Properties of Butyl Rubber (IIR)
Butyl rubber is a synthetic rubber that is derived from isobutylene and a small amount of isoprene. It is known for its excellent impermeability to gases and liquids, making it a popular choice for applications where airtight seals or resistance to moisture and chemicals is required.
The following table provides a comprehensive list of butyl rubber (IIR) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the icon to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Category | Elastomer |
| Density | 917 kg/m3 |
| Mechanical Properties | Metric |
| Ultimate Tensile Strength | 17 MPa |
| Young’s Modulus (E) | 0.3 - 3.4 GPa |
| Elongation at Break | 700 - 950% |
| Shore Hardness (A) | 30 - 100 |
| Thermal Properties | Metric |
| Thermal Conductivity | 0.13 - 0.23 W/m·K |
| Specific Heat Capacity (Cp) | 1950 J/kg·K |
| Glass Transition Temperature (Tg) | -65 °C |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.5081 |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.