Silicone Plastic vs. Thermoset PI

Both silicone plastic and thermoset PI are thermoset plastics. There are 12 material properties with values for both materials. Properties with values for just one material (16, in this case) are not shown.

For each property being compared, the top bar is silicone plastic and the bottom bar is thermoset PI.

Silicone Plastic Thermoset Polyimide (PI)

Metric UnitsUS Customary Units

Mechanical Properties

Tensile Strength: Ultimate (UTS), MPa		38
Tensile Strength: Ultimate (UTS), MPa		37 to 81

Thermal Properties

Glass Transition Temperature, °C		200
Glass Transition Temperature, °C		360

Maximum Temperature: Decomposition, °C		480
Maximum Temperature: Decomposition, °C		330

Specific Heat Capacity, J/kg-K		850
Specific Heat Capacity, J/kg-K		1130

Thermal Conductivity, W/m-K		0.35
Thermal Conductivity, W/m-K		0.29 to 1.7

Thermal Expansion, µm/m-K		35
Thermal Expansion, µm/m-K		38 to 54

Electrical Properties

Dielectric Strength (Breakdown Potential), kV/mm		30
Dielectric Strength (Breakdown Potential), kV/mm		20

Electrical Resistivity Order of Magnitude, 10^x Ω-m		12
Electrical Resistivity Order of Magnitude, 10^x Ω-m		15

Otherwise Unclassified Properties

Density, g/cm³		1.9
Density, g/cm³		1.4 to 1.6

Common Calculations

Strength to Weight: Axial, points		5.5
Strength to Weight: Axial, points		6.5 to 16

Strength to Weight: Bending, points		13
Strength to Weight: Bending, points		16 to 30

Thermal Diffusivity, mm²/s		0.22
Thermal Diffusivity, mm²/s		0.18 to 0.95