Comparison
Gas Impermeable Isobutylene Isoprene Rubber vs PETG
A side-by-side comparison of Isobutylene Isoprene Rubber (Butyl Rubber) and Polyethylene Terephthalate Glycol.
Physical
Density
0.92 - 0.94 g/cm³
1.27 g/cm³
Water Absorption (24h)
0.1 %
0.13 %
Transparency
Opaque
Transparent
Shrinkage
2.0 - 3.0 %
0.2 – 0.5 %
Mechanical
Young's Modulus
0.01 - 0.05 GPa
2.1 GPa
Tensile Strength
5 - 20 MPa
50 MPa
Elongation at Break
300 - 700 %
120 %
Impact Strength (Izod)
N/A
100 J/m
Flexural Strength
—
70 MPa
Thermal
Glass Transition Temperature
-60 to -70 °C
80 °C
Melting Point
N/A
—
Continuous Service Temperature
-50 to 120 °C
65 °C
Heat Deflection Temperature
N/A
70 °C
CTE
—
68 × 10⁻⁶ /K
Electrical
Dielectric Constant
2.5 - 3.0
3.3
Volume Resistivity
10^13 - 10^14 Ohm-cm
10¹⁴ Ω·cm
Dielectric Strength
20 - 30 kV/mm
—
Chemical resistance
Acids
Good
Good
Bases
Good
Fair
Solvents
Good resistance to polar solvents, water, steam; Poor resistance to hydrocarbons
—
UV Resistance
Excellent
Fair
Alcohols
—
Good
Oils
—
Good
Sustainability
Recyclability
Limited
Recyclable
Recycling Code
N/A
1
Carbon Footprint
Moderate
~2.7 kg CO₂e / kg
Bio-based Content
—
0 %