Comparison
Gas Impermeable Isobutylene Isoprene Rubber vs PEEK
A side-by-side comparison of Isobutylene Isoprene Rubber (Butyl Rubber) and Polyether Ether Ketone.
Physical
Density
0.92 - 0.94 g/cm³
1.32 g/cm³
Water Absorption (24h)
0.1 %
0.15 %
Transparency
Opaque
Opaque (amber)
Shrinkage
2.0 - 3.0 %
1.1 – 1.4 %
Mechanical
Young's Modulus
0.01 - 0.05 GPa
3.6 GPa
Tensile Strength
5 - 20 MPa
100 MPa
Elongation at Break
300 - 700 %
50 %
Impact Strength (Izod)
N/A
55 J/m
Flexural Strength
—
170 MPa
Thermal
Glass Transition Temperature
-60 to -70 °C
143 °C
Melting Point
N/A
343 °C
Continuous Service Temperature
-50 to 120 °C
260 °C
Heat Deflection Temperature
N/A
160 °C
Electrical
Dielectric Constant
2.5 - 3.0
3.2
Volume Resistivity
10^13 - 10^14 Ohm-cm
10¹⁶ Ω·cm
Dielectric Strength
20 - 30 kV/mm
—
Chemical resistance
Acids
Good
Excellent
Bases
Good
Excellent
Solvents
Good resistance to polar solvents, water, steam; Poor resistance to hydrocarbons
Excellent
UV Resistance
Excellent
Fair
Hydrolysis (steam)
—
Excellent
Sustainability
Recyclability
Limited
Recyclable (specialty)
Recycling Code
N/A
7
Carbon Footprint
Moderate
~30 kg CO₂e / kg