# Silicone Plastic

Silicone plastic is a thermoset plastic. It has the lowest heat capacity among thermoset plastics. In addition, it has a fairly high density and a fairly high dielectric strength. The graph bars on the material properties cards below compare silicone plastic to other thermoset plastics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

## Thermal Properties

Glass Transition Temperature

200 *°C* 390 *°F*

Maximum Temperature: Decomposition

480 *°C* 890 *°F*

Specific Heat Capacity

850 *J/kg-K* 0.2 *BTU/lb-°F*

Thermal Conductivity

0.35 *W/m-K* 0.2 *BTU/h-ft-°F*

Thermal Expansion

35 *µm/m-K*

## Electrical Properties

Dielectric Strength (Breakdown Potential)

30 *kV/mm* 1.2 *V/mil*

Electrical Resistivity Order of Magnitude

12 *10 ^{x} Ω-m*

## Other Material Properties

Density

1.9 *g/cm ^{3}* 120

*lb/ft*

^{3}Elastic (Young's, Tensile) Modulus

9.0 *GPa* 1.3 *x 10 ^{6} psi*

Tensile Strength: Ultimate (UTS)

38 *MPa* 5.4 *x 10 ^{3} psi*

## Common Calculations

Stiffness to Weight: Axial

2.6 *points*

Stiffness to Weight: Bending

36 *points*

Strength to Weight: Axial

5.5 *points*

Strength to Weight: Bending

13 *points*

Thermal Diffusivity

0.22 *mm ^{2}/s*

Thermal Shock Resistance

8.5 *points*

## Followup Questions

## Further Reading

Thermosets: Structure, Properties and Applications, Qipeng Guo (editor), 2012

Modern Plastics Handbook, Charles A. Harper (editor), 1999

Plastics Materials, 7th ed., J. A. Brydson, 1999