Celazole® PBI

Celazole® PBI (Polybenzimidazole) is one of the highest performing engineering thermoplastic available today.  It offers the highest heat resistance and mechanical property retention at temperatures over 400°F of any unfilled polymer.  It has better wear resistance and load carrying capabilities at extreme temperatures than any other reinforced or unreinforced engineering thermoplastic.

As an unreinforced material, Celazole® PBI is very “clean” in terms of ionic impurity and it does not outgas (except water) in a vacuum.  These characteristics make this material very attractive to semiconductor manufacturers for vacuum chamber applications. Celazole® PBI has excellent ultrasonic transparency which makes it an ideal choice for parts such as probe tip lenses in ultrasonic measuring equipment.

Celazole® PBI is also an excellent thermal insulator. Other plastics in melt do not stick to PBI.  These characteristics make it ideal for contact seals and insulator bushings in plastic production and molding equipment.

  • Highest mechanical properties of any plastic above 400°F (204°C)
  • Highest heat deflection temperature 800°F (427°C), with a continuous service capability of 750°F (399°C) in inert environments, or 650°F (343°C) in air with short term exposure potential to 1,000°F (538°C)
  • Lowest coefficient of thermal expansion and highest compressive strength of all unfilled plastics.
Specification Test Value Units
Specific Gravity, 73°F D792  1.3 –
Tensile Strength @ Yield, 73°F D638  16,000 psi
Tensile Modulus of Elasticity, 73°F D638  850,000 psi
Tensile Elongation (at break), 73°F D638  2 %
Flexural Strength, 73°F D790  32,000 psi
Flexural Modulus of Elasticity D790  950,000 psi
Shear Strength, 73°F D732   psi
Compressive Strength – Ultimate     psi
Compressive Strength at 2% Deformation D695   psi
Compressive Strength at 10% Deformation D695  50,000 psi
Deformation Under Load     %
Compressive Modulus of Elasticity, 73°F D695  900,000  
Compressive Strength ⊥ to Laminate (Modulus)     psi
Compressive Strength ⊥ to Laminate (Yield)     psi
Compressive Strength ⊥ to Laminate (Ultimate)     psi
Hardness, Durometer (Shore “D” scale) D2240  94  
Hardness, Rockwell (Scale as noted) D785  125 Rockwell M
Izod Impact, Notched @ 73°F D256 Type A  .5 ft.lbs/in. of notch
Coefficient of Friction (Dry vs Steel) Static PTM55007  .25-.30  
Coefficient of Friction (Dry vs Steel) Dynamic PTM55007  .24  
Maximum Static Bearing Load (P) PTM55007  5,000 psi
Maximum Unlubricated No Load Bearing Velocity (V) PTM55007  400 ft/minute
Maximum Limiting PV (Unlubricated) PTM55007  37,500 psi x ft/min.
Wear Factor “K” x 10-10 PTM55010  60 Cubic in.-min/ft.lbs.hr
Sand Wheel Wear/Abrasion Test     UHMW=100
Minimum Mating Surface Hardness     Rockwell (Brinnell)
Coefficient of Linear Thermal Expansion E-831(TMA)  1.3 in/in/°F x 10-5
Coefficient of Thermal Expansion // to Laminates E-831(TMA)  1.3 in/in/°F x 10-5
Coefficient of Thermal Expansion I to Laminates E-831(TMA)  1.3 in/in/°F x 10-5
Softening Point     °F
Heat Deflection Temperature 264 psi D648  800 °F
Embrittlement Temperature     °F Min.
Continuous Service Temperature in Air    650 °F Max.
Short Term Service Temperature    1,000 °F Max.
Tg-Glass Transition (Amorphous) D3418  750 °F
Melting Point (Crystalline) Peak D3418   °F
Thermal Conductivity F433  2.8 BTU-in/(hr/ft2°F)
Dielectric Strength Short Term D149  550 Volts/mil
Volume Resistivity D257   ohm/cm
Surface Resistivity D257  > 1013 ohm/cm
Dielectric Constant, 106Hz D150  3.2  
Dissipation Factor, 106Hz D150  .003  
Flammability @ 3.1mm(1/8 in.) UL94 UL94  V-0  
Arc Resistance     seconds
Water Absorption, Immersion 24 Hours D570 (2)  .4 %
Water Absorption, Immersion Saturation D570 (2)  5.0 %
Machinability Rating   10 1=easy, 10=difficult
Rod Diameter Availability (Off the Shelf)   .375-4.75 inches
Sheet Thickness Availability (Off the Shelf)   .50-1.5 inches
Characteristics / Attributes Extreme Service Temp Rating / Low CoTe / High Retention of Mechanical Properties above 400 Degrees F.