BIIR - Bromobutyl rubber

Clwyd reference BIIR
ASTM classification BIIR

Both butyl and halobutyl rubbers provide excellent inflation pressure retention. They are an ideal choice for inner tubes of bicycles, trucks, and industrial and agricultural tires. In fact, halogenated butyl rubbers are the most widely used butyl rubbers for tire inner liners. Halobutyl rubbers are also used for hoses, seals, membranes, tank linings, conveyor belts, protective clothing and for consumer products, such as ball bladders for sporting goods. Halobutyls are generally a good choice when good resistance to chemicals, weathering, and ozone is required.

Typical applications
  • ‘O’ Rings
  • Vacuum seals and membranes
  • Steam hoses
  • Pharmaceutical closures
  • Tire inner tubes
  • High impermeability
  • Better heat resistance
  • Addition of bromine results in faster curing and better adhesion to unsaturated polymers
Lower resilience
Available hardness range (Shore A) 35 - 90
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) 650%
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 Good
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 Excellent
Radiation Good