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Polylactic Acid (PLA, Polylactide)

PLA is a thermoplastic, further classified as a polyester plastic. It has the highest heat capacity among the polyester plastics in the database. The graph bars on the material properties cards below compare PLA to: polyester plastics (top), all thermoplastics (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Thermal Properties

Glass Transition Temperature

60 °C 140 °F

Heat Deflection Temperature At 455 kPa (66 psi)

65 °C 150 °F

Maximum Temperature: Mechanical

50 °C 120 °F

Melting Onset (Solidus)

160 °C 320 °F

Specific Heat Capacity

1800 J/kg-K 0.43 BTU/lb-°F

Thermal Conductivity

0.13 W/m-K 0.075 BTU/h-ft-°F

Other Material Properties


1.3 g/cm3 78 lb/ft3

Elastic (Young's, Tensile) Modulus

3.5 GPa 0.51 x 106 psi

Elongation at Break

6.0 %

Flexural Modulus

4.0 GPa 0.58 x 106 psi

Flexural Strength

80 MPa 12 x 103 psi

Shear Modulus

2.4 GPa 0.35 x 106 psi

Tensile Strength: Ultimate (UTS)

50 MPa 7.3 x 103 psi

Common Calculations

Stiffness to Weight: Axial

1.6 points

Stiffness to Weight: Bending

40 points

Strength to Weight: Axial

11 points

Strength to Weight: Bending

24 points

Thermal Diffusivity

0.058 mm2/s

Followup Questions

Further Reading

Poly(lactic Acid): Synthesis, Structures, Properties, Processing, and Applications, Rafael Auras et al. (editors), 2010

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

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

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