Q: Silicone rubber

Short Name
Silicone rubber
EM - Elastomers
General Properties
Chemical Formula
Structural Formula


Glass Transition Temperature
-135 to -120 °C
Melting Temperature
-50 to -40 °C
Melting Enthalpy
35 J/g
Decomposition Temperature
530 to 600 °C
Young's Modulus
1 to 10 MPa
Coefficient of Linear Thermal Expansion
190 to 255 *10¯6/K
Specific Heat Capacity
1.3 to 1.5 J/(g*K)
Thermal Conductivity
0.22 W/(m*K)
1.25 g/cm³
Semi-crystalline rubber
General properties
Good aging, ozone and weather resistance. Good electrical insulating properties. Good cold flexibility
Cross-linking mostly by means of peroxides
Electrical industry (e.g., electric cable insulation). Aircraft industry (e.g., seals for window and cabin doors in planes). Accessories for instrument and apparatus engineering (e.g., O-rings)

Internet Links

NETZSCH Measurements

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


The amorphous portion of silicone rubber (Q) exhibits a very low glass transition temperature of -120°C (midpoint, 2nd heating, green). The crystalline portion exhibits a sharp melting transition with a peak temperature of -45°C (both heatings).
The detected glass transition with step heights (Δcp) of 0.08 J/(g.K), even in the 2nd heating after a controlled cooling at 10 K/min, indicates a relatively high amorphous content. Highly crystalline silicone rubbers often must be quenched (cooled very quickly) in order to make the glass transition step visible.
Due to the very low glass transition (-120°C), it is recommended to select a start temperature that is approx. 45°C to 50°C below the glass transition temperature, i.e., in this case at -165°C.

Back to List