Butyl Rubber (IIR)

Butyl Rubber (isobutylene-isoprene) is a synthetic rubber which was developed in the 1940’s. Butyl rubber demonstrates almost as good weather and ageing properties as EPM and EPDM as there only a few double bonds in its main chain which can be attacked.

Butyl rubber has one of the lowest permeabilities to gas of all rubber. This makes it excellent for use inner tubes for tyres and high pressure/vacuum sealing applications. IIR also has a low resilience and is often used in high energy absorbing applications.

Key Properties of Butyl Rubber:

• Low gas permeability
• Very low resilience
• Excellent weathering resistance

Drawbacks:

• Cannot be blended with or joined well to NR or SBR

Operating Temperature Range: -50 to +100 °C

Chemical Compatibility:

• Excellent resistance to heat, ozone, and weathering
• Resistance to dilute acids and alkalis
• Not suitable for use in mineral or petroleum-based fluids

Typical Applications:

• Reservoir linings
• Inner tubes
• Shock and vibration damping
• Diaphragms
• Gaskets
• O-rings
• Seals
• Speaker surrounds
• Bottle Closures