Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer that is used as an insulator in the electrical and electronics industries. It is a thermoplastic crystalline polymer, and a type of polyester. PBT resists solvents, shrinks very little during forming, is mechanically strong, is heat-resistant up to 150 °C (or 200 °C with glass-fibre reinforcement), and can be treated with flame retardants to make it noncombustible
