# PBI vs. Thermoset PI

Both PBI and thermoset PI are thermoset plastics. There are 22 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.

For each property being compared, the top bar is PBI and the bottom bar is thermoset PI.

Metric UnitsUS Customary Units

## Mechanical Properties

Compressive (Crushing) Strength, MPa | 350 | |

120 to 210 |

Elongation at Break, % | 3.0 | |

2.0 to 5.9 |

Flexural Modulus, GPa | 6.5 | |

3.1 to 4.8 |

Flexural Strength, MPa | 220 | |

60 to 100 |

Impact Strength: Notched Izod, J/m | 27 | |

21 to 43 |

Tensile Strength: Ultimate (UTS), MPa | 160 | |

37 to 81 |

## Thermal Properties

Glass Transition Temperature, °C | 410 | |

360 |

Heat Deflection Temperature At 1.82 MPa (264 psi), °C | 430 | |

370 |

Maximum Temperature: Decomposition, °C | 590 | |

330 |

Maximum Temperature: Mechanical, °C | 340 | |

260 |

Specific Heat Capacity, J/kg-K | 930 | |

1130 |

Thermal Conductivity, W/m-K | 0.41 | |

0.29 to 1.7 |

Thermal Expansion, µm/m-K | 23 | |

38 to 54 |

## Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 MHz | 3.8 | |

3.1 |

Dielectric Strength (Breakdown Potential), kV/mm | 23 | |

20 |

Electrical Resistivity Order of Magnitude, 10^{x} Ω-m |
13 | |

15 |

## Otherwise Unclassified Properties

Density, g/cm^{3} |
1.3 | |

1.4 to 1.6 |

Limiting Oxygen Index (LOI), % | 58 | |

40 |

Water Absorption After 24 Hours, % | 0.4 | |

0.14 to 0.24 |

## Common Calculations

Strength to Weight: Axial, points | 34 | |

6.5 to 16 |

Strength to Weight: Bending, points | 50 | |

16 to 30 |

Thermal Diffusivity, mm^{2}/s |
0.34 | |

0.18 to 0.95 |