Polybutylene terephthalate (PBT) is a thermoplastic engineering grade plastic known for its mechanical strength and ability to withstand heat up to 150°C. It has excellent heat resistance, is tough, highly impact resistant, chemically resistant, weather resistant, and electrically insulating. Therefore, it is often used as an insulator in the electrical and electronic industry, as well as for automotive structures, plug connectors, and household applications. It is also used to make toothbrush fibers and false eyelashes.