CAP vs. PMP

Both CAP and PMP are thermoplastics. There are 13 material properties with values for both materials. Properties with values for just one material (17, in this case) are not shown.

For each property being compared, the top bar is CAP and the bottom bar is PMP.

Cellulose Acetate Propionate (CAP)Polymethylpentene (PMP)

Metric UnitsUS Customary Units

Mechanical Properties

Elongation at Break, %		35 to 50
Elongation at Break, %		30

Tensile Strength: Ultimate (UTS), MPa		28 to 45
Tensile Strength: Ultimate (UTS), MPa		24

Thermal Properties

Glass Transition Temperature, °C		190
Glass Transition Temperature, °C		30

Specific Heat Capacity, J/kg-K		1480
Specific Heat Capacity, J/kg-K		1750

Thermal Conductivity, W/m-K		0.25
Thermal Conductivity, W/m-K		0.17

Thermal Expansion, µm/m-K		14
Thermal Expansion, µm/m-K		120

Electrical Properties

Dielectric Strength (Breakdown Potential), kV/mm		15
Dielectric Strength (Breakdown Potential), kV/mm		28

Electrical Resistivity Order of Magnitude, 10^x Ω-m		16
Electrical Resistivity Order of Magnitude, 10^x Ω-m		14

Otherwise Unclassified Properties

Density, g/cm³		1.2
Density, g/cm³		0.83

Refractive Index		1.5
Refractive Index		1.5

Common Calculations

Strength to Weight: Axial, points		6.5 to 10
Strength to Weight: Axial, points		8.0

Strength to Weight: Bending, points		17 to 23
Strength to Weight: Bending, points		22

Thermal Diffusivity, mm²/s		0.14
Thermal Diffusivity, mm²/s		0.12