PES vs. Silicon Nitride

PES and silicon nitride belong to fundamentally different material chemistries. PES is a polymeric material, while silicon nitride is ceramic. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 13 material properties with values for both materials. Properties with values for just one material (22, in this case) are not shown.

For each property being compared, the top bar is PES and the bottom bar is silicon nitride.

Polyethersulfone (PES)Silicon Nitride (Si₃N₄)

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		2.6
Elastic (Young's, Tensile) Modulus, GPa		140 to 310

Flexural Strength, MPa		130
Flexural Strength, MPa		130 to 810

Thermal Properties

Maximum Temperature: Mechanical, °C		200
Maximum Temperature: Mechanical, °C		1000 to 1330

Specific Heat Capacity, J/kg-K		1100
Specific Heat Capacity, J/kg-K		720 to 800

Thermal Conductivity, W/m-K		0.18
Thermal Conductivity, W/m-K		12 to 31

Thermal Expansion, µm/m-K		53
Thermal Expansion, µm/m-K		2.5 to 3.2

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 MHz		3.5
Dielectric Constant (Relative Permittivity) At 1 MHz		8.0 to 10

Dielectric Strength (Breakdown Potential), kV/mm		16
Dielectric Strength (Breakdown Potential), kV/mm		18

Electrical Resistivity Order of Magnitude, 10^x Ω-m		15
Electrical Resistivity Order of Magnitude, 10^x Ω-m		11 to 12

Otherwise Unclassified Properties

Density, g/cm³		1.4
Density, g/cm³		2.2 to 3.4

Common Calculations

Stiffness to Weight: Axial, points		1.1
Stiffness to Weight: Axial, points		34 to 53

Stiffness to Weight: Bending, points		33
Stiffness to Weight: Bending, points		65 to 78

Thermal Diffusivity, mm²/s		0.12
Thermal Diffusivity, mm²/s		7.5 to 13