Properties of Polybutylene (PB)
Polybutylene (PB) is a thermoplastic polymer formerly used in plumbing and water distribution systems due to its low cost and flexibility. Despite its initial popularity from the late 1970s to the mid-1990s, its widespread use declined after issues with long-term durability emerged. Today, PB remains relevant for educational and material comparison purposes, especially in engineering research.
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The following table provides a comprehensive list of polybutylene (PB) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the button to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Category | Thermoplastic |
| Density | 935 kg/m3 |
| Water Absorption | 0.03 %wt/day |
| Mechanical Properties | Metric |
| Yield Tensile Strength | 16 - 18 MPa |
| Young’s Modulus (E) | 0.3 GPa |
| Flexural Modulus | 0.75 GPa |
| Shore Hardness (D) | 60 |
| Thermal Properties | Metric |
| Melting Point | 127 °C |
| Thermal Conductivity | 0.22 W/m·K |
| Coefficient of Thermal Expansion (αL) | 1.3×10-5 1/°C |
| Vicat Softening Temperature | 113 °C |
| Electrical Properties | Metric |
| Relative Permittivity (@1 MHz) (εr) | 2.53 |
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)