CAP vs. PS

Both CAP and PS are thermoplastics. There are 15 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 PS.

Cellulose Acetate Propionate (CAP)Polystyrene (PS)

Metric UnitsUS Customary Units

Mechanical Properties

Elongation at Break, %		35 to 50
Elongation at Break, %		1.8 to 40

Flexural Strength, MPa		29 to 56
Flexural Strength, MPa		62 to 80

Tensile Strength: Ultimate (UTS), MPa		28 to 45
Tensile Strength: Ultimate (UTS), MPa		32 to 44

Thermal Properties

Glass Transition Temperature, °C		190
Glass Transition Temperature, °C		100

Specific Heat Capacity, J/kg-K		1480
Specific Heat Capacity, J/kg-K		1250 to 1400

Thermal Conductivity, W/m-K		0.25
Thermal Conductivity, W/m-K		0.14 to 0.22

Thermal Expansion, µm/m-K		14
Thermal Expansion, µm/m-K		80 to 98

Vicat Softening Temperature, °C		85 to 110
Vicat Softening Temperature, °C		100 to 110

Electrical Properties

Dielectric Strength (Breakdown Potential), kV/mm		15
Dielectric Strength (Breakdown Potential), kV/mm		18 to 20

Electrical Resistivity Order of Magnitude, 10^x Ω-m		16
Electrical Resistivity Order of Magnitude, 10^x Ω-m		14 to 15

Otherwise Unclassified Properties

Density, g/cm³		1.2
Density, g/cm³		1.0

Water Absorption After 24 Hours, %		1.4 to 1.7
Water Absorption After 24 Hours, %		0.040 to 0.080

Common Calculations

Strength to Weight: Axial, points		6.5 to 10
Strength to Weight: Axial, points		8.5 to 12

Strength to Weight: Bending, points		17 to 23
Strength to Weight: Bending, points		22 to 26

Thermal Diffusivity, mm²/s		0.14
Thermal Diffusivity, mm²/s		0.11 to 0.15