# 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 10 ^{3} psi*

Elastic (Young's, Tensile) Modulus

1.4 *GPa* 0.2 *x 10 ^{6} psi*

Elongation at Break

80 *%*

Flexural Modulus

1.5 *GPa* 0.22 *x 10 ^{6} psi*

Flexural Strength

41 *MPa* 5.9 *x 10 ^{3} psi*

Impact Strength: Notched Izod

42 *J/m* 0.79 *ft-lb/in*

Rockwell R Hardness

90

Tensile Strength: Ultimate (UTS)

36 *MPa* 5.1 *x 10 ^{3} 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

2.2

Dielectric Strength (Breakdown Potential)

26 *kV/mm* 1.0 *V/mil*

## Otherwise Unclassified Properties

Density

0.91 *g/cm ^{3}* 56

*lb/ft*

^{3}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 *mm ^{2}/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