PBT – Polybutylene Terepthalate

PBT polyesters are semi-crystalline. They are versatile materials with a good range of properties. They have excellent electrical properties and are abrasion resistant. PBT has been extensively compounded giving a very wide range of properties. PBT performs much like Nylon but can handle higher temperatures and does not absorb moisture. PBT has excellent impact strength but is very notch sensitive. PBT is very anisotropic in shrinkage, so it is difficult to mold to extremely tight tolerances.

Applications: Industrial equipment applications, business equipment, automotive housings-under the hood, power tool casings.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
6,000-13,000 psi 300,000-1,200,000 psi 1 ft-lb/in notched izod 250°-420° F Fair to Good


  • Good flow
  • Tough
  • Hydrollysis Resistant
  • High impact
  • Easily Processed


  • Low Max. Use temperature
  • Lower Stiffness than similar PET
  • Lower Strength than similar PET
  • Attacked by Strong Bases

Brand Names: Celanex, Valox, Ultradur.