Butyl Rubber
Butyl Rubber (IIR) is produced by copolymerizing isobutylene with small amounts of isoprene (typically 98% polyisobutylene and 2% isoprene). Butyl rubber was first commercialized in the early 1940s and hash excellent gas impermeability and air retention along with good flex properties.
Typical applications
- Air-tight seals
- Bladders in sports balls (football, basketball etc.)
- Gas masks
Advantages
Disadvantages
Properties
Resistance
Advantages
- It is impermeable to water and air (acts as barrier). It has good flex properties and good physical strength
Disadvantages
- Poor flame resistance
- Poor oil resistance
- Poor compatibility with other polymers – low adhesion properties
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% |
Resistance
| 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 |
