Properties of High Impact Polystyrene (HIPS)
High Impact Polystyrene (HIPS) is a type of plastic polymer that is derived from polystyrene. It is known for its toughness and impact resistance, which is achieved by blending polystyrene with a rubbery material, usually polybutadiene. This combination results in a material that is easy to process, has good dimensional stability, and is often used in the production of various consumer and industrial products.
The following table provides a comprehensive list of high impact polystyrene (HIPS) 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 | Thermoplastic |
| Density | 1040 kg/m3 |
| Water Absorption | 0.1 %wt/day |
| Mechanical Properties | Metric |
| Ultimate Tensile Strength | 35 - 100 MPa |
| Yield Tensile Strength | 25 MPa |
| Young’s Modulus (E) | 1.6 - 2.4 GPa |
| Flexural Modulus | 2.07 GPa |
| Poisson’s Ratio (ν) | 0.34 |
| Elongation at Break | 36 - 50% |
| Rockwell Hardness (L) | 73 |
| Thermal Properties | Metric |
| Thermal Conductivity | 0.124 W/m·K |
| Specific Heat Capacity (Cp) | 1250 J/kg·K |
| Coefficient of Thermal Expansion (αL) | 9×10-5 1/°C |
| Glass Transition Temperature (Tg) | 100 °C |
| Vicat Softening Temperature | 98 °C |
| Electrical Properties | Metric |
| Relative Permittivity (@1 MHz) (εr) | 2.3 - 2.5 |
| Electrical Resistivity | 1016 Ω·cm |
| Dielectric Field Strength (Ed) | 177 - 240 kV/cm |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.59 - 1.60 |
| Hazardous Data | Metric |
| Flammability Rating (ANSI/UL 94) | V-0 |
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)