Comparison
EPP Automotive vs Polycarbonate
A side-by-side comparison of Expanded Polypropylene for Automotive Applications and Polycarbonate.
Physical
Density
0.03-0.1 g/cm³ (foam)
1.20 g/cm³
Water Absorption (24h)
<1 %
0.15 %
Transparency
Opaque
Transparent (88% light transmission)
Shrinkage
N/A (foam)
0.5 – 0.8 %
Mechanical
Young's Modulus
Highly variable (foam)
2.3 – 2.4 GPa
Tensile Strength
Highly variable (foam)
60 – 70 MPa
Elongation at Break
Highly variable (foam)
100 – 150 %
Impact Strength (Izod)
Excellent energy absorption
600 – 900 J/m
Flexural Strength
—
90 – 100 MPa
Hardness (Rockwell M)
—
70
Thermal
Glass Transition Temperature
N/A (amorphous)
147 °C
Melting Point
160-165 °C (solid PP)
—
Continuous Service Temperature
90-110 °C
115 – 130 °C
Heat Deflection Temperature
N/A (foam)
130 – 140 °C
Thermal Conductivity
—
0.20 W/m·K
CTE
—
65 – 70 × 10⁻⁶ /K
Electrical
Dielectric Constant
Around 1.5 (foam)
2.9 – 3.0
Volume Resistivity
>10¹³ Ω⋅cm (foam)
10¹⁶ Ω·cm
Dielectric Strength
High (foam)
15 kV/mm
Chemical resistance
Acids
Good resistance
—
Bases
Good resistance
Poor
Solvents
Good resistance
—
UV Resistance
Poor (requires stabilization)
Poor (unless coated)
Acids (dilute)
—
Good
Alcohols
—
Fair
Oils
—
Good
Gasoline
—
Fair
Acetone
—
Poor (attacks)
Sustainability
Recyclability
Recyclable
Recyclable
Recycling Code
5 (PP)
7
Carbon Footprint
Moderate
~5 kg CO₂e / kg
Bio-based Content
—
0 – 50 % (bio grades)