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Unfilled PP Homopolymer

Unfilled PP homopolymer is a grade of PP homopolymer. It has the lowest strength and highest ductility compared to the other variants of PP homopolymer. The graph bars on the material properties cards below compare unfilled PP homopolymer to: polypropylene 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.

Mechanical Properties

Compressive (Crushing) Strength

45 MPa 6.5 x 103 psi

Elastic (Young's, Tensile) Modulus

1.4 GPa 0.2 x 106 psi

Elongation at Break

80 %

Flexural Modulus

1.5 GPa 0.22 x 106 psi

Flexural Strength

41 MPa 5.9 x 103 psi

Impact Strength: Notched Izod

42 J/m 0.79 ft-lb/in

Rockwell R Hardness


Tensile Strength: Ultimate (UTS)

36 MPa 5.1 x 103 psi

Thermal Properties

Glass Transition Temperature

170 °C 340 °F

Heat Deflection Temperature At 1.82 MPa (264 psi)

73 °C 160 °F

Heat Deflection Temperature At 455 kPa (66 psi)

110 °C 220 °F

Maximum Temperature: Autoignition

370 °C 700 °F

Maximum Temperature: Decomposition

350 °C 660 °F

Maximum Temperature: Mechanical

120 °C 250 °F

Melting Onset (Solidus)

160 °C 320 °F

Specific Heat Capacity

1900 J/kg-K 0.45 BTU/lb-°F

Thermal Conductivity

0.15 W/m-K 0.087 BTU/h-ft-°F

Thermal Expansion

90 µm/m-K

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 Hz


Dielectric Strength (Breakdown Potential)

26 kV/mm 1.0 V/mil

Otherwise Unclassified Properties


0.91 g/cm3 56 lb/ft3

Limiting Oxygen Index (LOI)

17 %

Water Absorption After 24 Hours

0.010 %

Water Absorption At Saturation

0.010 %

Common Calculations

Stiffness to Weight: Axial

0.86 points

Stiffness to Weight: Bending

41 points

Strength to Weight: Axial

11 points

Strength to Weight: Bending

27 points

Thermal Diffusivity

0.087 mm2/s

Thermal Shock Resistance

20 points

Followup Questions

Further Reading

ASTM D883: Standard Terminology Relating to Plastics

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