ABSTRACT
PET was the first thermoplastic polyester to be invented and PBT is the engineering member of the family. PEN is the most recent addition to the family having been invented in the 1990s.
PET is a saturated, thermoplastic polyester. This distinguishes it from its thermoset counterpart that is referred to as UP-resin or unsaturated polyester. UP-resin, a thermoset material is most notable as the “work horse” resin and matrix for composites.
