Synthesis of Poly(ethylene terephthalate-co-isophthalate) by Copolymerization of Ethylene Isophthalate Cyclic Dimer and Bis(2-hydroxyethyl) Terephthalate

Ethylene isophthalate cyclic dimer (EI c-2mer) and bis(2-hydroxyethyl) terephthalate (BHET) were successfully copolymerized in the bulk state by microwave heating to give a polymer with Mw>20000. Terminal functionalities of the copolymers obtained were investigated by the MALDI-TOF mass analysis technique. The first stage of the copolymerization reaction involves homopolymerization of BHET. In the second stage, reactive end-group of poly(ethylene terephthalate) or BHET itself can attack the EI c-2mer and gradually produce an EI-terminated copolymer. In the third stage, the propagation reaction of EI-terminated copolymer occurs through the three types of elementary reaction route.