is absent in the 2nd heating (green) after controlled cooling, indicating that vulcanization was completed in the 1st heating. As a result, the Tg in the 2nd heating is shifted to a slightly higher temperature (midpoint of -44°C compared to -45°C in the 1st heating). The step height (Δcp) of approx. 0.5 J/(g·K) remained almost
unchanged. This small effect of post-cross linking on temperature and height of the glass transition step is typical for elastomers.
A melting transition due to additives with peak temperatures of 23°C and 34°C and an enthalpy of approx. 4 J/g is also seen in the DSC curve of the 2nd heating.

Back to List