Cellulose Acetate (CA)

CA is a thermoplastic material, further classified as a cellulosic plastic.

It has two common variants, each represented as a separate material.

Material Properties

Density1.3 g/cm3 (81 lb/ft3)

Dielectric Constant (Relative Permittivity)3.6

Dielectric Strength (Breakdown Potential)15 kV/mm (0.59 V/mil)

Electrical Resistivity Order of Magnitude16 10x Ω-m

Elongation at Break25 to 30 %

Flexural Modulus1.7 to 2.1 GPa (0.25 to 0.3 x 106 psi)

Flexural Strength40 to 55 MPa (5.8 to 8.0 x 103 psi)

Glass Transition Temperature230 °C (450 °F)

Heat Deflection Temperature At 1.82 MPa (264 psi)65 to 75 °C (150 to 170 °F)

Heat Deflection Temperature At 455 kPa (66 psi)75 to 85 °C (170 to 190 °F)

Heat of Combustion (HOC)18 MJ/kg

Limiting Oxygen Index (LOI)17 %

Refractive Index1.5

Specific Heat Capacity1500 J/kg-K

Strength to Weight Ratio23 to 28 kN-m/kg

Tensile Strength: Ultimate (UTS)30 to 37 MPa (4.4 to 5.4 x 103 psi)

Tensile Strength: Yield (Proof)26 to 33 MPa (3.8 to 4.8 x 103 psi)

Thermal Conductivity0.25 W/m-K

Thermal Diffusivity0.13

Thermal Expansion14 µm/m-K

Vicat Softening Temperature100 to 110 °C (210 to 230 °F)

Water Absorption After 24 Hours2.3 %

Further Reading

Modern Plastics Handbook, Charles A. Harper (editor), 1999

Plastics Materials, 7th ed., J. A. Brydson, 1999

SPI Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., 5th ed., Michael L. Berins (editor), 2000