IIR - Butyl rubber (IIR)

Clwyd reference IIR
ASTM classification IIR
Typical applications
  • Air-tight seals
  • Bladders in sports balls (football, basketball etc.)
  • Gas masks

Its impermeable to water and air (acts as barrier). It has good flex properties and good physical strength.

  • Poor flame resistance
  • Poor oil resistance
  • Poor compatibility with other polymers – low adhesion properties
Available hardness range (Shore A) 35 - 85
Upper continuous service temp. 130°C
Min. temp. for sealing applications -50°C
Minimum non-brittle  temp.  -70°C
Tensile strength (up to) 18 MPa
Elongation at break (up to) >700%
Price Bracket Very low
ASTM 1 Oil None
ASTM 2 Oil None
ASTM 3 Oil None
Kerosene None
Liquid B None
Liquid 101 None
Phosphate ester Good
Ketone None
Toluene None
Iso-octane None
Methanol Excellent
Acid (weak) Good
Acid (strong) None
Base (weak) Excellent
Base (strong) Good
Hydrogen sulphide Excellent
Steam Good
Ozone Good
Radiation Good