PETG vs. CAB

Both PETG and CAB are thermoplastics. There are 17 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 PETG and the bottom bar is CAB.

Glycol-Modified Polyethylene Terephthalate (PETG, PET-G)Cellulose Acetate Butyrate (CAB)

Metric UnitsUS Customary Units

Mechanical Properties

Flexural Modulus, GPa		2.1
Flexural Modulus, GPa		0.8 to 1.7

Flexural Strength, MPa		77
Flexural Strength, MPa		21 to 57

Tensile Strength: Ultimate (UTS), MPa		53
Tensile Strength: Ultimate (UTS), MPa		20 to 50

Thermal Properties

Glass Transition Temperature, °C		81
Glass Transition Temperature, °C		140

Heat Deflection Temperature At 1.82 MPa (264 psi), °C		69
Heat Deflection Temperature At 1.82 MPa (264 psi), °C		53 to 82

Heat Deflection Temperature At 455 kPa (66 psi), °C		73
Heat Deflection Temperature At 455 kPa (66 psi), °C		68 to 92

Specific Heat Capacity, J/kg-K		1200
Specific Heat Capacity, J/kg-K		1460

Thermal Conductivity, W/m-K		0.29
Thermal Conductivity, W/m-K		0.25

Thermal Expansion, µm/m-K		68
Thermal Expansion, µm/m-K		14

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 MHz		2.4
Dielectric Constant (Relative Permittivity) At 1 MHz		3.6

Dielectric Strength (Breakdown Potential), kV/mm		16
Dielectric Strength (Breakdown Potential), kV/mm		15

Otherwise Unclassified Properties

Density, g/cm³		1.3
Density, g/cm³		1.2

Refractive Index		1.6
Refractive Index		1.5

Water Absorption After 24 Hours, %		0.2
Water Absorption After 24 Hours, %		1.2 to 1.6

Common Calculations

Strength to Weight: Axial, points		12
Strength to Weight: Axial, points		4.8 to 12

Strength to Weight: Bending, points		25
Strength to Weight: Bending, points		14 to 25

Thermal Diffusivity, mm²/s		0.19
Thermal Diffusivity, mm²/s		0.14 to 0.15